Vol.29-Issue 1 - 2005 Abstracts

Vol.29-Issue 1- 2005

Comparative study of mandibular glands of Melipona bicolor
queens obtained from polygynic and monogynic colonies
LUCIANA FIORETTI GRACIOLI-VITTI, FÁBIO CAMARGO ABDALLA AND REGINA LÚCIA MORELLI SILVA DE MORAES
Departamento de Biologia, Instituto de Biociências, Universidade Estadual Paulista (UNESP), Rio Claro, SP, Brasil.

Key words: Melipona bicolor, mandibular gland, morphology, polygynic colonies.

ABSTRACT: The aim of the present study was analyze, by histological and morphometrical studies, mandibular glands of Melipona bicolor queens collected from monogynic and polygynic colonies and compare their level of development. The results showed that the glands of physogastric queens from monogynic colony present a higher level of activity in relation to the queens of polygynic colonies; this is explained by the fact that just a unique queen controls the monogynic colony. In the polygynic colonies, the queens may divide such control to each other.

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Effects of filgrastim on granulopoietic cells of mice pretreated
with methotrexate
LILIAN BARRIOS AND OSCAR HÉCTOR POLETTI
Departamento de Ciencias Básicas, Fisiología Humana, Facultad de Medicina, Universidad Nacional del Nordeste (UNNE).
Moreno 1240, (3400) Corrientes. Argentina.

Key words: methotrexate, filgrastim, granulopoiesis, bone marrow, spleen.

ABSTRACT: We have evaluated the effect of filgrastim on proliferation and differentiation activity of granulopoietic cells in mice pretreated with methotrexate. Filgrastim was injected daily, from day 8 to 28 after cytotoxic agent administration. The granulopoiesis changes were measured by assessment of GM-CFU cells content, marrow and spleen granuloid cells pool as well as circulating neutrophils. In MTX pretreated mice, bone marrow GM-CFU oscillating values were higher than normal values, but these changes were not followed by high proliferative activity in granuloid precursor cell compartment. After MTX treatment, filgrastim administration was unable to stimulate marrow granulopoiesis as observed in normal mice. In the spleen,
MTX led to dramatic changes in the proliferative activity of GM-CFU cells, but did not result in spleen granuloid cell changes. However, filgrastim treatment induced a spleen granuloid amplification, similar to the changes observed in circulating neutrophils values. We suggest that these findings can be explained by inhibition of differentiation of marrow GM-CFU cells into the more mature granulopoietic cells and/or by an inhibited proliferative activity of marrow granuloid cells. They can be also explained in terms of an unfavorable marrow microenvironment for granulopoiesis, contrary to a supportive spleen microenvironment.

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Key words: Melipona bicolor, mandibular gland, morphology, polygynic colonies.

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Fine structural analysis of the epithelial cells in the
hepatopancreas of Palaemonetes argentinus (Crustacea,
Decapoda, Caridea) in intermoult
LILIANA G. SOUSA1, ELENA I. CUARTAS2, AND ANA MARÍA PETRIELLA1, 3
1. Departamento de Ciencias Marinas.
2. Departamento de Biología, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata.
Funes 3350. B7602AYL, Mar del Plata. Argentina.
3. CONICET.

Keywords: Crustacea, Caridea, hepatopancreas, ultrastructure

ABSTRACT: The aim of this study is to describe the ultrastructure of the hepatopancreas of P. argentinus in intermoult. P. argentinus hepatopancreas was studied using standard TEM techniques. Each tubule consists of four cellular types: E (embryonic), F (fibrillar), R (resorptive) and B (blister like). E-cells have embryonic features and some of them were found in mitosis. F, R and B cells possess an apical brush border. F-cells have a central or basal nucleus, a conspicuous RER, and dilated Golgi cisternae. R cells show a polar organization of organelles in three areas: apical, with numerous mitochondria and sER tubules, a central area with the nucleus and RER, and a basal area containing a sER-like tubule system and mitochondria. B-cells were observed at different stages of their life cycle. In an early differentiation stage they comprise an apical endocytotic complex and Golgi vesicles. The fusion of endocytotic and Golgi vesicles originates subapical vacuoles. During maturation, a big central vacuole is formed by coalescence of subapical vacuoles. The central vacuole is eliminated by holocrine secretion. The ultrastructure suggests that F-cells synthesize proteins, Rcells storage nutrients and B-cells have a secretory or excretory function, and confirms the independent origin of F, B and R cells from the embryonic cells.

