PubMed Health⌕ Search

Biomedical subjects

J Iglesias

Publications and source records attributed to J Iglesias.

At least 19 recordsLinked to original sources
PubMed1997

A study on the emotional-processing of visual stimuli through event-related potentials.

The effect of emotional charge of visual stimuli on cerebral activity was investigated through ERPs. This emotional charge is explained through two dimensions: arousal (relaxing-activating) and valence (attractive-repulsive). Stimuli were 12 paintings selected through questionnaires: three activating-attractive pictures (A+ group), three activating-repulsive (A-), three relaxing (R), and three neutral (N). The ERPs were recorded from the 31 subjects at F3, Fz, F4, C3, Cz, C4, P3, Pz and P4. N200 and P300 did not show significant reactions to the emotional charge of the stimuli. N300 showed greater amplitudes in response to activating stimuli: at frontal sites for A+ and at parietal sites for A-.

Adolescent↗
PubMed1997

N300, P300 and the emotional processing of visual stimuli.

Two components of the ERPs elicited by emotional visual stimuli, N300 and P300, were investigated. The emotional charge is explained through two dimensions: arousal (relaxing (R) or activating (A)) and valence (attractive (+) or repulsive (-)). Stimuli were slides of nudes (A+), human remains (A-), landscapes (R), and buildings (neutral (N)). The peculiar structure of the stimuli, along with a distracting task which allowed us to disguise the real aim of the experiment, helped to avoid a sort of 'relevance-for-task effect', mainly related to cognitive processes, which could explain P300 reactions in response to emotional visual stimuli found in several experiments. The ERPs were recorded from 32 subjects at F3, Fz, F4, C3, Cz, C4, P3, Pz and P4. In contrast to previous studies, P300 did not show greater amplitudes in response to emotional stimuli than to N. N300 showed greater amplitudes in response to A+ at parietal sites, the greatest differences being those with respect to A-. No inter-hemispheric differences were found. N300 confirms its usefulness as a variable for studying emotional reactions to visual stimuli.

Adult↗
PubMed1997

Gastric intramucosal pH changes after volume replacement with hydroxyethyl starch or crystalloid in patients undergoing elective abdominal aortic aneurysm repair.

PURPOSE: Gastric intramucosal pH (pHi), a surrogate marker of tissue oxygenation, falls following abdominal aorta aneurysm (AAA) repair. We tested the hypothesis that volume replacement with a hydroxyethyl starch solution would result in better preserved splanchnic oxygenation than would volume replacement with crystalloid solutions. MATERIALS AND METHODS: This was a prospective, randomized, nonblinded study set in a university-affiliated community hospital. Thirty patients undergoing elective AAA repair were studied. Patients were randomly selected to receive intraoperative and postoperative fluid replacement with either hetastarch or crystalloid. According to the study protocol, patients could not receive in excess of 3,000 mL of hetastarch. Tissue oxygenation was assessed indirectly by measuring pHi using a nasogastric tonometer. Hemodynamic, oxygenation, and pHi data were collected preoperatively, preclamp, before unclamping, at the end of the procedure and postoperatively for 24 hours. Coagulation parameters were determined preoperatively and postoperatively for 24 hours. RESULTS: Fifteen patients were randomized to each group. There were 18 male and 12 female patients, whose mean age was 66 +/- 9 years. The intraoperative fluid balance was significantly greater in the crystalloid compared with the hetastarch group (4,194 +/- 1,500 mL v 2,949 +/- 1,123 mL; P = .05, 95% confidence interval [C] 23 to 2,519 mL). There were no significant differences in the amount of intraoperative blood loss or postoperative transfusion requirements between the two groups. The difference between the preoperative pHi and nadir was 0.07 +/- 0.03 in the hetastarch group compared with 0.13 +/- 0.04 in the crystalloid group (P = .001, Cl 0.03 to 0.09). By multivariate analysis the only variable that influenced the fall in pHi was the type of resuscitation fluid (F ratio of 7.63; P = .01). There were no significant differences in hemodynamic- and oxygenation-derived variables or coagulation parameters between the two groups of patients. The length of mechanical ventilation, intensive care unit, and hospital stay was comparable between the two groups of patients. CONCLUSION: In patients undergoing major surgery, volume resuscitation with hydroxyethyl starch solutions may improve microvascular blood flow and tissue oxygenation.

