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81.
It is becoming widely accepted that the inflammatory response is involved in neurodegenerative disease. In this context, we have developed an animal model of dopaminergic system degeneration by the intranigral injection of lipopolysaccharide (LPS), a potent inductor of inflammation. To address the importance of the inflammatory response in the LPS-induced degeneration of nigral dopaminergic neurones, we carried out two different kinds of studies: (i) the possible protective effect of an anti-inflammatory compound, and (ii) the effect of the intranigral injection of inflammatory cytokines (TNF-alpha, IL-1beta and IFN-gamma) on dopaminergic neurones viability. Present results show that dexamethasone, a potent anti-inflammatory drug that interferes with many of the features characterizing pro-inflammatory glial activation, prevented the loss of catecholamine content, Tyrosine hydroxylase (TH) activity and TH immunostaining induced by LPS-injection and also the bulk activation of microglia/macrophages. Surprisingly, injection of the pro-inflammatory cytokines failed to reproduce the LPS effect. Taken together, our results suggest that inflammatory response is implicated in LPS-induced neurodegeneration. This damage may be due, at least in part, to a cascade of events independent of that described for TNF-alpha/IL-1 beta/IFN-gamma. 相似文献
82.
Cytometric,morphologic and enzymatic characterisation of haemocytes in Anodonta cygnea 总被引:2,自引:0,他引:2
Soares-da-Silva IM Ribeiro J Valongo C Pinto R Vilanova M Bleher R Machado J 《Comparative biochemistry and physiology. Part A, Molecular & integrative physiology》2002,132(3):541-553
The haemocytes in bivalve mussels are involved in many processes such as lesion repair, shell repair, elimination of small particles and toxic substances. In Anodonta cygnea there are two categories of haemolymph cells, the granulocytes and hyalinocytes. Two groups of cells were identified by flow cytometry and morphological studies: one with larger size and granularity representing 75%, and another group of cells (25%) which were approximately half the size. The cytochemical reactions showed peroxidase activity in the larger cells and a weak prophenoloxidase activity in the smaller cells. These characteristics suggest that the most common haemocytes are granulocytes and hyalinocytes are less common. Enzymatic studies showed clear activities of few enzymes in different compartments of the mantle. Both haemocytes presented significant variations for alpha-manosidase and beta-glucurosidase activities depending on the acid or alkaline pH. Almost all were sensitive to the pH changes, mainly the beta-galactosidase in the haemolymph plasma. On the contrary, the same enzymatic analysis in the extrapallial elements showed more stabilised activities. The simulation of acidic and alkaline condition with the observation of significant morphological and enzymatic activity changes, allow us to speculate some functional role, mainly in the haemolymph elements. The granulocytes may be speculated to have intense involvement in the digestion of small residues with the formation of calcareous stores while the hyalinocytes are more responsible for the elimination of soluble cytotoxic compounds. 相似文献
83.
Macedo ML das Graças Machado Freire M Novello JC Marangoni S 《Biochimica et biophysica acta》2002,1571(2):83-88
Bruchid larvae cause major losses in grain legume crops throughout the world. Some bruchid species, such as the cowpea weevil and the Mexican bean weevil, are pests that damage stored seeds. Plant lectins have been implicated as antibiosis factors against insects, particularly the cowpea weevil, Callosobruchus maculatus. Talisia esculenta lectin (TEL) was tested for anti-insect activity against C. maculatus and Zabrotes subfasciatus larvae. TEL produced ca. 90% mortality to these bruchids when incorporated in an artificial diet at a level of 2% (w/w). The LD(50) and ED(50) for TEL was ca. 1% (w/w) for both insects. TEL was not digested by midgut preparations of C. maculatus and Z. subfasciatus. The transformation of the genes coding for this lectin could be useful in the development of insect resistance in important agricultural crops. 相似文献
84.
The attachment of Clinostomum sp. to the oesophagus of the bird definitive host Ardea cocoi is reported. The parasite attaches to the mucous layer of the oesophagus by the acetabulum, oral sucker, and oral collar. The mucous layer of the oesophagus engulfed by the oral sucker presents an intense liquefactive necrosis, and the engulfment is not likely to contribute significantly to the attachment of the parasite. The oral collar of the parasite, surrounding the oral sucker, is juxtaposed to the oesophagus mucous layer, showing a perfect fitting of both surfaces. It is concluded that the main attachment mechanism of the parasites to the oesophagus of the host is provided by the acetabulum and by the juxtaposition of the oral collar of the parasites to the oesophagus host surface. 相似文献
85.
Pigeons were placed in a long chamber equipped with one key and feeder at each end side and one key and houselight at the middle. To obtain food the birds had to choose one side key after a short signal and the other side key after a long signal. The signals consisted of the illumination of the center key and the houselight and were initiated by a peck at the center key. The chamber had sensitive floor panels that enabled us to measure the location of the bird during the signals. In Experiment 1, after the birds learned the discrimination we reversed the assignment of keys to signals. In Experiment 2, we examined performance on two pairs of discriminations holding the same ratio. In Experiment 3, after the pigeons learned to discriminate two signals, we changed the duration of the long signal. The results showed that (a) the birds' motion during the signal was highly stereotypical, i.e. the birds moved to the short side, waited a few seconds, and then departed to, and stayed on the long side; (b) this motion pattern predicted the results of generalization tests with novel durations; (c) the mean of the times of departure from the short side approached its steady state values quicker than the standard deviation and consequently superposition of behavioral measures became stronger with training; (d) only the duration of the short signal influenced significantly the moment the birds departed from the short side; finally (e) the times of arrival at and departure from the short side were positively correlated, but the times of arrival and residence at the short side were negatively correlated. 相似文献
86.
