Clinical outcome of maraviroc-containing therapy in heavily pre-treated HIV-1-infected patients.

Available data on the use of maraviroc (MVC) in clinical settings are limited. In this cohort study, the clinical outcomes of HIV-1-infected patients treated with MVC were analysed and the predictive values of different tropism assays were compared. Baseline viral tropism was assessed and compared by phenotypic (Trofile and MT-2) and genotypic assays. Virological and immunological responses were evaluated. In total, 62 predominantly extensively pre-treated patients started MVC [median GSS 2.0 (IQR 2.0-2.5)]. Tropism assays were performed on baseline samples of 58 patients (93.5%). Thirty-two samples (80.0%) were classified as R5 by Trofile, 41 (80.4%) by genotypic tropism test (GTT) and 17 (81.0%) by MT-2. At least two types of tropism assay were performed on samples from 39 patients, whereas in 15 patients all three assays were performed (concordance 84.8-94.1%). Plasma HIV-RNA was <50 copies/mL in 82.1%, 85.0% and 68.8% of patients after 12, 24 and 36 months, respectively; median CD4 cell increase was 199 (IQR 108-283), 291 (IQR 187-413) and 234 (IQR 106-444)cells/µL. The predictive values of different tropism assays were comparably high: at Month 24, 92.9% (Trofile and GTT) and 100.0% (MT-2) of patients had plasma HIV-RNA <50 copies/mL. Three patients stopped MVC treatment because of suspected side effects. Five patients died during follow-up. In this heavily pre-treated cohort, treatment with MVC was well tolerated and resulted in good immunological and virological responses. Results generated by the different tropism assays correlated well with each other and had a high predictive value.

Efficacy and user preference of two CO2 detectors in an infant mannequin randomized crossover trial.

Assessment of effective ventilation in neonatal mask ventilation can be difficult. This study aims to determine whether manual ventilation with a T-piece resuscitator containing an inline CO2 detector (either a Pedi-Cap® CO2 detector or a Neo-StatCO2

Resveratrol preconditioning induces cellular stress proteins and is mediated via NMDA and estrogen receptors.

Resveratrol pretreatment has been shown to provide neuroprotection in models of cerebral ischemia. This phenomenon, commonly termed preconditioning, promotes ischemic tolerance and may involve mild activation of endoplasmic reticulum stress pathways in the affected tissue. Systemic injection of resveratrol (2 x 10(-3), 2 x 10(-4), 1 x 10(-4) mg/kg) 30 min prior to a 4 h period of right middle cerebral artery occlusion significantly reduced infarct area in the insular region of rat prefrontal cortex. This affect was blocked when resveratrol treatment was combined with a non-selective estrogen receptor antagonist, or preceded by intracortical injection of an NMDA receptor antagonist. The neuroprotective effect of resveratrol was associated with reduced renal sympathetic nerve activity as well as induction of resident endoplasmic reticulum chaperone proteins, glucose-regulated proteins 78 and 94. The calcium-sensitive chaperone heat shock protein 70 and the cysteine protease m calpain did not respond to resveratrol pretreatment. However, a significant induction of heat shock protein 70 was observed in the contralateral cortex of resveratrol pretreated rats following 4 h of right middle cerebral artery occlusion. These data suggest that resveratrol preconditioning promotes ischemic tolerance in the short term, in part via effects mediated through activation of estrogen and NMDA receptors, as well as through mild activation of cellular stress proteins.

Role of oestrogen in the central regulation of autonomic function.

