Fetal hemoglobin accumulation in vitro. Effect of adherent mononuclear cells

In clonal cultures of erythroid burst-forming units (BFU-E) obtained from blood, the accumulation of fetal and adult hemoglobins (Hb F and Hb A) was measured by radioligand immunoassay. Inclusion of adherent mononuclear cells in the culture promoted a striking increase in the relative amount of Hb F in each of 44 experiments with 14 donors. In two-thirds of the instances, this was accounted for by a selective increase in the absolute amount of Hb F. The differential effect on Hb F and Hb A accumulation was achieved without altering the maturity of the erythroid cells, their mean hemoglobin content, or the asynchrony of the production of the two hemoglobins. Virtually all bursts produced Hb F, and the population of BFU-E as a whole, rather than a selected subset, appeared to be the target of adherent cell action. When the adherent cells were excluded from the culture input, the base-line value of Hb F was reproducible for each donor over a period of several months, and correlated with the number of in vivo circulating F cells.     

Permanent transvenous balloon occlusion of the inferior vena cava: experience with 60 patients.

Traditional operations to obstruct the IVC are often unsatisfactory because the morbidity and mortality is appreciable: poor risk patients do not tolerate surgical and anesthetic trauma. Furthermore, if the patient is anticoagulated, an operation requires that such desirable treatment be stopped. Ten years ago a study was begun to develop a transvenous method of IVC occlusion in the awake anticoagulated patient. Animal studies were done prior to patient application. A technique was evolved wherein IVC interruption could be accomplished with a balloon bearing catheter inserted through the jugular vein. The balloon was positioned with venography and after inflation held in place by lateral pressure in the distensible IVC. The catheter was then removed, leaving the balloon in position. Balloon occlusion has been used in the management of 60 selected patients since 1970. Twenty-nine patients were simultaneously anticoagulated without complication. Very sick patients tolerated the procedure well. No patient experienced further pulmonary emboli. Nine hospital deaths occurred from a variety of causes, none related to the balloon catheter. Late follow-up shows that the occluding balloon gradually deflates in about 12 months. The remnant has remained stable in all patients, contained in a scar that permanently interrupts the IVC.     

Vertebral vacuum phenomenon

Gas lucency within intervertebral disc spaces, the vertebral vacuum phenomenon (VVP) was visible radiographically in 12/42 (28%) women with adenocarcinoma of the breast metastatic to bone. In 7/12 (17%) the VVP occurred adjacent to vertebra involved with metastatic tumor and free of significant degenerative changes. Vertebral collapse occurred in all seven women, but was minimal in some when the VVP was prominent. Metastatic malignancy should be considered along with degenerative disease when the VVP is observed.     

The effect of insulin infusion upon protein metabolism in neonates on extracorporeal life support

OBJECTIVE: Critically ill neonates on extracorporeal life support (ECLS) demonstrate elevated rates of protein breakdown that, in turn, are associated with increased morbidity and mortality. This study sought to determine if the administration of the anabolic hormone insulin improved net protein balance in neonates on ECLS. METHODS: Twelve parenterally fed neonates, on ECLS, were enrolled in a randomized, prospective, crossover trial. Subjects were administered a hyperinsulinemic euglycemic clamp and a control saline infusion. Protein metabolism was quantified using ring-D5-phenylyalanine and ring-D2-tyrosine stable isotopic infusions. Statistical comparisons were made by paired sample t tests (significance at P < 0.05). RESULTS: Serum insulin concentration increased 20-fold during insulin infusion compared with saline infusion control (P < 0.0001). Protein breakdown was significantly decreased during insulin infusion compared with controls (7.98 +/- 1.82 vs. 6.89 +/- 1.03 g/kg per day; P < 0.05). Serum amino acid concentrations were significantly decreased by insulin infusion (28,450 +/- 9270 vs. 20,830 +/- 8110 micromol/L; P < 0.02). Insulin administration tended to decrease protein synthesis (9.58 +/- 2.10 g/kg per day vs. 8.60 +/- 1.20; P = 0.05). For the whole cohort, insulin only slightly improved net protein balance (protein synthesis minus protein breakdown) (1.60 +/- 0.80 vs. 1.71 +/- 0.89 g/kg per day; P = 0.08). In neonates receiving > or =2 g/kg per day of dietary amino acids insulin significantly improved net protein balance (2.17 +/- 0.34 vs. 2.40 +/- 0.26 g/kg per day; P < 0.01). CONCLUSIONS: Insulin effectively decreases protein breakdown in critically ill neonates on ECLS. However, this is associated with a significant reduction in plasma amino acids and a trend toward decreased protein synthesis. Insulin administration significantly improves net protein balance only in those ECLS neonates in whom adequate dietary protein is provided.