MOS4-associated complex contributes to proper splicing and suppression of ER stress under long-term heat stress in Arabidopsis

Plants are often exposed not only to short-term (S-) but also to long-term (L-)heat stress over several consecutive days. A few Arabidopsis mutants defective in L-heat tolerance have been identified, but the molecular mechanisms are less understood for this tolerance than for S-heat stress tolerance. To elucidate the mechanisms of the former, we used a forward genetic screen for sensitive to long-term heat (sloh) mutants and isolated sloh3 and sloh63. The mutants were hypersensitive to L- but not to S-heat stress, and sloh63 was also hypersensitive to salt stress. We identified the causal genes, SLOH3 and SLOH63, both of which encoded splicing-related components of the MOS4-associated complex (MAC). This complex is widely conserved in eukaryotes and has been suggested to interact with spliceosomes. Both genes were induced by L-heat stress in a time-dependent manner, and some abnormal splicing events were observed in both mutants under L-heat stress. In addition, endoplasmic reticulum (ER) stress and subsequent unfolded protein response occurred in both mutants under L-heat stress and were especially prominent in sloh63, suggesting that enhanced ER stress is due to the salt hypersensitivity of sloh63. Splicing inhibitor pladienolide B led to concentration-dependent disturbance of splicing, decreased L-heat tolerance, and enhanced ER stress. These findings suggest that maintenance of precise mRNA splicing under L-heat stress by the MAC is important for L-heat tolerance and suppressing ER stress in Arabidopsis.

LHT1/MAC7 contributes to proper alternative splicing under long-term heat stress and mediates variation in the heat tolerance of Arabidopsis

Natural genetic variation has facilitated the identification of genes underlying complex traits such as stress tolerances. We here evaluated the long-term (L-) heat tolerance (37°C for 5 days) of 174 Arabidopsis thaliana accessions and short-term (S-) heat tolerance (42°C, 50 min) of 88 accessions and found extensive variation, respectively. Interestingly, L-heat-tolerant accessions are not necessarily S-heat tolerant, suggesting that the tolerance mechanisms are different. To elucidate the mechanisms underlying the variation, we performed a chromosomal mapping using the F2 progeny of a cross between Ms-0 (a hypersensitive accession) and Col-0 (a tolerant accession) and found a single locus responsible for the difference in L-heat tolerance between them, which we named Long-term Heat Tolerance 1 (LHT1). LHT1 is identical to MAC7, which encodes a putative RNA helicase involved in mRNA splicing as a component of the MOS4 complex. We found one amino acid deletion in LHT1 of Ms-0 that causes a loss of function. Arabidopsis mutants of other core components of the MOS4 complex-mos4-2, cdc5-1, mac3a mac3b, and prl1 prl2-also showed hypersensitivity to L-heat stress, suggesting that the MOS4 complex plays an important role in L-heat stress responses. L-heat stress induced mRNA processing-related genes and compromised alternative splicing. Loss of LHT1 function caused genome-wide detrimental splicing events, which are thought to produce nonfunctional mRNAs that include retained introns under L-heat stress. These findings suggest that maintaining proper alternative splicing under L-heat stress is important in the heat tolerance of A. thaliana.

MAP KINASE PHOSPHATASE1 promotes osmotolerance by suppressing PHYTOALEXIN DEFICIENT4-independent immunity

Initial exposure of plants to osmotic stress caused by drought, cold, or salinity leads to acclimation, termed acquired tolerance, to subsequent severe stresses. Acquired osmotolerance induced by salt stress is widespread across Arabidopsis (Arabidopsis thaliana) accessions and is conferred by disruption of a nucleotide-binding leucine-rich repeat gene, designated ACQUIRED OSMOTOLERANCE. De-repression of this gene under osmotic stress causes detrimental autoimmunity via ENHANCED DISEASE SUSCEPTIBILITY1 and PHYTOALEXIN DEFICIENT4 (PAD4). However, the mechanism underlying acquired osmotolerance remains poorly understood. Here, we isolated an acquired osmotolerance-defective mutant (aod13) by screening 30,000 seedlings of an ion beam-mutagenized M2 population of Bu-5, an accession with acquired osmotolerance. We found that AOD13 encodes the dual-specificity phosphatase MAP KINASE PHOSPHATASE1 (MKP1), which negatively regulates MITOGEN-ACTIVATED PROTEIN KINASE3/6 (MPK3/6). Consistently, MPK3/6 activation was greater in aod13 than in the Bu-5 wild-type (WT). The aod13 mutant was sensitive to osmotic stress but tolerant to salt stress. Under osmotic stress, pathogenesis-related genes were strongly induced in aod13 but not in the Bu-5 WT. Loss of PAD4 in pad4 aod13 plants did not restore acquired osmotolerance, implying that activation of immunity independent of PAD4 renders aod13 sensitive to osmotic stress. These findings suggest that AOD13 (i.e. MKP1) promotes osmotolerance by suppressing the PAD4-independent immune response activated by MPK3/6.

Mitochondrial Fission Complex Is Required for Long-Term Heat Tolerance of Arabidopsis

Plants are often exposed not only to short-term (S) heat stress but also to long-term (L) heat stress over several consecutive days. A few Arabidopsis mutants defective in L-heat tolerance have been identified, but the molecular mechanisms involved are less well understood than those involved in S-heat tolerance. To elucidate the mechanisms, we isolated the new sensitive to long-term heat5 (sloh5) mutant from EMS-mutagenized seeds of L-heat-tolerant Col-0. The sloh5 mutant was hypersensitive to L-heat but not to S-heat, osmo-shock, salt-shock or oxidative stress. The causal gene, SLOH5, is identical to elongatedmitochondria1 (ELM1), which plays an important role in mitochondrial fission in conjunction with dynamin-related proteins DRP3A and DRP3B. Transcript levels of ELM1, DRP3A and DRP3B were time-dependently increased by L-heat stress, and drp3a drp3b double mutants were hypersensitive to L-heat stress. The sloh5 mutant contained massively elongated mitochondria. L-heat stress caused mitochondrial dysfunction and cell death in sloh5. Furthermore, WT plants treated with a mitochondrial myosin ATPase inhibitor were hypersensitive to L-heat stress. These findings suggest that mitochondrial fission and function are important in L-heat tolerance of Arabidopsis.

