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1.
Monoclonal antibodies (MoAbs) raised against Trypanosoma cruzi microsomal fraction (Mc) and cross-reactive with mammalian tissues were used to evaluate the ability of cross-reactive T. cruzi antigens to induce an immune response in Chagas' disease. Thus, we studied the ability of sera from Chagas' disease patients (CDP) with different degrees of cardiac dysfunction to block the immune recognition of these MoAb to the target antigen determining for each serum an inhibition index (II). By means of this approach we inferred that blocking of monoclonal antibody binding to T. cruzi microsomes by subjects' serum represents antibodies with the same reactivity. After serological and medical examinations, individuals were separated into the following groups: Chagas' disease patients without manifest cardiac involvement (CDP-0), CDP with suspected or borderline cardiac disease (CDP-1), CDP with moderate myocardial dysfunction (CDP-2), CDP with overt cardiac dysfunction (CDP-3) and controls including healthy subjects (HS) and patients with idiopathic myocarditis (IMP). The reactivity between MoAb 5F2 and its target antigen was significantly (p < 0.05) inhibited by sera from CDP irrespective of the clinical stage [CDP: n = 46, 50 +/- 20, mean II +/- SD: control: n = 16, 18 +/- 8]. Moreover, 5F2 was able to distinguish (p < 0.05) sera from CDP with mild disease (CDP clinical grade 0/1: n = 26, 34 +/- 18) from that of CDP with severe disease (CDP clinical grade 2/3: n = 20, 67 +/- 7). Moreover, the inhibitory capacity of sera from asymptomatic CDP (CDP-0) correlated with patients age (r = 0.66, p < 0.05). CDP-0 below or equal 40 years of age had results (n = 15, 25 +/- 13) comparable (p > 0.05) to that of controls while mean inhibition of CDP-0 over 40 years of age (n = 5, 60 +/- 5) was indistinguishable (p > 0.05) from that of patients with severe disease. Competitive assay with MoAb 5A9B11 also showed significant differences (p < 0.05) between sera from CDP (n = 46, 46 +/- 24) and controls (n = 13, 5 +/- 5). On the contrary, the differences observed between CDP with different cardiac involvement was not significant (mild: n = 26, 31 +/- 22; severe: n = 20, 66 +/- 11). However a thorough study of data from asymptomatic sera revealed the existence of two levels of reactivity, with low and high capacity to inhibit the reaction of 5A9B11 against Mc. On the contrary, CDP sera showed a blocking activity for 1A10C11 comparable to that of controls (CDP: n = 25, 19 +/- 9; control: n = 12, 14 +/- 6). Some cross-reactive MoAbs recognized epitopes partially composed of carbohydrates. Interestingly, 5F2 and 5A9B11 epitopes did not appear to have carbohydrates moieties. In summary, immunoinhibition assays revealed differences in the immune response of chronic chagasic patients against parasite epitopes. These results have opened the possibility to identify a prognosis marker of the disease suggesting the clinical utility of monitoring levels of these anti-Mc antibodies in patients with chronic Chagas' disease.  相似文献   

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BACKGROUND: Pemphigus vulgaris is a potentially life-threatening autoimmune disease. Although combination therapies with prednisone and azathioprine are usually effective in controlling the disease, some patients either do not respond to this treatment or show early relapses. OBJECTIVE: To find out whether mycophenolate mofetil would be an effective drug in controlling pemphigus vulgaris in patients who failed initial treatment with azathioprine and prednisone. RESULTS: Twelve patients who were initially diagnosed as having pemphigus vulgaris and had relapsed while undergoing treatment with azathioprine (1.5-2 mg/kg of body weight) and prednisolone (2 mg/kg of body weight) subsequently received combination therapy with mycophenolate mofetil (2 x 1 g/d) and prednisolone (2 mg/kg of body weight per day). Eleven of the 12 patients responded to therapy and showed no relapse of their disease even after tapering of the steroid dose. One patient did not respond. Toxic effects were low with only mild gastrointestinal symptoms in 5 patients and mild lymphopenia (World Health Organization grade I) in 9 patients. During the 9- to 12-month follow-up, none of the 11 patients showed reappearance of pemphigus lesions. CONCLUSION: Treatment of pemphigus vulgaris with mycophenolate is a safe and effective treatment.  相似文献   

