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Biomedical subjects

M Anders

Publications and source records attributed to M Anders.

69 records · Page 4Linked to original sources
PubMed1983

The basis of the insensitivity of Salmonella typhimurium strain TA98/1,8-DNP6 to the mutagenic action of nitroarenes.

Salmonella typhimurium tester strain TA98/1,8-DNP6 is resistant to the mutagenicity of 1,8-dinitropyrene because it lacks an esterification enzyme which is needed for the formation of the ultimate mutagen, presumably the corresponding hydroxamic acid ester. This enzyme does not appear to be required for the activation of all nitroarenes and arylamines, as some of these are fully active in TA98/1,8-DNP. It is suggested that these form electrophilic arylnitrenium ions nonenzymatically from nitroso- and N-hydroxylamino-arenes intermediates. The esterification enzyme appears to be a transacetylase. An assay using 2-aminofluorene as the acetyl acceptor is described. Derivatives of S. typhimurium TA100 also lacking this enzyme were obtained by Tn5-mediated mutagenesis.

Biotransformation↗
PubMed1982

Phenotypic instability of Salmonella typhimurium tester strains: an example of a plasmid-enhanced genetic drift?

Strains derived from Salmonella typhimurium LT-2, which are used as tester strains in mutagenicity assays, show significant changes in biochemical phenotypes. The presence of plasmid pKM101 in these strains greatly increases both the frequency of these shifts as well as the spectrum of phenotypes involved. It is suggested that in plasmid-free strains these variations reflect the effects of endogeneously induced mutations which are amplified in the absence of a functional uvrB gene product. In plasmid-containing strains this genetic drift may be promoted further by the pKM101-coded error-prone DNA repair system. The observation of a plasmid-mediated genetic drift lends support to the suggestion that transposons may contribute to the carcinogenic process.

Escherichia coli↗
PubMed1980

A bactericidal activity of microsomal preparations.

Exposure of suspension of Salmonella typhimurium tester strains TA1535, TA1537 and TA98 to mouse hepatic post-mitochondrial supernatants (S9) resulted in appreciable loss of bacterial viability. This lethal activity was destroyed by heating at 56 degrees C for 30 min. The toxic component of the S9 has not been identified.

Animals↗
PubMed1980

Interocular comparison of contrast sensitivities in glaucoma patients and suspects.

Glaucoma affected the ability to detect low-contrast, flickering patterns ('DRC' measurement). DRC patterns were foveally viewed, of low spatial frequency, and flickering at 8 hertz. Interocular comparisons were performed in control subjects, in ocular hypertensives, and in glaucoma patients with asymmetric damage. Interocular differences in DRC tended to be of greater magnitude in the glaucoma patients than in the ocular hypertensive patients or control subjects. In the glaucoma patients DRC was consistently lower in the eye with the greater field defect than in the other (more normal) eye. In patients with optic disc asymmetry DRC was lower in the eye with the more abnormal disc. Treatment asymmetries did not appear to play a significant role in these relationships. When examined by interocular comparisons DRC showed no consistent relationship to Snellen visual acuity or to level of intraocular pressure at the time of DRC testing.

Form Perception↗
PubMed1980

Investigation of insulin sensitivity in early diabetes. II. Insulin resistance in asymptomatic diabetics.

Thirty-eight non-obese and seven obese subjects were classified by a 2-hour glucose infusion test as having a normal carbohydrate tolerance. Sixteen non-obese ad ten obese patients showed a pathological carbohydrate tolerance (asymptomatic diabetes). For the characterization of insulin sensitivity a 1-hour priming dose-constant infusion technique consisting of two 30-minute-periods was applied in all subjects. A decrease of glycemia during this insulin infusion of less than 22.5 per cent has been accepted as a criterion of insulin insensitivity. Sixty-three per cent of non-obese and seventy-eight per cent of obese asymptomatic diabetics exhibited a reduced responsiveness to insulin. There ws an inverse relationship between the per cent decrease of plasma glucose concentration and the insulin secretion pattern revealed by the glucose infusion test. The results suggest that insulin resistance is a characteristic feature of obese and non-obese asymptomatic diabetics.

Blood Glucose↗
PubMedDate not supplied

Portal vein erosion and acute abdominal hemorrhage as a complication of acute pancreatitis.

The case of a 35-year-old male with portal vein erosion and acute life-threatening abdominal hemorrhage as a complication of acute pancreatitis is reported. Erosion of arterial walls is the most common complication of pancreatitis and pancreatic pseudocysts, and erosion of the portal vein leading to a fistula between the pancreas and the portal vein is very rare. Diagnosis was made by multislice spiral computed tomography, and nonsurgical treatment was elected, leading to complete recoverage.

Acute Disease↗
PubMedDate not supplied

[Manifestation of neuro-Behçet disease in cyclosporin A therapy].

Behçet's disease is a chronic inflammatory disorder characterized by the triad of oral and genital ulcers and ocular lesions. One of the most life-threatening manifestations results from involvement of the central nervous system, presenting as necrotising meningo-encephalitis, most typically affecting the brain stem, internal capsula and basal brain ganglia. We report on a young Caucasian mate with Behçet's disease (HLA B 51+) and recurrent uveitis, who presented with acute neurologic involvement under CyA therapy 5 years after first diagnosis. At the time of admission MRI showed two high intensity lesions in the brain stem on T1 weighted images enhanced with Gd-DTPA, reflecting active inflammation. Shortly after admission the CyA treatment was stopped and a therapy with high dose steroids and chlorambucil, starting with a dose of 2 mg daily was initiated. This led to improvement of neurologic symptoms, also documented by brain stem evoked potentials and investigations of cerebrospinal fluid, as well as of ophtalmologic symptoms within few days of treatment. Steroids were reduced to a maintenance dose of 12 mg Prednyliden daily. The brain MRI taken 8 weeks after onset of chlorambucil treatment showed the same lesions in the brain stem, with low intensity in the T1 weighted images an no longer enhanced Gd-DTPA uptake. Chlorambucil dose was reduced to 2 mg every second day after 8 months. There was no exacerbation in the follow-up of 12 months. We conclude that a 6-week Chlorambucil therapy consisting of 2 mg/p.o./d led to remission of neurologic involvement firstly evolving under CyA-medication which suggests superiority of chlorambucil as a treatment modality in neurologic as well as ophtalmologic features of the disease.

Adult↗