Hepatitis B surface antigen incorporated in dissolvable microneedle array patch is antigenic and thermostable

Alternatives to syringe-based administration are considered for vaccines. Intradermal vaccination with dissolvable microneedle arrays (MNA) appears promising in this respect, as an easy-to-use and painless method. In this work, we have developed an MNA patch (MNAP) made of hydroxyethyl starch (HES) and chondroitin sulphate (CS). In swines, hepatitis B surface antigen (HBsAg) formulated with the saponin QS-21 as adjuvant, both incorporated in HES-based MNAP, demonstrated the same level of immunogenicity as a commercially available aluminum-adjuvanted HBsAg vaccine, after two immunizations 28 days apart. MNAP application was associated with transient skin reactions (erythema, lump, scab), particularly evident when the antigen was delivered with the adjuvant. The thermostability of the adjuvanted antigen when incorporated in the HES-based matrix was also assessed by storing MNAP at 37, 45 or 50 °C for up to 6 months. We could demonstrate that antigenicity was retained at 37 and 45 °C and only a 10% loss was observed after 6 months at 50 °C. Our results are supportive of MNAP as an attractive alternative to classical syringe-based vaccination.

Protection from avian influenza H5N1 virus infection with antibody-impregnated filters

There is worldwide concern over the possibility of a new influenza pandemic originating from the highly pathogenic avian H5N1 influenza viruses. We herein demonstrate that functional air filters impregnated with ostrich antibodies against the hemagglutinin of the H5N1 virus protect chickens from death by H5N1 transmission. These results suggest that the use of ostrich antibody-impregnated filters might be a powerful way to prevent the transmission of H5N1.

Polyamines: essential factors for growth and survival

Polyamines are low molecular weight, aliphatic polycations found in the cells of all living organisms. Due to their positive charges, polyamines bind to macromolecules such as DNA, RNA, and proteins. They are involved in diverse processes, including regulation of gene expression, translation, cell proliferation, modulation of cell signalling, and membrane stabilization. They also modulate the activities of certain sets of ion channels. Because of these multifaceted functions, the homeostasis of polyamines is crucial and is ensured through regulation of biosynthesis, catabolism, and transport. Through isolation of the genes involved in plant polyamine biosynthesis and loss-of-function experiments on the corresponding genes, their essentiality for growth is reconfirmed. Polyamines are also involved in stress responses and diseases in plants, indicating their importance for plant survival. This review summarizes the recent advances in polyamine research in the field of plant science compared with the knowledge obtained in microorganisms and animal systems.

Overexpression of the Arabidopsis thaliana EDS5 gene enhances resistance to viruses

The Arabidopsis thaliana ENHANCED DISEASE SUSCEPTIBILITY 5 gene (EDS5) is required for salicylic acid (SA) synthesis in pathogen-challenged plants. SA and EDS5 have an important role in the Arabidopsis RCY1 gene-conferred resistance against the yellow strain of Cucumber mosaic virus [CMV(Y)], a Bromoviridae, and HRT-conferred resistance against the Tombusviridae, Turnip crinkle virus (TCV). EDS5 expression and SA accumulation are induced in response to CMV(Y) inoculation in the RCY1-bearing ecotype C24. To further discern the involvement of EDS5 in Arabidopsis defence against viruses, we overexpressed the EDS5 transcript from the constitutively expressed Cauliflower mosaic virus 35S gene promoter in ecotype C24. In comparison to the non-transgenic control, the basal level of salicylic acid (SA) was twofold higher in the 35S:EDS5 plant. Furthermore, viral spread and the size of the hypersensitive response associated necrotic local lesions (NLL) were more highly restricted in CMV(Y)-inoculated 35S:EDS5 than in the non-transgenic plant. The heightened restriction of CMV(Y) spread was paralleled by more rapid induction of the pathogenesis-related gene, PR-1, in the CMV(Y)-inoculated 35S:EDS5 plant. The 35S:EDS5 plant also had heightened resistance to the virulent CMV strain, CMV(B2), and TCV. These results suggest that, in addition to R gene-mediated gene-for-gene resistance, EDS5 is also important for basal resistance to viruses. However, while expression of the Pseudomonas putida nahG gene, which encodes the SA-degrading salicylate hydroxylase, completely suppressed 35S:EDS5-conferred resistance against CMV(Y) and TCV, it only partially compromised resistance against CMV(B2), indicating that SA-dependent and -independent mechanisms are associated with 35S:EDS5-conferred resistance against viruses.

Whether or not prophylactic excision of the extrahepatic bile duct is appropriate for patients with pancreaticobiliary maljunction without bile duct dilatation

BACKGROUND/AIMS

The standard treatment for patients with a pancreaticobiliary maljunction (PBM) without bile duct dilatation remains controversial.

METHODOLOGY

We followed up 29 patients with such PBM who mainly underwent a cholecystectomy alone. The ages of the patients ranged from 3 to 76 years (average age 47.3 years) and the ratio of males to females was 8 vs. 21. When the diameter of the common bile duct was less than 10mm, such bile ducts were diagnosed to have no dilatation. The main clinical indications for surgery were cholecystolithiasis in 15 patients, choledocholithiasis in 3, cholecystocholedocholithiasis in 2, gallbladder polyp in 2, adenomyomatosis in 2, cholecystitis in 2, and protein plug in 1.

RESULTS

The amylase levels of gallbladder bile in 20 patients ranged from 115 to 460,200 IU/mL (a mean of 191,698 IU/mL). One patient died of gastric cancer 182 months after surgery and two patients died of other diseases 153, 171 months after surgeries, respectively. The remaining 26 patients have all been doing well for 36 months to 326 months after surgery (a median follow-up period, 160.5 months). The 10- and 15-year survival rates were 100% and 89.7%.

CONCLUSIONS

In conclusion, a prophylactic resection of the extrahepatic bile duct and biliary diversion could be unnecessary for patients with PBM without bile duct dilatation.

Psychrophilic Pseudomonas syringae requires trans-monounsaturated fatty acid for growth at higher temperature

A psychrophilic bacterium, Pseudomonas syringae (Lz4W) from Antarctica, was used as a model system to establish a correlation, if any, between thermal adaptation, trans-fatty acid content and membrane fluidity. In addition, attempts were made to clone and sequence the cti gene of P. syringae (Lz4W) so as to establish its characteristics with respect to the cti of other Pseudomonas spp. and also to in vitro mutagenize the cti gene so as to generate a cti null mutant. The bacterium showed increased proportion of saturated and trans-monounsaturated fatty acids when grown at 28 degrees C compared to cells grown at 5 degrees C, and the membrane fluidity decreased with growth temperature. In the mutant, the trans-fatty acid was not synthesized, and the membrane fluidity also decreased with growth temperature, but the decrease was not to the extent that was observed in the wild-type cells. Thus, it would appear that synthesis of trans-fatty acid and modulation of membrane fluidity to levels comparable to the wild-type cells is essential for growth at higher temperatures since the mutant exhibits growth arrest at 28 degrees C. In fact, the cti null mutant-complemented strain of P. syringae (Lz4W-C30b) that was capable of synthesizing the trans-fatty acid was indeed capable of growth at 28 degrees C, thus confirming the above contention. The cti gene of P. syringae (Lz4W) that was cloned and sequenced exhibited high sequence identity with the cti of other Pseudomonas spp. and exhibited all the conserved features.

