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PubMedDate not supplied

An etheral extract of Kamala (Mallotus philippinensis (Moll.Arg) Lam.) seed induce adverse effects on reproductive parameters of female rats.

The present study was designed to investigate the adverse effects of indigenous Kamala seed etheral extract on various reproductive parameters of female rats. Animals were treated with various doses (50, 75 and 100 mg/kg body weight, (bw)) of seed extract through gavage for 30 days. Treatment with a higher dose of seed extract (100mg/kg bw) significantly reduced serum levels of FSH, LH and estradiol. At this dose level, relative weights of ovary and uterus was significantly reduced, whereas lower doses (75 and 50 mg/kg bw) did not show any untoward effect. Qualitative analysis regarding histology of ovary revealed reduction in the developing follicles and an increase in the atretic follicles in treated animals as compared to the untreated. Kamala seed extract-induced follicular atresia was further supported by immunoblot/densitometry analysis that ovarian lysate from treated animal had 2.5 times more bax protein expression compared to control ovaries. The number of ovulated eggs and corpora lutea per animal were reduced significantly. Similarly, higher doses of seed extract reduced number of oestrous cycle, whereas the length of cycle was increased significantly. The oestrous and proestrous phases were reduced, while metestrous and diestrous phases were significantly increased. When the females treated with Kamala seed extract were mated with non-treated males, rate of infertile mating increased in a dose-dependent manner with reduced pregnancy rate and number of implantation sites. Taken together, these data indicate that Kamala reduced serum FSH and LH levels probably by affecting hypothalamic/pituitary axis in treated animals. Thus, reduced levels of FSH and LH and estradiol might have affected the follicular development, quality and number of ovulated eggs, corpora lutea formation, oestrous cycle, establishment and maintenance of pregnancy in treated rats.

Animals↗
PubMed2002

Laboratory fecundity as predictor of field success in Trichogramma carverae (Hymenoptera: Trichogrammatidae).

Laboratory fecundity assessments are routinely used to determine the quality of commercially reared Trichogramma egg parasitoids before release for pest control, but there is little information on the relevance of this trait to the field success of Trichogramma. Herein, we characterize the parasitism success of strains of Trichogramma carverae Oatman & Pinto in the laboratory on a factitious (Sitotroga cerealella Olivier) and a natural (Epiphyas postvittana Walker) host. Differences in fecundity of the strains in the laboratory were consistent with a heritability of approximately 10%, allowing ranking of the strains from highest to lowest fecundity. The strains with particularly high and low fecundities were tested for successful parasitism in the field. Results of the field releases show that strain differences in laboratory fecundity did not influence field performance. The implications of this result for fecundity as a quality indicator for commercial stocks are discussed.

Animals↗
PubMed1997

Effects of consecutive thiouracil exposures in the juvenile and adult single comb White Leghorn chicken on body weight and reproductive performance.

The effects of consecutive exposures to dietary thiouracil (TU) in juvenile and adult Single Comb White Leghorn chickens on plasma thyroxine (T4) concentrations, egg production (EP), egg weight (EW), concentrations eggshell quality were determined. Thiouracil was provided in the feed at levels of 0, 0.1, or 0.2% (PTRT) from 0 to 6 wk of age and at levels of 0 or 0.1% (TRT) from 32 to 38 wk of age. Body weight gain was simulated but T4, EW, EP, and eggshell quality were generally reduced by 0.1% TU TRT. However, TU PTRT alleviated a latent depressing effect of TU TRT on BW after 38 wk of age. Thiouracil PTRT, particularly at the 0.2% level, induced significant decreases in EW but increased EP between 32 and 50 wk. The effects of early thyroid suppression in juveniles with TU PTRT on the subsequent reproduction of adults were primarily in response to a delay in the onset of sexual maturity, and not directly to prolonged responses in T4 or BW that extended into lay.

Aging↗
PubMed1999

Symposium summary and challenges for the future.

