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S Morales

Publications and source records attributed to S Morales.

At least 19 recordsLinked to original sources
PubMed2006

Determination of the force necessary for the propagation of tears in ostrich and calf pericardium.

The durability of prosthetic heart valve leaflets made of biological materials is limited. A tear in the biomaterial accelerates their early failure, but microtearing of the collagen fibers may be responsible for their medium-term failure. We studied the force necessary to propagate tearing in two biomaterials: ostrich and calf pericardium. One hundred twenty samples of each tissue were tested in an Elmendorf pendulum capable of measuring the force required to tear a tissue in which a predefined slit had been made. The forces required to produce tears, ranging between 2.5 and 0.25 cm in length, were determined. For ostrich pericardium, this force ranged between 67.67 and 4.80 newton, while that required to tear the same lengths of calf pericardium ranged between 70.67 and 4.70 newton. The function that relates the tearing force to the length of the tear was expressed as follows: y = 20.62x + 1.77x(2) (R(2) = 0.923) for ostrich pericardium and y = 45.57x - 7.21x(2) (R(2) = 0.936) for calf pericardium, where y is the force in newton and x is the length in centimeter. Calf pericardium was found to have a greater resistance to tearing. However, these results should be interpreted with caution owing to the fact that the thickness of the majority of the samples of ostrich pericardium was significantly less than that of calf pericardium. A more careful selection and utilization of adult ostrich pericardium would probably improve these results.

Animals↗
PubMed2005

Aquatic degradation of triclosan and formation of toxic chlorophenols in presence of low concentrations of free chlorine.

The degradation of 2-(2,4-dichlorophenoxy)-5-chlorophenol (triclosan) in chlorinated water samples was investigated. Sensitive determination of the parent compound and its transformation products was achieved by gas chromatography with mass spectrometry detection after sample concentration, using a solid-phase extraction sorbent and silylation of the target compounds. Experiments were accomplished using ultrapure water spiked with chlorine and triclosan concentrations in the low mg/l and ng/ml ranges respectively. Chlorination of the phenolic ring and cleavage of the ether bond were identified as the main triclosan degradation pathways. Both processes led to the production of two tetra- and a penta-chlorinated hydroxylated diphenyl ether, as well as 2,4-dichlorophenol. The formation of 2,3,4-trichlorophenol was not detected in any experiment; however, significant amounts of 2,4,6-trichlorophenol were noticed. All of these five compounds were also identified when triclosan was added to tap-water samples with free chlorine concentrations below 1 mg/l. Minor amounts of three di-hydroxylated phenols, containing from one to three atoms of chlorine in their structures, were also identified as unstable triclosan chlorination by-products. The analysis of several raw wastewater samples showed the co-existence of important concentrations of triclosan and its most stable by-products (2,4-dichlorophenol and 2,4,6-trichlorophenol), reinforcing the potential occurrence of the described transformations when products containing triclosan are mixed with chlorinated tap water.

Chlorine↗
PubMed2005

Microwave assisted extraction followed by gas chromatography with tandem mass spectrometry for the determination of triclosan and two related chlorophenols in sludge and sediments.

A procedure for the determination of 2-(2,4-dichlorophenoxy)-5-chlorophenol (Triclosan) and two possible transformation compounds, 2,4-dichlorophenol (2,4-DCP) and 2,4,6-trichlorophenol (2,4,6-TCP), in sludge from sewage treatment plants (STP) and sediments is presented. Extraction was performed using an acetone:methanol (1:1) mixture under the action of a microwave field. The centrifuged supernatant was diluted with a NaOH aqueous solution and twice extracted with n-hexane for removing neutral and basic interferences. The aqueous layer was acidified and processed as a waste water sample. After concentration analytes were silylated and determined by gas chromatography with tandem mass spectrometry (GC-MS/MS). Influence of experimental conditions on the yield of the extraction process and on the efficiency of the further clean-up step was thoroughly evaluated. Performance of MS/MS detection in comparison to single MS is described. Under final working conditions quantification limits between 0.4 and 0.8 ng/g and recoveries from 78% to 106% were obtained. The method was applied to the analysis of several sludge and sediment samples. Only low levels of TCS were detected in some of the sediments; however, all three compounds were found in sludge samples at concentrations ranging from 7 to 316 ng/g, in the case of chlorophenols, and from 420 to 5400 ng/g, for Triclosan.

