Luteinizing hormone sensitivity to naloxone in maturing male chimpanzees.

We have systematically investigated the involvement of endogenous opioids in gonadotropin secretion during primate sexual maturation by examining LH/FSH responses to gonadotropin-releasing hormone (GnRH) and changes in LH secretion during infusions of saline or naloxone, an opiate antagonist, in ten male chimpanzees between one and nine years of age. Animals were anesthetized with ketamine (10 mg/kg) and injected or infused IV with GnRH, naloxone or saline. Circulating levels of serum LH were elevated to the same extent (approximately 400%) in response to GnRH (100 micrograms) in animals 1-5 years old (juvenile) and in animals 6-9 years old (pubertal). No differences were noted between the two groups in GnRH-stimulated levels of serum FSH. During treatment with naloxone (0.14 mg/kg bolus followed by 0.2 mg/kg/h maintenance infusion for 3 h), serum LH levels in pubertal animals were significantly (p less than 0.05) elevated by as much as 95% over LH levels found during treatment with saline. Juvenile animals, on the other hand, failed to demonstrate significant increases in serum LH following naloxone at the doses tested. A strong correlation (r = .84) was found between circulating testosterone and serum LH levels during naloxone treatment. These data indicate that opioid inhibition of LH secretion can be reversed by naloxone only when puberty is reached in chimpanzees and suggest an alteration in opioid regulation of GnRH near the time of puberty. The strong correlation between testosterone levels and LH responses to naloxone suggests that steroids may participate in the maturation of opioid control of LH during puberty of nonhuman primates.     

OVERHEATING IN BED AS AN IMPORTANT FACTOR IN MANY COMMON DERMATOSES

Background. Extensive questioning of patients with a wide variety of skin disorders led to the impression that nocturnal overheating was probably an important factor in the initiation and the perpetuation of many skin disorders. Methods. In order to test the hypothesis, 12 “clean-skinned” subjects (6M/6F) aged 18 to 45 years were monitored electronically every 30 seconds during an 8 hour sleep period (2300 to 0700 hours), sleeping under a standard 10 tog duvet. Results. All the subjects were too hot by 3 to 4°C. All showed changes in their EEG patterns with reduced REM sleep, increased awakenings, and all showed changes in their sleep stage patterns. In addition, they all showed evidence of increased sweating in the “heat-sink” area. Conclusions. The mechanisms where by such changes could be implicated in the precipitation and perpetuation of skin disease are discussed. “Lifestyle” modification as a very effective, noninvasive, therapeutic regime is recommended. Further research along these lines would probably be very valuable and instructive.     

Treatment of refractoriness to platelet transfusion by protein A column therapy

Ten thrombocytopenic patients (platelets < 10–24 × 10(9)/L) who were refractory to platelet transfusion were investigated for their responsiveness to staphylococcal protein A column therapy. Nine patients had previously been treated with steroids, intravenous immune globulin, and/or other forms of immunosuppressive therapy without improvement in their transfusion response. All patients were receiving multiple platelet transfusions without achieving 1-hour corrected count increments (CCIs) > or = 7500. Eight patients had antibodies that reacted with platelets and were directed against HLA class I antigens, ABO antigens, and/or platelet-specific alloantigens. Plasma (500-2000 mL) from each patient was passed over a protein A silica gel column and then returned to the patient. Patients received from 1 to 14 treatments. A positive response to protein A therapy was defined as at least a doubling of the pretreatment platelet count and/or two successive 10- to 120-minute posttransfusion CCIs > or = 7500. Following plasma treatments, 6 of 10 patients responded with daily platelet counts that averaged 48 +/− 11 × 10(9) per L as compared with counts of 16 +/− 7 × 10(9) per L (p < 0.0005) before treatment. Posttransfusion CCI values determined in four of these patients averaged 2480 +/− 810 and 10,010 +/− 3540 (p < 0.005) before and after treatment, respectively. In contrast, among the four unresponsive patients, platelet counts averaged 10 +/− 9 and 13 +/− 10 × 10(9) per L (p = NS), respectively, while posttransfusion CCIs were 700 +/− 1410 and 1520 +/− 2460 (p = NS), respectively.(ABSTRACT TRUNCATED AT 250 WORDS)     

Optic chiasm glioma associated with inappropriate secretion of antidiuretic hormone,cerebral ischemia,nonobstructive hydrocephalus and chronic ascites following ventriculoperitoneal shunting

An optic chiasm glioma may cause loss of vision, endocrine disturbances, hydrocephalus and cerebral ischemia due to its proximity to the pituitary, hypothalamus, III ventricle and internal carotids. A 3-month-old infant with optic chiasm glioma developed hypopituitarism and inappropriate secretion of antidiuretic hormone with plasma hypo-osmolality. The cerebrospinal fluid (CSF) protein concentration was markedly elevated. The impairment of fluid absorption via arachnoid villi and peritoneum by the high protein content, and reversed osmotic gradient between protein-rich CSF and hypo-osmolar plasma may have contributed to both nonobstructive hydrocephalus and recurrent ascites following ventriculoperitoneal shunting. Cerebral ischemia from carotid compression may have led to cerebral atrophy.     

Minimal displacement of novel self-anchoring catheters suitable for temporary prostate implants.

Catheters were developed that can be fixed in the prostate gland by self-expanding parts for use in PDR brachytherapy. Daily CT-scans were made to investigate the magnitude of catheter displacement. The mean absolute displacement during the 3 day treatment was 1.2 mm. The resulting minor alterations in dose-volume parameters were of no clinical importance.