The poultry industry has grown and prospered over the past 50 yr by a repeated pattern of careful analysis of factors limiting production, followed by replacement of biological functions with management practices. Examples include assisted incubation, selection of sires, and survival via novel housing. Each resulted in a period of enhanced product output. Trends developing over the past decade raise the potential for consideration of another intervention, that of assisted reproduction. Examples illustrating the need to consider, and adopt at several levels, assisted reproduction are provided. Three critical aspects of poultry production should be monitored by careful documentation of: 1) genetic throughput from pedigree to product, best assessed by monitoring number of chicks produced per male; 2) product cost, best assessed by optimizing rate of lay and fertility of laid eggs for each hen; and 3) product quality, reflected in the homogeneity of progeny for desired traits. Each segment of the industry (turkey, egg or broiler; breeder or producer) will find unique solutions to these interacting factors. Presentations within the symposium are reviewed and integrated, and comments are provided relative to challenges facing the industry in the 21st century.

Animal Husbandry↗
PubMed2002

Oviposition on and mining in bolls of Bt and non-Bt cotton by resistant and susceptible pink bollworm (Lepidoptera: Gelechiidae).

Transgenic cotton that produces insecticidal crystal protein Cry1Ac of Bacillus thuringiensis (Bt) has been effective in controlling pink bollworm, Pectinophora gossypiella (Saunders). We compared responses to bolls of Bt cotton and non-Bt cotton by adult females and neonates from susceptible and Cry1Ac-resistant strains of pink bollworm. In choice tests on caged cotton plants in the greenhouse, neither susceptible nor resistant females laid fewer eggs on Bt cotton bolls than on non-Bt cotton bolls, indicating that the Bt toxin did not deter oviposition. Multiple regression revealed that the number of eggs laid per boll was negatively associated with boll age and positively associated with boll diameter. Females also laid more eggs per boll on plants with more bolls. The distribution of eggs among bolls of Bt cotton and non-Bt cotton was clumped, indicating that boll quality rather than avoidance of previously laid eggs was a primary factor in oviposition preference. Parallel to the results from oviposition experiments, in laboratory no-choice tests with 10 neonates per boll, the number of entrance holes per boll did not differ between Bt cotton and non-Bt cotton for susceptible and resistant neonates. Also, like females, neonates preferred younger bolls and larger bolls. Thus, acceptance of bolls by females for oviposition and by neonates for mining was affected by boll age and diameter, but not by Bt toxin in bolls. The lack of discrimination between Bt and non-Bt cotton bolls by pink bollworm from susceptible and resistant strains indicates that oviposition and mining initiation are independent of susceptibility to Cry1Ac.

Animals↗
PubMed2004

Interactions among host diet, nutritional status and gastrointestinal parasite infection in wild bovids.

In this study, I explored the interactions among host diet, nutritional status and gastrointestinal parasitism in wild bovids by examining temporal patterns of nematode faecal egg shedding in species with different diet types during a drought and non-drought year. Study species included three grass and roughage feeders (buffalo, hartebeest, waterbuck), four mixed or intermediate feeders (eland, Grant's gazelle, impala, Thomson's gazelle) and two concentrate selectors (dik-dik, klipspringer). Six out of the nine focal species had higher mean faecal egg counts in the drought year compared to the normal year, and over the course of the dry year, monthly faecal egg counts were correlated with drought intensity in four species with low-quality diets, but no such relationship was found for species with high-quality diets. Comparisons of dietary crude protein and faecal egg count in impala showed that during the dry season, individuals with high faecal egg counts (> or =1550 eggs/g of faeces) had significantly lower crude protein levels than individuals with low (0-500 eggs/g) or moderate (550-1500 eggs/g) egg counts. These results suggest that under drought conditions, species unable to maintain adequate nutrition, mainly low-quality feeders, are less able to cope with gastrointestinal parasite infections. In particular, during dry periods, reduced protein intake seems to be associated with declining resilience and resistance to infection.

