On the pathway of the rectosphincteric reflex

In several rat models, including those with circular and semicircular rectal aganglionosis, the rectosphincteric reflex was examined. The reflex was confirmed to be essentially an intramural one and its route is considered to run mainly in the longitudinal and partly in the oblique directions.

Isolation of an eosinophil chemotactic lymphokine as a natural mediator for eosinophil chemotaxis from concanavalin A-induced skin reaction sites in guinea-pigs

An intradermal injection with 20 micrograms concanavalin A (Con A) induce a marked tissue eosinophilia peaking at 24 h after the injection in guinea-pigs. Two different eosinophil chemotactic factors (ECFs) were isolated from the Con A-induced skin reaction sites. A non-dialysable ECF with mol. wt of about 70,000 closely resembled delayed ECF-a, which had been isolated from active cutaneous anaphylactic skin lesions and confirmed to be a product of T lymphocytes by antigenic stimulation, by virtue of the antigenicity, the chromatographic profiles on Sephadex G-100 and on DEAE-Sephadex, affinity to Con A-Sepharose, and other physicochemical properties. The activity of the factor paralleled the intensity of tissue eosinophilia, suggesting that the factor may function for the tissue eosinophilia as a natural mediator. Although another ECF with a low mol. wt (dialysable) was isolated from the same skin lesions, the dialysable factor may not contribute to the tissue eosinophilia because the activity of the factor paralleled the intensity of tissue basophilia but not that of eosinophilia.

Quantitative evaluation of fatty liver by computed tomography in rabbits

Biochemical, histologic, and computed tomographic (CT) examinations of the liver were performed in 32 rabbits in which fatty liver was induced by prolonged intravenous fat infusion. In two groups of rabbits, in which 2 and 4 g/kg/day of fat emulsion was administered, respectively, posttreatment reduction in CT value of mild degree was observed, but the reduction was insignificant from the standpoint of diagnosis from CT images. In the group that received 8 g/kg/day of fat emulsion, posttreatment change in CT value was -14.9 +/- 5.1 H, a sufficient reduction for a diagnosis of fatty liver of moderate degree. No significant change in CT value was seen in the no-treatment group or in the group in which 80 ml/kg/day of normal saline solution was infused for 4 weeks. Reduction in CT value in fatty liver might be due largely to accumulation of triglyceride and cholesterol in the liver cells. Significant correlation was found between changes in CT value of the liver and degrees of histologic fat accumulation in the liver cells. Consecutive measurement of CT values of the liver during prolonged intravenous hyperalimentation is a nonaggressive method of diagnosing fatty liver.

Facilitation of tumor metastasis by operative stress and participation of cell-mediated immunity. Experimental study

5-week-old syngeneic female SD rats were inoculated subcutaneously at the dorsal flank with 200 mg of a metastasizing rat's mammary tumor, MRMT-1. A significantly higher incidence of lung metastasis was observed in the cases in which tumor excision on day 14 was accompanied by 30 min laparotomy than in the cases of simple tumor excision. PHA lymphoblastogenesis on day 17 was significantly lower in the cases of tumor excision plus laparotomy on day 14 than in the cases of simple tumor excision. Winn's assay using splenocytes revealed a postoperative enhanced suppressor activity in the cases undergoing laparotomy stress. Possible participation of the raised suppressor activity to facilitation of metastasis was discussed.

[Antitumor immunity in the relatively early period after cryosurgery. Experimental study using rat's metastasizing mammary tumor]

Six-week-old female Sprague-Dawley rats were inoculated with a mammary tumor, MRMT-1. At 2 weeks after inoculation, one of the following 4 treatments was done: surgical tumor excision (SE), cryosurgery (CR), surgical excision plus re-inoculation of freezing-thawing-produced vaccine (FT), and surgical excision plus fasting for 72 hours (FA). In FT and FA groups, incidence of metastatic death were higher than in SE group, while that in CR group was similar as in SE group. Specific footpad reactivity at 2 and 3 weeks after treatment was lower in CR than in SE group. Winn's neutralization assay revealed that antitumor activity of spleen cells at 1 and 3 week(s) after treatment was lower in CR than in SE groups. In vivo observation on effect of inactivated serum at 1 week after treatment showed tumor enhancement in SE group and tumor inhibition in CR group. In conclusion, the observed mild reduction in antitumor immunity in the relatively early period after cryosurgery might not be due to blocking action of superfluous tumor antigens, but probably due to activation of suppressor cells consequent on cryosurgical stress or on slow absorption of tumor antigens.

