The relation of psychosocial dimensions of work with coronary heart disease risk factors: a meta-analysis of five United States data bases

The relation of job psychologic demands and decision latitude to four coronary heart disease risk factors (cholesterol, smoking, and systolic and diastolic blood pressures) was tested among 12,555 men in five investigations conducted in the United States during the period 1959-1980 (National Health and Nutrition Examination Surveys I and II, National Health Examination Survey, Western Collaborative Group Study, and Exercise Heart Survey). Using an imputation strategy, the authors attached measures of the two job characteristics above to persons in each data base by occupation. In 19 possible tests, decision latitude was related (p less than 0.05) to cholesterol and smoking in two instances in the predicted direction in the Exercise Heart Survey, when controlling for Type I error rate. Psychologic demands were not related to any of the risk factors. When a meta-analysis was performed across data bases, all relations were in the predicted direction except for the relation of psychologic demands to systolic pressure, and two of these were statistically significant (p less than 0.05): the relation of job decision latitude to smoking and to systolic pressure. The interaction of psychologic demands and decision latitude was not related to any of the risk factors when two common forms of an interaction were tested. These results indicate that psychosocial aspects of work, in particular the decision latitude of the job, may be related to some cardiovascular risk factors.     

Complications of reduction mammaplasty: comparison of nipple-areolar graft and pedicle

A retrospective study of breast reductions in 268 patients by two plastic surgeons was performed. Particular attention was paid to those patients treated by inferior pedicle techniques; these patients were compared with those treated by free nipple grafts. According to our findings, patients with skin loss were heavier and had longer suprasternal notch-to-nipple distances. Patients who had free nipple grafts were older and heavier and had larger specimen weights and longer suprasternal notch-to-nipple distances. Fifty-four of the original 268 patients were included in a substudy of larger breasts, defined as those with a specimen weight of over 700 g. Nineteen patients underwent free nipple grafts, and 35 underwent inferior pedicle techniques. None of the 19 patients having free nipple grafts developed complications, whereas 6 of the 35 undergoing inferior pedicle techniques sustained significant complications. We conclude that free nipple grafts should be considered over inferior pedicles in heavier patients with breast ptosis.     

CYCLOSPORINE A IMMUNOSUPPRESSION IN SHEEP WITH RESPONSE ENHANCEMENT BY CONCOMITANT KETOCONAZOLE

1. The pharmacokinetics of a single dose of Cyclosporine A (CsA) administered to sheep by intravenous (i.v.) route were examined. 2. Concomitant administration of ketoconazole was found to increase the area under the blood CsA concentration-time curve (AUC) and was effective when adminstered by the oral or intraperitoneal route. 3. The effects of CsA and ketoconazole on the immune system of sheep were also assessed. 4. A single dose of CsA 5mg/kg resulted in abrogation of in vitro lymphocyte function manifest at 24h after injection of CsA. Normal responsiveness recovered in 48-72h. Numbers of T lymphocytes in peripheral blood were elevated transiently at 48h although no other significant alteration in lymphocyte subsets was observed with this treatment. 5. Concomitant ketoconazole administration enhanced the CsA-induced suppression of in vitro lymphocyte responses. Blood levels of CsA (AUC values to 24h) were significantly elevated with concomitant ketoconazole administration and depression of lymphocyte responses to mitogens were also significantly enhanced. An increase in the proportion of T4 positive cells in the blood was observed at 48h and at 7 days after administration of CsA with ketoconazole. 6. These findings indicate that CsA effectively abrogates immunocompetence in the sheep and this immunosuppressive effect is enhanced by concomitant administration of ketoconazole.     

Persistent CT nephrogram: significance in the diagnosis of contrast nephropathy

The prospective study involved 50 patients without known renal masses or previous renal surgery who received intravascular contrast medium for various radiologic procedures and subsequently underwent unenhanced computed tomography (CT) of the kidneys 22-26 hours later. In 42 patients, cortical readings did not exceed 50 HU and corticomedullary attenuation differences (CMADs) did not exceed 10 HU. In seven patients (intermediate group), there was persistent cortical enhancement (mean attenuation, 58.3-84.8 HU; CMAD, 10.3-40.3 HU), but there was no significant rise in levels of blood urea nitrogen or serum creatinine. A single patient had contrast nephropathy and exhibited a mean cortical attenuation of 141.6 HU and a mean CMAD of 85.8 HU on the 24-hour CT scan. The authors have seen two additional cases of contrast nephropathy presaged by mean cortical attenuations of 162 and 209 HU on the 24-hour CT scan. One of these patients had been in the intermediate group in the prospective study. A cortical attenuation of 55-110 HU on a 24-hour postcontrast scan may help identify a group of patients with subclinical renal impairment who are at high risk of nephropathy on subsequent exposure to contrast medium, while cortical attenuations in excess of 140 HU seem to be an early indicator of contrast nephropathy.     