Martinez EM Correia JA Villela EV Duarte AN Ferreira LF Bello AR 《Memórias do Instituto Oswaldo Cruz》2003,98(Z1):59-62
Random amplified polymorphic DNA analysis was applied to DNAs extracted from Trichuris trichiura eggs recovered from human fecal samples. Four out of 6 primers tested displayed 18 distinct and well defined polymorphic patterns, ranging from 650 to 3200 base pairs. These results, upon retrieval and DNA sequencing of some of these bands from agarose gels, might help in establishing. T. trichiura specific genetic markers, not available yet, and an important step to design primers to be used in molecular diagnosis approaches. 相似文献
87.
Neves RH Costa-Silva M Martinez EM Biolchini Cde L Lenzi HL Gomes DC Machado-Silva JR 《Memórias do Instituto Oswaldo Cruz》2003,98(3):361-365
Schistosoma mansoni adult worms with genital anomalies isolated from Nectomys squamipes (Muridae: Sigmodontinae) were studied by confocal laser scanning microscopy under the reflected mode. One male without testicular lobes (testicular agenesia/anorchism) and two females, one with an atrophied ovary and another with 17 uterine eggs, were identified. The absence of testicular lobes occurred in a worm presenting otherwise normal male adult characteristics: tegument, tubercles and a gynaecophoric canal with spines. In both female specimens the digestive tube showed a vacuolated appearance, and the specimen with supernumerary uterine eggs exhibited a developing miracidium and an egg with a formed shell. The area of the ventral sucker was similar in both specimens however the tegument thickness, ovary and vitelline glands of the specimen with the atrophied ovary were smaller than those of the one with supernumerary eggs. These reported anomalies in the reproductive system call attention to the need to improve our understanding of genetic regulation and the possible role of environmental influences upon trematode development. 相似文献
88.
Mello GC Oliva ML Sumikawa JT Machado OL Marangoni S Novello JC Macedo ML 《Journal of Protein Chemistry》2001,20(8):625-632
A second trypsin inhibitor (DMTI-II) was purified from the seed of Dimorphandra mollis (Leguminosae-Mimosoideae) by ammonium sulfate precipitation (30–60%), gel filtration, and ion-exchange and affinity chromatography. A molecular weight of 23 kDa was estimated by gel filtration on a Superdex 75 column SDS-PAGE under reduced conditions showed that DMTI-II consisted of a single polypeptide chain, although isoelectric focusing revealed the presence of three isoforms. The dissociation constant of 1.7 × 10–9 M with bovine trypsin indicated a high affinity between the inhibitor and this enzyme. The inhibitory activity was stable over a wide pH range and in the presence of DTT. The N-terminal sequence of DMTI-II showed a high degree of homology with other Kunitz-type inhibitors. 相似文献
89.
Melo AC Valle D Machado EA Salerno AP Paiva-Silva GO Cunha E Silva NL de Souza W Masuda H 《Insect biochemistry and molecular biology》2000,30(7):549-557
The synthesis and secretion of vitellogenin by the ovary of Rhodnius prolixus was investigated. Using whole ovary or epithelial cells isolated from follicles of different sizes, it is shown that the follicle cells are a site of synthesis for this protein in the ovary. The ovaries or follicle cells were incubated in vitro with [(35)S]-methionine or (32)Pi and the secretion of newly synthesized ovarian vitellogenin (O-Vg) was estimated by the radioactivity associated with the immunoprecipitate or acid-precipitate proteins in the culture medium. The radioactive O-Vg was analyzed by SDS-PAGE followed by autoradiography or after elution from a DEAE-Toyopearl column. The presence of O-Vg inside the follicle cells was detected by immunofluorescence and immunogold labels. Both methods revealed strong labeling inside the follicle cells. While the capacity for total protein synthesis by the follicle cells was maximal during the early phase of vitellogenesis (in small follicles), the synthesis of O-Vg reached its peak during the late phase of oocyte growth, just before formation of the chorion. A possible role for ovarian vitellogenin in Rhodnius and its relationship with Vg synthesis by the fat body is discussed. 相似文献
90.
Machado BH Castania JA Bonagamba LG Salgado HC 《American journal of physiology. Heart and circulatory physiology》2000,279(1):H67-H75
The effect of sequential blockade of N-methyl-D-aspartic acid (NMDA) receptors with DL-2-amino-5-phosphonopentanoic acid (AP-5) and non-NMDA receptors with 6,7-dinitroquinoxaline-2,3 dione (DNQX) in the nucleus tractus solitarii (NTS) on the cardiovascular responses to electrical stimulation (ES) of the aortic depressor nerve (ADN) was evaluated in awake rats. Two protocols were used. In protocol 1, bilateral microinjection of AP-5 into the NTS (n = 7) reduced the hypotensive response to ES of the ADN; subsequent microinjection of DNQX produced additional reduction in this response. AP-5 reduced the bradycardic response, and DNQX almost abolished this response. In protocol 2, bilateral microinjection of DNQX into the NTS (n = 6) reduced the hypotensive response, and subsequent microinjection of AP-5 significantly reduced this response. DNQX produced a significant reduction in bradycardic response, and AP-5 abolished this response. The data indicate that processing of the parasympathetic component of the NTS aortic baroreceptor afferents is mediated by both NMDA and non-NMDA receptors, whereas processing of the sympathoinhibitory component seems to be only partially mediated by ionotropic receptors. 相似文献