Animal Nutritional Physiological Phenomena↗
PubMed2004

Unscrambling an egg: protein disaggregation by AAA+ proteins.

Aprotein quality control system, consisting of molecular chaperones and proteases, controls the folding status of proteins and prevents the aggregation of misfolded proteins by either refolding or degrading aggregation-prone species. During severe stress conditions this protection system can be overwhelmed by high substrate load, resulting in the formation of protein aggregates. In such emergency situations, Hsp104/ClpB becomes a key player for cell survival, as it has the extraordinary capacity to rescue proteins from an aggregated state in cooperation with an Hsp70 chaperone system. The ring-forming Hsp104/ClpB chaperone belongs to the AAA+ protein superfamily, which in general drives the assembly and disassembly of protein complexes by ATP-dependent remodelling of protein substrates. A disaggregation activity was also recently attributed to other eubacterial AAA+ proteins, while such an activity has not yet been identified in mammalian cells. In this review, we report on new insights into the mechanism of protein disaggregation by AAA+ proteins, suggesting that these chaperones act as molecular crowbars or ratchets.

Journal Article↗
PubMed2006

Habitat difference in abundance of willow leaf beetle Phratora vulgatissima (Coleoptera: Chrysomelidae): plant quality or natural enemies?

Herbivorous insects are influenced by both 'bottom-up' forces mediated through host plants and 'top-down' forces from natural enemies. Few studies have tried to evaluate the relative importance of the two forces in determining the abundance of insects. The leaf beetle Phratora vulgatissima Linnaeus sometimes occurs at high densities and severely damages the willow Salix cinerea in forest habitats. For willows growing in open agricultural landscapes (farmland S. cinerea), the leaf beetle generally occurs at low densities and plants receive little damage. The purpose of the present study was to evaluate the relative importance of host plant quality and natural enemies behind the observed difference in P. vulgatissima abundance. Female egg-laying and larval performance (growth and survival) were studied on caged willow branches in the field to investigate if plant quality differs between S. cinerea trees growing in forest and farmland habitats. The survival of eggs exposed to natural enemies was examined to see if predation could explain the low abundance of leaf beetles on farmland willows. The results indicated no difference in plant quality; female egg laying and larval performance did not differ between the forest and the farmland. However, heteropteran predators (true bugs) were more abundant, and the survival of eggs was lower, on plants in the farmland habitat than in the forest habitat. The data suggest that the low abundance of P. vulgatissima on farmland willows could not be explained by a poor quality of plants, but more likely by high predation from heteropterans.

Animals↗
PubMed2000

Nutritional contribution of eggs to American diets.

OBJECTIVES: The main purposes of this study were (1) to assess the nutritional significance of eggs in the American diet and (2) to estimate the degree of association between egg consumption and serum cholesterol concentration. METHODS: Data from the most recent National Health and Nutritional Examination Survey (NHANES III, 1988-94) were utilized to compare the nutritional quality indicators of diets that contained eggs (USDA food grouping system) with those that did not. Nutrient intake (from 24-hour dietary recall), egg intake (from food frequency questionnaire), sociodemographic data and blood cholesterol levels of subjects who met inclusion criteria (n = 27,378) were grouped according to the occurrence and frequency of egg consumption and were analyzed using SUDAAN. RESULTS: Daily nutrient intake of egg consumers (EC) was significantly greater than that of nonconsumers (NC) for all nutrients studied (except dietary fiber and vitamin B6). Eggs contributed < 10% of daily intake of energy and vitamin B6, 10% to 20% of folate and total, saturated and polyunsaturated fat, and 20% to 30% of vitamins A, E and B12 in EC. Compared to EC, NC had higher rates of inadequate intake (defined by Estimated Average Requirements (EAR) or < 70% Recommended Dietary Allowance (RDA)) for vitamin B12 (10% vs. 21%), vitamin A (16% vs. 21%), vitamin E (14% vs. 22%) and vitamin C (15% vs. 20%). After adjusting for demographic (age, gender and ethnicity) and lifestyle variables (smoking and physical activity), dietary cholesterol was not related to serum cholesterol concentration. People who reported eating > or = 4 eggs/wk had a significantly lower mean serum cholesterol concentration than those who reported eating < or = 1 egg/wk (193 mg/dL vs. 197 mg/dL, p < 0.01). More frequent egg consumption was negatively associated with serum cholesterol concentration (beta = -6.45, p < 0.01). CONCLUSIONS: In this cross-sectional and population-based study, egg consumption made important nutritional contributions to the American diet and was not associated with high serum cholesterol concentrations.

