"My Patients Asked Me If I Owned a Fruit Stand in Town or Something." Barriers and Facilitators of Personalized Dietary Advice Implemented in a Primary Care Setting.

Primary care is especially well positioned to address prevention of non-communicable diseases. However, implementation of health promotion activities such as personalized dietary advice is challenging. The study aim was to understand barriers and facilitators of the personalized dietary advice component of a lifestyle intervention in primary care, as perceived by health center professionals and program participants.

Effect of nervous stimulation on ovarian steroid secretion in amphibians.

In the present study, the effect of nerve stimulation on the secretory activity of the ovary of adult females was analyzed for the first time in amphibians. Results revealed that in Rhinella arenarum the stimulation of nerves that supply the gonad induced an increase in estradiol and progesterone secretion, this response showing differences during the reproductive cycle of the species. During the postreproductive period, an increase in estradiol secretion was observed while, in the reproductive period, progesterone secretion increased.

Effects of nerve stimulation on amphibian oviductal activity.

The present study describes, for the first time in an anuran amphibian, the nerve stimulation effects on the secretory and motor activity of the oviduct of adult females. The results reveal that in Rhinella arenarum oviducts, the epithelial and glandular secretory cells of the mucosa of the pars convoluta respond to nerve stimulation secreting the products synthetized and stored in their cytoplasm. The ultrastructural analysis showed that the cell content released is made up of granular, fibrillar and floccular material, exocytosis being the main secretory mechanism found in epithelial secretory cells, although apocrine and holocrine processes could also be observed.

Electron microscopy observations on testis and spermatozoa of Leptodactylus chaquensis (Anura, Leptodactylidae).

Scanning and transmission electron microscopy were used to investigate the fine structure of the testis and spermatozoa of toad Leptodactylus chaquensis. Our observations indicate that germinal compartment contains Sertoli (SC) and germ cells. The tight junctions and desmosomes among SC indicate the existence of an hematotesticular barrier in charge of maintaining the differences in the composition of the germinal and interstitial compartments.

Ultrastructure of the oviductal mucosa of Leptodactylus chaquensis. Analysis of the preovulatory and postovulatory periods.

In the present study we analysed the ultrastructural characteristics of the oviductal mucosa of Leptodactylus chaquensis during the preovulatory period and immediately after ovulation. Epithelial secretory cells, ciliated cells, basal cells and glandular secretory cells are described. During the preovulatory period, the oviduct exhibits its maximum degree of development at both the epithelial and the glandular levels, with numerous secretory cells that contain a large number of secretory granules whose contents are released into the oviductal lumen by apocrine and exocytotic secretory processes.

Homeostasis and secretion of calcium in the oviductal mucosa of toad Rhinella arenarum.

The presence of a calcium pump, calbindin D-28KD, and calmodulin in the secretory cells (SC) of the oviductal pars convoluta (PC) of Rhinella arenarum was established for the first time in amphibians using immunohistochemical techniques. Marked variations were observed in the localization and degree of expression of these proteins according to the duct segment and the period of the sexual cycle analyzed. During the preovulatory and ovulatory periods the calcium pump colocalized with calbindin D-28KD can be seen mainly in the apical border of the SC, which are located in the first zones of PC and synthesize and secrete the components of the inner jelly coat layers.

Innervation of amphibian reproductive system. Histological and ultrastructural studies.

In the present study we describe for the first time in anuran amphibians the histological and ultrastructural characteristics of innervation in the female reproductive organs. The observations in Rhinella arenarum revealed the presence of nerve fibers located predominantly in the ovarian hilium and in the oviduct wall. In both organs the nerves fibers are placed near blood vessels and smooth muscles fibers.

Structural analysis of toad oviductal mucosa in relation to jelly components secretion throughout the reproductive cycle.

