Biomedical subjects

F E Barr

Publications and source records attributed to F E Barr.

5 recordsLinked to original sources

PubMed2001

Modified Norwood operation for hypoplastic left heart syndrome.

BACKGROUND: We examined early results in infants with hypoplastic left heart syndrome undergoing the Norwood operation with perioperative use of inhaled nitric oxide and application of extracorporeal membrane oxygenation. METHODS: Medical records were reviewed retrospectively. RESULTS: Between April 1997 and March 2001, 50 infants underwent a modified Norwood operation for hypoplastic left heart syndrome. Mean age at operation was 7.5 +/- 5.7 days, and mean weight was 3.1 +/- 0.5 kg. Five infants had a delayed operation because of sepsis. The mean diameter of the ascending aorta by echocardiography was 3.6 +/- 1.8 mm. Ductal cannulation was used to establish cardiopulmonary bypass in all patients. Mean circulatory arrest time was 39.4 +/- 4.8 minutes. The size of the pulmonary-systemic shunt was 3.0 mm in 6 infants, 3.5 mm in 37, and 4.0 mm in 7. Infants with persistent hypoxia (partial pressure of oxygen < 30 mm Hg) received nitric oxide after they were weaned from cardiopulmonary bypass. Extracorporeal membrane oxygenation was initiated in 8 infants in the pediatric intensive care unit primarily for low cardiac output and in 8 in the operating room because of the inability to separate them from cardiopulmonary bypass. The 30-day mortality rate was 22% (11 of 50 patients), and the hospital mortality rate was 32% (16 of 50 patients). Mean follow-up was 17 months. Ten patients (20%) underwent stage-two repair, with one operative death. One survivor had a Fontan procedure, and 2 underwent heart transplantation, with one death. CONCLUSIONS: Early application of extracorporeal membrane oxygenation for hemodynamic instability and selective use of nitric oxide for persistent hypoxia in the immediate postoperative period may improve survival of patients with hypoplastic left heart syndrome. Renal failure requiring hemofiltration during extracorporeal membrane oxygenation (p < 0.05) and cardiopulmonary arrest in the pediatric intensive care unit (p < 0.05) were predictors of hospital mortality.

Administration, Inhalation↗

PubMed2000

The pharmacologic mechanism by which inhaled epinephrine reduces airway obstruction in respiratory syncytial virus-associated bronchiolitis.

Inhaled racemic epinephrine relieves airway obstruction in patients with respiratory syncytial virus bronchiolitis. The contribution of alpha- versus beta-adrenoreceptor stimulation toward this clinical effect is unknown. We describe an infant treated with propranolol for supraventricular tachycardia in whom respiratory syncytial virus bronchiolitis developed. Inhaled racemic epinephrine improved his respiratory symptoms, whereas nebulized albuterol did not.

Administration, Inhalation↗

PubMed2000

Use of high-dose corticosteroids and high-frequency oscillatory ventilation for treatment of a child with diffuse alveolar hemorrhage after bone marrow transplantation: case report and review of the literature.

BACKGROUND: Other than relapse, pulmonary complications are the most common cause of mortality in patients who undergo bone marrow transplantation (BMT). Diffuse alveolar hemorrhage (DAH) is one noninfectious pulmonary complication of BMT. Presenting clinical findings include nonproductive cough usually without hemoptysis, dyspnea, hypoxemia, a decrease in hematocrit, and diffuse infiltrates on chest radiograph. PATIENT: We report a case of DAH after allogeneic BMT in a 6-yr-old female patient. Although a chest radiograph revealed patchy bilateral alveolar densities and large volumes of bright red blood were suctioned from the endotracheal tube, there was no evidence of coagulopathy and no infectious agent was identified on examination of bronchoalveolar lavage fluid, blood, and urine. INTERVENTION: The child was treated with high-dose corticosteroids and high-frequency oscillatory ventilation and experienced a complete clinical recovery from her pulmonary disease. RESULTS: The definition, presenting symptoms, findings and timing, and associated risk factors of DAH after BMT are reviewed. Prospective hypotheses for the pathogenesis of DAH after BMT are presented. Evidence for the role of high-dose corticosteroids for treatment of DAH after BMT and the role of high-frequency oscillatory ventilation for treatment of acute hypoxemic respiratory failure in children with diffuse alveolar disease is also reviewed. CONCLUSION: This case supports the contention that early treatment with high-dose corticosteroids is warranted in children with DAH after BMT.

