154 resultados para acetyl group specificity
em Scielo Saúde Pública - SP
Resumo:
Platelet-activating factor (PAF) is one of the most potent lipid mediators involved in inflammatory events. The acetyl group at the sn-2 position of its glycerol backbone is essential for its biological activity. Deacetylation induces the formation of the inactive metabolite lyso-PAF. This deacetylation reaction is catalyzed by PAF-acetylhydrolase (PAF-AH), a calcium independent phospholipase A2 that also degrades a family of PAF-like oxidized phospholipids with short sn-2 residues. Biochemical and enzymological evaluations revealed that at least three types of PAF-AH exist in mammals, namely the intracellular types I and II and a plasma type. Many observations indicate that plasma PAF AH terminates signals by PAF and oxidized PAF-like lipids and thereby regulates inflammatory responses. In this review, we will focus on the potential of PAF-AH as a modulator of diseases of dysregulated inflammation.
Resumo:
Vaccinal and wild strains of Newcastle Disease virus (NDV) were analyzed for cell receptor binding and fusogenic biological properties associated with their HN (hemagglutinin-neuraminidase) and F (fusion protein) surface structures respectively. The evaluation of the biological activities of HN and F was carried out respectively by determination of hemagglutinating titers and hemolysis percentages, using erythrocytes from various animal origins at different pH values. Significant differences in hemagglutination titers for some strains of NDV were detected, when interacting with goose, sheep, guinea-pip and human "O" group erythrocytes at neutral pH. Diversity of hemolysis percentagens was observed between different NDV strains at acid pH. These analysis were developed to evaluate particular aspects of the actual influence of the receptor specifity and pH on the receptor binding and fusogenic processes of Newcastle Disease viruses.
Resumo:
The clinical value of an in-house cytomegalovirus nested polymerase chain reaction (CMV-PCR) and a commercial molecular assay hybrid capture CMV DNA assay (HCA) was evaluated in monitoring a group of renal transplant patients for six months follow up. In this study, the sensitivity, specificity, positive predictive value, and negative predictive value of nested CMV DNA PCR assay and HCA at the beginning of the study were 70, 42.9, 46.7, 66.7, and 60, 78.6, 66.7, and 73.3% respectively. After six months, they were 80, 66.7, 80, 66.7 for CMV PCR and 73.3, 88.9, 91.7, 66.7% for HCA respectively. These results indicate that in monitoring and predicting CMV infections in renal transplant recipients, not only qualitative but also quantitative assays must be used together in order to decide the preemptive strategies.
Resumo:
Angiostrongylus cantonensis and Gnathostoma spinigerum are the two most common causative parasites of eosinophilic meningitis (EOM). Serological tests are helpful tools for confirming the identity of the pathogen. Recent reports determined the specificity of such tests by using normal healthy controls. There have been limited studies done to rule out the cross-reactivity between these two causative parasites of EOM. This study aims to assess the specificity of the serological test in EOM by using each condition as a control for the other. Thirty-three patients with a diagnosis of EOM were enrolled. Sera from 22 patients with a positive 29-kDa antigenic diagnostic band of A. cantonensis were tested for the 21 and 24-kDa antigenic bands of G. spinigerum. Similarly, sera of 11 gnathostomiasis patients were tested for the 29-kDa diagnostic band for A. cantonensis. Only one patient in the angiostrongyliasis group had a positive result for the 21 and 24-kDa antigenic bands of G. spinigerum, while no gnathostomiasis patients showed a positive result for the 29-kDa antigenic band of A. cantonensis. The specificity of the 21 and 24-kDa antigenic bands for gnathostomiasis and the 29-kDa antigenic band for A. cantonensis was 95.5% and 100%, respectively. The antigenic bands for the diagnosis of gnathostomiasis and angiostrongyliasis in EOM were highly specific.
Resumo:
The treatment of some mesenchymal malignancies has made significant gains over the past few decades with the development of effective systemic therapies. In contrast, the treatment of chondrosarcoma has been limited to surgical resection, with the most significant prognostic indicators being surgical margins and histologic grade. We have reported that MMP-1/TIMP-1 gene expression serves to prognosticate for tumor recurrence in this group of patients. This led to the hypothesis that collagenase activity facilitates cell egression from the cartilaginous matrix. In the current study we examine the specificity of collagenase gene expression in archival human chondrosarcoma samples using semi-quantitative PCR. Messenger RNA was affinity extracted and subject to reverse transcription. The subsequent cDNA was amplified using novel primers and quantitated by densitometry. Ratios of gene expression were constructed and compared to disease-free survival. The data demonstrate that the significance of the MMP-1/TIMP-1 ratio as a predictor of recurrence is confirmed with a larger number of patients. Neutrophil collagenase or MMP-8 was observed in only 5 of 29 samples. Collagenase-3 or MMP-13 was observed in all samples but the level did not correlate with disease-free survival. Since the collagenases have similar activity for fibrillar collagens and cleave the peptide in the same location, post-transcriptional regulatory mechanisms may account for the observed specificity. The determination of the MMP-1/TIMP-1 gene expression ratio not only serves to identify those patients at risk for recurrence but may also serve as a novel therapeutic avenue as an adjunct to surgical resection.