1. In recent years, the role of oestrogen in women's health has been a subject of considerable scientific and popular debate. There is unquestionable evidence that oestrogen has both potent and long-lasting effects on several vital organ systems, including the cardiovascular system, the autonomic nervous system and, most recently, within the central nervous system itself. 2. The research and medical community continues to debate whether the benefits of oestrogen therapy outweigh the risks in the treatment of the symptoms of menopause, the attenuation of the risk for cardiovascular insults, such as stroke and heart disease, and even the retardation of the progression of Alzheimer's disease. 3. The recent evidence provided by the Heart and Estrogen/Progestin Replacement Study (HERS) II clinical trial suggesting that long-term exposure to combined oestrogen and progestin in post-menopausal women who have previously had a heart attack or stroke (for secondary prevention) may actually increase their risk of a subsequent cardiovascular insult has further fuelled the debate. However, there remain considerable gaps in our knowledge with respect to the actual mechanisms by which oestrogen exerts its various beneficial effects at the cellular level for the primary prevention of cardiovascular disease. This information is essential if we are to harness the positive aspects of oestrogen therapy in such a manner as to avoid or minimize the associated risks of increased oestrogen exposure in women who we know, with some certainty, to be at an increased risk of cancers of the uterus, cervix and breast tissue.

Estrogen limits ischemic cell death by modulating caspase-12-mediated apoptotic pathways following middle cerebral artery occlusion.

Estrogen has received considerable attention as a potential therapeutic agent against various forms of neurodegenerative diseases including stroke. Experimental data in animal models of stroke have provided exhaustive evidence of the neuroprotective properties of this steroid hormone. Our laboratory in particular has demonstrated that acute estrogen treatment in male rats significantly reduced (approximately 50%) ischemic cell death within 4 h following permanent occlusion of the middle cerebral artery occlusion (MCAO). However, the cellular and molecular mechanisms implicated in the protective actions of estrogen in this experimental model have yet to be elucidated. Accumulating evidence suggests that in various in vivo and in vitro models, estrogen can be pro-apoptotic and that this effect may be mediated by an estrogen-induced up-regulation of the Fas/FasL system and the subsequent activation of caspase-12. We therefore hypothesized that under ischemic conditions following MCAO, estrogen would up-regulate protective endoplasmic reticulum (ER) stress pathways leading to caspase-12 activation, thus limiting infarct volume. Our results showed that estrogen significantly increased activated caspase-12 at 2, 3 and 4 h post-MCAO. Immunostaining of brain sections showed a significantly higher number of terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling positive cells in estrogen-treated animals at 4 h, but not at 2 h, post-MCAO. These findings correlate with previous observations that differences in infarct volume between saline and estrogen-treated animals are not seen until 3 and 4 h post-MCAO. A decrease in m-calpain expression was observed in the infarct region only at 4 h post-MCAO following estrogen pre-treatment, suggesting m-calpain may not be involved in regulating estrogen-induced caspase-12 activation. Based on these cellular changes correlated to estrogen pretreatment, we conclude that estrogen may up-regulate ER-specific apoptotic pathways, thus limiting the extent of necrotic cell death which is responsible for the spreading depression and growth of the infarct volume following MCAO.

Estrogen-mediated neuroprotection in the cortex may require NMDA receptor activation.

Several studies have suggested that a potential mechanism for estrogen-mediated neuroprotection following experimental stroke is a result of modulating glutamate-mediated excitotoxicity. Our laboratory has shown that in male rats, estrogen injection (systemic or direct intracortical injection) resulted in an immediate depolarization of cortical neurons. Therefore, the present study was designed to investigate whether the estrogen-induced depolarization of cortical neurons was required in mediating the early events associated with this neuroprotection. We tested this hypothesis by co-injecting selective antagonists of the NMDA (MK-801) or AMPA (DNQX) glutamatergic receptors with estrogen. Systemic injection of estrogen significantly attenuated the MK-801-induced decrease in infarct volume following middle cerebral artery occlusion (MCAO). Similarly, when estrogen and MK-801 were co-injected directly into the cortex, no neuroprotection was observed. However, when estrogen or MK-801 was injected centrally 10 min prior to the injection of the other drug, significant neuroprotection was observed. This led us to hypothesize that estrogen-mediated neuroprotection required an initial activation of NMDA receptors. Furthermore, our results suggest that this estrogen-mediated neuroprotection was also associated with a significant increase in m-calpain and activation of an endoplasmic reticulum (ER) specific caspase-12. Finally, the results of current clamp experiments showed that estrogen significantly depolarized cortical neurons as well as enhanced NMDA-induced depolarization. Taken together, these results suggest that estrogen pretreatment may activate NMDA receptors resulting in modification of ER-associated molecular mechanisms involved in neuroprotection following MCAO.

