Biomedical subjects

Javier Herrera

Publications and source records attributed to Javier Herrera.

7 recordsLinked to original sources

PubMed2006

[Surgical site infection in general surgery: 5-year analysis and assessment of the National Nosocomial Infection Surveillance (NNIS) index].

INTRODUCTION: The aim of this study was to describe the rate of surgical site infections (SSI), classified according to the NNIS index and its components, as well as to evaluate this scale and assess the importance of several factors that influence the development of an SSI. PATIENTS AND METHOD: All episodes of SSI were prospectively registered over a 5-year period. All patients (infected or not) were given an NNIS index and an NNIS category. Postoperative hospital stay and bacteria cultured from the surgical site were also analyzed. Chi2 test, Student's t-test and multiple logistic regression were used. RESULTS: There were 6,218 patients and 513 SSI (8.25%). The infection rate was 2.27% for clean surgery, 9.17% for clean-contaminated surgery, 11.40% for contaminated surgery, and 19.14% for dirty surgery; 4% for ASA I, 8.23% for ASA II, 13.54% for ASA III, 19.55% for ASA IV, and 33.33% for ASA V; 6.97% for length of procedure = 75th percentile, and 23.01% for > 75th percentile; 3.95% for NNIS 0, 8.17% for NNIS 1, 22.08% for NNIS 2, and 37.23% for NNIS 3. Among the components of the NNIS index, the length of the surgical procedure had the greatest influence on the rate of SSI (OR = 3.43 versus OR = 2.60 for the grade of contamination and OR = 2.20 for ASA index). The infection rates according to the type of intervention were: 30.9% in hepatobiliopancreatic surgery, 24.3% in small bowel surgery, 16.1% in colorectal surgery, 15.4% in gastroduodenal surgery; 8.5% in other soft tissue interventions, 7.7% in exploratory laparotomies, 6.4% in appendicectomies for appendicitis, 5.0% in cholecystectomy, 5.0% in other interventions of the digestive tract, 3.3% in breast surgery, 1.5% in herniorrhaphies, and 0.7% in endocrine surgery. CONCLUSIONS: The NNIS index is a valid instrument for classifying surgical patients according to the risk of developing an SSI. Of the three components, the length of the intervention has the greatest influence on increasing the risk of infection. The NNIS categories also distinguish different levels of risk of infection.

Female↗

PubMed2005

[Association between microsatellite instability and clinico-pathological characteristics in sporadic colon cancer].

BACKGROUND AND OBJECTIVE: Currently, colon cancer is a leading cause of cancer death world-wide. It progresses according to three molecular pathways, named suppressor, mutador and methylator. Microsatellite instability is a hallmark of the lack of reparation, of DNA mismatches and it characterizes a subset of colon tumors (unstable tumors, MSI). MSI-H patients (high degree of microsatellite instability) seem to share clinico-pathological differences with MSS (microsatellite stable) and MSI-L (low degree of microsatellite instability) patients. In this study, associations between high degree of microsatellite instability and pathological (location, mucinous content, differentiation grade, stages T3N0, stages II and III) and clinical features (response to chemotherapy, disease-free survival and overall survival) were evaluated. PATIENTS AND METHOD: 117 patients with sporadic colon cancer were classified into two populations (MSS/MSI-L and MSI-H) by using PCR and electrophoresis of seven microsatellites, according to the National Cancer Institute recommendations. RESULTS: MSI-H tumors tended to be located in the right colon (p = 0.022) and were of mucinous histologic type (p = 0.04). No differences in disease-free survival and overall survival between group of stage II and III patients with MSS/ MSI-L and corresponding ones with MSI-H colon cancer were found (p = 0.54, p = 0.37, respectively). Conversely, MSI-H patients with stage II colon cancer had a favourable prognosis (p = 0.027). Nevertheless, response to 5-fluorouracil (5-FU) and leucovorin was similar in MSS/ MSI-L and MSI-H groups (p = 0.38). CONCLUSIONS: MSI-H patients are characterized by certain pathological features; those MSI-H patients with a stage II seem to have a better prognosis than MSS/ MSI-L patients.

Colonic Neoplasms↗

PubMed2005

Bile duct replacement using an autologous femoral vein graft: an experimental study. Preliminary results.

The repair of common bile duct injuries is a complex procedure with a significant rate of postoperative morbidity and mortality. The aim of this study was to demonstrate the usefulness of the autologous vein graft in replacement of the bile duct. Twelve male Sprague-Dawley rats weighing 350+/-550 g were used in the study and were divided at random into two groups: the control group (60) and the experimental group in which a 3-mm segment of the bile duct was resected and the biliary tract was replaced by a segment of vein aided by stent (G1). Both groups were subdivided into pairs of rats to study at 30, 60, and 120 days. All of the animals underwent radioisotope cholangiography, a repeat laparotomy, and blood tests for further pathologic study. The clinical evaluation and biochemical nuclear medicine and pathologic studies showed no evidence of cholestasis. The histologic study of the graft showed replacement of the endothelium by biliary-appearing epithelium. The use of an autologous vein graft with a supporting stent proves to be a feasible and alternative procedure for bile duct reconstruction. Further experimental studies should be carried out to validate these findings so they can be implemented in clinical cases.

