116 resultados para Slow Crack-growth
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E. coli was submitted to a 5G electromagnetic field generated by a alternate 60 Hz voltage source. The differences on growth and glucose consume in control and exposed groups were evaluated using the non-parametric Mann-Whitney U-test. There was a significant difference in glucose consume and growth in E. coli after 8 hours of exposition to electromagnetic field. It can be concluded that electromagnetic field had a positive effect in consume of glucose and growth of E. coli. The cause of these results can be explained by an increasing of glucose entrance through membrane due to the stimulated transport system via Facility Diffusion or cyclotron resonance. The growth can be caused by shortening of lag phase and excitement of log phase.
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Leishmanias can be produced by inoculation in conditioned McCoy cell culture growth medium (CGM). Leishmania (Leishmania) infantum chagasi (100 parasites) grown in NNN medium was inoculated in 2.5 mL CGM, kept in plates (24 wells) and its multiplication was observed for five days (120 hours). After day 5, the medium was saturated with the flagellate forms of the parasite (promastigotes). The reproduction of the leishmanias was observed every 24 hours and the number of parasites was calculated by counting the parasites in a drop of 10 µ L and photomicrographied. So the number of Leishmanias was adjusted to 1 mL volume. The advantage of the technique by isolation of Leishmania in CGM demonstrated in this study is its low cost and high efficacy even with a small quantity of parasites (10² promastigotes) used as inoculum. Additionally, isolation of the leishmania can be obtained together with an increase in their density (180 times) as observed by growth kinetics, within a shorter time. These results justify the use of this low-cost technique for the isolation and investigation of the behavior and multiplication of Leishmania both in vertebrates and invertebrates, besides offering means of obtaining antigens, whether whole antigens (leishmanias) or the soluble antigens produced by the parasites which may be useful for the production of new diagnostic kits.
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The kinetics of growth of Leishmania performed in vitro after internalization of the promastigote form in the cell and the occurrence of the transformation of the parasite into the amastigote form have been described by several authors. They used explants of macrophages in hamster spleen cell culture or in a human macrophage lineage cell, the U937. Using microscopy, the description of morphologic inter-relationship and the analysis of the production of specific molecules, it has been possible to define some of the peculiarities of the biology of the parasite. The present study shows the growth cycle of Leishmania chagasi during the observation of kinetic analysis undertaken with a McCoy cell lineage that lasted for a period of 144 hours. During the process, the morphologic transformation was revealed by indirect immunofluorescence (IF) and the molecules liberated in the extra cellular medium were observed by SDS-PAGE at 24-hour intervals during the whole 144-hour period. It was observed that in the first 72 hours the promastigote form of L. chagasi adhered to the cell membranes and assumed a rounded (amastigote-like) form. At 96 hours the infected cells showed morphologic alterations; at 120 hours the cells had liberated soluble fluorescent antigens into the extra cellular medium. At 144 hours, new elongated forms of the parasites, similar to promastigotes, were observed. In the SDS-PAGE, specific molecular weight proteins were observed at each point of the kinetic analysis showing that the McCoy cell imitates the macrophage and may be considered a useful model for the study of the infection of the Leishmania/cell binomial.
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In regions with high prevalence, Blastocystis hominis is frequently found in association with Entamoeba histolytica/E. dispar in xenic cultures. Its exacerbated growth is often superimposed on the growth of amebas, thus impeding the continuation of the amebas in the culture, within a few generations. The present study reports on the excellent efficacy (100%) of the antifungal agent miconazole in eliminating B. hominis from cultures of E. histolytica/E. dispar, thereby maintaining the integrity of the trophozoites of the amebas. Nystatin presented low efficacy (33.3%).
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BACKGROUND: The quantitation of serum HBeAg is not commonly used to monitor viral response to therapy in chronic hepatitis B. METHODS: In this study, 21 patients receiving varying therapies were followed and their viral response monitored by concomitant viral load and HBeAg quantitation in order to study the meaning and the kinetics of both parameters. RESULTS: It was possible to distinguish between three different patterns of viral response. The first was characterized by a simultaneous decrease in serum HBV DNA and HBeAg. The second pattern was characterized by a decrease in serum HBeAg but persistent detection of HBV DNA. The third pattern was characterized by undetectable HBV DNA with persistent HBeAg positivity, which points to a non-response (Pattern III-B) except when HBeAg levels showed a slow but steady drop, characterizing a "slow responder" patient (Pattern III-A). CONCLUSIONS: The first pattern is compatible with a viral response. A long-term HBeAg seropositivity with a slow and persistent decrease (Pattern III-A) is also compatible with a viral response and calls for a prolongation of anti-viral treatment.
