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Biomedical subjects

H Reyes

Publications and source records attributed to H Reyes.

At least 19 recordsLinked to original sources
PubMed1996

Improving physician prescribing patterns to treat rhinopharyngitis. Intervention strategies in two health systems of Mexico.

To improve prescribing practices for rhinopharyngitis, an interactive educational intervention and a managerial intervention were carried out in 18 primary care facilities in metropolitan Mexico City. Four family medicine clinics of the Mexican Social Security Institute (IMSS) and 14 health centres of the Ministry of Health (SSA) were included. A quasi-experimental design was employed. One hundred and nineteen physicians (IMSS 68, SSA 51) participated. Sixty-five physicians (IMSS 32, SSA 33) were in the study group, while 54 were in the control group (IMSS 36, SSA 18). The study had four stages: (I) baseline, to evaluate the physicians' prescribing behaviour for rhinopharyngitis; (II) intervention, using an interactive educational workshop and a managerial peer review committee; (III) post-intervention evaluation of short-term impact; and (IV) follow-up evaluation of long-term effect 18 months after the workshop. The control group did not receive any intervention but was evaluated at the same time as the study group. At baseline, most patients in both institutions received antibiotic prescriptions (IMSS 85.2%, SSA 68.8%). After the workshop, the percentage of patients receiving antibiotic prescriptions in the IMSS went from 85.2% to 48.1%, while in the SSA it went from 68.8% to 49.1%. Appropriateness of treatment was analyzed using the physician as the unit of analysis. At baseline, 30% of IMSS physicians in the study group treated their patients appropriately. After the intervention, this percentage increased to 57.7%, and at the 18-month follow-up it was 54.2%. The SSA study group increased the appropriate use of antibiotics from 35.7% to 46.2%, with this percentage falling to 40.9% after the 18-month follow-up period. In the control group there were no significant changes in prescribing patterns with respect to either the prescribing of antibiotics or the appropriateness of treatment. The intervention strategies were successful in both institutions. Forty per cent of physicians improved their prescribing practices after the workshop, with this change remaining in 27.5% of them throughout the follow-up period. On the other hand, 42.5% of the physicians did not change their prescribing practices after the intervention. The rest (17.5%) showed appropriate prescribing practices during all the stages of the study. We conclude that it is possible to improve the physicians' prescribing practices through interactive educational strategies and managerial interventions. This type of intervention can be an affordable way to provide continuing medical education to primary care physicians who do not have access to continuing educational activities, and to improve the quality of care they provide.

Adult↗
PubMed1996

Impact of oral rehydration and selected public health interventions on reduction of mortality from childhood diarrhoeal diseases in Mexico.

Reported are the results of an analysis of mortality trends from diarrhoeal diseases among under-5-year-olds in Mexico between 1978 and 1993 in relation to the impact of education, basic sanitation, and selected medical care practices. The study period was divided into three stages; the first pre-dated the widespread application of oral rehydration therapy (ORT); the second, covered the implementation of a nationwide programme promoting ORT; and the third included additional measures, such as immunization and improvements in basic sanitation. Mortality rates decreased progressively, at an average of 1.8% per year in the first stage, 6.4% in the second, and 17.8% in the third. The importance of literacy campaigns for women and the promotion of ORT was confirmed. Both of these measures reduced mortality; however, a greater reduction resulted from a massive immunization campaign against measles and improvements in sanitation (expansion of the drainage and piped water systems, improved water chlorination procedure, and effective prohibition of the use of sanitary sewage for vegetable irrigation).

Adult↗
PubMed1995

Multireactive pattern of serum autoantibodies in asymptomatic individuals with immunoglobulin A deficiency.

