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L Pineda

Publications and source records attributed to L Pineda.

12 recordsLinked to original sources
PubMed2006

Noninvasive ventilation for prevention of post-extubation respiratory failure in obese patients.

Current recommendations for management of obese patients post-extubation are based on clinical experience and expert opinions. It was hypothesised that the application of noninvasive ventilation (NIV) during the first 48 h after extubation in severely obese patients would reduce post-extubation failure and avert the need for reintubation. Following protocol-driven weaning trials, 62 consecutive severely obese patients (body mass index > or =35 kg x m(-2)) were assigned to NIV via nasal mask immediately post-extubation and compared with 62 historically matched controls who were treated with conventional therapy. The primary end-point was the incidence of respiratory failure in the first 48 h post-extubation. Compared with conventional therapy, the institution of NIV resulted in 16% (95% confidence interval 2.9-29.3%) absolute risk reduction in the rate of respiratory failure. There was a significant difference in the intensive care unit and lengths of hospital stay between the two groups. Subgroup analysis of hypercapnic patients showed reduced hospital mortality in the NIV group compared with the control group. In conclusion, noninvasive ventilation may be effective in averting respiratory failure in severely obese patients when applied during the first 48 h post-extubation. In selected patients with chronic hypercarbia, early application of noninvasive ventilation may confer a survival benefit.

Adult↗
PubMed2000

CFTR mutations in three Latin American countries.

We analyzed 192 cystic fibrosis (CF) alleles in three Latin American countries: Mexico, Colombia, and Venezuela. Mutation screening was performed by polymerase chain reaction (PCR) and a reverse dot blot detection kit that enables determination of 16 of the most common CF mutations worldwide. Mutations were detected in 47.9% of the screened CF alleles. The most prevalent CF allele was DeltaF508 (39. 6%). The remaining 16 non-DeltaF508 detectable mutations represented 8.3% of the CF alleles. Among them, the G542X, N1303K, and 3849+10kb C>T were the most common. Although the frequency of DeltaF508 described here is lower than that reported for Caucasian populations, including in Spain, it is remarkable that mutation prevalences found in this study resemble those observed in Spain. Two of these mutations, G542X and 3849+10kb C>T, that were relevant in this analysis, have a particularly high incidence in Spanish communities. The low frequency of DeltaF508 described here may be explained by the Amerindian, Caucasian, and Black admixture that occurred in Latin America after the discovery of the New World, and also by the probable occurrence of mutations contributed by the original natives, which were undetectable in this analysis.

Colombia↗
PubMed2000

Bone regeneration in segmental defects with resorbable polymeric membranes: IV. Does the polymer chemical composition affect the healing process?

Diaphyseal segmental defects 10 mm in length in the radii of 36 skeletally mature rabbits were covered with tubular microporous membranes prepared from poly(L/D-lactide) (18 rabbits) and poly(L/DL-lactide) (18 rabbits) to determine whether chemical composition of the membrane affected the bone healing in the defect. The results of a previous study in which similar defects of the rabbits radii were not covered with membranes or covered with poly(L-lactide) membranes were used as controls. The control defects were rapidly filled with overlying muscle and soft tissues, producing a radio-ulnar synostosis. The osseous activity of control defects was limited to the bone ends. The defects covered with membranes were progressively filled with new bone. At 1 year, complete bone regeneration in the defects covered with the poly(L/D-lactide) membrane was found in 16 cases, no regeneration in 1 animal and pseudoarthrosis in 1 animal. For the poly(L/DL-lactide) membrane there was complete bone regeneration in 17 cases (1 animal died during surgery). The quality of the interface between the new bone and the membrane seemed to be affected by the chemical structure of the polylactides used for membranes preparation. For poly(L/D-lactide), the connective tissue layer entirely separated the new bone from the polymeric membrane. This has been observed before for poly(L-lactide) membranes. In the case of poly(L/DL-lactide) the new bone was formed in some places in direct contact with the membrane and the membrane fragments were osteointegrated. The differences in chemical composition of the polylactide membranes did not have an evident effect on the bone regeneration process in segmental defects of the rabbit radii.

Animals↗
PubMed2000

Quadriceps fatigue after cycle exercise in patients with chronic obstructive pulmonary disease.

Patients with COPD have derangements in respiratory mechanics that may cause them to stop exercising before the exercising limb muscles reach their functional limits. However, because lung disease makes activity unpleasant, patients with chronic obstructive pulmonary disease (COPD) often adapt a sedentary lifestyle leading to progressive deconditioning. Deconditioning will lead to progressive deterioration in limb muscle function, which could adversely affect exercise capacity. The purpose of this study was to determine whether fatigue of the quadriceps muscle occurs after high intensity cycle exercise to the limits of tolerance in patients with moderate to severe COPD. Nineteen male patients with COPD (FEV(1) 1.54 +/- 0. 12 L; 42 +/- 3% predicted) exercised at 60 to 70% of their predetermined maximal work capacity until exhaustion. The femoral nerve was supramaximally stimulated with a figure-of-eight magnetic coil, and quadriceps twitch force (TwQ) was measured before and at 10, 30, and 60 min postexercise. Patients exercised at 53.7 +/- 4.1 watts for 10.4 +/- 1.4 min. Peak V O(2) was 1.24 +/- 0.08 L/min (51. 3 +/- 3.6% predicted). TwQ fell significantly postexercise; 79.2 +/- 5.4% of baseline value at 10 min postexercise (p < 0.005), 75.7 +/- 4.8% at 30 min postexercise (p < 0.001), and 84.0 +/- 5.0% at 60 min postexercise (p < 0.005). Acceptable M-waves from the quadriceps muscle (not obscured by stimulus artifact) were obtained in six subjects. M-wave amplitude was unchanged from baseline at all times postexercise indicating that the fall in TwQ was due to contractile fatigue and not to transmission failure. In conclusion, contractile fatigue of the quadriceps muscle occurs after high intensity cycle exercise to the limits of tolerance in patients with COPD.

