Search PubMed⌕ Search

Biomedical subjects

A Hahn

Publications and source records attributed to A Hahn.

At least 127 records · Page 7Linked to original sources
PubMed1983

Analysis of human class I antigens by two-dimensional gel electrophoresis. I. Polymorphism, evidence for additional (non-HLA-A, B, C) gene products, and identification of variant HLA-A, B antigens.

Class I antigens were isolated by immunoprecipitation from cell extracts prepared from mitogenically stimulated and internally radiolabeled peripheral blood lymphocytes (PLBs). The precipitating antibodies used are monomorphic and recognize a determinant on the heavy chain of HLA-A, B, C antigens regardless of their allelic specificities when complexed with beta 2m, or determinants on beta 2m itself. Comparison of class I molecules isolated from 25 different homozygous typing cells (HTC) and analyzed by two-dimensional (2-D) gel electrophoresis allowed the identification of those HLA-A, B locus specificities most common in the European Caucasoid population. Class I antigens isolated from HTC that are HLA identical are biochemically indistinguishable also. Evidence was obtained for the expression of additional class I antigens besides the HLA-A, B, C locus products: for some haplotypes, up to six class I genes may be active in mitogenically activated PBLs.No differences in molecular weight and isoelectric point of the class I heavy chains were observed between the antigens recognized by W6/32, the anti-heavy chain reagent, and anti beta 2m reagents. The nature of the mitogenic stimulus, i.e., pokeweed mitogen or phytohemagglutinin, was irrelevant with respect to the class I antigens isolated by this method. Using the HTCs as reference, a panel of HLA-B27 positive heterozygous cells was analyzed. Two types of HLA-B27 antigens, distinct by CML typing were represented. These two forms differed also in their biochemical properties. In addition, we obtained evidence for the existence of an A2 variant. This finding was likewise confirmed by CML typing.

Electrophoresis, Agar Gel↗
PubMed1982

Phenotypic modulation of the canine prostate after long-term treatment with androgens and estrogens.

Fine structural alterations of the canine prostate induced by long-term treatment of castrated adult animals with estrogens and/or androgens and also in combination with antiandrogens and/or antiestrogens for six months have been studied with particular respect to their topographic location within the gland. Three major patterns of structural responses of the epithelium have been distinguished: squamous metaplasia, atrophy, and hypertrophy, while in stroma, regression, hypertrophy, or sclerosis were observed. In addition to cellular alterations of stromal fibrocytes and smooth muscle cells, characteristic changes in the arrangement, distribution, and pattern of the different stromal elements occurred. General squamous metaplasia of the epithelium and regressive alterations of stromal cells were most obvious in animals treated with estradiol plus androstanediol. Atrophy of the epithelium and stromal sclerosis were the salient features of antiandrogen-treated castrated animals, while hypertrophy or hyperplasia of both the epithelium and stroma was a major finding in androstanediol-substituted castrated animals. Combined treatment caused rather heterogeneous structural patterns seemingly dependent on the location within the gland. The results indicate that the prostatic epithelial cells dispose of a broad variety of structural reaction patterns that, in case of combined hormonal treatment, are expressed in a manner typical for their locations within the ductal system of the gland. However, with the exception of combined treatment with estradiol, tamoxifen, and androstanediol of castrated dogs, none of the experimental protocols used induced a morphologic response of the gland comparable to that seen in human benign prostatic hyperplasia. The canine prostate therefore is of rather limited value as a model for human BPH.

Androgens↗
PubMed1981

A new double-layered launderable bed sheet for patients with urinary incontinence.

In a skilled nursing facility, 36 patients (chiefly elderly) with persistent urinary incontinence were the subjects of this study. In their management, the usual disposable pads were compared with a new launderable bed sheet (Kylie) which absorbs urine in the second layer while maintaining a dry surface next to the patient's skin. There was a 42 percent reduction in the frequency of bedding changes with the new bed sheets. The patients experienced increased comfort due to decreased skin wetness and decreased creasing of the sheets. The reduced frequency of bed linen changes permitted longer undisturbed periods for the patient. Management costs were reduced by 40 percent with the launderable bed sheets. There were no adverse effects on the condition of the patients or in the quality of care.

Adult↗
PubMed1981

Interfacial tension of some biological fluids: a comparative study.

In describing physiochemical properties of interfacial interactions, the interfacial tension is a major parameter. In the case of biological or body fluids, the presence of surface active substances influence the value of the surface tension. Thus, several proposals have been made for methods to investigate the changes in surface tension. Alterations of surface tension (compared to those of the normal values, e.g. of amniotic fluid) may indicate a pathophysiological status. This report presents data of systematically measured surface tensions of a few physiological fluids. Problems of methodology and data interpretation are discussed together with suggestions for new approaches, and comparisons are made with previously reported measurements.

Body Fluids↗
PubMed1981

Thyroid hormone changes in obese subjects during fasting and a very-low-calorie diet.

Total fasting was compared with VLCD (1.28 MJ, 300 kcal/day; 56 g protein, 12 g CHO) in 14 euthyroid obese patients, selected as matched pairs, over a period of 28 days. The weight loss was significantly greater during fasting than during the VLCD (16.5 kg vs. 12.7 kg). The basal metabolic rate of (BMR) showed a significant decrease (25 per cent) during total fasting, but was unchanged with the VLCD. With both diets there was a transient increase in T4, FT4 and FT4I, and a tendency for TSH to decrease. There was a decrease in T3 and a transient increase in rT3. Nitrogen balance was attained in five of seven patients on the VLCD after four weeks.

Adult↗
PubMed1979

Familial fatal Parkinsonism with alveolar hypoventilation and mental depression.

The clinical, pathological, and neurochemical characteristics of a newly recognized inherited neurological disorder are reported. Lethargy and mental depression are early symptoms, followed by mild parkinsonism and progressive weight loss. Failure of automatic respiratory control develops and may result in sudden death. Advanced degeneration of the substantia nigra, cell loss and gliosis of the basal ganglia, and focal gliosis in the medulla are seen on pathological study. Degeneration of the nigrostriatal dopaminergic system is evidenced by low levels of tyrosine hydroxylase, dopamine, homovanillic acid, and L-dopa decarboxylase in postmortem brain samples. Taurine concentrations in fasting plasma and CSF are somewhat depressed; brain contents of taurine are within normal limits.

Brain↗
PubMed1979

Nerve and muscle biopsy: electrophysiology and morphology in polyneuropathy.

We correlated the results of biopsy of a muscle nerve, a sensory nerve, and tibialis anterior muscle with electrophysiologic studies in 13 patients with sensorimotor polyneuropathy and 6 patients with normal findings. There were significant correlations between teased fiber changes and conduction abnormalities in both muscle nerves and sensory nerves. The density of large myelinated fibers in the lateral fascicle of the deep peroneal (LFDP) nerve correlated significantly with both the motor unit estimate and compound action potential amplitude of the extensor digitorum brevis (EDB) muscle. Other characteristics of the EDB muscle compound action potential related poorly to teased fiber abnormalities. There was good correlation of needle electrode study of the EDB muscle with teased fiber analysis of the LFDP nerve and with the morphology of the tibialis anterior muscle in 75 percent of the cases, and only minor discrepancies in the remainder. These results emphasize the close relationship between certain structural and electrophysiologic changes in subacute and chronic polyneuropathy.

Adult↗