Manejo del HIV/SIDA en el Embarazo

El control obstétrico de las pacientes y sus implicaciones donde se detalla el historial clínico, estudios cervicovaginal para detectar el estadio clínico de la infección por VIH. Esta guía contiene los pasos para el diagnóstico y tratamiento del SIDA en la mujer embarazada. Aunque es importante mencionar el bajo peso en pacientes infectadas, los tratamientos antirretrovirales permiten una mejoría y expectativas en pacientes infectadas por el VIH.

Morbimortalidad fetoneonatal relacionada con diabetes y embarazo y sus varianciones histomorfológicas placentarias / Fetal neonatal morbidity and mortality associated with diabetes and pregnancy and placental histomorphologic variations

El embarazo asociado a hiperglucemia es en nuestra población uno de los factores de riesgo más importantes, así también en la morbi-mortalidad pre y perinatal. La diabetes incluye dos grandes grupos bien conocidos Tipo I insulinodependiente y Tipo II no insulinodependiente, es necesario aclarar que es vital el control permanente del embarazo en pacientes diabéticas. Nuestro trabajo descriptivo y prospectivo se realizó con el estudio anátomo patológico de 120 placentas en pacientes diabéticas confirmadas distribuidas en grupos: Tipo I, Tipo II y Gestacional. Todas fueron atendidas en consultas prenatales y partos en el Hospital Materno Provincial "Felipe Lucini" de la Ciudad de Córdoba, el estudio se realizó en el Servicio de Patología de la Institución, incluyó macroscopia y microscopia; las placentas fueron coloreadas con H/E, PAS y Masson, y los hallazgos fueron relacionados con la clínica y la bibliografía. De los resultados obtenidos concluimos que en las embarazadas estudiadas en nuestro hospital existen diferencias significativas similares a las encontradas en la literatura. Especialmente en lo referido a edad y tipo de diabetes. Se evidenció que excepto en la diabetes I, se manifestaron similitudes en lo referido al avance de cambios coincidentes con tendencia a la cronicidad. En la gestacional hubo mayor incidencia de macrosomía. Nuestros resultados fueron coincidentes en pacientes mal controladas prenatalmente y en disbalance metabólico. Finalmente las alteraciones patológicas placentarias se encontraron en los tres grupos con variación de intensidades. Cabe concluir que no existen lesiones anátomo-patológicas específicas patognomónicas de Diabetes en las placentas de nuestra casuística...

The morphological observations of some lingual papillae in the prenatal and prepuberal stages of red Sokoto goats (Capra hircus) / Observaciones morfológicas de algunas papilas linguales en las etapas prenatal y prepuberal de cabras rojas de Sokoto (Capra hircus)

This study was carried out to investigate the morphological development of the tongue in the foetal and prepubertal stages of Red Sokoto goats by light microscopy. In foetuses of about 50 days, the tongue tissues showed thickening of the epithelium into about 2-3 layers of cells. In fetuses of about 65 days, mesenchymal tissue was observed under the epithelium.Rudiments of some papillae were observed at this time. Collagenous fibre and blood vessels were scant in the lamina propria. In the 80-day-old foetuses, their was further differentiation of the epithelium rudiments into some papillae and this continued to mature until in foetuses of about 90 and 110 days, were early rudiments of taste buds were observed. Evidence of keratinization was apparent in the prepubertal stages.

El objetivo de este estudio fue investigar el desarrollo morfológico de la lengua en las etapas fetal y prepuberal de la cabra roj a de Sokoto por microscopía de luz. En los fetos de alrededor de 50 días, los tejidos linguales mostraron un engrosamiento del epitelio en cerca de 2-3 capas de células. En los fetos de alrededor de 65 días, se observó tejido mesenquimático bajo el epitelio. Rudimentos de algunas papilas se observaron en esta etapa. Fibras colágenas y vasos sanguíneos fueron observados de manera escasa en la lámina propria. En los 80 días de edad fetal, se observó la mayor diferenciación del epitelio con algunos rudimentos de papilas, lo que continuó hasta la maduración de los fetos, alrededor de los 90 y 110 días, donde fueron observados de manera temprana rudimentos de botones gustativos. Evidencia de queratinización fue evidente en las etapas prepuberales.

