PubMed Health⌕ Search

Biomedical subjects

J Velasco

Publications and source records attributed to J Velasco.

At least 73 records · Page 4Linked to original sources
PubMed1993

The production of cephalosporin C by Acremonium chrysogenum is improved by the intracellular expression of a bacterial hemoglobin.

A DNA vector for expressing an oxygen-binding heme protein (Vitreoscilla hemoglobin, or VHb) in filamentous fungi was constructed and introduced into a cephalosporin C-producing strain of Acremonium chrysogenum. Expression of VHb in transformants was demonstrated by Western immunoblot analysis and by increased carbon monoxide binding activity of cell extracts. Several VHb-expressing transformants produced significantly higher yields of cephalosporin C than control strains in batch culture experiments. Using the same vector system, VHb was also expressed in the related fungus Penicillium chrysogenum.

Acremonium↗
PubMed1993

Protective effect of triflusal against acute myocardial infarction in patients with unstable angina: results of a Spanish multicenter trial. Grupo de Estudio del Triflusal en la Angina Inestable.

A multicenter, double-blind, placebo-controlled study was carried out to evaluate the effect of a new antiplatelet agent, triflusal (2-acetoxy-4-trifluoromethyl benzoic acid), in the prevention of nonfatal myocardial infarction and cardiac or vascular death (principal end-points) in patients with unstable angina. 281 patients were randomly assigned to triflusal (300 mg t.i.d.; n = 143) or placebo (n = 138). After 6 months of treatment, the incidence of nonfatal acute myocardial infarction was significantly lower in the triflusal than in the placebo group: 6 patients (4.2%) versus 17 (12.3%), p = 0.013. The low number of deaths (2/143 triflusal versus 0/138 placebo recipients) hampered statistical analysis of mortality rates. The need for revascularization was similar in the two groups: 24 patients (16.8%) in the triflusal group and 28 (20.3%) in the placebo group, p = 0.449. In conclusion, the results show that treatment with triflusal can reduce the incidence of myocardial infarction in patients with unstable angina.

Administration, Oral↗
PubMed1992

The cefG gene of Cephalosporium acremonium is linked to the cefEF gene and encodes a deacetylcephalosporin C acetyltransferase closely related to homoserine O-acetyltransferase.

The gene (cefG) encoding the acetyl coenzyme A:deacetylcephalosporin C acetyltransferase of Cephalosporium acremonium (synonym Acremonium chrysogenum) C10 has been cloned. It contains two introns and encodes a protein of 444 amino acids with an M(r) of 49,269 that correlates well with the M(r) deduced by gel filtration. The cefG gene is linked to the cefEF gene (encoding the bifunctional deacetoxycephalosporin C synthase/hydroxylase), but it is expressed in an orientation opposite that of the cefEF gene. Two transcripts of 1.2 and 1.4 kb were found in C. acremonium that correspond to the cefEF and cefG genes, respectively; the degree of expression of the cefG gene was clearly lower than that of the cefEF gene in 48-h cultures. The cloned cefG complemented the deficiency of deacetylcephalosporin acetyltransferase in the nonproducer mutant C. acremonium ATCC 20371 and restored cephalosporin biosynthesis in this strain. Heterologous expression of the cefG genes took place in Penicillium chrysogenum. The deacetylcephalosporin acetyltransferase showed a much higher degree of homology with the O-acetylhomoserine acetyltransferases of Saccharomyces cerevisiae and Ascobolus immersus than with other O-acetyltransferases. The cefEF-cefG cluster of genes encodes the enzymes that carry out the three late steps of the cephalosporin biosynthetic pathway and is not linked to the pcbAB-pcbC gene cluster that encodes the first two steps of the pathway.

Acetyltransferases↗
PubMed1992

Trypanosoma cruzi: infectivity and virulence of trypomastigotes incubated with leukocytes and serum from patients with Chagas' disease.

An important issue for the understanding of the host-parasite relationship in Chagas' disease is the extent of the action of the immune system on the parasite. To advance our understanding of this aspect, we evaluated the effect of leukocytes and/or sera from patients with Chagas' disease on trypomastigotes of Trypanosoma cruzi. We incubated, in vitro, leukocytes and sera, from patients with Chagas' disease without evidence of heart disease (INF), patients with Chagasic cardiopathy (CDM) and healthy controls (VOL), with trypomastigotes at 37 degrees C for three hours. Mice were inoculated with parasites at the end of the incubation. We kept a record of the survival time of each animal and every three days we evaluated their Parasitemia. INF (36.4%) and CDM (42.9%) prolonged the prepatent period, but not Vol. Only CDM (57.1%) extended the survival time. The sera from CDM patients that extended the survival of mice prolonged the prepatent period. However serum alone did not extend the survival time, providing evidence that leukocytes are required to decrease the virulence of the inoculum. The capacity of leukocytes and sera, from CDM, to prolong survival time shows that the immune system of patients with Chagasic cardiomyopathy can affect the parasite more intensely than IFN. On the other hand, the higher frequency of positive xenodiagnosis in CDM (11), suggests that, in vivo, occur a down regulation of the immune response.

Adult↗
PubMed1991

The accuracy of the Biox 3700 pulse oximeter in patients receiving vasoactive therapy.

The accuracy of pulse oximetry for the prediction of oxygen saturation of arterial blood in patients with shock has been hardly studied. This study was undertaken to determine if O2 arterial saturation estimated by the Biox 3700 pulse oximeter (SpO2) with an ear probe could reliably substitute for the measurements of O2 saturation (HbO2) with an IL-282 Co-Oximeter in samples of arterial blood obtained from 24 caucasian patients. All patients were mechanically ventilated and needed vasoactive drugs (dopamine and/or dobutamine). Of 24 patients 13 had shock: cardiogenic (n = 6) and septic (n = 7). The mean difference between HbO2 and SpO2 was 2.49% +/- 4.24, with a 95% confidence interval of 0.7% to 4.3% (p = 0.009). There were clinically important differences between both methods since in 9 of 24 patients (37%) SpO2 values were at least 4% lower or greater than HbO2. This disagreement was also apparent in patients with (6/13, 46%) or without shock (3/11, 27%). To conclude, pulse oximetry is not always a sufficiently reliable method to predict HbO2 in patients with or without shock treated with vasoactive drugs.

Blood Pressure↗
PubMed1985

[Nephropathy of the Schöenlein-Henoch syndrome: long-term prognosis in non-selected patients].

Nephritis plays a major role in long-term prognosis of Schönlein-Henoch syndrome. We have studied a group of 142 children with this syndrome; 43 (30.2%) showed clinical evidence of renal disease. Renal biopsy was obtained in 12 cases. A subgroup of 36 patients have been controlled during a much greater two years period. Thirty-five are asymptomatic and one with minor urinary anomalies. Thereafter in our experience the long-term prognosis (means = five years) of Schönlein-Henoch syndrome is excellent in unselected patients.

Adolescent↗
PubMed1984

Amyloidosis in Behçet's disease.

A 36-year-old man with Behçet's disease developed nephrotic syndrome and chronic renal failure. The renal biopsy confirmed renal amyloidosis, and the potassium permanganate staining indicated that the amyloid was of the AA protein type. To our knowledge, this is the first report of Behçet's disease with amyloidosis and chronic renal failure in maintenance hemodialysis.

Adult↗