68 resultados para plasma immersion ion implantation (PIII)
em Scielo Saúde Pública - SP
Resumo:
The aim of the method described here is to remove hemoglobin, the major contaminant in the bovine plasma obtained from slaughterhouses, by adding a mixture of 19% cold ethanol and 0.6% chloroform, followed by fibrinogen and globulin precipitation by the Cohn method and nonspecific hemagglutinin by thermocoagulation. The experimental volume of bovine plasma was 2,000 ml per batch. Final purification was performed by liquid chromatography using the ion-exchange gel DEAE-Sepharose FF. The bovine albumin thus obtained presented > or = 99% purity, a yield of 25.0 ± 1.2 g/l plasma and >71.5% recovery. N-acetyl-DL-tryptophan (0.04 mmol/g protein) and sodium caprylate (0.04 mmol/g protein) were used as stabilizers and the final concentration of albumin was adjusted to 22.0% (w/v), pH 7.2 to 7.3. Viral inactivation was performed by pasteurization for 10 h at 60°C. The bovine albumin for the hemagglutination tests used in immunohematology was submitted to chemical treatment with 0.06% (w/v) glutaraldehyde and 0.1% (w/v) formaldehyde at 37°C for 12 h to obtain polymerization. A change in molecular distribution was observed after this treatment, with average contents of 56.0% monomers, 23.6% dimers, 12.2% trimers and 8.2% polymers. The tests performed demonstrated that this polymerized albumin enhances the agglutination of Rho(D)-positive red cells by anti-Rho(D) serum, permitting and improving visualization of the results.
Resumo:
Plasma amino acid levels have never been studied in the placental intervillous space of preterm gestations. Our objective was to determine the possible relationship between plasma amino acids of maternal venous blood (M), of the placental intervillous space (PIVS) and of the umbilical vein (UV) of preterm newborn infants. Plasma amino acid levels were analyzed by ion-exchange chromatography in M from 14 parturients and in the PIVS and UV of their preterm newborn infants. Mean gestational age was 34 ± 2 weeks, weight = 1827 ± 510 g, and all newborns were considered adequate for gestational age. The mean Apgar score was 8 and 9 at the first and fifth minutes. Plasma amino acid values were significantly lower in M than in PIVS (166%), except for aminobutyric acid. On average, plasma amino acid levels were significantly higher in UV than in M (107%) and were closer to PIVS than to M values, except for cystine and aminobutyric acid (P < 0.05). Comparison of the mean plasma amino acid concentrations in the UV of preterm to those of term newborn infants previously studied by our group showed no significant difference, except for proline (P < 0.05), preterm > term. These data suggest that the mechanisms of active amino acid transport are centralized in the syncytiotrophoblast, with their passage to the fetus being an active bidirectional process with asymmetric efflux. PIVS could be a reserve amino acid space for the protection of the fetal compartment from inadequate maternal amino acid variations.
Resumo:
In two distinct experiments, immature S. mansoni worms (LE strain, Belo Horizonte, Brazil), aged 20 days, obtained from the portal system of white outbred mice, were irradiated with 14 and 4 Krad, respectively. Afterwards, the worms were directly inoculated into the portal vein of normal mice. Inoculation was performed with 20 irradiated worms per animal. Fifty days after inoculation, the mice that received 4 and 14 Krad-irradiated worms and their respective controls were infected with S. mansoni cercariae (LE strain), by transcutaneous route. Twenty days after this challenge infection, the animals were sacrificed and perfused for mature irradiated (90-day-old) and immature (20-day-old) worm counts. Analysis of the results showed that statistically significant protection against cercariae occurred in both groups with irradiated worms.
Resumo:
Schedule for vaccination against HBV infection has usually been based on three separate injections of 20 meg of the vaccine by intramuscular route. One of the main shortcomings to its use in large scale programs has been its high cost. Ninety out of 300 health workers were submitted to three injections of 2 meg of plasma-derived vaccine (PDV) by intradermal (ID) route on days 0, 30, and 180. Anti-HBs was detected in 74 (82.2%) after the second dose and in 80 (88.9%) after the third dose, a non-significant difference. However, levels above 10 times the cut-off were observed in 29 (32.2%) and 77 (85.5%), respectively (p < 0.001). The results showed that a low-dose schedule is effective when used in health workers and should be tried with other risk groups.
