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  • sural nerve  (5)
  • pathology  (3)
  • Transfer cell  (2)
  • 1
    Digitale Medien
    Digitale Medien
    Springer
    Planta 165 (1985), S. 191-196 
    ISSN: 1432-2048
    Schlagwort(e): Apoplast ; Plasmatubule ; Pisum (plasmatubules) ; Symplast ; Transfer cell ; Vein (minor)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Plasmatubules are tubular evaginations of the plasmalemma. They have previously been found at sites where high solute flux between apoplast and symplast occurs for a short period and where wall proliferations of the transfer cell type have not been developed (Harris et al. 1982, Planta 156, 461–465). In this paper we describe the distribution of plasmatubules in transfer cells of the leaf minor veins of Pisum sativum L. Transfer cells are found in these veins associated both with phloem sieve elements and with xylem vessels. Plasmatubules were found, in both types of transfer cell and it is suggested that the specific distribution of the plasmatubules may reflect further membrane amplification within the transfer cell for uptake of solute from apoplast into symplast.
    Materialart: Digitale Medien
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  • 2
    ISSN: 1432-0428
    Schlagwort(e): Diabetic neuropathy ; nerve blood flow ; sural nerve ; sural sensory conduction velocity ; temperature ; exercise
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Severe microvascular disease exists at the stage of clinical diabetic neuropathy. A non-invasive test that will identify those diabetic subjects who will eventually develop neuropathy is essential for early intervention. Sural sensory conduction velocity was recorded (x 3) in 12 non-neuropathic diabetic subjects, 15 diabetic subjects with established neuropathy and 16 age-matched normal control subjects, before and after exercise to 80% age/sex predicted maximum heart rate. Fixed sural electrodes were used. Subcutaneous temperature was recorded by a needle thermocouple placed near the sural nerve. Sural sensory conduction velocity increased significantly after exercise in normal subjects (p〈0.01, mean increase 5.07 m/s) and non-neuropathic diabetic subjects (p〈0.02, mean increase 3.99 m/s) but not in neuropathic subjects (mean increase 0.99 m/s). Subcutaneous temperature rose significantly in normal subjects (p〈0.01, mean increase 2.07°C) and non-neuropathic diabetic subjects (p〈0.001, mean increase 2.52 °C) but not in neuropathic subjects (mean increase 0.15 °C). However, sural sensory conduction velocity increased by 1.2 m · s−1. °C−1 following direct warming of the limb in six neuropathic subjects which was comparable to that of normal and non-neuropathic subjects (1.49 and 1.48 m · s−1. °C−1). The impairment of exercise conduction increment in diabetic neuropathy suggests impaired nerve blood flow in diabetic neuropathy.
    Materialart: Digitale Medien
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  • 3
    ISSN: 1432-0428
    Schlagwort(e): Keywords Insulin neuritis ; diabetic neuropathy ; sural nerve ; nerve blood flow ; arterio-venous shunting ; nerve ; hypoxia ; new vessel formation ; fluorescein angiography.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Insulin neuritis, or painful neuropathy following rapid improvement in glycaemic control, is well recognised but its aetiology is unclear. An understanding of the processes involved in the genesis of acute painful neuropathy of rapid glycaemic control may give an insight into the early pathogenetic factors leading to diabetic nerve damage in general. We have identified five subjects with insulin neuritis including one who developed severe autonomic neuropathy following treatment with insulin. Subjects underwent: 1) assessment of neuropathic symptom and deficit scores; 2) quantitative sensory and electrophysiological studies and 3) sural nerve epineurial vessel photography and fluorescein angiography in vivo. The sural nerve photographs were independently graded by an ophthalmologist. All subjects with insulin neuritis presented with severe sensory symptoms but clinical examination and electrophysiological tests were normal except in the subject with the severe autonomic neuropathy in whom all the tests were abnormal. On nerve photography, there was an abundance of epineurial nutrient vessels although these showed severe abnormalities including arteriolar attenuation, tortuosity and arterio-venous shunting in all subjects. Proliferating neural ’new vessels' which bear striking similarities to those found in the retina and that were more leaky to fluorescein than normal vessels, were observed in three subjects. Venous distension and/or tortuosity was also observed in three subjects and this was most marked in the subject with severe autonomic neuropathy. This study shows that epineurial nutrient vessel anatomy is abnormal in subjects with acute painful neuropathy of rapid glycaemic control, a condition previously thought to be purely metabolic in origin. The presence of epineurial arterio-venous shunting and a fine network of vessels resembling the new vessels of the retina, may lead to a ’steal' effect rendering the endoneurium ischaemic. This process may be important in the genesis of neuropathic pain, and further supports the importance of vascular factors in the pathogenesis of diabetic neuropathy. [Diabetologia (1996) 39: 329–335]
    Materialart: Digitale Medien
