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Biomedical subjects

A Muñoz

Publications and source records attributed to A Muñoz.

At least 487 records · Page 27Linked to original sources
PubMed1985

The regulation of translation in reovirus-infected cells.

The regulation of translation in reovirus-infected cells has been investigated by double-infection experiments. Different cell lines were able to translate uncapped encephalomyocarditis (EMC) virus mRNA and capped vesicular stomatitis virus (VSV) mRNAs both early and late during reovirus infection. These results are not fully in agreement with a previously suggested model in which, in the early phase of reovirus infection, only capped mRNAs are translated, whereas in the late phase the cells are modified to translate exclusively uncapped mRNAs. The observations that EMC virus and VSV shut down host protein synthesis more efficiently than reovirus translation in the late phase in double-infections indicate that competition for a message-discriminatory factor may not be involved in the shut-off of host protein synthesis in these animal virus-infected cells.

Animals↗
PubMed1985

The relationship of respiratory infections in early childhood to the occurrence of increased levels of bronchial responsiveness and atopy.

We assessed the relationship of antecedent acute respiratory illness to the occurrence of airway responsiveness and atopy in a population-based cohort of 194 children 12 to 16 yr of age from East Boston, Massachusetts. A history of croup or bronchiolitis as reported by their parents was determined at study onset when the children were 5 to 9 yr of age. During the second and third years of the study, acute respiratory illness was assessed. Five years after the prospective respiratory illness assessment, airway responsiveness was evaluated with eucapneic hyperpnea to subfreezing air, and atopy was evaluated with skin tests to 4 environmental antigens. Both a prior history of croup of bronchiolitis (OR = 2.29, p = 0.04) and greater than 2 acute lower respiratory illnesses (OR = 3.72, p = 0.012) were associated with increased levels of airway responsiveness. Neither index of respiratory illness experience was related to the presence of atopy. However, maternal cigarette smoking was significantly associated with atopy in these children (OR = 2.24, p = 0.02). These data suggest that respiratory illness in early life is associated with airway hyperresponsiveness as measured later in childhood. The data further suggest the need for longitudinal studies to better assess the etiologic role of these potential risk factors.

Adolescent↗
PubMed1985

Effect of cigarette smoking on the pulmonary function of children and adolescents.

The effect of personal cigarette smoking on the growth of lung function in children and adolescents has been assessed in a longitudinal study of a group of 669 subjects 5 to 19 yr of age at initial examination. Subjects were seen annually and assessed with standard questionnaires and measurements of forced expiratory volume in one second (FEV1) and forced expiratory flow during the middle half of the forced vital capacity (FEF25-75). Multiple regression analysis revealed that after correction for previous FEV1 or FEF25-75, age, sex, height, change in height, interactions of age and change in height, and sex and height, and mother's smoking, the personal smoking by the children led to a significant decrease in the rate of growth of FEV1 (p less than 0.001) and FEF25-75 (p = 0.033). On the basis of this analysis, it is estimated that, on average, children who begin to smoke at 15 yr of age and continue to smoke would achieve only 92% (95% confidence limit, 87 to 96%) of their expected FEV1 and 90% (95% confidence limit, 81 to 99%), of their expected FEF25-75 at 20 yr of age. These data suggest that relatively small amounts of cigarette use (median total consumption of 7,300 cigarettes in this study) by adolescents can lead to significant effects on the growth of lung function.

Adolescent↗
PubMed1985

A comparative trial of cefazolin and moxalactam as prophylaxis for preventing infection after abdominal hysterectomy.

In a randomized, double-blind clinical trial, 208 women who underwent abdominal hysterectomy received either cefazolin (N = 108) or moxalactam (N = 100) as perioperative antimicrobial prophylaxis. There were no differences between the two groups in rates of serious infection, minor wound infection, standard febrile morbidity, duration of hospitalization, proportion receiving other postoperative antibiotics, or rates of rehospitalization. Women who received moxalactam had significantly more urinary tract infections, 87% of which were caused by the enterococcus. It is concluded that perioperative prophylaxis with third-generation cephalosporins is not justified at this time.

Adult↗
PubMed1984

Synthesis of heat-shock proteins in HeLa cells: inhibition by virus infection.

Incubation of HeLa cells at supraoptimal temperatures induces the synthesis of a class of proteins known as heat-shock or stress-response proteins. After restoration of cells to physiological temperatures heat-shock protein synthesis continues for several hours. Normal cellular translation eventually recovers even if cells are treated with actinomycin D, indicating that neither normal cellular mRNAs nor components of the translation machinery are irreversibly modified by heat treatment. The synthesis of heat-shock proteins after poliovirus infection is more resistant to inhibition than normal host proteins. Nevertheless, their synthesis is also inhibited in infected cells, even in cells treated with human interferon under which conditions viral RNA replication and viral translation are blocked. Translation of heat-shock proteins is also resistant to hypertonic shock indicating that their mRNAs bind ribosomes with high affinity.

