Energy restriction does not alter bone mineral metabolism or reproductive cycling and hormones in female rhesus monkeys

Energy restriction (ER) extends the life span and slows aging and age-related diseases in short-lived mammalian species. Although a wide variety of physiological systems have been studied using this paradigm, little is known regarding the effects of ER on skeletal health and reproductive aging. Studies in rhesus monkeys have reported that ER delays sexual and skeletal maturation in young male monkeys and reduces bone mass in adult males. No studies have examined the chronic effects on bone health and reproductive aging in female rhesus monkeys. The present cross-sectional study examined the effects of chronic (6 y) ER on skeletal and reproductive indices in 40 premenopausal and perimenopausal (7-27 y old) female rhesus macaques (Macaca mulatta). Although ER monkeys weighed less and had lower fat mass, ER did not alter bone mineral density, bone mineral content, osteocalcin, 25-hydroxyvitamin D, 1,25-hydroxyvitamin D or parathyroid hormone concentrations, menstrual cycling or reproductive hormone concentrations. Body weight and lean mass were significantly related to bone mineral density and bone mineral content at all skeletal sites (total body, lumbar spine, mid and distal radius; P: < or = 0.04). The number of total menstrual cycles over 2 y, as well as the percentage of normal-length cycles (24-31 d), was lower in older than in younger monkeys (P: < or = 0.05). Older monkeys also had lower estradiol (P: = 0.02) and higher follicle-stimulating hormone (P: = 0.02) concentrations than did younger monkeys. We conclude that ER does not negatively affect these indices of skeletal or reproductive health and does not alter age-associated changes in the same variables.     

Osteopontin: possible role in prostate cancer progression.

Human prostate cancer has the propensity to metastasize to the bone where reciprocal cellular interactions between prostate cancer and bone cells are known to occur. Osteopontin (OPN), a noncollagenous bone extracellular matrix, is a secreted adhesive glycoprotein with a functional RGD cell-binding domain that interacts with the alpha(v)beta3 cell surface integrin heterodimer. OPN has been associated with malignant transformation as well as being ligand to the CD44 receptor. Polyclonal antibodies to human OPN (hOPN) were prepared, and specificity was shown by preabsorption with recombinant hOPN. The stimulatory effect of hOPN protein and the inhibitory effect of hOPN antibody on human prostate cancer cell lines LNCaP and C4-2 were assessed by induction or inhibition of anchorage-independent growth, respectively. Expression of hOPN mRNA in prostate cancer cell lines and human prostate cancer tissue specimens were measured by mRNA blot analysis. Protein expression was assessed by immunohistochemistry in human prostate cancer specimens and by Western blot analysis in prostate cancer cell lines. hOPN stimulated anchorage-independent growth of the human prostate cancer cell lines LNCaP and C4-2 in vitro. Antibodies to hOPN inhibited the growth-stimulatory effect by endogenous OPN, which can be overcome by the addition of exogenous hOPN. hOPN mRNA and protein are expressed in human prostate cancer cell lines in vitro and in clinical human prostate cancer specimens. These findings taken together suggest that OPN may act as a paracrine and autocrine mediator of prostate cancer growth and progression.     

The stabilizing effect of various implants on the torn acromioclavicular joint. A biomechanical study

A biomechanical in vitro test was performed to determine the stabilizing effect of various implants for the surgical treatment of the torn acromioclavicular joint. In a specially designed testing device, plastic and cadaver specimens of the shoulder girdle were stressed in various ways. Different dislocations between the acromion and the clavicle and between the clavicle and the coracoid were determined, as well as the stiffness of the implants. A convenient stabilizing effect combined with less rigid fixation to secure the newly treated AC joint was provided by K-wire fixation with cerclage. Interfering shear and bending stresses could be avoided with this method, while the other implants showed various disadvantages. From a biomechanical point of view, a carbon-fiber ligament replacement provides sufficient stability in cases of chronic acromioclavicular separation.     

Naltrexone modifies the palatability of basic tastes and alcohol in outbred male rats.