In amphibians, the components of the jelly coats that surround the oocytes at the time of fertilization and coordinate gamete interaction are secreted by the oviduct. We analysed the histological variations in the mucosa of the oviductal pars convoluta (PC) of Rhinella arenarum during the reproductive cycle and its relationship with secretion. During the preovulatory period, the mucosa reaches a high degree of morphological and functional development, with a large number of epithelial (ESC) and glandular secretory cells (GSC) loaded with contents that are secreted into the oviductal lumen.

Spermatogenesis in Leptodactylus chaquensis. Histological study.

The organization and the histological characteristics of Leptodactylus chaquensis testis throughout the reproductive cycle were analyzed in the presented study. Gonads of adult males, processed with routine techniques for optical microscopy, revealed that during the reproductive period the seminiferous tubules were characterized by presentation of a large number of cysts, germ cells at the same maturation stage supported by Sertoli cells. All the germ line cells were also present in the postreproductive period and maintained their morphological characteristics.

Histopathological and biological studies of the effect of cadmium on Rhinella arenarum gonads.

This study was to determine the lethal dose 50 (LD(50)) of CdCl(2) in adult Rhinella arenarum and analyzed the effect of two sublethal doses (0.5 and 5 mg/kg) of the xenobiotic in gonads. The 48 h LD(50) were 50.

Effect of oviductal secretion components on the fertilizing capacity of amphibian sperm: biological and ultrastructural studies.

The present study was carried out to analyze the fertilization-supporting activity of Rhinella arenarum egg-jelly components. Spermatozoa were treated with diffusible factor (DF) constituted by the components released from the jelly coat into deionized water or with full jelly (FJ) containing all the components secreted by the oviductal pars convoluta (PC) during the transit of the oocytes through the duct, or with washed jelly (WJ) constituted only by structural components. Both jellies were solubilized by ultraviolet irradiation.

Role of cations as components of jelly coats in Bufo arenarum fertilization.

The role of monovalent (Na+, K+) and divalent (Ca2+, Mg2+) cations in Bufo arenarum fertilization was analysed. Our results showed that the highest fertilization percentages were obtained when strings of uterine oocytes (UO) were inseminated. Under these conditions, full jelly (FJ), which represents the jelly coats surrounding the oocytes at the time of deposition, contained 68.

Analysis of Bufo arenarum oviductal secretion during the sexual cycle.

SummaryBufo arenarum oocytes are oviposited surrounded by jelly coats, one component of the extracellular matrix required for fertilization. The secretion, released to the oviductal lumen, was analysed by SDS-PAGE. The coomassie blue staining evidenced an electrophoretic pattern with molecules ranging between 300 and 19 kDa that showed variations in their secretion profiles during the sexual cycle.

Subcellular localization of calcium and Ca-ATPase activity during nuclear maturation in Bufo arenarum oocytes.

The localization of calcium and Ca-ATPase activity in Bufo arenarum oocytes was investigated by ultracytochemical techniques during progesterone-induced nuclear maturation, under in vitro conditions. No Ca2+ deposits were detected in either control oocytes or progesterone-treated ones for 1-2 h. At the time when nuclear migration started, electron dense deposits of Ca2+ were visible in vesicles, endoplasmic reticulum cisternae and in the space between the annulate lamellae membranes.

Modulators of Bufo arenarum ovulation.

In this study we investigated ovulation in vitro using ovary samples from Bufo arenarum with respect to their response to stimulation with homologous pituitary homogenate (HPH) or with progesterone and prostaglandins (PGF2alpha and PGE1) as intermediates of pituitary action. Ovary samples were obtained from animals captured during the breeding period. Our results demonstrate that the ovulatory response to all different inducers was dose dependent, the highest percentage of ovulated oocytes being obtained with HPH treatment.

Effect of steroid hormones on Bufo arenarum oviduct. Ultrastructural study.

