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Biomedical subjects

H Vogel

Publications and source records attributed to H Vogel.

At least 19 recordsLinked to original sources
PubMed2024

Phylogenomic reconstruction of Cryptosporidium spp. captured directly from clinical samples reveals extensive genetic diversity.

Cryptosporidium is a leading cause of severe diarrhea and mortality in young children and infants in Africa and southern Asia. More than twenty Cryptosporidium species infect humans, of which C. parvum and C. hominis are the major agents causing moderate to severe diarrhea. Relatively few genetic markers are typically applied to genotype and/or diagnose Cryptosporidium. Most infections produce limited oocysts making it difficult to perform whole genome sequencing (WGS) directly from stool samples. Hence, there is an immediate need to apply WGS strategies to 1) develop high-resolution genetic markers to genotype these parasites more precisely, 2) to investigate endemic regions and detect the prevalence of different genotypes, and the role of mixed infections in generating genetic diversity, and 3) to investigate zoonotic transmission and evolution. To understand Cryptosporidium global population genetic structure, we applied Capture Enrichment Sequencing (CES-Seq) using 74,973 RNA-based 120 nucleotide baits that cover ~92% of the genome of C. parvum. CES-Seq is sensitive and successfully sequenced Cryptosporidium genomic DNA diluted up to 0.005% in human stool DNA. It also resolved mixed strain infections and captured new species of Cryptosporidium directly from clinical/field samples to promote genome-wide phylogenomic analyses and prospective GWAS studies.

Cryptosporidium↗
PubMed1992

Intracerebral (parenchymal) infusion of methotrexate: report of a case.

This report describes the neuropathological findings in a 32 year old woman with acute myelogenous leukemia (AML) and central nervous system (CNS) involvement, who received a total of 48 mg of methotrexate (MTX) intended to be delivered to the ventricle. At autopsy, the tip of the infusion catheter was found to have been inadvertently placed in the left basal ganglia. The delivery of the MTX at that site caused white matter lesions characteristic of those previously reported in MTX encephalopathy following diverse modes of administration. This case is unusual in that there was the direct infusion of MTX into cerebral parenchyma, circumventing both the blood:brain and cerebrospinal fluid:brain barriers. Axonal abnormalities were widespread in the MTX-infused tissue, frequently but not always accompanied by myelin loss. Since radiation therapy had not been employed, this case permitted the assessment of pathologic changes largely attributable to MTX.

Adult↗
PubMed1992

H-CAM expression in the human nervous system: evidence for a role in diverse glial interactions.

H-CAM (CD44/Hermes antigen) is an 85-95 kDa widely-distributed cell surface adhesion molecule that participates in diverse cellular interactions. It is an important cell surface receptor of hyaluronate, and has been implicated in the binding of circulating lymphocytes of endothelial cells in the process of lymphocyte homing. Here we define the immunohistological distribution of H-CAM in the human nervous system as a means of assessing its possible participation in nervous system ontogeny and function. H-CAM is widely expressed in human CNS white matter by subsets of glial cells, and within the neuropil of several grey matter structures. Neurons appear uniformly negative. H-CAM+ cells and processes are first detected at 20 weeks gestation in a diffuse subependymal pattern, and staining of the anchoring processes but not the cortical extensions of radial glia is seen by 24 weeks. Beginning at 26 weeks, H-CAM+ astrocytes also demarcate fascicles of axons in developing white matter tracts, becoming diffusely distributed in all CNS white matter by full term gestation. In the mature CNS, fibrous and subpial astrocytes, glial outlines within the glomeruli of the cerebellar granule cell layer, Bergmann glia, and extraneuronal grey matter matrix in certain locations are H-CAM+. In reactive gliosis occurring in foetal and developed brains, H-CAM is strongly and uniformly expressed by GFAP+ astroglial cells. In the PNS, dorsal roots express substantially higher levels of H-CAM than ventral roots, and there is an accompanying inverse staining pattern displayed by weakly immunoreactive posterior horns and positive anterior horns. Also, there is an abrupt cessation of H-CAM expression at the junction of the central and peripheral segments of cranial nerves. These findings indicate the dynamic regulation of H-CAM expression in the developing human nervous system, and suggest the hyaluronate-binding activity and potentially other cell-cell or cell-matrix adhesive functions of H-CAM may play an important role in development of the nervous system.

