Hippocampal mineralocorticoid receptor mRNA expression was increased in male hamsters exposed to 18 days of short photoperiod relative to animals maintained under long day illumination (p < 0.05). Short day hamsters were also characterized by increased weight gain, and heavier adrenal glands (p < 0.05). The larger adrenals showed selective increases in the widths of the zonae reticularis and glomerulosa (p < 0.001). Incidences of torpor and reduced body temperature were observed in the short day animals. No changes were found in reproductive organ weights, systolic blood pressure, open-field behavior, or stress levels of plasma corticosteroids. We conclude that the hamster brain-adrenal axis responds rapidly to changes in photoperiod, raising the possibility that this axis is a primary mediator of shortened photoperiod responses.

<p>Mnogi lekovi registrovani za razne druge indikacije mogu da deluju selektivno na tumorske receptore, signalne puteve, metaboličke procese, bioenergetske faktore, enzime, proteine, gene koji reguli&scaron;u proliferaciju, apoptozu i neoangiogenezu tumora ne pogađajući ove procese kod zdravih ćelija. Uvođenje novih lekova je izrazito dug, složen i skup proces istraživanja. Kori&scaron;ćenjem principa otkrivanja antikancerskog efekta kod već registrovanih lekova za druge indikacije, direktno se utiče na skraćivanje vremena i tro&scaron;kova istraživanja. Eksperimentalno je ispitana efikasnost antitumorskog delovanja mebendazola, metformina, itrakonazola, diklofenaka, nitroglicerina i deoksiholne kiseline na fibrosarkom hrčka izazvan BHK21/C13 tumorskom ćelijskom linijom praćenjem veličine i histologije lečenih tumora. Eksperimentalno je ispitana mogućnost primene deoksiholne kiseline, nitroglicerina, kofeina i itrakonazola kao adjuvansa u kombinaciji sa pojedinim ispitivanim lekovima (metformin, itrakonazol, diklofenak) za lečenje fibrosarkoma hrčka. Kako je ispitivanje vr&scaron;eno na mladuncima imladim hrčkovima i kako su sarkomi najče&scaron;ći u dečijem uzrastu, definisanje potencijalne antikancerske uloge ispitivanih lekova se odnosi prvenstveno na njihovu primenu u pedijatriji. Pokazano je da metformin, kombinacije metformina sa kofeinom, metformina sa itrakonazolom i metformina sa nitroglicerinom deluju u pogledu svih ispitivanih parametara tumora antitumorski na fibrosarkom hrčka. Kofein, itrakonazol i nitroglicerin pojačavaju antitumorsko dejstvo metformina na fibrosarkom hrčka. Tokom svih eksperimenata realizovanih u okviru ove disertacije, pokazalo se da nije bilo delotvornog tretmana, koji ne sadrži metformin.</p> / <p>Many drugs registered for various other indications can act selectively to tumor receptors, signaling pathways, metabolic processes, bioenergetic factors, enzymes, proteins, genes that regulate proliferation, apoptosis, and neoangiogenesis of the tumor without affecting these processes in the healthy cells. The introduction of new drugs is a very long, complex and expensive process of research. Using the principle of detecting the anticancer effect in already registered drugs for other indications, directly affects the reduction of time and cost of research. The efficacy of mebendazole, metformin, itraconazole, diclofenac, nitroglycerin and deoxycholic acid antitumor activity on hamster fibrosarcinoma induced experimentally by the BHK21/C13 tumor cell line was tested by monitoring the size and histology of the treated tumors. The possibility of using deoxycholic acid, nitroglycerin, caffeine and itraconazole as an adjuvant in combination with investigated drugs (metformin, itraconazole, diclofenac) for the treatment of hamster fibrosarcoma has been experimentally tested. As the examination was carried out on young cubs and young hamsters and that sarcomas are the most common in childhood, defining the potential anti-cancer role of the investigated drugs relates primarily to their application in pediatrics. Metformin, combinations of metformin with caffeine, metformin with itraconazole and metformin with nitroglycerin have shown antitumor action on the hamster fibrosarcoma in terms of all tested tumor parameters. Caffeine, itraconazole and nitroglycerin increase the antitumor effect of metformin on the hamster fibrosarcoma. During all the experiments carried out within this dissertation, there has been no effective treatment, which does not contain metformin.</p>

