10 research outputs found

    Ascending and descending axon-collaterals from cervical spinal neurons : a retrograde fluorescent double-labeling study in the rat.

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    In order to gain insight into the function of the central nervous system it is of importance to know the lay-out of fiber connections between its constituent cells and cell-groups. Much is already known of the anatomy of the spinal cord and its afferent and efferent fibers; this will be reviewed in Chapter 2. A large part of the spinal neuronal network consists of propriospinal connections representing the anatomical basis for integration of information within the spinal cord itself. The present study was undertaken to investigate propriospinal neurons in more detail. Specifically, a search was made for neurons which project to more than one target area by way of divergent side-branches, or collaterals, of their axon. Earlier anatomical findings already suggested that such "branching" neurons' might be present within the spinal cord. Thus retrograde HRP studies in the cat [254, 286, 288, 359, 416] identified the spinal neurons which give rise to descending propriospinal fibers. The distribution of these neurons largely overlaps that of the neurons giving rise to ascending propriospinal and supraspinal fibers [286, 288]. Therefore some of these neurons may be "branching" neurons which give rise to ascending and descending collaterals. In fact, such neurons were already noted in several Golgi studies [68, 242, 344], but their collaterals could be traced only over short distances. Electrophysiological studies [9, 146, 173, 360] supported these Golgi findings, indicating that some cervical spinal neurons projecting to lumbar levels also give rise to ascending supraspinal collaterals. In the present series of experiments in the rat, an attempt was made: a) to determine the location and relative numbers of such branching neurons in the cervical cord, and b) to approximate the rostral and caudal extent of projection of their collaterals. To this purpose we used the retrograde fluorescent double-labeling method (described in Chapter 3). The results of the first set of experiments (Chapter 4), in which tracer injections were made at various spinal levels, indicated that many neurons in the cervical grey matter in the rat are branching neurons, distributing ascending collaterals to upper cervical or supraspinal levels, and descending collaterals to thoracic or lumbosacral levels. Most descending collaterals of the branching cervical neurons were found to terminate at short distances, i.e. in the upper thoracic cord. On the other hand, the majority of the ascending collaterals were distributed to supraspinal levels. Although the findings suggested that many of these collaterals projected to the caudal brainstem, it remained unsettled whether the supraspinally ascending fibers specifically belonged to any of the various ascending tracts. Therefore, further sets of experiments were designed to clarify this issue, investigating the presence and relative numbers of supraspinal collaterals to the cerebellum (Chapter 5), the thalamus and tectum (Chapter 6) and the dorsal medulla (Chapter 7). Summarizing, the results of the latter series of experiments indicate that relatively many of the supraspinally ascending collaterals are distributed to the medulla, only few to the thalamus and tectum and extremely few to the cerebellum

    Identifying relevant determinants of in-hospital time to diagnosis for ANCA-associated vasculitis patients

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    Objectives Diagnosing patients with ANCA-associated vasculitis (AAV) can be challenging owing to its rarity and complexity. Diagnostic delay can have severe consequences, such as chronic organ damage or even death. Given that few studies have addressed diagnostic pathways to identify opportunities to improve, we performed a clinical audit to evaluate the diagnostic phase. Methods This retrospective, observational study of electronic medical records data in hospitals focused on diagnostic procedures during the first assessment until diagnosis. Results We included 230 AAV patients from nine hospitals. First assessments were mainly performed by a specialist in internal medicine (52%), pulmonology (14%), ENT (13%) or rheumatology (10%). The overall median time to diagnosis was 13 [interquartile range: 2-49] days, and in patients primarily examined by a specialist in internal medicine it was 6 [1-25] days, rheumatology 14 [4-45] days, pulmonology 15 [5-70] days and ENT 57 [16-176] days (P = 0.004). Twenty-two of 31 (71%) patients primarily assessed by a specialist in ENT had non-generalized disease, of whom 14 (64%) had ENT-limited activity. Two hundred and nineteen biopsies were performed in 187 patients (81%). Histopathological support for AAV was observed in 86% of kidney biopsies, 64% of lung biopsies and 34% of ENT biopsies. Conclusion In The Netherlands, AAV is diagnosed and managed predominantly by internal medicine specialists. Diagnostic delay was associated with non-generalized disease and ENT involvement at presentation. Additionally, ENT biopsies had a low diagnostic yield, in contrast to kidney and lung biopsies. Awareness of this should lead to more frequent consideration of AAV and early referral for a multidisciplinary approach when AAV is suspected