An ER-Golgi Tethering Factor SLOH4/MIP3 Is Involved in Long-Term Heat Tolerance of Arabidopsis

Plants are often exposed not only to short-term (S-) heat stress but also to diurnal long-term (L-) heat stress over several consecutive days. To reveal the mechanisms underlying L-heat stress tolerance, we here used a forward genetic screen for sensitive to long-term heat (sloh) mutants and isolated sloh4. The mutant was hypersensitive to L-heat stress but not to S-heat stress. The causal gene of sloh4 was identical to MIP3 encoding a member of the MAIGO2 (MAG2) tethering complex, which is composed of the MAG2, MIP1, MIP2 and MIP3 subunits and is localized at the endoplasmic reticulum (ER) membrane. Although sloh4/mip3 was hypersensitive to L-heat stress, the sensitivity of the mag2-3 and mip1-1 mutants was similar to that of the wild type (WT). Under L-heat stress, the ER stress and the following unfolded protein response (UPR) were more pronounced in sloh4 than in the WT. Transcript levels of bZIP60-regulated UPR genes were strongly increased in sloh4 under L-heat stress. Two processes known to be mediated by INOSITOL REQUIRING ENZYME1 (IRE1) - accumulation of the spliced bZIP60 transcript and a decrease in the transcript levels of PR4 and PRX34, encoding secretory proteins - were observed in sloh4 in response to L-heat stress. These findings suggest that misfolded proteins generated in sloh4 under L-heat stress may be recognized by IRE1 but not by bZIP28, resulting in the initiation of the UPR via activated bZIP60. Therefore, it would be possible that only MIP3 in the MAG2 complex has an additional function in L-heat tolerance, which is not related to the ER-Golgi vesicle tethering.

Simultaneous Fluorescent Identification of Odontoblasts and Ameloblasts

The tooth is mainly composed of dentin and enamel. Identification of dentin-producing odontoblasts and enamel-producing ameloblasts using reporter techniques is useful to study tooth development and regeneration with tissue engineering. Ameloblasts express Amelogenin, Ameloblastin, Enamelin, and Amelotin, whereas odontoblasts express Dentin sialophosphoprotein (Dspp) and Dentin matrix protein1 (Dmp1). Although there are several transgenic lines using promoter elements or bacterial artificial chromosomes (BACs) to label odontoblasts and ameloblasts, there is a possibility that the expression patterns vary from the endogenous genes. Here, we established 2 lines of mice where tdTomato was knocked into the second exon of X-chromosomal Amelogenin (Amelx), and green fluorescent protein (GFP) was knocked into the second exon of Dspp. tdTomato and GFP were highly expressed on secretory ameloblasts and secretory and fully differentiated odontoblasts, respectively. In addition, DSPP and AMELX were not produced in the dentin matrix and enamel matrix of Dspp^GFP/GFP and Amelx^tdTomato male mice (as representative of Amelx^tdTomato/Y hemizygous male mice), respectively. Moreover, micro-computed tomography analysis of Amelx^tdTomato male mice revealed a notable reduction in enamel volume but increased dentin mineral density. Dspp^GFP/GFP mice had reduced dentin mineral density. To identify odontoblasts and ameloblasts from developing tooth, we examined the expression of mesenchymal cell surface molecules CD90, CD166 and epithelial cell surface molecules CD49f, Epcam1 with fluorescence on odontoblasts and ameloblasts in these mice. We found that GFP⁺ odontoblasts and tdTomato⁺ ameloblasts in tooth germ from 0.5-d-old Dspp^GFP/+ mice and Amelx^tdTomato male mice were enriched in CD45^-/Ter119^-/Epcam1^-/CD90⁺/Integrin α4⁺cell fractions and CD45^-/Ter119^-/Epcam1⁺/CD49f⁺/CD147⁺ cell fractions, respectively. By using antibodies against mesenchymal and epithelial cell surface molecules and fluorescence, we can easily distinguish odontoblasts from ameloblasts and isolate each cell for further studies. These mice would serve as useful models for tooth development and regeneration as well as provide concurrent observation for the differentiation processes of odontoblasts and ameloblasts in vivo and in vitro.

CATALASE2 plays a crucial role in long-term heat tolerance of Arabidopsis thaliana

Plants are often exposed not only to short-term (S-) heat stress but also to diurnal long-term (L-) heat stress over several consecutive days; nevertheless, most previous studies of heat tolerance have used S-heat stress, such as 42 °C for 30-60 min, for evaluation. Yet the mechanisms underlying L-heat tolerance remain poorly understood. Here we found that hydrogen peroxide (H₂O₂) in Arabidopsis thaliana plants increased time-dependently under L-heat stress (37 °C, 5 days) but not under S-heat stress (42 °C, 40 min). To reveal the contribution of reactive oxygen species (ROS) scavenging to heat tolerance, we evaluated the heat tolerance of ROS mutants. Only cat2 mutants, in which catalase (CAT) activity is defective, were hypersensitive to L-heat stress, but they were S-heat tolerant. We further revealed that (1) CAT2 was induced by L-heat stress but not by S-heat stress; (2) H₂O₂ accumulated highly in cat2 under L-heat stress, but not in cat1, cat3, or wild type; and (3) CAT activity was significantly reduced in cat2 under both normal and L-heat conditions. These results suggest that ROS scavenging is responsible for L-heat tolerance, and CAT2 plays a crucial role. On the other hand, since overexpression of CAT2 in wild-type plants did not enhance L-heat tolerance, CAT2 activity is necessary but insufficient for increasing L-heat tolerance.

Quantitation of Tebuconazole in Liquid and Solid Formulations by Capillary GC: Collaborative Study

A capillary gas chromatographic method has been developed for quantitation of tebuconazole (Folicur, Elite, Raxil, Lynx) in liquid and solid formulations. Tebuconazole is a broad-spectrum, systemic foliar fungicide used to control diseases of wheat, barley, peanut, and grasses grown for seed. Samples are dissolved in acetone and analyzed by capillary gas chromatography (GC) with dicyclohexyl phthalate as internal standard. Twenty-two laboratories from 11 countries participated in a collaborative study of the method. Each collaborator was provided reference standard, internal standard, and blind duplicate samples from 6 formulations: aqueous flowable (F), aqueous emulsifiable concentrate (EW), emulsifiable concentrate for seed treatment (ES), flowable for seed treatment (FS), wettable powder (WP), and dry flowable (DF). Collaborators were instructed to use peak area measurements for quantitation. The seed treatment flowable formulation required confirmation of accurate integration values by the collaborator. Relative standard deviation values for reproducibility (RSDR) for analysis of the formulations were as follows: 3.6 lb/gal F, 1.22; 250 g/L EW, 1.13; 15 g/L ES, 2.40; 25 g/L FS, 2.65; 25% WP, 0.96; 25% DF, 0.72; 45% DF, 0.72. The capillary GC method for quantitation of tebuconazole in fungicide formulations has been adopted first action by AOAC INTERNATIONAL.

