Permanent germinal epithelium and reproductive cycle of Atractosteus tropicus (Lepisosteiformes: Lepisosteidae) males, Tabasco, Mexico / Epitelio germinal permanente y ciclo reproductivo en machos de Atractosteus tropicus (Lepisosteiformes: Lepisosteidae) Tabasco, México

Abstract:The tropical gar A. tropicus plays an important ecological role as it regulates other fish stocks in different water bodies in Southeastern México. Nevertheless, wild populations are declining, and one conservation alternative is the aquaculture production and basic knowledge of reproductive biology; for males, this requires the study of germ and somatic structures of testes, to characterize the reproductive cycle, and to provide basic knowledge for exploitation and conservation models and strategies. With this aim, a total of 24 males with an average sL = 47.2 cm were collected from wild populations from the Laguna Pomposú, municipality of Jalpa de Mendez (18°19' - 93°01'12" W), Tabasco, Mexico. Fish were collected with a trawl net and were transported live to the Tropical Aquaculture Laboratory, División Académica de Ciencias Biológicas (DACBiol), Universidad Juárez Autónoma de Tabasco (UJAT). Males were killed by prolonged immersion in MS222. Testes samples were collected from each specimen and were processed using the standard histological procedures, that consisted of dehydration in an ascending ethanol series, xylol, embedding in paraffin, sectioning at 7 µm, and staining with hematoxylin-eosin (HE). The diameter of 20 seminiferous tubules (Dst), height of germinal epithelium (Hge), gonadosomatic index (GSI) and gonad volume (gV) were determined monthly. Based on morphometric and morpho-physiological characteristics, the testes consisted of a network of anastomosed tubules with non-restricted cystic spermatogenesis, and a permanent germinal epithelium. This is the first report of a permanent germinal epithelium in A. tropicus. Five reproductive classes were histologically identified: Class I Regressed; Class II Early Maturation; Class III Mid Maturation; Class IV Late Maturation; Class V Regression. Monthly GSI, gV and Dst values were lower in January and February, the testis showed spermatozoa remains and a regenerating discontinuous germinal epithelium. In March spermiogenesis increased and proliferation of spermatogonia decreased. Male tropical gar followed a seasonal reproductive cycle, indicated by the monthly variation of the reproductive classes and the reproductive season processes observed, and for which temperature and rainfall seem to stimulate reproductive activity and spermiation. Rev. Biol. Trop. 64 (4): 1597-1609. Epub 2016 December 01.

Resumen:A. tropicus tiene un papel ecológico importante, como regulador de otras poblaciones de peces, en los cuerpos de agua de México, pero sus poblaciones silvestres se reducen. Una alternativa de conservación es el cultivo, el cual requiere caracterizar el ciclo reproductivo por medio del estudio de estructuras germinales y somáticas de los testículos, conocimientos que son básicos para formar modelos de aprovechamiento y conservación. Se capturaron mensualmente tres machos sexualmente maduros (N = 24), con un promedio de sL = 47.2 cm en Laguna de Pomposú, Jalpa de Méndez (18°19´59" N - 93°01´12" W), Tabasco, México, de octubre 2009 a septiembre 2010. La técnica de captura fue red de arrastre, se transportaron vivos al laboratorio de acuicultura tropical, DACBiol, UJAT. Los machos recolectados se sacrificaron con baños de inmersión en sobredosis de MS222, los testículos se procesaron para análisis histológico. Se determinó mensualmente el diámetro de 20 túbulos seminíferos (Dst), altura de epitelio germinal (Hge), índice gonadosomático (GSI) y volumen de gónada (gV). Características morfo-fisiológicas del testículo muestran que está constituido de una red de túbulos anastomosados con espermatogénesis quística no restringida, y un epitelio germinal permanente, de nuestro conocimiento es la primera vez que se reporta este tipo de epitelio en Holostei (Lepisosteiformes: Lepisosteidae). Se identificaron cinco clases reproductivas: Clase I Recrudescencia, Clase II Madurez temprana, Clase III Madurez intermedia, Clase IV Maduración tardía, Clase V Regresión, que al contrastarlo con el valor mensual de los indicadores sexuales "GSI, gV, Dst" muestra un patrón de variación; durante enero-febrero se presentan valores bajos, se observa un epitelio germinal discontinuo en regeneración; durante marzo se incrementa la proliferación de espermatogonias disminuyendo la espermatogénesis. Los machos de A. tropicus muestran una actividad reproductora estacional anual, explicado por las variaciones mensuales de los indicadores reproductores, donde la temperatura y la precipitación parecen tener un papel importante como factores que estimulan la actividad reproductora y por tanto la espermiación.

