Human labor is associated with reduced decidual cell expression of progesterone, but not glucocorticoid, receptors.

CONTEXT: Unchanging plasma progesterone (P4) levels suggest that human labor is initiated by reduced P4 receptor (PR) expression, which elicits functional P4 withdrawal. The glucocorticoid receptor (GR) is also implicated in this process. OBJECTIVE: Our objective was to compare PR and GR staining in human decidual cells (DCs) and interstitial trophoblasts (ITs) of gestational age-matched pre- and postcontraction specimens and to evaluate steroid effects on PR and GR expression in human DC cultures. INTERVENTIONS AND MAIN OUTCOME MEASURES: Decidua basalis and parietalis sections were immunostained for PR or GR and then for the cytoplasmic DC and IT markers vimentin and cytokeratin. Western blotting measured PR and GR levels in nuclear extracts of cultured leukocyte-free term DCs after incubation with estradiol-17beta (E2) with or without medroxyprogesterone acetate (MPA). RESULTS: PR histological scores (HSCOREs) were significantly higher in DC nuclei from pre- vs. post-uterine-contraction decidua basalis and parietalis sections with PR immunostaining absent from ITs. In contrast, immunoreactive GR was localized in IT and DC nuclei. GR HSCORES were significantly higher in ITs than DCs but similar in pre- vs. post-uterine-contraction specimens. In term DC monolayers, PR-A and PR-B were enhanced by E2 and inhibited by MPA, whereas E2 plus MPA produced intermediate PR expression. The GR was constitutively expressed. CONCLUSIONS: In post- vs. pre-uterine-contraction specimens, significantly lower HSCOREs in DC nuclei, but not IT, and unchanging GR levels in DCs and ITs suggest that functional P4 withdrawal may occur in DCs and is unlikely to involve the GR. Nuclear extracts from DC monolayer cultures express steroid-regulated PR-A and PR-B and constitutive GR.

Arabidopsis thaliana, a new tool to investigate Polymyxa betae-host interactions.

Little is known about the genome of Polymyxa betae and its interactions with sugar beet, due partly to the obligate nature of the protist and the patents on Beta vulgaris sequences. The identification of an ecotype of Arabidopsis thaliana compatible with the protist would help to improve this knowledge. The infection and development of P. betae in 14 worldwide ecotypes of A. thaliana were studied. The detection of plasmodia and resting spores and the production of zoospores in the roots of A. thaliana were obtained in three bioassays, using automatic immersion systems and individual glass tubes. Detection was done using molecular detection and microscopy. Compatible interactions were established between 13 A. thaliana ecotypes of the 14 that were tested and the monosporosoric Belgian strain of P. betae, A26-41. The ecotype Cvi-0 (N1096), from the Cape Verde Islands, was the most compatible with the protist. This ecotype is also susceptible to Plasmodiophora brassicae, another plasmodiophorid. Polymyxa betae infection in A. thaliana was relatively very low compared with B. vulgaris, but every stage of the life cycle of the protist was present. The spore-forming phase was promoted at the expense of the sporangial phase, probably caused by the stress of this new environment. In addition, the protist revealed a new phenotype. This new model study will allow molecular tools available for A. thaliana to be used in order to gain a better understanding of the P. betae-plant interaction during the spore-forming phase.

Heat recovery ventilators prevent respiratory disorders in Inuit children.

UNLABELLED: Inuit infants have high rates of reported hospitalization for respiratory infection, associated with overcrowding and reduced ventilation. We performed a randomized, double-blind, placebo controlled trial to determine whether home heat recovery ventilators (HRV) would improve ventilation and reduce the risk of respiratory illnesses in young Inuit children. Inuit children under 6 years of age living in several communities in Nunavut, Canada were randomized to receive an active or placebo HRV. We monitored respiratory symptoms, health center encounters, and indoor air quality for 6 months. HRVs were placed in 68 homes, and 51 houses could be analyzed. Subjects had a mean age of 26.8 months. Active HRVs brought indoor carbon dioxide concentrations to within recommended concentrations. Relative humidity was also reduced. Use of HRV, compared with placebo, was associated with a progressive fall in the odds ratio for reported wheeze of 12.3% per week (95%CI 1.9-21.6%, P = 0.022). Rates of reported rhinitis were significantly lower in the HRV group than the placebo group in month 1 (odds ratio 0.20, 95%CI 0.058-0.69, P = 0.011) and in month 4 (odds ratio 0.24, 95%CI 0.054-0.90, P = 0.035). There were no significant reductions in the number of health center encounters, and there were no hospitalizations. Use of HRVs was associated with in improvement in air quality and reductions in reported respiratory symptoms in Inuit children. PRACTICAL IMPLICATIONS: Reduced ventilation is common in the houses of Inuit children in arctic Canada, and is associated with an increased risk of respiratory infection. Installation of HRV brings indoor carbon dioxide concentration, as a marker of adequate ventilation, to within recommended concentrations, although relative humidity is also reduced. Installation of HRV is associated with improvements in indoor air quality, and a reduced risk of wheezing and rhinitis not associated with cold air exposure in young Inuit children. Further research is required to explore traditional Inuit cultural attitudes about air movement in dwellings.

