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C Vazquez

Publications and source records attributed to C Vazquez.

At least 19 recordsLinked to original sources
PubMed2001

Electron-transfer salts of 1,2,3,4,5-pentamethylferrocene, Fe(II)(C5Me5)(C5H5). Structure and magnetic properties of two 1:1 and two 2:3 Fe(C5Me5)(C5H5) electron-transfer salts of tetracyanoethylene.

The reaction of Fe(II)(C5Me5)(C5H5), FeCpCp, with percyano acceptors, A [A = C4(CN)6 (hexacyanobutadiene), TCNQF4 (perfluoro-7,7,8,8-tetracyano-p-quinodimethane), and DDQ (2,3-dichloro-5,6-dicyanobenzoquinone)], results in formation of 1:1 charge-transfer salts of [Fe(III)CpCp]*]*+[A]*- composition. With A = TCNQ (7,7,8,8-tetracyano-p-quinodimethane) a 1:2 electron-transfer salt with FeCpCp forms. With A = TCNE (tetracyanoethylene) a pair of 1:1 salts as well as a pair of 2:3 salts of [FeCpCp]2[TCNE]3.S (S = CH2Cl2, THF) have been isolated and characterized by single-crystal X-ray diffraction. [FeCpCp][TCNE] consists of parallel 1-D.D(*+)A(*-)D(*+)A(*-)D(*+)A(*-). chains, while [FeCpCp][TCNE].MeCN has a herringbone array of D(*+)A2(2-)D(*+) dimers separated by solvent molecules. Although each [TCNE](-) is disordered, the diamagnetic [TCNE]2(2-) dimer is structurally different from those observed earlier with an intradimer separation of 2.79 A. The [TCNE](-) in the 2:3 [FeCpCp]2[TCNE]3.S exists as an eclipsed diamagnetic [TCNE]2(2-) dimer with an intradimer ethylene C.C separation of 2.833 and 2.903 A for the CH2Cl2- and THF-containing materials, respectively. The bond distances and angles for all the cations are essentially equivalent, and the distances are essentially equivalent to those previously reported for [FeCp2](*+) and [FeCp2](*+) cations. The average Fe-C5H5-ring and Fe-C5Me5-ring centroid distances are 1.71 and 1.69 A, respectively, which are 0.05 A longer than reported for Fe(II)CpCp. The one-electron reduction potential for Fe(II)CpCp is 0.11 V (vs SCE). The 5 K EPR of [FeCpCp](*+)[BF4](-) exhibits an axially symmetric powder pattern with g(parallel) = 4.36 and g(perpendicular) = 1.24, and the EPR parameters are essentially identical to those reported for ferrocenium and decamethylferrocenium. The high-temperature magnetic susceptibility for polycrystalline samples of these complexes can be fit by the Curie-Weiss law, chi = C/(T - theta), with low theta values and mu(eff) values from 2.08 to 3.43 mu(B), suggesting that the polycrystalline samples measured had varying degrees of orientation. [FeCpCp][TCNE] exhibits the highest effective moment of 3.43 mu(B)/Fe and weak ferromagnetic coupling, as evidenced from the theta of 3.3 K; however, unexpectedly, it does not magnetically order above 2 K. The formation of the four phases comprising FeCpCp and TCNE emphasizes the diversity of materials that may form and the present inability to predict neither solid-state compositions nor structure types.

Journal Article↗
PubMed2001

Randomized comparison of efficacy of cooled tip catheter ablation of atrial flutter: anatomic versus electrophysiological complete isthmus block.

There is a subset of patients with failed ablation of the cavotricuspid isthmus (CTI) using standard catheters and with 10% of the patients having recurrences. The purpose of this study was to compare the cooled and standard ablation with regard to acute successful electrophysiological achievement of bidirectional isthmus block and the subacute anatomic characteristics of the lesions. This randomized, experimental study compares the effects of ablation on the isthmus using a cooled catheter with those of a standard ablation catheter in 16 pigs. In 12 animals, CTI block was achieved after ablation (8/8 cooled and 4/8 standard). In two animals, it was not possible to achieve complete isthmus block and two had persistent slow conduction (all four using the standard catheter). After 1 week, the animals were slaughtered. The size of the lesion was greater with the irrigated tip catheters. Transmural lesions were found in 14 animals. A complete line of anatomic isthmus block was not documented after thefirst line in six animals, four with the standard and two with the cooled catheter. A conduction block was never present across gaps > or = 5 mm. In conclusion cooled catheters achieved a complete line of electrophysiological and anatomical block in a significantly higher percentage than the standard catheters.