Selective immunoglobulin A (IgA) deficiency (sIgAD) is associated with certain autoimmune states. Increased production of autoantibodies and eventual development of overt autoimmune disease are related in part to genetic and environmental factors as well as to the immune deficiency. We surveyed serum specimens from 60 healthy subjects with sIgAD for the presence of 21 different autoantibodies by enzyme-linked immunosorbent assays. The frequencies of 16 autoantibodies were higher in sIgAD patients than in normal healthy controls. Autoantibodies to Jo-1 (28%), cardiolipin (21%), phosphatidylserine (20%), Sm (15%), asialo-GM1 (21%), sulfatide (32%), sulfoglucuronyl paragloboside (11%), and collagen type I (10%) were detected at high frequencies in comparison to those of normal healthy controls. Many of the serum samples were multireactive (i.e., exhibited binding to more than two autoantigens). Forty percent (24 of 60) of sIgAD serum samples reacted against six or more autoantigens; 10% (6 of 60) of sIgAD serum samples were not reactive with any of the 21 autoantigens. Three percent (7 of 209) of consecutive serum samples submitted for autoimmune antibody analysis that were positive for autoantibodies were from patients with IgA deficiency. Our finding of an increased frequency of autoantibodies in sIgAD patients supports the notion of polyclonal stimulation by repeated environmental stimuli as an etiologic mechanism. Alternatively, the increased frequency may be caused by a dysregulation of the immune response in such individuals. The mere detection of autoantibodies cannot predict whether a subject with sIgAD will develop an autoimmune disease or determine which specific disease will emerge.

Antigen-Antibody Reactions↗
PubMed1995

[Can a selenium deficiency affect the pathogenesis of cholestasis in pregnancy?].

UNLABELLED: In search of an environmental factor which modulates the expressivity of cholestasis of pregnancy and explains the seasonal and annual variations observed in Finland and Chile, the authors measured selenium (Se) concentration in the plasma and erythrocytes by atomic absorption spectrophotometry and the activity of the glutation peroxidase enzyme dependent on Se (GSH-Px) by a spectrophotometric method in 10 patients with cholestasis of pregnancy, 22 normal pregnant women, 43 non pregnant women and in 15 men, all of whom had normal weight/height, and similar ages, ethnic and geographic origin. Blood samples were obtained weekly from the pregnant women during the third trimester and 24-72 hours postpartum. RESULTS: In non pregnant women and in men plasma Se was 0.83 +/- 0.02 mumol/l (range 0.6-1.2) and the GSH-Px activity was 306 +/- 5 U/L (range 203-459). Both parameters were correlated and were similar to those of other populations whose ingestion of Se is low (Finland, New Zealand, and certain regions of China). In normal pregnant women studied between weeks 20 and 32, the plasma Se and GSH-Px activity were lower than in non pregnant women (0.71 +/- 0.02 mumol/l and 260 +/- 5 U/l, respectively) with both progressively decreasing at the end of pregnancy and rapidly recovering post partum. The erythrocytic GSH-Px activity was similar in normal pregnant women than in non pregnant women (27.7 +/- 0.8 versus 28.1 +/- 0.6 U/g Hb). In patients with cholestasis of pregnancy, plasma and erythrocytic Se and GSH-Px activity were lower than in normal pregnant women (p < 0.05 in similar stages of pregnancy).(ABSTRACT TRUNCATED AT 250 WORDS)

Chile↗
PubMed1995

Is dietary erucic acid hepatotoxic in pregnancy? An experimental study in rats and hamsters.

The hypothesis that dietary erucic acid may contribute to the pathogenesis of intrahepatic cholestasis of pregnancy has been examined in pregnant rats and hamsters after prolonged feeding of diets containing 25% rapeseed oil rich in erucic acid (40% of fatty acids) or corn oil, without erucic acid. Both dietary oils were well tolerated, although weight gain was 17% to 20% less in animals receiving rapeseed oil. Rats and hamsters were studied on the last day of pregnancy and compared with age- and diet-matched nonpregnant animals. Histological examination showed no major morphologic abnormalities in liver, heart, kidneys, and adrenals. Similar microscopic deposits of fat were found in the livers and hearts of pregnant hamsters of both dietary groups. Chromatographic analysis of fatty acids in liver, heart, and kidney homogenates of hamsters and in isolated rat liver cells reflected the fatty acid composition of the dietary oils: oleic (18:1) and linoleic (18:2) acids were among the predominant fatty acids. Erucic acid was found in a higher proportion in the heart (14% by weight of total fatty acids) than in the liver (3%) and kidneys (3%) of animals fed rapeseed oil. Bile flow and biliary lipid composition was similar in rats and hamsters fed rapeseed or corn oil. Bile flow tended to be less in pregnant than in nonpregnant animals. Pregnant hamsters fed rapeseed oil tended to have the lowest bile flow. The lithogenic index of bile was slightly decreased in pregnant rats and increased in pregnant hamsters, although these proportional changes were similar for both diets. In all circumstances the lithogenic index remained below a value of 1.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1995

Laboratory diagnosis of antiphospholipid syndromes.