El Campus Virtual de Salud Pública: seis años de formar recursos humanos en México / Virtual Campus of Public Health: six years of human resources education in Mexico

Este trabajo muestra, desde el punto de vista de la normatividad de la Organización Panamericana de la Salud (OPS), el proceso de gestación, la metodología de implementación y los resultados obtenidos de la iniciativa de formación de recursos humanos en salud vía e-learning a través del Campus Virtual de Salud Pública de la Universidad de Guadalajara, México, a seis años de su inicio. Se trata de un informe especial del trabajo realizado por el comité institucional del campus virtual en la región occidental de México para generar un portal de Internet que se ajustara a los lineamientos del Modelo Estratégico establecido por el Nodo México y la OPS para la Región de las Américas. Este Campus Virtual inició sus actividades en el año 2007. Su filosofía es el uso de software libre y la colaboración entre instituciones. El nodo fue implementado en un año y ha logrado capacitar a más de 500 profesionales de la salud a través de cursos virtuales, su plataforma educativa y un repositorio de recursos virtuales de aprendizaje con interoperabilidad con los repositorios de México y de la Región de las Américas. El comité del Campus Virtual de la Universidad de Guadalajara ha intentado respetar lo más posible al modelo propuesto, lo que ha permitido cumplir la mayoría de los objetivos fijados en el plan de trabajo inicial, aunque ha enfrentado una serie de dificultades administrativas y de motivación de sus integrantes.

This paper discusses the gestation process, implementation methodology, and results obtained from the initiative to use e-learning to train human resources for health, six years after the launch of the Virtual Campus of Public Health of the University of Guadalajara (Mexico); the discussion is framed by Pan American Health Organization (PAHO) standards and practices. This is a special report on the work done by the institutional committee of the Virtual Campus in western Mexico to create an Internet portal that follows the guidelines of the strategic model established by Nodo México and PAHO for the Region of the Americas. This Virtual Campus began its activities in 2007, on the basis of the use of free software and institutional collaboration. Since the initial year of implementation of the node, over 500 health professionals have been trained using virtual courses, the node's educational platform, and a repository of virtual learning resources that are interoperable with other repositories in Mexico and the Region of the Americas. The University of Guadalajara Virtual Campus committee has followed the proposed model as much as possible, thereby achieving most of the goals set in the initial work plan, despite a number of administrative challenges and the difficulty of motivating committee members.

Developmental changes in cell proliferation and apoptosis in the normal duck bursa of Fabricius

The aim of this work was to investigate developmental changes in cell proliferation and apoptosis in normal duck bursa of Fabricius using flow cytometry and immunohistochemistry. Studies were carried out on Tianfu ducks on days 24 and 27 of embryogenesis (E24 and E27) along with days 20, 70, and 200 of postnatal development (P20, P70, and P200). Results showed that the percentage of G0/G1 bursa cells significantly increased between E24 and P200 while the percentage of cells in the S phase or G2 + M phase as well as the proliferating index obviously decreased during the same period. Proliferation cell nuclear antigen was detected in lymphocyte and interfollicular epithelium. The proliferative lymphocyte density tended to decrease from E24 to P200. Apoptotic bodies in macrophages, free apoptotic bodies, or nuclei with condensed chromatin in lymphocytes in follicles were identified by transferase-mediated dUTP nick-end labeling. Both flow cytometry and microscopic analysis reveal that the proportion of apoptotic cells and apoptotic lymphocyte density increased from E24 to P20, fell on P70, then rose again on P200. Our foundings demonstrate that cell proliferation decreases and apoptosis increases with age. These changes may account for duck bursa development and involution.

