Behavior of plastid nucleoids during male gametogenesis in Plumbago auriculata

We characterized the behavior of plastid (pt) and mitochondrial (mt) nucleoids during male gametogenesis in Plumbago auriculata in three dimensions. The behavior of pt-nucleoids and mt-nucleoids differed throughout male gametogenesis. Pt-nucleoids were distributed in a characteristic manner in three stages: in the early microspore, pt-nucleoids assemble around cell nucleus; in the mid-generative cell, pt-nucleoids gather at the internal side of the pollen; in the late-generative cell, pt-nucleoids aggregation turns its pole to the external side of the pollen. We also studied organelle nucleoids in the egg and the central cell by a method in which semi-thick sections of resin-embedded anthers and ovaries were observed by confocal laser scanning microscopy. The number of pt-nucleoids in the sperm cell did not differ significantly from that in the egg. These results suggest that the behavior of DNA-containing organelles is regulated strictly during male gametogenesis in P. auriculata, and that a biparental inheritance of plastids in the Plumbago embryo is more favored than was previously thought.

Treatment of dark-grown Arabidopsis thaliana with a brassinosteroid-biosynthesis inhibitor, brassinazole, induces some characteristics of light-grown plants

When a brassinosteroid biosynthesis inhibitor, brassinazole (Brz), was applied at concentrations ranging from 0.1 to 2 microM. Arabidopsis thaliana (L.) Heynh seedlings grown in the dark exhibited morphological features of light-grown plants, i.e. short hypocotyls, expanded cotyledons, and true leaves, in a dose-dependent manner. Control (non Brz-treated) seedlings grown in the dark for 40 d did not develop leaf primordia. However, treatment with the lowest concentration of Brz induced the development of leaf buds, although it hardly induced any short hypocotyls, and treatment with the highest concentration of Brz induced both short hypocotyls and leaves. Labeling experiments with the thymidine analogue 5-bromo-2'-deoxyuridine revealed that amplification of cell nuclei and organellar nucleoids is activated in the shoot apical meristems of dark-grown Brz-treated seedlings. These results suggest that Brz-treatment induces development of true leaves. Furthermore, condensation and scattering of plastid nucleoids, which is known to occur during the differentiation of etioplasts into chloroplasts, was observed in the plastids of dark-grown Brz-treated cotyledons. In addition, high levels of ribulose-1,5-bisphosphate carboxylase-oxygenase proteins accumulated in the plastids of the cotyledons. Electron microscopy showed that the plastids were etioplasts with a prolamellar body and few thylakoid membranes. These results suggest that Brz treatment in the dark induces the initial steps of plastid differentiation, which occur prior to the development of thylakoid membranes. This is a novel presumed function of brassinosteroids. These cytological changes seen in Brz-treated Arabidopsis were exactly the same as those seen in a brassinosteroid-biosynthesis-deficient mutant, det2, supporting the hypothesis that Brz has no side-effects except inhibiting brassinosteroid biosynthesis, and should prove a useful tool in clarifying the role of brassinosteroids.

Relationship between plasma levels of vascular endothelial growth factor and serum levels of interleukin-12 in patients with colorectal cancer

BACKGROUND

Vascular endothelial growth factor (VEGF) is thought to be the most potent angiogenic factor in the numerous malignant tumors and a prognostic indicator for cancer patients. Interleukin 12 (IL-12) is a heterodimeric cytokine that has potent anti-tumor and anti-metastatic activities. Recently, it has been suggested that IL-12 regulates VEGF in a murine breast cancer model.

MATERIALS AND METHODS

Blood from 26 patients with colorectal cancer was obtained prior to surgery. Plasma levels of VEGF and serum levels of IL-12 were assessed using the quantitative sandwich enzyme immunoassay technique. We investigated the preoperative relationships between plasma levels of VEGF, serum levels of IL-12 and clinicopathological factors in patients with colorectal cancer.