Living Donor Liver Transplantation for Progressive Familial Intrahepatic Cholestasis Type 1: Two Reported Cases

BACKGROUND

Progressive familial intrahepatic cholestasis type 1 (PFIC1) is an inherited disease characterized by cholestatic features. We report two patients with PFIC1 who underwent liver retransplantation.

CASE REPORT

One patient was a 3-year-old female who underwent liver transplantation for PFIC1. She presented with severe diarrhea and fatty liver, and went into liver failure. She therefore underwent liver retransplantation and external biliary diversion 8 years after the initial liver transplantation. The explanted liver was histologically diagnosed with chronic rejection. Her intractable diarrhea stopped after the retransplantation. She was diagnosed with a fatty liver 8 months after the retransplantation and died 4 years after retransplantation due to bleeding from an ileostomy. The other patient was a 3-year-old male. This patient underwent liver retransplantation due to liver cirrhosis caused by steatohepatitis 9 years after the initial liver transplantation. The biliary tract was not diverted. He also experienced severe diarrhea after the retransplantation and requires home parenteral nutrition due to an eating disorder.

CONCLUSIONS

Liver transplantation is the only treatment to resolve life-threatening issues due to PFIC1, but requires further improvement as a therapeutic modality.

Crosstalk between NRF2 and HIPK2 shapes cytoprotective responses

Homeodomain interacting protein kinase-2 (HIPK2) is a member of the HIPK family of stress-responsive kinases that modulates cell growth, apoptosis, proliferation and development. HIPK2 has several well-characterised tumour suppressor roles, but recent studies suggest it can also contribute to tumour progression, although the underlying mechanisms are unknown. Herein, we have identified novel crosstalk between HIPK2 and the cytoprotective transcription factor NRF2. We show that HIPK2 is a direct transcriptional target of NRF2, identifying a functional NRF2 binding site in the HIPK2 gene locus and demonstrating for the first time a transcriptional mode of regulation for this kinase. In addition, HIPK2 is required for robust NRF2 responsiveness in cells and in vivo. By using both gain-of-function and loss-of-function approaches, we demonstrate that HIPK2 can elicit a cytoprotective response in cancer cells via NRF2. Our results have uncovered a new downstream effector of HIPK2, NRF2, which is frequently activated in human tumours correlating with chemoresistance and poor prognosis. Furthermore, our results suggest that modulation of either HIPK2 levels or activity could be exploited to impair NRF2-mediated signalling in cancer cells, and thus sensitise them to chemotherapeutic drugs.

Significance of hepatitis-B and hepatitis-C viral sequences frequently detected in hepatocellular-carcinoma tissues

Serum HBsAg or anti-HCV were identified in over 90% of hepatocellular carcinoma (HCC) patients in Japan with positive rates approximately 20% and 70%, respectively. In this study, we detected HBV DNA and HCV RNA sequences in tumor or non-tumor tissues obtained from 16 hepatectomized HCC cases, using the polymerase chain reaction (PCR) method for HBV x gene and reverse transcription (RT)-PCR for HCV RNA. Only 3 cases were positive of HBsAg in serum, however, HBV x gene could be detected in the tumor or non-tumor tissues of 13 cases among 16 HCC patients. In two cases, HBV x gene was detected exclusively in tumor or non-tumor tissues. Whereas HCV RNA was detected in both tumor and non-tumor in 9 cases, which results coincided with the anti-HCV testing in sera. These results indicate that HBV x gene might be detected as the integrated form in the liver genomic DNA, while HCV RNA as viremia. The frequent detection of HBV DNA suggests that HBV may be associated with the development of HCC predominantly or cooperatively with HCV.

Hepatitis B virus DNA integration frequently observed in the hepatocellular carcinoma DNA of hepatitis C virus-infected patients

Human hepatitis B virus (HBV) and hepatitis C virus (HCV) are two major etiologic agents of chronic hepatitis, which is closely related to the development of hepatocellular carcinoma (HCC). We investigated the role of HBV coinfection in ongoing HCV-related liver diseases in HCV-infected patients. We found a high prevalence of anti-HBc in anti-HCV-positive/HBsAg-negative HCC patients and also found a close correlation between anti-HBc positivity and integration of HBV DNA into HCC DNA of anti-HCV-positive/HBsAg-negative patients. The present data suggest that integrated HBV DNA may play an important role in the development of HCC in the anti-HCV-positive/HBsAg-negative patients carrying the anti-HBc antibody.

Taste sensitivity to trehalose and its alteration by gene dosage in Drosophila melanogaster

The taste sensitivity to the disaccharide trehalose of Drosophila melanogaster is under the genetic control by the Tre gene on the X chromosome. The gene is genetically dimorphic for high and low sensitivity and is likely to be functioning in the primary step of chemoreception. We have determined the cytological localization of the Tre gene to be between 5A10 and 5B1-3 by analyzing the sensitivity to trehalose in flies which are segmentally aneuploid bearing either deficiencies or duplicated fragments of T(X;Y) translocations. We also constructed flies which are aneuploidy and thus carry different dosage of Tre and/or Tre(+) alleles in order to examine the gene dosage effect on trehalose sensitivity and to deduce the nature of the gene's action. Trehalose sensitivity decreased in females carrying half the normal dosage of a given Tre allele, but a proportional increase in sensitivity was not observed in flies bearing a duplication of the Tre alleles. The changes in sensitivity in various aneuploid flies suggest that there is an upper limit to the number of molecules that can be incorporated into the receptor membrane. Genetic evidence strongly suggests that Tre is the structural gene for the trehalose receptor. We present a model to account for the mechanism of genetical control on the sensitivity to trehalose.

Role of epidermal growth factor receptor in maintaining airway goblet cell hyperplasia in rats sensitized to allergen

BACKGROUND

Stimulation of epidermal growth factor receptor (EGFR) induces airway goblet cell hyperplasia, but the role of this molecule in the maintenance of this pathologic change remains uncertain.

OBJECTIVE

To determine the mechanisms by which goblet cell hyperplasia is maintained in airway epithelium, we investigated EGFR-induced signalling pathways that lead to both mucin production and antiapoptosis in vitro. We also tested whether the inhibition of EGFR tyrosine kinase speeds reversal of established goblet cell hyperplasia to normal epithelial phenotype in vivo.

METHODS

MUC5AC production was measured by immunoassay, and antiapoptotic responses were determined by Bcl-2 expression and terminal deoxynucleotidyl transferase-mediated dUTP-biotin Nick End Labelling staining using NCI-H292 cells. The effect of an inhibitor of EGFR tyrosine kinase (AG1478) on goblet cell hyperplasia was also determined in rats sensitized with ovalbumin (OVA).