Association between up-regulation of stress-responsive genes and hypomethylation of genomic DNA in tobacco plants

Transcripts that specifically accumulate in transgenic tobacco plants expressing an anti-sense construct for a tobacco type I DNA methyltransferase, NtMET1, were screened by the differential display method. Of the 31 genes identified, 16 encoded proteins with known functions; ten of these were related to biotic and abiotic stress responses, and the other six to cellular functions. In order to examine whether expression of these genes is correlated with DNA methylation status under natural stress conditions, a pathogen-responsive gene (NtAlix1) was selected as representative, and assayed for transcript induction and genomic methylation in tobacco plants infected with tobacco mosaic virus (TMV). In inoculated leaves of wild-type plants, NtAlix1 transcripts began to accumulate 12 h after the onset of the hypersensitive response (HR), and levels remained high for up to 24 h. Changes in the methylation status at the locus became obvious 24 h later, as detected by digestion of genomic DNA with a methylation-sensitive restriction enzyme. The results suggest that the level of DNA methylation may change in response to external stresses, and that this is closely related to the activation of stress-responsive genes.

Identification of early-responsive genes associated with the hypersensitive response to tobacco mosaic virus and characterization of a WRKY-type transcription factor in tobacco plants

In order to identify genes that are involved in the defense reaction against pathogen attack, we screened for examples that are regulated during the hypersensitive response (HR) to infection by tobacco mosaic virus (TMV) of tobacco ( Nicotiana tabacum cv. Xanthi nc) carrying the N gene, which confers resistance to TMV. Among seven genes initially identified by fluorescent differential display, one clone was further characterized because its transcripts accumulated rapidly and transiently after the onset of HR. Its full-length cDNA of 1346 bp encoded a polypeptide consisting of 258 amino acids. The deduced protein contained a single WRKY domain, a Cys(2)His(2) zinc-finger motif and a leucine-zipper motif, showing high similarity to WIZZ, a member of the family of WRKY transcription factors in tobacco. The gene was thus designated TIZZ. A GFP-TIZZ fusion protein was found to localize to the nucleus upon introduction into epidermal cells of onion. Bacterially expressed TIZZ was able to bind to the W-box (TTGAC) element that is recognized by other WRKY proteins, but transactivation assays showed it to be unable to activate reporter gene expression by itself. TIZZ transcripts were induced in TMV-infected nahG transgenic tobacco plants, in which salicylic acid fails to accumulate. Neither exogenously applied salicylic acid nor mechanical wounding induced TIZZ transcript accumulation. These results indicate the presence of salicylic acid-independent pathways for HR signal transduction, in which a novel type of WRKY protein(s) may play a critical role for the activation of defense.

Assignment of Pseudomonas sp. strain E-3 to Pseudomonas psychrophila sp. nov., a new facultatively psychrophilic bacterium

A facultatively psychrophilic bacterium, previously described as Pseudomonas sp. strain E-3, has been reassigned by phenotypic characterization, chemotaxonomic analysis, DNA-DNA hybridization, and 16S rRNA gene phylogenetic analysis. The organism was a gram-negative, aerobic. straight rod with polar flagella. It was catalase positive and oxidase positive, able to grow at -1 degree C but not at 40 degree C, and produced acid from D-glucose under aerobic conditions. The major isoprenoid quinone was ubiquinone-9, and the DNA G + C content was 57.2 mol%. Phylogenetic analysis based on 16S rRNA gene sequencing indicated that the bacterium is a member of the genus Pseudomonas and was closest to Pseudomonas fragi. Determination of the DNA-DNA relatedness between strain E-3 and P. fragi revealed too low a level of homology (47.9%-51.3%) to identify them as the same species. On the basis of phenotypic characteristics, phylogenetic analysis, and DNA-DNA relatedness data, it is concluded that strain E-3 represents an individual species. Accordingly, the name Pseudomonas psychrophila is proposed. The type strain is E-3T (= JCM 10889).

Specific association of transcripts of tbzF and tbz17, tobacco genes encoding basic region leucine zipper-type transcriptional activators, with guard cells of senescing leaves and/or flowers

Induction by low temperature is a common feature of the lip19 subfamily members of the basic region leucine zipper gene family in plants. Here, we characterize two tobacco (Nicotiana tabacum) genes, tbzF and tbz17, belonging to the lip19 subfamily, whose gene products, TBZF and TBZ17, show 73% identity and are located in nuclei. They preferentially bind to DNA fragments spanning A-box/G-box and C-box/G-box hybrid motifs and show transactivation activity in cobombarded tobacco BY-2 cells, indicating they function as transcriptional activators. Transcripts of tbzF were detected at a high level in senescing leaves and flowers. In contrast, tbz17 transcripts could be shown to accumulate in aged leaves but not in flowers. In situ hybridization analysis revealed transcripts of tbzF and tbz17 to be predominantly located in guard cells and vascular tissues of senescing leaves. These results suggest that TBZF and TBZ17 are both involved in controlling gene transcription related to functions of guard cells in senescing leaves and that TBZF bifunctionally acts in floral development.

Natural progression of untreated hepatolithiasis that shows no clinical signs at its initial presentation

GOALS

To elucidate the natural progression of hepatolithiasis that showed no signs at the time of initial presentation.

STUDY

Over a 17-year period, we observed 122 of 311 patients with hepatolithiasis who reported no symptoms and, thus, who received no treatment at initial presentation. The follow-up period was for up to 15 years (mean, 10.08 years).

RESULTS

Fourteen of 112 patients (11.5%) developed some symptoms attributed to hepatolithiasis. The interval until the onset of symptoms ranged from 9 months to 7.33 years (mean, 3.42 years ). The developing symptoms included abdominal pain, hepatic abscess, cholangitis, and cholangiocarcinoma. Nine of the 14 patients (64.3%) developed stone migration to the extrahepatic bile duct at the onset of clinical symptoms. The incidence of lobar liver atrophy on computed tomography in the patients with symptomatic hepatolithiasis (13 of 14 patients; 92.9%) was significantly higher than that in the patients with asymptomatic hepatolithiasis (14 of 108 patients; 13.0%). The prognosis of the patients with symptomatic hepatolithiasis were as follows: 2 died of cholangiocarcinoma, 1 died of hepatic failure, and 11 survived. Fifteen of asymptomatic patients died, but none of these deaths were attributed to hepatolithiasis.

CONCLUSIONS

Close observation is an alternative management at initial presentation for patients with asymptomatic hepatolithiasis without extrahepatic stones or lobar liver atrophy.