Quality control of automatically defined cancer cases by the automated registration system of the Venetian Tumour Registry. Quality control of cancer cases automatically registered.

BACKGROUND: In the Venetian Tumour Registry a substantial quota of cases (55%) is accepted using an algorithm that automatically evaluates diagnostic evidence: this study aims at assessing the reliability of the information produced in this way. METHODS: A reabstraction study was conducted, which put a stratified sample of 1539 automatically accepted cases through a double-blind manual revision. RESULTS: A significantly higher proportion of prevalent cases were found among breast, prostate and larynx cancer cases without microscopic confirmation, while there is a clear strong inverse relationship between the number of concordant diagnostic sources and the proportions of discordant diagnoses: cases based only on a single cytology record are particularly unreliable. A small number of multiple cancers are not detected because of one of the rules applied. CONCLUSION: The overall proportion of incorrect decisions is not high and similar to those reported by other registries, but errors are correlated to the diagnostic evidence pattern. As a further check, we decided to revise clinical cases for the three sites mentioned manually, in order to reduce the numbers proportion of both prevalent cases, and all cytology-based diagnoses, so as to reduce the number of 'false positives'. Coverage of hospital discharge source has been extended in order to decrease the proportion of cases based only on pathology records.

Randomized clinical trial to assess the effect of an educational programme designed to improve nurses' assessment and recording of postoperative pain.

BACKGROUND: The aim of this study was to evaluate the impact of an intervention designed to improve postoperative pain assessment and recording by nurses. METHODS: This cluster randomized clinical trial included two intervals of 3 months each: a preintervention observational study (period 1) followed by a period of intervention (period 2). Six surgical wards were randomly assigned to receive either an experimental intervention, including educational seminars for nurses on pain, pain assessment and the use of a visual analogue scale (n = 3), or standard care (control group; n = 3). The main outcome measures were the percentage of patients in whom pain was assessed, number of pain assessments per patient and postoperative pain intensity scores. RESULTS: A total of 2278 patients were included. Significant improvements were found in the percentage of patients in whom pain was assessed and the number of daily pain assessments per patient in the intervention group between periods 1 and 2. In contrast, these outcomes were unchanged between the two intervals in wards randomized to standard care. During period 2, pain scores at 48 h were significantly decreased in the intervention wards compared with those in the control group. CONCLUSION: An educational programme dedicated to nurses strongly increased the use of regular pain assessment, and may have contributed to a modest improvement in postoperative analgesia.

Involvement of nuclear factor kappa B in the regulation of rat luteal function: potential roles as survival factor and inhibitor of 20alpha-hydroxysteroid dehydrogenase.

