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Biomedical subjects

R Gibbs

Publications and source records attributed to R Gibbs.

34 records · Page 2Linked to original sources
PubMed1996

Impairment of endothelium-dependent pulmonary vasodilation in patients with primary pulmonary hypertension.

BACKGROUND: Pulmonary vascular tone may be modulated by endothelium-derived vasoactive mediators. Endothelial dysfunction is thought to occur in primary pulmonary hypertension. The aim of this study was to evaluate the vascular responses of patients with severe primary pulmonary hypertension to endothelium-dependent vasodilators (for example, substance P) and non-endothelium-dependent vaasodilators (for example, adenosine). METHODS: Six patients with primary pulmonary hypertension (mean (SE) systolic, diastolic, and pulmonary artery pressures 91.1 (7), 45.2 (3), and 62 (4.2) mm Hg, respectively, and baseline total pulmonary vascular resistance (TPVR) 1949 (164) dynes.s.cm-5) underwent sequential infusions of substance P (5-100 pmol/min) and adenosine (5-50 micrograms/kg/min) in random order. Pulmonary and systemic haemodynamics were monitored by indwelling radial and pulmonary arterial catheters. RESULTS: Substance P caused a marked fall in systemic vascular resistance (SVR) but minimal pulmonary vasodilation (mean maximal percentage change from baseline in TPVR:SVR ratio 27.85 (6.5)%, p < 0.01). Adenosine caused TPVR to fall, but resulted in no change in SVR (mean maximum percentage change from baseline in TPVR:SVR ratio -9.85 (3.5)%, p < 0.05). CONCLUSION: Endothelium-dependent vasodilation is deficient in the pulmonary circulation of patients with primary pulmonary hypertension and may contribute to the abnormalities of pulmonary vascular tone and reactivity seen in that condition.

Adenosine↗
PubMed1996

Percutaneous endoscopic gastrojejunostomy with a tapered tip, nonweighted jejunal feeding tube: improved placement success.

OBJECTIVES: Gaining enteral access to the small bowel for patients unable to tolerate gastric feedings is a difficult challenge for today's endoscopist. A new over-the-guidewire method for placement of a percutaneous endoscopic gastrojejunostomy (PEG/J) is prospectively studied using a nonweighted, tapered tip, distal feed through jejunal tube (J-tube). METHODS: Twenty five hospitalized patients were referred to the nutrition service for enteral access. A Wilson-Cook 24/12-French PEG/J system was placed and followed until removal or patient death. RESULTS: The PEG/J system was placed in 25/25 patients in an average of 26 min and 45 s. The tip of the J-tube was in the distal duodenum in 52% of patients and in the jejunum in 48% of patients. J-tube complications occurred in 20% of patients and included one incidence of clogging (4%) and four cases of inadvertent removal (16%). Average longevity of the J-tube was 63.9 days, with most patients converted to either oral or gastric feedings. CONCLUSION: The use of an nonweighted, tapered tip J-tube and the over-the-guidewire placement technique has resulted in a reliable method of accessing the small bowel for enteral nutrition.

Adult↗
PubMed1994

A novel beta-thalassaemia mutation in the 5' untranslated region of the beta-globin gene.

A thymidine deletion at position +10 of the 5' untranslated region of the beta-globin gene was detected in a beta-thalassaemia intermedia patient carrying a beta(0)39 stop codon mutation on the other chromosome; this new mutation, +10(-T), was detected by automated fluorescent DNA sequencing and verified by dot-blot allele-specific hybridizations. The +10(-T) mutation is a 'silent carrier', is associated with a reduced amount of steady-state beta-globin mRNA, and establishes a connection between the 5' untranslated region of the beta-globin gene and the regulation of its expression.

Aged↗
PubMed1992

Long-term followup of 150 patients with testicular cancer treated at a single institution.