Submitted by Cleide Dantas (cleidedantas@ufpa.br) on 2014-02-11T16:15:35Z No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_InfeccaoExperimentalHamsters.pdf: 2790075 bytes, checksum: 7188971dc75068f0e71978c12c97f993 (MD5) / Approved for entry into archive by Ana Rosa Silva (arosa@ufpa.br) on 2014-04-14T14:16:05Z (GMT) No. of bitstreams: 2 Dissertacao_InfeccaoExperimentalHamsters.pdf: 2790075 bytes, checksum: 7188971dc75068f0e71978c12c97f993 (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) / Made available in DSpace on 2014-04-14T14:16:05Z (GMT). No. of bitstreams: 2 Dissertacao_InfeccaoExperimentalHamsters.pdf: 2790075 bytes, checksum: 7188971dc75068f0e71978c12c97f993 (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Previous issue date: 2007 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Os flebovírus (família Bunyaviridae; gênero Phlebovirus), possuem importância considerável em saúde publica, pois podem causar uma variedade de síndromes clínicas. Na região amazônica brasileira até o momento já foram isolados 23 flebovírus sendo que quatro se destacam por terem sido isolados de humanos: Virus Alenquer, Virus Candiru, Virus Morumbi e Virus Serra Norte. Estes mais o Virus Itaituba, isolado de Didelphis marsupialis, fazem parte do Complexo Candiru (grupo Candiru) e foram utilizados para estudos de caracterização genética e de infecção experimental em hamsters dourados (Mesocricetus auratus). Os Hamsters mostraram-se suscetíveis a infecção por esses flebovírus, apesar de não terem apresentado sinais de doença. A análise histopatológica demonstrou aspectos lesionais no fígado, nos rins, no baço, nos pulmões e no sistema nervoso central, sendo as lesões mais intensas no fígado comprovadas pela presença dos antígenos virais empregando a técnica de imunohistoquímica. A análise das seqüências nucleotídicas parciais dos segmentos PRNA e MRNA obtidas para os cinco flebovírus estudados mostraram maior similaridade genética entre si do que com outros membros do gênero Phlebovirus. Sendo as mesmas geneticamente mais relacionadas ao Virus Punta Toro. Filogeneticamente, independentemente do segmento genômico analisado, os cinco flebovírus constituem um grupo monofilético, sendo que a análise pelo método de máxima verossimilhança demonstrou diferentes origens evolutivas para os segmentos de RNA o que sugere a ocorrência de rearranjo genético em natureza entre estes cinco flebovírus amazônicos. / The phleboviruses (family Bunyaviridae, genus Phlebovirus) are of considerable public health importance, due to their association with human diseases causing different clinical syndromes. In the Brazilian Amazon region, 23 phlebovirus were presently isolated, four of them have been isolated from humans: Alenquer virus, Candiru virus, Morumbi virus, and Serra Norte virus. These and Itaituba virus, isolated from Didelphis marsupialis belong to the Candiru Complex (Candiru group) and were used for studies on genetic characterization and experimental infection using gold hamsters (Mesocricetus auratus) as animal model. Hamsters showed to be susceptible to infection by these viruses; however signs of disease were not observed. The histophatological analysis demonstrated damages in the liver, kidneys, lung, and central nervous system. More intense lesions were observed in the liver which were characterized by the presence of viral antigens detected by immunohistochemistry assay. The analysis of the partial SRNA and MRNA nucleotide sequences obtained for the five studied phleboviruses showed more similarity among them than with other members of the genus Phlebovirus.More over, is was demonstrated that these phleboviruses were more genetically related to Punta Toro virus. Phylogenetically, regardless of the genome segment analyzed, the five phleboviruses constitute a monophyletic group. In addition the analysis by maximum likelihood method demonstrated different evolutionary origins for the RNA segments, suggesting the occurrence of natural genetic reassortment among the five Amazonian phleboviruses.

No description available.