Chemical Fractionation↗
PubMed2005

Interleukin 12 (IL12B), interleukin 12 receptor (IL12RB1) and interleukin 23 (IL23A) gene polymorphism in systemic lupus erythematosus.

OBJECTIVE: The aim of this study was to assess the possible association between the interleukin-12B (IL12B) and interleukin-12 receptor beta 1 (IL12RB1) gene polymorphisms with systemic lupus erythematosus (SLE). In addition, we have undertaken a systematic search for genetic variants of interleukin 23 (IL23A). METHODS: The study was conducted on 559 SLE patients and 603 ethnically matched healthy controls. Genotyping of the IL12B [IL12Bpro and IL12B 3' untranslated region (UTR)] and IL12RB1 (641A-->G, 1094T-->C and 1132G-->C) polymorphisms was performed with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and PCR-fluorescent methods, whereas IL23A genetic variants were realized with direct sequencing. RESULTS: No statistically significant differences in the distribution of the IL12B and the IL12RB1 genotypes and alleles were observed when comparing SLE patients and control subjects. Additionally, no differences in the genotype and allele distribution were found when SLE patients were stratified according to the presence or absence of lupus nephritis. Despite an extensive analysis in 30 individuals, variations located in the exons and in the 5' and 3' UTR regions of IL23A gene were not found in any case. CONCLUSIONS: These results suggest that polymorphisms located in IL12B, IL12RB1 and IL23A genes may not play a relevant role in the susceptibility or severity of SLE in the Spanish population.

Adult↗
PubMed2004

Phase II study of a fixed dose-rate infusion of gemcitabine associated with docetaxel in advanced non-small-cell lung carcinoma.

PURPOSE: To evaluate the efficacy and toxicity profile of the combination of docetaxel and prolonged gemcitabine infusion in front-line chemonaive patients with advanced non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: A total of 50 chemonaive patients diagnosed with advanced NSCLC according to the AJCC/TNM classification system were included in the present study. Treatment consisted of 1000 mg/m(2) gemcitabine given as a 100-min continuous infusion (10 mg/m(2) per min) on days 1 and 8 of each course and 75 mg/m(2) docetaxel as a 60-min infusion on day 8, repeating each course every 21 days. RESULTS: The ECOG performance status of the patients were as follows: 0 (10%), 1 (60%), and 2 (30%). All patients had two-dimensionally measurable disease. Their median age was 63 years (range 41-75 years). Of the 50 patients, 28 (56%) had squamous cell carcinoma, 14 adenocarcinoma (28%), and 8 (16%) large-cell carcinoma, and 40% and 60% of patients presented with stage IIIB and IV disease, respectively. Of those with stage IV disease, 33% had more than one metastatic site. A total of 220 courses were administered with a median of five courses per patient. Of 46 patients assessed for response, 12 (26%) had a partial remission (95% CI 13-39%). In 19 patients (41%) the disease remained stable, while disease progression was observed in 15 (33%). The median time to disease progression was 4 months, and median survival time was 7 months. At 1 year, 25% of patients remained alive, and the main grade 3/4 toxicity (according to the WHO scale) consisted of neutropenia ( n=6, 12%), asthenia ( n=4, 8%), peripheral edema ( n=3, 6%), dyspnea ( n=3, 6%), and diarrhea ( n=2, 4%). CONCLUSIONS: Prolonged gemcitabine infusion combined with docetaxel is well tolerated and its efficacy is similar to that of other chemotherapeutic schemes used for NSCLC treatment. However, the prolonged infusion of gemcitabine did not appear to result in any improvement in outcome or toxicity versus the standard dose rate.

Adult↗
PubMed2004

Docetaxel and high-dose epirubicin as neoadjuvant chemotherapy in locally advanced breast cancer.