Diabetes y Embarazo: contribución de la citomorfología en el diagnostico y tratamiento / Diabetes and pregnancy: contribution of the citomorfología in the diagnosis and tratameinto

INTRODUCCIÓN: Considerando que la diabetes mellitus y sus complicaciones constituyen la tercera causa de muerte en los países industrializados,tendencia en crecimiento continuo(30) , que la diabetes gestacional aumenta el riesgo de diversas complicaciones obstétricas (sufrimiento fetal, macrosomía(36), (suerte intrauterina y problemas neonatales,etc. (24)), que éstas pacientes tienen un riesgo aumentado de morbimortalidad fetal y que probablemente el 60 por ciento de las mismas desarrollarán diabetes en los siguientes 15 años después del parto(28),, en el presente trabajo se analiza las subpoblaciones linfocitarias (CD4 y CD8) como método contribuyente en la detección de diabetes gestacional, y como una herramienta del diagnóstico, tratamiento y seguimiento de los casos, tendiendo a hacer prevenciones sobre el sistema inmunológico. OBJETIVOS de la INVESTIGACIÓN: 1)Detectar variaciones en la subpoblación linfocitaria CD4 y CD8 en pacientes embarazadas, analizando su comportamiento durante el embarazo.2)Evaluar al embarazo como un estado precursor de una futura diabética

Expression of dorsal-ventral genes during early development of Rhynchosciara americana embryos

The establishment of dorsal-ventral polarity in Drosophila is a complex process which involves the action of maternal and zygotically expressed genes. Interspecific differences in the expression pattern of some of these genes have been described in other species. Here we present the expression of dorsal-ventral genes during early embryogenesis in the lower dipteran Rhynchosciara americana. The expression of four genes, the ventralizing genes snail (sna) and twist (twi) and the dorsalizing genes decapentaplegic (dpp) and zerknüllt (zen), was investigated by whole-mount in situ hybridization. Sense and antisense mRNA were transcribed in vitro using UTP-digoxigenin and hybridized at 55°C with dechorionated fixed embryos. Staining was obtained with anti-digoxigenin alkaline phosphatase-conjugated antibody revealed with NBT-BCIP solution. The results showed that, in general, the spatial-temporal expression of R. americana dorsal-ventral genes is similar to that observed in Drosophila, where twi and sna are restricted to the ventral region, while dpp and zen are expressed in the dorsal side. The differences encountered were subtle and probably represent a particular aspect of dorsal-ventral axis determination in R. americana. In this lower dipteran sna is expressed slightly later than twi and dpp expression is expanded over the lateral ectoderm during cellular blastoderm stage. These data suggest that the establishment of dorsal-ventral polarity in R. americana embryos follows a program similar to that observed in Drosophila melanogaster.

Impacts of a new transcription factor family: mammalian GCM proteins in health and disease.

GCM proteins constitute a small transcription factor family with a DNA-binding domain exhibiting a novel fold composed of two subdomains rigidly held together by coordination of one of two structural zinc cations. In all known cases, GCM proteins exert the role of master regulators: the prototypical family member determines gliogenesis in Drosophila melanogaster, whereas mammalian GCM proteins orchestrate divergent aspects of development and physiology in placenta, kidney, thymus, and parathyroid gland. Recent data point to an involvement of GCM proteins in different pathological contexts, such as preeclampsia, hyper- or hypoparathyroidism, and parathyroid gland tumors.

PTENless means more.

Recent studies indicate that certain key molecules that are vital for various developmental processes, such as Wnt, Shh, and Notch, cause cancer when dysregulated. PTEN, a tumor suppressor that antagonizes the PI3 kinase pathway, is the newest one on the list. The biological function of PTEN is evolutionarily conserved from C. elegans to humans, and the PTEN-controlled signaling pathway regulates cellular processes crucial for normal development, including cell proliferation, soma growth, cell death, and cell migration. In this review, we will focus on the function of PTEN in murine development and its role in regulating stem cell self-renewal and proliferation. We will summarize the organomegaly phenotypes associated with Pten tissue-specific deletion and discuss how PTEN controls organ size, a fundamental aspect of development. Last, we will review the role of PTEN in hormone-dependent, adult-onset mammary and prostate gland development.