Aged↗
PubMed1997

Regulation of mevalonate 5-pyrophosphate decarboxylase in HeLa cells. Inhibition of enzymatic protein synthesis by serum lipoproteins.

Mevalonate 5-pyrophosphate decarboxylase (EC 4.1.1.33) has been considered as a secondary site of regulation of cholesterogenesis. Because of this, we have studied the regulation of decarboxylase in HeLa cells by serum lipoproteins in the cell culture medium. A first group of experiments was performed with cells grown in Eagle's medium with 10% foetal calf serum. The specific activity of decarboxylase was increased when whole foetal calf serum was replaced with lipoprotein-poor serum. This increase was clearly reduced in the presence of cycloheximide. Addition of serum lipoproteins to a medium containing lipoprotein-poor serum led to a clear decrease in the decarboxylase activity. An identical decrease was observed after the addition of lipoproteins alone or in combination with cycloheximide. These results suggest for the first time that the effect of serum lipoproteins on decarboxylase activity should be a decrease in the rate of enzymatic protein synthesis, and corroborate the important role of reactions other than those catalysed by 3-hydroxy-3-methylglutaryl-CoA reductase in the regulation of cholesterogenesis.

Blood Proteins↗
PubMed1997

Insulin promotes the hydrolysis of a glycosyl phosphatidylinositol in cultured rat astroglial cells.

Glycosyl phosphatidylinositols have been implicated in insulin signaling through their action as precursors of second messenger molecules in peripheral tissues. In the present study, cultured rat astrocytes were used to investigate whether glycosyl phosphatidylinositol might be involved in the mechanism of insulin signal transduction in neural cells. A glycosyl phosphatidylinositol sensitive to hydrolysis by both phosphatidylinositol-specific phospholipase C and glycosyl phosphatidylinositol-specific phospholipase D and to nitrous acid deamination was purified. When astrocytes were exposed to 10 nM insulin, a rapid and significant reduction in the content of glycosyl phosphatidylinositol was observed within 1-2 min. In addition, an inverse concentration-dependent relationship between glycosyl phosphatidylinositol and diacylglycerol levels was found, suggesting a phospholipase C-mediated hydrolysis of glycosyl phosphatidylinositol in response to insulin. The effects of insulin were mediated through its own receptors and not through insulin-like growth factor (IGF)-I and/or IGF-II receptors, as demonstrated by affinity cross-linking studies. Also, the effects of 5 nM IGF-1 or 5 nM IGF-II on glycosyl phosphatidylinositol and diacylglycerol levels were different from those caused by insulin and were not essentially modified by pretreatment of the cells with either platelet-derived growth factor (PDGF) or epidermal growth factor (EGF). When cells were sequentially incubated with PDGF and EGF, a reduction in both glycosyl phosphatidylinositol and diacylglycerol contents was observed; the diacylglycerol but not the glycosyl phosphatidyl content was reversed after incubation with IGF-I, and especially with IGF-II, for 10 min. Despite the remarkable homology among insulin, IGF-I, and IGF-II, our results indicate that in astrocytes these compounds probably use different signal transduction pathways.

Animals↗
PubMed1997

Downstream effects of splanchnic ischemia-reperfusion injury on renal function and eicosanoid release.

