Morphology and morphometry of the vagus nerve in male and female spontaneously hypertensive rats

The vagus nerve is an important component of the efferent arm of the baroreflex. Blood pressure levels as well as baroreflex control of circulation are significantly different in male and female spontaneously hypertensive rats (SHR). We proposed to investigate the morphometric differences between genders using the vagus nerve of SHR. Adult animals (20 weeks old) were anesthetized and had their arterial pressure (AP) and heart rate (HR) recorded by a computerized system. The rats were then systemically perfused with a fixative solution and had their cervical vagi nerves prepared for light microscopy. Proximal and distal segments of the left and right vagi nerves were evaluated for morphometric parameters including fascicle area and diameter, myelinated fiber number, density, area and diameter. Comparisons were made between sides and segments on the same gender as well as between genders. Differences were considered significant when p<0.05. Male SHR had significantly higher AP and HR. Morphometric data showed no differences between the same levels of both sides and between segments on the same side for male and female rats. In addition, no significant morphometric differences were observed when genders were compared. This is the first description of vagus nerve morphometry in SHR indicating that gender differences in AP and HR cannot be attributed to dissimilarities in vagal innervation of the heart. These data provide a morphological basis for further studies involving functional investigations of the efferent arm of the baroreflex in hypertension. (C) 2007 Elsevier B.V. All rights reserved.

MHM assay: molecular sexing based on the sex-specific methylation pattern of the MHM region in chickens

Bird sex determination using molecular methods has proved to be a valuable tool in different studies. Although it is possible to sex most birds by coupling the CHD assay with others available methods, no sex-determining gene like SRY in mammalians has been identified in birds. The male hypermethylated (MHM) region on the Z chromosome has been found to be hypermethylated in males and hypomethylated in females in birds of the order Galliformes. We analyzed the DNA from feathers of 50 adult chickens to verify the methylation pattern of the MHM region by PCR and the restriction enzyme HpaII (a method named MHM assay). The results, visualized in agarose gel, were compared with PCR amplification of the CHD-Z and CHD-W genes (polyacrylamide gel) and with the birds` phenotype. All males (25) showed hypermethylation of the MHM region, and all females (25) showed hypomethylation. The sexing by MHM assay was in according with phenotype and CHD sexing. To our knowledge, this is the first study that uses the MHM region for sexing birds. Although the real role of the MHM region in the sex determination is still unclear, this could be a universal marker for sexing birds and may be involved in sex determination by its influence on transcriptional processes. The MHM assay could be a good alternative for CHD assay in developmental studies.

Evaluation of Sexual Function in Brazilian Pregnant Women

The objective of the present study was to evaluate the sexual function of pregnant women and to identify the potential variables associated with it. The study was conducted on 137 low-risk, sexually active pregnant women who filled out the Female Sexual Function Index (FSFI) questionnaire. Although 61% of the women assessed presented an FSFI score 26.5, they declared that they were satisfied with the emotional proximity to their partner, with their relationship, and with their sex life. A positive association was detected between sexual dysfunction and gestational age and a report of urinary incontinence and excessive weight gain in the current pregnancy.

Hospitalizations for HIV/AIDS: Differences Between Sexes

Background: Women are especially vulnerable to HIV infection because of biological, social, cultural, and economic factors. In Brazil, AIDS was initially seen predominantly in homosexual men, but the epidemic gradually reached a gender balance as increasing numbers of women became infected with HIV. Objective: The aim of the present study was to identify the clinical and epidemiologic characteristics of hospitalized patients with HIV/AIDS of both sexes and compare the differences between them. Methods: This epidemiologic cross-sectional study evaluated gender differences in demographic, social, clinical, and epidemiologic characteristics of patients diagnosed with HIV/AIDS who were admitted for any reason to the Public Hospital of the Medical School of the Federal University of Triangulo Mineiro, Uberaba, Minas Gerais State, Brazil. Results: A total of 363 patients were included in the analysis, with a male/female ratio of 1.1:1.0. Forty-one percent of women were pregnant. Mean age at hospitalization and duration of hospitalization were significantly greater among men (P < 0.05). Men and nonpregnant women were admitted because of infection significantly more often than were pregnant women (P < 0.05). Significantly more single men who reported homosexual, bisexual, or heterosexual behavior associated with drug use were admitted compared with women (P < 0.05). Women admitted for treatment were significantly more likely than men to be employed (P < 0.05). Adherence to antiretroviral treatment and T CD4+ lymphocyte count indicated important differences between the sexes, with better parameters observed among nonpregnant and pregnant women compared with men. Conclusions: In the present study, women with HIV/AIDS who were admitted to the hospital for any reason were in better clinical condition compared with men. This observation may be partially explained by the proportion of pregnant women in the study population. These findings suggest that future studies should examine pregnant women with HIV/AIDS as a separate population group to avoid bias in analysis. (Gend Med. 2010;7:28-38) (C) 2010 Excerpta Medica Inc.

