Diffuse pollution monitoring and modelling of small urban watershed in Brazil Cerrado.

The stormwater runoff carries different pollutants that can reduce the quality of receiving waters due to diffuse pollutant loads. This research was aimed at evaluating the concentration of pollutants in stormwater and the application of SWMM (Storm Water Management Model) to an urban catchment in Lake Paranoá watershed to carry out the simulation of flow discharge with the hydraulic model, and subsequently to estimate the loads conveyed to the lake in ordinary events of precipitation. This study was carried out based on rainfall and runoff monitoring during events. It was confirmed that this model's results fit well in simulation of this type of watershed, leading to high value of the Nash-Sutcliffe coefficient after calibration but, as expected, precipitation distribution is a very important factor for calibration. Concerning water quality, it was observed that the event mean concentration values of suspended solids and chemical oxygen demand were high, indicating that the diffuse pollution is an important source of pollution of the receiving waters. The monitoring and modelling of stormwater are essential to identify diffuse pollution discharge, in searching for a sustainable solution.

Activity of megestrol acetate in postmenopausal women with advanced breast cancer after nonsteroidal aromatase inhibitor failure: a phase II trial.

BACKGROUND: As novel treatments carry substantial price tags and are mostly cost-prohibitive in low- and middle-income countries, there is an urgent need to develop alternatives, such as off-patent drugs. Megestrol acetate (MA) has a longstanding history in the treatment of breast cancer, but recently it is being used less often due to the advent of newer agents. PATIENTS AND METHODS: This two-stage phase II trial evaluated the antitumor activity and toxicity of MA in postmenopausal women with hormone-sensitive advanced breast cancer who had experienced disease progression on a third-generation nonsteroidal aromatase inhibitor (NSAI). Eligible patients had metastatic breast cancer treated with a NSAI with at least 6-month progression-free survival (PFS), or relapse after ≥1 year on adjuvant NSAI. Patients received MA at a single daily oral dose of 160 mg. Primary end point was clinical benefit rate (CBR). RESULTS: Forty-eight patients were enrolled. The CBR was 40% [95% confidence interval (CI) 25% to 55%], and the median duration of clinical benefit was 10.0 (95% CI 8.0-14.2) months. The median PFS was 3.9 (95% CI 3.0-4.8) months. The most common grade 3 adverse events were anemia (2%), dyspnea (2%), fatigue (2%), musculoskeletal pain (4%), deep vein thrombosis (10%), and weight gain (2%). CONCLUSIONS: This is the first study to prospectively evaluate the efficacy and safety of MA in postmenopausal women with hormone-sensitive disease progressing on a NSAI. MA has demonstrated activity and acceptable tolerability in this setting, and therefore remains a reasonable treatment option in a cost-sensitive environment. These results also provide the background for further evaluation of progestins in the treatment of breast cancer. CLINICAL TRIALS: local trial number, related to the approval by the IRB: CEP 108/06.

Dyadic dynamics of perceived social support in couples facing infertility.