This study examines the hypothesis that intestinal ischemia-reperfusion (I/R) injury contributes to renal dysfunction by altered renal eicosanoid release. Anesthetized Sprague-Dawley rats underwent 60 min of sham or superior mesenteric artery (SMA) occlusion with 60 min of reperfusion. The I/R groups received either allopurinol, pentoxifylline, 1-benzylimidazole, or carrier before SMA occlusion. In vivo renal artery blood flow was measured by Transonic flow probes, the kidneys were then perfused in vitro for 30 min, and the effluent was analyzed for eicosanoid release and renal function. Intestinal I/R caused a twofold increase in the ratio of renal release of thromboxane B2 to prostaglandin E2 and to 6-ketoprostaglandin F1alpha compared with the sham level, with a corresponding 25% decrease in renal sodium and inulin clearance and renal blood flow. Pentoxifylline or allopurinol pretreatment restored renal eicosanoid release and renal sodium and inulin clearance to the sham level but did not alter renal blood flow. Pretreatment with 1-benzylimidazole restored renal function, eicosanoid release, and renal blood flow to sham levels. These data suggest that severe intestinal I/R contributes to the downregulation of renal function. The decrease in renal function is due in part to toxic oxygen metabolites, which occur in the milieu of altered renal eicosanoid release, reflecting a decrease in vasodilator and an increase in vasoconstrictor eicosanoids.

Allopurinol↗
PubMed1997

Gemcitabine in the treatment of elderly patients with advanced non-small cell lung cancer.

Gemcitabine is active against non-small cell lung cancer (NSCLC), with single-agent response rates of 20% or more in previously untreated patients. Its mild toxicity profile suggests that it should be well tolerated by older patients. To assess the impact of age on the efficacy and tolerance of gemcitabine, the results of four phase II trials of single-agent gemcitabine for the treatment of NSCLC were analyzed retrospectively. Starting doses for gemcitabine ranged from 800 to 1,250 mg/m2/wk, and in all studies gemcitabine was administered weekly for 3 weeks followed by a 1-week rest period. Response rates, toxicity, and dose delivery were compared for two age groups, less than 65 years (255 patients) or > or = 65 years (105 patients). The pretreatment characteristics for both patient groups were well balanced. Overall response rates were 16% and 24% for the younger and older patients, respectively (P = .072). Median survival and 1-year survival rates were 8.1 months and 27% and 9.1 months and 36%, respectively, for patients aged less than 65 years and > or = 65 years. Hematologic and nonhematologic toxicities were similar for both age groups. The number of cycles associated with dose reductions or dose omissions and the mean number of treatment cycles administered were also similar. In summary, gemcitabine is active and well tolerated in elderly patients with NSCLC, and is a promising new alternative for the treatment of this patient population.

Aged↗
PubMed1996

Non-Hodgkin's lymphoma after liver transplantation: response to chemotherapy.

An increased incidence of lymphoproliferative disorders in immunosuppressed organ transplant recipients has long been recognised. Lymphoproliferative disorders occur in 2% of orthotopic liver transplant patients. Different therapies have been used, but the optimal treatment remains unknown. Relatively little information is available on experience with cytotoxic chemotherapy. Three children who developed Burkitt-like, non-Hodgkin's lymphomas after liver transplantation are described. The disease failed to regress after initial management, which included a reduction in immunosuppression. With cytotoxic chemotherapy all three achieved complete remission, which continued 36+, 35+, and 16+ months after diagnosis. Results suggest that in selected cases chemotherapy can be safe in late-onset lymphomas appearing after solid organ transplantation.

Burkitt Lymphoma↗
PubMed1995

Tumor antigens CA 19.9, CA 125, and CEA in carcinoma of the uterine cervix.