Estrogen synthesis in the central nucleus of the amygdala following middle cerebral artery occlusion: role in modulating neurotransmission.

Stroke-induced lesions of the insular cortex in the brain have been linked to autonomic dysfunction (sympathoexcitation) leading to arrhythmogenesis and sudden cardiac death. In experimental models, systemic estrogen administration in male rats has been shown to reduce stroke-induced cell death in the insular cortex as well as prevent sympathoexcitation. The central nucleus of the amygdala has been postulated to mediate sympathoexcitatory output from the insular cortex. We therefore set out to determine if endogenous estrogen levels within the central nucleus of the amygdala are altered following stroke and if microinjection of estrogen into the central nucleus of the amygdala modulates autonomic tone. Plasma estrogen concentrations were not altered by middle cerebral artery occlusion (22.86+/-0.14 pg/ml vs. 21.24+/-0.33 pg/ml; P>0.05). In contrast, estrogen concentrations in the central nucleus of the amygdala increased significantly following middle cerebral artery occlusion (from 20.83+/-0.54 pg/ml to 76.67+/-1.59 pg/ml; P<0.05). Local infusion of an aromatase inhibitor, letrozole, into the central nucleus of the amygdala at the time of middle cerebral artery occlusion prevented the increase in estrogen concentration suggesting that this increase was dependent on aromatization from testosterone. Furthermore, bilateral microinjection of estrogen (0.5 microM in 200 nl) directly into the central nucleus of the amygdala significantly decreased arterial pressure and sympathetic tone and increased baroreflex sensitivity, and these effects were enhanced following co-injection with either an N-methyl-D-aspartate or non-N-methyl-D-aspartate receptor antagonist. Taken together, the results suggest that middle cerebral artery occlusion resulted in synthesis of estrogen within the central nucleus of the amygdala and that this enhanced estrogen level may act to attenuate overstimulation of central nucleus of the amygdala neurons to prevent middle cerebral artery occlusion-induced autonomic dysfunction.

Reduction in infarct size by local estrogen does not prevent autonomic dysfunction after stroke.

Systemic estrogen administration in male rats has been shown to normalize the autonomic dysfunction and reduce the infarct size after permanent middle cerebral artery occlusion (MCAO). Therefore, the present investigation determined if local microinjection of estrogen at the site of the infarct also promoted recovery of autonomic function and reduction of the infarct size. Experiments were done in anesthetized (thiobutabarbitol sodium; 100 mg/kg) male Sprague-Dawley rats instrumented to record baseline and reflex changes in cardiovascular and autonomic parameters. The right middle cerebral artery was permanently occluded using bipolar coagulation. Local microinjection of estrogen into the insular cortex before MCAO significantly reduced the infarct size but did not attenuate the MCAO-induced autonomic dysfunction. Injection of ICI-182,780 alone significantly increased infarct area; however, the greater infarct area was not associated with enhanced autonomic dysfunction. These results suggest that within the insula, endogenous estrogen activity can affect the extent of MCAO-induced cell death, but extracortical central nervous system sites may be responsible for mediating the beneficial effects of estrogen on the autonomic disturbances.

Toxicity of PCB 28 in the rat liver: a quantitative ultrastructural study.

