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Biomedical subjects

A Klein

Publications and source records attributed to A Klein.

At least 325 records · Page 18Linked to original sources
PubMed1988

[Surgery of the juvenile adrenal glands. Surgical protocol, intra- and perioperative monitoring].

Surgical and non-surgical conditions of the adrenal cortex and medulla are presented. Besides general principles of operative treatment (e.g. surgical approach, safe operative technique, bilateral exploration) specific aspects associated with this procedure in childhood are discussed. The perioperative management and pharmacotherapeutical preparation (e.g. hormonal substitution) are emphasized.

Adrenal Gland Diseases↗
PubMed1988

Corynebacterium xerosis septic arthritis.

A 62-year-old man developed acute septic arthritis due to Corynebacterium xerosis. The patient was treated with ampicillin and rapidly recovered. To the authors' knowledge this is the only reported case of septic arthritis due to C. xerosis. Clinical features of this case and the five previously reported cases of diphtheroid arthritis are discussed.

Acute Disease↗
PubMed1988

Direct monitoring of microvascular anastomoses with the 20-MHz ultrasonic Doppler probe: an experimental and clinical study.

The 20-MHz ultrasonic Doppler probe was used to determine its efficacy as a continuous monitoring technique for microvascular anastomoses. A 1-mm2 piezoelectric crystal embedded in a soft silicone sleeve was sutured directly to the blood vessel distal to the anastomosis. Using the dog femoral artery, simultaneous measurement of velocity and blood flow with an electromagnetic flowmeter established a direct correlation between flow and velocity with a 14 percent error at maximum flow and an 18 percent error at minimum flow conditions. The probe was then implanted in the rabbit femoral artery for 1 week (n = 3) and 4 weeks (N = 6), demonstrating that a continuous tracing could be obtained without injury to the vessel. Our clinical study included 63 patients undergoing free-tissue transfers monitored with the implantable probe for 7 to 29 days (average 10.5 days). Twenty-three flaps were buried. Two patients experienced loss of arterial tracing due to malfunction of the probe (3 percent). Three patients had a venous thrombosis with a present arterial tracing. There were no flap failures per se. All probes were removed without mishap, and there were no complications related to the probe. We conclude that the 20-MHz ultrasonic Doppler probe holds promise as a useful monitoring method.

Anastomosis, Surgical↗
PubMed1988

Analysis of drug resistance in the archaebacterium Methanococcus voltae with respect to potential use in genetic engineering.

The sensitivity of the methanogenic archaebacterium Methanococcus voltae to 12 inhibitors was tested in liquid medium. Four compounds appeared to be inhibitors of growth. Their MICs were as follows: pseudomonic acid, 0.1 micrograms/ml (0.19 microM); puromycin, 2 micrograms/ml (3.6 microM); methionine sulfoximine, 30 micrograms/ml (170 microM); and fusidic acid, 100 micrograms/ml (170 microM). On solid medium, the MICs were similar and the frequency of spontaneous resistance was found to be 5 X 10(-5) (methionine sulfoximine), 10(-7) (pseudomonic acid), and less than 10(-7) (puromycin and fusidic acid). Pseudomonic acid was found to inhibit isoleucyl-tRNA synthetase activity as measured by the in vitro aminoacylation of M. voltae tRNA with L-[U-14C]isoleucine. Fusidic acid and puromycin were shown to inhibit poly(U)-dependent polyphenylalanine synthesis in S30 extracts. Acetylpuromycin was inhibitory at much higher concentrations both in vivo and in vitro for M. voltae. Thus, the pac gene of Streptomyces alboniger, which is responsible for acetylation of puromycin and which conferred resistance to puromycin when introduced in eubacteria and eucaryotes, is a potential selective marker in gene transfer experiments with M. voltae. The latter was recently shown to be transformable. The same would be true for the cat gene of Tn9, which encodes resistance to fusidic acid in eubacteria in addition to resistance to chloramphenicol.

Anti-Bacterial Agents↗
PubMed1988

Cloning and characterization of the methyl coenzyme M reductase genes from Methanobacterium thermoautotrophicum.

The genes coding for methyl coenzyme M reductase were cloned from a genomic library of Methanobacterium thermoautotrophicum Marburg into Escherichia coli by using plasmid expression vectors. When introduced into E. coli, the reductase genes were expressed, yielding polypeptides identical in size to the three known subunits of the isolated enzyme, alpha, beta, and gamma. The polypeptides also reacted with the antibodies raised against the respective enzyme subunits. In M. thermoautotrophicum, the subunits are encoded by a gene cluster whose transcript boundaries were mapped. Sequence analysis revealed two more open reading frames of unknown function located between two of the methyl coenzyme M reductase genes.

Base Sequence↗
PubMed1988

Cloning and physical mapping of RNA polymerase genes from Methanobacterium thermoautotrophicum and comparison of homologies and gene orders with those of RNA polymerase genes from other methanogenic archaebacteria.

The structural genes encoding the four largest subunits of RNA polymerase, A, B', B", and C, were physically mapped in Methanobacterium thermoautotrophicum Winter. The genes formed a cluster in the order B", B', A, C and had a common orientation. DNA hybridization experiments yielded different degrees of homology between RNA polymerase gene sequences of different species of Methanobacterium and Methanococcus voltae. No homology was detectable between Methanobacterium thermoautotrophicum and Methanosarcina barkeri. From Southern hybridization experiments in which probes of the four genes from Methanobacterium thermoautotrophicum Winter and restriction digests of the genomic DNAs of the different methanogens were used, a common gene order of the RNA polymerase genes could be deduced.

Archaea↗
PubMed1988

Effect of ethanol extract of cancer patients' serum on the vulnerability of lymphocytes to cortisol.