Animals↗
PubMed1999

Transient expression of nitric oxide synthase in the hypoglossal nucleus of the rat during early postnatal development.

The present study investigates the presence of nitric oxide synthase (NOS) by the nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) histochemical reaction and immunohistochemistry with neuronal NOS (nNOS) antibody during postnatal development of hypoglossal nucleus (XII) in the rat. Our results showed that the enzyme expression was limited to a subset of cells in the dorsal division of the nucleus. Retrogradely labeling with diamidino yellow (DY) from the tongue indicates that these cells were motoneurons. NOS expression was transient, being detectable during the first 3 postnatal weeks, suggesting a role for nitric oxide in the development and maturation of this subset of cranial motoneurons.

Animals↗
PubMed1999

IFN-gamma and CD8+ T cells restore host defenses against Pneumocystis carinii in mice depleted of CD4+ T cells.

Host defenses against infection are profoundly compromised in HIV-infected hosts due to progressive depletion of CD4+ T lymphocytes and defective cell-mediated immunity. Although recent advances in antiretroviral therapy can dramatically lower HIV viral load, blood CD4+ T lymphocytes are not restored to normal levels. Therefore, we investigated mechanisms of host defense other than those involving CD4+ T lymphocytes against a common HIV-related opportunistic infection, Pneumocystis carinii (PC) pneumonia. Using CD4-depleted mice, which are permissive for chronic PC infection, we show that up-regulation of murine IFN-gamma by gene transfer into the lung tissue results in clearance of PC from the lungs in the absence of CD4+ lymphocytes. This resolution of infection was associated with a >4-fold increase in recruited CD8+ T lymphocytes and NK cells into the lungs. The role of CD8+ T cells as effector cells in this model was further confirmed by a lack of an effect of IFN-gamma gene transfer in scid mice or mice depleted of both CD4+ and CD8+ T cells. Cytokine mRNA analysis revealed that recruited, lung-derived CD8+ T cells had greater expression of IFN-gamma message in animals treated with the IFN-gamma gene. These results indicate that CD8+ T cells are capable of clearing PC pneumonia in the absence of CD4+ T cells and that this host defense function of CD8+ T cells, as well as their cytokine repertoire, can be up-regulated through cytokine gene transfer.

Adenoviridae↗
PubMed1999

Crossover iliofemoral bypass grafting for treatment of unilateral iliac atherosclerotic disease.

PURPOSE: In patients with unilateral iliac disease, a less invasive procedure than aortobifemoral bypass grafting may be desirable, especially in poor-risk patients or when sexual dysfunction is feared. In these cases, femorofemoral (FF) bypass grafting is often proposed. Compared with FF bypass grafting, iliofemoral (IF) bypass grafting avoids bilateral exposure of the groins, which may reduce the risk of infection. When the primitive iliac artery is occluded from its origin or heavily calcified, one may use the contralateral artery as inflow, after a small retroperitoneal exposure, to perform a crossover iliofemoral (CIF) bypass grafting procedure, through the Retzius space. Our 10-year experience with CIF bypass grafting in a select group of patients was studied. METHODS: Between 1986 and 1996, 36 patients underwent CIF bypass grafting for symptomatic unilateral iliac occlusion or stenosis. All patients were examined by means of Doppler ultrasound scanning and underwent bilateral multiplane angiography. Patients were considered for this procedure when the ipsilateral common iliac artery was occluded from its origin or was diffusely and heavily calcified. The decision to perform a CIF bypass grafting procedure was made when no significant disease of the contralateral common iliac artery was seen, and patients who had features of contralateral iliac disease were excluded. The main outcomes were perioperative mortality and morbidity, long-term primary and secondary patency rates, and limb salvage rate. RESULTS: The study included 31 men and five women, with a mean age of 58.8 years. Indications for bypass grafting were disabling claudication (26 of 36 patients, 72%) and limb-threatening ischemia (10 of 26 patients, 28%). Twelve procedures were performed simultaneously: endarterectomy of the recipient common femoral artery (n = 3), femoropopliteal bypass grafting (n = 4, 11.1%), profundoplasty (n = 4, 11%), and right internal carotid endarterectomy (n = 1). New postoperative erectile dysfunction did not develop in any of the patients. The survival rate was 97.3% at 1 year and 68.5% at 5 years. The primary and secondary patency rates were 94% and 100%, respectively, at 1 year and 76.7% and 95%, respectively, at 5 years. The limb salvage rate was 100% at 1 year and 87% at 3 years. CONCLUSION: The operative mortality associated with CIF is low. The long-term primary and secondary patency rates are satisfactory, and they are lower than those reported for aortobifemoral bypass grafting. This procedure does not preclude a later performance of an aortobifemoral bypass grafting procedure. CIF bypass grafting is not only suitable for poor-risk patients with a limited life expectancy who have the appropriate arterial anatomy, but also may be warranted for young patients in whom erectile dysfunction is feared.

