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Biomedical subjects

J Vega

Publications and source records attributed to J Vega.

At least 55 records · Page 3Linked to original sources
PubMed1998

Occupational asthma by Anisakis simplex.

BACKGROUND: No cases of occupational asthma caused by the inhalation of antigens from Anisakis simplex have been published. OBJECTIVE: The purpose of this study was to evaluate the possibility that A simplex can play a role in the asthma experienced by 2 workers when handling fish and fish flour. METHODS: Skin prick and bronchial challenge tests with A simplex were performed. We also carried out measurements of specific IgE to A simplex and immunoblotting. RESULTS: Both patients had strong positive skin test responses, challenge test responses, and specific IgE to A simplex. Immunoblotting showed that both patients also had IgE against several bands in the fish flour extract, suggesting contamination by Anisakis allergens. CONCLUSION: These 2 patients provide evidence for occupational asthma caused by A simplex, based on in vivo and in vitro tests for Anisakis-specific IgE.

Allergens↗
PubMed1998

Assessment of person-to-person transmission of hantavirus pulmonary syndrome in a Chilean hospital setting.

Person-to-person transmission of Andes hantavirus among healthcare workers was reported in Argentina for the first time in 1996. To determine whether such transmission of the virus occurred during a 1997 outbreak of hantavirus pulmonary syndrome (HPS) in southern Chile due to Andes virus, we conducted a serological and epidemiological study in the Coyhaique Regional Hospital, where the majority of HPS patients were admitted. Workers in every department of the hospital were evaluated for immunoglobulin G (IgG) and IgM hantavirus antibodies using the enzyme-linked immunosorbent assay (ELISA). A standardized questionnaire was used to determine the type and extent of exposure to HPS patients, as well as other potential risk factors and previous febrile respiratory illnesses requiring hospitalization. Less than half (44%) reported always using gloves when touching patients or their secretions; respiratory protection was not used. Of the 319 participants (87.9% of those eligible), 12 (3.7%) had IgG antibodies. This finding is consistent with the antibody prevalence in the community in which the participants lived. Of the 12 positive healthcare workers, six reported contact with HPS patients. A similar exposure was found in those who tested negative [6/140 (4%) compared to 6/179 (3%), P = 0.66]. There was no significant difference in the types of hospital activities performed or the number of hospitalizations for febrile respiratory illnesses between antibody-positive and antibody-negative individuals. These data suggest that there was no person-to-person transmission among healthcare workers during a recent outbreak of HPS in Southern Chile in 1997, despite the inconsistent use of any precautions against transmission.

Chile↗
PubMed1998

Impact of a Simple Inexpensive Quality Assurance Effort on Physician's Choice of Thrombolytic Agents and Door-to-Needle Time: Implication for Costs of Management.

The objective of this study were to assess the impact of a quality assurance effort on the door-to-needle time and the choice of thrombolytic agent for the management of acute myocardial infarction in the emergency department. The study design involved a prospective collection of data on a series of consecutive patients who received a thrombolytic agent for a presumed acute myocardial infarction. The study was carried out in the emergency department of a major university urban tertiary care center. A total of 349 patients were studied from September 1989 to March 1994. The quality assurance program began in 1989 and included chart review of all patients receiving thrombolytic therapy, with special attention to all patients with door-to-needle times >60 minutes to identify causes for delay. Feedback was directed to pharmacy, nursing, and physician staff. Biannual reports were distributed throughout the hospital and the emergency department. Nursing-specific feedback led to the development of protocols for all aspects of the delivery of thrombolytic agents. The choice of thrombolytic agent was not dictated by the protocol, but the physician staff was continuously updated on the results of the latest clinical trials comparing one thrombolytic agent with another. The mean age was 58 years for men and 67 years for women in this cohort consisting of 78% men and 22% women. Thirty-seven percent of the myocardial infarctions were in an anterior location and 56% were in an inferior location. The median duration of chest pain before presentation to the emergency department was 120 minutes. Hospital mortality was 3%. Median door-to-needle time fell from 46 (1989-1991) to 36 (1992-1994) minutes, P& < 0.01. The percentage of patients with a door-to-needle time >60 minutes decreased from 35% (1989-1991) to 16% (1992-1994) minutes, P < 0.0001. Corresponding with the ISIS-3 report, there was a significant increase in the proportion of patients receiving streptokinase over the first 3 years of the study (P < 0.0001), which changed to a trend toward increased utilization of tissue plasminogen activator with the GUSTO report in the final 6 months of the study. In conclusion, a quality assurance program led to a significant reduction in the door-to-needle time, and recent megatrials were found to influence the choice of thrombolytic agent used.