Involvement of cadherins 7 and 20 in mouse embryogenesis and melanocyte transformation.

We have determined the expression profiles of cdh7, and the related cdh20 during development. Both transcripts are found in the adult brain, but only cadherin-20 mRNA was detected during embryogenesis. In mouse embryos, cadherin-20 is synthesized by the forebrain, anterior neural ridge, developing visual system, primitive external granular layer of the cerebellum and a subset of neural crest cells likely to develop into melanoblasts. We found that the other embryonic tissues in which cadherin-20 was synthesized depended on genetic background. Melanoma cell lines contained transcripts for cadherin-7 but not for cadherin-20. The majority of the malignant melanoma cell lines produced N-cadherin (N-Cad) and/or cadherin-7 whereas melanocyte cell lines did not. The converse was observed for E-cadherin (E-Cad). Our data suggest that during development cadherin-20 is a key player in compartmentalization of the neural tube and establishment of neural circuitry. Finally, during oncogenesis, cadherin-7, N-cad and E-cad could be used as an efficient marker set for melanoma.

The TALE homeodomain protein Pbx2 is not essential for development and long-term survival.

Pbx2 is one of four mammalian genes that encode closely related TALE homeodomain proteins, which serve as DNA binding partners for a subset of Hox transcription factors. The expression and contributions of Pbx2 to mammalian development remain undefined, in contrast to the essential roles recently established for family members Pbx1 and Pbx3. Here we report that Pbx2 is widely expressed during embryonic development, particularly in neural and epithelial tissues during late gestation. Despite wide Pbx2 expression, mice homozygous mutant for Pbx2 are born at the expected Mendelian frequencies and exhibit no detectable abnormalities in development and organogenesis or reduction of long-term survival. The lack of an apparent phenotype in Pbx2(-)/(-) mice likely reflects functional redundancy, since the Pbx2 protein is present at considerably lower levels than comparable isoforms of Pbx1 and/or Pbx3 in embryonic tissues. In postnatal bone marrow and thymus, however, Pbx2 is the predominant high-molecular-weight (MW)-isoform Pbx protein detectable by immunoblotting. Nevertheless, the absence of Pbx2 has no measurable effect on steady-state hematopoiesis or immune function in adult mice, suggesting possible compensation by low-MW-isoform Pbx proteins present in these tissues. We conclude that the roles of Pbx2 in murine embryonic development, organogenesis, hematopoiesis, immune responses, and long-term survival are not essential.

Protein inhibitor of activated STAT Y (PIASy) and a splice variant lacking exon 6 enhance sumoylation but are not essential for embryogenesis and adult life.

Protein inhibitor of activated STAT Y (PIASy) is the shortest member of the PIAS family and has been reported to modulate the transcriptional activities of STAT1, lymphoid enhancer factor 1 (LEF-1), and the androgen receptor. PIAS proteins have also been identified as E3 ligases for the small ubiquitin-like modifier (SUMO) proteins. PIASy in particular has been reported to mediate SUMO-2/3 modification of LEF-1, sequestering it into nuclear bodies, and SUMO-1 ligation to c-Myb, modulating its transcriptional activation properties. We have cloned murine Piasy and a splice variant which omits exon 6, containing the nuclear retention PINIT motif. Cell culture studies indicate that both the full length and the splice variant are localized in the nucleus but differentially enhance SUMO ligation. To further understand the functions of PIASy, we have generated PIASy-deficient mice. Surprisingly, Piasy(-/-) mice appear phenotypically normal. Activation of STAT1 is not significantly perturbed in Piasy(-/-) cells, and sumoylation patterns for SUMO-1 or SUMO-3 modification are similar when comparing tissues and embryonic fibroblasts from wild-type and knockout mice. Our study demonstrates that at steady state, PIASy is either dispensable or compensated for by other PIAS family members or by other mechanisms when deleted.

Snail blocks the cell cycle and confers resistance to cell death.

