Biomedical subjects

J Rios

Publications and source records attributed to J Rios.

17 recordsLinked to original sources

PubMed2006

Body weight and comorbidity predict mortality in COPD patients treated with oxygen therapy.

The aim of this study was to investigate the association between clinical variables and all-cause and respiratory mortality in patients with chronic obstructive pulmonary disease (COPD) undergoing long-term oxygen therapy (LTOT). The authors retrospectively studied a historic cohort of 128 patients with COPD (126 males, mean age+/-SD 68.9+/-9.7 yrs, body mass index (BMI) 25.1+/-4.5 kg.m-2, and forced expiratory volume in one second 25.4+/-8.8% predicted), who were being treated with long-term oxygen therapy in a tertiary teaching hospital between 1992 and 1999. Comorbidity, assessed with the Charlson Index, was present in 38% of the patients. Vital status and cause of death were assessed through the population death registry. A total of 78 patients (61%) had died by the end of follow-up. Three-year survival was 55%. Death was due to respiratory causes in 77% of cases. On Cox analysis, BMI<25 kg.m-2, comorbid conditions, age>or=70 yrs and cor pulmonale were associated with all-cause mortality. The BMI and comorbidity were the only significant predictive factors when the analysis was restricted to respiratory mortality. In conclusion, body mass index<25 kg.m-2 and comorbidity were predictors of all-cause and respiratory mortality in a cohort of chronic obstructive pulmonary disease patients treated with long-term oxygen therapy. These factors should be taken into account when considering the management and prognosis of these patients.

Aged↗

PubMed2003

Leuconostoc bacteremia in a healthy infant.

Infections by Leuconostoc species bacteria are uncommon, and usually affect patients with an underlying disease, or those fitted with a venous catheter or subjects previously treated with vancomycin. The most common clinical presentation is fever secondary to a central venous line infection. We report a case of Leuconostoc sp. bacteremia in an otherwise apparently healthy 2.5 month-old infant. The patient was successfully treated with cefotaxime. Leuconostoc sp. is an emerging pathogen that should be considered in the differential diagnosis of vancomycin-resistant Gram-positive bacteremia.

Anti-Bacterial Agents↗

PubMed2002

Early onset of neonatal sepsis due to group A streptococcus.

Neonatal infections by group A beta-hemolytic streptococcus are very rare in the antibiotic era. There are only a few cases in the first 72 hours after birth. The authors describe a case in which it was confirmed that the bacteria responsible, group A beta-hemolytic streptococcus, had grown in the newborn's blood and in the mother's lochia. The transmission mechanisms are also reviewed.

Humans↗

PubMed2001

IP(3) receptor function and localization in myotubes: an unexplored Ca(2+) signaling pathway in skeletal muscle.

We present evidence for an unexplored inositol 1,4,5-trisphosphate-mediated Ca(2+) signaling pathway in skeletal muscle. RT-PCR methods confirm expression of all three known isotypes of the inositol trisphosphate receptor in cultured rodent muscle. Confocal microscopy of cultured mouse muscle, doubly labeled for inositol receptor type 1 and proteins of known distribution, reveals that the receptors are localized to the I band of the sarcoplasmic reticulum, and this staining is continuous with staining of the nuclear envelope region. These results suggest that the receptors are positioned to mediate a slowly propagating Ca(2+) wave that follows the fast Ca(2+) transient upon K(+) depolarization. This slow wave, imaged using fluo-3, resulted in an increase in nucleoplasmic Ca(2+) lasting tens of seconds, but not contraction; the slow wave was blocked by both the inositol trisphosphate receptor inhibitor 2-aminoethoxydiphenyl borate and the phospholipase C inhibitor U-73122. To test the hypothesis that these slow Ca(2+) signals are involved in signal cascades leading to regulation of gene expression, we assayed for early effects of K(+) depolarization on mitogen-activated protein kinases, specifically extracellular-signal related kinases 1 and 2 and the transcription factor cAMP response element-binding protein (CREB). Within 30-60 seconds following depolarization, phosphorylation of both the kinases and CREB was evident and could be inhibited by 2-aminoethoxydiphenyl borate. These results suggest a signaling system mediated by Ca(2+) and inositol trisphosphate that could regulate gene expression in muscle cells.