Electrophoresis, Polyacrylamide Gel↗
PubMed1984

A multivariate analysis of risk factors for hepatitis B virus infection among hospital employees screened for vaccination.

Previous studies of risk factors for hepatitis B virus infection among hospital employees have been based on surveys in single institutions or have been analyzed with univariate techniques. From November 1980 through August 1981, the authors performed a multi-institutional seroepidemiologic survey of hospital employees screened for entrance into a hepatitis B vaccine trial who represented groups at high risk for hepatitis B infection. Using a logistic regression model for the analysis of risk factors, the investigators determined the relative odds and 95% confidence intervals for risk of hepatitis B infection to be as follows: race (nonwhite/white: 3.4; 2.4-4.8) (p less than 0.001); history of acute viral hepatitis of an unspecified type (3.6; 2.2-5.9) (p less than 0.001); and employment at hospitals 1 through 5 as compared with hospital 6 (1.8; 1.1-2.9) (p = 0.015). In addition, certain job categories and the duration of employment within some of these categories were associated with increasing risk for hepatitis B infection over time. Laboratory workers (1.4; 1.2-1.7), surgical staff (1.2; 1.1-1.4), and medical staff (1.3; 1.1-1.5) had significant (p less than 0.05) increased risk of prior infection with longer duration of employment. Such time-job interaction was not demonstrable for nursing staff, anesthesiology staff, dental personnel, pathology staff, or ancillary personnel. The logistic regression model also shows that the highest gradient of risk for laboratory workers, surgeons, and medical staff occurs during the first five years of employment. An effective preventive strategy, such as the use of hepatitis B vaccine, should be targeted for these groups at the time of initial employment.

Adult↗
PubMed1984

Action of human lymphoblastoid interferon on HeLa cells infected with RNA-containing animal viruses.

Protein synthesis in interferon-treated HeLa cells infected by different animal RNA viruses has been studied. Synthesis of vesicular stomatitis virus (VSV) proteins was not detected in cells treated with concentrations of HuIFN-alpha (Ly) above 10 IU/ml. No specific inhibition of glycosylation of the G protein was observed. In addition, inhibition of host protein synthesis in IFN-treated cells occurred when high multiplicities of VSV were used, even though no viral protein synthesis was detected. For other viruses, such as Newcastle disease virus, Semliki Forest virus, encephalomyocarditis virus and poliovirus, treatment of cells with interferon also led to inhibition of viral protein synthesis. However, influenza virus and reovirus protein synthesis in interferon-treated cells stayed at control levels. The finding of viral translation in influenza virus and reovirus-infected cells treated with interferon suggests that, at least for these two systems, the antiviral state is not mediated by the bulk inhibition of viral protein synthesis through the dsRNA-activated protein kinase, or the 2'-5' oligo(A) system.

Encephalomyocarditis virus↗
PubMed1984

Formation of non-infective herpesvirus particles in cultured cells treated with human interferon.

Treatment of HeLa cells with human lymphoblastoid interferon [HuIFN-alpha(Ly)] induced an antiviral state that rendered the cells refractory to infection by herpes simplex virus type 1 (HSV-1), and the yield of infectious HSV-1 was reduced by 98%. Analysis of the mechanism of the anti-herpes action of IFN indicated that no gross inhibition of viral protein synthesis took place and late proteins appeared, although the synthesis of some of them was partially inhibited. No differences were apparent between the glycoproteins or phosphoproteins synthesized in control and IFN-treated HSV-1-infected HeLa cells. No inhibition of the formation of new virus particles from IFN-treated cells was evident as assessed by electron microscopy and biochemical analyses, although their infectivity was drastically reduced. These virions exhibited some differences in their content of a few proteins as determined by PAGE. Studies on the second infection cycle with virions obtained from IFN-treated cells suggested that they attached and penetrated HeLa cells but that their development was impaired, since no viral protein synthesis was observed during the second infection. Altogether these results do not support the idea that the molecular mechanism of action of human IFN against HSV-1 is mediated via the 2'-5' A system, or by the inactivation of initiation factors. Rather, they focus the problem of the anti-herpes action of IFN at the level of formation of defective virions.

Glycoproteins↗
PubMed1984

Diesel exposure and mortality among railway workers: results of a pilot study.