The Snail zinc-finger transcription factors trigger epithelial-mesenchymal transitions (EMTs), endowing epithelial cells with migratory and invasive properties during both embryonic development and tumor progression. During EMT, Snail provokes the loss of epithelial markers, as well as changes in cell shape and the expression of mesenchymal markers. Here, we show that in addition to inducing dramatic phenotypic alterations, Snail attenuates the cell cycle and confers resistance to cell death induced by the withdrawal of survival factors and by pro-apoptotic signals. Hence, Snail favors changes in cell shape versus cell division, indicating that with respect to oncogenesis, although a deregulation/increase in proliferation is crucial for tumor formation and growth, this may not be so for tumor malignization. Finally, the resistance to cell death conferred by Snail provides a selective advantage to embryonic cells to migrate and colonize distant territories, and to malignant cells to separate from the primary tumor, invade, and form metastasis.

Oncofetal splice-pattern of the human H19 gene.

H19 is an imprinted gene that demonstrates maternal monoallelic expression in fetal tissues and in some cancers, and very likely does not code for a protein. H19 is involved in the regulation of cell proliferation, embryonic growth, and differentiation through upstream and downstream cis elements that influence the expression of IGF2, a closely physically linked gene, and also through its RNA involved in metastasis and angiogenic processes. We report the identification of an alternatively spliced variant of H19 RNA that lacks part of exon 1. This variant was detected in human embryonic and placental tissues, but not in bladder or hepatocellular carcinomas. A very low level of this variant was also detected in colon carcinoma. The observed pattern of expression suggests that this splice variant is a developmentally regulated H19 gene transcript.

Transient in utero knockout (TIUKO) of C-MYC affects late lung and intestinal development in the mouse.

BACKGROUND: Developmentally important genes often result in early lethality in knockout animals. Thus, the direct role of genes in late gestation organogenesis cannot be assessed directly. In utero delivery of transgenes was shown previously to result in high efficiency transfer to pulmonary and intestinal epithelial stem cells. Thus, this technology can be used to evaluate late gestation development. RESULTS: In utero gene transfer was used to transfer adenovirus with either an antisense c-myc or a C-MYC ubiquitin targeting protein to knockout out c-myc expression in late gestation lung and intestines. Using either antisense or ubiquitin mediated knockout of C-MYC levels in late gestation resulted in similar effects. Decreased complexity was observed in both intestines and lungs. Stunted growth of villi was evident in the intestines. In the lung, hypoplastic lungs with disrupted aveolarization were observed. CONCLUSIONS: These data demonstrated that C-MYC was required for cell expansion and complexity in late gestation lung and intestinal development. In addition they demonstrate that transient in utero knockout of proteins may be used to determine the role of developmentally important genes in the lungs and intestines.

Effects of triploidy on early human development.

OBJECTIVE: The morphologic features of 18 triploid embryos are described. METHOD: Embryoscopic examination of the embryo in cases of missed abortion before instrumental evacuation from the uterus. Cytogenetic and histologic analysis of the chorionic villi. RESULTS: Seventeen out of 18 triploid embryos showed structural defects on embryoscopic examination. The most common defects were facial anomalies (n = 15), limb abnormalities (n = 13), microcephaly (n = 11) and neural tube defects (n = 10); 3 embryos were classified as growth disorganized. Placenta of 12 grossly abnormal embryos was diagnosed as partial hydatidiform moles on histological examination. CONCLUSIONS: The grossly abnormal development of the embryo observed in 12 partial hydatidiform moles indicate that, in aborted triploid embryos, the presence of two paternal genomes might have both placental and embryonic consequences. Transcervical embryoscopy in cases of missed abortion can serve as a central component in additional studies using molecular determination of parental origin of triploidy to establish the true proportion of diandric triploidy among grossly abnormal triploid embryos.

Loss of cell polarity causes severe brain dysplasia in Lgl1 knockout mice.

Disruption of cell polarity is seen in many cancers; however, it is generally considered a late event in tumor progression. Lethal giant larvae (Lgl) has been implicated in maintenance of cell polarity in Drosophila and cultured mammalian cells. We now show that loss of Lgl1 in mice results in formation of neuroepithelial rosette-like structures, similar to the neuroblastic rosettes in human primitive neuroectodermal tumors. The newborn Lgl1(-/-) pups develop severe hydrocephalus and die neonatally. A large proportion of Lgl1(-/-) neural progenitor cells fail to exit the cell cycle and differentiate, and, instead, continue to proliferate and die by apoptosis. Dividing Lgl1(-/-) cells are unable to asymmetrically localize the Notch inhibitor Numb, and the resulting failure of asymmetric cell divisions may be responsible for the hyperproliferation and the lack of differentiation. These results reveal a critical role for mammalian Lgl1 in regulating of proliferation, differentiation, and tissue organization and demonstrate a potential causative role of disruption of cell polarity in neoplastic transformation of neuroepithelial cells.