We have shown previously that cortisol-sensitive lymphocytes (thymocytes) have a much lower capacity than cortisol-resistant cells to catabolize cortisol. We have also shown that sera of cancer patients (CPS) possess ethanol-extractable substance(s) which can inhibit the catabolism of cortisol by lymphocytes (CCL). Recently, we noted that unsaturated fatty acids can both inhibit CCL and modulate the sensitivity of lymphocytes to cortisol. In the present study, we attempt to identify the compounds responsible for CCL inhibition and to demonstrate that inhibition of CCL may make cortisol-resistant lymphocytes vulnerable to the steroid. The enzymes DNase, RNase, pronase and lipase were added to ethanol extracts of serum as a first step in our efforts to identify the nature of the inhibitors of CCL. Only lipase had an effect on the inhibition. In fact, lipase enhanced the inhibition of CCL. This finding correlates with our previous observations that unsaturated fatty acids are potent inhibitors of CCL. Examining the effect of ethanol extracts of CPS and normal serum on the vulnerability of lymphocytes to cortisol, we noted that ethanol extracts of normal serum had no significant killing effect, whereas an ethanol extract of CPS makes lymphocytes more sensitive to cortisol. Since the adsorbance of free fatty acids of CPS by defatted albumin reduced but did not eliminate the capacity of the serum to inhibit CCL, we assume that other compounds besides free fatty acids might also be involved in CCL inhibition and modulation of the sensitivity of lymphocytes to cortisol.

Deoxyribonucleases↗
PubMed1988

[Results of long-term treatment with depot neuroleptics in schizophrenic patients].

An examination was instituted to determine the effectiveness of maintenance therapy involving depot neuroplegics in out-patient after-care during an average follow-up of six years. At the time of examination, 172 patients treated with Depot-Lyogen showed statistically significant lower relapse and rehospitalisation rates, a reduction of the productive schizophrenic symptoms, and improved chance of rehabilitation, compared with 55 patients without treatment. In 22% of the 270 patients on Depot-Lyogen, there were early extrapyramidal side-effects, in 4.7% late dyskinesis, and in 4.3% depressive symptoms relating to medication. 35% of the patients did not receive consistent maintenance therapy. The improvement of after-care is discussed.

Dose-Response Relationship, Drug↗
PubMed1988

The biological activity and immunotherapeutic properties of AS-101, a synthetic organotellurium compound.

AS-101 (ammonium trichloro[dioxoethylene-O,O'-]tellurate) is a newly developed synthetic compound with immunomodulating properties and minimal toxicity. We evaluated the effects of AS-101 on various parameters of the activation and function of immunocompetent cells. AS-101 induced IL-2 receptor expression, IL-2 production and proliferation by human and mouse lymphocytes in vitro and enhanced the production colony-stimulating factor (CSF) by mouse spleen cells. In vivo treatment of Balb/c mice with AS-101 caused a significantly increased production of IL-2 and CSF in vitro in the presence of mitogen. When administered systemically to mice, AS-101 mediated antitumor effects in vivo. These results suggest that AS-101 is an active biological response modifier, which might have potential use in the treatment of conditions such as malignancy, AIDS and some types of immune deficiency.

Adjuvants, Immunologic↗
PubMed1987

Purification and characterization of an 8-hydroxy-5-deazaflavin-reducing hydrogenase from the archaebacterium Methanococcus voltae.

A methylviologen and 8-hydroxy-5-deazaflavin(F420)-reducing hydrogenase was purified over 800-fold to near homogeneity from the archaebacterium Methanococcus voltae with 10 U mg-1 F420-reducing activity. It is the only hydrogenase in this organism. The enzyme showed Km values of 16 microM for F420 and 1.2 mM for methylviologen. A turnover number of 1050 min-1 was calculated for the minimal active unit. The protein tends to aggregate. The molecular mass of the minimal active unit is 105 kDa. Larger molecules of 745 kDa were regularly observed. The enzyme was resolved into subunits with molecular masses of 55 kDa, 45 kDa, 37 kDa and 27 kDa by SDS/polyacrylamide gel electrophoresis. Reversible conversion of an anionic into an uncharged form was observed by DEAE-cellulose chromatography with concomitant changes in substrate specificities. The methylviologen-reducing activity was heat-resistant up to 65 degrees C and was not affected by antiserum raised against the native enzyme, while F420 reduction was inactivated by both treatments. Nickel and selenium contents were determined as 0.6-0.7 mol each, FAD content as 1 mol and iron as 4.5 mol/mol protein (105 kDa), respectively. Electron micrographs taken from the purified enzyme show ring-shaped molecules of 18 nm diameter, which represent the high-molecular-mass species of the enzyme.

Archaea↗
PubMed1987

Coagulation factor XIII: genetic linkage studies with F13B.

Linkage relations of the F13B gene with 38 marker genes are analyzed, which, along with the data of earlier reports on the same subject, brings the number of comparisons to a total of 49. Practically all the lod scores are totally negative. This will mean that the F13B gene can hardly be located on the chromosomes/chromosome arms 1p, 2p, 4q, 6p, 14p, 15p, 20q, 21p, 22 and also not on longer segments of 3q, 6q, 7q, 9p, 9q, 11q, 13q, 14q, 16p, and 16q.

Child↗
PubMed1987

The crowded carpal sign in volar perilunar dislocation.

Three cases of volar perilunar dislocation were seen at North Carolina Baptist Hospital over a 6-year period. An important finding on anteroposterior radiographs was the overriding of proximal and distal carpal rows giving rise to the "crowded carpal" appearance. Review of the literature demonstrates this configuration in all illustrations of volar perilunar dislocation. Although some authors have noted its presence, the diagnostic significance of this finding has not, to our knowledge, been emphasized.

Adult↗