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Biomedical subjects

P Ruiz

Publications and source records attributed to P Ruiz.

At least 55 records · Page 3Linked to original sources
PubMed2003

Prostate-specific antigen in the assessment of organ donors.

Transplantation is limited worldwide by the shortage of organs, thus, donors of older ages are necessary to be used to meet the increasing demand for transplants. To minimize the transmission of cancer from this population, it is mandatory to rule out the presence of neoplasms. We present our experience with analysis of the prostate-specific antigen (PSA) for male donors older than 50 years of age. Eleven (5.9%) had PSA levels >6 ng/mL, 2 had prostate cancer. In 7 donors with high PSA levels postextraction study of the whole prostate gland showed carcinoma in 1 and prostate infarction in 1; the other 5 were reported as normal or having benign prostatic hypertrophy (BPH). Donors with high PSA levels are suitable for transplantation if urgent pathological studies do not find prostate cancer. Nevertheless, in most donors, increased PSA levels are secondary to causes other than malignant tumors, thus, the risk of transmission of prostate cancer with transplants is minimal. In conclusion, measurements of PSA levels alone prior to extraction are not sufficient to diagnose cancer in organ donors. We conclude that this analysis must be restricted to donors with a past history of prostate disease. Meanwhile, better tests to avoid false-positive results are required.

Adult↗
PubMed2003

Intestinal transplantation: advances in immunosuppression and surgical techniques.

Campath-1H is being used as induction immunosuppression for intestinal/multivisceral transplantation. Patient and graft survival in this preliminary experience is similar to previous studies but there has been a significant decrease in the incidence and severity of acute rejections without increase of opportunistic infections. Collage of the abdominal wall (transplantation of a composite graft of the abdominal wall) can provide biologic coverage of the newly transplanted abdominal organs if necessary. Partial abdominal exenteration, ex vivo resection, and intestinal autotransplantation may be useful in removing otherwise unresectable lesions of the root of the mesentery.

Graft Rejection↗
PubMed2003

Current interest of isoniazid in the chemotherapy of tuberculosis in the light of its in vitro activity.

Isoniazid is one of the most useful drugs for the treatment of tuberculosis. However, in the last few years treatment with this drug has become long, complicated, and occasionally inefficient because of the increasing number of cases with resistance. The aim of our work was to know the isoniazid resistance level of 1,496 Mycobacterium tuberculosis strains that were submitted to the Mycobacteria Reference Center, Córdoba, during the years 1993-2000. A total of 1,186 strains were from pulmonary sources and 196 from extrapulmonary sources; no source was provided for 114 strains. All M. tuberculosis strains were previously identified by different methods. For sensitivity testing, the BACTEC 460 TB system was used initially and then the ESP II system was also used. The control strains used in this study were ATCC27294 (sensitive to SM, RP, EB, and INH) and ATCC35822, resistant to INH. The overall resistance rate obtained was 14.8%, of which 2.3% and 1.4% accounted for primary and secondary resistance types, respectively. Ninety-six out of the 221 resistant strains were resistant to INH only, and 8 strains were resistant to INH plus SM. A total of 117 multiresistant strains were found. An apparent increase in the resistance rate to INH in the last few years was observed. Secondary resistance has decreased, whereas primary resistance has increased. A continuous surveillance of resistance is required and, therefore, any patient with tuberculosis should undergo sensitivity testing to confirm therapy to be used.

Antitubercular Agents↗
PubMed2003

[Streptomycin as second-line chemotherapy for tuberculosis].

Streptomycin was the first antibiotic to be used against Mycobacterium tuberculosis. It was used for years in monotherapy regimens, thereby resulting in the appearance of resistance and the relegation of its use. The resistance detected against drugs currently employed has led to a renewed interest in streptomycin. Its mechanism of action is centered on the ribosome, inhibiting the protein synthesis of the microbacteria. Resistance appears when mutations in the genes codifying for rRNA 16S and for protein S12 are produced. We studied the use of streptomycin against 899 M. tuberculosis strains, 713 of which were from pulmonary and 186 from extrapulmonary isolates. The BACTEC 460 TB system was initially employed as was the ESP II system. As controls, the ATCC27294 pattern strains (susceptible to streptomycin, rifampicin, ethambutol and isoniazid) were used. The results showed 2.1% secondary resistance in all the cases. Multiresistance was observed in 12 strains.

Antitubercular Agents↗
PubMed2002

Investigation of the in vitro activity of streptomycin against Mycobacterium tuberculosis.

Streptomycin was the first antibiotic used against Mycobacterium tuberculosis. It was used for years in monotherapy regimens, leading to the emergence of resistance; therefore, its use gradually waned. Given the resistance rates detected with current antituberculosis drugs, the use of streptomycin has gained renewed interest. The mechanism of action of streptomycin is inhibition of protein synthesis of mycobacteria in the ribosome. Resistance emerges when mutations appear in genes encoding 16S rRNA and protein S12. The activity of streptomycin against 1,496 M. tuberculosis strains was investigated; 1,186 and 196 strains corresponded to pulmonary and extrapulmonary specimens, respectively. For 114 strains, the source was not indicated. Initially, the BACTEC 460 TB system was used for antibiotic susceptibility testing. Since 1996, the ESP II system was used. The strains ATCC27294 (sensitive to streptomycin, rifampin, ethambutol, and isoniazid) and ATCC35820 (resistant to streptomycin) were used as controls. An overall resistance rate of 2.2% was obtained. In all cases secondary resistance was observed. Multiresistance was observed in 23 strains.

Antibiotics, Antitubercular↗
PubMed2002

GenoType mycobacterium assay for identification of mycobacterial species isolated from human clinical samples by using liquid medium.

The GenoType Mycobacterium assay was used to identify 98 mycobacteria isolates by using liquid cultures from positive BACTEC, MGIT, and ESP bottles. This system identifies 16 mycobacteria. There was complete agreement between the GenoType results and the laboratory identifications for Mycobacterium tuberculosis complex and other Mycobacterium spp. GenoType also identified mixed mycobacterial infections.

Bacteriological Techniques↗