RESUMEN

The corpus luteum (CL) releases progesterone, which acts on the endometrium to induce release of histotroph that supports the free-floating conceptus and prepares for epithelial-chorial placentation. Two steroidogenic cell types, which are classified based on size, contribute to serum progesterone concentrations. Large luteal cells produce the bulk of progesterone because of constitutively active protein kinase A. Small luteal cells also contribute to serum progesterone concentrations through release of progesterone in response to luteotrophic stimuli. The CL is maintained in ruminants until endometrial-derived prostaglandin F2 alpha (PGF) initiates functional and structural regression. The decline in serum progesterone and loss of negative feedback on the hypothalamus and anterior pituitary sets up hormonal responses resulting in a new estrous cycle that is characterized by estrus, ovulation and formation of a new CL. If a conceptus is present, interferon tau (IFNT) is released from the conceptus, which binds receptors in the endometrium and prevents up-regulation of estrogen receptor (ESR1) and consequently oxytocin (OXT) receptor (OXTR). As a consequence, pulses of PGF are disrupted which results in rescue of the CL from lu teolysis. In addition to these paracrine actions, early pregnancy also has direct endocrine action on the CL through inducing IFN- stimulated genes (ISGs) in the CL and resistance of the CL to PGF. Endocrine actions of IFNT have been described through detection of IFNT in uterine vein blood, induction of several ISGs in the CL during pregnancy, and following both in vivo (via miniosmotic pumps) and in vitro (in cultured small, large, and mixed luteal cells) delivery of recombinant ovine (ro) IFNT. These endocrine actions of IFNT might be applied to reducing embryo mortality and associated economic consequences in ruminants.

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RESUMEN

The corpus luteum (CL) releases progesterone, which acts on the endometrium to induce release of histotroph that supports the free-floating conceptus and prepares for epithelial-chorial placentation. Two steroidogenic cell types, which are classified based on size, contribute to serum progesterone concentrations. Large luteal cells produce the bulk of progesterone because of constitutively active protein kinase A. Small luteal cells also contribute to serum progesterone concentrations through release of progesterone in response to luteotrophic stimuli. The CL is maintained in ruminants until endometrial-derived prostaglandin F2 alpha (PGF) initiates functional and structural regression. The decline in serum progesterone and loss of negative feedback on the hypothalamus and anterior pituitary sets up hormonal responses resulting in a new estrous cycle that is characterized by estrus, ovulation and formation of a new CL. If a conceptus is present, interferon tau (IFNT) is released from the conceptus, which binds receptors in the endometrium and prevents up-regulation of estrogen receptor (ESR1) and consequently oxytocin (OXT) receptor (OXTR). As a consequence, pulses of PGF are disrupted which results in rescue of the CL from lu teolysis. In addition to these paracrine actions, early pregnancy also has direct endocrine action on the CL through inducing IFN- stimulated genes (ISGs) in the CL and resistance of the CL to PGF. Endocrine actions of IFNT have been described through detection of IFNT in uterine vein blood, induction of several ISGs in the CL during pregnancy, and following both in vivo (via miniosmotic pumps) and in vitro (in cultured small, large, and mixed luteal cells) delivery of recombinant ovine (ro) IFNT. These endocrine actions of IFNT might be applied to reducing embryo mortality and associated economic consequences in ruminants.(AU)

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The ovine conceptus releases interferon-tau (IFNT), which prevents upregulation of the endometrial estrogen receptor (ESR1) and, consequently, oxytocin receptor (OXTR), thereby disrupting pulsatile release of prostaglandin F2alpha (PGF) in response to oxytocin. IFNT, through paracrine action on the endometrium, protects the corpus luteum (CL) during maternal recognition of pregnancy. Pregnancy also induces IFN stimulated genes (ISGs) in peripheral blood mononuclear cells (PBMCs), which is interpreted to reflect a "prompted" antiviral and immune cell response peripherally in ruminants. IFNT was recently demonstrated to be released from the uterus in amounts of 200 microg (2 x 10(7) U)/24 h via the uterine vein and to induce ISGs in the CL during maternal recognition of pregnancy. Delivery of recombinant ovine (ro) IFNT into the uterine vein in a location that is upstream of the utero-ovarian plexus from Day 10 to 17 maintained serum progesterone concentrations and extended normal 16-17 d estrous cycles to beyond 32 d. It is concluded from these studies that IFNT is released into the uterine vein and initiates a peripheral antiviral response to protect pregnancy from maternal viral infection. It also may have endocrine action through inducing luteal resistance to PGF and longer-term survival of the CL and maintenance of pregnancy.

