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At least 1,279 records · Page 71Linked to original sources
PubMed2006

Type-1 cannabinoid receptor expression in the frog, Rana esculenta, tissues: a possible involvement in the regulation of testicular activity.

Endogenous cannabinoids and type-1 cannabinoid receptor (CB1) are widely produced and distributed in the central nervous system (CNS) and peripheral nerves in mammals. In addition, the detection of endocannabinoids and corresponding receptors in non nervous peripheral tissues indicates an involvement of the system in the control of a wide range of physiological activities, including reproduction. Recently, the existence of CB1 was also observed in lower vertebrates and in urochordate suggesting that the endocannabinoid system is phylogenetically conserved. Using RT-PCR, CB1 mRNA expression profiles were characterized in a wide range of tissues of the anuran amphibian, the frog, Rana esculenta. Besides a strong expression in the CNS, CB1 was also present in testis, kidney, liver, ovary, muscle, heart, spleen, and pituitary. The CB1 expression pattern has been characterized in both testis and CNS during the annual sexual cycle. In testis, CB1 is poorly expressed during the winter stasis of the spermatogenesis rising during the breeding season and resumption period. An expression profile mismatching to that observed in testis was detected in whole-brain preparations during the sexual cycle; in particular in the diencephalon, the encephalic area mainly involved in the control of reproductive functions. Furthermore, fluctuations inside isolated encephalic areas and spinal cord were observed all over the reproductive cycle. In conclusion, CB1 receptor is expressed in R. esculenta CNS and testis. As far as the gonad it concerns, our results suggest the involvement of the endocannabinoids in the control of reproductive function.

Animals↗
PubMed1998

Identification of encephalomyocarditis virus in clinical samples by reverse transcription-PCR followed by genetic typing using sequence analysis.

The objective of the present study was to gain a better understanding of the epidemiology of encephalomyocarditis virus (EMCV) infections in pigs by applying molecular techniques. The diagnostic potential of a reverse transcription-PCR (RT-PCR) targeting 286 nucleotides at the 3' end of the gene which encodes the viral polymerase was assessed with experimental and field samples. In addition, the use of the amplified sequences for an epidemiological study was evaluated. The heart was clearly shown to be the most suitable organ. The detection limit was determined to be 1 viral particle in 100 mg of heart tissue. The sensitivity and specificity of the assay on the basis of the results obtained in this study were 94 and 100%, respectively. Phylogenetic analysis of the amplified sequences classified EMCVs in two distinct lineages. Group A consists of the reference strain ATCC 129B, all isolates collected between 1991 and 1994 in Belgium in association with reproductive failure, and all Greek isolates. All Belgian isolates collected since the first isolation of EMCV in relation to myocardial failure in fatteners in Belgium group together with the isolates from Cyprus (1996 and 1997), Italy (1986 to 1996), and France (1995) in group B irrespective of their pathogenicity. The analyzed part of the 3D gene differed by 13.0% between Groups A and B. In contrast to the sequence homogeneity of the Belgian isolates collected between 1991 and 1994, molecular diversity, which ranged between 0 and 2%, was observed among the Belgian isolates collected in 1995 and 1996. Among all Greek isolates the diversity ranged between 1 and 8%. However, this diversity does not seem to reflect geographical links between the outbreaks. A RT-PCR for the rapid and specific diagnosis of EMCV in a variety of clinical samples followed by nucleotide sequence analysis proved to be valuable for molecular epidemiological studies.

Animals↗
PubMed2004

Effects of genistein or soy milk during late gestation and lactation on adult uterine organization in the rat.