An outcome analysis and long-term viability of cryopreserved cultured epidermal allografts: assessment of the conservation of transplantable human skin allografts

PURPOSE: To assess the viability of cultured epithelium and preserved by freezing for periods varying from one month to one year. METHODS: Samples of cultured epithelium were incubated in cryoprotectant medium (Group A), packed in aluminum envelopes and packed in polystyrene boxes. The boxes were subjected to a temperature of-70ºC. After freezing for a period of time ranging from one to 12 months, cultured epithelial samples were assessed for their viability by vital staining (Trypan blue) and metabolic analysis based on glucose consumption and lactate production. Samples of not frozen cultured epithelium (Group B) were also tested for viability and the results obtained were used as comparison parameter for the variation of viability. RESULTS: Statistical analysis between the group A and B indicate that the mean age of the donors (p=0.51) and the culture time (p=1.18) showed no statistical difference. In 30 days we obtained 37% of the original viability of cultured epithelium, 25% at six months and one year, less than 15%. This trend was confirmed statistically with a reduction of approximately 1.8% of the original viability epithelium cultured every 30 days of storage. In the analysis by lactate production, similar results were observed. In the analysis by the glucose consumption results were not significant. The viability indices show statistically significant difference between the group A and B (p<0.0001). CONCLUSIONS: Although cryopreserved cultured epithelium showed significant reduction of viability, all samples remained viable. It was also found that the viability of cryopreserved cultured epithelial decreased as a function of storage time.

Avaliação das variações de espessura de epitélio em queilite actínica comparadas ao grau de displasia epitelial e à expressão imuno-histoquímica da proteína p53 mutada / Evaluation of epithelial thickness variations in actinic cheilitis compared to the degree of epithelial dysplasia and immunohistochemical expression of mutated p53 protein

O carcinoma epidermoide de lábio é precedido por uma desordem potencialmente maligna, a queilite actínica. Histologicamente o epitélio da lesão é caracterizado pela presença de hiperqueratose ou hiperparaqueratose, presença de displasia epitelial e, muitas vezes, pela presença de variações de espessura de epitélio, sendo estas a acantose e a atrofia. O desenvolvimento da queilite actínica está ligado a exposição excessiva a luz solar que contém radiação UV, esta pode produzir mutações com assinatura UV no DNA através de um fenômeno conhecido como fotocarcinogênese. As mutações com assinatura UV estão presentes no gene supressor de tumor TP53, quando este gene se encontra mutado, muitas vezes, ele codifica uma proteína que sofre um dobramento e exibe uma conformação específica. Esta pesquisa pretendeu determinar, à partir de 458 casos de queilite actínica, a porcentagem de casos que apresentaram espessura normal de epitélio, acantose ou atrofia, relacionando os graus de displasia epitelial, segundo o sistema da OMS e o sistema binário e também relacionar estas variações de espessura com a presença de proteína p53 mutada através de análise imuno-histoquímica. O que se observou foi que 20,31% dos casos apresentavam espessura normal de epitélio, 38,65% apresentavam acantose e 41,05% apresentavam atrofia. Não houve relevância estatística quando a variação de espessura foi comparada com a proteína p53 mutada. Concluiu-se que há uma dificuldade real em determinar quais queilites actínicas evoluirão para uma lesão maligna, por tanto, o acompanhamento clínico desses pacientes tem caráter essencial.

Squamous cell carcinoma of the lip is preceded by a potentially malignant disorder, the actinic cheilitis. Histologically the lesion is characterized by the presence of hyperkeratosis or hyperparakeratosis, the presence of dysplasia, and often, the presence of variations in thickness of the epithelium, which is acanthosis or atrophy. The development of actinic cheilitis is linked to the excessive exposure to sunlight containing UV radiation, this can produce UV signature mutations through the photocarcinogenesis. UV signature mutations are present in the tumor supressor gene TP53, when this gene is mutated, often it encodes a protein that undergoes bending and displays a specific conformation. This research intended to determine, from 458 cases of actinic cheilitis, the percentage of the cases whitch had normal thickness of the epithelium, acanthosis or atrophy and relate to the degree of dysplasia, and relates them to the presence of mutated p53 protein through immunohistochemical analysis. There was noted that 20.31% of cases showed normal thickness of the epithelium, 38.65% had acanthosis and 41.05% had atrophy. There was no statistical significance when the thickness variation was compared to the mutated p53, it was concluded that there is a real difficulty to determining which actinic cheilitis evolve to a malignant lesion, and therefore, clinical monitoring of these patients is of essential nature.

