Biomedical subjects
Publications and source records attributed to M Haber.
As used for structural analysis of DNA, benzoylated DEAE-cellulose is subject to deterioration which affects chromatographic performance. This change, which specifically occurs during storage of the resin, has been characterized in terms of anomalous patterns of DNA binding. Subjecting benzoylated DEAE-cellulose to boiling in aqueous suspension, and appropriate storage, ensures maintenance of normal affinity for DNA.
An exact test is proposed for the hypothesis stating that the ABO blood group distribution follows the Hardy-Weinberg law. The test is based on the conditional distribution of the observed phenotypic frequencies, given the estimated gene frequencies. For sample sizes of 20 or less, the exact test can be carried out with the aid of a table that lists the significant outcomes.
The exact two-sided test of the hypothesis of 'no interaction' in a 2 X 2 X 2 table with fixed totals of rows X columns is considered. A method of approximating the power of the test, based on the limiting conditional distribution of a cell entry (Godambe and Harkness, 1975, Communications in Statistics 4, 699-709), is introduced and found to provide a close fit. This method can be utilized to calculate the sample sizes required to detect interaction effects with a pregiven power.
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The aim of this work is to examine the validity of several chi2 criteria, when used to test the fit of genotypic frequencies to the Hardy-Weinberg law. The exact type I error probabilities were compared to the nominal significance levels for two genetic models. The Pearson's chi2 test usually provided the best approximations. This test was found to be remarkably robust, when in situations involving very small expected frequencies.
The problem of detection of inbreeding effects by the chi-square goodness-of-fit test is investigated. The noncentrality parameter of the limiting chi-square distribution is considered as a function of the inbreeding coefficient in two models: (1) a gene locus with m codominant alleles and (2) the generalized ABO model. Previous results by Ward and Sing and by Chakraborty and Rao were based on inadequate statistical reasoning. In the first model, the resulting noncentrality parameter is identical with that found by Ward and Sing. For the second model, the limiting noncentrality parameter is found to be zero.
Asparatame, a new artificial sweetener, was administered to 45 obligate phenylketonuric adults for 28 wk. This new sweetening agent was well tolerated, and no untoward medical or biochemical changes were noted.
Strain BALB/c female mice bearing syngeneic implants of 2 mammary adenocarcinomata were treated with MER, x-irradiation or both. MER was administered either subcutaneously at a site contralateral to the neoplastic growth or both into such a site and directly at the tumour location. None of the treatments effected cures but many of the treated animals survived significantly longer than did the saline injected controls. There was no evidence that introduction of MER into, or directly adjacent to, a tumour is a generally more efficacious route of administration than application at only a distal site and there was, indeed, the strong contrary impression that distal treatment alone bestowed survival protection more often and to a greater extent. In no instance was there a shortening of survival time following administration of MER at a location away from the tumour implant.
Female BALB/c mice carrying established isografts or simulated local recurrence implants of 2 rapidly growing mammary adenocarcinomas were treated either by injection of the methanol extraction residue (MER) fraction of killed Bacillus Calmette-Guérin organisms (given s.c. or into the tumor) or by focal X-irradiation or by both. None of the modalities of therapy effected cures, but in many instances there was a significant retardation of tumor cevelopment and prolongation of the lives of the mice. Administration of MER alone offered protection in a number of cases but less often than the other forms of treatment. Combined therapy with MER and irradiation was, on the whole, the most successful therapeutic intervention. MER or irradiation administered alone enhanced the neoplastic process only on rare occasions; this appeared to be the case even more infrequently with combined treatment. MER was most likely to be effective alone or in combination when small quantities were used and when only 1 treatment or 1 cycle of combined therapy was given. The therapeutic action of MER was not dependent on direct introduction of the agent into a neoplastic focus; s.c. administration distal to the tumor site was almost always at least as satisfactory as injection directly into the tumor mass and indeed was often more efficacious.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
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BACKGROUND: Data from large, multicenter, US studies determining the efficacy of triple therapy for the eradication of Helicobacter pylori are lacking, especially for a treatment duration of less than 14 days. METHODS: Patients with H pylori infection and active duodenal ulcer disease or a history of duodenal ulcer disease within the past year were randomized to receive 30 mg of lansoprazole, 1 g of amoxicillin, and 500 mg of clarithromycin twice daily for 10 or 14 days. The primary efficacy end point was the eradication of H pylori as confirmed by negative histological and culture results at 4 to 6 weeks after the completion of treatment. RESULTS: Of 284 patients enrolled in the study from 46 US sites, 236 met the entry criteria. At 4 to 6 weeks after the end of therapy, H pylori was eradicated in 85% (96/ 113) of the patients receiving 14-day triple therapy and in 84% (103/123) of those receiving 10-day triple therapy by per-protocol analysis (95% confidence interval for treatment group differences, -10.5 to 8.1; P>.05). There was also no significant difference between the 14- and 10-day treatment groups when analyzed by an intent-to-treat analysis of H pylori eradication. A similar proportion of patients in each treatment group reported an adverse event related to therapy (34% [46/136] vs 38% [56/148], respectively). CONCLUSIONS: In patients with an active or a recent history of duodenal ulcer, lansoprazole-based triple therapy for 10 or 14 days is highly effective in the eradication of H pylori. The duration of therapy may be reduced from 14 to 10 days without a significant effect on regimen efficacy.