Actinin↗

PubMed2000

Characterization of Cr(VI) binding and reduction to Cr(III) by the agricultural byproducts of Avena monida (oat) biomass.

Chromium contamination of the environment has become an important issue due to the potential health threat it poses. Conventional technologies to clean up heavy metal ions from contaminated waters have been utilized, but these technologies are not cost-effective. However, the use of agricultural waste byproducts for the removal of Cr(VI) from contaminated waters may be a new cost-effective alternative. Oat byproducts from the Juarez Valley in Mexico were studied for the ability to bind Cr(VI) under different temperature and time conditions. The metal binding ability of oat byproducts was calculated from experimental data collected at temperatures of 8, 26, and 54 degrees C, and time exposures of 1, 6, 24, 48, and 72 h at each temperature. These results showed that the binding of Cr(VI) to oat biomass increased as time and temperature increased. The bound chromium was recovered from the oat biomass by treatment with 0.2M HCl. Through the use of X-ray absorption spectroscopy, the reduction of Cr(VI) to Cr(III) was determined to occur by the oat byproducts. These results indicate that the use of agricultural waste byproducts could be a better alternative for the removal and subsequent reduction of Cr(VI) to Cr(III) from contaminated waters.

Agriculture↗

PubMed2000

Mapping of a syndrome of X-linked thrombocytopenia with Thalassemia to band Xp11-12: further evidence of genetic heterogeneity of X-linked thrombocytopenia.

X-linked thrombocytopenia with thalassemia (XLTT; Online Mendelian Inheritance in Man [OMIM] accession number 314050) is a rare disorder characterized by thrombocytopenia, platelet dysfunction, splenomegaly, reticulocytosis, and unbalanced hemoglobin chain synthesis. In a 4-generation family, the gene responsible for XLTT was mapped to the X chromosome, short arm, bands 11-12 (band Xp11-12). The maximum lod score possible in this family, 2.39, was obtained for markers DXS8054 and DXS1003, at a recombination fraction of 0. Recombination events observed for XLTT and markers DXS8080 and DXS8023 or DXS991 define a critical region that is less than or equal to 7.65 KcM and contains the gene responsible for the Wiskott-Aldrich syndrome (WAS; OMIM accession number 301000) and its allelic variant X-linked thrombocytopenia (XLT; OMIM accession number 313900). Manifestations of WAS include thrombocytopenia, eczema, and immunodeficiency. In WAS/XLT the platelets are usually small, and bleeding is proportional to the degree of thrombocytopenia. In contrast, in XLTT the platelet morphology is normal, and the bleeding time is disproportionately prolonged. In this study no alteration in the WAS gene was detected by Northern blot or Western blot analysis, flow cytometry, or complimentary DNA dideoxynucleotide fingerprinting or sequencing. As has been reported for WAS and some cases of XLT, almost total inactivation of the XLTT gene-bearing X chromosome was observed in granulocytes and peripheral blood mononuclear cells from 1 asymptomatic obligate carrier. The XLTT carrier previously found to have an elevated alpha:beta hemoglobin chain ratio had a skewed, but not clonal, X-inactivation pattern favoring activity of the abnormal allele. Clinical differences and results of the mutation analyses make it very unlikely that XLTT is another allelic variant of WAS/XLT and strongly suggest that X-linked thrombocytopenia mapping to band Xp11-12 is a genetically heterogeneous disorder.

Blotting, Northern↗

PubMed2000

Genetic differentiation among geographically isolated populations of Criollo cattle and their divergence from other Bos taurus breeds.

