Sex differences in the phenotypic expression of obsessive-compulsive disorder: an exploratory study from Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

SEX-RELATED DIFFERENCES IN THE ANALGESIC RESPONSE TO THE RAT TAIL IMMERSION TEST

The analgesic response was evaluated by the tail immersion test in adult male (N = 30), female (N = 21) and androgenized female Wistar rats (N = 15). The reaction time for tail withdrawal from the hot water bath was faster for male than for female rats (3.48 +/- 0.12 vs 6.46 +/- 0.42 s). The reaction time of androgenized female rats was similar to that of male rats (3.08 +/- 0.16 s). Blockade of opiate receptors with naloxone (2 mg/kg, ip) decreased the sensitivity to the noxious stimuli in males (4.08 +/- 0.10 s) and in androgenized females (3.69 +/- 0.19 s) but increased it in female rats (5.01 +/- 0.41 s). These data show sex-related differences in the analgesic response evaluated by the tail immersion test and indicate that administration of androgens to newborn female rats affects their pain sensitivity.

SEX-RELATED DIFFERENCES IN CARDIOVASCULAR-RESPONSES TO COMMON CAROTID OCCLUSION IN CONSCIOUS RATS

Mean arterial pressure and heart rate were determined in conscious, unrestrained groups of 10 male, female and androgenized female Wistar rats 20 s (early pressor response) and 1 min (late sustained response) after bilateral carotid artery occlusion. The early pressor response, which is of carotid reflex origin, was 40% greater in female than in male rats (45 +/- 2 vs 63 +/- 3 mmHg, respectively). The late sustained response, which is of central origin (probably ischemic), did not differ between male and female rats (32 +/- 2 vs 37 +/- 4 mmHg, respectively). The magnitude of the early pressor response of androgenized female tats (50 +/- 2 mmHg) was similar to that of male rats (45 +/- 2 mmHg) but the late sustained response was 19% smaller (26 +/- 2 mmHg). Common carotid occlusion caused increases in heart rate which were greater in female (51 +/- 9 and 34 +/- 9 beats/min in the early pressor response and late sustained response, respectively) than in male rats (31 +/- 5 and 8 +/- 4 beats/min, respectively). In androgenized female rats, heart rate decreased during common carotid occlusion (34 +/- 7 and 35 +/- 8 beats/min after 20 s and 1 min, respectively). These data provide evidence that there are substantial sex-related differences in the cardiovascular responses to common carotid occlusion in conscious rats and indicate that administration of androgens to newborn female rats affects the baroreceptor reflex control of their arterial pressure.

Scent-marking behaviour in free-ranging golden-faced saki monkeys, Pithecia pithecia chrysocephala: Sex differences and context

Scent-marking behaviour of golden-faced saki monkey, Pithecia pithecia chrysocephala, was observed intermittently between 1987 and 1990 for a family group in a Central Amazonian forest fragment. of 95 scent-marking events (during 275.5 hours of observation), throat-and-chest rubbing accounted for all except one anogenital rubbing. Nine of the throat-and-chest markings also involved touching groin with hands and eight markings (including the anogenital), urinating on the marked branch. Marking behaviour is strongly sex related, with the adult male making 88.4% of the markings. Scent-marking frequency by the adult male increased during breeding periods. Scent-marking behaviour seems related to courtship, and possibly stimulates sexual behaviour. All regularly marked spots consisted of horizontal branches on commonly travelled routes. Eleven occurred in feeding trees and lianas, but none in sleeping trees. Scent-marking behaviour in the monkeys studied here was not related to intergroup encounters and probably did not have a territorial function, although it may do so where different groups interact.

Sex and reproductive stage differences in the growth, metabolism, feed, fecal production, excretion and energy budget of the Amazon River prawn (Macrobrachium amazonicum)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Gender differences in obsessive-compulsive disorder: a literature review

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Size distribution and sex ratio in the spider crab Epialtus brasiliensis (Dana 1852) associated with seaweed on a rocky shore in southeastern Brazil (Crustacea, Decapoda, Brachyura, Majoidea, Epialtidae).