Adolescent↗
PubMed2003

[Comparison of the results of an assisted-reproduction program related with the day of follicular aspiration].

UNLABELLED: The proper time for the oocyte retrieval allow us to obtain good quality oocytes In assisted reproduction techniques, improving fertilization and pregnancy rates. The follicular aspiration has been done by vaginal ultrasounds when we can see at least 3 follicles > or = 16 mm diameter. OBJECTIVE: To compare oocyte quality, fertilization and pregnancy rate-according to the day of the follicular aspiration. MATERIAL AND METHODS: 438 cycles were studied in the Instituto para el Estudio de la Concepción Humana in Monterrey Mexico, comparing oocyte quality, fertilization and pregnancy rate. RESULTS: If egg retrieval was done on day 12 of the cycle, we obtained a mean of 7.61 good quality oocytes, 51% of them fertilized and the pregnancy rate was 36.8%, when the aspiration was performed on day 13 of the cycle, we obtained a mean of 7 good quality oocytes, 59% of them fertilized and the pregnancy rate was 34%, and if the oocyte retrieval was on day 14 of the cycle, we obtained a mean of 6.42 good quality oocytes, 57% of the fertilized and the pregnancy rate was 31.7%. DISCUSSION: The oocyte quality, fertilization and pregnancy rate were slightly better if the oocyte retrieval was performed on day 12 or 13 of the cycle, rather than day 14. However this was no statistical significative.

Adult↗
PubMed1987

Immunity after treatment of human schistosomiasis mansoni. III. Long-term effects of treatment and retreatment.

Group mean Schistosoma mansoni reinfection patterns are presented for 2 years after treatment with oxamniquine in 1981 of over 100 9- to 16-year-old Kenyan schoolchildren, and for one year after retreatment in 1983 with either oxamniquine or praziquantel when most (nearly 700) infected people in the whole community were treated. Quality control confirmed comparable Kato egg counts throughout the study. Continuing transmission after 1981 raised prevalence to nearly its original level within 6 months, but intensity remained suppressed throughout the 2 year follow-up and very few children reacquired heavy infections (greater than 400 eggs/g). Age and sex had significant effects: reinfection diminished with age, especially among boys--a pattern not apparently attributable to differential water contact. Children with heavy pretreatment infections tended to develop heavy reinfections but this trend was not statistically significant on a group basis, nor were similar trends during the period of less pronounced transmission following the 1983 community treatment. Oxamniquine was equally effective in children receiving it in both 1981 and 1983, and the efficacy of praziquantel resembled that of oxamniquine. In this area of Kenya, repeated chemotherapy will be needed to contain transmission, probably annually or biennially, unless supplemented with other, effective control measures. These findings confirm the beneficial effects of treating even a limited segment of a community at intervals of a year or more without necessarily stopping transmission. They are also compatible with recent findings on potential immune mechanisms in man.

Adolescent↗
PubMed2006

Maternal programming of defensive responses through sustained effects on gene expression.

There are profound maternal effects on individual differences in defensive responses and reproductive strategies in species ranging literally from plants to insects to birds. Maternal effects commonly reflect the quality of the environment and are most likely mediated by the quality of the maternal provision (egg, propagule, etc.), which in turn determines growth rates and adult phenotype. In this paper we review data from the rat that suggest comparable forms of maternal effects on defensive responses stress, which are mediated by the effects of variations in maternal behavior on gene expression. Under conditions of environmental adversity maternal effects enhance the capacity for defensive responses in the offspring. In mammals, these effects appear to 'program' emotional, cognitive and endocrine systems towards increased sensitivity to adversity. In environments with an increased level of adversity, such effects can be considered adaptive, enhancing the probability of offspring survival to sexual maturity; the cost is that of an increased risk for multiple forms of pathology in later life.

