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Biomedical subjects

S B Corn

Publications and source records attributed to S B Corn.

9 recordsLinked to original sources
PubMed1998

Thrombopoietin in normal pregnancy and preeclampsia.

OBJECTIVE: In normal pregnancy and pregnancies complicated by preeclampsia it has been demonstrated that there is increased activation of platelets and the clotting and fibrinolytic system. We measured plasma levels of thrombopoietin, a major regulator of platelet production in these conditions. STUDY DESIGN: We compared the thrombopoietin plasma levels of healthy term pregnant patients (n = 21) with those of healthy nonpregnant controls (n = 17), as well as patients with severe preeclampsia (n = 8) and the hemolysis, elevated liver enzymes, low platelets syndrome (n = 6). RESULTS: Thrombopoietin levels in normal pregnant patients and pregnancies complicated by the hemolysis, elevated liver enzymes, low platelets syndrome were statistically significantly higher than thrombopoietin levels in nonpregnant controls. Data were analyzed with the Kruskal-Wallis one-way analysis of variance by ranks. CONCLUSIONS: This study is the first to report thrombopoietin levels in pregnancy. Thrombopoietin levels are significantly greater in pregnant patients and in pregnancies complicated by the hemolysis, elevated liver enzymes, low platelets syndrome compared with nonpregnant controls.

Adult↗
PubMed1996

The anesthesia machine valve tester: a new device and method for evaluating the competence of unidirectional anesthetic valves.

OBJECTIVE: Current methods of determining anesthesia machine unidirectional valve (UDV) competence are time-consuming, ineffective, or carry the risk of transmitting infectious disease to the anesthetist or patient. New methods of testing these valves are needed. The purpose of this study was to determine the prevalence of incompetent UDVs at one institution by employing the Anesthesia Machine Valve Tester (AMVT), a new way to test anesthesia machine UDVs. METHODS: We tested each expiratory and inspiratory UDV on all anesthesia machines in functioning operating rooms at the Brigham and Women's Hospital. If a UDV was found to be incompetent, we cleaned and reseated it, and then tested it again with the AMVT. RESULTS: We found a 13% prevalence of UDV malfunction in our machines. Three of the 10 incompetent valves were repaired quickly by us and were made competent by either reseating the valve or by first cleaning and then reseating it. CONCLUSIONS: We found that the AMVT was able to detect UDV failure quickly with no risk to the tester or to the patient. We conclude that the AMVT can be used to check the UDV as recommended by the FDA anesthesia machine check-out protocol.

Anesthesia, Closed-Circuit↗
PubMed1983

Substrate and phospholipid specificity of the purified mannitol permease of Escherichia coli.

D-Mannitol is transported and phosphorylated by a specific enzyme II of the phosphotransferase system of Escherichia coli. This protein was purified previously in detergent solution and has been partially characterized. As one approach in understanding the structure and mechanism of this enzyme/permease, we have tested a number of sugar alcohols and their derivatives as substrates and/or inhibitors of this protein. Our results show that the mannitol permease is highly, but not absolutely, specific for D-mannitol. Compounds accepted by the enzyme include those with substitutions in the C-2(= C-5) position of the carbon backbone of the natural substrate as well as D-mannonic acid, one heptitol and one pentitol. All of these compounds were both inhibitors and substrates for the mannitol permease except for D-mannoheptitol, which was an inhibitor but was not phosphorylated by the enzyme. No compound examined, however, exhibited an affinity for the enzyme as high as that for its natural substrate. We have also investigated the phospholipid requirements of the mannitol permease using phospholipids purified from E coli. The purified protein was significantly activated by phosphatidylethanolamine, but little activation was observed with phosphatidylglycerol or cardiolipin. These observations partially delineate requirements for interaction of sugar alcohols and phospholipids with the mannitol permease. They suggest approaches for the design of specific active site probes for the protein, and strategies for stabilizing the enzyme's activity in vitro.

Escherichia coli↗