RESULTS

Although not statistically significantly, high plasma levels of VEGF and low serum levels of IL-12 tended to occur with more advanced colorectal cancer. Plasma levels of VEGF in patients who had circumferential involvement of the tumor greater than 1/2 were only significantly increased. The preoperative relationship between plasma levels of VEGF and serum levels of IL-12 tended to be negatively correlated.

CONCLUSION

These results suggest that high plasma levels of IL-12 or low serum levels of IL-12 may be observed in more advanced colorectal cancer patients. Thus, these patients may require additional immunochemotherapy after surgery. IL-12 may regulate VEGF in the patients diagnosed with colorectal cancer.

Paradoxical pleural response to antituberculous chemotherapy and isoniazid-induced lupus. Review and report of two cases

Among 28 inpatients receiving antituberculous chemotherapies including isoniazid (INH) and rifampicin, we found 2 patients with newly developing pleural effusion in the hemithorax during the initial phase of successful chemotherapy. The analysis of the effusion fluids revealed an elevated level of antinuclear antibody and a decreased level of total component, which are findings compatible with lupus pleuritis. The peripheral lymphocyte stimulation test using INH was positive in 1 patient. To the best of our knowledge, there has been no published discussion of the relationship between a paradoxical response to antituberculous treatment and INH-induced lupus.

Production of nitric oxide from endothelial cells by 31-amino-acid-length endothelin-1, a novel vasoconstrictive product by human chymase

Human chymase selectively converts big endothelin (ET)-1 to 31-amino-acid-length ET-1 [ET-1(1-31)]. In this study we examined effect of ET-1(1-31) on endothelial function. ET-1(1-31) evoked contraction in a concentration-dependent manner at > 10(-8) M, which was about 10 times weaker than that of conventional ET-1 [ET-1(1-21)]. BQ485, an ETA receptor antagonist, completely abolished ET-1(1-31)-induced contraction, but BQ788, an ETB receptor antagonist, slightly enhanced it, suggesting that ET-1(1-31) relaxes artery via endothelium. On endothelial cells, ET-1(1-21) and ET-1(1-31) increased [Ca2+]i and produced NO, both of which were significantly inhibited by BQ788 and not by BQ485. These results indicate that ET-1(1-31) increased [Ca2+]i and produced NO in endothelial cells through ETB receptor similarly with ET-1(1-21), although slight difference in effect on smooth muscle cells.

Extracellular adenosine 5'-ATP-induced calcium signaling in isolated vestibular ganglion cells of the guinea pig

Extracellular adenosine 5'-triphosphate (ATP)-induced intracellular calcium concentration ([Ca2+]i) changes in acutely isolated vestibular ganglion cells (VGCs) of the guinea pig were investigated using the Ca2+ -sensitive dye Fura-2. Extracellular ATP induced an increase in [Ca2+]i in VGCs in a dose-dependent manner. ATP induced an increase in [Ca2+]i even in the absence of extracellular Ca2+ (1 mM Ethylene Glycol-bis (beta-aminoethyl Ether) N,N,N',N'-Tetraacetic Acid (EGTA)), thus suggesting that ATP induces Ca2+ release from the intracellular stores. The P2-receptor antagonists suramin and reactive blue 2 inhibited the ATP-induced [Ca2+]i increase in a dose-dependent manner. The P1-receptor agonist adenosine did not induce any changes in [Ca2+]i. These results suggest that VGCs may possess a P2-purinergic receptor but not a P1-purinergic receptor. La3+, a receptor-mediated calcium channel blocker, inhibited the ATP-induced [Ca2+]i increase but, in contrast, nifedipine, a L-type calcium channel blocker, did not. These results suggest that ATP induces both a Ca2+ -release from the intracellular stores and a Ca2+ influx from the extracellular space through La3+ -sensitive and nifedipine-insensitive Ca2+ channels in VGCs. Our results also suggest that extracellular ATP may act as a neurotransmitter or neuromodulator of the vestibular peripheral system in the guinea pig.