Polychlorinated biphenyls (PCBs) are persistent environmental contaminants that bioaccumulate in the food chain and thus pose a health risk to both humans and other animals. PCB 28 was administered via the diets to male and female Sprague-Dawley rats for 13 weeks in concentrations of 0.05, 0.5, 5 and 50 ppm. The chemical was mixed in corn oil and animals that served as controls received only corn oil in their diets. Use of transmission electron microscopy and stereology revealed significant (P < 0.05) elevations in the mean volume fraction (VF) of liver smooth reticulum (SER) profiles (5 and 50 ppm groups) in the females. Also, the hepatocytes of the male rats contained a significantly greater baseline VF of SER compared to those of the females. Statistically significant alterations were not detected in VP of mitochondria, rough endoplasmic reticulum, peroxisomes or lipid droplets. We estimated in Sprague-Dawley rats a no observable adverse effect level (NOAEL) of 0.5 ppm for congener 28.

Estrogen-induced recovery of autonomic function after middle cerebral artery occlusion in male rats.

Several studies have provided evidence to suggest that estrogen results in a significant reduction (approximately 50%) in the size of the ischemic zone in the middle cerebral artery occlusion (MCAO) model of stroke in a rat. The current study was done to demonstrate whether this estrogen-induced reduction in infarct size is associated with normalization of the autonomic dysfunction observed in an acute model of stroke in male rats. Experiments were done in anesthetized (thiobutabarbitol sodium; 100 mg/kg) male Sprague-Dawley rats instrumented to record baseline and reflex changes in cardiovascular and autonomic parameters. Estrogen was intravenously administered 30 min before, immediately before, or 30 min after MCAO. Estrogen administration resulted in a recovery of autonomic function and prevented the detrimental changes in autonomic tone observed following a stroke. In addition, infarct size was significantly increased in the presence of the estrogen antagonist ICI-182,780. These results suggest that both pre- or poststroke estrogen administration prevents or reverses acute stroke-induced autonomic dysfunction and that endogenous estrogen levels in males can contribute to this neuroprotection.

High-density lipoproteins and endothelial function.

Elevated plasma levels of HDL cholesterol or apolipoprotein A-I, the major protein moiety of HDL particles, are protective against coronary artery disease. HDL particles remove cholesterol from peripheral cells and transfer it to the liver for bile acid synthesis. The interaction between lipoproteins is not mediated through simple contact between 2 phospholipid membranes but involves specific protein-receptor interactions, charged phospholipid-phospholipid contact, and activation of cellular signaling pathways. These lead to regulation of genes or the modification of proteins involved in vasomotor function, platelet activation, thrombosis and thrombolysis, cell adhesion, apoptosis and cell proliferation, and cellular cholesterol homeostasis.

Estrogen blocks the cardiovascular and autonomic changes following vagal stimulation in ovariectomized rats.

The current investigation examines the effect of acute and chronic estrogen administration on baroreflex sensitivity and autonomic tone following 2 h of vagal afferent stimulation in ovariectomized female rats. Female Sprague-Dawley rats were ovariectomized and supplemented daily for 7 days with either estrogen (OVX-E2; 0.5 microg/kg; s.c.) or saline (OVX-S; 0.9%; s.c.). On the 8th day the animals were anaesthetized (sodium thiobutabarbitol; 100 mg/kg) and instrumented for recording blood pressure, heart rate and efferent vagal and renal nerve activities. The baroreflex was evoked using intravenous injection of various doses of phenylephrine hydrochloride (0.025, 0.05+/-0.1 mg/kg). Electrical stimulation of vagal afferents for 2 h produces autonomic imbalance characterized by sympathoexcitation and parasympathetic withdrawal. This protocol of vagal stimulation produced a significant increase in renal nerve activity (from 20+/-6 to 140+/-20 spikes/2 s) and decreases in both vagal nerve activity (from 22+/-3 to 10+/-2 spikes/2 s) and baroreflex sensitivity (from 0.55+/-0.05 to 0.3+/-0.05) in OVX-S female rats. However. vagal stimulation had no effect on baroreflex sensitivity or autonomic nerve activities in OVX-E2 rats. Administration of a single, bolus dose of estrogen (1 x 10(-2) mg/kg) to OVX-S rats immediately prior to termination of vagal stimulation blocked the changes in autonomic nerve activities and baroreflex sensitivity previously observed. These results suggest that both chronic and acute estrogen supplementation may provide resistance to the autonomic disturbances associated with visceral afferent activation.

