Reproductive and sexual behavior changes in male rats exposed perinatally to picrotoxin

Previous studies in rats suggested that picrotoxin, a GABA(A) receptor antagonist, may cause long-term changes in male reproductive physiology and behavior in rats exposed during prenatal and postnatal periods. The present study has further examined this phenomenon. Wistar rat dams were dosed subcutaneously with 0.75 mg/kg picrotoxin in saline, or vehicle alone, during the perinatal period (day 19 of gestation, immediately after parturition, and once a day during the first 5 days of lactation). Birth weight and sexual maturation of pups were unchanged; however, plasma testosterone levels and sexual behavior was altered in male offspring. Although fertile, these males showed altered mating behavior in terms of a decrease in the mean number of mounts during a 30-min observation period with normal females. Some showed homosexual behavior when castrated and pretreated with exogenous estrogen. These findings suggest that perinatal exposure to picrotoxin alters sexual dimorphism in the developing rat brain, manifesting as altered reproductive performance and sexual behavior of males. (c) 2004 Elsevier B.V. All rights reserved.

Expression of protease nexin-1 and plasminogen activators during follicular growth and the periovulatory period in cattle

Extracellular matrix remodeling occurs during ovarian follicular development, mediated by plasminogen activators (PAs) and PA inhibitors including protease nexin-1 (PN-1). In the present study we measured expression/activity of the PA system in bovine follicles at different stages of development by timed collection of ovaries during the first follicular wave and during the periovulatory period, and in follicles collected from an abattoir. The abundance of mRNA encoding PN-1, tissue-type PA (tPA), urokinase (uPA) and PA inhibitor-1 (PAI-1) were initially upregulated by human chorionic gonadotropin (hCG) in bovine preovulatory follicular wall homogenates. PN-1, PAI-1 and tPA mRNA expression then decreased near the expected time of ovulation, whereas uPA mRNA levels remained high. PN-1 concentration in follicular fluid (FF) decreased and reached the lowest level at the time of ovulation, whereas plasmin activity in FF increased significantly after hCG. Follicles collected from the abattoir were classified as non-atretic, early-atretic or atretic based on FF estradiol and progesterone content: PN-1 protein levels in FF were significantly higher in non-atretic than in atretic follicles, and plasmin activity was correspondingly higher in the atretic follicles. No changes in PN-1 levels in FF were observed during the growth of pre-deviation follicles early in a follicular wave. These results indicate that PN-1 may be involved in the process of atresia in non-ovulatory dominant follicles and the prevention of precocious proteolysis in periovulatory follicles.

Propolis: Effect of different concentrations, extracts and intake period on seric biochemical variables

Propolis is a resinous substance produced by honeybees that possesses many biological activities, such as antitumor, antioxidant, antimicrobial, anti-inflammatory, and immunomodulatory, among others. The purpose of the present study was to investigate the biochemical profile of propolis-treated rats to observe whether propolis might lead to side effects after administration. Three different treatments were analyzed: (1) rats were treated with different concentrations of propolis (1, 3 and 6 mg/kg/day) during 30 days; (2) rats were treated with I mg/kg/day of ethanolic or water extracts of propolis (EEP, WEP) during 30 days; (3) rats were treated with I mg/kg/day of ethanolic extract of propolis during 90 and 150 days. Our results demonstrated no alterations in the seric levels of cholesterol, HDL-cholesterol, total lipids, triglycerides and in the specific activity of aminotransferases (AST) and lactic dehydrogenase (LDH) of propolis-treated groups when compared to controls. on the basis of our findings, since propolis does not induce any significant change in seric parameters, it is claimed that long-term administration of propolis might not have any cardiac injury. (c) 2005 Elsevier B.V.. All rights reserved.