Nuclear factor kappa B (NFkappaB) is an important intracellular conveyor of extracellular signals and modulates a number of gene responses. Due to the potential significance of NFkappaB in regulating ovarian gene expression, we examined in the rat: (i) whether NFkappaB is activated and developmentally regulated in the corpus luteum (CL) throughout pregnancy; (ii) the proteins forming the NFkappaB complex in luteal cells; and (iii) the role of this transcription factor in luteal function. Western analysis and immunohistochemistry revealed that p65 and p50 were highly expressed throughout pregnancy and were located in both the nucleus and cytoplasm of luteal cells. In addition, because NFkappaB is maintained in the cytoplasm bound to IkappaB, whose phosphorylation allows NFkappaB translocation to the nucleus, we studied the developmental expression of phosphorylated and nonphosphorylated forms of IkappaBalpha. Western analysis revealed that IkappaBalpha was present and phosphorylated throughout pregnancy in the CL whereas by protein/DNA array and electromobility shift assays we found that luteal nuclear extracts bind to an NFkappaB consensus sequence, and that the binding activity decreased along pregnancy. The specific binding was supershifted only by an anti-p65 antibody and not by antibodies against p50, p52, cRel, or RelB. Using day 4 postpartum ovaries, we found higher NFkappaB binding activity in the newly formed CL than in old CL of pregnancy. Furthermore, NFkappaB DNA binding activity was enhanced by prolactin in luteinized granulosa cells. In our first functional study, blockade of NFkappaB/p65 binding to DNA with the sesquiterpene lactone helenalin in luteinized granulosa cells correlated with induction of cell death in a dose-dependent manner. In a second functional study, overexpression of NFkappaB/p65 in luteal cells resulted in inhibition of 20alpha-hydroxysteroid dehydrogenase (20alphaHSD) promoter activity as well as endogenous 20alphaHSD mRNA expression. In summary, we have shown that: (i) NFkappaB is expressed within the CL, primary luteinized granulosa cells, and a rat luteal cell line; (ii) NFkappaB activation within the CL is developmentally regulated in pregnancy, depends on the age of the gland, and can be upregulated by prolactin; (iii) inhibition of NFkappaB/p65 binding to an NFkappaB DNA consensus sequence correlates with induction of cell death in ovarian luteinized granulosa cells; and (iv) overexpression of NFkappaB in luteal cells inhibits 20alphaHSD gene expression. The results further support a role for NFkappaB as a survival factor in the CL.

A 6-month prospective survey of cutaneous drug reactions in a hospital setting.

BACKGROUND: Few prospective studies are available on the incidence and analysis of the characteristics of adverse cutaneous drug reactions in hospital settings. OBJECTIVES: A 6-month prospective study was managed in our hospital among hospitalized patients to: (i) evaluate the incidence of cutaneous allergic reactions from systemic drugs; (ii) study characteristics of patients with cutaneous drug reactions; (iii) describe the adverse cutaneous reactions; and (iv) evaluate drug reaction imputability and preventability. METHODS: All suspected allergic cutaneous reactions to systemic drugs were collected during a 6-month period (November 2000 to May 2001). Exhaustivity of recording was ensured by regular dissemination of information about this study to the practitioners; a simple method for inclusion by fax was established. Inclusion criteria were suspected cutaneous allergic reactions induced by systemic drugs responsible for hospitalization or developed during hospitalization. A physical examination was done by a dermatologist who completed a standardized questionnaire. Requested information included patient characteristics (associated disorders, severity score), drug intake (list and chronology of the drug intake during the 3 weeks preceding the adverse reaction) and characteristics of the skin reaction (type, course). A group comprising dermatologists and pharmacologists evaluated the drug imputability and preventability. RESULTS: Forty-eight cases were collected. A prevalence of 3.6/1000 among hospitalized patients was estimated. The prevalence rate was higher in patients hospitalized in medical departments (0.5%) than in surgical departments (0.01%) (P < 0.001). The cases were mostly recruited in departments of infectious diseases and dermatology. The most frequent associated disorders were: human immunodeficiency virus (HIV) infection (19%), connective tissue disease (10%) and viral or autoimmune hepatitis (12%). Of these patients, 31% had had a previous immunological drug reaction. Adverse cutaneous drug reactions were principally exanthematous (56%). Reactions were considered severe in 34% of cases because they were responsible for hospitalization (18%), increased the duration of hospitalization (14%) or were life threatening (2%). Principal imputable drugs were antibiotics, mainly penicillins. An imputability score was likely in 56% of cases, but it was only possible to conclude definitively in 44% of patients. In 15% of the cases, the side-effect was considered to be preventable. CONCLUSIONS: This study finds a lower incidence than other studies that reported an incidence of 2% of cutaneous drug reactions in hospitalized patients, but only allergic adverse cutaneous reactions induced by systemic drugs were collected in this study. The previous studies were principally done in selected patients hospitalized only in general internal medicine or medical divisions. Our results confirm some data already known about skin drug reactions: HIV infection as a risk factor (P < 0.0001), high prevalence of adverse cutaneous reactions due to antibiotics, and difficulty in ascertaining the imputability of a drug. A high proportion (34%) of these reactions was severe and 15% were avoidable; these two facts justify the development of an intensive programme of clinical pharmacology.

Luteal expression of cytochrome P450 side-chain cleavage, steroidogenic acute regulatory protein, 3beta-hydroxysteroid dehydrogenase, and 20alpha-hydroxysteroid dehydrogenase genes in late pregnant rats: effect of luteinizing hormone and RU486.