Evaluation of the sexually abused child, including the role of colposcopy.

The magnification and excellent lighting provided by the colposcope make it an excellent diagnostic tool when enhanced direct observation is required. What can be accomplished with this tool in a pediatric or adolescent patient depends upon the examiner understanding how to best perform the examination related to these age groups and knowing what they see. This article describes common techniques used in the examination of the young gynecologic patient and common normal and abnormal findings. This knowledge should be especially helpful to the practitioner who is called upon to perform a sexual abuse examination in this population.

Acute injection of 17beta-estradiol enhances cardiovascular reflexes and autonomic tone in ovariectomized female rats.

Among the many benefits of long-term hormone replacement therapy to postmenopausal women is a significant reduction in risk for and progression of cardiovascular disease. However, long-term estrogen replacement therapy has been associated with several undesirable, and likely dose-dependent, side-effects. There is some evidence to suggest that the dose of estrogen which confers optimal beneficial effects on the cardiovascular system is much lower than that which is currently prescribed for postmenopausal women. The following experiments were conducted to determine the dose-response relationship of acutely administered estrogen on autonomic tone and reflex control of heart rate in ovariectomized Sprague-Dawley female rats. Rats were anaesthetized with sodium thiobutabarbital (100 mg/kg) and instrumented to record blood pressure, heart rate and efferent parasympathetic and sympathetic nerve activities. The sensitivity of the cardiac baroreflex was tested using intravenous injection of either phenylephrine hydrochloride (0.025-0.1 mg/kg) or sodium nitroprusside (0.0025-0.01 mg/kg). Intravenous injection of estrogen produced dose-dependent increases in the magnitude of the baroreflex sensitivity and parasympathetic tone while reducing sympathetic tone with a maximal effect observed at 1 x 10(-3) mg/kg. Prior administration of the selective estrogen receptor antagonist, ICI 182,780 blocked the estrogen-induced changes in baroreflex sensitivity and autonomic tone. These results demonstrate that acutely administered, low-dose estrogen has beneficial effects on autonomic tone and cardiovascular reflexes.

Autonomic and cardiovascular reflex responses to central estrogen injection in ovariectomized female rats.

The role of estrogen in central autonomic nuclei was examined in ovariectomized female Sprague-Dawley rats supplemented daily for 7 days with either estrogen (5 microg/kg; sc) or saline (0.9%; sc). Animals were subsequently anaesthetized with sodium thiobutabarbital (Inactin; 100 mg/kg; ip) and instrumented to record blood pressure and heart rate. Efferent vagal parasympathetic (VPNA) and renal sympathetic (RSNA) nerve activities were recorded and used to assess baseline and reflexive changes in autonomic tone. The cardiac baroreflex was evoked using a single bolus injection of phenylephrine (0.1 mg/kg) both before and following either intrathecal injection of estrogen (0.5 microM; 1 microl) or bilateral injection of estrogen (0.5 microM; 100 nl/side) into several central autonomic nuclei. In estrogen-replaced rats, both the baseline and PE-evoked values for mean arterial pressure and RSNA were significantly decreased following injection of estrogen into the nucleus tractus solitarius (NTS), rostral ventrolateral medulla (RVLM), parabrachial nucleus (PBN), central nucleus of the amygdala (CNA) and the intrathecal space. Baseline heart rate and VPNA were significantly decreased following injection of estrogen into NTS, nucleus ambiguous (Amb), PBN and the intrathecal space. PE-evoked changes in heart rate and VPNA were significantly enhanced following injection of estrogen into these same nuclei. Injection of estrogen into the insular cortex (IC) produced significant decreases in baseline and PE-evoked RSNA only. The cardiac baroreflex was significantly enhanced following injection of estrogen into all nuclei and the intrathecal space. In saline-replaced females, injection of estrogen into NTS, RVLM, Amb and the intrathecal space had similar effects on both baseline and PE-evoked parameters although of a reduced magnitude compared to estrogen-replaced rats. However, no significant changes in autonomic tone and baroreflex function were observed following the injection of estrogen into the PBN, CNA or IC of saline-replaced rats. These results demonstrate a role for estrogen in central autonomic nuclei in female rats and suggest a possible alteration of estrogen receptor distribution or efficacy within the central nervous system of estrogen-deficient female rats.

