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Biomedical subjects

M Díaz

Publications and source records attributed to M Díaz.

At least 91 records · Page 5Linked to original sources
PubMed1999

When is research participatory? Reflections on a reproductive health project in Brazil.

This article addresses women's participation in an organization development project designed to improve public sector family planning and reproductive health services in Brazil. Although community women collaborated in aspects of the intervention and research, the project nonetheless raises the basic question whether such involvement of community women does or does not correspond to what scientific writers consider to be the essence of participatory research. We review key project features in the context of recent literature and conclude that although the project is committed to the sharing of power and control, it does not fully correspond to the characteristics of participatory research. Moreover, we argue that given the project's central focus on reproductive health outcomes, complete adherence to the process-oriented, pure version of participatory research would have been inappropriate.

Brazil↗
PubMed1999

Expanding contraceptive choice: findings from Brazil.

This article presents findings from a participatory action research project in a municipality in southern Brazil that models a new and holistic approach to broadening women's contraceptive choices. The project encourages a collaborative process between researchers, community members, and public health managers to diagnose service-delivery problems, to design and implement interventions, and to evaluate their effectiveness. Findings from the baseline evaluation revealed major constraints in availability of and access to family planning and reproductive health services for women, as well as severe deficiencies in quality of care. Interventions designed to address these weaknesses, bound by the limited resources of the public sector, focused on training, restructuring of providers' roles and service-delivery patterns, the management process, the creation of a referral center, and the introduction of injectables, vasectomy services, and a program for adolescents. Evaluation results show the project's considerable impact in broadening reproductive options, although not all issues, especially those related to sustainability, have been resolved.

Adolescent↗
PubMed1999

[Height increase among school children assisting to first grade during the last decade in Chile].

BACKGROUND: In most developing countries, the prevalence of height deficit among schoolchildren correlates well with poverty. Therefore this indicator is frequently used to monitor the quality of life of a population. AIM: To assess the changes in height of children entering first grade during the last decade. MATERIAL AND METHODS: The records of the Chilean Board of School Assistance, that recollects anthropometric data on 80% of the national population of school age children, were used. For the purposes of this analysis, data from first graders in 1987, 1990, 1993 and 1996 were considered. The absolute variation of height, height for age Z scores were calculated. Children were grouped by sex and by age, using 7 years old as the cutoff value. RESULTS: During the last decade, height has increased significantly in men and women and in all ages. The increase has been greater in younger children. There is a higher proportion of males than women with height deficit. CONCLUSIONS: The increase in height can be attributed to the improvement in social, economic and biological conditions of our population as well as to the targeting strategies of existing food programs.

Anthropometry↗
PubMed1998

Renal transplantation with limit donors: to what should the good results obtained be attributed?

BACKGROUND: With the aim of offsetting the reduction in donors of kidneys for transplantation, we extended the acceptance criteria, considering donors over 60 years old. METHODS: The results obtained in 84 transplants carried out with this type of donor (group A) was compared with those of a control group of 125 transplants carried out with kidneys from donors under 60 years old (group B). The protocol for selection of donors was appropriate creatinine clearance, minimum proteinuria, and normal renal scan. The histological study was not included because it was not considered appropriate to assess the extent of the possible glomerulosclerosis, as this has a focal, segmented distribution. There were no significant differences between the recipients except for age (57.8 years old in group A vs. 39.2 years in group B). RESULTS: After the transplantation, there were significant differences in the duration of hospitalization (26.8 days vs. 21.8 days, P<0.009), annual plasma creatinemia (177, 225, 233, 235, and 205 micromol/L vs. 136, 150, 121, 111, and 133 micromol/L, P<0.0002/0.0004), graft survival (87%, 85%, 81%, 81%, and 81% vs. 89%, 88%, 86%, 86%, and 85%, P<0.03), and patient survival (92%, 89%, 85%, 85%, and 85% vs. 99%, 99%, 97%, 96%, and 95%, P<0.0004). Death of the patient was the only significantly more frequent cause of graft loss among group A patients (7 vs. 1 death, P<0.004). No kidney was "never working" and none were lost because of chronic rejection. CONCLUSIONS: It was concluded that elderly donors should be considered as suitable for transplantation irrespective of their chronological age, provided that they fulfill the acceptance criteria. The quality of life achieved was comparable in both groups. Despite the lower renal function in group A, this remained constant during the follow-up period.

Age Factors↗
PubMed1998

[Markers of thrombin generation in kidney failure of children with epidemic hemolytic uremic syndrome].