Bone Marrow Transplantation↗

PubMed2000

Surfactant protein-A enhances uptake of respiratory syncytial virus by monocytes and U937 macrophages.

Surfactant protein (SP)-A is a known opsonin for a variety of pulmonary pathogens. SP-A enhances ingestion of these pathogens by interaction with an SP-A receptor (SP-AR) found on phagocytic cells such as peripheral blood monocytes (PBMC) and alveolar macrophages. Respiratory syncytial virus (RSV) is the most important respiratory pathogen in children. Recent studies have indicated that SP-A levels may be decreased in RSV bronchiolitis and pneumonia. In this study we examined the role of SP-A in uptake of RSV by both PBMC and U937 macrophages, a human macrophage cell line known to express SP-ARs. In addition, we studied the effect of SP-A- mediated uptake of RSV on production of tumor necrosis factor (TNF)-alpha and interleukin (IL)-10 by these cells because incomplete immunity to recurrent RSV infection has been partially attributed to abnormal cytokine responses by macrophages. SP-A enhanced binding and uptake of fluorescently labeled RSV (RSV-FITC) by PBMC in a dose-dependent manner, with a maximal effect seen with 10 to 15 microg/ml SP-A as measured by both percent fluorescent monocytes and linear mean fluorescence (lmf) of individual cells. SP-A also enhanced uptake of RSV-FITC by U937 macrophages, with a maximal effect seen with 20 microg/ml SP-A as measured by both percent fluorescent monocytes and lmf. With respect to TNF-alpha levels, RSV alone slightly enhanced TNF-alpha production by PBMC and decreased TNF-alpha production by U937 macrophages measured at 12 h after addition of RSV. SP-A-mediated uptake of RSV significantly enhanced TNF-alpha production by PBMC and reversed the RSV-induced depression of TNF-alpha by U937 macrophages. RSV significantly enhanced IL-10 production by both cell types, which was reversed by SP-A-mediated uptake. These findings suggest that SP-A is an important opsonin for RSV and that SP-A-mediated uptake of RSV may alter some of the unusual cytokine responses that are postulated to be involved in incomplete immunity to recurrent infection.

Humans↗

PubMed1983

Melanin: the organizing molecule.

The hypothesis is advanced that (neuro)melanin (in conjunction with other pigment molecules such as the isopentenoids) functions as the major organizational molecule in living systems. Melanin is depicted as an organizational "trigger" capable of using established properties such as photon-(electron)-phonon conversions, free radical-redox mechanisms, ion exchange mechanisms, and semiconductive switching capabilities to direct energy to strategic molecular systems and sensitive hierarchies of protein enzyme cascades. Melanin is held capable of regulating a wide range of molecular interactions and metabolic processes primarily through its effective control of diverse covalent modifications. To support the hypothesis, established and proposed properties of melanin are reviewed (including the possibility that (neuro)melanin is capable of self-synthesis). Two "melanocentric systems"--key molecular systems in which melanin plays a central if not controlling role--are examined: 1) the melanin-purine-pteridine (covalent modification) system and 2) the APUD (or diffuse neuroendocrine) system. Melanin's role in embryological organization and tissue repair/regeneration via sustained or direct current is considered in addition to its possible control of the major homeostatic regulatory systems--autonomic, neuroendocrine, and immunological.

Animals↗