RESULTS

MUC5AC was constitutively expressed and few apoptotic cells were observed in NCI-H292 cells under non-stimulated condition. TGF-alpha increased MUC5AC and Bcl-2 expression, an effect that was prevented by inhibitors of EGFR tyrosine kinase (AG1478), MEK (PD98059), and NF-kappaB (CAPE). After the addition of TGF-alpha, AG1478 and an inhibitor of phosphatidylinositol 3 kinase/Akt (LY294002), but not PD98059, induced a marked apoptotic response, which was prevented by the caspase inhibitor Z-VAD fmk. Goblet cell hyperplasia and EGFR expression in airway epithelium were noted in the OVA-sensitized rats. Intratracheal instillation of AG1478 induced apoptosis of goblet cells, reverting the airway epithelium to normal epithelial phenotype.

CONCLUSION

These findings indicate that EGFR plays an important role in the maintenance of goblet cell hyperplasia. We speculate that inhibitors of the EGFR cascade might be an effective therapy of airway remodelling.

Interleukin-9 and Interleukin-13 augment UTP-induced Cl ion transport via hCLCA1 expression in a human bronchial epithelial cell line

BACKGROUND

IL-9 and IL-13 induce airway goblet cell metaplasia, which is associated with expression of a Ca(2+)-activated Cl channel, hCLCA1.

OBJECTIVE

As UTP stimulates both mucin secretion and Cl ion transport via a Ca(2+)-dependent pathway, the purpose of this study is to determine whether IL-9 and IL-13 affect UTP-induced Cl ion transport in human bronchial epithelial cell line 16HBE cells, and if they do, to elucidate whether such an effect is associated with hCLCA1 expression.

METHODS

The increases in short-circuit current (I(sc)) in response to UTP were measured in the presence of amiloride by the Ussing chamber method. The morphology of epithelial cells was assessed by light microscopic findings, and hCLCA1 expression was investigated by immunocytochemistry and immunoblotting.

RESULTS

UTP-induced increases in I(sc) in the cells treated with IL-9 or IL-13 for 48 h were greater than those in non-treated cells, and the potency of IL-13 was greater than that of IL-9. Pre-treatment with Ca(2+)-activated Cl channel inhibitors diisothocyanatostilbene-2, 2-disulphonic acid and niflumic acid completely inhibited the augmenting effects of IL-9 and IL-13 on I(sc). The epithelial layer of the cells treated with IL-9 or IL-13 was thicker than that of non-treated cells. The expression of hCLCA1 protein was induced by IL-13 in a concentration-dependent manner. These effects of IL-13 were more potent than those of IL-9.

CONCLUSION

IL-9 and IL-13 augmented UTP-induced Cl ion transport, probably via proliferation of the cells with hCLCA1 expression, and IL-13 was more potent than IL-9 in producing such an effect in 16HBE cells.

Adenocarcinoma of the esophagogastric junction: a summary of responses to a questionnaire on adenocarcinoma of the esophagus and the esophagogastric junction in Japan

Adenocarcinoma of the esophagogastric junction is recognized as a distinct clinical entity; however, the choice of surgical approaches is controversial. To analyze the results of surgery among patients with adenocarcinoma of the esophagus (type I) and the cardia (type II) based on Siewert's classification in Japan, surgical procedures, histopathologic characteristics, and outcome were re-evaluated according to the TNM classification in 1263 patients with adenocarcinoma of the esophagus (type I) and the cardia (type II) through a questionnaire sent to the members of the Japanese Society of Esophageal Diseases. One hundred and thirty-four (10.6%) patients had type I tumors and 1129 (89.4%) patients had type II tumors. There were significant differences in sex distribution and associated intestinal metaplasia in the esophagus between patients with type I and type II tumors. Although different surgical approaches were performed, the overall 5-year survival rate was 53% without any difference between the two groups. The significant prognostic factors in general linear models were R category, pN category, and differentiation, but not pT category. There was no difference in survival between patients with stage IIB and III disease. The survival rate of the patients who underwent a transhiatal approach was similar to that of those undergoing a transthoracic approach. The results suggest that Siewert's classification (type I and type II) is useful in planning treatment strategy for adenocarcinoma of the esophagogastric junction. Lymph node metastasis was the most important prognostic factor, and staging based on the number of lymph node metastases or the extent of lymph node metastasis is necessary.

Beta-adrenergic receptor-mediated growth of human airway epithelial cell lines

Abnormal growth of airway epithelium and the resultant thickening of airway walls may produce narrowing of airway calibre, thereby contributing to deterioration of bronchoconstriction in chronic obstructive pulmonary disease (COPD). Beta2-adrenergic agonists have been widely used for the treatment of COPD, but their effects on the growth of airway epithelial cells is unknown. Growth of three human airway epithelial cell lines was studied in vitro. Exposure to salbutamol in serum-free medium increased 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium-bromide reduction and intracellular deoxyribonucleic acid (DNA) contents in 16-human bronchial epithelium (16-HBE) cells and NCI-H292 cells, but not in A549 cells. The growth-promoting effect of salbutamol in 16-HBE cells was equipotent to 10% foetal bovine serum and was inhibited by propranolol and a cyclic adenosine monophosphate (cAMP) antagonist, Rp-adenosine 3',5'-cyclic monophosphorothioate triethylammonium salt (Rp-cAMPS). Likewise, forskolin and 8-bromoadenosine 3',5'-cyclic monophosphate (8-Br-cAMP) caused cell growth and DNA synthesis. Western blot analysis showed that salbutamol, forskolin, and 8-Br-cAMP each induced expression of the phosphorylated form of mitogen-activated protein (MAP) kinase, and that the salbutamol-induced phosphorylation was inhibited by propranolol, Rp-cAMPS, and the MAP kinase-kinase inhibitor PD98059. These results suggest that in certain airway epithelial cell lines stimulation of beta2-adrenergic receptors and the consequent production of cyclic adenosine monophosphate may upregulate cell growth, probably through activation of the mitogen-activated protein kinase cascade.

Structural features of a wheat plastome as revealed by complete sequencing of chloroplast DNA

Structural features of the wheat plastome were clarified by comparison of the complete sequence of wheat chloroplast DNA with those of rice and maize chloroplast genomes. The wheat plastome consists of a 134,545-bp circular molecule with 20,703-bp inverted repeats and the same gene content as the rice and maize plastomes. However, some structural divergence was found even in the coding regions of genes. These alterations are due to illegitimate recombination between two short direct repeats and/or replication slippage. Overall comparison of chloroplast DNAs among the three cereals indicated the presence of some hot-spot regions for length mutations. Whereas the region with clustered tRNA genes and that downstream of rbcL showed divergence in a species-specific manner, the deletion patterns of ORFs in the inverted-repeat regions and the borders between the inverted repeats and the small single-copy region support the notion that wheat and rice are related more closely to each other than to maize.