In utero and lactational exposure to estrogenic agents has been shown to influence morphological and functional development of reproductive tissues. Thus, consumption of dietary phytoestrogens, such as isoflavones, during pregnancy and lactation could influence important periods of development, when the fetus and neonate are more sensitive to estrogen exposure. In this study, reproductive outcomes after developmental exposure to isoflavones were examined in Long-Evans rats maternally exposed to isoflavones via a commercial soy beverage or as the isolated isoflavone, genistein. Most reproductive endpoints examined at birth, weaning, and 2 months of age were not significantly modified in pups of either sex after lactational exposure to soy milk (provided to the dams in place of drinking water) from birth until weaning. However, soy milk exposure induced a significant increase in progesterone receptor (PR) in the uterine glandular epithelium of the 2-month-old pups. In pregnant dams treated with genistein (GEN; 15 mg/kg body weight) by gavage, from Gestational Day 14 through weaning, PR expression in the uterine glandular epithelium from 2-month-old GEN-treated females (postexposure) was also significantly increased. Diethylstilbesterol (DES) also stimulated uterine PR expression only in the glandular but not luminal epithelial cells. However, unlike DES, in utero/lactational exposure to GEN did not increase expression of the proliferation marker, proliferating cell nuclear antigen (PCNA), in the luminal epithelial cells of the 2-month-old rat uteri. These experiments demonstrate that developmental exposure to dietary isoflavones, at levels comparable to the ranges of human exposure, modify expression of the estrogen-regulated PR in the uterus of sexually mature rats weeks after exposure ended. Since the PR is essential for regulating key female reproductive processes, such as uterine proliferation, implantation, and maintenance of pregnancy, its increased expression suggests that soy phytoestrogen exposure during reproductive development may have long-term reproductive health consequences.

Animal Feed↗
PubMed2002

Campylobacter fetus subspecies venerealis surface array protein from bovine isolates in Brazil.

The electrophoretic patterns of 31 Campylobacter fetus subspecies venerealis capsular Surface Array Protein (SAP) isolated from bovines in reproduction from different regions of Brazil were analyzed. The persistence of the bacteria in the reproductive tract of naturally infected bovines and the dynamic of SAP expression were also evaluated. Cervical mucous and prepucial aspirates from five animals naturally infected were cultured for isolation of Campylobacter fetus and the SAPs extracted from the bacteria isolated were analyzed by SDS-PAGE. Ten different patterns of SAP expression were demonstrated by the identification of proteins with molecular mass of 97, 100, 127, and 149 kDa, respectively. The most prevalent identified protein had a molecular mass of 100 kDa (41.9%). Taking into consideration the time during which the five animals were evaluated, it was possible to conclude that one of these animals persisted with the etiological agent up to 171 days. The five naturally infected bovines analyzed presented variation on their surface protein pattern during the period of this study. C. fetus subspecies venerealis persisted in the reproductive tract of naturally infected animals. In natural condition of infection C. fetus subspecies venerealis persisted in an intermittent condition and an alteration of the protein surface was shown.

Animals↗
PubMed2000

Reproductive mode and speciation: the viviparity-driven conflict hypothesis.

In birds and frogs, species pairs retain the capacity to produce viable hybrids for tens of millions of years, an order of magnitude longer than mammals. What accounts for these differences in relative rates of pre- and postzygotic isolation? We propose that reproductive mode is a critically important but previously overlooked factor in the speciation process. Viviparity creates a post-fertilization arena for genomic conflicts absent in egg-laying species. With viviparity, conflict can arise between: mothers and embryos; sibling embryos in the womb, and maternal and paternal genomes within individual embryos. Such intra- and intergenomic conflicts result in perpetual antagonistic coevolution, thereby accelerating interpopulation postzygotic isolation. In addition, by generating intrapopulation genetic incompatibility, viviparity-driven conflict favors polyandry and limits the potential for precopulatory divergence. Mammalian diversification is characterized by rapid evolution of incompatible feto-maternal interactions, asymmetrical postzygotic isolation, disproportionate effects of genomically-imprinted genes, and "F(2) hybrid enhancement. " The viviparity-driven conflict hypothesis provides a parsimonious explanation for these patterns in mammalian evolution.

Animals↗
PubMed1992

Isolation of swine infertility and respiratory syndrome virus (isolate ATCC VR-2332) in North America and experimental reproduction of the disease in gnotobiotic pigs.