A pilot study of the mortality of railway workers was undertaken to evaluate the feasibility of studying the association of exposure to diesel exhaust and cause specific mortality. The cohort consisted of 2519 white male subjects aged 45-64 with at least 10 years of railway service by 1967. Subjects were selected on the basis of job classification, and cause specific mortality was ascertained for subjects who died (n = 501) up to 1979. The total follow up period was 28.4 (X 1000) person-years. The standardised mortality ratio (SMR) for the cohort, based on United States national rates, was 87 (95% confidence limits 80, 95), and there were no significant differences from expected number of deaths for any specific neoplasm. The directly standardised rate ratio for respiratory cancer among diesel exposed subjects relative to unexposed subjects was 1.42 +/- 0.50 (means +/- SE). A proportional hazards model was consistent with the findings of the standardised rate ratio, but in neither analysis was the increased risk of respiratory cancer in diesel exposed subjects statistically significant.

Age Factors↗
PubMed1984

The relationship of airways responsiveness to cold air, cigarette smoking, and atopy to respiratory symptoms and pulmonary function in adults.

The response to eucapnic hyperventilation with subfreezing air was studied in a population based sample of 171 adults, all of whom also completed a respiratory questionnaire, spirometry, and skin testing. A positive response to the cold air challenge was defined as [initial FEV1-post-challenge FEV1)/initial FVC) X 100) greater than or equal to 9%. Cigarette smoking was with a positive cold air response: 12 of 128 current and ex-smokers (9.4%) versus 1 of 43 nonsmokers (2.3%) (p = 0.095). Among current and ex-smokers, a positive response to the cold air challenge was significantly associated with asthma (p = 0.046). Using a logistic regression model, both current smoking and response to cold air were significant predictors of the presence of "persistent wheeze" or asthma. A positive skin test to any of the 4 environmental antigens used (ragweed, housedust, trees, and grasses) was significantly associated with cigarette smoking (p = 0.018) and hay fever (p = 0.003 among current and ex-smokers) but not with wheezing or asthma. Though not statistically significant, cold air responders had a lower percentage of positive skin test reactivity than nonreactors. The findings of this cross-sectional analysis suggest that in adults, both airways responsiveness and cigarette smoking are important predictors of wheezing and asthma. Furthermore, the data suggest that airway hyperresponsiveness and atopy are independent traits. However, in adults, these traits are associated with cigarette smoking, a common environmental exposure.

Child↗
PubMed1984

Effect of diabetic hyperglycemia and other sugars on plasma dopamine-beta-hydroxylase activity.

The plasma glycoprotein, dopamine-beta-hydroxylase (DBH), is present in markedly increased amounts in experimental, streptozocin (STZ)-diabetic rats, reaching a maximum at about the first week and maintaining a plateau for several months afterward. High glycemia values are observed simultaneously. Insulin treatment is observed to keep the glycemia and plasma DBH activity values at levels seen in control rats. The heterologous half-life of DBH in STZ-diabetic rats is significantly increased compared with that of control animals. The glucose analogue, 2-deoxy-D-glucose, has a similar effect on plasma DBH activity levels, eliciting high glycemia values. In STZ-diabetic animals, this increase is more significant, as if it were the additive effect of the two sugars. Other sugars that can compete for glycoprotein catabolic receptors can also modulate the plasma DBH activity levels. The lack of effect of galactose on DBH levels, together with the induced increase of DBH by alpha-methyl-D-mannoside and, to a lesser extent, by inulin, suggest an important rate for the mannose/glucose/N-acetyl glucosamine/fructose receptor in the catabolic clearance of DBH from plasma and explain the abnormal values seen for DBH in diabetes mellitus.

Animals↗
PubMed1984

Antibiotic prophylaxis for cardiovascular surgery. Efficacy with coronary artery bypass.

Two hundred twenty patients were randomly assigned to receive either ceforanide or cephalothin as perioperative antibiotic prophylaxis during cardiovascular surgery. More infections were seen among cephalothin recipients (8 deep, 32 total) than among ceforanide recipients (1 deep, 17 total). Among patients who had only coronary artery bypass grafting, more cephalothin recipients had infection than did ceforanide recipients (19 of 82 as opposed to 7 of 83; p = 0.001; relative risk, 2.7; 95% confidence interval, 1.22 to 6.18). The difference between the two regimens was attributable to fewer blood, wound, and urinary tract infections. Among patients who had other procedures, there was no difference in the efficacy of the two regimens. Cephalothin recipients who developed wound or blood stream infections had lower antibiotic levels in their atrial appendages than recipients not developing such infections (p = 0.02). If one assumes that cephalothin does not increase the risk of infection, then these data show that antibiotic prophylaxis prevents infection after coronary artery bypass surgery, and, in the dosages used, that ceforanide is superior to cephalothin.

Cefamandole↗