Biomedical subjects

J C Vazquez

Publications and source records attributed to J C Vazquez.

9 recordsLinked to original sources

PubMed2000

Treatments for symptomatic urinary tract infections during pregnancy.

BACKGROUND: Urinary tract infections, including pyelonephritis, are serious complications that can result in significant maternal and neonatal morbidity and mortality. There is a large number of drugs, and combination of them, available to treat urinary tract infections, most of them tested in non-pregnant women. Attempts to define the optimal antibiotic regimen for pregnancy has, therefore, been problematic. OBJECTIVES: The objective of this review was to try to determine, from the best available evidence from randomized control trials, which agent is most effective for the treatment of symptomatic urinary tract infections during pregnancy in terms of cure rates, recurrent infection, incidence of preterm delivery and premature rupture of membranes, admission to neonatal intensive care unit, need for change of antibiotic, and incidence of prolonged pyrexia. SEARCH STRATEGY: The Cochrane Pregnancy and Childbirth Group trials register, the Cochrane Controlled Trials Register and reference lists of articles were searched. SELECTION CRITERIA: All trials were considered where the intention was to allocate participants randomly to one of at least two alternative treatments for any symptomatic urinary tract infection. DATA COLLECTION AND ANALYSIS: Trial quality assessment and data extraction were performed by the two reviewers. MAIN RESULTS: Five studies were included. There were no significant differences between studied treatments with regard to cure rates, recurrent infection, incidence of preterm delivery and premature rupture of membranes, admission to neonatal intensive care unit, need for change antibiotic and incidence of incidence of prolonged pyrexia. REVIEWER'S CONCLUSIONS: Although antibiotic treatment is effective for the cure of urinary tract infections, there are insufficient data to recommend any specific treatment regimen for symptomatic urinary tract infections during pregnancy. All of the antibiotics studied were shown to be very effective in decreasing the incidence of outcomes measured. Complications were very rare. All included trials had very small sample sizes to try to detect important differences between treatments. Future studies should evaluate the most promising antibiotics, in terms of class, timing, dose, acceptability, maternal and neonatal outcomes and costs.

Anti-Infective Agents, Urinary↗

PubMed1999

Use of embryonic and somatic cells for production of transgenic domestic animals.

In contrast to the highly developed genetic modification systems available for manipulating the mouse genome, at this time only simple gain of function modifications can be undertaken in domestic species. Clearly, the greatest barrier to gene targeting in domestic species has been the unavailability of cell lines that can be modified in vitro and still be used to generate a living organism. In the mouse, the embryonic stem (ES) cells and embryonic germ (EG) cells have fulfilled that role. While the nuclear transfer procedures have solved this problem in sheep and cattle, in swine ES and EG cells are still needed. In addition, targeting in domestic species is affected by the need to develop targeting constructs containing isogenic DNA regions. As a result, it is necessary to isolate the gene of interest, sequence required regions, and develop isogenic targeting constructs by technologies such as long-range PCR. On the positive side, enrichment protocols developed in the mouse can be applied to domestic species, thus facilitating the identification of correctly modified cell lines. Hence, progress in mammalian cloning, the development of EG cell lines, and advances in gene targeting presently allows the introduction of precise genetic modifications into the domestic animal genome.

Journal Article↗

PubMed1998

Tricuspid annuloplasty and ventricular plication for Ebstein's malformation.

BACKGROUND: Seven patients with the diagnosis of Ebstein's malformation of the tricuspid valve were operated on. Mean age was 12 years (range, 7 to 16 years). All were cyanotic, with severe tricuspid regurgitation. Thromboembolism was not present. No associated cardiac malformations were present. METHODS: Surgical repair included tricuspid annuloplasty associated with longitudinal plication of the atrialized portion of the right ventricle. This was attained by approximating the anterior-posterior commissure with either the posterior-septal commissure or the septal leaflet remnant. The thin atrialized ventricular wall thus excluded remained as a cul du sac and was plicated by suturing along the longitudinal axis of the heart. When present, the dysplastic posterior leaflet was included in the plication. In essence, a monocuspid right atrioventricular valve was fashioned out of the anterior leaflet. The remaining septal leaflet played a minimal functional role. No additional procedures for treatment of arrhythmia were associated with the technique described. RESULTS: The postoperative course was uneventful in all patients. Mean follow-up is 4.3 years (range, 1 to 10 years). Doppler echocardiographic studies reveal satisfactory monocusp valve function in all patients, with adequate coaptation of the anterior leaflet and the septal structures. CONCLUSIONS: This technique seems applicable to most forms of Ebstein's malformation and is reproducible. The technique relies on the adequate mobilization of the anterior leaflet. Occasionally it is necessary to free fibrous adhesions of the leaflet to the underlying ventricular surface.

