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Biomedical subjects

A Barkan

Publications and source records attributed to A Barkan.

63 records · Page 4Linked to original sources
PubMed1981

Pyrexia of unknown origin. Presenting sign of hypothalamic hypopituitarism.

A 62-year-old man was admitted to hospital 10 times over 12 years because of pyrexia of unknown origin. Hypothalamic hypopituitarism was diagnosed by dynamic tests including clomiphene, LRH, TRH and chlorpromazine stimulation. Lack of ACTH was demonstrated by long and short tetracosactrin tests. The aetiology of the disorder was believed to be previous encephalitis. Following substitution therapy with adrenal and gonadal steroids there were no further episodes of fever.

Fever of Unknown Origin↗
PubMed1980

Effect of tumor removal on the presence of lymphocytic cortisol metabolism-enhancing factor in plasma of cancer patients.

Because lymphocytic cortisol metabolism-enhancing factor (LCMEF) is absent in the plasma of cancer patients (CP), this study was undertaken to determine the influence of tumor removal on this phenomenon. Known concentrations of human lymphocytes were incubated with cortisol in media containing 50% phosphate-buffered saline (PBS) and 50% of one of the following: a) homologic normal plasma (HP),b) plasma from patients with noncancerous diseases (NCD) before surgery, c) plasma from patients with NCD after surgery, d) plasma from CP before tumor removal, e) plasma from CP after tumor removal, f) plasma from long-surviving CP (LSCP), and g) PBS. With the exception of plasma from the LSCP group, all the plasma had the capacity to enhance the lymphocytic cortisol metabolism (LCM) when compared with that of PBS. There was no significant difference between the metabolism obtained with HP and that obtained with plasma from patients with NCD either before or after surgery. The plasma from CP led to a significant reduction in activity, with no significant difference in conversion rates before and after tumor removal. The plasma from LSCP failed to enhance LCM, had a conversion rate similar to that of PBS and significantly lower than that of the plasma from CP, and appeared to contain no LCMEF. These findings, which showed that the lack of LCMEF in CP is not influenced by tumor removal, may indicate 1) that the lack of LCMEF preceded the appearance of cancer or 2) irreversibility of a possible anti-LCMEF synthesis effect was induced by the tumor.

Biological Products↗
PubMed1980

Primary hyperparathyroidism: possible cause of primary hyperaldosteronism in a 60-year-old woman.

Hypertension and hypokalemia were found in a 60-yr-old woman suffering from primary hyperparathyroidism. Laboratory investigations in this patient disclosed 1) elevated levels of plasma aldosterone (PA) which could not be suppressed by a high sodium diet alone or in combination with fludrocortisone (Florinef); 2) a decline of the elevated PA levels after 4 h of ambulation; and 3) low PRA which was unresponsive to stimulation by a low sodium diet coupled with diuretic-induced volume depletion and 4 h of ambulation. These findings were consistent with the diagnosis of primary hyperaldosteronism. Extirpation of a parathyroid adenoma reduced the patient's serum calcium level to normal, and subsequently, a normalization of her blood pressure, serum electrolytes, PA, and PRA were observed. On the basis of these data is is suggested that in this case hyperaldosteronism may have been caused directly or indirectly by primary hyperparathyroidism.

Adenoma↗
PubMed1980

Detection of cancer in patients by reduced lymphocytic cortisol metabolism-enhancing effect.

A double-blind study was done on the plasma from 59 hospitalized patients to determine whether a diminished lymphocytic cortisol metabolism-enhancing effect among cancer patients could be used to distinguish them from persons with noncancerous diseases. Known concentrations of human lymphocytes from healthy donors were incubated with cortisol in media containing 50% phosphate-buffered saline (PBS) and 50% of one of the following additives: 1) homologous plasma (HP), 2) plasma from the patient being tested, or 3) additional PBS. Plasma in which the metabolism-enhancing effect was less than 70% of that obtained with HP was considered to be that of a cancer patient. Among the 19 patients known to have cancer, there were only two false-negative results, whereas among the 40 patients diagnosed as having noncancerous diseases, there were six false-positive results. Thus the test findings and the pathologic diagnosis were obviously correlated in approximately 90% of the patients.

Adolescent↗
PubMedDate not supplied

Participation of nuclear genes in chloroplast gene expression.

The expression of the plastid genome is dependent on a large number of nucleus-encoded factors. Some of these factors have been identified through biochemical assays, and many others by genetic screens in Arabidopsis, Chlamydomonas and maize. Nucleus-encoded factors function in each step in plastid gene expression, including transcription, RNA editing, RNA splicing, RNA processing, RNA degradation, and translation. Many of the factors discovered via biochemical approaches play general roles as components of the basic gene expression machinery, whereas the majority of those identified by genetic approaches are specifically required for the expression of small subsets of chloroplast genes and are involved in post-transcriptional steps. Some of the nucleus-encoded factors may play regulatory roles and modulate chloroplast gene expression in response to developmental or environmental cues. They may also serve to couple chloroplast gene expression with the assembly of the protein products into the large complexes of the photosynthetic apparatus. The convergence of biochemical approaches with those of classical and reverse genetics, and the contributions from large scale genomic sequencing should result in rapid advances in our understanding of the regulatory interactions that govern plastid gene expression.

Cell Nucleus↗
PubMedDate not supplied

Cardiac denervation and other multisystem manifestations caused by isolated autonomic neuropathy in a young diabetic patient.

A young, diabetic woman suffering from fainting spells, vomiting, and diarrhea is described. Extensive investigations showed total cardiac denervation, orthostatic hypotension, and disturbances in the the pupillary and sudomotor functions, as well as impairment of glucagon secretion during hypoglycemia. These disturbances were found to be caused by autonomic neuropathy. No signs of peripheral neuropathy could be detected. To the best of our knowledge this is the second case of total cardiac denervation due to diabetic neuropathy described in the literature.

Adult↗