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  • Children  (81)
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  • Electronic Resource  (1,550)
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  • 1995-1999  (1,550)
  • 1930-1934
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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Der Radiologe 39 (1999), S. 467-471 
    ISSN: 1432-2102
    Keywords: Schlüsselwörter Fremdkörper ; Aspiration ; Diagnostik ; Kinder ; Atemwege ; Key words Foreign body ; Aspiration ; Diagnostic imaging ; Children ; Respiratory tract
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary Aspiration of foreign bodies is a common cause of respiratory distress in children between the age of 6 months and 3 years. The diagnosis of radiopaque foreign bodies is easy when the whole respiratory tract is depicted. Nonopaque foreign bodies need a more differentiated diagnostic approach. The first step should be plain films in inspiration and expiration. The performance of additional chest radiographs, fluoroscopy and if need be CT or nuclear scans depends on the result of the plain films. The chest radiograph may reveal a variety of findings, the commonest of which is unilateral air trapping. Rarely, atelectasis, recurrent pneumonia at the same localisation and inspiratory obstruction are found. Combinations of the above-mentioned findings are possible. Moreover, the absence of positive radiological findings does not exclude the diagnosis of foreign body aspiration.
    Notes: Zusammenfassung Die Fremdkörperaspiration stellt eine häufige Ursache für Atemnot und respiratorische Insuffizienz bei Säuglingen und Kleinkindern zwischen 6 Monaten und 3 Jahren dar. Röntgendichte Fremdkörper bereiten bei Abbildung des gesamten Respirationstraktes keine diagnostischen Schwierigkeiten. Nicht röntgendichte Fremdkörper erfordern ein differenzierteres Vorgehen, wobei der erste radiologische Schritt in einer konventionellen Thoraxaufnahme in In- und Exspiration bestehen sollte. Zusätzliche Aufnahmen, Durchleuchtungsuntersuchung und gegebenenfalls die Durchführung einer computertomographischen oder szintigraphischen Untersuchung hängen vom Ergebnis der Thoraxaufnahme ab. Häufigstes radiologisches Erscheinungsbild ist die einseitige exspiratorische Ventilstenose mit Überblähung des betroffenen Lungenabschnittes. Seltener finden sich Atelektasen, rezidivierende Pneumonien an identischer Lokalisation und inspiratorische Ventilstenosen. Kombinationsbilder sind möglich, selbst ein unauffälliges Untersuchungsergebnis kann eine Aspiration nicht ausschließen.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Der Radiologe 39 (1999), S. 472-477 
    ISSN: 1432-2102
    Keywords: Schlüsselwörter Fremdkörper ; Ingestion ; Kinder ; Diagnostik ; Key words Foreign body ; Ingestion ; Children ; Diagnosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary Foreign body ingestion is not infrequent in infants and children. The diagnosis of radiopaque foreign body ingestion does not pose a major problem. It is crucial to take an X-ray from the pharynx to the level of the pylorus. If a foreign body that might get stuck at the ileocoecal valve is ingested, it is necessary to perform a radiograph of the whole abdomen. Foreign bodies that do not pass the cardia must be extracted endoscopically. In the case of foreign bodies with a smooth contour that have passed the pylorus, parents are advised to check the child’s stool or collect it and bring it for X-raying. If after a week there is no definite evidence that the foreign body has been excreted a follow-up radiograph is carried out. If the foreign body is still in the stomach or duodenum, endoscopy is necessary. The detection of nonopaque foreign bodies can be facilitated by giving oral contrast medium, making the depiction of the foreign body as a filling defect possible. As a complication, perforation can occur, the diagnosis of which may entail the use of sonography, conventional radiography and, to a lesser extent, CT.
    Notes: Zusammenfassung Fremdkörperingestion ist im späten Säuglings- und frühen Kleinkindalter kein seltenes Ereignis. Die Diagnose röntgendichter Fremdkörper bereitet keine Schwierigkeiten. Hierbei ist jedoch zu beachten, daß die Region vom Pharynx bis zum Pylorus abgebildet sein sollte. Wurden Fremdkörper verschluckt, bei denen die Gefahr der Einklemmung in der Bauhin’schen Klappe besteht, sollte das komplette Abdomen bis zum Anus dargestellt werden. Fremdkörper, welche die Kardia nicht passieren, müssen endoskopisch extrahiert werden. Haben glatt begrenzte Fremdkörper den Pylorus passiert, werden die Eltern aufgefordert, den Stuhl zu untersuchen oder zu sammeln und ihn zur röntgenologischen Untersuchung mitzubringen. Sollte der Fremdkörper innerhalb einer Woche nicht auffindbar sein, wird eine Kontrolluntersuchung durchgeführt. Ist der Fremdkörper dann noch im Magen oder im Duodenum, sollte er ebenfalls extrahiert werden. Der Nachweis nicht röntgendichter Fremdkörper kann mittels Gabe von positivem Kontrastmittel als Aussparungsfigur gelingen. Als Komplikation kann eine Perforation auftreten. Hierbei dienen Sonographie, konventionelles Röntgen und gegebenenfalls CT zur Diagnosefindung.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Neuroradiology 41 (1999), S. 512-516 
    ISSN: 1432-1920
    Keywords: Key words Meninges ; Tumours ; Children
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Childhood meningeal tumours are uncommon and mostly meningiomas. We reviewed the histological and radiological findings in meningeal tumours in six children aged 12 years or less (four benign meningiomas, one malignant meningioma and one haemangiopericytoma). Compared to the adult counterpart, childhood meningiomas showed atypical features: cysts, haemorrhage, aggressiveness and unusual location. MRI features varied according to the site of the tumour, histology, haemorrhage, and presence of intra- or peritumoral cysts. Diagnosis of the extra-axial tumour was relatively easy in two patients with meningiomas, one malignant meningioma and one haemangiopericytoma. MRI findings strongly suggested an intra-axial tumour in two patients with benign meningiomas, because of severe adjacent edema. Awareness of the variable findings of childhood meningiomas and similar tumours may help in differentiation from brain tumours.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Neuroradiology 41 (1999), S. 929-934 
    ISSN: 1432-1920
    Keywords: Key words Magnetic resonance imaging ; diffusion weighted ; Myelination ; Children
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We studied the changes in brain water diffusion in childhood as seen on diffusion-weighted MRI in 30 children from 1 day of life to 17 years to provide a data base and to investigate the correlation of diffusion changes with known patterns of white matter maturation. The apparent diffusion coefficient (ADC) and apparent anisotropy (AA) were calculated in numerous regions of the brain to include major white matter tracts and gray matter. ADC and AA values were directly related to the structural maturity and compactness of the white matter tracts and changed with aging in a way that predated early myelination markers such as signal change on T1- or T2-weighted images. Diffusion of water is sensitive to structural changes in the brain such as white matter maturation and may be useful in investigating white matter disorders.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Der Nervenarzt 70 (1999), S. 1-10 
    ISSN: 1433-0407
    Keywords: Schlüsselwörter Tic-Störung ; Zwangsstörung ; Kinder ; Jugendliche ; Neurobiologie ; Psycho- pharmakologie ; Verhaltenstherapie ; Key words Tic-disorder ; Obsessive-compulsive disorder ; Children ; Adolescents ; Neurobiology ; Psychopharmacology ; Behavior therapy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary In children and adolescents motor/vocal tics and obsessive-compulsive behavior are known to be closely related. Thereby, a continuum of symptoms ranging from single tics to a mixed picture of tics/rituals/obsessive-compulsive traits to clinically relevant obsessions and compulsions could be described. As neurobiological substrates dysfunctions in corresponding cortico-striato-thalamo-cortical circuits (sensorimotor circuit in tic symptomatology, orbitofrontal circuit in obsessive-compulsive behavior) were postulated. For both disturbances behavioral therapy can be used to improve control mechanisms to counterregulate tics and obsessive-compulsive behavior, respectively, and psychopharmacological agents can be administerd to compensate dysbalances in neurotransmitter systems. In case of a mixed symptomatologic picture it is necessary to include interventions for both pols of the symptom-continuum in the therapeutic programme to achieve extensive improvement as a basis for a further positive development of the patient.
    Notes: Zusammenfassung Motorische/vokale Tics und zwanghafte Verhaltensweisen kommen bei Kindern und Jugendlichen häufig gemeinsam vor; dabei kann ein Symptomkontinuum von solitär auftretenden Tics über ein Mischbild von Tics und Ritualen/zwanghaften Gedanken und/oder Handlungen bis hin zu eindeutigen Zwangsphänomenen beschrieben werden. Neurobiologisch können diesem Symptomkontinuum unterschiedlich ausgebreitete Dysfunktionen entsprechender kortiko-striato-pallido-thalamo-kortikaler Regulationssysteme zugrunde liegen. Therapeutisch lassen sich bei beiden Verhaltensauffälligkeiten mittels verhaltenstherapeutischer Techniken Steuerungs- und Kontrollmöglichkeiten zur Gegenregulation der Auffälligkeiten verbessern sowie durch Einsatz von Psychopharmaka Dysbalancen von Neurotransmittersystemen ausgleichen. Bei einem Mischbild von Tics und Zwängen sind therapeutische Interventionen für beide Zielbereiche erforderlich. Nur so können umfassende Verbesserungen erreicht und günstige Entwicklungsbedingungen für die betroffenen Kinder und Jugendlichen eröffnet werden.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    HNO 47 (1999), S. 535-540 
    ISSN: 1433-0458
    Keywords: Schlüsselwörter Hörschäden ; Knalltrauma ; Kinder ; Tinnitus ; Erweiterte Hochtonaudiometrie ; Key words Hearing loss ; Acoustic trauma ; Children ; Tinnitus ; High-frequency audiometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary The study presents an analysis of 20 cases of acute acoustic trauma caused by toy pistols. The problem generally involves boys within the age range from 6 to 11 years. Half of the incidents involved attacks with toy pistols used as weapons. Auditory damage appeared in two types, each of which had a notch in the audiogram at the frequency range between 10 and 14 kHz. In children, a shot close to one ear can damage both ears. Great differences in the severity of tinnitus were apparent. The most severe cases of tinnitus were observed in the children with no or minor premanent auditory damage. Children experiencing long periods of uninterrupted tinnitus suffer significantly. This is not only detrimental to family-life but also to the performance of the children at school. The total expenses of treatment for these 20 cases were estimated to be approximately 80,000 DM (40.000 Euro).
    Notes: Zusammenfassung Im Rahmen einer Studie wurden 20 Fälle von Knalltraumata durch Kinderpistolen erfaßt und ausgewertet. Die Problematik betrifft fast nur männliche Personen und schwerpunktmäßig den Altersbereich von 6–11 Jahren. Die Hälfte der Vorfälle waren Angriffe, bei denen die Kinderpistole als Waffe eingesetzt wurde, 2 Typen von Hörschäden sind festzustellen, die jedoch beide durch eine Senke im Bereich von 10–14 kHz charakterisiert sind. Bei Kindern kann der Schuß in eines der Ohren auch das andere Ohr schädigen. Sehr große Unterschiede bestehen im Auftreten von Tinnitus. Die Fälle mit starkem Tinnitus haben keine oder nur geringe bleibende Hörschäden. Die von Knalltraumata betroffenen Kinder leiden oft sehr stark unter langanhaltendem Tinnitus. Dabei wird nicht nur das Leben der Familien beeinträchtigt, sondern auch die schulischen Leistungen der Kinder leiden teilweise sehr stark darunter. Für die Therapie dieser 20 Fälle entstanden Gesamtkosten von ca. 80.000,- DM
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Monatsschrift Kinderheilkunde 147 (1999), S. 328-332 
    ISSN: 1433-0474
    Keywords: Schlüsselwörter Asthma bronchiale ; Schulkinder ; Türkische Kinder ; Key words Asthma ; Children ; Turkish children
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary Objectives: In Germany 4.2% (in Munich 8.6%) of all children under 15 years of age are of Turkish origin, representing the largest ethnic minority in this age group. However, very little is known about the prevalence, severity and management of asthma and other atopic diseases in Turkish children living in Germany. Methods: In a cross-sectional survery the prevalence, severity and treatment of asthma and other atopic diseases was assessed in 7,445 schoolchildren aged 9 to 11 years, living in Munich, southern Germany. Questionnaires were distributed to the parents for self-completion and children underwent skin-prick tests and cold-air hyperventilation challenge. Results: Of those returning the questionnaires (n = 6490/87%), 5,030 (77.5%) were of German and 451 (7%) of Turkish origin. Turkish children showed a significantly lower prevalence of asthma (5.3% versus 9.4%, P 〈 0.05) than their German peers. Furthermore, Turkish children with asthma were less frequently free of symptoms (10.5% versus 34.6%, P 〈 0.05), reported more severe symptoms (41.2% versus 10.9%, P 〈 0.05) and more hospital admissions (55.6% versus 21.6%, P 〈 0.05) due to asthma than German children. Conclusions: The results of this study indicate that despite the lower prevalence of asthma and allergy in the Turkish population living in Germany, asthma is a major health problem for Turkish children. Furthermore, these findings suggest inadequate management of asthma in Turkish children.
    Notes: Zusammenfassung Fragestellung: Türkische Kinder stellen in der Bundesrepublik Deutschland mit 4,2% und in München mit 8,6% den größten Anteil nicht-deutscher Kinder in der Altersgruppe bis 15 Jahren. Wenig ist jedoch bisher über Häufigkeit, Symptome und Behandlung von Asthma bronchiale und anderer atopischer Erkrankungen der türkischen Minderheit in Deutschland bekannt. Methodik: In einer Querschnittstudie wurde bei 7445 Schulkindern im Alter von 9 bis 11 Jahren im Großraum München die Häufigkeit, der Schweregrad und die Behandlung des Asthma bronchiale und anderer atopischer Erkrankungen untersucht. Fragebögen wurden von den Eltern ausgefüllt, Lungenfunktionsuntersuchungen und Hautpricktests wurden bei den Kindern durchgeführt. Ergebnisse: Von denen, die die zugeschickten Fragebögen ausfüllten (n = 6490/87%), waren 5030 (77,5%) deutscher und 451 (7%) türkischer Nationalität. Die türkischen Kinder zeigten eine niedrigere Prävalenz von Asthma bronchiale (5,3% versus 9,4%, p 〈 0,05) und Neurodermitis (1,6% versus 12,9%, p 〈 0,001) im Vergleich zu den deutschen Kindern. Signifikante Unterschiede bestanden zwischen türkischen und deutschen Kindern in Art der Symptome und der Krankheitswahrnehmung. Türkische Kinder mit Asthma bronchiale waren seltener beschwerdefrei (10,5% versus 34,6%, p 〈 0,05) berichteten von schwereren Symptomen (41,2% versus 10,9%, p 〈 0,05) und von einer größeren Anzahl von Krankenhausaufenthalten (55,6% versus 21,6%, p 〈 0,05) aufgrund von Asthma bronchiale. Schlußfolgerung: Die Ergebnisse der Studie legen den Schluß nahe, daß Asthma bronchiale trotz der niedrigeren Prävalenz in der türkischen Bevölkerungsgruppe ein erhebliches Gesundheitsproblem bei türkischen Schulkindern darstellt. Die höhere Anzahl von Fehltagen in der Schule und die deutlich höhere Anzahl von Klinikaufenthalten aufgrund von Asthma bronchiale sprechen für eine mangelhafte präventive Behandlung dieser Erkrankung bei türkischen Kindern.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Monatsschrift Kinderheilkunde 147 (1999), S. 351-355 
    ISSN: 1433-0474
    Keywords: Schlüsselwörter Latexallergie ; Neuogene Blasenentleerungsstörung ; Kinder ; Key words Latex allergy ; Neurogenic bladder dysfunction ; Children
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary Objectives: The risk to suffer from natural latex allergy is increased in children with congenital neurogenic bladder dysfunction. We, therefore, evaluated whether or not a serologic screening for detection of sensitization to latex is reasonable in these children. Patients and Methods: 40 children aged from 6 months to 17 years were examined by specific questionnaire-based patient histories, and by determination of total serum immunoglobuline E (total IgE) and natural latex-specific serum immunoglobulin E (latex-IgE) by solid-phase immunoassays. Results: 5 children had a history of allergic reaction to rubber containing materials. In 10 children, latex-IgE was elevated 〉 0.35 kU/l, 6 out of these 10 children without a history of allergic reactions to rubber containing materials. There was a positive correlation of elevated latex-IgE values and the number of former surgical procedures (p 〈 0.006), while no correlation was found between elevated latex-IgE values and clean intermittent catheterization (p = 0.408). Conclusion: Compared to questionnaire-based patient histories, serologic screening examination including determination of latex-IgE values may better identify children at risk to suffer from sensitization to natural latex.