[Effect of endothelin on DNA synthesis in human bronchial epithelium: role of MAP kinase cascade]

To elucidate the effect of endothelin (ET) on airway epithelial cell proliferation, we measured intracellular DNA levels and assessed a possible contribution of mitogen activated protein kinase (MAPK) cascade to the ET action. Incubation of transformed human bronchial epithelial (16 HBE) cells with ET in the serum-free medium caused time-dependent increases in DNA synthesis and MTT reduction, an effect that was attenuated by the MAPK kinase inhibitor PD 98059 in a concentration-dependent manner. Western blot analysis showed that ET induced the expression of phosphorylated MAPK protein, indicating an activation of MAPK, and that this effect was inhibited in the presence of PD 98059 or the ETA receptor antagonist BQ-123. These results suggest that ET may stimulate the proliferation of human airway epithelium via ETA receptors and the concomitant activation of MAPK cascade.

Cooperative functions of the mannoprotein-encoding genes in the biogenesis and maintenance of the cell wall in Saccharomyces cerevisiae

To elucidate the roles of genes involved in the cell wall biogenesis and function in Saccharomyces cerevisiae, we isolated and characterized mutants that were lethal in a strain in which the SED1 gene encoding a cell wall mannoprotein was disrupted. Thus, double mutants of SED1 and either MNN9 or MNN10 were unable to grow and YOL155c on a multicopy plasmid could suppress their synthetic lethality. A Yol155cp-GFP fusion protein was found to localize to the cell wall, suggesting that it might also be a cell wall mannoprotein. Subsequently, we analysed the effects of the shut-off of SED1 in a sed1 and mnn9 double mutant: cells after the shut-off showed anomalous cellular morphology and died in the mitotic M phase. From these and other results, we postulate that these genes function cooperatively with each other and in a cell cycle-dependent manner in the biogenesis and maintenance of cell wall in S. cerevisiae.

Mouse homologue of coq7/clk-1, longevity gene in Caenorhabditis elegans, is essential for coenzyme Q synthesis, maintenance of mitochondrial integrity, and neurogenesis

coq7/clk-1 was isolated from a long-lived mutant of Caenorhabditis elegans, which showed sluggish behavior and an extended life span. Mouse coq7 is homologous to Saccharomyces cerevisiae coq7/cat5 that is required for biosynthesis of coenzyme Q (CoQ), an essential cofactor in mitochondrial respiration. Here we generated COQ7-deficient mice to investigate the biological role of COQ7 in mammals. COQ7-deficient mouse embryos failed to survive beyond embryonic day 10.5, exhibiting small-sized body and delayed embryogenesis. Morphological studies showed that COQ7-deficient neuroepithelial cells failed to show the radial arrangement in the developing cerebral wall, aborting neurogenesis at E10.5. Electron microscopic analysis further showed the enlarged mitochondria with vesicular cristae and enlarged lysosomes filled with disrupted membranes, which is consistent with mitochondriopathy. Biochemical analysis demonstrated that COQ7-deficient embryos failed to synthesize CoQ(9), but instead yielded demethoxyubiquinone 9 (DMQ(9)). Cultured embryonic cells from COQ7-deficient mice were rescued by adding bovine fetal serum in vitro, but exhibited slowed cell proliferation, which resembled to the phenotype of clk-1 with delayed cell divisions. The result implied the essential role of coq7 in CoQ synthesis, maintenance of mitochondrial integrity, and neurogenesis in mice.

Trehalose sensitivity in Drosophila correlates with mutations in and expression of the gustatory receptor gene Gr5a

Drosophila taste gene Tre is located on the distal X chromosome and controls gustatory sensitivity to a subset of sugars [1, 2]. Two adjacent, seven-transmembrane domain genes near the Tre locus are candidate genes for Tre. One (CG3171) encodes a rhodopsin family G protein receptor [3, 4], and the other (Gr5a) is a member of a chemosensory gene family encoding a putative gustatory receptor [5-7]. We carried out molecular analyses of mutations in Tre to elucidate their involvement in the gustatory phenotype. Here, we show that Tre mutations induced by P element-mediated genomic deletions disrupt Gr5a gene organization and the expression of Gr5a mRNA, while disruption of the CG3171 gene or its expression was not always associated with mutations in Tre. In flies with the spontaneous mutation Tre(01), both CG3171 and Gr5a mRNAs are transcribed. Coding sequences of these two candidate genes were compared among various strains. A total of three polymorphic sites leading to amino acid changes in CG3171 were not correlated with the gustatory phenotype. Among four nonsynonymous sites in Gr5a, a single nucleotide polymorphism leading to an Ala218Thr substitution in the predicted second intracellular loop cosegregated with Tre(01). Taken together, the mutation analyses support that Gr5a is allelic to Tre.

Cross-genomic analysis of the translational systems of various organisms

We have characterized the genes encoding ribosomal proteins (r-proteins) as well as other translation-related factors of 15 eubacteria and four archaebacteria, and the genes for the mitochondrial r-proteins of Saccharomyces cerevisiae by using the complete genomic nucleotide sequence data of these organisms. In eubacteria, including two species of Mycoplasma, the operon structure of the r-protein genes is well conserved, while their relative orientation and chromosomal location are quite divergent. The operon structure of the r-protein genes in archaebacteria, on the other hand, is quite different from eubacteria and also among themselves. In addition, many archaebacterial r-proteins show similarity to rat cytoplasmic r-proteins. Nonetheless, characteristic features of several genes encoding proteins of functional importance are well conserved throughout the bacterial species including archaebacteria, as well as in S. cerevisiae. We searched for the genes encoding mitochondrial r-proteins in yeast by combining informatics and genetic experiments. Furthermore, we characterized some of the r-proteins genes by exchanging portions between Escherichia coli and S. cerevisiae and performed functional analysis of some of the genes from different evolutionary points of view. Our work may be extended towards phylogenetic analysis of organisms producing secondary metabolites of various sorts.

Phase II evaluation of protracted infusion of cisplatin and 5-fluorouracil in advanced squamous cell carcinoma of the esophagus: a Japan Esophageal Oncology Group (JEOG) Trial (JCOG9407)

BACKGROUND

Surgery for advanced esophageal carcinoma has its limits as regards aggressiveness and therapeutic effect, therefore effective multimodality treatment is required to obtain better survival. The objective of this study was to evaluate whether daily continuous infusion of CDDP could achieve a higher clinical response rate with less toxicity than its drip infusion in the previous phase II study that we had conducted.

