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  • 1
    ISSN: 1433-2965
    Schlagwort(e): Key words:: Osteoporosis – Pulmonary function, Quality of life – Vertebral fractures
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract: Vertebral deformation in spinal osteoporosis results in spinal and thoracic deformation, causing pain, disability and an overall decrease in quality of life. We sought to determine whether thoracic spinal deformation may lead to impaired pulmonary function. We studied expiratory relaxed vital capacity (VC) and forced expiratory volume in 1 s (FEV1) in 34 patients with spinal osteoporotic fractures and 51 patients with chronic low back pain (CLBP) due to reasons other than osteoporosis. Measurements of pulmonary function tests were calculated as a percentage of the normal range adjusting for age, sex, and height using the equations for normal values of the EKGS (Europäische Gesellschaft für Kohle und Stahl). Severity of osteoporosis was determined by calculation of the spine deformity index (SDI-total and SDI-anterior) on lateral radiographs of the spine and clinical measures of body stature (height reduction, distance from lowest ribs to iliac crest and distance from the occiput to the wall). Patients with osteoporosis had a lower vital capacity (%VC of the reference value) than patients with CLBP. The differences were more prominent (p〈0.05) when the previous body height, at age 25 years, was used as reference for calculation of VC (mean ± SD: 93.6%± 15.3% in patients with osteoporosis v 105.6%± 15.1% in patients with CLBP). FEV1 was significantly (p〈0.05) lower in patients with osteoporosis when previous body height was considered, in comparison with patients with CLBP (mean ± SD: 85.0%± 14.2% in patients with osteoporosis v 92.4%± 13.6% in patients with CLBP). In patients with osteoporosis VC (standardized on previous body height) was significantly negatively correlated with SDI-anterior (r=–0.4, p〈0.03). Furthermore, VC standardized on previous body height showed a weak but significant negative correlation with some clinical measures of osteoporosis (height reduction vs %VC: r=–0.34, p〈0.05; distance from the lowest ribs to iliac crest vs %VC: r= 0.35, p〈0.04). In conclusion, we found that pulmonary function is significantly diminished in patients with spinal osteoporotic fractures as compared with CLBP patients without evidence of manifest osteoporosis. Reduction of pulmonary function is correlated significantly with clinical and radiological measures of severity of spinal deformation due to osteoporotic fractures.
    Materialart: Digitale Medien
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  • 2
    Digitale Medien
    Digitale Medien
    Springer
    Calcified tissue international 6 (1970), S. 143-150 
    ISSN: 1432-0827
    Schlagwort(e): Calcitonin ; Bone ; Atrophy ; Formation ; Tetracycline
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Beschreibung / Inhaltsverzeichnis: Résumé La patte arrière gauche de trente rattes Sprague-Dawley a été immobilisée par une attelle plâtrée. Dix rattes témoins ont été utilisées (groupe A): les 30 rattes plâtrées ont été réparties en 4 groupes. Le groupe B n'a pas reçu de traitement. Le groupe C a reçu, par injection sous-cutanée quotidienne, 50 MRC mU de calcitonine (préparée par les auteurs) dans 5% de gélatine. Le groupe D a reçu 5% de gélatine. Le groupe E a reçu 50 MRC mU de calcitonine (Ciba), dans 5% de gélatine par jour, en sous-cutanée. Après 6 jours, les fémurs et tibias ont été pesés, radiographiés et étudiés histologiquement. Les os du groupe A sont normaux. Les os des groupes B, C, D et E présentent une ostéoporose d'immobilisation du coté gauche, avec diminution de l'os trabéculaire, sans traduction radiologique. Le traitement à la calcitonine n'a pas inhibé l'ostéoporose. La pression exercée par les attelles plâtrées a induit une apposition périostée, au niveau de quelques tibias. Après traitement à la calcitonine, une apposition augmentée a été observée au niveau des fémurs et tibias. La gélatine, seule, n'a pas eu d'effet. Bien que la calcitonine n'ait pas agi sur l'ostéoporose d'immobilisation, elle semble pourtant favoriser les processus ostéogéniques provoqués par d'autres mécanismes.
