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Biomedical subjects

J A Perez

Publications and source records attributed to J A Perez.

At least 19 recordsLinked to original sources
PubMed2000

Low-dose nitric oxide therapy for persistent pulmonary hypertension of the newborn. Clinical Inhaled Nitric Oxide Research Group.

BACKGROUND: Inhaled nitric oxide improves gas exchange in neonates, but the efficacy of low-dose inhaled nitric oxide in reducing the need for extracorporeal membrane oxygenation has not been established. METHODS: We conducted a clinical trial to determine whether low-dose inhaled nitric oxide would reduce the use of extracorporeal membrane oxygenation in neonates with pulmonary hypertension who were born after 34 weeks' gestation, were 4 days old or younger, required assisted ventilation, and had hypoxemic respiratory failure as defined by an oxygenation index of 25 or higher. The neonates who received nitric oxide were treated with 20 ppm for a maximum of 24 hours, followed by 5 ppm for no more than 96 hours. The primary end point of the study was the use of extracorporeal membrane oxygenation. RESULTS: Of 248 neonates enrolled, 126 were randomly assigned to the nitric oxide group and 122 to the control group. Extracorporeal membrane oxygenation was used in 78 neonates in the control group (64 percent) and in 48 neonates in the nitric oxide group (38 percent) (P=0.001). The 30-day mortality rate in the two groups was similar (8 percent in the control group and 7 percent in the nitric oxide group). Chronic lung disease developed less often in neonates treated with nitric oxide than in those in the control group (7 percent vs. 20 percent, P=0.02). The efficacy of nitric oxide was independent of the base-line oxygenation index and the primary pulmonary diagnosis. CONCLUSIONS: Inhaled nitric oxide reduces the extent to which extracorporeal membrane oxygenation is needed in neonates with hypoxemic respiratory failure and pulmonary hypertension.

Administration, Inhalation↗
PubMed1998

Osteopetrosis.

Osteopetrosis is a rare hereditary bone disorder that presents in one of three forms: osteopetrosis tarda, osteopetrosis congenita and "marble bone" disease. Osteopetrosis tarda, the benign form, presents in adulthood, while the two more malignant variants, osteopetrosis congenita and marble bone disease, present in infancy and childhood, respectively. In all three forms, the main features are pathologic alteration of osteoclastic bone resorption and thickening of cortical and lamellar bones. Osteopetrosis tarda is usually discovered accidentally on routine radiographs and is often asymptomatic; however, patients may present because of related degenerative joint disease. Osteopetrosis congenita results in bone marrow failure and is almost always fatal. Marble bone disease causes short stature, cerebral calcification and mental retardation. Bone marrow transplant is the only chance for survival in patients with osteopetrosis congenita.

Age of Onset↗
PubMed1998

Neuropharmacological activity of Solanum nigrum fruit.

The ethanol extract of the fruit of Solanum nigrum L. (Solanaceae) was studied for its neuropharmacological properties on experimental animals. On intraperitoneal injection, the extract significantly prolonged pentobarbital-induced sleeping time, produced alteration in the general behavior pattern, reduced exploratory behavior pattern, suppressed the aggressive behavior, affected locomotor activity and reduced spontaneous motility. The observations suggest that the fruit of S. nigrum possesses potential CNS-depressant action.

Animals↗
PubMed1996

Alpha 1-antitrypsin expression in human thyroid papillary carcinoma.

