935 resultados para MAMMARY-GLAND


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By considering controversial discussions in the literature with regard to gland denomination in Indigofera species, as well as the taxonomic value of secretory structures in Leguminosae, we aim to morphologically detail glands that had been previously observed in I. microcarpa and I. sabulicola, and to investigate the occurrence of glands in vegetative and reproductive organs of other six Neotropical species that belong to the genus. Glands analyzed through scanning electronic microscopy (SEM) in combination with anatomic analyses correspond to secretory trichomes that Lire classified into seven types. Main variations in relation to types occurred with regard to head shape and peduncle size. Trichome heads were multicellular, with a thin cuticle. Hollow heads with conspicuous inner space characterized only one type (type I); the other trichome types had massive heads. Peduncles, which varied from biseriate to multiseriate, had thick, pecto-cellulosic cell walls. Trichomes were found on sterns, stipules, petioles, rachis, petiolules, leaflets, bracteoles, sepals, standards and fruits, more commonly along the margins. Each of the eight Indigofera species analyzed had at least two different trichome types out of the seven types that occurred in reproductive and vegetative organs of these taxa. Various types of secretory trichomes were found in I. campestris, I. lespedezioides, I. microcarpa, I. spicata. I. Suffruticosa and I. truxillensis. Stems and rachis were the vegetative organs in which a greater variety of trichomes occurred, and sepals were parts of reproductive organs with the same status. Five out of the seven secretory trichome types occurred on both vegetative and reproductive organs. Distribution and gland types differed between species and these gland distribution patterns can be used as diagnostic characters. Reports of glands in Indigofera campestris, I. hirsuta, I. lepedezioides, I. suffruticosa, I. spicata and I. truxillensis, their recognition as secretory trichomes. and the morphological variety of types found for such trichomes are novel data for Indigofera. (C) 2008 Elsevier GmbH. All rights reserved.

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The aim of this study was to evaluate some biological characteristics and toxicity of basic formulations of dentifrices containing such substances, and to compare them with two existing products in market which also contains silic in their formulations. In this way, it was evaluated some biological parameters: weight of the animals, oral toxicity, hematological parameters, urinary analysis, and histological evaluation. The thrombocytes were also statistically at normal levels. The glutamate-pyruvate transaminase (TGP) showed normal aspect in 5 of the tested groups, as in control. Meanwhile, the oxalacetic transaminase (AST) in one group had a small increase in the control group. Regarding urine, in exception the rats of one group, the rats of the 4 other experimental groups showed leukocytosis urinary statistically higher than the control group. The histological evaluation of the animals showed that specimens from liver, stomach, kidney and submandibular gland presented normal aspects for these organs, without significant characteristics related to inflammatory infiltrates in any of the 6 samples tested in their respective groups.

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The apparent absence of salt glands in marine and estuarine Crocodilia has long been a puzzle. However, we have identified glands in the tongue of Crocodylus porosus which exude a concentrated secretion of sodium chloride. The glands are similar in ultrastructure to other reptilian salt glands and undoubtedly play a major role in electrolyte regulation.

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To date, the laboratory has cloned seven unique human sulfotransferases; five aryl sulfotransferases (HAST1, HAST2, HAST3, HAST4 and HAST4v), an estrogen sulfotransferase and a dehydroepiandrosterone sulfotransferase. The cellular distribution of human aryl sulfotransferases in human hepatic and extrahepatic tissues has been determined using the techniques of hybridization histochemistry and immunohistochemistry. Human aryl sulfotransferase expression was detected in liver, epithelial cells of the gastrointestinal mucosal layer, epithelial cells lining bronchioles and in mammary duct epithelial cells. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.

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In sheep intracerebroventricular injection of PACAP (10 nmol) significantly (P < 0.01) stimulated the levels of the dopamine metabolite DOPAC within the medial basal hypothalamus las measured by in vivo microdialysis) and this effect was temporally correlated with a significant (P < 0.05) suppression in peripheral prolactin concentrations. This result is in accord with the hypothesis that PACAP suppresses prolactin secretion from the anterior pituitary gland by stimulating dopamine release from tuberoinfundibular dopaminergic neurons. (C) 1998 Elsevier Science B.V.