A recent epizootic of swine infertility and respiratory syndrome (SIRS) in a Minnesota swine herd was investigated. Examination of a sow, neonatal piglets, and stillborn fetuses obtained during the epizootic from the affected herd revealed interstitial pneumonitis, lymphomononuclear encephalitis, and lymphomononuclear myocarditis in the piglets and focal vasculitis in the brain of the sow. Fetuses did not have microscopic lesions. No cause for the infertility and respiratory syndrome was determined. Therefore, attempts were made to experimentally reproduce the disease. Eleven 3-day-old gnotobiotic piglets exposed intranasally to tissue homogenates of piglets from the epizootic became inappetent and febrile by 2-4 days postexposure and had interstitial pneumonitis and encephalitis similar to that seen in the field outbreak. After 2 blind passages in gnotobiotic piglets, tissue homogenates were cultured on continuous cell line CL2621, and a cytopathic virus (ATCC VR-2332), provisionally named SIRS virus, was isolated. Gnotobiotic piglets exposed intranasally to the SIRS virus developed clinical signs and microscopic lesions that were the same as those in piglets exposed to the tissue homogenates, and the virus was reisolated from their lungs. This is the first isolate of SIRS virus in the United States that fulfills Koch's postulates in producing the respiratory form of the disease in gnotobiotic piglets and the first report of isolation and propagation of the virus on a continuous cell line (CL2621). The virus is designated as American Type Culture Collection VR-2332.

Animals↗
PubMed2001

The combined effect of isolation and Fasciola hepatica infection on the life history traits of Fossaria cubensis.

Life history traits of Fossaria cubensis were compared between isolated and paired snails after infection with three miracidia of Fasciola hepatica. Four experimental groups were tested: isolated-unexposed, paired-unexposed, isolated-infected, and paired-infected. A repeated-measures ANOVA showed statistically significant interactions among isolation, infection, and age effects for shell size, number of egg masses per snail, number of eggs per snail, and number of viable eggs per snail. Isolated-unexposed snails exhibited the higher values of these variables and those of survival and finite and intrinsic rates of natural increase. Infection stimulated shell growth during the prepatent period, but differences were present only in paired snails since isolation causes a similar effect. Reproduction, in terms of the number of egg masses per snail and the number of eggs per mass per snail, decreases in the presence of parasitic infection, whereas isolation stimulates it. These effects were observed from early stages of infection.

Animals↗
PubMed2002

A comparison of virus isolation, immunohistochemistry, fetal serology, and reverse-transcription polymerase chain reaction assay for the identification of porcine reproductive and respiratory syndrome virus transplacental infection in the fetus.

Virus isolation (VI), immunohistochemistry (IHC), fetal serology, and reverse-transcription polymerase chain reaction assay (RT-PCR) were performed on samples from 107 fetuses comprising 10 litters taken from sows experimentally infected with porcine reproductive and respiratory syndrome virus (PRRSV). In addition to comparing the relative sensitivity and specificity of each test, RT-PCR was evaluated with respect to the relative suitability of thoracic fluids and tissues as samples, the effects of autolysis, and the effects of pooling of fetal specimens. VI, IHC, and fetal serology identified PRRSV infection in 48.6%, 23.4%, and 14.9% of 107 fetuses, respectively, and identified at least 1 infected fetus in 10, 10, and 5 of 10 litters, respectively. In utero death with autolysis reduced the test efficacy of all 3 methods. Fetal thoracic fluid and tissues were equally suitable for RT-PCR detection of PRRSV. Pooling fetal tissues or fluids from VI-positive animals with comparable material from negative controls had no detrimental effect on RT-PCR results when evaluated at dilutions of 1:1, 1:2, 1:4, and 1:8. The results of RT-PCR testing were positive in 100%, 94.4%, and 83.3% of VI-positive specimens allowed to autolyze at 4, 21, or 37 C, respectively, for 24, 48, and 96 hours. Compared with the other testing modalities, RT-PCR appeared to be impacted the least by the adverse effects of autolysis.

Animals↗
PubMed2006

Effects of waterborne zinc on reproduction, survival and morphometrics of Gyrodactylus turnbulli (Monogenea) on guppies (Poecilia reticulata).