PURPOSE: Epirubicin and docetaxel are two of the most active drugs against breast carcinoma. As the achievement of a pathological complete response (pCR) is important for survival of patients with locally advanced disease, we used both drugs as neoadjuvant chemotherapy. PATIENTS AND METHODS: Women with locally advanced or inflammatory breast cancer received epirubicin 120 mg/m2 followed by docetaxel 75 mg/m2, both on day 1, every 21 days for four cycles. Lenograstim was administered for 10 days in all cycles. RESULTS: Of 51 patients included, 50 received a total of 188 cycles, with a median of 4 per patient. The median age was 47 years, tumour stage was IIIA in 14 patients and IIIB in 36. Oestrogen receptors were positive in 65% of tumours. There were 10 clinical complete responses (20%) and 29 partial responses (58%). Surgery consisted of mastectomy in 40 patients and tumorectomy in 6. After surgery, 9 pCR were recorded (18%). One patient progressed and died soon after the end of chemotherapy. After a median follow-up of 22 months, the median disease-free survival was 33.7 months. Grade 3/4 neutropenia was observed in 32% of patients, anaemia in 6%, and thrombocytopenia in 4%. Five patients had febrile neutropenia. There were no toxic deaths or grade 4 nonhaematological toxicities. CONCLUSIONS: Docetaxel plus high-dose epirubicin showed promising activity in patients with locally advanced and inflammatory breast cancer, at the cost of moderate toxicity.

Adult↗
PubMed2003

Cisplatin plus gemcitabine versus a cisplatin-based triplet versus nonplatinum sequential doublets in advanced non-small-cell lung cancer: a Spanish Lung Cancer Group phase III randomized trial.

PURPOSE: To compare the survival benefit obtained with cisplatin plus gemcitabine, a cisplatin-based triplet, and nonplatinum sequential doublets in advanced non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: Stage IIIB to IV NSCLC patients were randomly assigned to receive cisplatin 100 mg/m2 day 1 plus gemcitabine 1,250 mg/m2 days 1 and 8, every 3 weeks for six cycles (CG); cisplatin 100 mg/m2 day 1 plus gemcitabine 1,000 mg/m2 and vinorelbine 25 mg/m2 days 1 and 8, every 3 weeks for six cycles (CGV); or gemcitabine 1,000 mg/m2 plus vinorelbine 30 mg/m2 days 1 and 8, every 3 weeks for three cycles, followed by vinorelbine 30 mg/m2 days 1 and 8 plus ifosfamide 3 g/m2 day 1, every 3 weeks for three cycles (GV-VI). RESULTS: Five hundred fifty-seven patients were assigned to treatment (182 CG, 188 CGV, 187 GV-VI). Response rates were significantly inferior for the nonplatinum sequential doublet (CG, 42%; CGV, 41%; GV-VI, 27%; CG v GV-VI, P =.003). No differences in median survival or time to progression were observed. Toxicity was higher for the triplet: grade 3 to 4 neutropenia (GC, 32%; CGV, 57%; GV-VI, 27%; P <.05); neutropenic fever (CG, 4%; CGV, 19%; GV-VI, 5%; P <.0001); grade 3 to 4 thrombocytopenia (CG, 19%; CGV, 23%; GV-VI, 3%; P =.0001); and grade 3 to 4 emesis (GC, 22%; GCV, 32%; GV-VI, 6%; P <.0001). CONCLUSION: On the basis of these results, CG remains a standard regimen for first-line treatment of advanced NSCLC.

Adult↗
PubMed2002

Fiber capillarization relative to mitochondrial volume in diaphragm of shrew.