Adult↗
PubMed1998

Routine ultrasound screening for abdominal aortic aneurysm among 65- and 75-year-old men in a city of 200,000 inhabitants.

Unruptured abdominal aortic aneurysm (AAA) is seldom recognized. Thus it is difficult to know whether the incidence of AAA in the general population is high enough to warrant routine screening at least in men after a certain age. Ultrasound screening studies to evaluate the incidence of AAA have been carried out in several English-speaking and Scandinavian countries. The purpose of this report is to describe the results of a study carried out in Belgium. All 65- and 75-year-old men living in the city of Liege, Belgium, were given the opportunity to undergo a free ultrasound examination. Only 41% of the target population was examined. AAA defined as abdominal aortic diameter of >30 mm was observed in 28 subjects (incidence: 3.8%). Mean abdominal aortic diameter was 34.7 mm. A diameter >29 mm was observed in 33 subjects (incidence 4.5%). Mean abdominal aortic diameter was 30.4 mm. On the basis of epidemiological data collected, a high-risk population for AAA was identified. Arterial hypertension (p < 0.05), previous coronary artery surgery (p < 0.05), and smoking (p < 0.06) were more common in subjects with than without AAA. The overall cost of screening was $18.175. The cost per AAA diagnosed was $551.00.

Aged↗
PubMed1998

The potential role of antioxidant vitamins in preventing cardiovascular diseases and cancers.

Cardiovascular diseases and cancers constitute major public health problems in all industrialized countries, where they are the main causes of premature mortality. There is a large body of evidence suggesting that free-radical production can directly or indirectly play a major role in cellular processes implicated in atherosclerosis and carcinogenesis. Here we present mechanistic data and results of epidemiologic studies on the relationship between antioxidant vitamin intake or biochemical status and the risk of cancer and cardiovascular diseases. Most epidemiologic data obtained on this topic were based on an observational approach, i.e., ecologic, case-control, or prospective studies. All these studies indicate that a high dietary intake or high blood concentrations of antioxidant vitamins are associated with a reduced risk of cardiovascular diseases and cancer at several common sites. Although the results of these studies are convergent, they merely suggest a relationship at the population and individual level but do not affirm a causality link. Only intervention studies (randomized trials), by specifically changing antioxidant vitamin intake, can provide conclusive answers. The apparent discrepancies between the results of four recently published trials may be explained by the type of population (general or high-risk subjects), the differing doses of supplementation (nutritional levels or higher), the number of antioxidants tested (one, two, or more), and the type of administration (alone or in balanced association). It thus appears that a low risk of pathologies may be related to multiple nutrients consumed at nutritional doses and in combination. Optimal effects may be expected with a combination of nutrients at levels similar to those found in a healthy diet. A single antioxidant vitamin given at high doses in subjects with high risk of pathologies (smokers, asbestos-exposed subjects) may not have substantial benefits and could even have negative consequences.

Animals↗
PubMed1998

The use of Newton's rings for characterising ophthalmic lenses.

The interference technique of Newton's Rings is widely used for the quality control of optical surfaces because the precision obtained with this method proves to be very satisfactory. The dimensions of the rings permits calculation of the radii of curvature of the analysed surfaces and deformation of the interference pattern can be utilised to calculate other parameters, such as astigmatism. We describe the study of progressive surfaces by means of this technique, whereby the analysis of the various points of the progressive corridor is made, and also include information on the power function for these lenses, as well as the addition and corridor length.