We present herein the levels of the early markers of blood coagulation activation and TNF-alpha in 12 children with the epidemic form of the hemolytic-uremic syndrome, median age 16 months, range 12-18. All patients recovered from the disease within 2 to 4 weeks. Four blood samples were collected: at admission, 1 week and 2 weeks later and on remission. Prothrombin fragments 1 + 2 (F1 + 2), thrombin-antithrombin complex (TAT) and tumor necrosis factor alpha (TN-alpha) were assayed by commercial ELISA techniques, while von Willebrand factor (vWf) was measured by Laurell's method. At admission, F1 + 2 and TAT levels were 7.8 nM (3.7-12.3) and 22.7 ng/ml (8-76), respectively. Besides, significant correlations were obtained for F1 + 2 levels vs blood creatinine, r: 0.57 p < 0.001; F1 + 2 vs urea, r: 0.66 p < 0.001; TAT vs blood creatinine, r: 0.77 p < 0.001; TAT vs blood urea, r: 0.59 p < 0.001. Median vWf value at admission in 11/12 children was 260% (170-420), correlating with F1 + 2, r: 0.77 p < 0.001 and with TAT, r: 0.41 p < 0.01. Such values tended to normalize with the improvement of the disease. A negative correlation was found for platelet count vs F1 + 2, r: -0.64 p < 0.001. TNF-alpha levels were increased in 5/12 children, 22.2 pg/ml (17.2-53.7). These results may be attributable to similar stimuli on endothelial cells.

Antithrombins↗
PubMed1998

[Comparison of the effects of digoxin or enalapril in the treatment of heart failure due to mitral insufficiency].

BACKGROUND: There is not much evidence about the usefulness of digoxin or enalapril in the treatment of heart failure due to mitral insufficiency. AIM: To compare digoxin and enalapril in the treatment of heart failure due to mitral insufficiency. PATIENTS AND METHODS: Patients with mitral insufficiency, in sinus rhythm, with a heart failure grade II or III and with echocardiographic left ventricular dilatation were eligible for the study. They received sequentially, during 12 weeks each, digoxin 0.25 mg/day or enalapril in doses up to 20 mg/day, with a washout in-between period of 2 weeks. The order of the sequence was determined randomly. At the start and end of treatment, functional class according to NYHA and maximal exercise tolerance in the treadmill were assessed and a color Doppler echocardiogram was done to measure ventricular dimensions, function and degree of mitral insufficiency. RESULTS: Nine patients on enalapril and 12 on digoxin improved their functional capacity. Digoxin improved exercise time in 76 +/- 168 sec (p = 0.022), whereas this change was not significant with enalapril (38 +/- 158 sec; p = 0.2). With enalapril treatment, ventricular diastolic dimension decreased from 59.3 +/- 8.1 to 58 +/- 9.3 mm and the area of mitral insufficiency decreased from 8.1 +/- 3.5 to 6.6 +/- 3.1 cm2. Digoxin did not induce any significant echocardiographic change. CONCLUSIONS: In these patients, digoxin and enalapril improved functional class. Digoxin improved exercise time and enalapril reduced ventricular dimensions and mitral insufficiency.

Adult↗
PubMed1997

Use of cardiac troponin T rapid assay in the diagnosis of a myocardial injury secondary to electrical cardioversion.

BACKGROUND AND HYPOTHESIS: This study was carried out to determine whether cardiac troponin T test in rapid assay gives positive results in patients previously submitted to cardioversion or electrical defibrillation. METHODS: Forty patients with supraventricular tachyarrhythmias lasting no more than 2 days were treated with electrical cardioversion. The total creatine phosphokinase (CPK)-MB isoenzyme and troponin T in rapid assay were measured at baseline and at 6, 12, and 24 h thereafter. RESULTS: Total CPK baseline levels were normal in all cases; within 4 h, the serum CPK levels increased by 98%, at 6 h by 111.5%, at 12 h by 168%, and at 24 h by 225% (p > 0.01). The CPK-MB isoenzyme showed no percentage increase of total CPK higher than 5%, measured at 6, 12, and 24 h after the shock, independent of the number of attempts of cardioversion. The troponin T test was also negative in all cases at baseline and at 6, 12, and 24 h after cardioversion. CONCLUSION: We conclude that the absence of elevations in CPK-MB levels and cardiac troponin T levels matched clinical and electrocardiographic results showing absence of myocardial damage after electrical cardioversion.

Aged↗
PubMed1997

Possible thiol group involvement in intracellular pH effect on low-conductance Ca(2+)-dependent K+ channels.

We have studied the effect of intracellular pH (pHi) shifts on the activity of Ca(2+)-dependent, inwardly rectifying K+ channels of HeLa cells. Recordings of macroscopic currents in symmetrical 145 mK K+ and internal pH of 7.4 gave moderate inward rectification of the current. At pH 6.4, inward rectification was more marked, whereas it switched to outward rectification at pH 8.2. In excised inside-out membrane patches, similar changes in pHi did not affect the single-channel conductance of the channels underlying the Ca(2+)-dependent K+ currents. At neutral pH, the open state probability (Po) was independent of voltage in the range from -70 to 70 mV. At alkaline pH, Po became voltage dependent, decreasing at negative potentials and increasing with depolarization compared with pH 7.4. These changes accounted for the pH-dependent changes in rectification of the macroscopic current. The possibility that voltage dependence might arise from the ionization of a thiol group was tested by using thiol-directed reagents. The decrease in Po produced by intracellular alkalinization at negative potential was reverted by treatment with N-ethylmaleimide, 5,5'-dithiobis(2-nitrobenzoic acid), and 2,2'-dithiodipyridine. The effect of intracellular alkalinization is speculated to occur through ionization of a cysteine group(s) within the field of the membrane affecting gating.

