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Biomedical subjects

L Cuevas

Publications and source records attributed to L Cuevas.

At least 19 recordsLinked to original sources
PubMed2004

Evidence for affluence-related hypertension in urban Brazil.

Cardiovascular diseases are a leading cause of mortality, and systemic hypertension is a major risk factor. There is an increasing prevalence of hypertension in urban areas of developing countries, due to lifestyle changes associated with economic transition and urbanisation. This study aimed to describe the prevalence and identify risk factors for hypertension in an urban area of South America (Coroa do Meio district in Aracaju, Sergipe State, north-east Brazil) and to examine intraurban hypertension prevalence differences. A cross-sectional survey of 400 adults aged 25 years and over was carried out. Information about health and lifestyle was obtained from a structured interview, followed by assessment of blood pressure (BP) and anthropometry. There were 31.8% (95% confidence interval 27.3-36.6%) participants with hypertension (defined as a systolic BP >140, diastolic BP >90 mmHg, or on antihypertensive medication). Hypertension was independently associated with older age, central obesity (greater waist-to-hip ratio), shorter height and residing in a high socio-economic residential area. Of the four neighbouring areas, hypertension prevalence was 52% in the area of highest income and education, compared with 19, 24 and 34% in the other three areas. The high prevalence of hypertension in this population, and the strong independent association with relative affluence, demonstrates the need for effective primary prevention of hypertension, targeted at modifiable risk factors.

Adult↗
PubMed1998

Use of laboratory assays to predict cytomegalovirus disease in renal transplant recipients.

Eight laboratory assays, viz., the pp65 direct antigenemia test, a quantitative cytomegalovirus (CMV)-specific immunoglobulin G (IgG) assay (Biomerieux VIDAS), a CMV-specific IgM assay (Biomerieux VIDAS), the Hybrid Capture system (Murex), an in-house PCR with plasma (P-PCR) and leukocytes (L-PCR), and a commercial PCR (Roche AMPLICOR) with plasma (P-AMP) and leukocytes (L-AMP), were compared for their abilities to predict CMV disease before the onset of illness in a prospective study of 37 renal transplant recipients. By using an expanded criterion for active infection (two or more of the markers positive) and a clinical definition of disease, 22 (59%) patients were identified as having active CMV infection and 13 (35%) were identified as having CMV disease. Of the 13 CMV-seronegative recipients who received seropositive kidneys (R- group), 8 had active infection and disease. All assays were 100% specific and 100% predictive of CMV disease in the R- group. The leukocyte PCRs (L-PCR and L-AMP) were the most sensitive assays, had positive results an average of between 8 and 13 days before the onset of illness, and were the assays of choice. The performance of the assays was less satisfactory for the 24 patients who were CMV seropositive before transplantation (R+ group). A negative result was more useful for this group. Overall, P-AMP had the best results, and it could be the assay of choice for monitoring R+ patients. The non-PCR-based methods generally had high specificities but often gave late positive results and were not sensitive enough for use as prediction tools for either group of patients.

Antibodies, Viral↗
PubMed1997

Amelia: analysis of its epidemiological and clinical characteristics.

Eighteen cases of amelia in the Spanish Collaborative Study of Congenital Malformations (ECEMC) were analyzed epidemiologically. Prevalence at birth was 0.15 per 10,000 newborn infants, which is not different from that reported by other authors. Affected females outnumbered males. When compared with the control group, a lower birth weight, shorter gestation, lower placental weight, greater frequency of single umbilical artery, noncephalic presentation at birth, and more frequent maternal vaginal bleeding were observed in amelia cases. There were no significant variations of parental age. None of these patients was exposed to known teratogens, apart from 1 born to a diabetic mother; 3 patients had a genetic condition. Comparison of these variables with other studies is difficult because there is only one study that specifically analyzed amelia. Our data together with previous observations suggest that the genetic basis of amelia might be more important than has been considered previously.

Birth Weight↗
PubMed1997

Ligation of CD53/OX44, a tetraspan antigen, induces homotypic adhesion mediated by specific cell-cell interactions.