The objective was to examine fiber capillarization in relation to fiber mitochondrial volume in the highly aerobic diaphragm of the shrew, the smallest mammal. The diaphragms of four common shrews [Sorex araneus; body mass, 8.2 +/- 1.3 (SE) g] and four lesser shrews (Sorex minutus, 2.6 +/- 0.1 g) were perfusion fixed in situ, processed for electron microscopy, and analyzed by morphometry. Capillary length per fiber volume was extremely high, at values of 8,008 +/- 1,054 and 12,332 +/- 625 mm(-2) in S. araneus and S. minutus, respectively (P = 0.012), with no difference in capillary geometry between the two species. Fiber mitochondrial volume density was 28.5 +/- 2.3% (S. araneus) and 36.5 +/- 1.4% (S. minutus; P = 0.025), yielding capillary length per milliliter mitochondria values (S. araneus, 27.8 +/- 1.5 km; S. minutus, 33.9 +/- 2.2 km; P = 0.06) as high as in the flight muscle of the hummingbird and small bats. The size of the capillary-fiber interface (i.e., capillary surface per fiber surface ratio) per fiber mitochondrial volume in shrew diaphragm was also as high as in bird and bat flight muscles, and it was about two times greater than in rat hindlimb muscle. Thus, whereas fiber capillary and mitochondrial volume densities decreased with increased body mass in S. araneus compared with S. minutus Soricinae shrews, fiber capillarization per milliliter mitochondria in both species was much higher than previously reported for shrew diaphragm, and it matched that of the intensely aerobic flight muscles of birds and mammals.

Aerobiosis↗
PubMed2001

B-cell-mediated lysis of cells infected with the neurotropic JHM strain of mouse hepatitis virus.

Cells expressing the spike (S) glycoprotein of the neurotropic JHM strain (JHMV) of mouse hepatitis virus (MHV) are susceptible to lysis by B cells derived from naïve mice, including B cells from perforin-deficient mice. Cytolysis requires interaction of the virus receptor and the viral S glycoprotein, is independent of other viral-induced components, and is not a unique property of B cells. Neutralizing anti-S-protein monoclonal antibodies (mAb) and a mAb specific for the viral receptor inhibit lysis. However, cells infected with an MHV strain unable to induce cell-cell fusion are resistant to lysis and lysis of JHMV-infected cells is inhibited by an anti-S-protein nonneutralizing mAb which prevents S-protein-mediated cell fusion. These data suggest that B cells may function as antibody-independent innate immune response during JHMV infection in vivo.

Animals↗
PubMed2001

A redox-based mechanism for the contractile and relaxing effects of NO in the guinea-pig gall bladder.

The purpose of this study was to determine the effects of sodium nitroprusside (SNP), 2,2'-(hydroxynitrosohydrazino)bis-ethanamine (DETA/NO) and 3-morpholinosydnonimine (SIN-1), NO donors which yield different NO reactive species (NO+, NO* and peroxynitrite, respectively), as well as exogenous peroxynitrite, on gall bladder contractility. Under resting tone conditions, SNP induced a dose-dependent contraction with a maximal effect (10.3 +/- 0.7 mN, S.E.M.) at 1 mM. Consistent with these findings, SNP caused a concentration-dependent depolarization of gall bladder smooth muscle. The excitatory effects of SNP were dependent on extracellular calcium entry through L-type Ca2+ channels. Furthermore, the contraction and depolarization were sensitive to tyrosine kinase blockade, and an associated increase in tyrosine phosphorylation was detected in Western blot studies. DETA/NO induced dose-dependent relaxing effects. These relaxations were sensitive to the guanylyl cyclase inhibitor 1H-[1,2,4]oxidiazolo[4,3-a]quinoxaline-1-one (ODQ, 2 microM) but they were not altered by treatment with the potassium channel blockers tetraethylammoniun (TEA, 5 mM) and 4-aminopyridine (4-AP, 5 mM). When tested in a reducing environment (created by 2.5 mM 1,4-dithiothreitol, DTT), SNP caused a relaxation of gall bladder muscle strips. Similarly, the SNP-induced contraction was converted to a relaxation, and associated hyperpolarization, when DTT was added during the steady state of an SNP-induced response. SIN-1 (0.1 mM), which has been shown to release peroxynitrite, induced relaxing effects that were enhanced by superoxide dismutase (SOD, 50 U ml(-1)). The relaxations induced by either SIN-1 alone or SIN-1 in the presence of SOD were strengthened by catalase (1000 U ml(-1)) and abolished by ODQ pretreatment. However, exogenous peroxynitrite induced a concentration-dependent contraction, which was dependent on activation of leukotriene (LT) metabolism and extracellular calcium. The peroxynitrite-induced contraction was abolished in the presence of the peroxynitrite scavenger melatonin. These results suggest that SIN-1 behaves as an NO* rather than a peroxynitrite source. We conclude that, depending on the redox state, NO has opposing effects on the motility of the gall bladder, being a relaxing agent when in NO * form and a contracting agent when in NO+ or peroxynitrite redox species form. Knowledge of the contrasting effects of the different redox forms of NO can clarify our understanding of the effects of NO donors on gall bladder and other smooth muscle cell types.