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Comparative study of DNA synthesis and nucleolar organizer
regions of sinusoid littoral cells in mouse regenerating liver
CARLOS A. MARTÍN, JOSÉ MIGUEL SURUR, MARCELA N. GARCÍA, FÉLIX CORRONS, AND AMADO F. BADRÁN
Instituto de Embriología, Biología e Histología. Facultad de Ciencias Médicas. UNLP. Calle 60 y 120. (1900) La Plata. Argentina.

Key words: liver regeneration, sinusoid littoral cell, bromodeoxyuridine, AgNOR, immunohistochemistry

ABSTRACT: Variations in DNA synthesis (DNAs) and Nucleolar Organizer Regions (NORs) were studied in the littoral cell population from regenerating liver of C3HS inbred mice standardized for periodicity analysis. Immunohistochemical detection of Bromodeoxyuridine (BrdU) with a monoclonal antibody and silver staining of NORs (AgNORs) were assessed by means of a digital image analysis system in histological sections. Tissue samples were obtained every four hours from the 30th to the 54th hours after a partial hepatectomy. The results showed, in both parameters, a gradual increment of the values during the period studied, with highest values (DNAs 107.1 ± 16.1 SE; AgNORs 77.3 ± 3.4 SE) located at 16:00/54 Time of Day / Hours Post-Hepatectomy (TD/HPH), which were significantly different (p <0.001) from the values of the first sample (DNAs 38.1 ± 9.5 SE; AgNORs 27.3 ± 1.0 SE) taken at 16:00/30 TD/HPH. The results of our experiment demonstrate the existence of a strong correlation of DNA synthesis measured by BrdU immunohistochemistry
and AgNORs numbers in sinusoid littoral cells from mouse regenerating liver.

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Morphoquantitative evaluation of the duodenal myenteric
neuronal population in rats fed with hypoproteic ration
MARIA RAQUEL MARÇAL NATALI, SONIA LUCY MOLINARI, LUIZ CRISTIANO VALENTINI, AND MARCÍLIO HUBNER DE MIRANDA NETO.
Departamento de Ciências Morfofisiológicas, Universidade Estadual de Maringá, BRASIL.

Key words: myenteric neurons, small intestine, morphometric, hypoproteic ration

ABSTRACT: The purpose of this work was to analyze the morphoquantitative behavior of the neurons of the myenteric plexus, as well as the morphometry of the duodenal wall, in adult rats fed with normoproteic (22%) and hypoproteic (8%) rations, killed at the age of 345 days. For neuronal assessments duodenal wholemounts stained with the Giemsa method were used, and for the evaluation of the duodenal wall routine histological processing and staining with Hematoxilin-Eosin were employed. The means of the number of neurons in 80 microscopic fields (12.72 mm2) and of the size of the neuronal cell bodies did not reveal statistically significant differences between the groups, but there was a greater incidence of large neurons in the protein restriction group (RP). The duodenum was markedly smaller in the RP group and, although there was no difference in the thickness of its wall, the mucosa was larger and the muscular layer was smaller in group RP. It was concluded that the neuronal and non-neuronal components of the duodenum adjust themselves to
the nutritional condition, assuring the maintenance of their functions.

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Extracellular matrix of ostrich articular cartilage
TATIANA CARLA TOMIOSSO, LAURECIR GOMES, BENEDICTO DE CAMPOS VIDAL AND EDSON ROSA PIMENTEL
Departamento de Biologia Celular, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), Campinas, SP, CEP 13083-863, Brazil.

Key words: articular cartilage, collagen, decorin, ostrich, proteoglycan.

ABSTRACT: The composition and organization of the extracellular matrix of ostrich articular cartilage was investigated, using samples from the proximal and distal surfaces of the tarsometatarsus. For morphological analysis, sections were stained with toluidine blue and analyzed by polarized light microscopy. For biochemical analysis, extracellular matrix components were extracted with 4 M guanidinium chloride, fractionated on DEAE-Sephacel and analyzed by SDS-PAGE. Glycosaminoglycans were analyzed by electrophoresis in agarose gels. Structural analysis showed that the fibrils were arranged in different directions, especially on the distal surface. The protein and glycosaminoglycan contents of this region were higher than in the other regions.
SDS-PAGE showed the presence of proteins with molecular masses ranging from 17 to 121 kDa and polydisperse components of 67, 80-100, and 250-300 kDa in all regions. The analysis of glycosaminoglycans in agarosepropylene diamine gels revealed the presence of only chondroitin-sulfate. The electrophoretic band corresponding to putative decorin was a small proteoglycan containing chondroitin-sufate and not dermatan-sulfate, unlike other cartilages. The higher amounts of proteins and glycosaminoglycans and the multidirectional arrangement of fibrils seen in the distal region may be correlated with the higher compression normally exerted on this region.

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