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.

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.

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.

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.

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.

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.

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.

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.

The throat carrier rate of group A and other beta hemolytic streptococci among patients in general practice

In a one-year multicenter study in general practice the rate of asymptomatic throat carriage of group A beta hemolytic streptococci (GABHS) was investigated. 2,626 patients, none of whom had had sore throat or any other streptococcal illness during the preceding three months, were evaluated. The GABHS carrier rate was 2.2% with no sex or season dependent variation, and it was 10.9% in patients less than or equal to 14 years of age, 2.3% in patients between 15 and 44 years old, and 0.6% in patients greater than or equal to 45 years old. An additional 7.2% of the patients carried beta hemolytic streptococci of groups B, C, or G. For groups C and G the influence of age on carrier rates was similar to that found for GABHS. Tetracycline resistance was found in 21% of the group A strains, in 61% of the group B strains, and in 28% of the group C and group G strains.

Lack of reliability of primary grouping of beta-hemolytic streptococci by culture of throat swabs with streptocult supplemented with bacitracin disks in general practice

Fifty-eight general practitioners took throat swabs from 434 patients with sore throats. Office cultures were performed on Streptocult supplemented with bacitracin disks in an attempt to carry out primary grouping of beta-hemolytic streptococci (BHS). In 424 cases the findings were compared with those obtained in a microbiological laboratory. Streptocult showed a sensitivity of 75% and a specificity of 84% in the detection of BHS. The office-performed grouping procedure of the correctly detected BHS, however, only had a sensitivity of 65% and a specificity of 87%. Overall, as many as 45% of the patients with BHS group A were misdiagnosed. The unsatisfactory results obtained with primary grouping of BHS may be due partly to incorrect determinations of the diameter of the inhibition zone around the bacitracin disks and partly to an inappropriate choice of breakpoint. It is concluded that cultures of throat swabs on Streptocult in general practice should not be accompanied by attempts to carry out primary grouping with bacitracin disks. A laboratory investigation showed that incubation at room temperature for 48 h and at 35 degrees C for 24 h gave identical BHS positivity rates.

Silver sulfadiazine: an antibacterial agent for topical use in burns. A review of the literature

Topical antibacterial treatment is of major importance in the burn patient. Silver sulfadiazine is an effective agent with low toxicity and few side effects. Deposition of silver in tissues, and absorption of sulfadiazine are both minimal. Present and future problems are represented by the emergence of resistant Gram negative bacilli, including Pseudomonas aeruginosa. The development of related metal sulfadiazines to be used against resistant bacteria is on an investigational stage, and clinical trials are few. Silver sulfadiazine may be used in a variety of other conditions than burns.

Blood ammonia measurement using a simple reflectometer

We have assessed a compact Blood Ammonia Checker System (Ammonia Checker) consisting of a reflectometer which measures the intensity of colour formed by blood ammonia on a bromocresol green indicator reagent plate. The results show good correlation (r = 0.95) with our routine chemical method and a regression line y = 0.835X - 1.468. The Ammonia Checker has good precision (CV less than 10%) at the critical blood ammonia concentration and accurately measures predetermined ammonia concentrations. Blood sampling is improved with a precision pipette. The Ammonia Checker is simple, convenient and reliable and is ideally suited for a laboratory required to perform an urgent blood ammonia measurement.

Fatal meningitis with group JK Corynebacterium in a leukopenic patient

A case of fatal meningitis and septicemia with group JK Corynebacterium species in a leukopenic patient is reported. The strain was susceptible to rifampicin and vancomycin only. The finding of diphtheroids in bacteriological samples from immunocompromised patients should not be ignored. The literature regarding meningitis caused by diphtheroid bacilli is reviewed.

The survival of anaerobic bacteria at 4 degrees C and 22 degrees C on swabs in three transport systems. Statistical evaluation by application of a variance component model

The survival of anaerobic bacteria on swabs in three transport systems at 4 degrees C and 22 degrees C was evaluated. The transport systems were a charcoal-impregnated cotton swab in modified Stuart's transport medium (MS), a plain cotton swab in a dry aerobic tube (DA) and a plain cotton swab in an aerobic agar tube (AA). The test strains were Bacteroides fragilis, B. melaninogenicus ss. intermedius, Fusobacterium necrophorum, Peptostreptococcus anaerobius, Eubacterium lentum and Clostridium ramosum. Inoculated swabs were kept at the described conditions for time periods ranging from 22 1/2 min through 32 d, after which surviving organisms were recovered quantitatively. Results were described by the survival rate, defined as the percentage of organisms initially present, that had survived storage for 24 h. The survival rate was uniformly higher at 4 degrees C than at 22 degrees C. In Stuart's transport medium at 4 degrees C the survival rate was 81.9% compared to 4.3% in dry aerobic tube at 4 degrees C. At 22 degrees C the survival rate in dry aerobic tube and aerobic agar tube was 0.003% or less whereas in Stuart's transport medium growth occurred with B. fragilis, E. lentum and C. ramosum.

