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Biomedical subjects

G Valdivia

Publications and source records attributed to G Valdivia.

10 recordsLinked to original sources
PubMed2000

[Bronchial asthma and atopic diseases as an emerging problem in public health: new etiological hypothesis. The experience of developed societies].

Developed countries report increasing trends in the prevalence of asthma and atopic diseases over the last 40 years. This change cannot be attributed to artefactual effects. Emerging from these information, new approaches have been generated to explore these novel findings. Among the most important new factors to be explored, scientific research is pointing out to variables related with physical environment, socio-economic and genetic background, anthropometry at birth, nutritional status, diet, exercise and hormonal profile. Changes in the epidemiology of asthma and atopic conditions in developed countries were also preceded by increases in the prevalence of chronic diseases and their risk factors. Chile does not have information about time trends on these diseases, but several studies are reporting a high prevalence of asthma among adults. Conversely, results from the collaborative ISAAC study carried out in children, have shown a relative low prevalence of asthma in Chilean children. An increasing trend in chronic diseases and their risk factors has been reported in Chile, suggesting an epidemiological pattern similar to that experienced by industrialised countries, when the prevalence of asthma and atopic began to increase. This article review current information about etiological research emphasising the need to develop local research on asthma and atopic diseases taking into account our epidemiological situation.

Asthma↗
PubMed1999

[Gastric cancer and cerebrovascular diseases. A natural history with common elements? Analysis of the salt theory in Chile (1955-1994)].

BACKGROUND: In the last forty years, a sustained reduction in the gastric cancer and cerebrovascular disease mortality has been recorded. Joossens has postulated that sodium intake has an influence in the natural history of both diseases. AIM: To analyze the mortality caused by both diseases in Chile. MATERIAL AND METHODS: The mortality of people aged 35 to 64 years old, due to gastric cancer and cerebrovascular diseases in the period 1955-1994, was analyzed. An analysis according to regions, using temporal series and correlation techniques was performed. RESULTS: In the studied period, the mortality due to gastric cancer decreased by 71.6% in men and by 79.5% in women. Mortality due to cerebrovascular diseases decreased by 56.9% in men and by 63.9% in women. There was a correlation coefficient of +0.91 between the mortality due to both diseases. Cerebrovascular disease mortality appears as a predictor of gastric cancer mortality in temporal series analysis. CONCLUSIONS: Joossens theories are supported by the present data. Prospective studies should be designed to confirm the hypothesis.

Adult↗
PubMed1997

[Respiratory symptoms and cough reflex in populations exposed to different degrees of environmental pollution].

BACKGROUND: Santiago is a city with a high degree of environmental pollution caused by particulate matter and ozone, producing adverse effects in the respiratory system. AIM: To compare respiratory symptoms and cough reflex in adults from Santiago and from a rural area with low levels of environmental pollution. SUBJECTS AND METHODS: One hundred twenty six non-smoker adults from Santiago and 116 from a rural area with low levels of pollution answered a respiratory symptom questionnaire. Of these 101 subjects from Santiago and 116 from the rural area inhaled doubling concentrations of capsaicin from 0.5 to 500 microM or until five coughs were elicited. The lowest concentration eliciting 2 or more coughs (CD2) or 5 or more coughs (CD5) was recorded. Levels of environmental particulate matter were also recorded in both locations. RESULTS: Levels of particulate matter were 102 +/- 41 and 64 +/- 24 micrograms/m3 in Santiago and the rural area respectively. People from Santiago had higher rates of throat clearing, cough and phlegm. CD2 geometric mean and confidence limits in Santiago and the rural area were 6.9 (5.2-7.4) and 2.8 (2.7-2.9) respectively (p < 0.001). No differences in CD5 were observed between both locations. Multivariate analysis disclosed the variable location (city) as the only independent predictor of respiratory symptoms. CONCLUSIONS: The increased CD2 found in Santiago suggests that the higher rates of respiratory symptoms related to air pollution can be associated to a decreased sensitivity of the cough reflex.

Adolescent↗
PubMed1996

Late motor deficits of Chilean manganese miners: a blinded control study.

High-level chronic manganese (Mn) exposure produces dystonic rigidity and proximal tremor. The late effects of asymptomatic exposure are uncertain. To evaluate hand movements of asymptomatic Chilean miners, we utilized a manual tremormeter (EAP) and a digitizing tablet (MOVEMAP). In Andacollo, Chile, we examined 59 individuals aged > 50 years (mean age, 64.4 years). Twenty-seven exposed miners had heavy Mn dust exposure in Mn mines for more than 5 years (mean duration, 20.25 years), ending at least 5 years previously. Thirty-two control miners had never worked in Mn mines or had short-term Mn employment. Tests of resting tremor (EAP Tremormeter, MOVEMAP Steady paradigm), action tremor (MOVEMAP Square paradigm), and repetitive hand movements (EAP Tapping Test and Orthokinesimeter) differentiated performance of exposed miners from that of controls. Chronic asymptomatic Mn exposure results in detectable late-life abnormalities of movement.

Chile↗
PubMed1996

[Hip fracture: a case-control study in the metropolitan region I].

