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Biomedical subjects

M Lopez

Publications and source records attributed to M Lopez.

At least 19 recordsLinked to original sources
PubMed2007

Edelfosine protects precultured heart fragments against the invasion of malignant cells through altered sialylation.

1-O-octadecyl-2-O-methylglycero-3-phosphocholine (ET-18-OMe)-treated precultured heart fragments (PHF) are resistant to the invasion of malignant cells. Previous studies have demonstrated that this effect is due to the alterations of the N-linked glycoproteins in PHF after 48-h ET-18-OMe treatment. Moreover, the observed effect was still present seven days after ET-18-OMe was omitted. The present study reveals that approximately 13.4% of the administered ET-18-OMe was taken up by PHF and about 75% of the initial uptake was still present after ET-18-OMe was removed. In addition, we found significant changes in the sialic acid content and sialyltransferase activities in both conditions. Overall, these results clearly demonstrate that the uptake and retention of ET-18-OMe are responsible for the resistance to the invasion of malignant cells due to the altered sialylation of the cell surface glycoproteins in PHF.

Animals↗
PubMed2006

Correlated break at PARK2/FRA6E and loss of AF-6/Afadin protein expression are associated with poor outcome in breast cancer.

Common fragile sites (CFSs) are regions of chromosomal break that may play a role in oncogenesis. The most frequent alteration occurs at FRA3B, within the FHIT gene, at chromosomal region 3p14. We studied a series of breast carcinomas for break of a CFS at 6q26, FRA6E, and its associated gene PARK2, using fluorescence in situ hybridization on tissue microarrays (TMA). We found break of PARK2 in 6% of cases. We studied the PARK2-encoded protein Parkin by using immunohistochemistry on the same TMA. Loss of Parkin was found in 13% of samples but was not correlated with PARK2 break. PARK2 break but not Parkin expression was correlated with prognosis. Alteration of PARK2/FRA6E may cause haplo-insufficiency of one or several telomeric potential tumor suppressor genes (TSG). The AF-6/MLLT4 gene, telomeric of PARK2, encodes the Afadin scaffold protein, which is essential for epithelial integrity. Loss of Afadin was found in 14.5% of cases, and 36% of these cases showed PARK2 break. Loss of Afadin had prognostic impact, suggesting that AF-6 may be a TSG. Loss of Afadin was correlated with loss of FHIT expression, suggesting fragility of FRA6E and FRA3B in a certain proportion of breast tumors.

Acid Anhydride Hydrolases↗
PubMed2006

Liver-specific deletion of insulin receptor substrate 2 does not impair hepatic glucose and lipid metabolism in mice.

AIMS/HYPOTHESIS: Hepatic insulin resistance is thought to be a critical component in the pathogenesis of type 2 diabetes but the role of intrinsic insulin signalling pathways in the regulation of hepatic metabolism remains controversial. Global gene targeting in mice and in vitro studies have suggested that IRS2 mediates the physiological effects of insulin in the liver. Reduced hepatic production of IRS2 is found in many cases of insulin resistance. To investigate the role of IRS2 in regulating liver function in vivo, we generated mice that specifically lack Irs2 in the liver (LivIrs2KO). MATERIALS AND METHODS: Hepatic insulin signalling events were examined in LivIrs2KO mice by western blotting. Glucose homeostasis and insulin sensitivity were assessed by glucose tolerance tests and hyperinsulinaemic-euglycaemic clamp studies. The effects of high-fat feeding upon glucose homeostasis were also determined. Liver function tests were performed and expression of key metabolic genes in the liver was determined by RT-PCR. RESULTS: Proximal insulin signalling events and forkhead box O1 and A2 function were normal in the liver of LivIrs2KO mice, which displayed minimal abnormalities in glucose and lipid homeostasis, hepatic gene expression and liver function. In addition, hepatic lipid homeostasis and the metabolic response to a high-fat diet did not differ between LivIrs2KO and control mice. CONCLUSIONS/INTERPRETATION: Our findings suggest that liver IRS2 signalling, surprisingly, is not required for the long-term maintenance of glucose and lipid homeostasis, and that extra-hepatic IRS2-dependent mechanisms are involved in the regulation of these processes.

