Oocyte morphometry in female dogs (Canis familiaris, Linnaeus, 1758)

In the present study, the ovaries of 15 healthy bitches divided into three groups according to age were analysed by histology and morphometry: group 1 (1-3 years), group 2 (> 3-5 years) and group 3 (> 5-7 years). After ovariosalpingohysterectomy, the ovaries were fixed, routinely processed for embedding in paraffin and stained with haematoxylin-eosin. The following morphometric parameters were analysed: maximum and minimum diameter (mu m), perimeter (mu m), area (mu m(2)) and roundness of the cytoplasm and nucleus of oocytes from different types of follicles. Significant differences in the cytoplasmic and nuclear parameters of follicular oocytes between the experimental groups were determined by ANOVA and the Tukey test (5%). For the biotechnology of reproduction, the present results showed that in vitro maturation yielded the best performance for oocytes from primordial follicles in group 3 females and for oocytes embedded in secondary and tertiary follicles in group 2 females. In addition, the present findings will help in the diagnosis and prognosis of diseases affecting bitches, and will especially contribute to a better understanding of these cells by researchers in the field of histology and canine reproduction.

Detection of HPV in mouth floor squamous cell carcinoma and its correlation with clinicopathologic variables, risk factors and survival

The human papillomavirus (HPV) has been historically associated with head and neck cancers, although its role in oral carcinogenesis remains poorly defined. The purpose of this study was to investigate the prevalence of HPV in mouth floor squamous cell carcinoma and correlate it with clinicopathologic variables, risk factors and survival. HPV presence was evaluated by nested polymerase chain reaction (nPCR) in 29 paraffin-embedded specimens of mouth floor squamous cell carcinoma. HPV DNA was detected in 17.2% (5 of 29) of the specimens; the highest prevalence was observed in non-smoking patients over the age of 60 years. All HPV DNA positive specimens were detected in men with clinical stage III and IV lesions, being most of which were moderately differentiated. Despite this correlation there were no statistically significant differences observed among the analyzed variables, including patients' survival. The relatively low incidence of HPV DNA present in these tumors suggests that this virus does not, by itself, have a significant role in the development of mouth floor squamous cell carcinoma. J Oral Pathol Med (2008) 37: 593-598

Influence of temperature on larval survival, development and respiration in Chasmagnathus granulata (Crustacea, Decapoda)

Larvae of an estuarine grapsid crab Chasmagnathus granulata Dana 1851, from temperate and subtropical regions of South America, were reared in seawater (32 ‰) at five different constant temperatures (12, 15, 18, 21, 24 °C). Complete larval development from hatching (Zoea I) to metamorphosis (Crab I) occurred in a range from 15 to 24 °C. Highest survival (60% to the first juvenile stage) was observed at 18°C, while all larvae reared at 12°C died before metamorphosis. The duration of development (D) decreased with increasing temperature (T). This relationship is described for all larval stages as a power function (linear regressions after logarithmic transformation of both D and T). The temperature-dependence of the instantaneous developmental rate (D-1) is compared among larval stages and temperatures using the Q10 coefficient (van't Hoff's equation). Through all four zoeal stages, this index tends to increase during development and to decrease with increasing T (comparing ranges 12-18, 15-21, 18-24 °C). In the Megalopa, low Q10 values were found in the range from 15 to 24 °C. In another series of experiments, larvae were reared at constant 18°C and their dry weight (W) and respiratory response to changes in T were measured in all successive stages during the intermoult period (stage C) of the moulting cycle. Both individual and weight-specific respiration (R, QO2) increased exponentially with increasing T. At each temperature, R increased significantly during growth and development through successive larval stages. No significantly different QO2 values were found in the first three zoeal stages, while a significant decrease with increasing W occurred in the Zoea IV and Megalopa. As in the temperature-dependence of D, the respiratory response to changes in temperature (Q10) depends on both the temperature range and the developmental stage, however, with different patterns. In the zoeal stages, the respiratory Q10 was minimum (1.7-2.2) at low temperatures (12-18 °C), but maximum (2.2-3.0) at 18-24 °C. The Megalopa, in contrast, showed a stronger metabolic response in the lower than in the upper temperature range (Q10 = 2.8 and 1.7, respectively). We interpret this pattern as an adaptation to a sequence of temperature conditions that should typically be encountered by C. granulata larvae during their ontogenetic migrations: hatching in and subsequent export from shallow estuarine lagoons, zoeal development in coastal marine waters, which are on average cooler, return in the Megalopa stage to warm lagoons. We thus propose that high metabolic sensitivity to changes in temperature may serve as a signal stimulating larval migration, so that the zoeae should tend to leave warm estuaries and lagoons, whereas the Megalopa should avoid remaining in the cooler marine waters and initiate its migration towards shallow coastal lagoons.