Predictive factors for long-term survival in patients with intrahepatic cholangiocarcinoma

BACKGROUND

In order to elucidate the predictive factors for long-term survival in patients with intrahepatic cholangiocarcinoma (ICC), we evaluated 7 patients who survived for more than 5 years (5-year survivors).

METHODS

We examined the clinicopathologic and biologic factors of the 5-year survivors, and these findings were then compared with those in 20 patients who died within 5 years after surgery (control group).

RESULTS

In the 5-year survivors, the gross appearance of the tumors included a mass-forming (MF) type in 5 cases, an intraductal growth (IG) type in 1, and another type (microcarcinoma with hepatolithiasis) in 1. No case demonstrated a periductal infiltrating (PI) type. Except for 1 case with an IG type tumor, no lymph node metastasis was seen in any patients. All of the 5-year survivors were classified from stage I to III, and all also underwent a curative resection. The clinicopathologic factors demonstrating significant differences between the 5-year survivors and the control group included the gross type of the tumor, lymph node involvement, the surgical margin, curability, and pTNM stage.

CONCLUSION

The predictive factors for long-term survival in patients with ICC are thus suggested to include not only tumor staging and curability, but also lymph node metastasis and the gross type of the tumors.

Long-term results of hepaticojejunostomy for hepatolithiasis

The results of a hepaticojejunostomy as a biliary-enteric bypass for benign disease are usually excellent. On the other hand, hepatolithiasis features a high rate of residual and recurrent stones with cholangitis after surgery. This study aims to evaluate the long-term results of a hepaticojejunostomy for hepatolithiasis regarding both the degree of the occurrence of postoperative cholangitis and the outcome. The clinical records of 159 patients with hepatolithiasis who underwent surgical treatment over a 23-year period were also retrospectively reviewed. Ninety-four of 159 patients underwent a hepatecetomy and 65 patients were subjected to liver-preserving surgery by means of intra- and postoperative endoscopic lithotripsy. In addition 72 patients underwent a hepaticojejunostomy. The rate of residual or recurrent stones was 31.4 per cent after complete stone removal. Twenty-two (30.6%) of the 72 patients developed some kind of cholangitis. This rate was significantly higher than that (three of 87 patients) of the non-biliary-enteric anastomosis group regarding the occurrence of biliary complications. We conclude that the use of a hepaticojejunostomy for patients with possible residual stones or intrahepatic bile duct lesions remains controversial.

Detoxification of cadmium in tobacco plants: formation and active excretion of crystals containing cadmium and calcium through trichomes

In tobacco (Nicotiana tabacum L.), long and short trichomes can be distinguished morphologically. The established function of long trichomes is to exude a sticky gum containing diterpenes, whereas that of short trichomes is not known. When tobacco seedlings were exposed to toxic levels of cadmium (Cd), growth was retarded, but trichome number was increased up to 2-fold in comparison with untreated samples. Observation by variable-pressure scanning electron microscopy (VP-SEM) indicated that large crystals of 150 microm in size were formed on head cells of both short and long trichomes. An energy-dispersive X-ray analysis system fitted with VP-SEM revealed the crystals to contain amounts of Cd and calcium (Ca) at much higher concentrations than in the head cells themselves. Transmission electron microscopy demonstrated crystal formation in amorphous osmiophilic deposits in vacuoles. When seedlings were treated with Cd in the presence of Ca, tolerance was increased in proportion to the increase in Ca concentration. These results indicate that tobacco plants actively exclude toxic Cd by forming and excreting Cd/Ca-containing crystals through the head cells of trichomes.

Successful resection for advanced hepatoblastoma, combined with perioperative chemotherapy

The aim of this study was to evaluate our results of surgical treatment with intensive perioperative chemotherapy for hepatoblastoma in infants and children. Seven patients (mean age, 30 months; range 1 month to 6 years) with hepatoblastoma who were followed-up for more than 3 years were reviewed. All patients underwent hepatectomy, performed using a microwave tissue coagulator, after they had received neoadjuvant chemotherapy comprising up to four cycles of cisplatinum and doxorubicin. The main outcome criteria were the clinical response rates to neoadjuvant chemotherapy and the overall survival. Neoadjuvant chemotherapy markedly reduced the tumor volume on computed tomography (mean regression rate, 73%). Alpha-fetoprotein (AFP) levels also decreased, from a mean value of 138 x 104 to 990 ng/ml (excluding values for one patient with tumor thrombus in the portal vein). The surgical procedures included extended right lobectomy in one patient, extended left lobectomy in two patients, hepatic left trisegmentectomy in one patient, and hepatic subsegmentectomy in three patients. The postoperative clinical courses in all seven patients were good, and no serious complications were observed. No relationship was observed between the DNA ploidy pattern and the histopathological findings of the resected specimens regarding survival. Six patients (excluding the patient with a tumor thrombus in the portal vein) who underwent complete resections survived without any signs of recurrence during a follow-up period ranging from 47 to 150 months. In conclusion, the perioperative chemotherapy greatly improved both the resection rate and overall survival in patients with hepatoblastoma. DNA ploidy pattern analysis may be useful when predicting the prognosis of patients with hepatoblastoma. The use of the microwave coagulator was safe for performing hepatectomy, even in infants.

Migrating site of bleeding in a right colon demonstrating angio-dysplasia following a segmental resection of the colon. A unique variant of angiodysplasia

BACKGROUND/AIM

A case of angiodysplasia of the right colon presenting with a migrating site of bleeding following a segmental resection of the colon in a 38-year-old Japanese is herein reported.

METHODS

The case records of a patient with severe intestinal bleeding and multiple surgeries were reviewed, and then the histologic features were compared with the operative findings. The patient received many units of packed red blood cells and had also undergone three segmental colectomies and most recently a curative ileocolostomy. Despite an exhaustive evaluation, the bleeding sites could not be detected clinically.

RESULTS

Ectatic, tortuous submucosal veins were presented in four sections of the colon (cecum, ascending colon and transverse colon, respectively) out of a total of 30 sections that were examined. These veins pierced the proper muscle layer of the colon, but did not traverse the muscularis mucosa. Our case of segmental microscopic angiodysplasia may represent a previously unreported unique variant, because the angiodysplastic lesions were present in the segmental colon and they developed bleeding from the distal remnant colon immediately after each segmental colectomy until an extended right hemicolectomy containing the oral part of the descending colon was done. In spite of the severe bleeding, the mucosa of the colon appeared to be essentially normal during a macroscopic inspection.

CONCLUSION

Gastrointestinal bleeding from angiodysplasia is generally assumed to arise from macroscopically visible vascular lesions within the mucosa. However, angiodysplastic lesions are often unrecognizable and multiple in the gastrointestinal tract, and especially tend to affect both the cecum and ascending colon. When this disease process is recognized, a subtotal colectomy may thus be called for to control bleeding.