A decrease in serum progesterone at the end of pregnancy is essential for the induction of parturition in rats. We have previously demonstrated that LH participates in this process through: 1) inhibiting 3beta-hydroxysteroid dehydrogenase (3beta-HSD) activity and 2) stimulating progesterone catabolism by inducing 20alpha-hydroxysteroid dehydrogenase (20alpha-HSD) activity. The objective of this investigation was to determine the effect of LH and progesterone on the luteal expression of the steroidogenic acute regulatory protein (StAR), cytochrome P450 side-chain cleavage (P450(scc)), 3beta-HSD, and 20alpha-HSD genes. Gene expression was analyzed by Northern blot analysis 24 and 48 h after administration of LH or vehicle on Day 19 of pregnancy. StAR and 3beta-HSD mRNA levels were lower in LH-treated rats than in rats administered with vehicle at both time points studied. P450(scc) mRNA levels were unaffected by LH. The 20alpha-HSD mRNA levels were not different between LH and control rats 24 h after treatment; however, greater expression of 20alpha-HSD, with respect to controls, was observed in LH-treated rats 48 h after treatment. Luteal progesterone content dropped in LH-treated rats at both time points studied, whereas serum progesterone decreased after 48 h only. In a second set of experiments, the anti-progesterone RU486 was injected intrabursally on Day 20 of pregnancy. RU486 had no effect on 3beta-HSD or P450(scc) expression but increased 20alpha-HSD mRNA levels after 8 h treatment. In conclusion, the luteolytic effect of LH is mediated by a drop in StAR and 3beta-HSD expression without effect on P450(scc) expression. We also provide the first in vivo evidence indicating that a decrease in luteal progesterone content may be an essential step toward the induction of 20alpha-HSD expression at the end of pregnancy in rats.

Opposite effect of prolactin and prostaglandin F(2 alpha) on the expression of luteal genes as revealed by rat cDNA expression array.

It is well established that prolactin (PRL) sustains, while prostaglandin F(2 alpha) (PGF(2 alpha)) curtails, progesterone production by the rat corpus luteum (CL). We have previously shown that the actions of both molecules converge on the 20 alpha-HSD gene and control its expression in a dramatically opposed manner. In this investigation, we have found twelve more genes that are inversely regulated by PRL and PGF(2 alpha). In addition to 20 alpha-HSD, PGF(2 alpha) stimulated and PRL inhibited PGF(2 alpha)-receptor, phospholipase C delta(1) and TGF beta(1) expression. In contrast PRL stimulated and PGF(2 alpha) inhibited the LH receptor, 11 beta-HSD2, sterol carrier protein 2, mitochondrial glutathione S-transferase (GST), GST mu(2), inhibitory DNA-binding proteins 1, 2, and 3, and calcium binding protein 2. We have also identified new target genes for PRL and PGF(2 alpha). PGF(2 alpha) stimulated the expression of genes involved in cell signaling such as cell adhesion kinase-beta, ERK3, FRA2, IL-2 receptor, and 14-3-3 proteins. PGF(2 alpha) also up-regulated the expression of the sodium channel beta(1), Na/K ATPase, annexin IV, GST7pi, and P450 reductase. In contrast PGF(2 alpha) inhibited the expression of two genes involved in cell cycle: cyclin D2 and retinoblastoma related protein (Rb2/p130). It also inhibited genes involved in estradiol (P-450(AROM)) and cholesterol biosynthesis (HMG-CoA synthase), as well as genes involved in tissue remodeling: VEGF and TIMP3. PRL had a profound inhibitory effect on the expression of genes encoding the ADP-ribosylation factor 3, annexin V and c-jun, yet increased the expression of P450scc, 3beta-HSD, and SR-B1 (HDL-receptor), all genes involved in steroidogenesis. PRL also stimulated the expression of beta(2)-microglobulin, TIMP2, cytochrome c oxidase IV, cathepsin H and L, and copper-zinc superoxide dismutase as well as elongation factor SIII, heat shock protein-60 and mitochondrial ATP synthase-D. In conclusion, this investigation has revealed a "yin-yang" relationship between PRL and PGF(2 alpha) in regulating certain critical genes in the rodent CL, and has demonstrated novel regulation by these factors of other important genes involved in luteal function.

Prostaglandin F2alpha-induced expression of 20alpha-hydroxysteroid dehydrogenase involves the transcription factor NUR77.