Epithelial-Mesenchymal Transitions of Bile Duct Epithelial Cells in Primary Hepatolithiasis

The purpose of this study was to explore the role of epithelial-mesenchymal transition in the pathogenesis of hepatolithiasis. Thirty-one patients with primary hepatolithiasis were enrolled in this study. Expressions of E-cadherin, alpha-catenin, alpha-SMA, vimentin, S100A4, TGF-beta1 and P-smad2/3 in hepatolithiasis bile duct epithelial cells were examined by immunohistochemistry staining. The results showed that the expressions of the epithelial markers E-cadherin and alpha-catenin were frequently lost in hepatolithiasis (32.3% and 25.9% of cases, respectively), while the mesenchymal markers vimentin, alpha-SMA and S100A4 were found to be present in hepatolithiasis (35.5%, 29.0%, and 32.3% of cases, respectively). The increased mesenchymal marker expression was correlated with decreased epithelial marker expression. The expressions of TGF-beta1 and P-smad2/3 in hepatolithiasis were correlated with the expression of S100A4. These data indicate that TGF-beta1-mediated epithelial-mesenchymal transition might be involved in the formation of hepatolithiasis.

Morphology and histological annual changes of the oviduct of chaetophractus villosus (Mammalia, Xenarthra, Dasypodidae) / Morfología y cambios histológicos anuales del oviducto de Chaetophractus villosus (Mammalia, Xenarthra, Dasypodidae)

The morphological features of the oviduct in the armadillo Chaetophractus villosus (Desmarest, 1804) were studied. In the simple columnar epithelium, ciliated cells, secretory cells, and cells of the bottom of the folds are described. The most remarkable findings are the increase in number of ciliated cells, when present, from the fimbriae to the uterus, being the isthmus practically lined by ciliated cells, and that secretory cells are more abundant in the apical zone of the ampulla and fimbriae, than in the isthmus. Morphological changes along the year in the different portions are described.

Se estudiaron las características morfológicas del oviducto del armadillo Chaetophractus villosus (Desmarest, 1804). En el epitelio, columnar simple, se describen células ciliadas, secretoras y células del fondo de los pliegues. Las células ciliadas, cuando están presentes, aumentan en número desde las fimbrias hacia el útero, estando el istmo prácticamente tapizado por células ciliadas, las células secretoras son más abundantes en la zona apical de la ampolla y en las fimbrias, que en el istmo. Se describen los cambios morfológicos en las diferentes porciones a lo largo del año.

The mechanism of gentisic acid-induced relaxation of the guinea pig isolated trachea: the role of potassium channels and vasoactive intestinal peptide receptors

We examined some of the mechanisms by which the aspirin metabolite and the naturally occurring metabolite gentisic acid induced relaxation of the guinea pig trachea in vitro. In preparations with or without epithelium and contracted by histamine, gentisic acid caused concentration-dependent and reproducible relaxation, with mean EC50 values of 18 æM and Emax of 100 percent (N = 10) or 20 æM and Emax of 92 percent (N = 10), respectively. The relaxation caused by gentisic acid was of slow onset in comparison to that caused by norepinephrine, theophylline or vasoactive intestinal peptide (VIP). The relative rank order of potency was: salbutamol 7.9 > VIP 7.0 > gentisic acid 4.7 > theophylline 3.7. Gentisic acid-induced relaxation was markedly reduced (24 + or - 7.0, 43 + or - 3.9 and 78 + or - 5.6 percent) in preparations with elevated potassium concentration in the medium (20, 40 or 80 mM, respectively). Tetraethylammonium (100 æM), a nonselective blocker of the potassium channels, partially inhibited the relaxation response to gentisic acid, while 4-AP (10 æM), a blocker of the voltage potassium channel, inhibited gentisic acid-induced relaxation by 41 + or - 12 percent. Glibenclamide (1 or 3 æM), at a concentration which markedly inhibited the relaxation induced by the opener of ATP-sensitive K+ channels, levcromakalim, had no effect on the relaxation induced by gentisic acid. Charybdotoxin (0.1 or 0.3 æM), a selective blocker of the large-conductance Ca2+-activated K+ channels, caused rightward shifts (6- and 7-fold) of the gentisic acid concentration-relaxation curve. L-N G-nitroarginine (100 æM), a NO synthase inhibitor, had no effect on the relaxant effect of gentisic acid, and caused a slight displacement to the right in the relaxant effect of the gentisic acid curve at 300 æM, while methylene blue (10 or 30 æM) or ODQ (1 æM), the inhibitors of soluble guanylate cyclase, all failed to affect gentisic acid-induced relaxation. D-P-Cl-Phe6,Leu17[VIP] (0.1 æM), a VIP receptor antagonist, significantly inhibited (37 + or - 7 percent) relaxation induced by gentisic acid, whereas CGRP (8-37) (0.1 æM), a CGRP antagonist, only slightly enhanced the action of gentisic acid.

