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Biomedical subjects

M C King

Publications and source records attributed to M C King.

At least 163 records · Page 9Linked to original sources
PubMed1981

Epidemiology of breast fluid secretion: association with breast cancer risk factors and cerumen type.

The epidemiology of breast fluid secretion was studied on the basis of nipple aspirates of breast fluid obtained from 3,929 nonlactating women of various racial groups. The results confirmed and extended earlier findings by our group: Variation in the proportion of secretors was related to most breast cancer risk factors, including age, race, age at menarche, age at first pregnancy, age at menopause, clinically diagnosed fibrocystic disease, menopausal estrogen use, and cerumen phenotype. Secretory activity as measured by nipple aspiration appeared to reflect hormonal and genetic effects on breast epithelium.

Adolescent↗
PubMed1980

Allele increasing susceptibility to human breast cancer may be linked to the glutamate-pyruvate transaminase locus.

The patterns of the occurrence of breast cancer in 11 high-risk families were evaluated by segregation and linkage analysis. These patterns were consistent with the hypothesis that increased susceptibility to breast cancer was inherited as an autosomal dominant allele with high penetrance in women. The postulated susceptibility allele in these families may be chromosomally linked to the glutamate-pyruvate transaminase (E.C. 2.6.1.2, alanine aminotransferase) locus. Confirmation of this linkage in other families would establish the existence of a gene increasing susceptibility to breast cancer. Since there is no association in the general population between a woman's glutamate-pyruvate transaminase genotype and her cancer risk, the glutamate-pyruvate transaminase linkage cannot be used as a screening test for breast cancer.

Alanine Transaminase↗
PubMed1980

Diagnosis of twin zygosity by self-assessment and by genetic analysis.

For 173 pairs of like-sex adult twins, self-assessment of zygosity was verified by laboratory diagnosis. Seventeen percent of twins who were very likely monozygous (MZ) believed themselves dizygous (DZ), frequently citing two placentas at their delivery as "evidence." We suggest that twins be asked what leads them to their assessment of their own zygosity. For 93% of Caucasian and 89% of American Black like-sex twins in our sample, DZ twins could be differentiated based on six polymorphic markers retrievable from frozen sera. MZ twins who believe themselves DZ can be considered "environmentally DZ, genetically MZ" twins, and might be used to study genetic and environmental influences on the treatment of twins and on twins' choices of social characteristics.

Alleles↗
PubMed1979

Laterality of breast cancer in families.

A new method for analyzing concordance for a binary variable in extended pedigrees was developed to study tumor laterality in families with high incidence of breast cancer. It was found that related breast cancer patients in 15 high-risk Midwestern US families did not have their tumors on the same side more frequently than would be expected by chance. This finding is in contrast to previous studies in London and Denmark that reported a significant concordance for tumor laterality in related breast cancer patients. This result may reflect an increasing incidence of sporadic breast cancer in genetically susceptible families or, alternatively, independent determination of cancer susceptibility and tumor laterality.

Adult↗
PubMed1978

Cholecystokinin cholecystography in the diagnosis of acalculous extrahepatic biliary tract disorders.

Cholecystokinin cholecystography represents a study designed to identify patients with acalculous extrahepatic biliary tract disorders. In this study, a positive cholecystokinin cholecystogram (CCK-GB) was defined as both reproduction of the patient's biliary tract-type pain plus one or more of various roentgen abnormalities. Using these criteria, 20 patients had a positive CCK-GB. After failure of medical management, 19 of these patients came to surgery. Seventeen of 18 available for follow-up were cured of their biliary tract pain by surgery. Follow-up of this group of patients has ranged from one month to 60 months. In view of our findings plus those in other reported series, we conclude that CCK-GB provides a reliable study for the diagnosis of acalculous extrahepatic biliary tract disorders.

Adolescent↗
PubMed1977

Genetic markers and cancer epidemiology.

The study of potential associations between genetic markers and various cancers has a long history in cancer epidemiology. Such investigations are subject to serious problems of statistical significance and the choice of appropriate control populations. A promising future for the use of human population genetics in cancer epidemiology may be in the investigation of genetic markers (such as the HL-A complex) which code for proteins of potential immunological or physiological importance in susceptibility or resistance to cancer. The cerumen gentic marker has played a central part in a hypothesis formulated in our laboratory for the etiology of breast cancer. A second new development in this field is likely to be the investigation of genetic markers in families with high incidence of cancer. Such families permit the simultaneous study of genetic hypotheses of cancer inheritance and the association of marker genotypes with cancer through segregation and linkage analysis.

ABO Blood-Group System↗
PubMed1977

Classifying intergral stimuli.