The fetoprotein transcription factor (FTF) gene is essential to embryogenesis and cholesterol homeostasis and is regulated by a DR4 element.

The fetoprotein transcription factor (FTF) gene was inactivated in the mouse, with a lacZ gene inserted inframe into exon 4. LacZ staining of FTF+/- embryos shows that the mFTF gene is activated at initial stages of zygotic transcription. FTF gene activity is ubiquitous at the morula and blastocyst stages and then follows expression patterns indicative of multiple FTF functions in fetal development. FTF-/- embryos die at E6.5-7.5, with features typical of visceral endoderm dysfunction. Adult FTF+/- mice are hypocholesterolemic, and express liver FTF at about 40% of the normal level. Overexpression of liver FTF in transgenic mice indicates in vivo that FTF is an activator of CYP7A1. However, CYP7A1 expression is increased in FTF+/- liver. Gene expression profiles indicate that higher CYP7A1 expression is caused by attenuated liver cell stress signaling. Diet experiments support a model where FTF is quenched both by activated c-Jun, and by SHP as a stronger feedback mechanism to repress CYP7A1. A DR4 element is conserved in the FTF gene promoter and activated by LXR-RXR and TR-RXR, qualifying the FTF gene as a direct metabolic sensor. Liver FTF increases in rats treated with thyroid hormone or a high cholesterol diet. The FTF DR4 element tightens functional links between FTF and LXRalpha in cholesterol homeostasis and can explain transient surges of FTF gene activities during development and FTF levels lower than predicted in FTF+/- liver. The FTF-lacZ mouse establishes a central role for FTF in developmental, nutritive, and metabolic functions from early embryogenesis through adulthood.

The development of cytogenetically normal, abnormal and mosaic embryos: a theoretical model.

Assisted reproduction and preimplantation genetic diagnosis (PGD) involve various complicated techniques, each of them with its own problems. However, the greatest problem with PGD for chromosome abnormalities is not of a technical nature but is a biological phenomenon: chromosomal mosaicism in the cleavage stage embryo. Here, we present a hypothetical, quantitative model for the development of chromosomally normal, abnormal and mosaic embryos. The arising of mosaicism in 2-8-cell embryos was described by a binomial probability model on the occurrence of mitotic events inducing chromosomal changes in the blastomeres. This model converted the 'mean' rate of mosaicism found in cross-sectional studies (60%) into an equal rate of mosaic embryos at arrival at the 8-cell stage (59.8%). The disappearance of > 90% of the mosaic embryos or the mosaicism itself from surviving embryos during the morula stage was explained by mitotic arrest of most of the mitotically changed cells under increasing cell cycle control. In our model, 25.9 and 14.3% of the embryos at the 8-cell stage are normal and abnormal respectively. The remaining 59.8% of the embryo shows mosaicism: 34.6% of abnormal/normal cells and 25.2% of abnormal/abnormal cells. The high proportion of abnormal and mosaic embryos together explains the high rate of abnormal laboratory findings in PGD for chromosomal abnormalities and aneuploidy screening. The poor representation of a 1- or 2-cell biopsy for the 7- or 6-cell post-biopsy embryo in the case of mosaicism explains the high rate of false-negative and false-positive results.

Tid1, a cochaperone of the heat shock 70 protein and the mammalian counterpart of the Drosophila tumor suppressor l(2)tid, is critical for early embryonic development and cell survival.