The search for clinical outcomes associated with antiphospholipid antibodies (aPL) has been ongoing for a decade. This article focuses on the clinical use of tests for the detection of aPL. A review of the current thinking regarding the pathophysiology of antiphospholipid syndromes is relevant to the discussion of different aPL assays and methodologies. The value of aPL testing in specified patient populations is analyzed.

Antiphospholipid Syndrome↗
PubMed1995

[Responsibility of universities in the scientific education of our professionals].

The universities have a leading role and responsibility in the scientific education of future professionals. Scientific research training should be considered essential in the teaching of professionals in areas such as biology, chemistry, physics, mathematics and in medicine. During the recent years, Chilean universities seem to have focused their undergraduate curricular activities into pragmatic aspects of professional practice and the relevance of involving undergraduate students in high-level scientific research receives little consideration. While resources provided by the government to scientific and technological research in Chile are slowly but gradually increasing, the participation of undergraduate students in specific research projects conducted by faculty members is minimal. The author proposes that this situation could be modified if the students are stimulated to participate in these research projects by receiving preferential scores when their elective activities are devoted to it.

Chile↗
PubMed1995

[Who finances medical research in Chile?].

To identify those institutions granting medical research in Chile, every issue of Revista Médica de Chile published between 1987 and 1994 was reviewed, under the assumption that a vast majority (over 70%) of papers released by Chilean authors in topics of internal medicine and related subspecialties would have been submitted for publication in this journal. This assumption was based in the solid prestige of Revista Médica de Chile among Chilean physicians and investigators: it is one of the oldest medical journals in the world (founded in 1872) and its inclusion in the most important international indexes (e.g. Index Medicus, Current Contents) qualifies it in the "mainstream literature". Papers classified as "Original Articles", "Clinical Experiences", "Review Articles", "Public Health", "Case Reports", "Clinical Laboratory", "Special Articles" and "Medical Education" were screened for acknowledgment of financial support beyond the resources needed for routine clinical work. Among 1,528 manuscripts published, 344 were "Original Articles" and 61.3% of them acknowledged special financial support. Five hundred and one manuscripts were "Clinical Experiences" and 21.5% of them received special financial support; similar proportions were detected in "Review Articles" and "Public Health" topics. The institution ranked as providing support most often was the "Fondo Nacional de Ciencias y Tecnología" (FONDECYT), a governmental fund that assigns resources to research in all areas of science and technology through a peer-reviewed nationwide annual contest. FONDECYT was identified as provider of financial support to 45.2% of the "Original Articles" and "Clinical Experiences"; Chilean universities were mentioned by 33.6% and other entities (including pharmaceutical companies, other national and foreign organizations) by 23.1%. The University of Chile was the main Chilean university mentioned in the acknowledgments. The proportion of papers receiving special financial support was lower in Revista Médica de Chile than in three leading journals from developed countries (70% of Articles published in Annals of Internal Medicine, 74% in Lancet and 78% in The New England Journal of Medicine) but this proportion has been steadily increasing since 1987. The increase has been due only to FONDECYT and it would be unreasonable to expect that this institution will maintain such an expansion indefinitely. Therefore, Chilean investigators should attract more resources from the universities, the pharmaceutical companies and other non-governmental institutions.

Chile↗
PubMed1995

From research to public health interventions. I. Impact of an educational strategy for physicians to improve treatment practices of common diseases.

Errors in treating common diseases occur very frequently in primary health care practice. While many of these mistakes are not life-threatening, the costs of abuse in drug prescription may be greatly increased. An educational strategy aimed to improve physicians' prescribing practices for acute diarrhea (AD) and acute respiratory infection (ARI) was developed as a research study, involving three medical care units. The strategy was largely based on promoting active participation of the trainees in the whole process, including: (a) group participation in a literature review of updated articles related to management of AD and ARI; (b) analysis of prescribing practices before the intervention; (c) participation in the development of a clinical algorithm for the therapeutic management of these illnesses; and (d) discussion of the usefulness of the algorithm during peer review committee meetings. Successful results of this intervention, as judged by the improvement of treatment practices and the persistence of changes for up to 2 years after the intervention, as well as its ease of application and low costs, motivated its extension to a health District and a State. In these sites, the intervention was in charge of medical leaders from the clinics and medical heads of the local health systems, respectively. The extension of the educational strategy was accompanied by a relative reduction in AD from 46.7% to 6.5% and in ARI from 32.6% to 8.5%. However, the benefit-cost ratio showed a dramatic increase when comparing results from the research study and from the State intervention, for both AD (from 3.3 to 4.4) and ARI (from 16.2 to 21.6), for an overall net increase of 33.3%. Based on these results, the educational strategy was adopted by the National Program for the Control of Diarrheal Diseases, and was used to train public health physicians throughout the country, from 1992 to 1994.

