Group C MAP kinases phosphorylate MBD10 to regulate ABA-induced leaf senescence in Arabidopsis

Abscisic acid (ABA) is a phytohormone that promotes leaf senescence in response to environmental stress. We previously identified methyl CpG-binding domain 10 (MBD10) as a phosphoprotein that becomes differentially phosphorylated after ABA treatment in Arabidopsis. ABA-induced leaf senescence was delayed in mbd10 knockout plants but accelerated in MBD10-overexpressing plants, suggesting that MBD10 positively regulates ABA-induced leaf senescence. ABA-induced phosphorylation of MBD10 occurs in planta on Thr-89, and our results demonstrated that Thr-89 phosphorylation is essential for MBD10's function in leaf senescence. The in vivo phosphorylation of Thr-89 in MBD10 was significantly downregulated in a quadruple mutant of group C MAPKs (mpk1/2/7/14), and group C MAPKs directly phosphorylated MBD10 in vitro. Furthermore, mpk1/2/7/14 showed a similar phenotype as seen in mbd10 for ABA-induced leaf senescence, suggesting that group C MAPKs are the cognate kinases of MBD10 for Thr-89. Because group C MAPKs have been reported to function downstream of SnRK2s, our results indicate that group C MAPKs and MBD10 constitute a regulatory pathway for ABA-induced leaf senescence.

Accumulation of Phosphorylated SnRK2 Substrate 1 Promotes Drought Escape in Arabidopsis

Plants adopt optimal tolerance strategies depending on the intensity and duration of stress. Retaining water is a priority under short-term drought conditions, whereas maintaining growth and reproduction processes takes precedence over survival under conditions of prolonged drought. However, the mechanism underlying changes in the stress response depending on the degree of drought is unclear. Here, we report that SNF1-related protein kinase 2 (SnRK2) substrate 1 (SNS1) is involved in this growth regulation under conditions of drought stress. SNS1 is phosphorylated and stabilized by SnRK2 protein kinases reflecting drought conditions. It contributes to the maintenance of growth and promotion of flowering as drought escape by repressing stress-responsive genes and inducing FLOWERING LOCUS T (FT) expression, respectively. SNS1 interacts with the histone methylation reader proteins MORF-related gene 1 (MRG1) and MRG2, and the SNS1-MRG1/2 module cooperatively regulates abscisic acid response. Taken together, these observations suggest that the phosphorylation and accumulation of SNS1 in plants reflect the intensity and duration of stress and can serve as a molecular scale for maintaining growth and adopting optimal drought tolerance strategies under stress conditions.

Growth Promotion or Osmotic Stress Response: How SNF1-Related Protein Kinase 2 (SnRK2) Kinases Are Activated and Manage Intracellular Signaling in Plants

Reversible phosphorylation is a major mechanism for regulating protein function and controls a wide range of cellular functions including responses to external stimuli. The plant-specific SNF1-related protein kinase 2s (SnRK2s) function as central regulators of plant growth and development, as well as tolerance to multiple abiotic stresses. Although the activity of SnRK2s is tightly regulated in a phytohormone abscisic acid (ABA)-dependent manner, recent investigations have revealed that SnRK2s can be activated by group B Raf-like protein kinases independently of ABA. Furthermore, evidence is accumulating that SnRK2s modulate plant growth through regulation of target of rapamycin (TOR) signaling. Here, we summarize recent advances in knowledge of how SnRK2s mediate plant growth and osmotic stress signaling and discuss future challenges in this research field.

Arabidopsis Raf-like kinases act as positive regulators of subclass III SnRK2 in osmostress signaling