STUDY QUESTION: Is perceived social support from partner, family, and friends associated with increased infertility-related stress? SUMMARY ANSWER: While men's perceived support did not seem to influence their partners' stress, women's perceptions of spousal and familial support can affect the way men deal with the challenge of infertility. WHAT IS KNOWN ALREADY: Previous studies showed that low levels of social support are associated with poor psychosocial adjustment and treatment termination in women and men. Studies examining the impact of social support using the couple as unit of analysis are lacking. STUDY DESIGN, SIZE, DURATION: A cross-sectional sample of 613 Portuguese patients participated in the research, online over a 3-month period, and in a public fertility clinic over 11 months. PARTICIPANTS/MATERIALS, SETTING, METHODS: The final sample comprised 213 married or cohabiting couples (191 from the fertility clinic) who were actively attempting to have a child, were seeking infertility treatment and had not undergone previous preimplantation genetic diagnosis. Perceived social support was assessed through the Multidimensional Scale of Perceived Social Support and infertility-related stress was assessed with the fertility problem inventory. Hypotheses were tested by applying the actor-partner interdependence model using structural equation modeling. MAIN RESULTS AND THE ROLE OF CHANCE: Couples had been living together for an average (±SD) of 6 ± 3.5 years, and attempting a pregnancy for 3.8 ± 2.6 years. Nearly half of the couples had undergone infertility treatment (41.3%). Infertility stress was found to be associated with low family support for women (ß = -0.27, P = .003), and low partner support for both men (ß = -0.29, P = .001) and women (ß = -0.45, P = .006). Both women and men's perceived friend support were not significantly related to male or female infertility stress. Men infertility stress was also associated with their partners low levels of partner (ß = -0.24, P = .049) and family support (ß = -0.23, P < .001). No significant partner effects were observed for women. Despite being related to actor effects alone (female partner and family support), the explained variance of the model in women's fertility stress was greater (R(2) = 21%) than that (R(2) = 15.6%) for the combined actor and partner effects in men's fertility stress (male partner support, female partner and family support). LIMITATIONS, REASONS FOR CAUTION: The study data are cross-sectional and the generalizability of results is limited by self-selection. The characteristics of non-participants in both the clinical and online samples were not available, the perception of infertility-specific supportive behaviors was not assessed and differential analyses according to infertility diagnosis were not included in this study. WIDER IMPLICATIONS OF THE FINDINGS: Our data underline the importance of partner support in alleviating the burden of infertility. Men may experience infertility indirectly through the impact that it has on their partners. Our findings reinforce the need to involve the male partner throughout the whole treatment process and for couple-based interventions when providing infertility counseling. Further prospective research should be aimed at investigating the male experience of infertility. STUDY FUNDING/COMPETING INTEREST: This research was supported by a PhD scholarship from the Portuguese Foundation for Science and Technology granted to M.M. (FCT, SFRH/BD/44232/2008). The authors have no conflicts of interest to declare.

NEOVAGINOPLASTY WITH NILE TILAPIA SKIN GRAFT IN A PATIENT WITH GONADAL DYSGENESIS: A CASE REPORT.

BACKGROUND: Gonadal dysgenesis, a genetic condition characterized by incomplete of defective formation of the gonads, can present with vaginal agenesis in individuals with 46,XY karyotype. CASE: We report an innovative intervention in the management of vaginal agenesis in a 19-year-old female with gonadal dysgenesis. Despite initial attempts with vaginal dilators, the patient presented unresponsive, leading to the adoption of a neovaginoplasty using Nile Tilapia Fish Skin (NTFS) as graft. The procedure, based on the McIndoe technique, involved the creation of a 10cm x 3cm vaginal canal with an NTFS-wrapped acrylic mold without complications. DISCUSSION: The use of NTFS as a graft for neovaginoplasty in gonadal dysgenesis, a novel approach not previously reported in medical literature for this diagnosis, demonstrated favorable outcomes in terms of functionality and patient well-being.

Transforming growth factor-alpha gene expression in the hypothalamus is developmentally regulated and linked to sexual maturation.

Hypothalamic injury causes female sexual precocity by activating luteinizing hormone-releasing hormone (LHRH) neurons, which control sexual development. Transforming growth factor-alpha (TGF-alpha) has been implicated in this process, but its involvement in normal sexual maturation is unknown. The present study addresses this issue. TGF-alpha mRNA and protein were found mostly in astroglia, in regions of the hypothalamus concerned with LHRH control. Hypothalamic TGF-alpha mRNA levels increased at times when secretion of pituitary gonadotropins--an LHRH-dependent event--was elevated, particularly at the time of puberty. Gonadal steroids involved in the control of LHRH secretion increased TGF-alpha mRNA levels. Blockade of TGF-alpha action in the median eminence, a site of glial-LHRH nerve terminal association, delayed puberty. These results suggest that TGF-alpha of glial origin is a component of the developmental program by which the brain controls mammalian sexual maturation.

In vitro 3D assay to test angiogenic effects of human CD14+ monocytes seeded on macroporous PLGA/CaP polymers with a CaP nanostructured surface.

