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Biomedical subjects

S Hoffmann

Publications and source records attributed to S Hoffmann.

197 records · Page 11Linked to original sources
PubMed1979

Comparison of antiviral properties in mice of bis-pyrrolidinoacetamido-fluorenone (MLU-B75), bis-dipropylaminoacetamido-fluorenone (MLU-B76), and tilorone hydrochloride.

Like tilorone . HCl, its analogues, bis-pyrrolidinoacetamido-fluorenone (MLU-B75), and bis-dipropylaminoacetamido-fluorenone (MLU-B76), significantly protected mice against intraperitoneal challenge with a lethal dose of Mengo virus when administered prophylactically in a single oral dose of 250 mg per kg body weight. At lower doses the antiviral activity of MLU-B75 and MLU-B76 decreased more rapidly than that of tilorone. HCl. At the dose of 250 mg per kg the degree of antiviral protection and the titre of interferon induced by tilorone. HCl correlated well, but there was no correlation between the extent of protection and the detected amount of virus inhibitor induced by MLU-B76. It remains to be determined whether the antiviral protection elicited by the analogues of tilorone is mediated by interferon.

Animals↗
PubMed1979

Interferon induction in human lymphocytes by complexes of vinyl copolymers with polynucleotides.

Analogues of the dsRNA poly(I).poly(C), namely double-stranded like complexes of poly(I) or poly(C), respectively, with corresponding vinyl nucleobases copolymerized with various vinyl compounds are highly effective interferon inducers in human lymphocyte cultures. Like poly(I).poly(C) they stimulate the liberation of an inhibitor(s) of interferon activity and, moreover, display mitogenic effect. With respect to the extent of these effects the various inducers differ considerably.

DNA↗
PubMedDate not supplied

Diagnosis of streptococcal tonsillitis in general practice by clinical assessment and by office culture of throat swabs on Streptocult.

In a one-year study 274 general practitioners performed office cultures on Streptocult of throat swabs from 2,699 patients with acute pharyngotonsillitis in order to identify those with beta-haemolytic streptococci in the throat. The finding of group A beta-haemolytic streptococci by laboratory culture of corresponding throat swabs was used as a reference when determining the diagnostic value of either clinical assessment or Streptocult culture for the identification of patients with streptococcal pharyngotonsillitis. Based on 2,150 cases, sensitivity was 70% and 84%, respectively; specificity, 63%, respectively 77%; positive predictive value, 38%, respectively 53%; and negative predictive value, 87%, respectively 94%. Compared to the clinical assessment of the etiology, use of Streptocult resulted in the additional identification of 14% of the patients with group A streptococci and 13% of the patients without this organism present in the throat, as judged by laboratory culture. Overall, 78% of the patients were correctly diagnosed by the use of Streptocult, compared to 65% by clinical assessment. It is concluded that the use of Streptocult in general practice may be of substantial benefit in the identification of patients with group A streptococcal tonsillitis.

Bacteriological Techniques↗
PubMedDate not supplied

Detection of group A streptococcal antigen from throat swabs with five diagnostic kits in general practice.

During a 5-month period, 248 general practitioners from 164 general practice offices obtained duplicate throat swabs from 2469 patients with acute pharyngotonsillitis. At the general practice office, one of the swabs was assayed for the presence of group A streptococcal antigen, using one of five commercially available diagnostic kits. (The participants did not receive instruction in the use of the kits). The other swab was cultured in our laboratory for the presence of group A streptococci. The diagnostic parameters for the five kits were as follows: Abbott TestPack Strep A--sensitivity, 79% (110/139) and specificity, 98% (490/501); Direct Strep A EIA (Roche)--sensitivity, 79% (104/132) and specificity, 63% (178/281); Respirastick--sensitivity, 55% (46/84) and specificity, 96% (298/309); Reveal Colour Strep A--sensitivity, 82% (114/139) and specificity, 83% (223/268); Tandem ICON Strep A--sensitivity, 78% (111/143) and specificity, 98% (362/368). The antigen detection test results were heavily influenced by the clinical prediction of a streptococcal or viral etiology. It is concluded that in the absence of a standard throat culture, the Abbott TestPack Strep A kit and the Tandem ICON Strep A kit both offer a more safe diagnostic alternative than clinical assessment. Depending on the current prevalence of group A streptococci, the additional use of a throat swab culture should be considered in case of negative antigen detection test results.