Journal Article↗
PubMed1998

[Social inequalities and health. Socioeconomic level and infant mortality in Chile in 1985-1995].

BACKGROUND: The strong relationship between social inequalities and health have been extensively reported. AIM: To measure the effects of social inequalities, assessed through maternal educational level, on infant mortality in Chile. MATERIAL AND METHODS: Using death and birth electronic databases of the Instituto Nacional de Estadisticas, the annual rates of infant mortality per years of approved studies of both parents and per cause were calculated. RESULTS: In the 1990-1995 period, there is a clear gradient of infant mortality according to the level of education of the mother (38.2 per 1000 born alive among those without education versus 7.8 per 1000 born alive among those with university education). The same tendency is maintained for neonatal and post-neonatal mortality. All groups of causes had a similar effect, standing out diseases of the respiratory system with a relative risk (RR) of 14.3 and a population attributable risk (PAR) of 73%, trauma with a RR of 11.3 and a PAR of 69% and infectious diseases with a RR of 10.8 and a PAR of 62%. Between 1985 and 1995, absolute inequalities decreased but relative inequalities remained constant. CONCLUSIONS: The great social inequality in infant mortality has persisted in Chile during the last years. To adequately assess the national progresses in population health using infant mortality as an indicator, the gaps between social groups must be born in mind.

Cause of Death↗
PubMed1997

[Conversion from +Sandimmune to Neoral in kidney transplant recipients treated with cyclosporine and ketoconazole].

BACKGROUND: Microemulsion cyclosporine is a new pharmaceutical form whose intestinal absorption is more constant, resulting in a better bioavailability. AIM: To assess dose adjustments and variability of blood levels after the conversion of cyclosporine to microemulsion cyclosporine in renal transplant recipients function receiving cyclosporine-ketoconazole. PATIENTS AND METHODS: Thirty four patients with more than one year after the transplantation, with stable renal function and receiving triple immunosuppression were studied. Conventional cyclosporine was changed to the microemulsion form maintaining the same daily dose. Drug serum levels, serum creatinine and blood pressure were measured within two to eight months after the conversion. Doses of microemulsion cyclosporine were adjusted to achieve serum levels of 150 +/- 40 ng/ml. RESULTS: Microemulsion cyclosporine induced a slight initial increase in blood cyclosporine levels. Afterwards, levels were more stable than with conventional cyclosporine (165-185 and 145-210 ng/ml respectively) and the dispersion of values were lower (standard deviations of 70 and 100 ng/ml respectively). Twenty three patients did not require dose adjustments, in four it was reduced and in five it was increased. There were no changes in serum creatinine or blood pressure after the conversion. CONCLUSION: More stable serum levels without adverse reactions were obtained with microemulsion cyclosporine. Doses of cyclosporine need not to be changed during the conversion.

Adolescent↗
PubMed1997

[Chronic exposure to environmental lead in Chilean infants].