In this study we present a three-dimensional angiogenesis assay in vitro that allows the evaluation of the influence of Poly(lactic-co-glycolic acid) based implants seeded with VEGF-A165 stimulated/activated human CD14+ monocytes on the attraction and migration of human micro vascular endothelial cells (HMVEC-L). Primary HMEC of the capillary bed were cultured on an extracellular matrix generated by bovine corneal endothelial cells (BCEC). The HMEC layer was covered by an agarose gel, upon which a Poly(lactic-co-glycolic acid)/CaP polymer with a Calcium-Phosphate (CaP) nanostructured surface was placed. This scaffold has already been shown to interact with endothelial cells and endothelial progenitor cells respectively in vivo. It was seeded with angiogenically stimulated (VEGF-A165) human CD14+ monocytes, to get a monocyte/macrophage fraction, which can promote angiogenesis, tissue remodelling and tissue repair due to the secretion of growth factors, cytokines, chemokines and enzymes. The study demonstrated that this assay is suitable to test angiogenic effects by stimulated human CD14+ monocytes on human microvascular endothelial cells influenced by Poly(lactic-co-glycolic acid)/CaP scaffolds with a nanostructured CaP surface. The assay can exclude effects on migration caused by gravity and also allows testing in a physiological environment on an extracellular matrix secreted by endothelial cells.

Effects of surgical removal of mandibular third molar on the periodontium of the second molar.

OBJECTIVE: The effects on periodontal tissues of adjacent second molars after semi-impacted mandibular third molar surgery were evaluated. The influence of flap design was studied. METHODS: Twenty volunteers randomly underwent the three-cornered flap technique (group A) or the distal wedge flap technique (group B). The periodontal probing depth was measured by using a 'Williams'-type probe just prior to surgery and three months post-operatively. Six sites, mesio-buccal, buccal, disto-buccal, disto-lingual, lingual and mesio-lingual, around the second molar were selected for measurement. Kruskal-Wallis test and Dunn test (post hoc) were used. Significance level was set at 5%. RESULTS: There were no complications (oedema, alveolitis, etc.) in any of the patients of the study. The results showed that both methods caused shallow pocket depth (P > 0.05) and there were no statistically significant differences between the flap techniques (P > 0.05). Flap design was not an important factor affecting the periodontal status of the second molar. CONCLUSION: The decision to use any of the various flap designs for access to mandibular third molars should be based on operator preference rather than on the assumption that periodontal health of the adjacent second molar will be improved.

In vitro inhibitory effect of cranberry (Vaccinium macrocarpom Ait.) juice on pathogenic microorganisms.

The purpose of this study was to determine the inhibitory effects of cranberry juice on pathogenic microorganisms. The microorganisms analyzed were Escherichia coli from patients with urinary infections, Salmonella spp., Listeria monocytogenes, Pseudomonas aeruginosa, and Staphylococcus aureus. The disc method was used to determine the sensitivity of bacteria to cranberry juice (CJ, both concentrated and diluted). A lawn of 10(6) cfu/ml was grown on agar surfaces in Petri dishes and on Whatman discs that had been previously saturated with CJ and CJ : water 1 : 1 to 1 : 50 juice solutions had been placed on the discs, which were cultured and incubated. The results indicated that S. aureus was more susceptible to cranberry juice inhibition than the other microorganisms. L. monocytogenes was the most resistant to the inhibitory action of cranberry juice, showing a significant difference from the inhibition of P. aeruginosa, uropathogenic E. coli, Salmonella spp., and S. aureus. This study also demonstrated that the inhibitory activity of cranberry juice for E. coli took place up to a dilution of 1 : 20.

Magnetization reversal in orthorhombic Sr-doped LaFe0.5Cr0.5O3-δ.

In this paper we studied the reversal magnetization of La1-x Sr x Fe0.5Cr0.5O3-δ (x = 0, 0.1 and 0.2) samples produced by combustion synthesis. The structural analysis was carried out by x-ray diffraction with Rietveld analysis. These analyses revealed that all samples have an orthorhombic structure with space group Pbnm (62) and that the Sr-doping induces a decrease of the lattice parameter. The x-ray photoelectron spectroscopy analysis indicates that the Sr-doping favor the change of the valence states of the Fe3+ to Fe4+. The magnetization as a function of the temperature reveals an unusual magnetic behavior with a reversal of magnetization. The increase of the Sr content induces a decrease of the temperature where occurs an inversion of the magnetization and do the value of the magnetization at 5 K more negative. This effect is attributed to the increase of the concentration of Fe4+ with increasing of the Sr content. The Fe and Cr with a valence of 4+ act as paramagnetic impurities in the antiferromagnetic lattice and are responsible for the changes in the magnetic behavior.