The CD53 antigen is a member of the tetraspan family of proteins with unknown function. Stimulation of rat IR938F B-cell lymphoma cells with monoclonal antibody MRC OX44 (anti-rat CD53) triggered a homotypic adhesion reaction which reached a maximum effect at 24 hr. This effect occurred at 37 degrees C but not at 4 degrees C. Adhesion was prevented by removal of divalent cations, Ca2+ and Mg2+, with EGTA and EDTA as chelating agents. The adhesion induced by MRC OX44 was inhibited by cycloheximide and actinomycin D, suggesting that de novo protein synthesis was required for this effect. The addition of mAb WT1 against rat LFA-1 (CD11a) antigen had no effect on adhesion, suggesting that the cell-cell interaction is not mediated by the expression of LFA-1 antigen. The intracellular signals required to induce adhesion were inhibited by two tyrosine kinase inhibitors, genistein and piceatannol. Wortmannin, a selective inhibitor of phosphoinositide 3-kinase activity, completely blocked adhesion. Two protein kinase C inhibitors, H7 and bisindolylmaleimide, inhibited the adhesion, suggesting that part of the signal is mediated by PKC. Electron microscopy of aggregated cells showed that the interaction is localized to short membrane regions, where contact areas of higher density in opposing zones from both cells were detected. We postulate that there is a common adhesion mechanism that is modulated by several tetraspan family members and associated proteins. This adhesion structure might represent a novel form of cell communication among lymphoid cells.

Animals↗
PubMed1996

Epidemiological analysis of rare polydactylies.

This work includes all cases with extra digits (polydactyly) registered from a birth sample of over four million births aggregated from two comparable birth series: the Latin-American Collaborative Study of Congenital Malformations: ECLAMC (3,128,957 live and still births from the 1967 to 1993 period), and the Spanish Collaborative Study of Congenital Malformations: ECEMC (1,093,865 livebirths from April 1976 to September 1993, and 7,271 stillbirths from January 1980 to September 1993). All but 2 of 6,912 registered polydactyly cases fit well into one of the following 11 preestablished polydactyly types (observed number of cases in parentheses): Postaxial hexadactyly (5,345), Preaxial-I hexadactyly (1,018), Seven or more digits (57), synpolydactyly (15), crossed polydactyly (45), 1st digit triphalangism (33), 2nd digit duplication (39), 3rd digit duplication (18), 4th digit duplication (22), Haas polysyndactyly (3), and high degree of duplication (4). The birth prevalence rates observed in both series were similar except for postaxial polydactyly, which was more frequent in the ECLAMC (150.2/100,000) than in the ECEMC (67.4/100,000), as expected due to the higher African Black ethnic extraction of the South-American than of the Spanish populations. This similar frequency for the rare polydactylies (5.4 per 100,000 in South America and 5.7 in Spain), and for each one of the 9 categories, suggests that the values reported here are valid for most populations. The rare polydactylies are frequently syndromal: one third of them (77/236) were found in association with other congenital anomalies, 11.0% (26/236) in MCA cases and 21.6% (51/236) in recognized syndromes.

Fingers↗
PubMed1996

Lactobacillus GG and acute diarrhoea in young children in the tropics.

A prospective, placebo controlled, triple blind clinical trial was undertaken in Thailand to determine the effect of Lactobacillus GG on recovery from acute diarrhoea in children. Thirty-nine children (mean age = 8 months) were enrolled and following rehydration received either oral Lactobacillus GG (n = 20) as a freeze-dried preparation or placebo (n = 19) twice daily for 2 days. The clinical characteristics of the study groups were similar. There was no significant difference overall in clinical response detected between the study groups. When only those with acute non-bloody diarrhoea (n = 26) were considered, the mean duration of diarrhoea was significantly shorter in the lactobacillus group (1.9 days) than in the placebo group (3.3 days) (P < 0.055). Stool frequency was less on the second day in the lactobacillus group (P < 0.05). The results suggest that Lactobacillus GG accelerates recovery from acute watery diarrhoea in young children in a tropical setting.

Acute Disease↗
PubMed1995

Lactobacillus GG promotes recovery from acute nonbloody diarrhea in Pakistan.

A prospective, placebo-controlled, triple blind clinical trial was carried out in Pakistan to determine the effect of Lactobacillus GG on the course of acute diarrhea in hospitalized children. Forty children (mean age, 13 months) were enrolled and after rehydration received either oral Lactobacillus GG (n = 21) or placebo (n = 19) twice daily for 2 days, in addition to the usual diet. The clinical course of diarrhea was followed during the treatment period. Features on admission into the study groups were similar and were characterized by severe diarrhea, malnutrition and inappropriate management before presentation. Response was evident on Day 2 when the frequency of both vomiting and diarrhea was less in the Lactobacillus group. In those who had presented with acute nonbloody diarrhea (n = 32), the percentage of children with persistent watery diarrhea at 48 hours was significantly less in the Lactobacillus group: 31% vs. 75% (P < 0.01). No significant difference was observed by 48 hours in those presenting with bloody diarrhea. The relevance of this finding to the management of diarrhea in the tropics is discussed.

