Tyrosine kinase A receptor (trkA): a potential marker in epithelial ovarian cancer.

OBJECTIVES: To evaluate the role of trkA receptor as a potential tumor marker in serous epithelial ovarian cancer and its relationship with the angiogenic factors expression as vascular endothelial growth factor (VEGF) and nerve growth factor (NGF). Additionally, to examine whether NGF and VEGF secreted by epithelial ovarian cancer (EOC) explants and from epithelial ovarian cancer cell line (A2780) are involved in the process of angiogenesis, such as cellular proliferation, migration and differentiation of the human endothelial cell line (EA.hy926). METHODS: The mRNA levels of VEGF, NGF and trkA receptors were measured using PCR in 60 ovarian samples. Cellular localization and semi-quantitative estimation of VEGF, NGF, total trkA and p-trkA was performed using IHC in epithelial cells. NGF, total trkA and p-trkA protein were also evaluated in endothelial cells from the same tissues. Human endothelial cell line EA.hy926 was cultured with conditioned media obtained from both EOC explants and from the A2780 cell line, with or without NGF stimulus. RESULTS: Significantly higher levels of NGF, total trkA and p-trkA protein expressions were observed in epithelial and endothelial cells in poorly differentiated EOC versus normal ovary. Interestingly, the p-trkA receptor expression level showed the most significant difference and its presence was only found in borderline tumor and EOC samples indicating the importance of trkA receptor in EOC as a potential tumor marker. A significant increase in proliferation, migration and differentiation of EA.hy926 cells was observed with NGF, and this effect was significantly reverted when NGF was immuno-blocked and when a trkA inhibitor was used, showing that NGF is an important angiogenic factor in EOC by activating its trkA receptor. CONCLUSION: These results indicate that p-trkA may be considered as a new potential tumor marker in EOC, and that NGF may also act as a direct angiogenic factor in EOC.

Propylthiouracil-induced hypothyroidism delays apoptosis during the first wave of spermatogenesis.

Mammalian germ cell apoptosis plays a key role in controlling the correct number of germ cells supported by Sertoli cells during the first wave of spermatogenesis in mammalian puberty. However, little is known about hormonal factors that could influence the rate of germ cell apoptosis during puberty or adulthood. In this work we evaluate germ cell apoptosis under hypothyroidism induced by goitrogen propylthiouracil (PTU) during the first wave of spermatogenesis. Neonatally administered PTU promoted a delay in the differentiation of Sertoli cells as evaluated by the expression of clusterin using immunohistochemistry and RT-PCR. Clusterin had different expression levels in control and PTU-treated animals, but under both conditions the highest levels were found in 35-day-old rats. In addition, clusterin displayed a cytoplasmic localization in control testes, but appeared located in the nucleus in PTU-treated animals. The wave of apoptosis (determined by caspase activity and quantification of apoptotic cells) characteristic of the first round of spermatogenesis was delayed by at least 10 days in these animals. The expression levels of proapoptotic genes like BAX or BAD were different between control and PTU-treated rats; although in both groups the highest level was found at the same age (days). Thus our results indicate that the characteristic pubertal apoptotic wave during rat spermatogenesis is delayed in neonatal hypothyroid rats.

[Risk factors associated with complications of peripherally inserted central catheter in newborn infants]. / Factores de riesgo asociados a complicaciones de catéteres centrales de inserción periférica en recién nacidos.

OBJECTIVE: To describe the outcome and associated complications with the use of peripherally inser ted central venous catheters in neonates, and to identify risk factors associated with the presence of major complications. SUBJECTS AND METHOD: Analytical study of the follow-up of catheters placed in 541 neonates hospitalized in a neonatal intensive care unit. Outcome and complications were descri bed. To assess risk factors associated with major complications, multivariate logistic regression analy sis was used. RESULTS: 655 catheters were placed in 541 infants with birth-weight ranging from 420g to 4.575g. The mean duration was 11.6 ± 8.5 days. 29 patients (4.4%) presented major complications, and associated bloodstream infection was the most frequent (n = 17), determining an infection rate of 2.25 %o catheter days. Infections were more frequent among catheters lasting > 14 days: 9/179 (5%) vs 8/476 (1.7%) of those lasting ≤ 14 days (p < 0.05). Other complications included: pleural effusion due to extravasation (n = 6) and atrial thrombosis (n = 3). Multivariate analysis showed that the presence of major complications was associated with a gestational age < 28 weeks: OR 5.9 (95% CI 1.2 to 40), and upper extremities use: OR 3.2 (95% CI 1.1-7.0). Infections were associated with a greater number of punctures during placement: OR 2.1 (95% CI 1.2-4.8) for each puncture and ges tational age < 28 weeks: OR 7.9 (95% CI: 1.4-73). CONCLUSION: The use of catheters was long-lasting and with a low rate of major complications, which were more common in extremely preterm infants. Infections were associated with an increased number of punctures and duration > 14 days. Other complications were more frequent when upper extremities insertion was used.