TiO2 anatase nanorods with non-equilibrium crystallographic {001} facets and their coatings exhibiting high photo-oxidation of NO gas.

Development of highly active photocatalysts is mandatory for more widespread application of this alternative environmental technology. Synthesis of photocatalysts, such as anatase TiO2, with more reactive, non-equilibrium, crystallographic facets is theoretically justified by a more efficient interfacial charge transfer to reactive adsorbed species, increasing quantum efficiency of photocatalyst. Air and vacuum calcinations of protonated trititanate nanotubes lead to their transformation to anatase nanorods. The nanorods synthesized by air calcination demonstrate photo-oxidation of NO gas more than three times superior to the one presented by the benchmark P-25 photocatalyst. This performance has been explained in terms of 50% higher specific surface area and, more importantly, through the predominance of more reactive, non-equilibrium, {001} crystallographic facets of the anatase nanorods. These facets present a high density of undercoordinated Ti cations, which favors adsorption of reactant species, and strained Ti-O-Ti bonds, leading to more efficient photo-oxidation reactions. Reduced Ti species, such as Ti3+, were not observed in the as-obtained nanorods, while reactive adsorbed molecules are scarce on the nanorods obtained through vacuum calcination. Dip-coating of TiO2 anatase nanorods (air calcined) over soda-lime glass plates was used to prepare visible light transparent, superhydrophilic and highly adherent photocatalytic coatings with homogenously distributed nanopores.

Nitrogen Sources Screening for Ethanol Production Using Carob Industrial Wastes.

Nowadays, bioethanol production is one of the most important technologies by the necessity to identify alternative energy resources, principally when based on inexpensive renewable resources. However, the costs of 2nd-generation bioethanol production using current biotechnologies are still high compared to fossil fuels. The feasibility of bioethanol production, by obtaining high yields and concentrations of ethanol, using low-cost medium, is the primary goal, leading the research done today. Batch Saccharomyces cerevisiae fermentation of high-density sugar from carob residues with different organic (yeast extract, peptone, urea) and inorganic nitrogen sources (ammonium sulfate, ammonium nitrate) was performed for evaluating a cost-effective ethanol production, with high ethanol yield and productivity. In STR batch fermentation, urea has proved to be a very promising nitrogen source in large-scale production of bioethanol, reaching an ethanol yield of 44 % (w/w), close to theoretical maximum yield value and an ethanol production of 115 g/l. Urea at 3 g/l as nitrogen source could be an economical alternative with a great advantage in the sustainability of ethanol production from carbohydrates extracted from carob. Simulation studies, with experimental data using SuperPro Design software, have shown that the bioethanol production biorefinery from carob wastes could be a very promising way to the valorization of an endogenous resource, with a competitive cost.

On the phonon dissipation contribution to nanoscale friction by direct contact.

The friction phenomenon is a ubiquitous manifestation of nature. Models considering phononic, electronic, magnetic, and electrostatic interactions are invoked to explain the fundamental forces involved in the friction phenomenon. In order to establish the incidence of the phonon prompting at the nanoscale friction by direct contact, we study a diamond spherical dome sliding on carbon thin films containing different amount of deuterium and hydrogen. The friction coefficient decreases by substituting hydrogen by deuterium atoms. This result is consistent with an energy dissipation vibration local mechanism from a disordered distribution of bond terminators.

Growth kinetics and physiological behavior of co-cultures of Saccharomyces cerevisiae and Kluyveromyces lactis, fermenting carob sugars extracted with whey.

