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Biomedical subjects

S Hoffmann

Publications and source records attributed to S Hoffmann.

At least 163 records · Page 9Linked to original sources
PubMed1988

Effects of beta-casomorphin in isolated heart preparations.

beta-Casomorphin-5, a novel opioid peptide Tyr-Pro-Phe-Pro-Gly, was tested in isolated heart preparations of guinea pigs in comparison with other morphine related peptides and cardioactive drugs. The substance induced a dose-dependent change in the cardiac contraction force, showing a positive inotropic effect in low concentrations (10(-9) - 10(-7) mol/l) but a cardiodepressive action at higher doses (10(-7) - 10(-5) mol/l). Similarly, potentiation phenomena due to varied pacing rates of right-ventricular strips were enhanced at 10(-8) mol/l and lowered at 10(-6) mol/l beta-casomorphin-5. The coronary flow continuously increased. The observed changes of heart action were not mediated by opioid receptors: specifically acting opioid peptides were without influence and naloxone had no inhibitory effect. Peptides with similar sequences may exert a regulatory role in cardiac function, possibly mediated by an influence on the cellular calcium fluxes. The results may prove to be useful for the detection and estimation of more stable and cardioactive peptides.

Animals↗
PubMed1987

Detection of group A streptococcal antigen from throat swabs by use of a latex agglutination test kit in general practice.

In 11 general practice offices, with a total of 29 general practitioners, throat swabs from 468 patients with acute pharyngotonsillitis were assayed for group A streptococci with a commercial antigen detection test kit (Culturette Brand Ten-Minute Group A Strep ID; Marion Scientific, Div. of Marion Laboratories, Inc., Kansas City, MO 64114, USA). Compared to aerobic cultures carried out in our laboratory, the sensitivity of the antigen detection test was 73%; the specificity, 98%; the positive predictive value, 96%; the negative predictive value, 84%; and the overall agreement with laboratory findings, 88%. The prevalence of group A streptococci was 42%. Tests performed by assistants were significantly less sensitive (52%) than tests carried out by the physicians themselves (77%). The sensitivity of office cultures was 83% for blood agar plates supplemented with bacitracin discs, and 77% for Streptocult. We conclude that antigen detection tests should not presently be substituted for office cultures in the diagnosis of group A streptococcal throat infections.

Acute Disease↗
PubMed1987

Use of reference specimens for throat swab cultures on Streptocult.

Seventy-five general practitioners (GPs) who regularly used Streptocult for culture of throat swabs participated in a study aimed at evaluating the need for and the possible educational effect of examining reference specimens. Their pre-study and post-study accuracy in the interpretation of cultures of simulated throat specimens were analyzed. One group of 38 GPs received instructions as well as supplementary reference specimens during the study, while no instructions were given to the remaining 37 GPs. There was no discernible difference in the post-study accuracy of the two groups. Before the study, 80% of the GPs had felt to be in need of reference specimens; after the study, 61% did so. A majority suggested that three reference specimens should be distributed once or twice a year. Eighty-six per cent had never checked the temperature in their incubator. After doing so, only 54% measured a temperature within the recommended range of 35-37 degrees C.

Bacteriological Techniques↗
PubMed1987

Synthesis and cloning of a human beta-casomorphin-5 gene.

As so far a singularity among opioid peptides, bovine beta-casomorphin-5 has been shown to display pronounced cardiatic activities. The gene sequence of a human beta-casomorphin-5, including plasmid insertion and fusion protein expression and cleavage instrumentary, has been synthesized by a manual phosphoramidite procedure and cloned in a bacterial system.

Amino Acid Sequence↗
PubMed1986

Commercial kits are not equally sensitive in detecting the group antigen of group A streptococcus.

The relative sensitivities of four commercially available kits for the demonstration of the group antigen of group A streptococcus were estimated in laboratory experiments. Two kits gave positive reactions with swabs charged with approximately 10(5) colony-forming units of group A hemolytic streptococci of five common T-types. The two other kits required inocula ten times higher. Application of the antigen detection reagents from each kit to antigen extracts prepared by extraction reagents from the other kits revealed that the differences in sensitivity were largely attributable to differences in the extraction abilities. The four kits did not differ appreciably in their ability to demonstrate group A antigen in human pus mixed with group A streptococci; the minimum inoculum detectable was approximately 10(6) colony-forming units per 0.04 ml of pus.

Antigens, Bacterial↗
PubMed1986

Incidence and management of sore throat in general practice.

A total of 1051 patients with sore throat were registered by 358 general practitioners (GPs) each participating for one week some time during a one-year study period. Contacts related to emergency medical service work, and contacts by telephone only were also included. The annual incidence of sore throat was estimated to be 100 per 1 000 person years. A bacterial or presumedly bacterial etiology was clinically diagnosed in 64% of the patients, and a viral or presumedly viral etiology in 30% of cases, while for six per cent of the patients, the GP was in doubt as to the etiology. The strategy of management was as follows: nine per cent had a throat swab taken and antibiotics prescribed; 15% were swabbed, and did not receive an immediate prescription; 54% were prescribed antibiotics without being swabbed; and 23% were neither swabbed nor treated with antibiotics. With increasing age of the doctor, increasing frequencies were found regarding the clinical assumption of a bacterial etiology and prescribing of antibiotics, whereas the frequency of obtaining throat swabs decreased. Similar findings were made when the type of contact was home visit as opposed to contact at the surgery.

Adolescent↗
PubMed1986

Hyperammonaemia and hepatotoxicity during chronic valproate therapy: enhancement by combination with other antiepileptic drugs.

Erythrocyte (ENH3) and plasma (PNH3) ammonia levels, liver function tests and plasma valproate concentration were measured in 81 epileptic patients, comprising three therapeutic groups: Group 1 (23 patients) received sodium valproate (VPA) monotherapy, group 2 (33 patients) received sodium valproate combined with phenytoin, carbamazepine, phenobarbitone and/or primidone and group 3 (25 patients) received one or more of these anti-epileptic drugs without sodium valproate. The mean ENH3 and PNH3 of patients in group 1 (41.1 +/- 30.7 mumol l-1 and 37.1 +/- 31.8 mumol l-1, respectively) and group 2 (44.5 +/- 21.3 and 37.6 +/- 21.4 mumol l-1, respectively) were significantly (P less than 0.01) higher than those in group 3 (28.7 +/- 10.6 and 21.5 +/- 7.8 mumol l-1, respectively) and the reference range (30.1 +/- 7.9 and 20.8 +/- 5.7 mumol l-1, respectively). Hyperammonaemia was more prevalent amongst patients in group 2, for both ENH3 (45.5%) and PNH3 (54.6%), than amongst patients in group 1 (30.4% and 52.2%, respectively) and group 3 (8% and 8%, respectively). There was a significant (P less than 0.05) positive correlation between plasma VPA and total bilirubin concentrations. Chronic VPA therapy was also associated with an increase in bilirubin concentrations measured on average four months apart.

Adolescent↗
PubMed1986

An enzymatic method for calibration of serum lipase assays.

An enzymatic method for the calibration of a turbidimetric lipase assay is described, based on measurement of free fatty acids liberated by the action of lipase. The substrate of the turbidimetric assay is a colipase-containing triolein emulsion. For determination of the free fatty acids a commercial test kit including acyl-CoA synthetase, acyl-CoA oxidase, and peroxidase is used. Intra- and interassay imprecision (CV) is about 5% at above-normal lipase activities, about 10% at normal values. Temperature coefficients are 1.24 and 1.45, respectively, for measurements at 30 and 37 degrees C vs 25 degrees C.

Animals↗