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Biomedical subjects

F Sánchez

Publications and source records attributed to F Sánchez.

At least 19 recordsLinked to original sources
PubMed2003

Is azithromycin the first-choice macrolide for treatment of community-acquired pneumonia?

Combination treatment with a beta-lactam plus a macrolide may improve the outcome for elderly patients with community-acquired pneumonia (CAP). The prognoses and mortality rates for elderly patients with CAP who receive ceftriaxone combined with a 3-day course of azithromycin or a 10-day course of clarithromycin were compared in an open-label, prospective study. Of 896 assessable patients, 220 received clarithromycin and 383 received azithromycin. There were no significant differences between groups with regard to the severity score defined by the Pneumonia Patient Outcomes Research Team (PORT) study group; the incidence of bacteremia was also not significantly different. However, for patients treated with azithromycin, the length of hospital stay was shorter (mean+/-SD, 7.4+/-5 vs. 9.4+/-7 days; P<.01) and the mortality rate was lower (3.6% vs. 7.2%; P<.05), compared with those treated with clarithromycin. There might be a difference in the outcome for patients with CAP depending on the macrolide used. A shorter treatment course with azithromycin may result in better compliance with therapy.

Adult↗
PubMed2003

Strains of Turnip mosaic potyvirus as defined by the molecular analysis of the coat protein gene of the virus.

Turnip mosaic virus (TuMV) is a member of the potyvirus genus with a wide host range and highly variable in its biological characteristics. Analysis of the CP gene sequences from databases, combined with the experimental analysis of the CP gene of further isolates, using data derived from sequence or restriction analysis, has allowed the genetic classification of 60 TuMV isolates or sequences. Two main genetic clusters MB (mostly Brassica isolates) and MR (mostly Radish isolates) were found, together with several apparently independent lineages. Isolates in the latter could be grouped as Intermediate between Brassica and Radish clusters (IBR) or outside Brassica and Radish clusters (OBR), according to their genetic distance to the main clusters. The genetic diversity of TuMV isolates deposited in the databases was increased with the sequences of the CP gene of seven selected isolates, mainly belonging to IBR or OBR groups. There was a correlation between the MR genetic cluster and JPN 1 serotype.

Brassica napus↗
PubMed2003

C-reactive protein levels in community-acquired pneumonia.

The diagnostic value of C-reactive protein (CRP) admission serum levels as an indicator of the aetiology of community-acquired pneumonia (CAP) was evaluated. A cohort of 1,222 patients with CAP was assessed. CRP levels were analysed in 258 patients with a single aetiological diagnosis. The mean CRP values in patients with pyogenic, atypical, viral and Legionella pneumophila pneumonia were: 16 mg x dL(-1), 13 mg x dL(-1), 14 mg x dL(-1) and 25 mg x dL(-1), respectively. CRP levels were not significantly different among patients outcome research team (PORT) groups (19 mg x dL(-1) in groups I-II, 16 mg x dL(-1) in group III and 16 mg x dL(-1) in groups IV-V). A cut-off point of 25 mg x dL(-1) had a sensibility, specificity, positive predictive value and negative predictive value of 0.6, 0.83, 0.3, and 0.94, respectively. After controlling for age and PORT score, the odds of having a CRP level >25 mg x dL(-1) was 6.9 times higher in patients with L. pneumophila pneumonia than in those with non-L. pneumophila pneumonia. Patients with Legionella pneumophila pneumonia had higher C-reactive protein levels than those with pneumonia of any other aetiology, independently of severity of infection. Being a cheap and readily available test, C-reactive protein may be a useful adjunctive procedure in the diagnosis of community-acquired pneumonia.

Aged↗
PubMed2002

[Clinical and functional analysis of long-term results of uvulopalatopharyngoplasty].

