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Biomedical subjects

C Hurtado

Publications and source records attributed to C Hurtado.

At least 37 records · Page 2Linked to original sources
PubMed1998

Phagocytosis and killing of slime-producing Staphylococcus epidermidis bypolymorphonuclear leukocytes. Effects of sparfloxacin.

The interaction of slime-producing Staphylococcus epidermidis (S+ strain) with human polymorphonuclear leukocytes (PMNs) was analyzed. The phagocytosis index (PI) and the killing index (KI) were evaluated, and the effect of subinhibitory concentrations (sub-MICs) of sparfloxacin in this interaction was determined. The study was carried out in parallel with a non-slime-producing strain (S- strain). The MIC values of sparfloxacin against both strains was 0. 06 mg/ml. In the S- strain the mean values of PI and KI were 82% and 31%, respectively, whereas in the S+ strain these values diminished to 49% and 8%, respectively (p <0.05) when the inocula were prepared in aerobiosis. In a constant flow atmosphere of 5% CO2, the results were similar to the previous ones in the S- strain (PI = 79% and KI = 27%), whereas in the S+ strain a increase in the PI (59%) and a similar value to the KI (9%) were observed. Significant increases (p <0.05) in the PI were noted when PMNs were preincubated with 1/4 and 1/16 MIC of sparfloxacin, and S. epidermidis S+ grown in aerobiosis were used. In the other assays the variations in PI and KI were not statistically significant (p >0.05). Our results confirm that slime protects against phagocytosis and killing by PMNs, although they also suggest that the S+ strains possess additional properties which make them resistant to the action of the PMNs.

Aerobiosis↗
PubMed1998

[Prevalence and genotypes of hepatitis C virus in blood donors and in patients with chronic liver disease and hepatocarcinoma in a Chilean population].

BACKGROUND: The impact of hepatitis C virus infection in Chile has not been well established. AIM: To assess hepatitis C virus infection in normal Chileans and in patients with liver disease. SUBJECTS AND METHODS: Antibodies against hepatitis C virus were investigated in 21,000 blood donors, 133 patients with non alcoholic chronic liver disease and in 50 patients with hepatocarcinoma. Viral RNA was studied by polymerase chain reaction in all positive blood donors, in 51 patients with chronic liver disease and in all patients with hepatocarcinoma. Hepatitis C virus genotype was established using restriction fragment length polymorphism in 118 RNA positive samples. RESULTS: In blood donors, a 0.3% prevalence of positive antibodies was found. The figure for chronic liver disease was 53% and for hepatocarcinoma, 48%. Viral RNA was detected in 100% of patients with chronic liver disease and hepatocarcinoma and in 68% of blood donors with positive antibodies. Genotype 1b was identified in all infected patients with hepatocarcinoma, in 86% of patients with chronic liver disease and in 46% of blood donors. CONCLUSIONS: Hepatitis C virus infection is an important etiologic agent for chronic liver disease in Chile. The predominance of genotype 1b among patients with the most severe form of liver disease is in agreement with observations made abroad.

Adult↗
PubMed1997

Influence of N-acetylcysteine on the formation of biofilm by Staphylococcus epidermidis.

The influence of various concentrations (0.003-8 mg/mL) of N-acetylcysteine on the formation of biofilms by 15 strains of Staphylococcus epidermidis has been studied. A dose-related decrease in biofilm formation was observed, except with the lowest concentrations. The 'slime' index relative to the control was 63%, 55%, 46%, 34%, 26% and 26% in the presence of 0.25, 0.5, 1, 2, 4, and 8 mg/mL of N-acetylcysteine, respectively. These data are statistically significant. The inhibitory effect of 2 mg/mL of N-acetylcysteine on slime formation was also verified by electron microscopy.

Acetylcysteine↗
PubMed1997

Incubation temperatures affect adherence to plastic of Candida albicans by changing the cellular surface hydrophobicity.

