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Biomedical subjects

I García

Publications and source records attributed to I García.

At least 37 records · Page 2Linked to original sources
PubMed2004

Significance of cytosolic hyaluronan levels in gastric cancer.

BACKGROUND: Hyaluronan a high-molecular weight glycosaminoglycan, is considered to be involved in the growth and progression of malignant tumours. The objective of this work was to evaluate the cytosolic hyaluronan content in gastric cancer cells, its possible relationship with clinicopathological tumour parameters and its potential prognostic significance. METHODS: Cytosolic hyaluronan levels were examined utilizing immunoenzymatic techniques in 129 patients with gastric cancer. The mean follow-up period for these patients was 28 months. RESULTS: Cytosolic hyaluronan levels ranged widely in tumours as well as in adjacent mucosal samples (median (range) 2822 (50-24,523) versus 3650 (507-20,782) ng/mg protein). Statistical analysis showed that tumour hyaluronan levels correlated significantly with patient's sex and the presence of lymphatic invasion. In addition, high tumour hyaluronan levels were significantly associated with shorter overall survival period (p<0.05). CONCLUSIONS: Our results suggest that high tumoral cytosolic hyaluronan levels are associated with lesions of unfavorable outcome in gastric cancer patients. Thus, hyaluronan may provide additional prognostic information to that given by other biochemical markers currently used in gastric cancer.

Adenocarcinoma↗
PubMed2004

Soil pollution by a pyrite mine spill in Spain: evolution in time.

Soil pollution was studied after the spill of the Aznalcóllar pyrite mine between 1998 and 2001, analyzing As, Zn, Cd, Cu and Pb both in total concentrations as well as in soluble and bioavailable forms. The main remediation measures were: clean-up of the tailings and polluted soils, plus application of amendment materials (liming). The results indicate that, after three years, 50-70% of the acidic soils and 25-30% of the basic soils are still highly polluted in total arsenic. The limit of 0.04 mg kg(-1) for water-soluble arsenic is exceeded in 15-20% of all soils. The EDTA-extractable arsenic (bioavailable) exceeds the limit of 2 mg kg(-1) only in the acidic sectors. After clean-up, the homogenization of the upper 20-25 cm of the soils appears to be the most recommended measure in the reduction of pollution.

Biological Availability↗
PubMed2003

Detection of the plasmid-mediated quinolone resistance determinant qnr among clinical isolates of Klebsiella pneumoniae producing AmpC-type beta-lactamase.

OBJECTIVES: Plasmid pMG252 contains the qnr locus, which is responsible for low-level resistance to quinolones by protecting the DNA gyrase. pMG252 also encodes the AmpC-type beta-lactamase (pACBL), FOX-5. The aim of this study was to determine the prevalence of qnr in strains from different geographical locations in America and Europe. METHODS: Four hundred and twenty-five (159 Klebsiella pneumoniae and 266 Escherichia coli) clinical isolates were studied. The detection of qnr was by PCR using specific primers for an internal fragment of 543 bp. RESULTS: qnr was detected in three cefoxitin-resistant K. pneumoniae strains, which also produced a pACBL. None of the E. coli isolates tested contained qnr. The three qnr-positive K. pneumoniae came from the USA, and all transferred a conjugative plasmid coding for cefoxitin resistance to E. coli J53. qnr was also transferred by the same plasmid in two out of the three strains. The sequences of amplified qnr fragments from the three strains were identical to the qnr sequence from pMG252. CONCLUSIONS: The qnr determinant is uncommon among clinical isolates of K. pneumoniae and E. coli, but its identification in three pACBL+ K. pneumoniae from the USA indicates the emergence of this quinolone resistance mechanism.

Bacterial Proteins↗
PubMed2003

Accumulation and activity of cethromycin (ABT-773) within human polymorphonuclear leucocytes.