Alcoholic fermentation of carob waste sugars (sucrose, glucose and fructose) extracted with cheese whey, by co-cultures of Saccharomyces cerevisiae and Kluyveromyces lactis has been analyzed. Growth and fermentation of S. cerevisiae in the carob-whey medium showed an inhibition of about 30% in comparison with water-extracted carob. The inhibition of K. lactis on carob-whey was greater (70%) when compared with the whey medium alone, due to osmolarity problems. Oxygen availability was a very important factor for K. lactis, influencing its fermentation performance. When K. lactis was grown alone on carob-whey medium, lactose was always consumed first, and glucose and fructose were consumed afterwards, only at high aeration conditions. In co-culture with S. cerevisiae, K. lactis was completely inhibited and, at low aeration, died after 3 days; at high aeration this culture could survive but growth and lactose fermentation were only recovered after S. cerevisiae became stationary. To overcome the osmolarity and K. lactis' oxygen problems, the medium had to be diluted and a sequential fermentative process was designed in a STR-3l reactor. K. lactis was inoculated first and, with low aeration (0.13vvm), consumed all the lactose in 48h. Then S. cerevisiae was inoculated, consuming the total of the carob sugars, and producing ethanol in a fed-batch regime. The established co-culture with K. lactis increased S. cerevisiae ethanol tolerance. This fermentation process produced ethanol with good efficiency (80g/l final concentration and a conversion factor of 0.4g ethanol/g sugar), eliminating all the sugars of the mixed waste. These efficient fermentative results pointed to a new joint treatment of agro-industrial wastes which may be implemented successfully, with economic and environmental sustainability for a bioethanol industrial proposal.

Neuregulins signaling via a glial erbB-2-erbB-4 receptor complex contribute to the neuroendocrine control of mammalian sexual development.

Activation of erbB-1 receptors by glial TGFalpha has been shown to be a component of the developmental program by which the neuroendocrine brain controls mammalian sexual development. The participation of other members of the erbB family may be required, however, for full signaling capacity. Here, we show that activation of astrocytic erbB-2/erbB-4 receptors plays a significant role in the process by which the hypothalamus controls the advent of mammalian sexual maturation. Hypothalamic astrocytes express both the erbB-2 and erbB-4 genes, but no erbB-3, and respond to neuregulins (NRGs) by releasing prostaglandin E(2) (PGE(2)), which acts on neurosecretory neurons to stimulate secretion of luteinizing hormone-releasing hormone (LHRH), the neuropeptide controlling sexual development. The actions of TGFalpha and NRGs in glia are synergistic and involve recruitment of erbB-2 as a coreceptor, via erbB-1 and erbB-4, respectively. Hypothalamic expression of both erbB-2 and erbB-4 increases first in a gonad-independent manner before the onset of puberty, and then, at the time of puberty, in a sex steroid-dependent manner. Disruption of erbB-2 synthesis in hypothalamic astrocytes by treatment with an antisense oligodeoxynucleotide inhibited the astrocytic response to NRGs and, to a lesser extent, that to TGFalpha and blocked the erbB-dependent, glia-mediated, stimulation of LHRH release. Intracerebral administration of the oligodeoxynucleotide to developing animals delayed the initiation of puberty. Thus, activation of the erbB-2-erbB-4 receptor complex appears to be a critical component of the signaling process by which astrocytes facilitate the acquisition of female reproductive capacity in mammals.

Nerve growth factor receptors in the peripubertal rat ovary.

We previously demonstrated that the immature rat ovary synthesizes nerve growth factor (NGF), and that interference of NGF actions by immunoneutralization during neonatal life prevents development of the ovarian sympathetic innervation and delays follicular maturation. Since the actions of NGF are exerted via binding to specific cell surface receptors, the present study was undertaken to define and characterize the presence of NGF receptors (NGFrec) in the developing rat ovary. NGF interacts with two classes of NGFrec. The most abundant is a low affinity form expressed in the central nervous system and peripheral tissues. This receptor is encoded by a single 3.8-kilobase mRNA species. Cross-linking of [125I]NGF to ovarian membranes followed by immunoprecipitation, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and autoradiography showed the presence of a approximately 90-kilodalton molecular species which corresponds in size to the predominant NGF receptor species cross-linked to its ligand. While ovarian NGFrec may be of neuronal origin and reach the gland exclusively by anterograde axonal transport, RNA blot hybridization demonstrated that the ovary expresses the NGFrec mRNA species that encodes the low affinity NGF receptor and, thus, implicated the ovary itself as a site of NGFrec synthesis. NGFrec mRNA levels decreased abruptly after the first ovulation, suggesting that NGFrec may be synthesized in growing follicles and that this capacity is lost after follicular rupture and luteinization.(ABSTRACT TRUNCATED AT 250 WORDS)

Kinetic and Energetic Parameters of Carob Wastes Fermentation by Saccharomyces cerevisiae: Crabtree Effect, Ethanol Toxicity, and Invertase Repression.

