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Biomedical subjects

J Frank

Publications and source records attributed to J Frank.

At least 397 records · Page 22Linked to original sources
PubMed1980

[Thyroid gland surgery, results and experiences in a small number of patients].

Results of surgical treatment of thyroid diseases are reported in a limited number of cases. Preoperative diagnostics as well as our own indication for surgical interventions are described. The course of preoperative therapy and the operative technique are described. Postoperative therapy with special reference to problems of recidivity is discussed. Histological classifications are analyzed with special reference to adenomas and carcinomas. Postoperative complications are discussed. Questionnaires are evaluated in view of compliance with recidivity prophylaxis, absence of complaints, changes of the voice following operation and patient's judgement of the operation scar.

Adenoma↗
PubMed1980

Averages of glutamine synthetase molecules as obtained with various skin and electron dose conditions.

Averaged projections of individual glutamine synthetase molecules have been obtained by using electron microscopy and image processing. The methodology of correlation averaging under low dose conditions is described in detail. Because of their low signal-to-noise ratio, images made under low dose conditions cannot be directly interpreted in terms of high resolution features. Computer averaging of these images reveals a division of the subunit projection into two domains whose sizes agree with results of Lei et al [2] limited proteolysis experiments.

Chemical Phenomena↗
PubMed1980

Structural details of membrane-bound acetylcholine receptor from Tropedo marmorata.

A projection, at 15- to 20-A resolution, is presented of the structure of the membrane-bound acetylcholine receptor protein from Torpedo marmorata. The projection has its axis perpendicular to the membrane plane; its main contribution originates from a hydrated portion of the protein, which extends from the membrane into the aqueous medium. The structure is distinctly asymmetric, with individual morphological subunits barely resolvable. These results have been obtained by noncrystallographic averaging, using correlation functions, applied to electron micrographs of receptor-rich membrane fragments. The micrographs had been taken with minimal beam exposure in a scanning transmission electron microscope.

Animals↗
PubMed1980

Structure and activity of the prosthetic group of methanol dehydrogenase.

The reconstructive ability of the isolated prosthetic group of methanol dehydrogenase with the apoenzyme of glucose dehydrogenase and the results of electron spin resonance measurements suggest that the prosthetic group has not been modified during the isolation. This result, and the properties of the directly isolated prosthetic group and derivatives, confirm the suggestion that its structure is 2,7,9-tricarboxy-1H-pyrrolo[2,3-f]quinoline-4,5-dione. From the activity shown by derivatives of the prosthetic group and of structural analogues in the apoenzyme test it is concluded that the o-quinone structure is essential for activity. Hence the trivial name pyrrolo-quinoline quinone would be appropriate. The testing of the analogues also shows that the pyrrolo ring and the 9-carboxylic acid group are not essential for activity as they can be replaced by a pyridinol ring and a 9-hydroxy group respectively. The determination of the molar absorption coefficient of the prosthetic group (18 400 M-1 cm-1 at 249 nm) enables its quantitative anaysis. Thus it could be established that methanol dehydrogenase contains one prosthetic group per enzyme molecule. The consequences of this result in relation to already known properties of this 'quinoprotein' dehydrogenase are discussed.

Alcohol Oxidoreductases↗
PubMed1978

[Experimental coronary ligation in swine: reduction of myocardial infarct and hemodynamic and metabolic changes by means of the calcium antagonist RO 11-1781].

In a comparative study the effect of the new calcium antagonist Ro 11-1781 on experimental infarct size and left ventricular function in the pig has been investigated. The calcium antagonist was administered 30 min prior to ligation of the left anterior descending coronary artery and twice daily on the following 4 days. For morphometric assessment of infarct size the ventricular myocardium was cut into slices and stained with nitro-benztoluene. There was a significant reduction in infarct size of about 25% in the calcium antagonist-treated group in comparison with the control group. After coronary occlusion left ventricular function is equally depressed in both groups, as is myocardial lactate extraction, which becomes negative.

Animals↗
PubMed1978

[Ventricular arrhythmias in the acute stage of experimental swine myocardial infarct; effect of the beta blocker pindolol and the calcium antagonist Ro 11-1781].