7-Methylxanthine methyltransferase of coffee plants. Gene isolation and enzymatic properties

Caffeine is synthesized through sequential three-step methylation of xanthine derivatives at positions 7-N, 3-N, and 1-N. However, controversy exists as to the number and properties of the methyltransferases involved. Using primers designed on the basis of conserved amino acid regions of tea caffeine synthase and Arabidopsis hypothetical proteins, a particular DNA fragment was amplified from an mRNA population of coffee plants. Subsequently, this fragment was used as a probe, and four independent clones were isolated from a cDNA library derived from coffee young leaves. Upon expression in Escherichia coli, one of them was found to encode a protein possessing 7-methylxanthine methyltransferase activity and was designated as CaMXMT. It consists of 378 amino acids with a relative molecular mass of 42.7 kDa and shows similarity to tea caffeine synthase (35.8%) and salicylic acid methyltransferase (34.1%). The bacterially expressed protein exhibited an optimal pH for activity ranging between 7 and 9 and methylated almost exclusively 7-methylxanthine with low activity toward paraxanthine, indicating a strict substrate specificity regarding the 3-N position of the purine ring. K(m) values were estimated to be 50 and 12 microM for 7-methylxanthine and S-adenosyl-l-methionine, respectively. Transcripts of CaMXMT could be shown to accumulate in young leaves and stems containing buds, and green fluorescent protein fusion protein assays indicated localization in cytoplasmic fractions. The results suggest that, in coffee plants, caffeine is synthesized through three independent methylation steps from xanthosine, in which CaMXMT catalyzes the second step to produce theobromine.

Two novel genes encoding SNF-1 related protein kinases from Arabidopsis thaliana: differential accumulation of AtSR1 and AtSR2 transcripts in response to cytokinins and sugars, and phosphorylation of sucrose synthase by AtSR2

We searched for genes encoding members of the group-3 SNF1-related protein kinase (SnRK3) family in the Arabidopsis thaliana database, and seven independent sequences were identified. Transcripts of two of them were found to accumulate differentially upon treatment with light, cytokinins and sugars. Full-length cDNAs were isolated and designated as AtSR1 and AtSR2; they encode polypeptides of 442 and 429 amino acids with relative molecular masses of 50.3 kDa and 48.2 kDa, respectively. In etiolated seedlings, no transcripts of either gene were observed. However, upon exposure to light or cytokinins, transcripts of AtSR1 but not AtSR2 began to accumulate. The induction with light was greatly reduced in the presence of a cytokinin antagonist, suggesting that cytokinins are involved in light-signaling pathways. In contrast, transcription of AtSR2, but not of AtSR1, was greatly increased by sucrose, as well as glucose and fructose. AtSR2 expressed in E. coli efficiently phosphorylated sucrose synthase in the presence of manganese ions. These results suggest that, although SnRK3 proteins may generally be involved in sugar metabolism, expression of AtSR1 and AtSR2 is differentially and distinctly regulated by various external signals, and AtSR2 may function in the regulation of sucrose synthase by specific phosphorylation.

Specific binding of a 14-3-3 protein to autophosphorylated WPK4, an SNF1-related wheat protein kinase, and to WPK4-phosphorylated nitrate reductase

WPK4 is a wheat protein kinase related to the yeast protein kinase SNF1, which plays a role in catabolite repression. To identify proteins involved in signal transduction through WPK4, we performed yeast two-hybrid screens and isolated two cDNA clones designated as TaWIN1 and TaWIN2. Both encode 14-3-3 proteins that, upon autophosphorylation, bind the C-terminal regulatory domain of WPK4. Mutational analysis through amino acid substitution revealed that TaWIN1 and TaWIN2 primarily bind WPK4 through phosphoserines at the positions 388 and 418, both located in the C-terminal region. Mutations in the conserved residues of the TaWIN1 amphipathic groove impaired the ability of TaWIN1 to bind to WPK4. A screen for in vitro phosphorylation of proteins involved in nutrient metabolism revealed a putative WPK4 substrate, nitrate reductase; its hinge 1 region was efficiently phosphorylated by WPK4. Subsequent far Western blots showed that it specifically bound TaWIN1. Since nitrate reductase has been shown to be inactivated by phosphorylation upon 14-3-3 binding, the present findings strongly suggest that WPK4 is the protein kinase responsible for controlling the nitrogen metabolic pathway, assembling the nitrate reductase and 14-3-3 complex through its phosphorylation specificity.

Expression of ZmMET1, a gene encoding a DNA methyltransferase from maize, is associated not only with DNA replication in actively proliferating cells, but also with altered DNA methylation status in cold-stressed quiescent cells

A cDNA fragment encoding part of a DNA methyltransferase was isolated from maize. The putative amino acid sequence identically matched that deduced from a genomic sequence in the database (accession no. AF063403), and the corresponding gene was designated as ZmMET1. Bacterially expressed ZmMET1 actively methylated DNA in vitro. Transcripts of ZmMET1 could be shown to exclusively accumulate in actively proliferating cells of the meristems of mesocotyls and root apices, suggesting ZmMET1 expression to be associated with DNA replication. This was confirmed by simultaneous decrease of transcripts of ZmMET1 and histone H3, a marker for DNA replication, in seedlings exposed to wounding, desiccation and salinity, all of which suppress cell division. Cold stress also depressed both transcripts in root tissues. In contrast, however, accumulation of ZmMET1 transcripts in shoot mesocotyls was not affected by cold stress, whereas those for H3 sharply decreased. Such a differential accumulation of ZmMET1 transcripts was consistent with ZmMET1 protein levels as revealed by western blotting. Expression of ZmMET1 is thus coexistent, but not completely dependent on DNA replication. Southern hybridization analysis with a methylation-sensitive restriction enzyme revealed that cold treatment induced demethylation of DNA in the Ac/Ds transposon region, but not in other genes, and that such demethylation primarily occurred in roots. These results suggested that the methylation level was decreased selectively by cold treatment, and that ZmMET1 may, at least partly, prevent such demethylation.

Prostaglandin E(1) continuous hepatic arterial infusion in the treatment of postoperative acute liver failure: basic study on hepatic hemodynamics and clinical application

AIM

In the treatment of severe liver damage, it is of greater advantage to administer prostaglandin E(1) (PGE(1)) directly to the liver compared with systemic intravenous infusion, because of its high inactivation rate in the lungs. In comparison with intraportal infusion, hepatic arterial infusion is more advantageous because of its easier and safer accessibility. This study was designed to prove the superiority of hepatic arterial infusion to intravenous infusion.

METHODS

Changes in hepatic hemodynamics and oxygen delivery accompanying PGE(1) infusion using both methods were investigated in pigs. In addition, continuous hepatic arterial infusion was applied in 3 cases of postoperative acute liver failure, for patients in whom other conventional treatments like plasma exchange failed to improve the functioning of the liver.

