A retrospective analysis of 853 patients with cancer of the mouth, pharynx, and larynx operated on over a 30-year period was performed. Four hundred fifty-seven of them had a radical neck dissection (RND) at some point. Five hundred ninety patients had no clinically positive nodes (N-o) necks at the time of primary treatment; 99 of these had elective neck dissection, whereas 95 others had a delayed RND when nodes became clinically involved. Twenty-three percent of all N-o patients had microscopically involved nodes and less than half of these were among those patients selected for elective RND. Furthermore, 58% of those patients who had elective RND did not have positive nodes. Comparative analysis of elective RND, delayed therapeutic RND after clinical appearance of nodes, and composite operations for patients with N1-N3 disease indicates little difference in disease-free survival when the nodes in the elective RND were positive microscopically for tumors (56%, 49% and 47% respectively). It thus seems that elective RND offers no real advantage over a careful watchful waiting approach in most patients.
We addressed the role of thiamin, a cofactor for several enzymes involved in glucose metabolism, in the glucose metabolic response to endotoxin. Characterized by hyperglycemia, increased hepatic glucose production exceeding elevated rates of whole-body glucose utilization, this response is mediated by hormones and cytokines and is dependent on the immune and nutritional status of the host. We hypothesized that a thiamin-deficient state would impair the metabolic response to endotoxin. Rats were fed a thiamin-deficient or control diet for 6 wk before in vivo assessment of glucose kinetics. In control rats, Escherichia coli endotoxin increased the rate of glucose appearance (+76%), disappearance (+70%), and metabolic clearance (+50%). Thiamin deficiency resulted in increased plasma glucose (18%) and lactate (3- to 4-fold) as well as in a 30% decrease in insulin and an increase in glucagon (2.6-fold) and corticosterone (3.6-fold). Thiamin deficiency inhibited the endotoxin-induced hyperglycemia and the rise in hepatic glucose production, glucose utilization, and metabolic clearance rate.
A retrospective analysis of 390 determinate radical neck dissections (RND) performed for cancers of the mouth, pharynx, and larynx was carried out. There were 75 patients (19%) who had a modified RND. These were separately analyzed and the outcome was compared to those who had a standard total RND. Our goal was to assess the effectiveness of modified RND in controlling disease in the neck, and to identify its impact on survival and quality of life. Overall neck recurrence rate in the entire modified RND group was 28%, 35% in the partial RND, and 25% in the comprehensive modified RND. Neck recurrence rate was no worse in the comprehensive modified RND for N0 and N1 cases, but increased significantly (as compared to the group of patients with standard RND) in the N2 and N3 cases (52% vs. 33%). Treatment of neck recurrences following modified RND was primarily by surgery, with a 48% 3-year disease-free survival. Overall survival was the same for modified RND (68%) and for standard total RND (63%). This was true for all N stages individually. The morbidity of standard total RND is discussed and the goals of modified RND are analyzed. Definitions and a standardized nomenclature for the various types of modified RND are suggested for uniformity of reporting.
The effects of a thiamine-deficient diet on plasma and tissue vitamin concentrations and on whole-body glucose metabolism were assessed. Male Sprague-Dawley rats (175 to 200 g body weight) fed a thiamine-deficient (TD) or nutritionally complete purified diet were used for plasma thiamine mononitrate and monophosphate and for red blood cell and tissue thiamine pyrophosphate (TPP) determinations weekly for up to 5 weeks. Additional rats were used for assessment of basal glucose kinetics by using a primed constant infusion of [3-3H]glucose. Plasma thiamine mononitrate levels decreased 60% at 1 week and were undetectable after 5 weeks on the diet. Plasma thiamine monophosphate decreased 80% after 1 week on the TD diet, and levels were undetectable after 4 weeks on the diet. Red blood cell TPP in the TD group decreased progressively with time: 54% at 1 week, 86% at 3 weeks, and 92% at 5 weeks. At 1 and 4 weeks, the decrease in tissue TPP was significant in the liver (65% and 89%, respectively), gut (52% and 94%, respectively), spleen (40% and 60%, respectively), and skeletal muscle (37% and 76%, respectively), with the brain (7% and 84%, respectively) showing the slowest initial rate of depletion. The TD diet did not alter plasma glucose concentrations, but it increased plasma lactate by 75% and plasma pyruvate by 50% to 75%. Rates of hepatic glucose production and peripheral glucose utilization were not different between the control and TD rats at 2 weeks, but they were 25% higher in the TD rats after 6 weeks on the diet.(ABSTRACT TRUNCATED AT 250 WORDS)
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