Status of ion sources at National Institute of Radiological Sciences.

The National Institute of Radiological Sciences (NIRS) maintains various ion accelerators in order to study the effects of radiation of the human body and medical uses of radiation. Two electrostatic tandem accelerators and three cyclotrons delivered by commercial companies have offered various life science tools; these include proton-induced x-ray emission analysis (PIXE), micro beam irradiation, neutron exposure, and radioisotope tracers and probes. A duoplasmatron, a multicusp ion source, a penning ion source (PIG), and an electron cyclotron resonance ion source (ECRIS) are in operation for these purposes. The Heavy-Ion Medical Accelerator in Chiba (HIMAC) is an accelerator complex for heavy-ion radiotherapy, fully developed by NIRS. HIMAC is utilized not only for daily treatment with the carbon beam but also for fundamental experiments. Several ECRISs and a PIG at HIMAC satisfy various research and clinical requirements.

Monitoring of p53 autoantibodies after resection of colorectal cancer: relationship to operative curability.

OBJECTIVE: To investigate the clinical use of p53 autoantibodies as a marker in the postoperative monitoring of colorectal cancer. DESIGN: Retrospective study. SETTING: Teaching hospital, Japan. SUBJECTS: 40 patients with colorectal cancer who had p53 autoantibodies in their serum preoperatively. INTERVENTIONS: Serial assay of p53 autoantibodies by ELISA before and after resection. MAIN OUTCOME MEASURES: Interpretation by a qualitative analysis. RESULTS: A significant correlation was observed between curability by surgical resection and postoperative disappearance of p53 autoantibodies. Twenty-seven (96%) of 28 patients, who had p53 autoantibodies and whose cancer was completely removed, had no such antibodies after resection and no recurrence after 7 to 26 months. CONCLUSIONS: Postoperative assays of p53 autoantibodies are potentially useful for predicting recurrence of colorectal cancer in patients who have p53 autoantibodies preoperatively.

[Clinical significance of serum p53 antibody detection in a chemosensitivity assay in cases of human colorectal cancer].

Alteration of the p53 gene product occurs frequently during the progression of colorectal cancer. Recently, mutated p53 protein was found to induce the production of anti-p53 antibodies in the serum of patients. The purpose of this study was to evaluate the relationship between p53 status in serum and chemosensitivity in resectable colorectal cancer patients. A total of 35 patients with primary colorectal cancer who underwent surgical treatment were examined by chemosensitivity test with the viable tumor samples using Histoculture Drug Response Assay (HDRA). Serum samples of these patients to test for p53 antibodies were obtained before tumor resection, and assayed in duplicate by using an enzyme-linked immunosorbent assay (ELISA) kit. The inhibition index of 5-FU and CDDP, determined by the HDRA method, in the sero-positive group was significantly lower than that of the sero-negative group (p < 0.01). Furthermore, significant statistical differences in chemosensitivity to 5-FU and CDDP were revealed depending on the presence of serum p53 antibodies. There was no relationship between chemosensitivity assay and tumor marker positivity or clinicopathological features in these patients. Detection of serum p53 antibodies, which reflects p53 mutations in tumor tissue, is a simple method which correlates with chemosensitivity, and may contribute to the selection of favorable chemotherapeutic strategies of colorectal cancer.

Differential expression of plastidic aldolase genes in Nicotiana plants under salt stress.

Two homologous genes of plastidic fructose-1,6-bisphosphate aldolase (AldP) isozymes were isolated from green leaves of a salt stress-tolerant Nicotiana species, Nicotiana paniculata, by differential screening. The products of the corresponding genes, NpAldP1 and NpAldP2, were 91% identical to each other and 70-85% identical to the other known plant plastidic aldolases. Although these two genes showed similar organ-specific expression and daily cycles, their responses to salt stress differed: mRNA accumulation of NpAldP2 increased, but that of NpAldP1 slightly decreased. The mRNA accumulations of their counterparts of two other Nicotiana species, NeAldP1 and NeAldP2 (Nicotiana excelsior), and NaAldP1 and NaAldP2 (Nicotiana arentsii) were studied under the same stress condition. N. arentsii conserved accumulation profiles similar to N. paniculata, but N. excelsior did not. In N. excelsior, accumulation of NeAldP1 decreased to 50% of the control after stress and gradually recovered thereafter, whereas accumulation of NeAldP2 temporarily decreased and reached 250% of the control by the third day of stress. Southern blot analysis indicated that NpAldP1, NpAldP2, NaAldP1, and NaAldP2 include one or two closely related genes and NeAldP1 and NeAldP2 several.