METHODS

Patients with primary extensive or relapsed esophageal carcinoma after esophagectomy, which had distant organ metastasis and histologically proven SCC, were eligible for this study. A dose of 20 mg/m(2) of cisplatin and 800 mg/m(2) of 5-fluorouracil was given by continuous infusion for 24 h on days 1-5. This treatment was repeated every 4 weeks for up to four cycles. A total of 36 men and six women with a median age of 64 (range 39-75) years were registered and 36 patients were eligible.

RESULTS

The overall response rate of the registered patients was 33.3% (12/36) and the median response duration was 175 days. Median survival time was 201.5 days and the 1-year survival rate was 27.8%. Change from bolus to continuous infusion of cisplatin affected neither the type nor the degree of toxicity.

CONCLUSION

Daily continuous infusion of cisplatin was not associated with higher response or lower toxicity than those seen with the high-dose bolus or multibolus treatment regimens. We conclude that this regimen in this setting is not worthy of further phase III trials. JEOG is now evaluating other drug combination regimens.

Prognosis of patients with advanced carcinoma of the esophagus with complete response to chemotherapy and/or radiation therapy: a questionnaire survey in Japan

BACKGROUND

We estimated the survival of patients with advanced carcinoma of the esophagus in Japan who achieved complete response (CR) with chemotherapy and/or radiation therapy.

METHODS

A questionnaire was designed for patients with cancer of the esophagus with pretreatment stage II-IV (excluding organ metastasis [M1]), who were treated with chemotherapy and/or radiation therapy and achieved either a clinical CR continuing for more than 1 year, or a pathological CR in surgical specimens. All patients were treated between January 1, 1990, and December 31, 1997, in Japan.

RESULTS

Of the 169 eligible patients for whom adequate data were available, 106 patients with continuing clinical CR were defined as group A and 63 with pathological CR as group B. The overall survival rates at 5 years were 62.4% in group A and 64.8% in group B. In each of groups A and B, there was no significant difference in overall survival among subgroups of patients classified by initial pretreatment clinical stage. In group A, the survival rate of patients with concurrent chemotherapy and radiation therapy was significantly better than the rates for patients with chemotherapy alone or radiotherapy alone. In group A, the frequency of first failure at the local site of esophageal carcinoma was 7.7%. Of the 12 patients in group B (19%) who died less than 1 year postoperatively, 6 died of postoperative complications.

CONCLUSION

The effect of CR to chemotherapy and/or radiation therapy for carcinoma of the esophagus on survival was marked. In patients with esophageal carcinoma who achieve CR, the prognosis may be independent of the initial pretreatment stage. Local failure in group A patients remains a problem, however.

Molecular cloning, genetic mapping, and expression of the mouse Sf3b1 (SAP155) gene for the U2 snRNP component of spliceosome

SAP155, a subunit of the U2 snRNP, is essential for prespliceosome assembly and splicing catalysis of the major spliceosome. Moreover, the protein has been identified in the minor (U12-dependent) spliceosome. These facts strongly suggest that SAP155 is shared by two distinct complexes owing to its importance in the removal of any type of intron. Here we have isolated a cDNA encoding the 146-kDa mouse homolog, designated Sf3b1. The amino acid sequence of Sf3b1 is very highly conserved among homologs from Schizosaccharomyces pombe (52.4% identity) to human (99.6%), and the C-terminal 825 residues of these Sf3b1 homologs show even higher identities. This C-terminal region shows significant similarity to the PR65 subunit of protein phosphatase 2A, which is composed of 15 tandem repeats of a 39 amino acid sequence. Mouse genome analyses showed Sf3bh1 to be a single-copy gene mapping to the central part of Chromosome (Chr) 1. Northern blot analysis and whole mount in situ hybridization revealed Sf3b1 to be ubiquitously expressed in a variety of adult tissues and mid-gestation embryos.

Serum p53 antibody as a useful marker for monitoring of treatment of superficial colorectal adenocarcinoma after endoscopic resection

BACKGROUND

Mutation of the p53 gene is a genetic alteration found in human cancers. Overexpression of p53 has been found to induce antibody production in serum, and, recently, the simple detection of serum antibody has been made possible. The aim of this study was to evaluate the potential role of serum p53 antibody in the early diagnosis of superficial colorectal cancer and in the monitoring of its treatment after endoscopic resection.

METHODS

In a prospective study, our subjects were 27 patients with superficial colorectal adenocarcinomas, whose results were compared with those in 38 patients with benign adenomas; all patients were treated by endoscopic resection. The correlation between serum p53 antibody levels before and within 3 weeks after resection was determined, using an immunoassay. Immunohistological staining for p53 was also performed, and its sensitivity was compared with that of two other tumor markers.

RESULTS

Preoperatively, serum p53 antibody was detected in 63.0% (17/27) patients with adenocarcinoma and in 2.6% (1/38) patients with adenoma, showing a significant difference (P < 0.001). However, the two other markers carcinoembryonic antigen (CEA) and carbohydrate antigen CA19-9, showed no significant difference between superficial colorectal adenocarcinoma and adenoma. The serum p53 antibody status was strongly correlated with p53 immunostaining in adenocarcinoma (P = 0.0065), but there was no significant correlation in adenoma (P = 0.973). Sixteen (94.1%) of 17 seropositive adenocarcinoma patients, showed negative conversion after complete tumor resection, and all these 16 patients remained seronegative.

CONCLUSION

The detection of serum p53 antibody is expected to serve as a new genetic marker, determined by serological analyses, for aiding in the early diagnosis of superficial colorectal cancer and indicating its local curability after endoscopic treatment.

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.

Impact of preoperative serum carcinoembryonic antigen, CA 19-9 and alpha fetoprotein levels in gastric cancer patients

The relationship between preoperative serum carcinoembryonic antigen (CEA), CA 19-9 and alpha-fetoprotein (AFP) levels and their clinicopathological features were evaluated in gastric cancer patients. The positive rates of CEA, CA 19-9 and AFP were 24.8, 27.6 and 12.7%, respectively. Gastric cancer with deeper tumor invasion was significantly more common among patients positive for these tumor markers. Patients with positive CEA or CA 19-9 values had a significantly high risk of lymph node metastases (p = 0.045 and p = 0.002, respectively). Synchronous liver metastases was more commonly found in patients with a positive CA 19-9 value. A significant difference (p < 0.001) in survival rate was found between patients with positive CA 19-9 values and those with negative values. CA 19-9 is useful for the prognosis of gastric cancer patients, whereas CEA, although unsuitable for prognosis, contributes to the prediction of cancer invasion.

