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Biomedical subjects

G R Lee

Publications and source records attributed to G R Lee.

At least 19 recordsLinked to original sources
PubMed1993

Gender differences in parent care: demographic factors and same-gender preferences.

This study tested the hypothesis that, when aging parents are assisted in the tasks of daily living by their adult children, the gender of the child providing care depends in part upon the gender of the parent requiring care. Data on 4,371 infirm elders and their 13,172 adult children from the National Long-Term Care Survey were analyzed by means of logistic regression. Separate analyses show that adult children are more likely to provide care to a parent of the same gender, and infirm elders are more likely to receive care from a child of the same gender. Because the substantial majority of elderly parents requiring care from children are mothers, this tendency toward gender consistency in the caregiving relationship partially accounts for the fact that daughters are more likely than sons to be involved in parent care.

Activities of Daily Living↗
PubMed1989

Retirement and marital satisfaction.

This study examined the effects of retirement status, length of retirement, and spouse's retirement status on marital satisfaction. Although some previous research and theory suggest that retirement has salutary effects on the quality of marriage, we find no such pattern here. Instead, some small negative effects are observed, particularly involving effects of husbands' retirement on the marital satisfaction of employed wives. These results suggest an explanation in terms of the household division of labor, employing insights from equity theory. Overall, there is no indication of any beneficial impact of retirement on the marital satisfaction of either husbands or wives.

Aged↗
PubMed1989

Social relations and the self-esteem of older persons.

This study employs survey data from a sample of persons 55 years of age and older to examine the antecedents of self-esteem. Hypotheses are derived from a theoretical orientation that hinges on the ability of the individual to terminate relations that might be productive of negative reflected appraisals. Consistent with hypotheses, friendship interaction is positively related to self-esteem, whereas kinship interaction is not. Marital satisfaction also affects self-esteem positively; among men, this effect is stronger for the retired than for the employed. Finally, never-married and nonemployed older women have lower self-esteem than other women have. Implications are drawn regarding the importance and role of self-esteem in theories of psychological well-being among older persons.

Aged↗
PubMed1983

Social integration and fear of crime among older persons.

This study was designed to test the hypothesis that fear of crime is inversely proportional to social integration among elderly adults. Data were obtained by mailed questionnaire from a large sample (N = 2,832) of residents of Washington State aged 55 and over. The results indicate that the most important antecedents of fear of crime, among the variables included here, were indicators of previous direct or indirect victimization experience. Neighborhood integration for men, and voluntary association participation for women, were related negatively to fear of crime as expected. Other dimensions of social involvement, however, evinced little or no relationship to fear. The implications of these findings for the further development of explanatory theory are discussed.

Crime↗
PubMed1983

The anemia of chronic disease.

The anemia of chronic disease (ACD) is defined as a mild anemia associated with a chronic inflammatory, infectious or neoplastic illness and with a characteristic disturbance of iron metabolism. Many of the findings in ACD can be accounted for by release of a monokine called leukocyte endogenous mediator (LEM), endogenous pyrogen, or interleukin-1. This substance is released from "activated" monocytes. Bacterial endotoxins, certain lymphokines and phagocytic challenges are among the factors stimulating its biosynthesis. LEM induces fever, leukocytosis, biosynthesis. LEM induces fever, leukocytosis, and a variety of biochemical changes, including hypoferremia and alterations in plasma protein synthesis, collectively known as the "acute phase response." It is proposed that ACD results from the long-term elaboration of LEM and that release of this material is the common pathogenetic factor found in the illnesses that are associated with ACD. Some suggestions are made for testing the hypothesis. The hypoferremia associated with ACD is probably caused by defective release of iron from cells--particularly from macrophages, but also from hepatocytes and intestinal epithelium. Two possible mechanisms for this abnormality have been proposed: liberation of lactoferrin from neutrophilic leukocytes and induction of apoferritin synthesis. Neither mechanism has been established. Erythrokinetic studies in ACD have detected a modest reduction of erythrocyte survival without an adequate compensatory increase in the rate of red cell production. The reduced erythrocyte survival is probably related to an increase in phagocytic activity by activated macrophages. Impaired bone marrow response is partly related to the restricted iron supply, but there is substantial evidence for an additional defect in erythropoietin secretion. In some malignant diseases, there is evidence of an additional abnormality: impaired marrow response to a normal amount of erythropoietin. The nature of the erythropoietic defects and the relation of LEM to them remain to be established.