Calcium↗
PubMed1997

The strategic approach to contraceptive introduction.

The introduction of new contraceptive technologies has great potential for expanding contraceptive choice, but in practice, benefits have not always materialized as new methods have been added to public-sector programs. In response to lessons from the past, the UNDP/UNFPA/WHO/World Bank Special Programme of Research, Development, and Research Training in Human Reproduction (HRP) has taken major steps to develop a new approach and to support governments interested in its implementation. After reviewing previous experience with contraceptive introduction, the article outlines the strategic approach and discusses lessons from eight countries. This new approach shifts attention from promotion of a particular technology to an emphasis on the method mix, the capacity to provide services with quality of care, reproductive choice, and users' perspectives and needs. It also suggests that technology choice should be undertaken through a participatory process that begins with an assessment of the need for contraceptive introduction and is followed by research and policy and program development. Initial results from Bolivia, Brazil, Burkina Faso, Chile, Myanmar, South Africa, Vietnam, and Zambia confirm the value of the new approach.

Africa↗
PubMed1997

Oxidative stress and membrane fluidity in erythrocytes from patients with hemolytic uremic syndrome.

In order to investigate the implications of oxidative disturbances in the hemolysis associated with the Hemolytic Uremic Syndrome (HUS), basal levels of lipid peroxidation products, the response to t-butyl hydroperoxide induced damage and membrane fluidity were assayed by the technique of electron spin resonance in erythrocytes spin labeled with 5-Doxyl stearic acid obtained from eight children with HUS, during the 1st, 2nd, 4th and 12th weeks after diagnosis. During the acute phase of the disease, red blood cells (RBC) showed increased initial lipid peroxidation products, a higher susceptibility to oxidative insult and a lower membrane fluidity. All parameters reached control values the 12th week after diagnosis. The results suggest that in the acute phase of HUS, RBCs are exposed to an oxidative imbalance that could contribute to hemolysis directly through oxidative damage and/or by decreasing membrane fluidity.

Adolescent↗
PubMed1997

[Hemangiomas and vascular malformations. Review and update].

In 1982, Mulliken and Glowacki classificated congenital vascular lesions in two biological groups with different treatment, evolution and prognosis: Haemangiomas and Vascular malformations. We have seen 230 patients, 145 with haemangiomas and 85 with vascular malformations (74 with low flow and 11 with high flow). We have reviewed clinical, evolutive and ecographic findings. Depending on the type and localization of the lesion, we completed the study with CT, MRI and angiography. Among all the patients with haemangiomas; 45 were treated with local or systemic steroids because of bleeding, ulceration or affection in functional areas. In two more, we used interferon alfa 2a because of Kassabach-Merritt Syndrome. 23 were operated on with good aesthetic results. Patients with vascular malformations were managed with embolization, sclerotherapy, surgical approach or conservatively. Capillary malformations were treated with lasertherapy. We emphasize in correct classification of vascular lesions prior to start diagnosis, treatment or parents information.

Arteriovenous Malformations↗
PubMed1997

[Clinical pharmacology and indications of meropenem in severe pediatric infection].

The choice of an antibiotic for the treatment of a serious paediatric infection is generally a difficult problem. The arrival of Carbapenem resulted an important advance in the field of medicine due to its broad-spectrum, low incidence of resistances and good safety profile. Among Carbapenems, Meropenem introduction represents a progress because of its pharmacokinetics characteristics and blood-brain barrier penetration. Meropenem dosage depends on the patient weight, and the way of administration is potentially easier. Meropenem has been compared with the most used paediatric antimicrobial in controlled and randomised clinical trials, showing a high efficacy in the treatment of several infections (respiratory, urinary, intraabdominal, dermatological, septicemia) and in neutropenic and cystic fibrosis patients aged between one month and twelve years old. Meropenem is specially useful in the bacterial meningitis treatment because it penetrates into the cerebrospinal fluid of patients with inflamed meninges and reaches therapeutic concentrations, and because appearance of seizures is low. Adverse reactions produced by Meropenem show a poor incidence and its severity is usually mild. With regard to this characteristics, it can be concluded that Meropenem is an antimicrobial which efficacy and safety profiles guarantee its use in the treatment of severe paediatric infections.

Bacterial Infections↗
PubMed1996

Ammonium inhibition of Ca(2+)-dependent inwardly rectifying K+ currents in HeLa cells.

The patch-clamp technique was used to examine the effect of ammonium on inwardly rectifying Ca(2+)-dependent K+ channels of HeLa cells. Ammonium added extracellularly blocked macroscopic K+ currents with an IC50 of 1.6 mM. Inhibition was fully reversible and voltage-independent and is not likely to be secondary to an increase in intracellular pH as this would have the opposite effect. In these experiments ammonium appeared to have an intracellular site of action. Intracellular ammonium rapidly and reversibly inhibits the activity of single Ca(2+)-dependent K+ channels underlying the macroscopic currents. This compound is often employed to manipulate intracellular pH but its use would not be indicated when full activity of the type of channels studied here needs to be unaltered.

Ammonium Chloride↗