Lenses↗
PubMed1997

Exacerbation of murine Pneumocystis carinii infection by adenoviral-mediated gene transfer of a TNF inhibitor.

The role of mononuclear phagocytes and their cytokine products in host defense against Pneumocystis carinii (PC) remains unclear. The cytokine tumor necrosis factor (TNF) has been proposed as critical for host defense against this pathogen. To investigate the role of this cytokine in PC infection, we treated immunocompetent mice (CD4+) or mice depleted of CD4 lymphocytes (CD4-) with a recombinant adenovirus encoding a TNF inhibitor gene (AdTNF-R). AdTNF-R treated CD4+ animals displayed delayed clearance of PC after intratracheal inoculation, whereas AdTNF-R treated CD4 animals developed more severe chronic infection. Moreover, AdTNF-R treated CD4- animals, in contrast to control CD4- mice, failed to show any interleukin-6 (IL-6) gene induction in the lung after PC challenge. The results firmly implicate TNF in host defense against PC, and support a role for TNF in orchestrating the intrapulmonary cytokine cascade in PC infection.

Adenoviridae↗
PubMed1996

Specific oncological contribution of cathepsin D and pS2 in human breast cancer: their relationship with TNM status, estradiol receptors, epidermal growth factor receptor and neu amplification.

The present study attempts to clarify the specific contribution of cathepsin D (CD) and pS2 to the progression of breast cancer (BC) by examining the relationship between these two factors and TNM status, tumour grade, estradiol receptors (ER) and the prognosis factors epidermal growth factor receptor (EGFR) and neu amplification in a group of 270 BC patients. CD and pS2 were determined by an immunoradiometric procedure in tumour cytosols obtained for ER. Neu amplifications were evaluated by dot-blot, in tumour DNA. EGFR was determined in membrane tumour preparations obtained from ER cytosols by a two-point radiometric saturation assay. CD is basically related to bad prognosis factors and has a direct correlation with tumour size (P = 0.025) and EGFR content (P = 0.007) and is associated with the presence of metastases (P = 0.000). pS2 is mostly related to good prognosis factors and showed an inverse correlation with the Scarff-Bloom Index (P = 0.011) and a direct correlation with ER content (P = 0.014). Finally, pS2 and CD also showed a strong mutual association (P = 0.009) and the fact that both correlated with ER content confirms in tumours the experimental finding that they are estrogen-induced proteins.

Adult↗
PubMed1996

A female compound heterozygote (pre- and full mutation) for the CGG FMR1 expansion.

Fragile X syndrome is the most common cause of inherited mental retardation. The incidence has been estimated to be 1 in 1250 males and 1 in 2000 females. Molecular studies have shown that 95% of fragile X syndrome cases are caused by the expansion of a CGG triplet in the FMR1 gene with hypermethylation of the adjacent CpG island. In spite of the high incidence of this syndrome, a female with both FMR1 genes in the expanded form has never been reported. We presenting mental retardation and attention problems. Molecular analysis has revealed that both of her FMR1 genes have the CGG expansion, one with a premutation and the other with a full mutation. We have studied the CGG repeat in the FMR1 gene in 64 members of her family and detected 33 normal individuals, 14 carriers with the premutation (1 male and 13 females), and 18 individuals with full mutations (8 males and 10 females). The index case illustrates that the possibility of both parents being carriers of the fragile X syndrome premutation should be considered in consanguineous families or in small communities.

Adult↗
PubMed1996

Thirteen cystic fibrosis patients, 12 compound heterozygous and one homozygous for the missense mutation G85E: a pancreatic sufficiency/insufficiency mutation with variable clinical presentation.

To study the severity of mutation G85E, located in the first membrane spanning domain of the CFTR gene, we studied the clinical features of 13 Spanish patients with cystic fibrosis (CF) carrying this mutation. G85E accounts for about 1% of Spanish CF alleles. One patient was homozygous G85E/G85E and the rest were compound heterozygotes for G85E and other mutations (delta F508 nine patients, delta I507 two patients, and 712-1G > T one patient). The characteristics of the pooled G85E/any mutation group were compared with those of 30 delta F508 homozygotes. Mean age at diagnosis and percentage of ideal height for age were higher in the G85E/any mutation group (4.2 (SD 4.7) v 2.4 (SD 2.3), p < 0.05, and 102.8 (SD 4.7) v 97.8 (SD 4.1), p < 0.01), both probably related to the greater prevalence of pancreatic sufficiency (70% v 0%, p < 0.01). The G85E homozygote was pancreatic sufficient. Sweat sodium levels were slightly higher, and salt loss related problems more frequent, in the G85E/any group. Two of the G85E patients died of respiratory failure aged 6 and 14 years. Striking discordance in the phenotype was observed in two pairs of sibs, one of them dizygotic twins, suggesting that factors, genetic and environmental, other than CFTR genotype are important in determining CF phenotype.