Naltrexone, an opioid antagonist, has been shown to reduce the palatability of 10% alcohol solutions in rats, as measured by taste reactivity. In the present study, the effect of acute naltrexone treatment on taste reactivity to a variety of taste solutions and concentrations was tested to determine whether naltrexone has generalized effects on taste responsiveness. Thirty minutes before a taste reactivity test, rats were injected with either naltrexone (3 mg/kg; n = 15) or saline (n = 15). On separate days, rats were tested with distilled water and three concentrations each of sucrose (0.1, 0.5, and 1.0 M), sodium chloride (0.06, 0.10, and 0.30 M), quinine hydrochloride (0.0005, 0.001, and 0.005 M), and alcohol [10%, 20%, and 40% (vol./vol.)]. In Experiment 1, naltrexone consistently reduced the palatability of alcohol and sodium chloride solutions (across concentrations), as reflected by a decrease in ingestive responding and an increase in aversive responding. Naltrexone increased aversive responding for sucrose but did not affect ingestive responding for these solutions. Finally, there was no significant effect of naltrexone on responding to quinine hydrochloride. A second experiment with naive rats and five concentrations of sucrose (0.01, 0.05, 0.1, 0.5, and 1.0 M) replicated the initial data: Across concentrations, naltrexone produced a significant increase in aversive responding but did not alter ingestive responding. In Experiment 3, naive rats were tested with five concentrations of quinine hydrochloride (0.00001, 0.00005, 0.0001, 0.0005, and 0.005 M). Results indicated that naltrexone significantly altered taste reactivity to the bitter solutions (less ingestive responding and more aversive responding), particularly at the lower concentrations. The results indicate that naltrexone treatment has significant effects on taste reactivity to some aqueous solutions (alcohol, sodium chloride), regardless of solution concentration. The effects of naltrexone on sucrose and quinine reactivity are more difficult to describe because the drug effects seemed to be dependent on the specific measure examined (ingestive vs. aversive responses) and the concentration of the solution. These results support the suggestion that naltrexone has a fairly generalized effect on taste reactivity to taste solutions; specifically, naltrexone seems to make solutions more aversive, as revealed by a decrease in ingestive responding and an increase in aversive responding.     

The effectiveness of continuation-maintenance ECT in reducing depressed older patients' hospital re-admissions

Background:We report on the outcomes in aged patients with severe, treatment-resistant depression or psychosis who were given ongoing outpatient continuation-maintenance ECT of varying duration to prevent remission and relapse following a successful course of acute ECT.Methods:A retrospective chart review of 58 consecutive patients of three Australian aged psychiatry services comparing the number and length of psychiatric admissions before and after the start of continuation-maintenance ECT.Results:Four patients had only one treatment and two received over 50 (mean 14.7). Five were still enrolled in a maintenance program two years later. In the two years after continuation-maintenance ECT started, admissions fell by 53% in number and 79% in duration compared with the previous two years. Within the actual treatment period which varied from one patient to another, admissions fell by 90% in number and 97% in duration compared with the same period beforehand.Conclusion:A treatment effect cannot be proven but the severity and chronicity of patients' conditions make placebo effects and spontaneous remission unlikely. Randomised, controlled trials are almost impossible in this setting and so carefully conducted reviews and case–control studies are still of value. Our findings suggest that continuation-maintenance ECT is effective in carefully selected patients at high risk of relapse.     

Melatonin administered systemically alters the properties of visual cortex cells in cat: further evidence for a role in visual information processing

The effects of melatonin given systemically at night-time were investigated in the visual system of cats by means of electrophysiological recordings from single cells in the striate cortex (area 17). Following intravenous injection of melatonin, the spontaneous discharge rate (SDR) was found to decrease in the majority of units when compared to control situations. In addition, the amplitude of responses to photic stimulation (moved light bars on a dark background) was augmented. These results reveal that, following application of melatonin, an improved signal-to-noise ratio is found in response to visual stimuli. The physiological source and putative action sites of melatonin are discussed with regard to its physiological role as a neuromodulating substance. The present data, in addition to previous work, suggest that melatonin is involved in visual information processing such as object detection and dark adaptation.