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  • 4
    ISSN: 1432-0428
    Schlagwort(e): Diabetic neuropathy ; sural nerve ; nerve blood flow ; epineurial vessel photography ; fluorescein angiography ; arterio-venous shunting ; vasa nervorum
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary New techniques of sural nerve photography and fluorescein angiography which are able to provide an index of nerve blood flow have been developed. Under local anaesthetic, 3 cm of sural nerve was exposed at the ankle using an operating microscope. Without disturbing the epineurium, vessels were identified and photographed at a standard magnification (× 30). These were independently graded by an ophthalmologist not otherwise involved with the study. Fluorescein angiography was then carried out on the exposed nerve. The fluorescein appearance time and intensity of fluorescence were quantified, using computer analysis of digitised images. Thirteen subjects with chronic sensory motor neuropathy, five non-neuropathic diabetic and nine normal control subjects were studied. The mean epineurial vessel pathology score of the neuropathic group was significantly higher than the combined normal control and non-neuropathic diabetic groups (p 〈0.01). Direct epineurial arteriovenous shunting was observed in six neuropathic and one non-neuropathic diabetic patients and not in any of the normal control subjects. The nerve fluorescein appearance time was significantly delayed in subjects with chronic sensory motor neuropathy (51.5 ± 12 s) compared to both normal (34.7 ± 9 s, p 〈0.01) and non-neuropathic diabetic subjects (33.4 ± 11 s, p 〈0.025). The mean intensity of fluorescence at 96, 252 and 576 s, was significantly lower in subjects with chronic sensory motor neuropathy compared with both of the other groups (p 〈0.05). The epineurial vessel pathology score was significantly related to reduced sural (p 〈0.01) and peroneal (p 〈0.001) nerve conduction velocities, elevated vibration (p 〈0.01) and thermal (p 〈0.001) perception and the severity of retinopathy (p 〈0.002). The fluorescein appearance time was significantly related to reduced sural sensory (p 〈0.02) conduction velocity, elevated vibration (p 〈0.01) perception and epineurial vessel (p 〈0.002) pathology score, but it failed to relate to peroneal motor (p = 0.06) conduction velocity, thermal (p = 0.1) perception and the severity of retinopathy (p = 0.3). Intensity of fluorescence was significantly related to fluorescein appearance time (at 96 s, p 〈0.001; at 576 s, p 〈0.05) but did not relate to measures of neuropathic severity. These techniques have enabled us to observe that epineurial vessel anatomy is abnormal and that nerve blood flow is impaired in subjects with chronic sensory motor neuropathy. In addition epineurial arterio-venous shunting may be a feature of diabetic neuropathy. These techniques may further be applied to study nerve blood flow in early diabetic neuropathy.
    Materialart: Digitale Medien
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  • 5
    ISSN: 1432-0428
    Schlagwort(e): Insulin neuritis ; diabetic neuropathy ; sural nerve ; nerve blood flow ; arterio-venous shunting ; nerve ; hypoxia ; new vessel formation ; fluorescein angiography
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Insulin neuritis, or painful neuropathy following rapid improvement in glycaemic control, is well recognised but its aetiology is unclear. An understanding of the processes involved in the genesis of acute painful neuropathy of rapid glycaemic control may give an insight into the early pathogenetic factors leading to diabetic nerve damage in general. We have identified five subjects with insulin neuritis including one who developed severe autonomic neuropathy following treatment with insulin. Subjects underwent: 1) assessment of neuropathic symptom and deficit scores; 2) quantitative sensory and electro-physiological studies and 3) sural nerve epineurial vessel photography and fluorescein angiography in vivo. The sural nerve photographs were independently graded by an ophthalmologist. All subjects with insulin neuritis presented with severe sensory symptoms but clinical examination and electrophysiological tests were normal except in the subject with the severe autonomic neuropathy in whom all the tests were abnormal. On nerve photography, there was an abundance of epineurial nutrient vessels although these showed severe abnormalities including arteriolar attenuation, tortuosity and arterio-venous shunting in all subjects. Proliferating neural ‘new vessels’ which bear striking similarities to those found in the retina and that were more leaky to fluorescein than normal vessels, were observed in three subjects. Venous distension and/or tortuosity was also observed in three subjects and this was most marked in the subject with severe autonomic neuropathy. This study shows that epineurial nutrient vessel anatomy is abnormal in subjects with acute painful neuropathy of rapid glycaemic control, a condition previously thought to be purely metabolic in origin. The presence of epineurial arterio-venous shunting and a fine network of vessels resembling the new vessels of the retina, may lead to a ‘steal’ effect rendering the endoneurium ischaemic. This process may be important in the genesis of neuropathic pain, and further supports the importance of vascular factors in the pathogenesis of diabetic neuropathy.