Acute Disease↗
PubMed1994

Detection of HIV-p24 antigen in body fluids by immunotrapping on Staphylococcus aureus (Cowan 1) bacteria, gold immunolabelling and backscattered electron analysis in a scanning electron microscope.

An immunosorbent electron microscopical (ISEM) method, the Protein A-coated bacteria technique/gold, (PA-CBT/G), was developed for the detection of non-particulate soluble antigens. The method is based on immunotrapping of antigens on antibody coated, glutaraldehyde cross-linked, Protein A-rich, Staphylococcus aureus bacteria. The 'trapped' antigen is then identified by colloidal-gold immunolabelling. Gold particles are observed in a scanning/transmission electron microscope by analysis of backscattered electrons. With this method it was possible to detect the presence of p24 HIV antigens in blood, semen, saliva, crevicular and cerebrospinal fluids from HIV seropositive cases. Although the PA-CBT/G identified correctly the p24 antigen in only 80% of the ELISA HIV-antigen positive sera, it detected, more frequently than ELISA, HIV-antigen in seminal and oral fluids. The PA-CBT/G method could thus be useful to fully characterise individual HIV excretion patterns in body fluids other than sera even from patients negative for HIV-antigen by ELISA.

Body Fluids↗
PubMed1994

[A survey of the basic knowledge of chronic respiratory patients].

Sixty patients diagnosed as having chronic respiratory diseases were surveyed in order to establish how many knew the name of their disease, the medications they were taking, the name of the medical specialty dedicated to treating their condition and the nature of spirometry. Only 23 patients (38%) knew the name of their disease; among them were all those suffering asthma or silicosis, but only 24% of those with other diseases. Thirty-three (55%) were unable to name their medications. Only 22% knew what a pneumologist does or could define spirometry, although at least 45% of these patients had undergone the procedure. The majority, on the other hand, knew what a cardiologist (70%) does and what an electrocardiogram (80%) is. A large number of patients with chronic respiratory diseases know very little about basic aspects of their conditions. Use of correct terminology appears to be necessary if patient knowledge is to increase.

Aged↗
PubMed1991

The effect of low-dose dopamine infusion on cardiopulmonary and renal status in premature newborns with respiratory distress syndrome.

To study the effects of infusion of low doses of dopamine hydrochloride on cardiopulmonary and renal status in premature newborns with respiratory distress syndrome, 49 newborns were randomly assigned to three groups: group 1 (18 patients) received no dopamine and was the control group; group 2 (16 patients) was infused with a dose of dopamine measuring 1.0 micrograms/kg of body weight per minute for 72 hours; and group 3 (15 patients) was infused with a dose of dopamine measuring 2.5 micrograms/kg of body weight per minute for 72 hours. Birth weights, gestational ages, post-natal ages, and cardiopulmonary status of all groups at the start of the study were comparable. Continuous infusion of these low doses of dopamine for 3 days after birth did not significantly improve levels of blood gases, acid-base balance, or clinical outcome. In newborns with systemic hypotension, dopamine improved cardiovascular status and caused early return of blood pressure to the normal range. Infusion of low doses of dopamine produced mild to moderate natriuresis and insignificant increases in glomerular filtration rate and urine volume.

Acid-Base Equilibrium↗
PubMed1990

Tracheal agenesis.

Tracheal agenesis is a rare congenital anomaly. We report a case and review the cases previously reported. Clinical features that might indicate tracheal agenesis include antenatal polyhydramnios, severe respiratory distress, absence of an audible cry, failure to advance an endotracheal tube beyond the larynx, a palpable distal trachea, clinical improvement after esophageal intubation, and roentgenographic absence of a tracheal air column with an abnormal position of the carina. For immediate management of the affected infant, we recommend intubation of the esophagus with an endotracheal tube to provide an air passage, and determination of the level of the defect by careful use of contrast material and roentgenography. Infants having type I tracheal agenesis may benefit from immediate tracheostomy.

Bronchial Fistula↗