Prostaglandin F(2)alpha (PGF(2)alpha) binding to its receptor on the rat corpus luteum triggers various signal transduction pathways that lead to the activation of a steroidogenic enzyme, 20alpha-hydroxysteroid dehydrogenase (20alpha-HSD), which in turn catabolizes progesterone. The molecular mechanism underlying PGF(2)alpha-induced 20alpha-HSD enzyme activity has not yet been explored. In this report we show, using mice lacking PGF(2)alpha receptor and pregnant rats, that PGF(2)alpha is responsible for the rapid and massive expression of the 20alpha-HSD gene at the end of pregnancy leading to a decrease in progesterone secretion. We also present evidence that PGF(2)alpha enhances 20alpha-HSD promoter activity. We have determined a region upstream of the -1590 position in the 20alpha-HSD promoter that confers regulation by PGF(2)alpha in ovarian primary cells. This region encompasses a unique transcription factor-binding site with a sequence of a NUR77 response element. Deletion of this motif or overexpression of a NUR77 dominant negative protein caused a complete loss of 20alpha-HSD promoter activation by PGF(2)alpha. NUR77 also transactivated the 20alpha-HSD promoter in transient transfection experiments in corpus luteum-derived cells (GG-CL). This induction required the NUR77-transactivating domain. We also show that PGF(2)alpha induces a very rapid expression of NUR77 that binds to a distal response element located at -1599/-1606 but does not interact with another proximal putative NUR77 response element located downstream in the promoter. A rapid increase in NUR77 mRNA was observed in mice corpora lutea just before parturition at a time when 20alpha-HSD becomes expressed. This increase in the expression of both genes was not seen in PGF(2)alpha receptor knockout mice. By using cyclosporin A and PGF(2)alpha treatment, we established that inhibition of NUR77 DNA binding in vivo prevents PGF(2)alpha induction of the 20alpha-HSD gene in the corpus luteum. Taken together, our results demonstrate, for the first time, that PGF(2)alpha induces in the corpus luteum the expression of the nuclear orphan receptor and transcription factor, NUR77, which in turn leads to the transcriptional stimulation of 20alpha-HSD, triggering the decrease in serum progesterone essential for parturition.

Progesterone receptor is not required for progesterone action in the rat corpus luteum of pregnancy.

In this study, we investigated whether progesterone exerts a local action regulating the function of the corpus luteum of pregnancy in rats. The luteal activities of the enzymes 3beta-hydroxysteroid dehydrogenase (3beta-HSD), involved in progesterone biosynthesis, and 20alpha-hydroxysteroid dehydrogenase (20alpha-HSD), that catabolizes progesterone and reduces progesterone secretion by the corpus luteum, were evaluated after intrabursal ovarian administration of progesterone in pregnant rats that had received a luteolytic dose of prostaglandin F2alpha (PGF2alpha). Luteal 3beta-HSD activity decreased and 20alpha-HSD activity increased after PGF2alpha treatment (100 microg x 2 intraperitoneally on Day 19 of pregnancy at 12:00 p.m. and 4:00 p.m.) when compared with controls sacrificed at 8:00 p.m. on Day 20 of pregnancy. This effect of PGF2alpha on the luteal 3beta-HSD and 20alpha-HSD activities was abolished in animals that also received an intraovarian dose of progesterone (3 microg/ovary on Day 19 of pregnancy at 8:00-9:00 a.m.). In a second functional study, luteal cells obtained from 19-day pregnant rats responded to the synthetic progestin promegestone (R5020) in a dose-dependent manner, with an increase in the progesterone output. In addition, the glucocorticoid agent hydrocortisone did not affect progesterone accumulation in the same luteal cell culture. We also examined by immunocytochemistry the expression of progesterone receptors (PR) in the corpora lutea during pregnancy and demonstrated the absence of PR in this endocrine gland in all the days of pregnancy studied. In the same pregnant rats, positive staining for PR was observed in cells within the uteroplacental unit, such as cells of the decidua basalis and trophoblast giant cells of the junctional zone. In addition, positive PR staining was observed in the ovarian granulosa and theca cells of growing follicles, but not in corpora lutea of ovaries obtained from cycling rats at proestrus. In summary, this report provides further evidence of a local action of progesterone regulating luteal function in the rat despite the absence of a classic PR.

Luteinizing hormone inhibits conversion of pregnenolone to progesterone in luteal cells from rats on day 19 of pregnancy.