Resumo:
Estudos sobre sistemas etários na África Oriental têm focado principalmente as regras que regulam recrutamento, com ênfase ao modo em que se mantém a autoridade e os cargos políticos, assim como à natureza não-militar e não-política dos sistemas etários. Apesar de contribuírem enormemente para a nossa compreensão das organizações etárias na região, esses estudos não lidam explicitamente com a questão da propriedade e com o modo em que ela constitui um dos principais focos para atividades de organizações etárias. De fato, quando se menciona a propriedade, ela é vista em função das famílias e, portanto, do parentesco. Apresentando e discutindo uma variedade de casos envolvendo o modo em que a propriedade é tratada por lideranças de um conjunto etário/geracional e residentes Hor e não-Hor do território Hor, este estudo conclui que a posse, o uso e controle de recursos não constitui um assunto que pertence exclusivamente à esfera de grupos de parentesco; trata-se também de uma questão central para organizações etárias. Apesar de haver, aparentemente, alguma ambigüidade decorrente da ênfase equilibrada que os Hor dedicam ao parentesco e às categorias etárias e suas complementaridades em assuntos relacionados à economia, à religião e ao direito, dados referentes aos Hor revelam uma tendência a tratar questões referentes ao uso de recursos cruciais em termos de organização etária. Trata-se de um estudo sobre os Hor (Arbore), um povo pastoril do Sudoeste da Etiópia.
Resumo:
A study of health knowledge and practices of prostitutes is presented here. The study took place at the V. D. Center in Saigon, Vietnam. It was designed with the objective of obtaining information to be used in preparing an educational program to be offered to the prostitutes at the Center, and for using, in preparing educational materials with focus on V. D. prevention. The outline of a course is also presented.
Resumo:
Since the number and proportion of old people increases worldwide, health professionals and systems should be made aware and prepared to deal with their problems. Cognitive deficit and symptoms of depression are commom among the elderly, and may occur in relation to various risk factors such as health conditions and psychosocial variables. In order to study cognitive deficit and the presence of signs and symptoms of depression, 62 elderly community subjects enrolled at a Community Health Unit in Porto Alegre, southern Brazil, were interviewed. They were evaluated by means of the Mini Mental State Exam, the Montgomery-Asberg Depression rating scale, and a questionnaire on health conditions, living arrangements and social variables. Higher levels of symptoms of depression were observed among subjects exposed to major risk factors for cerebrovascular diseases (diabetes and coronary disease), while impaired cognitive performance was seen among individuals who could not count on the presence of a confidant (social network variable). The results suggest that the early identification of major risk groups among old people can help to prevent institutionalization and keep individuals in the community.
Resumo:
OBJECTIVE: To analyze the core group for sexually transmitted infections (STI) among college students. METHODS: Cross-sectional study carried out in a convenience sample comprising 711 college students of the public university of Morelos, Mexico, between 2001 and 2003. Sociodemographic and sexual behavior information were collected using self-applied questionnaires. Herpes simplex 2 (HSV-2) infection was tested in the blood. The number of sexual partners in the last year and cocaine consumption were used as indicators to construct the dependent variable "level of STI risk" in three categories: low, medium and high risk (core group). A multinomial analysis was conducted to evaluate whether different sex behaviors were associated with the variable "level of STI risk". RESULTS: There was significant association between HSV-2 seroprevalence and the variable "level of STI risk": 13%, 5.6% and 3.8% were found in high (core group), medium and low categories, respectively. There were gender differences regarding the core group. Men started having sexual intercourse earlier, had more sex partners, higher alcohol and drug consumption, higher frequency of sex intercourse with sex workers, exchanging sex for money, occasional and concurrent partners compared to women. CONCLUSIONS: The study findings suggest existing contextual characteristics in the study population that affect their sex behavior. In Mexico, the cultural conception of sexuality is determined mainly by gender differences where men engage in higher risky sexual behavior than women.
Resumo:
IIF in the detection of invasive and classic enteropathogenic E. coli and Shigella serotypes was compared with traditional coproculture methods. IIP results agreed with the coproculture findings in 128 out of 140 cases tested for enteropathogenic E. coli (91%) and in 108 out of 112 for Shigella (96%). All cases with positive reactions by coproculture were confirmed by IIP. In the control group it were obtained by IIF 12 cases with positive reactions for enteropathogenic E. coli and 4 cases for Shigella, including two cases of mixed infection by E. coli 026/Sh. dysenteriae and E. coli 0124/Sh. dysenteriae. It was discussed the high sensitivity and specificity of the IIF when compared with the traditional methods, being suggested that IIF is a valuable tool in epidemiological studies involving these organisms and an important aid in the stablishment of an early presumptive diagnosis of the acute infantile diarrhea.