Given their sessile nature, land plants must use various mechanisms to manage dehydration under water-deficit conditions. Osmostress-induced activation of the SNF1-related protein kinase 2 (SnRK2) family elicits physiological responses such as stomatal closure to protect plants during drought conditions. With the plant hormone ABA receptors [PYR (pyrabactin resistance)/PYL (pyrabactin resistance-like)/RCAR (regulatory component of ABA receptors) proteins] and group A protein phosphatases, subclass III SnRK2 also constitutes a core signaling module for ABA, and osmostress triggers ABA accumulation. How SnRK2 is activated through ABA has been clarified, although its activation through osmostress remains unclear. Here, we show that Arabidopsis ABA and abiotic stress-responsive Raf-like kinases (AtARKs) of the B3 clade of the mitogen-activated kinase kinase kinase (MAPKKK) family are crucial in SnRK2-mediated osmostress responses. Disruption of AtARKs in Arabidopsis results in increased water loss from detached leaves because of impaired stomatal closure in response to osmostress. Our findings obtained in vitro and in planta have shown that AtARKs interact physically with SRK2E, a core factor for stomatal closure in response to drought. Furthermore, we show that AtARK phosphorylates S171 and S175 in the activation loop of SRK2E in vitro and that Atark mutants have defects in osmostress-induced subclass III SnRK2 activity. Our findings identify a specific type of B3-MAPKKKs as upstream kinases of subclass III SnRK2 in Arabidopsis. Taken together with earlier reports that ARK is an upstream kinase of SnRK2 in moss, an existing member of a basal land plant lineage, we propose that ARK/SnRK2 module is evolutionarily conserved across 400 million years of land plant evolution for conferring protection against drought.

Sevoflurane suppresses tumour necrosis factor-α-induced inflammatory responses in small airway epithelial cells after anoxia/reoxygenation

BACKGROUND

Lung ischaemia-reperfusion (I/R) injury is correlated with poor clinical outcome. The inflammatory cytokines interleukin (IL)-6, IL-8, and monocyte chemotactic protein-1 (MCP-1) are produced by pulmonary epithelial cells during lung transplantation and are considered to be involved in I/R injury. The volatile anaesthetic sevoflurane has been shown to exert a protective effect on I/R injury in various organs. We investigated the effect of sevoflurane on the inflammatory functions of pulmonary epithelial cells in vitro.

METHODS

Human normal small airway epithelial cells (SAEC) were incubated under anoxic conditions for 24 h with or without sevoflurane and then stimulated with tumour necrosis factor (TNF)-α under hyperoxic conditions for 5 h with or without sevoflurane. After incubation, IL-6, IL-8, and MCP-1 mRNA expression was analysed by quantitative real-time RT-PCR. The production of IL-6, IL-8, and MCP-1 was assayed by enzyme-linked immunosorbent assay, the effects of sevoflurane on inflammatory gene expression were examined by DNA microarray analysis, and the effects of sevoflurane on NF-κB-mediated inflammatory cytokine production were examined by immunoblotting.

RESULTS

Sevoflurane suppressed TNF-α-induced IL-6, IL-8, and MCP-1 gene expression and the production of IL-6 and IL-8 in SAEC under anoxia/reoxygenation conditions. DNA microarray analysis indicated that sevoflurane modulated NF-κB-related gene expression. Sevoflurane significantly inhibited TNF-α-induced translocation of p65 NF-κB into the nucleus. Sevoflurane enhanced TNF-α-induced gene expression of inhibitor κB (IκB) but not of NF-κB.

CONCLUSIONS

Sevoflurane suppressed the NF-κB-mediated production of pulmonary epithelial cell-derived inflammatory cytokines, including IL-6 and IL-8, which are capable of causing I/R injury.

Usefulness of TC-99M GSA liver scintigraphy for the assessment of recurrent hepatitis C after living-donor liver transplantation: a case report

BACKGROUND AND AIMS

Recurrence of hepatitis C after living-donor liver transplantation was investigated using technetium-99m-diethylenetriaminepentaacetic acid-galactosyl human serum albumin (Tc-99m-GSA) liver scintigraphy.

METHODS

A 55-year-old woman with cirrhosis due to chronic hepatitis C virus (HCV) infection underwent liver transplantation with a graft from her husband. Scintigraphy was used to determine the hepatic uptake ratio of the tracer corrected for disappearance from the blood, as well as the maximal removal rate of the tracer by hepatocytes, as parameters of hepatic functional reserve.

RESULTS

Conventional liver function parameters and the graft volume (computed tomography) were almost unchanged up to 18 months after transplantation. Serum HCV RNA was elevated from 3 months after transplantation, and was twofold higher at 12 months compared with 6 months. At 18 months postoperatively, liver biopsy showed an increase of histologic activity, and there was also evidence of recurrent hepatitis C. The corrected hepatic uptake ratio and maximal removal rate were decreased at 3 months postoperatively, and thereafter remained low.