Animal Feed↗
PubMed2006

FOLFIRI with or without celecoxib in advanced colorectal cancer: a randomized phase II study of the Gruppo Oncologico dell'Italia Meridionale (GOIM).

BACKGROUND: The aim of the study was to verify the efficacy and safety of the addition of celecoxib to FOLFIRI combination therapy in patients affected by advanced colorectal cancer. PATIENTS AND METHODS: Eighty-one chemotherapy-naïve patients entered in this randomized phase II trial of the GOIM (protocol no. 2301). Patients were randomized to receive FOLFIRI regimen (arm A): irinotecan 180 mg/m(2) on day 1 with LV5FU2 regimen (LV at 100 mg/m(2) administered as a 2-h infusion before FU at 400 mg/m(2) as an intravenous bolus injection, and FU at 600 mg/m(2) as a 22-h infusion immediately after 5-FU bolus injection on day 1 and 2); or FOLFIRI plus celecoxib 400 mg twice daily for 14 days (arm B). Both treatments were repeated every 2 weeks. RESULTS: Seventy-seven patients (38 in arm A and 39 in arm B) were evaluable for response. The overall response rate was 41% in arm A (95% CI 27% to 57%) and 35% in arm B (95% CI 20% to 50%). When only assessable patients were analyzed, overall response rate was 45% in arm A (95% CI 29% to 61%) and 36% in arm B (95% CI 21% to 51%). Median time to progression, median duration of response and survival were, respectively, 8 months, 9 months and 16 months in arm A, and 7 months, 9 months and 19 months in arm B. All patients were evaluable for toxicity, which was globally mild in both arms; grade 3-4 toxicity was uncommon, and gastrointestinal disturbances were the most common. CONCLUSIONS: FOLFIRI regimen is effective and well-tolerated as a first-line treatment in patients with advanced colorectal cancer. The addition of celecoxib to FOLFIRI regimen does not improve results.

Adult↗
PubMed2006

High activity of salvage treatment with biweekly paclitaxel-gemcitabine combination in heavily pretreated breast cancer patients.

The treatment of refractory metastatic breast cancer is primarily palliative, without a significant impact on overall survival. Among the innovative combinations in this unfavourable setting, paclitaxel and gemcitabine showed a possible synergistic action and an encouraging activity in some clinical trials. This phase II study was carried out to evaluate paclitaxel-gemcitabine combination in very heavily pretreated advanced breast cancer on a bi-weekly schedule.Thirty-nine women with advanced breast cancer were treated with paclitaxel 150 mg/m2 as 3 hrs infusion, and gemcitabine 1,500 mg/m2 as 30 mins infusion, both drugs administered on days 1, 15, with cycles repeated every 28 days. All but two patients received granulocyte colony stimulating factor (G-CSF) on days 7 to 9 and 20 to 22 of every cycle. More than two third (71%) of the patients had previously received two or more chemotherapy regimens for advanced disease, including almost all active agents in this disease. Objective responses were observed in 18 out of 34 evaluable patients (53%; 95% CI, 36% to 70%). Disease remained stable in 7 patients (21%). Responses by sites were 67% in soft tissue and in bone, and 48% in visceral disease. Median time to progression and overall survival were 9 and 20 months, respectively. Treatment was well tolerated, with G3-4 neutropenia in 8%, and G 1-2 thrombocytopenia in 13% of the patients; non-hematological toxicities were mild, with G3 hepatotoxicity in 5% of the patients, and G3 peripheral neurotoxicity in 10% of the patients. Biweekly paclitaxel/gemcitabine combination with G-CSF support appears to be very active as salvage therapy in heavily pretreated breast cancer patients, with a very favourable safety profile.

Adult↗
PubMed2005

Modulation of 5-fluorouracil as adjuvant systemic chemotherapy in colorectal cancer: the IGCS-COL multicentre, randomised, phase III study.