In order to evaluate the clinical and functional effectiveness of uvulopalatopharyngoplasty (UPPP) in chronic roncopathy, we studied the subjective improvement of operated patients and compared to pulsioximetry findings before and after surgery. A follow-up was made on 72 patients entitled of chronic roncopathy--51 with obstructive sleep apnea syndrome (OSAS) and 21 with simple snoring-, for a mean period of time of 41 months. Preoperatory study included on ENT exploration, fibre optic endoscopy, Müller maneuver, pharyngeal CT, value of daytime sleepiness with Epworth's scale, espirometry and pulsioximetry, and the postoperatory study included of pulsioximetry and a health questionnaire over snoring and daytime sleepiness. Snoring improved or disappeared in 13 of 21 patients (61.8%), and daytime sleepiness did it in 26 of 39 (66.6%). Therapeutic failure in snoring was mainly due to an increase in the body mass index. After UPPP in OSAS, only 21 patients (41.1%) showed all positive response criteria (decrease into ODI > or = 50% or in absolute values < 6, CT 90% < 1%, and SaO2 Min > or = 85%). UPPP failed in long term evaluation in the rest of individuals. Patient selection is mandatory to optimize clinical response of UPPP for snoring, without OSAS success depends on body mass index, respiratory disturbances ratios and the eventual presence of another upper airways collapses below velopharyngeal segment.

Adult↗
PubMed2002

[Massive bilateral adrenal hemorrhage after conservative tumor surgery in the isthmus of a horseshoe kidney].

OBJECTIVE: To present a fatal case of massive bilateral suprarrenal haemorrhage (MBSH) after partial nephrectomy. CLINICAL CASE: An 82 year old male treated with oral anticoagulants was diagnosed by means of CT scan and arteriography of having an avascular tumor located at the isthmus of a horseshoe kidney. A tumorectomy with safety surgical margins was performed; It was diagnosed of having a renal adenocarcinoma, which was almost completely necrotic. During the postoperative period, the patient presented abdominal pain, nausea, fever, hypotension and severe respiratory distress. Biochemical studies showed mild hyponatremia and azotemia, accompanied by anemia, leucocytosis and thrombocytosis. An abdominal CT scan demonstrated a MBSH, which produced the patients death soon afterwards. DISCUSSION: Tumoral pathology of horseshoe kidneys presents important topographic and anatomopathologic differences with respect to non-fused kidneys. MBSH is a rare complication of many stress processes especially if an anticoagulant treatment coexists. The treatment has to be initiated as soon as we suspect MBSH, which should be confirmed by hormonal determinations and/or the presence of hyperdense suprarenal lesions at the CT scan.

Adenocarcinoma↗
PubMed2002

[Are we diagnosing people infected with HIV in time?].

OBJECTIVE: To describe the number of AIDS cases who did not know of their HIV infection until they developed AIDS, and the factors relating to this situation. DESIGN: Descriptive study of data of the National AIDS Register.Setting. Spain.Patients. Cases of AIDS in the over-14s diagnosed between 1997 and 1999. RESULTS: Of the 6910 cases of AIDS studied, 35% (n = 2421) knew that they were HIV-positive at the same time as they were diagnosed with AIDS (in the same month or the previous one). The multi-variate analysis showed that this situation occurred less commonly in women (OR = 0.61; 95% CI, 0.53-0.71), in cases diagnosed in prison (OR = 0.19; 95% CI, 0.13-0.27), in cases diagnosed early (OR = 0.49; 95% CI, 0.41-0.60) and among residents in provinces with AIDS rates higher than the Spanish average (OR = 0.88; 95% CI, 0.78-0.99). Ignorance of HIV infection until the AIDS diagnosis was associated to ages of under 25 and over 34, homo/bisexual transmission (OR = 3.20; 95% CI, 2.69-3.80) and heterosexual transmission (OR = 4.88; 95% CI, 4.21-5.65) compared with intravenous drug users, and to the person coming from countries other than Spain, both developed (OR = 2.78; 95% CI, 1.89-4.08) and under-developed (OR = 1.85; 95% CI, 1.26-2.72) countries. CONCLUSIONS: A considerable number of people diagnosed with AIDS were unaware of their HIV infection, especially among people who had never injected drugs. HIV needs to be diagnosed earlier so as to improve prevention and treatments.