    Materialart: Digitale Medien
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  • 6
    ISSN: 1432-0428
    Schlagwort(e): Keywords Diabetic neuropathy ; spectrophotometry ; sural nerve ; nerve blood flow ; oxygen saturation.
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Aims/hypothesis. Experimental studies have shown that abnormalities of nerve microcirculation are important factors in the pathogenesis of diabetic neuropathy but there have been few clinical studies. We have applied microlightguide spectrophotometry to measure intravascular oxygen saturation (HbO2%) and blood flow in human sural nerve. Methods. We studied ten patients with mild-moderate sensory motor diabetic neuropathy, nine patients without neuropathy and nine control subjects. We took 300 measurements of oxygen saturation under direct visual control through a 1.9 mm rigid endoscope over three regions of the nerve. Spectrophotometric measurements of nerve fluorescence were taken after an intravenous injection of sodium fluorescein and the rate of increase in nerve fluorescence (rise time) was used as an indicator of nerve blood flow. Results. Nerve oxygen saturation was reduced in patients with neuropathy compared with control subjects (67.1 ± 2.2 % vs 76.7 ± 2.1 %, p = 0.006). Fluorescein rise time was prolonged in patients with neuropathy compared with the control group (48.5 ± 7.0 s vs 14.0 ± 3.1 s, p = 0.001) suggesting impaired nerve blood flow. There was a correlation between rise time, nerve oxygen saturation, glycaemic control and sural nerve sensory conduction velocity (p 〈 0.01). Conclusion/interpretation. The combination of microlight-guide spectrophotometry and micro-endoscopy provides a valuable minimally invasive technique for clinical investigation of nerve microcirculation. We have shown reduced nerve oxygenation and impaired blood flow in diabetic neuropathy and these findings strongly support a central role of microvascular disease in the pathogenesis of diabetic neuropathy. [Diabetologia (1999) 42: 737–742]
    Materialart: Digitale Medien
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  • 7
    Digitale Medien
    Digitale Medien
    Springer
    Planta 156 (1982), S. 461-465 
    ISSN: 1432-2048
    Schlagwort(e): Apoplast ; Hordeum (plasmatubules) ; Plasmalemmasome ; Plasmatubule ; Symplast ; Transfer cell
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Tubular evaginations of the plasmalemma of the scutellar epithelial cells of barley are described. The evaginations are similar to those present at other sites where solute flux occurs for a limited period only and wall development of the transfer-cell form has not occured. Differential uptake of the fluorescent dyes fluorescein, which moves into the symplast, and 8-anilino-1-naphthalene sulphonic acid, which remains in the apoplast only, indicates that the scutellar epithelial cells contain the boundary between the apoplast and symplast. We suggest that i) the plasmalemma evaginations, which have a specific form and localisation, may be referred to as plasmatubules rather than by the general term plasmalemmasome, and that ii) the plasmatubules may act in membrane amplification in a short-term structural modification which is an alternative to transfer cells.