A novel 31-amino-acid-length endothelin, ET-1(1-31), can act as a biologically active peptide for vascular smooth muscle cells

Human chymase produces a novel endothelin-1 with 31 amino-acid length ¿ET-1(1-31)¿, which is longer than conventional ET-1, ¿ET-1(1-21)¿. The aim of our study was to investigate the role of ET-1(1-31) on porcine coronary vascular smooth muscle cell (VSMC). Although the increase in [Ca(2+)](i) by ET-1(1-31) was 10 times weaker than that of ET-1(1-21), ET-1(1-31) showed equivalent potency in VSMC proliferation, c-fos/c-myc mRNA expression and cell cycle analysis with ET-1(1-21). ET-1(1-31) significantly induced expression of cyclin D1 but not those of cyclin D2 or D3. These effects were specifically inhibited by BQ485, an ET(A) receptor antagonist, although that of ET-1(1-21) was not specific to BQ485, suggesting different receptor specificity from ET-1(1-21). These results indicate that ET-1(1-31) also can involve a VSMC proliferation process such as atherosclerosis, although it has weaker vasoconstricting potency and different receptor subtypes on VSMC from those of ET-1(1-21).

Relationship between inflammatory cells in bronchoalveolar lavage fluid and pathologic changes in the lung interstitium

Bronchoalveolar lavage (BAL) is recognized as an important research tool for various lung diseases, but it is still uncertain whether inflammatory cells in BAL fluid (BALF) accurately reflect pathologic changes in the lung interstitium. We used a morphometric method to quantify the density of inflammatory cells in the lung interstitium by utilizing a computer-aided graphic analyzer and compared those findings with BALF results. Two types of animal models were studied, i.e., endotoxemia (Escherichia coli endotoxin) and hypersensitivity pneumonitis (inhaled ovalbumin). Male Wistar rats were used; the right lungs were lavaged and the left lungs were prepared for morphometric study. In the endotoxemia model, the neutrophil fraction in BALF and the neutrophil density in the lung interstitium correlated significantly at 18 h (r = 0.81, p < 0.05) and 24 h (r = 0.81, p < 0.05) but not at any other time points after injection. In the hypersensitivity pneumonitis model, the neutrophil fraction in BALF and the neutrophil density in the lung interstitium correlated significantly (r = 0.80, p < 0.05) only at 3 h after inhalation. The lymphocyte fraction in BALF and the lymphocyte density in the lung interstitium were correlated positively at 3 h (r = 0.83, p < 0.05), 1 day (r = 0.82, p < 0.05), 2 days (r = 0.67, p = NS), and 4 days (r = 0.87, p < 0.05), but not at 6 days after inhalation. Our data suggest that neutrophil fraction in BALF does not reflect neutrophil populations in the lung interstitium except at the time of maximal neutrophil count in lung lavage. For lymphocytes in the hypersensitivity pneumonitis model, those in BALF and in the lung interstitium roughly correlate in the majority of measurements.

Metastatic pulmonary epithelioid hemangioendothelioma with peculiar radiographic features

We report a case of a pulmonary epithelioid hemangioendothelioma presenting as a solitary pulmonary nodule with subsequent systemic spread, including histologically documented gingival metastasis. Chest radiography and computed tomography at initial evaluation showed a solitary 2 cm pulmonary nodule, associated with pleural indentation and vascular convergence. The tumor later spread systemically, including multiple pulmonary nodules, bilateral pleural effusions, and gingival swelling and erosion. A biopsy of the gingival lesion showed histologic features identical to that of the lung biopsy.

Repetitive intermittent hypoxia-ischemia and brain damage in neonatal rats

OBJECTIVE

To know the effect of brief-repetitive intermittent hypoxia-ischemia on the development of perinatal brain damage.

