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Biomedical subjects

A O Varma

Publications and source records attributed to A O Varma.

17 recordsLinked to original sources
PubMed1991

Breast cancer risk and oral contraceptive use: results from a large case-control study.

The association between oral contraceptive use and breast cancer risk was examined using data from a case-control study of breast cancer in Long Island, New York. Cases were defined as female residents of Nassau and Suffolk Counties between the ages of 20 and 79, diagnosed with breast cancer between January 1, 1984 and December 31, 1986. Age- and county-matched controls were selected from driver's license files. Among all women under age 70 at diagnosis, there was no association between oral contraceptive use and breast cancer; there was, however, a positive association in the subgroup ages 20-49 (adjusted odds ratio = 1.68, 95% CI: 1.16-2.42). Risk increased with increasing duration of use, but did not differ between women who first used oral contraceptives before the first pregnancy and those who first used them later, or between women who first used oral contraceptives before age 25 and those who first used them at a later age. Risk also appeared to increase with number of years of use before the first pregnancy or before age 25, although numbers were small. History of benign breast disease did not influence risk. The association of breast cancer risk with oral contraceptive use appeared stronger in women from Suffolk County than Nassau County.

Adult↗
PubMed1988

Longitudinal study of the caries susceptibility of occlusal and proximal surfaces of first permanent molars.

Ten- to 13-year-old children were examined annually for three years to determine the caries activity in the proximal and occlusal surfaces of first permanent molars. Almost every tooth with an unsound (carious or filled) proximal surface also had an unsound occlusal surface. Caries scores in proximal surfaces remained relatively constant and low. The percentage of teeth with occlusal caries or fillings increased throughout the study, even though the teeth had been erupted for seven to ten years by the end of the study. Within the age range studied, the time that teeth were in the mouth had little effect on the vulnerability of occlusal surfaces to caries attack.

Adolescent↗
PubMed1988

Radiographic measures of hyperinflation in clinical emphysema. Discrimination of patients from controls and relationship to physiologic and mechanical lung function.

In a retrospective study we investigated the accuracy of radiographic measurements of hyperinflation in distinguishing a sample of patients with a clinical diagnosis of pulmonary emphysema (n = 44) from a sample of age- and sex-matched control subjects (n = 39). The relationship of the hyperinflation parameters to pulmonary function test results (PFTs) and arterial blood gas measurements (ABGs) in the emphysema patients was also examined. The radiographic measurements were diaphragmatic angle of depression, lung height, lung width, heart size, diaphragm level, radiographic total lung capacity (TLC), and size of the retrosternal air space. By discriminant function analysis, the best contributors to the function were lung height and diaphragmatic angle of depression, followed by radiographic TLC and heart size. The derived classification rule had a diagnostic accuracy of 88 percent. The radiographic measures, largely independent of one another, showed moderate correlations with percentage PFTs, ABGs, portable percentage spirometric studies, height, and weight. High correlations were found between several of the radiographic measurements and the PFTs that represent actual static lung volumes. The correlation between radiographically measured TLC and PFT TLC measured by the helium dilution technique was .90.

Female↗
PubMed1987

Tumor-associated antigens in bilateral breast cancer.

The purpose of our present study is to determine whether monoclonal antibodies can define an antigenic phenotype which expresses itself in a concordant fashion in synchronous bilateral breast cancer. The monoclonal antibodies DF.3 and B72.3 were reacted (ABC immunoperoxidase) with formalin-fixed, paraffin-embedded sections of bilateral synchronous breast cancers from 19 patients. MAb DF.3 demonstrated a P less than .01 correlation of right-sided vs left-sided reactivity. This suggested that MAb DF.3 could be used as a biologic marker for synchronous bilateral breast cancer. We hypothesized that the majority of clinically asynchronous breast cancers are really biologically synchronous. We used the immunoperoxidase technique in a similar fashion on bilateral metachronous tumors in 17 patients. DF.3 antigen expression correlated (right to left side) at P less than .01 value. This data, supported by previous information, suggests that the term "metachronous" breast cancer is a clinically arbitrary definition but that biologically most "metachronous" cancers may well be synchronous.