PCB 128-induced ultrastructural lesions in the rat liver.

PCB 128 (2,2',3,3',4,4'-hexachlorobiphenyl) prepared in 4% corn oil and mixed in diets was given to weanling Sprague-Dawley rats. The animals were placed in eight groups, each comprising 10 males or 10 females; each group received a diet that contained 0.05, 0.5 or 5 ppm PCB. Ten animals of each gender that served as the controls were given diets mixed with only corn oil. Thirteen weeks after the commencement of dosing, animals were euthanized and liver specimens were harvested and prepared for transmission electron microscopy. The architecture of the liver parenchymal cell was indistinguishable in the animals of the lowest concentration group from those in the controls. However, smooth endoplasmic reticulum profiles increased, and abnormal mitochondria were noted in the liver of rats, regardless of gender, from 0.5 and 5 ppm groups. Based on our previous work, PCB 128 is estimated to be equally toxic as PCB 153, another di-ortho substituted PCB congener.

Medullary and intrathecal injections of 17beta-estradiol in male rats.

The following experiments were designed to investigate the role of estrogen in central autonomic nuclei on autonomic tone and reflex control of heart rate. Male Sprague-Dawley rats were anesthetized with sodium thiobutabarbital (100 mg/kg) and instrumented to record blood pressure and heart rate. Efferent vagal and renal nerve activities were recorded and used to assess changes in parasympathetic and sympathetic tone, respectively. The cardiac baroreflex was evoked using a single bolus injection of phenylephrine (0.1 mg/kg) both before and following either intrathecal injection of estrogen (0.5 microM; 1 microl) to influence sympathetic preganglionic neurons of the intermediolateral cell column or bilateral injection of estrogen (0.5 microM; 100 nl/side) into the nucleus tractus solitarius, rostral ventrolateral medulla or nucleus ambiguus. The cardiac baroreflex was significantly enhanced following both intrathecal and medullary injections of estrogen. Efferent vagal nerve activity was significantly increased following injection of estrogen into the nucleus tractus solitarius, nucleus ambiguus and the intrathecal space. Renal sympathetic nerve activity was significantly depressed following injection of estrogen into the nucleus tractus solitarius, rostral ventrolateral medulla and the intrathecal space. In all cases, simultaneous injection of estrogen with the selective estrogen receptor antagonist, ICI 182,780 (1 pM) blocked all previously observed changes in baroreflex function and autonomic tone. These results demonstrate a role for estrogen in the reflex control of heart rate and as a central modulator of autonomic tone in male rats.

A longitudinal study of relations between job stressors and job strains while controlling for prior negative affectivity and strains.

Interpretation of observed relations between job stressors and job strains in cross-sectional surveys is often ambiguous because of possible 3rd variables (both stable background factors, such as personality, and transitory occasion factors, such as mood). In this longitudinal study, negative affectivity (NA) and strains were assessed both in college and later on the job. Stressors were assessed only on the job. Evidence was found that some background factors affected measures of job stressors and job strains in that college measures were significantly related to subsequent measures on the job. Relations between job stressors and job strains, however, were in most cases not affected significantly when prior strains and NA were controlled for. Furthermore, the results suggested that NA measures are subject to occasion factors.