Biomedical subjects

S Imai

Publications and source records attributed to S Imai.

At least 883 records · Page 49Linked to original sources

PubMedDate not supplied

Infraciliary bands in the rumen ophryoscolecid ciliate Ostracodinium gracile (Dogiel, 1925), observed by light microscopy.

Morphological features of the rumen ciliate Ostracodinium gracile (Dogiel, 1925) are described from pyridinated silver carbonate-impregnated specimens. Ostracodinium gracile has a characteristic arrangement of infraciliary bands not present in other ophryoscolecid ciliates. Buccal infraciliature is composed of three polybrachykineties. The adoral polybrachykinety does not completely encircle the circumference of the vestibular opening, but arches ventrally from its right to left side. The dorsoadoral polybrachykinety extends laterally along the dorsal side of the vestibular opening. The vestibular polybrachykinety extends along the dorsal wall of the long tubular vestibulum. Dorsal infraciliature consists of the dorsal polybrachykinety that extends laterally along the dorsal side of the body. During binary fission, four primordia, that is ventral, right, left, and dorsal primordia, form in the stomatogenic field and develop into the adoral, dorsoadoral, vestibular, and dorsal polybrachykineties of the opisthe, respectively.

Animals↗

PubMedDate not supplied

Rumen ciliated protozoan fauna of the yak (Bos grunniens) in China with the description of Entodinium monuo n. sp.

Rumen ciliate species composition was surveyed in domestic yaks kept in Tibet, Sichuan, and Inner Mongolia, China. Twelve genera including 36 species with 18 formae were identified. The species compositions were slightly different among the three areas: yaks in Tibet had the simplest fauna, in contrast, the fauna of yaks in Inner Mongolia were the most abundant and similar to those found in the cattle kept in the same area. This suggests that the rumen ciliate composition of yaks is affected by that of cattle kept together or in proximity. A new species belonging to the genus Entodinium, Entodinium monuo n. sp., was recognized from the yaks in all areas. This new species was common in the yaks but was not detected in the cattle fed near yaks in Inner Mongolia. There was a similar generic ciliate composition in yaks kept in respective areas. Entodinium was the most predominate ciliate (51.9-61.0%) with total ciliate densities estimated as 10(5)/ml per yak.

Animals↗

PubMedDate not supplied

Light microscopic observations of infraciliature and morphogenesis in six species of rumen Ostracodinium ciliates.

Infraciliature and morphogenesis of six rumen ciliates, Ostracodinium mammosum, O. munham, O. dilobum, O. rugoloricatum, O. iwawoi, and O. tiete are described from pyridinated silver carbonate-impregnated specimens. These six Ostracodinium have a similar polybrachykinety arrangement, distinct from that of other ophryoscolecid ciliates and intermediate between those of O. gracile and 0. damaliscus. Buccal infraciliature is composed of three polybrachykineties, a kinety loop, and paralabial kineties. Small dorso-adoral polybrachykinety, slender vestibular polybrachykinety, and kinety loop are characteristic. Dorsal infraciliature consists of the dorsal polybrachykinety that extends laterally along the dorsal side of the body. Morphogenesis is different from that of O. gracile, because the right end of ventral primordium extends dorsally to grow into a right primordium without separation.

Animals↗

PubMedDate not supplied

Characterization of major phosphoproteins in the cGMP-mediated protein phosphorylation system of vascular smooth muscle membranes.

G(0) (215-250 kD) and G(1) (120-140 kD), the unidentified major phosphoproteins in the cGMP-mediated protein phosphorylation system of vascular smooth muscle membranes, were compared for biochemical and immunological properties with the type 1 inositol 1,4, 5-trisphosphate receptor (InsP(3)R, 240 kD) and the myosin-binding subunit (MBS, 138 kD) of myosin phosphatase, both of them substrates for cGMP-dependent protein kinase. Two microsomal proteins that were immunoreactive with antibodies to InsP(3)R and MBS were detected, and comigrated with G(0) and G(1), respectively, on SDS-PAGE. When thiophosphorylated G(0) and G(1) were subjected to immunoprecipitation, MBS antibody induced the precipitation of a 138-kD phosphoprotein, but did not significantly affect the amount of G(1) remaining in the supernatant, while InsP(3)R antibody precipitated G(0) almost completely. Unexpectedly, InsP(3)R antibody coprecipitated a large portion of G(1), which did not cross-react with either antibody to MBS or InsP(3)R. Just like InsP(3)R, G(0) bound to the calmodulin column in a Ca(2+)-dependent manner, and, again, a large portion of G(1) was copurified with G(0). These results suggest that G(0) is identical to InsP(3)R, while G(1) consists of several phosphoproteins, including the 138-kD protein associated with InsP(3)R as a major component. MBS is not G(1) or may represent only a minor component of it.