Adolescent↗
PubMed2002

[Effectivity versus toxicity of minoxidil as antiproliferative agent for lens epithelial cells. In vitro study].

PURPOSE: To evaluate the inhibitory effect of minoxidil on cultured proliferating lens epithelial cells (LECs) versus cytotoxic effect over corneal endothelial cells in culture, because minimum side effects over anterior chamber structures and particularly on corneal endothelium are required for successful therapy and prevention of posterior capsular opacification (PCO). METHODS: New Zealand Rabbit LECs and corneal endothelium were cultured in DMEM at 35 degrees C in 5% CO2 in multiwells during 7 days. Both types of cells were exposed to minoxidil (1, 2 and 4 mM) for 1 and 24 hours. Control group and balanced salt solution group were included. After seven days multiwells were processed for light microscopy study. Morphometric study of cellular population of LECs and corneal endothelium cells were done using a computed planimetry system. RESULTS: Dose-dependent effect on LECs proliferation was noted and non-confluent colonies of cells were observed on all treated groups. Morphologic changes in normal appearance of corneal endothelial cells after 1 hour of minoxidil treatment was observed and intracellular alterations were confirmed even with the lowest dose exposure. CONCLUSIONS: Although effectiveness of minoxidil suppressing in vitro LECs proliferation could be suggest as a useful therapeutic agent to prevent PCO, however the inhibitory effect of different concentrations on corneal endothelial cells conditioned its possible use on ocular surgery.

Animals↗
PubMed2001

Mediterranean and low-fat diets improve endothelial function in hypercholesterolemic men.

BACKGROUND: The regulatory function of the endothelium is altered in hypercholesterolemia, and the subsequent endothelial dysfunction plays a central role in the development of atherosclerosis. OBJECTIVE: To determine whether endothelial function in hypercholesterolemic patients is affected by replacing a saturated fat-enriched diet with a low-fat, low-saturated fat diet (the U.S. National Cholesterol Education Program stage 1 [NCEP-1] diet) or a diet rich in monounsaturated fat (such as that common in Mediterranean countries). DESIGN: Intervention dietary study with a baseline phase and two randomized crossover dietary periods. SETTING: Hospital Universitario Reina Sofía, Córdoba, Spain. PATIENTS: 22 hypercholesterolemic men. INTERVENTION: Patients followed a diet high in saturated fat, then were assigned in a crossover design to the NCEP-1 diet or a Mediterranean diet. Each dietary period lasted 28 days. MEASUREMENTS: Plasma P-selectin levels, lipid concentrations, and endothelial function. RESULTS: Compared with the saturated fat diet, flow-mediated dilatation increased during the Mediterranean diet but not during the NCEP-1 diet. In addition, levels of plasma cholesterol, low-density lipoprotein cholesterol, apolipoprotein B, and P-selectin decreased during the NCEP-1 and Mediterranean diets. CONCLUSION: In hypercholesterolemic men, diets low in fat (especially saturated fat) and diets rich in monounsaturated fats improve endothelial function.

Adolescent↗
PubMed2001

[Early diagnosis of retinoblastoma: usefulness of searching for RB1 gene mutations].

BACKGROUND: Retinoblastoma, the intraocular malignancy most common in children,occurs in both familial and sporadic (bilateral or unilateral). Hereditary predisposition is caused by a germ-line mutation while non-hereditary is due to two somatic mutations in a retinal cell. This work was carried out in order to analyse genetically, the high number of families with some affected member and to go deep into the molecular mechanisms responsible of this pathology. PATIENTS AND METHOD: 59 families with one or more affected members were analysed. Cytogenetics and with polymorphic markers studies were carried out and a search for mutations was performed in DNA from white cells and from available tumoral tissue. RESULTS: In four of the 5 familial cases, the responsible mutation was established,the same as in 9 of the 13 bilateral sporadic. In the 7% of the unilateral sporadic cases, mutation was found in leucocytary DNA. Lost of heterozygosity as a second mutational event was mainly due to mitotic recombination. CONCLUSIONS: Among the mutations of our series, a higher frequency of punctual mutations,responsible of the first mutational event, was observed at constitutional level. Lost of heterozygosity was the mechanism observed in the majority of the tumours.