Aged↗
PubMed2000

[Chromosomal abnormalities in malignant hematologic diseases].

The inclusion of cytogenetic studies in the protocol study of patients with hematological malignant diseases is a very important contribution because these results contribute to establish better precision of diagnosis, prognostic and suggest adequate therapeutic management precociously. The Karyotypes of 200 patients between ages of 2 and 84 years, 56/200 acute lymphoblastic leukemia (ALL), 55/200 acute myeloid leukemia (AML), 63/200 chronic myeloid leukemia (CML), 20/200 myelodysplastic syndrome (MDS), and 6/200 chronic lymphocytic leukemia, (CLL), are analyzed. Certain differences were noted. In ALL, hyperdiploidy was the chromosomal abnormality more frequently observed and no cases of Ph+ chromosome were reported; with respect to AML, the autosomal monosomy and trisomy were the most frequent findings. MDS reports only one case with 5q deletion, 10% of patients presented trisomy 14, rarely reported. CML do no report any case with double Ph+ and only one case with i(17q); nevertheless, one case with 21q deletion was found, which is an unreported anomaly. CLL did not present any case with trisomy 12. These findings are discussed in the context of geographical heterogeneity of chromosomal abnormalities in leukemia, and emphasize the importance of continued epidemiological studies.

Acute Disease↗
PubMed1999

Mixed gonadal dysgenesis: a syndrome of broad clinical, cytogenetic and histopathologic spectrum.

Mixed gonadal dysgenesis (MGD) is an abnormality of sexual differentiation (ASD), which encompasses an heterogeneous group of different gonadal and phenotypic abnormalities. This study describes the main clinical features found in 16 patients with MGD, relating the clinical presentation with cytogenetic evaluation and histopathological findings. For purpose of this study, MGD was considered in those patients who fulfilled the following diagnostic criteria: 1) müllerian and/or wolfflan derivatives; 2) any of the following gonadal characteristics: a) bilateral intrabdominal or scrotal immature testicular tissue; b) intrabdominal or scrotal immature testicular tissue with contralateral streak gonad. Patients were selected from an ASD study which was carried out in Medical Genetic Unit of University of Zulia (UGM-LUZ), Maracaibo, Venezuela, from 1980 to 1997. The following information was extracted from the medical history at UGM-LUZ: age, gender which patient was reared, clinical presentation, cytogenetic evaluation, laparoscopic findings and gonadal biopsy. Sixteen patients fulfilled the diagnostic criteria and ranged in age from 1.2 to 39.4 years with an average of 12.65 years. Only 5 patients were reared as males. Twelve patients consulted for genital ambiguity. Chromosomal evaluation was as following: 8 patients with 45,X/46,XY mosaicism: 5 had a 46,XY normal male karyotype and the remaining patients: 46,XX; 46,XX/46,XY and 45,X/46,Xi(Xq) karyotypes, respectively. All patients showed müllerian derivatives and occasionally wolffian derivatives. Gonadal tumors were present in 2 patients. Molecular studies of genes that govern gonadal development are necessary for a better understanding of the wide heterogeneity present in MGD.

Adolescent↗
PubMed1992

Clinical profile and factors affecting mortality in acute renal failure.

The records of 110 patients with acute renal failure (ARF) admitted to the Department of Medicine of the Philippine General Hospital during a 5-year period (1983-1988) were reviewed. The objectives were to evaluate the clinical profile of ARF patients and to determine what factors influenced mortality. Infection significantly influenced the causation and prognosis of ARF. Fifteen patients died, for an overall mortality rate of 14%. Forty-six clinical variables were analyzed in order to identify factors correlated with mortality. Four variables significantly increased the risk of death from ARF: older age, hyperkalemia, oliguria, and presence of sepsis on admission. These characteristics define a subset of patients for whom more aggressive treatment of ARF is warranted.

Acute Kidney Injury↗
PubMed1985

Estimation of inbreeding by isonymy in Iberoamerican populations: an extension of the method of Crow and Mange.

The method of isonymy for the estimation of inbreeding levels was extended to use the potentialities offered by the Iberoamerican surname system, in which a child inherits his surnames both from the father and the mother. Four possible types of isonymy were recognized between the family names of a husband-wife pair. It was found that, limited to simple consanguinity, the ratio between isonymy and the inbreeding coefficient of consanguineous individuals, starting from first cousins, is constant and equal to 16. Consanguinity levels were studied in four Venezuelan groups, Isla de Toas, Los Teques, Quibor, and Colonia Tovar, using genealogies, classical isonymy, and the extended method. It was found that, for Iberoamerican populations, the extended method is more precise than the classical method.

Consanguinity↗