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The development of an antigen presentation system based on the plum pox potyvirus (PPV) is here described. The amino-terminal part of PPV capsid protein was chosen as the site for expression of foreign antigenic peptides. Modifications in this site were engineered to avoid the capability of natural transmission by aphids of this PPV vector. As a first practical attempt, different forms of an antigenic peptide (single and tandem repetition) from the VP2 capsid protein of canine parvovirus (CPV) were expressed. Both chimeras are able to infect Nicotiana clevelandii plants with similar characteristics to wild-type virus and remain genetically stable after several plant passages. The antigenicity of purified chimeric virions was demonstrated, proving the suitability of this system for diagnostic purposes. Moreover, mice and rabbits immunized with chimeric virions developed CPV-specific antibodies, which showed neutralizing activity.  相似文献   

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Measures of functional vision are needed to assess elderly low vision patients, their success in using devices, and their ability to manage outside the treatment setting. A new test devised to measure functional ability through the performance of everyday tasks was administered to 94 patients who had acuities of 20/100 or worse in their better eye. Consisting of three versions and four subtests: spot reading, short-term text reading, identifying paper currency and clock reading, the test used standardized items and was timed. In a multiple regression model predicting test performance higher scores were associated with better near acuity (P = .002), higher education (P = .022) and higher levels of self-reported visual skills (P = .072). These predictors plus distance acuity, age and sex only accounted for 35 percent of the variance in test scores. Repeated administration of the test to a different group of 21 patients showed the test to be reliable (intraclass correlation = .85, P < .01) and to have no practice or version effects or differences between raters. This new test may be useful for natural history studies and clinical trials involving low vision patients but further evaluation of its sensitivity to change over time is required.  相似文献   

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1. Nicotinylalanine, an inhibitor of kynurenine metabolism, has been shown to elevate brain levels of endogenous kynurenic acid, an excitatory amino acid receptor antagonist. This study examined the potential of nicotinylalanine to influence excitotoxic damage to striatal NADPH diaphorase (NADPH-d) and gamma-aminobutyric acid (GABA)ergic neurones that are selectively lost in Huntington's disease. 2. A unilateral injection of the N-methyl-D-aspartate (NMDA) receptor agonist, quinolinic acid, into the rat striatum produced an 88% depletion of NADPH-d neurones. Intrastriatal infusion of quinolinic acid also produced a dose-dependent reduction in striatal GABA content. 3. Nicotinylalanine (2.3, 3.2, 4.6, 6.4 nmol 5 microl(-1), i.c.v.) administered with L-kynurenine (450 mg kg(-1)), a precursor of kynurenic acid, and probenecid (200 mg kg(-1)), an inhibitor of organic acid transport, 3 h before the injection of quinolinic acid (15 nmol) produced a dose-related attenuation of the quinolinic acid-induced loss of NADPH-d neurones. Nicotinylalanine (5.6 nmol 5 microl(-1)) in combination with L-kynurenine and probenecid also attenuated quinolinic acid-induced reductions in striatal GABA content. 4. Nicotinylalanine (4.6 nmol, i.c.v.), L-kynurenine alone or L-kynurenine administered with probenecid did not attenuate quinolinic acid-induced depletion of striatal NADPH-d neurones. However, combined administration of kynurenine and probenecid did prevent quinolinic acid-induced reductions in ipsilateral striatal GABA content. 5. Injection of nicotinylalanine, at doses (4.6 nmol and 5.6 nmol i.c.v.) which attenuated quinolinic acid-induced striatal neurotoxicity, when combined with L-kynurenine and probenecid produced increases in both whole brain and striatal kynurenic acid levels. Administration of L-kynurenine and probenecid without nicotinylalanine also elevated kynurenic acid, but to a lesser extent. 6. The results of this study demonstrate that nicotinylalanine has the potential to attenuate quinolinic acid-induced striatal neurotoxicity. It is suggested that nicotinylalanine exerts its effect by increasing levels of endogenous kynurenic acid in the brain. The results of this study suggest that agents which influence levels of endogenous excitatory amino acid antagonists such as kynurenic acid may be useful in preventing excitotoxic damage to neurones in the CNS.  相似文献   