Animals↗

PubMed2004

Flower size variation in Rosmarinus officinalis: individuals, populations and habitats.

BACKGROUND AND AIMS: Flowers are relatively invariant organs within species, but quantitative variation often exists among conspecifics. These variations represent the raw material that natural selection can magnify, eventually resulting in morphological divergence and diversification. This paper investigates floral variability in Rosmarinus officinalis, a Mediterranean shrub. METHODS: Nine populations were selected in three major southern Spanish habitats (coast, lowland and mountains) along an elevation gradient. Flower samples from randomly chosen plants were collected from each population, and a total of 641 flowers from 237 shrubs were weighed while still fresh to the nearest 0.1 mg. Leaves from the same plants were also measured. Variations among habitats, sites and plants were explored with general linear model ANOVA. Leaf-flower covariation was also investigated. KEY RESULTS: Most (58%) mass in flowers was accounted for by the corolla, whose linear dimensions correlated directly with flower mass. Averaged over plants, the mass of a flower varied between 12 mg and 38 mg. Habitat, site (within habitat) and shrub identity had significant effects on mass variance. Flowers from the coast were the smallest (17 mg) and those from the mountains the largest (25 mg on average). A pattern of continuously increasing flower size with elevation emerged which was largely uncoupled from the geographical pattern of leaf size variation. CONCLUSIONS: As regards flower size, a great potential to local differentiation exists in Rosmarinus. Observed divergences accord with a regime of large-bodied pollinator selection in the mountains, but also with resource-cost hypotheses on floral evolution that postulate that reduced corollas are advantageous under prevailingly stressful conditions.

Climate↗

PubMed2004

Phenotypic correlations among plant parts in Iberian Papilionoideae (Fabaceae).

BACKGROUND AND AIMS: Different plant organs may show varying degrees of form diversification or conservatism across phylogenetically related taxa. The present study uses data from a recent systematic study of Iberian Papilionoideae to investigate diversification and covariation in reproductive and vegetative plant parts. The appropriateness of imprecise (but comprehensive) taxonomic quantitative information is tested. METHODS: Organ size covariation and phenotypic correlations were studied among tribes, genera and species. Scale relationships were investigated by Reduced Major Axis regression. Variables used were the maximum dimensions of calyx, corolla, keel petal, fruit, seed, stipule, leaflet and petiole. KEY RESULTS: As regards tribe averages, the length of the corolla and that of calyx correlated positively and significantly. In contrast, pod length was unrelated to corolla size and largely tribe-specific. Within genera, the sizes of calyx, corolla and fruit sometimes covaried linearly (e.g. Lathyrus species) and other times did not (Genista, Astragalus). CONCLUSIONS: Information from taxonomic studies can be useful to establish major phenotypic correlations in plants. Results underscore the implications of tribal ownership in the Papilionoideae and illustrate the extensive morphological diversification of pods relative to flowers in this group.

Fabaceae↗

PubMed2003

Nonlinear distortion generated by semiconductor optical amplifier boosters in analog optical systems.

Closed-form theoretical expressions for the second- and third-order harmonic distortions generated by a semi-conductor optical amplifier (SOA) operating under slight saturation conditions are derived for what is believed to be the first time. The distortion results provided by these expressions agree very well with those obtained by means of simulation and experiments, showing that one should carefully adjust the optical power launched into the SOA to obtain both the good linearity and high dynamic range required by analog optical systems.

Journal Article↗

PubMedDate not supplied

Lymphoepithelial cysts of the pancreas: case report and review of the literature.

The aim of this report was to describe the clinical and pathologic features of lymphoepithelial cysts of the pancreas, establish the differential diagnosis of other pancreatic cysts, and review the literature. A 53-year-old man was incidentally diagnosed with a pancreatic lesion after an abdominal CT scan. This study showed a solid mass in the tail of the pancreas not enhanced by helical CT. Endoscopic ultrasound examination revealed a low-density tissue mass on the surface of the pancreas, less echogenic than the surrounding parenchyma. Distal pancreatectomy and splenectomy were performed with a suspected diagnosis of mucinous cystic tumor. The patient has had an uneventful postoperative period, and the pathologic finding was a lymphoepithelial cyst of the pancreas. Lymphoepithelial cyst of the pancreas is an unusual and benign entity that must be taken into consideration when evaluating a cystic lesion of the pancreas because a different therapeutic approach may be required.

Diagnosis, Differential↗