The aims of this multicentre, randomised phase III trial were to evaluate: (1) the role of levamisol (LEV); and (2) the role of folinic acid (FA), added to 5-fluorouracil (5FU) in the adjuvant treatment of colorectal cancer. Patients with histologically proven, radically resected stage II or III colon or rectal cancer were eligible. The study had a 2x2 factorial design with four treatment arms: (a) 5FU alone, (b) 5FU+LEV, (c) 5FU+FA, (d) 5FU+LEV+FA, and two planned comparisons, testing the role of LEV and of FA, respectively. From March 1991, to September 1998, 1327 patients were randomised. None of the two comparisons resulted in a significant disease-free (DFS) or overall (OAS) survival advantage. The hazard ratio (HR) of relapse was 0.89 (95% confidence intervals (CI): 0.73-1.09) for patients receiving FA and 0.99 (95% CI 0.80-1.21) for those receiving LEV; corresponding HRs of death were 1.02 (95% CI: 0.80-1.30) and 0.94 (95% CI 0.73-1.20). Nonhaematological toxicity (all grade vomiting, diarrhoea, mucositis, congiuntivitis, skin, fever and fatigue) was significantly worse with FA, while all other toxicities were similar. In the present trial, there was no evidence that the addition of FA or LEV significantly prolongs DFS and OAS of radically resected colorectal cancer patients.

Adult↗
PubMed2005

Epirubicin, cisplatin and docetaxel combination therapy for metastatic gastric cancer.

BACKGROUND: Docetaxel is a new agent with activity in metastatic gastric cancer. This phase II study was designed to evaluate the activity and safety of an epirubicin, cisplatin and docetaxel combination in patients with this disease. PATIENTS AND METHODS: Forty-six patients with gastric adenocarcinoma with measurable distant metastasis were eligible for the study. Patients received epirubicin 50 mg/m(2) and docetaxel 60 mg/m(2), on day 1, and cisplatin 60 mg/m(2) on day 2. Granulocyte colony-stimulating factor 300 mug/day subcutaneously was given on days 5 and 6. Cycles were repeated every 3 weeks for a maximum of eight courses. RESULTS: All patients were evaluable for response and toxicity. Two complete and 21 partial responses were observed, with an overall response rate of 50% [95% confidence interval (CI) 36% to 64%]. Stable disease was observed in 13 patients (28%) and progressive disease in 10 patients (22%). The median time to progression was 6 months (95% CI 5-7) and the median overall survival was 11.2 months (95% CI 8.5-13.9). Grade 3/4 neutropenia, thrombocytopenia and anemia occurred in 46%, 7% and 13% of patients, respectively. There were five episodes of febrile neutropenia in four patients. Other grade 3 toxicities included mucositis in three patients (6.5%), vomiting in four patients (8.7%) and diarrhea in one patient (2%). There were no cardiac toxicity, severe neurotoxicity or treatment-related deaths. CONCLUSIONS: The epirubicin, cisplatin and docetaxel combination is an active and well tolerated novel chemotherapy regimen for treating metastatic gastric cancer and deserves further evaluation in randomized studies.

Adenocarcinoma↗
PubMed2005

Benefits of the thoracoscopic approach for short- or long-gap esophageal atresia.

OBJECTIVE: To evaluate the feasibility and results of thoracoscopy in various types of esophageal atresia (EA). MATERIALS AND METHODS: From April 2001 to August 2002, 5 patients with EA were treated by thoracoscopy. Their mean gestational age was 38 weeks and mean birth weight was 2700 g. Two patients had short-gap atresia with tracheo-esophageal fistula (type III according to Ladd's classification). Three had long-gap atresia: 2 with low fistula to the carina (type IV) and 1 without fistula (type I). Patients were placed in a prone position with the right side elevated at 80 degrees . Four intrapleural ports were necessary. The fistula when present was dissected and sutured with intrathoracic knots and esophageal anastomosis performed in the same manner. RESULTS: Positive airway pressure increased in all patients after insufflation but was kept in a safe range to prevent lung injury. An esophageal anastomosis was performed in 3 cases (2 short gaps and 1 long gap). Oral feeding started on day 6, and their mean length of hospital stay was 14 days. For one child with type IV EA, the anastomosis was impossible because of a long gap confirmed by an immediate thoracotomy. The ends were just approximated. A "spontaneous" fistula developed, and normal feeding was possible 2.5 months later. For the child with type I EA, the pouches could be only approximated at 2 months of age. A spontaneous fistula developed with a stenosis. A redo anastomosis by open surgery allowed for normal feeding. CONCLUSION: The thoracoscopic repair of an esophageal atresia is a reasonable choice for experienced surgeons treating patients, including those with long gaps.