CONCLUSIONS

The decrease of scintigraphic parameters at 3 months after transplantation suggested recurrent hepatitis C affecting the graft. Tc-99m-GSA liver scintigraphy is a useful noninvasive method for evaluating graft functional reserve.

Correlation between colonic motility and defecatory disorders after anterior resection of the rectum in canine models

The objective of this study was to describe the correlation between changes in colonic motility and defecatory disorders in four experimental canine models, with an emphasis on denervation. Therefore, we constructed a model by dividing 20 healthy mongrel dogs into four groups, i.e. control, denervation, transection and anterior resection of the rectum (AR) (denervation plus transection), and focused on the correlation between colonic motility and defecatory disorders by counting the colonic migrating motor complexes (CMMCs) and colonic non-migrating motor complexes (CNMCs). Gastrointestinal and colonic contractile activities were continuously recorded on a computer with strain gauge force transducers. The dogs' feces were checked daily, and their consistency was recorded as normal, semisolid, or watery. Compared with the control group, the transection group showed elongation of the propagation time (P < 0.05), and the mean motility index of colonic contractile activity at C4 and C5 in the denervation group was greater than that in the control group (P < 0.05). The AR group showed three features of colonic motility: (i) elongation of the mean CMMC cycle (P < 0.05); (ii) shortening of the propagation time (P < 0.05); and (iii) increment of the number of CNMCs. Concerning fecal consistency, the AR group only showed watery diarrhoea. In conclusion, we revealed the existence of a correlation between defecatory disorders and changes in colonic motility. Increased knowledge among colorectal surgeons of the changes in colonic motility that occur following colorectal surgery is very important and could lead to the curtailment of defecatory disorders among patients.

Prevention of graft-versus-host disease by intrabone marrow injection of donor T cells: involvement of bone marrow stromal cells

We have developed a new and effective method for bone marrow transplantation (BMT): bone marrow cells (BMCs) are injected directly into the bone marrow (BM) cavity of recipient mice. The intrabone marrow injection of BMCs (IBM-BMT) greatly facilitates the engraftment of donor-derived cells, and IBM-BMT can attenuate graft-versus-host reaction (GVHR), in contrast to conventional intravenous BMT (i.v.-BMT). Here, we examine the mechanisms underlying the inhibitory effects of IBM-BMT on GVHR using animal models where GVHR is elicited. Recipient mice (C57BL/6) were irradiated and splenic T cells (as donor lymphocyte infusion: DLI) from major histocompatibility complex-disparate donors (BALB/c) were injected directly into the BM cavity (IBM-DLI) or injected intravenously (i.v.-DLI) along with IBM-BMT. The BM stromal cells (BMSCs) from these recipients were collected and related cytokines were examined. The recipient mice that had been treated with IBM-BMT + i.v.-DLI showed severe graft-versus-host disease (GVHD), in contrast to those treated with IBM-BMT + IBM-DLI. The suppressive activity of BMSCs in this GVHD model was determined. The cultured BMSCs from the recipients treated with IBM-BMT + IBM-DLI suppressed the proliferation of responder T cells remarkably when compared with those from the recipients of IBM-BMT + i.v.-DLI in mixed leucocyte reaction. Furthermore, the level of transforming growth factor-beta and hepatocyte growth factor in cultured BMSCs from IBM-BMT + IBM-DLI increased significantly when compared with those from the recipients of IBM-BMT + i.v.-DLI. Thus, the prevention of GVHD observed in the recipients of IBM-BMT + IBM-DLI was attributable to the increased production of immunosuppressive cytokines from BMSCs after interaction with host reactive T cells (in DLI).

