Occurrence and significance of vascular invasion in multinodular adenomatous goiter

Solitary follicular neoplasms of the thyroid gland are usually classified as adenomas or carcinomas according to two main criteria: vascular invasion and capsular penetration. No information is available on the occurrence of vascular invasion in multinodular goiter lesions, except for the case of a follicular carcinoma within a goiter. One thousand consecutive cases of multinodular adenomatous goiter were reviewed. After screening all H&E-stained slides, 5 patients with histological features typical of adenomatous goiter but displaying foci of vascular invasion at the periphery of the nodes were selected. A single vessel (2 patients) and 2–4 vessels (3 patients) at the periphery of different nodules were involved, with clusters of follicular cells lined by endothelium and partly filling the lumen. Clinical information was obtained from all patients: No recurrences or progressive disease were reported 14 to 16 years after operation. These findings indicate that presence of minimal vascular invasion, although a valuable criterion of differentiation in solitary follicular lesions of the thyroid, has little diagnostic importance in the setting of multinodular adenomatous goiter. It does not appear to justify a diagnosis of malignancy and does not indicate a need for further therapy.     

Effects of gastrointestinal hormones on vascular smooth muscle.

The effects of the gastrointestinal hormones secretin and cholecystokinin (CCK) were investigated on rat portal-vein mechanical activity. Doses of 0.03-0.60 units/ml Boots secretin; 0.18-0.60 units/ml pure, natural secretin; and 0.12-0.60 units/ml CCK elicited dose-dependent decreases in amplitude and simultaneous increases in frequency of spontaneous contractions that were unaffected by alpha-or beta-adrenergic or cholinergic blocdade. These effects were mimicked by isoproterenol, theophylline, and cyclic AMP, and all agents tested were also effective in reducing K-or norepinephrine-induced tension. Additionally, subthreshold doses of CCK and secretin elicited responses when given in combination, and the effects of the hormomes at all doses were potentiated by theophyline, indicating an interaction berween these hormones on rat portal vein thatmay involve cyclic AMP. It is suggested that part of the mechanism of hormone-induced mesenteric vasodilatation may involve a direct relaxing effect of the hormones on vascularsmooth muscle.     

Interaction between octapeptide-cholecystokinin, gastrin, and secretin on cat gallbladder in vitro.

Effects of OP-CCK, gastrin, and secretin were studied on isometric tension development in strips of cat gallbladder. Effective molar concentrations were 2.2 X 10(-10) to 5.3 X 10(-9) for OP-CCK, and 1.13 X 10(-7) to 1.5 X 10(-6) for gastrin. The maximal response to gastrin averaged 66% the maximal response to OP-CCK and effects were not blocked by atropine. Secretin was weakly stimulatory or ineffective by itself. Prior addition of submaximal doses of gastrin shifted the dose-response curve of OP-CCK to the right, but neither the slope nor the calculated maximal response (CMR) was significantly changed. This suggests that gastrin and OP-CCK compete for a common receptor on cat gallbladder. On the other hand, a background dose of secretin shifted the dose-response curves for both OP-CCK and gastrin to the left and increased the slopes significantly with increase in the respective CMRs. The combined action of OP-CCK (or gastrin) and secretin are supra-additive. These experiments suggest that OP-CCK and gastrin act at a common receptor site which is different from the secretin-receptor site.     

Ventricular remodeling following myocardial infarction: a description of the pathologic process, current investigation, and suggested therapy.

The pathophysiologic process of ventricular remodeling after AMI involves an alteration in myocardial cell contraction. The stretching and redistribution of myocardial cells in the ischemic area promote dyssynergic contraction and an overall reduction in ventricular function. Expansion of the infarcted area and volume-overload hypertrophy of the uninfarcted area remodel the shape of the ventricle. Ventricular enlargement and dilation are associated with early mortality and morbidity. This has prompted further study to identify measures that can attenuate the process. Limited investigation on human subjects suggests that ACE inhibition reduces ventricular wall stress and preserves ventricular shape and function. A multicenter trial, SAVE, is under way to study the effects of long-term captopril therapy for patients suffering from AMI. This study and future investigations will focus on inhibition of ventricular remodeling following AMI in the hope of reducing symptomatic CHF and mortality.     

Hemodynamic effects of vasodilators across iliac stenoses in dogs

Blood flow and pressure gradients were measured in dogs across externally applied iliac artery stenoses following 3 minutes of reactive hyperemia and injection of tolazoline (0.4 mg/kg), papaverine (0.04 mg/kg), and prostaglandin E1 (0.033 micrograms/kg) into the iliac artery. Stenoses of borderline and definite hemodynamic significance at rest were produced. The gradients produced with all four modalities of vasodilatation following borderline stenosis were significantly greater than those produced with each modality before the induction of stenosis. The peak effects of all modes of vasodilatation occurred within 30 seconds, although the effects of prostaglandin E1 were continued the longest. Our results indicate that pharmacologic or reactive hyperemia can help assess the significance of borderline iliac stenoses in patients with intermittent claudication.     

Emptying the gallbladder prior to intravenous cholangiography: effect on gallbladder visualization.

Experiments were done to test the hypothesis that emptying the gallbladder prior to intravenous cholangiography (IVC) would result in earler and better opacification of the gallbladder. Five dogs were studied on two separate days in a crossover experiment. Each dog had a standard IVC (15-minute infusion of meglumine iodipamide) 2.5 cc/kg of following a 14-16-hour fasting period. On one of the days, 0.3 mcg/kg of Ceruletide was intramuscularly administered to each dog 30 to 45 minutes prior to the iodipamide infusion. Films obtained at the end of infusion and at 20, 40, 60, and 90 minutes were evaluated independently by three radiologists. The results indicate that pretreatment with Ceruletide produces a significant (p less than 0.05) improvement in the quality of gallbladder opacification during the first 90 minutes following iodipamide infusion. We conclude that earlier and better opacification of the gallbladder during IVC can be obtained by prior emptying of the gallbladder with a cholecystokinetic agent.     

Demonstration of specific IgA in human feces after immunization with live Ty21a Salmonella typhi vaccine

An enzyme-linked immunosorbent assay was applied to evaluate the appearance of specific IgA in fecal eluates of 11 normal subjects given oral live Salmonella typhi Ty21a vaccine. All subjects after immunization showed a detectable rise in levels of specific IgA to both lipopolysaccharide and flagellar antigens of S. typhi.