Antigens, Bacterial↗
PubMedDate not supplied

Development of a sensitive microtitration plate enzyme-immunoassay for the anabolic steroid trenbolone.

The development of a competitive microtitration plate enzyme-immunoassay for monitoring trenbolone application to animals is described. 'Bridge heterology' was achieved with a rabbit antibody raised against 17 beta-trenbolone-hemisuccinate-BSA and 17 alpha-trenbolone glucuronide-alkaline phosphatase as a tracer. The required 17 alpha-trenbolone glucuronide was prepared by application of trenbolone acetate to a calf following isolation from urine by three HPLC steps. The glucuronide was linked to alkaline phosphatase by the mixed anhydride procedure. The EIA was performed by coating affinity purified sheep IgG antirabbit IgG to the microtitration plate well followed by the addition of sample, tracer and hormone-specific antibody. The absolute detection limit was less than 1 pg; 50% relative binding at approximately 3 pg which is about 20 times superior to our RIA. The sample blanks of purified extracts from urine, bile, faeces, liver and muscle were similar in both methods (EIA and RIA) and much lower than required for a reliable detection of positive samples. Assay variations were always less than 15%. For the EIA, radiolabelled trenbolone, which is not commercially available, is not necessary and according to our experience the EIA is more practicable and economic.

Alkaline Phosphatase↗
PubMedDate not supplied

Influence of antibiotic treatment on the isolation rate of group A streptococci from peritonsillar abscesses.

In a prospective one-year study, group A streptococci were cultured from pus specimens from 13 of 71 patients (18%) with peritonsillar abscesses. The isolation rate was significantly lower (7/57 = 12%) in patients who had received antibiotic treatment before specimen collection than in patients who had not received such treatment (6/12 = 50%). Group A streptococcus antigen detection tests on pus, using a commercially available diagnostic kit, had a low sensitivity (5/13 = 38%). It was concluded that in patients treated with antibiotics prior to collection of specimens, the absence of group A streptococcus on culture does not rule out that this organism could have been the principal etiologic agent.

Adolescent↗
PubMedDate not supplied

Antisense p53 oligonucleotides inhibit proliferation and induce chemosensitivity in follicular thyroid cancer cells.

BACKGROUND: The potential of MTp53 knockout by oligodesoxyribonucleotide phosphothioates (ODNs) to affect proliferation, apoptosis and chemosensitivity in undifferentiated thyroid cancer (UTC) cells with a recessive MTp53 mutation was evaluated. MATERIALS AND METHODS: Transient transfections with ODNs complementary to p53 and control ODN (HIV-RT) were carried out in FTC 133 cells. In vitro proliferation was evaluated by cell counting of 10 random fields and by the MTT assay. A single pulse of 100 microg/ml Cytarabine was added to each well and the cells were incubated for an additional day. Chemosensitivity was calculated as the ratio of apoptotic and necrotic cells versus viable cells by flow cytometry (FACS). RESULTS: Transfection of UTC cells with ODN decreased the cell number by up to 70% (p < 0.002). The proliferation rate also decreased up to 35% (p < 0.03), without inducing apoptosis. ODNs rendered FTC cells sensitive to treatment with Cytarabine, inducing apoptosis in 35% of cells, as compared to 17% of cells transfected with the reverse transcriptase gene of HIV (ODN-HIV) and less than 10% of non-transfected cells (p < 0.05). CONCLUSION: Transient MTp53 knockout with ODNs complementary to p53 nucleotide sequences inhibited proliferation and increased chemosensitivity in the UTC cell line FTC133.

Adenocarcinoma, Follicular↗