RESULTS

Hepatic arterial flow increased significantly accompanying hepatic arterial infusion of PGE(1) at a rate of 0.1 microg/kg/min compared with intravenous infusion at the same rate in pigs. Such an increase resulted in elevation of total hepatic blood flow and oxygen delivery to the liver. Correspondingly, bile flow significantly increased accompanying hepatic arterial infusion of PGE(1). Continuous hepatic arterial infusion was applied in 3 cases of postoperative acute liver failure. The infusion was continued for 7-9 days at a rate of 0.01 microg/kg/min without any complications through heparin-coated catheters inserted via the femoral artery. Significant increase in bile flow was observed in 2 cases in whom bile was collected, serum total bilirubin began to decrease in all these 3 cases, and the patients recovered from acute liver failure.

CONCLUSION

Hepatic arterial infusion of PGE(1) is very useful and effective in the treatment of acute liver failure.

Difference in hepatic tissue oxygenation between total vascular exclusion and inflow occlusion of the liver and the possible role of hepatic venous blood under liver ischemia

The difference between total vascular exclusion (TVE) and inflow occlusion (IO) of the liver was assessed by the extent of DNA injury in rats and by hepatic tissue oxygen saturation (SahtO2) in pigs. Moreover, the role of hepatic venous blood under liver ischemia was discussed. Seventy percent of the rat livers were exposed to complete IO (hepatic artery + portal vein) or to TVE (IO + hepatic vein) for 30 or 60 min. DNA strand breaks following blood flow interception were measured using the in situ nick translation technique as an indicator of liver damage. IO/TVE were performed on pigs as well under portosystemic bypass, and the oxygen saturation of the hepatic venous blood (SahvO2) was altered by changing the fraction of inspiratory oxygen or by oxygenating the inferior caval blood using an extracorporeal membrane oxygenator. The changes in SahtO2 were measured sequentially using near-infrared spectroscopy. The results were as follows: (1) DNA injury occurred more severely under TVE than under IO of the rat liver at the end of ischemia, as well as 30 min after revascularization. (2) SahtO2 during TVE was significantly lower than that during IO. (3) The increase in SahvO2 by oxygenation of the inferior caval blood resulted in the elevation of SahtO2 under IO. In conclusion, TVE could cause greater damage to the liver than IO due to the lack of the hepatic venous blood. Hepatic venous blood might play an important role in hepatic tissue oxygenation in the case of hepatic blood flow interception.

Radiation-associated rectal cancer: report of four cases

BACKGROUND/AIMS

Radiation-associated rectal cancer is a remarkable clinical entity. We demonstrate 4 patients (mean age 68 years, range 63-74) who had undergone pelvic radiotherapy for cervical cancer. We indicate some characteristics of radiation-associated rectal cancer.

RESULTS

Two patients had received intracavitary and external pelvic radiotherapy, while the remaining 2 had external pelvic radiotherapy following hysterectomy. The mean total radiation dose was 63 Gy, though radiation dose information was not available for 1 patient. Colorectal cancer developed at a mean time of 20.7 years (range 11-30) after radiation therapy. All patients presented with chronic radiation colitis, and 3 demonstrated abnormal tumor markers. Colonoscopy revealed an ulcerative, localized well-differentiated adenocarcinoma of the rectosigmoid colon in 1 patient, and diffusely infiltrating cancers of the lower rectum, one signet-ring cell carcinoma and two mucinous carcinomas in the remaining 3. One case was stage I, 2 were stage IIIa, and the remaining case was stage IV. Three patients underwent abdominoperineal resection. The remaining patient was felt to be inoperable. The colorectal wall demonstrated the changes of chronic radiation injury. Two patients died within a short time because of their advanced cancers.

CONCLUSION

Radiation-associated rectal cancer has a tendency to be diagnosed in the advanced stage and to have a poor prognosis. A literature review and our case report suggest that since there are no reliable clinical or laboratory indicators of the presence of a curable colorectal cancer in the setting of chronic radiation proctocolitis, surveillance with a colonoscope should be done 10 years after irradiation in patients with previous pelvic radiotherapy.

Screening of wound-responsive genes identifies an immediate-early expressed gene encoding a highly charged protein in mechanically wounded tobacco plants

In order to identify genes that are temporally and spatially regulated during wound response, a cDNA population in mechanically wounded tobacco leaves was screened by the fluorescence differential display method. Of 28 clones initially identified to have altered levels of transcripts within 3 h of wounding, eight were characterized. Although each clone showed a unique pattern of transcript accumulation, one distinct clone was further characterized because of its immediate-early response. Its transcripts began to accumulate 10 min after wounding, reached a maximum level within 1 h and disappeared after 2 h. The response, which occurred repeatably and systemically, was observed by the treatment with propionic acid or erythrosin B, indicating that cytosolic acidification could be one of the signals for immediate-early response of this gene. The cDNA encodes a polypeptide of 513 amino acids with a relative molecular mass of 60,952. The putative polypeptide is rich in lysine (K), glutamic acid (E) and aspartic acid (D), which constitute up to 70% of total amino acids, and was therefore designated as KED. The KED polypeptide is composed of a highly hydrophilic N-terminal region and a relatively hydrophobic C-terminal region, suggesting that KED may function through electrostatic interactions with cellular components.

Efficacy of hepatic arterial infusion of prostaglandin E1 in the treatment of postoperative acute liver failure--report of a case

Prostaglandin E1 (PGE1) has received attention for its protective effects against various types of liver damage. However, it is known that approximately 70% of PGE1 is inactivated during a single passage through the lung. Therefore, direct infusion of PGE1 into the liver bloodstream is preferable to intravenous infusion. A 66-year-old man with hepatocellular carcinoma with liver cirrhosis developed postoperative acute liver failure following posterior segmentectomy under hepatic total vascular exclusion exceeding 1 hour. Because his liver function did not recover in spite of plasma exchange starting on postoperative day 8 and intravenous infusion of PGE1, hepatic arterial continuous infusion of PGE1 at a rate of 0.01 microgram/kg/min was carried out for 7 days from postoperative day 17. Immediately after the start of the arterial infusion, the bile flow significantly increased compared to before the arterial infusion, and the serum total bilirubin level decreased thereafter and finally recovered from the hepatic failure. In addition to its highly efficient drug delivery, the hepatic arterial infusion of PGE1 seems to be more advantageous in oxygen delivery to the liver compared with intravenous infusion. In conclusion, the hepatic arterial infusion of PGE1 may be useful in the treatment of acute liver failure.