Clinical significance of serum vascular endothelial growth factor in colorectal cancer patients: correlation with clinicopathological factors and tumor markers.

Vascular endothelial growth factor (VEGF) is known as a potent inducer of angiogenesis in various human cancers. Serum VEGF concentrations of colorectal cancer patients was assessed for their clinical significance as a tumor marker. Serum samples were obtained at admission from 24 healthy volunteers and 111 patients with colorectal cancer. Preoperative serum VEGF concentrations, which are significantly higher than those of healthy controls, reflect clinical stage progression, depth of invasion, liver metastasis, lymph node metastasis and lymphatic invasion. Consequently, detection of VEGF could serve as a clinically useful marker for colorectal cancer progression and metastasis independent of other markers.

A patient with rectal ulcer with severe stenosis presenting with perforated peritonitis.

We report a patient with rectal ulcer with severe stenosis, who underwent urgent surgical treatment for perforated peritonitis. The 54-year-old man suddenly developed cramping abdominal pain and fever while hospitalized, with signs of peritoneal irritation. An emergency laparotomy was performed, and severe stenosis of the rectum and a perforated lesion on the oral side approximately 10 cm distant from the stenosis were found, with massive abdominal purulent fluid. He was treated by rectosigmoid colon resection with transverse colon loop colostomy. Histopathologically, the stenosis was caused by ulceration extending to all muscular layers of the rectum, with inflammatory changes. Benign rectal stenosis is so rare that differential diagnosis from malignancy may be difficult when there are inflammatory changes in the surrounding tissues. However, it is necessary to keep in mind the likelihood of this disease in differentiation from rectal cancer.

Characterization of an auxin-inducible 1-aminocyclopropane-1-carboxylate synthase gene, VR-ACS6, of mungbean (Vigna radiata (L.) Wilczek) and hormonal interactions on the promoter activity in transgenic tobacco.

A genomic clone for VR-ACS6, an isozyme of auxin-inducible ACC synthase of mungbean, was isolated, and its promoter activity was examined in transgenic tobacco. The clone contained 1,612 bp long 5' untranscribed region and its coding sequence consisted of three exons and two introns. Genomic Southern hybridization indicated that VR-ACS6 is a single copy gene. The transcription initiation site was a cytosine present at 231-base upstream the translation start codon. The VR-ACS6 promoter contained DNA sequences homologous to various functionally identified auxin-responsive elements. To demonstrate hormonal response of the promoter region, transgenic tobacco plants carrying the 1,719 bp VR-ACS6 promoter/-glucuronidase (GUS) fusion gene were generated. Strong GUS expression occurred by auxin treatment of leaves of T0 transformants and hypocotyls of T1 etiolated seedlings. Magnitude of the response to auxin was dose-dependent, and the increased GUS activity was detected at 0.1 microM and higher concentrations of IAA. Other plant hormones did not induce GUS activity, but greatly modified the response to auxin. Cytokinin enhanced the IAA-induced expression of GUS reporter gene, whereas ABA and ethylene suppressed the expression. These characteristics of VR-ACS6 promoter activity in transgenic tobacco are in good accordance with the expression patterns of the gene in mungbean hypocotyls. Histochemical staining showed that GUS activity was evident in both etiolated and light grown seedings treated with IAA. Cytokinin enhanced the intensity of auxin-induced GUS stain and also expanded the stained area, whereas ABA and ethylene reduced both intensity and area of the stain.

Clinical significance of serum p53 antibody detection on chemosensitivity assay in human colorectal cancer.

BACKGROUND AND OBJECTIVES: Alteration of the p53 gene product occurs frequently during progression of colorectal cancer. Recently, mutated p53 protein was found to induce the production of anti-p53 antibodies in the serum of patients. The purpose of this study was to evaluate the relationship between p53 status in serum and chemosensitivity in resectable colorectal cancer patients. METHODS: A total of 22 patients with primary colorectal cancer who underwent surgical treatment were examined for chemosensitivity with iable tumor samples using the Histoculture Drug Response Assay (HDRA). Serum samples of these patients for p53 antibodies were obtained before tumor resection and assayed in duplicate using an enzyme-linked immunosorbent assay kit. RESULTS: The inhibition index of 5-fluorouracil and cis-diamminedichloroplatinum (CDDP), determined by the HDRA method, in the seropositive group was significantly lower than that in the seronegative group (P < 0.01). Furthermore, significant statistical differences in chemosensitivity to 5-fluorouracil and CDDP were revealed depending on the presence of serum p53 antibodies. CONCLUSIONS: Detection of serum p53 antibodies, which reflects p53 mutations in tumor tissue, is a simpler method which correlates with chemosensitivity and may contribute to the selection of favorable chemotherapeutic strategies for colorectal cancer.