Acetylcholine↗
PubMed2001

Vinorelbine, ifosfamide and cisplatin as first-line treatment in patients with inoperable non-small cell lung cancer.

To assess, in a multicenter setting, the effectiveness of a combination of vinorelbine, ifosfamide and cisplatin in the treatment of non-small cell lung cancer, 123 patients (males=116) with a mean age of 60 years (range 27-75) with stage IIIb/IV non-small cell lung cancer (NSCLC) and performance status <or=2 were treated with vinorelbine (VNR; 25 mg/m(2)) on days 1 and 8; ifosfamide (IFO; 3 g/m(2)) on day 1; and cisplatin (CDDP; 80 mg/m(2)) on day 1, in repeated cycles of 21 days. Response rates, overall patient survival and toxicity profiles of the three-drug combination were assessed. The number of evaluable patients was 112, with a total of 441 cycles administered (mean=3.6 cycles/patient). Dose intensities (mg/m(2)/week; calculated in patients who concluded the proposed treatment and expressed as mean, median, and standard deviation) were: VNR 13.65, 13.32, 4.7; IFO 918.88, 868.97, 258.1; CDDP 23, 24.68, 6.98. Response rates were: complete response=3 (2.4%); partial response=58 (47.2%%); stable disease=20 (16.3%). The most frequent toxic events were nausea and vomiting (G1=33%, G2=31%, G3=8%). Neutropenia was the dose limiting toxicity (G1=6%, G2=11%, G3=10%, G4=7%). Alopecia G3 was a common undesirable effect in all the patients. Time to progression was 296 days (95% confidence interval 261-332) and the mean survival time was 338 days (95% CI 301-374). We conclude that the described therapeutic schedule is effective with good survival rates and response ratios together with a good tolerance and an acceptable toxicity level.

Adult↗
PubMed2001

Relaxation of canine gallbladder to nerve stimulation involves adrenergic and non-adrenergic non-cholinergic mechanisms.

Electrical field stimulation (EFS) of dog gallbladder strips induced a frequency-dependent contractile response followed by an off-relaxation that was turned into a pure inhibitory response after atropine pretreatment. Guanethidine reduced the atropine-induced relaxing responses, so an adrenergic mechanism can partially account for the nerve-mediated gallbladder relaxation. However, guanethidine pretreatment also revealed a nonadrenergic noncholinergic (NANC) relaxation induced by EFS, which was frequency independent. NANC relaxations were reduced by L-arginine methyl ester (L-NAME, 100 micromol L-1), a nitric oxide synthase inhibitor (D-p-Cl-Phe6, Leul7; 10 micromol L-1), a vasoactive intestinal peptide (VIP) receptor antagonist, and an inhibitor of haem oxygenase, (copper protoporphyrin IX; CuPP-IX; 10 micromol L-1), suggesting that nitric oxide (NO), VIP and carbon monoxide (CO), respectively, are released in response to EFS. Immunoreactivities for haem oxygenase-2 (HO-2) and VIP, and histochemical staining for NADPH diaphorase were observed in nerve cell bodies and fibres, demonstrating the presence of CO, VIP and NO as putative NANC neurotransmitters in dog gallbladder. These data support the hypothesis that NO, VIP and CO contribute to NANC relaxation of the canine gallbladder.