Adolescent↗

PubMed1998

Aortico-right ventricular tunnel.

A successful operation on an infant with a tunnel through which the aorta communicated with the right ventricle is reported. The diagnosis was suspected preoperatively on the basis of two-dimensional Doppler color echocardiography and confirmed by cardiac catheterization. The aortico-right ventricular tunnel originated independently from the left coronary ostium and above the sinus of Valsalva. Patch closure from inside the tunnel under deep hypothermia was successfully performed. Follow-up is satisfactory 5 years later.

Aorta↗

PubMed1998

Factors affecting the efficiency of introducing precise genetic changes in ES cells by homologous recombination: tag-and-exchange versus the Cre-loxp system.

The introduction of genetic modifications in specific genes by homologous recombination provides a powerful tool for elucidation of structure-function relationships of proteins of biological interest. Presently, there are several alternative methods of homologous recombination that permit the introduction of small genetic modifications in specific loci. Two of the most widely used methods are the tag-and-exchange, based on the use of positive-negative selection markers, and the Cre-loxP system, based on the use of a site-specific recombinase. The efficiency of detection of targeting events at different loci using the two systems was compared. Additionally, we analysed how the distance between two gene markers placed within the region of homology of a targeting vector affects the rate at which both markers are introduced into the locus during the homologous recombination event. Our results indicate that the method based on the use of positive-negative selection markers was less efficient than the Cre-loxP based system, irrespective of locus or type of positive-negative selection. It was also determined that as the distance between the selectable marker and the genetic modification being introduced increases, there is a progressive reduction in the efficiency of detecting events with the desired genetic modification.

Animals↗

PubMed1995

Bidirectional cavopulmonary shunt in patients with multiple risk factors.

BACKGROUND: Twenty-five patients in whom a modified Fontan operation was deferred because of multiple risk factors underwent a bidirectional cavopulmonary shunt. Two or more of the following risk factors were present in all: age less than 1 year, severe pulmonary artery distortion, impaired left ventricular function, subaortic obstruction, anomalous systemic-pulmonary venous connection, atrioventricular valve incompetence, and increased mean pulmonary artery pressure. METHODS: Additional procedures included take-down of systemic-pulmonary artery shunt, atrial septectomy, pulmonary artery reconstruction, bulboventricular foramen enlargement, and atrioventricular valve repair. RESULTS: There were three hospital deaths (12%). Mean follow-up is 21 months. There was no late mortality. Mean oxygen saturation increased from 71% to 83%. Results obtained from pulmonary artery reconstruction, enlargement of bulboventricular foramen, and atrioventricular valve repair were satisfactory for the patients in whom these risk factors were present preoperatively. Ventricular function also improved in the survivors in whom it was previously deteriorated, this being related to the suppression of the sources of ventricular volume overload. CONCLUSIONS: In this risk group of patients for a modified Fontan operation, a bidirectional cavopulmonary shunt provided adequate palliation at reasonable low risk. Early bidirectional cavopulmonary shunt would minimize complications originating from systemic-pulmonary shunts such as pulmonary artery distortion and the potential harm of chronic ventricular volume overload.

Child↗

PubMed1991

Total anomalous pulmonary venous connection.