Carob waste is a useful raw material for the second-generation ethanol because 50% of its dry weight is sucrose, glucose, and fructose. To optimize the process, we have studied the influence of the initial concentration of sugars on the fermentation performance of Saccharomyces cerevisiae. With initial sugar concentrations (S0) of 20 g/l, the yeasts were derepressed and the ethanol produced during the exponential phase was consumed in a diauxic phase. The rate of ethanol consumption decreased with increasing S0 and disappeared at 250 g/l when the Crabtree effect was complete and almost all the sugar consumed was transformed into ethanol with a yield factor of 0.42 g/g. Sucrose hydrolysis was delayed at high S0 because of glucose repression of invertase synthesis, which was triggered at concentrations above 40 g/l. At S0 higher than 250 g/l, even when glucose had been exhausted, sucrose was hydrolyzed very slowly, probably due to an inhibition at this low water activity. Although with lower metabolic rates and longer times of fermentation, 250 g/l is considered the optimal initial concentration because it avoids the diauxic consumption of ethanol and maintains enough invertase activity to consume all the sucrose, and also avoids the inhibitions due to lower water activities at higher S0.

A role for neurotransmitters in early follicular development: induction of functional follicle-stimulating hormone receptors in newly formed follicles of the rat ovary.

The initiation of follicular growth in the mammalian ovary is a gonadotropin-independent phenomenon. Although some of the intraovarian signaling molecules that control the later phases of this process have been recently identified, the factors involved in the acquisition of gonadotropin receptors by early growing follicles have not been fully defined. In the rat, development of the ovarian innervation precedes the onset of folliculogenesis and occurs before follicles acquire responsiveness to gonadotropins. Because vasoactive intestinal polypeptide (VIP) and norepinephrine (NE), two of the neurotransmitters contained in ovarian nerves, are present in the ovary before the gland becomes responsive to gonadotropins, we sought to determine if VIP and/or NE are able to act on early follicles to facilitate the process of molecular differentiation that leads to gonadotropin dependency. In vitro exposure of 2-day-old rat ovaries to isoproterenol (ISO), a beta-adrenoreceptor agonist, or VIP, a neurotransmitter contained in both sympathetic and sensory nerves, increased the steady state levels of the messenger RNAs encoding cytochrome P-450 aromatase (P-450arom) and FSH receptors (FSHR) within 8 h of treatment. A similar effect was observed following forskolin-induced activation of cAMP formation. In situ hybridization experiments revealed that both the P-450arom and FSHR hybridization signals were localized to follicles. The increase in FSHR messenger RNA was accompanied by formation of functional receptor molecules, as demonstrated by the ability of FSH to stimulate cAMP formation in ovaries preexposed to either ISO or VIP, but not in untreated ovaries. The stimulatory effect of ISO and VIP on the formation of FSHR coupled to the cAMP generating system was not reproduced by phenylephrine, an alpha-adrenergic agonist, or secretin, a member of the VIP family not recognized by ovarian VIP receptors. Treatment of VIP-primed ovaries with FSH resulted in follicular growth, demonstrating that exposure of the gland to the neurotransmitter led to the formation of a functional complement of FSH receptors. These results suggest that ovarian nerves, acting via neurotransmitters coupled to the cAMP generating system, contribute to the differentiation process by which newly formed primary follicles acquire FSH receptors and responsiveness to FSH. Follicles that begin to grow in more densely innervated ovarian regions, may have a selective advantage over those not exposed to neurotransmitter-activated, cAMP-dependent signals and, thus, may become more rapidly subjected to gonadotropin control.

Immature rat ovaries become revascularized rapidly after autotransplantation and show a gonadotropin-dependent increase in angiogenic factor gene expression.

