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J L Vazquez

Publications and source records attributed to J L Vazquez.

14 recordsLinked to original sources
PubMed2006

Preparation and characterization of copper-doped cobalt oxide electrodes.

Cobalt oxide (Co3O4) and copper-doped cobalt oxide (CuxCo(3-x)O4) films have been prepared onto titanium support by the thermal decomposition method. The electrodes have been characterized by different techniques such as cyclic voltammetry, scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy (XPS). The effect on the electrochemical and crystallographic properties and surface morphology of the amount of copper in the oxide layer has been analyzed. The XPS spectra correspond to a characteristic monophasic Cu-Co spinel oxides when x is below 1. However, when the copper content exceeds that for the stoichiometric CuCo2O4 spinel, a new CuO phase segregates at the surface. The analysis of the surface cation distribution indicates that Cu(II) has preference for octahedral sites.

Cations, Divalent↗
PubMed2006

Incidence of unilateral fertilizations after low dose deep intrauterine insemination in spontaneously ovulating sows under field conditions.

A new procedure for non-surgical deep intrauterine insemination (DUI) in unrestrained sows hormonally induced to ovulate, has been reported. In comparison with standard artificial insemination (AI), with this procedure, the sperm numbers inseminated can be reduced 20-fold without reducing the reproductive performance of these hormonally treated sows. The present study evaluated, using two experiments, the reproductive performance applying 20-fold different sperm numbers per AI dose using DUI or standard AI in spontaneously ovulating sows, under field conditions. In experiment 1, AI was applied to crossbred sows at 12, 24 and 36 h after onset of spontaneous oestrus using one of the following two regimes: (i) DUI (treatment) with 0.15 x 10(9) fresh boar spermatozoa in 5 ml of Beltsville thawing solution (BTS) extender (n = 95), and (ii) standard cervical AI (control) with 2.85 x 10(9) fresh spermatozoa in 95 ml of BTS extender (n = 95). The farrowing rates of the two groups of sows were statistically similar (NS). However, a decrease (p < 0.002) in litter size and the total number of pigs born alive was observed in sows inseminated with the DUI procedure. In experiment 2, 42 post-weaned oestrus sows were inseminated following the same design described for experiment 1 during spontaneous oestrus. On day 6 after onset of oestrus, the proximal segment of the uterine horns of the sows were flushed under surgery to retrieve eventual embryos and evaluate the success of fertilization per cornua (e.g. occurrence of effective uni- vs bilateral sperm transport rendering uni- or bilateral, complete or partial fertilization). Retrieved embryos were assessed for cleavage and number of accessory spermatozoa. Although identical overall pregnancy rates were achieved in both insemination groups, the percentage of sows with partial bilateral fertilization and unilateral fertilization was markedly higher (p < 0.05) in the DUI group (35%) compared with the control (standard AI) group (5%), with a consequent lower (p < 0.001) percentage of viable early embryos after DUI. The number of accessory spermatozoa in the zona pellucida of the embryos was highly variable, but higher (p < 0.001) in control animals than in DUI-AI. No accessory spermatozoa were found in oocytes retrieved from sows depicting unilateral fertilization. In conclusion, DUI in spontaneously ovulating sows with 0.15 x 10(9) spermatozoa renders similar farrowing rates but a lower litter size compared with use of standard AI with a 20-fold higher sperm dose. The lower litter size ought to be related to a decreased distribution of spermatozoa after DUI leading to a higher incidence of partial bilateral and unilateral fertilization.

Animals↗
PubMed2005

An update on reproductive technologies with potential short-term application in pig production.

Over the past decade, there has been an increase in the development and/or in the improvement of emerging reproductive technologies in pigs. Among emerging reproductive technologies with potential short-term application in pig production are: artificial insemination with low number of spermatozoa, cryopreservation of spermatozoa and embryos, sperm sexing, and non-surgical embryo transfer. The following review will give emphasis to recent advancements in these reproductive technologies that are starting to show possibilities of serious applications under field conditions.

Animals↗
PubMed2004

Retransplantation for hepatitis C-related cirrhosis under long-term pegylated interferon therapy.

INTRODUCTION: Because of an increased organ shortage, one of the most controversial questions is whether hepatic retransplantation should be offered to transplant recipients with hepatitis C virus (HCV)-related graft failure because of their worse survival and the inevitable denial of other patients to access to primary transplantation. The objective of the present study was to review our experience with HCV-infected transplant recipients undergoing re-orthotopic liver transplantation (OLT) for HCV graft cirrhosis and receiving pegylated interferon and ribavirin on a prophylactic basis. RESULTS: With a median follow-up of 26 months, all 5 patients are alive with stable graft function. Four patients are still receiving pegylated interferon at a mean duration of 20 months (range, 15-32 months). Although none of the patients has cleared HCV RNA by polymerase chain reaction the mean serum levels have decreased significantly when compared with pre-retransplantation amounts. One year after re-OLT, both grade and fibrosis stage had significantly decreased; the rate of post-retransplantation fibrosis progression was significantly lower than that pre-retransplantation (3.4 +/- 0.2 vs 0.6 +/- 0.3; P <.05).