Prognostic value of preoperative serum tumor markers, including CEA, Cyfra21–1, SCC, CA19–9, SCC, CA125, TPA, NSE, and SLX, in patients with completely resected pathological stage I non-small cell lung cancer

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Background: Recent randomized control trials have shown a survival benefit of adjuvant chemotherapy in patients with stage II or more advanced NSCLC, while surgery alone is still the standard therapy for stage I patients. There is, however, a subgroup of patients among the stage I patients who have a poor prognosis, for whom adjuvant chemotherapy can be as effective as has been observed for the patients with more advanced disease. Preoperative serum CEA level has been reported to be an independent prognostic factor for stage I NSCLC. However, many other tumor markers have also been reported as prognostic indicators in different studies using different tumor markers. It is unknown which tumor marker is the most effective for selecting poor prognostic subgroup of patients with stage I NSCLC for which adjuvant chemotherapy can be applied. Methods: A total of 355 patients underwent complete resection, and were diagnosed as having stage I NSCLC from 1995 to 2003. Analyzed tumor markers included CEA, Cyfra21–1, SCC, CA19–9, SCC, CA125, TPA, NSE, and SLX. Cut-off values for each tumor marker are listed in the table . Clinicopathologic factors including age, gender, histology, vessel invasion, pleural invasion, and pathologic T indicator are also analyzed in the multivariate analysis. Results: Among the 355 patients, 211 patients were male, 249 had adenocarcinoma, 82 had squamous cell carcinoma, and 253 had pathologic T1 tumors. Percentages of elevated value for each tumor marker are listed in the table in combination with related survival data. Cox proportional hazard model demonstrated age, pleural invasion, histology, and CEA were significantly independent prognostic factors. Conclusions: CEA is thought to be the best tumor marker for selecting the poor prognostic subgroup of patients with resected stage I NSCLC because of its high percentage of abnormal value and high ability to differentiate prognostic subgroups.

No significant financial relationships to disclose.

[Table: see text]

The peptide hormone xenin induces gallbladder contractions in conscious dogs

Xenin is a 25-amino acid peptide isolated from human gastric mucosa. The biological activities of xenin include modulating intestinal motility and affecting exocrine pancreatic secretion and gastric acid secretion. The physiological effect of xenin on the gastrointestinal tract, however, is incomplete. The objective of this study is to investigate the effects of xenin on the gastrointestinal tract motility of conscious dogs. Gastrointestinal tract and gallbladder contractions were monitored by chronically implanted force transducers. Synthetic xenin was injected intravenously during the interdigestive state with or without pretreatment with cholinergic blockers. The effects of xenin following cholecystectomy and truncal vagotomy were also investigated. Xenin induced gallbladder and jejunal contractions, although a dose-dependent response was shown only with gallbladder contractions. These effects were inhibited by pretreatment with cholinergic blockers, but were not enhanced by truncal vagotomy. The jejunal contractions were completely inhibited by cholecystectomy. The only direct effect of xenin in terms of gastrointestinal motility was to induce gallbladder contractions in conscious dogs. The neural pathway mediating xenin's action was cholinergic, but not the vagal. This novel finding indicates a new role of xenin.

Phase I/II study of S-1 combined with paclitaxel in patients with unresectable and/or recurrent advanced gastric cancer

Both paclitaxel and S-1 are effective against gastric cancer, but the optimal regimen for combined chemotherapy with these drugs remains unclear. This phase I/II study was designed to determine the maximum tolerated dose (MTD), recommended dose (RD), dose-limiting toxicity (DLT), and objective response rate of paclitaxel in combination with S-1. S-1 was administered orally at a fixed dose of 80 mg m-2 day-1 from days 1 to 14 of a 28-day cycle. Paclitaxel was given intravenously on days 1, 8, and 15, starting with a dose of 40 mg m-2 day-1. The dose was increased in a stepwise manner to 70 mg m-2. Treatment was repeated every 4 weeks unless disease progression was confirmed. In the phase I portion, 17 patients were enrolled. The MTD of paclitaxel was estimated to be 70 mg m-2 because 40% of the patients given this dose level (two of five) had DLT. The RD was determined to be 60 mg m-2. In the phase II portion, 24 patients, including five with assessable disease who received the RD in the phase I portion, were evaluated. The median number of treatment courses was six (range: 1-17). The incidence of the worst-grade toxicity in patients given the RD was 28 and 8%, respectively. All toxic effects were manageable. The response rate was 54.1%, and the median survival time was 15.5 months. Our phase I/II trial showed that S-1 combined with paclitaxel is effective and well tolerated in patients with advanced gastric cancer.