    Kurzfassung: Zusammenfassung 30 weibliche Sprague-Dawley-Ratten erhielten zur Immobilisation der linken hinteren Extremität einen Gipsverband. Die Tiere wurden in folgende 4 Gruppen unterteilt: B) keine Therapie. C) 50 MRC mE Calcitonin (eigene Präparation) in 5% Gelatine täglich s.c. D) Lösungsmittel in 5% Gelatine täglich s.c. E) 50 MRC mE Calcitonin (Ciba) in 5% Gelatine täglich s.c. Zusätzlich diente eine Gruppe ohne Gipsverband sowie ohne Therapie als Kontrolle (A). Nach 6 Wochen Versuchsdauer wurden die Femora und Tibiae geröntgt, gewogen und histologisch untersucht. In der Kontrollgruppe(A) bestand kein Unterschied zwischen rechter und linker Seite. In den Gruppen B, C, D und E hatte sich eine deutliche Immobilisationsosteoporose entwickelt (Rarefizierung der Spongiosa des Femurhalses), die röntgenologisch nicht nachgewiesen werden konnte. Die Therapie mit Calcitonin konnte diese Immobilisationsatrophie nicht verhindern. Der mechanische Reiz des Gibsverbandes erzeugte eine periostale Apposition in einigen Tibiae der Gruppen B und D. Nach Gabe von Calcitonin entwickelte sich diese periostale Neubildung in allen Femora und Tibiae der Gruppen C und E. Außerdem war das Ausmaß der Apposition unter Calcitonintherapie wesentlich größer. Das Lösungs-mittel allein hatte keinen Einfluß auf die beschriebenen Veränderungen. Calcitonin konnte die Entwicklung einer Immobilisationsosteoporose nicht verhindern, die Knochenneubildung nach Auslösung durch mechanische Einflüsse wurde dagegen wesentlich verstärkt.
    Notizen: Abstract In thirty female Sprague-Dawley rats the left hind leg was immobilized with plaster casts. According to treatment they were divided into the following groups: A) Control, no casts. B) No treatment. C) 50 MRC mU calcitonin (own preparation) in 5% gelatin subcutaneously per day. D) Vehicle alone subcutaneously. E) 50 MRC mU calcitonin (Ciba) in 5% gelatin subcutaneously per day. In addition, untreated rats without casts served as control (group A). After 6 weeks the femora and tibiae were X-rayed, weighed and examined histologically. The bones of the left and right legs did not differ in control group A. In groups B, C, D, and E a disuse osteoporosis had developed in the left legs (rarefication of trabecular bone volume of femur neck) which could not be seen in X-rays. Calcitonin treatment did not prevent the development of the bone atrophy. However, the pressure of the plaster casts had induced a periosteal apposition in some tibiae, and under calcitonin treatment the extent of this new formation in all femora and tibiae was markedly increased. The vehicle alone was ineffective. It can be concluded that whereas calcitonin is without effect on disuse osteoporosis, it probably favours new bone formation which is induced by other mechanisms.
    Materialart: Digitale Medien
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  • 3
    ISSN: 1432-0827
    Schlagwort(e): Key words: Androgen receptor — Androgens — Osteoblasts — Bone — Skeletal site.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Abstract. There are obvious sexual differences in adult skeletal morphology which for the most part are related to differences in size. Higher androgen serum levels in males exert potent osteoanabolic effects and therefore may contribute to this sexual dimorphism of the skeleton. The presence of androgen receptors (AR) in bone cells is a prerequisite for a direct osteoanabolic action of androgens. To investigate the possibility that, in addition to gender-related differences in androgen serum levels, there are also gender-related differences in the osteoblastic expression pattern of the androgen receptor, we examined AR mRNA expression, androgen binding sites, and mitogenic responses to the androgen dihydrotestosterone (DHT) in human osteoblastic cell (HOC) populations. HOCs were isolated from bone biopsy specimens derived from different skeletal sites of healthy adult males and females (2–69 years old). We found that male and female HOCs of all examined ages express similar AR mRNA levels and similar numbers of androgen binding sites. Using whole-cell-binding assays, we observed 3129–8417 androgen binding sites per femoral HOC with apparent KDs of 1.45–2.83 nM depending on the age of the investigated HOC population. Mandibular and cortical HOC of both sexes expressed higher AR mRNA levels, significantly more androgen binding sites per cell, and exhibited significantly greater mitogenic responses to DHT than iliac crest-derived and trabecular HOC of the same skeletal system and the same skeletal-site, respectively. In early adulthood, HOCs of both sexes appear to express somewhat higher AR mRNA levels and to possess more androgen binding sites than prepubertal and senescent HOC. Because sex hormone serum levels rise in puberty, we investigated the regulation of the AR mRNA expression by various steroids. We found that dexamethasone (dexa) and in some experiments also 17β-estradiol (E2) and 1,25-dihydroxyvitamin D3 (D3) increased AR mRNA levels and androgen binding in HOC cultures. A pretreatment with dexa, E2, and D3 significantly increased the mitogenic response of HOCs to DHT. We conclude that (1) higher androgen serum levels in males together with a higher AR expression at certain skeletal sites may contribute to the development of sex-related differences in skeletal morphology, (2) glucocorticoids induce AR gene expression in HOC cultures, and (3) glucocorticoids, E2, and D3 enhance the mitogenic action of DHT.