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The neuropeptide galanin elicits a range of biological effects by interaction with specific G-protein-coupled receptors. Human and rat GALR1 galanin receptor cDNA clones have previously been isolated using expression cloning. We have used the human GALR1 cDNA in hybridization screening to isolate the gene encoding GALR1 in both human (GALNR) and mouse (Galnr). The gene spans approximately 15-20 kb in both species; its structural organization is conserved and is unique among G-protein-coupled receptors. The coding sequence is contained on three exons, with exon 1 encoding the N-terminal end of the receptor and the first five transmembrane domains. Exon 2 encodes the third intracellular loop, while exon 3 encodes the remainder of the receptor, from transmembrane domain 6 to the C-terminus of the receptor protein. The mouse and human GALR1 receptor proteins are 348 and 349 amino acids long, respectively, and display 93% identity at the amino acid level. The mouse Galnr gene has been localized to Chromosome 18E4, homoeologous with the previously reported localization of the human GALNR gene to 18q23 in the same syntenic group as the genes encoding nuclear factor of activated T-cells, cytoplasmic 1, and myelin basic protein.  相似文献   

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We report here a counter-selectable marker system for genetic transformation of the yeast Schwanniomyces alluvius, based on the complementation of uracil auxotrophs defective in either orotidine-5'-phosphate decarboxylase (URA3) or orotidine-5'-pyrophosphate (URA5). Uracil auxotrophs of S. alluvius were obtained by ethyl methanesulphonate mutagenesis and complemented using the ura3 gene from S. cerevisiae. A transformation frequency of approximately 10(4)/micrograms DNA was obtained, which is tenfold higher than results described in either reports. Transformants were analysed by Southern blot hybridisation and were found to be mitotically stable. The extrachromosomal nature of the transforming DNA was confirmed by Southern hybridisation and plasmid rescue. The rescued plasmid DNA had a restriction pattern identical to that of the parent plasmid.  相似文献   

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The morphologic and functional characteristics of cultured hair follicle dermal papilla (DP) cells, dermal sheath (DS) cells and interstitial dermal fibroblasts (DF cells) derived from human scalp tissue are compared. DP and DS cells, but not DF cells, showed aggregative behavior at a preconfluent density. All three types of cells stained positive for type I collagen, type IV collagen, laminin and heparan sulfate proteoglycan. Only DP and DS cells expressed smooth muscle alpha-actin. DP and DS cells also synthesized more glycosaminoglycans (GAG) than DF cells, while there was no significant difference between DP and DS cells in GAG synthesis. Ultrastructurally, 7 out of 10 strains of DP and 2 out of 10 strains of DS cells were found to form intranuclear rodlets, while none of the 10 strains of DF cells examined formed intranuclear rodlets. The conditioned medium of the three types of cells was collected and tested for the presence of interleukin (IL)-1 beta, tumor necrosis factor (TGF)-beta 2, IL-6, platelet-derived growth factor-AB, epidermal growth factor, b-FGF, GM-CSF, insulin-like growth factor (IGF)-1 and HGF (hepatocyte growth factor) by ELISA or RIA. Among the tested cytokines and growth factors, TGF-beta 2, IL-6 and IGF-I were detectable in at least some conditioned media. The others were undetectable. There was no significant difference in the production of IL-6 and IGF-I among the three types of cells. In contrast, DP cells produced the highest levels of TGF-beta 2, DS cells produced intermediate levels of TGF-beta 2, and DF cells produced the lowest levels of TGF-beta 2. DP and DS cells are morphologically and functionally different from the nonfollicular, interstitial DF cells. Moreover, the presence of some minor biologic differences between DP and DS cells suggests that they represent follicular mesenchymal cells in different functional or differentiation states.  相似文献   

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Insulin receptor substrate (IRS) proteins are key regulators of basic functions such as cellular growth and metabolism. They provide an interface between multiple receptors and a complex network of intracellular signaling molecules. Two members of this family (IRS-1 and IRS-2) have been identified previously. In this investigation, we analyzed a mouse expressed sequence tag clone that proved to be a new member of the IRS family. Sequence analysis of this clone and comparison with the sequences deposited in GenBank demonstrates this protein may be the murine homolog of rat IRS-3, recently purified and cloned from rat adipocytes. Accordingly, we have named our protein mouse IRS-3. The expressed sequence tag clone contains the complete coding sequence of 1485 bp, encoding a protein of 495 amino acids. Sequence alignment with the other members of the IRS family shows that this protein contains pleckstrin homology and phosphotyrosine-binding domains that are highly conserved. In addition, there is conservation of many tyrosine phosphorylation motifs responsible for interactions with downstream signaling molecules containing SH2 domains. The murine IRS-3 messenger RNA (2.4 kilobases in length) is expressed in many tissues, with highest levels in liver and lung. Mouse IRS-3 is highly expressed in the first part of the embryonic life, when IRS-1 messenger RNA is barely detectable. Unlike the genes encoding IRS-1 and IRS-2, the IRS-3 gene contains an intron (344 bp in length) in the region between the pleckstrin homology and the phosphotyrosine-binding domains. Fluorescent in situ hybridization localized the mouse IRS-3 gene on the telomeric region of chromosome 5G2. Cloning of the murine IRS-3 gene will make it possible to apply genetic approaches to elucidate the physiological role of this new member of the IRS family of proteins.  相似文献   