[Experimental study on immunological effect of splenectomy on tumor-bearers]

In view of popularity of splenectomy in combination with gastrectomy for gastric cancer, immunological effect of splenectomy was studied experimentally, using SD rats and 3-methylcholanthrene-induced mammary cancer, MRMT -1. Splenectomy was performed on day -14, 2, 7, 14 or 21 of sc inoculation of 200 mg (about 4 X 10(6) cells) of MRMT -1 at the back of 4-week-old female rats. Tumor growth and immunocompetence of peripheral lymphocytes, spleen cells and thymus cells were examined. Tumor growth on day 35 tended to be inhibited in rats splenectomized on day -14, 2, or 14, while it tended to be promoted in rats splenectomized on day 7. PHA-induced blastogenesis and NK activity of spleen cells were reduced on day 2, rose on day 7 and gradually decreased on days 14 and 21. Winn's neutralization assay revealed that spleen cells on days 2, 14 and 21 of tumor inoculation had suppressor activities. In conclusion, spleen cells of tumor-bearing rats showed a reduced immunocompetence on day 2 (the early tumor-bearing stage) and on day 14 and later (the late tumor-bearing stage), while they showed a raised immunocompetence on day 7 (the middle tumor-bearing period).

Stress ulcer accompanying subarachnoid hemorrhage--a new rat model

New rat model of stress ulcer, related to subarachnoid hemorrhage (SAH) was devised. A 0.2 ml of the arterial blood, obtained from another rat of the same litter, was injected into the cisterna magna and 4 days later, mild stress, consisting of restraint plus water-immersion for 3 hours to the injected rat, produced gastric ulcers. These lesions were far more marked than in usual rats undergoing the same stress (P less than 0.001). Using this "SAH-stress model", effects of various counteracting measures were examined. Based on the results, we concluded that SAH produced a hypersensitivity or an abnormal excitability of the autonomic nervous centers, and the relatively mild stress effectively weakened the gastric defensive factors and strengthened the gastric aggressive factors, thus resulting in ulcer formation.

Experimental study on merits and demerits of splenectomy in tumor bearers

Immunologic merits and demerits of splenectomy were studied using a rat's experimental tumor. When splenectomy was done on day - 14, 2, or 14 of tumor inoculation, subsequent tumor growth was inhibited, but when it was done on day 7, tumor enhancement was observed. On day 2, cpm values of phytohemagglutinin (PHA)-induced blastogenesis of splenocytes was lower than in normal rats, on day 7 they significantly increased as compared with day 2, and on day 14 they significantly decreased as compared with day 7. Stimulation index (SI) ratio of PHA-induced blastogenesis and natural cell-mediated killing (NK) activity were also investigated using splenocytes, thymocytes, and peripheral lymphocytes. The results indicated that immunological competency of splenocytes of tumor bearers was reduced in the early, late, and final tumor-bearing periods, while it was increased in the middle tumor-bearing period. Tumor growth following splenectomy was considered to be controlled by these changes in immunological competency of splenocytes.

Effect of Intralipid-infusion on erythrocyte membrane in rabbits

Through Intralipid infusion in rabbits, the phospholipids derived from Intralipid were incorporated into erythrocytes, although Intralipid is mainly composed of triglycerides. This is supported by the increase in oleic acid and the compensatory decrease in linoleic acid of the phospholipids in the erythrocyte membrane, corresponding to the content of linoleic acid in the phospholipids from Intralipid. The excess phospholipid rendered the membrane more fluid, probably by overwhelming the rigidifying effect of the increased cholesterol content. Furthermore, the shape of erythrocytes was changed from biconcave to spur, dose dependently. The morphological alterations in erythrocyte membranes could not be completely elucidated by the changes in lipid. These results suggested that the alteration in lipid metabolism in Intralipid-infused rabbits caused various effects on the erythrocyte membrane, through the elevation of triglyceride, cholesterol, and phospholipid contents in plasma.

[A study on postoperative long-term continuous immuno-chemotherapy with PSK and 5-FUDS for advanced gastric and colo-rectal cancers]

Since 1976, postoperative long term immunochemotherapy (PLIC) with PSK and 5-FU Dry Syrup (5-FUDS) was performed after tumor resection in gastric and colorectal cancer patients. Successful continuation over one year of the therapy was done in 40 cases at stages III and IV (+V) in the period between January 1976 and April 1979. These cases were analyzed and following results were obtained. Two-and 3-year survival rates were 80% and 65% respectively when the total cases of one year survival was taken as 100%. However, there were recurrent or tumor-bearing patients being treated by PLIC and, if they had died within the respective years, 2-and 3-year survival rates would have been reduced to 67.5% and 32.5%, respectively. These survival rates were roughly similar as those of historical control group, in which no immuno-chemotherapy was done. Characteristic features of non-specific immunological parameters seen in the recurrent or tumor-bearing cases of relatively good clinical course were improvement in T cell percentage, reduction or stop of in IgG-FcR (+) T cell percentage and maintenance of a good nutritional condition.

[Immunological effect of splenectomy in tumor-bearing rat]

Immunologic merit and demerit of splenectomy were studied, using experimental model in rat.

