Biomedical subjects
Publications and source records attributed to A Baruchin.
A small series of melanomas of the external ear is presented. The presentation in general was late and they varied from 2.6 mm to 4.8 mm in thickness. The outcome in most of the patients (9 patients) was bad and within 3 years only 4 survived. The fact that 9 patients remembered having a nevus that suddenly changed to melanoma emphasizes the need for early removal of such nevi.
A series of 20 patients (15 men and 5 women) suffering from malignant melanoma of the scalp is reported. Their epidemiologic data and outcome are described. The ages ranged from 48 to 78 years (mean 63 years). Analysis of the cases demonstrated that lesions occurring posterior to the tragal line (in hair-bearing area) have the worst prognosis. The 5-year survival rate was poor; 12 patients died within this period. Two representative cases are described, and the preventable aspects of the disease are emphasized.
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Previously, we reported that cold stress induces a rapid increase in adrenomedullary PNMT mRNA levels, followed by concomitant increases in PNMT immunoreactivity (10). In the present study, the extracellular signals mediating this adaptive response to stress were investigated using northern analysis and RNA slot-blot hybridization. Although adrenal denervation significantly diminished cold-induced increments in adrenomedullary PNMT mRNA levels, it did not completely abolish the cold stress response. In contrast to these results, splanchnectomy completely inhibited cold-induced increments in TH mRNAs in the same tissue samples. These findings indicate that the effects of cold exposure on PNMT mRNA levels are mediated by both neural and non-neural mechanisms, and that adrenal PNMT and TH are differentially regulated in response to cold stress. Surprisingly, the neural component of the PNMT stress response could not be attenuated by peripheral administration of chlorisondamine, a powerful nicotinic ganglionic blocking agent. In contrast, chlorisondamine was effective in inhibiting sympathetic neural activity, as judged by the drug's ability to completely block increases in blood pressure, heart rate, and plasma catecholamines resulting from spinal cord stimulation in pithed rats. The administration of atropine, a muscarinic receptor antagonist, also failed to inhibit cold-induced alterations in adrenal PNMT mRNA. These results suggest that the trans-synaptic induction of adrenal PNMT mRNA involves a non-cholinergic component, and that cold-induced increases in PNMT mRNA are not coupled to acetylcholine-mediated adrenal catecholamine release.
The differential effects of insulin-induced hypoglycemia and cold exposure on adrenal medullary epinephrine (Epi) and norepinephrine (NE) cells were investigated in male Sprague-Dawley rats. In rats fasted overnight, insulin produced a marked hypoglycemia that resulted in a 70% decrease in adrenal medullary Epi content 3 h after the insulin was administered. No change in NE content was observed. Plasma Epi concentration was increased markedly after insulin, with a smaller increment in NE. In contrast, exposure to a 4 degrees C environment selectively reduced adrenal NE content, with the effect reaching statistical significance at 18 h. Cold exposure also led to a significant rise in plasma NE but not Epi. Both insulin-induced hypoglycemia and cold exposure significantly elevated adrenal dopamine, indicating that catecholamine synthesis was stimulated. Further evidence of enhanced catecholamine formation was the observation that inhibition of synthesis with alpha-methyl-p-tyrosine (AMT) greatly augmented the ability of insulin-induced hypoglycemia to selectively reduce adrenal medullary Epi content. Similarly, in cold-exposed animals, AMT pretreatment accelerated the NE depletion so that a significant decline was observed at 3 h. These results support the conclusion that the two major populations of adrenal catecholamine-secreting cells may be preferentially stimulated by different stressors. Moreover, augmented synthetic activity functions to maintain catecholamine stores in both Epi- and NE-secreting cells.
The charts of patients with burns covering more than 40 per cent of the body surface area (BSA) who were admitted to the Burn Unit of the Soroka Medical Center, Beersheva, Israel, between the years 1964 and 1988 were reviewed for mortality rate and causes of deaths. The factors affecting survival are reviewed and analysed.
Long-term cold exposure (5-7 days) is known to induce concomitant increases in the levels of adrenomedullary tyrosine hydroxylase (TH) RNA, protein, and enzyme activity. In this report, we compare the time courses of these changes and investigate the effects of cold exposure on the levels of biopterin, the cofactor required for tyrosine hydroxylation. After only 1 h of cold exposure, TH mRNA abundance increased 71% compared with nonstressed controls. Increases in total cellular TH RNA levels were maximal (threefold over control values) within 3-6 h of cold exposure and remained elevated throughout the duration of the experiment (72 h). TH protein levels increased rapidly after 24 h of cold exposure and reached a maximal value threefold above that of controls at 48-72 h. Despite the relatively rapid and large elevations in TH RNA and protein content, only modest increases in TH activity were detected during the initial 48 h of cold exposure. Adrenomedullary biopterin increased rapidly after the onset of cold exposure, rising to a level approximately twofold that of the nonstressed controls at 24 h, and remained at this level throughout the duration of the stress period. Taken together, the results of this time course study indicate that cold-induced alterations in adrenal TH activity are mediated by multiple cellular control mechanisms, which may include pre- and posttranslational regulation. Our findings also suggest that cold stress-induced increases in the levels of the TH cofactor may represent another key event in the sympathoadrenal system's response to cold stress.