Alpha 1-antitrypsin is a plasma serine protease inhibitor originally used as a marker for tumors of histiocytic origin. Our casual finding of immunoreactive alpha 1-antitrypsin in one case of thyroid papillary carcinoma led us to investigate its presence in 10 thyroid papillary carcinomas by applying immunocytochemical and immunochemical techniques to tissue sections and Western blots of tissue homogenates prepared from neoplastic tissue and from uninvolved normal areas in the vicinity of each tumor. The immunocytochemical study was performed in both thyroid tissue and metastatic regional lymph nodes. This analysis revealed immunoreactivity for alpha 1-antitrypsin in nine of the 10 cases studied. Immunoreactivity was intense in some of the cells forming the papillar and follicular structures. These cells were intermingled with completely unstained tumoral cells. In contrast to neoplastic tissue, the normal thyroid tissue present in the vicinity of each tumor showed no staining for alpha 1-antitrypsin. The electrophoretic analysis performed on homogenates prepared from both tumoral and normal thyroid tissue revealed a drastic reduction in the band corresponding to thyroglobulin in the tumoral tissue compared with normal thyroid extracts, where it represented the major protein. Western blotting and immunoprinting with a polyclonal alpha 1-antitrypsin antibody confirmed the results obtained with immunocytochemistry about the presence of this protease inhibitor in neoplastic thyroid tissue. Immunoprinting with the anti-alpha 1-antitrypsin antibody revealed an intense immunoreactive band of 53 kDa in the extracts prepared from tumoral tissue. This band had exactly the same apparent molecular mass previously described by others for alpha 1-antitrypsin purified from plasma and was identical to the molecular mass of the purified commercial standard employed.

Adolescent↗
PubMed1996

Glutathione supplements protect preterm rabbits from oxidative lung injury.

The main objective of this study was to determine if glutathione (GSH) supplementation attenuated hyperoxic lung injury. Preterm (29 days) rabbits were delivered and exposed for 24 h to 1) room air, 2) room air and GSH, 3) 95% oxygen and GSH. GSH supplements (1 mM) were delivered in the nutritional support of 10% dextrose and saline through a peritoneal catheter. Animals assigned to oxygen had decreased lung volumes at 35 cmH2O, decreased lung compliance, increased edema, decreased cell viability, and decreased lung tissue and lavage-reduced/oxidized GSH levels, compared with control animals. Despite exposure to hyperoxia, animals supplemented with GSH were not different from room air controls with respect to lung mechanics, edema, cell viability, or tissue and lavage GSH. These studies suggest that GSH supplementation maintains normal lavage and lung tissue GSH levels in preterm animals exposed to hyperoxia and attenuates the changes in lung mechanics associated with oxygen-induced lung injury.

Animals↗
PubMed1995

Characterization of the invertase from Pichia anomala.

Synthesis of invertase (EC 3.2.1.26) in Pichia anomala is controlled by the carbon source in the culture medium. The enzyme was purified to homogeneity from P. anomala cells fully derepressed for invertase synthesis and shown to be a multimeric glycoprotein composed of identical subunits with an apparent molecular mass of 86.5 kDa. The carbohydrate moiety accounts for approx. 30% of the total mass of the molecule and consists of manno-oligosaccharides N-linked to the polypeptide. Most of the characteristics of the enzyme analysed in this study were similar to those previously reported for other yeast invertases, with the remarkable exception of its thermal sensitivity which appears after 15 min incubation at temperatures above 32 degrees C.

Carbohydrates↗
PubMed1995

The cardiovascular clinical nurse specialist as case manager during endovascular revascularization of renal artery stenosis.

The management of renovascular hypertension includes recent advances in detection, evaluation and treatment. Patients with confirmed renovascular hypertension require coordination of their care during the diagnostic and interventional phases of treatment. Renal artery angioplasty is often the selected intervention for renovascular hypertension Nurses caring for patients during the periprocedural period are challenged to provide preadmission instructions that often involve medication adjustments, information related to angioplasty, and discharge instructions that address vascular access site care and renovascular care. Comprehensive nursing care extends from the outpatient diagnostic phase, through the acute hospital phase and concludes with outpatient follow-up and telephone consultation. Case management during these relatively short episodes of care expedites care delivery, minimizes duplication of services, and involves patients as active participants. This study applies a case management model to a patient with renal artery stenosis treated with angioplasty and stent placement. The value of collaborative, clinical nurse specialist-coordinated care and patient education is emphasized.

Aged↗
PubMed1995

Anti-hepatitis A virus antibody response elicited in mice by different forms of a synthetic VP1 peptide.