Animals↗

PubMedDate not supplied

Lung cancer associated with pulmonary bulla. case report and review of literature.

A few reports have suggested the possible association between lung cancer and bullous disease. We report a surgical case of lung adenocarcinoma located in close proximity to pulmonary bullae. A 48-year-old nonsmoker, asymptomatic male was found to have a pulmonary tumor mass and giant bulla in the right lung. Thoracotomy identified a tumor arising from a firm, scarred and contracted area close to the bulla wall. Based on this report and review of other cases in the literature, we emphasize the need for physicians to be aware of the potential development of lung cancer in patients with pulmonary bulla.

Adenocarcinoma↗

PubMedDate not supplied

Isolation of the Epstein-Barr virus in scirrhous gastric cancer by efficiency-monitored representational difference analysis.

We applied an improved representational difference analysis (RDA), efficiency-monitored RDA (EM-RDA), to analyze the genetic alterations of scirrhous gastric cancer. Clinical samples of this cancer are difficult to analyze genetically because of the large number of normal cells in the stroma. The entire 3rd difference product obtained from EM-RDA was subcloned. This is equivalent to the scirrhous gastric cancer DNA with the normal gastric tissue DNA subtracted from it. The difference clones, which were confirmed by Southern blot as being derived from the cancer, were sequenced. As a result, two difference clones were identified as DNA fragments of the Epstein-Barr virus (EBV). The existence of EBV in the scirrhous gastric cancer cells was proved by EBV-encoded small RNA 1 in situ hybridization. EM-RDA made it possible to detect the first case of EBV-related gastric cancer in a young woman.

Adult↗

PubMedDate not supplied

Comparison of adenosine, dobutamine, and exercise radionuclide ventriculography in the detection of coronary artery disease.

The diagnostic values of adenosine, dobutamine, and exercise radionuclide ventriculography (RNVG) in the detection of coronary artery disease (CAD), and the characteristics of those patients who showed myocardial ischemia during the infusion of adenosine or dobutamine were assessed in 41 patients with suspected CAD. Sensitivity, specificity, and accuracy, respectively, for detecting patients with CAD were 35 (p < 0.01 vs. exercise RNVG), 100 and 46% (p < 0.01 vs. exercise RNVG) with adenosine RNVG, 74, 100 and 78% with dobutamine RNVG and 88, 71 and 85% with exercise RNVG. There was a significant difference in physiologic parameters during the provocation of ischemia by adenosine versus exercise RNVG, although these parameters were similar by dobutamine and exercise RNVG. Stepwise discriminant analysis revealed that the number of stenotic vessels was an important and independent predictor for the myocardial ischemia induced by each stress; the peak filling rate was the only predictor for adenosine-induced ischemia. Dobutamine induced myocardial ischemia in a way similar to that of exercise, and was more useful than adenosine for pharmacologic stress RNVG. The mechanism of the adenosine-induced ischemia seemed to differ from that of the ischemia induced by dobutamine or exercise, and to be closely associated with left ventricular diastolic function.

Adenosine↗

PubMedDate not supplied

Sodium butyrate inhibits the enhancing effect of high fat diet on mammary tumorigenesis.

We have studied the effect of butyrate on mammary tumorigenesis by 7,12-dimethylbenz(a)anthracene. As reported previously, a high incidence of mammary tumors was observed in rats fed a basal diet containing 20% margarine. However, the enhancing effect of margarine was inhibited when sodium butyrate was supplemented in the high margarine diet. Sodium butyrate did not cause any effect when it was supplemented in the basal diet. The result suggests a possibility that a part of the inhibitory effect of butter on mammary tumorigenesis, which we had previously reported, was caused by butyrate milk lipids.

