Biomedical subjects

M Bravo

Publications and source records attributed to M Bravo.

At least 55 records · Page 3Linked to original sources

PubMed1997

Mortality discrimination in acute myocardial infarction: comparison between APACHE III and SAPS II prognosis systems. PAEEC Group.

OBJECTIVE: To compare the Acute Physiology, Age and Chronic Health Evaluation (APACHE) III with the Simplified Acute Physiology Score (SAPS II) in discriminating in-hospital mortality for intensive care unit (ICU) patients with acute myocardial infarction (AMI). DESIGN: Prospective, observational, multicenter study. SETTING: 70 Spanish ICUs. PATIENTS AND PARTICIPANTS: 1711 patients with AMI and representative of Spanish ICUs. MEASUREMENTS AND RESULTS: APACHE III score, APACHE III system probability of death (APACHE III probability), SAPS II score and in-hospital mortality were noted for each patient. Two hundred and twenty three (13.0 %) patients died in the hospital. The sensitivity (+/- SE), specificity (+/- SE), and accuracy (+/- SE) for the APACHE III score were, respectively, 75.8 +/- 2.9, 75.9 +/- 1.1, and 75.9 +/- 1.0. The corresponding figures for APACHE III probability were 75.3 +/- 2.9, 79.2 +/- 1.1, and 78.7 +/- 1.0, and for SAPS II 72.2 +/- 3.0, 75.9 +/- 1.1, and 75.4 +/- 1.0. CONCLUSIONS: The results indicate good discrimination by the three tests. APACHE III probability shows a statistically significant improvement in accuracy and specificity when compared with the two scores.

APACHE↗

PubMed1997

A 48-month survival analysis comparing sealant (Delton) with fluoride varnish (Duraphat) in 6- to 8-year-old children.

The objective of this study was to compare Delton visible-light fissure sealant with Duraphat fluoride varnish in the prevention of occlusal caries in permanent first molars. A 48-month clinical trial was carried out in three groups of 6- to 8-year-old schoolchildren: a sealant group (104 children), in which Delton was used; a varnish group (112 children), in which Duraphat was used; and a control group (128 children). Sealant or varnish was applied to all sound permanent first molars, according to group. Replacement (sealant) and reapplication (varnish) was carried out every 6 months. A survival analysis was used to describe the molar failures over time in the three groups. A Cox proportional hazards regression model was built to test the influence of group on molar failure. The median survival times were 28.6 months for the control molars and more than 48 months for both sealed and varnished molars. The Cox model indicated a hazard ratio of 0.177 for the sealant vs control comparison, 0.463 for varnish vs control and 0.382 for sealant vs varnish.

Bisphenol A-Glycidyl Methacrylate↗

PubMed1997

A 24-month study comparing sealant and fluoride varnish in caries reduction on different permanent first molar surfaces.

OBJECTIVE: The aim of this study was to determine the separate effects of dental sealants and fluoride varnish on dental caries in fissured and nonfissured surfaces of permanent first molars. METHODS: A clinical trial was conducted with three groups of 6- to 8-year-old schoolchildren: a sealant group (n = 100), in which Delton was applied to first molars; a varnish group (n = 98), in which Duraphat was applied to first molars; and a control group (n = 116), which had no intervention as part of the study. Absolute and percent caries reductions were compared at 24 months. RESULTS: Compared to the controls, sealants resulted in a 68 percent and 87 percent reduction on fissured and nonfissured surfaces, respectively. The corresponding figures for varnish were 38 percent and 66 percent. CONCLUSION: Sealant and fluoride varnish are effective in preventing caries in both fissured and nonfissured surface.

Bisphenol A-Glycidyl Methacrylate↗

PubMed1997

The epidemiology of mental disorders in the adult population of Puerto Rico.