Three Arabidopsis genes encoding proteins with differential activities for cysteine synthase and beta-cyanoalanine synthase

Three cDNA clones encoding putative cysteine synthases (O-acetylserine (thiol) lyase, EC 4.2.99.8) were isolated from Arabidopsis thaliana and designated AtcysC1, AtcysD1 and AtcysD2, respectively. Southern blot analyses suggested that the corresponding genes were present as a single copy, or at most two copies, in the A. thaliana genome. Escherichia coli complementation analyses confirmed that the cDNAs encode cysteine synthase and the corresponding proteins produced in E. coli clearly showed cysteine synthase activity. In addition, AtcysC1 protein showed beta-cyanoalanine synthase (EC 4.4.1.9) activity, but the other two did not. Kinetic analysis suggests that AtcysC1 actually functions as beta-cyanoalanine synthase rather than cysteine synthase in vivo. The mRNA accumulation of AtcysC1, AtcysD1 and AtcysD2 differed in various organs, but did not change markedly when A. thaliana seedlings were subjected to various stresses, including nutrient deprivation. In vivo targeting experiments indicated that AtcysD1 and AtcysD2 are cytoplasmic isozymes, and AtcysC1 is a mitochondrial isozyme.

A tobacco NtMET1 cDNA encoding a DNA methyltransferase: molecular characterization and abnormal phenotypes of transgenic tobacco plants

A cDNA encoding a DNA methyltransferase, with a predicted polypeptide of 1556 amino acid residues containing all motifs conserved in this enzyme family, was isolated from tobacco plants, and the corresponding gene was designated as NtMET1. RNA blot analysis indicated NtMET1 transcripts to accumulate in dividing tissues of tobacco plants, and they could be detected during the S phase in synchronized dividing BY2 cells. In situ hybridization revealed the transcripts to be localized exclusively in actively proliferating tissues around axillary apical meristem. In order to ascertain physiological roles, transgenic tobacco plants that had the antisense construct were made and examined for phenotypes. Methylation levels of genomic DNA from transgenic plants significantly decreased in comparison with wild-type levels, and distinct phenotypic changes including small leaves, short internodes and abnormal flower morphology were noted. Microscopic observation revealed that leaf structure differed between transgenic and wild-type plants. These results suggest that NtMET1 functions during DNA replication, and that DNA methylation plays an important role in plant morphogenesis.

Rice gibberellin-insensitive gene homolog, OsGAI, encodes a nuclear-localized protein capable of gene activation at transcriptional level

This paper reports isolation and properties of a rice gene, OsGAI, a putative homolog of the GAI of Arabidopsis thaliana. OsGAI encodes a polypeptide of 625 amino acids, which shows 53-55% identity to GAI and RGA from A. thaliana, and 85% identity to wheat rht-D1a and maize d8. Genomic DNA blot analysis indicated the OsGAI to be a single-copy gene in the rice genome. RNA blot hybridization showed that OsGAI transcripts increased within 6h upon GA(3) but not ABA application. This GA-induced increment in OsGAI transcripts did not require de novo protein synthesis. High levels of OsGAI transcripts were detected in nodes, internodes, leaf sheaths and ears of adult plants and leaf sheaths of young seedlings, where GA enhances cell elongation and division. Transiently expressed OsGAI-GFP fusion protein located to the nucleus in onion epidermal cells. Transactivation assays clearly indicated that OsGAI protein is a transcriptional activator or a coactivator.

Diverse response of rice and maize genes encoding homologs of WPK4, an SNF1-related protein kinase from wheat, to light, nutrients, low temperature and cytokinins

The wheat gene WPK4 encodes a 56-kDa protein kinase that belongs to group 3 of the SNF1-related protein kinase family (SnRK3), and is up-regulated by light and cytokinins and down-regulated by sucrose. In order to determine whether or not this particular regulation pattern is general among plant species, we isolated and characterized homologous genes from rice and maize. Two rice genes, OsPK4 and OsPK7, encode proteins comprising 508 and 520 amino acids, and show, respectively, 75% and 76% sequence similarity to WPK4. OsPK4 and OsPK7 proteins produced in Escherichia coli were able to phosphorylate themselves and myelin basic proteins, the reaction requiring magnesium and/or manganese ions. Transcripts of OsPK4 were detected in all tissues tested, and amounts were increased upon illumination, nutrient deprivation and treatment with cytokinins. In contrast, transcripts of OsPK7 were not found in any tissues except in mature leaves at low levels, and did not accumulate under any of the stress conditions examined. A maize gene, ZmPK4, encodes a protein with 518 amino acids that shows 74% similarity to WPK4. Its transcripts were constitutively expressed in all tissues, regardless of light, nutrient and cytokinin status, but were increased upon exposure to low temperature. These results indicate that, despite the sequence similarity between their products, genes for SnRK3 proteins are differentially regulated in response to environmental stimuli.

Secreted proteins of tobacco cultured BY2 cells: identification of a new member of pathogenesis-related proteins

Cultured cells of tobacco BY2 secrete more than 100 proteins into culture medium. Six major proteins were purified, and partial protein sequences were determined. Five of them were found to be similar to an ascorbic acid oxidase, three peroxidase isozymes and a beta-1,3-exoglucanase, respectively. A cDNA clone encoding the remaining polypeptide, whose amino acid sequence showed no similarity with earlier reported proteins, was isolated. It encoded a putative 27 kDa protein of 242 amino acids with resemblance to WCI-5, a wheat protein induced by benzo(1,2,3)thiadiazole-7-carbothioic acid S-methyl ester (BTH) which activates genes involved in systemic acquired resistance. Transcripts of this clone accumulated upon tobacco mosaic virus infection, mechanical wounding and drought treatment, an induction profile that satisfies the definition of pathogenesis-related (PR) proteins by van Loon et al. (Plant Mol. Biol. Rep. 12 (1994) 245). No similar PR proteins have so far been reported, and therefore our newly designated NtPRp27 points to the existence of a novel PR protein family in tobacco plants.

Rapid systemic accumulation of transcripts encoding a tobacco WRKY transcription factor upon wounding

An immediate-early, transiently activated wound-responsive gene was identified in tobacco by fluorescent differential display screening. The full-length cDNA encodes a polypeptide of 356 amino acids with a relative molecular mass of 39,082 Da. The deduced amino acid sequence shows two characteristic features; a leucine-zipper motif found in the more N-terminal region and a WRKY domain containing a zinc-finger motif located in the central region. The gene was designated as wizz (wound-induced leucine zipper zinc finger). Northern analysis showed that upon wounding wizz transcripts were locally and systemically accumulated within 10 min, reached a maximum level by 30 min, and decreased thereafter to the basal level. Analyses of a WIZZ-GFP fusion protein clearly indicated that WIZZ is a nuclear factor. WIZZ specifically binds to sequences containing two TTGAC core motifs that are separated by a spacer of appropriate length. The binding activity was dependent on bivalent cations, most probably zinc. In transient reporter assays, however, WIZZ did not show transactivation activity in tobacco suspension cells, suggesting that it functions together with other components. The results indicate that WIZZ is a new transcription factor which participates in early stages of the wound response.

