Factors affecting the uptake of 99mTc-sulfur colloid by the lung and kidney

Occasionally patients injected with 99mTc-sulfur colloid (TSC) for liver--spleen imaging show increased uptake by the lungs or kidneys. In animals, increased lung uptake of TSC can be produced by injecting endotoxin intraperitoneally. Using an intraperitoneal endotoxin model, we studied the effect of heparin on dose-response curves for TSC uptake by the lungs and kidneys. Over a dose range of 1 mug to 10 mg of endotoxin, TSC uptake by the lungs increased progressively; heparin had no effect. In the kidneys, endotoxin in doses from 1 mug to 1 mg resulted in an increased TSC uptake which was less marked than that in the lungs and which was also unaffected by heparin. However, at a dose of 10 mg of endotoxin, a marked increase occurred in TSC uptake by the kidneys, and this could be prevented by heparin. Although the increased TSC uptake by the kidneys at lower doses of endotoxin and by the lungs at all doses is probably not related to intraavascular coagulation, the marked increase in TSC uptake by the kidneys at 10 mg of intraperitoneal endotoxin probably is related to intravascular coagulation, possibly by entrapment in fibrin deposits in the renal capillaries.     

Medial calcinosis of M?nckeberg. A review of the problem and a description of a patient with involvement of peripheral, visceral and coronary arteries

Massive medial calcific deposits (M?nckeberg's calcinosis) are described in the peripheral and visceral arteries, and similar but small-sized deposits in the coronary arteries of a 41 year old woman with diabetes mellitus. Although observed by roentgenogram fairly commonly during life in the muscular arteries of the legs in middle-aged men, medial calcinosis infrequently involves the visceral arteries and has never, to our knowledge, been documented in the coronary arteries. Although it may be associated with intimal atherosclerosis, medial calcinosis, per se, does not obstruct the lumens of the arteries and, therefore, does not lead to symptoms or signs of limb or organ ischemia. The cause of medial calcinosis remains a mystery, but it appears to affect people with diabetes more frequently than those without.     

Cryosurgical ablation of accessory atrioventricular connections: a method for correction of the pre-excitation syndrome

Cryothermia, a new technique for definitive treatment of the pre-excitation syndrome, is described in two patients. The first patient presented with a normal P-R interval with a delta wave and reciprocating tachycardia. Preoperative electrophysiologic study suggested a free-wall atrioventricular connection on the left posterior atrioventricular (A-V) groove. At surgery, epicardial mapping confirmed the site of pre-excitation on the posterior left ventricular (LV) wall. An electrogram arising from the accessory pathway (AP) was recorded at the site of earliest ventricular activation. Interatrial delay combined with an apparently long accessory pathway to the ventricle caused the P-R interval to appear normal. Local pressure abolished pre-excitation. The site of early ventricular activation was cooled to -60 degrees C with a specially designed cryoprobe. All evidence of pre-excitation and arrhythmias disappeared. The second patient presented with a refractory reciprocating tachycardia and was found to have an AP in the septum capable of only retrograde conduction. Retrograde conduction was abolished by applying a temperature of 0 degrees C to the anulus at this site during tachycardia. Conduction over the AP and reciprocating tachycardia returned with rewarming. Ablation of the AP was obtained by applying a temperature of -60 degrees C for 90 seconds on two occasions to the same area. The His bundle was not injured.     

Technique of parathyroidectomy

The goal of the surgical treatment of primary hyperparathyroidism is ablation of the proper amount of hyperfunctioning tissue. This paper presents our operative technique based on an experience in the treatment of 190 patients with primary hyperparathyroidism. The technique is based on a complete knowledge of the anatomy of the normal parathyroid gland as well as the pathology in primary hyperparthyroidism. We also propose a systematic and methodical search for possible abnormal locations incorporating a thorough knowledge of the specific embryology.     

Carcinoid tumors of the appendix

OBJECTIVE: A retrospective study of 41 patients with histologically confirmed diagnosis of appendix carcinoid tumors was undertaken by reviewing the surgical records at Massachusetts General Hospital. METHODS: There were 8 male and 33 female patients (mean age 32 years). Twenty-two patients (54%) presented with signs and symptoms suggestive of acute appendicitis. In 19 patients (46%) the lesions were discovered incidentally. The tumors were located in 32 patients at the tip, in 6 patients in the middle third, and in 3 patients at the base of the appendix. The tumor was less than 1 cm in diameter in 32 patients, between 1 and 2 cm in 7 patients, and was bigger than 2 cm in 2 patients. In 29 patients, the depth of tumor penetration was confined to the submucosa or to the muscle layers of the appendix, and in 8 patients the serosa was involved. In 4 patients, evidence of tumor extension into the meso-appendicular fat was present, including one patient with a tumor bigger than 2 cm and local lymph-node metastases. Forty patients underwent appendectomy alone. One patient with a tumor size bigger than 2 cm in diameter with positive lymph nodes in the mesoappendix underwent secondary right hemicolectomy. Complete follow-up was achieved in 35 patients, and all patients remained free of tumor recurrence. CONCLUSIONS: The authors conclude that appendiceal carcinoids are rare and most often are asymptomatic. Tumors of less than 1 cm are adequately managed by appendectomy alone. The appropriate treatment for tumors of 1 to 2 cm continues to be controversial. Right hemicolectomy is recommended for all tumors larger than 2 cm, whereas preference for an aggressive approach should be given in young patients.     

Plasma amino acids of infants consuming soybean proteins with and without added methionine

Fasting plasma free amino acids were determined in 54 convalescent malnourished infants: seven infants while consuming a diet based on isolated soybean protein, containing 4.0% to 5.3% of dietary metabolizable energy (calories) as protein (A), 20 at 6.4% to 6.7% protein calories (B), 23 at 6.4% to 6.7% protein calories with added DL-methionine (C), and four with 8.0% to 12.3% protein calories (D). There were no differences in total amino acid concentration (TAA) among the four groups; the molar fraction of essential amino acids (EAA:TAA) was lower for group A; there were no differences among the four groups in Lys:EAA or 1/2 cystine:EAA ratios or in Met concentration. Met:EAA was higher in C than B, with considerable overlap of individual values. In 10 of 13 infants who were represented in both B and C, Met concentration and Met:EAA ratio were higher in group C. Fasting plasma AA levels are not consistently reliable for field or clinical assessment of dietary Met adequacy. Fasting and postprandial (3- and 4-hour) plasma AA were determined in 29 infants: in 12 the preceding diet and the test meal were both Met-deficient with less than 6.7% protein calories (E), in five the preceding diet was milk-based but the test meal was Met-deficient at less than 6.7% (F), in five the preceding diet and test meal were based on isolated soybean protein at less than 6.7% with DL-Met added (G), and in seven the test meal was soy-based with greater than 9.0% protein calories (H). Plasma Met concentration and Met:EAA fell significantly at 3 and 4 hours in groups E and F, but not in groups G and H, suggesting that a postprandial fall in Met:EAA ratio can be used to identify dietary Met deficiency in field situations.