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The gross morphology, histology, and ultrastructure of the thyroid gland of the koala, Phascolarctos cinereus, is described. Generally, the glands were found to contain large-diameter follicles in association with an epithelium of low height. Morphometric analysis demonstrated a high relative thyroid weight (0.3 +/- 0.2 g/kg) for koalas compared with the 0.07-0.24 g/kg typical of eutherian mammals and 0.03-0.1 g/kg found in other marsupials. The relative thyroid weight of glands (0.33 +/- 0.21 g/kg) from the coastal population (less than 28 km from the coastline) was found to be significantly higher (ANOVA: P = 0.007, significant at the 1% level) than that for glands (0.21 +/- 0.11 g/kg) of noncoastal koalas (greater than 28 km from the coastline). Follicle size was positively correlated (at the 0.1% level) with relative thyroid weight in the overall koala sample. The presence of C cells, occurring singly in the epithelial layer, was demonstrated in electron micrographs. Structural features such as low epithelial height, large follicle length and width, and large intercellular spaces in association with low concentrations of free TS (3.3 +/- 2.1 pM) and free T-3 (1.4 +/- 0.9 pM) as reported previously (Lawson et al., 1996) are consistent with an unusually low level of glandular activity in the koala thyroid even though iodine concentrations in the thyroid gland [4.7 +/- 1.6 mg/g (dry weight)] as well as leaf [0.8 +/- 0.3 mu g (dry weight)] and soil samples [3.8 mu g/g (dry weight)] from the koalas' habitat appear unremarkable. (C) 1998 Academic Press.

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Familial hyperaldosteronism type II (FH-II) is characterized by autosomal dominant inheritance and hypersecretion of aldosterone due to adrenocortical hyperplasia or an aldosterone-producing adenoma; unlike FH type I (FH-I), hyperaldosteronism in FH-II is not suppressible by dexamethasone. Of a total of 17 FH-II families with 44 affected members, we studied a large kindred with 7 affected members that was informative for linkage analysis. Family members were screened with the aldosterone/PRA ratio test; patients with aldosterone/PRA ratio greater than 25 underwent fludrocortisone/salt suppression testing for confirmation of autonomous aldosterone secretion. Postural testing, adrenal gland imaging, and adrenal venous sampling were also performed. Individuals affected by FH-II demonstrated lack of suppression of plasma A levels after 4 days of dexamethasone treatment (0.5 mg every 6 h). All patients had neg ative genetic testing for the defect associated with FH-I, the CYP11B1/CYP11B2 hybrid gene. Genetic linkage was then examined between FH-II and aldosterone synthase (the CYP11B2 gene) on chromosome 8q. A polyadenylase repeat within the 5'-region of the CYP11B2 gene and 9 other markers covering an approximately 80-centimorgan area on chromosome 8q21-8qtel were genotyped and analyzed for linkage. Two-point logarithm of odds scores were negative and ranged from -12.6 for the CYP11B2 polymorphic marker to -0.98 for the D8S527 marker at a recombination distance (theta) of 0. Multipoint logarithm of odds score analysis confirmed the exclusion of the chromosome 8q21-8qtel area as a region harboring the candidate gene for FH-II in this family. We conclude that FH-II shares autosomal dominant inheritance and hyperaldosteronism with FH-I, but, as demonstrated by the large kindred investigated in this report, it is clinically and genetically distinct. Linkage analysis demonstrated that the CYP11B2 gene is not responsible for FH-II in this family; furthermore, chromosome 8q21-8qtel most likely does not harbor the genetic defect in this kindred.