Recent reviews indicate that pollutants in the surrounding macroenvironment directly influence the population dynamics, distribution and dispersal of fish ectoparasites, often leading to increased parasitism. The aim of the current study was to explore the effects of sublethal concentrations of waterborne zinc (up to 240 microg Zn/L) on survival, reproduction and morphometrics of Gyrodactylus turnbulli, a viviparous monogenean infecting the skin and fins of the guppy, Poecilia reticulata. Parasite survival and reproduction on the fish were recorded daily for individual parasites maintained in isolated containers. Both survival and reproduction were reduced in 30 and 120 microg Zn/L, compared with 0, 15, and 60 microg Zn/L indicating direct toxic effects of Zn on the parasite. However, as generation time was unaffected by Zn, we attribute the reduced reproduction to the shorter lifespan. Parasite survival off the fish was monitored hourly. Average lifespan of the detached parasites decreased linearly from 19.5 h in 0 microg Zn/L to 17.3h in 240 microg Zn/L, further supporting the direct toxic effect of Zn to the parasite. In addition, temporal dynamics of parasite morphometrics were monitored from mini-epidemics sampled after 1, 5, 10, and 15 days exposure to various Zn concentrations. All morphological parameters decreased significantly in response both to concentration and duration of exposure to waterborne Zn. Together these data clearly indicate that concentrations as low as 120 microg Zn/L are directly toxic to G. turnbulli.

Animals↗
PubMed2005

Soy protein isolates of varying isoflavone content exert minor effects on serum reproductive hormones in healthy young men.

Inverse associations between soy and prostate cancer and the contribution of hormones to prostate cancer prompted the current study to determine whether soy protein could alter serum hormones in men. Thirty-five men consumed milk protein isolate (MPI), low-isoflavone soy protein isolate (SPI) (low-iso SPI; 1.64 +/- 0.19 mg isoflavones/d), and high-iso SPI (61.7 +/- 7.35 mg isoflavones/d) for 57 d each in a randomized crossover design. Twenty-four-hour urine samples indicated that urinary isoflavones were significantly increased by the high-iso SPI relative to the low-iso SPI and MPI. Serum collected on d 1, 29, and 57 of each treatment revealed that dihydrotestosterone (DHT) and DHT/testosterone were significantly decreased by the low-iso SPI [9.4% (P = 0.036) and 9.0% (P = 0.004), respectively] and the high-iso SPI [15% (P = 0.047) and 14% (P = 0.013), respectively], compared with the MPI at d 57. Other significant effects included a decrease in testosterone by the low-iso SPI relative to the MPI (P = 0.023) and high-iso SPI (P = 0.020) at d 29; an increase in dehydroepiandrosterone sulfate by the low-iso SPI relative to the MPI at d 29 (P = 0.001) and relative to the MPI (P = 0.0003) and high-iso SPI (P = 0.005) at d 57; and increases in estradiol and estrone by the low-iso SPI relative to the MPI at d 57 (P = 0.010 and P = 0.005, respectively). In conclusion, soy protein, regardless of isoflavone content, decreased DHT and DHT/testosterone with minor effects on other hormones, providing evidence for some effects of soy protein on hormones. The relevance of the magnitude of these effects to future prostate cancer risk requires further investigation.

Adult↗
PubMed2005

Endocrine changes in maturing primary queens of Zootermopsis angusticollis.

Termite queens are highly specialized for reproduction, but little is known about the endocrine mechanisms regulating this ability. We studied changes in the endocrinology and ovarian maturation in primary reproductive females of the dampwood termite Zootermopsis angusticollis following their release from inhibitory stimuli produced by mature queens. Winged alates were removed from their natal nest, manually dewinged, then paired in an isolated nest with a reproductive male. Development was tracked by monitoring ovarian development, in vitro rates of juvenile hormone (JH) production by corpora allata, and hemolymph titers of JH and ecdysteroids. The production rate and titer of JH were positively correlated with each other but negatively correlated with ecdysteroid titer. Four days after disinhibition, JH release and titer decreased while ecdysteroid titer increased. The new levels persisted until day 30, after which JH increased and ecdysteroids decreased. Fully mature queens had the highest rates of JH production, the lowest ecdysteroid titers, and the greatest number of functional ovarioles. The results support the hypothesis that JH plays a dual role in termite queens depending on their stage of development; an elevated JH titer in immature alates may maintain reproductive inhibition, but an elevated JH titer in mature queens may stimulate ovarian activity. The decline in JH production and the elevation in ecdysteroid titer correspond to a period of physiological reorganization and activation. The specific function of ecdysteroids is unknown but they may help to modulate the activity of the corpora allata.

Animals↗
PubMed1996

Porcine reproductive and respiratory syndrome virus (PRRSV): monoclonal antibodies detect common epitopes on two viral proteins of European and U.S. isolates.

