Suppression of interferon production in mouse spleen cells by cytochalasin D

Cytochalasin D is thought to impair microfilament function. The present study has investigated its effects on four different systems in which interferon is formed, namely (1) mouse fibroblasts induced with virus (2) mouse spleen cells induced with virus, or (3) with endotoxin or (4) by allogeneic stimulation. Cytochalasin D did not suppress formation of interferon by fibroblasts (L cells) or spleen cells stimulated with either HVJ or NDV. However it did suppress production of interferon by spleen cells in response to endotoxin or an allogeneic stimulation; here its action was apparently not on the secretion of interferon, but on some earlier event. It also suppressed the production of interferon by mouse spleen cells induced with HVJ if this had been u.v. irradiated for more than 15 min: this suggests that cytochalasin D sensitive structures do play some role in interferon production by mouse spleen cells when stimulated with HVJ, as well as when they are stimulated with endotoxin or an allogeneic stimulus.

A clinical trial of cell-wall skeleton of BCG in chemoimmunotherapy of acute leukemia

A clinical trial of chemoimmunotherapy using cell-wall skeleton of BCG (BCG-CWS) was conducted in 28 patients with acute leukemia in complete remission. Chemotherapy consisted of monthly intensification therapy for 2 months and bimonthly therafter. Immunotherapy with 200 microgram of oil-attached BCG-CWS mixed with 10(7) autochthonous leukemic cells was given intradermally at either of upper or lower extremities every week, except when the patients were on maintenance therapy. No serious systemic side effect attributable to BCG-CWS was noted. Six patients developed mild and transient temparature elevation. Most importnat side effect was local skin reaction. Indulated papules developed in all patients, resulting in draining ulcerations in 26 patients. Increase of immunological reactivity of the patients receiving BCG-CWS was noted. Skin test response to PPD, Varidase, and candida extract showed definite increase. In vitro lymphocyte blastogenic response to PPD, concanavalin-A, and pokeweed mitogen revealed significant increase.

Acute lymphoblastic leukaemia of the B-cell type refractory to intensive chemotherapy

Four patients, aged 15-50, with acute lymphoblastic leukaemia (ALL) shown to be of the B-cell type, since they formed rosettes with complement-coated sheep erythrocytes (EAC) and had lymphocytes bearing IgA on the cell surface. Clinically, they had massive leukaemic infiltration associated with hepatosplenomegaly and were extremely resistant to multiple, conventional chemotherapy, as demonstrated by prolonged therapy to achieve a remission or a short-term remission. The surface characteristics of the lymphoblasts in the circulating blood seemed to remain unchanged throughout the course of the leukaemia, despite intensive chemotherapy. The evaluation of surface markers on leukaemic cells might give better information for a forecast of the prognosis of the disease.

Basic Investigation of Built-Up-Edge

The formation of a built-up-edge has been differentiated into two mechanisms, that is, adhesion or nucleation of built-up-edge and growth of adhered metal. As to adhesion, the affinity between tool and work material has been investigated experimentally. The findings are that the position of a metal in the periodic table and the solubilities of the mating metals are substantially associated with the strength of adhesion. Although the temperature at the interface is primarily significant to accelerate the adhesion, the effect of relative velocity has been revealed to be negligible. Theoretical analogy and experimental analysis have led to a conclusion that work-hardenability is a requisite condition for the existence and growth of built-up-edge.

Basic Investigation of Tool Wear

This paper treats a fundamental investigation of tool wear and tool life mainly from the viewpoint of flank wear. The result reveals that the mechanism of tool wear in turning can be classified into two basic types: The mechanical abrasion which is directly proportional to the cutting distance and independent of the temperature; and the other is, so to speak, a physicochemical type which is considered to be a rate process closely associated with the temperature, of course. Although it depends upon the cutting condition which type of wear plays a more important role, the latter is predominant under usual conditions. According to the analyses and the experimental results, it has been found out that the tool life from the standpoint of flank wear can be predicted to a first approximation by the initial cutting temperature.

A Photoelastic Analysis of Machining Stresses

Direct measurements of the distributions of normal and frictional stresses on a rake face under cutting conditions have been considered to be practically impossible. However, as reported in this paper, the stress distributions have been successfully obtained photoelastically by using a tool made of a photoelastic material. According to the authors’ experiment, the frictional stress on the rake face is distributed uniformly over a wide range of the tool-chip contact length, but it decreases rapidly near the point of chip-separation on the rake face. As to the normal stress, it has a peak near the cutting edge, being rather stationary in the middle part of the contact length and decreasing gradually toward the point of chip-separation.