Synergistic effects of injection of bone marrow cells into both portal vein and bone marrow on tolerance induction in transplantation of allogeneic pancreatic islets

We have established a new method for allogeneic pancreatic islet (PI) transplantation: relatively low doses of irradiation followed by simultaneous transplantation of PIs and bone marrow cells (BMCs) via the portal vein (PV). In the present study, we have compared this method with intra-bone marrow (IBM)-bone marrow transplantation (BMT), and with a combination of both methods. Streptozotocin (STZ)-induced diabetic-recipient rats, Fischer 344 (F344, RT1A(l), RT1B(l)), were irradiated 1 day before transplantation. PIs of Brown Norway rats (BN, RT1A(n), RT1B(n)) were transplanted into the liver of the diabetic F344 rats via the PV. BMCs from BN rats were injected into the recipients' bone marrow (IBM), PV or intravenously (IV) or by a simultaneous combination of PV plus IBM (PV+IBM). We compared graft survival among the groups of '9 Gy+IBM'(10/10 accepted), '9 Gy+PV'(7/10 accepted), '9 Gy+IV'(0/7 accepted), '9 Gy+PV+IBM'(8/8 accepted), '8.5 Gy+IBM'(4/9 accepted), '8.5 Gy+PV'(0/7 accepted), '8.5 Gy+IV'(0/7 accepted), '8.5 Gy+PV+IBM'(9/12 accepted), '8 Gy+IBM'(2/10 accepted) and '8 Gy+PV+IBM'(2/8 accepted). As we reported previously, PV-BMT is more effective in inducing the acceptance of allogeneic PIs than IV-BMT. However, IBM-BMT requires less pretreatment than PV-BMT. (PV+IBM)-BMT was found to be the most effective in inducing the acceptance of allogeneic PIs. These results suggest that allogeneic PI-transplantation in conjunction with (PV+IBM)-BMT could become a viable strategy.

Long-term outcome of adult-to-adult living donor liver transplantation for post-Kasai biliary atresia

Our objective was to analyze problems in the perioperative management and long-term outcome of living donor liver transplantation (LDLT) for biliary atresia (BA). Many reports have described the effectiveness of liver transplantation (LT) for BA, particularly in pediatric cases, but little information is available regarding LT in adults (> or =16 years old). Between June 1990 and December 2004, 464 patients with BA underwent LDLT at Kyoto University Hospital, of whom 47 (10.1%) were older than 16 years. In this study, we compared the outcomes between adult (> or =16 years old) and pediatric (<16 years old) patients. The incidence of post-transplant intestinal perforation, intra-abdominal bleeding necessitating repeat laparotomy and biliary leakage was significantly higher (p < 0.0001, <0.001 and <0.001, respectively) in adults. Overall cumulative 1-, 5- and 10-year survival rates in pediatric patients were significantly higher (p < 0.005) than in adults. Two independent prognostic determinants of survival were identified: a MELD score over 20 and post-transplant complications requiring repeat laparotomy. Outcome of LDLT in adult BA patients was poorer than in pediatric patients. It seems likely that LT will be the radical treatment of choice for BA and that LDLT should be considered proactively at the earliest possible stage.

Phase II study of weekly chemotherapy with paclitaxel and gemcitabine as second-line treatment for advanced non-small cell lung cancer

17096

Background: Second-line chemotherapy has become almost routine in non-small cell lung cancer (NSCLC) patients (pts) with good performance status (PS). The availability of the new pharmacological agents opens up new possibilities for their use in pts who have retained a good PS following relapse or progression after first-line chemotherapy. Paclitaxel (PTX) and Gemcitabine (GEM) are among the most active new agents in NSCLC and are worth considering for second-line chemotherapy. In phase II study, we evaluated the tolerability and activity of the combination of weekly PTX and GEM in second-line treatment of NSCLC. Methods: PTX (100mg/m2) and GEM (1000 mg/m2) were administered on days 1 and 8 at every 3–4 weeks. A total of 40 pts (M/F, 27/13 pts; median age 59.3 years [33–75]; PS 0/1/2, 7/27/6 pts) were enrolled between October 2000 and July 2003. Results: The number of cycles conducted was 1 in 5 pts, 2 in 8 pts, 3 in 10 pts, and 4 in 17 pts (mean: 4). The final efficacy was PR in 13, NC in 26 and PD in 1 for a response rate of 32.5 % (95% CI: 18.0–47.0%). The median survival time was 41.7 weeks (95% CI: 28.5–54.7 weeks). The median time to progressive disease was 19 weeks. Hematologic toxicities observed included Grade 3 or 4 neutropenia in 60%, Grade 3 or 4 anemia in 20%, and Grade 3 or 4 thrombocytepenia in 10%. Non-hematologic toxicities were mild except Grade 3 diarrhea in 3 pts and Grade 3 pneumonitis in 2 pts. There were no toxic deaths. Conclusions: The combination of weekly PTX and GEM is a feasible, well-tolerated, and active scheme for second-line treatment of advanced NSCLC.