BACKGROUND: Hip fracture is a preventable cause of disability among elderly people AIM: To study factors associated to hip fractures in Chile. PATIENTS AND METHODS: Patients admitted to seven public hospitals in Chile, with hip fracture not due to major accidents, were considered as cases. To each, at least one age and sex matched hospitalized control, without or neoplastic diseases, was assigned. All patients were subjected to an inquiry, using an instrument devised by the WHO. RESULTS: Two hundred sixty eight cases and 501 controls were studied. Cases and controls has similar educational and labor histories. The right hip was fractures in 47% of cases and the left in the rest. Compared with controls, cases had a higher body mass index, loss of height during life, rate of hysterectomy, incidence of smoking and a lower consumption of diary products. Cases had higher risk of falls inside their homes and controls outside. CONCLUSIONS: The obtained information may contribute to the development of preventive measures and reduce the public health impact of hip fracture.

Aged↗
PubMed1994

[Frequency of lumbar spine osteopenia in an asymptomatic postmenopausal Chilean population].

The aim of this study was to assess lumbar spine bone density in a group of chilean postmenopausal females and to estimate the frequency of vertebral osteopenia in the national urban female population. A clinical assessment and lumbar spine bone density measurement were performed to 171 healthy women over 40 years of age and not receiving medications that modify bone turnover. Calcium ingestion was recalled in 77 of these. Fifty women (29.2%) had osteopenia, defined as a bone density of less than 0.92 g/cm2. Extrapolating this figure to the national urban population, an osteopenia frequency of 21.7% was estimated. Body mass index was 25.5 +/- 3.8 and 57% of the sample was overweight. Calcium ingestion was 740.3 +/- 331.7. These two parameters did not correlative with bone density. Women with osteopenia were older and had a longer postmenopausal lapse than those with normal bone density. The completion of further clinical an epidemiological studies is recommended to know the real magnitude of osteoporosis in Chile.

Absorptiometry, Photon↗
PubMed1992

Development of a program of behavior modification directed to the rehabilitation of drug-dependent patients: treatment and follow-up of 223 cases.

The study reports treatment and follow-up of compulsive drug-consuming patients (mainly of coca paste). The program used was based on a behavioral cognitive and instructional model. The traditional functional analysis was modified to include the therapeutical work in seven behavioral areas: (1) drug use; (2) behavior during free time; (3) behavior at work; (4) social behavior; (5) self- and environmental management behaviors; (6) problem solving and decision-making behaviors; (7) recognition, evaluation, and modification of irrational beliefs. For each area objectives, therapeutical procedures, control and evaluation methods, and termination criteria were determined. Patients engaged in a multiple activity program and received individual and group therapy. Out of 223 male patients, 130 were discharged (that is, they fulfilled all the conditions stated by the program) and 93 patients abandoned treatment. For evaluation purposes a test was used to determine the accomplishment of the behavioral objectives. Follow-up interviews after 6 to 72 months showed that although 24 patients relapsed to drug use, 106 (81.48%) of the patients who had finished the program restrained from using drugs and obtained high scores in all seven behavioral areas.

Adolescent↗
PubMed1990

[Gallbladder cancer mortality in Chile and its relation to cholecystectomy rates. An analysis of the last decade].

Extrahepatic biliary tract cancer (mainly gallbladder cancer) mortality rates have increased from 7.84 x 100.000 to 9.6 x 100.000 in Chile during the last decade. The most significant risk factor for gallbladder cancer is gallstone disease. However, no apparent changes in the prevalence of gallstone disease has occurred during this period. In contrast, cholecystectomy rates have consistently decreased during the decade. The aim of this study was to correlate extrahepatic biliary tract cancer mortality and cholecystectomy rates of previous years during the last decade in our country. The best correlation coefficient between both variables was obtained when mortality was correlated with cholecystectomy rates two years prior to the mortality rate (r = -0.92). This finding is consistent with the hypothesis that changes in the number of cholecystectomies performed in a specific geographic area would reciprocally change gallbladder cancer mortality rate. It was estimated that increasing cholecystectomies by 12,500 per year would decrease at mortality rate from this cancer by approximately 1.0 x 100.000 two years in Chile.

Chile↗
PubMedDate not supplied

Cellular immune response of intracecally inoculated Mongolian gerbils with Entamoeba histolytica trophozoites.

We analyzed the local and systemic cellular immune response in mongolian gerbils inoculated with Entamoeba histolytica. Two groups were intracecally inoculated with E. histolytica trophozoites and two groups were used as controls. A inoculated groups and a control groups were sacrificed on days 10 and 30 post inoculation (p.i), the spleen and mesenteric lymph nodes (MLNs) lymphocytes (Ly) were isolated and incubated in vitro with 2 different amebic antigens. The proliferative Ly response of inoculated groups was greater than the Ly mitogenic response seen in control groups, at day 10 p.i. as well as day 30 p.i. (alpha = 0.05). Ly response of MLNs was greater in comparison to those of the spleen (alpha = 0.05). In other four groups, intradermal reactions with a antigen were used to demonstrated delayed hypersensitivity in gerbils after being inoculated with E. histolytica trophozoites. The percentage of volume increase of the plantar pad swelling were measured. Groups inoculated presented greater increases (alpha = 0.05) than groups controls. The evidence presented herein demonstrates that the presence of E. histolytica trophozoites in cecum induced a local and systemic cellular immune response.

Animals↗