[Influence of helminthic infections and nutritional status on immune response in Venezuelan children]

We investigated the influence of nutritional status, as determined from anthropometric measurement, and of helminthic infections on the immune response of children of low socioeconomic status in two rural communities in Venezuela: El Cardón in the state of Nueva Esparta and San Daniel in the state of Miranda. A total of 125 boys and girls between 2 and 15 years old participated in the study. Their socioeconomic stratum was determined by a modified Graffar method. A physical examination was performed, as was also an anthropometric evaluation that took into account three indicators--weight-for-height, weight-for-age, and height-for-age--according to parameters established by the World Health Organization. Other examinations included feces, secretory IgA in saliva, total serum IgE, and anti-Ascaris-specific immunoglobulins. The children in both of the communities were in strata IV and V of the of Graffar scale, with a significantly greater number of stratum V inhabitants in San Daniel (P < 0.001). The results suggest that exposure level and individual susceptibility to the parasites are determining factors in parasitic infection and immune system behavior. The intensity of the parasitic burden plays an important role in stimulating polyclonal IgE, which diminishes the effectiveness of the specific response to those infections. On the other hand, nutritional deficiencies could change the immune mechanisms of the mucous membranes, negatively influence the synthesis of secretory IgA, and stimulate the production of polyclonal IgE. Poor sanitary and socioeconomic conditions promote more exposure to gastrointestinal parasites and a deficient nutritional status, which modulates the immune response and affects serum IgE and secretory IgA production mechanisms.

Update in internal medicine

More than 500,000 new medical articles are published every year and available time to keep updated is scarcer every day. Nowadays, the task of selecting useful, consistent, and relevant information for clinicians is a priority in many major medical journals. This review has the aim of gathering the results of the most important findings in clinical medicine in the last few years. It is focused on results from randomized clinical trials and well-designed observational research. Findings were included preferentially if they showed solid results, and we avoided as much as possible including only preliminary data, or results that included only non-clinical outcomes. Some of the most relevant findings reported here include the significant benefit of statins in patients with coronary artery disease even with mean cholesterol level. It also provides a substantial review of the most significant trials assessing the effectiveness of IIb/IIIa receptor blockers. In gastroenterology many advances have been made in the H. pylori eradication, and the finding that the cure of H. pylori infection may be followed by gastroesophageal reflux disease. Some new antivirals have shown encouraging results in patients with chronic hepatitis. In the infectious disease arena, the late breaking trials in anti-retroviral disease are discussed, as well as the new trends regarding antibiotic resistance. This review approaches also the role of leukotriene modifiers in the treatment of asthma and discusses the benefit of using methylprednisolone in patients with adult respiratory distress syndrome, among many other advances in internal medicine.

Congestive heart failure in the United States: is there more than meets the I(CD code)? The Corpus Christi Heart Project

BACKGROUND

Congestive heart failure (CHF) is increasing as a public health problem in the United States. The ability to quantify this problem has been limited by a lack of data regarding the validity of CHF identification.

OBJECTIVE

To assess the validity of the use of International Classification of Diseases, Ninth Revision, Clinical Modification (ICD) codes to identify hospitalizations with clinical evidence of an episode of acute CHF in data of The Corpus Christi Heart Project, a population-based surveillance program for hospitalized coronary heart disease.

METHODS

The validation standard was a composite variable including the presence of physician diagnosed acute CHF or radiographic evidence of pulmonary edema. Data were abstracted from the medical records of 5083 patients identified as hospitalized for possible acute myocardial infarction, aortocoronary bypass surgery, percutaneous transluminal coronary angioplasty, and related revascularization procedures in the Corpus Christi Heart Project. Discharge diagnoses, a secondary source of data, were used to apply 3 computer algorithms to assess the assignment of ICD codes.

RESULTS

The prevalence of clinically documented CHF was 27.1% (1376/5083). The ICD code 428 (CHF), assigned as the primary or a secondary discharge diagnosis, was associated with 62.8% sensitivity, 95.4% specificity, 83.5% positive predictive value, 87.4% negative predictive value, and a 24.8% underenumeration of CHF-related hospitalizations. An algorithm based on a series of ICD codes was associated with 67.1% sensitivity, 92.6% specificity, 77.1% positive predictive value, 88.3% negative predictive value, and a 13.0% underenumeration of CHF-related hospitalizations.

CONCLUSIONS

Reliance on ICD codes results in the exclusion of one third of the patients with clinical evidence of acute CHF. This underenumeration is compounded by the typical reliance on the first listed diagnosis. Congestive heart failure may be a greater public health problem than currently recognized. The allocation of resources for relevant surveillance, research, medical care, and preventive efforts should be reevaluated.