    Materialart: Digitale Medien
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  • 4
    Digitale Medien
    Digitale Medien
    Springer
    Calcified tissue international 62 (1998), S. 383-387 
    ISSN: 1432-0827
    Schlagwort(e): Key words: Osteoporosis—Bone densitometry—DXA—SPA—pQCT.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Abstract. Measurement of bone mineral density (BMD) is used for clinical estimation of fracture risk in osteoporosis. The precision of the method is important for the evaluation of true and clinical relevant changes in BMD in patients with osteoporosis. We measured BMD of the forearm in 14 young, healthy probands (10 males, 4 females), aged 24.6 ± 1.5 years with five different instruments using dual-energy X-ray absorptiometry (DXA), single-photon absorptiometry (SPA), and peripheral quantitative computed tomography (pQCT). Precision was expressed as the percentage coefficient of variation (CV%). In addition, the standardized CV% (sCV%) and the root mean square standard deviation (rmsSD%) was calculated for long-term precision. CV% ranged from 1.04 (SPA, distal BMD) to 2.75% (pQCT, trabecular BMD) for short-term precision and from 1.49 (DXA, QDR 1000, 1/3-distal BMD) to 4.33% (SPA, ultradistal) for long-term precision, respectively. The results for the rmsSD% were higher but correlated well with the CV%. A change that exceeds 2 √2 CV% has been considered as being significant. On this basis, 24.0 ± 5.1% (mean ± SEM) of the participants in our study would be expected to have a significant change in BMD without any correlation to the time-delay between the two measurements. Measurements of BMD were done at two locations with all five instruments: ultradistal and middistal BMD using DXA and SPA and total and trabecular BMD using pQCT, respectively. Coefficients of correlation for ``between-instrumental'' correlation were greater than 0.5 for almost all instruments. Distal and ultradistal BMD measured by SPA and trabecular and total BMD measured by pQCT correlated better with ultradistal BMD measured by DXA. Correspondingly, ``within-instrumental'' correlation was better for pQCT and SPA than for DXA. The coefficients of correlation between the different DXA methods were greater than 0.95 when corresponding locations were compared. We conclude that the clinical value of monitoring bone loss by measurement of forearm BMD is compromised by the low precision which was seen for DXA methods as well as for SPA and even pQCT in young healthy controls.
    Materialart: Digitale Medien
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  • 5
    ISSN: 1432-0827
    Schlagwort(e): Key words: Regional acceleratory phenomenon — Systemic acceleratory phenomenon — Inflammation-mediated osteopenia — Bone healing — Woven bone.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Abstract. We have previously shown that restoration of a local bone defect in the rat not only leads to a regional acceleratory phenomenon (RAP), but also to a systemic acceleration of osteogenesis (SAP) at distant sites of the skeleton. In this study, we investigated whether specific inhibition of osteoblasts would affect the local RAP and the systemic acceleratory phenomenon (SAP) healing sites. Systemic inhibition of osteoblasts was induced by inflammation-mediated osteopenia (IMO), a nonspecific type of inflammation initiated by S.C. injections of sterile talc. A drill hole defect 1.2 mm in diameter was performed at the midshaft of the left tibia of female rats. On day 7, during the formation phase of the local healing process, IMO did not influence the number of osteoblasts or the bone volume in the marrow cavity of the local healing site, whereas it did lead to a significant reduction of osteoblast number and bone volume at the systemic site (subepiphyseal spongiosa of the tibia). By contrast, on days 14 and 21, during the resorption phase of bone healing, IMO led to a significant reduction in both osteoblast number and bone volume in the marrow cavity of the local healing site. At the same time, however, it did not influence the cortical area of the bone defect where newly formed bone is needed to ensure mechanical stability. In summary, our model of bone healing reveals that a humoral noxious osteoblast stimulus such as IMO is able to inhibit systemically osteoblasts stimulated by SAP, whereas it is not able to inhibit osteoblasts either from producing woven bone during a RAP or from producing bone that is needed to mechanically stabilize a defect.