Tid1 is the mammalian counterpart of the Drosophila tumor suppressor Tid56 and is also a DnaJ protein containing a conserved J domain through which it interacts with the heat shock protein 70 (Hsp70) family of chaperone proteins. We generated a Tid1 conditional mutation in mice, and the subsequent global removal of the Tid1 protein was achieved by crossing these conditional knockout mice with general deletor mice. No Tid1(-/-) embryos were detected as early as embryonic day 7.5 (E7.5). Nonetheless, Tid1-deficient blastocysts were viable, hatched, formed an inner cell mass and trophectoderm, and implanted (E4.5), suggesting that the homozygous mutant embryos die between E4.5 and E7.5. To assess the function of Tid1 in embryonic cells, mouse embryonic fibroblasts with the homologous Tid1 floxed allele were produced. Tid1 removal in these cells led to massive cell death. The death of Tid1-deficient cells could be rescued by ectopic expression of wild-type Tid1 but not by expression of the Tid1 protein that had a mutated J domain and was thus incapable of binding to Hsp70. We propose that Tid1 is critical for early mammalian development, most likely for its function in sustaining embryonic-cell survival, which requires its association with Hsp70.

Histone H3-K9 methyltransferase ESET is essential for early development.

Methylation of histone H3 at lysine 9 (H3-K9) mediates heterochromatin formation by forming a binding site for HP1 and also participates in silencing gene expression at euchromatic sites. ESET, G9a, SUV39-h1, SUV39-h2, and Eu-HMTase are histone methyltransferases that catalyze H3-K9 methylation in mammalian cells. Previous studies demonstrate that the SUV39-h proteins are preferentially targeted to the pericentric heterochromatin, and mice lacking both Suv39-h genes show cytogenetic abnormalities and an increased incidence of lymphoma. G9a methylates H3-K9 in euchromatin, and G9a null embryos die at 8.5 days postcoitum (dpc). G9a null embryo stem (ES) cells show altered DNA methylation in the Prader-Willi imprinted region and ectopic expression of the Mage genes. So far, an Eu-HMTase mouse knockout has not been reported. ESET catalyzes methylation of H3-K9 and localizes mainly in euchromatin. To investigate the in vivo function of Eset, we have generated an allele that lacks the entire pre- and post-SET domains and that expresses lacZ under the endogenous regulation of the Eset gene. We found that zygotic Eset expression begins at the blastocyst stage and is ubiquitous during postimplantation mouse development, while the maternal Eset transcripts are present in oocytes and persist throughout preimplantation development. The homozygous mutations of Eset resulted in peri-implantation lethality between 3.5 and 5.5 dpc. Blastocysts null for Eset were recovered but in less than Mendelian ratios. Upon culturing, 18 of 24 Eset(-/-) blastocysts showed defective growth of the inner cell mass and, in contrast to the approximately 65% recovery of wild-type and Eset(+/-) ES cells, no Eset(-/-) ES cell lines were obtained. Global H3-K9 trimethylation and DNA methylation at IAP repeats in Eset(-/-) blastocyst outgrowths were not dramatically altered. Together, these results suggest that Eset is required for peri-implantation development and the survival of ES cells.

Disruption of forkhead transcription factor (FOXO) family members in mice reveals their functional diversification.

Genetic analysis in Caenorhabditis elegans has uncovered essential roles for DAF-16 in longevity, metabolism, and reproduction. The mammalian orthologs of DAF-16, the closely-related FOXO subclass of forkhead transcription factors (FKHR/FOXO1, FKHRL1/FOXO3a, and AFX/FOXO4), also have important roles in cell cycle arrest, apoptosis and stress responses in vitro, but their in vivo physiological roles are largely unknown. To elucidate their role in normal development and physiology, we disrupted each of the Foxo genes in mice. Foxo1-null embryos died on embryonic day 10.5 as a consequence of incomplete vascular development. Foxo1-null embryonic and yolk sac vessels were not well developed at embryonic day 9.5, and Foxo1 expression was found in a variety of embryonic vessels, suggesting a crucial role of this transcription factor in vascular formation. On the other hand, both Foxo3a- and Foxo4-null mice were viable and grossly indistinguishable from their littermate controls, indicating dispensability of these two members of the Foxo transcription factor family for normal vascular development. Foxo3a-null females showed age-dependent infertility and had abnormal ovarian follicular development. In contrast, histological analyses of Foxo4-null mice did not identify any consistent abnormalities. These results demonstrate that the physiological roles of Foxo genes are functionally diverse in mammals.