Effects of sex hormonal levels and phases of the menstrual cycle in the processing of emotional faces

Several neuropsychiatry disorders have shown a sexual dimorphism in their incidence, symptom profile and therapeutic response. A better understanding of the impact of sex hormones in emotional processing sexual dimorphism could bring tight to this important clinical finding. Some studies have provided evidence of sex differences in the identification of emotional faces, however, results are inconsistent and such inconsistency could be related to the lack of experimental control of the sex hormone status of participants. More recently, a few studies evaluated the modulation of facial emotion recognition by the phase of the menstrual cycle and sex hormones, however, none of them directly compared these results with a group of men. We evaluated the accuracy of facial emotion recognition in 40 healthy volunteers. Eleven women were assigned to early follicular group, nine women to the ovulatory group and 10 women to luteal group, depending on the phase of menstrual cycle, and a group of 10 men were also evaluated. Estrogen, progesterone and testosterone levels were assessed. The performance of the groups in the identification of emotional faces varied depending on the emotion. Early follicular group were more accurate to perceive angry faces than all other groups. Sadness was more accurately recognized by early follicular group than by luteal group and regarding the recognition of fearful faces a trend to a better performance and a significantly higher accuracy was observed, respectively, in the early follicular group and in the ovulatory group, in comparison to men. In women, estrogen negatively correlated to the accuracy in perception of angry mate faces. Our results indicate sex hormones to be implicated in a sexual dimorphism in facial emotion recognition, and highlight the importance of estrogen specifically in the recognition of negative emotions such as sadness, anger and fear. (C) 2009 Elsevier Ltd. All rights reserved.

Comparison of the effects of aerobic and resistance training on cardiac autonomic adaptations in ovariectomized rats

We have compared the effects of two types of physical training on the cardiac autonomic control in ovariectomized and sham-operated rats according to different approaches: double autonomic blockade (DAB) with methylatropine and propranolol; baroreflex sensibility (BRS) and spectral analysis of heart rate variability (HRV). Wistar female rats (+/- 250 g) were divided into two groups: sham-operated and ovariectomized. Each group was subdivided into three subgroups: sedentary rats, rats submitted to aerobic trained and rats submitted to resistance training. Ovariectomy did not change arterial pressure, basal heart rate (HR), DAB and BRS responses, but interfered with HRV by reducing the low-frequency oscillations (LF = 0.20-0.75 Hz) in relation to sedentary sham-operated rats. The DAB showed that both types of training promoted an increase in the predominance of vagal tonus in sham-operated rats, but HR variations due to methylatropine were decreased in the resistance trained rats compared to sedentary rats. Evaluation of BRS showed that resistance training for sham-operated and ovariectomized rats reduced the tachycardic responses in relation to aerobic training. Evaluation of HRV in trained rats showed that aerobic training reduced LF oscillations in sham-operated rats, whereas resistance training had a contrary effect. In the ovariectomized rats, aerobic training increased high frequency oscillations (HF = 0.75-2.5 Hz), whereas resistance training produced no effect. In sham-operated rats, both types of training increased the vagal autonomic tonus, but resistance training reduced HF oscillations and BRS as well. In turn, both types of training had similar results in ovariectomized rats, except for HRV, as aerobic training promoted an increase in HF oscillations. (C) 2011 Elsevier B.V. All rights reserved.