We have previously reported that intrabursal ovarian administration of LH at the end of pregnancy in rats induces a decrease in luteal progesterone (P4) synthesis and an increase in P4 metabolism. However, whether this local luteolytic effect of LH is exerted directly on luteal cells or on other structures, such as follicular or stromal cells, to modify luteal function is unknown. The aim of the present study was to determine the effect of LH on isolated luteal cells obtained on Day 19 of pregnancy. Incubation of luteal cells with 1, 10, 100, or 1000 ng/ml of ovine LH (oLH) for 6 h did not modify basal P4 production. The addition to the culture medium of 22(R)-hydroxycholesterol (22R-HC, 10 microgram/ml), a membrane-permeable P4 precursor, or pregnenolone (10(-2) microM) induced a significant increase in P4 accumulation in the medium in relation to the control value. When luteal cells were preincubated for 2 h with oLH, a significant (p < 0.01) reduction in the 22R-HC- or pregnenolone-stimulated P4 accumulation was observed. Incubation of luteal cells with dibutyryl cAMP (1 mM, a cAMP analogue) plus isobutylmethylxanthine (1 mM, a phosphodiesterase inhibitor) also inhibited pregnenolone-stimulated P4 accumulation. Incubation with an inositol triphosphate synthesis inhibitor, neomycin (1 mM), or an inhibitor of intracellular Ca2+ mobilization, (8,9-N, N-diethylamino)octyl-3,4,5-trimethoxybenzoate (1 mM), did not prevent the decrease in pregnenolone-stimulated P4 secretion induced by oLH. It was concluded that the luteolytic action of LH in late pregnancy is due, at least in part, to a direct action on the luteal cells and that an increase in intracellular cAMP level might mediate this effect.

[Analysis of the management of patients aged 75 and older in an admitting and emergency service of a large hospital]. / Analyse de la prise en charge des personnes âgées de 75 ans et plus par le service des Admissions et Urgences d'un grand Hôpital.

A prospective survey carried out over two periods (35 days total) presented a typology of people aged 75 and older entering the admitting and emergency unit of a university hospital center, and underlined the specifics of the care they received. These patients represent 27.8% of patients received in the unit. The women (60.9%) live preferentially alone at home or in group establishment. The majority of admissions are the result of a referral from the patients' doctors. Tuesday remains the busiest day for admissions (19.7% of total admissions). 10.9% of patients arrive alone and without health records. The specialist is solicited for 41.3% of older people. Their autonomy level (measured with the AGGI R grid) is evaluated during the emergency visit. An analysis of pathological profiles shows a preponderance of acute problems with risk of degenerative problems (54.9%). Social problems (8.2% of patients) particularly affect the group with multiple pathologies. The choice of placement is more often in specialty services (61.3%) than geriatric services (18.7%). A return to ones previous home is more rarely re-envisaged. The placement obtained corresponds to the desired placement in 68% of cases. Lack of beds is the main cause in cases where the desired placement is not achieved. While the care of older people admitted for "specialised" reasons poses little problem many pathologies including "social" issues, and are admitted for "general" reasons) is a very different issue.

Antisteroidogenic action of nitric oxide on human corpus luteum in vitro: mechanism of action.

To analyze the mechanism by which nitric oxide (NO) exerts its antisteroidogenic action, human luteal cells were cultured during 24 and 48 h with L-arginine (L-Arg, 1 mmol/L); 1,2(2-trifluoromethylphenyl)imidazole (TRIM) (50 micromol/L and 1 mmol/L) and cyclic guanosine monophosphate (cGMP) analog (8-Br-cGMP, 1 mmol/L). Estradiol, nitrite, and P450 AROM activity were determined in culture media. Total cGMP concentration was evaluated in the cells and culture media by radioimmunoassay, and NADPH diaphorase was used as a histochemical marker for NO synthase (NOS) activity. During the corpus luteum (CL) life-span, NO affected estradiol secretion in an age-dependent manner, with an inhibition in mid-CL (37%; p < 0.05) in agreement with our previous results, and no significant modification in early and late CL. Basal nitrite concentration in 24 and 48 h of midluteal cell cultures (42 and 93 pmol/10(6) cells, respectively) was increased by L-Arg (53% and 88%) and inhibited by the two TRIM concentrations; also, an intense diaphorase reactivity was observed in endothelial cells and luteal parenchyma. Total cGMP was not detected in cell cultures and 8-Br-cGMP did not modify estradiol secretion, whereas aromatase activity was strongly inhibited by L-Arg (70%, p < .05). These results suggest that both NOS isoforms are active in midluteal cells, and the mechanism of action for NO on in vitro estradiol secretion may be an inhibition of P450 AROM activity.