BACKGROUND: In Chile, there are several sources of environmental lead exposure. However, the few studies about lead levels in Chilean infants, do not allow to establish the prevalence of high lead levels in this population. AIM: To measure blood lead levels in nursing infants, living in rural and urban areas, from birth until two years of age. SUBJECTS AND METHODS: Newborns from public maternity hospitals in Santiago and a rural area were selected for the study. An umbilical cord blood sample was obtained at birth and venous blood samples thereafter, every 6 months until the age of 24 months. Lead levels were measured by atomic absorption spectrophotometry. Atmospheric lead was measured simultaneously every week in Santiago and the rural area. RESULTS: Three hundred twelve children from Santiago and 113 from the rural area completed the 24 months follow-up. The mean lead exposure for infants living in Santiago and in the rural area was 1.23 +/- 0.66 and 0.19 +/- 0.15 micrograms/m3 respectively (p < 0.001). Mean blood levels were always higher in infants from Santiago, compared to those from the rural area. At 24 months, 4.5% of children from Santiago and 0.7% of children from the rural area had blood lead levels over 10 micrograms/dl. Significant risk factors for high lead levels were recent painting of the house where the infant lives, eating soil, biting banisters and familiar labor exposure to lead. CONCLUSIONS: Infants living in an urban area and exposed to increased atmospheric lead levels have higher blood lead levels than infants living in a rural area.

Air Pollutants↗
PubMed1996

Time-related ultrastructural changes in an experimental model of whole brain irradiation.

To stimulate therapeutic irradiation, we exposed rats to conventional fractionation (200 +/- 4 cGy/d, 5 d/wk; total dose, 4000 cGy). The effects of this regimen were assessed by electron microscopic examinations of brain microvascular and parenchymal cells 15 and 90 days after irradiation. Studies of the transendothelial passage of horseradish peroxidase provided information about the functional status of the blood-brain barrier. At 15 days after irradiation, there was an increased vesicular transport of horseradish peroxidase across the intact endothelium without opening of the tight junctions, and without evidence of structural alterations of neuropil, neuronal bodies, and astrocytes. Ninety days after irradiation, well-defined ultrastructural alterations were observed, involving the microvasculature, the neuropil, the neuronal bodies, and astrocytes. The main ultrastructural feature of cortical microvessels was their collapsed aspect, associated with perivascular edema containing cell debris. Altered neurons and reactive activated astrocytes were also noticeable. These data suggest a possible association, not necessarily causal, between damage of the microvascular/glial unit of tissue injury and development of radiation-induced brain toxicity.

Animals↗
PubMed1996

[Acute kidney failure in patients with and without sepsis: prognosis and clinical course].

The purpose of this prospective study was to determine whether the course and prognosis of acute renal failure (ARF) in patients with and without sepsis are different. Two hundred fifty-two (8%) of 3086 consecutive patients admitted to a medical-surgical intensive care unit (ICU) developed ARE. One hundred forty-nine (59%) were septic and 103 (41%) were non-septic. No differences were found between groups regarding the incidence of oliguria, hyperkalemia, hypercatabolism, gastrointestinal bleeding, duration of oligria and renal deficit, severity of axotemia, dialysis requirements and duration of stay in the hospital. There were statistically significant differences between septic and non septic patients with respect of hyponatremia (67.8 vs 54.4%, p < 0.04), respiratory failure (68 vs 54%, p < 0.04), and thrombocytopenia (64 vs 48%, p < 0.02). Mortality in septic patients was higher than in non-septics (56 vs 42.7%, p < 0.009). Factors associated with increased mortality in ARF septic patients were respiratory failure, metabolic acidosis and oliguria while in the non-septics they were hepatic dysfunction, hyperkalemia, respiratory failure and infection acquired during the course of renal failure. We conclude that ARF developing in septic patients has a higher mortality than that of non-septic patients, whereas the incidence of hypercatabolism and oliguria was not different between both groups.

Acute Kidney Injury↗
PubMed1995

Nonimmediate reactions to betalactams: prevalence and role of the different penicillins.

