Immunosuppression induced in vitro by cell-free extracts of Friend leukemia virusinfected splenocytes

The immunologic responsiveness by normal BALB/c spleen lymphocytes immunized in vitro with sheep erythrocytes was markedly suppressed by calrified cell-free homogenates of Friend leukemia virus (FLV)-infected mouse spleens. Suppression was achieved with a 3,000Xg supernatant of FLV-containing homogenates freed of cellular debris but not with crude unclarified homogenates or pelleted material after centrifugation. The immunosuppressive effects of the virus were dose dependent, whether the virus was added directly to the target spleen cells or separated from them by a 0.4mu Nuclepore filter. Suppression was prevented by heating of the virus at 100 degrees C for 10 minutes or by neutralization with antiserum to FLV. Addition of the virus as late as 48 hours after in vitro immunization of splenocytes affected the immune response. However, suppression was maximum when the clarified virus was added to the splenocytes 1 or 2 days before immunization. The agent in the FLV-infected spleen homogenates responsible for immunosuppression appeared to be the virus per se; however, virus-associated soluble factor(s) might have been involved.

Restoration of in vitro immune responsiveness of mastocytoma-suppressed splenocytes by activated T cells

Spleen cells from normal DBA/2 mice pretreated with a soluble factor from mastocytoma cells or from ascitic fluid of mastocytoma-bearing mice were markedly impaired in terms of antibody formation to SRBC in vitro. Such immunosuppression by mastocytoma homogenates or ascitic fluid was reversed when syngeneic T cells activated to SRBC were added to the cultures, but not when peritoneal exudate cells or anti-theta-treated normal splenocytes were used. Activated T cells, as well as normal B lymphocytes prepared from spleens of lethally irradiated mice reconstituted with bone marrow cells, were less sensitive to the immunosuppressive factor than non-activated T cells. The ability of educated T cells to restore immunocompetence of suppressed spleen cells in vitro suggests that the target of the immunosuppressive factor from mastocytoma cells may be non-activated T cells, especially those involved in T cell helper function.

Randomised controlled trial of yoga and bio-feedback in management of hypertension

34 hypertensive patients were assigned at random either to six weeks' treatment by yoga relaxation methods with bio-feedback or to placebo therapy (general relaxation). Both groups showed a reduction in blood-pressure (from 168/100 to 141/84 mm. Hg in the treated group and from 169/101 to 160/96 mm Hg in the control group). The difference was highly significant. The control group was then trained in yoga relaxation, and their blood-pressure fell to that of the other group (now used as controls).

Immunosuppression induced in vitro by mastocytoma tumor cells and cell-free extracts

Suppressed anti-sheep RBC responses occurred when spleen cells from mastocytoma-bearing mice were incubated in vitro and immunized with red blood cells. Marked immunosuppression also occurred when mastocytoma cells were added to spleen cell cultures from normal mice immunized in vitro with the sheep RBC. Suppressed immune responses also occurred when the mastocytoma cells were separated from the normal cells by 0.4-mu nucleopore membranes, but not by dialysis membranes in double chambered culture vessels. Cell-free homogenates prepared from mastocytoma cells, as well as ascitic fluid from tumor-bearing mice, also impaired the responsiveness of normal splenocytes to the SRBC. The suppressive activity of the cell-free homogenates was abolished by heating at 56 degrees C for 30 min. The immunosuppressive activity, however, was retained in supernatant ultracentrifugates of the cell-free homogenate after 100,000 times G for 90 min. Immunosuppression was most evident when mastocytoma extracts were added to cultures of normal splenocytes at the time of in vitro immunization and culture initiation. Suppression was not reversed by washing of the cultured cells and addition of fresh medium. Immunosuppression also occurred when mastocytoma extracts were incubated with spleen cells from allogeneic tumor resistant C57BL/6 mice. Additional physicochemical analyses should provide information as to the nature and specificty of the inhibitory factor(s) and its role as an immunoregulatory substance important in the host-tumor relationship.

Yoga and biofeedback in the management of 'stress' in hypertensive patients

1. Psychophysical relaxation exercises based on yogic principles and reinforced by biofeedback instruments were used for behaviour modification in sixteen hypertensive subjects. 2. Preliminary studies indicated that their pressor response to emotional and physical stimuli became less exaggerated and less protracted compared with controls.

12-month follow-up of yoga and bio-feedback in the management of hypertension

Twenty hypertensive patients treated by psychophysical relaxation exercises were followed up monthly for 12 months. Age and sex matched hypertensive controls were similarly followed up for 9 months. Statistically significant reductions in blood-pressure (BP) and antihypertensive drug requirements were satisfactorily maintained in the treatment group. Mere repetition of B.P. measurements and increased medical attention did not in themselves reduce B.P. significantly in control patients.

Synthesis and polarographic studies of beta-substituted phenylcystine derivatives

The synthesis of N-benzoyl-threo-β-p-substituted phenylcystine ethyl esters via azlactone intermediates is reported. A polarographic method for their determination using 0.1 M sodium acetate in anhydrous methanol as the supporting electrolyte was investigated. The relationship between the half-wave potential and the Taft polar substituent constant, σ*, was studied.