Aged↗
PubMed1991

Sensorimotor neuropathy in hemophagocytosis syndrome.

Hemophagocytosis syndromes are uncommon disorders marked by generalized proliferation of benign histiocytes and multiple organ failure. A 24-year-old woman presented with a fulminant illness consisting of fever, hepatic insufficiency and anemia, followed by respiratory compromise, cardiomyopathy, and uremia. She developed a sensorimotor polyneuropathy, with normal cerebrospinal fluid findings. Sural nerve biopsy demonstrated mild to moderate axonopathy, with regeneration and occasional segmental demyelination/remyelination. The recent and old hemorrhages present in the perineurium, and the marked infiltration by foamy histiocytes (macrophages) distributed mostly in the subperineural space, were presumably responsible for the Wallerian degeneration. Documentation of histiocytes in peripheral nerves in hemophagocytosis syndrome has not previously been shown.

Adult↗
PubMed1991

Multipolar mitosis in procaine-treated polyspermic sea urchin eggs and in eggs fertilized with UV-irradiated spermatozoa with a computer model to simulate the positioning of centrosomes.

Procaine-treated eggs can be penetrated by more than one spermatozoon. Supernumerary male pronuclei can fuse with the female one giving raise to multipolar spindles or remain isolated within the egg's cytoplasm forming their own spindle. In all types of multiple mitotic figures (asters and spindles) the distribution of asters is equidistant either uniplanar or at maximum distance like at the apices of a polyhedron. Astral rays are not different from spindle fibers: they can attach to and attract chromosomes of "foreign" mitotic figures. When several mitotic figures are present in one egg, the partner asters are always of the same size, and microtubules of one aster never interdigitate with those of others. The hypothesis that positioning of centrosomes is brought about by spreading of a centrosome organizer in the form of an expanding calotte on the surface of the nucleus (Mazia, D., Int. Rev. Cytol. 100, 49-92 (1987)) is supported by a computer model.

Animals↗
PubMed1990

Hypoplasia of posterior spinal roots and dorsal spinal tracts with arthrogryposis multiplex congenita.

We report a male infant with arthrogryposis multiplex congenita (AMC) who survived for 19 weeks following birth at 36 weeks gestational age. No heritable or acquired cause of neuromuscular disease was found. He manifested joint contractures of upper and lower extremities, diffuse hypotonia requiring ventilatory support, and areflexia; the general examination also showed facial dysmorphisms, and an ichthyotic rash. Pathological examination of the brain and spinal cord revealed severe hypoplasia of dorsal roots and posterior columns, nondecussation of pyramidal tracts, and anterior horns of an unusual configuration; the brain was normal, and the cerebellum contained Purkinje cell heterotopias. Muscle spindles could not be identified. To our knowledge, these spinal cord abnormalities in association with AMC have not been previously reported, thus raising interesting speculations about the possible role of such abnormalities in the pathogenesis of AMC.

Arthrogryposis↗
PubMed1990

Primitive pineal tumor with retinoblastomatous and retinal/ciliary epithelial differentiation: an immunohistochemical study.

A one year old boy was found to have a large tumor encompassing the pineal region and extending towards the third and lateral ventricles and quadrigeminal plate. The tumor was composed mostly of small, undifferentiated cells. Some small cells were arranged in Flexner-Wintersteiner rosettes and a few displayed fleurettes. The tumor contained immature cartilage and skeletal muscle and numerous clusters of pigmented epithelial-like cells which, histologically, resembled those found in melanotic neuroectodermal tumors of infancy (retinal anlage tumors) and retinal or ciliary epithelium. Immunologic stains demonstrated neurofilaments synaptophysin and retinal S-antigen in some of the small cells and transthyretin in some of the epithelial-like cells. The findings indicate that certain primary pineal parenchymal tumors have features in common with tumors of the ocular medullary epithelium.

Brain Neoplasms↗
PubMed1990

The brain in the 18q-syndrome.

The authors describe the cerebral neuropathological findings of a 25 1/2-year-old male with 18q-syndrome. An abnormal gyral pattern, atrophy of the olfactory and optic nerves and small neocerebellar hemispheres with hemispheral lobular sclerosis were noted. Microscopically there were pial glioneuronal heterotopias; misplacement of neurons in the molecular layer of the cortex, as well as in deep white matter; not readily identifiable Betz cells; gliosis of olfactory and optic tracts and elsewhere; and loss of Purkinje cells. Further detailed studies of other cases are needed to determine whether these abnormalities are characteristic of the 18q-syndrome.