In patients treated with penicillins, adverse cutaneous reactions can occur within minutes or may take several days to develop. IgE antibody-mediated reactions are well documented, but other mechanisms may also be involved. In particular, nonimmediate reactions have not been studied extensively, and the purpose of the present work was to establish the incidence of such reactions among a large group of patients and to study the penicillins involved. A total of 380 subjects with a history of a cutaneous reaction following administration of a penicillin antibiotic was included in the study. Skin tests and specific IgE measurements (RAST) were carried out using various penicillins and penicillin-related reagents, and patients were also challenged with various penicillins. In some patients with delayed skin test responses, skin biopsies were carried out. The tests confirmed that 74 subjects (19.4% of total investigated) had suffered a cutaneous reaction to a penicillin derivative, and 29 of these subjects (7.6% of total or 39% of confirmed) showed evidence of having suffered a nonimmediate reaction. The latter group were identified by giving a positive delayed direct challenge, and in 65% of the cases a delayed skin test response was detected. In most cases, these responses were to amino penicillins. Skin biopsies showed a lymphomonocytic cell infiltrate. Nonimmediate reactions to penicillins are a reproducible phenomenon, suggesting that a specific mechanism is responsible. By direct challenge, 93% of responders were positive to amino penicillins (10.3% ampicillin, 82.7% amoxicillin), indicating a major role for these penicillins in nonimmediate reactions.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

The effect of outdoor air pollution on mortality risk: an ecological study from Santiago, Chile.

The aim of this ecological study was to investigate the effect of outdoor air pollution on the mortality risk of metropolitan inhabitants in Santiago de Chile. Cause-specific deaths by the day for the years 1988-1991 in Santiago de Chile were extracted from mortality data tapes of the National Center for Statistics. Deaths from accidents were excluded. Total and some specific respiratory diseases deaths were compared calculating the risk of death by municipality and month of the year using age-adjusted standardized mortality ratios (SMRs) controlling for socioeconomic level. Daily counts of deaths were regressed using a Poisson model on the total and fine suspended particles, SO2, CO and ozone on the preceding day, controlling for temperature and humidity. A clear pattern in the geographical distribution of risk of death, both for general mortality and specific respiratory causes (pneumonia, COPD and asthma) was found using SMR, with higher values in the most polluted areas regardless of socioeconomic and living conditions. A highly significant positive association was found between total mortality and both fine suspended particles and CO level. The association remained significant for those days with fine suspended particles levels below 150 micrograms/dl suggesting a no-threshold effect for the total number of deaths. These results are in agreement with previously reported associations, and they add to the body of evidence showing that particulate pollution is associated with increases daily mortality.

Adolescent↗
PubMed1994

Behavioral and electrophysiological correlates of the quinolinic acid rat model of Huntington's disease in rats.

The influence of bilateral intrastriatal injection of quinolinic acid (QA, 300 nmol) was studied in male Wistar rats. Behavioral and electrophysiological experiments were conducted in 15 lesioned plus 15 vehicle-injected (control) animals. With respect to control animals, QA-lesioned rats showed marked, statistically significant alterations from both the behavioral (greater motor activation in response to d-amphetamine, place-learning deficit in the Morris water maze), and the electroencephalographic (reduced voltage amplitude and EEG power at the level of frontal cortex) points of view. In addition, a significant loss in body weight and a marked striatal gliosis (GFAP staining) were observed in lesioned rats. Conversely, QA-lesioned rats did not show modifications in posttetanic potentiation (P.T.P.) or long-term potentiation (L.T.P.) in CA1 hippocampal area. The present results confirm that QA lesions of rat striatum may be regarded as a suitable model of Huntington's disease (HD).

Animals↗
PubMed1994

Comparison of high frequency chest compression and conventional chest physiotherapy in hospitalized patients with cystic fibrosis.

