Biomedical subjects
Publications and source records attributed to J B Anderson.
The Irving sterilization technique is a very reliable method of surgical contraception, with only two prior mentions of failure in the literature. We present the third case of failure of an Irving operation. A discussion on the surgical aspects of the Irving technique is also presented.
Current methods used for determining residual nitrite concentration in foods involve forming an azo dye that is measured spectrophotometrically. Conventional procedures do not specify control of pH for the final colored solution. Because many indicator dyes are pH-dependent, absorbance of the azo dye may vary not only because of nitrite concentration differences, but also because of pH variation. Thus, erroneous results could arise from a standard curve developed at one pH and used for a test sample at a different pH. This would cause an inaccurate concentration conversion from the standard curve. In this study, absorbances at lambda max wavelengths were recorded at 28 pH values (range 1.0-4.5) for each of 5 nitrite concentrations. A mathematical equation was fitted to these data and its plot gives a 3-dimensional response surface showing the relationships between pH, nitrite concentration, and absorbance. A modification for the spectrophotometric measurement of nitrite is proposed.
We have measured the product of the ras oncogene, ras p21, in random un-timed urine samples using an immunoblotting method which relies upon enhanced chemiluminescence for visualisation of the nitrocellulose filter. Urine samples were analysed from groups of patients with prostate (n = 10) or bladder (n = 25) cancer and a control group (n = 30) with no apparent urological disease. The mean concentration of urinary ras p21 in the groups with either bladder or prostate cancer was not significantly higher than that of the control group. The most striking difference between the control and clinical groups was the presence of a previously un-reported ras p21 "doublet" in the electrophoretic patterns obtained from 20% of the bladder cancer group and 10% of the prostate cancer group. This doublet was not present in any of the control samples analysed. This doublet is strongly suggestive of a mutation within the ras oncogene.