ANIMALS

SD rat. Tumor: Metastasizing Rat's Mammary Tumor No. 1 (MRMT-1) originally induced by 3-MC administration to SD rat. Experimental study: Splenectomy was done on day before and after subcutaneous inoculation of 200mg of MRMT-1 at the back of 4 week-old female SD rats. Tumor growth following splenectomy and immunological competency of rat's peripheral lymphocytes, spleen cells and thymus cells was investigated and following results were obtained. When splenectomy was done pre-operatively or on the 2nd or 14th day after tumor inoculation, subsequent tumor growth was inhibited, however, when it was done on the 7th day after the inoculation, tumor enhancement and shortening of survival period were observed. When it was done on the 21st day, tumor growth was almost the same as in the rats without splenectomy. The results of cpm values and SI ratio of PHA-induced blastogenesis, and NK-activity indicated that immunological competency of spleen cells of tumor bearers was reduced during the early tumor-bearing period and the late tumor bearing period, while it was increased in the middle tumor bearing period. Tumor growth following splenectomy was considered to be controlled by immunological competency of spleen cells. Thus, it may not be unreasonable that tumor growth is inhibited on some occasions and it is facilitated on other occasions after splenectomy.

Influences of operative stress on cell-mediated immunity and on tumor metastasis and their prevention by nonspecific immunotherapy: experimental studies in rats

Influences of operative stress on nonspecific cell-mediated immunity and on liability to tumor metastasis and preventive effects thereon of a nonspecific immunopotentiator OK-432 were examined. Syngeneic female SD rats were inoculated SC with 200 mg of a transplantable mammary carcinoma MRMT-1 at the dorsal flank. After 2 weeks the tumor was surgically excised simply or combined with 30-min laparotomy. It was revealed by follow-up examination that the laparotomy stress significantly increased incidence of postoperative lung metastasis. It was found that PHA-induced blastogenesis of peripheral lymphocytes was markedly reduced in the early period following laparotomy. Preoperative or post-operative (especially the former) administration of OK-432 was effective for preventing both the postlaparotomy facilitation of lung metastasis and the postlaparotomy reduction in PHA lymphoblastogenesis.

[Antitumor effect of intraperitoneal administration of a streptococcal preparation, OK-432, in carcinomatous peritonitis. I. Experimental study in the rat]

The effect of intraperitoneal (ip) OK-432 administration and its mechanism were investigated with experimental tumor of rats.

ANIMALS

4 week-old female SD rats (Slc/SD, closed colony). Tumor: An ascitic tumor, produced by intraperitoneal inoculation of strain cells. These have been established from MRMT-1, which originally was induced by 3-methyl cholanthrene administration. Experimental study: On day 4 or 6 of ip inoculation of 1 x 10(6) tumor cells, 50 KE/kg of OK-432 was administered intraperitoneally and cells were daily examined microscopically. Morphological changes around tumor cells were investigated with Papanicolaou-stained preparations. Following results were obtained: A marked increase in neutrophils was noted in ascitis at 24 hours after ip administration of OK-432; macrophages and lymphocytes appearing later than neutrophils. A subsequent decrease in neutrophils was accompanied by gradual increase in tumor cells. When OK-432 was administered intraperitoneally on day 4 of ip inoculation of tumor cells, aggregation of neutrophils around tumor cells was observed on day 6, and rosette formations around tumor cells with 76 to 10 neutrophils were noted on days 7 and 8. Subsequently tumor cells forming centers of rosettes were found to be destroyed and disappeared. On days 10 to 12, regrowth of tumor cells within incomplete rosette formation was found in ascites. The above reactions were not remarkable, when OK-432 was administered intraperitoneally on day 6 of ip inoculation of tumor cells, and were never observed in untreated cases. These results indicated that cytotoxic effects of ip administration of OK-432 were displayed mainly by rosette formation with neutrophilic cells.

[Experimental study on levamisole modulation of antitumor immunity--1]

Experimental studies on modulation of antitumor immunity by administration of levamisole (LMS) were performed using a metastasizing rat's mammary tumor (MRMT-1) which was routinely inoculated subcutaneously at one back side of the Slc-SD rat. Experiment 1: The optimal ip dose of LMS for getting antitumor effects was found to be 2.5 mg/kg/day, administered every other day for 7 times. Administration at doses between 0.5 mg/kg and 2.5 mg/kg tended to cause tumor suppression and the doses over 10 mg/kg tended to cause tumor progression. Experiment 2: Optimal timing of starting LMS administration was found to be on day 2 of tumor inoculation. Starting LMS on day 14 of inoculation caused a tendency of transient tumor progression. Experiment 3: A slight tumor suppression was observed when splenectomy was done on day 14 of inoculation. However, when LMS was, given simultaneously, the tumor suppressive effect of splenectomy was cancelled. Experiment 4: According to immunological parameters with whole lymphocyte of peripheral blood, spleen cells and thymus cells, the mechanism of modulation of antitumor immunity by LMS administration was suggested to be an increase in immunocompetency of peripheral lymphocytes and augmentation of specific cytotoxicity. Immunocompetency of NK cells was found to be reduced. LMS was found to have some effects also on spleen and thymus cell functions.