STUDY DESIGN

Seven-day-old Wistar rats underwent ligation of the unilateral common carotid artery. The animals were allocated to three groups (n=12 in each group) and exposed to 8% oxygen as follows: group A: continuous exposure for 180 min; group B: continuous exposure for 90 min; and group C: 10 min of exposure repeated at 10-min intervals over a period of 180 min (total exposure time, 90 min). Seventy-two hours after exposure to hypoxia, the cerebral cortex was examined to assess the degree of neuronal necrosis and brain damage was classified into four grades of severity, 0-3. To evaluate the extent of brain damage, we used immunohistochemical staining with TIB-128 antibody, which reacts to MAC-1 antigen specific to microglia, and observed the glial reaction in the cerebral cortex, hippocampus, thalamus, and striatum.

RESULTS

All the brain damage observed in groups A-C occurred on the side where the ligation was performed. The most severe damage was found in group A animals, of which seven showed significant neuronal necrosis, having a grade 2 or more advanced lesion. In group B, neuronal necrosis was modest, with only one animal having a grade 2 lesion. In group C, a significant neuronal necrosis was found in six animals despite having the same period of hypoxic exposure as those in group B. MAC-1 positive cells appeared in the cerebral cortex of histologically damaged animals and extended to the hippocampus, thalamus, and striatum in severely damaged animals from groups A, B, and C.

CONCLUSION

Examination of the neonatal rat model suggested that repetitive and intermittent, rather than continuous hypoxia-ischemia, causes pronounced damage in the immature brain.

Establishment of a human colon cancer cell line (PMF-ko14) displaying highly metastatic activity

A new human colon cancer cell line (PMF-ko14) derived from a peritoneal disseminated tumor has been established and maintained for over 25 months. In tissue culture, the cells grew in a mainly monolayered sheet with a population doubling time of about 27 h. Chromosome counts at the 60th passage ranged from 79 to 84 with a modal number of 83. Flow cytometry of the cell surface antigen expression indicated that CD49b, CD29, carcinoembryonic antigen (CEA), sialyl Lewis a (sLea), and CD49c were positive in more than 70% of the cells. The nude mouse xenograft models indicated are: subcutaneous or intraperitoneal injection model, spleen injection-liver metastasis model, and orthotopic implantation-spontaneous metastasis model. As PMF-ko14 has highly metastatic activity it should prove to be a useful tool for research in biological behavior of metastatic colon cancer.

Recovery of pathogenic measles virus from cloned cDNA

Reverse genetics technology so far established for measles virus (MeV) is based on the Edmonston strain, which was isolated several decades ago, has been passaged in nonlymphoid cell lines, and is no longer pathogenic in monkey models. On the other hand, MeVs isolated and passaged in the Epstein-Barr virus-transformed marmoset B-lymphoblastoid cell line B95a would retain their original pathogenicity (F. Kobune et al., J. Virol. 64:700-705, 1990). Here we have developed MeV reverse genetics systems based on the highly pathogenic IC-B strain isolated in B95a cells. Infectious viruses were successfully recovered from the cloned cDNA of IC-B strain by two different approaches. One was simple cotransfection of B95a cells, with three plasmids each encoding the nucleocapsid (N), phospho (P), or large (L) protein, respectively, and their expression was driven by the bacteriophage T7 RNA polymerase supplied by coinfecting recombinant vaccinia virus vTF7-3. The second approach was transfection with the L-encoding plasmid of a helper cell line constitutively expressing the MeV N and P proteins and the T7 polymerase (F. Radecke et al., EMBO J. 14:5773-5784, 1995) on which B95a cells were overlaid. Virus clones recovered by both methods possessed RNA genomes identical to that of the parental IC-B strain and were indistinguishable from the IC-B strain with respect to growth phenotypes in vitro and the clinical course and histopathology of experimentally infected cynomolgus monkeys. Thus, the systems developed here could be useful for studying viral gene functions in the context of the natural course of MeV pathogenesis.