OBJECTIVES: To evaluate the penetration of ketolide cethromycin (ABT-773) into human polymorphonuclear leucocytes (PMNs) and its intracellular activity. METHODS: The uptake of radiolabelled cethromycin by PMNs was determined by a velocity gradient centrifugation technique. The activity of cethromycin against intracellular Staphylococcus aureus ATCC 25923 in PMNs was also evaluated. RESULTS: The cellular to extracellular concentration (C/E) ratio for cethromycin was >200 at an extracellular concentration of 2 mg/L. The uptake of cethromycin into PMNs was rapid and saturable. Cethromycin was slowly released from the loaded PMNs (cell associated drug>50% after 2 h of incubation). Intracellular penetration was significantly affected by the environmental temperature (C/E ratio at 4 degrees C and 37 degrees C: 13 +/- 6 and 226 +/- 31, respectively; P < 0.05), by cell viability (C/E ratio for dead and viable cells: 100 +/- 38 and 226 +/- 31, respectively; P < 0.05), by pH (C/E ratio was significantly increased at basic pH) and by the metabolic inhibitors 2,4-dinitrophenol and carbonyl cyanide m-chlorophenylhydrazone. The intracellular accumulation of cethromycin also decreased significantly when cells were activated with phorbol myristate acetate or opsonized zymosan. These data indicate that a potentially active mechanism could be involved in the uptake of cethromycin by PMNs. At high extracellular concentrations of 5 and 10 mg/L, cethromycin showed significant intracellular activity against S. aureus. CONCLUSIONS: Cethromycin achieves high intracellular concentrations within human PMNs, remaining active intracellularly.

2,4-Dinitrophenol↗
PubMed2003

Effect of proinflammatory cytokines (IL-6, TNF-alpha, IL-1beta) on hemodynamic performance during orthotopic liver transplantation.

BACKGROUND: Proinflammatory cytokines (IL-6, IL-1beta, TNF-alpha) released during liver transplantation may affect hemodynamic stability. The aim of the present study was to analyze the association between IL-6, TNF-alpha, and IL-1beta and systemic vascular resistance during the phases of liver transplantation. MATERIAL AND METHODS: The proinflammatory cytokines IL-6, IL-1beta, and TNF-alpha were analyzed in the blood of 20 consecutive patients who underwent transplantation. Blood samples were drawn from the pulmonary artery at serial times during surgery. Hemodynamic parameters were determined using a cardiac output monitor. Correlations between parameters were analyzed using the Spearman's rho and Kendall's tau-b methods. RESULTS: Both in the vena cava and the pulmonary artery, significant association was observed between basal values of IL-6 during hepatectomy and systemic vascular resistance during the phases of liver transplantation: hepatectomy phase (r=.76, P=.02), anhepatic phase (r=.78, P=.03) and reperfusion phase (r=.87, P=.005). CONCLUSIONS: Basal values of IL-6 may be considered a prognostic factor for hemodynamic performance during the phases of liver transplantation.

Biomarkers↗
PubMed2003

Changes in the incidence and severity of recurrent hepatitis C after liver transplantation over 1990-1999.

BACKGROUND/AIM: Changes in immunosuppression and other factors may have changed the severity of recurrent hepatitis C during recent years. This study sought to establish the changes in incidence and severity of recurrent hepatitis C, and its association with the changes in acute rejection and induction immunosuppressive therapy between 1990 and 1999. PATIENTS AND METHODS: Among 213 liver transplants in HCV-infected recipients, 129 grafts were selected for this study: all grafts with severe recurrent hepatitis C (fibrosis 3-4 in Scheuer's score or fibrosing cholestatic hepatitis), and those grafts without severe recurrence with at least 2 years of follow up. Grafts were divided in 5 groups depending on the year of transplantation to compare recurrent hepatitis C-related variables, AR incidence and induction immunosuppression. RESULTS: Hepatitis-free survival decreased in recent years (p=0.015). The incidence of fibrosing cholestatic hepatitis was higher among 1996-1997 and the 1998-1999 periods (p=0.019). Survival free of severe hepatitis at 1 year follow up was 95% in 1990-1991 and 80% in 1998-1999; however, in the long-term the survival was similar between groups (p=0.933). HCV-related graft survival at 5 years was 93.5% in the 1990-95 period and 82.5% in 1996-99 (p=0.068). Neither AR nor any regimen of induction immunosuppression was associated with changes in the occurrence of recurrent hepatitis C related survival. CONCLUSIONS: Severity of recurrent hepatitis C and HCV-related graft loss after liver transplantation were higher in the second half of the 1990s; however, there was no association with AR or induction immunosuppression.

Disease-Free Survival↗
PubMed2003

Preliminary experience with living donor liver transplantation in adults and children.