    Identifying relevant determinants of in-hospital time to diagnosis for ANCA-associated vasculitis patients

    No full text
    Objectives Diagnosing patients with ANCA-associated vasculitis (AAV) can be challenging owing to its rarity and complexity. Diagnostic delay can have severe consequences, such as chronic organ damage or even death. Given that few studies have addressed diagnostic pathways to identify opportunities to improve, we performed a clinical audit to evaluate the diagnostic phase. Methods This retrospective, observational study of electronic medical records data in hospitals focused on diagnostic procedures during the first assessment until diagnosis. Results We included 230 AAV patients from nine hospitals. First assessments were mainly performed by a specialist in internal medicine (52%), pulmonology (14%), ENT (13%) or rheumatology (10%). The overall median time to diagnosis was 13 [interquartile range: 2-49] days, and in patients primarily examined by a specialist in internal medicine it was 6 [1-25] days, rheumatology 14 [4-45] days, pulmonology 15 [5-70] days and ENT 57 [16-176] days (P = 0.004). Twenty-two of 31 (71%) patients primarily assessed by a specialist in ENT had non-generalized disease, of whom 14 (64%) had ENT-limited activity. Two hundred and nineteen biopsies were performed in 187 patients (81%). Histopathological support for AAV was observed in 86% of kidney biopsies, 64% of lung biopsies and 34% of ENT biopsies. Conclusion In The Netherlands, AAV is diagnosed and managed predominantly by internal medicine specialists. Diagnostic delay was associated with non-generalized disease and ENT involvement at presentation. Additionally, ENT biopsies had a low diagnostic yield, in contrast to kidney and lung biopsies. Awareness of this should lead to more frequent consideration of AAV and early referral for a multidisciplinary approach when AAV is suspected.Nephrolog

    Clinical Practice Audit on the Management of Antineutrophil Cytoplasmic Antibody-Associated Vasculitis in the Netherlands

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    Introduction: Managing complex and rare systemic autoimmune diseases such as antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) can be challenging and is often accompanied by undesirable variations in clinical practice. Adequate understanding of clinical practice can help identify essential issues to improve the care for AAV patients. Therefore, we studied the real-life management and outcomes of AAV patients in the Netherlands.Methods: In this cohort study, we investigated clinical practice in university and nonuniversity teaching hospitals with respect to patients with a clinical diagnosis of AAV. We retrospectively collected clinical data encompassing clinical variables, medication details, and outcome parameters.Results: Data of 230 AAV patients were collected in 9 Dutch hospitals. Of these, 167 patients (73%) were diagnosed with granulomatosis with polyangiitis, 54 (24%) with microscopic polyangiitis and 9 (4%) with eosinophilic granulomatosis with polyangiitis. One hundred sixty-six patients (72%) had generalized disease. The median year of diagnosis was 2013 (range 1987-2018). Besides steroids, oral cyclophosphamide was the most used drug (50%) for induction therapy and azathioprine (68%) for maintenance therapy. Adverse outcomes were major infections in 35%, major relapses in 23%, malignancy in 10%, major cardiovascular events in 8%, and end-stage renal disease in 7%.Conclusion: Oral cyclophosphamide was the most frequently used induction therapy, azathioprine for maintenance therapy; over time, the use of rituximab is increasingly employed. Major infection and relapses are the most prevalent adverse outcomes. This audit resulted in important indicators for treatment of AAV patients that can be implemented for future, national audits to improve the outcomes of AAV patients.Nephrolog

    A single immunization with covaccine HT-adjuvanted H5N1 influenza virus vaccine induces protective cellular and humoral immune responses in ferrets