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Despite the effectiveness of combination antiretroviral therapy in the treatment of people living with HIV/AIDS (PLWHA), nonadherence to medication has become a major threat to its effectiveness. This study aimed to estimate the prevalence of self-reported irregular use of antiretroviral therapy and the factors associated with such an irregularity in PLWHA. A cross-sectional study of PLWHA who attended two referral centers in the city of Recife, in Northeastern Brazil, between June 2007 and October 2009 was carried out. The study analyzed socioeconomic factors, social service support and personal habits associated with nonadherence to antiretroviral therapy, adjusted by multivariable logistic regression analysis. The prevalence of PLWHA who reported irregular use of combination antiretroviral therapy (cART) was 25.7%. In the final multivariate model, the irregular use of cART was associated with the following variables: being aged less than 40 years (OR = 1.66, 95%-CI: 1.29-2.13), current smokers (OR = 1.76, 95%-CI: 1.31-2.37) or former smokers (OR = 1.43, 95%-CI: 1.05-1.95), and crack cocaine users (OR = 2.79, 95%-CI: 1.24-6.32). Special measures should be directed towards each of the following groups: individuals aged less than 40 years, smokers, former smokers and crack cocaine users. Measures for giving up smoking and crack cocaine should be incorporated into HIV-control programs in order to promote greater adherence to antiretroviral drugs and thus improve the quality of life and prolong life expectancy.
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Introduction: Maternal HIV infection and related co-morbidities may have two outstanding consequences to fetal health: mother-to-child transmission (MTCT) and adverse perinatal outcomes. After Brazilian success in reducing MTCT, the attention must now be diverted to the potentially increased risk for preterm birth (PTB) and intrauterine fetal growth restriction (IUGR). Objective: To determine the prevalence of PTB and IUGR in low income, antiretroviral users, publicly assisted, HIV-infected women and to verify its relation to the HIV infection stage. Patients and Methods: Out of 250 deliveries from HIV-infected mothers that delivered at a tertiary public university hospital in the city of Vitória, state of Espírito Santo, Southeastern Brazil, from November 2001 to May 2012, 74 single pregnancies were selected for study, with ultrasound validated gestational age (GA) and data on birth dimensions: fetal weight (FW), birth length (BL), head and abdominal circumferences (HC, AC). The data were extracted from clinical and pathological records, and the outcomes summarized as proportions of preterm birth (PTB, < 37 weeks), low birth weight (LBW, < 2500g) and small (SGA), adequate (AGA) and large (LGA) for GA, defined as having a value below, between or beyond the ±1.28 z/GA score, the usual clinical cut-off to demarcate the 10th and 90th percentiles. Results: PTB was observed in 17.5%, LBW in 20.2% and SGA FW, BL, HC and AC in 16.2%, 19.1%, 13.8%, and 17.4% respectively. The proportions in HIV-only and AIDS cases were: PTB: 5.9 versus 27.5%, LBW: 14.7% versus 25.0%, SGA BW: 17.6% versus 15.0%, BL: 6.0% versus 30.0%, HC: 9.0% versus 17.9%, and AC: 13.3% versus 21.2%; only SGA BL attained a significant difference. Out of 15 cases of LBW, eight (53.3%) were preterm only, four (26.7%) were SGA only, and three (20.0%) were both PTB and SGA cases. A concomitant presence of, at least, two SGA dimensions in the same fetus was frequent. Conclusions: The proportions of preterm birth and low birth weight were higher than the local and Brazilian prevalence and a trend was observed for higher proportions of SGA fetal dimensions than the expected population distribution in this small casuistry of newborn from the HIV-infected, low income, antiretroviral users, and publicly assisted pregnant women. A trend for higher prevalence of PTB, LBW and SGA fetal dimensions was also observed in infants born to mothers with AIDS compared to HIV-infected mothers without AIDS.