A study was designed to examine ventricular arrhythmias in the acute phase of experimental myocardial infarction in the pig and to evaluate possible antiarrhythmogenic influence of the beta-adrenergic blocking drug pindolol (Visken) and the calcium antagonist Ro 11-1781. Ventricular fibrillation (VF) occurred in 17 of 18 animals, in 4 almost immediately after coronary occlusion and in 12 with a delay of about 17 min. VF was almost always induced by episodes of ventricular tachycardia (VT) which were started by single ventricular premature beats (VPBs). VPBs occurred in 3 phases, whereas VT and VF coincided only with phase 1 and phase 3. The prematurity index QR/QT of single VPBs decreased significantly with time after coronary occlusion. The beta-adrenergic blocking drug pindolol and the calcium antagonist Ro 11-1781 did not prevent VT or VF.

Acute Disease↗
PubMed1978

Purification and properties of methanol dehydrogenase from Hyphomicrobium x.

(1) A method for the isolation of methanol dehydrogenase (alcohol:(acceptor) oxidoreductase, EC 1.1.99.8) from Hyphomicrobium X is decribed. The purified enzyme was resolved by polyacrylamide gel electrophoresis into one main and two minor active bands. Iron and manganese were the only detected metals in the enzyme preparation. (2) The substrate, methanol, was oxidized to formic acid by a stoichiometric amount of artificial electron acceptor. During the reaction, no free formaldehyde could be detected. Other primary alcohols were oxidized to the corresponding aldehydes were a poor substrate or no substrate at all. (3) Some new and efficient one-electron acceptors were found. With these electron acceptors, the enzyme had a high pH optimum and ammonia was still required in the assay system. (4) ESR spectroscopy showed the presence of an enzyme-bound organic free radical. With X-band ESR the signal had a peak-to-peak linewidth of about 0.7 mT. The signal was further resolved by Q-band ESR and the values gparallel = 2.0024 and gperpendicular = 2.0056 were derived. (5) Under denaturing conditions the ESR signal and enzymatic activity disappeared at the same time as fluorescence appeared. Enzymatic activity is not restored when extracted cofactor and apoenzyme are brought together under normal conditions. Some properties of the unusual prosthetic group are presented in a preliminary form.

Alcohol Oxidoreductases↗
PubMed1978

A phase II study of phenesterin (NSC-104469).

Phenesterin was evaluated in 222 patients with two different dosage regimens, one by daily treatment and the other with an intermittent schedule. Toxicity was moderate with both programs. The largest group of patients treated had breast cancer; they experienced a 10% response rate. Of interest was a higher percentage of responses in ovarian cancer (36%). An expanded study of patients with ovarian cancer would be of interest.

Adult↗
PubMed1978

Reconstruction of glutamine synthetase using computer averaging.

The axial projection of the glutamine synthetase molecule has been reconstructed from electron micrographs of a stained preparation by using a new method of correlation search and averaging. The average over 50 individual molecules appears as a radial pattern with sixfold symmetry. The handedness evident in the average is attributed to nonuniformity of the negative stain.

Bacillus↗
PubMed1978

Ioglycamide (Biligram) studies in man--relation between plasma concentration and billary excretion.

Plasma ioglycamide concentration was linearly related to the rate of intravenous infusion over a dose range of from 1 to 4 mg per kg per min. The relation between plasma and biliary concentration of ioglycamide was studied in 15 anicteric patients with a T-tube in situ. Peak biliary concentrations and excretory rates of ioglycamide were seen when the plasma concentration was greater than 1500 micrograms per ml. The mean biliary transport maximum (Tm) for ioglycamide in man was 31.6 mg/min (range 22.0-40.4). The results suggest that near optimal concentrations of iodine in the bile duct can be obtained during intravenous cholangiography if ioglycamide is infused for one hour at a rate of about 4 mg per kg per min.

Bile↗
PubMed1978

Ioglycamide (Biligram) studies in man. Radiological opacification of the bile duct. A comparison of a number of different methods.

Intravenous cholangiography was carried out in 80 anicteric patients using ioglycamide (Biligram). Twenty patients were given a 30 ml ampoule of 35% ioglycamide as a slow hand injection over ten minutes; the remainder were given ioglycamide by one hour slow drip infusion at a rate of 2, 3, or 4 mg per kg body weight per minute. The radiological opacification of the bile duct was then assessed independently by two radiologists. There was a statistically significant difference between the bile duct opacification found in patients given either 3 or 4 mg/kg/min of ioglycamide for one hour compared with those given ioglycamide either by ten minute injection or by 2 mg/kg/min drip infusion.

Adult↗