OBJECTIVES: The main objective of the manuscript is to present a review of the literature of the psychiatric epidemiological studies carried out in Puerto Rico in the last decade. BACKGROUND: Data from three major epidemiological surveys carried out in the last decade is presented which provide evidence against prior long standing observations that Puerto Ricans reported higher levels of psychiatric symptomatology as compared to other populations and ethnic groups in the United States. METHODS: The studies selected for review were the universe of population epidemiological studies carried out in Puerto Rico in the last decade. All studies used island wide probability sampling procedures to select the study population. RESULTS: Rates of psychiatric disorders in Puerto Rico were found to be significantly different from those obtained in United States communities. Exceptions were somatization disorder and symptoms which were found to be significantly more common in Puerto Rico and drug abuse/dependence which was found to be considerably less common in the island as compared to the Unites States adults in the age range of 17 to 67 years old. CONCLUSION: In spite of several indicators of social disruption in the island, the prevalence of most psychiatric disorders does not appear to be more prevalent than in other communities in the United States and other parts of the world. Risk factors for mental disorders are also similar, although sex ratios for gender linked disorders are more marked in the island.

Adolescent↗

PubMed1996

Influence of enamel prophylaxis on wettability of three commercially available orthophosphoric acids.

An in vitro study was performed to assess the wettability of orthophosphoric acid after different procedures for cleaning the enamel surface. Ninety noncarious third molars were randomly distributed into three groups with different enamel surface treatments: an air-powder polisher unit, prophylaxis pastes, and no enamel surface cleaning. Three commercially available orthophosphoric acids were used, and there were 10 teeth in each group. Acid viscosity values and contact-angle measurements were obtained. Each enamel surface was also examined with the scanning electron microscope. Results suggested that the surface treatment with which the best spreading of the acid solution was attained was the air-powder polisher. The least spreading of the acid was obtained with prophylaxis pastes, in which contact angles were even higher than those obtained on the untreated enamel surface. The 3M acid solution was the one that showed the best spreading onto the enamel surface.

Acid Etching, Dental↗

PubMed1996

The Diagnostic Interview Schedule for Children (DISC-2.1) in Spanish: reliability in a Hispanic population.

The reliability across time, informants and interviewers of the Spanish translation of the DISC-2.1 was tested on a Puerto Rican Hispanic sample using a test-retest design. Levels of reliability between clinic and community samples and between younger and older children were compared to explore the sources of low reliability for certain psychiatric disorders. Parents' reports tended to be more reliable than those of their children, although the difference was less obvious with older children. Reliability was generally higher for the externalizing disorders and when the second interviewer was a psychiatrist rather than a lay interviewer.

Adolescent↗

PubMed1996

Effectiveness of visible light fissure sealant (Delton) versus fluoride varnish (Duraphat): 24-month clinical trial.

The present study compares visible-light Delton with Duraphat fluoride varnish for the prevention of occlusal caries in permanent first molars. A clinical trial was carried out in three groups of 6-8-yr-old schoolchildren: a sealant group (100 children), in which Delton light-polymerized fissure sealant was applied to permanent first molars; a varnish group (98 children), in which Duraphat was applied to permanent first molars; and a control group (116 children). Replacement (sealant) and reapplication (varnish) was carried out every 6 months. Percent effectiveness at 24 months (percentage of saving from caries taking molars as analysis unit) for those molars initially healthy and with complete occlusal eruption was analyzed. 272, 252 and 238 molars met the inclusion criteria in the control, varnish and sealant groups, respectively. Of these, 45.2%, 28.2% and 10.5% developed caries after 24 months. The effectiveness was greater in the sealed molars than in the varnished molars (62.7%).

Bias↗

PubMed1996

The influence of dft index on sealant success: a 48-month survival analysis.

Early loss of pit and fissure sealants is considered to be primarily dependent on inadequate isolation of the tooth from salivary contamination during application. Gradual additional loss is considered to be caused by occlusal wear, shearing forces, and marginal failure. Our hypothesis is that the caries risk of the child may be an additional factor in sealant loss. The objective of this study was to analyze the influence of caries history in primary teeth (dft index) on the success of sealants. Delton light-polymerized sealant was applied in 104 six- to eight-year-old children, followed for four years on a six-month-visit basis. All sound permanent first molars were sealed during the study. A survival analysis was used to describe sealant success over time. A Cox proportional hazards regression model was built to test the influence on sealant success of the dft index and site of sealant application (mandibular occlusal surface, maxillary fossae, and maxillary distolingual fissure), controlling for some potential confounders. Sealant half-life was 46 months. Site and dft index were related to sealant survival. The maxillary fossae showed the best retention, followed by the mandibular occlusal site and the maxillary disto-lingual fissure. The higher the dft, the higher the risk of sealant failure. This study has implications for sealant study designs and public sealant programs.

