984 resultados para EXOCRINE GLANDS


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The salivary glands of Drosophila saltans ( saltans group, saltans subgroup) analyzed in an advanced stage of programmed cell death showed the appearance of a single, round, nucleolar corpuscle inside the highly altered nucleus of every gland cell, at a time during which the integrity of the original nucleolus was already lost and the original nucleolar material apparently disappeared. In the same nuclei, which already had also lost the characteristic chromosome structure, some delicate chromosome threads were maintained. In many cells, the new nucleolar corpuscle and these chromosome threads are associated. These findings are novel. However, the hypothesis put forward concerning their meaning remains dependent on other studies.

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Oenocytes of adult workers and queens of Apis mellifera L. were studied in different ages or life stages, by means of morphometric and histologic techniques. In workers, the oenocytes were found in the head, near the mandibles and in the abdomen, immersed in the parietal fat body mainly below the sterna, close to the wax glands. In queens, two populations of oenocytes different in size and localization were found within the parietal and visceral fat body, respectively. The oenocytes of workers and queens show the presence of acid lipids and acid phosphatase. The role of these cells in the castes differences is discussed.

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The superior cervical ganglion (SCG) provides sympathetic input to the head and neck, its relation with mandible, submandibular glands, eyes (second and third order control) and pineal gland being demonstrated in laboratory animals. In addition, the SCG's role in some neuropathies can be clearly seen in Horner's syndrome. In spite of several studies published involving rats and mice, there is little morphological descriptive and comparative data of SCG from large mammals. Thus, we investigated the SCG's macro- and microstructural organization in medium (dogs and cats) and large animals (horses) during a very specific period of the post-natal development, namely maturation (from young to adults). The SCG of dogs, cats and horses were spindle shaped and located deeply into the bifurcation of the common carotid artery, close to the distal vagus ganglion and more related to the internal carotid artery in dogs and horses, and to the occipital artery in cats. As to macromorphometrical data, that is ganglion length, there was a 23.6% increase from young to adult dogs, a 1.8% increase from young to adult cats and finally a 34% increase from young to adult horses. Histologically, the SCG's microstructure was quite similar between young and adult animals and among the 3 species. The SCG was divided into distinct compartments (ganglion units) by capsular septa of connective tissue. Inside each ganglion unit the most prominent cellular elements were ganglion neurons, glial cells and small intensely fluorescent cells, comprising the ganglion's morphological triad. Given this morphological arrangement, that is a summation of all ganglion units, SCG from dogs, cats and horses are better characterized as a ganglion complex rather than following the classical ganglion concept. During maturation (from young to adults) there was a 32.7% increase in the SCG's connective capsule in dogs, a 25.8% increase in cats and a 33.2% increase in horses. There was an age-related increase in the neuronal profile size in the SCG from young to adult animals, that is a 1.6-fold, 1.9-fold and 1.6-fold increase in dogs, cats and horses, respectively. on the other hand, there was an age-related decrease in the nuclear profile size of SCG neurons from young to adult animals (0.9-fold, 0.7-fold and 0.8-fold in dogs, cats and horses, respectively). Ganglion connective capsule is composed of 2 or 3 layers of collagen fibres in juxtaposition and, as observed in light microscopy and independently of the animal's age, ganglion neurons were organised in ganglionic units containing the same morphological triad seen in light microscopy. Copyright (c) 2007 S. Karger AG, Basel.

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The digestive gland of Pomacea lineata, a prosobranch gastropod mollusc inhabiting both fresh water and land, does not contain cholinomimetic compounds as do the glands of species of Aplysia, marine opisthobranch gastropods, in which both acetylcholine and urocanylcholine are present. The only pharmacological action detected for the digestive gland of Pomacea was spasmogenic activity of a crude homogenate containing 0.1 g tissue equivalents on the snail's own esophagus bathed in 10 ml of a physiological solution prepared on the basis of the animal's hemolymph composition. The spamodic activity was not blocked by atropine, bromlysergic acid diethylamide or anthazoline.

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The effects of chronic alcohol ingestion on the secretory epithelium of the seminal vesicle were studied in rats (Rattus norvegicus). Male adult albino Wistar rats were divided into two groups: alcoholic and control. Tips of the seminal vesicle were removed and prepared for light and electron microscopy. Ultrastructural observations on the epithelial cells of the seminal vesicle showed reduced epithelial cell size, decreased apical secretory vacuoles, irregularly shaped nuclei with deep infoldings, increased lipid droplets and dense bodies, a small number of microvilli covering the cell surface, and signs of degeneration. In addition to the hormonal effects, alcohol may act on the secretory epithelium of the seminal vesicle.