Adult↗
PubMed2005

FOLFIRI regimen in advanced colorectal cancer: the experience of the Gruppo Oncologico dell'Italia Meridionale (GOIM).

PURPOSE: To verify the experience of the GOIM in the treatment of advanced colorectal cancer patients with the FOLFIRI combination therapy. PATIENTS AND METHODS: Patients entered in three consecutive trials of the GOIM (protocols no. 9706, 9901, and 2301) were reported in this analysis. A total of 287 chemotherapy-naive patients were treated with FOLFIRI regimen: Irinotecan 180 mg/m(2) on day 1 with LV5FU2 regimen (LV at 100 mg/m(2) administered as a 2-hour infusion before FU at 400 mg/m(2) as an intravenous bolus injection, and FU at 600 mg/m(2) as a 22-hour infusion immediately after 5FU bolus injection on day 1 and 2); the treatment was repeated every 2 weeks. RESULTS: 287 patients entered in these three trials, and 264 (92%) were evaluable for response. The overall response rate was 34.5% (95% confidence interval [CI]: 29% to 40%). When only assessable patients were analyzed, overall response rate was 37% (95% CI: 31% to 43%). Median time to progression, median duration of response and survival were 7 months, 10.5 months and 14 months, respectively. All but three patients were evaluable for toxicity which was globally mild; grade 3-4 toxicity was uncommon, and gastrointestinal disturbances were the most common. CONCLUSIONS: FOLFIRI regimen is effective and well-tolerated as first-line treatment in patients with advanced colorectal cancer. Further studies needed to evaluate the improvement in results with the addition of new drugs to this combination therapy.

Adult↗
PubMed2005

Chromogenic substrates as fundamental tool to design new thrombin inhibitors. Determination of inhibition equilibrium constants.

The structure-activity relationship of dipetalogastin II, the strongest thrombin inhibitor isolated and cloned from the bug Dipetalogaster maximus, was examined by introducing gradual changes into the molecule by means of molecular biological methods. The effect upon its inhibition equilibrium constant was determined after each change by a chromogenic assay. This structural information was fundamental to design new dipetalogastin II-derived inhibitors. Our results suggested that the acidic sequence DEHDHDFEDT corresponding to amino acid residues 49 to 58 of dipetalogastin II reacts with the anion binding exosite (ABE) 1 of thrombin. Based on this finding, we constructed a chimeric molecule consisting of the active site blocking segment of dipetalogastin II (amino acid residues 1 to 48) and the ABE 1 blocking segment of hirudin. This construct showed better thrombin inhibitory activity than both separated segments only after the introduction of a glycine linker between both blocking segments. We thus obtained a thrombin inhibitor called dipetarudin with an inhibition equilibrium constant comparable to that of dipetalogastin II and a molecular mass below that of dipetalogastin.

Antithrombins↗
PubMed2004

Conditions required for laparoscopic repair of subacute volvulus of the midgut in neonates with intestinal malrotation: 5 cases.

BACKGROUND: This study aimed to evaluate the optimal conditions for laparoscopic management of neonatal subacute volvulus with malrotation. METHODS: Between 1994 and 2002, 13 neonates with midgut volvulus and malrotation entered the authors' institution. Five of these neonates met the eligibility criteria for laparoscopy: good hemodynamic parameters, no gut perforation, and no severe ischemic distress of the bowel shown on preoperative ultrasonography. RESULTS: The results were excellent for only three infants, associated with a shorter postoperative course. One underwent reoperation for a residual duodenal band, and one conversion to open laparotomy was necessary. The predictors of success were no difficulty identifying the abnormal anatomy, no important chylous stasis, and the learning curve of the surgeon. CONCLUSIONS: Despite its previously reported feasibility, neonatal laparoscopy for volvulus with intestinal malrotation is appropriate only for a small number of patients. Strict selection criteria with a clear understanding of the optimal conditions for success may improve the outcome.

Acute Disease↗
PubMed2004

Orexin 1 receptor messenger ribonucleic acid expression and stimulation of testosterone secretion by orexin-A in rat testis.