The influence of cellular surface hydrophobicity on the adherence capacity to plastic of Candida albicans was investigated at two culture temperatures (37 and 22 degrees C). The majority of the 42 strains studied were hydrophobic at 22 degrees C and hydrophilic at 36 degrees C. The hydrophobic cells showed a consistent adherence capacity which was absent from the hydrophilic strains. The culture temperatures affect adherence to plastic of C. albicans by changing the cellular surface hydrophobicity.

Adhesiveness↗
PubMed1997

[The study of patient survival in cerebral hemorrhagic and ischemic accident].

The aim of this study was to study stroke survival in Chile in a historic cohort from a random sample of 333 inpatients. All alive selected patients were visited and examined. All the death certificates were reviewed. The diagnosis was done by a neurologist, 35% had a CT scan. Survival was measured in days using lifetest procedure to generate survival curves, Cox's proportional hazards models in Stata 3.1 statistic package and logistic regression analysis. The mean age was 70.5 for the group of died and 62.3 years old for alive patients (p = 0.01). Infectious disease (p = 0.05), localization of stroke (p = 0.01) and rehabilitation (p = 0.005) were significant at univariate analysis. The cumulative probability of survival was 38 days, after one year and after five years, 48.1, 39.0 and 19.8%, respectively. The probability of survival by age, localization, heart disease and rehabilitation was statistically significant. Analysis of survival by sex, and previous stroke risk factors was not significant. Using Cox's proportional hazards regression we found that survival after 5 years depends on age (p = 0.03), rehabilitation (p = 0.008), infection (p = 0.05) and heart disease (p = 0.04). Stroke survival function is close to a decreasing exponential curve with high death probability at one month after the stroke. Survival is conditioned by stroke localization, age, heart disease and rehabilitation.

Age Distribution↗
PubMed1996

[Hepatitis E virus infection in Chile: preliminary report].

BACKGROUND: Hepatitis E virus is an enterally transmitted virus that produces an acute self limited infection. AIM: To study serum antibodies against hepatitis E virus in different patients. PATIENTS AND METHODS: Using and ELISA technique, IgG antibodies against hepatitis E virus were measured in 40 alcoholics, 40 hemophiliacs, 174 blood donors, 36 subjects with acute non A-non B-non C hepatitis and 66 subjects with acute hepatitis A. RESULTS: Antibodies were detected in one alcoholic (2.5%), 3 hemophiliacs (7.5%), 7 blood donors (4%), 3 patients with non A-non B-non C hepatitis (8.3%) and 3 patients with acute hepatitis A (4.5%). CONCLUSIONS: A low frequency of hepatitis E infection was detected in the studied subjects.

Adolescent↗
PubMed1995

Influence of the incubation atmosphere on the production of slime by Staphylococcus epidermidis.

The influence of various incubation atmospheres on the growth and slime production of 23 Staphylococcus epidermidis strains was studied. The atmospheres evaluated were aerobiosis (control), anaerobiosis, candle jar, 5% CO2 and 10% CO2. As compared to the aerobic control, growth was 55.7 +/- 19% (p < 0.01) in anaerobic incubation, 113.7 +/- 12% (p < 0.01) in 5% CO2, 112.8 +/- 13% (p < 0.01) in 10% CO2 and 106.4 +/- 7% (p > 0.1) in the candle jar. The slime production in relation to the aerobic control was 20.3 +/- 19% in anaerobiosis (p < 0.01), 22.3 +/- 27% (p < 0.01) in 5% CO2, 29.4 +/- 39% (p < 0.01) in 10% CO2 and 68.3 +/- 26% (p > 0.1) in the candle jar. The results of this study may explain the discrepancies which have been noted on occasion between slime formation data and pathogenicity.

Aerobiosis↗
PubMed1995

[Primary HIV infection. Clinical and serologic characteristics].