Child↗
PubMed1996

[Pulmonary valve replacement in children].

From February 1988 to October 1994, 15 pulmonary valve replacements (PVR) have been performed at St-Justine Hospital in children with a mean age of 145.7 months. Ten children previously had a correction of tetralogy of Fallot; two had absent pulmonary valve syndrome; one had been operated on for pulmonary atresia with intact ventricular septum, one other had a correction for a ventricular septal defect with pulmonary artery banding; the last patient developed degeneration of a pulmonary bioprosthesis. The time between the primary repair and the PVR ranged from 61 to 221 months. Fourteen bioprosthesis and one aortic homograft were implanted. All patients had antiplatelet treatment. There was one operative death due to a fatal anaphylactic reaction and one late death occurred unrelated to valvular surgery. At follow-up from 1 to 187 months (mean, 40.7 months) all patients were in New York Heart Association Class 1. No hemorrhagic nor thromboembolic complication have been observed and no reoperation for bioprosthesis failure was necessary. Nevertheless in subsequent echocardiographic studies, two patients with the smallest bioprosthesis (21 mm) have developed pulmonary gradients of 80 and 85 mmHg, 65 and 80 months following PVR. While our results with PVR in children have been satisfactory, this operation should be performed only in symptomatic patients with severe pulmonary regurgitation because of progressive deterioration of the available bioprosthesis.

Adolescent↗
PubMed1995

Time trends in acute childhood asthma in Basque Country, Spain.

To investigate recent changes in the epidemiology of acute asthma in children in a hospital setting, data from the Basque region of Bizkaia, Spain were reviewed for the period between 1987 and 1992. Over this period there was a 18% drop in hospital emergency visits for asthma in children aged 2-14 years from 1,697/100,000 to 1,382/100,000. It was associated with a decline in the number of annual episodes per patient and in the number of patients needing further hospital treatment for the same episode. Paradoxically, hospital admission rates rose by 35.9% from 298/100,000 to 405/100,000. A trend toward decreasing length of hospital stay, a fall in the number of intensive care unit admissions, and an absence of in-hospital deaths were observed. Comparing data from September 1987 with those of September 1992, a trend has been noticed toward greater intensity of emergency room treatment with increases in the number of doses of nebulized beta 2-agonists administered and in courses of oral prednisolone given. In September 1992 more patients were on maintenance "anti-inflammatory" inhaled therapy than in 1987.

Acute Disease↗
PubMed1994

Cytogenetic study of angiosarcoma of the breast.

Angiosarcoma of the breast is quite rare, and the development of cutaneous angiosarcoma after segmental mastectomy and radiation therapy is even less common. A cytogenetic analysis of a mammary angiosarcoma arising in a breast after previous irradiation and segmental mastectomy for infiltrating ductal carcinoma revealed multiple clonal rearrangements involving chromosomes X, 1, 2, 3, 4, 5, 6, 7, 8, 9, 15, 17, 20, and 22. No cytogenetically analyzed angiosarcomas of the breast have been reported before.

Breast Neoplasms↗
PubMed1994

Chloride deficiency as a presentation or complication of cystic fibrosis.

Thirteen children with cystic fibrosis (CF), aged 1.5 months-15 years, had 18 episodes of hypochloraemia and metabolic alkalosis over the period 1983-1991. Five patients were not known to have CF prior to developing these electrolyte disturbances. There were two distinct clinical presentations: 5 patients had an acute isolated picture of heat exhaustion while 8 patients (all infants) had a more chronic course associated with failure to thrive. Many episodes were not associated with particularly high environmental temperatures, although most occurred during the summer and early autumn months. Serum electrolytes should be assessed regularly in children with CF, and this diagnosis should be considered in any infant presenting with unexplained hypochloraemic metabolic alkalosis.

Acute Disease↗