This study analyzed a population of the spider crab Epialtus brasiliensis, in regard to its size distribution, sex ratio and Sexual maturity. The study was conducted on a rocky shore in the Ubatuba region, state of Silo Paulo, Brazil, where a wide strip of algae covers the intertidal zone. A total of 378 specimens were obtained: 200 males (128 juvenile and 72 adult crabs) and 178 females (46 juveniles and 132 adults). Their Sizes ranged from 3.4 to 16.7 mm carapace length (CL). Taking into account that the pubertal and terminal molts are coincident in majid crabs, the maximum sizes attained by males and females are especially dependent on the factors that influence sexual maturity, mainly food resources, temperature and intraspecific competition. Males of E. brasiliensis occurred in all size classes, whereas females occurred only as far the 10th size class (12-13 min CL). file total sex ratio did not differ statistically from 1 : 1, but when the juvenile and adult specimens were analyzed separately the differences between sexes were significantly different, with higher proportions of immature males and mature females. The CL50 calculated for males and females was 10.4, and 6.9 min CL, respectively. Thus, males reach their sexual maturity at a larger size than females. This feature may be important for the reproductive strategy of this species, because larger males probably have greater reproductive Success.

Morphologically differentiated sex chromosomes in neotropical freshwater fish

A general survey of the occurrence of morphologically differentiated sex chromosomes in the neotropical freshwater fishes is presented. The total number of 32 occurrences involving simple XX-XY and ZZ-ZW, and multiple X1X2Y, XY1Y2 and ZW1W2 sex chromosome systems is described, with comments on the aspects of sex chromosome evolution in this fish fauna. The occurrence of different sex chromosome systems in related species of the same genus, or in different populations of the same nominal species, involving male and sometimes female heterogamety, and differences in the molecular composition of sex-linked heterochromatin, are considered as indicative of the early stage of sex chromosomes evolution in fish.

Independent and Combined Effects of Physical Activity and Sedentary Behavior on Blood Pressure in Adolescents: Gender Differences in Two Cross-Sectional Studies

Objectives: To examine the independent and combined association of physical activity (PA) and sedentary behavior (SB) on both systolic (SBP) and diastolic blood pressure (DBP) in adolescents from two observational studies. Methods: Participants from two cross-sectional studies, one conducted in Europe (n = 3,308; HELENA study) and the other in Brazil (n = 991; BRACAH study), were selected by complex sampling. Systolic and diastolic blood pressure (outcomes), PA and SB, both independently and combined, and potential confounders were analyzed. Associations were examined by multilevel linear regression. Results: Performing the recommended amount of PA (≥60 min/d) attenuated the effect of SB on DBP in BRACAH study girls and in boys from both studies. In contrast, PA did not attenuate the effects of SB on the SBP of girls in the HELENA study. The combination of less than recommended levels of PA with 2-4 h/d of sedentary behavior was found to be associated with increased SBP in boys from both studies. Conclusions: Meeting current PA recommendations could mediate the association between SB and DBP in both sexes. In boys, the joint effect of low levels of PA and excessive sedentary activity increases SBP levels. Longitudinal studies are required to confirm these findings. © 2013 de Moraes et al.

Homogamy preferences for cognitive sex-typicality in women

Homogamy has been suggested as crucial for human mate preferences and mate choice. People are attracted to and choose romantic partners that are similar to them in socio-demographic, physical, and psychological traits. However, only a few studies have shown homogamy in preferences for evolved sex-typical traits. Here, we have investigated male and female preferences for the level of cognitive masculinity-femininity (MF). We tested whether self-reported MF positively correlates with preferences for MF. One hundred men and one hundred women from Brazil filled in questionnaires on their own level of cognitive MF and preferred level of cognitive MF in their ideal partner. Half of the respondents were asked to indicate their preferences for long-term, and the other half for short-term relationships. We found a positive correlation between self-ascribed and preferred level of cognitive MF in women (P = 0.002), but no significant correlation in men (P = 0.309). There was no significant effect of the temporal context of the relationship, but there was a positive correlation between self-ascribed and preferred level of cognitive MF only in women answering about long-term partner. By subtracting the preferred from the selfascribed level of cognitive MF, we created a self-similarity index. We found that women desire potential mates more self-similar and more masculine than men (P < 0.001) and that in men there is greater variation in the self-similarity index than in women. Our results thus add to previous evidence on the role of homogamy in human mating, by showing preferences for self-similarity also in cognitive MF for women, especially for long-term partner preferences. Future studies should cross-culturally test whether the higher self-similar preference found in women is universal.

Repetitive DNA sequences and evolution of ZZ/ZW sex chromosomes in characidium (teleostei: characiformes)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)