Orexins are hypothalamic neuropeptides primarily involved in the regulation of food intake and arousal states. In addition, a role for orexins as central neuroendocrine modulators of reproductive function has recently emerged. Prepro-orexin and orexin type-1 receptor mRNAs have been detected in the rat testis. This raises the possibility of additional peripheral actions of orexins in the control of reproductive axis, which remains so far unexplored. To analyze the biological effects and mechanisms of action of orexins in the male gonad, we evaluated testicular expression of orexin receptor 1 (OX(1)R) and orexin receptor 2 (OX(2)R) mRNAs in different experimental settings and the effect of orexin-A on testicular testosterone (T) secretion. Persistent expression of OX(1)R mRNA was demonstrated in the rat testis throughout postnatal development. In contrast, OX(2)R transcript was not detected at any developmental stage. Expression of OX(1)R mRNA persisted after selective elimination of mature Leydig cells and was detected in isolated seminiferous tubules at defined stages of the seminiferous epithelial cycle. In addition, testicular OX(1)R mRNA expression appeared to be under hormonal regulation; it was reduced by long-term hypophysectomy and partially restored by FSH replacement, whereas down-regulation was observed after exposure to increasing doses of the ligand in vitro. Moreover, OX(1)R mRNA expression was sensitive to neonatal imprinting by estrogen. Finally, orexin-A, in a dose-dependent manner, significantly increased basal, but not human choriogonadotropin-stimulated, T secretion in vitro. A similar stimulatory effect was observed in vivo after intratesticular administration of orexin-A. In conclusion, our present results provide the first evidence for the regulated expression of OX(1)R mRNA and functional role of orexin-A in the rat testis. Overall, our data are suggestive of a novel site of action of orexins in the control of male reproductive axis.

Aging↗
PubMed2004

Ideal timing of thoracoscopic decortication and drainage for empyema in children.

BACKGROUND: Thoracoscopy may be required for resistant empyema in children. This study aimed to determine the advantages of thoracoscopy performed soon after diagnosis and its ideal timing. METHODS: Between 1996 and 2002, 21 children who had undergone thoracoscopy as an initial procedure or after failure of medical treatment were retrospectively reviewed. The study compared outcome of early thoracoscopy (fewer than 4 days after diagnosis) and that of later surgery. The 4-day limit was chosen for physiopathologic reasons (organization of pleuresia in 72 h). RESULTS: In the early thoracoscopy group, the findings showed shorter operative time (p = 0.03) and postoperative hospital stay (p < 0.05), fewer technical difficulties, fewer complications, and no recourse to other surgical procedures. CONCLUSIONS: Early thoracoscopy is greatly beneficial for children with empyema by shortening disease progression. An initial short trial of medical treatment for nonorganising empyema may be attempted on the condition that thoracoscopy not be delayed more than 4 days.

Adolescent↗
PubMed2004

[A comparative study of the feasibility and limits of ambulatory surgery in infants under and over one year of age].

OBJECTIVE: Outpatient surgery in pediatrics is attractive for several reasons. Although 6-8 months has been generally acknowledged as the lower age limit, no minimal age has been clearly established. This study evaluated the outcomes and limits of outpatient surgery in infants from 4 months to 1 year of age. MATERIAL AND METHODS: Between 1996 and 2003, 935 patients were admitted to our hospital for outpatient surgery; of these, 152 were between 4 months and 1 year (mean: 6 months). The indications were essentially surgery to the external genitalia and surgery to remove hernias. The following were exclusion criteria: age below 4 months, ASA scores equal to or above 3, and premature birth with either respiratory distress syndrome or a near-miss of sudden death. RESULTS: More than 98% of the infants met the criteria for outpatient surgery. Cancellations (1.97 vs. 0.51%, P > 0.05), conversions to classic hospitalization (0.65 vs. 0.37%, P > 0.05), postoperative complications (0.65 vs. 0.25%, P > 0.05), rehospitalization (0.65 vs.0.25%, P > 0.05) and relapse of the initial pathology (0.65 vs. 0.63%, P > 0.05) were not more frequent in these infants than in infants over 1 year. CONCLUSION: Pediatric outpatient surgery can be proposed from the age of 4 months without increasing the postoperative risk, either anesthetic or surgical, included for selected former premature infants.

