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Biomedical subjects

L George

Publications and source records attributed to L George.

At least 37 records · Page 2Linked to original sources
PubMed1995

Percutaneous use of stents to correct pulmonary artery stenosis in young children after cavopulmonary anastomosis.

Pulmonary artery distortion is a risk factor among candidates for the Fontan procedure. In 57 patients evaluated by catheterization after successful cavopulmonary anastomosis, 8 had proximal left pulmonary artery (LPA) stenosis, either discrete (4 patients) or long segment (4 patients). Median age was 27 months (range 19 to 60 months). Median weight was 11.4 kg (range 9.1 to 20.0). Mean diameter at LPA stenosis was 4.4 +/- 0.4. Proximal right pulmonary artery mean diameter was 10.4 +/- 1.0 mm. After angiographic and hemodynamic assessment, short 11F sheaths were placed in the right internal jugular (6 patients) or subclavian veins (2 patients). Pulmonary artery angioplasty and stent placement were performed. LPA stenoses were enlarged using 10 Palmaz stents dilated to 10 mm (7 patients) or to 12 mm (3 patients). Poststent angiograms showed that narrowest LPA dimensions were significantly enlarged to 9.9 mm +/- 1.0 mm, p < 001). There were no complications. Follow-up studies (catheterizations in 4 patients, echocardiograms in 8 patients) were performed 4 to 9 months after stent implantation. No restenosis was observed. Five patients had completion of their Fontan procedures; three patients are pending Fontan completion. This study demonstrates the efficacy and safety of the percutaneous use of Palmaz stents to correct pulmonary artery stenosis in young children after cavopulmonary anastomosis.

Child, Preschool↗
PubMed1995

Measurement of serum concentrations of inhibin-A (alpha-beta A dimer) during human pregnancy.

OBJECTIVE: The aims were to measure concentrations of inhibin-A (alpha-beta A dimer) in peripheral serum during normal human pregnancy, to establish which molecular weight form(s) are present in pregnancy serum and to relate the concentrations of inhibin-A to those of oestradiol and progesterone. DESIGN: In a retrospective cross-sectional study 211 serum samples collected at 2-week intervals from week 8 to 38 of gestation were analysed for inhibin-A by enzyme immunoassay and oestradiol and progesterone by radioimmunoassay. Pooled samples corresponding to first, second and third trimester were subsequently used for fast protein liquid chromatography chromatographic analysis of inhibin forms present. PATIENTS: Blood samples were obtained from normal pregnant women attending the antenatal clinic. RESULTS: Concentrations of inhibin-A in peripheral serum gradually decreased from 1.76 +/- 0.15 microgram/l in week 8 of gestation to 0.86 +/- 0.12 microgram/l in week 16 (P < 0.01). Concentrations remained low during the second trimester but increased markedly (P < 0.01) during the third trimester reaching a maximal value of 5.68 +/- 0.89 microgram/l in week 36. Chromatographic analysis of pooled serum samples from the first, second and third trimester showed that the fully processed 31-kDa molecule is the predominant circulating form of inhibin-A throughout human gestation. Likewise, only the 31-kDa form was identified in extracts of term placenta which contained approximately 20 micrograms inhibin-A/kg tissue. CONCLUSION: Inhibin-A, principally the 31-kDa form, is present in peripheral blood throughout human gestation at concentrations up to 50 times greater than maximum values found during the spontaneous menstrual cycle (approximately 100 ng/l). The finding of highest serum values during the third trimester and of significant concentrations in term placenta firmly support a placental rather than luteal origin for this material.

Cross-Sectional Studies↗
PubMed1995

Health care network communications infrastructure: an engineering design for the Military Health Service System.