Participation of intraluteal progesterone and prostaglandin F2 alpha in LH-induced luteolysis in pregnant rat.

We examined the participation of the intraluteal levels of progesterone (P4) and prostaglandin F2 alpha (PGF2 alpha) in the induction of luteolysis by LH and its relationship with the induction of the 20 alpha-hydroxysteroid dehydrogenase activity (20 alpha-HSD). Subcutaneous administration of four doses of 10 microgram ovine LH (oLH) at 0800, 0900, 1000 and 1100 h on day 19 of pregnancy induced a decrease in the activity of the enzyme 3 beta-HSD 24 and 48 h after treatment and an increase in luteal 20 alpha-HSD activity 48 h after oLH treatment when compared with control rats. Intraluteal and serum P4 levels were lower than control values 24 and 48 h after oLH treatment, with a significant increase in luteal PGF2 alpha content and a decrease in corpus luteum (CL) weight 48 h after oLH treatment. Intrabursal ovarian (i.b.) treatment with an inhibitor of PG's biosynthesis (diclofenac) (70 microgram/ovary) or P4 (3 microgram/ovary) on day 20 of pregnancy, prevented the increase in 20 alpha-HSD activity observed 48 h after oLH treatment, without any effect on 3 beta-HSD activity. The i.b. administration of P4 prevented the increase in intraluteal PGF2 alpha content induced by oLH treatment and the increases in 20 alpha-HSD activity and intraluteal PGF2 alpha content observed in control animals on day 21 of pregnancy. The inhibition of PG biosynthesis also prevents the decrease in intraluteal and serum P4 level induced by oLH. These results provide good evidence of the important participation of intraluteal P4 and PGF2 alpha on the oLH-induced luteolysis in pregnant rats. We also found the P4 produced by the CL is involved, in part, in the regulation of luteal PG synthesis. Thus, the early decline in 3 beta-HSD activity and the consequent fall in intraluteal P4 content, may trigger the synthesis of PGs and thereafter the increase in luteal 20 alpha-HSD activity to establish luteolysis.

Luteolytic effect of LH: inhibition of 3 beta-hydroxysteroid dehydrogenase and stimulation of 20 alpha-hydroxysteroid dehydrogenase luteal activities in late pregnant rats.

The mechanisms associated with the onset of luteolysis in the pregnant rat are not well known. The effect of a specific rat LH antiserum (AS-rLH) and of ovine LH (oLH) on luteal steroidogenesis on day 19 of pregnancy was examined. Rat LH antiserum administered intrabursally at 1000-1100 h on day 19 of pregnancy prevented the physiological decrease in 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) activity, the increase in 20 alpha-hydroxysteroid dehydrogenase (20 alpha-HSD) activity and the fall in serum progesterone (P4) level observed at 1800 h on day 21 of pregnancy. To see if oLH has a direct effect on luteal steroidogenesis, the gonadotrophin was injected into the periovarian bursa. The intrabursa treatment with 1 microgram oLH on day 19 of pregnancy at 0800-0900 h did not modify corpus luteal function 36 h after treatment, but treatment with 4 micrograms oLH per ovary induced a significant progressive decrease in luteal 3 beta-HSD activity starting 12 h after treatment, while a significant increase in 20 alpha-HSD activity, concomitant with a decrease in serum P4 level, occurred 48 h after treatment. Luteal P4 content decreased with respect to control groups 36 and 48 h after intrabursal treatment with 4 micrograms oLH. The intrabursal administration of 8 micrograms oLH induced an increase in 20 alpha-HSD activity and a decrease in 3 beta-HSD activity 36 h after treatment. Administration of 4 micrograms oLH per ovary on day 8 of pregnancy induced a significant increase in serum P4 levels without modifying 3 beta-HSD activity. In rats treated with oLH on day 19 of pregnancy the decrease in 3 beta-HSD activity occurred 36 h before the significant increase in 20 alpha-HSD activity and serum P4 level. In conclusion, the luteal enzymatic activity changes and the significant decrease in the intraluteal P4 concentration induced by the intrabursal administration of oLH and the clear effect of AS-rLH preventing the physiological luteal changes preceding parturition provide good evidence of an intraovarian action of LH during the normal progression of luteolysis in late pregnant rats.

A computerised cancer registration network in the Veneto region, north-east of Italy: a pilot study.