Serum levels of carcinoembryonic antigen (CEA) and cancer antigens CA 125 and CA 19.9 were determined by immunoradiometric assay in 96 patients diagnosed of invasive carcinoma of the uterine cervix and 7 patients of cervical intraepithelial neoplasia. Elevated CEA levels were found in 33%, CA 19.9 in 32%, and CA 125 in 21.5% of invasive carcinoma patients. Specificity for each tumor marker was 98%. Increased CEA and CA 19.9 levels were found in relation to clinical stage. CA 125 and CA 19.9 mean levels were significantly higher in patients with adenocarcinoma compared with squamous cell carcinoma. Detection rate of CA 19.9 in stage III adenocarcinomas was higher than in stage III squamous cell carcinoma (50 vs 21%). Sensitivity of combined antigens was also higher for adenocarcinomas increasing 60% for CA 19.9 and/or CA 125 and to 70% of cases for one of the three tumor antigens. During follow-up of cases with no evidence of disease, antigen levels showed a tendency to decrease, but all cases with progressive disease, recurrence, or metastasis were detected by elevation of one of these three tumor antigens. In conclusion, CEA, CA 125, and CA 19.9 are useful markers for detection of cervical cancer and monitorization of clinical course of disease. CA 19.9 and CA 125 have been shown to be particularly useful in patients with adenocarcinoma.

Adenocarcinoma↗
PubMed1995

Detection of Brucella antibodies in eluted dried blood: a validation study.

In order to develop a rapid method for the diagnosis of human brucellosis, results of the ELISA test performed on dried whole blood spotted on filter paper were compared with those of the same test carried out on the serum of the same 160 subjects. Four patterns of elution were tested, combining incubation at 4 degrees C with different exposure times in an ultrasound bath. The best correlation (r = 0.79) for the IgG test, was obtained by using a 12-h incubation period plus a 20-min ultrasonic exposure; the same incubation period without ultrasound produced the best correlation for the IgM test (r = 0.81).

Antibodies, Bacterial↗
PubMed1995

An ERP study on the specificity of facial expression processing.

Facial expression processing specificity was investigated by means of event-related potentials (ERPs). Stimuli consisted on happiness facial expressions (H) along with three other visual stimuli with different physical and affective characteristics: neutral facial expressions, landscapes and grey slides. The 32 subjects had to rate the stimuli with respect to two affective dimensions: 'valence' and 'arousal'. EEG was recorded at T7, T8, Fz and Cz, and the epoch was of 1000 ms (100 ms prior to stimulus onset). Analyses revealed that the variability of N200 and P200 components, which were not able to detect a differential activity in response to H stimuli, could be explained in terms of physical complexity and relevance of the stimuli. N300 did detect a differentiation between H and the rest of stimuli, sharing some characteristics of previous and later components. With respect to late components, P300 seemed to reflect the trends of 'arousal' ratings and SW results suggest that its amplitude was influenced by the stimulus recognition effort. Not a clear right or left hemisphere advantage in facial expression processing was found. These ERP results suggest that the specificity of facial expression processing is not strictly circumscribed to a particular latency or to a specific neural area, but it resides in a particular combination of discrete processes.

Adult↗
PubMed1995

Alterations in interleukin secretion (IL-2 and IL-4) by CD4 and CD4 CD45RO cells from common variable immunodeficiency (CVI) patients.

The failure of B cells from CVI patients to secrete normal amounts of antibodies has been attributed either to an intrinsic B cell defect or to a lack of cooperation from T cells. In an attempt to improve the definition of the origin of this defect in one of the main cellular compartments, we studied the ability of helper CD4 cells and their CD4 CD45RO subpopulation from CVI patients to secrete interleukins (IL-2 and IL-4) in response to mitogen stimulation. We found that CD4 and CD4 CD45RO cells from some patients secrete abnormal amounts of interleukins (in general low levels of IL-2 and high levels of IL-4) upon stimulation with pokeweed mitogen (PWM). These irregularities may contribute to the defective differentiation of B cells in these patients.

Adolescent↗
PubMed1994

Clinical significance of hepatitis C virus (HCV) infection in liver transplant recipients. Role of serology and HCV RNA detection.