Oviposition and survival in females of Procornitermes araujoi under laboratory conditions (Isoptera, Termitidae, Nasutitermitinae)

After an enormous swarming of Procornitermes araujoi when a great number of females were collected, we investigated the occurrence of parthenogenesis beyond oviposition and survival of these females under laboratory conditions. The groups of virgin females were faster in their first oviposition than females of male-female pairs, nevertheless their eggs never hatch. The survival data showed higher longevity in the group of three females when compared with groups of two and four females.

Survival and conjugation of Bacillus thuringiensis in a soil microcosm

The survival and conjugation ability of sporogenic and asporogenic Bacillus thuringiensis strains were investigated in broth, in non-amended sterile clay soil monoculture and in mixed soil culture. The 75 kb pHT73 plasmid carrying an erythromycin resistance determinant and a cry1Ac gene was transferred in mating broth and soil microcosm. Survival of strains was assessed in soil monoculture and in mixed soil culture for up to 20 days. Sporogenic strains rapidly formed viable spores which were maintained until the end of the experiment. The asporogenic strains were no longer recovered after 8 days of incubation. This study shows that the environmental impact of asporogenic B. thuringiensis strains is lower than that of sporogenic B. thuringiensis strains. Thus, the use of asporogenic strains may significantly reduce any potential risk (gene transfer, soil and plant contamination) due to the dissemination of B. thuringiensis-based biopesticides in the environment. Copyright (C) 2000 Federation of European Microbiological Societies.

Complete replacement of the mitochondrial genotype in a Bos indicus calf reconstructed by nuclear transfer to a bos taurus oocyte

Due to the exclusively maternal inheritance of mitochondria, mitochondrial genotypes can be coupled to a particular nuclear genotype by continuous mating of founder females and their female offspring to males of the desired nuclear genotype. However, backcrossing is a gradual procedure that, apart from being lengthy, cannot ascertain that genetic and epigenetic changes will modify the original nuclear genotype. Animal cloning by nuclear transfer using host ooplasm carrying polymorphic mitochondrial genomes allows, among other biotechnology applications, the coupling of nuclear and mitochondrial genotypes of diverse origin within a single generation. Previous attempts to use Bos taurus oocytes as hosts to transfer nuclei from unrelated species led to the development to the blastocyst stage but none supported gestation to term. Our aim in this study was to determine whether B. taurus oocytes support development of nuclei from the closely related B. indicus cattle and to examine the fate of their mitochondrial genotypes throughout development. We show that indicus:taurus reconstructed oocytes develop to the blastocyst stage and produce live offspring after transfer to surrogate cows. We also demonstrate that, in reconstructed embryos, donor cell-derived mitochondria undergo a stringent genetic drift during early development leading, in most cases, to a reduction or complete elimination of B. indicus mtDNA. These results demonstrate that cross-subspecies animal cloning is a viable approach both for matching diverse nuclear and cytoplasmic genes to create novel breeds of cattle and for rescuing closely related endangered cattle.