Adult↗
PubMed2002

Minimum number of spermatozoa required for normal fertility after deep intrauterine insemination in non-sedated sows.

A fibreoptic endoscope procedure for non-surgical deep intrauterine insemination in non-sedated sows has been reported. However, the endoscope is an expensive and fragile instrument, and is unsuitable for use under field conditions. The aim of this study was to determine the minimum number of spermatozoa required to maintain optimal fertility using a flexible catheter (1.8 m in length, 4 mm in diameter) for deep intrauterine insemination in 2-6 parity non-sedated sows. Crossbred sows were treated with eCG 24 h after weaning and with hCG 72 h later to induce oestrus. Deep intrauterine insemination was performed 36 h after hCG treatment in 117, 126, 60 and 69 sows with 15.0, 5.0, 2.5 or 1.0 x 10(7) spermatozoa in 10 ml, respectively. Weaned sows (n = 147) not treated with hormones and used for standard artificial insemination (AI) (two inseminations per oestrus with 3 x 10(9) spermatozoa in 100 ml) served as controls. The flexible catheter was passed successfully through the cervix into one uterine horn in 95.4% of the sows in an average of 3.7 +/- 0.09 min. Farrowing rates after deep intrauterine insemination with 15 or 5 x 10(7) spermatozoa did not differ from those of the control group (82.9, 76.2 and 83.0%, respectively), but a significant decrease (P < 0.001) was observed in sows inseminated with 2.5 or 1.0 x 10(7) spermatozoa (46.7 and 39.1%, respectively). In contrast, the number of spermatozoa inseminated did not affect prolificacy. Laparotomy revealed that the tip of the flexible catheter reached approximately the anterior third of the uterine horn. Although deep intrauterine insemination was performed in only one uterine horn, the percentages of embryos collected from the tip of both uterine horns 2 days after deep insemination were not significantly different. The results show that in comparison with standard AI, a 20-60-fold reduction in the number of spermatozoa inseminated and an 8-10-fold reduction in the dose volume can be achieved without decreasing fertility when semen is deposited non-surgically into the upper first third of one uterine horn.

Animals↗
PubMed2001

Successful non-surgical deep intrauterine insemination with small numbers of spermatozoa in sows.

A 100-fold reduction of the standard dose for artificial insemination in pigs (3 x 10(9) spermatozoa in 80-100 ml fluid) can be used when spermatozoa are deposited surgically next to the uterotubal junction. The present study was performed to develop a technique for non-surgical deep intrauterine insemination in pigs without sedation of the animal. In Expt 1, sows were weaned, treated to induce oestrus and used to evaluate the difficulties involved in the insertion of a flexible fibre optic endoscope through the cervix and along the uterine horn. Deep uterine catheterizations were performed on each sow at 30-40 h after hCG treatment in the crate in which the animal was housed. The endoscope was inserted through an artificial insemination spirette, moved through the cervical canal and propelled forward along one uterine horn until the entire endoscope was inserted. In 30 sows (90.9%) no or minor difficulties were observed during insertion and in these animals the procedure was completed in 4.1 +/- 0.26 min. Insertion of the endoscope through the cervical canal was not possible in only one sow (3.03%). In Expt 2, endoscopic deep intrauterine insemination at 36 h after hCG treatment was performed in 15, 18 and 13 sows with 100, 20 or 5 x 10(7) spermatozoa, respectively, resulting in farrowing rates of 86.6%, 88.9% and 92.3%, respectively; there were no significant differences among groups. Farrowing rates after deep intrauterine inseminations were also not different from those achieved after standard intracervical insemination with 3 x 10(9) spermatozoa (control group: n = 48; 87.5%). Mean litter size (9.41 +/- 0.38 to 10.02 +/- 0.25) was also similar among the different experimental and control groups. In conclusion, endoscopic non-surgical deep intrauterine inseminations can be performed quickly in sows, and normal farrowing rates and litter sizes can be obtained after insemination with a small number of spermatozoa.

Animals↗
PubMed2001

Deep intrauterine insemination and embryo transfer in pigs.

A new method for non-surgical deep intrauterine catheterization of pigs, without sedation of the sow, is described. Insemination results obtained with this method using fresh spermatozoa demonstrate that, in comparison to conventional artificial insemination (AI) (3 x 10(9) spermatozoa in 80-100 ml), a 20-60-fold reduction in the number of spermatozoa inseminated and at least a 8-10-fold reduction in the dose volume can be used without affecting fertility if spermatozoa are deposited deep (middle or upper) into one of the uterine horns. Results from deep intrauterine insemination with frozen-thawed spermatozoa and flow-sorted spermatozoa are also presented and the effect of deep intrauterine insemination on sperm transport is discussed. In addition, a brief description of the advances made in non-surgical embryo transfer technology is reported.