The microsatellites HEL5, HEL9, INRA063, and BM2113 were used to analyze genetic similarities and differences of geographically isolated Criollo cattle herds in Mexico. Criollo cattle from five counties within the state of Chihuahua and one county from the state of Tamaulipas (n = 60) were sampled. The five counties in Chihuahua included Cerocahui (n = 14), Chinipas (n = 10), Guachochi (n = 15), Morelos (n = 30), and Temoris (n = 9). Samples of DNA were amplified by PCR and separated on a 7% polyacrylamide gel. Microsatellite size was established by comparison to M13mp18 DNA ladder and a documented set of four bovine controls. Allele frequencies and genotypic deviations from Hardy-Weinberg equilibrium were tested using the GENEPOP program. Eleven alleles were generated at HEL5 for the populations sampled (149 to 169 bp). Allele frequencies were greatest for the 163-bp allele in Criollo cattle from Cerocahui, Chinipas, Moralos, and Tamaulipas (0.23 to 0.5). Cattle from Guachochi had an allele frequency of 0.38 for the 151-bp allele, and cattle from Temoris had an allele frequency of 0.25 for the 149- and 167-bp alleles, with no 163-bp allele. Amplification with HEL9 produced 12 alleles (145, 149 to 169 bp) and showed common high-frequency alleles at 149, 157, and 159 bp for animals from all regions. The Chinipas population showed a moderate allele frequency at 145 bp; no other regions contained this allele. For INRA063 there were five alleles with 182 and 184 bp in low frequency. For BM2113 there were 10 alleles in the Criollo cattle (125 to 143 bp), with an equal distribution of frequencies for all alleles. In two regions, Guachochi and Morelos, genotypic frequencies deviated from Hardy-Weinberg equilibrium. Cattle from the Temoris region were genetically most distant from Criollo cattle of the other five regions.

Animals↗

PubMed2000

Early onset neonatal sepsis due to Neisseria meningitidis B.

The onset of meningococcal infection in the first 72 hours after birth has only been reported on a few occasions; The authors describe a case where it was confirmed that the bacteria responsible, Neisseria meningitidis group B, grew in the newborn's blood and in the mother's lochia. The transmission mechanisms are also reviewed.

Female↗

PubMed1998

Emergency medicine practice systems in Louisiana.

BACKGROUND: We surveyed emergency medicine practice systems in Louisiana. METHODS: We surveyed 105 emergency department (ED) directors in Louisiana requesting annual ED volume, hospital type, physician coverage scheduled, type of documentation used, use of physician extenders, use of minor care or observation areas, and employment status of emergency physicians. RESULTS: Directors of 71 EDs responded. Eighty-six percent of emergency physicians were employed as independent contractors. Public and teaching EDs accounted for 51% and 23%, respectively. Mode of documentation was handwritten in 56% and dictated in 21%; 23% used a combination. Physician extenders were used in 7%, with 4% using physician assistants and nurse practitioners. Minor care areas were used in 17%, observation areas in 25%. Nonteaching EDs had a significantly less mean annual volume and physician hours scheduled; they also treated significantly fewer patients per hour. Emergency departments using dictation, physician extenders, or accessory care areas had significantly greater mean annual patient volumes. CONCLUSIONS: Emergency departments in teaching hospitals, using dictation, physician extenders, and accessory care areas, have significantly greater system productivity than nonteaching hospitals.

Data Collection↗

PubMed1994

CFTR mutations in Chilean cystic fibrosis patients.

An analysis of five of the most common cystic fibrosis (CF) mutations worldwide (delta F-508, R-553X, G-551D, N-1303K and G-542X) was performed in 36 Chilean patients. Polymerase chain reaction (PCR) amplification of the DNA followed by allele specific restriction enzyme analysis was used for detection. The overall frequencies of the mutations in the chromosomes analyzed were 29.2% for delta F-508 and 4.2% for R-553X (n = 72). The G-542X, G-551D and N-1303 K mutations were absent in the Chilean sample. Our data suggest however that delta F-508 is not the most common CF mutation in Chilean patients. delta F-508 and R-553X account for only 33.4% of the alleles; 66.6% of them do not respond to the probes used and still remain uncharacterized.

Adult↗

PubMed1978