An acute clinical picture of variable intensity may occur during the initial primary phase of HIV infection, it may however pass unnoticed. We report 12 seronegative subjects (11 male homosexuals, 1 female heterosexual, aged 18 to 44 years old), that presented an acute clinical picture preceding seroconversion. All had a sudden beginning, resembling an acute mononucleosis in 10 and with an aseptic meningitis in two. Intensity and duration were variable, lasting a mean of 14 (range 5-44) days an remaining asymptomatic thereafter. Most patients presented a discrete leukopenia with lymphopenia at the expense of CD4 lymphocytes, followed by an absolute lymphocytosis in some, with an increase in CD8 lymphocytes. All became positive for HIV; circulating HIV antigen was identified in three and IgM anti-HIV antibodies were detected during the symptomatic period by third generation ELISA in other three. It is concluded that the clinical picture of primary HIV infection has identifiable clinical serological and immunological features and its recognition has diagnostic and preventive implications.

AIDS Serodiagnosis↗
PubMed1995

[Pre S1 antigen in different forms of hepatitis B virus infection].

Pre S1 antigen was measured using an ELISA technique in patients with different forms of hepatitis B virus infection. It was detected in 10 of 19 patients with acute hepatitis B (53%), 12 of 15 chronic hepatitis B virus carriers (80%), 9 of 11 patients with chronic hepatitis B (82%) and 3 of 4 patients with hepatoma and positive markers of hepatitis B virus infection. Pre S1 remained positive beyond 150 days in two patients with acute hepatitis that evolved to chronicity. Among subjects with chronic hepatitis B that received interferon, pre S1 antigen negativized only in the patient that had a complete response. Pre S1 detection is an index of hepatitis B virus replication and its persistence determines chronicity. Its negativization after antiviral therapy should have a predictive value.

Acute Disease↗
PubMed1994

Effects of cefpirome in comparison with cefuroxime against human polymorphonuclear leucocytes in vitro.

The interaction of cefpirome and cefuroxime, with human polymorphonuclear leucocytes (PMNs) was examined. The effects of therapeutic concentration (1, 10, and 50 mg/L) of both antimicrobial agents on the adherence, spontaneous mobility, chemotaxis, chemokinesis, phagocytosis and candidacidal capacity were studied in vitro. No statistically significant variations, in relation to the control, were observed in the ability of PMNs to adhere to nylon fibre at the concentrations of cefuroxime and cefpirome used. With both antimicrobial agents, PMN mobility increased as the antibiotic concentration was increased. A statistically significant increase (P < 0.05) in spontaneous mobility, chemotaxis and chemokinesis was observed with cefpirome at only 10 mg/L. However, only spontaneous mobility was increased significantly with cefuroxime at 10 mg/L. The strongest effects were observed with cefpirome at 50 mg/L with variations of about 70% (P < 0.01), in chemotaxis and chemokinesis. In general, cefpirome had a positive effect on phagocytosis and candidacidal power, which was significant at a concentration of 50 mg/L (P < 0.01). Cefuroxime, in general, produced no modifications in either phagocytosis or candidacidal power.

Candida albicans↗
PubMed1994

[Hepatitis B and C virus infections in children with congenital coagulation disorders].

The prevalence of hepatitis B and C virus infections, transmitted by blood transfusions, was studied in 79 children with congenital coagulation disorders. Twenty nine percent had evidences of hepatitis B virus infection and 52% evidences of hepatitis C virus infection. Older children and those with the higher number of transfusions had the highest rates of infections. It is concluded that children with congenital coagulation disorders constitute a high risk group for hepatitis B and C virus infections.

Adolescent↗
PubMed1993

[Hepatitis B virus vaccine: early and late response in Chileans with high risk of infection].