Animals↗
PubMed2000

Intraosseus teratoma of the iliac bone.

We present a 4-year-old child with a large iliac bone mass incidentally discovered in a plain abdominal radiograph. The pathological examination revealed a benign mature teratoma. To the best of our knowledge, the occurrence of intraosseous mature teratoma has not been previously reported. The child had had an immature teratoma of the neck discovered in a fetal ultrasound, and resected on day 6 of life. The neck teratoma recurred twice, at 16 months and at 3.5 years of age. In these two recurrences the lesion appeared progressively more mature. At the time of discovery of the iliac bone teratoma there was no evidence of residual neck disease. The radiological and pathological characteristics, differential diagnosis, and clinical course are discussed.

Age Factors↗
PubMed1999

Feeding difficulties in the first days of life: findings on upper gastrointestinal series and the role of the videofluoroscopic swallowing study.

BACKGROUND: Feeding difficulties in the newborn period are a common indication for an upper gastrointestinal (UGI) series. OBJECTIVE: To review the radiological findings in infants with feeding-related difficulties, with no other medical problems, and to evaluate the role, if any, of the videofluoroscopic swallowing study (modified barium swallow, MBSW). MATERIALS AND METHODS: We retrospectively reviewed all the UGI and MBSW studies performed at our institution over a 5-year period in infants under 1 month of age. We found a total of 77 patients referred for feeding-related problems. RESULTS: All patients had at least one UGI study performed at our institution, and 17 patients had at least one additional MBSW. The most frequently found abnormality that could directly account for the patients' symptoms was swallowing dysfunction. This was detected in 19 patients; in 10 of these patients the swallowing dysfunction was seen only on the MBSW. CONCLUSION: Swallowing dysfunction with aspiration is a common cause of feeding-related difficulties in childhood. In infants with feeding difficulties, a MBSW may demonstrate aspiration when the UGI is negative.

Deglutition↗
PubMed1998

Ossifying renal tumor of infancy presenting as a palpable abdominal mass.

We report a case of ossifying renal tumor of infancy, which presented as a palpable abdominal mass in an otherwise asymptomatic 10-month-old girl. The tumor was partially calcified and occupied the renal pelvis, causing severe hydronephrosis. The differential diagnosis for a patient this age included Wilms tumor, extra-adrenal neuroblastoma, infection, calculus, calcified hematoma and ossifying renal tumor of infancy. The child underwent heminephrectomy and is currently doing well.

Abdominal Neoplasms↗
PubMed1985

Evaluation and treatment of intraabdominal bilomas.

In a 3-year period, 21 intraabdominal bilomas developed in 18 patients. Fifteen of the patients had a solitary biloma, and the other three patients each had two separate concurrent bilomas. The major cause of biloma formation was postoperative bile leakage from a bile duct after laparotomy done primarily for surgery on the gallbladder or liver. Maximal diameter of the bilomas in the transaxial plane ranged from 2 to 19 cm. Sixteen of the bilomas were in the right upper quadrant, and five were in the left upper quadrant. Two large right-sided collections extended caudally into the lower abdomen. The contours of the bilomas were configured by the diaphragm, mesenteries, liver, and other abdominal organs. On CT and sonography, the bilomas were invariably well demarcated, but most did not have an identifiable capsule. CT did demonstrate a thin rim on four bilomas and a thick rim on one. In 19 bile collections, the CT numbers were less than 20 H. The combination of the clinical history, the location, and the CT appearance of the lesion led to the correct diagnosis in each case. Percutaneous drainage was an effective form of therapy that often eliminated the need for surgical drainage.

Abdomen↗
PubMedDate not supplied

Spectral features control temporal plasticity in auditory cortex.

Cortical responses are adjusted and optimized throughout life to meet changing behavioral demands and to compensate for peripheral damage. The cholinergic nucleus basalis (NB) gates cortical plasticity and focuses learning on behaviorally meaningful stimuli. By systematically varying the acoustic parameters of the sound paired with NB activation, we have previously shown that tone frequency and amplitude modulation rate alter the topography and selectivity of frequency tuning in primary auditory cortex. This result suggests that network-level rules operate in the cortex to guide reorganization based on specific features of the sensory input associated with NB activity. This report summarizes recent evidence that temporal response properties of cortical neurons are influenced by the spectral characteristics of sounds associated with cholinergic modulation. For example, repeated pairing of a spectrally complex (ripple) stimulus decreased the minimum response latency for the ripple, but lengthened the minimum latency for tones. Pairing a rapid train of tones with NB activation only increased the maximum following rate of cortical neurons when the carrier frequency of each train was randomly varied. These results suggest that spectral and temporal parameters of acoustic experiences interact to shape spectrotemporal selectivity in the cortex. Additional experiments with more complex stimuli are needed to clarify how the cortex learns natural sounds such as speech.

Acoustic Stimulation↗