Adult↗
PubMed1990

[Type A behavior--a uniform construct?].

Single dimensions of the Type-A-behaviour pattern and their contributions to the etiology and pathogenesis of cardiovascular and psychosomatic diseases are very often discussed. Our studies are concerned with the analysis of 40 blue collar workers and patients (40 patients with hyperuricemia, 36 psychotherapy patients) in definite groups of age. By item analysis and multivariate statistical procedures (variance, factor and discriminant analysis) we found an overlapping effect of psychosocial factors of work and on the other hand the influence of neurotic symptoms and behaviour patterns.

Adult↗
PubMed1990

[Patterns of psychosocial stress factors and health criteria].

Derived from the principles of capacity and of need's realization in the load-strain-coping-concept a 5-cluster result with parameters of subjective health and psychosocial factors is demonstrated. These patterns reflect the different connections between health and the person-environment interaction. A high subjective professional load is connected with a poor health state only in a low professional performance and/or deficits of need's realization.

Adaptation, Psychological↗
PubMed1990

[Experiences with computer-assisted occupational hygiene monitoring in ore mining].

An EDP-project has provided the conditions for a transfer from work-place-and shift-oriented occupational hygiene monitoring to individual long-term supervision. Individual exposure data are collected by coupling of the occupational technology with the corresponding exposure periods of the workers (from the wages-project). The results form an important basis for the continuous improving of working conditions as well as for occupational medical examination and research.

Computers↗
PubMed1989

A 35Cl(-)-NMR study of the singular anion-binding properties of dromedary hemoglobin.

35Cl(-)-NMR measurements of chloride binding to carbonmonoxy- and deoxy-dromedary hemoglobin reveal the existence of two classes of chloride-binding sites, one of high and the other of low affinity. Although this situation resembles that described for human hemoglobin, it was found that the number of binding sites as well as the association equilibrium constant for chloride binding are significantly higher in the dromedary protein. This difference may be due to the greater number of basic residues exposed to solvent and to the higher flexibility of dromedary hemoglobin. The two oxygen-linked polyanion-binding sites characteristic of this hemoglobin show competition for some of the high-affinity chloride-binding sites in keeping with their location in the cleft enclosed by the beta chains and between the alpha chains termini. It is suggested that the observed anion-binding properties of dromedary hemoglobin may contribute to the control of the physiological osmotic shock after rehydration.

Animals↗
PubMed1989

Steady-state intravenous pharmacokinetics of pirenzepine in patients with hepatic insufficiency and combined renal- and hepatic insufficiency.

The steady-state intravenous pharmacokinetics of pirenzepine has been investigated in patients with chronic liver disease and others with combined chronic liver disease and renal insufficiency. The plasma clearance (CL) of Pirenzepine, steady-state plasma concentration Cmin(ss) and dominant half life t1/2 gamma were not significantly altered in the chronic liver disease group. In patients with renal and hepatic insufficiency, CL was reduced, t1/2 gamma was prolonged from 11.1 to 19.4 h and Cmin(ss) was elevated from 36 ng/ml to 66 ng/ml compared to healthy controls. Plasma concentrations remained in the therapeutic range and the dosage regimen was well tolerated. Adjustment of the dose of pirenzepine need be considered only in cases of severe impairment of both renal and hepatic elimination.

Adult↗
PubMed1989

Steady-state intravenous pharmacokinetics of pirenzepine in patients with differing degrees of renal dysfunction.

The steady-state intravenous pharmacokinetics of pirenzepine has been investigated in 57 subjects whose renal function ranged from normal to chronic failure requiring regular haemodialysis. Pirenzepine renal clearance, total clearance and terminal (dominant) half-life were found to be correlated with the creatinine clearance (CLCR), but this was not the case for the volume of distribution and the nonrenal clearance. The therapeutic regimen was well tolerated by all subjects. Haemodialysis did not significantly contribute to the elimination of pirenzepine. Dosage adjustment need only be considered in patients with CLCR less than 25 ml/min in order to reduce the frequency of minor side-effects.

Adolescent↗