Inhibitory effect of essential oils against Lactobacillus rhamnosus and starter culture in fermented milk during its shelf-life period

The use of essential oils in foods has attracted great interest, due to their antagonistic action against pathogenic microorganisms. However, this action is undesirable for probiotic foods, as products containing Lactobacillus rhamnosus. The aim of the present study was to measure the sensitivity profile of L. rhamnosus and a yogurt starter culture in fermented milk, upon addition of increasing concentrations of cinnamon, clove and mint essential oils. Essential oils were prepared by steam distillation, and chemically characterised by gas chromatography-mass spectrometry (GC-MS) and determination of density. Survival curves were obtained from counts of L. rhamnosus and the starter culture (alone and in combination), upon addition of 0.04% essential oils. In parallel, titratable acidity was monitored over 28 experimental days. Minimum inhibitory concentration values, obtained using the microdilution method in Brain Heart Infusion medium, were 0.025, 0.2 and 0.4% for cinnamon, clove and mint essential oils, respectively. Cinnamon essential oil had the highest antimicrobial activity, especially against the starter culture, interfering with lactic acid production. Although viable cell counts of L. rhamnosus were lower following treatment with all 3 essential oils, relative to controls, these results were not statistically significant; in addition, cell counts remained greater than the minimum count of 10(8)CFU/mL required for a product to be considered a probiotic. Thus, although use of cinnamon essential oil in yogurt makes starter culture fermentation unfeasible, it does not prevent the application of L. rhamnosus to probiotic fermented milk. Furthermore, clove and mint essential oil caused sublethal stress to L. rhamnosus.

Candidemia in a Brazilian tertiary hospital: microbiological and clinical features over a six-year period

Yeasts are becoming a common cause of nosocomial fungal infections in immunocompromised patients. Such infections often develop into sepsis with high mortality rates. The aim of this study was to evaluate some of the numerous factors associated with the development of candidemia. Medical records were retrospectively analyzed of 98 Candida spp. patients. Results showed that the most prevalent risk factors for developing candidemia were: antibiotics and antifungal agents (93.9% and 79.6%, respectively); the use of central venous catheter (93.9%); mechanical ventilation (73.5%); and parenteral nutrition (60.2%). The main species of Candida found were: C. parapsilosis (37.76%), C. albicans (33.67%); and others (28.57%). C. glabrata showed the highest mortality rate (75%), followed by C. tropicalis (57.1%) and C. albicans (54.5%). The elevated mortality rate found in this study indicates that preventive measures against candidemia must be emphasized in hospitals.

Fetotoxicity caused by the interaction between zinc and arsenic in mice

Arsenic is an environmental pollutant that induces congenital malformations in experimental models and can contribute to human birth defects. The environmental exposure to arsenic is relatively small when compared with the doses required to cause teratogenicity in mice and other laboratory animals. In order to study the action of zinc in the arsenic-induced teratogenicity, in the present work mice were either pretreated with zinc and later with arsenic or were treated simultaneously with zinc and arsenic in vivo and in vitro. Following administration of arsenate on gestation day 8, pregnant females were killed on the 17th day of gestation; maternal and fetal data were collected by laparotomy and used to calculate reproductive parameters. Fetuses were analyzed for the presence of external malformation and, after the appropriate processing, visceral and skeletal analyses were accomplished. Conceptuses were exposed in whole embryo culture to arsenicals on gestation day 8 (3-6 somite stage). After a 26 h culture period, morphological development was assessed. Neither pretreatment with zinc nor simultaneous administration of zinc prevented arsenic teratogenicity in these experimental models. (C) 2002 Wiley-Liss, Inc.

Morphometric-stereological and functional epididymal alterations and a decrease in fertility in rats treated with finasteride and after a 30-day post-treatment recovery period

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Maternal undernutrition and the offspring kidney: from fetal to adult life

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

Squamata, Elapidae, Micrurus surinamensis (Cuvier, 1817): new records and distribution map in the state of Mato Grosso, Brazil, with notes on diet and activity period.

We report six new records of M. surinamensis and present the map of distribution with known records for this species of semiaquatic coral snake in the state of Mato Grosso, Brazil.