Infiltración linfocitaria tumoral como factor de buen pronóstico de supervivencia en pacientes con cáncer gástrico localmente avanzado / Tumor lymphocytic infiltration as a good prognostic factor for survival in patients with locally advanced gastric cancer

Introducción: La relación entre supervivencia e infiltración linfocitaria en el cáncer gástrico se ha determinado como factor pronóstico beneficioso, este estudio local tiene como objetivo determinar la probabilidad de supervivencia en los pacientes con cáncer gástrico estadios IB al IIIC de acuerdo con el porcentaje de infiltración linfocitaria tumoral. Metodología: El presente estudio longitudinal se realizó en el Hospital Oncológico Solón Espinosa Ayala Solca-Núcleo de Quito. El período de estudio de enero del 2013 a enero del 2016, el tiempo de seguimiento terminó en diciembre del 2018. El cálculo de la muestral fue no probabilístico en donde se incluyeron casos de pacientes mayores a 18 años con diagnóstico de cáncer gástrico con estadios clínicos IB al IIIC, que contaron con una muestra histopatológica de gastrectomías. Se usó la variable: "Porcentaje de infiltración" para el análisis la muestra y se dividió en 3 grupos: G1: infiltración linfocitaria leve, G2: moderada y G3: intensa. Las estimaciones de supervivencia se calcularon utilizando el método de Kaplan-Meier y la comparación entre los grupos con la prueba de rango logarítmico. Resultados: 173 pacientes con cáncer gástrico con estadios clínicos IB al IIIC, seguidos a 72 meses, el 60 % son hombres y el 40 % mujeres. Según el porcentaje de infiltración linfocitaria, el 52 % reportaron un porcentaje de infiltración leve, el 21 % moderada y el 27 % intensa. A los 72 meses de seguimiento la supervivencia en G1 fue del 31 %, en G2 fue del 48 %, y en G3 fue del 77 % (P= 0.001). Conclusión: Se encontró que el grado de infiltración linfocitaria intensa en los pacientes con cáncer gástrico estuvo asociado a una mejor supervivencia en el seguimiento a 72 meses.

Introduction: The relationship between survival and lymphocytic infiltration in gastric cancer has been determined to be a beneficial prognostic factor. This local study aims to assess the probability of survival in patients with gastric cancer stages IB to IIIC according to the percentage of lymphocytic infiltration. Methodology: This longitudinal study was conducted at the Solón Espinosa Ayala Solca-Núcleo Cancer Hospital in Quito. The study period was from January 2013 to January 2016; the follow-up time ended in December 2018. The sample calculation was nonprobabilistic and included cases of patients older than 18 diagnosed with gastric cancer with clinical stages IB at IIIC, which had a histo-pathological sample of gastrectomies. The variable "percentage of infiltration" was used to analyze the sample, and it was divided into three groups: G1: mild lymphocytic infiltration, G2: moderate, and G3: intense. Survival estimates were calculated using the Kaplan­Meier method and compared groups with the log-rank test. Results: A total of 173 patients with gastric cancer with clinical stages IB to IIIC were followed up for 72 months; 60% were men, and 40% were women. According to the percentage of lymphocytic infil-tration, 52% reported a rate of mild infiltration, 21% moderate, and 27% intense. At 72 months of follow-up, survival was 31% in G1, 48% in G2, and 77% in G3 (P= 0.001). Conclusion: The degree of intense lymphocytic infiltration in gastric cancer patients was associated with better survival at the 72-month follow-up.

Heterotopic sebaceous glands in the esophagus, a very rare histopathological diagnosis: a case report and review of the literature.

Sebaceous glands are very rarely found in the esophagus. Existing reports do not contain sufficient epidemiological, etiological, clinical, or prognostic data. Its histogenesis suggests heterotopia or metaplasia. Despite its extreme rarity, correct and generally easy identification enables establishing the proper patient monitoring.

Expression of the insulin receptor-related receptor is induced by the preovulatory surge of luteinizing hormone in thecal-interstitial cells of the rat ovary.