Between 1977 and 1988, 150 patients with disseminated primary testicular germ cell tumors were treated with cisplatin, vinblastine and bleomycin. Of the 150 patients 90 (60%) achieved a complete response to chemotherapy. An additional 33 patients achieved a complete response after removal of residual masses following chemotherapy. Thus, 123 of 150 patients (82%) achieved a disease-free status following chemotherapy with or without an operation. After a median followup of 49 months the estimated long-term probability of remaining without failure and of surviving is 77%. With this data base a multivariate analysis of prognostic factors determined the Indiana University staging system to be highly predictive. Other staging systems proved to be less useful. The subset of patients with minimal and moderate disease by Indiana staging containing mature teratoma in the orchiectomy specimen has a particularly excellent prognosis (99% actuarial survival) with chemotherapy.

Adolescent↗
PubMed1992

Genotypic confirmation from the original dried blood specimens in a neonatal hemoglobinopathy screening program.

Dried blood spots are used for newborn screening because of ease of sample collection, handling, and shipment. DNA is stable and accessible in the filter paper matrix. Genotypic confirmation using initial specimens is demonstrated for a regional screening program. Seventy-five blinded samples underwent DNA analysis after Hb electrophoresis. DNA was microextracted from a 1/2-inch semicircle (25 microL whole blood equivalent), amplified, and analyzed by four different methods. Direct amplification without microextraction and automated sequencing from microextracted DNA also was performed. All four analyses agreed for the A and S alleles in 70 of 75 specimens. Three disagreements were clarified by the other semicircle from the original sample: two were due to polymerase chain reaction contamination and one to contamination of one of four analytical tests. Two would have required analysis of a second specimen, one because of polymerase chain reaction failure and the second because the patient had S/beta-thalassemia. Direct amplification without microextraction was successful in an additional 77 of 78 specimens for analysis of the A, S, C, and E alleles. Automated direct sequencing from microextracted DNA was demonstrated for the A, S, and C alleles. Analysis of microextracted DNA from dried blood specimens for A and S alleles reduced the need for and costs of obtaining a second specimen for confirmation by 97%. Direct amplification without microextraction for analysis of A, S, and C alleles permits additional reduction in personnel time and costs. We have demonstrated that microextracted DNA is amenable to automated sequencing after asymmetric polymerase chain reaction. Direct genotypic confirmation can facilitate diagnosis and initiation of medical intervention.

Alleles↗
PubMed1989

The variable effects of angiotensin converting enzyme inhibition on myocardial ischaemia in chronic stable angina.

The effect of angiotensin converting enzyme inhibition on myocardial ischaemia was studied in 12 normotensive patients with chronic stable angina and exercise induced ST segment depression. The study was randomised, double blind, placebo controlled, and crossover with treatment periods of two weeks. Enalapril was used to inhibit angiotensin converting enzyme. Assessment was by angina diaries and maximum symptom limited treadmill exercise tests. The results for the whole group showed a significant reduction in systolic blood pressure at rest and at peak exercise. Mean total exercise duration was 466 s (95% confidence interval 406 to 525) when the patients were taking placebo and 509 s (436 to 583) when they were taking enalapril. Four patients prolonged their total exercise time (mean 450 to mean 591 s) by more than 20%. Two patients, however, developed ischaemia earlier on exercise and reduced their total exercise duration (mean 490 to mean 390 s). Although angiotensin converting enzyme inhibition tended to reduce myocardial ischaemia in the group as a whole, some patients improved while others deteriorated. Thus the effects of enalapril are variable and this may have important implications when enalapril is used to treat heart failure in patients with underlying severe ischaemic heart disease.

Aged↗
PubMed1985

Weight control.

Explore the source record for details and available documents.

Body Weight↗
PubMed1984

Intraoperative antibiotic irrigation as prophylaxis in abdominal hysterectomy: a preliminary report.

A preliminary report regarding the use of an intraoperative, intraperitoneal antibiotic solution in patients having transabdominal hysterectomy reveals that the postoperative morbidity assessed by the diagnosis of cuff cellulitis or pelvic abscess was 4.7%. This morbidity represents a substantial reduction in the incidence of cuff cellulitis (27.0%) noted in a comparison group of 367 patients having abdominal hysterectomy at our institution during a two-year period. These preliminary data strongly suggest that antibiotic solutions given intraperitoneally at the time of abdominal hysterectomy reduce morbidity due to cuff cellulitis.

Abscess↗