Anemia↗
PubMed1977

The anemia of vitamin E deficiency in swine: an experimental model of the human congenital dyserythropoietic anemias.

The ultrastructural and erythrokinetic characteristics of vitamin E deficiency in swine were investigated in an effort to evaluate the suitability of the swine disorder as a model of the human congenital dyserythropoietic anemias. The dominant erythrokinetic abnormality in vitamin E deficient pigs, as in the CDAs, is ineffective erythropoiesis. As in some patients with CDA, the activity of a number of erythrocyte enzymes was increased. Distinctive ultrastructual changes previously described in patients with CDA were found in normoblasts from vitamin E deficient pigs. The morphologic, erythrokinetic, biochemical and ultrastructural similarities between vitamin E deficiency in swine and the CDAs in man appear to justify the study of the animal disorder as a model of the human disease. A complete hematologic response was elicited by the administration not only of vitamin E, but also, as in the previous studies of vitamin E deficiency in monkeys, by hexahydrocoenzyme Q4. The partial hematologic response occurring after deletion of tocopherol stripped corn oil from the diet indicates that factors other than the dietary lack of vitamin E are important in the pathogenesis of this disorder.

Anemia↗
PubMed1977

Sampling in social gerontology: a method of locating specialized populations.

This paper describes a two-stage sampling design for obtaining probability samples of the elderly and other specialized populations. The first stage enumerates a sample of elderly individuals residing in a probability, sample of households; the second stage involves the mailing of a questionnaire to the eligible respondents located in the first stage. The results of this method for a study of noninstitutionalized elderly in Washington State are reported. These results indicate that (1) elderly individuals will respond in the two-stage sampling design does not appear to increase sample bias above that expected in normal mailed-questionnaire studies, and (3) the method is extremely inexpensive. Use of the two-stage design by social gerontologists is recommended.

Aged↗
PubMed1976

An inherited enzymatic defect in porphyria cutanea tarda: decreased uroporphyrinogen decarboxylase activity.

Uroporphyrinogen decarboxylase activity was measured in liver and erythrocytes of normal subjects and in patients with porphyria cutanea tarda and their relatives. In patients with porphyria cutanea tarda, hepatic uroporphyrinogen decarboxylase activity was significantly reduced (mean 0.43 U/mg protein; range 0.25-0.99) as compared to normal subjects (mean 1.61 U/mg protein; range 1.27-2.42). Erythrocyte uroporphyrinogen decarboxylase was also decreased in patients with porphyria cutanea tarda. The mean erythrocyte enzymatic activity in male patients was 0.23 U/mg Hb (range 0.16-0.30) and in female patients was 0.17 U/mg Hb (range 0.15-0.18) as compared with mean values in normal subjects of 0.38 U/mg Hb (range 0.33-0.45) in men and 0.26 U/mg Hb (range 0.18-0.36) in women. With the erythrocyte assay, multiple examples of decreased uroporphyrinogen decarboxylase activity were detected in members of three families of patients with porphyria cutanea tarda. In two of these families subclinical porphyria was also recognized. The inheritance pattern was consistant with an autosomal dominant trait. The difference in erythrocyte enzymatic activity between men and women was not explained but could have been due to estrogens. This possibility was supported by the observation that men under therapy with estrogens for carcinoma of the prostate had values in the normal female range. It is proposed that porphyria cutanea tarda results from the combination of an inherited defect in uroporphyrinogen decarboxylase and an acquired factor, usually siderosis associated with alcoholic liver disease.

