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Biomedical subjects

C G Thomas

Publications and source records attributed to C G Thomas.

At least 73 records · Page 4Linked to original sources
PubMed1980

Variations on the precolostomy.

The precolostomy as previously described is now infrequently used since the performance of divided colostomy with exteriorization of both segments at separate sites is usually associated with a more functional colostomy. This precolostomy concept has potential variations which have not been previously emphasized. We have used one of these in a patient with a radiation induced rectosigmoid lesion. This variation and the others described for patients with inoperable carcinoma of the esophagus and stomach may provide improved palliation.

Aged↗
PubMed1979

Contribution of negative cooperativity to the thyrotropin-receptor interaction in normal human thyroid: kinetic evaluation.

The kinetics of 125I-labeled thyrotropin (125I-TSH) binding to human thyroid receptors are presented. At pH 6.0, binding was maximal (30--35%) and there was one class of binding sites [Kd = 6.8 X 10(-9) M; binding capacity (Ro) = 57 pmol/mg of protein]. At pH 7.4, Scatchard plots of binding were nonlinear, indicating either a single class of negatively cooperative sites (Kd = 3.7 X 10(-9) M; Ro = 26 pmol/mg of protein) or, alternatively, independent high- (Kd = 5.0 X 10(-10) M; Ro = 3 pmol/mg of protein) and low-affinity (Kd = 1.7 X 10(-8) M; Ro = 26 pmol/mg of protein) binding sites. The role of negative cooperativity was evaluated from the rates of association and dissociation at pH 7.4. The kinetically determined binding constants (Kd = 1.7 X 10(-11) M; Ro = 2 pmol/mg of protein) were more similar to those determined for the high-affinity component than to those predicted from the negative cooperativity model. Dissociation of bound TSH was independent of initial site occupancy over a 40-fold range, corresponding to a 100-fold range of free TSH concentration. The dissociation rate of 125I-TSH was enhanced by unlabeled TSH to a similar degree, irrespective of initial binding site occupancy. Because the negative cooperativity model does not accommodate these data, it is concluded that TSH receptors in human thyroid behave kinetically and at equilibrium as a single class of high-affinity sites up to TSH concentrations well above the physiological range.

Allosteric Regulation↗
PubMed1979

Surgery for chronic pancreatitis. Drainage versus resection.

A retrospective study of 49 patients with chronic obstructive and chronic calcific pancreatitis is presented. All patients were operated upon and underwent either a partial pancreatectomy or internal drainage of the ductal system into a Roux-en-Y loop of jejunum. The criteria for selection of operation are discussed, and the follow-up of the two operative groups is given. In patients selected as described, internal drainage provided better relief of pain and was accomplished with a lower operative mortality and morbidity and with less postoperative pancreatic insufficiency.

Adult↗
PubMed1978

Selection of treatment in the management of thyrotoxicosis in childhood and adolescence.

The management of 105 patients between the ages of three and 18 years, 83 females and 22 males, with thyrotoxicosis was reviewed retrospectively (1952-1976) with the intent of identifying criteria that would help predict response to therapy with antithyroid drugs and thereby permit earlier selection of alternative treatment. All patients were initially treated with antithyroid drugs. Twenty-six per cent (27) achieved remission with thioamides, 68% (72) underwent subtotal thyroidectomy with three patients requiring subsequent therapy with radioiodine, 6% (6) received radioiodine with one patient subsequently requiring subtotal thyroidectomy. Failure of remission after thioamide therapy was related to drug toxicity, persistent disease, noncompliance and recurrence after an initial remission. During the last decade there was earlier selection of subtotal thyroidectomy based on prior experience. The most significant discriminants were sex, age, and regression of thyromegaly. Ninety-one per cent of the males, 89% of children over 11 years of age and all patients who had no regression of their thyromegaly after a sustained period of control of their thyrotoxicosis by thioamide therapy received subtotal thyroidectomy or radioiodine therapy for control of their thyrotoxicosis. Recognition of these factors at the time of diagnosis should permit earlier selection of the most suitable treatment and expedite patient care. Subtotal thyroidectomy has a low morbidity and is effective treatment for thyrotoxicosis in adolescence and childhood.

Adolescent↗
PubMed1977

Neonatal and infantile hypoglycemia due to insulin excess: new aspects of diagnosis and surgical management.