A putative binding protein for lipophilic substances related to butterfly oviposition

A unique protein of 23 kDa (Jf23) was found in the tarsus of the female swallowtail butterfly, Atrophaneura alcinous. Jf23 has 38% identity with a bilin-binding protein, which was found in the cabbage butterfly, Pieris brassicae, and which has two consensus sequences in common with the members of the lipocalin family, suggesting that it is a binding protein for lipophilic ligands. Western blot analysis showed that Jf23 was expressed only in the female, and not in the male. Electrophysiological response of the female tarsi was stimulated by methanolic extract of their host plant, Dutchman's pipe (Aristolochia debilis). The stimulated response was depressed by the presence of Jf23 antiserum. These results suggest that Jf23 is one of the chemosensory signaling proteins, which plays one or more roles in female butterfly oviposition.

Effect of suplatast tosilate, a Th2 cytokine inhibitor, on steroid-dependent asthma: a double-blind randomised study. Tokyo Joshi-Idai Asthma Research Group

BACKGROUND

Th2 cytokines play an important part in the pathogenesis of asthma. Our aim was to study the effect of suplatast tosilate, a selective Th2 cytokine inhibitor, on asthma control and asthma exacerbations during reduction of inhaled corticosteroid dose in patients with steroid-dependent asthma.

METHODS

85 patients with moderate to severe asthma taking high doses (> or = 1500 microg per day) of inhaled beclometasone dipropionate, were assigned suplatast tosilate (100 mg three times daily) or placebo for 8 weeks in a double-blind, randomised, parallel-group, multicentre trial. During the first 4 weeks, other medications remained unchanged (add-on phase); during the next 4 weeks, the doses of beclometasone were halved (steroid-reduction phase). Main outcome measures were pulmonary function, asthma symptoms, and use of beta2-agonists.

FINDINGS

Data were available from 77 patients. During the add-on phase, suplatast tosilate treatment, compared with placebo, was associated with higher forced expiratory volume in 1 s (mean difference between groups for changes from baseline at week 4, 0.20 L [95% CI 0.16-0.24], p=0.043), morning peak expiratory flow (18.6 L/min [14.1-23.1], p=0.037), and less diurnal variation in peak expiratory flow rate, asthma symptom scores (7.1 [6.6-7.6], p=0.029), and serum concentrations of eosinophil cationic protein and IgE. In the steroid-reduction phase, pulmonary function, asthma symptoms, and use of beta2-agonist deteriorated significantly more in the placebo group than in the suplatast group.

INTERPRETATION

Treatment with a Th2 cytokine inhibitor in steroid-dependent asthma improves pulmonary function and symptom control, and allows a decrease in dose of inhaled corticosteroid without significant side-effects. Some improvements in pharmacokinetics are, however, needed.

Effect of a thromboxane A(2) antagonist on sputum production and its physicochemical properties in patients with mild to moderate asthma

STUDY OBJECTIVE

To determine the effects of a specific thromboxane A(2) (TxA(2)) receptor antagonist, seratrodast, on asthma control and airway secretions.

DESIGN

Multicenter, double-blind, randomized, placebo-controlled study.

PATIENTS

Forty-five patients with mild to moderate asthma who had been continuously expectorating sputum of > 20 g/d. Patients with a current pulmonary infection or taking oral corticosteroids, antibiotics, or mucolytic agents were excluded from the trial.

INTERVENTIONS

Following a 2-week run-in period, while pulmonary function, sputum production, and mucociliary function were assessed, patients were assigned to receive seratrodast, 40 mg/d, or placebo for 6 weeks.

MEASUREMENTS AND RESULTS

During the treatment period, the changes in FEV(1) and peak expiratory flow (PEF) were not different between the two patient groups, but there were significant reductions in diurnal variation of PEF (p = 0.034), frequency of daytime asthma symptoms (p = 0.030), and daytime supplemental use of beta(2)-agonist (p = 0.032) in the seratrodast group. For sputum analysis, seratrodast treatment decreased the amount of sputum (p = 0.005), dynamic viscosity (p = 0. 007), and albumin concentration (p = 0.028), whereas it had no effect on elastic modulus or fucose concentration. Nasal clearance time of a saccharin particle was shortened in the seratrodast group at week 4 (p = 0.031) and week 6 (p = 0.025), compared with the placebo group.

CONCLUSION

Blockade of TxA(2) receptor has minimal effects on pulmonary function, but may cause an improvement in mucociliary clearance by decreasing the viscosity of airway secretions.

[A questionnaire survey on the self-assessment to the asthmatic treatment in Saitama Prefecture: results from 2825 cases]

The aim of this study was to survey the self-assessment to the treatment of adult bronchial asthmatics in Saitama prefecture. A questionnaire on daily symptoms and medications was distributed to 2825 adult asthmatic subjects who were treated at 125 hospitals/clinics in Saitama prefecture between September 15th and October 30th 1998. More than half (52.7%) of patients described that their general condition of asthma was poorly controlled. Even among the patients described that their condition was good or fair, 30.2% of them had some asthmatic symptoms such as shortness of breath or nocturnal awakening. Although inhaled corticosteroids were used in 66.2%, the ratio of patients who used spacer and kept drug compliance as prescribed were 59.6% and 45.8%, respectively. According to the physician's reports, cysteinyl leukotriene antagonist was used in 35.7%, which was comparable to the total of another anti-allergic drugs (37.3%). These results suggest that more than half of asthmatic patients in Saitama prefecture were not satisfied with their conditions of the disease control. Furthermore, more thorough education on the technique and compliance of inhaled corticosteroids would be required.

[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.

Molecular cloning of a cDNA encoding a novel Ca(2+)-dependent nuclease of Arabidopsis that is similar to staphylococcal nuclease

We have isolated a cDNA from Arabidopsis thaliana for a protein consisting of 323 amino acids with similarity to an extracellular nuclease from Staphylococcus. Nuclease assay using toluidine blue-DNA plates has demonstrated that the gene product has nuclease activity dependent on Ca(2+) and inhibited by Zn(2+), designated CAN (Ca(2+)-dependent nuclease). Differing from the staphylococcal nuclease, CAN has neither a signal peptide nor any long hydrophobic regions, suggesting that it is not a secreted protein.