    Materialart: Digitale Medien
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  • 6
    ISSN: 1432-0827
    Schlagwort(e): Key words: Bone — Osteoblasts — Endothelin-1 — 1,25(OH)2D3— Endothelial cells.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Abstract. Endothelial cell products may affect bone cell function, since trabecular and cortical bone are in close proximity to vascular endothelial cells. Incubation of cultured human osteoblastic cells with the endothelial cell polypeptide endothelin-1 (ET-1) resulted in a time- and dose-dependent stimulation of cell proliferation. Furthermore, markers of differentiated osteoblastic function, i.e., alkaline phosphatase and type-I collagen, were dose-dependently increased in response to ET-1. The effects of ET-1 on cell growth and function reached a maximum at higher ET-1 concentrations, and osteoblastic cells bound ET-1 specifically with a KD of 35 pM, corresponding to the biologic effects of ET-1 on bone cells. Under baseline conditions osteoblastic cells expressed 16,800 binding sites per cell. The effect of ET-1 was dependent on its binding to the endothelin-1 receptor A (ETRA), since an inhibitor of ET-1 binding blocked the biologic effects of ET-1. Northern blot analyses revealed that cultured human osteoblastic cells possess the transcript for the ETRA. Expression of ETRA mRNA was under control of 1,25-dihydroxyvitamin D3 [1,25 (OH)2D3]. Incubation of osteoblastic cells with 1,25(OH)2D3 increased ETRA mRNA levels, corresponding to an increased effect of ET-1 on osteoblastic proliferation and function. Thus, a concerted action of the endothelial cell polypeptide ET-1 and 1,25(OH)2D3 may mediate an osteoanabolic effect of the vascular and endocrine vitamin D system.
    Materialart: Digitale Medien
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  • 7
    Digitale Medien
    Digitale Medien
    Springer
    Calcified tissue international 57 (1995), S. 120-126 
    ISSN: 1432-0827
    Schlagwort(e): Glucocorticoids ; Osteoblasts ; Bone ; Osteoporosis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Abstract Clinical observations suggest that the onset and severity of glucocorticoid (GC) induced osteoporosis is dependent on the duration of the GC treatment and the applied GC compound. To test whether these in vivo observations are reflected by different in vitro effects of various synthetic GCs on human bone cell metabolism we isolated human osteoblast-like cells (HOC) from bone biopsies of healthy (no clinical symptoms of arthritis or arthrosis) adults who underwent selective orthopedic surgery. HOC were identified as bone cells by 1,25-vitamin D3-stimulated increase of specific alkaline phosphatase (ALP) activity, secretion of osteocalcin and type-I procollagen peptide, and the ability to form mineral in vitro. We investigated the effects of dexamethasone (dexa), methylprednisolone (mpred), prednisolone (pred), and deflazacort (defla) on DNA-synthesis, ALP, and osteocalcin (OC)- and type-I procollagen peptide secretion of HOC in vitro. In summary, (1) GC exposure stimulates DNA synthesis after 6–12-hour treatment periods; (2) dex and mpred strongly inhibit DNA (48-hour treatment) and collagen synthesis but stimulate ALP, whereas pred and defla exhibit smaller effects on DNA synthesis, ALP, and collagen production; and (3) all tested glucocorticoids inhibit OC secretion by HOC in vitro. Thus, the effect of GC on DNA synthesis of HOC varies with the duration of GC exposure, and dex and mpred more potently affect HOC metabolism in vitro than pred and defla.
