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Biomedical subjects

L Cohen

Publications and source records attributed to L Cohen.

At least 559 records · Page 31Linked to original sources
PubMed1977

Diet and endocrine-related cancer.

In women, dietary modification and life style affect the risk of breast cancer and may alter the hormonal status, while in experimental animals diet can alter the incidence of induced mammary tumors. In this study, a high fat diet increased the incidence of DMBA-induced tumors in rats while this increase in incidence was lowered and the effect of a high fat diet obliterated by an anti-prolactin during CB154. Premenopausal Japanese women had a higher estradiol level than their Caucasian counterpart. In Japanese but not Caucasian breast cancer patients, the estradiol decreased. When nurses were transferred from the Western to a vegetarian diet, the menstrual cycle was shortened, while their prolactin and testosterone decreased. Data indicate that dietary factors influence tumor incidence and hormone profile in rat mammary cancer and the hormonal status in women.

Adult↗
PubMed1977

Failure of selected endocrine organ ablation to modify the natriuresis of blood volume expansion in the dog.

1. Selected organ-ablation experiments were performed in dogs in an attempt to identify the source of the natriuretic hormone postulated to participate in the natriuresis of blood volume expansion. 2. An isolated dog kidney perfused with blood from the femoral artery of deoxycorticosterone-loaded dogs subjected to acute volume expansion with equilibrated blood served as the bioassay system for the natriuretic factor. Four groups were studied after the following procedures: group I, no ablation; group II, thyroparathyroidectomy; group III, hypophysectomy; group IV, adrenalectomy. 3. In all groups, the administration of equilibrated blood promoted a significant increase in sodium chloride excretion in the isolated kidney. The natriuresis was unrelated to changes in glomerular filtration rate, renal blood flow, renal arterial pressure, plasma protein concentration or packed cell volume. In the absence of volume expansion, sodium chloride excretion in the isolated kidney did not change or decreased. 4. These results argue against the thyroid, parathyroid, adrenal and pituitary glands as the source of natriuretic hormone.

Adrenalectomy↗
PubMed1977

Accumulation of nucleotides by starved Escherichia coli cells as a probe for the involvement of ribonucleases in ribonucleic acid degradation.

The acid-soluble ribonucleic acid degradation products formed by Escherichia coli cells starved for a carbon source have been identified. They comprise oligonucleotides, nucleoside diphosphates, 5'- and 3'-nucleoside monophosphates, nucleosides, and free bases. The majority of these products are excreted phates, nucleosides, and free bases. The majority of these products are excreted into the medium, and only small and constant amounts are kept in the pool. During carbon starvation at elevated temperatures, mutants deficient in ribonuclease I do not form oligonucleotides and 3'-nucleoside monophosphates, and mutants that contain a modified form of polynucleotide phosphorylase do not accumulate nucleoside diphosphates. 5'-Nucleoside monophosphates do accumulate, however, in a mutant containing thermoabile ribonuclease II, under conditions where more than 95% of all enzyme activity had been destroyed. The data presented confirm the participation of ribonuclease I and polynucleotide phosphorylase in the final steps of ribonucleic acid degradation and indicate that an exonuclease forming 5'-nucleoside monophosphates is also involved.

Endonucleases↗
PubMed1977

Adolescent Rorschach responses as a function of age at first institutionalization.

To test the hypothesis that age of first separation from a home environment is a factor in the emotional health of institutionalized boys, Rorschach protocols of 82 residents of Saint Francis Vocational School, a facility for deprived nondelinquent nonretarded youth aged 10 to 18, were examined. Seven Rorschach variables were used as dependent variables of emotional status. It was found that boys who had first been institutionized before age 10 gave more color-dominant and pure color responses (p less than .005), and more responses with pathological overtones (p less than .005), than did youth first placed at ages 10 to 13 or ages 14 to 17. Fixation was proposed as the basis for the group differences.

Adolescent↗
PubMed1977

Mural endocarditis associated with recurrent false aneurysm of the left ventricle.

Acute bacterial endocarditis developed in a 65-year-old man two years after surgical resection of a false aneurysm of the left ventricle. The patient had cerebral embolic manifestations, and coagulase-positive Staphylococcus aureus was cultured from each of six blood samples. A pericardial friction rub and a changing pansystolic murmur appeared during the third week of hospitalization. The presence of a false aneurysm was once again demonstrated on ventriculographic studies. This was successfully repaired, employing cardiopulmonary bypass. The sequence of events in this patient suggests that bacterial endocarditis at the site of a previous cardiomyotomy might have led to the development of the second pseudo-aneurysm.

Aged↗
PubMed1977

Thrombosed giant left atrium mimicking a mediastinal tumor.

A patient with rheumatic heart disease, mitral stenosis, and mitral insufficiency is described. The thrombosed giant left atrium paralyzed the left vocal cord and completely obstructed the bronchi to the middle and lower lobes of the right lung. The giant left atrium mimicked a mediastinal tumor on the chest x-ray film.

Airway Obstruction↗
PubMed1977

Effects of the simultaneous administration of diethylstilbestrol and prednisolone on serum enzymes in Duchenne's muscular dystrophy.

The effects of diethylstilbestrol (DES) and prednisolone (Pr), administered alone or in combination, on the serum enzyme activities in Duchenne's muscular dystrophy (DMD) have been evaluated. When DES and Pr were given simultaneously to four boys with DMD, the mean creatine phosphokinase and lactate dehydrogenase levels fell to about one half those achieved with either agent alone. No untoward or unexpected side effects were encountered. These observations, and our previous demonstration that both agents reduce enzyme efflux from skeletal muscle, give promise that a safe combination therapy may be found to approximately normalize the serum in DMD. This will permit us to test the hypothesis that lowering the serum enzymes, by reducing their loss from skeletal muscle, will slow or arrest the muscle deterioration characteristic of this disease.

