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Biomedical subjects

A Kagan

Publications and source records attributed to A Kagan.

At least 109 records · Page 6Linked to original sources
PubMed1977

Antitrypsin and chronic obstructive pulmonary disease among Japanese-American men.

A total of 161 patients with chronic obstructive pulmonary disease (COPD) plus 100 control subjects (identified during a study of heart disease in 6,860 Japanese-American men aged 52 to 75 years who were residing in Hawaii) were analyzed for phenotype in search of the antitrypsin gene Z, which has been shown to be associated with pulmonary emphysema in other racial groups. No carriers of the Z gene were found, and the question of whether the rarity or absence of this gene relates to a low frequency of COPD among Japanese-Americans is reviewed.

Chronic Disease↗
PubMed1977

Commingling in distributions of lipids and related variables.

In a sample of nearly 8,000 Japanese males, the distributions of casual cholesterol and triglyceride, hematocrit, glucose, uric acid, diastolic blood pressure, and weight (covariance adjusted) could not be normalized by a power transform and were significantly better fitted by a mixture of distributions. The evidence for admixture was nonsignificant for systolic blood pressure, significant but unimpressive for height and weight, and strong for the remaining variables. The minor component corresponded to high values, in low frequency except for triglyceride and glucose. These results favor an interpretation of elevated levels in terms of distinct entities, genetic or environmental or both, rather than cumulative small effects only. These entities appear to be megaphenic (i.e., with effects exceeding one phenotypic standard deviation). Consequences of this hypothesis are discussed.

Aged↗
PubMed1976

Serum lipoproteins and coronary heart disease in a population study of Hawaii Japanese men.

To ascertain the frequency of defined hyperlipoproteinemia and to investigate the relation between lipoprotein fractions and coronary heart disease, we measured serum lipoprotein cholesterol levels in a population-based sample of Hawaii Japanese men 50 to 72 years old. Type II hyperlipoproteinemia was present in 3 per cent of 1859 men, and Type IV in 26 per cent. Relative risks for coronary heart disease, based on 264 prevalence cases, were found to be 1.8, 1.8 and 0.46, between the upper and lower quartiles of total, beta, and alpha cholesterol, respectively. We found no significant relation between triglyceride and coronary heart disease. The inverse relation of alpha cholesterol of prevalence of coronary heart disease was independent of beta cholesterol, obesity, and other factors. The data suggest the need for further evaluation of the protective effect of the alpha lipoprotein fraction on the development of coronary heart disease.

Aged↗
PubMed1976

L-aspartic acid and urea supplementation of low-protein layer diets.

1. Urea supplementation of low-protein (125 g/kg) conventional-type diets for layers, whether containing fish meal or not, did not appear advantageous. 2. Supplementation of the low-protein diet with aspartic acid did not affect egg production rate of efficiency. 3. Soyabean meal supplementation of the low-protein diet increased egg weight significantly whereas aspartic acid did not.

Animal Feed↗
PubMed1976

Urea and aspartic acid supplementation of low-protein broiler diets.

1. L-Aspartic acid does not seem useful as a protein surrogate in conventionally formulated low-protein diets for broiler chicks. 2. Urea as a protein substitute does not enhance the value of conventional broiler diets. 3. Urea does not improve broiler diets that have been supplemented with fish meal or crystalline amino acids to satisfy requirements for all indispensable amino acids. 4. Urea is absorbed into the bloodstream, but is not assimilated into body proteins.

Animal Feed↗
PubMed1975

"Skip" metastases in osteosarcoma.

Careful study of 40 cases of osteosarcoma without evidence of multifocal disease, pulmonary metastasis, or history of exposure to predisposing factors has given histologic evidence of microscopic foci of osteosarcoma separate from the primary focus of osteogenic sarcoma. These "skip" lesions are to all pathologic examination completely separate from the primary focus of osteogenic sarcoma. They are more often found proximal to the primary, both intraosseously and transarticularly. Histologically, these "skips" represent areas of osteosarcoma which in many cases are a less-differenitated form of the tumor. The natural history of such tumors with "skips" following ablative surgery is an increased incidence of local recurrence and subsequent pulmonary metastases.