Immature brain injury via peroxynitrite production induced by inducible nitric oxide synthase after hypoxia-ischemia in rats

OBJECTIVE

To determine whether, and if so how, iNOS expresses and affects brain injury induced by hypoxia-ischemia in an immature brain.

MATERIAL AND METHODS

Seven-day-old Wistar rat pups were exposed to right common carotid artery ligation followed by 1.5 hours of hypoxia. The time course of iNOS mRNA expression, enzymatic activity, and protein production in the cerebral cortex were determined. The extent of the infarct area in the cerebral cortex and the production of 3-nitrotyrosine (a biomarker of peroxynitrite) were compared between the control pups and pups treated with S-methyl-isothiourea (a selective iNOS inhibitor).

RESULTS

In the cortex ipsilateral to carotid ligation, iNOS mRNA appeared from 6 hours to 24 hours after hypoxia-ischemia and disappeared at 48 hours. The iNOS protein and its activity also increased at 12 hours and reached a maximum level at 48 hours after the insult. The percentage of damage in the cerebral cortex was significantly higher in the control pups than in treated pups (31.9 vs 10.6%). Tri-nitrotyrosine following iNOS expression-positive cells were located predominantly at the infarct and peri-infarct regions.

CONCLUSIONS

iNOS expression might be an important determinant of ischemic immature brain injury.

The relationship between the response to external light stimulation and behavioral states in the human fetus: how it differs from vibroacoustic stimulation

OBJECTIVE

To determine the effects of external light stimulation on fetal behavioral states and know the difference from those of vibroacoustic stimulation.

METHODS

A flashlight and a vibroacoustic stimulator was applied directly on the maternal abdomen to determine the response of 56 normal fetuses at 36-40 weeks gestation. Fetal heart rate (FHR) and body movements were recorded using an actocardiograph, and fetal eye movements were observed using real-time ultrasonography. Using Nijhuis's criteria, the fetal behavioral states (1F-4F) were determined. FHR acceleration was considered a fetal response to the stimulations.

RESULTS

The lag time between stimulation and fetal response was within 4 s. A positive response rate to the light stimulation was higher at behavioral states 2F (82%) and 3F (83%) than at state 1F (4%). Light stimulation changed the behavioral state of two of the six 3F fetuses (33%) from 3F to 4F. No change of state was observed in fetuses that were in states 1F and 2F. For vibroacoustic stimulation, fetal response was 100% positive and changes of states were observed frequently irrespective of the behavioral state before the stimulation.

CONCLUSION

Fetal response to light stimulation is closely connected to fetal behavioral states and may reflect some distinct stages of the sleep-wakefulness cycle.

Characterization of brassinazole, a triazole-type brassinosteroid biosynthesis inhibitor

Screening for brassinosteroid (BR) biosynthesis inhibitors was performed to find chemicals that induce dwarfism in Arabidopsis, mutants that resembled BR biosynthesis mutants that can be rescued by BR. Through this screening experiment, the compound brassinazole was selected as the most potent chemical. In dark-grown Arabidopsis, brassinazole-induced morphological changes were nearly restored to those of wild type by treatment with brassinolide. The structure of brassinazole is similar to pacrobutrazol, a gibberellin biosynthesis inhibitor. However, in assays with cress (Lepidium sativum) plants, brassinazole-treated plants did not show recovery after the addition of gibberellin but showed good recovery after the addition of brassinolide. These data demonstrate that brassinazole is a specific BR biosynthesis inhibitor. Brassinazole-treated cress also showed dwarfism, with altered leaf morphology, including the downward curling and dark green color typical of Arabidopsis BR-deficient mutants, and this dwarfism was reversed by the application of 10 nM brassinolide. This result suggests that BRs are essential for plant growth, and that brassinazole can be used to clarify the function of BRs in plants as a complement to BR-deficient mutants. The brassinazole action site was also investigated by feeding BR biosynthesis intermediates to cress grown in the light.