    Notes: Zusammenfassung Fragestellung: Naturlatexallergien kommen bei Kindern mit angeborener neurogener Blasenentleerungsstörung gehäuft vor. Es wurde deshalb untersucht, ob bei dieser Patientengruppe ein serologisches Screening zur Erfassung einer Sensibilisierung gegenüber Naturlatex sinnvoll ist. Patienten und Methode: Untersucht wurden 40 Kinder im Alter von 6 Monaten bis 17 Jahren. Die Untersuchung umfaßte eine gezielte Anamneseerhebung durch Fragebogen sowie die Bestimmung des Gesamtimmunglobulin E (Gesamt-IgE) und des naturlatexspezifischen Immunglobulin E (Latex-IgE) im Serum durch Festphasenimmunoassays. Ergebnisse: 5 Kinder hatten anamnestisch Zeichen einer allergischen Reaktion nach Gummikontakt. 10 Kinder wiesen im Serum erhöhte Werte des Latex-IgE auf, wobei 6 dieser Kinder bisher noch keine Zeichen einer Latexallergie hatten. Pathologische Werte für das Latex-IgE korrelierten statistisch signifikant mit der Anzahl operativer Eingriffe (p 〈 0,0006), nicht aber mit einem durchgeführten sauber intermittierenden Einmalkatheterismus (p = 0,408). Schlußfolgerung: Im Vergleich zur alleinigen fragebogengestützen Anamneseerhebung können durch ein serologisches Screening mit Bestimmung des Latex-IgE mehr Kinder entdeckt werden, die durch eine Sensibilisierung gegenüber Naturlatex gefährdet sind.
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Cancer chemotherapy and pharmacology 44 (1999), S. 203-209 
    ISSN: 1432-0843
    Keywords: Key words Vincristine ; Pharmacokinetics ; Repetitive dosing ; Children
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Purpose: We studied vincristine disposition after 169 weekly i.v. bolus injections in 32 children with acute lymphoblastic leukemia, non-Hodgkin lymphoma, or Wilms' tumor. The aim of the study was to determine intrapatient and interpatient variability in vincristine disposition and demographic, clinical, and biochemical characteristics influencing this variability. Methods: Vincristine plasma concentrations were measured by a high-performance liquid chromatography assay with electrochemical detection. A limited sampling strategy was used based on a bayesian parameter estimation algorithm that is part of the ADAPT II software package. A two-compartment, first-order model was fitted to the data, and pharmacokinetic parameters were calculated from the model using the ADAPT II software. For statistical analysis, analysis of variance (ANOVA), t test, simple and multiple regression analysis, and non-parametric or robust equivalents were used. Results: Results showed a large intrapatient and interpatient variability in distribution half-life, elimination half-life, total body clearance, apparent volume of distribution at steady state, and area under the concentration–time curve. Intrapatient variability was significantly smaller than interpatient variability for all these parameters except distribution half-life. The diagnosis or treatment protocol turned out to be the most predictive characteristic; leukemia and non-Hodgkin lymphoma patients had a significantly higher total body clearance than Wilms' tumor patients. Conclusions: We conclude that both intrapatient and interpatient variability in vincristine pharmacokinetics is large in pediatric cancer patients and that variability, although significantly influenced by diagnosis, largely remains unpredictable.
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    European spine journal 8 (1999), S. 439-443 
    ISSN: 1432-0932
    Keywords: Key words Low back pain ; Children ; Clinical examination ; Questionnaire ; Prevalence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A study was undertaken to analyse the prevalence of low back pain (LBP) and confounding factors in primary school children in the city of Antwerp. A total of 392 children aged 9 were included in the study. All children completed a validated three-page questionnaire and they all underwent a specific lumbar spine oriented medical examination during their annual routine medical school control. This examination was performed by the city school doctors. The questionnaire was composed of easy “yes/no” questions and visual analogue scales. Statistical analysis was performed using Student’s t-test and chi-squared test at the significance level P 〈 0.05. The prevalence of LBP was high. No gender difference was found. A total of 142 children (36%) reported having suffered at least one episode of LBP in their lives. Of these, 33 (23%) had sought medical help for LBP from a doctor or physiotherapist. Sixty-four percent of children reporting LBP said that at least one of their parents suffered from or complained of LBP. This was significantly higher than for the children who did not report having suffered LBP. The way in which the school satchel was carried (in the hand, on the back) had no bearing on the incidence of LBP. There was significantly more LBP in children who reported playing video games for more than 2 h per day, but this was not so for television watchers. The visual analogue scales concerning general well-being were all very significantly correlated with self-reported LBP, with children who reported LBP being more tired, less happy, and worse sleepers. Of the 19 clinical parameters taken down during the medical examination, only one was significantly more prevalent in the group of children reporting LBP: pain on palpation at the insertion site on the iliac crest of the ilio-lumbar ligament. From this study we can establish that there are few clinical signs that can help to single out school children with LBP.
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  • 11
    ISSN: 1432-0975
    Keywords: Key words Otolith ; Chemistry ; ICP-MS ; Stock discrimination ; Epinephelus striatus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences
    Notes: Abstract  We examined the utility of otolith minor and trace element chemistry, assayed with inductively coupled plasma mass spectrometry (ICP-MS), as a means of delineating population structure in the Nassau grouper (Epinephelus striatus). We characterized the elemental composition of otoliths collected in 1993 from three locations in Exuma Sound, Bahamas and from Glover Reef, Belize in 1995. A single location in Exuma Sound was sampled in 1994 to test temporal variability in otolith composition. Five elements (Ca, Zn, Sr, Ba and Pb) were routinely detected, at levels significantly above background, by solution-based ICP-MS. Results from analysis of variance of elemental data, expressed as a ratio to Ca, indicated that there were no significant differences among the Exuma locations for any element, but significant variability was found between Glover Reef and the pooled Exuma localities for Zn/Ca, Sr/Ca and Ba/Ca ratios. Significant inter-annual differences at one Exuma Sound location was restricted to Ba/Ca ratios. Discriminant function analysis correctly classified 86% and 95% of the Belize and pooled Exuma sites, respectively. Otoliths from Belize were characterized by low Zn/Ca and high Ba/Ca and Pb/Ca ratios compared to otoliths from fish collected in Exuma Sound. Although differences in Ba levels may be related to upwelling at Glover Reef, more data are needed to definitely link otolith composition with regional differences in water chemistry.
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  • 12
    ISSN: 1432-1084
    Keywords: Key words: Optic nerves ; Neuritis ; Children ; Central nervous system ; MR imaging
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract. A 4-year-old boy developed bilateral optic neuritis. Although precise neuro-ophthalmological evaluation was difficult, the diagnosis was made with gadolinium-enhanced MR imaging using fat-suppression technique in the initial stage of the disease. Enhancement and enlargement of the intraorbital and intracanalicular optic nerve were demonstrated bilaterally as well as protrusion of the optic nerve head. The disease responded dramatically to intravenous steroid therapy. The etiologies in children usually differ from those in adolescent and adult patients.
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  • 13
    Electronic Resource
    Electronic Resource
    Springer
    European journal of pediatrics 158 (1999), S. 12-17 
    ISSN: 1432-1076
    Keywords: Key words Alternative medicine ; Complementary therapies ; Critical care ; Children
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The interest in alternative medicine (AM) is growing. In the USA and Canada, studies showed that 34% of adults and 11% of children use AM. In a prospective cohort study, we investigated the interest in AM among parents of critically ill children in the paediatric Intensive Care Unit (ICU) of a university hospital. From January 1996 to April 1997, we distributed questionnaires to the parents of critically ill children. These strictly anonymous questionnaires were completed at home and returned by mail. Exclusion criteria were short (〈1 day) or repeated hospitalizations, and insufficient proficiency of the German language. The inclusion criteria were fulfilled by 591 patients; 561 received the questionnaire (95%) and 289 (52%) were returned. Of the respondents, 70% would appreciate AM as a complementary therapy on the ICU, 23% found AM equally or more important than conventional medicine whereas only 7% regarded AM as unimportant. On the ICU, 18% used AM; surprisingly 41% of them did not discuss it with physicians or nurses. An additional 21% would have liked to use AM, but did not do so. Typically, AM-users administered AM also at home to their children and themselves. Their children were however, older. Conclusions A substantial proportion of parents used measures of alternative medicine in the intensive care unit, or would have like to do so. However, few had the confidence to discuss this wish with the medical personal. This suggests that alternative medicine is of great interest, even on an intensive care unit. Nevertheless, discussion about alternative medicine seems to be taboo in doctor-patient relations.
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  • 14
    ISSN: 1432-1076
    Keywords: Key words Gastro-intestinal bleeding ; Children ; Jejunal leiomyoma ; Neurofibromatosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Gastro-intestinal bleeding is an uncommon presentation in children with neurofibromatosis. Gastro-intestinal involvement caused by jejunal leiomyoma has only been described in adults. To the best of our knowledge, this is the first paediatric case of jejunal leiomyoma associated with neurofibromatosis. We present a 10-year-old girl with a 9-month history of anaemia and low gastro-intestinal bleeding. Abdominal sonography and small bowel series showed a submucosal mass in the proximal jejunum. On surgery, a submucosal tumour was excised and histological examination suggested a diagnosis of “smooth muscle tumour of undetermined malignant potential”. There were no recurrence of symptoms for 4 years after the operation. Conclusion Jejunal leiomyoma should be considered in a child with neurofibromatosis presenting with gastro-intestinal bleeding.
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  • 15
    Electronic Resource
    Electronic Resource
    Springer
    European journal of pediatrics 158 (1999), S. S117 
    ISSN: 1432-1076
    Keywords: Key words Stroke ; Coagulation ; Children
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Many studies have shown a high percentage of venous thromboses in children to be associated with haematological disorders. However, studies assessing the influence of haemostaseological disorders on paediatric stroke are rare. We compared 26 children with cerebral infarction (median age 2 months, range 0–16.2 years) and 17 with venous thrombosis (median age 4.5 years, range 0–17 years) with regard to prothrombotic risk factors. Prothrombotic disorders were found in 8 out of 26 patients with cerebral infarction (FV Leiden mutation: n = 4; protein C deficiency: n = 1; FV Leiden mutation + protein C deficiency: n = 2; prothrombin mutation G20210A: n = 1) and in 13 out of 17 with venous thrombosis (FV Leiden mutation n = 3; protein C deficiency n = 5; elevated HRGP + PAI: n = 1; combined deficiency of AT, protein C and plasminogen: n = 1; F XII deficiency: n = 1; lupus anticoagulans n = 1; FV Leiden + F XII deficiency + lupus anticoagulans + PAI: n = 1). Comparison of these prevalences with those of 150 healthy paediatric controls showed in children with FV Leiden mutation and/or protein C deficiency an increased risk of cerebral infarction (patients vs. controls: 26.9% vs. 6%; OR 5.77; 95%-CI 1.92–17.3; P = 0.0031) as well as of venous thrombosis (53% vs. 5.3% 19.9; 95%-CI 6–65.6; P 〈 0.0001). This result is in contrast with reports on thrombophilia in cerebral infarction in adult patients. Conclusion Our results indicate that FV Leiden mutation and protein C deficiency may contribute to the multifactorial aetiology of stroke in early childhood.
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  • 16
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    European journal of pediatrics 158 (1999), S. 519-522 
    ISSN: 1432-1076
    Keywords: Key words Pulmonary function test ; Adjustment ; Children ; Prediction equations ; Population specific
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Fitting adequate prediction equations for pulmonary function test (PFT) parameters is crucial in the analysis of lung function tests and their interpretation. Our work aimed at studying the necessity of building population specific prediction equations, rather than using prediction equations built-in in commercial equipment. We used as an example results of studies carried out among Israeli schoolchildren. Second to sixth grade children (7–13 years old), 1064 boys and 1211 girls, were studied in Tel-Aviv. PFT (forced vital capacity, forced expiratory volume in 1st second, peak expiratory flow, forced expiratory flow in 50% volume, forced expiratory flow in 75% volume) performed by these children were adjusted for height, weight and age, for each sex separately, by a multiple regression procedure. Predicted PFT parameters of 300 boys and 301 girls aged 7–13 years, living along the southern shore of Israel, were calculated using the equations built for the same aged Tel-Aviv children as well as the prediction equations built-in in the spirometer used. The ratios between the observed PFT parameters in the southern children and their expected values, using the Israeli population specific equations, were around 1.00. Using the built-in equations resulted in ratios around 0.90. Conclusion The development of population specific prediction equations for PFT parameters is necessary. Such equations should be used both in clinical assessment to minimize misclassification (healthy/sick child) and in epidemiological studies.
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  • 17
    ISSN: 1432-1076
    Keywords: Key words HIV-1 ; T-cells ; CD69 ; Activation ; Children
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We evaluated the use of a whole-blood assay that measures spontaneous and activation-induced CD69 expression on peripheral blood T-cells in vitro for assessment of T-cell function in HIV-1-infected paediatric patients. Heparinized venous blood from 28 HIV-1 positive children and adolescents and 23 healthy controls was incubated for 4 h with or without 5 μg/ml phytohaemagglutinin (PHA). Thereafter, analysis of CD69 expression on CD4+ and CD8+ T-cells was done by flow cytometry; simultaneously we determined CD4+ T-cell counts and plasma HIV-1 viral load. Neither spontaneous nor PHA-induced CD69 expression differed significantly between HIV-1 positive patients and healthy controls. However, T-cells from HIV-1 positive patients with plasma HIV-1 viral load levels above 70 × 103 copies/ml showed a higher spontaneous CD69 expression than T-cells from patients with lower plasma viral load levels in different stages of the disease. Antiretroviral treatment in four patients reduced spontaneous CD69 expression in CD4+ T-cells and PHA-induced CD69 expression in CD4+ and CD8+ T-cells significantly after 8 weeks of therapy. Conclusion Spontaneous and activation-induced expression of the early (activation) antigen CD69 on peripheral blood T-cells does not distinguish HIV-1 positive patients from HIV-1 negative healthy controls and is not correlated with peripheral blood CD4+ T-cell counts. This test may not be a reliable marker for functional T-cell deficiency during early stages of HIV disease. Increased spontaneous as well as PHA-induced CD69 expression on T-cells from HIV-1-infected children and adolescents in vitro may rather reflect HIV-induced pre-activation of T-cells in vivo.