Adolescent↗
PubMed1975

Left axis deviation and left anterior hemiblock among 8,000 Japanese-American men.

Electrocardiographic patterns of left axis deviation and left anterior hemiblock, defined by a frontal plane QRS axis of minus 30 degrees to minus 44 degrees and minus 45 degrees to minus 90 degrees, respectively, with normal QRS duration, were found to be fairly common (2.6 and 1.5 percent, respectively) in a community population of 8,000 Japanese-American men aged 45 to 69 years. More than 60 percent of men with these electrocardiographic patterns had no other cardiovascular abnormalities, and the incidence of fatal or nonfatal coronary heart disease and stroke in this group during observation periods of 3 to 6 years was not significantly different from that of control normal men. A significant association was found between these electrocardiographic patterns and the prevalence of hypertension, myocardial infarction and stroke. However, the association of myocardial infarction with left anterior hemiblock appeared to be coincidental and was attributed largely to the similarity of the electrocardiographic manifestations of left anterior hemiblock and inferior wall myocardial infarction. Men with left axis deviation were fatter and had higher blood pressure than the control population. No such difference could be demonstrated for men with left anterior hemiblock although this group was significantly older than control subjects and men with left axis deviation. The results of our study suggest that there are qualitative differences between the causative mechanisms and clinical features of left axis deviation and those of left anterior hemiblock.

Age Factors↗
PubMed1975

Evaluation of commercial radioimmunoassay kits.

By means of kits, RIA and competitive binding assays are beginning to fulfill their great clinical potential. The reliability of these kits is still difficult to assess. The great variety of assayable substances and differing methods prevent any standard approach to kit analysis. Nevertheless there are means of evaluating many features of RIA kits. More important even than the necessary reproducibility of assays are the means of testing for (1) tracer-specific activity, maximal bindability, damage, and free iodine; (2) assay sensitivity; (3) antisera stability, cross-reactivity, ability to measure plasma zero values, ability to accurately measure serial plasma dilutions; (4) comparability of standard curve slopes from assay to assay. Separation techniques need proper standardization. Correction for incubation damage is recommended. It is necessary to insist on reasonable precise manufacturer's specifications as to antibody specificity and sensitivity. Knowledge of RIA in general and each assay in particular adds to the usefulness of the results obtained in the laboratory.

Evaluation Studies as Topic↗
PubMed1975

Radioimmunoassay of insulin.

The powerful nuclear medicine tool of radioimmunoassay was very rapidly developed because of the favorable properties of insulin in such a procedure. The current method of insulin immunoassay in our laboratory is described, with emphasis on the details of the separation of bound and free using talc tablets; emphasis is also given to the correction for tracer damage. The clinical usefulness of the insulin radioimmunoassay is somewhat less than had been anticipated, although its use as a research tool has had immeasurable impact upon the study of metabolism. The presence of proinsulin in plasma is a factor that has to be considered during the radioimmunoassay. Radioimmunoassays for the connecting peptide of proinsulin have also been developed. A preliminary evaluation of two radioimmunoassay kits is described.

Adenoma, Islet Cell↗
PubMed1975

Epidemiologic studies of coronary heart disease and stroke in Japanese men living in Japan, Hawaii and California: introduction.

It has been observed that among men of Japanese ancestry, there is a gradient in CHD mortality increasing from Japan to Hawaii to California. A study of 11,900 Japanese men in Hiroshima and Nagasaki, Japan, Honolulu, Hawaii, and the San Francisco Bay Area of California has been conducted to investigate this disease difference. This paper describes the selection of the study populations and their age distributions, and outlines the study methods. This paper also introduces and briefly summarizes four papers that give the results for mortality comparisons, biochemical and blood pressure distributions and results for heart disease prevalence among the three cohorts.