Adaptation, Psychological↗
PubMed2004

Transmyometrial oocyte retrieval and pregnancy rates.

OBJECTIVE: To determine whether transvaginal, ultrasound-guided oocyte retrieval performed through the myometrium has a negative impact on IVF pregnancy rates. DESIGN: Retrospective cohort study. SETTING: Academic hospital and research center. PATIENT(S): A total of 5,115 IVF cycles performed at the Brigham and Women's Hospital between 1998 and 2001 were evaluated. In 85 cycles (1.7%), the oocyte retrieval needle passed through the myometrium because of ovarian position during retrieval. Each of these cases was matched to a control cycle by age, attempt number, and date of retrieval. INTERVENTION(S): Transmyometrial oocyte retrieval. MAIN OUTCOME MEASURE(S): Pregnancy rates. RESULT(S): There were no statistically significant differences in pregnancy rates between cases and controls. Cases were more likely than controls to have underlying tubal disease and adhesions as the primary cause of infertility. The groups did not differ significantly in terms of age, attempt number, estradiol level, follicle number, days stimulated, ampules of gonadotropins administered, number of eggs, number of embryos, or quality of embryos. CONCLUSION(S): Transmyometrial oocyte retrieval is an uncommon event. Clinicians and patients can be reassured that transmyometrial oocyte retrieval does not seem to decrease IVF pregnancy rates; however, a larger study with greater power might reveal a statistically significant difference.

Adult↗
PubMed2005

The programming of individual differences in defensive responses and reproductive strategies in the rat through variations in maternal care.

There are profound maternal effects on individual differences in defensive responses and reproductive strategies in species ranging literally from plants to insects to birds. Maternal effects commonly reflect the quality of the environment and are most likely mediated by the quality of the maternal provision (egg, propagule, etc.), which in turn determines growth rates and adult phenotype. In this paper, we review data from the rat that suggest comparable forms of maternal effects on both defensive responses to threat and reproductive behavior and which are mediated by variations in maternal behavior. Ultimately, we will need to contend with the reality that neural development, function and health are defined by social and economic influences.

Adaptation, Physiological↗
PubMed2000

Female bluethroats enhance offspring immunocompetence through extra-pair copulations.

Female birds frequently copulate with extra-pair males, but the adaptive value of this behaviour is poorly understood. Some studies have suggested that 'good genes' may be involved, where females seek to have their eggs fertilized by high-quality males without receiving any material benefits from them. Nevertheless, it remains to be shown that a genetic benefit is passed on to offspring. Here we report that nestling bluethroats, Luscinia svecica, sired by extra-pair males had a higher T-cell-mediated immune response than their maternal half-siblings raised in the same nest. The difference could not be attributed to nestling body mass, sex or hatching order, but may be an effect of paternal genotype. Extra-pair young were also more immunocompetent than their paternal half-sibs raised in the genetic father's own nest, which indicates an additional effect of maternal genotype. Our results are consistent with the idea that females engage in extra-pair copulations to obtain compatible viability genes, rather than 'good genes' per se.

Animals↗
PubMed1985

Incidence of (n-3) essential fatty acid deficiency on trout reproductive processes.