Antibodies, Monoclonal↗
PubMed1984

Specific non-parametric approaches to analyzing caries clinical trials.

The usual parametric procedures are valid for the analysis of most caries clinical trials. If the sample sizes are small, non-parametric procedures should probably be used, such as the Wilcoxon two-sample test or the Kruskal-Wallis test. The Wilcoxon test can be expressed in terms of the difference between one of the rank sums and its expected value. This difference is evaluated in terms of its standard deviation. The Wilcoxon test is extended to produce an overall test, which takes the stratification into account. The procedure accumulates the differences between the rank sum of one of the two treatments and its expected value, and the corresponding variances. The Kruskal-Wallis test can be expressed in an analysis-of-variance-like form. The test can also be expressed in terms of the differences between the observed and expected rank sums. To extend the test to two or more strata, we need the variance-covariance matrices of I - 1 of the rank sums. There is presently no test available for interaction. The expected values of the rank sums depend on the sample sizes, and these differ from stratum to stratum. The use of weights, to produce a common expected value for each stratum, may provide a test of interaction. This needs further exploration.

Analysis of Variance↗
PubMed1981

Physician knowledge and attitudes toward an emergency medical services system.

A survey was conducted to measure the knowledge, attitudes, and practices concerning emergency medical services (EMS) of physicians practicing in a suburban-rural county on Long Island, New York. Two hundred fifty-four physicians responded to a questionnaire formulated to determine the following: knowledge of the existing system; perceived changes in system components; opinions about factors affecting emergency department visits; physician recommendations to patients in hypothetical situations; reasons for choosing a particular hospital for emergency patients; interest in involvement in the county EMS training program; and physician socio-demographic characteristics. Such information is valuable in the planning of EMS programs.

Adult↗
PubMed1979

Immunologic and coagulation disorders in chlorpromazine-treated patients.

The prevalence of immunologic and coagulation disorders in 75 schizophrenic patients treated with chlorpromazine or other antipsychotic drugs was evaluated. Four groups were studied: Group A, chlorpromazine treatment for more than 2 1/2 years; Group B, chlorpromazine and other antipsychotic drug treatment for more than 2 1/2 years; Group C, chlorpromazine treatment for less than 2 1/2 years; Group D, no chlorpromazine, but other antipsychotic drug treatment. Significant elevation of serum IgM and prolongation of partial thromboplastin time were noted in patients who had long-term chlorpromazine treatment. The latter was caused by a circulating inhibitor resembling that seen with systemic lupus erythematosus. There was a significant correlation between the IgM level versus chlorpromazine dose or duration of treatment and the partial thromboplastin time versus chlorpromazine dose or duration of treatment. In Groups A and B, 63% had a positive antinuclear antibody test (greater than or equal to 1:80), 40% had antibodies to native DNA, and 58% had antibodies to nucleoprotein. These antibodies were negative in the other groups. The percentages of T lymphocytes were below normal in 13 of 41 patients treated with chlopromazine. Twenty of 42 patients in Groups A and B, and none of 28 in Groups C and D had splenomegaly. This study indicates that most patients on long-term chlorpromazine treatment develop one or more immunologic abnormalities.

Adult↗
PubMedDate not supplied

Double-blind evaluation of collagenase injections for herniated lumbar discs.

A randomized clinical trial of 30 patients with refractory lumbar disc disease with evidence of a herniation at a single intervertebral space on the myelogram is presented. Collagenase or a saline placebo was injected into the affected disc. Lack of pain reduction or lack of functional improvement was considered a therapeutic failure. Patients who failed to respond to the placebo could subsequently receive a collagenase injection. Thirty-three percent (33%) of the 15 patients who received a placebo and 80% of the 15 patients who received collagenase were rated successful 8 weeks after injection. The study demonstrates a statistically significant effectiveness of collagenase in the treatment of herniated lumbar disc disease.

Adult↗