Resorbable polyacrylic hydrogels derived from vitamin E and their application in the healing of tendons

A hydrogel containing vitamin E (alpha-tocopherol) was prepared by free radical polymerization of 2-hydroxyethyl methacrylate (HEMA) and alpha-tocopheryl methacrylate (VEMA), the latter being synthesized previously to its use. The hydrogel containing 20 wt % of VEMA showed equilibrium water content in the range of those of hydrogel networks, at any pH. The swelling of the hydrogel followed Fick's law, indicating that sorption of water molecules is controlled by diffusion, although the values of diffusion coefficients for the VEMA-containing hydrogel were lower than those of poly-HEMA in any medium. Surface characterization of the VEMA-containing hydrogel revealed a decrease in the surface energy of solid owing to a decrease of the polar component mainly. The application of finely powdered xerogel of HEMA-VEMA copolymer bearing 20 wt % of the vitamin E derivative gave a very fast and positive response showing an activated regeneration capacity, probably due to the stimulation of the cellular proliferation or the more plausible effect, the cellular protection associated to the antioxidant properties of the vitamin E residue.

Extracellular HIV type 1 Tat protein induces CD69 expression through NF-kappaB activation: possible correlation with cell surface Tat-binding proteins

The HIV-1 Tat protein, essential for HIV-1 gene expression and viral replication, is known to be secreted by infected cells and has pleiotropic effects on various cell functions. It seems that extracellular Tat may exert its functions on cellular targets by at least two different mechanisms, namely, by adsorptive endocytosis, and by a possible interaction with cell surface receptor(s). Here we report that extracellular Tat activates AIM/CD69 gene transcription through an NF-kappaB-dependent pathway in the erythroleukemia cell line K562. Tat induces NF-kappaB binding to DNA as a result of IkappaBalpha phosphorylation and degradation, which depend on the intracellular redox state. We found that the second Tat-coding exon is required for CD69 gene trans-activation, but not for HIV LTR gene transcription. Fluorescein-labeled Tat proteins were used to study cell surface binding sites and cellular uptake of the proteins. Full-length Tat protein has specific binding sites on the surface of K562 cells, whereas truncated Tat1-48, which is efficiently internalized by the cells, does not bind to the cell surface. Our results suggest that extracellular Tat may activate a cell surface-mediated pathway that induces intracellular signal transduction in K562 cells, leading to the activation of NF-kappaB and the transcription of NF-kappaB-dependent genes, such as CD69.

Hydrophilic acrylic biomaterials derived from vitamin E with antioxidant properties

Hydrogels based on polymeric derivatives of vitamin E for biomedical purposes have been prepared by copolymerization reaction of the alpha-tocopheryl methacrylate (V) with 2-hydroxyethyl methacrylate (H) in a range of composition between 5-20 wt % of V. The swelling behavior of the hydrogels in water, alkaline, and acidic media showed a slight decrease in the equilibrium water content with the content of V in the copolymer although in all cases it was superior to an EWC > 20%. The diffusion mechanism followed a Fickian behavior in all media. The values of the diffusion coefficients were in the range 2.5-1.6 10(-7) cm2/s. The states of water in the hydrogels were determined by DSC. A decrease in the content of freezing water was obtained with the V content for all media, and for all compositions lower values of freezing water were obtained in acidic or basic pHs than in distilled water. The copolymeric xerogels, analyzed by contact angle measurements, deviated from those expected taking into consideration those of the homopolymers and the average fraction of the monomers in the copolymer. The polar contribution dropped with the introduction of a small content (4 wt %) of the vitamin E-containing monomer, and it reached a value similar to that of poly-V for a composition of 49 wt % of V in the copolymer. This behavior is accounted for by the segregation of the macromolecular chains of both kinds of monomers, due mainly to differences in their polarity, molecular weights, and the reactivity of both monomers. Finally, thermogravimetric analysis showed a higher thermal (antioxidant) stability of the poly-V with respect to poly-H, giving rise to a residue of 18 wt %. The V-containing copolymers also showed an improved stability (antioxidant behavior), indicating the possibility of the V unit's interfering with the oxidative process, based on free-radical species, and, therefore, with the aging process at the cellular level.

Mealiness assessment in apples using MRI techniques

Small samples of Top Red apples stored 6 months under controlled atmosphere (expected to be non-mealy) and 2 degrees C (expected to be mealy) have been used for MRI imaging. Multi-slice-multi-echo magnetic resonance images (64*64 pixels) have been recorded with a 8 ms echo time. Three out of four apples corresponding to the sample maintained under controlled atmosphere did not developed mealiness while three out of four fruits corresponding to the sample stored at 2 degrees C became mealy after 6 months of storage. The minimum T2 values obtained for the mealy apples show to be significantly lower (F = 13.21) when compared with non-mealy apples pointing that a more desegregated structure and a lower juiciness content leads to lower T2 signal. Also, there is a significant linear correlation (r = -0.76) between the number of pixels with a T2 value below 35 ms within a fruit image and the deformation parameter registered during the Magness-Taylor firmness test. Finally, all T2 maps of mealy apples show a regional variation of contrast which is not shown for non-mealy apples. Significant differences (F = 19.43) between mealy and non-mealy apples are found in the histograms of the T2 maps as mealy apples show a skew histogram combined with a "tail" in their high T2 extreme which is not shown in the histograms of non-mealy apples. These histogram features are also shown for an apple showing internal breakdown indicating that in mealy apples there is a differential water movement that may precede internal breakdown.