The insulin receptor-related receptor (IRR) is a member of the insulin receptor family that, on its own, recognizes neither insulin nor any of the identified insulin-related peptides. In both the nervous system and peripheral tissues, IRR mRNA is detected in cells that also express trkA, the nerve growth factor tyrosine kinase receptor. In the ovary, the trkA gene is transiently activated in thecal-interstitial cells of large antral follicles at the time of the preovulatory surge of gonadotropins. The present study shows that the IRR gene is expressed in the same ovarian compartment, that IRR mRNA content increases strikingly in these cells in the afternoon of the first proestrus, and that--as in the case of trkA mRNA--the increase is caused by gonadotropins. The IRR mRNA species primarily affected is that encoding the full-length receptor; its increased abundance was accompanied by a corresponding change in IRR protein content. An extensive molecular search using several approaches, including the screening of cDNA libraries and PCR amplification with degenerate primers, did not yield an IRR ligand. Phylogenetic analysis of 20 insulin-related sequences and 15 relaxin family peptides from selected vertebrates indicated that the mammalian genome is unlikely to contain an additional ligand expressed from a distinct gene that is closely related to the insulin family. Although the functional nature of the relationship between IRR and trkA receptors is unknown, the remarkable temporal and spatial specificities of their coordinated expression in the ovary before ovulation suggests that they target a functionally related set of downstream events associated with the ovulatory process.

Loss of synaptonemal complex protein-1, a synaptonemal complex protein, contributes to the initiation of follicular assembly in the developing rat ovary.

In the rat ovary, germ and somatic cells become organized into primordial follicles 48-72 h after birth. Although several genes have been implicated in the control of early follicular growth, less is known about the factors involved in the formation of primordial follicles. Using the method of differential display of mRNAs, we found several genes differentially expressed at the time of follicular assembly. One of them encodes synaptonemal complex protein-1 (SCP1), a core component of the protein complex that maintains recombining chromosomes together during prophase I of the first meiotic division in germ cells. This association, evident during the pachytene stage, ends when chromosomal desynapsis begins in the diplotene stage at the end of prophase I. Oocytes become arrested in the diplotene/dictate stage before becoming enclosed into primordial follicles, suggesting that oocytes must complete meiotic prophase I before becoming competent to direct follicle assembly. We now show that attainment of the diplotene stage results in follicular formation. In developing rat ovaries, SCP1 mRNA expression is confined to oocytes and decreases precipitously within 24 h after birth, preceding the organization of primordial follicles. The premature loss of SCP1, achieved via treatment with an antisense oligodeoxynucleotide targeting SCP1 mRNA, resulted in more oocytes reaching the diplotene stage, as evidenced by a decrease in the number of oocytes containing germ cell nuclear antigen-1 (a nuclear protein whose expression ceases in diplotene) and an increase in the number of oocytes expressing MSY2 (a cytoplasmic Y box protein expressed in oocytes that have become arrested in diplotene). SCP1-deficient ovaries exhibited an increased number of newly formed follicles, suggesting that completion of meiotic prophase I endows oocytes with the ability to orchestrate follicular assembly.

Role of nerve growth factor and its TRKA receptor in normal ovarian and epithelial ovarian cancer angiogenesis.

In normal ovarian function a controlled angiogenesis is essential. Several growth factors are involved in this process, such as the vascular endothelial growth factor (VEGF) and nerve growth factor (NGF). The angiogenesis process in the normal ovary is a tightly controlled process that occurs in each ovarian cycle. Also, angiogenesis is critical for ovarian cancer development and it is responsible for tumor spread, metastasis and its peritoneal dissemination. Ovarian cancer is the fifth leading cause of cancer death in women and it is distinguished as the most lethal gynecologic cancer. In recent years angiogenesis has been given considerable attention in order to identify targets for developing effective anti-tumor therapies. Several molecules have been reported to promote angiogenesis, such as platelet-derived growth factor (PDGF) and its receptors, the angiopoietin/Tie ligand/receptor system and fibroblast growth factor (FGF). Primarily, VEGF has been identified to play key roles in driving angiogenesis. The above-mentioned molecules are candidate drug targets. Used in combination with other treatments, anti-angiogenic therapies have managed to reduce disease progression. The present review is focused in NGF and its high affinity receptor tyrosine kinase A (TRKA). The expression of VEGF, proliferation and the angiogenesis process in ovarian cancer is importantly induced by NGF, among other molecules.

Nerve growth factor induces vascular endothelial growth factor expression in granulosa cells via a trkA receptor/mitogen-activated protein kinase-extracellularly regulated kinase 2-dependent pathway.