5-Aminolevulinate Synthetase↗
PubMed1976

Role of copper in mitochondrial iron metabolism.

Heme synthesis by copper-deficient cells was investigated to elucidate the nature of the defect in intracellular iron metabolism. Iron uptake from transferrin by copper-deficient reticulocytes was 52% of normal, and the rate of heme synthesis was 33% of normal. Hepatic mitochondria isolated from copper-deficient animals were deficient in cytochrome oxidase activity and failed to synthesize heme from ferric iron (Fe III) and protoporphyrin at the normal rate. The rate of heme synthesis correlated with the cytochrome oxidase activity. Heme synthesis from Fe(III) and protoporphyrin by normal mitochondria was enhanced by succinate and inhibited by malonate, antimycin A, azide, and cyanide. It is proposed that an intact electron transport system is required for the reduction of Fe(III), thereby providing a pool of ferrous iron (Fe II) for protoheme and heme a synthesis.

Animals↗
PubMed1975

The role of iron in the pathogenesis of porphyria cutanea tarda. II. Inhibition of uroporphyrinogen decarboxylase.

Porphria cutanea tarda is characterized biochemically by excessive hepatic synthesis and urinary excretion of uroporphyrin I and 7-carboxylporphyrins. This pattern of excretion suggest an impaired ability to decarboxylate uroporphyrinogen to the paired ability to decarboxylate uroporphyringen to the 4-carboxyl porphyrinogen, coproporphyrinogen, a reaction catalyzed by the enzyme uroporphyringen decarboxylase. Because clinical evidence has implicated iron in the pathogenesis of porphyria cutanea tarda, these experiments were designed to study the effect of iron on uroporphyrinogen decarboxylase in procine crude liver extracts. Mitochondria-free crude liver extracts were preincubated with ferrous ion and aliquots were assayed for uroporphyrinogen decarboxylase activity. Uroporphyrinogens I and III, the substrates for the decarboxylase assay, were prepared enzymatically from (3H)porphobilinogen. The products of the decarboxylase reaction were identified and quantitated by three methods: (a) extraction into 1.5 N HCl and spectrophotometric quantitation; (b) adsorption onto talc, esterification, paper chromatographic identification, and quantitation by liquid scintillation counting; and (c) adsorption onto talc, esterification, thin-layer chromatographic identification on silica gel, and quantitation by liquid scintillation counting. The thin-layer scinllation method proved most sensitive as it was the only method which accurately identified and quantitated the 7-carboxyl porphyrin reaction product. Uroporphyrinogens I and III were decarboxylated at the same rate by porcine hepatic uroporphyrinogen decarboxylase, and the addition of iron induced marked inhibition of the decarboxylase activity. Ortholpehanthroline blocked the inhibitory effect of iron. The inhibition of uroporphyrinogen decarboxylase by ferrous ion, coupled with its previously reported inhibitory effect on uroporphyrinogen III cosynthetase, provides a possible biochemical explanation for the pattern of urinary porphyrin excretion observed in patients with porphyria cutanea tarda and the clinical association with disordered iron metabolism.

Animals↗
PubMed1975

Superoxide dismutase activity in copper-deficient swine.

These experiments demonstrate the dependency of cuprozinc superoxide dismutase activity in red cells and liver on an adequate dietary intake of copper. The superoxide dismutase activity in red cells decreased to 15% of control values and, therefore, these cells may be used as a convenient model for studying the physiologic consequences of free radicals

Animals↗
PubMed1975

Porphyria cutanea tarda associated with disinfectant misuse.

Porphyria cutanea tarda was detected in a 44-year-old janitress. The illness was probably caused by the unintentional synthesis of a polychlorinated phenol as a result of mixing commonly available household ingredients in toilet bowls and shower stalls. Although the evidence for this hypothesis is circumstantial, its likelihood and the wide-spread household use of these reagents justify calling attention to the innovative misuse of disinfectants as a potential source of toxic exposure.

Adult↗