Two reported experiments support holistic, as opposed to analytic, processing models for integral stimuli. Speeded classification data from different information-processing tasks (univariate and correlated) were predicted by distance between stimuli in similarity space but not by redundancy. The results of the filtering and condensation tasks and the notion of configural stimuli are also explicable in these terms. It is shown that some operational definitions commonly used to define integral stimuli are usually confounded with stimulus similarity. The assumption of independence between the attributes that combine to form multidimensional stimuli is not always met and is always an empirical question. When these attributes are not independent, physical and psychological spaces are not necessarily the same. Similarity structure is a crucial concern if inferences of cognitive processing are to be based on information-processing task results.

Association↗
PubMed1977

New data on glucose-6-phosphate dehydrogenase deficiency in Saudi Arabia. G6PD variants, and the association between enzyme deficiency and hemoglobins S.

67/369 male Saudi subjects (18%) were found to be G6PD deficient on screening, and electrophoresis of blood samples stored on filter paper strips revealed B-like variants with intermediate enzyme activityin 11%, presumed Mediterranean variant in 13%, Gd + (A+) in 2%, Gd--(A--7) in 0.8%, and indeterminate enzyme status in 6% of the subjects tested. A significant association between G6PD deficiency and hemoglobin S correlated with previous studies on similar samples from the general population.

Adolescent↗
PubMed1976

Association of Duffy blood groups with the sickle cell trait.

Among a small group of Saudi Arabs the Duffy blood group (Fy(a-b-)) was found to be associated with the sickle cell trait more often than could be explained by random gene combination thus supporting the concept that African gene flow brought the sickle cell trait to the Arabian peninsula. Based on recent observations concerning the possible role of Fy(a-b-) as a resistance factor against vivax malaria, it is proposed that the gene combination AS FyFy is likely to be selected in areas where falciparum and vivax infections are endemic and mixed infections occur frequently.

Anemia, Sickle Cell↗
PubMed1976

Screening for abnormal hemoglobins in the middle east: new data on hemoglobin S and the presence of hemoglobin C in Saudi Arabia.

48 of 391 apparently healthy adult Saudi males had an AS hemoglobin pattern on electrophoresis, four subjects had an S pattern, and two subjects AC. A dithionite screening test lacked sensitivity and specificity in detecting hemoglobin S under the conditions of this study. A sickle cell trait frequency of 0.123 evidenced by hemoglobin electrophoresis correlates closely with previous studies of hemoglobinopathies in Saudi Arabs. The presence of four subjects with sickle cell disease in the study group provides further evidence of the "benign" nature of sickle cell disease in Saudi Arabia.

Adolescent↗
PubMed1975

Social structuring of mammalian populations and rate of chromosomal evolution.

To test the hypothesis that the evolution of organisms is dependent to a large degree on gene rearrangement, we devised a way of estimating rates of evolutionary change in karyotype. This non-biochemical method is based on consideration of chromosomal variability within taxonomic groups having a fossil record. The results show that chromosomal evolution has been faster in placental mammals than in other vertebrates or molluscs. This finding is consistent with published evidence that placentals have also been evolving unusually fast in anatomy and way of life. However, the structural genes of placentals seem not to have experienced accelerated evolution. Possibly, therefore, anatomical evolution may be facilitated by gene rearrangement. To explain how placentals achieved this rate of chromosomal evolution, we consider the process by which a new gene arrangement becomes fixed and spreads. The structure and dynamics of placental populations may be especially favorable for this process. The key factor involved seems to be the type of social behavior which produces small effective population sizes and inbreeding. As Bush points out elsewhere, such social structuring of populations may promote rapid fixation of gene rearrangements and rapid speciation.

Animals↗
PubMed1975

Cellular composition of the nipple aspirate specimen of breast fluid. I. The benign cells.

A nipple aspirator device was used to obtain breast secretions for cytologic examination, as well as for viral and biochemical analysis. Examination of the first 1,456 specimens from 796 women revealed ductal epithelium in 54%. Ductal epithelial cells were often absent in specimens from normal women; however, 78.5% of women with benign breast disease on tissue biopsy had specimens containing ductal epithelium. Apocrine metaplastic cells were a further indication of the presence of breast disease, and were rarely found in specimens from asymptomatic women. Foam cells were often abundant in specimens from normal breasts, but were found in decreased numbers in specimens from women benign breast disease. Differences in the occurrence of ductal epithelial cells, apocrine metaplastic cells, and foam cells suggest an alteration in the rate of maturation of ductal epithelium in women with both benign and malignant breast disease. The finding of a relative abundance of cells in nipple aspirate specimens from women with breast disease and few or no cells in specimens from women with normal breasts is believed to be of great importance in the cytologic evaluation of nipple aspirate specimens.

Body Fluids↗