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Diabetes mellitus can lead to reproductive disorders that in turn result in weakened fertility brought about by morphofunctional changes in the testes and accessory sex glands. However, doubts persist concerning the basic biology of the secretory epithelial cells and the stroma of the coagulating gland of diabetic mice. Thus, the objective of the present study was to analyze the histological and ultrastructural changes associated with stereology of the coagulating gland of mice with alloxan-induced diabetes, and of spontaneously diabetic mice. Sixteen mice of the C57BL/6J strain, and eight non-obese diabetic (NOD) mice were used. The animals were divided into three groups: 1) control (C), 2) alloxan diabetic (AD), and 3) NOD. Thirty days after the detection of diabetic status in group 2, all of the animals were killed and then perfused with Karnovsky's solution through the left cardiac ventricle. The coagulating gland was then removed and processed for morphometric study by light microscopy and electron microscopy. The results showed thickening of the stroma, atrophy of secretory epithelial cells, and disorganization of the organelles involved in the secretory process in both NOD and alloxan-induced mice. Thus, it may be concluded that the coagulating gland suffered drastic morphological changes, and consequently impaired glandular function, in the presence of diabetes mellitus type I in both NOD and AD mice. (C) 2003 Wiley-Liss, Inc.

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Laboratory animals exposed to feeding ticks develop resistance which is reflected by a decline in tick engorgement weight, egg-laying by adults and reduced egg viability. Serum antibodies from these hosts and their reaction with tick antigens have been detected by different methods, including precipitation techniques, immunofluorescent techniques, ELISA and Western blots. However, little is known about the effects of antibodies on ticks that engorge on resistant hosts, or which tissues of the tick body are possibly immunogenic. Some researchers, using immunohistochemistry, have detected host antibodies in the gut, salivary glands and haemolymph of ticks engorged on resistant animals. The same technique has helped considerably in determining antigenic sites or antibody targets in other arthropods. Consequently, immunohistochemistry techniques were used in this study to detect cross-reactivity between sera raised against Amblyomma cajennense (Fabricius, 1787) with Amblyomma hebraeum (Koch, 1844), and vice versa. The results show the existence of shared antigens between the 2 tick species. In general, our results point more to a 1-way cross-reactivity of A. hebraeum with A. cajennense than a reciprocal cross-reactivity, suggesting that A. hebraeum is more immunogenic than A. cajennense.

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Motilin-immunoreactive cells in the duodenum, pyloric stomach and pancreas of Caiman latirostris and Caiman crocodilus were investigated using region specific antisera for porcine and canine motilin molecules. Motilin-immunoreactive cells were found in the duodenum, pyloric stomach and pancreas of both caiman species. These cells were primarily open-type endocrine ones in the epithelium of the duodenum and pyloric stomach. Motilin-immunoreactive cells were observed in both the exocrine and endocrine portions of the pancreas, and frequently exhibited one or more cytoplasmic processes of variable length. Since motilin-immunoreactive cells do not cross-react with serotonin or any of the other pancreatic and gut hormones, they are considered to be cell type independent from any of the other known pancreatic or gut endocrine cells. The molecular similarity between caiman motilin and porcine and canine motilins and the heterogeneity of the motilin molecule in the caiman digestive system is discussed.

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Numerous nymphoid reproductives were found in three field nests of Armitermes euamignathus collected in Brazil. We report here a morphological description and a biometric study of these individuals. Nymphoid replacements displayed narrow wing buds when compared with those present in nymphs from the three last instars. Thorax morphology of the nymphoids was similar to the penultimate nymphal instar (N4) or to the ultimate nymphal instar (N5), and their origin from these instars of nymphs is discussed. All the nymphoids had eyes, ocelli, and 15 antennal segments. The nymphoid females from nest 1 had different grades of physogastry and royal fat body. The nymphoid females from nests 2 and 3, the nymphoid males from all nests, and the primary king from nests 2 acid 3 had a common fat body, which is similar to that present in alates. The ovaries and the testes of nymphoids were fully mature and the corpora allata larger than those in imagoes. The mandibular glands were also enlarged in nymphoids but the tergal glands were absent. (C) 1999 Wiley-Liss, Inc.

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In female ants of the species Neoponera villosa the corpora allata are paired structures located dorsolaterally to the esophagus (Camargo-Mathias and Caetano, 1991). In the present study the glandular volume of the corpora allata was estimated and the activity of the glands was compared with the ovarian development. In the workers there was a relation between activity of these glands and ovaries in stages 0 to IV. In workers, with ovaries at stage V (maximum development) there was a smaller activity of the corpora allata. Another increasing activity was found in workers with ovaries at stage VII.In the queens, mainly those which were mated, whose ovaries were always fully developed, the volume of the corpora allata was smaller than those of the workers.

