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Sergio Sánchez

Publications and source records attributed to Sergio Sánchez.

5 recordsLinked to original sources
PubMed2006

Medium-term results of percutaneous vertebroplasty in multiple myeloma.

Vertebral compression fractures (VCFs) are common in multiple myeloma (MM). Percutaneous vertebroplasty (PVP) is used to stabilize vertebral collapse and treat the pain. Few studies have been carried out on PVP in MM and follow-up has tended to be short. We have prospectively evaluated the safety and efficacy of PVP in the VCFs resulting from MM or plasmacytomas. Nineteen PVP were performed in 12 consecutive patients. We monitored their pain and functional status using visual analog (VAS) and Eastern Cooperative Oncology Group (ECOG) scale, respectively. For a subjective assessment, every patient was asked about his/her degree of satisfaction. The mean age of the participants was 66 yr. Significant improvement occurred 1 d after PVP according to the VAS score (7.5 pre-PVP to 3.7, P < 0.0001) and ECOG assessment (3.1 to 2.5, P = 0.002). This significant improvement was maintained after 3.2 yr of follow-up. Sixty-three percent of patients were highly satisfied with the result of the PVP and 37% were satisfied. The peri-operative mortality was 0%. Leakage of the cement outside of the vertebral body was noted in 16 of 19 injected vertebrae (84%) but none of the patients developed any clinical or neurological symptoms. At the last follow-up, no further collapse in the treated or neighboring vertebrae was noted. VCFs caused by MM or plasmacytomas can be effectively treated by vertebroplasty. PVP is associated with early clinical improvement of pain and function and can be maintained after a long follow-up without major procedure-related complications.

Aged↗
PubMed2005

Microbial starch-binding domain.

Glucosidic bonds from different non-soluble polysaccharides such as starch, cellulose and xylan are hydrolyzed by amylases, cellulases and xylanases, respectively. These enzymes are produced by microorganisms. They have a modular structure that is composed of a catalytic domain and at least one non-catalytic domain that is involved in polysaccharide binding. Starch-binding modules are present in microbial enzymes that are involved in starch metabolism; these are classified into several different families on the basis of their amino acid sequence similarities. Such binding domains promote attachment to the substrate and increase its concentration at the active site of the enzyme, which allows microorganisms to degrade non-soluble starch. Fold similarities are better conserved than sequences; nevertheless, it is possible to notice two evolutionary clusters of microbial starch-binding domains. These domains have enormous potential as tags for protein immobilization, as well as for the tailoring of enzymes that play a part in polysaccharide metabolism.

Bacteria↗
PubMed2005

Pleiotropic effect of the SCO2127 gene on the glucose uptake, glucose kinase activity and carbon catabolite repression in Streptomyces peucetius var. caesius.

SCO2127 and SCO2126 (glkA) are adjacent regions located in Streptomyces coelicolor DNA. glkA encodes glucose kinase (Glk), which has been implicated in carbon catabolite repression (CCR) in the genus Streptomyces. In this work, the glkA and SCO2127 genes from S. coelicolor were used, either individually or together, to transform three mutants of Streptomyces peucetius var. caesius resistant to CCR. These mutants present decreased levels of Glk, and deficiency in glucose transport. When the mutants were transformed with a plasmid containing the SCO2127 sequence, glucose uptake and Glk activity values were increased to levels similar to or higher than those of the original strain, and each strain regained sensitivity to CCR. This result was surprising considering that the putative SCO2127 amino acid sequence does not seem to encode a glucose permease or a Glk. In agreement with these results, an increase in glkA mRNA levels was observed in a CCR-resistant mutant transformed with SCO2127 compared with those of the original strain and the CCR-resistant mutant itself. As expected, recombinants containing the glkA sequence reverted Glk to normal activity values, but glucose uptake remained deficient. The data suggest that the SCO2127 gene product enhances transcription of both genes, and support the first specific role for this region in Streptomyces species. The physiological consequence of this effect is an increase in the glucose catabolites that may be involved in eliciting CCR in this genus.

Antimetabolites↗
PubMed2003

Association of vitamin D receptor polymorphisms with osteoporosis in mexican postmenopausal women.

It has been reported that Vitamin D receptor polymorphisms are associated with osteoporosis, particularly those demonstrated by the BsmI and FokI restriction enzymes. Herein we report the results of a case-control study performed in postmenopausal Mexican women. We studied 65 osteoporotic women (< or = -2.5 SD bone mineral density [BMD] of young normal females) and 57 controls (over 90% > or = -1.5 SD BMD of young normal females. Restriction enzymes BsmI and FokI were used to identify polymorphisms. Odds ratios and their 95% confidence intervals were calculated, and analysis was performed controlling for age as a covariate. The BsmI genotypes revealed a higher frequency of the bb genotype in cases than in controls, contradicting much of the literature that suggests this genotype protects females against osteoporosis. Regarding the FokI genotypes, we were unable to confirm that the FF genotype has a protective effect against osteoporosis. The inconsistencies found in the literature and the results obtained in the present work suggest to us that other genetic and nongenetic factors are involved in the occurrence of osteoporosis, confounding the results of the possible association of osteoporosis and VDR polymorphisms.

Aged↗