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Biomedical subjects

M Evans

Publications and source records attributed to M Evans.

At least 19 recordsLinked to original sources
PubMed1992

Subxiphoid approach for implantable cardioverter defibrillator in patients with previous coronary bypass surgery.

From February 1988 until August 1991, 28 patients with prior coronary artery bypass grafting (CABG) received implantable cardioverter defibrillator (ICD) therapy via a subxiphoid approach. Only one patient required conversion to a median sternotomy incision. The mean defibrillation threshold was 11.9 +/- 4.4 J. The mean R wave was 8.2 +/- 3.7 mV. One perioperative death occurred due to heart failure (mortality rate 1/28 [3.50%]). No patient required reexploration for bleeding. The subxiphoid method for ICD electrode implantation is safe and reliable in patients with prior CABG surgery.

Coronary Artery Bypass↗
PubMed1979

Prevention by pyrazole of the effects of chronic ethanol administration on the redox states of the hepatic nicotinamide--adenine dinucleotide (phosphate) couples and on liver and brain tryptophan metabolism in the rat.

Chronic administration of pyrazole in the diet of rats does not cause toxicity and prevents the chronic effects of ethanol on: (1) the redox states of the hepatic NAD(P) couples; (2) liver tryptophan pyrrolase activity; (3) brain tryptophan and 5-hydroxytryptamine metabolism.

Animals↗
PubMed1979

Enhancement of rat brain tryptophan metabolism by chronic ethanol administration and possible involvement of decreased liver tryptophan pyrrolase activity.

1. Chronic ethanol administration enhances rat brain 5-hydroxytryptamine synthesis by increasing the availability of circulating tryptophan to the brain. This increased availability is not insulin-mediated or lipolysis-dependent. 2. Under these conditions, tryptophan accumulates in the liver and apo-(tryptophan pyrrolase) activity is completely abolished, but could be restored by administration of regenerators of liver NAD+ and/or NADP+. 3. All four regenerators used (fructose, Methylene Blue, phenazine methosulphate and sodium pyruvate) prevented the ethanol-induced increase in liver tryptophan concentration and the increased availability of tryptophan to the brain. 4. It is suggested that the enhancement of brain tryptophan metabolism by chronic ethanol administration is caused by the decreased hepatic tryptophan pyrrolase activity. The results are briefly discussed in relation to previous work with ethanol. 5. Fructose enhances the conversion of tryptophan into 5-hydroxyindol-3-ylacetic acid in brains of ethanol-treated rats, whereas Methylene Blue inhibits this conversion in both control and ethanol-treated animals.

Animals↗
PubMed1979

Colour lymphography in clinical surgery.

In 38 patients undergoing femoral artery profundaplasty and in 18 having simple mastectomy with pectoral node biopsy, a 6.2 per cent solution of sodium sulphan blue was injected peripherally to outline the lymph nodes in the groin or axilla. Nodes and vessels were easily seen and the technique is now in routine use.

Breast Neoplasms↗
PubMed1979

Fetal mediators of the relationships between increased pregnancy and labour blood pressure and newborn irritability.

A prospective study of primiparous English women and their newborns failed to replicate previous findings that greater irritability was related to higher maternal blood pressure during pregnancy and labour. This apparent lack of replication prompted a search for fetal variables capable of mediating the blood pressure--irritability relationships. Relative fetal growth retardation was found in newborns of women whose peak antenatal blood pressure occurred from 20 to 32 wk gestation. Prenatal growth retardation and exposure to either oxytocin-stimulated labour or higher maternal blood pressure during spontaneous labour were associated with lower intrapartum fetal heart rate. Lower heart rate, in turn, was associated with greater crying and more frequent changes of state during behavioural assessments on the first and fifth days. It is suggested that intrapartum hypoxia is an immediate antecedent of newborn irritability. The blood pressure--irritability relationships may therefore reflect the influence of growth retardation, attributable to increased pregnancy blood pressure, and higher labour blood pressure, respectively, on the ability of the fetus to withstand hypoxia and the degree of hypoxia encountered during labour.

Anesthesia, Obstetrical↗
PubMed1979

The influence of intra-incisional clindamycin on the incidence of wound sepsis after abdominal operations.

Two hundred and thirty consecutive patients undergoing laparotomy were randomly allocated to one of three single-dose intra-incisional prophylactic regimens: clindamycin, clindamycin plus cephaloridine, and cephaloridine alone. Wounds were classified on a bacteriological basis into four groups: clean, potentially contaminated, lightly contaminated and heavily contaminated. The first two of these groups had a low incidence of wound sepsis (6.6%), the third an incidence of 19.7% and the last of 53.1%. In the latter two groups clindamycin was a significantly less effective prophylactic than cephaloridine, and the combination of the two antibiotics was no more efficacious than cephaloridine alone. The high in vitro activity of cindamycin against Bacteroides species was not mirrored in vivo.

Abdomen↗
PubMed1979

Bioavailability of chlorpropamide.

1. The serum profiles of chlorpropamide obtained following single doses of two tablet preparations and from a suspension formulation have been compared in healthy volunteers. The amounts of chlorpropamide absorbed from the three formulations were similar but the drug was absorbed more rapidly from the suspension than from either tablet formulation. There was a small but therapeutically insignificant difference in the rate of absorption of the drug from the two tablets. 2. Changes in blood glucose concentrations were found to be related to the drug serum profile characteristics of the formulations.

Adolescent↗
PubMed1979

Disposition of indomethacin in preterm infants.

Indomethacin is currently used for the pharmacologic closure of PDA in preterm infants with respiratory distress syndrome. However, the response to the drug has been variable and the disposition of the drug in preterm infants is not well understood. We studied the pharmacokinetics of indomethacin in nine preterm infants with birth weights ranging from 800 to 1,960 gm and gestational ages of 28 to 36 weeks. Three different dose schedules (0.1, 0.25, 0.3 mg/kg dose) were used. The plasma half-life of indomethacin ranged from 11 to 20 hours. Peak levels were achieved within four hours and ranged from 0.027 to 0.310 microgram/ml. The half-life in infants less than 32 weeks' gestation was significantly prolonged compared to that in infants greater than 32 weeks. Protein-binding studies with 14C indomethacin showed that 98% of indomethacin was protein bound. Absorption of orally administered indomethacin appears to be poor and incomplete. No immediate major complications could be correlated to indomethacin therapy in this study.

Birth Weight↗
PubMed1979

Hormonal aspects of suction drainage after thyroidectomy.

Suction drainage, after thyroidectomy, for a variety of conditions, varied between zero and 92.5 milliliters. The levels of thyroxine in this fluid were greater than those in the serum, at the same time being an average of 14.0 micrograms per 100 milliliters. The loss of thyroxine for 24 hours could represent up to 11.6 per cent of the total serum thyroxine pool. The serum thyroxine level, after initial fluctuation in either direction settled down, or up, to an average euthyroid level of 6.09 micrograms per 100 milliliters by the 21st day after operation. Possible factors influencing these changes have been considered and discussed. Such changes did not outweigh the advantages most surgeons found in drainage but could be eliminated if the ideal of no drainage could be attained. There was no evidence of exfoliated acinar cells in the drainage fluid.

Female↗