No significant financial relationships to disclose.

Immunological evaluation of personalized peptide vaccination with gemcitabine for advance pancreatic cancer patients

14029

Background: A phase I clinical study was performed to determine safety and immunogenicity of personalized peptide vaccination with gemcitabine (GEM) in advanced pancreatic cancer patients (APC). Methods: Thirteen human histocompatibility leukocyte antigen (HLA)-A24+ or A2+ patients with unresectable (n=10) or recurrent (n=3) pancreatic cancer were treated with GEM plus up to four peptides that were positive for pre-vaccination measurement of peptide-specific IgG antibodies and/or cytotoxic T lymphocyte (CTL) precursors in the circulation (personalized peptide vaccine). GEM was administered at 1000mg/m2 as a 30-min intravenous infusion once a week for three week, followed by 1 week of rest. All patients were treated on outpatient basis. The cycle was repeated every 8 weeks. Results: Peptide doses of vaccination per week were planned as follows: level 1, 1mg; level 2, 2mg; and level 3, 3mg. The main grade 3 toxicities observed during the first cycle in each level were neutropenia (15%), anemia (23%) and thrombocytopenia (15%). No significant differences in the toxicities were found between each level. There was no dose limiting toxicity (DLT) observed in each level. Augmentation of peptide-specific CTL responses in the post-vaccination peripheral blood mononuclear cells was observed in each level, while increased titer of peptide-specific IgG antibodies was observed in the post-vaccination plasma in level 2 and level 3. Applicable responses were no complete response, two partial responses (15%), and 7 stable diseases (55%). Nevertheless 7 patients of them (54%) were under the second-line chemotherapy, disease control rate was 70%, the median TTP (time to progression) was 18.5 weeks and the MST (median survival time) was 7.6 months in this study. Conclusions: The combination therapy of personalized peptide vaccination with GEM for APC patients is feasible and safe. Because of positive immune responses under a full dose of GEM, the peptide vaccination of 3 mg is recommended.

No significant financial relationships to disclose.

Circulating dendritic cell as a new prognostic factor in pancreatic cancer patients

4095

Background: Pancreatic cancer is a cancer with very poor prognosis that might be associated with impaired immune defense. Dendritic cells (DC) are important for immune surveillance and play a central role in protection against infection and malignancy. A defective host antitumor immune response may allow tumor cells to escape from the host immune system. The aim of this study is to determine whether circulating DC could be one of new immunological markers that may predict the prognosis of the pancreatic cancer. Methods: We evaluated pretreatment circulating myeloid-lineage DC (C-DC1) rate in the peripheral blood mononuclear cell and various clinical parameters to determine their prognostic value in 104 pancreatic cancer patients (41 resected and 63 unresected patients) seen at our institution. Results: In unresected patients, univariate analysis demonstrated two risk factors for prognosis of albmin < 3.8g/dl (p = 0.0468), and C-DC1 < 0.27% (p = 0.0006), when all patients were divided by the median value of C-DC1 rate. Consequently, multivariate analysis demonstrated that only C-DC1 was a predominant independent predictor of survival (Hazard ratio; 9.330, 95% Confidential interval; 2.595–33.549, p = 0.0006). In resected patients, C-DC1 in patients with advanced disease (Stages 2b-4, n=28) was significantly lower than that in patients with lower staged cancer (Stage 1–2a, n = 13: 0.43 ± 0.67%, Stage 2b-4: 0.24 ± 0.30%, p < 0.05). The overall survival rates in patients with C-DC1 ≥ 0.27% were significantly longer than those in patients with C-DC1 < 0.27 (C-DC1 ≥ 0.27%, n = 20, 1/3 year survival: 100%/64%. C-DC1 < 0.27, n = 21, 1/3 year survival: 68%/26%. P < 0.05). Conclusions: The C-DC1 less than 0.27% could be one of prognostic factors in patients with pancreatic cancer, and such patients could be targets for the future therapeutic trials.

