Photographic documentation of the fluorescein test.

A new access incision for the extirpation of intraoral malignancies has been used in 16 cases, and it is described--together with its apparent advantages.     

An exact test of the Hardy-Weinberg law.

An exact distribution of a finite sample drawn from an infinite population in Hardy-Weinberg Equilibrium is described for k-alleles. Accordingly, an exact test of the law is presented and compared with two x2-tests for two and three alleles. For two alleles, it is shown that the "classical" c2-test is very adequate for sample sizes as small as ten. For three alleles, it is shown that a simpler formulation based on Leven's distribution approximates the exact test of this paper rather closely. However, it is recommended that researchers continue to employ the standard x2-test for all sample sizes and abide by it if the corresponding probability value is not "too close" to the critical level; otherwise, an exact test should be used.     

A rubella haemagglutination inhibition test not requiring removal of non-specific inhibitors. 1. Elaboration of the test

The rubella haemagglutination inhibition (HI) test can be simplified and the probelm of non-specific inhibitors circumvented by allowing the haemagglutinin to react with erythrocytes before addition of the serum specimen. The elaboration of the test procedure is described, and preliminary studies indicate that the new method may prove useful both in the diagnosis of rubella infection and for determination of immunity status.     

Dextrostix-Eyetone in the insulin hypoglycaemia test.

The Ames Dextrostix-Eyetone system was evaluated for monitoring the blood glucose concentration during insulin-induced hypoglycaemia. The results agreed well with laboratory values for plasma glucose, obtained by an orthotoluidine method, and the method was practicable as a bedside technique. In two cases quick results obtained with the Eyetone enabled the insulin tolerance test to be interrupted to prevent severe hypoglycaemia before the clinical indications were obvious. The extra time and effort required were minimal, and its value seems to far outweigh the disadvantage of the extra work entailed. Nevertheless, care in using the system was important, and the operator must familiarise himself with the system before the most reliable results can be obtained.     

Mutagenicity test of dyes used in cosmetics with the Salmonella/mammalian-microsome test.

37 dyes including 3 anthraquinone, 22 azo; 5 xanthene, 5 fluorandiol, and 2 thioindigo dyes, were tested for mutagenic potential with the Salmonella/mammalian-microsome test. Two frame-shift histidine mutants (TA1537 and TA98) and two base-pair substituted histidine mutants (TA1535 and TA100) of Salmonella typhimurium were employed. Both the spot test and the plate-incorporation assay indicated that one azo dye, D&C Orange No. 17, was mutagenic with three of the bacterial test strains. The mutagenic response of D&C Orange No. 17 was depressed by the addition of the microsomal fractions from rat livers. Of the chemicals used to synthesize D&C Orange No; 17 was depressed by the addition of the microsomal fractions from rat livers. Of the chemicals used to synthesize D&C Orange No. 17, beta-naphthol was not mutagenic but 2,4-dinitroaniline was mutagenic to the same Salmonella strains as D&C Orange No. 17 . Dimethyl sulfoxide extracts of lipsticks of similar formula but without D&C Orange No. 17 were tested in the plate incorporation assay. Only those containing D&C Orange No. 17 were mutagenic and the dye was mutagenic at concentrations consumed in normal daily use.