Affordability, cost-effectiveness and efficiency of primary health care: the Bamako Initiative experience in Benin and Guinea

Since 1986 two West African countries, Benin and Guinea, have been actively reorganizing their peripheral health systems according to strategies subsequently called the "Bamako Initiative". Two preceding articles described the strategies implemented and the increased effectiveness of primary health care (PHC) witnessed over a period of six years. This article presents an analysis of cost and coverage data from biannual monitoring sessions between 1988 and 1993 in approximately 200 health centres in Benin and 214 in Guinea. In order to assess affordability, the total and per capita recurrent costs for operational health centres are analysed and then compared. The cost analysis reveals a mean total cost per health centre per year of slightly over US+11,000 in Benin and nearly US+9,000 in Guinea. The median cost per capita per year is approximately US+1.0 in Benin and between US+0.60 and US+0.80 in Guinea. Comparisons of these costs between regions, health centres and over time (as coverage levels evolved) show very little variation in either country. Cost-effectiveness is estimated by allocating these costs to immunization, antenatal and curative care and comparing them to the coverage achieved with these interventions. First, the cost-effectiveness of the Bamako Initiative (BI) system as a whole is analysed. The cost per fully vaccinated child is calculated at US+10.9 in Benin and US+8.8 in Guinea. The cost per woman receiving at least three antenatal visits is US+7 in Benin and US+4.7 in Guinea. For curative care, cost per full treatment is US+1.6 in Benin and half this amount in Guinea. Cost-effectiveness is variable between regions, health centres reveals that these differences in cost-effectiveness are mainly caused by the coverage levels achieved, since total costs are relatively stable. Finally the efficiency of drug management and prescriptions as well as of outreach for the expanded programme of immunizations (EPI) is estimated by relating specific drug and outreach activities costs to the number of beneficiaries. The average cost of drugs per treatment is around US+0.5 in Benin and around US+0.3 in Guinea. Cost analysis of outreach activities undertaken for EPI in Guinea revealed a similar average cost per child completely vaccinated for health centres with different intensities of outreach (approximately US+10) and an additional cost per child vaccinated attributable to outreach of US+1-2.

[Central venous catheter location by endocavitary ECG: an alternative to chest radiography]

BACKGROUND

The location of a central venous catheter is checked with a chest radiograph. Right endocavitary electrocardiography (ECG), a technique in which the catheter is connected to the ECG recorder wire to record ECG in DII, might be an alternate method to check the position of the catheter. When the catheter enters the right atrium, there is a large increase in the amplitude of P wave. The aim of this study was to compare the efficacy of endocavitary ECG against the chest radiography as a method to check the position of a central catheter, and to determine whether the ECG method can replace the radiological method.

MATERIAL AND METHODS

One-hundred central catheters which location was checked by ECG and by chest X-ray entered the study. Efficacy of endocavitary ECG, delay between catheter insertion and radiological check, and the cost of the two methods were studied.

RESULTS

Endocavitary ECG determined that de catheter was in a correct position in 80 cases and malpositioned in 20 cases. ECG check agreed with radiological check in 93 catheters. There were 4 false-positive and 3 false-negative cases. The efficacy of endocavitary ECG was 93% (sensitivity: 82%; specificity: 81%; positive predictive rate: 95%; negative predictive rate: 85%). Catheter location was checked immediately on insertion by ECG in all cases, while radiological check was delayed 32 +/- 25 min in the emergency department and 68 +/- 206 min in the admitted patients. The cost of the ECG method was less than that of the radiological method.

CONCLUSIONS

The check of the position of a central venous catheter by endocavitary ECG is taster, cheaper, and of similar efficacy to the radiological method. Endocavitary ECG can replace chest X-rays to check the position of the catheter in more than 90% of cases.

Purification and characterization of a cytotoxin from Enterobacter cloacae

Leukotoxic activity was assayed in clinical isolates of Enterobacter cloacae. Two strains were selected out of 38 by their greater hemolytic activity in blood agar plates. Leukotoxin was purified by salt precipitation, dialysis, chromatography by gel filtration, and high pressure liquid chromatography (HPLC). Human leukocytes, when incubated with purified E. cloacae toxin, showed high percentages of death and lysis, with time and dose dependence. The chromatographic profile of gel filtration presented three protein peaks and toxic activity was detected in the second peak. After HPLC, leukotoxin coeluted with the hemolytic activity and both activities were detected only after 2-mercaptoethanol treatment. Coomassie-stained sodium dodecyl sulfate--polyacrylamide gels showed a single band. This band was estimated to represent a protein of 13300 Da on the basis of both sodium dodecyl sulfate-polyacrylamide gel electrophoresis and gel filtration chromatography.