Central activation of the sympathetic nervous system including the adrenals in anaesthetized guinea pigs by the muscarinic agonist talsaclidine

Talsaclidine, a novel M₁-receptor selective muscarinic agonist for cholinergic substitution therapy of Alzheimer’s disease, activates the sympathetic nervous system in guinea pigs and dogs at the orthosympathic ganglia and the paraganglionic adrenals. Results from guinea pigs provide indirect evidence for an additional central site of action. The present investigation in anaesthetized and vagotomized guinea pigs intended to demonstrate central activation of the sympathetic nervous system directly by comparing the blood pressure effects of intracerebroventricular and intravenous injections of small doses of talsaclidine. Increasing doses of 0.2 and 0.6mg/kg talsaclidine were injected alternately into the third cerebral ventricle and intravenously in 6 guinea pigs before and after blockade of peripheral muscarinic receptors with 1mg/kg ipratropium bromide i.v. In another group of 6 animals the injections were given into the cisterna cerebellomedullaris using the same protocol. In both groups central administration of talsaclidine caused dose-related hypertension while intravenous injections were hypotensive. Ipratropium bromide, a peripheral antimuscarinic drug, reversed this hypotensive action of intravenous talsaclidine into hypertension, but did not inhibit the effects of central administration. In contrast, atropine, an antimuscarinic drug which passes the blood-brain barrier, abolished the effect of 0.6mg/kg talsaclidine injected into the cisterna cerebellomedullaris of 8 guinea pigs. The hypertensive effect of a first injection of 0.6mg/kg talsaclidine into the cisterna cerebellomedullaris of 6 guinea pigs was approximately twice as large as that of a second given 90min after bilateral adrenalectomy. Sham operation in another 6 animals was not inhibitory. The results demonstrate that talsaclidine, a selective muscarinic M₁-receptor agonist, activates central parts of the sympathetic nervous system, including central projections of the adrenals by an action mediated by central muscarinic receptors. Received: 11 December 1997/ Accepted: 20 January 1998     

The Olfactory Bulbs Tonically Inhibit Serum Gonadotropin and Prolactin Levels in Male Hamsters on Long or Short Photoperiod

Bilateral removal of the olfactory bulbs (BX) inhibits the testicular regression associated with maintenance of golden hamsters on short photoperiod (10L:14D). The present study was done to examine the reproductive endocrine changes following BX of hamsters, to test whether BX increases gonadotropin secretion by enhancing the rate of metabolism of peripheral testosterone, and to determine whether BX inhibits the response to photoperiod by blocking chemosensory signals from conspecifics. BX resulted in a marked increase in tonic serum gonadotropin levels in pre-pubertal (23 days old) and adult hamsters maintained on long photoperiod (14L:10D). Maintenance on 10L14D inhibited gonadotropin secretion in BX hamsters, but this only reduced the previously elevated levels to those of the sham group on stimulatory photoperiod, and the testes therefore remained large. BX hamsters on 10L:14D had a higher post-castration increase in serum luteinizing hormone than sham-operated hamsters. Following testosterone replacement (20 mm Silastic capsules), BX animals had lower serum testosterone and higher serum follicle- stimulating hormone levels than the sham group. BX hamsters had a shorter mean half-time for disappearance of testosterone from serum following removal of the capsule, but some animals in the sham group also metabolized testosterone rapidly. Isolation in cages receiving air filtered to remove pheromonal type molecules did not affect the rate or degree of testicular regression in response to short days. We conclude that the olfactory bulbs tonically inhibit gonadotropin release in golden hamsters on long or short photoperiod. The olfactory bulbs may facilitate the negative feedback of testosterone and may inhibit testosterone metabolism, but there were also steroid-independent effects. The influence of the olfactory bulbs on the hamsters' response to short days is apparently not related to chemosensory information from other hamsters.