Peptide VP1 (11-25) of the capsid of hepatitis A virus was synthesized by the Fmoc-polyamide solid phase method, and administered to mice in different forms: (1) free, (2) encapsulated in multilamellar liposomes, (3) coupled to keyhole limpet hemocyanin (KHL), and (4) incorporated into a tetrameric branched lysine core. The highest anti-VP1 peptide responses were generated by synthetic peptides entrapped into liposomes and coupled to KLH. No anti-HAV response was generated with the free peptide, while all the other forms induced both anti-HAV and HAV-neutralizing antibodies. Maximum neutralization indices were observed in ascites from mice treated with liposome-entrapped and KLH peptides.

Adjuvants, Immunologic↗
PubMed1994

Endovascular intervention in patients with coronary and peripheral arterial disease.

Randomized clinical trials have typically demonstrated lower mortality rates for patients with coronary artery disease who participate in cardiac rehabilitation programs. The Multiple Risk Factor Intervention Trial, the Lifestyle Heart Trial, and the Aerobics Research Institute studies suggest that light to moderate amounts of exercise protect against early mortality from coronary artery disease. Walking is the cornerstone of cardiovascular rehabilitation. Patients with coronary artery disease who are limited by claudication may be unable to participate in their cardiovascular exercise program. In a subset of patients with combined coronary and peripheral arterial disease who have had failure with an oral hemorrheologic agent (Pentoxifylline) and an aggressive walking program, claudication is an indication for diagnostic angiography and revascularization. Percutaneous endovascular interventions that enable these patients to enroll in cardiac rehabilitation programs may favorably influence their long-term outcome. Selected case studies are used to illustrate this management approach for these patients who are at high risk.

Aged↗
PubMed1993

Direct determination of ephedrine and norephedrine in human urine by capillary zone electrophoresis.

This paper describes a simple and fast method for the simultaneous determination of ephedrine and norephedrine in urine by capillary zone electrophoresis. Separation and determination of these stimulants in human urine was performed in 50 mM phosphate buffer at pH 9.5, modifying the electroosmotic flow with acetonitrile. The method allows direct determination of the stimulants in urine in concentrations lower than 20.0 micrograms/ml, and has a limit of determination of 2.6 +/- 0.2 micrograms/ml for ephedrine and 2.3 +/- 0.2 micrograms/ml for norephedrine in urine and may be applied for doping control.

Electrophoresis↗
PubMed1993

Circulating Candida antigens and antibodies: useful markers of candidemia.

To investigate the utility of the 48-kDa antigen from Candida albicans in its commercial form (Directigen; Becton Dickinson) and three other serodiagnostic methods (detection of one antigen by Pastorex Candida [Sanofi Diagnostics Pasteur] and detection of immunoglobulin G [IgG] and IgM antibodies to C. albicans blastoconidia [bioMerieux]) for diagnosis of invasive Candida infection, we conducted a prospective clinical trial among 10 patients with candidemia (group 1), 30 patients colonized by C. albicans (group 2), 20 patients with bacteremia (group 3), and 20 subjects without clinical or microbiological evidence of infection. The Directigen system was positive for at least one serum sample each from eight patients in group 1. In groups 2, 3, and 4, it was positive for only three patients. There was no reaction to the Pastorex system in any of the patients infected with or colonized by C. albicans or in the non-Candida-carrying controls. The IgG antibody concentration oscillated between 100 and 800 (mean, 510 +/- 268) IU/ml for the patients in group 1. In this group, eight patients had IgG antibody levels of > 400 IU/ml. The percentages of persons with IgG antibody levels of > 400 IU/ml in groups 2, 3, and 4 were 43.3, 0, and 0, respectively. Specific IgM antibody was present in all group 1 patients but not in those in groups 2, 3, and 4. The sensitivity and specificity of the Directigen test were 65 and 97.1%, respectively. For the Pastorex test, the sensitivity was 0%. The sensitivity of IgG antibodies was 80%, with a specificity of 81.4%, while the IgM antibodies were 100% specific and sensitive. Both the positive and negative predictive values of specific IgM antibodies appeared to be superior to those of the other three tests.

Antibodies, Fungal↗