Bisphenol A-Glycidyl Methacrylate↗

PubMed1996

An in vitro comparison of micro leakage in three glass ionomer cements used as retrograde filling materials.

The aim of this study was to evaluate the sealing ability of conventional self-cured glass ionomer cement, silver glass ionomer cement and light-cured glass ionomer cement as retrofilling materials. Micro-leakage was assessed by introducing the samples into a 1 per cent solution of methylene blue for eight days at a constant temperature of 37 degrees C. Dye penetration was greater when silver glass ionomer cement was used in comparison to the other two materials tested; the difference was statistically significant. Conversely, the sealing ability of light-cured glass ionomer cement was significantly higher than that of conventional glass ionomer cement. The condition of the dentine-filling material interface and the marginal adaptation of the glass ionomer cements under study were assessed using scanning electron microscopy.

Cermet Cements↗

PubMed1996

Hydrolysis of synthetic peptides by cruzipain, the major cysteine proteinase from Trypanosoma cruzi, provides evidence for self-processing and the possibility of more specific substrates for the enzyme.

Two synthetic peptides, peptide G, with the sequence KEEASSAVVGGPG, consisting of the last 10 amino acid residues of the catalytic domain, plus the first 3 at the C-terminal domain, of cruzipain, and peptide R, with the sequence KEEASSAVVRGPG, were hydrolyzed by the enzyme, as shown by reversed-phase HPLC. Peptide R was the best substrate, with a Vmax/K(m) ratio 6-fold higher as compared with peptide G, in good agreement with previous studies indicating that, in small peptides, cruzipain prefers R or K at P1. The optimal pH values for hydrolysis of peptides G and R were 6.8 and 8.0, respectively. A p-nitroanilide derivative containing the P1-P3 residues, Z-VVR-pNA, was an excellent substrate for cruzipain, with a K(m) value (33 microM at pH 9.0) lower than that for Bz-PFR-pNA (66 microM). These results open the possibility of synthesizing more specific substrates and inhibitors of cruzipain.

Amino Acid Sequence↗

PubMed1996

Proliferating cell nuclear antigen (PCNA) as a marker of dysplasia in oral mucosa.

The development of head and neck cancer has been proposed to be a multistep process, with accumulation of genetic and phenotypic alterations resulting from carcinogen exposure. Proliferating cell nuclear antigen (PCNA), also called cyclin, is a 36-KD auxiliary protein of DNA polymerase-delta, that has been found to be a useful marker in immunocytochemical studies of cell proliferation because its expression correlates with the proliferative state of the cell. PCNA expression was analyzed in 10 samples of normal mucosa, 23 benign oral lesions (18 hyperplasia and 5 oral lichen plani), 10 oral lesions with epithelial dysplasia, and 10 dysplastic epithelia adjacent to tumors. Immunocytochemical stained sections were scored for the presence or absence of suprabasal PCNA positivity regardless of location. The results indicate that the PCNA expression in the suprabasal layers increased with the degree of epithelia dysplasia and in the samples of histological dysplastic epithelium adjacent to the tumors, while the percentage of suprabasal PCNA expression was insignificant in the samples of normal oral mucosa and benign oral lesions. The authors conclude that suprabasal PCNA expression could be a marker of dysplasia in oral mucosa, indicating a special proliferative cellular state in those lesions.

Biomarkers, Tumor↗

PubMed1995

Short-term changes in lymphocytes after placement of silver amalgam restorations in healthy subjects.

