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Biomedical subjects

M Quesada

Publications and source records attributed to M Quesada.

30 records · Page 2Linked to original sources
PubMed1985

Comparative studies on three isolates of Breda virus of calves.

Three isolates of Breda virus of calves were compared morphologically and antigenically. The isolates demonstrated similar morphology and shared common antigens, as determined by enzyme-linked immunosorbent assay and immunoelectron microscopy. On the basis of results of the hemagglutination-inhibition test, enzyme-linked immunosorbent assay, and immunoelectron microscopy, the 3 isolates were further subdivided into 2 serotypes: serotype 1 (Breda virus 1) represented by the Iowa isolate 1; and serotype 2 (Breda virus 2), by the Ohio isolate and the Iowa isolate 2. The 3 isolates caused diarrhea in gnotobiotic calves.

Animals↗
PubMed1984

[Determination of 25-hydroxycholecalciferol in serum].

A precise specific method for measuring 25-hydroxycholecalciferol (25-OH CC) in 2 ml of human serum is described. It includes extraction with acetonitrile, separation with Sep-Pak C-18 cartridges, purification through HPLC and a further quantitation by means of a protein-binding assay. An exhaustive study of this protein-binding method has been performed. The sensitivity of the protein-binding assay is 20 pg/tube and the inter and intra-assay coefficients of variation are 9.6% and 8.7% respectively. The precision of the overall process has been assessed by calculating the inter and intra-assay coefficients of variation, 15.5 and 10.4% respectively. Mean serum value of 25-OH CC in normal subjects (18-50 years old, during spring) is 11.2 +/- 5.5 ng/ml.

Acetonitriles↗
PubMed1983

[Dermatoglyphics in 2 Guaymi Indian populations of Costa Rica].

Twenty-three palmar and digital dermatogliphic characters were examined in two Guaymi Amerindian populations, Abrojo and Limoncito, in southeastern Costa Rica. Dermatogliphs were analyzed in relation to sex, bilaterality or assymetry and differences in pattern frequencies between localities. The sample included 134 males and 127 females in two groups, according to their ethnic and linguistic origin: Western Guaymi (Movere), from Limoncito and Abrojo, and Eastern Guaymi (Murire or Buglere) from Limoncito. When compared with other Amerindian groups, the Guaymi presented a very low finger pattern average, as well a low total ridge count. The Movere subgroup, showed similarities among different patterns both in Limoncito and Abrojo. However there are significant differences between the Murire and Movere groups in relation to the ridge count (ab; bc), atd angle; frequency of designs at the interdigital zone 4; bilaterality; and sex. The results obtained confirm the existence of a marked evolutionary divergence between the two groups.

Costa Rica↗
PubMed1981

[Coma states induced by craniocerebral injuries in children. Review of 20 cases].

From a total of three-hundred and fifty-six children admitted into the Department of Pediatrics at the Hospital Clínico of the University of Granada during of period of two years, twenty cases that needed admittance in critical pediatrics care unit are revised. Organic etiology that provoked coma, time of appearance, intensity, evolution, complications and short term outcome are analysed. A comparison is made of the incidences and prognosis of this type of coma with that of other authors presenting therapeutic outline carried. Two large evolutive groups; one which consisted of nine patients which entered into coma immediately after injury. The second group includes those patients which had lucid period before entering into coma. Following conclusions have been withdrawn: Severity and duration of coma does not have a definite relationship with the existence of a mass-lesion. Presence of an associated--mass-lesion is a sign of grave prognosis. For a good therapeutic response the following approaches are necessary: Immediate assistance monitoring and periodic or systematic maintenance of extracranial variants diagnostic, and treatment of the primary causing factor.

Brain Injuries↗
PubMed1977

Interdependence of decompression sickness and plasma enzymes on dive profile and vitamin B-6 status.

The mortality rate due to decompression injury was found to be significantly greater in a rat population with a mild vitamin B-6 deficiency, compared to an adequately fed control group, when subjected to a bends-producing N2-O2 dive. Relative post-dive changes in lactate dehydrogenase, creatine phosphokinase, and transaminase levels in plasma do not appear to be sufficiently different to allow a ready distinction in the degree of susceptibility of one nutritionally defined population from the other.

Alanine Transaminase↗
PubMed1975

Supportive evidence for altered platelet function in the dived rat.

A study was conducted on the changes in platelet function and platelet count in the Sprague-Dawley rat induced by a bends-producing N2-O2 compression-decompression cycle. In those instances where mild to moderate cases of decompression sickness were produced, a decrease in platelet reactivity to ADP-induced aggregation occurred immediately postdive along with an increase in inhibition of aggregation by prostaglandin E1. Both effects returned to control levels 24 hours postdive. In moderately affected animals, platelet counts were lower than normal 24 hours postdive but were similar to control values 72 hours postdive. These results tend to support current hypotheses regarding the etiological relationship between disseminated intravascular coagulation and decompression sickness as a function of bubble nucleation.

Adenosine Diphosphate↗
PubMedDate not supplied

[Evaluation of Helicobacter pylori susceptibility to rifaximin].

INTRODUCTION: Helicobacter pylori infection affects more than half the world's population. It is a major cause of chronic gastritis and there is a strong association with peptic ulceration and gastric adenocarcinoma. Rifaximin is a new nonabsorbable broad-spectrum antimicrobial agent that reaches high concentrations in the gastrointestinal tract. AIM: To evaluate the in vitro activity of rifaximin against H. pylori isolates. METHODS: Thirty-one H. pylori strains were analyzed by the agar dilution method. Clarithromycin was used as the control antibiotic. Staphylococcus aureus and Streptococcus pneumoniae were used as quality control strains. Plates were read at days 4 and 7 of incubation. The MIC50 and MIC90 of each antibiotic were calculated. Strains with a clarithromycin MIC of > 1 microg/ml were considered resistant. RESULTS: The MIC50 of clarithromycin at days 4 and 7 was 0.125 microg/ml and the MIC90 at days 4 and 7 ranged from 8 to 16 microg/ml, respectively. The MIC50 of rifaximin at days 4 and 7 ranged from 1 to 2 microg/ml, respectively, and the MIC90 was 4 microg/ml at both days 4 and 7. Twenty percent of H. pylori strains were resistant to clarithromycin. All clarithromycin-resistant strains were inhibited at a maximal rifaximin concentration of 4 microg/ml. CONCLUSION: These results indicate that this new antibiotic may be useful for eradication of H. pylori infection. Because rifaximin is active against H. pylori strains resistant to clarithromycin, it could be useful in combination with this drug or in the treatment of therapeutic failure.

Adult↗