Enzyme activity of induced auxotrophic mutants of El Tor Vibrio cholerae

Vibrio cholerae induced auxotrophic variants nonfermenting several carbohydrates simultaneously have been obtained for the first time. Eltor vibrio clones have been selected, referred to Heuberg's groups V and VI by their enzymic activities. The findings of the present study evidence that, when isolating Eltor vibrio strains negative towards differential carbohydrates, in case of a positive agglutination test, the incubation period should be prolonged to 3 days. The principal differential diagnostic test for this species, when cholera is bacteriologically diagnosed, should be a positive volumic agglutination test with species- and variant-specific sera, irrespective of Heuberg's group.     

Evaluation and assessment of high sensitivity thyrotropin methods as an index for thyroid function

We report the evaluation of four new commercially available sensitive assay kits for determination of thyrotropin (TSH) and their clinical utility in normal subjects and patients with thyroidal and non-thyroidal illnesses. The sensitivity for the reliable detection of serum TSH by these methods ranged from 0.1-0.4 mU/L and their decreasing order was : NML greater than Serono greater than Abbott EIA greater than Hybritech. The coefficient of variation ranged from 2.0-5.8% for intra-assay and 2.3-8.6% for interassay at different concentration levels. Patients studied (n = 130) were assigned into four groups on the basis of the serum thyroxine value and their clinical findings. In total, there were 17 discrepancies (five with Hybritech, three with NML, five with Abbott EIA, and four with Serono) in making the correct diagnosis using these sensitive TSH methods as a single diagnostic test. These discrepancies were mainly in the same patients who were clinically euthyroid but had subnormal TSH values. There were no discrepancies in making the correct diagnosis for patients with hyperthyroidism or hypothyroidism using these sensitive TSH methods. Our observations indicate that the sensitive TSH methods are reliable in measuring subnormal levels and may be used to detect hyperthyroidism without affecting in any way their value in detecting hypothyroidism.     

Contribution of nuclear medicine to vascular surgery

Radioisotopes have been used for many years in the diagnosis of vascular abnormalities. In some areas the technique is regarded as routine and essential, while in others its place is less certain. This is often the case because of competition from other diagnostic methods or the facility may not be readily available. With the active participation of the Department of Nuclear Medicine, radionuclides can be used to provide information in both clinical diagnosis and laboratory investigation. It is intended to emphasise those areas where the method appears to have a rewarding clinical application.     

Synthesis and antiviral activity of benzisatin β-oximes

Translated from Khimiko-farmatsevticheskii Zhurnal, Vol. 23, No. 11, pp. 1349–1352, November, 1989.     

Apparatus for the measurement of reaction time

An apparatus for the measurement of reaction time to both visual and auditory stimuli with a provision to vary intensity of stimuli and with facility for lateralisation of sound to the right or left ear has been described.     

Variations in serum thyroxine concentrations with time after an oral replacement dose

Serum thyroxine concentrations were measured sequentially in eight healthy male volunteers after the oral administration of one of two brand name, commercially available thyroxine tablets. In all cases, levels peaked at 2 hours and did not return to baseline values until 24 hours after dosing. From 2 through 10 hours, statistically significant elevations in serum thyroxine concentrations were observed. Such fluctuations may be important in evaluating laboratory results in patients receiving replacement doses of thyroxine.