Recurrent Hemorrhaging from Stomal Ulcers Following a Side to Side Longitudinal Pancreaticojejunostomy for Chronic Pancreatitis: Report of a Case

Gastrointestinal (GI) hemorrhaging secondary to stomal ulcers following a pancreaticojejunostomy for chronic pancreatitis is a rare postoperative condition that has not hitherto been reported in the literature. A 25-yr-old Japanese female was referred to Ryukyu University Hospital with GI hemorrhaging of unknown origin. She had undergone a modified Puestow procedure (Partington procedure) for chronic pancreatitis with pancreatolithiasis and an associated dilatation of the main pancreatic duct at 19 yr of age. A technetium-99m blood-flow scan demonstrated the pooling of radionuclides in the area of the jejunal loop, which was highly suggestive of bleeding into the jejunum. Over the next day, she demonstrated persistent melena. At exploratory laparotomy, the anastomotic jejunal loop was filled with clotted blood. Operative endoscopy through an incision of the jejunal loop in close proximity to the anastomosis showed oozing blood from the anastomotic jejunal mucosa. Following a resection of the affected anastomotic segment of the jejunum, a side to side longitudinal pancreaticojejunostomy was again performed on this patient. The resected jejunum showed pathologically pseudopolyp-like edema, congestion, and an ulceration of the stomal mucosa. The patient showed a good postoperative course and has been doing well for the past 8 yr since reoperation.

Transgenic plants of coffee Coffea canephora from embryogenic callus via Agrobacterium tumefaciens-mediated transformation

 Embryogenic calli were induced from leaf explants of coffee (Coffea canephora) on McCown's woody plant medium (WPM) supplemented with 5 μM N⁶-(2-isopentenyl)-adenosine (2-iP). These calli were co-cultured with Agrobacterium tumefaciens EHA101 harboring pIG121-Hm, containing β-glucuronidase (GUS), hygromycin phosphotransferase (HPT), and neomycin phosphotransferase II genes. Selection of putative transgenic callus was performed by gradual increase in hygromycin concentration (5, 50, 100 mg/l). The embryogenic calli surviving on medium containing 100 mg/l hygromycin showed a strong GUS-positive reaction with X-Gluc solution. Somatic embryos were formed from these putative transgenic calli and germinated on WPM medium with 5 μM 2-iP. Regenerated small plantlets with shoots and roots were transferred to medium containing both 100 mg/l hygromycin and 100 mg/l kanamycin for final selection of transgenic plants. The selected plantlets exhibited strong GUS activity in leaves and roots as indicated by a deep blue color. GUS and HPT genes were confirmed to be stably integrated into the genome of the coffee plants by the polymerase chain reaction.

Sucrose and Cytokinin Modulation of WPK4, a Gene Encoding a SNF1-Related Protein Kinase from Wheat

WPK4, a gene encoding a putative protein kinase, was initially identified in wheat (Triticum aestivum) and shown to be up-regulated by light, nutrient deprivation, and cytokinins. To confirm that WPK4 has protein kinase activity, the protein was produced in Escherichia coli as a fusion protein with glutathione S-transferase. The purified protein exhibited autophosphorylation activity and phosphorylated both myelin basic protein and a peptide fragment of rice 3-hydroxy-3-methylglutaryl-coenzyme A reductase. Levels of WPK4 transcripts in wheat seedlings were increased and decreased by the removal and addition of sucrose (Suc), respectively, to the culture medium. The introduction of the N-terminal kinase region of WPK4 into the yeast snf1 mutant cells, which cannot utilize Suc as a carbon source, rescued growth in Suc-containing medium. Cytokinins up-regulated the accumulation of WPK4 transcripts, but their effects were cancelled by the addition of Suc. Our results suggest that Suc negatively regulates the signaling pathway in which transcriptional activation of WPK4 is mediated by cytokinins.

Involvement of a MAP kinase, ZmMPK5, in senescence and recovery from low-temperature stress in maize

Four species of protein kinase were identified in senescent maize leaves using a gel assay for kinase activity with myelin basic protein (MBP) as the substrate. Most of these kinases were also found in healthy green leaves that had been exposed to low-temperature stress (5 degrees C) and then returned to 25 degrees C. A 41-kDa protein was activated in senescent leaves, whereas a 45-kDa protein was activated 3 h after up-shift from 5 degrees C to 25 degrees C as well as in senescent leaves. A 39-kDa protein was activated by cold stress. The other two proteins, of 35 kDa and 52 kDa, constitutively phosphorylated MBP during senescence and temperature up-shift. Judging from their molecular masses, cation requirements and substrate specificities, it seemed likely that the 39-kDa, 41-kDa and 45-kDa proteins represented mitogen-activated protein kinases (MAPKs). Subsequently two MAPK cDNAs were isolated from a cDNA library constructed using mRNAs from senescent leaves. Northern analysis showed that the transcript corresponding to one of the cDNAs, designated ZmMPK5, accumulated in healthy leaves 3 h after the up-shift to 25 degrees C as well as in senescent leaves, suggesting that the 45-kDa protein kinase is encoded by ZmMPK5. Western analysis using an antiserum against the C-terminal region of ZmMPK5 showed that the level of the ZmMPK5 protein increased in senescent leaves. These results indicate that a 45-kDa MAPK is involved in the process of senescence and in recovery from low-temperature stress in maize plants.

Results of retrograde transhepatic biliary drainage after a common bile duct exploration for choledocholithiasis

BACKGROUND/AIMS

The purpose of this study is to assess the benefits of retrograde transhepatic biliary drainage (RTBD) and a primary closure after a common bile duct (CBD) exploration for patients with choledocholithiasis.

METHODOLOGY

We analyzed 143 patients with choledocholithiasis who had been managed by RTBD after undergoing a CBD exploration retrospectively over a 12-year period. The main outcome criteria were frequency of occurrence of post-operative complications which needed a relaparotomy and the clinical long-term results. In addition, the radiographic diameter changes of the CBD at the site of the primary closure and liver function tests after RTBD were also evaluated.

RESULTS

The frequency of bile peritonitis in the patients undergoing the RTBD procedure was only 0.7% (1 out of 143 cases). Cholangiography via the RTBD tube revealed no severe stenosis at the site of primary closure. Liver function returned to normal on day 3 after RTBD (p<0.05). Recurrence of common bile duct stones developed in 2 patients in this series during the follow-up (1-12 years).

CONCLUSIONS

RTBD and a primary closure of the CBD after CBD exploration appears to be a clinically safe and effective method for such patients with choledocholithiasis who had undergone a complete stone removal intra-operatively.

Microsatellite instability in double cancers of the esophagus and head and neck

It is generally accepted that patients with squamous cancers of the esophagus are known to have a high risk of concomitant head and neck cancer. However, there have been only a few reports describing microsatellite instability (MSI) in patients with both esophageal squamous cell carcinoma and head and neck cancers. To evaluate the role of genetic instability in carcinogenesis in such patients, we analyzed six microsatellite loci in 21 tumors from 10 patients who had developed primary cancers of both the esophagus and the head and neck. MSI was detected in 6 out of 10 patients. In five patients with double cancer, MSI was observed at the same microsatellite loci in both the esophageal and the head and neck tumors obtained from the same individuals. These data suggest that such patients may have the same underlying defect in the mismatch repair system, providing insight into possible mechanisms for field carcinogenesis.