INTRODUCTION: Living donor liver transplantation (LDLT) is becoming a widespread technique with good results. Its use may sharply decrease waiting list mortality. However, donor safety is of primary concern. The aim of this work was the preliminary evaluation of the LDLT program initiated in our institution in 1995. PATIENTS AND METHODS: Among 875 liver transplants (LT) performed from 1986 12 are LDLT in nine adults (50.0+/-10.0 years) and three children (1.9+/-1.1 years). All donors were relatives: son/daughter (six), brother (three), and father/mother (three). RESULTS: Donor right lobe graft weight was 758.3+/-137.4 g; left liver 525.3+/-97.1 g; and left lobe 293.3+/-30.5 g, with a graft weight/recipient weight ratio of 0.91+/-0.21 (0.64-1.36) in adults. Complications in five donors (42%) included biliary fistula in the first three cases, two pleural effusions and one intra-abdominal collection. Mean hospital stay was 16.9+/-15.2 days (median 12). Recipient indications for adults were: four HCV cirrhosis (+ alcoholic in one), one HBV cirrhosis, one cryptogenic, one alcoholic, one PBC, and one retransplant due to cholangiopathy. In children, the etiologies were two biliary atresia and one liver fibrosis. The first case was the only mortality (8.3%). Two patients were retransplanted (16.6%) due to arterial thrombosis (AT) and graft dysfunction. Actuarial survival at 1 year was 91.7%+/-8.0% for patients and 83.3%+/-10.8% for grafts. Complications in the recipients included AT (two), Acinetobacter sepsis, jaundice and upper digestive hemorrhage (due to a "small-for-size" graft), biliary fistula after T-tube removal, volvulus around the T tube, and intra-abdominal collection. CONCLUSIONS: Our experience suggests that good results can be achieved with LDLT. Standardization of the technique will allow refinement of the operation and decrease waiting list mortality. However, donor safety remains a fearful threat.

Adult↗
PubMed2003

Liver transplantation and transjugular intrahepatic portosystemic shunt.

OBJECTIVE: Describe the results of liver transplantation after installing Transjugular Intrahepatic Portosystemic Shunt (TIPS) and compare them with those of a control group in a comparative, longitudinal, retrospective study. MATERIALS AND METHODS: Between April 1986 and October 2002, we performed 875 liver transplantations. Between January 1996 and October 2002, 26 transplantations were performed on TIPS carriers. This group was compared with a control cohort of 50 randomly selected patients who underwent transplantation in this period (non-TIPS carriers). Both groups were homogeneous with no significant differences between age, sex United Network for Organ Sharing (UNOS) score, Child stage, or etiology. RESULTS: Actuarial survival rates at 1 and 3 years: TIPS group 96.15% and 89.29% versus control cohort 87.8% and 81%, respectively. In 73.9%, the TIPS was clearly effective; in 88.9%, a postoperative Doppler revealed normal flow. There were no statistically significant differences compared with time on the waiting list for transplant, duration of the operation, ischemia times, intraoperative consumption of hemoderivates, vascular or nonvascular postoperative complications, duration of stay in the intensive care unit, hospital stay, or retransplantation rate. CONCLUSIONS: In our experience, TIPS insertion does not affect either the intraoperative or postoperative evolution and is not associated with an increased time on the liver transplant waiting list.

Actuarial Analysis↗
PubMed2003

Clinical significance of the epidermal growth factor receptor and HER2 receptor in resectable gastric cancer.

BACKGROUND: Epidermal growth factor receptor (EGFR or HER1) and its homolog c-erbB-2 (HER2) are membrane receptors. Both EGFR and HER2 genes are overexpressed in a variety of solid human cancers and are related to poor prognosis of the patients. The objective of this work was to evaluate the EGFR and HER2 contents in resectable gastric cancer, their possible relationship with clinicopathologic parameters of tumors, and their prognostic significance. METHODS: This was a prospective analysis of 63 patients with resectable gastric carcinomas, with a mean follow-up period of 40.7 months. Membranous EGFR levels were examined by radioligand binding assays, and cytosolic HER2 levels were examined by means of an immunoenzymatic assay. RESULTS: There was a wide variability of EGFR (1-1,239 fmol/mg of protein) and HER2 (7-20,863 NHU/mg of protein) levels in tumors. There was no significant correlation between these levels and patient or tumor characteristics. However, high levels of EGFR and HER2 were significantly associated with a shorter overall survival period (P =.03 and P =.02, respectively). CONCLUSIONS: There is a wide variability in membranous EGFR levels and in cytosolic HER2 levels in gastric cancer, which seems to be related to the biological heterogeneity of these tumors. In addition, high tumor EGFR and HER2 levels were associated with an unfavorable outcome in patients with resectable gastric cancer.