Comparative and morphologic evaluation of aspirin and ranitidine effects on wound repair of gastric mucosa

Esta investigación se realizó con el objetivo de verificar los efectos comparativos de la aspirina y de la ranitidina en la recomposición de la mucosa gástrica después de una agresión quirúrgica. La incisión quirúrgica, dentro de patrones definidos, fue efectuada en la mucosa gástrica de 12 ratones divididos en 3 grupos: placebo (PG), aspirina (AG) y ranitidina (RG). Las paredes gástricas y abdominal fueron suturadas en dos planos. A los ratones de los grupos PG, AG y RG se le administraron diariamente, por vía intragástrica, 1 ml de agua destilada, 250 mg/ka de aspirina y 25 mg/kg de ranitidina, respectivamente. Los estudios de la recomposición de la incisión en la mucosa en el 7º día pós-operatorio, a través de las microscopías de luz y electrónica de barrido, nos mostraron una reepitelización del tejido de granulación y de las células del epitelio que envuelven los bordes de la incisión quirúrgica. La importancia de las alteraciones fue observada de forma decreciente en la mucosa gástrica en los grupos AG, PG y RG

Expressäo de laminina no germe dental do primeiro molar de ratos em desenvolvimento / Expression of laminin in the germ of the first molar tooth of developing rats

A regulaçäo da diferenciaçäo e do desenvolvimento dos vários tecidos que formam o germe dental ainda näo está bem estabelecida. Tem-se atribuído à membrana basal e a seus componentes esse papel. O objetivo deste trabalho foi investigar a distribuiçäo de laminina no germe dental do primeiro molar de ratos, utilizando um anticorpo policlonal antilaminina. A análise imunohistoquímica mostrou que a lamina é expressa de forma contínua nas membranas basais dos epitélios interno e externo do orgäo do esmalte, nos pequenos vasos sangüíneos e nas fibrilas nervosas localizadas na papila e no folículo dentário de ratos recém-nascidos. Nas regiöes em que ocorreu diferenciaçäo de células mesenquimais em odontoblastos e de células do epitélio interno em ameloblastos, a expressäo de laminina näo foi mais observada. Essas mudanças sugerem que a expressäo de laminina na membrana basal está relacionada com a diferenciaçäo celular e com a secreçäo de matriz orgânica

El papel de los contactos celulares en la recuperación de canales de membranas de células epiteliales / The role of cellular contacts in the recuperation of ion channels of epithelial cell membranes

Las corrientes catiónicas en células MDCK son casi exclusivamente debidas a canales de K+. El tratamiento con tripsina-EDTA destruye la mayoría de estos canales. Cuando son resembradas, los canales se recuperaron por medio de un proceso que requiere síntesis de proteínas y de mensajero. El presente trabajo demuestra que la recuperación requiere del contacto entre las células y concentraciones normales de Ca2+ (1.8 mM). Las células en monocapas confluentes en presencia de 1.8 mM de Ca2+ exhiben corrientes de K+ de 343 ñ 82 pA; las confluentes en un medio con bajo Ca2+ tienen sólo 90 ñ 12 pA (27 por ciento del control); y las que no establecen contactos celulares o que son incubadas a su confluencia pero en Ca2+ extracelular normal, tienen 104 ñ 21 pA (31 por ciento del control), con base en estos resultados concluimos que la expresión de canales de K+ depende de contactos celulares y presencia de Ca2+ normal. Es probable, entonces que esta expresión este mediada por uvomorulina