    Materialart: Digitale Medien
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  • 8
    ISSN: 1569-8041
    Schlagwort(e): classification ; lymphoma ; pathology
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Background:Controversy in lymphoma classification dates back tothe first attempts to formulate such classifications. Over the years, much ofthis controversy arose from the assumption that there had to be a singleguiding principle – a `gold standard' – for classification, andfrom the existence of multiple different classifications. Design:The International Lymphoma Study Group (I.L.S.G.)developed a consensus list of lymphoid neoplasms, which was published in 1994as the `Revised European–American Classification of Lymphoid Neoplasms'(R.E.A.L.). The classification is based on the principle that a classificationis a list of `real' disease entities, which are defined by a combination ofmorphology, immunophenotype, genetic features, and clinical features. Therelative importance of each of these features varies among diseases, and thereis no one `gold standard'. In some tumors morphology is paramount, in othersit is immunophenotype, a specific genetic abnormality, or clinical features.An international study of 1300 patients, supported by the San SalvatoreFoundation, was conducted to determine whether the R.E.A.L. Classificationcould be used by expert pathologists and had clinical relevance. Since 1995,the European Association of Pathologists (EAHP) and the Society forHematopathology (SH) have been developing a new World Health Organization(WHO) Classification of hematologic malignancies, using an updated R.E.A.L.Classification for lymphomas and applying the principles of the R.E.A.L.Classification to myeloid and histiocytic neoplasms. A Clinical AdvisoryCommittee (CAC) was formed to ensure that the WHO Classification will beuseful to clinicians. Results:The International Lymphoma Study showed that the R.E.A.L.Classification could be used by pathologists, with inter-observerreproducibility better than for other classifications (〉85%).Immunophenotyping was helpful in some diagnoses, but not required for manyothers. New entities not specifically recognized in the Working Formulationaccounted for 27% of the cases. Diseases that would have been lumpedtogether as `low grade' or `intermediate/high grade' in the WorkingFormulation showed marked differences in survival, confirming that they needto be treated as distinct entities. Clinical features such as theInternational Prognostic Index were also important in determining patientoutcome. The WHO Clinical Advisory Committee concluded that clinical groupingsof lymphoid neoplasms was neither necessary nor desirable. Patient treatmentis determined by the specific type of lymphoma, with the addition of gradewithin the tumor type, if applicable, and clinical prognostic factors such asthe International Prognostic Index (IPI). Conclusions:The experience of developing the WHO Classificationhas produced a new and exciting degree of cooperation and communicationbetween oncologists and pathologists from around the world, which shouldfacilitate progress in the understanding and treatment of hematologicmalignancies.
    Materialart: Digitale Medien
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  • 9
    Digitale Medien
    Digitale Medien
    Springer
    Annals of oncology 9 (1998), S. 45-56 
    ISSN: 1569-8041
    Schlagwort(e): B cell ; classification ; EBV ; epidemiology ; Hodgkin's disease ; immunophenotype ; lymphoma ; molecular genetics ; pathology
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract In the past decade there have been many advances in our understanding of Hodgkin's disease. Among the most important is the discovery that the Reed-Sternberg cell is a lymphoid cell, in most cases a B cell, and that it is clonal, and thus a true lymphoma, deserving of a name change, to 'Hodgkin's lymphoma' (HL). Based on a combination of immunophenotype and morphology, the R.E.A.L. Classification recognizes two main types of HL: classical types (nodular sclerosis, mixed cellularity, lymphocyte-rich classical HL, and lymphocyte depletion) and nodular lymphocyte predominance type (NLPHL), which probably represent distinct biological entities. The immunophenotype and genetic features of both classical HL and NLPHL have been defined. These are useful in the subclassification of HL and in distinguishing HL from two recently-described, aggressive lymphomas that were in the past often diagnosed as HL: anaplastic large-cell lymphoma, T-cell type (ALCL), and T-cell/histiocyte-rich large B-cell lymphoma (T/HRBCL). Epstein-Barr virus has been detected in approximately 40% of the cases of classical HL, and is clonal, suggesting that this virus may play a role in the pathogenesis of at least some types of HL. The frequency of HL varies in different populations, and the frequency of EBV-positive HL appears to be inversely related to the overall frequency of HL in a given population. Thus, it is possible that its presence may simply reflect the prevalence of EBV-infected B cells in the individual. Despite the advances of the past ten years, many questions remain to be answered, and these will provide the challenges of the next decade.
    Materialart: Digitale Medien
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  • 10
    ISSN: 1569-8041
    Schlagwort(e): differential diagnosis ; grey zone ; Hodgkin's lymphoma ; immunohistochemistry ; pathology ; workshop report
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Despite advances in immunohistochemistry and molecular biology, the distinction between classical Hodgkin's lymphoma and related diseases such as nodular lymphocyte-predominant Hodgkin's disease, T-cell rich large B-cell lymphoma or anaplastic large cell lymphoma has remained difficult in rare cases. Lack of clear-cut diagnostic criteria represents a problem for both the pathologist and the clinician. To delineate this 'grey zone' between classical Hodgkin's lymphoma and non-Hodgkin's lymphoma (NHL) and to develop criteria for classification of such cases, 12 expert hematopathologists each submitted one to five borderline cases to a workshop. Cases were reviewed and classified at a multiheaded microscope and criteria were established for the diagnosis of questionable cases. Well established entities such as classical Hodgkin's lymphoma, anaplastic large-cell lymphoma and TCRBCL were defined more strictly and cases with unusual morphology or antigen expression could be identified. A distinctive subset of cases representing mediastinal large B-cell lymphomas with features of Hodgkin's lymphoma was identified.
    Materialart: Digitale Medien
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