Role of ascorbate in the activation of NF-kappaB by tumour necrosis factor-alpha in T-cells

The first product of ascorbate oxidation, the ascorbate free radical (AFR), acts in biological systems mainly as an oxidant, and through its role in the plasma membrane redox system exerts different effects on the cell. We have investigated the role of ascorbate, AFR and dehydroascorbate (DHA) in the activation of the NF-kappaB transcription factor in Jurkat T-cells stimulated by tumour necrosis factor-alpha (TNF-alpha). Here we show, by electrophoretic mobility shift assays, that ascorbate increases the binding of NF-kappaB to DNA in TNF-alpha-stimulated Jurkat cells. The ability of ascorbate to enhance cytoplasmic inhibitory IkBalpha protein degradation correlates completely with its capacity to induce NF-kappaB binding to DNA and to potentiate NF-kappaB-mediated transactivation of the HIV-1 long terminal repeat promoter in TNF-alpha-stimulated Jurkat cells but not in cells stimulated with PMA plus ionomycin. AFR behaves like ascorbate, while DHA and ascorbate phosphate do not affect TNF-alpha-mediated NF-kappaB activation. These results provide new evidence for a possible relationship between the activation of the electron-transport system at the plasma membrane by ascorbate or its free radical and redox-dependent gene transcription in T-cells.

Health seeking behaviour and household health expenditures in Benin and Guinea: the equity implications of the Bamako Initiative

Curative and preventive care utilization in Bamako Initiative health centres in Guinea and Benin increased significantly. Service based data and household survey results are compared and interpreted to evaluate the equity aspects of the Bamako Initiative programmes in these settings. Improvements in the use of preventive services are shared by the richer and poorer groups of the population. Inequities are more apparent regarding curative area. An important part of the population is not using Bamako Initiative Health Centres for financial reasons. However, the poor were found to use these Health Centres relatively more than richer socio-economic groups. Challenges of the future are identified and recommendations made as to how to tackle the problem of true indigence.

Local cost sharing in Bamako Initiative systems in Benin and Guinea: assuring the financial viability of primary health care

The fourth in a series of five, this article presents and analyses data on cost recovery and community cost-sharing, two key aspects of the Bamako Initiative which have been implemented in Benin and Guinea since 1986. The data come from approximately 400 health centres and result from the six-monthly monitoring sessions conducted from 1989 to 1993. Community involvement in the financing of local operating costs in the two national scale programmes is also described. In Benin and Guinea, a user fee system generates the community financed revenue with the aim of covering local operating costs including drugs. Health worker salaries remain the responsibility of the government and donor funding covers vaccine and investment costs. Village health committees manage and control resources and revenue. The community is also involved in decision making, strategy definition and quality control. In Benin in 1993, community financing revenue amounted to about US$0.6 per capita per year and generally covered all local recurrent non salary costs except vaccines and left a surplus. Although total costs and revenues were slightly lower in Guinea for the same period, over-all user fee revenue (around US$0.3 per capita per year) covered local recurrent costs (not including salaries or vaccines). A comparison of costs and revenue between regions and individual health centres revealed important differences in cost recovery ratios. In Benin, some centres recovered more than twice the local costs targeted for community financing. Twenty-five per cent of centres in Guinea did not manage to cover their designated local recurrent costs. The longitudinal analysis showed that the level of cost recovery remained stable over time even as preventive care (and especially EPI) coverage rose significantly. To better understand the most important characteristics affecting cost recovery levels, best performing health centres in terms of cost-recovery levels in 1993 were compared to worst performing centres. This analysis showed that the size of the target population of the health centre is a key determinant of cost-recovery in both countries. In addition, in Guinea the utilization of curative care linked to geographical access and in Benin the average revenue per case linked to the number of deliveries proved to be additional factors of importance. In best performing centres, financial viability improved over time in both countries between 1990 and 1993. Finally, the implications of these conclusions for the planning of health centre revitalization in West Africa are discussed.

Affordability, cost-effectiveness and efficiency of primary health care: the Bamako Initiative experience in Benin and Guinea

Since 1986 two West African countries, Benin and Guinea, have been actively reorganizing their peripheral health systems according to strategies subsequently called the "Bamako Initiative". Two preceding articles described the strategies implemented and the increased effectiveness of primary health care (PHC) witnessed over a period of six years. This article presents an analysis of cost and coverage data from biannual monitoring sessions between 1988 and 1993 in approximately 200 health centres in Benin and 214 in Guinea. In order to assess affordability, the total and per capita recurrent costs for operational health centres are analysed and then compared. The cost analysis reveals a mean total cost per health centre per year of slightly over US+11,000 in Benin and nearly US+9,000 in Guinea. The median cost per capita per year is approximately US+1.0 in Benin and between US+0.60 and US+0.80 in Guinea. Comparisons of these costs between regions, health centres and over time (as coverage levels evolved) show very little variation in either country. Cost-effectiveness is estimated by allocating these costs to immunization, antenatal and curative care and comparing them to the coverage achieved with these interventions. First, the cost-effectiveness of the Bamako Initiative (BI) system as a whole is analysed. The cost per fully vaccinated child is calculated at US+10.9 in Benin and US+8.8 in Guinea. The cost per woman receiving at least three antenatal visits is US+7 in Benin and US+4.7 in Guinea. For curative care, cost per full treatment is US+1.6 in Benin and half this amount in Guinea. Cost-effectiveness is variable between regions, health centres reveals that these differences in cost-effectiveness are mainly caused by the coverage levels achieved, since total costs are relatively stable. Finally the efficiency of drug management and prescriptions as well as of outreach for the expanded programme of immunizations (EPI) is estimated by relating specific drug and outreach activities costs to the number of beneficiaries. The average cost of drugs per treatment is around US+0.5 in Benin and around US+0.3 in Guinea. Cost analysis of outreach activities undertaken for EPI in Guinea revealed a similar average cost per child completely vaccinated for health centres with different intensities of outreach (approximately US+10) and an additional cost per child vaccinated attributable to outreach of US+1-2.