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The effects of temperature, pH, osmolarity and aeration on the growth and differentiation of a trypanosome ofthe subgenus Schizotrypanum isolatedfrom the bat Phyllostomus hastatus were studied. In general, the growth characteristics ofthe flagellate were similar to those of Trypanosoma (Schizotrypanum) cruzi. However, the parasite did not growth at 33 or 37C. Increase in the osmolarity and aeration promoted growth at 33C. Significant metacyclogenesis was detected only in the growth condition where maximal growth occured (28C, pH 7.3, 380m0s/kg, in tissue cullure flasks), at the end ofthe exponential growth phase. The begining of the metacyclogenesis process was coincident with most glucose utilization and lowest pH. During metacyclogenesis both culture medium pH and osmolarity increased steadly.
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Aedes aegypti (L) (Diptera: Culicidae) was reared in several concentrations of diflubenzuron and methoprene under laboratory conditions in Uberlândia, State of Minas Gerais, southeastern Brazil. Characteristics such as LC50 and LC95, the susceptibility of immature stages of different ages to these insect growth regulators and their residual effects were studied. The LC50 and LC95 of diflubenzuron and methoprene were 5.19 and 12.24 ppb; 19.95 and 72.08 ppb, respectively. While diflubenzuron caused great mortality in all larval instars, methoprene was more effective when the mosquito was exposed from the start of the fourth larval instar onwards. Commercial concentrations of these two insect growth regulators close to LC95 presented greater residual activity than did their respective technical formulations. The parameters were compared with those obtained elsewhere. The characteristics investigated here indicate that these insect growth regulators are effective alternatives for controlling the dengue vector in the Uberlândia region.
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INTRODUCTION: In Brazil there is a large area of overlap of visceral leishmaniasis (VL) and HIV infection, which favored a increased incidence of coinfection Leishmania/HIV. METHODS: This study evaluated 65 consecutive patients with VL and their clinical response to treatment in two health care settings in Belo Horizonte, Brazil. RESULTS: At baseline, the clinical picture was similar between both groups, although diarrhea and peripheral lymphadenomegaly were more frequent in HIV-infected subjects. HIV-positive patients had lower median blood lymphocyte counts (686/mm³ versus 948/mm³p = 0.004) and lower values of alanine aminotransferase (ALT) (48IU/L versus 75.6IU/L p = 0.016) than HIV-negative patients. HIV-positive status (hazard ratio = 0.423, p = 0.023) and anemia (HR = 0.205, p = 0.002) were independent negative predictors of complete clinical response following antileishmanial treatment initiation. CONCLUSIONS: This study reinforces that all patients with VL should be tested for HIV infection, regardless of their clinical picture. This practice would allow early recognition of coinfection with initiation of antiretroviral therapy and, possibly, reduction in treatment failure.
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INTRODUCTION: Metallo-β-lactamase (MBL) has been reported all over the world. METHODS: The inhibitory effect of mercaptopropionic acid (MPA) on bacterial growth was evaluated by comparison between disk diffusion and broth dilution methodology with determination of the minimum inhibitory concentration (MIC) for multidrug-resistant Acinetobacter baumanni strains. RESULTS: MPA significantly inhibited growth of the strains. CONCLUSIONS: The use of MPA can affect the results in phenotypic methods of MBL detection.
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Growth hormone (GH) and glutamine (GLN) are considered bowel trophic factors and are used experimentally after bowel resection. Their clinical uses in short bowel syndrome (SBS) are still not standardized. It is of interest to verify metabolic, nutritional and side effects of the association of GH and GLN in SBS. Three patients, 39 (A), 33 (B), and 01 years old (C) underwent bowel resection with jejunum anastomosis 15 cm (A) and 60 cm (B) distant from the Treitz angle, and 40 cm (C) preserving the ileo cecal valve. GH Saizen (Serono - A), Genotropin (Pharmacia - B), and Norditropin (Novonordisk C) were administered in doses of 0.14 mg /kg/day. GLN (0.4 g/kg/day) was given orally for 10 days (A), 30 days (B) and 60 days to patient C (0.28 g/kg/day). Central TPN and adequate oral diet was administered according to the bowel adaptation phase. On the first day after beginning treatment patient A exhibited symptoms of hypoglycemia. There were no other side effects. After treatment, body weight was higher and analysis by bioelectrical impedance showed more lean mass and less fat mass compared to pre-treatment measurements. Nitrogen retention was progressively higher with treatment. Simultaneous treatment with GH and GLN does not cause significant side effects, and is associated with a favorable distribution of the body compartments and nitrogen retention in patients with the short bowel syndrome.