Isolation of tridecaptins A, B and C (studies on antibiotics from the genus Bacillus. XXIII)

Three new antibiotics, tridecaptins A, B and C, were isolated from culture broths of strains of Bacillus polymyxa AR-110, B-2 and E-23, respectively. All are acyl tridecapeptides differing from each other in the fatty acid components and amino acid residues. They are weakly active against Gram-negative and Gram-positive bacteria in vitro and in vivo.

Reactivating effect of levamisole on cell-mediated immunity in gastrointestinal cancer patients

Cell-mediated immunity was studied in 23 cases of advanced gastrointestinal cancer. The patients received levamisole at 150 mg/day for three consecutive days each week for four weeks. In cases at the terminal stage of gastrointestinal cancer, the blastformation rate of peripheral blood lymphocytes against phytohemagglutinin (PHA) after the administration of levamisole showed a slight increase, but cases with blastformation rates over 40% increased markedly three or four weeks after the initial administration of levamisole. The peripheral blood lymphocyte count showed little change in these cases.

Correlation between postoperative prognosis in gastrointestinal cancer patients and blastformation rate of lymphocytes

Gastrointestinal cancer patients were followed up for up to 30 months postoperatively and their clinical status related to a parameter of nonspecific immunity, the blastformation rate of peripheral blood lymphocytes against phytohemagglutinin. By the fourth postoperative week, the blastformation rate had recovered from the effect of the operation. In patients who had undergone curative resection, the postoperative level rose to exceed the preoperative level, whereas whereas in those in whom resection had not been possible, the blastformation rate failed to show this rise by the fourth week, and continued at the decreased immediate postoperative level. Results for long-term follow-up (30 months postoperatively) showed that the blastformation rate continued at high levels (almost all over 40%) in cases of curative resection without recurrence, but remained low (under 40%) in those in which the tumor could not be removed. The 40% level of the blastformation rate test thus correlated well with the prognosis. The blastformation rate, therefore, proved a very good parameter for following the pre-and post-operative clinical course of gastrointestinal cancer patients.

Change of macrophage migration inhibitory factor: possible indicator for postoperative prognosis

Sixty three cancer cases who received minimum of the removal of the main tumor constitute the subjects of the present study. Macrophage migration inhibitory factor (MIF) of peripheral blood lymphocytes was studied using extirpated autochthonous tumor tissues as antigen and guinea-pig peritoneal exudative cells as indicator cells immediately before the operation and the fourth postoperative week. The results indicated that in those cases of relatively early stage, i.e. Stages I and II, whose tumor was believed to have been removed completely, MIF turned negative in 7/9 (77.8 per cent) after the operation, while in others with advanced cancer of Stage IV in which the tumor bearing tissue was probably not completely removed, MIF turned positive in most cases (13/17: 75.6 per cent) postoperatively, even though it was negative before the operation. In the cases of Stage III with cancer progressed to an intermediate degree, in about half of the cases (7/11: 63.6 per cent) MIF turned negative after the operation and in the other half (7/10: 70 per cent) MIF became positive postoperatively, suggesting that for MIF to persist the presence of certain amount of tumor tissue is necessary.

Cancer immunotherapy with surgery

With the recent advances in the immunological surveillance system, an understanding of the role of host immunity has become essential to the management of carcinogenesis, tumor proliferation, recurrence and metastasis. Although it is important to continue chemical and surgical treatment of cancer, support of the anti-tumor immune system of the host should also be considered. Long term remission has been reported in leukemia by treating with BCG after chemotherapy whereas surgical treatment is usually more effective in preventing cancer recurrence in digestive organ cancer. The first step is extirpating the tumor as thoroughly as possible and the second step is chemo-immunotherapy. Cancer immunity, however weak, constitutes the basis for other treatments in selectively attacking cancer cells remaining after surgery, chemotherapy or irradiation. Immunotherapy should thus not replace chemotherapy or radiotherapy, but these methods should be employed in combination to attain more favorable results.

Preoperative blastformation rate in gastrointestinal cancer patients

The rate of blastformation of peripheral blood lymphocytes in response to stimulation by phytohemagglutinin (PHA) was assessed preoperatively in 393 patients with gastrointestinal cancer. The series consisted of 291 cases of gastric cancer and 102 cases of colon cancer, all patients being under 70 years of age. The blastformation rate was related to the stage of cancer ground at operation. Preoperative blastformation rates for both colon cancer and gastric cancer decreased as the cancer progressed. With Stage I gastric cancer 81.4% of those that underwent curative resection had preoperative blastformation rates greater than 40%. However, the number of those with blastformation rates over 40% decreased markedly in the curative cases of gastric cancer Stage II to stage IV. Eighty three percent of cases that underwent curative resection with colon cancer, including advanced cancer, had preoperative blastformation rates of over 40%. These results indicated that the correlation of the preoperative blastformation rate with success of curative resection better for colon cancer than for gastric cancer.

Blastformation rate of peripheral blood lymphocytes before and after recurrence of cancer

Following curative resection for gastrointestinal cancer, it has been demonstrated that the blastformation rate rises slightly 3-4 months before the recurrence of cancer and that, during the two months prior to recurrence, the blastformation rate of peripheral blood lymphocytes to PHA decreases rapidly. The blastformation rate, therefore, if monitored routinely postoperatively, should be a significant improvement in predicting any recurrence of the cancer.

Preoperative cell-mediated immune status of gastric cancer patients

The status of cell-mediated immunity was studied in 360 patients with gastric cancer before surgery. For the skin test, tuberculin and DNCB were employed. For the in vitro test, the blastogenesis of peripheral blood lymphocytes to phytohemagglutinin (PHA), the ratio of rosette-forming T cells to sheep blood red cells, and the macrophage migration inhibiotry factor against autochthonous tumor antigens were measured. As a result, it was found that in progressive gastric cancers the cell-mediated immunity decreased specifically or nonspecifically, especially the DNCB reaction; and the blastogenesis against PHA showed an inverse correlation to the advance of gastric cancer.