DNA Mutational Analysis↗
PubMed2001

Quantitative hepatitis B virus DNA testing for the early prediction of the maintenance of response during lamivudine therapy in patients with chronic hepatitis B.

To determine whether a dramatic decrease in hepatitis B virus (HBV) DNA levels within the first months of lamivudine therapy can predict the emergence of YMDD variants in patients with chronic hepatitis B, quantitative testing was done every 3 months on serum samples from 35 patients who were treated with lamivudine for >1 year. The decline in HBV DNA levels from baseline to month 3 was higher in 22 responders than in 13 nonresponders (mean+/-SD, 4.16+/-1.06 vs. 2.88+/-1.77 log(10) copies; P=.002), whereas no differences were observed in patients with and without YMDD variants at 1 year of therapy. At 3 months, HBV DNA was undetectable in 77% of the responders, whereas, after 1 year, it was undetectable in 23% of nonresponders, 40% of patients with YMDD variants, and 74% of those without variants. Therefore, quantitative HBV DNA testing is very useful in deciding whether to continue therapy, because of the low likelihood of response in patients who remain HBV DNA positive at month 3 of treatment.

Adult↗
PubMed2001

Orthogonal combinatorial mutagenesis: a codon-level combinatorial mutagenesis method useful for low multiplicity and amino acid-scanning protocols.

We describe here a method to generate combinatorial libraries of oligonucleotides mutated at the codon-level, with control of the mutagenesis rate so as to create predictable binomial distributions of mutants. The method allows enrichment of the libraries with single, double or larger multiplicity of amino acid replacements by appropriate choice of the mutagenesis rate, depending on the concentration of synthetic precursors. The method makes use of two sets of deoxynucleoside-phosphoramidites bearing orthogonal protecting groups [4,4'-dimethoxytrityl (DMT) and 9-fluorenylmethoxycarbonyl (Fmoc)] in the 5' hydroxyl. These phosphoramidites are divergently combined during automated synthesis in such a way that wild-type codons are assembled with commercial DMT-deoxynucleoside-methyl-phosphoramidites while mutant codons are assembled with Fmoc-deoxynucleoside-methyl-phosphoramidites in an NNG/C fashion in a single synthesis column. This method is easily automated and suitable for low mutagenesis rates and large windows, such as those required for directed evolution and alanine scanning. Through the assembly of three oligonucleotide libraries at different mutagenesis rates, followed by cloning at the polylinker region of plasmid pUC18 and sequencing of 129 clones, we concluded that the method performs essentially as intended.

Amino Acid Substitution↗
PubMed2001

Apatite nucleation on silica surface: a zeta potential approach.

Zeta potential measurements on pure silica, prepared by the sol-gel method from tetraethoxysilane under acidic conditions, are reported in different suspensions. Water suspensions and suspensions containing calcium or phosphate ions with and without NaCl were tested. zeta potential measurements were carried out as a function of the pH and ion concentration. Also, calcium and phosphate adsorption on silica was determined experimentally. The results of zeta potential and adsorption measurements suggest that both calcium and phosphate ions can be adsorbed on the silica surface; however, calcium adsorption is stronger than phosphate adsorption. When calcium and sodium ions are present in the suspension, calcium adsorption decreases. It seems that certain sites on the silica surface are specific for calcium adsorption.

Apatites↗
PubMed2001

Prevalence of Neisseria meningitidis carriers in the school population of Catalonia, Spain.

