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Biomedical subjects

G A Chase

Publications and source records attributed to G A Chase.

At least 127 records · Page 7Linked to original sources
PubMed1978

Use of ambulatory health services by the near poor.

Individuals in the gray area between Medicaid eligibility and sufficient income to meet the costs of health care, the near poor, utilize health services less than other groups. As part of a study of health care behavior in an inner-city area based on a household survey of three distinct populations (HMO) members, public housing project residents, and a defined geographical area), we examined this question more thoroughly. Survey results show that the near poor had lower levels of use than Medicaid recipients when other factors were controlled. Particularly among those classified as in poor health, the near poor were more likely to be non-users and less likely to make multiple visits. However, differences in use between the near poor and the Medicaid recipients are substantially and consistently smaller for the HMO users (whose costs were covered by a special contract) than for users of a hospital outpatient department. The patterns persist for regular care received for a chronic condition but not for care sought for episodes of illness. These findings point to the special disadvantage faced by low income individuals who are not receiving Medicaid.

Ambulatory Care↗
PubMed1977

"Normal" children, "abnormal" results.

The relationship of sensitivity and specificity to disease frequency is considered in quantitative detail for typical screening situations. It is shown by illustrative examples that most screening procedures applied unselectively to total populations will yield a vast abundance of false positive results. The important role of prior probability in interpreting diagnostic test results is spelled out and applied to paradigms for screening.

Amino Acids↗
PubMed1977

Genetic counseling.

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Genetic Counseling↗
PubMed1977

'Mapping' of postulated Ir genes within HLA by studies in allergic populations.

Analysis of specific IgE responses to highly purified allergens provides a particularly good model to study the genetics of human immune response. The use of this model is illustrated by studies of large populations of allergic individuals in terms of their HLA phenotype, basal total IgE level and specific IgE-mediated sensitivities to rye grass group I (Rye I) and to ragweed Ra3. We find significant associations between HLA-B8 and Rye I response and HLA-A2 and Ra3 response, which become more striking in those atypical allergic subjects who have low total IgE levels. Our studies point to the importance of genetic regulation of basal IgE level in determining specific IgE response. Also, they suggest possible approaches toward a tentative 'mapping' of postulated Ir genes based on the linkage disequilibrium existing within the HLA complex.

Antibody Formation↗
PubMed1976

A matrix method for calculating recurrence risks of unilocal disorders for genetic counselling.

A matrix method to calculate conditional likelihoods in a pedigree and use them to determine recurrence risks for unilocal disorders in genetic risks is presented in this paper. Different matrices are assigned to individual members of the pedigree and combined into matrix expressions. The method is explained for X-linked recessive conditions and autosomal dominant conditions with incomplete penetrance.

Female↗
PubMed1975

A genetic-epidemiologic study of chronic obstructive pulmonary disease. I. Study design and preliminary observations.

Although certain environmental agents (e.g., cigarette smoking) are known to be causally related to chronic obstructive pulmonary disease (COPD), differential response to their deleterious effects suggests the importance of constitutional (host) factors. The voluminous literature on the familial occurrence of COPD as well as the association between genetically determined serum alpha 1-antitrypsin (alpha 1-at) deficiency and COPD, however, reveals many aspects yet to be clarified. Studies of alpha 1-at indicate that neither its nature nor its relationship to COPD is simple. Moreover, other familial factors are likely involved. To obtain a better understanding of the etiology and pathogenesis of COPD, both genetic and environmental factors are being examined in a multifaceted investigation. The preliminary observations are summarized. COPD patients have a higher frequency of Pi variant phenotypes than those without lung disease. Among other subjects, both cigarette smoking and Pi variant phenotypes are associated with increased pulmonary function abnormality. Finally, there is familial aggregation of pulmonary impairment that cannot be explained entirely by Pi type or smoking.

ABO Blood-Group System↗
PubMed1975

Tay-Sachs disease: high gene frequency in a non-Jewish population.

A non-Amish "Pennsylvania Dutch" semi-isolate was found to have a high frequency of Tay-Sachs gene. This high frequency could be ascribed to founder effect and may represent, in microcosm, how this mechanism could have produced the high gene frequency among Ashkenazi Jews.

Consanguinity↗
PubMed1973

Human genetics.

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Animals↗