Patofisiología de la disminución del flujo aéreo en fumadores: El papel de las vías aéreas pequeñas y del enfisemia pulmonar / Pathogenesis of the airflow limitation in smokers: the roles of small airways and pulmonary emphysema

La limitación del flujo aéreo en los fumadores es la característica funcional más importante que además condiciona su pronóstico. En términos generales, el enfisema y la enfermedad de la vía aérea pequeña son los eventos anatomopatológicos responsables de dicha obstrucción. En este trabajo se hizo una revisión detallada de la participación de la vía aérea pequeña en la patogénesis de la disminución del flujo aéreo en los pacientes con EPOC.

Comparaçäo do estesiômetro de Semmes-Weinsttein com o de Cochet & Bonnet na avaliaçäo da sensibilidade da córnea / Comparison between the Semmes-Weinstein and the Cochet & Bonnet esthesiometers in the evaluation of corneal sensibility

A sensibilidade da córnea provoca um dos reflexos de defesa mais eficientes do corpo humano. Ela pode estar diminuída em numerosas condiçöes locais e sistêmicas. O estesiômetro corneano constituido de nailon mais popular é o de Cochet & Bonnet (ECB). O estesiômetro de Semmes-Weinstein (ES-W) é também constituido de nailon, e tem sido usado para medir a sensibilidade da pele. Este último estesiômetro pode produzir forças até monofilamentos fixados perpendicularmente a um cabo de plástico. Decidiu-se entäo, avaliar oo ES-W no estudo da sensibilidade da córnea e comparar os limiares obtidos com este estesiômetro com os limiares obtidos com o ECB. A fragilidade epitelial foi também testada com ambos os estesiômetros. Foram examinados 276 olhos de 146 pacientes entre 15 e 59 anos de idade. Estes pacientes foram divididos em 3 grupos. O grupo I (62 indivíduos) e o grupo 2 (62 indivíduos foram subdivididos em 2 subgrupos, de acordo com a idade, até 40 anos e maiores de 40 anos. O grupo I teve a sensibilidade da córnea avaliada primeira com o ECB e em seguida com o ES-W. No grupo 2, invertemos esta ordem. No grupo 3 (22 indivíduos) testou-se a fragilidade epitelial. No OD, usou-se o ECB e, no OE, o ES-W. A correlaçäo entre os 2 estesiômetros foi para a regiäo central da córnea do olho direito de 0,50 para o grupo I e de 0,72 para o grupo 2. O ES-W é prático e fornece resultados semelhantes aos do ECB na avaliaçäo da sensibilidade da córnea. Ambos os estesiômetros podem causar lesäo de córnea na avaliaçäo da sensibilidade de córnea

Sistema de medidas automáticas de áreas de úlceras de córnea / Automatic measure systems of corneal ulcer area

Úlceras1 são feridas na córnea com alta potencialidade de cegueira, pois mesmo curadas tendem a tirar a transparência. Nos países em desenvolvimento e de natureza agrícola elas respondem por cerca de 10 por cento das causas de cegueira. Uma das formas do clínico acompanhar o tratamento delas é pela estimativa subjetiva de sua dimensão. Evoluções favoráveis tedem a promover uma diminuição da ferida. No entanto, as medidas existentes para essa estimativa são rudimentares. Assim, este trabalho apresenta o desenvolvimento de um sistema de captação de imagem em Lâmpada de Fenda (instrumento utilizado para analisar as córneas) e um "software" dedicado para o delineamento e cálculo da área úlcerada para ser implementado num hospital público (400 pacientes por semana). Inserido no contexto será desenvolvida uma biblioteca de arquivamento e análise de imagens de enfermidades corneanas.

Corneal Ulcer is a very common disease in agricultura! countries and it is responsible for 10% of the blindness causes. One of the main aspects to be observed in these cases is the increasing or decreasing of the affected area. We have been developing an automatic optical system in order to evaluate the affected area (the ulcer) to be implemented in a public hospital (400 patients per week are analyzed). The optical system is implemented in a Slit Lamp and connected to a CCD detector. The image is displayed in a PC monitor by a commercial frame grabber anda dedicated software for detennining the area ofthe ulcer has been developed.

