Ricardo R. Guerra

Progranulin is a stress-response factor in fibroblasts subjected to hypoxia and acidosis.

The growth factor progranulin (granulin–epithelin precursor, PC-derived growth factor or acrogranin) regulates proliferation and migration and is implicated in cancer, development, wound repair and neurodegenerative diseases. Under most conditions fibroblasts do not express progranulin in vivo, however its expression is activated following wounding. We hypothesised that progranulin is part of a fibroblast stress response. Fibroblasts in culture were exposed to two physiologically and clinically relevant microenvironmental stresses; hypoxia (1% oxygen) and acidosis, both of which increase progranulin expression. The greatest increases occurred when hypoxia and acidosis were combined. Increased progranulin expression is not a direct response to apoptosis since it occurred under conditions of pH and hypoxia under which cell viability remained high. Low concentrations of progranulin (2 nM) protected fibroblasts from apoptosis induced by extreme acidosis (pH 5.0 and 4.0). We propose that progranulin is part of a fibroblast stress response and is cytoprotective to acidotic stress.

Modulation of extracellular matrix by nutritional hepatotrophic factors in thioacetamide-induced liver cirrhosis in the rat.

Nutritional substances associated to some hormones enhance liver regeneration when injected intraperitoneally, being denominated hepatotrophic factors (HF). Here we verified if a solution of HF (glucose, vitamins, salts, amino acids, glucagon, insulin, and triiodothyronine) can revert liver cirrhosis and how some extracellular matrices are affected. Cirrhosis was induced for 14 weeks in 45 female Wistar rats (200 mg) by intraperitoneal injections of thioacetamide (200 mg/kg). Twenty-five rats received intraperitoneal HF twice a day for 10 days (40 mL.kg-1.day-1) and 20 rats received physiological saline. Fifteen rats were used as control. The HF applied to cirrhotic rats significantly: a) reduced the relative mRNA expression of the genes: Col-alpha1 (-53%), TIMP-1 (-31.7%), TGF-beta1 (-57.7%), and MMP-2 (-41.6%), whereas Plau mRNA remained unchanged; b) reduced GGT (-43.1%), ALT (-17.6%), and AST (-12.2%) serum levels; c) increased liver weight (11.3%), and reduced liver collagen (-37.1%), regenerative nodules size (-22.1%), and fibrous septum thickness. Progranulin protein (immunohistochemistry) and mRNA (in situ hybridization) were found in fibrous septa and areas of bile duct proliferation in cirrhotic livers. Concluding, HF improved the histology and serum biochemistry of liver cirrhosis, with an important reduction of interstitial collagen and increased extracelullar matrix degradation by reducing profibrotic gene expression.

Fat absorptive processes in the intestine of the Antarctic fish Notothenia coriiceps (Richardson, 1844)

Absorption of lipids by the enterocytes of Notothenia coriiceps, an omnivorous Antarctic and subAntarctic fish, was studied by light and electron microscopy. The lipids are absorbed by the anterior and middle intestine segments. They appear as fat droplets that measure from 0.5 to 7xa0μm of diameter and which accumulate in the apical cytoplasm within the first 24xa0h and seem to be the main fat storage form in the enterocytes. Fat is also observed as lipid particles with 60–300xa0nm inside the rough endoplasmic reticulum and cytoplasmic smooth vesicles. The epithelial intercellular space and the mucosal inner lamina contain lipid particles, which probably are the fat transport form. Our observations show that an intense lipid absorptive process takes place in N. coriiceps digestive system, due to the great extension of the intestine involved and due to the great lipid accumulation found in the epithelial compartment.

Stratum adiposum, a special structure of the African Catfish skin (Clarias gariepinus, Burchell 1822).

The skin histology of Clarias gariepinus, a scaleless teleost from south central Africa, is described. The African catfish epidermis is composed of epithelial cells representing 62.3% of volumetric density (Vv), club cells (Vvu2003=u200325.7%), mucous cells (Vvu2003=u200310.5%) and melanocytes (Vvu2003=u20031.4%). Its thickness amounts to approximately 240u2003μm. The dermis is distinguished by two well differentiated layers, the stratum adiposum, containing prominent amounts of adipose tissue, which forms large, oblong compartments circumscribed by dense connective tissue, and the stratum compactum, which is rich in compacted collagen fibres. Compared with other catfish species the dermis thickness is considerably thicker ranging from 1.3 to 2.3u2003mm. The function of this type of skin is discussed.

Avaliação morfológica das membranas fetais e da placenta de Mazama gouazoubira (veado-catingueiro) de vida livre no terço inicial da gestação

Mazama gouazoubira is a small-sized deer, which can be found in South America, from southern Uruguay to the north of Mato Grosso, Brazil. This study aimed to describe the fetal membranes and placenta of M. gouazoubira in the first third of pregnancy. Samples collected were macroscopically and microscopically analyzed. Uterus examination demonstrated univitelinic gestation with an embryo measuring a crown-rump length of 13mm. In the embryo analysis we could identify the pigmented eye, auricular hillocks, mesonephron and early metanephron, liver and its external prominence, stomach, thoracic members and buds of pelvic members. Placenta was oligocotyledonary and nine caruncles were found in the uterus. Gestational sac measured 15cm in length, and, as observed in the early gestation of domestic ruminants, cotyledons could not be identified macroscopically. A weak adhesion was found between caruncles and chorioallantoic membrane (cotyledons) forming the placentomes. The chorioallantoic membrane showed a well-vascularized allantoid composed by a thin layer of cells with stretched nucleus and cytoplasm. On the other side of the membrane, the chorion was composed by cubic cells with scant cytoplasm and large-rounded nuclei, features of trophoblast cells. Involving the embryo we identified a two-layered amniotic sac. Layers could be mechanically separated and had similar morphology, showing a non-vascularized squamous epithelium. There was no yolk sac in the gestational stage of this specimen. We concluded that the placenta of M. gouazoubira is an oligocotyledonary placenta, as observed in others cervids, and that the fetal membranes showed similarities with those from other domestic ruminants, including cytological characteristics. Further studies are required in order to determine the presence of the yolk sac and its regression time.