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  • 18
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    European journal of pediatrics 158 (1999), S. 662-667 
    ISSN: 1432-1076
    Keywords: Key words Somatosensory evoked potentials ; Far-field potentials ; Achondroplasia ; Foramen magnum stenosis ; Children
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Children with achondroplasia may have high cervical myelopathy due to stenosis of the cranio-cervical junction resulting in neurological disability and an increased rate of sudden death. To detect myelopathy we recorded somatosensory evoked potentials (SEPs) after median nerve stimulation in 30 patients with achondroplasia aged 13 months to 18 years (mean 6 years). In addition to the conventional technique of recording the cortical N20 and the central conduction time (CCT), we employed a noncephalic reference electrode recording the subcortical waveforms N13b and P13, generated near the cranio-cervical junction. The findings were related to the clinical status and MRI results. Eighteen patients had MRI evidence of spinal cord compression with indentation or narrowing of the upper cervical cord, and 13 showed signs of myelomalacia. Seven patients had neurological abnormalities. The sensitivities of the SEPs were 0.89 for cervical cord compression, 0.92 for myelomalacia and 1.0 for the clinically symptomatic patients. There were no false-positive results. The subcortical SEPs were more sensitive than the conventional recordings. However, the conventional SEPs were highly specific in the most severely affected patients; here the specificity was 1.0 for patients with myelomalacia and 0.96 for symptomatic patients. Postoperative SEPs improved after occipital decompression in two children. Conclusion The analysis of somatosensory evoked potentials, in particular of subcortical tracings, is useful in the detection of early cervical myelopathy in children with achondroplasia. Early neurosurgical decompression may prevent irreversible damage.
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  • 19
    ISSN: 1432-1076
    Keywords: Key words Heparin treatment ; Heparin-induced thrombocytopenia ; HIT antibodies ; Children ; Catheter patency
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The immunological form of heparin-induced thrombocytopenia (HIT) is a potentially life-threatening adverse reaction of heparin medication. It is mediated by multimolecular complexes consisting of platelet factor 4 (PF4)-heparin-IgG which bind to platelets via platelet Fcγ receptors. Cross-linking of multiple Fcγ receptors results in platelet activation, platelet aggregation and enhanced thrombin generation with a increasing risk of developing new thrombosis. In children, data on HIT are sparse. This review of the literature reports on 8 children aged 3 months to 15 years and 14 newborns suffering from HIT. Additionally, we report one new case treated with danaparoid sodium. Thrombotic complications were venous (n = 12) and arterial (n = 15). The children received heparin either for a spontaneous thrombotic event, for severe cardiac diseases or to maintain patency of intravascular catheters which are used for nutrition, blood sampling, and for application of medication. After diagnosis of HIT they were further anticoagulated with aspirin, warfarin, danaparoid sodium, lepirudin or low molecular weight heparin. Conclusion Although HIT is less frequently reported in newborns and children, paediatricians should be aware of HIT in childhood as a potential complication of heparin application. The widespread practice of flushing catheters with heparin should also be debated in view of the risk of triggering the primary immune-response of HIT. In 1999, treatment options for further parenteral anticoagulation of HIT patients are danaparoid sodium (a low-molecular weight heparinoid) and lepirudin (a direct thrombin inhibitor).
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  • 20
    ISSN: 1432-1076
    Keywords: Key words Factor V G1691A ; Prothrombin G20210A ; Lipoprotein (a) ; Central venous lines ; Children
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract To evaluate the role of inherited thrombophilia in the development of central venous line (CVL)-related thrombosis, the following parameters were determined in 77 pediatric-oncologic patients with CVL: activated protein C (APC)-ratio, factor V (FV) G1691A and prothrombin G20210A mutation, protein C, protein S, antithrombin, coagulation factor XII, lipoprotein (a) and homocysteine. An inherited prothrombotic risk factor was found in 17 patients (23%). Four out of 14 patients with a single defect (hyperlipoproteinemia, heterozygous FV G1691A and prothrombin G20210A mutation, protein C deficiency type I) and all three patients with combined defects (heterozygous FV G1691A mutation combined with heterozygous prothrombin G20210A variant, protein S deficiency or hyperlipoproteinemia) suffered from CVL-related thrombosis. In 11 out of 77 patients (14%) a CVL-related thrombosis was detected. In 2 children thrombosis occurred a few days after asparaginase therapy and in another three thrombosis was associated with CVL-related septicemia caused by Staphylococcus epidermidis. After removal of CVL, thrombosis was detected in 5 children, in 2 without clinical symptoms but in the presence of inherited prothrombotic risk factors. Conclusion The present study demonstrates the clinical importance of CVL in combination with inherited thrombophilia in the development of thrombosis in pediatric-oncologic patients. Before or shortly after insertion of CVL, patients should be tested for the presence of factor V G1691A mutation, prothrombin G20210A variant and increased lipoprotein (a) values.
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  • 21
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    European journal of pediatrics 158 (1999), S. S154 
    ISSN: 1432-1076
    Keywords: Key words Veno-occlusive disease ; Antithrombin ; Children ; Chemotherapy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Hepatic veno-occlusive disease (VOD) is a well-known complication of chemotherapy in Wilms tumor patients, particularly young children. Although this complication resolves uneventfully in most patients, fatal cases have been reported. Severe VOD after transplantation has a high mortality rate ranging from 45% to 98%. New hemostatic therapeutic strategies have significantly improved the prognosis of VOD. Chemotherapy-related VOD in Wilms tumor usually has a good prognosis. We describe two patients with Wilms tumor and one with acute lymphoblastic leukemia, who developed severe veno-occlusive disease of the liver according to the Baltimore criteria while undergoing chemotherapy; the symptoms were hepatomegaly, ascites, hyperbilirubinemia, weight gain and, in one patient, short-term lethargy. Elevated LDH levels of 872 to 12,000 U/l were observed in our patients. All patients had thrombocytopenia between 29,000 and 40,000/μl and decreased antithrombin (AT) and protein C levels; two patients had gastrointestinal bleeding. All patients developed a coagulopathy because of severe hepatic dysfunction. Two patients received low-dose heparin at the onset of VOD. The thrombolytic therapy was rapidly changed to AT supplementation (20–80 IU/kg bw 2× per day) without heparin when thrombocytes were very low or gastrointestinal bleeding occurred. Resolution of VOD was observed in all patients receiving AT alone. The chemotherapy was discontinued in a patient with accidental actinomycin D overdosage in view of the severity of symptoms. The remaining two patients received chemotherapy according to the therapy protocol after restitution. All patients survived without sequelae with a median follow-up of 28 months (range 8–48 months). Conclusion Hepatic veno-occlusive disease is a rare but increasingly recognized complication in pediatric cancer patients receiving conventional chemotherapy. AT supplementation constitutes a good alternative treatment of severe VOD in comparison with other thrombolytic therapies, particularly in patients at high risk of bleeding.
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  • 22
    ISSN: 1432-1076
    Keywords: Key words Antithrombin concentrate ; Children ; Septicaemia ; Acquired antithrombin deficiency
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Consumption coagulopathy is a serious problem in childhood. In addition to treatment of the underlying disease, consumption coagulopathy was previously treated with heparin. Nowadays it is treated by substitution of coagulation factors, especially antithrombin (AT) concentrate, alone or in combination with heparin. In this pilot study we administered AT concentrate (dosage 80 U/kgbw/d), without additional heparin treatment, to 29 children beyond infancy with acquired AT deficiency. Antithrombin, platelet count, fibrinogen, PT, and APTT were assayed before and during the course of AT substitution. These coagulation parameters returned to normal 48 hours after normalisation of the plasma AT level. AT levels normalised within 24 h of initial substitution in all children. Lethal outcome due to the underlying disease was observed in only two children. Conclusion Data of this pilot study suggest that, concomitantly with the treatment of the underlying disease, consumption coagulopathy in childhood can be managed successfully with early substitution of AT concentrate.
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  • 23
    ISSN: 1432-1076
    Keywords: Key words Coagulation ; Fibrinolysis ; Head injury ; Children
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The present study was designed to evaluate the post-trauma haemostatic changes in 27 children with severe cranio-cerebral trauma defined by a modified Glasgow Coma Score (GCS) 〈10. Blood samples for coagulation studies (fibrinogen, von Willebrand factor (vWf), factor VIII:C, antithrombin, protein C, plasminogen, tissue-type plasminogen activator (t-PA), plasminogen activator inhibitor-1 (PAI), D-dimer) were obtained within two hours of admission, 24 h later, and on days 3–5, 7–9, 21 and 35. Data of this study indicate that alterations of coagulation in paediatric patients are similar to those in adults: On hospitalisation, activated haemostasis was found with decreased fibrinogen, antithrombin and protein C along with enhanced t-PA and PAI. Twenty-four hours later, hypercoagulability with significantly increased vWF and fibrinogen started, with a peak level within the second week. Within 24 h of admission, 17 children developed disseminated intravascular coagulation (DIC) with a clear-cut decrease of antithrombin and fibrinogen together with platelet consumption and enhanced D-dimer. The outcome of children with DIC was significantly poorer than in those without DIC. Complete recovery was seen in five patients; sequelae no handicap and moderate disability were each found in six patients. Severe disability was diagnosed in two children, and fulminant DIC with lethal outcome occurred in eight patients. The GCS (P 〈 0.01) and the occurrence of DIC (P 〈 0.005) showed the strongest association with the patients' clinical outcome. Conclusion Our data underline the significance of post-trauma disturbances of the haemostatic system for the clinical course and outcome in children with severe cranio-cerebral injuries.
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  • 24
    ISSN: 1432-1084
    Keywords: Key words: Lung disease ; Pneumoconiosis ; Children
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract. We report two cases of children with malignancies and subpleural nodules found on computed tomography (CT) scan. In both cases the diagnosis was anthracosis. This pathologic condition has never been reported in children. Causes of anthracosis include a smoking environment, living in urban areas and air pollution.
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  • 25
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    Experimental brain research 126 (1999), S. 200-204 
    ISSN: 1432-1106
    Keywords: Key words Motor development ; Anticipatory postural adjustments ; Bimanual coordination ; Children ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Anticipatory postural adjustments (APA) are needed to perform a movement without perturbing posture. We investigated the development of APA in 3- to 4-year-old children during a bimanual load-lifting task. The task required maintaining a stable elbow position despite imposed or voluntary unloading of the forearm. Although children can compensate the consequences of unloading by using APA, their performance did not reach an adults’ level. In addition, children showed high intra-individual variability in the voluntary situation, revealed by the coexistence of both adult-like and immature patterns in kinematic and electromyographic data. In conclusion, the present study reports that APA, associated with a bimanual load-lifting task, are still being set up in 3- to 4-year-old-children. The intra-individual variability should decrease with age and be associated with a progressive mastering of the timing parameters characterizing APA.
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  • 26
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    Experimental brain research 125 (1999), S. 239-247 
    ISSN: 1432-1106
    Keywords: Key words Precision grip ; Motor development ; Motor control ; Children ; Object manipulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Recent evidence has shown that the anticipatory control of grip and load force is not innate and develops over several years in childhood. The present study examined the development of grasping behavior by quantifying the relationship between grip force and the vertical acceleration of an object. Children and adults were requested to use a precision grip to lift an instrumented object which varied in size and weight. Grip force, grip force rate and the vertical position and acceleration profiles of the test object were measured or calculated. The results demonstrated the presence of distinct developmental milestones in the maturation of precision grip from 2 to 9 years of age. With 2-year-old children, the peak acceleration was negatively correlated (r=–0.51, n=34, P〈0.01) with peak grip force during lifting. By 3 years of age, peak acceleration and peak grip force during lifting became positively correlated (r=0.28, n=104, P〈0.01) and the correlation continued to strengthen up to 9 years of age. Variations in the temporal coupling of both peak grip force and peak acceleration also decreased with maturation. Furthermore, starting at 4-years-old, children clearly controlled the acceleration and deceleration of the object in a symmetrical pattern and used a single burst of grip force rate to grasp the object with some regularity, suggesting that the emergence of an anticipatory control strategy had already begun.
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  • 27
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    European journal of pediatrics 158 (1999), S. 24-28 
    ISSN: 1432-1076
    Keywords: Key words Hashimoto thyroiditis ; Graves disease ; Children ; TSH function-blocking antibody ; Cytotoxic antibody
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In a cross-sectional study, 29 children aged between 1 month and 15.3 years (average age 6.8 years) born to mothers with Graves disease or Hashimoto thyroiditis were examined clinically, biochemically, and by sonography of the thyroid gland. At the time of examination all children were clinically euthyroid. Tests of thyroid peroxidase antibody, thyroglobulin antibody, TSH receptor antibody and free thyroxine (fT4) gave normal results. In 3 children subclinical hypothyroidism with elevated TSH and normal fT4 concentrations were found; one of these children had a minor decrease of total thyroxine. Three children with otherwise normal test results had marginally elevated tri-iodothyronine concentrations. Increased antibody titres were present in 8 out of 29 children. TSH function-blocking antibodies were elevated in 8 cases. In addition, cytotoxic antibodies were found in one of the children. The distribution pattern of antibodies was different in each child and unrelated to the type of maternal thyroid disease. Conclusion Children of mothers with auto-immune thyroid disease often have thyroid antibodies without signs of thyroid disease. Whether antibody-positive children have an increased risk of developing thyroid disorders later in life must be examined in a longitudinal study.
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  • 28
    ISSN: 1432-1076
    Keywords: Keywords Liver ; Steatosis ; HIV ; AIDS ; Children
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Thirty HIV-infected children were cross-sectionally examined for morphologic hepatic abnormalities, using ultrasonography or histology. Abdominal ultrasonography was performed in 27 children. The liver structure was normal in four patients, one of whom had moderate symptoms of the HIV infection and three of them severe symptoms. Abnormal liver structure, compatible with hepatic steatosis, was found in 23 (85%) patients. Five of them were in an early stage of the HIV infection (category N or A), three patients were ranked in category B and 15 patients in category C. Histological examination of the liver was performed in 11 children and steatosis was documented in ten (91%). In seven (70%) of these ten children steatosis had been suspected by ultrasonography. In conclusion, steatosis is common in HIV-infected children. It is non-specific and has no impact on disease, diagnostic evaluation or management. Conclusion Ultrasonography is a sensitive, accurate, non-invasive screening tool. It is more reliable than liver function tests.
