Splenic pseudocyst: aspiration or cyst decapsulation

A 12 year old boy with a splenic pseudocyst is reported. Percutaneous drainage resulted in complete emptying but rapid reaccumulation. Cyst decapsulation with splenic preservation was curative and is recommended for definitive therapy of splenic pseudocysts.     

Requirement for cations in the stimulation of C2 synthesis by human monocytes.

C2 synthesis by monocytes is stimulated by carbamylcholine acting on nicotinic receptors, phenylephrine acting on alpha 1 adrenergic receptors, and antigen-antibody complexes (IC) acting on Fc receptors. Stimulation of C2 synthesis is reversed by agents which block calcium (LaCl2, CoCl2, verapamil, nifedipidine, diltiazem) and sodium channels (tetrodotoxin) and calmodulin antagonists (trifluoperazine and W7). The changes in intracellular cyclic nucleotide levels that follow these receptor-ligand interactions (decreased cAMP, increased cGMP) do not occur in the presence of calcium and sodium channel blockers. These results suggest that the transmembrane signal which is involved in the stimulation of C2 synthesis is the entry of sodium and calcium ions. Whether this influx occurs by separate channels or a common channel has not been determined. The intracellular events involved in the stimulation of C2 synthesis appear to be calmodulin-dependent.     

Biochemical modulation of tumor-growth, metastasis and host metabolism

Exogenous nutrients, hormones and metabolites can significantly alter tumor growth, metastasis, and host nutritional status. Arginine, serine and methionine are critical amino acids required for protein, DNA and RNA synthesis and, thus, for cellular proliferation. To determine the effect of these specific amino acids on host metabolism, primary tumor growth and metastasis, 48 Lewis rats bearing the mammary adenocarcinoma MAC-33 were randomized to receive similar diets with 3% supplements of serine, arginine, methionine or glycine (control). After 25 days on each diet, animals were sacrificed to determine primary tumor biochemical composition and growth kinetics, number of lung metastases and carcass weight. A significant reduction in lung metastases occurred with serine and methionine supplementation (p<0.01) with no significant change in primary tumor size. However, increased mortality (p<0.001) and low carcass weight (p<0.05) were found in the methionine group indicating significant host toxicity. Serine-supplemented animals had a mortality rate and carcass weight comparable to the control group. Arginine supplementation had no effect on primary tumor growth, metastasis or carcass weight; however, increased mortality was observed in this group compared to controls. These results suggest that serine supplementation selectively supports host growth and inhibits metastasis in tumor-bearing animals. This study demonstrates the potential to differentially effect host and tumor growth with exogenous amino acid supplements.     

Comparison of the mouse spleen cell assay and a radioimmunoassay for the measurement of serum erythropoietin

The mouse spleen cell assay (MSCA) has been compared with a radioimmunoassay for the measurement of serum erythropoietin (Ep). In 20 normal subjects the serum values ranged from 15 to 73 mU/ml for the MSCA compared with 5-30 mU/ml for the RIA. For normal sera there was no correlation between the results of the two assays. In 37 patients with anaemias of differing aetiologies and at various stages of treatment values ranged from 10 to 3645 mU/ml for the MSCA and 13-10,000 mU/ml for the RIA. Although patient values from the two assays were highly correlated (r = 0.98, P less than 0.001), the MSCA results were generally lower. These discrepancies can be largely accounted for by two factors. Firstly the MSCA is sensitive to non-specific matrix effects. Secondly, heat inactivation of serum, a prerequisite for the MSCA, but not for the RIA, destroys a variable and unpredictable proportion of the Ep in the test sera leading to an underestimation of Ep in the MSCA. We conclude that the RIA is more reliable than the MSCA which, in its present form, cannot be recommended for the accurate measurement of serum erythropoietin.     

Nylon-fiber-induced neutrophil fragmentation

We have investigated the effects of mechanical elution of neutrophils from nylon-wool fiber (NWF) using the scanning electron microscope and biochemical analysis of elution fractions. We have determined that mechanical removal of neutrophils from nylon-wool fiber disrupts neutrophils adherent to nylon-wool fiber and augments release of granules, release of peripheral cytoplasmic fragments, and release of lactic dehydrogenase, a soluble cytoplasmic enzyme. Mechanical shearing of the adherent cell, and not adherence per se, causes the fragmentation. The extent of fragmentation is proportional to the NWF surface area available to neutrophils and is maximal at the temperature for optimal adherence and spreading. Agents that decrease cell spreading (n-ethylmaleimide and cold) diminish fragmentation. Cytochalasin B, an agent that destabilizes the neutrophil cortex, increases fragmentation. Fragmentation may be an important contributing cause of the abnormal morphology, function, and in vivo survival of nylon-wool-fiber procured human neutrophils. The prevention of fragmentation would appear to be necessary to insure the procurement of optimally functioning cells. Elution of NWF-adherent neutrophils in the cold might be a practical way to diminish neutrophil damage during clinical filtration leukapheresis.