Epithelial healing time and rate of the cornea after myopic epikeratoplasty

This study was performed to investigate the corneal epithelial healing time and rate according to the method for promoting the reepithelization after myopic epikeratoplasty. A prospective study was conducted on 30 myopic epikeratoplasties which were divided into 3 groups according to the method for promoting the epithelial healing. The groups consisted of 10 eyes with pressure patches, 10 eyes with Acuvue(R) disposable contact lens (CL) and 10 eyes with SeeQuence(R) disposable CL. The cornea epithelial healing time were 3.4, 3.5 and 3.4 postoperative days for the pressure patch, Acuvue(R) CL and SeeQuence(R) CL groups, respectively. The corneal epithelial healing rates during postoperative 1, 2, and 3 days were 0.33, 0.78, and 0.44 mm2/hour for the pressure patch group; 0.24, 0.92 and 0.37 mm2/hour for the Acuvue(R) CL group; and 0.30, 0.79 and 0.38 mm2/hour for the SeeQuence(R) CL group. These results suggest that a disposable contact lens may not hinder epithelial healing compared with a pressure patch.

Kinetics of spermatogenesis in megachiropteran bat, Rousettus leschenaulti (Desmarset): seminiferous epithelial cycle, frequency of stages, spermatogonial renewal and germ cell degeneration.

The paper describes in detail the cytomorphology of different types of germ cells, the 10 typical cellular associations or stages of the cycle of seminiferous epithelium (CSE), frequency of appearance of these stages, pattern of spermatogonial stem cell renewal and per cent degeneration of various germ cells in R. leschenaulti. Of the 14 steps of spermiogenesis (stained with PAS-haematoxylin) the first 10 were associated with the stages I-X, whereas, the remaining were found in association with one of the first six stages. The frequency of appearance of the various stages ranged from 3.84% (stage V) to 19.84% (stage I). These observations indicate that stage V is of shortest duration and stage I is of the longest duration in the bat. Five types of spermatogonia (A1, A2, A3, In and B) were identified based on their shape, size and nuclear morphology. Type A spermatogonia are oval with a large nucleus containing 1 or 2 nucleoli. The chromatin showed progressive condensation from A1 to A3 so that the latter appeared darkest among all the A type spermatogonia. The In type derived from A3 are smaller but appear darker than A3 due to heterochromatin crusts along the inner border of the nucleus. The B type spermatogonia derived from In are round and possess single nucleolus. The B type spermatogonia divided mitotically before entering meiosis or the actual production of the primary spermatocytes. The various spermatogonia divided mitotically at fixed stages of the cycle giving rise to their next generations.(ABSTRACT TRUNCATED AT 250 WORDS)

A propósito da renovaçäo do epitélio intestinal: II. Fatores intraluminais, sistêmico, influências neurovasculares e adaptaçäo pós-operatório, no cólon / Renewal of colonic intestinal epithelium: II. Action of intraluminal, systemic, neurovascular factors and postoperative adaptation

Vários estudos têm sido realizados com o objetivo de melhor determinar os múltiplos mecanismos envolvidos no precesso de renovaçäo do epitélio intestinal. Alguns fatores säo conhecidamente participantes deste fenômeno. Entretanto, existem inúmeras pesquisas com resultados contraditórios sobre o assunto, especialmente no que se refere ao cólon. Os autores fazem uma análise comparativa da participaçäo dos principais fatores atuantes no processo da renovaçäo epitelial colônica, associando condiçöes fisiológicas e/ou patológicas. O objetivo é para tentar elucidar algumas dúvidas, entre as inúmeras existentes, para melhor compreensäo de certas entidades mórbidas que, de maneira contumaz, assentam-se no intestino grosso

Interleucinas, interferón y desarrollo del epitelio endometrial / Interleukins, interferon and endometrial epithelium development

La regulación del crecimiento del epitelio endometrial por citocinas ha recibido escasa atención bibliográfica. Este artículo revisa los efectos de estos factores de crecimiento sobre el endometrio con la finalidad de ampliar el entendimiento de los mecanismos autócrinos, parácrinos y sistémicosinvlucrados en el crecimietno del epitelio endometrial y en el desarrollo de tumores epiteliales del endometrio humano.