Adenocarcinoma↗
PubMed2003

Results of an upper endoscopy protocol in liver transplant candidates.

OBJECTIVE: our aims is to understand endoscopic findings from a preoperative systematic study of patients with hepatic cirrhosis who were candidates for transplantation and their impact on a protocol for primary and secondary prophylaxis of variceal haemorrhage. PATIENTS AND METHODS: this study involves a retrospective evaluation of upper digestive tract lesions detected before inclusion and a prospective evaluation of new episodes of variceal haemorrhage, associated mortality rates, and factors that are likely to be involved in the development of this condition. Primary prophylaxis with beta-blockers was considered indicated in cases of varices of grande II or greater or with signs associated with increased risk. Secondary prophylaxis was essentially always associated with medical and endoscopic treatment. RESULTS: of 134 patients, there were 9 deaths, with a median time on the waiting list of 3 months. Of all patients, 33.6% presented with high risk oesophageal varices, 11.2 % with gastric varices, 42.6% with portal hypertensive gastropathy, and 26.9% with peptic lesions. Primary prophylaxis was indicated in 33 of 90 patients, and was initiated in almost half of the cases as a results of the study. Optimum fulfiment of the pre-established objectives was 75.3%. The incidence of new haemorrhagic events due to varices was 10.4% and accounted for almost half of the deaths during the monitoring period. The only statistically significant predictive factors were the presence of gastrict varices and previous history. CONCLUSION: upper endoscopy should play a role in the preoperative examination of liver transplant candidates due to the significant impact it has on subsequent management.

Esophageal and Gastric Varices↗
PubMed2002

Microwave-assisted extraction and mild saponification for determination of organochlorine pesticides in oyster samples.

A sample-preparation procedure (extraction and saponification) using microwave energy is proposed for determination of organochlorine pesticides in oyster samples. A Plackett-Burman factorial design has been used to optimize the microwave-assisted extraction and mild saponification on a freeze dried sample spiked with a mixture of aldrin, endrin, dieldrin, heptachlor, heptachorepoxide, isodrin, transnonachlor, p, p'-DDE, and p, p'-DDD. Six variables: solvent volume, extraction time, extraction temperature, amount of acetone (%) in the extractant solvent, amount of sample, and volume of NaOH solution were considered in the optimization process. The results show that the amount of sample is statistically significant for dieldrin, aldrin, p, p'-DDE, heptachlor, and transnonachlor and solvent volume for dieldrin, aldrin, and p, p'-DDE. The volume of NaOH solution is statistically significant for aldrin and p, p'-DDE only. Extraction temperature and extraction time seem to be the main factors determining the efficiency of extraction process for isodrin and p, p'-DDE, respectively. The optimized procedure was compared with conventional Soxhlet extraction.

Animals↗
PubMed2002

Evaluation of a "no-cost" Internet technology-based system for teleradiology and co-operative work.

The aim of this study was to assess the suitability of a no-cost system based on standard Internet technology components for teleradiology. The system was composed of free software (communication, DICOM viewer, compression) and standard off-the-shelf hardware components. For different image (CR, CT, MR) and network types (LAN and ISDN) the File Transfer, Audio and Video Conference, and Co-operative Work properties were examined and compared with the literature referring to standard complete packages and dedicated teleradiology systems. The main advantages of the no-cost system are: price; ease of use; independence from specific hardware; and potential connection to any possible partner. The performance of the File Transfer and the Audio and Video Conference was comparable to the other system groups with slight disadvantages in the usability. For Co-operative Work the employed "application sharing" technology does not meet the clinical requirements, which applies identically to the standard complete packages. Here the specialized systems prove superior, although they are proprietary. With minimal restraints the evaluated no-cost solution can be used for File Transfer and Conference scenarios. The usage for Co-operative Work with ISDN is not recommended, unless for the purpose of gaining experience or when dealing with small amounts of cases or images.

Computer Systems↗