Resumo:
Evaluation of TNF-alpha in patients with Kala-azar has drawn increasing interest due to its regulatory role on the immune system, in addition to its cachetizing activity. The objective of this study was to examine the association between plasma levels of TNF-alpha, measured by immunore-activity (ELISA) and bioactivity (cytotoxicity assay with L-929 cells), and clinical manifestations of visceral leishmaniasis. Plasma samples from 19 patients with Kala-azar were obtained before, during and at the end of antimonial therapy. TNF-alpha determinations was done by using the cytotoxicity assay (all patients) and the enzyme-linked immunoassay (ELISA - 14 patients). A discrepancy between results obtained by ELISA and cytotoxicity assay was observed. Levels of circulating TNF-alpha, assessed by ELISA, were higher in patients than in healthy controls, and declined significantly with improvement in clinical and laboratory parameters. Plasma levels before treatment were 124.7 ± 93.3 pg/ml (mean ± SD) and were higher than at the end of therapy 13.9 ± 25.1 pg/ml (mean ± SD) (p = 0.001). In contrast, plasma levels of TNF-alpha evaluated by cytotoxicity assay did not follow a predicted course during follow-up. Lysis, in this case, might be not totally attributed to TNF-alpha. The discrepancy might be attributed to the presence of factor(s) known to influence the release and activity of TNF-alpha.
Resumo:
The objective of this study was to assess vitamin A status and association between acute diarrhoea and plasma levels of vitamin A through cross-sectional comparison in children. Plasma vitamin A was measured by colorimetric method of Neeld & Pearson and RBP by radial immunodiffusion technique. Seventy eight children (aged 18-119 months), 26 with current history of diarrhoea and 52 children as controls (outpatient from the Santa Casa de Misericórdia Hospital in metropolitan area of São Paulo City, Brazil) were studied. Children with history of diarrhoea showed significant low levels (mean ± s.e.) as compared to controls, vitamin A (15.87 ± 1.4 µg/dl vs. 21.14 ± 1.15 µg/dl, p < 0.007) and RBP (1.70 ± 0.2 mg/dl vs. 2.52 ±0.11 mg/dl). Multivariate logistic regression adjusted by sex, age, nutritional status and mother education revealed association between diarrhoea and inadequate levels of vitamin A and RBP.
Resumo:
We determined the relationship between plasma and red blood cell concentrations of quinine in children with uncomplicated falciparum malaria from an endemic area of Amazonian region. Quinine was determined by high performance liquid chromatography with ultraviolet detection. In the steady state the ratio between plasma and red blood cell quinine concentration was 1.89 ± 1.25 ranging from 1.05 to 2.34. This result demonstrated that quinine do not concentrate in red blood cell of Brazilian children and characterize the absence of interracial difference in this relationship.
Resumo:
The question of whether HIV-1 RNA in cerebrospinal fluid (CSF) is derived from viral replication in the central nervous system or simply reflects the transit of infected lymphocytes from the blood compartment has long been a matter of debate. Some studies found no correlation between CSF and plasma viral load, whereas others did. The lack of a correlation between the two compartments suggests that the presence of HIV-1 RNA is not simply due to the passive passage of the virus from blood to CSF but rather due to intrathecal replication. To evaluate the correlation between plasma and CSF HIV-1 RNA levels and to identify situations in which there is no correlation between the two compartments, seventy patients were prospectively studied. The association between CSF and plasma viral load was evaluated in the total population and in subgroups of patients with similar characteristics. A correlation between the CSF and plasma compartments was observed for patients undergoing highly active antiretroviral therapy (HAART), those with a CD4 T lymphocyte count lower than 200 cells/mm³, and those with increased CSF protein content. On the other hand, no correlation was observed for patients without adequate virological control, who had a CD4 count higher than 200 cells/mm³ and who did not use HAART. The correlation between the two compartments observed in some patients suggests that CSF HIV-1 RNA levels may reflect plasma levels in these subjects. In contrast, the lack of a correlation between the two compartments in patients who were not on HAART and who had normal CSF proteins and a poor virological control possibly indicates compartmentalization of the virus in CSF and, consequently, plasma-independent intrathecal viral replication.
Resumo:
Plasmas de indivíduos normais e de pacientes com a forma crônica da doença de Chagas foram, intencionalmente, contaminados com cepa muito virulenta do Trypanosoma cruzi e, a seguir, congelados a -20°C, durante seis e 24 horas, como também no decurso de três ,sete, 14 e 21 dias. Depois de descongelamento em temperatura ambiente, ocorreram exame microscópico a fresco em contraste de fase, cultivo em meio de Warren e inoculação em camundongos, com subseqüente análise histopatológica do coração. Através dessas pesquisas, a sobrevivência do flagelado ficou avaliada, tendo sido verificado que o congelamento por três e 24 horas não impediu a persistência do parasita infetante. Salientaram os Autores que a investigação que levaram a efeito procurou contribuir no sentido de prestar orientação quanto às transfusões de plasmas, em Serviços de Hemoterapia, convindo frisar que no Brasil elas são efetuadas com razoável freqüênêcia, mediante utilização de doadores acometidos pela doença de Chagas e com a convicção de que baixas temperaturas promovem segura esterilização.