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The screening of a human genomic library with a chemokine receptor-like probe allowed us to obtain a putative member of the G protein-coupled receptor gene (GPCR) family, designated GPR31. Its deduced amino acid sequence encodes a polypeptide of 319 amino acids that shares 25-33% homology with members of the chemokine, purino, and somatostatin receptor gene families. Amino acid sequence comparison reveals that the best match in the protein databases is with the human orphan GPCR called HM74 (33% identity). Southern genomic analysis of the GPR31 gene shows a hybridization pattern consistent with that of a single-copy gene. Using fluorescence in situ hybridization, we have determined the chromosomal and regional localization of the GPR31 gene at 6q27. The GPR31 mRNA is expressed at low levels by several human cell lines of different cellular origins. The phylogenetic analysis suggests that the GPR31 receptor may represent a member of a new GPCR subfamily.  相似文献   

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Prostate-specific membrane antigen (PSMA) is a 100 kDa type II transmembrane protein with folate hydrolase and NAALAdase activity. PSMA is highly expressed in prostate cancer and the vasculature of most solid tumors, and is currently the target of a number of diagnostic and therapeutic strategies. PSMA is also expressed in the brain, and is involved in conversion of the major neurotransmitter NAAG (N-acetyl-aspartyl glutamate) to NAA and free glutamate, the levels of which are disrupted in several neurological disorders including multiple sclerosis, amyotrophic lateral sclerosis, Alzheimer's disease and schizophrenia. To facilitate analysis of the role of PSMA in carcinoma we have determined the structural organization of the gene. The gene consists of 19 exons spanning approximately 60 kb of genomic DNA. A 1244 nt portion of the 5' region of the PSMA gene was able to drive the firefly luciferase reporter gene in prostate but not breast-derived cell lines. We have mapped the gene encoding PSMA to 11p11-p12, however a gene homologous, but not identical, to PSMA exists on chromosome 11q14. Analysis of sequence differences between non-coding regions of the two genes suggests duplication and divergence occurred 22 million years ago.  相似文献   

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Drug-food interactions in hospitalised patients may result in decreased drug efficacy or increased drug toxicity. The increasing complexity of drug therapy regimens has increased the potential for drug-food interactions to occur, reinforcing the need to develop methods to prevent clinically significant drug-food interactions. Before selecting the optimal method, in terms of feasibility of implementation and successful outcome, drugs with the potential for clinically significant interactions with food must be identified. From an analysis of the literature, 6 methods to prevent drug-food interactions have been suggested as useful tools. Each method has its own advantages and disadvantages. Most have been developed in response to guidelines from the most well recognised agency for quality review in the US, the Joint Commission on Accreditation of Healthcare Organisations (JCAHO). Based on those recommendations, an ideal programme to prevent drug-food interactions would be a combined patient counselling and label system to select the most appropriate drug administration times and increase nurse and patient awareness of the potential for drug-food interactions. However, because of time constraints and limited resources, a label system or the provision of a drug-food interaction pamphlet to the patient before discharge would be a more practical method. Newsletters and educational in-services combined with patient counselling or a label system would be a valuable method to prevent drug-food interactions in hospitalised patients.  相似文献   

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A cDNA clone coding for human casein kinase I (CK1) has been isolated and sequenced. The insert of 1911 bp contained an open reading frame of 415 amino acids. The entire amino acid sequence of human CK1 was 97% homologous to that of rat CK1 delta, and their sequences in the kinase domain (284 amino acid residues) were completely identical, predicting that the obtained cDNA is for a human homolog of the CK1 delta isoform (CSNKID). The considerable similarity in the amino acid sequence of the kinase domain of human CK1 delta to the Saccharomyces cerevisiae CK1, HRR25 (66%), and to the Saccharomyces pombe CK1, HHP1 (78%), which are involved in the repair of DNA strand break, supports the speculation that human CK1 delta might also act in DNA metabolism through excision and recombinational repair. The human CK1 delta gene was mapped to chromosome 17q25.2-q25.3 by fluorescence in situ hybridization and polymerase chain reaction analysis of the human/rodent hybrid cell panels.  相似文献   

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