Transplacental transmission of Toxoplasma gondii in reinfected pregnant female canines

Twelve pregnant female canines, naturally infected with Toxoplasma gondii, were reinfected with T. gondii: three (GI) received tachyzoites subcutaneously (1.0 x 107), three (GII) were orally inoculated with oocysts (1.5 x 104), and six (GIII) were kept as a nonreinfected control group. All the reinfected female canines (GI and GII) miscarried or presented fetal death, while only one GIII female presented a stillborn in a litter of four pups (P < 0.01). Fever, lymphoadenopathy, miscarriage, and fetal death were the main clinical alterations observed. The highest serological titers detected through the indirect fluorescence antibody test (IFAT) were 1,024 (GI) and 4,096 (GII). In group III, the titers ranged between 64 and 256. By bioassays in mice, T. gondii was isolated in 17 organs of the reinfected adult canines, in 11 of the control group, and in 20 of the neonates. Positive immunostaining of cysts and/or tachyzoites were observed in 26 canine tissues (14 from GI and GII and ten from GIII). The agent was detected by immunohistochemistry in the encephalon of a neonate and in the spinal cord of a stillborn, thus, confirming that T. gondii infected canine fetuses, provoking miscarriages, even in bitches that presented primoinfection.

Plasticity of Opioid Receptors in the Female Periaqueductal Gray: Multiparity-Induced Increase in the Activity of Genes Encoding for Mu and Kappa Receptors and a Post-Translational Decrease in Delta Receptor Expression

The periaqueductal gray (PAG) has been reported as a potential site for opioid regulation of behavioral selection. Opioid-mediated behavioral and physiological responses differ between nulliparous and multiparous females. This study addresses the effects of multiple reproductive experiences on mu-, kappa- and delta-opioid receptor (Oprm1, Oprk1, and Oprd1 respectively) gene activity and mu, kappa and delta protein expression (MOR, KOR and DOR respectively) in the PAG of the female rats. This was done by evaluating the opioid gene expression using real-time (RT-PCR) and quantification of each protein receptor by Western blot analysis. The RT-PCR results show that multiple reproductive experiences increase Oprm1 and Oprk1 gene expression. Western blot analysis revealed increased MOR and KOR while DOR protein was decreased in multiparous animals. Taken together, these data suggest that multiple reproductive experiences influence both gene activity and opioid receptor expression in the PAG. Post-translational mechanisms seem particularly relevant for DOR expression. Thus, opioid transmission in the PAG might be modulated by different mechanisms of multiparity-induced plasticity according to the opioid receptor type.

Prejudice against female children: Economics and cultural explanations, and India evidence

Shows how economic theories based on parental self-interest may explain parental discrimination against daughters relative to sons. However, such theories often need to be adjusted (or even discarded) to allow for altruism of parents towards their children, and to take account of cultural influences on parental desires to have children of particular gender, and care equally for their children of different gender. The latter point is illustrated by a study of two different communities. In one situated in the Santal tribal belt I West Bengal, discrimination against daughters is found to be marked and accords (given the structure of society) with predictions of economic theories based on the pursuit of parental self-interest. By contrast, it is found that although the Knondh-dominated community in Orissa experiences similar economic conditions and social structures to the West Bengal communities, parental discrimination against daughters is almost absent. The differences seem to arise from a difference between the cultural values shared by the Kondhs in Orissa and those shared by the West Bengal community consisting of Santals and Bengali Hindus. This suggests that the applicability of economic theories of the family depends significantly on the social contexts in which they are to be applied. In this respect, both social structures and cultural values are important.

Maned wolf survival rate in central Brazil

Although many carnivores are of conservation concern, most are poorly studied. The maned wolf Chrysocyon brachyurus Illiger, 1811 is the largest South American canid with a broad distribution; however, the largest portion of its range is in the Brazilian Cerrado savannah, where due to intensive agricultural expansion, it is threatened by habitat loss. Maned wolf population trends are virtually unknown. We analyzed radio telemetry data from a 13-year study in Emas National Park, central Brazil, with Burnham`s live recapture/dead recovery models in the program MARK to obtain the first analytically sound estimate of the apparent maned wolf survival rate. We constructed 16 candidate models including variation in survival rate and resighting probability associated with an individual`s sex or age and year of study. Apparent adult survival rate throughout the study ranged from 0.28 (se=0.08) to 0.97 (se=0.06). There was no evidence for sex specificity but strong support for time variation. Model weights supported an age effect and the subadult survival rate was 0.63 (se=0.15). Results indicate similar life patterns for male and female maned wolves and similar mortality risks for adults and subadults in the study area. The observed temporal fluctuations of adult survival rate are important for population dynamics as they decrease average population growth rates. Population dynamics are central for conservation planning and our results are an important step towards a better understanding of the maned wolf`s ecology.