Repair of total anomalous pulmonary venous connection was performed on 31 patients aged 12 days to 14 years (18 less than 6 months). The connection type was supracardiac in 20 cases, cardiac in nine, infracardiac in one case and mixed in one. Deep hypothermia and circulatory arrest were used in 23 cases (74%). In supracardiac type cases the atrial septal defect was closed through the left atriotomy, without enlargement of the left atrium. Extubation in the operating room was possible in 26 cases (84%). Three patients (9.6%) died, one (with connection to the coronary sinus) soon after operation, due to a management error, another (with connection to the right superior vena cava) of pulmonary edema, and an infant with mixed-type connection 1 week postoperatively, presumably from an arrhythmia. No patient required reoperation because of late pulmonary venous stenosis. There were no late deaths. The technique of elevating the cardiac apex provided excellent exposure in the supracardiac and infracardiac types. Progressively earlier referral during the study period facilitated prompt operation and improved patient salvage.

Cardiac Surgical Procedures↗

PubMedDate not supplied

Polyacrylonitrile membrane interposition between a xenograft and an animal in fulminant liver failure. The concept of xenohemodiafiltration.

In fulminant liver failure (FLF) there is need for support as a bridge to liver transplantation. Based on the concepts of hemofiltration and xenotransplantation, the authors present a model of liver support in FLF. The authors performed a portacaval shunt and ligature of the hepatic artery in 12 pigs. In six pigs (Group A) continuous hemofiltration through a polyacrylonitrile membrane was performed. Six isolated dog's livers were catheterized through the portal vein and perfused with autologous erythrocytes, albumin, and electrolytes in a closed circuit. With the use of the auxiliary liver, the circuit was connected to one of the lateral outlets of the hemofilter, while the other lateral outlet was connected to the portal vein through the pump. Thus, a polyacrylonitrile exchange membrane was created between the blood of the pig with FLF and the auxiliary liver's circulation. In Group B (controls), six pigs were connected directly to the auxiliary liver through a pump. In Group A, the auxiliary liver worked for 8 hr, without evidence of macroscopic or histologic damage. Lactic acid and ammonia levels improved: lactic acid, 8.2 +/- 6 mmol/L to 1.6 +/- 1 mmol/L; ammonia 487 +/- 110 micrograms/dl to 117 +/- 13 micrograms/dl, p < 0.1. The lidocaine clearing (MEGX) test results remained at functional levels (> 90 ng/ml) at the end of the perfusion. In Group B, the perfusion was discontinued at 60 +/- 15 min because of evidence of necrosis of the auxiliary liver. Lactic acid levels increased from 8.19 +/- 1.1 mmol/L to 13 +/- 4 mmol/L, ammonia levels remained high (390 +/- 15 micrograms/dl to 480 +/- 80 micrograms/dl), and the MEGX test results showed levels below functional activity by the end of the perfusion (45 +/- 30 ng/ml). The authors conclude that the concept of xenohemodiafiltration based on the interposition of a polyacrylonitrile membrane between a xenograft and an animal in FLF is adequate to support functions of detoxification and could be used in the future in the support of patient with FLF.

Acrylic Resins↗

PubMedDate not supplied

Polyacrylonitrile membrane interposition between a xenograft and a patient in fulminant liver failure: the concept of xenohemodiafiltration in clinical practice.

Fulminant hepatic failure is an important cause of morbidity and mortality in intensive care units. Conventional therapies are not sufficiently effective. Liver transplantation may be life saving, but a "bridge therapy" is needed until transplantation is performed. Hepatic extracorporeal xenohemodiafiltration (XHDF) is aimed at the transitory support of a patient with fulminant hepatic failure. The first clinical case of XHDF is presented. The system consisted of cross-circulation between a porcine liver and a patient with fulminant liver failure through a polyacrylonitrile membrane. The procedure lasted for 5 hours and produced hemodynamic, biochemical, and metabolic improvements. Intracranial pressure decreased from 34 to 5 cm H2O, serum ammonia fell from 673 to 370 ng/dl, lactic acid from 11 to 5.3 mmol/L, and bilirubin from 7.4 to 2.5 mg/dl. Hemodynamic values were maintained stable throughout the procedure. The patient was able to undergo transplantation and remains alive 11 months later. XHDF is a clinical experimental method that can constitute an alternative clinical therapy to support patients with fulminant hepatic failure until an organ is available for transplantation.

Acrylic Resins↗