BACKGROUND: Hepatitis B vaccine has demonstrated to be very effective and safe preventing hepatitis B virus infection. Long term protection induced by hepatitis B vaccination depends on the initial immune response and the declining rate of anti-HBs titers. AIM. To investigate early and late response to hepatitis B vaccine in a sample of high risk Chilean population. MATERIAL AND METHODS: Thirty one subjects (20 relatives of hepatitis B chronic carriers, 10 health service workers and one HIV seropositive) were vaccinated with a plasma derivated hepatitis B vaccine. Early and late response were estimated by anti-HBs titers. RESULTS: Twenty eight subjects (90%) produced protective titers of anti-HBs after 2 months from the third dose of vaccine (early response), and they remained at these levels in 75% of vaccinated individuals after three years (late response). All the subjects without protective titers after the three year follow up had produced anti-HBs levels lower than 300 UI at the early response. Hepatitis B vaccination was not associated with significant side effects. CONCLUSIONS: This experience confirms that hepatitis B vaccine is safe and effective inducing immunity in high risk subjects. Our data suggest that the early response to hepatitis B vaccine is able to identify those subjects requiring closer surveillance for boosters.

Adolescent↗
PubMed1993

[Correlation between serum globulin levels and hepatitis C virus antibody].

BACKGROUND: some studies have suggested that the elevation of serum globulins in patients with chronic autoimmune hepatitis, paraproteinemias and rheumatoid arthritis could affect the determination of false positive hepatitis C virus antibodies (anti-HCV). AIM: to study the relationship between positive anti-HCV and serum levels of globulins in patients with liver disease. PATIENTS AND METHODS: one hundred thirty one patients with liver disease, 49 alcoholic, 38 cryptogenetic, 17 autoimmune and 27 with other causes, were studies prospectively measuring simultaneously anti-HCV and serum levels of total, gamma and immuno-globulins (IgA, IgG and IgM). These levels were compared between anti-HCV positive and negative groups and correlated with the ratio between serum optical density/cutoff optical density of the anti HCV assay. RESULTS: Twenty eight patients (21.3%) were anti-HCV positive, no differences in serum globulins between these patients and anti-HCV negative patients and no correlations between serum globulins and anti-HCV optical densities were observed. CONCLUSIONS: the hypergamma-globulinemia observed in these patients with liver diseases would not be responsible for positive hepatitis C virus antibodies.

Enzyme-Linked Immunosorbent Assay↗
PubMed1992

In vitro studies of activities of some antifungal agents against Candida albicans ATCC 10231 by the turbidimetric method.

Different criteria (the drug concentration which inhibited 50% of growth [IC1/2], the lowest drug concentration at which growth was just less than 30% of that in a positive control well [IC30], the visual inhibitory concentration [ICv], and the minimum fungicidal concentration [MFC]) were applied to study the effects of some antifungal agents against Candida albicans. Amphotericin B, flucytosine, and bifonazole produced total growth inhibition. Clotrimazole, itraconazole, ketoconazole, and miconazole produced partial growth inhibition. The values of IC1/2 and IC30 were similar for all agents and avoided the problems of partial inhibition; the values of ICv and MFC were higher than those of IC1/2 and IC30.

Antifungal Agents↗
PubMed1992

[Pre S2: a marker for chronicity and/or liver damage in hepatitis B infection?].

Pre S2 was investigated using a monoclonal ELISA in 100 samples from 52 patients with different forms of infection with Hepatitis B virus. Pre S2 was present in 18 of 19 patients with acute hepatitis. Its persistence for more than 150 days after beginning of symptoms was associated to a chronic hepatitis state. It was also present in 11 patients with chronic hepatitis or cirrhosis, 15 asymptomatic Hepatitis B carriers and 3 of 4 patients with hepatic carcinoma. Pre S2 became negative in only 1 of 3 patients treated with interferon who had a positive response according to HBe and HBs antigens. Thus, Pre S2 is present in patients with evidence of viral replication. It is more a marker of persistent Hepatitis B infection than of chronic liver damage.

Acute Disease↗