Clearance of bronchial secretions is essential in the management of cystic fibrosis (CF) patients admitted for acute pulmonary exacerbation. Conventional physiotherapy (CPT) is labor-intensive, time-consuming, expensive, and may not be available as frequently as desired during hospitalization. High frequency chest compression (HFCC), which uses an inflatable vest linked to an air-pulse delivery system, may offer an attractive alternative. To study this, we prospectively studied 50 CF patients admitted for acute pulmonary exacerbation who were randomly allocated to receive either HFCC or CPT three times a day. On admission, clinical status and pulmonary function tests (PFT) in the HFCC group were not significantly different from those measured in the CPT group. Significant improvements in clinical status and PFT were observed after 7 and 14 d of treatment, and were similar in the two study groups, leading to patient discharge after similar periods of hospitalization. We conclude that HFCC and CPT are equally safe and effective when used during acute pulmonary exacerbations in CF patients. We speculate that HFCC may provide an adequate alternative in management of CF patients in a hospital setting.

Acute Disease↗
PubMed1993

[Risk factors for low birth weight and intrauterine growth retardation in Santiago, Chile].

An epidemiologic case-control study to ascertain the determinants of low birthweight was carried out in Santiago, Chile, from January to December 1989. The cases were defined as livebirths < 2500 g. The controls were livebirths > or = 2500 g of birthweight. All cases and a random sample (1:1) of controls were selected among 8,254 singleton births occurring at the El Salvador Hospital in the Eastern area of Santiago. These deliveries represented 50% of institutional deliveries in the area. Home deliveries (2%) and private hospital deliveries were not included in the study. Information was obtained from hospital medical records by six trained medical students. Some information could not be obtained from the hospital medical records. Thus the second step in data collection was the tracking of all the selected subjects to their referring neighborhood health centers. For the analysis, the data were divided into 3 case (outcome) categories: 453 subjects were the total case group. From these, 153 were the IUGR case group and 300 were the LBW preterm case group. The general control group consisted of 605 normal birthweight infants. 565 were the IUGR control group and 40 were the preterm control group. A total of 25 risk factors showed a significant crude odds ratio for at least one of the groups. In the multivariate logistic regression analysis eight variables: No. of pregnancies, previous adverse outcomes, previous LBW, pregnancy maternal weight, No. of visits, month of first prenatal care visit, maternal smoking and intrahepatic cholestasis of pregnancy, were significantly associated with LBW after adjustment by confounding. Eight risk factors: IUGR in previous pregnancies, Previous adverse outcome, Maternal smoking, intrahepatic cholestasis, maternal pregnancy weight, maternal height, month first prenatal visit, No. of visit, were significant to IUGR. Only two variables: pregnancy weight, divorced mother, were significantly associated with low birth weight in the preterm group. The most relevant risk factors were included in stepwise logistic regression models carried out for the outcome LBW for the general group, term group and preterm group, in order to adjust by confounding. Adjusted odds ratios were then obtained. Prenatal care related factors and maternal adverse obstetric factors were at higher significance for LBW in the general and IUGR groups. Only nutritional factors were related to LBW in preterm group. Women who delivered a LBW or IUGR infant were more likely to have fewer pregnancies, a history of previous LBW, lower prepregnancy weight and lower gestational weight gain. ICP was associated with an elevated risk of LBW that was independent of gestational age.

Case-Control Studies↗
PubMed1993

[APS-2: comparative study on populations of critical patients in Chile, United States and New Zealand].

Between 1988 and 1991, the Acute Physiologic Score (APS-2) was applied to 1000 critically ill patients admitted to an intensive care unit of a general hospital in Chile. Its predictive capacity was assessed and compared with two series from United States and New Zealand. The mean admission APS-2 in Chilean patients was 12.8 and there was a progressive increase in mortality with elevating scores; no patient with an APS-2 over 30 survived. Admission APS-2 scores in USA and New Zealand were 10.7 and 14.2. Overall mortality in Chilean patients was 28%, compared with 12% in USA and 15% in New Zealand. Within different score ranges, mortality was higher in Chilean patients than those from USA or New Zealand. It is concluded that the assessment of admission APS-2 score underlying diagnosis, physiologic age and previous health status of a patient may help to predict the success of intensive care.

Adult↗