Persistent hypoglycemia in the neonate and young infant usually results from inappropriate, excessive secretion of insulin, or a deficiency of one of the hepatic gluco-regulatory enzymes. Hypoglycemia due to hyperinsulinism, whether associated with nesidioblastosis, islet cell hyperplasia, adenoma or normal islets, may have devastating consequences in this age group and demands recognition and effective treatment. Medical management consisting primarily of frequent feeding, the intravenous infusion of glucose and the administration of glucagon, glucocorticoids, epinephrine, and diazoxide is often ineffective and may be punctuated by repeated episodes of hypoglycemia, convulsions, and central nervous system damage. Although subtotal-total pancreatectomy is effective in restoring blood sugar to normal, almost half of the reported patients are mentally retarded. This may be due in part to unwarranted delays in performing pancreatectomy. Experience with 6 patients undergoing subtotal--total pancreatectomy for intractable hypoglycemia supports the contention that this procedure is effective. A euglycemic state was restored in all 6 patients and there was no evidence of residual central nervous system damage. The spleen should be preserved in view of its importance in maintaining normal immunodefense mechanisms.

Child↗
PubMed1976

Evaluation of dominant thyroid masses.

Controversy exists concerning the management of solitary thryoid nodules because of conflicting information converning the high clinical incidence of thyroid nodules, the varying incidence of cancer reported in those surgically excised and the infrequency of death from thyroid cancer. During the past several years, a plan for evaluating patients with dominant thyroid masses has evolved. The objective is to avoid unnecessary operations by identifying patients with a high risk of cancer. The criteria which are used are the age and sex of the patient, the duration of the mass, 125I or 99mTc scans, 75Selenomethionine scans, B-mode ultrasonography and the response of the mass to suppressive therapy. This is a report of the findings in 222 patients who have been studied employing this approach. Thirty per cent of the patients were operated upon. Forty per cent had neoplasms (well differentiated cancer--28.8%, adenoma--12.1%), 47.0%--nodular goiter, 6.1% cysts, and 6.1% chronic thyroiditis. The incidence of cancer in the 222 patients was 8.6% and adenoma 3.6%. Patients at greatest risk of having cancer are those with solid nonfunctioning nodules which fail to regress with suppressive therapy. This study indicates that the approach described above is effective in selecting for surgical excision those individuals at greatest risk of having thyroid cancer.

Adenoma↗
PubMed1976

Aneurysms of the hepatic artery.

Aneurysms of the hepatic artery are rare and, when symptomatic, they may present a triad of upper abdominal pain, gastrointestinal bleeding, and obstructive jaundice. Asymptomatic and unsuspected aneurysms are demonstrated occasionally by abdominal arteriography or are encountered infrequently during abdominal operation for an unrelated disease. Hepatic artery aneurysms have great potential for rupture with bleeding into the peritioneal cavity, the common bile duct, or an adjacent hollow viscus. Morbidity and mortality with a ruptured aneurysm are high, and aggressive and imaginative operative therapy is required. Patients with an asymptomatic aneurysm should have operation to prevent subsequent rupture and hemorrhage.

Abdomen↗
PubMed1975

Surgery of the thyroid.

The sophistication of current surgical treatment of thyroid disorders reflects a better understanding of the pathophysiology. The development of more methods of therapy with antithyroid drugs, beta-adrenergic blocking agents, thyroid hormones, and radioactive isotopes as well as external irradiation has had an important effect on the role that surgery plays in the management of diseases of the thyroid. Iodine, which was use for many disorders, is now probably contraindicated except for preparation of the hyperthyroid patient for surgical treatment. Surgery has now taken its place as one form of therapy for an endocrine organ that is subject to a variety of diseases. It is necessary for the surgeon who undertakes operations on the thyroid to have an understanding of thyroid physiology as well as its pathophysiology.

Adenocarcinoma↗
PubMed1975

Is childhood thyroid cancer a lethal disease?

The clinical, pathological, surgical, postoperative findings and survivorship of 58 patients younger and 513 patients older than 21 years at the time of diagnosis with thyroid neoplasms are reported. The younger patients have a predominance of well differentiated carcinomas which are more likely to be follicular. The lesions tend to be more advanced at the time of diagnosis, are treated by more aggressive surgery in the younger patients and are associated with a much better prognosis. Lack of progression of well to poorly differentiated neoplasms and a greater sensitivity to and dependence upon TSH in young patients, are two factors which may contribute to the striking difference in the prognosis of well differentiated thyroid carcinoma related to age.

Adenocarcinoma↗