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1 Voltage-operated calcium channel (VOCC) antagonists are effective antihypertensive and antianginal agents but they also depress myocardial contractility. 2 We compared four L-type calcium channel antagonists, felodipine, nifedipine, amlodipine and verapamil and a relatively T-type selective calcium channel antagonist, mibefradil, on human and rat isolated tissue assays to determine their functional vascular to cardiac tissue selectivity (V/C) ratio. 3 The V/C ratio was calculated as the ratio of the IC50 value of the antagonist that reduced (by 50%) submaximally contracted (K+ 62 mM) human small arteries from the aortic vasa vasorum (vascular, V) mounted in a myograph and the IC50 value of the antagonist that reduced (-)-isoprenaline (6 nM) submaximally stimulated human right atrial trabeculae muscle (cardiac, C) mounted in organ chambers. 4 The average pIC(50) Values (-log IC50 M) for the human vascular preparations were felodipine 8.30, nifedipine 7.78, amlodipine 6.64, verapamil 6.26 and mibefradil 6.22. The average pIC(50) values for the cardiac muscle were felodipine 7.21, nifedipine 6.95, verapamil 6.91, amlodipine 5.94, and mibefradil 4.61. 5 The V/C ratio calculated as antilog [pIC(50)V-pIC(50)C] is thus mibefradil 41, felodipine 12, nifedipine 7, amlodipine 5 and verapamil 0.2. 6 In rat small mesenteric arteries the pIC(50) values for the five drugs were similar to the values for human vasa vasorum arteries contracted by K+ 62 mM. However for methoxamine (10 mu M) contraction in the rat arteries the pIC(50) values were lower for felodipine 7.24 and nifedipine 6.23, but similar for verapamil 6.13, amlodipine 6.28 and mibefradil 5.91. 7 In conclusion in the human tissue assays, the putative T-channel antagonist mibefradil shows the highest vascular to cardiac selectivity ratio; some 3 fold higher than the dihydropyridine, felodipine, and some 200 fold more vascular selective than the phenylalkylamine, verapamil. This favourable vascular to cardiac selectivity for mibefradil, from a new chemical class of VOCC antagonist, may be explained by its putative T-channel selectivity.

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Bracken fern (Pteridium spp.) produces cancer of the urinary bladder and oesophagus in grazing animals and is a suspected human carcinogen, The carcinogenic principle ptaquiloside (PT), when activated to a dienone (APT), forms DNA adducts which eventually leads to tumor. Two groups of female Sprague-Dawley rats were given a chronic dose of 3 mg APT weekly for 10 weeks either by intravenous (iv) tail vein or by intragastric (ig) route, A third group was given a weekly dose of 6 mg of APT for 3 weeks by the ig route corresponding to acute dosing. Both chronic iv and ig dosed animals showed ischemic tubular necrosis in the kidney but only iv dosed animals developed adenocarcinomas of the mammary glands. Acutely dosed ig animals produced apoptotic bodies in the liver, necrosis of blood cell precursors in the bone marrow and ischemic tubular necrosis in the kidney but they did not develop tumors, No mutations were found in the H-ras and p53 genes in the mammary glands of either the ig rats or the tumor-bearing iv rats. However, the mammary glands of a fourth group of rats, which received APT by iv and killed before tumor development, carried Pu to Pu and Pu to Py double mutations in codons 58 and 59 of H-ras. This study indicates that the route of administration plays a role in the nature of the disease expression from ptaquiloside exposure. In addition to confirming the role of APT in the PT-induced carcinogenesis our finding suggests that activation of H-ras is an early event in the PT-carcinogenesis model. (C) 1998 Academic Press.