The Military Health Service System (MHSS) provides health care for the Department of Defense (DOD). This system operates on an annual budget of $15 Billion, supports 127 medical treatment facilities (MTFs) and 500 clinics, and provides support to 8.7 million beneficiaries worldwide. To support these facilities and their patients, the MHSS uses more than 125 different networked automated medical systems. These systems rely on a heterogeneous telecommunications infrastructure for data communications. With the support of the Defense Medical Information Management (DMIM) Program Office, our goal was to identify the network requirements for DMIM migration and target systems and design a communications infrastructure to support all systems with an integrated network. This work used tools from Business Process Reengineering (BPR) and applied it to communications infrastructure design for the first time. The methodology and results are applicable to any health care enterprise, military or civilian.

Computer Communication Networks↗
PubMed1995

Informed consent.

Explore the source record for details and available documents.

Dental Care↗
PubMed1994

Percutaneous closure of the small patent ductus arteriosus using occluding spring coils.

OBJECTIVES: This report summarizes our experience with the use of occluding spring coils to close the small patent ductus arteriosus. BACKGROUND: Several patent ductus arteriosus occluders (most notably the Rashkind device) have been developed and studied. Occluding spring coils have been used to close abnormal vessels and vascular connections. We previously reported the use of occluding spring coils to close the small patent ductus arteriosus in a small group of patients. This report describes our series of patients having patent ductus arteriosus closure with occluding spring coils. METHODS: Between June 1990 and June 1993, 30 patients underwent cardiac catheterization to have patent ductus arteriosus closure by occluding spring coils. Selection criteria were age > 6 months and narrowest patent ductus arteriosus internal dimension < or = 3.0 mm by color flow imaging. Definitive selection was based on review of aortograms performed at catheterization. A 5.2F coronary catheter was used to deliver one or two standard occluding spring coils. A loop was delivered in the main pulmonary artery, and the remainder of the coil was delivered across the patent ductus arteriosus and into the aortic diverticulum. Patent ductus arteriosus closure was confirmed by aortography or color flow imaging, or both. Follow-up after coil placement occurred at 6 weeks and 6 months and included two-view chest radiography, echocardiography and color flow imaging. RESULTS: Of the 30 patients, 29 had successful implantation by one (27 patients) or two (2 patients) occluding spring coils. Of these 29 patients, 19 had a clinically apparent and 10 had a silent patent ductus arteriosus. Average ductus minimal internal dimension was 1.7 mm (range 1.0 to 3.0). Complete closure of the ductus was confirmed in 27 patients by aortography or color flow imaging or both (in 24 within 4 h, in 2 after 6 weeks and in 1 after 6 months). Six weeks after implantation, two patients had a tiny residual patent ductus arteriosus noted on color flow imaging. One patient did not have successful implantation. This patient had a 3.2-mm ductus, and two coils migrated to the distal left pulmonary artery and could not be retrieved. There were no deaths or any significant complications noted during early or late follow-up in these patients. CONCLUSIONS: Occluding spring coils may have additional application in closing the small patent ductus arteriosus.

Aortography↗
PubMed1993

Management of systemic atrioventricular valve regurgitation in infants and children.

Since September 1979, 53 patients have required operation for systemic atrioventricular valve regurgitation at Children's Hospital and Health Center of San Diego. (Primary repairs of atrioventricular canal defects are excluded from this report.) Diagnoses include single ventricle, cardiomyopathy, congenital mitral insufficiency , Marfan's disease, rheumatic heart disease, and a history of prior repair of atrioventricular canal defect. Ages ranged from 4 months to 19 years; median age is 5 years. In 31 patients, the atrioventricular valve could be repaired. In 24 patients, the valve was replaced (including two patients previously repaired). There were four operative deaths, all in the valve replacement group: three following valve replacement, and one following emergency thrombectomy. Two early failures in the repair group required valve replacement. Techniques for repair included leaflet resection, commissural annuloplasty, ring annuloplasty, and chordal shortening. Follow-up reveals good-to-excellent status in 38 patients. There were seven late deaths: six following valve replacement (one death valve related). Current surgical technique permits repair of the systemic atrioventricular valve in many infants and children requiring operation for regurgitation. The long-term results of valve repair are good to excellent. Repair avoids the morbidity and mortality of valve replacement, e.g., anticoagulation, fixed orifice size, and catastrophic mechanical valve malfunction.