Neutrophils express tissue factor in a monkey model of sepsis

BACKGROUND

Although tissue factor (TF) is involved in hemostasis, thrombogenesis, inflammation, and cellular immune response, its source in sepsis remains controversial. Recently, we found that, in addition to monocytes and endothelial cells, neutrophils may express TF in a rabbit model. The purpose of this study was to determine whether neutrophils could be a source of TF in a monkey model of sepsis.

METHODS

TF messenger RNA (mRNA) and protein in neutrophils were assayed by in situ hybridization and immunohistochemistry in tissues obtained from monkeys after injection of lipopolysaccharide (LPS) (n = 3) and after injection of saline as a control (n = 2). Coagulation parameters were measured before and at 1.5 and 3 hours after injections.

RESULTS

In LPS-treated monkeys, TF mRNA and protein were induced not only in monocytes and endothelial cells, but also in neutrophils accumulating in the liver 3 hours after LPS injection. Thrombin-antithrombin III complex and fibrin degradation products D-dimer levels were significantly increased at 3 and 1.5 hours after LPS injection compared with controls.

CONCLUSIONS

Neutrophils are a source of TF and are implicated in direct activation of the coagulation cascade in the early phases of sepsis in the monkey. These results give important information for the treatment of sepsis.

Semiconductor-assisted photocatalytic degradation of reactive dyes in aqueous solution

This work reports the semiconductor-assisted photochemical degradation of reactive dyes. In an oxygenated-UV-ZnO system almost total decolorization of Remazol Brilliant Blue R, Remazol Black B, Reactive Blue 221 and Reactive Blue 222 was observed in reaction times of about 60 min. Extending the photochemical treatment up to 120 min, mineralization higher than 80% for all the dyes was observed. During the same period, the residual acute toxicity was significantly reduced only for Remazol Black B. A systematic optimization study carried out by factorial design showed that for the reactive dyes tested, the ZnO semiconductor exhibits a better efficiency than that observed with anatase TiO2. A synergistic effect in the coupled TiO2-ZnO system was not observed.

Association of Cbl with Fms and p85 in response to macrophage colony-stimulating factor

Tyrosine phosphorylation of Cbl and its association with signal-transducing molecules in response to macrophage colony-stimulating factor (M-CSF) were analyzed by using cell lines which express the wild-type and a mutant M-CSF receptor, Fms. We found that in a clone, F723 TF-1 cells expressing mutant Fms in which tyrosine 723 had been substituted with phenylalanine, the M-CSF stimulation-dependent association between Cbl and Fms was markedly impaired. However, phosphorylation of Cbl and its association with the p85 subunit of phosphatidylinositol 3-kinase were induced in these mutant cells as seen in the wild-type fms transfectant. These results suggest that phosphorylation of tyrosine 723 is particularly important for the recruitment of Cbl to the M-CSF receptor, but is not required for the phosphorylation and binding of Cbl to signal-transducing molecules such as p85.

Enhanced coexpression of YB-1 and DNA topoisomerase II alpha genes in human colorectal carcinomas

The transcription factor YB-1 is expressed in a wide range of cell types and has been implicated in the regulation of various genes involved in cell proliferation. Nuclear expression of YB-1 is correlated with MDR-1 gene expression in breast cancer and osteosarcoma. In this study, we asked whether YB-1 expression is enhanced in human colorectral carcinoma and if it is associated with the expression of target genes such as MDR-1, DNA topoisomerase II alpha and PCNA. YB-1, DNA topoisomerase II alpha, PCNA and MDR-1 expression were assessed by Western blotting, Northern blotting and immunohistochemistry in 26 human colorectal carcinomas. The involvement of YB-1 in DNA topoisomerase II alpha gene expression was examined by transient DNA transfection assays. YB-1 was overexpressed in almost all cancerous lesions in comparison with normal mucosa in surgically resected colorectal carcinomas of 26 patients. YB-1 expression correlated well with both DNA topoisomerase II alpha and PCNA expression. In contrast, no correlation was observed between YB-1 and MDR-1 expression. We also found that a transient co-transfection with a DNA topoisomerase II alpha promoter-luciferase plasmid and an antisense YB-1 expression construct resulted in a significant reduction of the promoter activity in KM12C human colon cancer cells. YB-1 may be an excellent proliferation-associated marker and may be a transcription factor regulating DNA topoisomerase II alpha gene expression in human colorectal carcinoma.