    Materialart: Digitale Medien
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  • 8
    ISSN: 1432-0827
    Schlagwort(e): Key words: Insulin-like growth factor-I — Transforming growth factor-β— Bone matrix — Growth — Rat.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Abstract. Our knowledge of the concentration of growth factors in growing bone is limited. In the present study, we examined the developmental changes in the concentrations of insulin-like growth factor I (IGF-I) and transforming growth factor beta (TGF-β) in the rat femur between weanling and maturity. We show that during the rapid growth phase there is a continuous rise in bone matrix IGF-I and TGF-β in all compartments of the femoral bone. The association between IGF-I and TGF-β is not only temporal, but with few exceptions is also observed within the animals of each age class. These data support the hypothesis that IGF-I and TGF-β play an important role in the growth-associated accumulation of bone mass.
    Materialart: Digitale Medien
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  • 9
    ISSN: 1432-0428
    Schlagwort(e): Keywords Oxidative stress ; nephropathy ; transcription factor NF-kB ; thrombomodulin ; thioctic acid.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Increased oxidative stress and subsequent activation of the transcription factor NF-kB has been linked to the development of late diabetic complications. To determine whether oxidative stress dependent NF-kB activation is evident in patients with diabetic nephropathy we used an Electrophoretic Mobility Shift Assay based semiquantitative detection system which enabled us to determine NF-kB activation in ex vivo isolated peripheral blood mononuclear cells. We examined 33 patients with diabetes mellitus (Type I and Type II). Patients with diabetic nephropathy showed higher NF-kB binding activity in Electrophoretic Mobility Shift Assays and stronger immunohistological staining for activated NF-kBp65 than patients without renal complications. NF-kB binding activity correlated with the degree of albuminuria (r = 0.316) and with thrombomodulin plasma concentrations (r = 0.33), indicative for albuminuria associated endothelial dysfunction. In a 3 day intervention study in which 600 mg of the antioxidant thioctic acid (α-lipoic acid) per day were given to nine patients with diabetic nephropathy oxidative stress in plasma samples was decreased by 48 % and NF-kB binding activity in ex vivo isolated peripheral blood mononuclear cells by 38 %.
    Materialart: Digitale Medien
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  • 10
    Digitale Medien
    Digitale Medien
    Springer
    Der Internist 40 (1999), S. 349-355 
    ISSN: 1432-1289
    Schlagwort(e): Schlüsselwörter Endokrinologie ; Standortbestimmung ; Diabetes ; Hypophyse ; Osteoporose ; Nebennieren ; Schilddrüse
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Zum Thema In dieser Arbeit wird ein sehr gedrängter Überblick – was könnte es bei dem riesigen Gebiet der Endokrinologie mehr sein –über den Stand des Fachgebiets sowie über die wichtigsten und gegenwärtig besonders aktuellen Entwicklungen der Grundlagen- und klinischen Forschung gegeben, er bezieht sich auf: Hypophyse, Schilddrüse, Nebennieren, metabolische Osteopathie sowie Diabetes und Stoffwechsel. Die Bedeutung der Endokrinologie als wichtige Teildisziplin der Inneren Medizin ist unstrittig. Innerhalb der Endokrinologie nimmt die Diabetologie wegen der enormen Bedeutung dieses Krankheitskomplexes einen besonders wichtigen Stellenwert ein. Die Verzahnung der Endokrinologie mit den anderen Teildisziplinen ist evident und durch die großen Volkskrankheiten gegeben: Hyperlipämie, Osteoporose, Hypertonie, Struma und Diabetes. Es besteht die Befürchtung, daß die gegenwärtig an mehreren Fakultäten vorgenommene Rückstufung endokrinologischer Lehrstühle auf eine niedrigere Ebene sich langfristig äußerst nachteilig auf Forschung, Lehre und Krankenversorgung auswirken könnte. Aber auch die allgemein-internistische Patientenversorgung setzt prinzipiell gut endokrinologische Grundkenntnisse voraus. Man will hierzulande keine „Nur-Endokrinologen” sondern die gleichwertig mit anderen Teildisziplinen bestehende Zuordnung zur Gesamt-Inneren Medizin auf höchstmöglichem Niveau.
    Materialart: Digitale Medien
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