Adrenergic Fibers↗
PubMed2001

Oral microemulsion cyclosporine in the treatment of steroid-refractory attacks of ulcerative and indeterminate colitis.

BACKGROUND: To assess the efficacy of oral microemulsion cyclosporine (CyA Neoral) in the treatment of steroid-refractory attacks of ulcerative an indeterminate colitis. METHODS: In this non-randomized study on the use of oral microemulsion cyclosporine in steroid refractory ulcerative colitis, we used CyA Neoral in 10 patients suffering from ulcerative colitis and in 1 patient suffering from indeterminate colitis with a steroid-refractory attack. The initial dose was 7-7.5 mg kg-1 day-1 adjusted to maintain whole blood cyclosporine levels between 250 and 350 ng/mL, as measured by RIA using monoclonal antibodies. RESULTS: Nine patients presented a favourable response in a mean time of 3.6 days, that is, 81.8% of cases. One initial responder developed megacolon on the 11th day and another did not respond; surgical treatment was performed in both cases. The remaining nine patients, followed for a mean period of 14.6 months (2-36 months). Nine patients presented side effects, the most frequent being slight hand tremor with hypomagnesaemia, followed by hypertension, slight increase in creatinine and hirsutism. No one needed to withdraw from treatment, but the dose was lowered in three cases. CONCLUSIONS: Oral microemulsion cyclosporine is an effective drug in the initial management of patients suffering from a steroid-refractory attack of ulcerative and indeterminate colitis. Additional controlled studies with the new oral formulation are required to confirm these results.

Administration, Oral↗
PubMed2001

Plasma ghrelin concentration and energy balance: overfeeding and negative energy balance studies in twins.

Central (intracerebral ventral) and peripheral (subcutaneous and intraperitoneal) administration of ghrelin causes obesity in rodents by increasing food intake and decreasing fat oxidation. Recent studies in humans have shown that plasma ghrelin concentration was inversely related to body fat and was lower in Pima Indians, a population susceptible to obesity. Whether ghrelin plays a role in the etiology of obesity in humans is unknown. We, therefore, measured plasma ghrelin concentration before and after two interventions in monozygotic twins previously studied at Laval University, Quebec City. Twelve pairs of monozygotic twins were overfed by 84,000 kcal over a 100-day period, whereas another seven pairs of monozygotic twins were submitted to a 53,000 kcal negative energy balance induced by exercise over a 93-day period. At baseline, for all the subjects, plasma ghrelin concentration was negatively correlated with body mass and body fatness (r varying from 0.36 to 0.45). The intraclass coefficient for the twin resemblance (r(I) = 0.75; p = 0.006) indicated that plasma ghrelin concentration is a familial trait. In response to the 100-day intervention, plasma ghrelin exhibited a non-significant decrease of 61 +/- 30 fmol/l (p = 0.18) with overfeeding and a non-significant increase of 58 +/- 34 fmol/l (p = 0.17) with negative energy balance. However, there was no relationship between baseline plasma ghrelin concentration and the magnitude of body weight change in both interventions. These first experimental data under "clamped energy balance conditions" do not provide evidence that plasma ghrelin is involved in the etiology of human obesity. However, studies in free-living individuals are needed to clarify this question.

Adipocytes↗
PubMed2000

Highly selective and efficient determination of US Environmental Protection Agency priority phenols employing solid-phase extraction and non-aqueous capillary electrophoresis.

Non-aqueous capillary electrophoresis has been used in the separation of a complete list of 26 priority phenols included in the 8041 US Environmental Protection Agency method and the 76/464/EEC European Union directive. A highly selective and efficient separation was obtained when the background electrolyte used was 150 mM ammonium acetate dissolved in N-methylformamide-acetonitrile (75:25). Solid-phase extraction was successfully assayed as an enrichment strategy for the analysis of low-concentration samples. A styrene-divinylbenzene functionalized cartridge provided excellent recoveries of phenols from water samples at neutral pH. The limits of quantification obtained permit the application of the proposed method to the determination of priority phenols in wastewater samples.

Electrophoresis, Capillary↗