Alteration of type A behavior and its effect on cardiac recurrences in post myocardial infarction patients: summary results of the recurrent coronary prevention project

One thousand thirteen post myocardial infarction patients were observed for 4.5 years to determine whether their type A (coronary-prone) behavior could be altered and the effect such alteration might have on the subsequent cardiac morbidity and mortality rates of these individuals. Eight hundred sixty-two of these individuals were randomly assigned either to a control section of 270 participants who received group cardiac counseling or an experimental section of 592 participants who received both group cardiac counseling and type A behavioral counseling. The remaining 151 patients, serving as a "comparison group," did not receive group counseling of any kind. Using the "Intention-to-Treat" principle, we observed markedly reduced type A behavior at the end of 4.5 years in 35.1% of participants given cardiac and type A behavior counseling compared with 9.8% of participants given only cardiac counseling. The cumulative 4.5-year cardiac recurrence rate was 12.9% in the 592 participants in the experimental group that received type A counseling. This recurrence rate was significantly less (p less than 0.005) than either the recurrence rate (21.2%) observed in the 270 participants in the control group or the recurrence rate (28.2%) in those of the comparison group not receiving any special treatment. After the first year, a significant difference in number of cardiac deaths between the experimental and control participants was observed during the remaining 3.5 years of the study. Overall, the results of this study demonstrate for the first time, within a controlled experimental design, that altering type A behavior reduces cardiac morbidity and mortality in post infarction patients.

Newborn screening for hemoglobin abnormalities. A comparison of methods

Peripheral blood from 1,000 newborn infants of black (641) and Southeast Asian (359) ancestry were screened for hemoglobin variants. Results obtained from the combination of cellulose acetate (CAC) and citrate agar (CAG) electrophoresis were compared with isoelectric focusing (IEF) electrophoresis. There was complete agreement between the two methods on assignment of Hb S trait, Hb C trait, Hb E trait, and homozygous Hb E. IEF identified small amounts of Hb A in two newborn infants with Hb S-beta + thalassemia; the CAC and CAG electrophoretic patterns were indistinguishable from sickle cell anemia. One hundred twenty newborn infants with Hb Bart's were detected by IEF; 51 of these were found on CAC. Although IEF was more sensitive in detecting small amounts of hemoglobin, it is not clear if the improvement in detection warrants adopting this form of electrophoresis for routine screening of newborn infants.

Evaluation of two bioluminescence-measuring instruments, the Turner Design and Lumac systems, for the rapid screening of urine specimens

Two bioluminescence-measuring instruments, the Turner Design and Lumac systems, were compared with a standard plate culture method for their ability to rapidly screen 400 urine specimens. For cultures with less than 1,000 CFU/ml the Turner Design, with old and new evaluation formulas, gave 6.5 and 50.6% false-positive results, respectively, versus 17.6% at greater than or equal to 500 relative light units with the Lumac. For cultures which had greater than 10(5) CFU/ml the Turner Design gave 39% (old formula) and 14% (new formula) false-negative results compared with 4% at less than 200 relative units with the Lumac. The microorganisms most frequently isolated in the false-negative cultures from either system were gram-positive cocci. Predictive values for a positive test at greater than 10(5) CFU/ml were 77.4% (old formula) and 35.7% (new formula) for the Turner Design versus only 50% for the Lumac at greater than or equal to 500 relative light units. Predictive values for a negative test for both instruments were greater than 88% at greater than 10(5) CFU/ml. The Turner Design and Lumac systems were 4.0 and 3.7 times as expensive, respectively, as the plate culture method. Although both systems greatly reduce the time required to process urine specimens, their high costs as compared with that of plate culture, their failure to detect many specimens having greater than 10(5) CFU of gram-positive cocci per ml, and the numerous false-positives reported by both instruments suggest that additional improvements in the systems are warranted.

Alteration of type A behavior and reduction in cardiac recurrences in postmyocardial infarction patients

Eight hundred sixty-two postmyocardial infarction patients volunteered to be randomly selected and enrolled into: (1) a control section of 270 patients, who received group cardiologic counseling; and (2) an experimental section of 592 patients, who received group type A behavior counseling in addition to group cardiologic counseling. Reduction in type A behavior at the end of 3 years was observed in 43.8% of the 592 participants, who initially were enrolled to receive group cardiologic and type A behavioral counseling. This degree of behavioral reduction was significantly greater than that observed in participants who initially were enrolled to receive only group cardiologic counseling. The 3-year cumulative cardiac recurrence rate was 7.2% in participants who initially were enrolled to receive group cardiologic and type A behavioral counseling. This was significantly less (p less than 0.005) than that (13%) observed in participants who initially were enrolled to receive only cardiologic counseling. This difference in recurrence rates was due to a lesser incidence of nonfatal infarctions in the patients who had been enrolled in the section receiving type A behavioral as well as cardiologic counseling. These data suggest that type A behavior can be altered in a sizable fraction of postinfarction patients and that such alteration is associated with a significantly reduced rate of nonfatal myocardial infarctions.