9,10-Dimethyl-1,2-benzanthracene↗

PubMedDate not supplied

Overexpression of the p53 gene product in canine mammary tumors.

p53, a tumor suppressor gene, is a target of genetic alternations in many human and animal cancers. Compared to normal tissues, cancer tissues overexpress mutant p53 protein thus allowing their detection by a number of immunochemical procedures. To what extent the expression of mutant p53 correlates with dog mammary tumorigenesis has not been fully studied. In the present study, 20 spontaneously arising canine mammary tumors were examined for overexpression of mutant p53. Two different monoclonal antibodies, BP53-12 and PAb122, which recognize different epitopes of the p53 product, were used. The canine tumors in the present study exhibited five different histological types: i) osteosarcoma (n=7); ii) carcinosarcoma (n=4); iii) solid carcinoma (n=5); iv) complex carcinoma (n=3); and v) tubulopapillar carcinoma (n=1). The positive ratios against BP53-12 and PAb122 antibodies were 50% (10/20) and 60% (12/20) respectively. Among these positive samples, 35% (7/20) reacted to both antibodies. Finally, 15 out of 20 tumors showed positivity against one of the monoclonal antibodies. Mostly, as in human mammary tumor cells, BP53-12 staining was observed in the nuclei of tumor cells. PAb122 staining, however, was confined to cytoplasm of osteosarcoma or carcinosarcoma cells. To confirm the location of the staining, immunoelectron microscopy was done. The results showed that the cytoplasm of cartilage cells in the sarcomas had positive staining. These results indicate that anti-p53 antibodies BP53-12 and PAb122, generated against human p53 are cross reacting with the same molecule in canine cells and that the role of p53 in tumorigenesis is not only confined to tumors in human. Our finding suggests that a combination of p53 monoclonal antibodies should be used to screen, not only canine mammary tumors but also human mammary tumors, to obtain a better tumor prognosis.

Adenocarcinoma↗

PubMedDate not supplied

Superselective embolization for bleeding from duodenal diverticulum: a case report.

Duodenal diverticulum is a well-known pathological entity. The majority of patients with this condition are asymptomatic. Although hemorrhage has been described, it is an infrequent complication. We report a patient who presented with massive upper gastrointestinal bleeding with hypovolemic shock, originating from a duodenal diverticulum. The diagnosis was made by emergency angiography. Superselective arterial embolization was performed with a successful outcome. To the best of our knowledge, superselective embolization for hemorrhage originating from a duodenal diverticulum has not previously been described in the literature.

Angiography↗

PubMedDate not supplied

Suppression by a pine cone extract of Pinus parviflora Sieb et Zucc of mammary tumour virus in milk of mice.

The intravenous or the oral administration of a pine cone extract of Pinus parviflora Sieb et Zucc (Fr VI) and the related synthetic agent (DHP-FA) to lactating SHN mice prevented an increase of milk levels of mouse mammary tumour virus (MMTV) from day 7 to day 14 of lactation. Furthermore, Fr VI decreased the MMTV level at the 2nd lactation compared to the 1st lactation. This is the first report on the inhibition of milk MMTV of mice in the in vivo system.

Administration, Oral↗

PubMedDate not supplied

Computed tomography of neck lymph nodes involved with malignant lymphoma: comparison with ultrasound.

CT images of 24 patients with head and neck lymphoma were retrospectively reviewed, compared with ultrasonograms, and compared with CT images of 13 patients with lymph node metastases. In nine (38%) of 24 patients, some lymph nodes with lymphomatous involvement showed a spotty or linear pattern of contrast enhancement. In two of these nine patients, a dendritic pattern of contrast enhancement between multiple enlarged lymph nodes was observed. The same pattern appeared as spotty, linear, or dendritic hyperechoic areas on the ultrasonogram. None of 13 patients with lymph node metastases showed a spotty, linear, or dendritic pattern of contrast enhancement. Ten of 13 (77%) showed ring-like contrast enhancement on CE-CT images. The spotty or linear contrast enhancement in enlarged lymph nodes and the dendritic contrast enhancement in confluent lymph nodes could be useful CT findings in diagnosing nodal involvement with malignant lymphoma.