A cancer registration network based on computerised coded diagnoses has been tested in the Veneto region, north-east Italy, with the goal of estimating cancer incidence during 1987-89. The results of the pilot study based on a population of 1,449,513 (33.1% of the total population of the region) indicate that the computer-assisted system successfully ascertained 61.3% of the cases. The quality indices appear to be close to those from other cancer registries in Europe. The increasing availability of computerised coded information from hospitals, pathology departments and death certificates can provide an important contribution to cancer registration, thus reducing the amount of manual work and consequently allowing cancer registration on larger populations at reduced costs.

Dual regulation of luteal progesterone production by androstenedione during spontaneous and RU486-induced luteolysis in pregnant rats.

The effect of androstenedione on luteal progesterone production was studied during luteolysis preceding parturition as well as that induced by the antiprogestin RU486 in late pregnant rats. Luteal cells from animals on days 19, 20 or 21 of pregnancy and incubated with 10 microM androstenedione increased progesterone production by 99, 136, and 277%, respectively. The animals receiving androstenedione (10 mg/rat s.c.) on day 19 of pregnancy showed an increase in serum progesterone levels, a decline in luteal 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) activity and an increase in corpus luteum weight without modifying 20 alpha-hydroxysteroid dehydrogenase (20 alpha-HSD) activity on day 21 of pregnancy. Androstenedione and testosterone but not dihydrotestosterone were able to prevent the decrease in serum progesterone concentration and corpus luteum weight observed 58 h after treatment with RU486 (2 mg/kg) on day 18 of pregnancy. However, the three androgens studied inhibited the luteal 3 beta-HSD activity but 20 alpha-HSD activity was not affected, when compared with animals receiving RU486 alone. The co-administration of androstenedione with the aromatase inhibitor 4-hydroxyandrostenedione or with the specific antioestrogen ICI 164,384 did not modify the effects induced by androstenedione in RU486-treated rats, indicating that the action of androstenedione on progesterone production and secretion at the time of luteolysis seems to occur through an androgenic mechanism and is not mediated by previous conversion of the androgens to oestrogens. In all experiments the high luteal 20 alpha-HSD activity, that characterizes a luteolytic process, was not modified by androgens. Androstenedione administered to adrenalectomized rats was also able to prevent the decrease in serum progesterone concentration observed in spontaneous or RU486-induced luteolysis. The administration of androstenedione to RU486-treated rats induced a decrease in luteal progesterone content concomitant with an increase in serum progesterone levels. These studies demonstrate that androgens during luteolysis, are able to stimulate luteal progesterone secretion, prevent the loss in corpora lutea weight and enhance the decrease in 3 beta-HSD activity, without affecting the increase in 20 alpha-HSD activity.

Luteolytic action of RU486: modulation of luteal 3 beta-hydroxysteroid dehydrogenase and 20 alpha-hydroxysteroid dehydrogenase activities in late pregnant rats.

The effect of the synthetic antiprogestin RU486 on luteal function in late pregnant rats was studied by evaluating the activities of the enzymes 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) and 20 alpha-hydroxysteroid dehydrogenase (20 alpha-HSD). RU486 (2 mg/kg) administered to rats on day 18 of pregnancy at 10.00 h induced preterm delivery 26.4 +/- 0.35 h (n = 8) after treatment. Luteal 3 beta-HSD activity increased 24 and 34 h after RU486 injection, but a significant and progressive decrease started at 48 h with the maximal reduction 72 h after RU486 treatment, when compared with controls. Serum progesterone concentration decreased at the time of 3 beta-HSD activity reduction. Interestingly, 20 alpha-HSD activity started to increase 58 h after RU486 injection. The administration of the cyclooxygenase inhibitor, diclofenac (1.3 mg/kg), on days 17-19 of pregnancy to RU486-treated rats, delayed abortion and the duration of delivery, and prevented the decrease in 3 beta-HSD and the increase in 20 alpha-HSD activities observed 58 h after antiprogesterone treatment. RU486 administered intrabursally (1 microgram per ovary) on day 20 (14.00-15.00 h) increased 3 beta-HSD and decreased 20 alpha-HSD luteal activities at 18.00 h on day 21 of pregnancy, without modifying serum progesterone concentration, when compared with normal pregnant rats. In conclusion, the luteolytic process after preterm delivery induced by RU486 administration in late pregnant rats is characterized by a decrease in luteal 3 beta-HSD activity and circulating progesterone, which may trigger the increase in luteal 20 alpha-HSD activity. Prostaglandins seems to be involved in the increase of 20 alpha-HSD activity and therefore, in the demise of corpora lutea.