Radiosensitivity of human breast cancer cells transduced with wild-type p53 gene is influenced by the p53 status of parental cells

Induction of apoptosis with chemotherapeutic agents or radiation in tumours is frequently related to the status of those p53 gene of the tumours. To examine whether forced expression of the wild-type p53 gene in tumour cells can modulate their susceptibility to radiation and anti-cancer agents, we retrovirally transduced two types of human breast cancer cell lines, which respectively harboured a mutated p53 gene (OCUB-M) or wild-type p53 gene (YMB-1), with the wild-type p53 gene. Transduced cells which consistently expressed the wild-type p53 gene (OCUB-M/p53, YMB-1/p53) proliferated at the same rate as control cells which were transduced with the beta-galactosidase gene (OCUB-M/lacz, YMB-1/lacz). However, sensitivity to radiation was increased in OCUB-M/p53 cells but not in YMB-1/p53 cells. In vitro chemosensitivity to DNA-damaging anticancer agents such as cyclophosphamide and 5-fluorouracil was not influenced by the transduction of the wild-type p53 gene in either cells. Expression of the wild-type p53 gene in p53-mutated human breast cancer cells can therefore increase their sensitivity to radiation but not their chemosensitivity. Therapeutic effects following by the transduction of the wild-type p53 gene were not observed in breast cancer cells already bearing the wild-type p53 gene.

Functional genomics of Escherichia coli in Japan

Completion of the genome sequence of the model bacterium Escherichia coli has produced nearly 2000 open reading frames (ORFs) that remain to be functionally characterized. To accomplish this goal, we have organized a working project team in Japan and have begun construction of clones containing each of the putative ORFs. The procedure has been conceived such that we shall be able to perform systematic analysis of the shut-off as well as forced expression in vivo of each ORF and purification of its protein product for further biochemical studies. In addition, we have started a collection of various genetic and biochemical data of E. coli published in the past, and analyses of the data from a bio-informatics point of view. Thus, we aim at reaching complete understanding of this model organism in the near future.

[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.

Evaluation of the accuracy of preoperative staging in thoracic esophageal cancer

BACKGROUND

Exact clinical staging before treatment of esophageal cancer has become increasingly important in the evaluation and comparison of the results of different treatment modalities, including surgery, chemotherapy, and radiotherapy.

METHODS

The accuracy of preoperative tumor staging by using an esophagography, esophagoscopy, percutaneous and endoscopic ultrasonography, and computed tomography was assessed in 224 patients with resectable esophageal cancer. The results of tumor staging by these tests were compared prospectively with the pathologic stage of the esophagectomy specimens with respect to the T and N categories defined by the International Union Against Cancer TNM classification.

RESULTS

For the T category, the overall accuracy was 80%. For the N category, overall accuracy was 72%, with a sensitivity of 78%, a specificity of 60%, and a positive predictive value of 78%. Overall, the accuracy of stage grouping was 56%.

CONCLUSIONS

Either the T or N categories can be predicted reliably by clinical staging techniques. However, the preoperative stage grouping might not be valid in resectable, localized esophageal cancer.

Rotational cine cholangiography: evaluation for use in diagnosing bile duct carcinoma

OBJECTIVE

We evaluated the usefulness of rotational cine cholangiography in the preoperative diagnosis of bile duct carcinoma.

SUBJECTS AND METHODS

Rotational cine cholangiography was performed in both the transverse and cephalad anterior oblique planes in 60 patients with obstructive jaundice. Using strict diagnostic criteria, the capability of this technique to detect the confluence of the right hepatic duct and the left hepatic duct, the right anterior segmental duct and the right posterior segmental duct, and the left medial segmental duct was investigated. The angle at which the confluence was revealed was also investigated. In 26 patients with resected bile duct carcinomas, the preoperative diagnosis of cancer spread obtained using this procedure was compared with the histopathologic findings.

RESULTS

Overall detectabilities of the confluences of the right hepatic ducts and left hepatic ducts, the right anterior segmental ducts and right posterior segmental ducts, and the left medial segmental ducts were 97.6%, 87.0%, and 93.1%, respectively. The angles of the confluences of the right hepatic ducts and left hepatic ducts and of the right anterior segmental ducts and right posterior segmental ducts were widely distributed: on the other hand, those of the left medial segmental ducts were distributed mainly from 0 degrees to 20 degrees . The accuracies of diagnosis of cancer invasion were 91.7% in the common hepatic ducts, 100% in the right hepatic ducts, 91.7% in the left hepatic ducts, 100% in the right anterior segmental ducts, 83.3% in the right posterior segmental ducts, and 100% in the left medial segmental ducts.

CONCLUSION

Rotational cine cholangiography is reliable not only in detecting the confluence of the bile ducts but also in diagnosing the longitudinal extent of cancer spread along the bile duct wall.

An Arabidopsis cDNA encoding a DNA-binding protein that is highly similar to the DEAH family of RNA/DNA helicase genes

A cDNA encoding a putative RNA and/or DNA helicase has been isolated from Arabidopsis thaliana cDNA libraries. The cloned cDNA is 5166 bases long, and its largest open reading frame encodes 1538 amino acids. The central region of the predicted protein is homologous to a group of nucleic acid helicases from the DEAD/H family. However, the N- and C-terminal regions of the Arabidopsis cDNA product are distinct from these animal DEIH proteins. We have found that the C-terminal region contains three characteristic sequences: (i) two DNA-binding segments that form a probe helix (PH) involved in DNA recognition; (ii) an SV40-type nuclear localization signal; and (iii) 11 novel tandem-repeat sequences each consisting of about 28 amino acids. We have designated this cDNA as NIH (nuclear DEIH-boxhelicase). Functional character-ization of a recombinant fusion product containing the repeated region indicates that NIH may form homodimers, and that this is the active form in solution. Based on this information and the observation that the sequence homology is limited to the DEAH regions, we conclude that the biological roles of the plant helicase NIH differ from those of the animal DEIH family.

Peritoneal lavage cytology findings as prognostic factor for gastric cancer

The validity of lavage cytology for accurate gastric cancer staging is demonstrated in this study. Between 1988 and 1996, 29 cases (8. 4%) were revealed as positive among 347 patients with resectable gastric cancer in whom peritoneal lavage cytology was performed. The survival rate of cytology-positive patients in each stage was found to be worse than that of all other patients in the same stage. The prognostic factors selected by the univariate analysis were enrolled for multivariate analysis using Cox's proportional hazards model with the backward stepwise procedure. As a result, although cytology finding was selected as an independent prognostic factor, macroscopic finding of dissemination was not selected. Our data indicate that positive cytology findings indicated a poor prognosis, and therefore the results of peritoneal lavage cytology should be included as a factor in gastric cancer staging.