Resumo:
The clinical and laboratory data of a disease in a resident of Ribeira Valley, São Paulo State, southeastern Brazil, caused by an agent close or identical to Caraparu, a Group C arbovirus, was described. Although there is evidence of an intensive circulation of several arboviruses in the area, no diagnosis of human disease by these agents has been made, except the encephalitis cases caused by Rocio virus during an epidemic in 1975-1977. An antigenic difference between Caraparu strains isolated in São Paulo and in Pará States and a close antigenic relationship between Caraparu strain from São Paulo and Bruconha virus were suggested by the serological tests.
Resumo:
A serologic study was undertaken in a group of 43 patients with active paracoccidioidomycosis who were treated in the same form (ketoconazole), for identical periods of time (6 months), and folio wed-up for various periods posttherapy. The tests employed were agar gel immunodiffusion (AGID) and complement fixation (FC). Also studied were 50 sera from patients with proven histoplasmosis and pulmonary aspergilloma, 30 patients with culturaly proven tuberculosis as well as 92 specimens from healthy individuals, residents in the endemic area for paracoccidioidomycosis. A single lot of yeast filtrate antigen was used throughout the study. The value of each test was measured according to GALEN and GAMBINO6. Both tests were highly sensitive, 89 and 93% respectively. Regarding their specificity, the AGID was totally specific while the CF exhibited 96.6% and 97% specificity in front of tuberculosis patients and healthy individuals respectively and 82% in comparison with patients with other mycoses. The concept of predictive value, that is, the certainty one has in accepting a positive test as diagnostic of paracoccidioidomycosis, favored the AGID procedure (100%) over the CF test. The latter could sort out with 93% certainty a patient with paracoccidioidomycosis among a group of healthy individuals and with 97.5% in the case of TB patients; when the group in question was composed by individuals with other deep mycoses, such certainty was lower (81%). The above results indicate that both the AGID and the CF tests furnish results of high confidence; one should not relay, however, in the CF alone as a means to establish the specific diagnosis of paracoccidioidomycosis.
Resumo:
A comparison of two different standardized reagent procedures for the passive haemagglutination test (PHA) in the detection of specific antibody to Cysticercus cellulosae in cerebrospinal fluid (CSF) was carried out. The formaldehyde-treated group O Rh-human red blood cells (HuRBC) and glutaraldehyde-treated sheep red blood cells (SRBC) were the supplies for the reagents preparation and, in the tests, they were designated as PHA-1 and PHA-2, respectively. For both reagents the cells were coated with the cysticerci total saline extract (TS) antigen. PHA-1 and PHA-2 were assessed in a total of 204 CSF from patients with neurocysticercosis, from non-related infections and from healthy individuals. The positivity and specificity indices obtained were respectively 81.7% and 94.4% for PHA-1 and for PHA-2, 88.7% and 96.6%. Since no significant differences were observed between the results provided by two reagents, at level of significance of 0.05, either processes of cell sensitization can alternatively be used according to the own laboratory convenience.
Resumo:
The antigenicity of promastigotes of Leishmania braziliensis braziliensis (L. b.braziliensis) treated with 1% sodium desoxycholate in 10 mM Tris-Hcl pH 8.2 was analysed by immunoblot using as probes sera from American cutaneous leishmaniasis (ACL), American visceral leishmaniasis (AVL), schistosomiasis, malaria and Chagas' disease. The ACL sera reacted constantly with a 60 kD band. No reactivity to this protein was observed with sera from the other diseases above mentioned indicating that the 60 kD protein may be used in serodiagnosis for ACL.
Resumo:
A dot enzyme-linked immunosorbent assay (DOT-ELISA) was developed to detect specific antibodies in cerebrospinal fluid (CSF) for human neurocysticercosis immunodiagnosis, with Cysticercus cellulosae antigen dotted on a new solid-phase. This was represented by sheets of a synthetic polyester fabric impregnated with a polymerized resin (N-methylol-acrylamide). A very stable preparation was thus obtained, the antigen being covalently bound by cross-linking with free N-methylol groups on the resin. Since robust, no special care was necessary for handling the solid-phase. The test could be performed at room-temperature. From 30 CSF samples assayed, 14 were positive, from a group of 15 cases of neurocysticercosis, with titers from 1 to 128; 15 other samples, from normals or other neurological diseases, were all negative. Test characteristics seem to indicate it as adequate for epidemiological surveys. A more detailed study on sensitivity, specificity, reproducibility and the use in serum samples is being conducted.