The mechanism of inhibition and "reversal" of mitogen-induced lymphocyte activation in a model of adenosine deaminase deficiency

The biochemical mechanism of lymphocyte dysfunction with adenosine deaminase deficiency has been investigated using cultured phytohemagglutinin stimulated normal peripheral blood lymphocytes and the adenosine deaminase (ADA) inhibitor 2'-deoxycoformycin. The addition of deoxyadenosine to ADA-inhibited (but not to uninhibited) cells generated increased dATP pools (up to 50-fold greater than controls) and depressed the mitogen response. dATP Accumulation was accompanied by depletion of the other three deoxynucleoside triphosphate (dNTP) pools (dTTP, dCTP, and dGTP). Suppression of the mitogen response could be prevented ("reversed") to 90% of control levels by the addition of deoxynucleoside precursors for the depleted dNTPs at the initiation of mitogen stimulation. "Reversal" restored the dTTP and possibly the dGTP pools. Thus the mechanism of toxicity in this model appears to be inhibition of ribonucleotide reductase by massive accumulation of dATP, resulting in starvation for the other three deoxyribonucleoside triphosphates. "Reversibility" of this toxicity by providing sources for the missing three deoxynucleoside triphosphates argues for ribonucleotide reductase inhibition rather than other mechanisms of deoxyadenosine toxicity in this model.

Effects of novelty and familiarity on illness-induced aversions to food and place cues in coyotes (Canis latrans)

Two experiments investigated the effects of novelty and familiarity on illness-induced aversions to taste and place cues in coyotes (Canis latrans). Coyotes were made ill on familiar food laced with lithium chloride in a novel place and then received preference tests. In Experiment 1, coyotes avoided the previously poisoned familiar food in the novel treatment place but readily ate the same familiar food in a familiar safe place. In Experiment 2, the results of Experiment 1 were replicated, and it was found that coyotes would eat a different familiar food in the novel treatment place. On the basis of the results of this and other studies, a model for averting animals from places where they are not wanted is presented.

A novel cell surface antigen (T305) found in increased frequency on acute leukemia cells and in autoimmune disease states

Monoclonal antibody T305, prepared by immunizing mice with the T-ALL derived cell line RPMI-8402, immunoprecipitates a single chain glycoprotein with m.w. 160,000 daltons (under reducing conditions) or 180,000 daltons (under nonreducing conditions). In immunofluorescence assays, antibody T305 reacted with a subpopulation of T cells in normal blood (22 +/- 6%), thymus (28 +/- 11%), and lymph node (24 +/- 6%). Increased frequency of T cells reactive with antibody T305 was found in peripheral blood of patients with infectious mononucleosis (greater than 80%), graft-vs-host disease after bone marrow transplantation (65 +/- 11%), acquired immunodeficiency syndrome (53 +/- 12%). The T cells in synovial fluid of patients with rheumatoid arthritis had increased frequency of antibody T305 reactive cells (59 +/- 8%) as compared to their peripheral blood (18 +/- 7%). Two color immunofluorescent studies demonstrated that the T305+ T cells predominantly co-stained with antibody Leu 2a (suppressor/cytotoxic subset) in both normals and disease state blood. After cell sorting to obtain T305+ and T305- subpopulations, we demonstrated that a) natural killer and antibody-dependent cellular cytotoxicity activity in normal blood was in the T305+ but not T305- T cells; b) cytotoxic T cells induced by mixed lymphocyte reaction were predominantly T305+; c) T305- T cells could be induced in vitro to express T305 antigen by mitogens or allogeneic B cells; d) the DNA content of T305+ and T305- T cells in normal blood was similar (greater 95% of cells with G0/G1 level); e) after mitogen stimulation, T305 antigen induction on previously T305- cells occurs before S-phase; and f) significantly more [3H]-thymidine after mitogen stimulation was incorporated by originally T305- cells than by originally T305+ cells (p less than 0.001). The T305 antigen was not restricted to T cells because it was also found on myeloid precursors in bone marrow but was not present on polymorphonuclear leukocytes, red blood cells, platelets, muscle, liver, skin, kidney, lung, or brain. Antibody T305 was found on 24/25 cases of acute leukemia (6 T-ALL, 10/11 cALL, 7 AML, and 1 AMOL) but not on 18 cases of chronic leukemia (B-CLL, T-CLL, null CLL, CML). The importance of the T305 antigen is that it is present on a high number of T cells in certain autoimmune diseases and on virtually all acute leukemia cells. Its distribution on immature and in vitro activated cells suggests that it may represent a receptor for signals related to cellular replication or differentiation.

