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Biomedical subjects

D R Andrews

Publications and source records attributed to D R Andrews.

6 recordsLinked to original sources

Use of the Medtronic Freestyle valve as a right ventricular to pulmonary artery conduit.

BACKGROUND: We have used the Medtronic Freestyle bioprosthesis as a right ventricular to pulmonary artery conduit recently in an attempt to overcome some of the problems associated with homografts and stented xenografts. The aim of this study was to review the performance of this prosthesis. METHODS: Prospectively collected data for patients having Freestyle bioprostheses implanted as a right ventricular to pulmonary artery conduit were reviewed to assess clinical outcome and echocardiographic results. RESULTS: Thirteen patients aged 13 days to 22.5 years (median, 7.9 years) underwent either primary repair (n = 5) or change of conduit (n = 8) using the Freestyle bioprosthesis. One neonate with truncus arteriosus died postoperatively of pulmonary hypertension. One conduit was explanted 27 months after repair of neonatal truncus arteriosus. There has been no incidence of significant prosthetic regurgitation, thromboembolism, or endocarditis at mean follow-up of 10.1 months (range, 2 weeks to 29 months). CONCLUSIONS: The Medtronic Freestyle valve is a reliable pulmonary valve substitute in the short term. Early results justify continued clinical use of the device in this setting with close follow-up.

Adolescent↗

Tracheal mucormycosis.

Pulmonary mucormycosis is a recognized entity occurring in diabetics and immunocompromised patients. It has a poor prognosis unless early diagnosis is made and appropriate surgical therapy instituted along with appropriate antifungal therapy. We describe here one of few cases of tracheal involvement by mucormycosis. Extensive destruction of the trachea and bibasal pneumonia led to the patient's death.

Aged↗

Effect of heat shock on synthesis and phosphorylation of nuclear and cytoplasmic proteins in the fungus Achlya.

Heat shock induced by an increase in temperature from 28 to 37 degrees C led to changes in synthesis and phosphorylation of cytoplasmic and nuclear proteins in the aquatic fungus Achlya. In the cytoplasmic fraction a marked increase in [35S]methionine labelling of proteins in the molecular weight range of 96 000, 85 000, 74 000, and 70 000 was observed. Two-dimensional electrophoresis resolved each of these classes of proteins into several components. Major changes in the nuclear fraction included the increased [35S]methionine labelling of 43 000 and 28 000-23 000 proteins. A marked decline in the synthesis of many other proteins was also evident. The heat-shock-induced changes in labelling patterns became evident as early as 20 to 60 min after treatment, but they were transient. With continued incubation at the heat-shock temperature, the cells appeared to adapt to the new temperature conditions. Both cytoplasmic and nuclear proteins returned to nearly normal labelling patterns within 100 to 140 min at 37 degrees C. Changes in phosphorylation of histone and nonhistone nuclear proteins were also noted. Achlya histone H3 and the putative oomycete-specific histone "alpha" appeared highly phosphorylated after heat shock. Since phosphorylation of histone H3 is primarily associated with chromatin condensation, it is possible that rapid chromatin condensation is an initial response to heat shock in Achlya.

Cells, Cultured↗