The aim of this study was to determine the prevalence of healthy Neisseria meningitidis pharyngeal carriers in a representative sample of the Catalonian school population, as well as its associated factors. The sample was divided into age groups: < or = 5, 6-7 and 13-14 years old. Parents were given a questionnaire to collect information on sociodemographic and epidemiological variables. Oropharyngeal swabs were collected with a cotton-tipped swab in an Amies transport medium and cultured on Thayer Martin plates at 35 degrees C in 5% CO2. The isolates were serogrouped and sero/subtyped. Of the 1406 children studied, 75 (5.34%) meningococcal carriers were detected: 63 B (4.5%), 9 non groupable (0.7%), 2 29E (0.1%) and 1X (0.07%). No serogroup C meningococci were found in this study, probably due to the high A+C vaccination coverage of up to 68.9% in children 6-7 years old. Bivariate analysis identified six statistically significant risk factors for meningococcal carriage: increasing age, recent upper respiratory tract infection, previous antibiotic treatment, number of students in the class, size of the classroom and social class. Multivariate analysis found that only age and previous antibiotic treatment remained statistically significant when the other factors were controlled.

Adolescent↗
PubMed2001

Biochemical characterization of profilin from seeds of Phaseolus vulgaris L.

The isoform composition of the 14.4 kDa profilin polypeptide was analyzed in seeds, leaves, flowers, roots and root-nodules from Phaseolus vulgaris L. Isoforms of pIs approximately 4.4-5 were present in all the tissues analyzed. The biochemical features of the protein present in seed tissue were determined. Seed profilin bound to Phenyl-Sepharose under low salt conditions which suggested a hydrophobic interaction; however, it was not associated with microsomal membranes nor it partitioned as a hydrophobic protein in Triton X-114. Fractions eluting from poly-L-proline or Phenyl-Sepharose columns contained well detectable amounts of profilin but no actin, suggesting that most of the protein was not present as profilactin in the seed. However, seed profilin appeared to be in some kind of complex since several molecular weight species were observed on native gels. In addition, profilin was found preferentially in the embryo axis and light microscopic immunolocalization showed a cytoplasmic distribution in this tissue.

Blotting, Western↗
PubMed2001

Different strategies to recover the activity of monomeric triosephosphate isomerase by directed evolution.

A monomeric version of triosephosphate isomerase from Trypanosoma brucei, MonoTIM, has very low activity, and the same is true for all of the additional monomeric variants so far constructed. Here, we subjected MonoTIM to directed evolution schemes to achieve an activity improvement. The construction of a suitable strain for genetic selection provided an effective way to obtain active catalysts from a diverse population of protein variants. We used this tool to identify active mutants from two different strategies of mutagenesis: random mutagenesis of the whole gene and randomization of loop 2. Both strategies converged in the isolation of mutations Ala43 to Pro and Thr44 to either Ala or Ser, when randomizing the entire gene or to Arg in the case of randomization of loop 2. The kinetic characterization of the two more active mutants showed an increase of 11-fold in k(cat) and a reduction of 4-fold in K(m) for both of them, demonstrating the sensitivity of the selection method. A small difference in growth rate is observed when both mutant genes are compared, which seems to be attributable to a difference in solubility of the expressed proteins.

Amino Acid Sequence↗
PubMed2001

Actin monoubiquitylation is induced in plants in response to pathogens and symbionts.

Most dramatic examples of actin reorganization have been described during host-microbe interactions. Plasticity of actin is, in part, due to posttranslational modifications such as phosphorylation or ubiquitylation. Here, we show for the first time that actins found in root nodules of Phaseolus vulgaris are modified transiently during nodule development by monoubiquitylation. This finding was extended to root nodules of other legumes and to other plants infected with mycorrhiza or plant pathogens such as members of the genera Pseudomonas and Phytophthora. However, neither viral infections nor diverse stressful conditions (heat shock, wounding, or osmotic stress) induced this response. Additionally, this phenomenon was mimicked by the addition of a yeast elicitor or H2O2 to Phaseolus vulgaris suspension culture cells. This modification seems to provide increased stability of the microfilaments to proteolytic degradation and seems to be found in fractions in which the actin cytoskeleton is associated with membranes. All together, these data suggest that actin monoubiquitylation may be considered an effector mechanism of a general plant response against microbes.

Actins↗