CONTEXT: Acquisition of ovulatory competence by antral follicles requires development of an adequate vascular supply. Although it is well established that ovarian angiogenesis is cyclically regulated by vascular endothelial growth factor (VEGF), the factors controlling VEGF production by ovarian follicles remain largely unknown. Nerve growth factor (NGF) may be one of these factors, because NGF promotes angiogenesis and synthesis of angiogenic factors in other tissues and is produced by human granulosa cells (hGCs). OBJECTIVE: The aim of the study was to determine whether NGF influences the production of VEGF by hGCs and to identify a potential signaling pathway underlying this effect. DESIGN: We conducted a prospective experimental study. PATIENTS: hGCs were obtained from 41 women participating in the in vitro fertilization program of our institution. METHODS: Changes in VEGF mRNA after exposure to NGF were evaluated in cultured hGCs by PCR and real-time PCR. The effect of NGF on VEGF secretion was determined by ELISA. The involvement of trkA, the high affinity NGF receptor, was examined by inhibiting the receptor's tyrosine kinase activity with K252a. The contribution of an ERK1/ERK2-mediated signaling pathway was identified by detecting NGF-dependent phosphorylation of these proteins and by blocking their activity with the inhibitor U0126. RESULTS: NGF promotes VEGF production in cultured hGCs. Blockade of trkA receptor tyrosine kinase activity blocks this effect. NGF induces MAPK-ERK2 phosphorylation, and blockade of this signaling pathway prevents the NGF-induced increase in VEGF production. CONCLUSIONS: NGF promotes ovarian angiogenesis by enhancing the synthesis and secretion of VEGF from hGCs via a trkA- and ERK2-dependent mechanism.

Fxna, a novel gene differentially expressed in the rat ovary at the time of folliculogenesis, is required for normal ovarian histogenesis.

In rodents, the formation of ovarian follicles occurs after birth. In recent years, several factors required for follicular assembly and the growth of the newly formed follicles have been identified. We now describe a novel gene, Fxna, identified by differential display in the neonatal rat ovary. Fxna encodes an mRNA of 5.4 kb, and a protein of 898 amino acids. Fxna is a transmembrane metallopeptidase from family M28, localized to the endoplasmic reticulum. In the ovary, Fxna mRNA is expressed in granulosa cells; its abundance is maximal 48 hours after birth, i.e. during the initiation of follicular assembly. Reducing Fxna mRNA levels via lentiviral-mediated delivery of short hairpin RNAs to neonatal ovaries resulted in substantial loss of primordial, primary and secondary follicles, and structural disorganization of the ovary, with many abnormal follicles containing more than one oocyte and clusters of somatic cells not associated with any oocytes. These abnormalities were not attributable to either increased apoptosis or decreased proliferation of granulosa cells. The results indicate that Fxna is required for the organization of somatic cells and oocytes into discrete follicular structures. As an endoplasmic reticulum-bound peptidase, Fxna may facilitate follicular organization by processing precursor proteins required for intraovarian cell-to-cell communication.

Propylthiouracil-induced hypothyroidism delays apoptosis during the first wave of spermatogenesis

Mammalian germ cell apoptosis plays a key role in controlling the correct number of germ cells supported by Sertoli cells during the first wave of spermatogenesis in mammalian puberty. However, little is known about hormonal factors that could influence the rate of germ cell apoptosis during puberty or adulthood. In this work we evaluate germ cell apoptosis under hypothyroidism induced by goitrogen propylthiouracil (PTU) during the first wave of spermatogenesis. Neonatally administered PTU promoted a delay in the differentiation of Sertoli cells as evaluated by the expression of clusterin using immunohistochemistry and RT-PCR. Clusterin had different expression levels in control and PTU-treated animals, but under both conditions the highest levels were found in 35-day-old rats. In addition, clusterin displayed a cytoplasmic localization in control testes, but appeared located in the nucleus in PTU-treated animals. The wave of apoptosis (determined by caspase activity and quantification of apoptotic cells) characteristic of the first round of spermatogenesis was delayed by at least 10 days in these animals. The expression levels of proapoptotic genes like BAX or BAD were different between control and PTU-treated rats; although in both groups the highest level was found at the same age (days). Thus our results indicate that the characteristic pubertal apoptotic wave during rat spermatogenesis is delayed in neonatal hypothyroid rats.

Estudio experimental de la dosificacion optima de morteros

Los objetivos principales del proyecto son : Determinar las combinaciones mas apropiadas del material para conseguir eficiencia en las mezclas del mortero. Definir sus usos y aplicaciones en nuestro medio. Aportar con metodos de ensayo para sentar las bases de una Norma Boliviana del mortero. Realizar un analisis de control de calidad de los cementos utilizados tres producidos en nuestro medio y uno importado del Peru en lo referente a su resistencia a compresión y al peso de las bolsas. Determinar las dosificaciones mas optimas y economicas en morteros de cemento y arena obteniendo las resistencias especificadas para los morteros de junta.Complementar el estudio realizando mezclas con la adicion de cal en diferentes porporciones y determinar la mas conveniente en cada tipo de mortero. Determinar el efecto que produce la cal en las principales propiedades del mortero. Obtener un analisis comparativo sobre el rendimiento de los diferentes cementos. Realizar un control de calidad de los cementos utilizados, en lo referente a resistencia.