A novel cell surface antigen (T305) found in increased frequency on acute leukemia cells and in autoimmune disease states

Monoclonal antibody T305, prepared by immunizing mice with the T-ALL derived cell line RPMI-8402, immunoprecipitates a single chain glycoprotein with m.w. 160,000 daltons (under reducing conditions) or 180,000 daltons (under nonreducing conditions). In immunofluorescence assays, antibody T305 reacted with a subpopulation of T cells in normal blood (22 +/- 6%), thymus (28 +/- 11%), and lymph node (24 +/- 6%). Increased frequency of T cells reactive with antibody T305 was found in peripheral blood of patients with infectious mononucleosis (greater than 80%), graft-vs-host disease after bone marrow transplantation (65 +/- 11%), acquired immunodeficiency syndrome (53 +/- 12%). The T cells in synovial fluid of patients with rheumatoid arthritis had increased frequency of antibody T305 reactive cells (59 +/- 8%) as compared to their peripheral blood (18 +/- 7%). Two color immunofluorescent studies demonstrated that the T305+ T cells predominantly co-stained with antibody Leu 2a (suppressor/cytotoxic subset) in both normals and disease state blood. After cell sorting to obtain T305+ and T305- subpopulations, we demonstrated that a) natural killer and antibody-dependent cellular cytotoxicity activity in normal blood was in the T305+ but not T305- T cells; b) cytotoxic T cells induced by mixed lymphocyte reaction were predominantly T305+; c) T305- T cells could be induced in vitro to express T305 antigen by mitogens or allogeneic B cells; d) the DNA content of T305+ and T305- T cells in normal blood was similar (greater 95% of cells with G0/G1 level); e) after mitogen stimulation, T305 antigen induction on previously T305- cells occurs before S-phase; and f) significantly more [3H]-thymidine after mitogen stimulation was incorporated by originally T305- cells than by originally T305+ cells (p less than 0.001). The T305 antigen was not restricted to T cells because it was also found on myeloid precursors in bone marrow but was not present on polymorphonuclear leukocytes, red blood cells, platelets, muscle, liver, skin, kidney, lung, or brain. Antibody T305 was found on 24/25 cases of acute leukemia (6 T-ALL, 10/11 cALL, 7 AML, and 1 AMOL) but not on 18 cases of chronic leukemia (B-CLL, T-CLL, null CLL, CML). The importance of the T305 antigen is that it is present on a high number of T cells in certain autoimmune diseases and on virtually all acute leukemia cells. Its distribution on immature and in vitro activated cells suggests that it may represent a receptor for signals related to cellular replication or differentiation.

Effect of calcitonin on urine concentration in the rat

Because mammalian distal nephron segments with both calcitonin- and antidiuretic hormone- (ADH) sensitive adenylate cyclase activity have been described, in vivo and in vitro experiments were performed to study the effect of calcitonin on rat distal nephron water permeability. Calcitonin 1 and 0.1 U/ml, but not 0.01 U/ml, significantly increased the diffusional water permeability in the isolated papillary collecting duct by 15 and 11%, respectively. However, this effect was small when compared with a 68% increase with a supramaximal concentration of ADH (from 4.0 +/- 0.3 to 6.7 +/- 0.9 microns/s; n = 6, P less than 0.01). The normal increase in water permeability with increasing concentration of ADH (0.02 and 0.2 mU/ml) was depressed by the previous addition of calcitonin (1 U/ml) to the bath but was unaltered with the supramaximal ADH concentration (2 mU/ml). Verapamil, a compound that antagonizes cellular calcium entry, did not alter the effect of calcitonin on diffusional water permeability. Calcitonin in concentrations of 0.05, 0.5, and 5 U/ml produced a significant reduction in urine flow and free water clearance. Pretreatment with calcitonin in these concentrations inhibited the antidiuretic action of ADH. These studies suggest that calcitonin acts as a partial agonist to ADH within the distal nephron. It is unclear whether such an action represents a physiological or a pharmacological effect.