Vascular reconstruction of the hepatic artery using the gastroepiploic artery: a case report

A 59 year-old woman with obstructive jaundice secondary to proximal bile duct carcinoma underwent percutaneous transhepatic biliary drainage (PTDB). This revealed complete obstruction of the bifurcation of the hilar hepatic duct and encasement of the right hepatic artery. Wedged hilar hepatectomy with combined resection of the extrahepatic bile duct, gallbladder, and the encased right hepatic artery was performed. The hepatic artery was reconstructed using an in situ right gastroepiploic artery (GEA) pedicle graft. The anastomosis was protected with fatty tissue from the greater omentum. This technique can be used to reconstruct the hepatic artery after radical surgery for malignant hepatobiliary and pancreatic disease.

Percutaneous transhepatic cholangioscopic lithotripsy and change of biliary manometry patterns

BACKGROUND/AIMS

Percutaneous transhepatic cholangioscopic lithotripsy (PTCSL) is used to remove bile duct stones. This work aims to evaluate the clinical usefulness of PTCSL and the reversibility of the terminal bile duct dysfunctions after PTCSL.

METHODOLOGY

Thirty patients who underwent PTCSL using mechanical and/or electrohydraulic lithotripsy over the past 10 years (20 patients with common bile duct stones and 10 with intrahepatic bile duct stones) were evaluated. Terminal bile ductal pressure was measured using the percutaneous transhepatic biliary drainage (PTBD) tube prior to and after lithotripsy by means of variable-load cholangiomanometry.

RESULTS

Complete stone extraction was possible in 26 patients (86.7%). The other 4 patients had intrahepatic stones. Complications included 2 cases of hemobilia, one of pneumonia, and 3 of localized peritonitis. Of 26 patients without residual stones, only 4 patients had a linear pressure flow (P-F) pattern which indicates normal biliary tract function prior to lithotripsy. In 17 of 22 patients with other type P-F patterns, however, these types also changed to a linear pattern after complete removal of stones. The P-F pattern of the other 5 patients remained unchanged.

CONCLUSIONS

PTCSL is a safe and efficient method treating biliary tract lesions while preserving the function of the sphincter of Oddi. The terminal biliary tract function normalized after stone removal. Thus, PTCSL was useful for patients with complicated bile duct stones not accessible to endoscopic retrograde management.

Extracorporeal bypass using a centrifugal pump during resection of malignant liver tumors

BACKGROUND/AIMS

Total hepatic vascular exclusion (THVE) during extracorporeal bypass is used for hepatic resection in patients with malignant liver tumors. The aim of this study was to determine the efficacy of hepatectomy during total hepatic vascular exclusion using a centrifugal pump (Bio-pump).

METHODOLOGY

Fourteen patients with malignant liver tumors who underwent hepatectomy during total hepatic vascular exclusion using the Bio-pump were studied retrospectively.

RESULTS

In 3 of 14 patients, insufficient hepatic vascular exclusion was achieved. Six patients underwent tumor resection during total hepatic vascular exclusion, without extracorporeal bypass. In the remaining 5 patients, flow exclusion averaging 1500 ml was achieved with the Bio-pump, and hepatectomy was performed during the procedure. In these 5 patients, the mean operative time and blood loss were 11 hours 38 minutes and 6850 +/- 2451 ml. The Bio-pump bypass time, the excluded blood flow and the mean blood pressure were 82 minutes, 1650 ml and 108/53 mmHg, respectively. The arterial ketone body ratio (AKBR) decreased from a pre-operative value of 1.85-0.32 during total hepatic vascular exclusion.

CONCLUSIONS

Total hepatic vascular exclusion was useful for hepatectomy in patients with tumor invasion into the hepatic vein and inferior vena cava, or tumor thrombus in the inferior vena cava and right atrium. However, this technique did not decrease blood loss or improve outcome in patients undergoing hepatectomy.

Gibberellin-responsive genes: high level of transcript accumulation in leaf sheath meristematic tissue from Zea mays L

In order to identify genes that are related to the gibberellin (GA) response in maize (Zea mays L.), mRNA species from wild-type and single-gene dwarf mutants, d5 and D8, were compared by fluorescent differential display. The d5 mutant is unable to produce biologically active GA, but recovers its tall stature on exogenous application of GA. D8 is insensitive to GA, despite the accumulation of a high level of endogenous GA, suggesting it to be a receptor mutant or a mutant in signal transduction pathway(s). After screening 7000 cDNA populations, one clone was isolated, for which transcripts were rare in d5 shoots but accumulated within 1 h after GA3 application. This clone, designated as ZmGR1a, encodes a polypeptide with a relative molecular mass of ca. 13 kDa, which shows significant homology to proline-rich proteins from several plant species. A similar experiment with D8 identified a clone, ZmGR2a, with low transcript levels, but accumulation within 6 h after GA3 treatment of d5 shoots. ZmGR2a encodes a polypeptide with a relative molecular mass of ca. 19 kDa, which shows no significant homology with any known protein. Southern blot analysis indicated that ZmGR1a and ZmGR2a form a small multigene family within the maize genome. In situ hybridization with wild-type seedlings showed transcripts on both to be abundant in leaf sheath meristematic tissue, in which GA enhances cell elongation and cell division.

Use of Tc-99m DTPA galactosyl human serum albumin to predict postoperative residual liver function

PURPOSE

Residual liver uptake at 15 minutes (RLU15), a new index for predicting residual liver function after excision of hepatocellular carcinoma, was evaluated using dynamic liver images and SPECT by Tc-99m DTPA galactosyl human serum albumin.

MATERIALS AND METHODS

In 13 cases of hepatectomy, RLU15 was compared with postoperative serum prothrombin levels, serum bilirubin levels, and ascites.

RESULTS

RLU15 showed good correlation with both the prothrombin activity and the serum bilirubin, with correlation coefficients of r = 0.829 and r = -0.757.

CONCLUSION

This new index appears useful for predicting residual liver function after hepatectomy.

Common bile duct blood clot: an unusual cause of ductal filling defects for calculi

We report a case of obstructive jaundice caused by a blood clot in the common bile duct in a 75-year-old man with cirrhosis. Five years prior to his admission, he had undergone a left hepatectomy for hepatocellular carcinoma. At the present admission, he appeared icteric, and endoscopic retrograde cholangiography revealed filling defects in the common bile duct. Choledochotomy was therefore performed for possible common duct stones, and exploration of the duct showed blood clot casts filling the duct. The casts were easily removed, and the patient's postoperative course was uneventful. However, he developed ascites and jaundice 1 month later and died of liver failure approximately 3 months after undergoing the choledochotomy. Autopsy revealed hemorrhagic necrosis in the proximal intrahepatic duct of the posterior segment, which was considered to be the cause of the observed hemobilia, as well as the blood clot in the common bile duct at surgery. We report this rare case and discuss the cause of hemobilia.