Analysis of cytotoxic effector cell function in patients with leukemia or aplastic anemia before and after marrow transplantation

Cytotoxic effector cells mediating natural killing (NK), antibody-dependent cellular cytotoxicity (ADCC), and lectin-dependent cellular cytotoxicity (LDCC) were studied in patients with leukemia or aplastic anemia before and/or after marrow transplantation. Before transplantation, about one-third to one-half of the patients were deficient in cytotoxic activity. In patients with leukemia, this was most likely due to large numbers of circulating blast cells diluting or replacing the effector cells. In patients with aplastic anemia there was an apparent absence of the effector cells in a proportion of the patients. After marrow transplantation, cytotoxic activity in all three systems returned to normal rapidly, by 30 days, and remained so through 100 days. However, about 20% of patients studied beyond 1 year were deficient in these functions. There were no significant associations between cytotoxic activity and important clinical parameters including infections, graft-vs-host disease, and recurrence of leukemia. Our findings do not support an immunosurveillance role for NK against leukemia after marrow transplantation. Furthermore, they point out the need for new in vitro approaches for meaningful monitoring of marrow transplant patients. Finally, our results showed a significant discordance between NK, ADCC, and LDCC activities in these immunologically perturbed individuals, indicating that either different cell populations or different cellular mechanisms are involved in these cytotoxic functions.     

Relation between extent of coronary artery disease and blood viscosity.

Blood viscosity (shear rate 100/s) and its major determinants (packed cell volume, plasma fibrinogen concentration, and plasma viscosity) were measured before coronary angiography in 50 men aged 30-55 and related to the extent of coronary artery disease. Twenty-six men had extensive disease (stenosis of two or three major coronary vessels), and 24 had either stenosis of one vessel or no stenosis. The 26 men with extensive disease had significantly higher mean blood viscosity than those with mild or no disease and 25 healthy controls (p less than 0.001). The increased viscosity was due partly to a higher packed cell volume and partly to a higher fibrinogen concentration; plasma viscosity was not significantly increased. These differences could not be explained by smoking history. These results suggest an association between increased blood viscosity and extensive coronary artery disease in men, which merits further investigation.     

Distribution of Acidic- and Neutral Peptidases in Germinating Barley

Activities of barley peptide hydrolases A (acidic peptidase) and H (neutral peptidase) were examined in the growing embryo and in the embryoless tissues of Himalaya barley incubated for 70 hours. Tissues examined were roots, shoots, embryo residue (scutellum + seutellar node + coleorhiza) and the embryoless portion of the kernel. Activity of the hydrolase A increased mainly in the embryo residue during 0 to 30 hours but little thereafter. Activity of hydrolase B increased mainly in the embryo residue but did so linearly over the 70 hour period. A small linear increase occurrence in the embryoless portion during this lime.     

Haemostatic Changes during Dialysis Associated with Thrombus Formation on Dialysis Membranes

Platelet counts, coagulation factors, and the fibrinolytic system were studied in seven regular dialysis patients during the course of haemodialysis by parallel flow (Gambro-Alwall) and coil (Travenol Ultra-Flo 100) dialysers. Significant falls in the patients'' platelet counts and rises in their factor V levels were found with both dialysis systems. The changes were more pronounced over the course of a Gambro-Alwall dialysis, when significant falls in the partial thromboplastin clotting time and in the plasminogen levels were also noted. These haemostatic changes were associated with the retention of platelets on the dialysis membranes and, in the case of the Gambro-Alwall dialyser, with the formation of platelet-fibrin thrombus. This thrombus formation may take place in spite of efficient heparin anticoagulation and may cause excessive blood loss to the regular dialysis patient.     

The Use of Density Gradient Centrifugation for the Separation of Germinated from Nongerminated Spores

S ummary : The density gradient centrifugation of a suspension of spores of B. subtilis 8057 on both sucrose and renografin gradients gave 2 distinct fractions. Germination evidence suggested that the heavier fraction consisted of dormant spores and the less dense fraction, germinated spores. It is concluded that density gradient centrifugation may provide a useful technique for the separation of germinated from nongerminated spores.     

On the use of historical control data to estimate dose response trends in quantal bioassay.

New tests for trend in proportions, in the presence of historical control data, are proposed. One such test is a simple score statistic based on a binomial likelihood for the "current" study and beta-binomial likelihoods for each historical control series. A closely related trend statistic based on estimating equations is also proposed. Trend statistics that allow overdispersed proportions in the current study are also developed, including a version of Tarone's (1982, Biometrics 38, 215-220) test that acknowledges sampling variation in the beta distribution parameters, and a trend statistic based on estimating equations. Each such trend test is evaluated with respect to size and power under both binomial and beta-binomial sampling conditions for the current study, and illustrations are provided.     

Inhibition of Nb2 T-lymphoma cell growth by transforming growth factor-beta.

1. Mitochondria isolated from the gut-dwelling nematodes Nippostrongylus brasiliensis and Ascaridia galli (muscle and gut + reproductive tissue) were examined for cytochromes, and it was observed that N. brasiliensis and A. galli muscle tissue mitochondria contained a-, b- and c-type cytochromes, but their stoichiometries were quite different (1:2:1.9 and 1:11.4:13.6 respectively); A. galli gut + reproductive-tissue mitochondria, however, only contained b and c cytochromes, in a ratio of 1:0.8. 2. CO difference spectra showed the presence of CO-reacting b-type cytochrome(s) in all three types of mitochondria; the fast-reacting species comprised 30, 44 and 39% of the total in N. brasiliensis, A. galli muscle and A. galli gut + reproductive-tissue mitochondria respectively. 3. Cytochrome aa3 was observed in N. brasiliensis mitochondria and in those from A. galli muscle, but was below the level of detectability (less than 0.005 nmol/mg of protein) for A. galli gut + reproductive-tissue mitochondria. 4. Photochemical action spectra for the reversal of CO inhibition of the endogenous respiration of whole worms (at 24 microM- and 40 microM-O2 respectively for N. brasiliensis and A. galli) gave maxima at 598 and 542-543 nm, corresponding to the alpha- and beta-absorption maxima of cytochrome aa3, and at 567 nm (b-type cytochrome) for both worms. These results suggest that cytochrome aa3 is the major functional oxidase in N. brasiliensis, whereas the CO-reacting b-type cytochrome dominates in A. galli.     

A medium for the detection of Lancefield Group D cocci in skimmed milk powder by measurement of conductivity changes

A selective medium for the detection of Lancefield Group D cocci in skimmed milk powder by conductivity measurements was developed and evaluated using the Bactometer M123 and Malthus 128H systems. This medium promoted large changes in conductance and capacitance. The calibration curve of detection times vs concentration of Lancefield Group D cocci showed a linear correlation coefficient of 0.93 and the method gave comparable results in both conductivity instruments. Naturally contaminated samples containing c. 10(3) cfu/g of Lancefield Group D cocci gave detection times within 16-18 h which was sufficiently rapid for the medium to be used for the routine screening of skimmed milk powder.