The ultrastructural aspects of vitellogenesis or oocyte secondary growth in Serrasalmus spilopleura (Teleostei, Characiformes, Serrasalminae)

Oocyte secondary growth in S. spiloleura corresponds to the period in which different vesicular structures are formed, including the cortical alveoli and the yolk granules. The oocytes with cortical alveolus formation show vesicular structures with filamentous content in the cortical cytoplasmic region, which are the cortical alveolus precursors. In these oocytes, electron-dense vesicles of heterogenous content are dispersed in the inner cytoplasmic region and their nuclei are irregular, showing many nucleoli of different sizes. The oocytes in vitellogenesis are filled with many vesicles. The cortical alveolus precursors are in the peripheral region, and electron-dense granules are seen near to the nucleus. These fuse and form yolk granules. The oocytes in vitellogenesis show a very irregular nucleus that has nucleoli of different sizes. In the oocytes in final vitellogenesis, the yolk granules are scattered throughout the cytoplasm, displacing the cortical alveoli toward cell periphery. The nucleus is similar to the other stages.

Inhibitory effect of deferoxamine on Paracoccidioides brasiliensis survival in human monocytes: Reversal by holotransferrin not by apotransferrin

The mechanisms used by Paracoccidioides brasiliensis to survive into phagocytic cells are not clear. Cellular iron metabolism is of critical importance to the growth of several intracellular pathogens whose capacity to multiply in mononuclear phagocytes is dependent on the availability of intracellular iron. Thus, the objective of this paper was to investigate the role of intracellular iron in regulating the capacity of P. brasiliensis yeast cells to survive within human monocytes. Treatment of monocytes with deferoxamine, an iron chelator, suppressed the survival of yeasts in a concentration-dependent manner. The effect of deferoxamine was reversed by iron-saturated transferrin (holotransferrin) but not by nonsaturated transferrin (apotransferrin). These results strongly suggest that P. brasiliensis survival in human monocytes is iron dependent.

Chloroquine inhibits Paracoccidioides brasiliensis survival within human monocytes by limiting the availability of intracellular iron

The mechanisms used by Paracoccidioides brasiliensis (Pb 18) to survive into monocytes are not clear. Cellular iron metabolism is of critical importance to the growth of several intracellular pathogens, including P. brasiliensis, whose capacity to multiply in mononuclear phagocytes is dependent on the availability of intracellular iron. Chloroquine, by virtue of its basic properties, has been shown to prevent release of iron from holotransferrin by raising endocytic and lysosomal pH, and thereby interfering with normal iron metabolism. Then, in view of this, we have studied the effects of CHLOR on P. brasiliensis multiplication in human monocytes and its effect on the murine paracoccidioidomycosis. CHLOR induced human monocytes to kill P. brasiliensis. The effect of CHLOR was reversed by FeNTA, an iron compound that is soluble at neutral to alkaline pH, but not by holotransferrin, which releases iron only in an acidic environment. CHLOR treatment of Pb 18-infected BALB/c mice significantly reduced the viable fungi recovery from lungs, during three different periods of evaluation, in a dose-dependent manner. This study demonstrates that iron is of critical importance to the survival of P. brasiliensis yeasts within human monocytes and the CHLOR treatment in vitro induces Pb 18 yeast-killing by monocytes by restricting the availability of intracellular iron. Besides, the CHLOR treatment in vivo significantly reduces the number of organisms in the lungs of Pb-infected mice protecting them from several infections. Thus, CHLOR was effective in the treatment of murine paracoccidioidomycosis, suggesting the potential use of this drug in patients' treatment.