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  • 29
    ISSN: 1432-1076
    Keywords: Key words Respiratory chain ; Mitochondria ; Children ; Infancy ; Liver failure ; AbbreviationsMRCD mitochondrial respiratory chain disease ; OLT orthotopic ; liver transplantation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Mitochondrial respiratory chain disease may lead to neonatal or late onset liver failure, requiring liver transplantation. In rare cases, the disease is restricted to the liver and the patient is cured after surgery. More frequently, other organs are simultaneously involved and neuromuscular or other extra-hepatic symptoms may pre-exist, or appear in the post-transplant follow up. Pre-transplant evaluation should aim to rule out neurological disease, which may be difficult to differentiate from signs accompanying liver insufficiency. Cerebrospinal fluid lactic acid levels, compared to blood lactate, may be suggestive of central nervous system involvement. Of 11 cases with respiratory chain disorders who had liver transplantation in various centres, 4 are alive and well on follow up, and 6 died, three of them having developed neurological disease post orthotopic liver transplantation. All three patients with initial liver and gastro-intestinal disease died early after transplantation, indicating that these may be poor candidates for this procedure. Conclusion Liver transplantation is feasible in hepatic respiratory chain disorders, but extra-hepatic disease should be ruled out before transplantation. Extra-hepatic manifestations may, however, appear and cause patient death despite successful transplantation.
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  • 30
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    European journal of pediatrics 158 (1999), S. S085 
    ISSN: 1432-1076
    Keywords: Key wordsα1-Antitrypsin ; Liver disease ; Liver transplantation ; Children ; AbbreviationsAATα1-antitrypsin deficiency ; OLT orthotopic liver transplantation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Only a minority of infants born with α1-antitrypsin deficiency will develop serious liver disease during childhood, mostly but not always after neonatal cholestasis. Early prognosis is difficult and all children have to be followed up carefully. The liver disease progresses with varying speed and it lacks specific features. At the time of liver transplantation the young patients have no pulmonary disease induced by the deficiency and in those with renal involvement, the kidney problems can mostly be dealt with by conservative therapy. The peri- and postoperative care of the patients who undergo liver transplantation does not differ from the usual routines.
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  • 31
    ISSN: 1432-1076
    Keywords: Key words Mild head injury ; Fractured bone ; Late sequelae ; Children
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Two years after an accident resulting in either a mild head injury or a fractured bone, two groups of 22 children each, aged 4–14 years, were examined for the existence of any neurobehavioural symptoms by means of a standardized questionnaire filled out by their caretakers. Selection of the children was based on reports of the Accident and Emergency Department in 1 year. Significantly more symptoms were reported after mild head injury. The main symptoms reported were headache, dizziness, fatigue and memory problems. The total number of symptoms in the children with mild head injury exceeded four times this in the group of children with a fractured bone. Conclusion Even 2 years after a mild head injury there are still residual symptoms in daily life.
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  • 32
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    European journal of pediatrics 158 (1999), S. 298-301 
    ISSN: 1432-1076
    Keywords: Key words Isolated ; Sphenoid ; Sinusitis ; Children
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Acute isolated infectious sphenoiditis is an uncommon, potentially dangerous condition which is often misdiagnosed because of its nonspecific symptoms and paucity of clinical signs. We present eight children with isolated sphenoiditis who were managed in our medical centre during the last 2 years and review the literature. All the patients were adolescents or pre-adolescents and all experienced moderate to severe refractory oppressive headache. Four had a history of sinusitis or allergic rhinitis. None had fever or any other directing clinical sign. Diagnosis was made by cranial computer tomography. All were treated with antibiotics and recovered completely without infectious or neurological complications. Conclusion Acute isolated infectious sphenoiditis should be considered in adolescents and pre-adolescents who present with constant moderate to severe oppressive headache. Awareness of this entity will enable early diagnosis and initiation of antibiotic treatment which is essential to avoid complications and surgical intervention.
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  • 33
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    European journal of pediatrics 158 (1999), S. 362-366 
    ISSN: 1432-1076
    Keywords: Key words Type 1 diabetes ; Children ; Risk factors ; Case control ; Environmental
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The aim of this study was to investigate environmental risk factors in the development of type 1 diabetes mellitus in a population-based case-control study. Parents of all patients with manifestation of type 1 diabetes between 1989 and 1994 in Vienna were asked to complete a questionnaire (n = 114). Control children (n = 495), matched for age and sex, were randomly recruited from all schools in Vienna. Fathers of diabetic children were significantly older at the time their children were born than fathers of control children (P = 0.015). Children with diabetes were more likely to be second- or third-born children (P 〈 0.05) and fewer went to kindergarten than the control group children (P = 0.007). No significant difference in duration of gestation, percentage of delivery by caesarean section, birth weight or length was found. Neonatal jaundice was more often observed in the patient group (P = 0.038). Breast feeding was reported by 82.7% of mothers of diabetic children and by 81% of mothers of control children, and the duration of breast feeding was longer in patients than in controls (n.s.). Conclusion In our study, the development of type 1 diabetes mellitus was associated with higher paternal age and neonatal jaundice. No correlation could be found with dietary intake of cow's milk products in early infancy, vaccination and other environmental factors.
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  • 34
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    European journal of pediatrics 158 (1999), S. 550-552 
    ISSN: 1432-1076
    Keywords: Key wordsShigella ; Toxic encephalopathy ; Children ; Brain oedema ; Shiga toxin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A 6-year-old girl is described who died following rapid neurological deterioration, ending in lethal cerebral oedema. Despite the absence of severe intestinal and metabolic derangement, Shigella was cultured from the stool. Toxic encephalopathy is responsible for death following this rare complication of childhood shigellosis in developed countries. The pathophysiology is unknown. Conclusion Lethal toxic encephalopathy can be caused by Shigella despite the absence of severe intestinal and metabolic derangement. If shigelllosis is suspected, headache may be a first significant sign for the development of toxic encephalopathy. Early recognition and rapid measures to prevent brain oedema may improve outcome.
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  • 35
    ISSN: 1432-1173
    Keywords: Schlüsselwörter Kinderdermatologie ; Exanthem ; Kinder ; Key words Pediatric dermatology ; Exanthema ; Children
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary Unilateral laterothoracic exanthem a (ULE) is a self-limited, probably infectious-allergic skin disease predominately affecting small children. We describe five such cases. The typical unilaterally located or at least unilaterally dominant exanthem usually starts in the axillary region and is characterized by red, partly confluent papules and fine scales. Two of the children presented with atypical manifestations of ULE. Due to its asymptomatic course, therapy is not necessary in the majority of cases.
    Notes: Zusammenfassung 5 Kinder mit der Diagnose eines unilateralen laterothorakalen Exanthems (ULE) werden vorgestellt. Beim ULE handelt es sich um eine selbstlimitierende, vermutlich infektallergische Hauterkrankung, die hauptsächlich im Kleinkindesalter auftritt. Das typischerweise streng einseitig lokalisierte, immer jedoch einseitig dominierende Exanthem geht meist von der Axillarregion aus und zeigt erythematöse, teils konfluierende Papeln. Zwei der fünf Kinder zeigten auch atypische Hautveränderungen eines ULE. Eine Behandlung ist aufgrund seines überwiegend asymptomatischen Verlaufs in der Mehrzahl der Fälle nicht notwendig.
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  • 36
    ISSN: 1248-9204
    Keywords: Contralateral hernia ; Children ; Incidence ; Predisposing disease
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary It is impossible to determine whether or not a child will develop a contralateral hernia after inguinal hernia repair. There exists no risk score for the occurrence of a contralateral hernia. This well-known fact prompted us to perform the underlying study. In a retrospective trial, we reviewed the files of all children operated on for inguinal hernias in our department from January 1986 until December 1994. During this period, we performed 1721 hernia repairs on 1708 children aged 0–16 years. In 96 (5.6%) of these patients, the indication to operate was a contralateral hernia following previous unilateral repair. Comparison of the ages at the time of primary inguinal repair of those children who developed a contralateral hernia (n=96) and those who did not (n=1612) showed a significantly increased incidence of contralateral hernias if the primary operation was performed before the age of two months (p〈0.0001). Diseases predisposing to hernias were found in 38% of all children (prematurity, dystrophia, ventriculo-peritoneal shunt, ascites, asthma). The authors recommend a contralateral exploration for children under the age of two months if they have any predisposing disease.
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  • 37
    ISSN: 1432-0584
    Keywords: Key words Hypergammaglobulinemia ; Polyclonal ; Acute myeloid leukemia ; Children
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Polyclonal hypergammaglobulinemia (PHG) associated with hematological malignancies is a rare occurrence. We reviewed our series of 47 children with AML in order to define the prevalence of PHG and its prognostic value in achieving complete remission (CR) after induction treatment. Patients were stratified by immunoglobulin levels into two groups: with PHG and without PHG. CR reached after induction chemotherapy was considered a positive response. Conditional exact tests were used for the statistical analysis; conditional maximum likelihood estimates of the odds ratio (OR) were obtained. Significance levels (p) were determined from two-tailed tests. Twenty-two of 38 (57.9%) evaluable children showed PHG. Children with PHG and AML were more likely to be in CR after first induction treatment (OR=6.25, p=0.021), independent of sex, age at diagnosis, white blood cell count, percentage of blasts in the bone marrow, FAB phenotype, and treatment protocol. Infections seemed to positively influence early treatment response (p=0.038). PHG and infections were not statistically associated (p=0.16). PHG may result from the uncontrolled stimulation of B lymphocytes by cytokines. Infections or transfusions may act as triggers for the immune system, leading to the antileukemic effect seen in patients with AML and PHG going into spontaneous remission. It could be that this activation caused the larger number of CRs observed in our series. Clarification of why PHG exerts a positive influence on children with AML could help us to understand the ways by which the organism is able to control a malignant disease.
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  • 38
    ISSN: 1432-0584
    Keywords: Key words Thrombopoietin ; Interleukin-11 ; Interleukin-6 ; Thrombocytopenia ; Children
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  We measured serum levels of thrombopoietin (TPO), interleukin (IL)-11, and IL-6 in 90 different samples from 67 pediatric patients with thrombocytopenia (TP). The cytokine levels were determined by enzyme-linked immunosorbent assays (ELISA), and the biological activity of TPO was measured using a cell line transfected with human c-mpl. In patients with impaired megakaryocytopoiesis, as found in diseases such as aplastic anemia, amegakaryocytic TP, or TP with absent radii, we found TPO levels which were highly elevated compared with normal values (mean=261 AU/ml, n=52, vs. 22 AU/ml in healthy controls). In contrast, patients suffering from idiopathic thrombocytopenic purpura (mean=16 AU/ml, n=31) or platelet function defects (mean=23 AU/ml, n=7) demonstrated normal TPO levels. The biological activity tested in the bioassay correlated well with the ELISA data. However, sera of some patients with amegakaryocytic TP demonstrated a remarkably higher biological activity of TPO than expected from the ELISA data. Within the different groups there was no correlation between platelet counts and TPO levels. Only 27% of all samples had elevated levels of IL-11 (mean=450 pg/ml, n=20). Elevated IL-6 serum levels were detected in only 13% of all samples analyzed (mean=42 pg/ml, n=12). We conclude that megakaryocytopoiesis is regulated mainly by TPO, that it is dependent on the platelet and the megakaryocytic mass, and that IL-11 plays an additional role in supporting the platelet production. IL-6 does not appear to be up-regulated in children with thrombocytopenia.
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  • 39
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    Italian journal of neurological sciences 20 (1999), S. 303-307 
    ISSN: 1126-5442
    Keywords: Key words Lyme disease ; Chronic neuroborreliosis ; Children ; MRI ; Demyelinating disease
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Lyme disease is a polymorphic and multisystemic disease caused by Borrelia burgdorferi. Neurological manifestations are found in 10%–50% of cases. We present 2 cases followed for 5 and 6 years of chronic relapsing-remitting neuroborreliosis. Diagnosis of neuroborreliosis in these cases was based on serum and cerebrospinal fluid findings. We discuss clinical, neurophysiological, laboratory and instrumental aspects regarding the difficulties of reaching a correct diagnosis. Further studies, especially in the field of immunology, should help identify the mechanisms responsible for the disease becoming chronic. With this knowledge, it may be possible to design immunological therapies for relapses, and to prevent the evolution of the disease.
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  • 40
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    Italian journal of neurological sciences 20 (1999), S. 119-128 
    ISSN: 1126-5442
    Keywords: Key words Learning ; Development ; Memory ; Children
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Immediate and 15-min delayed recall of semantically related or unrelated word lists was investigated in 144 normally developing children ranging from 5 to 10 years of age. Immediate recall for the related and unrelated lists increased in a parallel fashion as a function of age. The ability to cluster semantically related items during immediate recall also improved with age. However, in no age class recall scores and clustering indexes were significantly associated. Forgetting rate passing from the last immediate to the delayed recall trial increased for the unrelated list but decreased for the related list of words as a function of age. Results of regression analyses revealed that a developmental increase in forgetting on the unrelated list was actually due to the higher number of words recalled in the last immediate trial by older children. As for the related list, instead, the larger reliance on the clustering strategy of recall by older children was responsible for the progressive reduction of forgetting.
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  • 41
    ISSN: 1432-2099
    Keywords: Key words Case-control study ; Children ; CNS tumour ; Environmental exposure ; Indoor radon ; Leukaemia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Physics
    Notes: Abstract  A population-based case-control study on risk factors for childhood malignancies was used to investigate a previously reported association between elevated indoor radon concentrations and childhood cancer, with special regard to leukaemia. The patients were all children suffering from leukaemia and common solid tumours (nephroblastoma, neuroblastoma, rhabdomyosarcoma, central nervous system (CNS) tumours) diagnosed between July 1988 and June 1993 in Lower Saxony (Germany) and aged less than 15 years. Two population-based control groups were matched by age and gender to the leukaemia patients. Long-term (1 year) radon measurements were performed in those homes where the children had been living for at least 1 year, with particular attention being paid to those rooms where they had stayed most of the time. Due to the sequential study design, radon measurements in these rooms could only be done for 36% (82 leukaemias, 82 solid tumours and 209 controls) of the 1038 families initially contacted. Overall mean indoor radon concentrations (27 Bq m–3) were low compared with the measured levels in other studies. Using a prespecified cutpoint of 70 Bq m–3, no association with indoor radon concentrations was seen for the leukaemias (odds ratio (OR): 1.30; 95% confidence interval (95% CI): 0.32–5.33); however, the risk estimates were elevated for the solid tumours (OR: 2.61; 95% CI: 0.96–7.13), mainly based on 6 CNS tumours. We did not find any evidence for an association between indoor radon and childhood leukaemia, which is in line with a recently published American case-control study. There is little support for an association with CNS tumours in the literature.
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  • 42
    ISSN: 1435-1544
    Keywords: Key words Implantable cardioverter defibrillator ; Sudden cardiac death ; Children
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Implantable cardioverter defibrillators (ICDs) are the treatment of choice in adults with symptomatic ventricular tachycardia or aborted sudden cardiac death. Treatment with implantable defibrillators is also possible in children, although experience in this patient group is scanty. A review of the literature on the subject of defibrillator therapy in combination with epicardial electrodes is provided. Endocardial electrodes, which have now become the gold standard in adult treatment, have only rarely been used in children. However, our own experience shows that endocardial electrodes can be implanted in most children, which generally obviates the need for thoracotomy.