Greater incidence of hospitalized myocardial infarction among Mexican Americans than non-Hispanic whites. The Corpus Christi Heart Project, 1988-1992

BACKGROUND

Since Mexican Americans have adverse patterns of risk factors for myocardial infarction relative to non-Hispanic whites, the incidence of myocardial infarction should be greater among Mexican Americans than among non-Hispanic whites. This expectation conflicts with reports generated from death certificate registries.

METHODS AND RESULTS

Data regarding myocardial infarction attacks and incident events were collected for a 4-year period in the Corpus Christi Heart Project, a population-based surveillance project for hospitalized coronary heart disease events. For both women and men, Mexican Americans experienced greater hospitalization rates for both attacks and incident events than non-Hispanic whites. Age-adjusted attack rate ratios comparing Mexican Americans with non-Hispanic whites were 1.59 (95% CI, 1.05 to 2.41) and 1.31 (95% CI, 1.18 to 1.45) among women and men, respectively. Corresponding incidence ratios were 1.52 (95% CI, 1.28 to 1.80) and 1.25 (95% CI, 1.10 to 1.42).

CONCLUSIONS

This is the first report documenting greater incidence of hospitalized myocardial infarction among Mexican Americans than among non-Hispanic whites, a biologically plausible finding given the risk factor patterns observed in the Mexican-American population. Public health planners and clinicians should be aware of the importance of myocardial infarction as a health problem in the Mexican-American population. Culturally appropriate prevention strategies should be developed for and tested in Mexican-American populations.

Childcare needs of female street vendors in Mexico City

This article reports on strategies developed by female street vendors (vendedoras ambulantes) in Mexico City to ensure the care of their young children in the absence of a specific and operational government policy to fulfil this need. The information concerning child care and health was gathered by a survey of 426 street traders selected by multi-stage random cluster sampling in four of the administrative districts (delegaciones politicas) of Mexico City during 1990. It was found that, as mothers of young children, street vendors most frequently looked after their children personally on the street or left them with other members of the family. Related factors were availability of alternative child care providers in the family, the age of the children and working conditions of the mother. Children who remained on the streets with their mothers suffered more frequently from gastro-intestinal diseases and accidents than the national average. The incidence of acute respiratory diseases, however, was similar in the cases of maternal care in the street and care by family members in another environment. Existing public health measures show a greater concern for the health of food consumers than that of workers in this area. Current public policy seeks to regulate street vending activities and to concentrate traders in ad hoc areas and facilities. Our research results document the need for actions that can contribute to an improvement in the care and health conditions of these young children.

Bacteremia due to Acinetobacter baumannii: epidemiology, clinical findings, and prognostic features

The number of nosocomial infections caused by Acinetobacter baumannii has increased in recent years. During a 12-month study, there were 1.8 episodes of A. Baumannii bacteremia per 1,000 adults admitted to a hospital in Seville, Spain. Seventy-nine patients were included in the study. A. baumannii bacteremia occurred after a mean (+/- SD) hospitalization of 18 +/- 20 days. In all cases the infections were acquired nosocomially; 71% wee acquired in intensive care units. Ampicillin/ sulbactam was found to be the most active agent against A. baumannii. The common source of the bacteremia was the respiratory tract (32 cases [71%]). Twenty patients (25%) had septic shock, and 24 (30%) had disseminated intravascular coagulation (DIC). Treatment with imipenem or ampicillin/sulbactam was most effective (cure rates, 87.5% and 83%, respectively). The deaths of 27 patients (34%) were related to A baumannii bacteremia. The presence of DIC (odds ratio [OR] = 116.4; P < .0001) and inappropriate antimicrobial treatment (OR = 15.2; P < .01) were independently associated with mortality. We conclude that most A. baumannii isolates are multiresistant and that nosocomial A. baumannii bacteremia may cause severe clinical disease that is associated with a high mortality.

Women and Mexican Americans receive fewer cardiovascular drugs following myocardial infarction than men and non-Hispanic whites: the Corpus Christi Heart Project, 1988-1990

Mortality following myocardial infarction (MI) is greater among women than men and among Mexican Americans than non-Hispanic whites. Because therapy can affect mortality following MI, we examined differences in discharge therapy among these groups. Data regarding discharge therapy of 982 patients in the Corpus Christi Heart Project showed that women received fewer cardiovascular drugs than men, and Mexican Americans received fewer cardiovascular drugs than non-Hispanic whites. In multivariate analysis adjusting for age, cigarettes smoking, diabetes, hypertension, congestive heart failure, and serum cholesterol, the odds ratio for receipt of cardiovascular medications was 0.51 (95% CI: 0.28-0.93) for women versus men and 0.62 (0.3-1.15) for Mexican Americans versus non-Hispanic whites. Beta-blockers were prescribed rarely. Thus, treatment differences between ethnic and gender groups were observed following MI. Further research is needed to determine both the reasons for these differences and the extent to which these differences contribute to the observed survival patterns following MI.