Hepatitis C virus (HCV) infection was studied in 60 liver transplant recipients. Antibodies to HCV were tested by both a second-generation ELISA test and a four-recombinant immunoblot assay (4-RIBA) just before the transplant and every three months thereafter. HCV RNA detection was performed by polymerase chain reaction (PCR) at least three times after the transplant in all the patients. Thirty-nine patients tested negative by ELISA before LT (group A), 14 patients tested positive by both serological tests (group B), and seven tested positive only by ELISA (group C). Posttransplant hepatitis was diagnosed in 11/14 in group B in comparison with 3/39 in group A (P < 0.001) and 1/7 in group C (P < 0.05). HCV RNA was detected in the sera of 14/14 patients in group B but in only 1/7 in group C and 6/39 in group A. Only 2/15 patients developed posttransplant hepatitis in the absence of HCV RNA detection. These data suggest that HCV is the major cause of hepatitis after LT. Patients HCV seropositive by RIBA test before the transplant formed a group of high-risk patients for developing viremia and hepatitis afterwards.

Adult↗
PubMed1994

Laparoscopic Assisted Surgical Staging (LASS) for Endometrial Cancer

We report the first four cases of LASS for endometrial cancer in Mexico. Four patients diagnosed with endometrial adenocarcinoma were selected. These patients underwent peritoneal washing, vaginally assisted laparoscopic hysterectomy, bilateral salpingo-oophorectomy and pelvic biopsies. These biopsies included dissection of common iliac vessel, hypogastric and external vessels, and obturator nerve. An average of 10 nodes were obtained (8-11). In all patients both the nodes and the peritoneal washings were negative. The pathologic surgical staging was: three patients with IBG2 and one patient with IAG2. The patients were discharged on the sixth postoperative day, without complications. The follow-up is of 1 to 7 months and all are alive and without tumor activity. Patients with endometrial cancer often have associated obesity, diabetes and hypertension. For this reason the practice of minimally invasive surgery reduces morbidity. However, a full knowledge of anatomy, oncologic gynecology, and operative laparoscopy is imperative.

Journal Article↗
PubMed1994

Significance of ureteral carcinoma in situ in specimens of cystectomy.

In a retrospective review of 242 cystectomy specimens performed for bladder carcinoma, ureteral carcinoma in situ was found in 14 patients (5.7%), unilateral in 12 and bilateral in 2. Pathology of the bladder specimen was pT4 (6 cases), pT3 (3 cases), pT2 (1 case), pT1 (3 cases), and pT0 (1 case). In the cystectomy specimen and in previous biopsies, they all had grade 3 tumor, and 85% had bladder CIS. Two patients were lost during follow-up. Seven patients (58.4%) died of metastatic disease without evidence of upper tract recurrence (UTR). Their average survival was 15.8 months (range 4-60). Five patients (41.6%) are alive after an average follow-up of 33.6 months (range 18-72 months). In one case an UTR appeared 53 months after cystectomy. In patients with ureteral CIS and long-term survival, a careful follow-up is advisable. The incidence of UTR is increased in this subgroup (8% global and 20% of survivors) but mortality is due to progressive bladder disease.

Carcinoma in Situ↗
PubMed1993

Cholesterol synthesis and esterification in isolated enterocytes: regulation by cholesterol and cholestyramine feeding.

The purpose of the present study was to investigate the physiological control of the main regulatory enzymes of cholesterol metabolism in isolated enterocytes obtained from chick duodenum, jejunum and ileum. Cholesterol feeding resulted in an inhibition of 3-hydroxy-3-methyl-glutaryl-CoA reductase and mevalonate 5-pyrophosphate decarboxylase, while cholestyramine feeding increased reductase activity in all the regions studied and decarboxylase activity only in duodenum. Cholesterol feeding markedly increased acyl-CoA:cholesterol acyltransferase, but the effects of cholestyramine were less clear. The effects on transferase activity cannot be due to differences in the availability of acyl-CoA as exogenous substrate as no significant differences were found in acyl-CoA hydrolase activity after any of the dietary treatments. The effects of cholesterol feeding were related to changes in the cholesterol content of epithelial cells, whereas in the case of cholestyramine this relationship was less apparent.

Animals↗