Dinâmica populacional de Characidium lauroi e C. alipioi (Teleostei, Crenuchidae) na microbacia do Ribeirão Grande, serra da Mantiqueira Oriental, Estado de São Paulo

In low-order streams, the high and variable water flow rates offer both advantages and disadvantages to the life cycle of fishes. Even closely related species living in similar habitats can show differences in life history patterns. Based on oocyte-size distributions, C. lauroi was classified into the fractional spawning type, and C. alipioi into the total spawning type. The absolute fecundity of C. lauroi ranged from 1,313 to 2,925 oocytes; in C. alipioi the absolute fecundity ranged from 2,213 to 25,550 oocytes. The nonparametric Spearman correlation test showed statistical significance between the gonadosomatic index and fecundity for both species. The growth parameters, natural mortality rate and survival rate for females of C. lauroi were: K = 0.68 yr -1, L ∞ = 8.7 cm, t max = 4.4 years, M= 1.62 yr -1, S = 19.79%, and for males: K = 0.78 yr -1, L ∞ = 6.9 cm, t max = 3.8 years, M = 1.89 yr -1, S = 15.11%. The growth parameters, natural mortality rate and survival rate for females of C. alipioi were: K = 0.90 yr -1, L ∞ = 12.2 cm, t max = 3.3 years, M = 1.81 yr -1, S = 16.37%, and for males: K = 0.76 yr -1, L ∞ = 10.1 cm, t max = 3.9 years, M = 1.71 yr -1, S = 18.10%.

Analysis of culling probability in dairy buffalo using survival models

In order to contribute to the genetic breeding programs of buffaloes, this study aimed to determine the influence of environmental effects on the stayability (ST) of dairy female Murrah buffalo in the herd. Data from 1016 buffaloes were used. ST was defined as the ability of the female to remain in the herd for 1, 2, 3, 4, 5 or 6 years after the first calving. Environmental effects were studied by survival analysis, adjusted to the fixed effects of farm, year and season of birth, class of first-lactation milk yield and age at first calving. The data were analyzed using the LIFEREG procedure of the SAS program that fits parametric models to failure time data (culling or ST = 0), and estimates parameters by maximum likelihood estimation. Breeding farm, year of birth and first-lactation milk yield significantly influenced (P < 0.0001) the ST to the specific ages (1 to 6 years after the first calving). Buffaloes that were older at first calving presented higher probabilities of being culled 1 year after the first calving, without any effect on culling at older ages. Buffaloes with a higher milk yield at first calving presented a lower culling probability and remained for a longer period of time in the herd. The effects of breeding farm, year of birth and first-lactation milk yield should be included in models used for the analysis of ST in buffaloes. Copyright © The Animal Consortium 2010.

A síndrome do hiperestímulo ovariano não influencia os resultados clínicos após ciclos de descongelamento de embriões provenientes de ciclos de ICSI

Objective: The objective of this study was evaluate if the embryos cryopreservation from OHSS patients Intracytoplasmic Sperm Injection (ICSI) cycles could be influence the clinical outcomes when compared to patients who receive oocytes from donors but the endometrium was not prepared and the embryos were cryopreserved. Methods: Fifty eight couples submitted to ICSI cycles in which 26 with OHSS clinical manifestation (OHSS group) and 32 couples who have received oocytes from donors (control group). The embryos were frozen on day+2 or +3of development. All patients included in this study had embryos crypreserved before the transfer, and in the thawing cycle, only the endometrium preparation was performed. The embryo survival, implantation, pregnancy and miscarriage rates were evaluated in the embryo thawing cycle. Results: There was no difference among the groups in relation to fertilization rate (OHSS: 71.89% ± 15.45, Control: 79.75% ± 21.68, p= 0.234), survival embryos rate (OHSS: 68.85 ± 21.10, Control: 59.53 ± 36.79, p= 0.233), high quality embryos rate (OHSS: 25.20 ± 23.90, Control: 27.40 ± 30.30, p= 0.760), implantation rate (OHSS: 17.9 ± 26.9, Control: 12.5 ± 23.7, p= 0.435), pregnancy rate (OHSS: 38.50, Control: 28.60, p= 0.441) and miscarriage rate (OHSS: 40.00, Control: 25.00, p= 0.332). Conclusion: Our findings suggest that clinical outcomes in freeze and thawing cycles were not affected by the presence of ovarian hyperstimulation syndrome clinical manifestation after controlled ovarian stimulation.