[Detection of serum p53 antibodies in colorectal cancer patients and the clinical significance of postoperative monitoring].

p53 protein overexpression was found to induce the production of antibodies in patient serum and, recently, the easy detection of serum antibodies has been made possible. The aim of this study is to determine the significance of serum p53 antibodies in patients with primary colorectal adenocarcinoma in comparison with their clinicopathological features, and the tumor marker sensitivities of carcinoembryonic antigen (CEA), carcinoma antigen 19-9 (CA19-9) and alpha-fetoprotein (AFP). Thirty-nine of 86 patients (45.3%) were positive for serum p53 antibodies. However, there was no relation with the cancer progression or clinicopathological findings. The sensitivities of CEA, CA19-9 and AFP were 36.0%, 38.4%, and 8.1% respectively, but there was no relation between serum p53 antibodies and these three markers. When the sensitivity of serum p53 antibodies and CEA was evaluated according to clinical stage, the presence of serum p53 antibodies was more significantly associated with stage 0, I and II colorectal cancer than was CEA. Thirty-three patients who showed preoperative positivity for serum p53 antibodies were followed by serial evaluation of circulating antibodies after resection. Negative conversions after resection were significantly higher in the "Cur A" group than in the "Cur B" or "Cur C" groups. Serum p53 antibodies appear to be a useful tumor marker independent of the other markers, especially in the early stage, and are expected to be useful in the development of a method of early diagnosis for mass screening, and as a postoperative monitoring marker for colorectal cancer.

Identification of hepatitis B virus integration in hepatitis C virus-infected hepatocellular carcinoma tissues.

BACKGROUND/AIMS: The integration of HBV DNA is thought to be involved in the initial stage of hepatocarcinogenesis, and it has been reported that transactivating factors encoded by the X and preS2/S genes stimulate transcription of multiple viral and cellular genes. We assessed the possible contributions of hepatitis B virus integration to the occurrence of hepatocellular carcinoma in hepatitis C virus-infected as well as in hepatitis B virus-infected patients by identifying the integrated HBV DNA sequence, and the X and preS2/S regions were further investigated in HBV DNA-integrated cases. METHODS: Southern blot hybridization for detecting HBV DNA in tumor tissues from 28 hepatocellular carcinoma patients was carried out with full-length HBV DNA, and then with X and preS2/S regions as probes. We also carried out reverse transcription-polymerase chain reaction for detecting HCV RNA to confirm hepatitis C virus-infection in liver tissues. RESULTS: Clonally integrated HBV DNA sequences were demonstrated in 16 of 28 patients (57.1%), including five HBsAg seropositive and 11 HBsAg seronegative patients. Of these 11 HBsAg seronegative patients, 10 were also positive for anti-HCV in their sera, and all nine examined cases had HCV RNA in liver. Furthermore, the X region was identified in 14 of 16 HBV DNA integrated cases (87.5%), and the preS2/S region in 6/16 (37.5%). CONCLUSIONS: The present Southern blot analysis demonstrates that clonally integrated HBV DNA sequences were identified even in hepatitis C virus-infected hepatocellular carcinoma patients at a high rate (10/18, 55.6%), and suggests that integrated hepatitis B virus, whose major component is the X gene, may play an important role in hepatocarcinogenesis in hepatitis B virus-integrated cases with and without hepatitis C virus infection.

VR-ACS6 is an auxin-inducible 1-aminocyclopropane-1-carboxylate synthase gene in mungbean (Vigna radiata).

We have isolated four cDNA clones of ACC synthase from etiolated mungbean seedlings treated with auxin. pVR-ACS2, pVR-ACS3 and pVR-ACS6 contained the same sequences as the previously reported DNA fragments, pMAC2, pMAC3 (Botella et al. 1992b) and pMBA1 (Kim et al. 1992), respectively. pVR-ACS1 was identical with pAIM-1 (Botella et al. 1992a). VR-ACS6 was specifically induced in response to the auxin signal. The IAA-induction of VR-ACS6 was very rapid (within 30 min) and insensitive to cycloheximide treatment at concentrations up to 100 microM. Significant accumulation of VR-ACS6 mRNA was detected at 1 microM IAA. The IAA-induced expression of VR-ACS6 was suppressed by ABA and ethylene, but enhanced by BA. These characteristics of VR-ACS6 expression were well correlated with the physiological data of auxin-induced ethylene production in mungbean hypocotyls. VR-ACS1 was strongly induced by cycloheximide, but was found to be not auxin-specific. Inhibitors of either ethylene biosynthesis (AOA) or action (NBD) increased the basal level of VR-ACS1 mRNA.