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Chemokines are important mediators of the early inflammatory response to infection and modify a wide range of host immune responses. Functional homologs of cellular chemokines have been identified in a number of herpesviruses, suggesting that the subversion of the host chemokine response contributes to the pathogenesis of these viruses. Transcriptional and reverse transcription-PCR analyses demonstrated that the murine cytomegalovirus (MCMV) chemokine homolog, m131, was spliced at the 3' end to the adjacent downstream open reading frame, m129, resulting in a predicted product of 31 kDa, which is significantly larger than most known chemokines. The in vivo impact of m131/129 was investigated by comparing the replication of MCMV mutants having m131/129 deleted (Delta m131/129) with that of wild-type (wt) MCMV. Our studies demonstrate that both wt and Delta m131/129 viruses replicated to equivalent levels during the first 2 to 3 days following in vivo infection. However, histological studies demonstrated that the early inflammatory response elicited by Delta m131/129 was reduced compared with that of wt MCMV. Furthermore, the Delta m131/129 mutants failed to establish a high-titer infection in the salivary glands, These results suggest that m131/129 possesses proinflammatory properties in vivo and is important for the dissemination of MCMV to or infection of the salivary gland. Notably, the Delta m131/129 mutants were cleared more rapidly from the spleen and liver during acute infection compared with wt MCMV. The accelerated clearance of the mutants was dependent on NK cells and cells of the CD4(+) CD8(+) phenotype. These data suggest that m131/129 may also contribute to virus mechanisms of immune system evasion during early infection, possibly through the interference of NK cells and T cells.

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A method by which to overcome the clinical symptoms of atherosclerosis is the insertion of a graft to bypass an artery blocked or impeded by plaque. However, there may be insufficient autologous mammary artery for multiple or repeat bypass, saphenous vein may have varicose degenerative alterations that can lead to aneurysm in high-pressure sites, and small-caliber synthetic grafts are prone to thrombus induction and occlusion. Therefore, the aim of the present study was to develop an artificial blood conduit of any required length and diameter from the cells of the host for autologous transplantation. Silastic tubing, of variable length and diameter, was inserted into the peritoneal cavity of rats or rabbits. By 2 weeks, it had become covered by several layers of myofibroblasts, collagen matrix, and a single layer of mesothelium. The Silastic tubing was removed from the harvested implants, and the tube of living tissue was everted such that it now resembled a blood vessel with an inner lining of nonthrombotic mesothelial cells (the intima), with a media of smooth muscle-like cells (myofibroblasts), collagen, and elastin, and with an outer collagenous adventitia. The tube of tissue (10 to 20 mm long) was successfully grafted by end-to-end anastomoses into the severed carotid artery or abdominal aorta of the same animal in which they were grown. The transplant remained patent for at least 4 months and developed structures resembling elastic lamellae. The myofibroblasts gained a higher volume fraction of myofilaments and became responsive to contractile agonists, similar to the vessel into which they had been grafted. It is suggested that these nonthrombogenic tubes of living tissue, grown in the peritoneal cavity of the host, may be developed as autologous coronary artery bypass grafts or as arteriovenous access fistulae for hemodialysis patients.

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The reproductive system of many female Therevidae has a sac-like structure associated with the spermathecae. This structure, termed the spermathecal sac, has not been recorded previously from any other Diptera and appears unique to certain members of the Therevidae. There is enormous variety in spermathecal sac size and shape, with greatest development in the Australasian Therevidae. A histological examination of the reproductive system of two;Australian therevids, Agapophytus albobasalis Mann and Ectinorhynchus variabilis (Macquart) (Diptera: Asiloidea), reveals that the spermathecal sacs are cuticle-lined and that the intima is frequently highly folded. In some mated individuals, sperm was found within the spermathecal sac, suggesting that sperm and perhaps male accessory gland material is deposited there during copulation. (C) 2000 Elsevier Science Ltd. All rights reserved.