Redescription of the female, description of the male, and several new records of Amblyomma parkeri (Acari: Ixodidae), a South American tick species

The tick Amblyomma parkeri Fonseca and Arago was described in 1952, based on female and immature ticks collected in the states of So Paulo and Santa Catarina, Brazil. Thereafter, there has been no further report of A. parkeri, and the male has remained unknown. Herein, we examined ticks collected on porcupines from a locality in the state of So Paulo. Some of the ticks were identified as Amblyomma longirostre (Koch, 1844), whereas others as A. parkeri, including male specimens, for which we provide the first description. We also provide additional reports of A. parkeri after examining collections of A. longirostre and Amblyomma geayi Neumann, 1899 from different tick collections. Morphological evidence to support the original description of A. parkeri is presented, supported by molecular analyses of portions of the 16S rRNA and 12S rRNA mitochondrial genes. Morphological particularities to separate A. parkeri, A. longirostre, and A. geayi are provided.

HOME RANGE AND SPATIAL ORGANIZATION OF MANED WOLVES IN THE BRAZILIAN GRASSLANDS

The maned wolf (Chrysocyon brachyurus) is the largest canid in South America, weighing up to 30 kg, and exhibits an omnivorous diet based on fruits and small vertebrates. Maned wolves are considered to live in monogamous pairs defending a common territory, with mates living a largely solitary life, but these conclusions come from few studies with small samples. We captured maned wolves in Emas National Park, central Brazil, and monitored their use of space using radiotelemetry. Home-range size and overlap of 45 adults, and interactions between members of 5 pairs, were investigated. Home-range sizes of resident adults averaged 80.18 km(2) using the fixed kernel with 95% of the locations, and averaged 13.78 km(2) with 50% of the locations. Overlap of 95% ranges between male-male, female-female, or mixed dyads was similar, approximately 0.20, whereas 50% ranges of maned wolves showed less overlap overall but more tolerance for overlap with the opposite sex. Members of a pair were located alone more often than together, and even when located simultaneously maintained a mean distance of >0.5 km apart, independent of time of day. Results are in agreement with a spatial organization based on monogamous mating pairs with little intrapair sociality, but the latter needs to be investigated in more detail.

Fertility and female work force participation in Bangladesh: Causality and cointegration

This paper examines the causal links between fertility and female labor force participation in Bangladesh over the period 1974-2000 by specifying a bivariate and several trivariate models in a vector error correction framework. The three trivariate models alternatively include average age at first marriage for females, per capita GDP and infant mortality rate, which control for the effects of other socio-economic factors on fertility and female labor force participation. All the specified models indicate an inverse long-run relationship between fertility and female labor force participation. While the bivariate model also indicates bidirectional causality, the multivariate models confirm only a unidirectional causality – from labor force participation to fertility. Further, per capita GDP and infant mortality rate appear to Granger-cause both fertility and female labor force participation.

Effects of neonatal handling on central noradrenergic and nitric oxidergic systems and reproductive parameters in female rats

Early-life environmental events that disrupt the mother-pup relationship may induce profound long-lasting changes on several behavioral and neuroendocrine systems. The neonatal handling procedure, which involves repeated brief maternal separations followed by experimental manipulations, reduces sexual behavior and induces anovulatory estrous cycles in female rats. On the afternoon of proestrus, neonatally handled females show a reduced surge of luteinizing hormone (LH) and an increased content of gonadotropin-releasing hormone in the medial preoptic area (MPOA). In order to detect the possible causes for the reduced ovulation and sexual behavior, the present study aimed to analyze the effects of neonatal handling on noradrenaline (NA) and nitric oxide (NO) levels in the MPOA on the afternoon of proestrus. Neonatal handling reduced MHPG (NA metabolite) levels and MHPG/NA ratio in the MPOA, indicating decreased NAergic activity. Additionally, neonatal handling decreased NO levels, as measured by the metabolites (NO x), nitrite and nitrate in the same period. We may conclude that the neonatal handling procedure decreased activity of the NAergic and NOergic systems in the MPOA during proestrus, which is involved in the control of LH and FSH secretion, and this may possibly explain the anovulatory estrous cycles and reduced sexual behavior of the neonatally handled female rats. Copyright (c) 2007 S. Karger AG, Basel.