Biomedical subjects

M L McKenzie

Publications and source records attributed to M L McKenzie.

5 recordsLinked to original sources

PubMed1993

Regulation of pyruvate dehydrogenase activity in rat fat pads and isolated hepatocytes by levamisole.

The effect of levamisole on the catalytic activity of the pyruvate dehydrogenase (PDH) complex in rat adipose tissue segments and isolated hepatocytes was studied. Levamisole, an anthelmintic and immunotherapeutic agent with concentration-dependent oxidant/antioxidant properties, increased the catalytic activity of the pyruvate dehydrogenase complex in these systems. The activity of this enzyme complex may be regulated in part by protein-thiol modification. The treatment of rat adipose tissue segments and isolated hepatocytes with and without levamisole (0.1-3.0 mM) for 30 min resulted in a reversible increase in the catalytic activity of this enzyme complex. Levamisole at 1.5 mM and 2.0 mM were as potent as insulin (1.0 mU/ml) in adipose tissue and as dichloroacetate (2.0 mM) in isolated hepatocytes, respectively, in increasing the catalytic activity of the PDH complex. The stimulatory effects seen with levamisole were not accompanied by decreases in adenosine triphosphate (ATP) levels. The results of the present investigation suggest that the pyruvate dehydrogenase complex in adipose tissue and liver may be useful models for studying the mechanism of action of levamisole.

Adipose Tissue↗

PubMed1987

Interaction between insulin and thyroid hormones on the control of carbohydrate and lipid metabolism in rat adipose tissue.

Adipose tissue segments excised from normal rats and from rats rendered experimentally hypothyroid and hyperthyroid retained insulin responsiveness when studied in vitro. Basal rates of glucose oxidation to CO2, conversion into glyceride-glycerol, fatty acids, and total lipids, and the activities of pyruvate dehydrogenase and fatty acid synthetase were enhanced in fat pads from hyperthyroid rats when compared with values seen with tissue from euthyroid animals. The response of each of these parameters was further enhanced by treating tissue from hyperthyroid rats in vitro with insulin. Basal rates of glucose oxidation and the activities of pyruvate dehydrogenase and fatty acid synthetase were depressed as a result of hypothyroidism. However, all of these values could be restored to levels approaching the values seen in the basal state for euthyroid rats when tissue segments from hypothyroid rats were incubated in vitro with insulin. The basal rates for glucose conversion into glyceride-glycerol, fatty acids, and total lipids were not changed by hypothyroidism but retained insulin responsiveness. These data suggest that the insulin-effector system in adipose tissue is not altered by thyroid status and that thyroid hormones may act independently with insulin to regulate glucose and lipid metabolism in this tissue at multiple intracellular metabolic sites.

Adipose Tissue↗

PubMed1985

Epithelioid hemangioendothelioma of the wrist.

A rare case of epithelioid hemangioendothelioma occurring at the wrist is reported. No mitoses were seen in the tissue examined, but the cell type could not be identified by frozen section. Based on the report, the remaining neoplasm was resected and no structures vital to hand function were sacrificed. There has been no recurrence of the tumor in 3 1/2 years.

Female↗

PubMed1984

Mandibular reconstruction using silicone: fifteen-year follow-up.

A patient is presented in whom a carved Dacron felt-covered silicone prosthesis was used to replace the mandible. Although not recommended as the procedure of choice for mandibular reconstruction, the prosthesis remains in place 15 years following implantation, the jaw appears and moves satisfactorily, and speech is within normal limits.

Follow-Up Studies↗

PubMedDate not supplied

Logrolling: establishing consistent practice.

Logrolling is a common patient care procedure performed by many health care workers. The purpose of logrolling is to maintain alignment of the spine while turning and moving the patient who has had spinal surgery or suspected or documented spinal injury. Achieving consistency in logrolling practice across patient care settings is particularly challenging, but necessary for patient safety and satisfaction. A multidisciplinary group of health care providers developed regional policies and procedures for logrolling, logrolling with cervical spine (C-spine) precautions, and collar care. The process used for establishing best practice, staff education, and implementation is described.

Humans↗