Age Factors↗
PubMed2004

Thoracoscopic repair of H-type tracheoesophageal fistula in the newborn: a technical case report.

H-type tracheoesophageal fistula (H-TEF) without esophageal atresia makes up 4% to 5% of esophageal congenital abnormalities. The authors present the thoracoscopic treatment of a 2.47-kg newborn boy with a fistula between the second and third thoracic vertebrae diagnosed by esophagography. Four trocars were used for fistula closure, and tracheal and esophageal suturing were accomplished without intraoperative incident. Five days after surgery, results of a barium swallow excluded anastomotic leaks. The chest tube was removed, and oral feeding was initiated.

Humans↗
PubMed2004

Antigen characterization of major cork moulds in Suberosis (cork worker's pneumonitis) by immunoblotting.

BACKGROUND: We characterized by immunoblotting the antigenicity of the most frequent fungi colonizing cork during its industrial processing, Penicillium glabrum and Chrysonilia sitophila. Penicillium glabrum is the main causative agent of Suberosis, a hypersensitivity pneumonitis of cork workers. Chrysonilia sitophila induces both IgE sensitization and occupational asthma in the wood processing industry. METHODS: Serum-specific IgG, IgG4 and IgE to P. glabrum and C. sitophila from nine cork workers with hypersensitivity pneumonitis (HP) and seven with asthma (four with occupational asthma) were analysed by immunoblotting. RESULTS: Both HP and asthmatic patients' sera showed immunoreactivity to several proteins resolved in the specific immunoblot strips. The frequency of specific IgG recognition to 12-13.5 and 33 kDa proteins of P. glabrum was significantly higher in HP patients. The sera of HP patients had significantly higher specific IgG recognition to 16 and 51-55 kDa proteins of C. sitophila. There was no specific IgE recognition in the sera of HP or asthmatic patients to both fungi. CONCLUSIONS: Different patterns of antibody reactivity to P. glabrum and C. sitophila are seen in cork workers with hypersensitivity pneumonitis or asthma. The 12-13.5 and 33 kDa proteins of P. glabrum and the 16 and 51-55 kDa proteins of C. sitophila may be major antigens in Suberosis.

Adult↗
PubMed2004

Orexin A suppresses in vivo GH secretion.

BACKGROUND/AIMS: Orexins (OXs) are a newly described family of hypothalamic neuropeptides. Based on the distribution of OX neurons and their receptors in the brain, it has been postulated that they could play a role in the regulation of neuroendocrine function. GH secretion is markedly influenced by nutritional status and body weight. To investigate the role OX-A plays in the neuroregulation of GH secretion we have studied its effect on spontaneous GH secretion as well as GH responses to GHRH and ghrelin in freely moving rats. Finally, we also assessed the effect of OX-A on in vitro GH secretion. METHODS: We administered OX-A (10 microg, i.c.v.) or vehicle (10 microl, i.c.v.) to freely moving rats. Spontaneous GH secretion was assessed over 6 h with blood samples taken every 15 min. RESULTS: Administration of OX-A led to a decrease in spontaneous GH secretion in comparison with vehicle-treated rats, as assessed by mean GH levels (means+/-s.e.m. 4.2+/-1.7 ng/ml vs 9.4+/-2.2 ng/ml; P<0.05), mean GH amplitude (3.6+/-0.5 ng/ml vs 20.8+/-5.6 ng/ml; P<0.01) and area under the curve (848+/-379 ng/ml per 4 h vs 1957+/-458 ng/ml per 4 h; P<0.05). In contrast, OX-A failed to modify in vivo GH responses to GHRH (10 microg/kg, i.v.) although it markedly blunted GH responses to ghrelin (40 microg/kg, i.v.) (mean peak GH levels: 331+/-71 ng/ml, vehicle, vs 43+/-11 ng/ml in OX-A-treated rats; P<0.01). Finally, OX-A infusion (10(-7), 10(-8) or 10(-9) M) failed to modify in vitro basal GH secretion or GH responses to GHRH, ghrelin and KCl. CONCLUSIONS: These data indicate that OX-A plays an inhibitory role in GH secretion and may act as a bridge among the regulatory signals that are involved in the control of growth, nutritional status and sleep regulation.

Activity Cycles↗