[Advances and challenges in health economics]

Health economics is a specialized field of economic science that applies the economic perspective to the fields of health, the medical-industrial complex and health services. A brief review of the evolution of this speciality by subject, as well as the level achieved assessed in terms of generation, diffusion, reproduction and application of its specialized knowledge, is presented.

Avances y retos de la economía de la salud

La economía de la salud como especialidad, incorpora la perspectiva económica en el campo de la salud, los servicios, y el complejo médico industrial. Se presenta su evolución desde la perspectiva de sus áreas de interés y su consolidación reflejada en la generación, difusión, réplica y aplicación del conocimiento especializado.

Effect of atmospheric composition and pressure on the laser ablation of (GeTe)(85)Sn(15) chalcogenide thin films

Laser ablation of (GeTe)(85)Sn(15) thin films as a function of atmospheric exposure was monitored in real time by transient reflectivity. The observed optical changes were correlated with microstructural analysis. Among the key findings were that the presence of water in the atmosphere during laser irradiation of a thin-film structure reduced the incident laser power required for ablation by as much as a factor of 2. The magnitude of the effect was dependent on both H(2)O vapor pressure and duration of exposure to the vapor. The reduction of laser power necessary to ablate was partially reversed by exposure of the thin-film structure to vacuum. Significantly, exposure to other (dry) gases such as N(2) did not change the ablation threshold from that observed in vacuum. We determined that dome formation and ablation occurred at lower temperatures in the presence of water. In addition, the power necessary to crystallize the amorphous chalcogenide layer in the structure was independent of atmospheric composition or pressure. Microstructure analysis showed the presence of H(2)O fostered the formation of a nonuniform distribution of the chalcogenide material in the ablated region. The experimental results are consistent with our model that ablation is assisted by high pressures produced by vaporization of absorbed liquid water.

[Teaching of health economics in Mexico: 5-year experience]

Teaching strategies for a new specialty constitute a challenge to ensure the rapid development of human resources for the purpose of supporting these activities. In the health economics field a plan was applied for coping with the needs of teaching activities in the field. The activities developed in the plan are presented in this paper, included under the following items: A. Theoretical organization of the contents of the subject. B. Organization of contents according to the students' needs. C. Support given to teachers. D. The whole strategy also includes: academic interchange, technical advisory services, dissemination of results through meetings, publications and academic organizations. E. Median term agenda: Human resources; Financial resources; Teaching strategies; Interaction between health services and decision makers; and Collaborative network.

Improved detection of antibodies to hepatitis C virus in dialysis patients using a second-generation enzyme immunoassay

We tested serum samples from 99 patients undergoing maintenance hemodialysis for hepatitis C virus (HCV) antibodies using a first-generation, licensed anti-HCV enzyme immunoassay (EIA) and a second-generation anti-HCV EIA that detect three gene products c100-3, NS3, and core. Specimens that were repeatedly reactive by either or both screening assays were further evaluated by testing with supplemental EIAs and a dot blot immunoassay. There was 87.9% agreement between the licensed HCV EIA and the HCV EIA second generation. HCV EIA Second Generation detected 10 more positive specimens than HCV EIA, for an increase in detection from 33.3% (33/99) to 43.4% (43/99). We conclude that HCV EIA Second Generation improves detection of HCV infection in hemodialysis patients.

[T-lymphomas with splenic presentation]

Three cases of lymphomas with splenomegaly onset, without peripheric adenopathies, which required laparotomy to be diagnosed, are discussed. One of the cases was a primary splenic lymphoma and the other two were associated with reactive hemophagocytosis. Other malign lymphoproliferative processes of predominant splenic onset are discussed.

Glucosylenamines as glycosyl acceptors: synthesis of gentiobiosylenamines

The preparation of 2,3,4-tri-O-benzyl- (3), 2,3,4-tri-O-acetyl- (4), and 2,3,4-tri-O-benzoyl-N-(2,2-diethoxycarbonylvinyl)-6-O-trityl-beta- D-glucopyranosylamine (5) is described. The reaction of 3-5 with 2,3,4,6-tetra-O-acetyl-alpha-D-glucopyranosyl bromide yields 2,3,4-tri-O-benzyl- (9), 2,3,4-tri-O-acetyl- (10), and 2,3,4-tri-O-benzoyl-N-(2,2-diethoxycarbonylvinyl)-6-O-(2,3,4,6-tet ra-O- acetyl-beta-D-glucopyranosyl)-beta-D-glucopyranosylamine (11), respectively. 2,3,4-Tri-O-benzyl- (6), 2,3,4-tri-O-acetyl- (7), and 2,3,4-tri-O- benzoyl-N-(2,2-diethoxycarbonylvinyl)-beta-D-glucopyranosylamine (8) are also described.