Adult↗

PubMedDate not supplied

Splenectomy abolishes antitumor effect of immunotherapy with streptococcal preparation, OK-432, on mouse liver tumors.

In the present study, we investigated the therapeutic effects of oral and subcutaneous administration of OK-432 prior to or following the transplantation of murine liver tumors. In addition, the effect of splenectomy on the antitumor activity of OK-432 was investigated. Mice which received OK-432 orally prior to tumor transplantation exhibited significantly lower tumor weight and significantly improved survival, when compared to the control mice. Prior subcutaneous injection of OK-432 did not show any antitumor activity. On the other hand, both oral and subcutaneous administration of OK-432, subsequent to tumor transplantation, led to a significant improvement of survival and a decrease in the number of lung metastases, although tumor weight was not affected. The anti-tumor effect of OK-432 required the presence of the spleen, since the survival of the mice with liver tumors was not improved by OK-432 if splenectomy and tumor transplantation were performed simultaneously. These results suggest that immunotherapy with OK-432 may beneficial in the treatment of liver tumors and that these effects are dependent on the presence of the spleen.

Animals↗

PubMedDate not supplied

Effects of catecholamines on myocardial energy metabolism as studied by an organ redoximeter.

With the use of an organ redoximeter, the effects of noradrenaline, adrenaline, isoproterenol, and phenylephrine on the oxidation-reduction state of the myocardial pyridine nucleotides were studied in the canine heart-lung preparation supported by a donor. Noradrenaline and adrenaline produced an initial, transient improvement, and phenylephrine a sustained improvement, of the redox state, while isoproterenol produced a depression. Pretreatment of the preparation with adrenergic alpha-blockers resulted in an abolishment of the improvement by noradrenaline, adrenaline, and phenylephrine, while the depression by isoproterenol remained unchanged. Whereas noradrenaline and adrenaline produced a sustained improvement after an adrenergic beta-blocker, propranolol, the effect of isoproterenol was abolished. These findings suggest that sympathomimetic amines can produce an improvement of the myocardial energy metabolism through activation of the adrenergic alpha-receptor. The depression of the myocardial oxidation-reduction state was taken to represent an acceleration of glycolysis.

Animals↗

PubMedDate not supplied

Relationship of in vivo antitumor activities of fluorinated pyrimidines to thymidylate synthase activity and intratumoral concentrations of 5-fluorouracil and uracil.

MOPC-104E plasmacytomas were subcutaneously transplanted into BALB/c mice and after 7 days the mice were administered different fluorinated pyrimidines at 4 times the clinical doses, 5-fluorouracil (5-FU, 15 mg/kg), tegafur (FT, 100 mg/kg) or UFT (FT, 20 mg/kg + uracil, 44.8 mg/kg) daily for 7 days. Tumor growth was most effectively inhibited in the UFT group. The % inhibition of tumor growth on day 14, while not correlating with the concentration of 5-FU in the tumor, negatively correlated with the concentration of uracil, which was lowest in the UFT group. The activity of thymidylate synthase (TS) was measured using a 5-fluoro-deoxyuridine monophosphate (FdUMP) binding assay. The total and free TS activities in the tumor negatively correlated with the % inhibition of tumor growth, and were lowest in the UFT group. However, the % inhibition of TS activity in the tumor, which was about 80% in all 3 groups, did not correlate with the tumor-inhibitory effect. These results suggest that uracil in the tumor may play an important role in the metabolism of fluorinated pyrimidines, and that exogeneously administered uracil may decrease the amounts of uracil and TS in the tumor, and subsequently cause 5-FU accumulation.

Animals↗

PubMedDate not supplied

In vivo inhibitory effect of anticancer agents on human pancreatic cancer xenografts transplanted in nude mice.