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Reproductive strategy is the set of adaptations that promote the most efficient way that the species will survive under the particular conditions of a determined environment. Understanding these adaptations is important and can help pinpoint populations indicator of environmental changes. Spermatogenesis is a measurable biological process of these adaptations in spatial and temporal scales. We analyzed the morphology of the testes and oviducts of the lizard species that comprise the genus Tropidurus, taking into account the geographical distribution and sympatric relations. For the analysis and the testes were removed from the middle part of the oviducts from Tropidurus etheridge, T oreadicus, T itambere, T spinulosus and T Guarani species, collected in different places in the Mato Grosso state, Brazil. The reproductive period is synchronous for males and females and occurs in September, October and November. Reproductive males were characterized. In the testes are seminiferous tubules with germ cells at different stages of spermatogenesis, with a high epithelium, at present light, free spermatozoa in the lumen and reduction of interstitial tissue. For females, the reproduction peak occurs when the oviduct epithelium is high with secretions and basal nucleus. These months are characterized in the sampled areas over a period of heavy rain and high temperatures. The decline of reproductive period was observed in both sexes, between April and August. Low reproduction in males is characterized by ample light, absence of sperm, only germ cells in the early stages of spermatogenesis are observed (a few spermatogonia and spermatocytes) and interstitial tissue wide. In females, the period of reproductive decline is marked by the absence of unicellular glands in the oviduct epithelium, with higher affinity with the dye. This period corresponds to low rainfall periods and lower temperatures. We propose an analysis of zoological samples; this is a proposal to facilitate the work of many researchers through access to the species, especially rare species.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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The objectives of this investigation were to understand transplacental transport of iron by secreted uteroferrin (UF) and haemophagous areas of water buffalo placenta and clarify the role(s) of blood extravasation at the placental-maternal interface. Placentomes and interplacentomal region of 51 placentae at various stages of gestation were fixed, processed for light and transmission electron microscopy, histochemistry and immunohistochemistry. Haemophagous areas were present in placentomes collected between 4 and 10 months of pregnancy. Perl's reaction for ferric iron was negative in placentomes, but positive in endometrial glands. Positive staining for UF indicated areas in which it was being taken up by phagocytosis and/or fluid phase pinocytosis in areolae of the interplacentomal mesenchyme, with little staining in endometrial stroma. Imunohistochemistry detected UF in trophectoderm of haemophagous regions of placentomes and in other parts of the foetal villous tree, but the strongest immunostaining was in the epithelial cells and lumen of uterine glands. Ultrastructural analyses indicated that erythrophagocytosis was occurring and that erythrocytes were present inside cells of the chorion that also contained endocytic vesicles and caveolae. Results of this study indicate that both the haemophagous areas of placentomes and the areolae at the interface between chorion and endometrial glands are important sites for iron transfer from mother to foetal-placental tissues in buffalo throughout pregnancy.

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Purpose: Ultrasound (US) therapy is an elect rot hermotherapeutic modality that uses US energy to provoke physical and chemical alterations. US therapy has been widely used in physical therapy. However in clinical practice, it is contra-indicated in cancer patients due to the possibility of exacerbating tumor growth.Methods: Sixty-eight female Sprague-Dawley rats bred in UNIFAE vivarium were studied. At 50 days of age, 7, 12-dimetylbenz(a)anthracene (7, 12-DMBA) was administered to 35 rats by gastric gavage to induce mammary cancer After 90 days the mammary glands of the rats belonging to the group with mammary cancer induction and stimulated by US were removed. Animals received either continuous or pulsed US. US waves were generated at a frequency of 1 MHz during 10 days, with an intensity dose of 0.5 W in the continuous group, and 0.9 W (duty cycle: 20%) in the pulsed group.Results: Among the rats treated with continuous US, 44.4% developed local recurrence, while among the rats treated with pulsed US, 22.2% had local tumor recurrence (p < 0.05). No evidence of distant metastases was shown in any of the rats studied.Conclusion: The use ofcontinuous and pulsed therapeutic US promoted the development of local recurrence of mammary cancer in female Sprague-Dawley rats in the postoperative period.

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P>The reactivity of sera collected from guinea pigs after three infestations with Amblyomma triste nymphs on histological sections of the same tick species was investigated through immunohistochemistry to identify potential target cells and tissues. Six guinea pigs were infested thrice, at 30 day intervals, with 30 nymphs of A. triste per animal per infestation. Blood samples were collected from the guinea pigs 15 days after each infestation for serum separation; normal serum was obtained before the first infestation as control. Unfed A. triste nymphs' histological sections were submitted to indirect immunohistochemistry technique by using normal or hyperimmune guinea pig serum as primary antibody and a goat IgG-alkaline phosphatase-APase conjugate as secondary antibody. A weak to moderate APase activity was observed in cells of salivary glands, midgut and haemolymph of unfed nymphs incubated with hyperimmune serum.