The endocrine regulation of the mucosa of the oviductal pars convoluta was analyzed by ultrastructural studies demonstrating that ovariectomy, together with a decrease in ovarian steroids circulating levels, caused a marked regression in this portion of Bufo arenarum oviduct. Twenty-five days after ovariectomy, a decrease in the depth of the epithelial and glandular layers was observed due to the notable loss of secretory cells, whose number was clearly smaller than in nonovariectomized females. The remaining secretory cells showed involution signs, with few secretory granules in their cytoplasm, little endoplasmic reticulum near poorly developed Golgi complexes and a large amount of lipid droplets.

Role of prolactin in nuclear maturation and ovulation in amphibian oocytes.

The present study was undertaken to determine the effect of prolactin (Prl) on Bufo arenarum oocyte maturation and ovulation, two characteristic events of the breeding period, the stage of the sexual cycle in which gamete growth is complete. We observed that Prl, at the doses assayed, did not affect nuclear maturation per se. In addition, when follicles were pretreated with Prl and progesterone was later added to the medium as a physiological nuclear maturation inducer, the percentage of germinal vesicle breakdown obtained with the steroid was unaffected by Prl.

Changes in serum sex steroid levels throughout the reproductive cycle of Bufo arenarum females.

The changes in the serum levels of the sexual steroids estradiol-17beta (E(2)), testosterone (T), dihydrotestosterone (DHT), and progesterone (P) in Bufo arenarum females were determined by radioimmunoassay (RIA) during 3 consecutive cycles (1999-2001). The serum concentrations of T and DHT, which showed a close parallelism during the annual reproductive cycle, exhibited the highest levels during the preovulatory period, when oogenesis is advanced, while lowest serum levels of these hormones were found during the ovulatory period. The data obtained for E(2) showed a pattern contrary to that determined for androgens.

Involvement of catecholamines in the regulation of oocyte maturation in frogs.

The present study investigates the role of catecholamines in the regulation of Bufo arenarum oocyte maturation. The metabolic changes in the oxidation of carbohydrates and the meiotic resumption evinced by the germinal vesicle breakdown were used as indicators of cytoplasmic and nuclear maturation, respectively. The results obtained suggest that noradrenaline (norepinephrine) could be one of the factors responsible for the metabolic behaviour that characterises cytoplasmically immature oocytes.

Ultrastructural studies of the effect of steroid hormones on pars recta secretions in Bufo arenarum.

In amphibians, eggs are released from the ovaries into the coelomic cavity after hormonal stimulation, while related preparatory events occur in the oviducts. We have reported an association between the biological activity of the pars recta (PR), the female reproductive cycle, and ultrastructural modifications of PR epithelium induced by steroid hormones in Bufo arenarum. This article describes (1) the electron microscopic features of PR epithelium and its secretions after ovariectomy; and (2) the effect of either 17β-estradiol, 5α-dihydrotestosterone, progesterone, or a combination of progesterone plus 17β-estradiol on PR epithelium and secretions in ovariectomized animals.

Role of oviductal pars recta extract on interspecific fertilization between anurans.

During their journey through the oviductal pars recta, the vitelline envelope (VE) of Bufo arenarum oocytes encounter structural alterations that make them sensitive to attack by sperm lysin and thus to penetration by sperm cells. The role of pars recta (PR) on the specificity of fertilization between amphibians was analyzed by conditioning Bufo arenarum oocytes with either homologous PR extract (PRE) or Leptodactylus chaquencis PRE. The oocytes were thereafter exposed to sperm lysin preparations from both species.

EFFECT OF OVIDUCAL PROTEINASE UPON BUFO ARENARUM VITELLINE ENVELOPE. A FLUORESCENCE APPROACH.

The intrinsic fluorescence of vitelline envelope from amphibian eggs was enhanced after having been treated with pars recta secretion fluid. At the same time the total number of binding sites for 8-anilino-1-naphthalene sulfonate (ANS) was increased, with the affinity constant remaining unchanged. These observations are interpreted in terms of a structural change of the vitelline envelope submitted to pars recta fluid effect.