The effects of cold exposure on cholinergic binding sites in the rat adrenal gland were assessed by examining the binding of [125I]alpha-bungarotoxin (BTX), a nicotonic receptor antagonist and [3H]quinuclidinyl benzilate (QNB), a muscarinic receptor antagonist, to adrenal tissue homogenates. Cold exposure resulted in significant alterations in both nicotinic and muscarinic binding. Exposure to cold for 4 and 7 days resulted in a significant decrease in QNB binding. Scatchard analysis indicates that this alteration is due to a decrease in binding sites (Bmax) rather than a change in ligand affinity (Kd). In contrast, chronic cold exposure produced a significant increase in BTX binding sites. These results indicate that adrenal cholinergic receptors are altered in reciprocal fashion by chronic cold exposure, and that this change may represent a key event in the sympathoadrenal system's adaptive response to chronic cold stress.
Melkersson-Rosenthal syndrome consists of facial paralysis, facial edema, and scrotal tongue (lingua plicata). Granulomatous cheilitis, frequently associated with the name of Meischner, is generally accepted as a monosymptomatic form of the same syndrome, affects both sexes equally. The earliest manifestations usually develop in childhood or adolescence. We report a case in a 20-year-old woman in order to increase awareness of this entity, in both its classical and aberrant forms.
Intentional self-mutilation of the genitals in males is exceedingly rare and the most recent review included only about 50 cases. The ideal way to handle such cases is by microsurgical techniques, but they require special equipment, instruments and training. We therefore developed a simple, standard technique which can be performed by general surgeons. We report a 19-year-old male in whom the technique was used successfully.
Cold stress is known to increase the synthesis and release of catecholamines in the sympathoadrenal system. Previously, we have demonstrated that cold exposure results in a 3- to 4-fold increase in adrenomedullary tyrosine hydroxylase (TH) activity, which is mediated by concomitant alterations in TH mRNA and protein levels. To further investigate the effects of stress on the expression of the catecholamine biosynthetic enzymes, we have isolated a rat cDNA clone encoding the epinephrine-synthesizing enzyme phenylethanolamine N-methyltransferase (PNMT). The cDNA clone is 905 nucleotides in length and contains a single open reading frame corresponding to 270 amino acids. The amino acid sequence predicted from this nearly full-length cDNA is 89% and 86% identical to that of bovine and human PNMT, respectively. Using the rat PNMT cDNA as a hybridization probe, we have measured the effects of cold stress on the relative abundance of adrenomedullary PNMT mRNA. Levels of PNMT protein were also estimated using an immunoblot analysis. As in the case of TH, cold exposure resulted in a rapid and prolonged increase in PNMT mRNA abundance, followed by concomitant increases in PNMT immunoreactivity. However, there appear to be quantitative and qualitative differences in the adaptive response of TH and PNMT to cold stress.
Details of ten new cases of spondylothoracic dysplasia (the Jarcho-Levin syndrome) are presented. During follow-up, lasting between 8 and 21 years, two children in this group died. Our observations did not confirm Heilbronner's theory concerning the existence of two distinctive types of this syndrome: Type 1 or fatal, and Type 2, with a normal longevity. From the two illustrative cases presented in some detail, and the pertinent literature review, familiarity with spondylothoracic dysplasia is necessary in order to avoid an unjustifiably pessimistic prognosis and to permit correct parent counseling.
A simple, inexpensive, broadly applicable, and quickly applied substitute for the Hoffman apparatus is demonstrated. The procedure uses materials commonly available in hospital operating rooms and provides an excellent immobilization of transosseous pins in pedicled flap surgery and various open and closed fractures of long bones.
Hereditary sensory neuropathy is a rare syndrome characterized by the occurrence, in childhood or early adult life, of perforating ulcers of the feet, lightning pains, and loss of cutaneous sensation and tendon reflexes in the lower extremities. Three patients with hereditary sensory neuropathy were family members. Trophic ulcers may be caused by diseases other than diabetes, syphilis, and leprosy.
A cutaneous horn (Cornu Cutaneum) is a relatively rare tumour, most often arising on sun-exposed skin in elderly men, usually after the Vth decade. The tumor is often conical, consisting of marked retention of stratum corneum. This lesion can be caused by many primary underlying processes that may be benign, premalignant or malignant, thus the importance of accurate determination of the nature of the conditions at the base of the lesion. Surgery is the treatment of choice. We describe an illustrative case with cutaneous horn of the forearm. We also review various known causes of cutaneous horn and the pertinent literature.
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