Actuarial Analysis↗
PubMed1993

Infection rates, disease frequency, pilin gene rearrangement, and pilin expression in calves inoculated with Moraxella bovis pilin-specific isogenic variants.

Pili have been implicated as virulence factors that result in increased infectivity of Moraxella bovis, the causative agent of infectious bovine keratoconjunctivitis (IBK). Healthy calves' eyes were inoculated with I- or Q-piliate or nonpiliate M bovis Epp63 to compare the pathogenicity of these isogenic variants. Pathogenicity was determined by the rate of persistent M bovis infection and the prevalence of clinical IBK. Inoculation with M bovis expressing the Q pili resulted in the highest frequency of infection and IBK, whereas I-piliate M bovis elicited a lower rate and nonpiliate M bovis did not result in infection. In vivo pilin gene rearrangement and pilin-type switching were evaluated by DNA hybridization and immunoblot. Gene rearrangement and type switching varied dependently, and were observed only in eyes inoculated with Q-piliate M bovis. This study suggests that Q pili are specific for colonization of bovine corneal epithelium, whereas I pili enable maintenance of an established infection.

Animals↗
PubMed1993

Improved outcomes in intensive care units for AIDS-related Pneumocystis carinii pneumonia: 1987-1991.

Respiratory failure due to Pneumocystis carinii pneumonia (PCP) is the most common complication requiring an intensive care unit (ICU) for persons with AIDS. In this study, we evaluated patterns of ICU use for ICU patients with first-episode PCP in 15 Veterans Administration Medical Centers from 1987 to 1991. Twelve percent of all patients with PCP received care in the ICU. The survival rates improved steadily during these years. Although there was little variation in the relative frequency of ICU use, the effectiveness of ICU use appeared to improve over time. In the more recent years, relatively more survivors and relatively fewer nonsurvivors received care in an ICU. Changes in medical practice such as adjunctive use of steroids for severe cases of PCP and more effective use of scarce resources may account for the improved survival rates for patients with PCP who are treated in an ICU.

AIDS-Related Opportunistic Infections↗
PubMed1992

Hypertrophic osteopathy in three horses and a pony.

Hypertrophic osteopathy was diagnosed in 3 horses and in a pony, ranging in age from 8 to 21 years. There were 2 females, 1 sexually intact male, and 1 gelding. In 3 animals, hypertrophic osteopathy was associated with pulmonary abscesses, bronchogenic squamous cell carcinoma, and ovarian granulosa-cell tumor, respectively, and resulted in death or euthanasia. Duration of the condition ranged from 1 to 4 months. In 1 horse, hypertrophic osteopathy was believed to be secondary to pregnancy, and resolved following uncomplicated delivery of a live foal.

Animals↗
PubMed1992

Relation between hospital experience and in-hospital mortality for patients with AIDS-related Pneumocystis carinii pneumonia: experience from 3,126 cases in New York City in 1987.

There is marked debate about whether outcomes of care, particularly mortality, vary as a function of hospital and physician experience with a disease. This issue is especially important with respect to AIDS because greater than 200,000 individuals have now been diagnosed with this disease. We analyzed discharge data for 3,126 persons with AIDS who had Pneumocystis carinii pneumonia and who were treated at one of 73 New York City hospitals in 1987. In-hospital mortality was 25%. Factors associated with higher chances of short-term death were older age, being black, not having private health insurance, and being severely ill. A logistic regression model indicated that after controlling for differences in patient and hospital characteristics, the chances of death decreased when care was given at hospitals with higher caseloads of patients with Pneumocystis carinii pneumonia. Our findings suggest that hospital experience may decrease mortality in this subset of patients with human immunodeficiency virus disease, although it is unknown whether this is due to differences in quality of care.

Acquired Immunodeficiency Syndrome↗