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Biomedical subjects

R E Lynch

Publications and source records attributed to R E Lynch.

At least 73 records · Page 4Linked to original sources
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↗
PubMed1976

Inhibition by superoxide dismutase of methemoglobin formation from oxyhemoglobin.

The formation of methemoglobin from oxyhemoglobin in a solution containing photoreduced riboflavin and oxygen was inhibited by superoxide dismutase. The rate of the reaction was pH-dependent in the range of 6.8 to 7.8, increasing as the pH was reduced. Inhibition by superoxide dismutase was enhanced as the EDTA concentration increased and was dependent on enzymatic activity. Under conditions in which superoxide dismutase inhibition was incomplete, catalase inhibited the reaction but mannitol had no effect. The data support the mediation of methemoglobin formation by superoxide. The hypothesis is offered that superoxide anion reduced the heme-bound oxygen in oxygemoglobin by one electron, permitting the subsequent dissociation of ferrihemoglobin and peroxide. The ability of superoxide dismutase to inhibit the formation of methemoglobin may represent one of its functions in the mature erythrocyte.

Animals↗
PubMed1976

Kidney transplants in patients over 50.

Patients with end-stage renal failure shouldn't be denied the only possibility of cure just because they're old or have other chronic diseases. In this study of 69 patients over age 50-the largest series reported from a single medical center-kidney transplants from related donors had the same high rate of success as in younger patients. Over 80 percent of the patients who received kidneys from their children or siblings are still alive, in contrast to 52 percent of those who had to settle for a cadaver kidney. Infection posed the most serious hazard after surgery. Late complications, particularly hypertension and diabetes, were easily controoled and by no means debilitating. Four of the survivors still need hemodialysis, but over two-thirds have recovered completely.

Aged↗
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↗
PubMed1975

The prognosis in aplastic anemia.

The biphasic shape of the survival curve of 99 patients with aplastic anemia suggested that there may be at least two subgroups of patients with this disease, one with a very short survival and another with a longer survival. Patients who survived for 4 mo or less after the first clinic visit (group A) were different from the patients who survived longer (group B) with respect to their modes of onset, sex, intervals from the onset of symptoms to first clinic visit, and initial hematologic values. These differences suggested that short survival could be predicted from data available at the first contact with the physician. From these measurements, a prognostic index could be calculated which was useful in identifying the patients in group A. Although this method of prognostication needs further testing, if validated, it may prove useful in selecting patients for therapeutic trials and could explain the divergent results in previous studies of androgen treatment of aplastic anemia. When our androgen-treated subjects were compared with subjects with a similar prognostic index who had not received androgens, a beneficial effect of androgen therapy on survival could not be demonstrated.

Anemia, Aplastic↗