Expression of plasma membrane water channel genes under water stress in Nicotiana excelsior.

Deduced amino acid sequences encoded by the cDNAs related to the MIP gene family from Nicotiana excelsior were characterized. Phylogenetic characterization of the products of corresponding genes named NeMip1, NeMip2, and NeMip3 strongly suggested that they are water channel proteins localized in the plasma membrane. Organ specificity of the gene expression was examined in leaves, roots, and reproductive organs. NeMip1 was expressed in roots and reproductive organs; however, it was hardly detectable in leaves. Two other genes, NeMip2 and NeMip3, were expressed in all of organs examined. mRNA accumulation from the genes was investigated in leaves under salt- and drought-stresses. The results demonstrated that mRNA accumulation from all three genes increased under salt- and drought-stresses within one day. However, they showed different accumulation patterns. In addition to their up-regulation under salt- and drought-stresses, daily changes in NeMip2 and NeMip3 mRNA accumulation was observed under unstressed conditions in leaves.

DNA sequence requirement of a TATA element-binding protein from Arabidopsis for transcription in vitro.

We have analyzed the DNA sequence requirements for the functioning of TATA elements by examining the transcriptional activities associated with 24 promoters, including representatives of each of the 21 point mutations in the consensus sequence from plants, TATATATA, in a HeLa in vitro system and in a chimeric in vitro system in which human TATA-binding protein (hTBP) was replaced by purified TBP of Arabidopsis (aTBP-1). Although the relative transcriptional activities varied among these promoters, both systems gave virtually identical results. Among the mutant TATA elements, those with the sequences TAGAGATA and GAGAGAGA had undetectable activity. The rest had activities that ranged from 7% to 130% of the activity associated with the consensus element. These results suggest the functional conservation of TBP between plants and animals.

Identification of a basic glycoprotein induced by ethylene in primary leaves of azuki bean as a cationic peroxidase.

Ethylene causes the accumulation of seven different proteins (each designated AZxx according to its molecular mass, xx in kD) in excised primary leaves of azuki bean (Vigna angularis) (F. Ishige, H. Mori, K. Yamazaki, H. Imaseki [1991] Plant Cell Physiol 32: 681-690). A complementary DNA encoding an ethylene-induced basic glycoprotein, AZ42, from azuki bean was cloned and its complete nucleotide sequence was determined. Characterization of the cDNA was accomplished by monitoring expression of an immunoreactive protein in Escherichia coli that harbored the cDNA and by the identification of a partial amino acid sequence that was the same as that determined from the purified protein. An open reading frame (1071 base pairs) in the cDNA encoded a protein of 357 amino acids with a molecular mass of 39.3 kD. The amino acid sequence contained three regions that are highly conserved among peroxidases from eight different plants. Purified AZ42 exhibited peroxidase activity. The basic glycoprotein induced by ethylene was identified as a cationic isozyme of peroxidase. The corresponding mRNA was not present in leaves that had not been treated with ethylene, but it appeared after 1 h of treatment with ethylene and its level increased for the next 15 h. Accumulation of the mRNA was also induced after wounding or treatment with salicylate. The wound-induced increase in the level of the mRNA was suppressed by 2,5-norbornadiene, but the salicylate-induced increase was not.

Cloning of a complementary DNA that encodes an acidic chitinase which is induced by ethylene and expression of the corresponding gene.

A complementary DNA encoding an ethylene-inducible acidic chitinase of azuki bean (Vigna angularis) was isolated, and its complete nucleotide sequence was determined. The nucleotide and deduced amino-acid sequence were very similar to those of an acidic chitinase from cucumber leaves that had been infected with tobacco necrosis virus. The mRNA for the acidic chitinase was not detected in leaves of azuki bean that had not been treated with ethylene, but it appeared 3 h after initiation of treatment with ethylene and its level gradually increased over a period of 19 h. The mRNA also accumulated in response to salicylate or wounding. The expression of the gene in response to wounding was suppressed by 2,5-norbornadiene, but that in response to salicylate was not affected by this inhibitor.