OBJECTIVES: The purpose of this study was to evaluate the changes in lymphocyte subpopulations that have led to immune system alterations after amalgam restorations were placed. METHODS: A controlled, quasi-experimental pretest-posttest design was used to investigate the immune effects of silver amalgam restorations in a sample of 60 individuals (30 experimental and 30 control subjects) aged 18 to 21 y. Two blood samples were obtained 15 d apart from each participant. In each experimental subject, two amalgam restorations were placed in posterior teeth immediately after the first blood sample was collected. The changes in lymphocyte subpopulations in the two groups were compared by multivariate analysis. RESULTS: There was a greater change in T8 lymphocytes in experimental than in control subjects; increases in B, DR, NK, and CD45R lymphocytes were smaller in experimental than in control subjects; the changes in T3 and T4 lymphocytes did not differ significantly between the two groups. SIGNIFICANCE: Despite the statistical significance of some differences between the two groups, the differences are not considered to be clinically relevant for the 2 wk time period after placement.

B-Lymphocytes↗

PubMed1995

Effects of long-term treatment with antiepileptic drugs on serum lipid levels in children with epilepsy.

We determined serum levels of total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), very low-density lipoprotein cholesterol (VLDL-C), and triglycerides (TGs) in 125 healthy children and in 119 children with epilepsy who had been receiving carbamazepine (58 children), phenobarbital (22 children), or valproic acid (39 children) for 7 months to 10.5 years (mean, 5.8 years). None of the variables considered was significantly correlated with time elapsed since start of treatment or with drug concentration in serum. In the groups receiving carbamazepine or phenobarbital, mean TC, HDL-C, and LDL-C levels were higher than in the control group, the differences being statistically significant for all except LDL-C in the phenobarbital group. In neither group did mean TC/HDL-C ratio or mean LDL-C/HDL-C ratio differ significantly from the corresponding control-group mean. In the group receiving valproic acid, mean TC level, mean LDL-C level, mean TC/HDL-C ratio, and mean LDL-C/HDL-C ratio were significantly lower than in the control group. In none of the treated groups did mean VLDL-C or TG level differ significantly from the corresponding control-group mean. Our results suggest, in contrast to previous reports, that the effects on the serum lipid profile of long-term treatment with hepatic-enzyme-inducing antiepileptic drugs (such as carbamazepine and phenobarbital) are probably not beneficial as regards risk of atherosclerosis-related disease. Our results additionally suggest a need for careful monitoring of serum cholesterol levels in children with epilepsy receiving carbamazepine or phenobarbital.

Anticonvulsants↗

PubMed1995

Depressive symptomatology in single women heads of households in Puerto Rico: a comparative analysis.

The present study examines depressive symptomatology among women in Puerto Rico, using data from an island wide population-based sample. We focus on single women heads of households (SWHH) defined as divorced, separated, widowed and never married women with no permanent mate who have the main economic responsibility for their households. The study aims to identify social factors such as family responsibilities, stressful life events, and reduced levels of social support, that may contribute to the risk for depressive symptoms in these women. This is a growing population: the 1990 Census reported that 23% of all households in Puerto Rico were headed by women, an increase from 14% in 1970. The present study was based on a probability sample of adults (17-68 years), interviewed using a structured schedule, from which we analyzed the female subjects. Women were classified in three mutually exclusive groups: single women heads of households (SWHH, n = 138), single women not heads of households (SWNHH, n = 104), and married women not heads of households (MW, n = 275). Our finding that single women heads of households were especially vulnerable to depressive symptomatology is consistent with that of other studies in the United States. Also consistent with previous research, SWHH were found to be older, poorer, have less education and more often lived in urban areas, as compared to other women. Having children at home was associated with more depressive symptoms among both groups of single women, but not among married women. And the availability of emotional supporters had a weaker effect for SWHH. Furthermore, quality of support was found to be more important for these women than number of persons available for emotional support. The study has several implications for family policy and mental health prevention. Since SWHH are vulnerable for depressive symptomatology and their number is increasing, programs should be developed to attend the special needs of these women. These programs could include the provision of child care and the creation of self-help groups to build on their strengths and to combat isolation and loneliness.

Adolescent↗

PubMed1995

Disposition kinetics of dibekacin in patients with renal failure and in patients undergoing hemodialysis.