When the ovaries of 23-day-old juvenile rats are transplanted to an ectopic site, they recover within 1 week the ability to control gonadotropin secretion via steroid negative feedback. Vascular corrosion casting followed by scanning electron microscopy revealed that the transplanted ovary becomes profusely revascularized within 48 h after transplantation. Vascular ingrowth was accompanied by a 40- to 60-fold increase in expression of the genes encoding two angiogenic factors, vascular endothelial growth factor (VEGF) and transforming growth factor-beta 1 (TGF beta 1), as assessed by RNA blot hybridization of the corresponding mRNAs. Although TGF beta 3 mRNA levels also increased, no changes in the levels of mRNAs encoding other putative angiogenic factors, such as TGF alpha, basic fibroblast growth factor, and TGF beta 2, were observed. Hybridization histochemistry demonstrated that in intact ovaries, VEGF mRNA is mainly expressed in granulosa cells of the cumulus oophorus and thecal cells of large antral follicles. Transplantation is followed by an increase in mRNA abundance and a dramatic shift in cellular localization, so that the mRNA becomes predominantly expressed in cells of the outer ovarian cortex. In intact ovaries, low levels of TGF beta 1 mRNA were detected in thecal-interstitial cells; after transplantation, its expression also became more predominant in the ovarian outer cortex, but this change was not as marked as in the case of VEGF. Because ovarian autotransplantation is followed by a rapid increase in serum gonadotropin levels, experiments were conducted to determine the importance of this rise in the activation of VEGF and TGF beta 1 gene expression. After transplantation, some animals were treated with the LHRH antagonist Nal-Glu LHRH (50 micrograms/rat, once a day for 2 days) to prevent the posttransplantation rise in serum gonadotropins. Quantitation of VEGF and TGF beta 1 mRNA by RNase protection assay 48 h later showed that suppression of gonadotropin secretion diminished the increase in both VEGF and TGF beta 1 gene expression. Concomitant treatment with PMSG (8 IU/rat, single injection), which mainly bypasses the suppression of endogenous FSH levels, restored the TGF beta 1 mRNA response, but had no effect on VEGF mRNA. The results suggest that the increase in gonadotropin secretion following ovarian transplantation contributes to revascularization of the graft by up-regulating the gene expression of two major angiogenic factors.

Stimulation of cyclic adenosine 3',5'-monophosphate production enhances hypothalamic luteinizing hormone-releasing hormone release without increasing prostaglandin E2 synthesis: studies in prepubertal female rats.

A role for cAMP in the process of LHRH release was suggested several years ago, but only recently has the validity of this notion come under close scrutiny. In the present experiments we have used three probes, which stimulate adenylate cyclase activity via different mechanisms, to determine whether an increase in endogenous cAMP results in LHRH release from the hypothalamus of prepubertal female rats. Median eminences from juvenile, 28-day-old animals were incubated in vitro with either forskolin (F), cholera toxin (CT), or pertussis toxin (PT). All three substances enhanced LHRH release. The estimated ED50 values were 28.7 microM and 20.0 ng/ml, for F and PT, respectively. The effect of CT appeared biphasic and thus no ED50 could be calculated. None of these agents increased the release of prostaglandin E2 (PGE2), an obligatory component in the process of norepinephrine-induced LHRH secretion. Doses of PGE2 and F, which were maximally effective in stimulating LHRH release when administered separately, did not produce any further response when administered concomitantly, thus suggesting that PGE2 and F act along a common pathway. Blockade of phosphodiesterase activity with 1-methyl-3-isobutylxanthine increased LHRH secretion without enhancing PGE2 release, implying that cAMP metabolism was elevated in the median eminence nerve terminals in vitro. Addition of 1-methyl-3-isobutylxanthine augmented the LHRH response to CT and PT, but it did not increase further the already marked LHRH response to PGE2 or F. The results indicate that both an increase in adenylate cyclase activity and a decrease in phosphodiesterase activity lead to LHRH release from the median eminence. They also suggest that, upon proper (neurotransmitter?) stimulation, cAMP production increases subsequent to the activation in PGE2 synthesis, which itself causes LHRH release. Furthermore, the capacity of PT to induce LHRH release suggests the involvement of an inhibitory guanine nucleotide-binding regulatory protein in transducing inhibitory inputs impinging on LHRH-secreting neurons.