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Biomedical subjects

A Wolff

Publications and source records attributed to A Wolff.

At least 91 records · Page 5Linked to original sources

Evaluation of the origin of Mycobacterium leprae infections in the wild armadillo, Dasypus novemcinctus.

An enzyme-linked immunosorbent assay (ELISA) using the phenolic glycolipid-1 (PGL-1) antigen of Mycobacterium leprae and cross-reactive antisera specific for human IgM was developed to detect IgM antibodies to M. leprae in the nine-banded armadillo (Dasypus novemcinctus). Statistical definitions for positive and negative interpretations in the ELISA were developed by screening animals recently captured and experimentally inoculated with M. leprae. The ELISA was shown to have high sensitivity and specificity. Modern day armadillos of central Louisiana were observed to have a PGL-1 antibody prevalence rate as high as 20%, and a clinical disease rate as high as 5%. A retrospective serological survey of 182 armadillos taken in the years 1960-1964 and predating the use of armadillos in leprosy research was used to evaluate the 1968 environmental contamination hypothesis for the origin of M. leprae infections in the wild armadillo. Antibodies to the apparently species-specific PGL-1 antigen were detected in 17 of the samples taken in 1960-1964. Absorption with whole M. leprae, M. intracellulare, M. terrae, M. rhodesiae, M. scrofulaceum, M. diernhoferi, M. kansasii, M. phlei, M. avium, BCG, and 2 new armadillo-derived mycobacterial species showed these antibody reactions to be specific for PGL-1. Apparently, M. leprae was enzootic in armadillos as early as 1961, and original infection of these animals could not have occurred in 1968.

Animals↗

Thymoma epithelial cells secrete thymic hormone but do not express class II antigens of the major histocompatibility complex.

17 thymomas were studied by indirect immunofluorescence for the presence of thymic hormones and antigens of the major histocompatibility complex (MHC). The thymoma epithelial cells (specifically identified by their keratin content) contained thymic hormones (thymulin and thymosin alpha 1), a finding corroborated by the observation of elevated thymulin serum levels. In contrast with normal or hyperplastic thymuses, thymoma epithelial cells did not express HLA-DR and HLA-DC antigens as assessed by immunofluorescence as well as immunoblot analyses. Conversely, MHC class I antigens (HLA-ABC) were normally expressed. Thus, we conclude that thymoma epithelial cells are endocrinologically active but are defective for the expression of some MHC products (class II molecules) known to play an essential role in intrathymic T cell differentiation.

Adult↗

Neuropathy associated with transient diabetes mellitus in 2 cats.

A 9-year-old spayed cat that flinched when touched responded poorly to methylprednisolone and phenobarbital. Hyperalbuminemia, hyperproteinemia, hyponatremia, hypochloremia, hyperglycemia and glycosuria resolved with insulin treatment. The flinching disappeared in 2 weeks and insulin use was unnecessary after 6 weeks. A 6-year-old castrated cat with diabetic ketoacidosis and azotemia responded to fluid and insulin therapy but developed a head tilt and insulin shock 2 weeks later. The cat recovered after 6 days of supportive treatment and no longer required insulin after 4 weeks.

Animals↗

[Microheterogeneity of tubulin in the central nervous system of the quail (Coturnix coturnix japonica)].

Tubulin from the central nervous system of the Quail (Coturnix coturnix japonica) was analysed by two-dimensional gel electrophoresis. Either in soluble extracts or in tubulin enriched fractions, tubulin of forebrain, cerebellum and spinal cord is resolved into 3 components alpha, beta' and beta, characterized by their electrophoretic coordinates (alpha: pI = 5.4, MW = 54 kd, beta: pI = 5.2, MW = 52 kd; beta': pI = de mapping, by comparison with mouse brain alpha, beta and beta'-tubulin components. With highly resolutional isoelectric focusing 6 alpha isotubulins and 14 beta isotubulins are found in enriched-tubulin fractions of Quail forebrain and cerebellum.

Animals↗

Characterization of tubulin in mouse brain myelin.

Analysis of mouse brain myelin by sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that in the high-molecular-weight range it contained, besides the Wolfgram protein doublet, proteins comigrating with actin and with both subunits of tubulin. The occurrence of these alpha and beta subunits was confirmed by peptide mapping in myelin analyzed by two-dimensional electrophoresis. This tubulin did not arise from an artifactual binding of soluble brain tubulin to the myelin fraction: addition of exogenously labeled tubulin to brain homogenates proved that during myelin isolation by the procedure of Norton and Poduslo (1973) the contaminating tubulin was washed out. On the other hand, the distribution of tubulin isoforms in myelin was investigated by isoelectric focusing and compared with the distribution of the 21 isoforms listed for the whole brain soluble tubulin. It was shown that many isoforms were found in myelin (three isoforms for the alpha subunit and nine for the beta subunit), and that some isoforms were represented both in myelin and in soluble tubulin, but in different relative proportions.

Animals↗

High level of tubulin microheterogeneity in the mouse brain.

Using a high resolution isoelectric focusing method, we have demonstrated a high level of tubulin heterogeneity in mouse brain: 21 isotubulins were identified. Determination of the apparent molecular weight and analysis of the peptide map of each isotubulin species allowed us to identify 7 alpha and 14 beta tubulin subunits. Furthermore, variations in this tubulin population during brain development were confirmed; in particular, an increase in the number of beta isotubulins was observed at the beginning of the postnatal period.

Animals↗

Serratia marcescens in tracheotomy cultures.

Twenty-three consecutive tracheotomies were cultured after an apparent outbreak of Serratia marcescens was noted. Over a period of one year, six cases with positive cultures were found. The importance of these positive cultures in relation to the patient's clinical course is discussed. The treatment of Serratia marcescens septicemia is reviewed.

Adult↗