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  • 43
    ISSN: 1434-5196
    Keywords: Key words Methadone ; Dihydrocodeine ; Substitution ; Poisoning ; Children ; Schlüsselwörter Methadon ; Dihydrocodein ; Substitution ; Intoxikationen ; Kinder
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Law
    Description / Table of Contents: Zusammenfassung Es wird über 3 überlebte und 4 tödlich verlaufene akzidentelle Intoxikationen, sechs mit Methadon, eine mit Dihydrocodein, berichtet. Die Intoxikationen betrafen nicht die Substituierten selbst, sondern deren Familienangehörige, Bekannte oder Mit-Patienten. In allen Fällen wurden die Substitutionsmittel weitgehend ungesichert und teilweise vermutlich auch unbeschriftet stehengelassen. Den Substituierten selbst war dabei die Gefahr, die von ihrem Substitutionsmittel ausging, offenbar nicht ausreichend bewußt. Diese Fälle zeigen deutlich, daß qualitätssichernde Maßnahmen bei der immer großzügigeren Substitutionspraxis, insbesondere in Hinblick auf „take-home“-Dosen, notwendig sind.
    Notes: Abstract A total of seven cases of accidental ingestion of methadone or dihydrocodeine by four children and three adults are reported of which four were fatal. In each case, someone in the environment was taking methadone or dihydrocodeine as a substitute drug for heroin addiction who obviously did not realize the dangers of methadone for non-addicts. Possible preventive measures are the usage of child-proof containers with adequate labels for take-home medications. Furthermore substituted addicts have to be thoroughly indoctrinated concerning the toxicity and hazards of methadone.
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  • 44
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    European archives of oto-rhino-laryngology and head & neck 256 (1999), S. S8 
    ISSN: 1434-4726
    Keywords: Key words Cholesteatoma ; Children ; Tympanoplasty
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We studied retrospectively 28 cases of cholesteatoma in children whose ages were 3 to 13 years old. All had undergone surgery between 1989 and 1995. The intact canal wall technique was the predominant method used in the initial operation, with long term goals of an anatomically normal and infection-free ear. Cholesteatoma was found postoperatively in 15 cases and was considered to be residual in 6 cases and recurrent in 9. The residual cholesteatoma was relatively uncommon and usually removable in an exploratory second operation. Our findings showed that the intact canal wall technique was the best initial operation if two-stage surgery was planned. Avoidance of a retraction pocket, which tends to progress to a recurrent cholesteatoma, is important to successful treatment.
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  • 45
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    European archives of oto-rhino-laryngology and head & neck 256 (1999), S. 128-132 
    ISSN: 1434-4726
    Keywords: Key words Cochlear implant ; Management of ; complications ; Children ; Postoperative care ; Infection ; Device failure ; Reimplantation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In a retrospective analysis we evaluated the intra- and postoperative complications in children who underwent cochlear implantation between 1984 and 1993 at the Medizinische Hochschule Hannover. The data and records of 366 children were collected and analyzed. Relevant parameters were major complications such as significant infection, intraoperative bleeding, facial nerve injury, implant loss and device failure, as well as lesser complications, including delayed wound healing, chronic pain and vertigo. Late complications such as cholesteatoma or electrode dislocations were also registered. Cases of acute otitis media were managed with conservative treatment. Data presented indicate that cochlear implant surgery in children is a reliable and safe procedure with a low percentage of severe complications. Problems related to ear surgery can occur and should be manageable with standard procedures. Careful operative techniques and sufficient personal experience can help avoid severe postoperative problems.
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  • 46
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    European journal of epidemiology 15 (1999), S. 485-491 
    ISSN: 1573-7284
    Keywords: Blood lead levels ; Children ; Modeling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The key problem in environmental health is to identify the potential health hazards at the lowest possible cost based upon available environmental data. Biokinetic models such as IEUBK Lead 0.99d are very promising in this respect. We attempted a comparison between epidemiological data and predictions of the model. As input, we used the existing exposure data for the Katowice Voivodship (administrative district, Poland). Epidemiological analysis was based on the results of the screening programme ‘Prevention of the Environmental Lead Intoxication in Children Living in Katowice Voivodship’. The simulations consisted of predicted distributions of blood lead levels in children. They have been compared with observed distributions. Sensitivity analysis of simulations with respect to lead concentration in air, soil, water and diet has also been performed. The agreement between predicted and observed mean blood lead levels was quite good (relative difference of about 40%) as for the coarse exposure assessment employed. At the level of risk (fraction of population having blood lead levels exceeding 10 μg/dl) the difference is much higher (about a factor of 2). In order to explain this discrepancy we checked the goodness of fit for the log-normal distribution function (usually taken as a template distribution for lead in the population) in the right tail of the distribution. We noticed a systematic effect depleting the right tail of the actual distribution as compared with the log-normal one. Therefore one can expect that using (as a template) another skewed distribution better fitted in the right tail would improve the accuracy of risk assessment.
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  • 47
    ISSN: 1573-7284
    Keywords: Children ; ELISA ; Haemophilus influenzae type b ; Infants ; Natural immunity ; Vaccination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Prior to possible introduction of large-scale vaccination programmes, an estimation and comparison of naturally acquired immunity against Haemophilus influenzae type b (Hib) was carried out in two populations of age-stratified infants and children (from birth to 14 years old) in Burkina-Faso (West Africa) (n = 206) and France (n = 206). Hib capsular polysaccharide antibodies were detected by an ELISA method. The difference in the percentages of minimum protective levels for the two populations were not significant (0.15 μg/ml) for newborns (0–1 month) but became significant as early as 2 to 3 months of age (p 〈 0.01) when lower levels were found among infants from Burkina-Faso. Subsequently, the percentages in both countries remained low until 11 months of age and showed no significant differences. For children between 12 and 35 months, the results ≥ 0.15 μg/ml were significantly higher in France (p ≤ 0.05). From 36 months, the percentage of minimum seropositivity increased in Burkina-Faso, so that the difference was no longer significant. In each country, the percentage of children with the minimum protective level varied significantly (p les; 0.05) according to age (0–47 months). None of the children from Burkina-Faso or France had antibody levels 〉 1.0 μg/ml before one year of age. Thereafter, only 9.51% of French children in the 12- to 17-month age stratum and 19.2% over 4 years of age had antibody levels 〉 1.0 μg/ml. There were no non-detectable results for children over 4 years of age, and the means for natural detectable Hib CP antibodies were 〉 0.15 μg/ml for both populations. Hib invasive infections depend on climate, socioeconomic status and ethnic and genetic factors. In Burkina-Faso, the large number of infants and children under 4 years of age susceptible to Hib infections suggests that large scale vaccination programmes are needed soon after birth. However, it would first be necessary to evaluate such factors as the frequency of Hib diseases in this population.
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  • 48
    ISSN: 1573-7284
    Keywords: Asthma ; Atopic diseases ; Children ; Epidemiology ; Socio-economic status ; Tobacco smoke
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A cross-sectional survey of a cohort study was carried out between June and December 1994 in Valencia, Spain (population in 1994: 764,293 inhabitants). Two hundred sixty public and private schools randomly selected from the total of schools in Valencia were invited to participate; 3948 children aged 6–7 years cooperated in our study after informed consent was obtained from parents and school director. The survey in Valencia is part of the International Study of Asthma and Allergy in Childhood (ISAAC). Prevalences for asthma, rhinitis and atopic dermatitis were determined and contrasted with socioeconomic status (SES) among children. No statistically significant associations were established between the prevalences of asthma, rhinitis and atopic dermatitis, and SES. However, atopic dermatitis was found to be common among upper class children (21.5 per 100 children). Likewise, significant associations were observed between the severity of atopy (2 or 3 atopic manifestations) and SES (p=0.000), being greater for lower strata (4.5 per 100 children); for the three SES level significant differences were established (p = 0.008) regarding passive exposure to tobacco smoke in the home.
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  • 49
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    European journal of epidemiology 15 (1999), S. 907-912 
    ISSN: 1573-7284
    Keywords: Bedouin ; Children ; Diarrhea ; Environment ; Knowledge
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Diarrhea is still a major cause of morbidity and mortality among children in developing countries. As it is due to multiple causative agents including viruses, bacteria and parasites, biological interventions are not currently available to markedly reduce incidence and severity. We examined maternal knowledge and reported behavior during diarrheal episodes, as well as environmental factors to determine their association with diarrhea. The children and mothers were from a Bedouin township in southern Israel, which has developed preventive and curative health care facilities. The Bedouin population in Israel is in transition from a nomadic to a settled life style. While almost all mothers exhibited good knowledge regarding food storage and prevention of diarrhea episodes in the children, the rate of illness in the children remained relatively high (two episodes per child year of observation). In a multivariate analysis, cessation of breastfeeding during diarrhea, child sleeping with siblings and lack knowledge about risk factors, were the major risk factors for illness with odds ratios (OR): 4.6, p = 0.02, 5.6, p = 0.03 and 1.7, p = 0.06, respectively. These data indicate that even in this population with free access to preventive medical care, greater efforts should be made to educate mothers regarding risk factor for diarrheal disease identification and the benefits of maintaining breastfeeding during diarrhea episodes.
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  • 50
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    European journal of epidemiology 15 (1999), S. 685-687 
    ISSN: 1573-7284
    Keywords: Children ; Epidemiology ; Hib meningitis ; Italy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In 1994, the Italian Ministry of Health implemented a National Surveillance System to obtain data on the incidence of bacterial meningitis and its causative agents, including Haemophilus influenzae type b (Hib). As a consequence, case reporting of Hib meningitis is increasing year by year; in 1996, there were 126 notifications, of which 73% were in children under 2 years of age. Although underreporting still exists, parallel prospective or retrospective epidemiological surveys conducted in some Italian Regions allowed for partial correction of the incidence of Hib meningitis (up to 18.5/100,000 population in 1994).
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  • 51
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    European journal of epidemiology 15 (1999), S. 133-139 
    ISSN: 1573-7284
    Keywords: Children ; Emergency room charge ; Hospitalisation ; Injuries ; Socio-economic
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Although many studies have shown an association between socio- economic environment and childhood injury mortality rates, little research has focused on the association between injuries which require hospitalisation and the child's socio-economic environment. All municipal emergency care was free of charge before the beginning of 1991, from then on a moderate patient charge was introduced by the City of Helsinki. An earlier report from a completely different social environment suggest that even a moderate user charge might create systematic discrimination against indigent families. We studied the childhood injury hospitalisation rates during 1989–1994 in Helsinki and analysed the association between rates of hospitalisation and local socio-economic and demographic factors. We also examined the effect of introduction of emergency room user charges on the rate of hospitalisation. Data from 1607 injuries from Helsinki City Hospital and 769 injuries from Helsinki University Central Hospital from years 1989 through 1994 were used. Annual rates of child hospitalisation were calculated at city level. Local socio-economic and demographic variables were derived from the Helsinki Bureau of Statistics. The possible association between the explanatory variables and hospitalisation rates at Helsinki City Hospital was calculated using annual data from the 33 health districts in Helsinki. The overall rate of hospitalisation for injuries declined but not statistically significantly. No association between socio-economic and demographic variables and hospitalisation rates was found. The moderate user charge had no effect on hospitalisation rates, proving that, in this setting, the demand for care was rather inelastic in paediatric injuries severe enough to require hospitalisation.
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  • 52
    ISSN: 1573-7284
    Keywords: Children ; Clinical characteristics ; Lower respiratory tract infections ; Nosocomial infections ; Respiratory syncytial virus ; Therapy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract This paper has analyzed respiratory syncytial virus lower respiratory tract infections in 201 hospitalized children. In children with wheezing, erythrocyte sedimentation rate (ESR) was significantly higher in those with pneumonia than with syndroma pertussis, while the white blood cell (WBC) count was significantly lower in patients with bronchitis than in those with bronchiolitis and syndroma pertussis. Bronchodilatators were applied in 75.6% and corticosteroids in 20% of patients. Ten patients were ventilated. Fatal disease outcome was observed in one infant. Twelve consecutive-year study of respiratory syncytial virus (RSV) infections showed that 27.3% of these diseases were bronchiolitis and pneumonia.
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  • 53
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    Knee surgery, sports traumatology, arthroscopy 7 (1999), S. 243-245 
    ISSN: 1433-7347
    Keywords: Key words Patella ; Fracture ; Children
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Sports Science
    Notes: Abstract Fractures of the patella are relatively rare injuries for children. Fourteen patients with patellar fractures were reviewed. There were 12 boys and two girls with the age ranging between 9 and 15 years and an average of 11.4 years. Sleeve fractures were the most common type of patellar fractures observed (eight cases), followed by transverse fractures (four cases) and comminuted fractures (two cases). All the fractures were treated with open reduction and followed up for 2 to 20 years. Overall results were good in 13 patients, and flexion limitation of the knee was seen in one. Fractures of the patella in children are characterised by sleeve fractures. The prognosis of the patients treated with open reduction is generally good.
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  • 54
    ISSN: 1573-3629
    Keywords: Children ; visual acuity ; sociodemographic factors ; Hispanics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Sociodemographic correlates of visual impairment were examined in 6- to 19-year-old Hispanic children and adolescents using data from the Hispanic Health and Nutrition Examination Survey. Mexican American and Puerto Rican children whose parents had 0 to 6 years of education were more likely to remain visually impaired even when tested with their glasses or contact lenses, if any (i.e., with usual correction) than children whose parents reported 12 to 17 years of education. Mexican Americans residing below versus at or above the poverty line were more likely to remain visually impaired even with the usual correction. Mexican Americans enrolled in the Medicaid program or who were without health insurance were more likely to remain visually impaired than Mexican Americans with private health insurance. When tested without glasses or contact lenses, Cuban Americans and Mexican Americans born outside of the mainland United States had lower rates of visual impairment compared to those born in the United States; however, children in this latter group were more likely to remain visually impaired with usual correction than U.S.-born Mexican Americans. These findings suggest that Hispanic children from economically disadvantaged households and those born outside the United States may not be receiving optimal eye care that could improve visual function.
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  • 55
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    Child psychiatry & human development 30 (1999), S. 29-37 
    ISSN: 1573-3327
    Keywords: In-School Intervention ; Suspensions ; Reading ; Consistency ; Parents ; Schools ; Children ; Bullies ; Victims ; Anti-social Behavior
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract This study developed a method of in-school intervention that dramatically reduced the suspension rate and violence in elementary schools. It suggests that children who were not read to by their parents often become bullies and/or victims of bullies. Other parental practices, including inconsistent discipline in the home, also may be contributing factors.
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  • 56
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    European journal of applied physiology 79 (1999), S. 504-511 
    ISSN: 1439-6327
    Keywords: Key words Co-activation ; Children ; Knee ; Electromyography ; Isokinetic
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Determining the mechanisms of co-activation around the knee joint with respect to age and sex is important in terms of our greater understanding of strength development. The purpose of this study was to examine the effects of age, sex and muscle action on moment of force and electromyographic (EMG) activity of the agonist and antagonist muscle groups during isokinetic eccentric and concentric knee extension and flexion. The study comprised nine pubertal boys [mean age 12.6 (SD 0.5) years], nine girls [12.7 (SD 0.5) years] nine adult men [23.1 (SD 2.1) years] and nine adult women [23.7 (SD 3.1) years] who performed maximal isometric eccentric and concentric efforts of knee extensors and flexors on a dynamometer at 30° · s−1. The moment of force and surface EMG activity of vastus lateralis and biceps femoris muscles were recorded. The moment of force:agonist averaged EMG (aEMG) ratios were calculated. The antagonist aEMG values were expressed as a percentage of the aEMG activity of the same muscle, at the same angle, angular velocity and muscle action when the muscle was acting as agonist. Three-way analysis of variance (ANOVA) designs indicated no significant effects of age or sex on moment:aEMG ratios. Eccentric ratios were significantly higher than the corresponding concentric ones (P 〈 0.05). The results also indicated no significant effect of age and sex on the aEMG of the vastus lateralis and biceps femoris muscles when acting as antagonists. The antagonist aEMG was significantly greater during concentric agonist efforts compared with the corresponding eccentric ones (P 〈 0.05). These findings would suggest that the moment exerted per unit of agonist EMG and the antagonist activity are similar in children compared with adults and are not sex dependent. Future comparisons between eccentric and concentric moments of force and agonist ENG should take into consideration the antagonist effects, irrespective of age or sex.
