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Biomedical subjects

R C Read

Publications and source records attributed to R C Read.

225 records · Page 13Linked to original sources
PubMedDate not supplied

Glutamine facilitates chemotherapy while reducing toxicity.

Dose intensification of chemotherapy is thought to increase survival. With recent advances in hemopoietic cell modulators such as granulocyte colony stimulating factor, the limiting toxicity of intensifying chemotherapeutic regimens has become the severity of the associated enterocolitis. In animal models, glutamine protects the host from methotrexate-induced enterocolitis. This study evaluates the effects of a glutamine-supplemented diet on the tumoricidal effectiveness of methotrexate. Sarcoma-bearing Fisher 344 rats (n = 30) were pair-fed an isocaloric elemental diet containing 1% glutamine or an isonitrogenous amount of glycine beginning on day 25 of the study. Rats from each group received two intraperitoneal injections of methotrexate (5 mg/kg) or saline on days 26 and 33 of the study. On day 40, rats were killed, tumor volume and weight were recorded, and tumor glutaminase activity and tumor morphometrics were measured. Blood was taken for arterial glutamine content, complete blood count, and blood culture. The gut was processed for glutaminase activity and synthesis phase of the deoxyribonucleic acid. In rats receiving methotrexate, the tumor volume loss was nearly doubled when glutamine was added to the diet. Significant differences in tumor glutaminase activity and morphometrics were not detected. The toxicity to the host was ameliorated. Significantly increased synthesis phase of deoxyribonucleic acid of the whole jejunum, decreased bacteremia, "sepsis," and mortality were demonstrated. Glutamine supplementation enhances the tumoricidal effectiveness of methotrexate while reducing its morbidity and mortality in this sarcoma rat model.

Animals↗
PubMedDate not supplied

Uninfected anastomotic false aneurysms following arterial reconstruction with prosthetic grafts.

Thirteen men, aged 49 to 76 years, average 60, were treated at the Little Rock, Arkansas Veterans Administration Hospital between January 1, 1969 and January 1, 1974 for 1-3 false aneurysms, a total of 18, following prosthetic arterial grafting. Most (ten patients, 15 aneurysms) had aorto-femoral bifurcation grafts for Leriche syndrome. Dacron prostheses were employed in ten, Teflon in three. The interval between the initial operation and the appearance of the aneurysms averaged six years. The end-to-side femoral anastomosis broke down in all ten patients with Leriche syndrome. Six of the eight unilateral aneurysms were on the right side, two had bilateral aneurysms and one patient had three. Five patients died some months or years after repair from vascular accidents. Three other patients required amputations sometime later because their grafts clotted. Silk sutures were employed in only two patients. Plastic sutures in the others were found to have pulled out of the recipient vessels. The aneurysms were all uninfected and were repaired by local stitching in four and the addition of further plastic grafting in nine. We conclude that false aneurysms occur with plastic sutures and they relate primarily to disruption of the end-to-side femoral artery attachment from the stresses of movement at the hip joint.

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PubMedDate not supplied

Plasma catecholamine concentration during and after aorto-femoral bypass grafting.

Mean arterial plasma concentration of norepinephrine and epinephrine [NE + E], increased from 2.84 nM (post-induction) to 7.50 nM at the end of an approximately 4-hour operation for aortofemoral bypass grafting (plus unilateral lumbar sympathectomy) in 13 men. It increased to 18.25 nM during the first hour of recovery, and fell to 9.58 nM by the next morning. Thus during recovery, arterial [NE + E], by exceeding the minimum of 10.6 nM [NE] necessary for vasoconstriction, is a probable contributor to postoperative vasospasm as previously hypothesized.

Adult↗
PubMedDate not supplied

Vasospasm in the lower extremities during and following arterial reconstruction.

Foot temperatures of 36 patients were recorded continuously in the operating room and in the surgical intensive care unit (SICU) for 1-3 days. Operations included aortofemoral endarterectomy, arterioplasty, and bypass grafting. Regardless of severity of the operation, all had cold extremities on entering the SICU. The subsequent warming of the big toes, which started after 4-12 hours in the SICU, if at all, was classified according to a scheme of 6 deviations from a basic trend. This latter was a bilateral, continuous increase in 1-2 hours to 34 degrees C or higher where it remained with minor oscillations. Unilateral deviations were either diminished warming or no warming on one side. Bilateral deviations included stepwise increments to 34 degrees C, diminished increments, and no warming. Neurogenic vasospasm appeared to be the principal factor diminishing blood flow, with circulating vasoconstrictors and organic blocks as additional less important factors. Subsequent amputations of nine limbs were partially correlated with the categories of digital warming.

Aged↗
PubMedDate not supplied

Operative correction of proximal blocks of the subclavian or innominate arteries.

Ninety-four operations were performed on 90 individuals with occlusive disease of the subclavian or innominate arteries during the past 17 years. The left subclavian was occluded in 71, the right in 10, and the innominate in 9. Presenting symptomatology was neurological in 34, arm ischemia in 30 and combined in 26. Blood pressure was reduced by 30 mmHg on the involved side in all. An extrathoracic approach was used in 78 and a transthoracic approach in 16. Early mortality 18.7% and morbidity 18.7% was associated with the transthoracic approach. Long subcutaneous axillo-axillary and axillo-carotid are prone to thrombosis and skin erosion. Carotid-subclavian grafts used in 64 remain patent, occasionally become infected (4.7%), are associated with a low mortality and do not develop "carotid steal". When associated with vascular insufficiency of the lower extremity (44%) the brachiocephalic lesion should be corrected first.

Adult↗
PubMedDate not supplied

The role of primary and secondary profundaplasty in the treatment of vascular insufficiency.

Profundaplasty has been performed on 58 limbs (45 primary and 13 secondary) in 45 men. Thirty-four of these had incapacitating claudication, 14 rest pain, and 10 either gangrene or ischemic ulceration. In 19 treated by profundaplasty alone there were no deaths but three subsequently had amputation for ischemic pain. In 39 with profundaplasty plus a proximal operative augmentation there were two (6.7%) operative deaths and one (3.4%) late death but only one extremity had to be amputated. Radionuclide flow studies confirmed physical and arteriographic findings. After profundaplasty alone and profundaplasty plus aortofemoral bypass there was moderate increase in calf blood flow but in only those with a patent superficial femoral did the flow studies return to normal. Profundaplasty is an important addition to the armamentarium of the vascular surgeon in dealing with arteriosclerotic insufficiency of the lower extremities.

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