[Risk factors for the heterosexual transmission of HIV from man to woman: a Spanish multicenter study]

BACKGROUND

The aims of this study were to estimate the rate of heterosexual transmission of HIV in a population of intravenous drug users (IVDU), as to well as to identify the possible risk factors associated.

METHODS

One hundred thirty heterosexual couples were analyzed in which the male was seropositive for the human immunodeficiency virus (HIV) with the only possible risk factor for the companion being the sexual intercourse with the case index.

RESULTS

The rate of global transmission estimated was 16% (confidence interval of 95% = 10-22.4%). The risk factors significantly associated to HIV transmission were: case index of over 30 years of age (OR = 3.1), clinical status IV (OR = 4.1), less than 0.8 x 10(8) lymphocytes/I (OR = 7), antecedents of sexually transmitted disease (STD) in the woman (OR = 4), and the practice of anal intercourse (OR = 3.1). In the multivariate analysis only the clinical status of the case index and the STC antecedents of the woman were statistically significant (p less than 0.05).

CONCLUSIONS

In this study some of the classical risk factors for the heterosexual transmission of HIV have been confirmed, and the importance of decreasing the prevalence of STD in the IVDU collective in Spain has been corroborated to lower heterosexual transmission and, indirectly the vertical transmission of AIDS.

Diastereotopic covalent binding of the natural inhibitor leupeptin to trypsin: detection of two interconverting hemiacetals by solution and solid-state NMR spectroscopy

The naturally occurring peptidyl protease inhibitor leupeptin (N-acetyl-L-leucyl-L-leucyl-L-argininal) has been prepared labeled with 13C at the argininal carbonyl. 13C chemical shift data for the trypsin-leupeptin inhibitor complex in the pH range 3.0-7.6 reveal the presence of two pH-dependent covalent complexes, suggestive of two interconverting diastereomers at the new asymmetric tetrahedral center created by covalent addition of Ser195 to either side of the 13C-enriched aldehyde of the inhibitor. At pH 7 two signals are observable at delta 98.8 and delta 97.2 (84:16 ratio), while at pH 3.0 the latter signal predominates. In the selective proton 13C-edited NOE spectrum of the major diastereomer at pH 7.4, a strong NOE is observed between the hemiacetal proton of the inhibitor and the C2 proton of His57 of the enzyme, thus defining the stereochemistry of the high pH complex to the S configuration in which the hemiacetal oxygen resides in the oxyanion hole. pH titration studies further indicate that the 13C chemical shift of the S diastereomer follows a titration curve with a pKa of 4.69, the magnitude of which is consistent with direct titration of the hemiacetal oxygen. Similar pH-dependent chemical shifts were obtained by using CPMAS 13C NMR, providing evidence for the existence of the same diastereomeric equilibrium in the solid state.

[Jails and AIDS. Risk factors for HIV infection in the prisons of Madrid]

The spread and risk factors for HIV infection were studied in 288 men and 95 women at the prisons of Carabanchel and Yeserias, Madrid. These men and women requested care at the AIDS prevention program in the jails of Madrid, from April to December 1987. Among the men studied at Carabanchel, 55% were positive to HIV (77% seropositivity among intravenous drug users, IVDU). Tattooing (OR = 2.8), and number of times in prison (OR = 4.5 comparing those who had been 8 or more times in prison with those who had been in prison only once) were independent risk factors for infection, after controlling for IVDU. No association was found between seropositive status to HIV and reported anal intercourse. Among the women studied at Yeserias, the proportion of HIV seropositive women was 26% (70% of the IVDUs were seropositive). Tattooing, number of times in prison, history of prostitution and history of syphilis were associated with HIV infection. When controlling for IVDU, number of times in prison and history of prostitution were not independent risk factors for infection. These data indicate that there is a need for control measures to avoid further spread of the HIV infection among the inmate population, in particular through the use of contaminated needles while in prison.

Familial superior mesenteric artery syndrome

Five members of a family of eight, including the father and four daughters, presented with symptoms previously attributed to the superior mesenteric artery syndrome. The four daughters also had radiographic studies supporting that diagnosis. This familial clustering raises the possibility of a genetic predisposition to this symptom and radiographic complex.

Outcome of patients with human immunodeficiency virus on maintenance hemodialysis

Fifty-one adults with HIV infection, including 20 chronic hemodialysis patients with superimposed HIV infection and 31 patients with HIV-associated nephropathy requiring chronic maintenance hemodialysis were followed to evaluate survival on outpatient dialysis in relation to the clinical stage of the HIV infection. Regardless of when they contracted the infection, AIDS patients who required maintenance hemodialysis had a poor prognosis. All 17 patients who developed AIDS died after a mean of 93 +/- 32 days on hemodialysis (median 30 days; range 2 to 540 days). On the other hand, 12 asymptomatic HIV carriers were alive after a mean follow-up on chronic hemodialysis of 488 +/- 75 days (median 420 days; range 142 to 850 days); and five hemodialyzed patients with ARC were alive after 564 +/- 191 days (median 420 days; range 150 to 1230 days). The data confirm the lack of effectiveness of maintenance hemodialysis for prolonging life in patients with AIDS. This dismal prognosis was evident whether renal failure antedated HIV infection or whether it was HIV-associated. In asymptomatic HIV carriers and in patients with ARC, however, maintenance hemodialysis provides meaningful, long-term life support.