The recovery of anaerobic bacteria from swabs in three transport systems. Statistical evaluation by application of a variance component model

The recovery of six anaerobic species from swabs in three transport systems was quantitatively evaluated. The test strains were Bacteroides fragilis, B. melaninogenicus ss. intermedius, Fusobacterium necrophorum, Peptostreptococcus anaerobius, Eubacterium lentum, and Clostridium ramosum. The transport systems were a charcoal-impregnated cotton swab in modified Stuart's transport medium (MS), or a plain cotton swab in either a dry aerobic tube (DA) or an aerobic agar tube (AA). Swabs were charged with a known number of organisms of the test strain and inserted in the appropriate transport systems. Immediately hereafter the swabs were transferred to glass tubes with reduced buffer. After vigorous shaking, aliquots from the buffer were seeded onto blood agar plates, and the number of colony forming units (CFU) was counted after incubation. The number of CFUs from independent replications had a variation that was too large to be accounted for by the Poisson distribution. The probability of recovery (POR) was defined as the number of CFU recovered from a swab as a percentage of the original inoculum. The logarithms of the POR values were analyzed with a variance component model. This showed that estimated values of POR were significantly higher in DA (44%) than in AA (23%), while the value for MS (33%) did not differ significantly from those for AA or DA. It is concluded that in MS, friction between swab and medium does not contribute significantly to bacterial recovery loss, as compared to AA and DA.

Bacteriuria caused by Acinetobacter calcoaceticus biovars in a normal population and in general practice

A total of 14 strains of Acinetobacter calcoaceticus biovar anitratus and 93 strains of A. calcoaceticus biovar lwoffi from a total of 97 patients participating in studies of significant bacteriuria were cultured. These studies involved an interview survey of asymptomatic significant bacteriuria and a multiple-center investigation of urinary tract infection diagnosed in general practice. Antibiotic susceptibilities of the strains as determined by a disk diffusion technique were generally in agreement with the results in the available literature, although we found high activity exhibited by ampicillin, cephalosporin, chloramphenicol, erythromycin, and streptomycin. The following resistance patterns were seen. (i) The strains from the interview survey were more often resistant to ampicillin, oxacillin, and tetracycline than were strains from the general practice study. (ii) More biovar anitratus strains than biovar lwoffi strains were resistant to chloramphenicol, erythromycin, and mecillinam. (iii) More biovar anitratus strains than biovar lwoffi strains were resistant to carbenicillin in the interview survey. The literature relevant to the incidence and significance of A. calcoaceticus biovars in urinary cultures, as well as predisposing factors, was reviewed. The incidence of these organisms in significant bacteriuria seems to be increasing. We concluded that A. calcoaceticus biovars can cause urinary tract infection in abnormal hosts as well as in basically healthy individuals.

Comparison of two methods for very low density and low density lipoprotein cholesterol determination

It is shown that VLDL-cholesterol cannot be calculated from serum triacylglycerol at elevated triacylglycerol concentrations (above 2 g/l). Using the method of Friedewald et al. ((1972) Clin. Chem. 18,499-502), VLDL-cholesterol is usually overestimated in these sera and, consequently, LDL-cholesterol underestimated. Quantitative lipoprotein electrophoresis according to Wieland & Seidel ((1979) Innere Medizin 5,290-300), on the other hand, yields VLDL-cholesterol values which correspond to ultracentrifugation data within narrow limits, even in sera with high triacylglycerol contents. A nomogram has been developed for the evaluation of electropherogram.

Effect of temperature, humidity and exposure to oxygen on the survival of anaerobic bacteria

The relative effect of humidity, temperature and exposure to oxygen on the survival of 11 strains of Bacteriodes spp., Fusobacterium necrophorum, Eubacterium lentum, Clostridium ramosum, Peptococcus asaccharolyticus and Peptostreptococcus anaerobius was evaluated. Suspensions of the test strains were applied to membrane filters either in empty sterile petri dishes or on plates of non-nutrient agar to provide dry or moist conditions. The filters were stored aerobically or anaerobically in an atmosphere containing 10% CO2 at either 4 degrees C or 35 degrees C. After holding periods of 0.375-384 h, the filters were transferred to nutrient plates inside an anaerobic glove box. After incubation the growth on the filters was compared with that on control filters that had not been stored. Survival was better at 4 degrees C than at 35 degrees C. For the gram-negative organisms, survival was better under moist than under dry conditions, whereas for gram-positive organisms this finding was sometimes reversed. The results indicate that, generally, anaerobic bacteria kept under aerobic conditions survive best under moist conditions at 4 degrees C.

Macrophage-related suppressor cells in human renal transplant recipients

In this study 66 renal transplant recipients were studied by in vitro immunologic monitoring assays in an attempt to delineate some immune reactivity parameters which migh explain the successful long-term survival of HLA incompatible allografts. Ninety percent of the recipients were found to be responsive to their specific donors in one-way mixed lymphocyte culture assays, indicating the presence of antigen reactive proliferating T cells. In contrast, studies of the in vitro generation of cytotoxic T cells showed that 73% of the long-term recipients demonstrated a marked hyporesponsiveness to the donor in cell-mediated lympholysis (CML) assays. Longitudinal studies indicated that specific CML hyporesponsiveness to the donor developed after transplantion. In the majority of recipients, CML hyporesponsiveness could be related to a suppressor cell phenomenon, since recipient mononuculear cells specifically suppressed the CML reactivity of third-party cells to the donor. Recipient CML hyporesponsiveness to the donor could be abrogated by removal of recipient adherent cells, most of which were monocytes or macrophages. The suppressor cell effect on CML is postulated to be related to macrophages which are either acting independently or under the regulation of suppressor T cells. These studies are among the first to suggest that suppressor cell regulation of relevant effector T cell activity may be important in the facilitation of successful human renal transplantation.

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.