Inherited polymorphism in the N-acetyltransferase 1 (NAT1) and 2 (NAT2) genes and susceptibility to gastric and colorectal adenocarcinoma

The polymorphic arylamine N-acetyltransferases (NAT1 and NAT2) have been implicated in increased susceptibility to certain malignancies. We analyzed genetic polymorphisms in both the NAT1 and NAT2 genes among 140 gastric adenocarcinoma patients, 103 colorectal adenocarcinoma patients and 122 healthy controls from Japan. The frequency of the specific genotype NAT1*10 allele, which contains a variant polyadenylation signal, was higher among all gastric adenocarcinoma cases, but this increase did not reach statistical significance. After grouping according to tumor differentiation of gastric adenocarcinoma patients, NAT1 polymorphism was a risk factor among the well-differentiated type of tumors (OR = 3.03, 95% CI 1. 08-8.46). Stratifying by smoking status, we found that the OR for heavy smokers with the NAT1*10 allele was 2.97 (95% CI 1.23-7.14). When the combined risk of NAT1*10 allele from smoking and tumor differentiation was calculated, we found that the risk of the NAT1*10 allele with heavy smoking was increased among the well - differentiated type of gastric adenocarcinoma (OR = 4.24, 95% CI 0. 87-20.6). The NAT1*10 genotype was not a significant risk factor in colorectal adenocarcinoma. No statistically significant differences were observed in the frequency of NAT2 rapid acetylation genotype in gastric (91.4%) or colorectal (95.2%) adenocarcinoma patients when compared with the control population (94.3%). Our results suggest the NAT1*10 allele may be an important genetic determinant of the well-differentiated type of gastric adenocarcinoma, which may be induced by smoking.

Inherited polymorphism in the N-acetyltransferase 1 (NAT1) and 2 (NAT2) genes and susceptibility to gastric and colorectal adenocarcinoma

The polymorphic arylamine N-acetyltransferases (NAT1 and NAT2) have been implicated in increased susceptibility to certain malignancies. We analyzed genetic polymorphisms in both the NAT1 and NAT2 genes among 140 gastric adenocarcinoma patients, 103 colorectal adenocarcinoma patients and 122 healthy controls from Japan. The frequency of the specific genotype NAT1*10 allele, which contains a variant polyadenylation signal, was higher among all gastric adenocarcinoma cases, but this increase did not reach statistical significance. After grouping according to tumor differentiation of gastric adenocarcinoma patients, NAT1 polymorphism was a risk factor among the well-differentiated type of tumors (OR = 3.03, 95% CI 1. 08-8.46). Stratifying by smoking status, we found that the OR for heavy smokers with the NAT1*10 allele was 2.97 (95% CI 1.23-7.14). When the combined risk of NAT1*10 allele from smoking and tumor differentiation was calculated, we found that the risk of the NAT1*10 allele with heavy smoking was increased among the well - differentiated type of gastric adenocarcinoma (OR = 4.24, 95% CI 0. 87-20.6). The NAT1*10 genotype was not a significant risk factor in colorectal adenocarcinoma. No statistically significant differences were observed in the frequency of NAT2 rapid acetylation genotype in gastric (91.4%) or colorectal (95.2%) adenocarcinoma patients when compared with the control population (94.3%). Our results suggest the NAT1*10 allele may be an important genetic determinant of the well-differentiated type of gastric adenocarcinoma, which may be induced by smoking.