The clinical spectrum of renal disease associated with human immunodeficiency virus

A nephrology consultation was called on 100 adult patients of 1,635 (6.1%) patients with human immunodeficiency virus (HIV) infection seen between 1982 and 1987 at the University of Miami/Jackson Memorial Medical Center. Renal disease was observed in all groups of patients with a risk factor for HIV infection with a lesser incidence, however, among homosexuals. Intravenous drug (IVD) use and possibly race appear to be important factors in the development of renal complications. Renal disease was the dominant clinical feature in eight asymptomatic HIV carriers and in 34 patients with AIDS-related complex (ARC) who had not developed the opportunistic infections and/or malignancies associated with acquired immunodeficiency syndrome (AIDS). Ninety-one percent of consultations were requested for evaluation of proteinuria and/or renal failure. Nephrotic range proteinuria, in excess of 3 g/24 h, was present in 52 patients, and was less prevalent in homosexuals than in other groups at risk. Renal failure (serum creatinine greater than or equal to 5 mg/dL), initially present in 32 patients, eventually developed in 69 and improved in only 18 of them. A renal biopsy, obtained for work-up of nephrotic syndrome (22 patients) or renal insufficiency (3 patients), uncovered a picture of focal and segmental glomerulosclerosis in all 25 instances. Overall, 76 patients are dead, seven are lost to follow-up, and 17 are alive, of whom eight (four HIV carriers, two patients with ARC, and two with AIDS) are on maintenance hemodialysis with a mean survival time of 217 days.

Lack of transmission of human immunodeficiency virus in chronic hemodialysis patients

We carried out a prospective 2-year study on the transmission of human immunodeficiency virus (HIV) infection in a chronic dialysis unit with a high prevalence (11%) of the infection. Only 1 of 45 HIV-negative patients seroconverted, and this was related to the administration of contaminated blood. We conclude that current Centers for Disease Control criteria are sufficient to prevent transmission of HIV infection in dialysis units.

How do elderly veterans who fail to keep outpatient clinic appointments differ from those who do not

The study asked how do elderly veterans who fail to keep appointments in the General Medicine and Surgery Out-Patient Clinics in the San Juan, VA Hospital differ from those who do not. Three hypothesis were formulated: 1. Elderly patients who fail to keep appointments have other medical alternatives in non-VA facilities. 2. Elderly patients who fail to keep appointments have a longer waiting time between appointments. 3. Elderly patients who are given appointments in various clinics within a short period of time fail to keep appointments. A sample of fifty-three elderly veterans from the Medical Out-Patient Clinics was drawn. A face-to-face structured interview was used to collect the data. The interview was designed to obtain socio-demographic characteristics, use of clinics, and recommendations to improve services. A percentage analysis was used to point out differences and similarities. The findings supported the hypothesis that patients who failed to keep appointments not only used private non-VA facilities, but also had the financial resources to pay for them. Data confirmed that those who failed to keep appointments have to wait a longer time between appointments. Patients who failed to keep appointments considered them too infrequent which resulted in forgetting the appointments.

Sensitivity, specificity, and predictive values of bronchoscopy in neoplasm metastatic to lung

Bronchoscopic examination to diagnose lung metastases has not been as rewarding as in primary lung cancer. Despite a lower expected yield, we believe the procedure has value in certain patients, ie, those with clinical findings of endobronchial disease. To determine better the value of bronchoscopy in this population, we retrospectively reviewed records of patients at five community teaching hospitals over a 66-month period. These patients all underwent fiberoptic bronchoscopy. They had a history of prior nonpulmonary malignancy and an abnormal chest roentgenogram suspicious for recurrent malignant disease, or they presented with abnormal chest roentgenographic findings and further evaluation showed the lung disease to be metastatic. Bronchoscopy for metastatic lung disease was most likely diagnostic in patients with primary colorectal cancer (79 percent) and breast cancer (57 percent), and least likely in patients with genitourinary tract cancer (33 percent). Hemoptysis, signs of local airway obstruction, or a roentgenogram showing either atelectasis or diffuse lung disease especially favored a positive biopsy. Bronchoscopy is a valuable diagnostic procedure in selected patients with metastatic lung disease.

Pulsed frequency-modulation spectroscopy as a means for fast absorption measurements

Absorption measurements are accomplished by utilizing short pulses of frequency-modulated (FM) light. The absorption is measured by detecting the heterodyne beat signal that occurs when the FM spectrum is distorted by the absorption feature of interest. By using a single short laser pulse it is demonstrated that the beat signal can build up far above the noise level within 1 microsec. The entire absorption structure can be probed by a few laser pulses. Thus pulsed FM spectroscopy permits ultrafast absorption measurements to be made by using an overall light exposure several orders of magnitude smaller than is necessary for traditional absorption techniques.