Two‐dimensional ultra‐small‐angle X‐ray scattering (2D‐USAXS) apparatus at SPring‐8 has been characterized. 2D‐USAXS is a promising tool to study the structural change of the hierachical aggregate structure of fillers such as carbon black and silica particles in rubber. The aggregate structure of fillers is key to understanding the reinforcement effects which fillers show in rubber. We have applied 2D‐USAXS to rubber filled with spherical silica particles and proved it to be a powerful technique.
We measured expression of the MDR1 gene (also known as the PGY1 gene) in the human gastrointestinal tract. MDR1 messenger RNA (mRNA) levels were elevated in 13 of 15 colorectal carcinoma specimens and in six of 13 gastric carcinoma specimens. Well-differentiated colorectal carcinomas contained significantly higher concentrations of MDR1 mRNA than moderately differentiated colorectal carcinomas. Similarly, moderately differentiated gastric carcinomas contained higher concentrations of MDR1 mRNA than poorly differentiated gastric carcinomas. MDR1 gene expression in normal colorectal and gastric tissues adjacent to carcinomas was similar to that in the carcinomas. MDR1 gene expression in xenografts of colorectal and gastric carcinomas in nude mice was also investigated. Elevated expression of the MDR1 gene was seen in only four of 18 xenografts of colorectal carcinoma and was not seen in any xenografts of gastric carcinoma. P-glycoprotein was distributed over the luminal surface of the colorectal carcinoma. These results imply that the higher levels of MDR1 mRNA found in well-differentiated carcinomas derived from colorectal tissues are the results of increased expression of the MDR1 gene in the luminal surface cells. The level of expression of the MDR1 gene in colorectal and gastric carcinomas appears to correlate with the degree of differentiation and also appears to be affected by transplantation into nude mice.
A tumor growth inhibitory factor (TGIF) was induced in the culture supernatant from mixed culture of human peripheral blood mononuclear cells (PBMC) and a streptococcal preparation, OK-432, in vitro. The activity generated in the supernatant increased in a time-dependent fashion and first appeared 6 h after the initiation of culture, reaching its maximum around 48 h. The TGIF was cytostatic against seven of ten human tumor targets, but not against three murine tumor targets. Tumor cell growth was inhibited by a transient contact, i.e., 1 h, with TGIF. The TGIF was produced by lymphocytes but not by monocytes, because the activity was usually enhanced by elimination of plastic-adherent cells from the original PBMC fraction. The TGIF was relatively stable against heating at 56 degrees C for 30 min, but the activity was totally destroyed after heating at 70 degrees C for 5 min. The molecular weight of TGIF was estimated to be about 43 x 10(3) daltons by gel filtration. No interferon (IFN) activity was detected in the TGIF-positive fractions obtained by gel filtration, and the TGIF-positive fractions did not inhibit the growth of tumor necrosis factor (TNF)-sensitive mouse L929 cells. The TGIF activity was not significantly affected in neutralizing tests using specific antibodies against human IFN and TNF. The OK-432 was administered i.p. for management of cancer patients with malignant ascites. Ascites-derived mononuclear cells (ASMC) were obtained before and 3 to 5 days after OK-432 injection. The ASMC obtained after the injection produced TGIF in vitro in the absence of OK-432; the preinjection ASMC showed no such production. A positive correlation was found between TGIF-producing activity by ASMC and the effect of OK-432 injection on ascites volume. These results indicate that TGIF is induced in mononuclear cells by OK-432 not only in vitro but also in vivo and plays an important role in inhibition of tumor growth in cancer patients.
The production of a tumor growth inhibitory factor (TGIF) was induced in human peripheral blood mononuclear cells (PBMC) by a streptococcal preparation, OK-432, in vitro. The antitumor effect of locally injecting PBMC treated with OK-432 into the tumor site was studied. PBMC were collected from patients with gastric cancer 5 to 12 days before their operation, and cultured with OK-432 for 24 hr in vitro. After the culture, the PBMC were washed thoroughly to eliminate the OK-432. The washed PBMC went on producing TGIF for more than 72 hr in vitro in the absence of OK-432. A small number of TGIF-producing PBMC, approximately 10(7) cells, were injected around the lesion under endoscopic observation. A remarkable antitumor effect was observed in 2 out of 10 cases of resectable gastric cancer. Histological examinations indicated that the antitumor effect is due to antitumor cytokines such as TGIF produced by PBMC rather than to the OK-432-activated PBMC themselves.
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