Child↗
PubMed1977

Variable effects of corticosteroid treatment of serum enzyme activities in Duchenne's muscular dystrophy.

Corticosteroid administration on alternate days to five boys with Duchenne's muscular dystrophy (DMD) lowered the high serum creatine kinase and lactate dehydrogenase activities in three, caused no change in one, and increased these activities in one. These observations indicate that, as given, this therapy can partially normalize a major biochemical abnormality of this disease in some but not all patients with DMD.

Adolescent↗
PubMed1977

Portal hypertension and esophageal varices in hemangiomatosis of the spleen.

Bleeding esophageal varices and severe portal hypertension developed in a patient with capillary hemangiomatosis of the spleen. No signs of cirrhosis were found at postmortem examination, and preoperative celiac angiography suggested an intrasplenic shunt as the cause of the high portal pressure. Although a very rare condition, this possibility should be considered in the differential diagnosis of esophageal varices.

Arteriovenous Fistula↗
PubMed1977

Penicillamine effects on enzyme efflux from skeletal and heart muscle.

We have previously shown that pretreatment of mice with diethylstilbestrol (DES) or prednisolone (Pr) lowered enzyme efflux from isolated mouse skeletal muscle. These same agents also lowered the high serum enzyme activities in boys with Duchenne's muscular dystrophy (DMD). In a continuing search for other agents with similar effects, the influence of penicillamine (Pe) on enzyme efflux from isolated muscle was assessed, because it lowered the high plasma creatine phosphokinase (CPK) and produce beneficial effects in avian muscular dystrophy. Three groups of mice received 0, 1, or 10 mg Pe daily for 14 days. All mice were given supplementary pyridoxine. The egress of CPK and lactate dehydrogenase from the isolated left gastrocnemius and heart was determined over a 5 hour period. Pe produced more modest effects than did DES or Pr. The 10 mg dose reduced enzyme efflux from the gastrocnemius by 10%. In contrast, heart enzyme efflux was augmented by 20%. Similar dose-related disparate effects on enzyme efflux from skeletal muscle and heart have been previously noted for DES and Pr. Pe is the third agent found to lower the high serum enzyme activities in muscular dystrophy and reduce gastrocnemius enzyme efflux from isolated mouse skeletal muscle. This further establishes the usefulness of the mouse assay for identifying agents that lower the high serum enzyme activities in muscular dystrophy.

Animals↗
PubMed1977

Abolition of the diethylstilbestrol reduction of enzyme leakage from muscle by a 3,3' diallyl substitution.

Diethylstilbestrol (DES) lowers enzyme efflux from isolated mouse skeletal muscle. It also lowers the high serum enzyme activities in Duchenne's muscular dystrophy. We have begun a systematic study of DES congeners, to identify those portions of the DES molecule which are critical to these effects, and to tailor a molecule which might have fewer feminizing effects. The first compound tested was the 3,3' diallyl derivative of DES (DAS). It was selected because previous reports indicated that it was as anabolic as DES, but only 1/10 to 1/30 as estrogenic. Doses of 20, 100 and 250 microgram/mouse/day were administered in 0.05 ml sesame seed oil vehicle to C57BL/6 mice. Control animals received only the vehicle. In contrast to DES which has consistently reduced muscle enzyme efflux 30-50%, DAS was inert. The substitution of the two allyl groups in the 3 and 3' positions blocks access to the neighboring ethyl groups and partially covers the two phenolic hydroxyl groups of DES. This suggests that these molecular sites have pertinence to the reduction of enzyme efflux from mouse skeletal muscle by DES, and possibly the reduction of the high serum enzyme activities in Duchenne's muscular dystrophy.

Allyl Compounds↗
PubMed1976

Requirement of precommitted cells as targets for the augmentation of lymphocyte proliferation by leukocyte dialysates.

After our initial report tha leukocyte dialysates containing transfer factor augment the thymidine incorporation of antigen-stimulated lymphocytes, we have adapted the system to microleukocyte cultures. This modification permits both (a) the simultaneous assay of a single dialysate on the cells of multiple individuals, and (b) the assay of multiple dialysates on the cells of a single individual. The data thus secured, demonstrate that dialysates from both skin-test-positive and -negative donors produced similar degrees of augmentation whether the data are expressed as an arithmetic difference or as a ratio. When expressed as an arithmetic difference, the amount of augmentation is increased in proportion to the level of thymidine incorporation of the assay cells when they were stimulated by antigen alone. When expressed as a ratio, however, the degree of augmentation is independent of the response of the assay cells. An analysis of the ability of dialysates to engage previously uncommitted lymphocytes and thus to augment thymidine incorporation, revealed that precommitted cells were required. In these experiments, antigen-reactive cells were deleted from populations of peripheral blood lymphocytes by incubation with purified protein derivative of tuberculin, diphtheria toxoid, or streptokinase-streptodornase in the presence of [3H]thymidine of high specific activity. This deletion depressed or abolished the effect of dialysate on the residual population when it was recultured with the same antigen, but the effect on the response of the remaining lymphocytes to other antigens was unaltered. In this study, leukocyte dialysate appeared to augment nonspecifically the thymidine incorporation of an antigen-specific precommitted clone of lymphocytes. The relationship of these adjuvant effects on peripheral blood lymphocytes in vitro to the specific and nonspecific activities of transfer factor in vivo remains to be elucidated.

Adjuvants, Immunologic↗