Morfologia e desenvolvimento ultraestrutural do sistema renal de embriões bovinos com idade gestacional entre 10 e 50 dias

O presente estudo teve como objetivo descrever o desenvolvimento dos sistemas renais de bovinos durante o periodo embrionario compreendido entre 10 e 50 dias. Embrioes bovinos coletados em frigorifico foram fotografados e medidos utilizando-se o metodo Crow-Rump (CR) para estimar a idade gestacional. Os embrioes destinados a miscroscopia optica foram fixados em solucao de Bouin para a avaliacao do desenvolvimento do sistema renal, assim como suas estruturas. Alguns embrioes tambem foram fixados em Glutaraldeido 2,5% e destinados a microscopia eletronica de transmissao para o estudo ultraestrutural das celulas do sistema renal. Embrioes entre o 14° e o 15° dia de desenvolvimento (E14-15) nao apresentaram pronefro, mas apresentaram mesonefro, assim como indicios morfologicos que indicam sua atividade funcional. O mesonefro apresentou, no interior de suas celulas tubulares, inumeras mitocondrias e interdigitacoes, indicando uma alta atividade de transporte ionico. O metanefro, ou rim definitivo, iniciou seu desenvolvimento em E23-24. Os achados emonstram que a involucao do mesonefro acontece simultaneamente com a diferenciacao metanefrogenica. Em E45-46, ja iniciando a fase fetal, o metanefro possuiu unidades filtradoras (nefrons), com seus respectivos glomerulos, tubulos contorcidos proximais e distais e alca de Henle. Nessa fase, o rim ainda nao apresenta lobacao externa.

Anatomical description of arterial segment of spleen of deer

With 2 figures

Modelo de suplementação nutricional com fatores hepatotróficos aumenta proliferação celular em fígado de ratos sadios

ABSTRACT Two protocols of hepatotrophic factors (HF) administration, in solution composed by aminoacids, vitamins, mineral salts, glucose, insulin, glucagon, and triiodothyronine were evaluated in healthy rats. This solution was administered for 10 days, (40mg/kg/day) i.p., in two (group 2xFH; n=15) or three daily doses (group 3xFH n=15). The effects on hepatocytes cell proliferation, angiogenesis, and hepatic extracellular matrix, and also possible adverse reactions were analyzed. Animals of groups 2xFH and 3xFH presented an increase in hepatic mass of 30.1% and 22.5%, respectively, when compared rats of control group (CT; n=15). Hepatocellular proliferation index was higher in rats of groups 2xFH (1.4%) and 3xFH (1.2%) when compared to CT group animals (0.53%), and the relative densitometry of the vascular endothelial growth factor analyzed with immunoblot did not show a significant difference among the three groups. Rats of groups 2xFH and 3xFH showed a reduction of interstitial collagen when compared to CT rats. HF solution stimulated hepatic growth and reduced the volume of perisinusoidal collagen. Administration in three daily doses resulted in 26.7% mortality, possibly due to excessive stress from manipulation and lower physiological adaptation of rats, which did not occur in rats of groups 2xFH and CT. The more appropriate and safer experimental procedure for this approach in rats with higher chance of animal adaptation and significant results is the application of HF in two daily doses. Keywords: rat, collagen, hepatotrophic factors, experimental model, parenteral nutrition

Morfologia e funcionalidade do pneumócito tipo II e sua relação e variação com a idade gestacional em bovinos

The aim of this study was to characterize the presence of type II pneumocyte and the beginning of the surfactant protein production in bovines to the correlated gestational age. Lungs of fetuses at 4 months gestational age were found to be in the canalicular development phase, without presence of type II pneumocytes or appearance of electrophoretic bands compatible with the presence of the surfactant protein. In fetuses at 5 months of gestational age, the lungs were at the terminal sac phase, with the presence of primitive alveolus, formed by cubical epithelium and areas formed by pneumocytes I and pneumocytes II. No electrophoretic bands compatible to the surfactants proteins were identified. In contrast, lungs of fetuses at 6 months of gestational age showed, development of terminal sac phase, with the presence of type I and type II pneumocytes. In this phase, proteic determination for the SDS - PAGE analysis showed the presence of bands between 26 to 36kDa, demonstrating SP – A production, which is the surfactant protein found in highest amount. From the 7th gestational month on, the phase of terminal sac is more evident and complex, with intense sprouting vascularization. The type I pneumocyte had a more squamous aspect and type II pneumocyte were more globular. In the SDS – PAGE analysis of the bronchial – alveolar wash, surfactant protein bands had been observed with a profile similar to that of the newborn animals. In newborn animals, lungs in alveolar phase showed the development of type I and II pneumocytes. The profile of