Acute Disease↗
PubMed1994

Frequency of biochemical hypothyroidism in sera referred for autoantibody testing.

We examined sera submitted for autoantibody testing for thyroid microsome antibodies (TMA), elevated thyroid-stimulating hormone (TSH), and free thyroxine concentrations. The frequency of TMA in antinuclear antibody-positive sera was higher (19%) than that in antinuclear antibody-negative sera (12%). Elevated TSH concentrations in serum and subnormal thyroxine concentrations in serum were associated with the presence of TMA; TMA titer and the frequency of elevated TSH concentrations were also associated with the presence of TMA.

Adult↗
PubMed1994

Acute fatty liver of pregnancy: a clinical study of 12 episodes in 11 patients.

Twelve episodes of acute fatty liver of pregnancy (AFLP) were diagnosed in 11 patients during the past 18 years in a general hospital in Santiago, Chile, with a prevalence of 1 per 15,900 deliveries. Acute fatty liver of pregnancy started between the 31st and 38th weeks of pregnancy, with malaise, vomiting, jaundice, and lethargy as the main clinical manifestations. Polydipsia (in nine episodes) and skin pruritus (in seven episodes) were unusual clinical findings. In two patients, pruritus started two and four weeks before AFLP, suggesting that an intrahepatic cholestasis of pregnancy preceded AFLP in those patients. Considering the current prevalence of both diseases in Chile, their association should be considered fortuitous. In another patient, two consecutive pregnancies were affected by AFLP, raising to three the number of reported patients with recurrent AFLP. In 11 episodes, liver biopsies supported the diagnosis of AFLP by showing small and midsized vacuolar cytoplasmic transformation as the most prominent histopathological feature. Positive intracellular fat staining was found in the four samples analysed. Studies by electron microscopy showed megamitochondria with paracrystalline inclusions in four samples. All the mothers survived, but fetal mortality was 58.3%. Several extrahepatic complications delayed maternal recovery for up to four weeks after delivery. This study confirms an improvement in maternal prognosis in AFLP, discusses the possibility of an epidemiological association with intrahepatic cholestasis of pregnancy, and increases the number of patients reported with recurrent AFLP.

Acute Disease↗
PubMed1994

[Phylogenetic vision of bile acids].

Bile acids are the most important solutes of bile: they are essential in cholesterol degradation, solubilization and excretion; they are determinants of bile flow and secretion; and their role is crucial in the intestinal absorption of lipids and lipid soluble vitamins. In amphibia and in cartilaginous fish, the 27C cholestane molecule is hydroxylated to alcohols. In birds, the terminal 27C-OH group is oxydated to cholestanoic acids. In vertebrates of a more recent evolutionary origin, the lateral chain is shortened to 24C and oxydated to cholestanoic acids. Further transformations include chemical changes in the cholestane skeleton and in the lateral chain (hydroxylations, dehydroxylations, epimerization, etc). In the intestinal lumen, the saprophytic flora provides enzymes catalysing new changes that originate "secondary" bile acids. During entero-hepatic circulation, another variety of bile acids appear, commonly termed "tertiary" bile acids. A recent study of Lee R Hagey characterized bile acid composition of over 600 species of vertebrates, showing that bile acid composition of bile has been the subject of an interesting evolutionary phenomenon and that it is a chemical marker of biodiversity in vertebrates.

Animals↗
PubMed1994

Missile embolization revisited: a rationale for selective management.

Embolization of missiles is an unusual presentation of penetrating trauma. Often the management of these injuries may be quite challenging, and selective management continues to be subject to controversy. We report a case of a bullet embolus to the right ventricle from the internal iliac vein in a 15-year-old boy that was managed with observation. An algorithm for diagnosis and management of this phenomenon mandates exploration of emboli to the aorta and peripheral arteries with repair of the vascular entry site and embolectomy. It also recommends operative intervention for symptomatic venous emboli to the heart and pulmonary circulation. Nonoperative management may be considered in patients with asymptomatic emboli to the right heart or the cerebral and pulmonary circulation.

Adolescent↗