Resumo:
A atividade colinesterásica foi medida no plasma e em eritrócitos de 32 indivíduos. Em 16 pacientes, seguramente portadores de megacolo chagásico, os níveis de colinestera- se no plasma (1.540 ±318 Ul/L) e nos eritrócitos (53,2 ±9,1 Ul/g Hb) estavam significativamente diminuídos, quando comparados com os níveis enzimáticos no plasma (2.554 ± 826 Ul/L) e nos eritrócitos (63,6 ±11 Ul/g Hb) do grupo controle (n=16). Os resultados mostram um paralelismo entre a atividade colinesterásica sistêmica e os achados histopato lógicos.
Resumo:
The osmotic threshold for vasopressin release was studied in normal patients (n = 7) and in patients with the chronic form of Chagas'disease (n = 11). Positive correlation between osmotic threshold and plasma cortisol concentration was obtained for the Controls (y1 = 273,30 + 0,75x i; r = 0,78;P < 0,05), suggesting a modulating effect of cortisol on vasopressin release. The lack of correlation between the two parameters for the chronic chagasic patients was interpreted, on the basis of the general denervation associated with Chagas ' disease, to be the result of neuronal destruction in hypothalamic and/or extrahypothalamic centers related to the secretory control of vasopressin.
Resumo:
A atividade colinesterásica foi determinada no plasma e em eritrócitos de 10 indivíduos normais e em 26 pacientes chagásicos crônicos, sendo 6 com insuficiência cardíaca congestiva compensada, 10 com cardiopatia sem insuficiência cardíaca congestiva e 10 com a forma indeterminada. Os valores enzimáticos encontrados foram (média ±sd): 2196 ± 442 UI/L no plasma e 19,4 ± 3,3 Ul/g Hb em eritrócitos do grupo controla; 2291 ± 317 UI/L no plasma e 19,2 ±3,7 Ul/g Hb em eritrócitos dos chagásicos com insuficiência cardíaca congestiva compensada; 2445 ± 357 UI/L no plasma e 18,3 + 3,0 Ul/g Hb em eritrócitos dos cardiopatas chagásicos sem insuficiência cardíaca congestiva; 2006 ± 327 UI/L no plasma e 17,8 ± 3,1 Ul/g Hb em eritrócitos de chagásicos com a forma indeterminada. Nossos dados mostram que o comprometimento neuronal que ocorre nos cardiopatas chagásicos crônicos não é suficiente para levar a alterações significativas (p > 0,05) das atividades colinesterásicas no plasma e em eritrócitos.
Longitudinal comparison between plasma and seminal HIV-1 viral loads during antiretroviral treatment
Resumo:
This study was designed to investigate the impact of anti-retroviral therapy on both plasma and seminal HIV-1 viral loads and the correlation between viral loads in these compartments after treatment. Viral load, CD4+ and CD8+ T-cell counts were evaluated in paired plasma and semen samples from 36 antiretroviral therapy-naïve patients at baseline and on days 45, 90, and 180 of treatment. Slopes for blood and seminal viral loads in all treated patients were similar (p = 0.21). Median HIV-1 RNA titers in plasma and semen at baseline were 4.95 log10 and 4.48 log10 copies/ml, respectively. After 180 days of therapy, the median viral load declined to 3.15 log10 copies/ml (plasma) and 3.2 log10 copies/ml (semen). At this timepoint 22 patients presented HIV-1 viral load below 400 copies/ml in either plasma or semen, but only 9 had viral loads below 400 copies/ml in both compartments.
Resumo:
Pouco se conhece a cerca de alterações nos lipídeos plasmáticos devido à reinfecção por Schistosoma mansoni. Neste trabalho, foram avaliadas alterações nos lipídeos plasmáticos decorrentes de uma reinfecção por Schistosoma mansoni no primata não humano Callithrix jacchus (sagüi). Amostras de sangue dos animais, antes e após serem infectados e reinfectados, foram coletadas por punção venosa, anticoaguladas com EDTA (1mg/mL) e centrifugadas a 2.500xg para obtenção do plasma. Os níveis plasmáticos de colesterol total, colesterol éster, fosfolipídeo total e triglicerídeo foram determinados por métodos espectrofotométricos. Os resultados mostraram haver redução significativa nas concentrações de colesterol total, colesterol esterificado, triglicerídeo e fosfolipídeo total em plasma de animais reinfectados por Schistosoma mansoni, em comparação com os mesmos animais antes da infecção e após uma infecção. Este estudo mostra que uma segunda infecção por Schistosoma mansoni causa alterações lipídicas plasmáticas significativamente mais acentuadas que as decorrentes de uma única infecção.