Dibekacin pharmacokinetics was studied in 3 healthy volunteers, 5 patients with renal failure presenting Clcr, between 4.0 and 67 ml min-1 per 1.73 m2 of body surface and 5 anephric patients given as a 30 minute intravenous infusion. The antibiotic was assayed in plasma and urine by means of a high performance liquid chromatography (HPLC) method. A two compartment kinetic model was used to describe the bi-phasic decline of plasma concentration and to calculate the different pharmacokinetic parameters. Slow disposition and elimination rate constants beta and k10 respectively, and total body clearance were markedly diminished in anephric patients (p << 0.001): t1/2 beta = 2.12 h, k10 = 0.642 h-1 and Cl = 0.882 ml/min per kg, in normal subjects and t1/2 beta = 4.73 h, k10 = 0.278 h-1 and Cl = 0.693 ml/min per kg in anephric patients. The apparent volumes of distribution increased while the creatinine clearance of the patients decreased. Thus Vd(area) of volunteers with normal renal function was statistically significantly lower than that of anephric patients (p < 0.001), from a value of 0.162 to 0.281 l/kg respectively. A good correlation (r = 0.982) between patient's slow disposition constant beta and creatine clearance was found. Urinary recovery at 24 h was 85.6% of the dose given to normal volunteers. This value decreased while impairment increased. The mean extraction coefficient, during hemodialysis was about 0.35.

Acute Kidney Injury↗

PubMed1994

Psychometric properties of parents and children as informants in child psychiatry epidemiology with the Spanish Diagnostic Interview Schedule for Children (DISC.2).

Parent and child reports were examined to study how epidemiological researchers can best use the information provided to describe childhood psychopathology. As part of a multisite methodologic study of mental disorders in children, a probability sample (N = 248) of children aged 9 to 17 years from the San Juan metropolitan area was selected. This sample was enriched with 74 clinic cases. Both parents and children were administered the DISC.2. Results showed that prevalence estimates were influenced by the informant. The clinicians' diagnosis is more concordant with children's reports of depression and with parents' reports of disruptive disorders. Parents and children provided unique information when interviewed with a structured psychiatric interview about child psychopathology. Their unique perspectives contributed to the observed discordance that emerged when DISC parent and DISC child results are compared. Combining the two perspectives with a simple "OR" rule at the symptom level did not seem to capture the unique perspectives.

Adolescent↗

PubMed1994

Defective G2 repair in Down syndrome: effect of caffeine, adenosine and niacinamide in control and X-ray irradiated lymphocytes.

Lymphocytes from both Down syndrome (DS) patients and age-matched control donors have been investigated to identify a possible disturbance in chromosomal G2 repair. Analyses of caffeine treatments during G2 have shown that the frequency of chromosomal aberrations is higher in DS lymphocytes than in normal lymphocytes. Likewise, G2 duration is longer in DS cells than in normal cells. In both control and DS lymphocytes, caffeine treatments increase the frequencies of chromatid breakages and decrease the average of G2 duration. The reversal of the caffeine potentiation effect by adenosine and niacinamide is higher in DS cells than in normal cells. Furthermore, ATP content per cell in DS lymphocytes is one third of that estimated in normal lymphocytes. The increase of ATP level produced by adenosine or niacinamide generally correlates with the reversal of the caffeine effect on chromosome aberrations. Under the experimental conditions tested, a good negative exponential correlation between ATP level and chromosome aberrations has been detected in both normal and DS lymphocytes which were or were not X-irradiated. Finally, we postulate a decrease in G2 repair capability of DS lymphocytes caused by a low availability of ATP and/or some other factor correlating with it.

Adenosine↗

PubMed1994

The prevalence of multiple sclerosis in the Sanitary District of Vélez-Málaga, southern Spain.

Since little is known about the prevalence of multiple sclerosis (MS) in Spain, we undertook an epidemiologic study to ascertain the prevalence of MS in the Sanitary District of Vélez-Málaga, close to the city of Málaga, in southern Spain. The crude prevalence rate of MS in Vélez-Málaga was 53 per 100,000, twice as high as the prevalence previously reported in both the city and province of Málaga. The MS prevalence in the Sanitary District of Vélez-Málaga is similar to that in Sicily and in Cyprus.

Adult↗