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Biomedical subjects

M J Carmichael

Publications and source records attributed to M J Carmichael.

27 records · Page 2Linked to original sources
PubMed1983

Aortic and mitral valve replacement through a single transverse aortotomy: a useful approach in difficult mitral valve exposure.

Replacement of the mitral valve through a standard vertical left atriotomy in patients requiring both aortic and mitral valve replacement can be very difficult. This is especially true in patients who have undergone previous median sternotomy. Replacement of the mitral valve through the aortic root after excision of the aortic valve is described in two case reports. This is a convenient approach when traditional exposure of the mitral valve is impractical in patients requiring double valve replacement.

Journal Article↗
PubMed1982

Comparison of body protein metabolism during total parenteral nutrition using glucose or glucose and fat as the energy source.

Direct measurement of body protein metabolism using L-(1-14C) leucine during total parenteral nutrition following cholecystectomy demonstrated no significant difference between isocaloric isonitrogenous regimens containing glucose alone (n = 5) or with a fat emulsion (n = 5) as the energy substrates. It would appear that providing the obligatory requirement for glucose is met (about 150g d(-1)), fat and carbohydrate calories are inter-changeable with regards to fueling protein metabolism in the early period following moderately severe trauma.

Journal Article↗
PubMed1982

Increased incorporation of an infused labelled amino acid into plasma proteins as a means of assessing the severity of injury or activity of disease in surgical patients.

Following injury there is increased synthesis of several plasma proteins. During a constant rate infusion of 1-(1-14C) leucine some of the labeled amino acid became incorporated into plasma proteins, the amount being readily determined after precipitation with perchloric acid. This value was correlated with the clinical state of the patient to see if an index of severity of injury could be derived. Before operation 6.7 +/- 0.5% (mean +/- SD, n = 16) of the infused labeled amino acid was incorporated in asymptomatic patients, irrespective of their dietary intakes, while in the presence of symptomatology this value rose, correlating with tumor staging in patients with colorectal neoplasia (r = 0.988, p = 0.001). It returned to normal following tumor resection, but was elevated in the presence of recurrence or residual disease. After operation it also rose, being maximal in the early postoperative period and following the more major surgical procedures, the increase correlating with the change in cortisol level in patients following cholecystectomy (r = 0.84, p less than 0.01; n = 8). The pattern of distribution of the label among the plasma proteins did not change with increased incorporation. The increase in incorporation of 1-(1-14C) leucine into plasma proteins would appear to offer a good index for severity of injury of activity of a disease state.

Blood Proteins↗
PubMed1980

Whole body protein turnover, synthesis and breakdown in patients with colorectal carcinoma.

As a basis for assessing protein metabolism in cancer patients, whole body protein turnover, synthesis and breakdown were measured preoperatively using a constant rate infusion of L-(1-14C) leucine in patients with differing stages of colorectal carcinoma. The levels of protein synthesis and breakdown were correlated with the extent of disease as measured by the percentage incorporation of the labelled amino acid into plasma protein (1) and the subsequent modified Dukes' classification (2). Eleven apyrexial patients were divided into two groups; 6 of whom had normal appetites while 5 were anorectic. Protein synthesis increased with advancement of disease in both groups, as did protein breakdown. Protein synthesis and breakdown were lower in the anorectic group, suggesting some degree of starvation adaptation. All patients were in positive balance, despite anthropometric data to support loss of host body protein. This suggests translocation of protein stores from muscle to areas of more rapid protein synthesis such as tumour. Remodelling of body protein is an important facet of metabolism in cancer patients.

Adenocarcinoma↗
PubMed1977

Effect of abdominal surgery on intestinal myoelectric activity in the dog.

The effect of cholecystectomy and small bowel transection on the myoelectric activity of the small intestine was determined in conscious dogs. Three animals were implanted with electrodes spaced approximately 25 cm apart along the serosal surface of the small intestine. Recordings were made with dogs in the unanesthetized fasted state. After completion of control recordings, the gallbladder was removed from each animal. Recordings were made each day after surgery for a period of one week and then periodically during the next two weeks. At the end of three weeks, transection and end-to-end anastomosis of the mid-ileum was done. Once again recordings were obtained each day for one week and periodically for two subsequent weeks to insure return to normal fasted patterns. Neither cholecystectomy nor transection and anastomosis had an inhibitory effects of the myoelectric activity of the small intestine.

Abdomen↗
PubMedDate not supplied

MR imaging of blood pool signal variation with cardiac phase in aortic dissection.

Electrocardiographic gated magnetic resonance imaging of the thoracic aorta was performed on a patient with aortic dissection. Magnetic resonance demonstrated the intimal flaps and double lumina, allowing correct classification of the dissection as proven surgically. The blood pool signal in the false lumen was low during diastole and higher during systole, which has not been previously described. This signal pattern allows definition of false luminal patency using a single spin-echo pulse sequence.

Aged↗
PubMedDate not supplied

Cardiectomy for implantation of a total artificial heart: a modification.

The surgical implantation technique of a total artificial heart is important to improve its efficiency. The cardiectomy used for transplantation has been modified to leave different atrial remnants. The reasons, the advantages, and the technical modification are described.

Cardiac Surgical Procedures↗