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OBJECTIVES: To determine seroprevalence and determinants of herpes simplex virus 2 (HSV-2) seropositivity, in a random sample of a population based cohort of 10 049 women of Guanacaste, Costa Rica, using a highly sensitive and specific serological assay. METHODS: Seroprevalence was determined by a type specific HSV-2 ELISA assay in an age stratified random sample of 1100 women. Univariate and multivariate logistic regression was used to calculate odds ratios and 95% confidence intervals for risk factors of seropositivity. RESULTS: Overall age adjusted HSV-2 seroprevalence was 38.5% (95% CI, 37.5 to 39.5), and it was strongly associated with increasing age (p(Trend<0.0001)), both among monogamous women and women with multiple sexual partners. A greater number of lifetime sexual partners increased the risk of seropositivity, with a 28.2% (95% CI, 24.4 to 32.2) seroprevalence among monogamous women and 75% (95% CI, 65.6 to 83.0) seroprevalence for those with four or more partners (OR = 7.6 95% CI, 4.7 to 12.4 p(Trend<0.0001)). Barrier contraceptive use was negatively associated with HSV-2 seropositivity (OR 0.54, 95% CI, 0.31 to 0.94). Women with antibodies against HPV 16, 18, or 31 were 1.6 times more likely to be HSV-2 seropositive (OR 1.6, 95% CI, 1.2 to 2.1). CONCLUSIONS: HSV-2 infection is highly endemic in Guanacaste, even among lifetime monogamous women, suggesting a role of male behaviour in the transmission of the infection. Until vaccination against HSV-2 is available, education to prevent high risk sexual behaviour and the use of condoms appear as preventive measures against HSV-2.

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BACKGROUND: Data comparing type-specific herpes simplex virus type 2 (HSV-2) seroprevalence and risk factors between comparable populations are largely unavailable, particularly from less-developed countries. GOAL: To examine the seroprevalence of HSV-2 infection and the risk factors for this infection among women in São Paulo, Brazil, and Manila, the Philippines. STUDY DESIGN: Altogether, 552 middle-aged women participating as control subjects in two cervical cancer studies were screened for type-specific HSV-2 antibodies. RESULTS: Herpes simplex virus type 2 seroprevalence was higher in Brazil (42%) than in the Philippines (9.2%). The mean ages of Brazilian (n = 181) and Filipino (n = 371) women were 52.4 and 46.6 years, respectively. Brazilian participants had more lifetime sexual partners, less education, and more often a husband with other sexual partners than Filipino women. Herpes simplex virus type 2 was independently associated with younger age at first intercourse in both countries. More than one lifetime sexual partner, a husband with other sexual partners, urban/semi-urban residence, and no history of condom use were HSV-2 risk factors in Brazil, but not in the Philippines, where long-term hormonal contraceptive use was associated with increased risk. CONCLUSIONS: The higher HSV-2 seroprevalence in Brazil than in the Philippines may be explained largely by differences in the sexual behavior of women and their husbands. Herpes simplex virus type 2 seroprevalence data may be used as a marker of past sexual behavior for the direct comparison of different population groups.

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OBJECTIVES: This study examined the prevalences of antibodies to Treponema pallidum, Chlamydia trachomatis, and herpes simplex virus type 2 in a sample of Peruvian adults. METHODS: Among adults seeking health certification in Lima, Peru, 600 were randomly selected to undergo interviews and serologic testing. RESULTS: Men's reported mean lifetime number of partners (10.6) far exceeded women's (1.1), yet antibody to sexually transmitted infection pathogens among sexually experienced participants was 2.8 times more prevalent among women than among men. Among men, female sex workers accounted for 37% of recent partners, and only sex with female sex workers while using condoms less than half of the time was independently associated with antibody (odds ratio = 3.6, 95% confidence interval = 1.5, 8.8). among women, number of partners was associated with any sexually transmitted infection antibody, while intercourse before 18 years of age was associated with C trachomatis antibody. At every level of perceived risk, sexually transmitted infection antibody was more frequent among women. CONCLUSIONS: Men having unprotected sex with female sex workers had the greatest risk of acquiring infections and (by inference) of transmitting them to women.

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