Serum levels of interleukin-12 in patients with gastrointestinal cancer

Interleukin 12(IL-12) is a heterodimeric cytokine that has potent anti-tumor and anti-metastatic activities. Although clinical trials of recombinant human IL-12 have begun in patients with several advanced malignancies, very few studies have investigated the preoperative serum levels of IL-12 in patients with gastric or colorectal cancer. The purpose of the present study was to investigate the relationships between the preoperative serum levels of IL-12 and clinicopathological factors in patients with gastric or colorectal cancer. Blood was obtained before surgery from 14 patients with gastric cancer and 15 patients with colorectal cancer. Serum levels of IL-12 was assessed using the quantitative sandwich enzyme immunoassay technique. Although not statistically significantly, low serum levels of IL-12 tended to be associated with gastric cancer patients who were node-positive, CEA positive, had tumors that penetrated the serosa, had tumors greater than 5 cm in diameter, were more than 60 years-old, or were more advanced than stage IIIA(TNM) or stage IIIa(Japanese Research Society for Gastric Cancer). Patients with colorectal cancer who were node-positive, had tumors that penetrated the serosa, were more than 60 years-old, or were more advanced than stage III(TNM), stage IIIa(Japanese Society for Cancer of the Colon and Rectum) and Dukes' C also tended to have low serum IL-12 levels. These results suggest that low serum levels of IL-12 may be observed in more advanced gastric and colorectal cancer patients. Thus, patients with low serum levels of IL-12 in gastric or colorectal cancer may require additional immunochemotherapy after surgery.

Enhanced coexpression of YB-1 and DNA topoisomerase II alpha genes in human colorectal carcinomas

The transcription factor YB-1 is expressed in a wide range of cell types and has been implicated in the regulation of various genes involved in cell proliferation. Nuclear expression of YB-1 is correlated with MDR-1 gene expression in breast cancer and osteosarcoma. In this study, we asked whether YB-1 expression is enhanced in human colorectral carcinoma and if it is associated with the expression of target genes such as MDR-1, DNA topoisomerase II alpha and PCNA. YB-1, DNA topoisomerase II alpha, PCNA and MDR-1 expression were assessed by Western blotting, Northern blotting and immunohistochemistry in 26 human colorectal carcinomas. The involvement of YB-1 in DNA topoisomerase II alpha gene expression was examined by transient DNA transfection assays. YB-1 was overexpressed in almost all cancerous lesions in comparison with normal mucosa in surgically resected colorectal carcinomas of 26 patients. YB-1 expression correlated well with both DNA topoisomerase II alpha and PCNA expression. In contrast, no correlation was observed between YB-1 and MDR-1 expression. We also found that a transient co-transfection with a DNA topoisomerase II alpha promoter-luciferase plasmid and an antisense YB-1 expression construct resulted in a significant reduction of the promoter activity in KM12C human colon cancer cells. YB-1 may be an excellent proliferation-associated marker and may be a transcription factor regulating DNA topoisomerase II alpha gene expression in human colorectal carcinoma.

Circulating intercellular adhesion molecule-1, vascular cell adhesion molecule-1, and E-selectin in patients with type 2 diabetes mellitus

Serum levels of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and E-selectin in patients with type 2 diabetes mellitus (n = 64) and control subjects (n = 40) were studied. Serum ICAM-1 concentrations in diabetic patients were significantly higher than those of control subjects (378.2 +/- 70.0 versus 220.4 +/- 31.8 ng/ml, P < 0.01). By multiple regression analysis, hemoglobin A1c was independently associated with serum ICAM-1 concentration in patients with diabetes. The serum VCAM-1 concentration of diabetic patients with macroangiopathy was higher than those of patients without macroangiopathy and of control subjects (806.9 + 276.5 versus 639.0 +/- 146.0 (P < 0.01), and 652.1 +/- 146.9 ng/ml (P < 0.01), respectively). There was no difference in serum E-selectin concentration between diabetic patients with or without macroangiopathy and normal control subjects. These results suggest that adhesion molecules may contribute to the development of atherosclerosis in the diabetic state.