A feeding experiment was conducted on rainbow trout broodstock for one year to investigate the influence of the quality of dietary lipids on egg and fry fatty acid composition, embryonic development and hatching efficiency. The broodstock were fed either a commercial control diet or a (n-3) fatty acid-deficient diet; their liver, eggs and fry were analysed to determine the fatty acid composition of their neutral and polar lipids. The fatty acid pattern in liver, eggs and fry was markedly different due to the qualitative difference of the dietary lipids. The most striking difference was the low amount of 22:6 (n-3) and the high levels of 20:4 (n-6) and 22:5 (n-6) in phospholipids of fish receiving the (n-3)-deficient diet containing a high level of 18:2 (n-6). While fertilization efficiency was equivalent in the first two days of development, whatever the diet, two peaks of mortality were observed, one at day 8 and the other at day 22 after fertilization, during the time the eggs produced by the deficient fish were incubated. A shorter period of vitellus resorption (50 vs 65 day) was observed in (n-3)-deficient alevins as compared to controls. Morphological study of the development of the (n-3)-deficient embryos showed some cleavage disorders at the 16 to 32-cell stage, a blocking effect before gastrulation, and later various alterations in organogenesis. It was concluded that (n-3) fatty acids, and especially 22:6 (n-3), play a crucial and specific role in trout embryo development. These fatty acids could be involved in cellular recognition processes through their oxygenated derivatives. The need for long-term nutritional deficiency to induce the reported biochemical and physiological alterations is discussed.

Animals↗
PubMedDate not supplied

Biotic and abiotic factors affect the nest environment of embryonic leatherback turtles, Dermochelys coriacea.

Clutches of leatherback turtles, Dermochelys coriacea, have lower hatching success than those of other sea turtles, but causes of high embryonic mortality are unknown. We measured characteristics of clutches along with spatial and temporal changes in PO(2) and temperature during incubation to determine the extent to which they affected the developmental environment of leatherback embryos. Minimum PO(2) in nests decreased as both the total number and mass of metabolizing embryos increased. Increases in both the number and mass of metabolizing embryos caused an increase in maximum nest temperature. However, neither PO(2) nor temperature was correlated with hatching success. Our measurements of relatively high nest PO(2) (lowest 17.1 kPa or 16.9% O(2)) indicate that hypoxia apparently does not cause the low hatching success of leatherback clutches. Oxygen partial pressure increased and temperature decreased from the center toward the periphery of leatherback nests. We inferred from these measurements that positions of eggs within nests vary in quality and potentially affect overall developmental success of entire clutches. The large metabolic mass of leatherback clutches and limits to gas flux imposed by the sand create a situation in which leatherback embryos collectively affect their own environment.

Animals↗
PubMed1975

Effects of quantity and quality of dietary protein and variation in certain enzyme activities on glucose metabolism in the rat.

This study attempted to determine whether the quantity and the quality of protein intake could influence the activity of some enzymes involved in carbohydrate metabolism. Thus, adult rats were fed for 23 days a diet containing different levels (10 to 70%) and qualities (casein, wheat gluten, and egg yolk) of protein. Variations in liver enzyme activities of pyruvate kinase (PK), glucose-6-phosphate dehydrogenase (G6PDH), malic enzyme (ME), glucose-6-phosphatase (G6Pase), and phosphoenolpyruvate carboxykinase (PEPCK) were studied. Also the changes in enzyme activities were compared with changes in food intake and body weight gain. Increasing the protein level produced a progressive fall in the activities of ME and PK. The decrease in PK activity was greater when the biological value of the dietary proteins was higher (P less than 0.05). On the other hand, the activities of G6PDH and PEPCK increased as the protein level increased. The activity of G6Pase was unchanged. The relationship between the two opposing enzyme activities PK and PEPCK, in relation to protein intake, shows that for each protein studied, the equilibrium between glycolysis and gluconeogenesis was obtained at different protein intakes (1.5, 1.9, and 2.2 g of protein/day/100 g of body weight, respectively, for egg yolk, casein, and wheat gluten) regardless of daily consumption of energy as carbohydrate, which are similar (8 to 9 kcal/day/100 g of body weight). This equilibrium also corresponded to the maximum weight gain (5 g) of the experimental animals. In conclusion, the experimental method used permits a simultaneous assessment of the protein and carbohydrate requirements ensuring the best weight gain in young adult rats.

Animals↗