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    Highly pathogenic avian influenza A viruses of the H5N1 subtype continue to circulate in poultry, and zoonotic transmissions are reported frequently. Since a pandemic caused by these highly pathogenic viruses is still feared, there is interest in the development of influenza A/H5N1 virus vaccines that can protect humans against infection, preferably after a single vaccination with a low dose of antigen. Here we describe the induction of humoral and cellular immune responses in ferrets after vaccination with a cell culture-derived whole inactivated influenza A virus vaccine in combination with the novel adjuvant CoVaccine HT. The addition of CoVaccine HT to the influenza A virus vaccine increased antibody responses to homologous and heterologous influenza A/H5N1 viruses and increased virus-specific cell-mediated immune responses. Ferrets vaccinated once with a whole-virus equivalent of 3.8 μg hemagglutinin (HA) and CoVaccine HT were protected against homologous challenge infection with influenza virus A/VN/1194/04. Furthermore, ferrets vaccinated once with the same vaccine/adjuvant combination were partially protected against infection with a heterologous virus derived from clade 2.1 of H5N1 influenza viruses. Thus, the use of the novel adjuvant CoVaccine HT with cell culture-derived inactivated influenza A/H5N1 virus antigen is a promising and dose-sparing vaccine approach warranting further clinical evaluation. Copyrigh

    Patient blood management : a solution for South Africa

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    For more than 70 years the default therapy for anaemia and blood loss was mostly transfusion. Accumulating evidence demonstrates a significant dose-dependent relationship between transfusion and adverse outcomes. This and other transfusion-related challenges led the way to a new paradigm. Patient blood management (PBM) is the application of evidence-based practices to optimise patient outcomes by managing and preserving the patient’s own blood. ‘Real-world’ studies have shown that PBM improves patient outcomes and saves money. The prevalence of anaemia in adult South Africans is 31% in females and 17% in males. Improving the management of anaemia will firstly improve public health, secondly relieve the pressure on the blood supply, and thirdly improve the productivity of the nation’s workforce. While high-income countries are increasingly implementing PBM, many middle- and low-income countries are still trying to upscale their transfusion services. The implementation of PBM will improve South Africa’s health status while saving costs.http://www.samj.org.zapm2020Medical Oncolog

    Clinical nephrology-epidemiology-clinical trials: Determinants of outcome in ANCA-associated glomerulonephritis: A prospective clinico-histopathological analysis of 96 patients

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    Background. The predictive value of clinical and renal histological features for renal outcome in patients with anti-neutrophil cytoplasmic autoantibody (ANCA)-associated glomerulonephritis was investigated in a prospective analysis of 96 patients with ANCA-associated vasculitis, and moderate renal involvement (creatinine <500 \uce\ubcmol/L). Methods. The extent of 39 histological features in 96 biopsies (performed at entry in a clinical trial) was scored by two independent observers, according to a standardized protocol. Age, gender, diagnosis, glomerular filtration rate at entry (GFR0), ANCA-specificity, proteinuria, and treatment of these 96 patients were also taken into account. Treatment was standardized and started after the biopsy was performed. Endpoints included renal function at 18 months (GFR18), GFR18 corrected for GFR0 (CORGFR18), and the occurrence of relapse or death. Results. Parameters that most strongly correlated with GFR18 were GFR0 (r = 0.67), interstitial fibrosis (r = -0.45), glomerulosclerosis (r = -0.37), and tubular atrophy (r = -0.36). Parameters that most strongly correlated with CORGFR18 were segmental (r = 0.45) and cellular (r = 0.30) crescents, and fibrinoid necrosis (r = 0.46). None of the clinical and histological features predicted the occurrence of relapse or death. By applying a stepwise linear multiple regression analysis, we designed a formula for the estimation of renal function at 18 months: GFR18 (mL/min) = 17 + 0.71 \uc3\u97 GFR0 (mL/min) + 0.34 \uc3\u97 fibrinoid necrosis (%) + 0.33 \uc3\u97 segmental crescents (%), (r2 = 0.60; standard deviation = 19 mL/min). Our results were independent of diagnosis, ANCA-specificity, and treatment limb. Conclusions. These data suggest that in ANCA-associated glomerulonephritis, GFR0 and predominantly chronic renal lesions are potent predictors of GFR18. Active lesions are associated with renal function recovery and may be reversible. The formula for the estimation of GFR18 shows that a combination of GFR0 and renal histology is a better predictor for GFR18 than GFR0 only
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