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  • 57
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    European journal of applied physiology 80 (1999), S. 118-124 
    ISSN: 1439-6327
    Keywords: Key words Exercise ; Children ; Ventilation ; Gas exchange
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The purposes of this investigation were to quantify the noise component of child breath-by-breath data, investigate the major determinants of the breath-to-breath noise, and to characterise the noise statistically. Twenty-four healthy children (12 males and 12 females) of mean (SD) age 13.1 (0.3) years completed 25 min of steady-state cycle ergometry at an exercise intensity of 50 W. Ventilatory and gas exchange variables were computed breath-by-breath. The mean (SD) oxygen consumption (V˙O2) ranged from 0.72 (0.16) to 0.92 (0.26) l · min−1; mean (SD) carbon dioxide production (V˙CO2) ranged from 0.67 (0.20) l · min−1 to 0.85 (0.16) l · min−1; and mean (SD) minute ventilation ranged from 17.81 (3.54) l · min−1 to 24.97 (5.63) l · min−1. The majority of the breath-to-breath noise distributions differed significantly from Gaussian distributions with equivalent mean and SD parameters. The values of the normalised autocorrelation functions indicated a negligible breath-to-breath correlation. Tidal volume accounted for the majority of the V˙O2 (43%) and V˙CO2 (49%) variance. The breath-to-breath noise can be explained in terms of variations in the breathing pattern, although the large noise magnitude, together with the relatively small attainable response amplitudes in children reduces the certainty with which ventilatory and gas exchange kinetics can be measured.
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  • 58
    ISSN: 1615-2573
    Keywords: Endomyocardial biopsy ; Dilated cardiomyopathy ; Children ; Ultrastructure ; Basal lamina layering of capillary
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary We analyzed the electron-microscopic features of endomyocardial biopsy from pediatric patients with dilated cardiomyopathy (DCM). The specimens examined were taken from the right ventricle of ten patients aged from 2 to 15 years (mean 9.7 years). Biopsy specimens from eight patients with congenital heart disease (tetralogy of Fallot), aged from 3 to 12 (mean 7.3 years), and ten adult patients with DCM, aged from 32 to 60 (mean 45 years), were also examined. Patients considered to have endocardial fibroelastosis, arrhythmogenic right ventricular cardiomyopathy, specific cardiomyopathy, or coronary heart disease were excluded from this study. Specimens from pediatric patients with DCM showed various degrees of ultrastructural abnormalities of myocytes, including myofibrillar fragmentation, mitochondrial abnormalities, and intracellular edema. The ultrastructurally determined contractility failure index based on the severity of myocardial degeneration at the electronmicroscopic level was 4.9 ± 1.1. This value was significantly higher than that in patients with tetralogy of Fallot (0.9 ± 0.6,P 〈 0.001) but was not significantly different from that in adult patients with DCM (6.1 ± 2.6). The index of pediatric patients with DCM who died within 3 years was high (6.0 ± 0.8). Basal lamina layering of a capillary (BLL) in the myocardium was revealed in 1 of the 10 (10%) pediatric patients with DCM and in 6 of the 10 (60%) adult patients with DCM (P 〈 0.05). No BLL was noted in the patients with tetralogy of Fallot. These findings may be related to the pathogenesis of DCM in children and adults.
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  • 59
    ISSN: 1434-193X
    Keywords: Nitrosobenzenes ; ortho-Nitrosoanilines ; 2-Nitroso-1,3-phenylenediamines ; Nucleophilic aromatic substitution ; Oxidative nucleophilic substitution of hydrogen ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: -The reaction of primary amines bearing tertiary alkyl groups (e.g. R-NH2; R = tBu, 1-adamantyl) with nitrosobenzenes has been found to proceed by oxidative nucleophilic aromatic substitution of hydrogen, thereby affording N-(tert-alkyl)-ortho- and -para-nitrosoanilines. The replacement of hydrogen proceeds more rapidly than the replacement of ortho- or para-nitro or -bromo substituents. With p-nitronitrosobenzene, both ortho-hydrogen atoms are substituted to afford N,N′-di(tert-alkyl)-4-nitro-2-nitroso-1,3-phenylenediamines 8a,b. The addition of oxidizing agents (e.g. MnO2) increases the yield of products. 1H-, 13C-, 14N- and 15N-NMR studies have confirmed the structures of the compounds under investigation. In ortho-nitrosoanilines, the rotamer with the nitroso group syn to the amino group is favored.
    Additional Material: 3 Tab.
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  • 60
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    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1999 (1999), S. 57-60 
    ISSN: 1434-193X
    Keywords: Benzyne ; Dehydroanthracene ; Matrix isolation ; Photochemistry ; Bergman reaction ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: -9,10-Didehydroanthracene (1) is an interesting derivative of p-benzyne that has been subject of several studies. In contrast to an earlier report, the photochemical decarbonylation of 9,10-dicarbonyl-9,10-dihydroanthracene (2) does not lead to 1 but rather to the ring-opened ene-diyne 4. The key intermediate for this reaction is keto carbene 7 which is formed by monodecarbonylation of 2. Carbene 7 is labile towards visible-light irradiation and easily looses the second CO molecule to give 4. Carbene 7 and diyne 4 are characterized by IR and UV/Vis spectra, the IR spectra are compared to calculations at the B3LYP/6-31G(d,p) level of theory.
    Additional Material: 2 Ill.
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  • 61
    ISSN: 1434-193X
    Keywords: Nucleophilic addition ; Solvent effect ; Reversal of diastereoselectivity ; Temperature effect ; Imines ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: -Commonly observed, but rarely explored, is the possibility of modifying the diastereomeric excess (de%) by means of temperature. A complete reversal in the diastereofacial selectivity could be obtained whenever the diastereoisomers concerned are differentially favored by enthalpy and entropy. The enthalpic or entropic dominance of a diastereoisomer depends greatly on the reaction solvent used.
    Additional Material: 1 Ill.
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  • 62
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1999 (1999), S. 73-81 
    ISSN: 1434-193X
    Keywords: Donor-acceptor systems ; Cage compounds ; Stelladione ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: -A number of condensations could be carried out using tricyclo[3.3.0.03,7]octane-2-one (stellanone, 4) and tricyclo[3.3.0.03,7]octane-2,6-dione (2,6-stelladione, 5) as starting materials. The components for condensations were 2-trimethylsilyl-1,3-dithiane (6), 1,1-bis(trimethylsilyl)-1H-cyclopropa[b]naphthalene (7), its 3,6-dimethoxy-substituted analogue 8, fluorene (12), xanthene (13), diethyl malonate (14), and malononitrile (15). The condensation reactions with 5 yielded mono- and disubstituted products, among them were the donor-acceptor-substituted 2,6-stellanes 33-35. The structures of 18 (prepared from stellanone and fluorene), 19, 24, 27, 31 and 32 (synthesized by condensation of 2,6-stelladione and 2-trimethylsilyl-1,3-dithiane and malononitrile, respectively) were determined by X-ray crystallography.
    Additional Material: 1 Ill.
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  • 63
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1999 (1999), S. 87-90 
    ISSN: 1434-193X
    Keywords: Water ; α-Nitrocycloalkanones ; ω-Nitro acids ; Surfactant ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: -The reaction of various α-nitrocycloalkanones 1 with aqueous 0.05 M NaOH, at 80 °C, in the presence of cetyltrimethylammonium chloride (CTACl) as a cationic surfactant, produces ω-nitro acids 2 in good yields. Reduction of the latter with HCOONH4/Pd-C, in methanol, at 80 °C affords ω-amino acids 3. The synthesis of methyl 9-oxodecanoate (8) is also reported.
    Additional Material: 2 Tab.
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  • 64
    ISSN: 1434-193X
    Keywords: O-Alkylation ; Ambident nucleophile ; Thiazolethione ; Thiohydroxamic acid ; Phase-transfer reaction ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: -O-Alkylation of cyclic thiohydroxamic acids 1 and 3-5 has been studied with a view to developing an efficient method for the synthesis of N-(alkoxy)pyridine-2(1H)-thiones and N-(alkoxy)thiazole-2(3H)-thiones. Four issues have been addressed and the following conclusions can be drawn: (i) Thiones 1 and 5 exist as O-H acids in the solid state. (ii) According to NMR investigations (1H, 13C), the thione structures should be largely retained in CDCl3, [D6]DMSO, and CD3OD solutions of acids 1, 3-5, as is also the case for pyridinethione salts 2a-h. (iii) O-Alkylation of pyridinethione salts occurs in competition with S-alkylation. Selective O-alkylation is however possible, if thiohydroxamate salts with large countercations, such as M = NBu4, are treated with hard alkylating reagents in polar aprotic media. (iv) As tetrabutylammonium thiohydroxamates, such as 2f, are highly useful in the synthesis of cyclic thiohydroxamic acid O-esters, we have developed an efficient protocol for the preparation of N-(alkoxy)pyridine-2(1H)-thiones directly from acid 1 using phase-transfer conditions (alkyl halide or sulfonic acid ester, CH3CN, K2CO3, Bu4NHSO4). This method has proved particularly successful for the synthesis of N-(alkoxy)thiazole-2(3H)-thiones 11, 20-28, which were obtained in yields of up to 87%.
    Additional Material: 2 Ill.
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  • 65
    ISSN: 1434-193X
    Keywords: Fluorine ; Pheromones ; Sulfoxides ; Sulcatol ; Asymmetric synthesis ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: -The pheromone (R)-(-)-sulcatol (10a) and three of its enantiomeric mono-, di-, and trifluoro analogues 10b-d have been synthesized, in six steps and with good overall yields, starting from chiral (R)-2-methyl-5-[(4-methylphenyl)sulfinyl]pent-2-ene (1) and commercially available fluorinated or non-fluorinated acetates.Supporting information for this article is available on the WWW under http://www.wileY-Vch.de/contents/jc_2046/1999/98375_s.pdf or from the author.
    Additional Material: 2 Tab.
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  • 66
    ISSN: 1434-193X
    Keywords: Fluorine ; Lactones ; Annulation ; Ketene ; Sulfoxides ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: -Enantiomerically pure α,α-dichloro β-fluoroalkyl γ-p-tolylthio γ-butyrolactones trans-6a-c have been obtained with excellent stereocontrol (〉 98:2) and enantiomeric purity (〉 98:2) by sulfoxide-directed lactonization (Marino's annu-lation reaction) of β-fluoroalkyl vinyl sulfoxides (R)-(E)-5a-c with dichloroketene. Highly chemoselective dechlorination and desulfurization reactions performed on trans-6c efficiently provided the β-chlorodifluoromethyl γ-butyrolactone (S)-8c, the absolute stereochemistry of which was determined by X-ray diffraction analysis of its γ-p-tolylthio precursor (2R,3S)-7c.
    Additional Material: 1 Ill.
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  • 67
    ISSN: 1434-193X
    Keywords: Alkenes ; Methylthiomethyl sulfone ; Carbenoids ; Hetero-substituted carbanions ; Vinyl sulfides ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: -The reaction of methylthiomethyl p-tolyl sulfone with alkyl sulfones when lithiated gives regioselectively vinyl sulfides in high yields in the presence of Ni(acac)2 or Fe(acac)3.
    Additional Material: 2 Ill.
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  • 68
    ISSN: 1434-193X
    Keywords: Fluorinated dideoxynucleosides ; Through-space interactions ; Hydrogen bonds ; Long-range coupling constants ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: -A collection of 5′-O-benzyl-2′,3′-dideoxy-4′-(fluoromethyl)nucleosides carrying both purinic and pyrimidinic nucleobases (uracil, 5-Br-uracil, 5-O2N-uracil, 6-Cl-purine and inosine) were synthesized in both the α and the β form. Through-space-transmitted 6JCF NMR coupling constants between F and C-6 (pyrimidinic base) or C-8 (purinic base) were observed for all of the α anomers of the compounds examined, whilst the corresponding 7JHF coupling constants were resolved only for the 5-substituted uracil derivatives. The absolute values of all the through-space couplings were found to decrease monotonically with increasing solvent polarity (CDCl3, MeOD, [D6]acetone, [D6]DMSO). This trend suggests that the through-space interaction is mediated by an intramolecular (sp3)C-F…H-C(sp2) hydrogen bond. The possibility of any relevant solvent-induced conformational change influencing the F/base mutual spatial relationship in the molecules investigated was ruled out by heteronuclear steady-state 1H{19F}-NOE experiments. A linear correlation was observed between 6JCF and 7JHF coupling constants and the Kamlet-Taft's hydrogen bond basicity parameter β. The crystal structures of the α and β anomers of the 5-nitrouracil nucleoside show evidence that the H-6 of the nucleobase forms hydrogen-bond-like interactions involving the O-benzyl oxygen atom in the β anomer, and that in the case of the α anomer this is replaced by the F atom of the fluoromethyl group.
    Additional Material: 4 Ill.
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  • 69
    ISSN: 1434-193X
    Keywords: Alkynes ; Cyclic voltammetry ; Diazabutadienes ; Electronic structure ; UV/Vis spectroscopy ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: -The introduction of alkynyl groups into the 2,3-positions of the 1,4-diazabuta-1,3-diene (DAD) backbone succeeds along two complementary synthetic routes either by condensing triisopropylsilyl-terminated dialkynyl-1,2-diones with primary aromatic amines or by a palladium-mediated alkynylation of bis(imidoyl chlorides). X-ray crystallographic analyses of two dialkynyl DAD derivatives reveals their planar (E-s-trans-E) conformations in the solid state. However, the central CC bond of both DAD backbones investigated has a length of 1.491(2) Å, and is therefore too long to indicate efficient delocalization across the DAD core. The UV/Vis spectra of dialkynyl DADs demonstrate that their absorptions in comparison to those of non-alkynyl DADs are bathochromically shifted by more than 40 nm, thereby demonstrating the suitability of the title compounds for developing NIR chromophores. The electron absorption properties of differentially N,N′-disubstituted dialkynyl DADs gave no indication for a push-pull effect across the DAD skeleton and suggest the ynimine moiety as the active chromophore of dialkynyl DADs. The electrochemical properties of the title compounds were determined by cyclo- and steady state voltammetry and show that introducing alkynyl groups leads to more easily reducible DAD systems. Again, the perception of dialkynyl DADs as covalently linked, but electronically decoupled ynimine units is corroborated by the redox potential of a differentially N,N′-disubstituted dialkynyl DAD. Similar conclusions were drawn from semiempirical MO (PM3) calculations of dialkynyl DADs.
    Additional Material: 5 Ill.