No significant financial relationships to disclose.

Ghrelin does not stimulate gastrointestinal motility and gastric emptying: an experimental study of conscious dogs

Ghrelin is a peptide that was discovered in endocrine cells of the stomach. However, its action in regulating the fasted and fed motor activity of the digestive tract is not fully understood. In the present study, we examined the effects of an intravenous (i.v.) injection of canine ghrelin on the physiological fasted and fed motor activities in the stomach, duodenum, jejunum and colon of freely moving conscious dogs. An i.v. injection of canine ghrelin released growth hormone in a dose-dependent manner; however, it did not stimulate the motor activity of the digestive tract in either the fasted or the fed state. Moreover, an i.v. injection of high-dose canine ghrelin significantly reduced the motility index in the gastric body in the fasted state. Ghrelin did not accelerate gastric emptying, either. These results differ from previous reports dealing with rodents. It is significant that such results were obtained in research with dogs, which are larger animals.

Induction of inducible nitric oxide synthase in hepatocytes isolated from rats with ischemia-reperfusion injury

BACKGROUND

Recent evidence indicates that nitric oxide (NO) has a crucial role in hepatic ischemia-reperfusion (I/R) injury. However, little is known about how I/R influences the gene expression of inducible nitric oxide synthase (iNOS) in hepatocytes. Under inflammatory conditions, we compared the induction of iNOS in hepatocytes isolated from normal and I/R-treated rats.

METHODS

Hepatocytes were isolated using the collagenase perfusion method from rats treated with I/R (30-minute ischemia of middle and left lobes, followed by 3-hour reperfusion) or sham operation (control): Primary cultures of rat hepatocytes were incubated with an inflammatory cytokine, interleukin-1beta (IL-1beta), to compare the iNOS induction/NO production between the 2 groups.

RESULTS

Both control and I/R groups had no production of nitrite (a stable metabolite of NO) in the absence of IL-1beta. In the control group, IL-1beta stimulated dose- and time-dependent production of NO. The I/R group showed more than 2-fold increased levels of NO production. Western and Northern blot analyses revealed that the I/R group also showed increased levels of iNOS protein and its messenger RNA.

CONCLUSION

These results suggest that I/R directly affects the inducibility of the iNOS gene in hepatocytes by IL-1beta. Increased NO may be associated with protective or toxic effects in hepatic I/R injury.

Effects of pirfenidone on endotoxin-induced liver injury after partial hepatectomy in rats

BACKGROUND

In living donor liver transplantation, restrictions on graft size are a serious obstacle to expand indications for adult recipients. The sequence of gram-negative infection, septicemia, and multiple-organ failure is a common cause of early mortality after liver transplantation. An effective therapy has not been established for endotoxemia following extended hepatectomy in donors or small-for-size grafts in recipients. Pirfenidone (PFD), a new experimental antifibrotic agent, was used to ameliorate on endotoxin-induced liver injury following partial hepatectomy.

METHODS

Male Sprague-Dawley rats were intravenously administered lipopolysaccharide (LPS) 48 hours after 70% hepatectomy. Prior to LPS administration, PFD (300 mg/kg) or its vehicle (0.5% carboxymethylcellulose) was given orally twice.

RESULTS

The survival rate of the PFD-treated group was markedly improved compared with that of the controls. PFD prevented the increases in the activities of serum enzymes (aspartate transaminase [AST], alanine transaminase [ALT], and lactate dehydrogenase [LDH]) and total bilirubin. The serum and liver tissue levels of inflammatory cytokines, such as tumor necrosis factor-alpha, interleukin-1beta, interferon-gamma, and interleukin-6, were significantly lower among the PFD than the control group. Furthermore, the degree of necrosis in the remnant liver was significantly decreased in the PFD-treated rats compared with controls.

CONCLUSION

These results indicate that PFD alleviates endotoxin-induced liver injury after partial hepatectomy through the inhibition of production of inflammatory cytokines in the residual liver. PFD may be useful to prevent endotoxin-induced liver injury after hepatectomy.