Changes in abiotic characteristics of water in the Paranapanema River and three lateral lagoons at mouth zone of the Jurumirim Reservoir during the flood period, São Paulo, Brazil

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

Reproductive period and size at the onset of sexual maturity of mottled purse crab, Persephona mediterranea (Herbst, 1794) (Brachyura, Leucosioidea) on the southeastern Brazilian coast

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

Population structure and reproductive period of the tropical hermit crab Calcinus tibicen (Decapoda : Diogenidae) in the region of Ubatuba, São Paulo, Brazil

The population of the hermit crab Calcinus tibicen in the Ubatuba region was studied with emphasis on seasonal abundance, seasonal size-frequency distribution, sex-ratio, and reproductive period based on the percentage of ovigerous females. The animals were collected at 2-month intervals for 2 consecutive years (from January 1993 to November 1994). Total mean animal size in shield length was 5.14 +/- 1.23 mm for males, 4.23 +/- 0.79 mm for females, and 4.53 +/- 0.60 for ovigerous females. A discontinuity in reproduction was observed, with an absence of ovigerous females in July (winter) and a high incidence from September to May (spring to autumn). Calcinus tibicen is sexually dimorphic in relation to size, with a higher growth rare in males. The sex-ratio pattern changes with season, indicating that it is more a function of season or habitat than of size.

Ecological distribution and reproductive period of the hermit crab Loxopagurus loxochelis (Anomura, Diogenidae) on the northern coast of São Paulo State, Brazil

The present study aimed to determine the ecological distribution of Loxopagurus loxochelis as a function of selected environmental factors, as well as its reproductive period based on the combined analysis of the presence of ovigerous females and the development of the gonad. The collections were carried out monthly from January to December 2000 in the region of Ubatuba (SP), using a fishing boat equipped with two double rig nets, in isobaths of 5, 10, 15, 20, 25, 30, 35 and 40 m, at which depths samples of sediment and water were collected. The cephalothoracic shield length and sex of the animals were determined; the abdomen was dissected to verify gonad development stages. A total of 334 individuals was obtained ( 196 males, 48 ovigerous females and 90 non-ovigerous females) with sizes varying from 3.0 to 8.6 mm (5.7 +/- 1.0 mm). A greater abundance of L. loxochelis (95.2%) was observed at depths of 20 and 25 m. These sites mainly revealed a substratum stable with a very fine sand fraction, which facilitates the habit of embedding shown by this hermit. With regard to gonadal analysis, it was possible to classify four gonad development stages for each sex: immature, rudimentary, developing and developed. It was observed that in the winter months about 71% of the females had gonads either developing or developed and 67% were ovigerous. Therefore, the winter period can be considered the peak of reproduction for this species, characterizing a typical seasonal-continuous reproduction.

Reproductive cycle and recruitment period of Ocypode quadrata (Decapoda, Ocypodidae) at a sandy beach in southeastern Brazil

The reproductive cycle and recruitment period of a ghost crab population from Ubatuba, São Paulo, Brazil were investigated by means of examining the developmental stages of gonads of breeding crabs and the ingress of young recruits to the studied population. Monthly collections over a one-year period were carried out during nocturnal low-tide periods at Vermelha beach. The morphology of the abdomen and pleopods was used for sex determination. All captured crabs were measured for carapace width and dissected for the determination of the development stage of the gonads. A total of 582 specimens was captured: 271 males, 241 females, and 70 juveniles. Size ranged from 8.5 to 37.5 mm for males, from 9.5 to 39.2 mm for females, and from 5.8 to 12 mm for early juveniles. Median size of males and females did not differ statistically. The frequency of ovigerous females was markedly low. The onset of sexual maturity in females is achieved at around 23 mm of carapace width. Mature females with advanced gonad stages were not recorded from May to September. Recruitment of young was highest during summer, but the presence of early and late juvenile specimens throughout the year indicates that continuous recruitment is taking place in the studied population.

Population structure and breeding period of Pachycheles monilifer (Dana) (Anomura, Porcellanidae) inhabiting sabellariid sand reefs from the littoral coast of São Paulo State, Brazil

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