Sixteen hybridoma cell lines secreting monoclonal antibodies (mAbs) directed against two dutch isolates of the causative virus of Porcine Reproductive and Respiratory Syndrome (PRRSV) were produced. The hybridoma cells resulted from fusions of SP2/0 myeloma cells with splenocytes of STU mice immunized with purified PRRSV after induction of immunotolerance against host cell constituents. Screening of supernatant fluids was performed by an indirect immunofluorescence assay on PRRSV-infected porcine alveolar macrophages. Immunoblotting studies revealed that the mAbs had different protein specificities. One mAb reacted with a viral 15 kD protein, eleven were directed against a 40-50 kD protein, and four against a 30-40 kD protein. The mAb against the 15 kD putative nucleocapsid protein as well as five mAbs against the 40-50 kD protein recognized epitopes on these proteins which are conserved in various European and U.S. isolates of PRRSV.

Animals↗
PubMedDate not supplied

Heterothallic mating observed between Mexican isolates of Glomerella lindemuthiana.

Although several reports have described the occurrence of the teleomorphic state of Glomerella lindemuthiana (anamorph, Colletotrichum lindemuthianum), there has been a lack of continuity in this research. To identify G. lindemuthiana isolates capable of developing the teleomorphic state, 19 Mexican isolates were analyzed. Three types of response were observed: (i) negative, where only mycelial growth with or without acervuli was observed; (ii) potential, where in addition to the above, spherical perithecia-like structures were observed; (iii) positive, where perithecia containing asci and ascospores were observed. All strains were self-sterile and only one combination of strains produced fertile perithecia. From this fertile combination 168 individual ascospore cultures were isolated, including five from a single ascus. Forty-four monoascospore cultures were characterized with AFLP, confirming that these individuals were progeny from a sexual cross between the original two G. lindemuthiana isolates and that sexual reproduction in G. lindemuthiana is heterothallic in nature. Analysis of the parental strains with degenerate PCR primers indicated that sequences homologous to the HMG box of the MAT1-2 idiomorph are present in both parental isolates. This supports previous observations in other Glomerella species where the standard ascomycete configuration of distinct idiomorphs at the MAT locus does not hold true. The significance of these results is discussed.

Amino Acid Sequence↗
PubMed1995

Extended HLA profile of an inbred isolate: the Schmiedeleut Hutterites of South Dakota.

HLA-A, -B, -C, -DR, and -DQ typings of the Schmiedeleut Hutterites of South Dakota were collected as part of an ongoing genetic-epidemiologic study of HLA and fertility. A total of 1,082 individuals, including 852 married adults representative of the reproductive population of this isolate, were characterized for five-locus HLA haplotypes. HLA-A1, A2, A3, and A24 accounted for 75% of observed HLA-A alleles and HLA-B27, B35, B51, and B62 accounted for 55% of observed HLA-B alleles. S-leut Hutterites are derived from 68 or fewer ancestors. However, only 48 ancestral HLA haplotypes were observed and nine of these accounted for over 52% of the observed haplotypes. Measures of two-locus linkage disequilibrium derived from these haplotypes indicated that one-third to half of the observed HLA-A/B, B/DR, and A/DR allele combinations exhibited highly statistically significant linkage disequilibrium. Allele and haplotype frequencies did not differ between males and females. Recombination rates of 0.004% and 0.005% between HLA-A and -C and between HLA-B and -DR, respectively, were observed. This HLA profile points out a paucity of HLA alleles and haplotypes in this population and marked linkage disequilibrium among the HLA alleles that are present.

Alleles↗
PubMed2003

Reproduction and metabolism at - 10 degrees C of bacteria isolated from Siberian permafrost.

We report the isolation and properties of several species of bacteria from Siberian permafrost. Half of the isolates were spore-forming bacteria unable to grow or metabolize at subzero temperatures. Other Gram-positive isolates metabolized, but never exhibited any growth at - 10 degrees C. One Gram-negative isolate metabolized and grew at - 10 degrees C, with a measured doubling time of 39 days. Metabolic studies of several isolates suggested that as temperature decreased below + 4 degrees C, the partitioning of energy changes with much more energy being used for cell maintenance as the temperature decreases. In addition, cells grown at - 10 degrees C exhibited major morphological changes at the ultrastructural level.

Bacteria↗