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  • 70
    ISSN: 1434-193X
    Keywords: Phosphonate analogs ; Mannose 6-phosphate (M6P) ; M6P receptors ; Recognition markers ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: -Two phosphonate analogs of mannose 6-phosphate (M6P) have been synthesized. The isosteric analog 1 was obtained by a Wittig-Horner reaction at position 6 of a sugar aldehyde. The non-isosteric analog 2 was obtained by a Michaelis-Arbuzov rearrangement of a 6-bromo derivative. In contrast to the non-isosteric analog 2, the isoster 1 was shown to bind to M6P receptors as effectively as does M6P itself, thus demonstrating the considerable potential of the system in drug design.
    Additional Material: 1 Ill.
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  • 71
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    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1999 (1999), S. 459-462 
    ISSN: 1434-193X
    Keywords: Electrophilic substitution ; Metalations ; Monoterpene ; Protective groups ; Superbase ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: -When treated with butyllithium and potassium tert-butoxide for 2 h at 0 °C in hexanes, the unsaturated monoterpenic alcohol isopulegol is simultaneously deprotonated at the hydroxy function and the allylic methyl group. The metaloxy allylmetal species thus generated can be silylated, alkylated, carboxylated and oxidized to afford the expected products in good to excellent yields. Thus, a specific protection of hydroxy groups is not required, alcohols being instantaneously converted by superbases into alcoholates.
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  • 72
    ISSN: 1434-193X
    Keywords: Proteins ; Cross coupling ; Drug research ; Photochemistry ; Toxicology ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: -To gain insight into the chemical nature of drug-induced photoallergy, model studies have been carried out on the photochemical modification of proteins by tiaprofenic acid. Irradiation of decarboxylated tiaprofenic acid (DTPA) in the presence of p-cresol leads to C-C- and C-O-connected p-cresol “dimers”, together with DTPA hydrodimers. The p-cresol-DTPA cross-coupling product was not detected in this reaction. However, a product of this type is formed using a more hindered phenol, such as 2,6-di-tert-butylphenol. Similar results are obtained when tiaprofenic acid (TPA) or its methyl ester are used as photosensitizers. The observed formation of “dimers” can be related to protein photo-crosslinking, through the coupling of two tyrosine units. On the other hand, phenol-(D)TPA cross-coupling may be relevant to the understanding of drug-protein photobinding.
    Additional Material: 5 Ill.
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  • 73
    ISSN: 1434-193X
    Keywords: Enantiomerically pure (2-bromophenyl)acetaldehyde acetals ; Halogen-metal exchange ; Diastereoselective addition to imines ; Asymmetric synthesis ; Tetrahydroisoquinolines ; NMDA antagonists ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: -A novel asymmetric synthesis of 1-aryl-1,2,3,4-tetrahydroisoquinolines has been developed. The key step in this synthesis is the diastereoselective addition of homochiral (2-lithiophenyl)acetaldehyde acetals to the sulfonylimine 25 and to the arylimines 28 and 31. The best diastereoselectivity is obtained by addition of the bis(2-methoxypropan-2-yl)-substituted 1,3-dioxolane 6e to benzylidene-p-anisidine (31) with an HPLC-determined diastereomeric ratio 32c/33c = 92.1:7.9. The N-tosyl and the N-(4-methoxyphenyl) groups of the addition products 26d, 27d, 32c, and 33c are cleaved with sodium in liquid ammonia and ammonium cerium(IV) nitrate, respectively, to yield the primary amines 35 and 36. The acid-catalysed cyclization of the sulfonamides 26d and 27d and the carbamates 37 and 38, prepared from 35 and 36, leads to the enantiomerically pure dihydroisoquinolines 40 and 41, respectively. During the cyclization of the sulfonamides 26d, 27d and the carbamates 37, 38 the chiral auxiliary - the diol 39 - is cleaved unchanged and can be recovered in good yields.
    Additional Material: 4 Tab.
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  • 74
    ISSN: 1434-193X
    Keywords: Pinacol coupling ; Aldehydes ; Samarium diiodide ; 1,2-Diols ; Diastereoselectivity ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: -The samarium diiodide pinacol coupling of benzaldehyde and cyclohexanecarboxaldehyde in the presence of a variety of polyethylene glycols, including derivatives containing carbohydrates has been studied. Whereas such complexing agents allow for the formation of 1,2-diols, in the case of benzaldehyde the erythro-isomer predominates with diastereoselectivities of up to 7:1, while with cyclohexanecarboxaldehyde a stereoselectivity of up to 10:1 was observed but in favor of the threo-isomer. This divergence in the stereoselectivity of these two aldehydes suggests the presence of two different mechanisms occurring in these pinacol coupling reactions.
    Additional Material: 5 Ill.
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  • 75
    ISSN: 1434-193X
    Keywords: Benzocyclobutenes ; o-Quinodimethanes ; Pericyclic reactions ; Retrodisproportionation ; 9-Anthryl radicals ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: -7,8-Dimethoxy-7,8-diphenyl- (1c), 7,8-dimethyl-7,8-diphenyl- (1d), 7-methoxy-7,8,8-triphenyl- (1e), 7-methyl-7,8,8-triphenyl- (1f), 7-isocyano-7,8,8-triphenyl- (1g), and 7,7,8-triphenylbenzocyclobutene (1h) are amenable to a variety of thermal rearrangements following initial electrocyclic ring-opening to the corresponding 7,8-diphenyl- (2c,d) and 7,8,8-triphenyl-o-quinodimethanes (2e-h). meso-1c was found to undergo a facile meso/rac isomerization at room temperature, indicating that other processes such as a symmetry-forbidden disrotatory ring-opening or a stepwise reaction compete with the symmetry-allowed conrotatory process. An estimate of the energy profile of the 1c/2c reaction system was made by kinetic simulation in combination with oxygen trapping of the intermediate o-quinodimethanes (2c) and semiempirical PM3 calculations, and revealed that the barrier for the symmetry-forbidden pathway is merely about 4 kJ·mol-1 higher than that for the symmetry-allowed one. o-Quinodimethanes 2c, 2g, 2e, and 2h underwent further electrocyclic hexatriene-cyclohexadiene ring-closure to give 4a,10-dihydroanthracene derivatives at temperatures between 20 and 80 °C. The 4a,10-dihydroanthracenes were further transformed to 9,10-disubstituted anthracenes by elimination of methanol or HCN, as well as to 9,10-substituted 9,10-dihydroanthracene derivatives. ESR and ENDOR spectroscopic detection of related 9-anthryl radicals lends support to the view that 9,10-dihydroanthracene products are formed by a homolytic hydrogen-transfer reaction (retrodisproportionation). By way of contrast, the aforementioned transformations play only a minor role in the case of methyl-substituted benzocyclobutenes 1d, 1f as here they are overruled by faster 1,5-H shift reactions of the corresponding o-quinodimethanes 2d, 2f, leading to styrene derivatives.
    Additional Material: 11 Ill.
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  • 76
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    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1999 (1999), S. 597-605 
    ISSN: 1434-193X
    Keywords: S Heterocycles ; Cyclic oligosulfides ; Pentathiepanes ; Conformational analysis ; Sulfuration ; Ring inversion ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: -Acenaphtho[1,2-a]acenaphthylene (1) was sulfurated with elemental sulfur to give a pentathiepane derivative (2). A dynamic NMR spectrum analysis revealed that the two naphthalene rings of 2 are chemically nonequivalent up to 100 °C. The pentathiepane ring of 2 was shown to adopt a chair conformation both in solution and crystals. In accordance with the NMR spectrum analysis, the sulfuration of 5-phenylacenaphtho[1,2-a]acenaphthylene (12) gave a pair of conformers (16a and 16b), which were isolated in pure form. The Friedel-Crafts acetylation of 2, followed by dithioacetalization with 1,2-ethanedithiol, also gave a pair of isolable conformers (18a and 18b). These two pairs of conformers isomerized, as a result of the ring inversion, to each other in solution at room temperature in the first-order kinetics. The activation parameters for this process, Ea, ΔH#, and ΔS#, were determined. Based on the experimental observations, a probable mechanism for the inversion process is proposed.
    Additional Material: 2 Ill.
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  • 77
    ISSN: 1434-193X
    Keywords: Cerium(III) chloride heptahydrate ; Catalysis ; 1,3-Dicarbonyl compounds ; Enones ; Michael reactions ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: -Cerium(III) chloride heptahydrate in the presence of sodium iodide catalyses the Michael addition of 1,3-dicarbonyl compounds to α,β-unsaturated ketones and α,β-unsaturated aldehydes with extraordinary efficiency. The very mild conditions allow high chemoselectivity as shown by the absence of the typical side reactions, which can be observed in the conventional base-catalyzed processes. More interestingly, when at least one of the starting materials is liquid at room temperature, the reaction can also be performed without solvents. The CeCl3· 7 H2O/NaI catalyst system can be easily separated from the reaction mixture and it can be reused without an appreciable loss of activity. Advantages of the present procedure, which utilizes cheap and “friendly” reagents, over the previously reported ones, are discussed.
    Additional Material: 1 Ill.
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  • 78
    ISSN: 1434-193X
    Keywords: Hydroaminomethylation ; Rhodium ; Catalysis ; Carbonylation ; Heterofunctionalised allylic compounds ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: -Heterofunctionalised allylic ethers 1, silanes 5, and amines 9 are hydroformylated in the presence of primary or secondary amines 2 to form the corresponding γ-amino- and δ-amino-functionalised compounds. The rhodium(I)-catalysed reaction sequence proceeds by aldehyde formation and subsequent reductive amination to generate the corresponding functionalised secondary or tertiary amines. This selective one-pot hydroaminomethylation procedure establishes access to γ-amino- and δ-amino-functionalised ethers, amines or silanes with potential biological activity.
    Additional Material: 4 Tab.
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  • 79
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    Liebigs Annalen 1999 (1999), S. 679-683 
    ISSN: 1434-193X
    Keywords: Biomimetic oxidations ; Cytochrome P450 ; Metalloporphyrins ; Denaverine ; Metabolism ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: -The behavior of denaverine (1) in various chemical model systems based on metalloporphyrins as catalysts was investigated to determine the possible oxidative metabolism. The resulting derivatives were compared to a biological model system and in vivo metabolism in rat and human.
    Additional Material: 2 Tab.
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  • 80
    ISSN: 1434-193X
    Keywords: Single-electron transfer ; Ring contractions ; 1,4-Dihydro-1,2,4-triazine ; Photochemical reduction ; Chemical reduction ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: -Chemical reduction (Zn/AcOH) of the arene 1 and of 2(4),5-dihydro-1,2,4-triazine 7 has been reinvestigated, resulting in the amendment of literature data concerning this reaction. Chemical, electrochemical, and photochemically induced reductions and ring contractions of 1,2,4-triazine derivatives have been compared. The first example of a triaryl-1,4-dihydrotriazine has been prepared. Some further evidence is presented that supports the proposed mechanism of the photochemically induced reduction and ring contraction of 1,2,4-triazines.
    Additional Material: 2 Tab.
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  • 81
    Electronic Resource
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    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1999 (1999), S. 691-696 
    ISSN: 1434-193X
    Keywords: Carbohydrates ; 4-Thiofuranosides ; Nucleosides ; Reaction mechanisms ; NOE measurements ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: -1-O-Acetyl-2,3,5-tri-O-benzyl-4-thio-L-arabino-furanose (9) has been prepared from D-xylose via the 1,4-dithio-L-arabino-furanoside 8. The crucial step of the reaction, i.e. the intramolecular cyclization of the open-chain dithioacetal 5, has been achieved in a yield of 90% by applying tetrabutylammonium iodide as promoter. Reaction of 9 with bis(trimethylsilyl)uracil or -thymine led to the benzyl derivatives 12 and 13 from which the deprotected 4′-thionucleoside analogues 14 and 15 have been prepared by debenzylation with boron tribromide.
    Additional Material: 1 Ill.
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  • 82
    ISSN: 1434-193X
    Keywords: Epoxidations ; Diastereoselectivity ; Allylic alcohols ; Homogeneous catalysis ; Methyltrioxorhenium ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: -The steric effects of allylic substituents in the epoxidations with methyltrioxorhenium/urea/hydrogen peroxide adduct (MTO/UHP) have been assessed for a series of 3-alkyl-substituted cyclohexenes. The trans selectivity increases with the size of the substituent and the diastereoselectivities follow an excellent linear correlation with the steric substituent constants of Taft (Es) or Charton (ν). Good cis selectivity is observed in the epoxidation of the cyclic allylic alcohols 2-cyclopentenol and 2-cyclohexenol due to a hydroxy-directing effect through hydrogen bonding; however, for 2-cycloheptenol and 2-cyclooctenol hydrogen bonding is ineffective and steric interactions cause a higher trans selectivity. The conformationally fixed cis- and trans-5-tert-butyl-2-cyclohexenols serve as suitable substrates for gauging the dihedral angle of the transition states for the oxygen transfer in these epoxidations. Thus, the MTO/UHP oxidant favours a quasi-equatorial arrangement of the hydroxy group for effective hydrogen bonding (hydroxy-group directivity), in analogy to m-chloroperbenzoic acid (m-CPBA) and dimethyldioxirane (DMD), and a dihedral angle of ca. 130° is suggested.
    Additional Material: 2 Ill.
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  • 83
    ISSN: 1434-193X
    Keywords: Phenylselenenyl sulfate ; Selenium-catalyzed reactions ; Stereoselective syntheses ; Dihydrofurans ; Tetrahydrofurans ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: -A stereoselective multi-step one-pot procedure for converting 2-methoxycarbonyl-3-alkenols into 3-methoxycarbonyl-2,5-dihydrofurans, using only catalytic amounts of diphenyl diselenide and an excess of ammonium persulfate, has been developed. The erythro alkenols give the trans dihydrofurans, while the threo stereoisomers give the corresponding cisproducts. The configurations of the starting alkenols were deduced from those of the intermediate phenylseleno tetrahydrofurans, which were independently obtained from reactions of the alkenols with stoichiometric amounts of phenylselenenyl sulfate.
    Additional Material: 3 Tab.
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  • 84
    ISSN: 1434-193X
    Keywords: Carbohydrates ; Amino sugars ; Imidazole ; Glycosidases ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: -Some naturally occurring carbohydrates, of which several hydroxy groups had been selectively protected, were condensed with formamidine to give the expected imidazole derivatives in the D-arabino (9), D-lyxo (12), L-xylo (17), D-threo (21), and in the L- and D-erythro (24) series. Introduction of a strong leaving group at the remaining free alcohol function of these products led at once to intramolecular SN2 cyclisation to the corresponding bicyclic aza sugar derivatives. This was followed by total deprotection to give the target aza sugars in the L-xylo (7), L-ribo (14), D-arabino (19), as well as in the D-threo (22) and the L- and D-erythro (26) series. Inhibitory assays with four glycosidases showed that the D-arabino aza sugar 19 is the only potent inhibitor (for an α-mannosidase of jack bean).
    Additional Material: 1 Tab.
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  • 85
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1999 (1999), S. 923-930 
    ISSN: 1434-193X
    Keywords: Bridged benzo[a]phenoxazinium salts ; Diazo compounds ; Cyclocondensation ; Absorption ; Fluorescence ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: -By condensation of bridged 4-arylazo-substituted 3-hydroxyanilines 18 and bridged or unbridged 4-arylazo-substituted 1-naphthylamines 19-23 with bridged 1-naphthylamines 15-17 and 3-aminophenols 14, respectively, in the presence of perchloric acid, bridged naphthoxazinium perchlorates 24-30 have been prepared. The spectral properties of the products have been compared with those of the bridged phenoxazinium salt 31 as well as with data for some unbridged analogues.