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BACKGROUND. Prostate secretory granules (PSG) represent the basic secretory unit of the prostate gland, containing many of its exocrine proteases. Recent analysis of intraluminal corpora amylacea, a proposed by-product of PSG secretion, detected sulfated glycosaminoglycans (GAG) possibly keratan sulfate (KS),indicating a secretory mechanism for GAG in the human prostate surface epithelial cell. METHODS. Immunostains using anti-KS and anti-prostate-specific antigen (PSA) were evaluated on 10 sequential radical prostatectomy specimens, three of which had received neoadjuvant antiandrogen therapy. Extracts of normal secretory tissue as well as a sample composed almost entirely of prostatic stroma were subjected to Western blot analysis, using the same antibody panel. RESULTS. Keratan sulfate secretion from the normal prostate epithelial cell has been confirmed and correlates, as does PSA, with the presence of cytoplasmic PSG. No such correlation exists in most adenocarcinomas or in benign epithelium after androgen ablation. Western blot analyses confirmed tissue immunostains and demonstrated a secretory proteoglycan of 70-95 kDa. CONCLUSIONS. Recognition of PSG heralds a novel secretory mechanism within the human prostate gland that is linked to the secretion of KS. The role of KS in normal prostate secretion remains unknown, although it appears downregulated in neoplastic and androgen-ablated cells. (C) 2000 Wiley-Liss, Inc.

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Perforin (pfp) and interferon-gamma (IFN-gamma) together in C57BL/6 (B6) and BALB/c mouse strains provided optimal protection in 3 separate tumor models controlled by innate immunity. Using experimental (B6, RM-1 prostate carcinoma) and spontaneous (BALB/c, DA3 mammary carcinoma) models of metastatic cancer, mice deficient in both pfp and IFN-gamma were significantly less proficient than pfp- or IFN-gamma -deficient mice in preventing metastasis of tumor cells to the lung. Pfp and IFN-gamma -deficient mice were as susceptible as mice depleted of natural killer (NK) cells in both tumor metastasis models, and IFN-gamma appeared to play an early role in protection from metastasis, Previous experiments in a model of fibrosarcoma induced by the chemical carcinogen methylcholanthrene indicated an important role for NK1.1(+) T cells, Herein, both pfp and IFN-gamma played critical and independent roles in providing the host with protection equivalent to that mediated by NK1.1+ T cells, Further analysis demonstrated that IFN-gamma, but not pfp, controlled the growth rate of sarcomas arising in these mice. Thus, this is the first study to demonstrate that host IFN-gamma, and direct cytotoxicity mediated by cytotoxic lymphocytes expressing pfp independently contribute antitumor effector functions that together control the initiation, growth, and spread of tumors in mice, (C) 2001 by The American Society of Hematology.

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Pheochromocytomas are tumors of the adrenal medulla originating in the chromaffin cells derived from the neural crest. Ten % of these tumors are associated with the familial cancer syndromes multiple endocrine neoplasia type 2, von Hippel-Lindau disease (VHL), and rarely, neurofibromatosis type 1, in which germ-line mutations have been identified in RET, VHL, and NF1, respectively. In both the sporadic and familial forms of pheochromocytoma, allelic loss at 1p, 3p, 17p, and 22q has been reported, yet the molecular pathogenesis of these tumors is largely unknown. Allelic loss at chromosome 1p has also been reported in other endocrine tumors, such as medullary thyroid cancer and tumors of the parathyroid gland, as well as in tumors of neural crest origin including neuroblastoma and malignant melanoma, In this study, we performed fine structure mapping of deletions at chromosome 1p in familial and sporadic pheochromocytomas to identify discrete regions likely housing tumor suppressor genes involved in the development of these tumors. Ten microsatellite markers spanning a region of similar to 70 cM (Ipter to 1p34.3) were used to screen 20 pheochromocytomas from 19 unrelated patients for loss of heterozygosity (LOH). LOH was detected at five or more loci in 8 of 13 (61%)sporadic samples and at five or more loci in four of five (80%) tumor samples from patients with multiple endocrine neoplasia type 2. No LOH at 1p was detected in pheochromocytomas from two VHL patients, Analysis of the combined sporadic and familial tumor data suggested three possible regions of common somatic loss, designated as PCI (D1S243 to D1S244), PC2 (D1S228 to D1S507), and PC3 (D1S507 toward the centromere). We propose that chromosome Ip may be the site of at least three putative tumor suppressor loci involved in the tumorigenesis of pheochromocytomas. At least one of these loci, PC2 spanning an interval of <3.8 cM, is Likely to have a broader role in the development of endocrine malignancies.