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G Schönfeld

Publications and source records attributed to G Schönfeld.

9 recordsLinked to original sources
PubMed1996

Membrane protein subunit fractionation by means of inverse pore gradient elution polyacrylamide gel electrophoresis.

We report here the preparative scale isolation of the four subunits of the nicotinic acetylcholine receptor (nAChR) applying short inverse pore gradient SDS gels on an elution-PAGE apparatus. The nAChR subunits are of similar molecular weights (alpha, 50.2 kDa; beta, 53.7 kDa; gamma, 56.3 kDa; delta, 57.6 kDa) and isoelectric point (approx 5.5) and share the typical properties of amphiphatic membrane proteins that are difficult to separate by chromatographic procedures. Preparative PAGE, which has proved to be the method of choice for nAChR-subunit fractionation, however, is time-consuming and achieves only moderate resolutions yielding dilute fractions. We present here the fractionation of a membrane preparation of Torpedo electric organ (2 mg of total protein) on short gels (2 cm) with linear or concave inverse pore gradients. All of the four subunits are isolated in homogeneous fractions of approx 70 micrograms/ml within only 4 h. Compared to the standard method, this means a 50% reduction in separation times with threefold higher concentrated protein fractions. We also give the theoretical explanation and experimental validation of the improved features resulting from short inverse-gradient polyacrylamide gels.

Animals↗
PubMed1990

[Significance of echocardiography for the diagnosis and strategy in infectious endocarditis].

The echocardiographic results of 29 patients--clinically suspected of infective endocarditis--were compared with clinical, intraoperative, histologic, autoptic data and the available outcome of cardiac catheterization. The purpose of this retrospective study was to define the potential valence of echocardiography for planning of therapy and success. Valvular vegetations of different histological ages were established on 35 valves. The sensitivity was 96.3%, the specificity 100% considering this topic. Following visual assessed sonographical intensity of such vegetations echographical floridity was postulated. In 26 vegetations the sensitivity--considering this floridity statement--was 92% and the specificity 86% compared with the results of histology and intraoperative assessment. The type of pathogens and the time interval between beginning of the clinical symptomatic and the echocardiographic procedure were important for the prognosis in this study. In the case of longer latency time prevailed bivalvular vegetations (n = 6) combined with a high mortality. No patient died in the case of univalvular vegetations. The whole group had a mortality of 17.2%. Considering these results using echocardiographic methods an exact identification of vegetations (infective and noninfective) and additional a quantification of subsequent valvular damaging and actual ventricular function is possible. A qualified sonographical technique permits an earlier diagnosis of bacterial endocarditis (especially in the absence of bacteriaemia) and in the followings a more opportune indication for prosthetic valve replacement.

Adult↗
PubMedDate not supplied

Efficacy and tolerability of olsalazine (dipentum) in the treatment of patients with ulcerative colitis--results of a field study.

BACKGROUND/AIMS: In the treatment of ulcerative colitis, 5-aminosalicylic acid is the standard therapy for both acute exacerbations of the disease and the maintenance of remission. Clinical studies have shown that olsalazine (Dipentum)--a prodrug converted to two molecules of 5-ASA by colonic bacteria-induces and maintains remission. This study aimed to investigate the efficacy and tolerability of olsalazine in patients with ulcerative colitis who were being treated in daily practice by private physicians specializing in gastroenterology. METHODOLOGY: A total of 260 patients with ulcerative colitis (aged 17-77 years, 116 men) were studied. The doses of olsalazine and the clinical data (including acute disease symptoms and the occurrence of adverse events) were recorded over a 6-month period. RESULTS: Twenty per cent of patients had pancolitis, 48% had left-sided disease and 32% had proctitis or proctosigmoiditis. At study entry, 86% of patients had active disease; the percentages of these patients in remission after 6 weeks and 6 months were 42% and 91%, respectively. Patients with active disease received a mean dose of olsalazine - 2324mg per day initially and 1325mg per day at 6 months. The corresponding figures for patients in remission at study entry were 1386mg and 1162mg per day, respectively. Seventy-three per cent of patients took olsalazine with food, as recommended. The overall rate of adverse events was low; no serious adverse events occurred. CONCLUSIONS: Olsalazine therapy resulted in a rapid regression in the acute symptoms of ulcerative colitis. Olsalazine was also effective in maintaining remission. The drug was well tolerated.

Adult↗