    Additional Material: 1 Ill.
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  • 86
    ISSN: 1434-193X
    Keywords: Iminium salts ; Triflic anhydride ; Arylamines ; 2-Trifluoromethyl quinolines ; 3-Trifluoromethyl-cinnamaldehydes ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: -The reaction of iminium triflates 2 and 7 with various aromatic amines were investigated. The 2-Rf-substituted quinolines 3 and 8 were prepared in excellent yields by the reaction of 2 and 7, respectively, with substituted anilines. The reactions of 2 and 7 with diarylamines proceeds, suprisingly, to afford the corresponding 3-Rf-substituted cinnamaldehydes 4 and 9.
    Type of Medium: Electronic Resource
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  • 87
    ISSN: 1434-193X
    Keywords: Heterocycles ; Alkaloids ; Castanospermine ; Metathesis ; Azasugars ; Manzamine A ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: -The application of the ring-closing metathesis (RCM) reaction to the construction of a wide variety of nitrogen-containing ring systems is described. The examples include pyrrolizidine, indolizidine, and quinolizidine derivatives related to azasugars. A formal total synthesis of castanospermine (5) is presented. The utilisation of two RCM steps in the synthetic sequence leading to the multicyclic ABCDE nucleus 7 of the complex alkaloid manzamine A (6) is discussed.
    Additional Material: 3 Ill.
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  • 88
    ISSN: 1434-193X
    Keywords: Hydrogen transfer ; Zirconium ; Alkenes ; Isobutylzirconocene chloride ; Lewis acid catalysis ; Lewis acid catalysis ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: -The hydrozirconation reaction of monosubstituted alkenes with iBuZrCp2Cl can be significantly accelerated by catalytic amounts of various Lewis acidic metal compounds, most notably AlCl3, Me3SiI, and Pd complexes, such as Li2PdCl4 and Cl2Pd(PPh3)2.Supporting information for this article is available on the WWW under -http://www.wileY-Vch.de/contents/jc_2046/1999/99042_s.pdf or from the author.
    Additional Material: 1 Tab.
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  • 89
    ISSN: 1434-193X
    Keywords: Alkenes ; Chirality ; Longicorn beetle ; Pheromones ; Psacotheahilaris ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: -Both the enantiomers of (Z)-21-methyl-8-pentatriacontene (1), the major component of the female-produced contact sex pheromone of the yellow-spotted longicorn beetle (Psacotheahilaris), were synthesized by starting from the enantiomers of citronellol (2)
    Type of Medium: Electronic Resource
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  • 90
    ISSN: 1434-193X
    Keywords: Catenanes ; Molecular machines ; Pseudorotaxanes ; Template-directed synthesis ; Tetrathiafulvalenes ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: -Two bis(2-oxy-1,3-propylenedithio)tetrathiafulvalene-containing acyclic polyethers and two macrocyclic polyethers, each incorporating one bis(2-oxy-1,3-propylenedithio)tetrathiafulvalene unit and one p-phenylene ring, have been synthesized. The two acyclic polyethers are bound by cyclobis(paraquat-p-phenylene) with pseudorotaxane geometries in solution. The two macrocyclic polyethers have been mechanically interlocked with this tetracationic cyclophane to form [2]catenanes in a kinetically controlled self-assembly process. The X-ray crystallographic analysis of one of the two [2]catenanes and 1H-NMR-spectroscopic studies of both compounds showed that the p-phenylene ring of the macrocyclic polyether is located inside the cavity of the tetracationic cyclophane, while the bis(2-oxy-1,3-propylenedithio)tetrathiafulvalene unit resides alongside. The [2]pseudorotaxanes and [2]catenanes show broad bands around 780 nm, arising from the charge-transfer (CT) interaction between the electron-donor tetrathiafulvalene-(TTF-)type unit and the electron-acceptor units of the tetracationic cyclophane. 1H-NMR-spectroscopic studies have shown that the [2]pseudorotaxanes dissociate into their separate components upon oxidation of the TTF-type unit, as a result of disruption of the CT interaction and electrostatic repulsion between the tetracationic host and the newly formed monocationic guest. The subsequent reduction of the guest to its neutral state affords back the pseudorotaxane-type complex restoring the original equilibrium. The results obtained from electrochemical experiments are consistent with the reversible, redox-driven dethreading/rethreading process observed by 1H-NMR spectroscopy. Variable-temperature 1H-NMR-spectroscopic investigations have revealed two dynamic processes, both involving the relative movements of the mechanically interlocked components in the [2]catenanes. The two consecutive oxidation processes involving the TTF-type unit, observed electrochemically, are displaced toward more positive potentials compared with the free cyclic polyethers. The two reversible two-electron reduction processes, characteristic of free cyclobis(paraquat-p-phenylene), separate into four reversible one-electron processes because of the topological difference between the “inside” and “alongside” electron-acceptor units in the [2]catenane.
    Additional Material: 11 Ill.
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  • 91
    ISSN: 1434-193X
    Keywords: Asymmetric synthesis ; Chiral synthons ; P-(o-Hydroxyaryl)diazaphospholidine P-oxides ; Rearrangements ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: -The totally regio- and stereoselective P-O-to-P-C rearrangement in the synthesis of various chiral P-(o-hydroxyaryl)diazaphospholidine P-oxides has been investigated. This reaction proceeds with excellent yields ranging from 72 to 92%, total retention of configuration at the phosphorus atom, and complete regioselectivity. An exception was found with naphthyl derivatives, which gave mixtures of two regioisomers. In all cases, the products generated have been unambiguously characterized by 1H-, 13C-, and 31P-NMR spectroscopy as well as by X-ray-diffraction analysis.
    Additional Material: 3 Ill.
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  • 92
    ISSN: 1434-193X
    Keywords: Cyclocarbonylation ; Alkynes ; Catalysis ; Palladium ; Vinyl triflates ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: -o-Ethynylphenols react with vinyl triflates, in the presence of tetrakis(triphenylphosphane)palladium(0) and under carbon monoxide, to form 3-alkylidene-2-coumaranones in good yield.
    Additional Material: 1 Tab.
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  • 93
    ISSN: 1434-193X
    Keywords: Sulfur-linked thiooligosaccharides ; Oligosaccharin thio analogs ; Phytoalexin elicitor thio analogs ; Soybean glucan-binding assays ; Structure-activity relationships ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: -The sulfur-linked pentathiohexasaccharide 3I,3IV-di-β-D-glucopyranosylthiogentiotetraose (12) has been prepared by a convergent approach involving the reaction of 1,2,4-tri-O-acetyl-6-deoxy-6-iodo-3-S-(2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyl)-3-thio-β-D-glucopyranose (10) with the sodium salt of 2,3,4-tri-O-acetyl-6-S-[2,4-di-O-acetyl-3,6-di-S-(2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyl)-3,6-dithio-β-D-glucopyranosyl]-1,6-dithio-β-D-glucopyranose (4). A further reaction, involving the sodium salt of the peracetylated β-1-thio derivative of 12 with 1,2,3,4-tetra-O-acetyl-6-deoxy-6-iodo-β-D-glucopyranose (26), afforded the homologous sulfur-linked hexathioheptasaccharide 3II,3V-di-β-D-glucopyranosylthiogentiopentaose (28). Related sulfur-linked positional isomers 3II,3IV-di-D-β-glucopyranosylthiogentiotetraose (34) and 3III,3V-di-β-D-glucopyranosylthiogentiopentaose (39) have been prepared using analogous synthetic strategies. Thus, SN2 displacement of the iodine atom in 10 by the sodium salt of 2,4-di-O-acetyl-3,6-di-S-(2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyl)-1,3,6-trithio-β-D-glucopyranose afforded a tetrathiopentasaccharide, which resulted in the pentathiohexasaccharide 34 by a sequence of reactions involving the 1-thioglycose 32 in reaction with 26. The hexathioheptasaccharide 39 was obtained conveniently by the reaction of 26 with the acetylated 1-thio-6I, 3II, 6II, 3IV, 6IV-pentathio derivative 37, followed by deacylation. The four isomeric pentathiohexa- and hexathioheptasaccharides 12,34 and 28,39, respectively, were all found to be active in eliciting phytoalexin accumulation in soybean cotyledon tissue and in binding to a glucan-binding protein of soybean, although to a lesser extent than the corresponding O-oligosaccharides, the alternate thiohexa- and thioheptasaccharides 12,28 being more active as compared to the geminally branched isomers 34,39.
    Additional Material: 3 Tab.
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  • 94
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1999 (1999), S. 1213-1221 
    ISSN: 1434-193X
    Keywords: Diazo compounds ; Carbenes ; Carbenoids ; Silicon ; Heterocycles ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: -Copper(I) triflate catalyzes the transformation of α-[(2-alkynyl)oxy]silyl-α-diazoacetates 1a-g into 1,2-bis(2,5-dihydro-1,2-oxasilol-4-yl)ethenes 2 and/or 2H-1,2-oxasilines 3. With rhodium(II) perfluorobutyrate as catalyst, 1a-e furnish only 3 but no 2. Bicyclic 2-methoxyfurans 6 are formed when 1a,c,e (containing terminal alkyne functions) are treated with catalytic amounts of copper(I) chloride. The experimental observations are explained in terms of metal-mediated intramolecular cyclopropenation and subsequent metal-assisted ring-opening of the strained bicyclic cyclopropene leading to vinylcarbene-metal complexes. An unusual autoxidation of 2H-1,2-oxasilines 3a,c,e is also described.
    Additional Material: 1 Ill.
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  • 95
    ISSN: 1434-193X
    Keywords: Pheromones ; Aspidiotus nerii ; Sex attractant ; Cyclobutane ; Enantiomeric purity ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: -Synthesis of both enantiomers of the Aspidiotus nerii sex pheromone and their diastereomers has been achieved using, as a key step, an intramolecular ester enolate alkylation reaction for the formation of the cyclobutane ring with a good control of the relative configurations of the asymmetric centers. Stereoselective synthesis of a number of other trisubstituted cyclobutane derivatives also proves the versatility of the methodology used for the synthesis of the Aspidiotus nerii sex pheromone.
    Additional Material: 2 Ill.
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  • 96
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1999 (1999), S. 1249-1252 
    ISSN: 1434-193X
    Keywords: Amino alcohols ; Amine N-oxides ; Asymmetric synthesis ; Hydrogen bonds ; Structure determination ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: -Enantiopure 2-azabicyclo[3.3.0]octanes 1a-d and ent-1e were oxidized with mCPBA to provide either diastereomeric pairs of N-oxides (2a/3a and 2b/3b) or diastereomerically pure compounds (2c,d and ent-2e). The structure of compounds 2a and ent-2e was confirmed by an X-ray study. The factors that affect the oxidation process are discussed.
    Additional Material: 2 Ill.
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  • 97
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1999 (1999), S. 1259-1263 
    ISSN: 1434-193X
    Keywords: Inositols ; Epimerisation ; Acetals ; Carbohydrates ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: -Methoxycyclitol 4 was acetalized in a non-classical one-pot procedure with chloral/dicyclohexylcarbodiimide forming the 4-epi derivative 6. The stepwise deprotection of compound 6 is also described. Thus, decarbamoylation to the acetal 7 was achieved by heating 6 with methanolic sodium methoxide, and cleavage of the acid-stable trichloroethylidene moiety was realised in two steps via the corresponding ethylidene acetals 8 and 9; the ethylidene function was removed with aqueous trifluoroacetic acid (compound 10 from 6 via 9). Finally, the carbamoyl derivative 10 was converted into the tetra-O-acetyl product 12 via the tetrol 11.
    Additional Material: 2 Ill.
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  • 98
    ISSN: 1434-193X
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: -No abstract
    Type of Medium: Electronic Resource
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  • 99
    ISSN: 1434-193X
    Keywords: Matrix isolation ; IR spectroscopy ; Photochemistry ; Diradicals ; Isomerizations ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: -Bicyclopropylidene (3) and 1,2-dimethylenecyclobutane (7) have been irradiated in rare-gas matrices. If 1,2-dimethylenecyclobutane (7) is exposed to the light of a KrF excimer laser (λ = 248 nm), an isomeric species is produced, showing an absorption at 793.1 cm-1 (argon matrix) or 791.2 cm-1 (xenon matrix) in the IR spectrum. The back reaction can be induced with light of λ = 254 nm. This photochemical interconversion, together with the comparison between the experimental and calculated band positions, supports the assignment of the IR absorption near 790 cm-1 to tetramethyleneethane (5).
    Additional Material: 2 Ill.
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  • 100
    ISSN: 1434-193X
    Keywords: Alkoxyl radical ; Cyclizations ; Radicals ; Tetrahydrofuran ; Thiazolethione ; Thiazolethione ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: -N-(Hydroxy)thiazole-2(3H)-thiones 6-10 have been prepared in a short and efficient synthesis from p-substituted acetophenones. Alkylation of heterocycles 6-10 in the form of their potassium or tetraalkylammonium salts 11-15 affords N-alkoxy-4-arylthiazole-2(3H)-thiones 16-20 in good to satisfactory yields. The hitherto unknown thiones 16-20 have been subjected to a detailed structural investigation (NMR spectroscopy and X-ray crystallography) and furthermore to a mechanistic study in order to explore their utility as sources of oxygen-centered radicals in solution. From the results of these studies, the following conclusions can be drawn: (i) X-ray analyses of the p-chlorophenyl-substituted acid 9, of the O-alkyl derivatives 19c, 19f, and of the O-mixed anhydride 19k indicate short C-S bonds [C2-S2 = 1.637(5)-1.684(2) Å] and long N-O connectivities [N3-O1 = 1.369(3)-1.379(2) Å] in the thiohydroxamate functionalities. Furthermore, O-alkyl- or O-acyl substituents at O1 are twisted out of the thiazolethione plane by ca. 90°, which points to lone-pair repulsion between nitrogen and oxygen atom as the underlying structural motif of the cyclic thiohydroxamate derivatives. (ii) Alkylation of ambidentate thiohydroxamate anions (salts 11-15; oxygen and sulfur nucleophiles) affords almost exclusively O-esters 16-20 (alkylation at the oxygen atom). (iii) Based on the results of X-ray diffraction studies and on the 1H- and 13C-NMR spectra, guidelines for the characterization of N-(alkoxy)thiazolethiones 16-20 and 2-(alkylsulfanyl)thiazole N-oxides 21-25, i.e. the products of S-alkylation of thiohydroxamate salts 11-15, could be derived. (iv) Photolyses of substituted N-(4-pentenoxy)-4-arylthiazolethiones 16-20 in general and in particular of p-chloro derivatives 19 were carried out in the presence of the hydrogen donor Bu3SnH, and afforded substituted tetrahydrofurans 31 or tetrahydropyrans 32 as major products in good yields. The observed stereo- and regioselectivities of ethers 31 and 32 point to alkoxyl radicals 30 as reactive intermediates, which add intramolecularly by selective 5-exo-trig or 6-endo-trig pathways to the olefinic double bonds. In terms of synthetic access and ease of handling of the radical precursors, the p-chlorophenyl-substituted thiazolethiones 9 and 19 exhibit significant advantages over all the other thiones used in this study and are considered as excellent substitutes for the pyridinethiones as efficient sources of free alkoxyl radicals. Consequently, the present compounds may be of use in both mechanistic and synthetic studies.
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