Aged↗
PubMed1975

Epidemiologic studies of coronary heart disease and stroke in Japanese men living in Japan, Hawaii and California: distribution of biochemical risk factors.

Distributions of serum cholesterol, glucose, uric acid and triglycerides are examined among Japanese men living in Japan, Hawaii and California. Laboratory methods are described in detail and efforts to assure comparability of these methods. In every age group studied, the mean, median and percentile for each of the biochemical variables are lower for men in Japan than in Hawaii and California.

Aged↗
PubMed1975

Epidemiologic studies of coronary heart disease and stroke in Japanese men living in Japan, Hawaii and California: blood pressure distributions.

Blood pressure measurements were made on three Japanese populations residing in Japan, Honolulu, and Northern California. A common protocol was utilized in an effort to standardize inter-observer variability. Zero terminal digit preference varied among the three areas and there was differential clustering of diastolic values at 80 mm Hg and 90 mm Hg in Hawaii and California, respectively. Diastolic blood pressure did not rise with age in any of the three populations while systolic blood pressure rose in each. Blood pressure levels in Japanese in Japan were intermediate to those in Hawaiian and Northern California Japanese, California having the higher blood pressure levels. Since the relative weights of the Japanese migrants to Hawaii and California were substantially higher than the relative weights of the non-migrant populations in Japan, the blood pressures were adjusted for these differences. When this was done, most of the differences among the various study subgroups were explained. The findings indicate that the blood pressure distributions of the Japanese populations residing in Japan, Hawaii, and Northern California cannot of themselves account for the observed differences in coronary heart disease and stroke occurrence among these populations in which there is a gradient from high stroke rates in Japan to low rates in California and a reverse trend for coronary heart disease.

Age Factors↗
PubMed1975

Epidemiologic studies of coronary heart disease and stroke in Japanese men living in Japan, Hawaii and California: prevalence of coronary and hypertensive heart disease and associated risk factors.

A study of coronary heart disease (CHD) among Japanese migrants compared with Japanese living in Japan provided the opportunity to study factors possibly responsible for the high rates of CHD in America as compared with Japan. Comparable methods were employed in examining 11,900 men of Japanese ancestry aged 45--69 living in Japan, Hawaii and California. The age-adjusted prevalence rates for definite CHD as determined by ECG were: Japan 5.3, Hawaii 5.2 and California 10.8/1000. For definite plus possible CHD the rates were 25.4, 34.7 and 44.6. The prevalence of angina pectoris and pain of possible myocardial infarction, determined by questionnaire, showed a similar gradient. Elevated serum cholesterol showed a Japan-Hawaii-California gradient, but the prevalence of hypertension in Japan was intermediate between the prevalence in Hawaii and the higher prevalence in California. The three geographic locations were compared as to prevalence of CHD at comparable levels of blood pressure and cholesterol. At each blood pressure level and at each cholesterol level, the greater prevalence of CHD in California persisted. These facts, plus the near universality of smoking in Japan, suggest that conventional risk factors only partly explain the observed gradient in CHD.

Age Factors↗
PubMed1975

The implications of "skip" metastases in osteosarcoma.

A prospective study of 40 consecutive classic primary osteosarcomas employing tomography, angiography, radio-scanning, tetracycline labelling, macroscopic and microscopic study revealed that in 10 (25%) "skip" metastases were found. In 8 the "skips" were completely unsuspected prior to computation. It is evident that patients with "skips" are more prone to local recurrence and have a worse prognosis following amputation than those without such satellite lesions. Through-bone amputation entails a considered risk of leaving micro-foci of tumor; proximal disarticulation does not obviate the risk of cross joint "skips" when the lesion is in a sub-articular site. What affect such residual foci has upon the effectiveness of adjunct therapy and conversely whether such therapy will permit more conservative surgery by suppressing residual "skips" is an important but unanswered question.

Adolescent↗