Pancreatic cancer is one of the neoplasms resistant to chemotherapy. In the present study human pancreatic cancer xenografts (3 adenocarcinomas and 1 cystoadenocarcinoma) were subcutaneously transplanted in nude mice and after the tumors grew to 100-300 mm3, the mice were intraperitoneally administered with mitomycin C (MMC), adriamycin (ADR), 5-fluorouracil (5-FU), carboquone (CQ), cisplatinum (CDDP), nimustine chloride (ACNU) or DWA2114R at 1/3 LD50 on days 0.4, and 8. The tumor sizes on day 12 were compared with those on day 0. MMC and CQ significantly inhibited the tumor growth of 3 lines, and ACNU, CDDP and ADR inhibited the growth of 1 line. Further, 5-FU, futrafur, carmofur, UFT and L-phenylalanine mustard (L-PAM) were orally administered to mice into which 1 adenocarcinoma line had been transplanted. While none of fluoropyrimidines inhibited tumor growth, L-PAM at 4 mg/kg significantly inhibited growth, although it was accompanied by severe body weight loss. In the present study several agents significantly inhibited tumor growth, but none of them could induce the regression of the tumor when used singly. These results suggest that CQ, ACNU, CDDP and L-PAM may be applied to the chemotherapy of pancreatic cancer. However, the effect of a single agent is restricted and the development of new combination treatments is urgently required.

Adenocarcinoma↗

PubMedDate not supplied

In vitro and in vivo antineoplastic activity of a new platinum antineoplastic agent, (R)-(-)-1,1-cyclobutanedicarboxylate (2-aminomethylpyrrolidine)-platinum (II) (DWA2114R) on freshly separated human tumor cells and human tumor xenografts transplanted in nude mice--a comparison with cis-diammine-dichloroplatinum (CDDP).

The in vitro antimetabolic effect of a newly synthesized platinum antineoplastic agent, DWA2114R, on 72 fresh human tumors was compared with that of cis-platinum (CDDP). DWA2114R is reported to have a lower nephrotoxicity than CDDP, but is as strong an inhibitor of DNA synthesis as CDDP. In vitro IC50 was assessed in 10 tumors; the IC50 of DWA2114R ranged between 9.2 and 107 microM (mean +/- S.D., 45.9 +/- 36.6) and that of CDDP ranged between 0.9 and 40 microM (18.3 +/- 15.1). DWA2114R had an antitumor spectrum similar to that of CDDP. Primary esophageal and pancreatic cancers were sensitive to DWA2114R, and cells separated from malignant effusion or metastatic lymph nodes were more sensitive than those from primary lesions. Nude mice were transplanted with 3 kinds of human tumor xenografts (esophageal, pancreatic and bile duct cancer lines), and were then treated with CDDP or DWA2114R at 4 times the clinical doses. CDDP significantly inhibited the growth of all the 3 lines, and DWA2114R inhibited the growth of 2 of the lines. The effect of DWA2114R on body weight was smaller than that of CDDP. These results suggest that DWA2114R may be less potent than CDDP but may be useful as a new platinum antineoplastic agent with lower grade of side effects than CDDP.

Adenocarcinoma↗

PubMedDate not supplied

Binding and internalization of human immunoglobulin G conjugated with melphalan (K18) to human tumor cell lines.

The binding and internalization of melphalan-conjugated human immunoglobulin G (K18) to human tumor cell lines were studied using 14C-K18 (IgG conjugated with 14C-melphalan) and were compared with those of 14C-melphalan. K18 and melphalan dose-dependently bound to tumor cells, and the saturation binding analysis revealed a receptor-mediated binding of K18 but not of melphalan, to tumor cells. Intracellular distribution of 14C-K18 differed from that of 14C-melphalan, but a DNA unwinding experiment using a hydroxylapatite column showed that 14C-melphalan or 14C-K18 bound to DNA. These results suggest that after being bound to receptors K18 may be internalized in a macromolecular form and degraded into peptide binding melphalan. Moreover, the quantity of K18 that bound to 7 different human tumor cell lines was significantly larger than those that bound to lymphocytes of normal donors. These results suggest that K18 may be beneficial for cancer chemotherapy.

Antineoplastic Agents↗