Duodenogastric reflux following biliary reconstruction after excision of choledochal cyst

Duodenogastric reflux (DGR) was assessed in patients surgically treated for choledochal cyst, with emphasis on two different biliary reconstruction methods: Roux-en-Y hepaticojejunostomy (HJ) and hepaticoduodenostomy (HD). Gastric bile monitoring with the Bilitec device revealed excessive DGR in patients in the HD group. Endoscopic findings demonstrated mild to moderate gastric mucosal erosion in patients after HD. In contrast, neither DGR nor gastritis was found in patients after HJ. This preliminary study suggests that HJ, rather than HD, should be recommended as a method of biliary reconstruction for pediatric patients with choledochal cyst. Careful observation of DGR should be continued in patients who have undergone HD.

[An adult congenital bronchoesophageal fistula with massive hemoptysis; report of a case]

A 67-year-old female was referred to our hospital because of bronchoesophageal fistula detected by upper gastro-intestinal series for cancer screening. The patient has had a history of coughing on liquid ingestion since childhood and she has been hospitalized 4 times for treatment of pneumonia during the past 20 years. While waiting the treatment, she was emergently admitted to the hospital because of massive hemoptysis. Transcatheter embolization of feeding arteries including the right inferior phrenic artery successfully controlled her hemoptysis. After reembolization of the feeding arteries for preventing massive hemorrhage during operation, posterolateral thoracotomy was performed. Surgical findings disclosed the bronchoesophageal fistula without inflammatory changes. She underwent fistulectomy combined resection of the middle and lower lobes which were destroyed by the repeated pneumonia. This case was considered type I congenital bronchoesophageal fistula according to Braimbridge and Keith classification because of the presence of diverticular projection which connected to the bronchus. Early diagnosis and rapid treatment are thought to be important for treating this disease.

Effect of hepatocyte growth factor on induction of cytokine-induced neutrophil chemoattractant in rat hepatocytes

BACKGROUND

Restrictions on graft size are a serious obstacle to the expansion of indications for adult recipients in living donor liver transplantation. Hepatocyte growth factor (HGF) has a crucial role in regeneration following hepatic injury. Rat cytokine-induced neutrophil chemoattractant (CINC), a member of the interleukin-8 superfamily in humans, has been implicated in chronic liver diseases or development of liver ischemia-reperfusion injury. Studies were performed to examine whether HGF influences the induction of CINC in hepatocytes.

METHODS

Primary cultures of rat hepatocytes were treated with or without recombinant human (rh) HGF. The release of CINC into the culture medium and levels of CINC mRNA were measured using an enzyme-linked immunosorbent assay and Northern blot analysis. Transcription of nuclear factor (NF)-kappa B was detected by electrophoretic mobility shift assays.

RESULTS

rhHGF increased the release of CINC in the medium dose- and time-dependently, showing a maximal effect at 100 ng/mL. Genistein (100 mumol/L) blocked the release of CINC stimulated by rhHGF. Levels of CINC mRNA were also increased, reaching a maximum at 8 hours after addition of rhHGF. Electrophoretic mobility shift assays revealed rhHGF activated transcription factor, NF-kappa B.

CONCLUSION

These results suggest that HGF stimulates the induction of CINC gene expression through activation of NF-kappa B. CINC may be involved in the function of HGF during liver regeneration.

Safety of hepatectomy for living donors as evaluated using asialoscintigraphy

In the living donor operation, accurate estimation of hepatic functional reserve is essential. Technetium-99m-galactosyl-human serum albumin (GSA) is a liver scintigraphy agent that binds to asialoglycoprotein receptors. We evaluated the preoperative assessment of the safety of an elective hepatectomy using GSA liver scintigraphy in 152 patients. GSA scintigraphy was performed after intravenous injection of GSA. The maximal removal rate of GSA (GSA-Rmax) was calculated using a radiopharmacokinetic model. We determined the areas for resection preoperatively depending on the operative procedures and calculated the local GSA-Rmax in the predicted residual liver (GSA-RL). A significant correlation was obtained between the GSA-Rmax and the 15-minute retention rate of indocyanine green. With sub- and monosegmentectomy, 2 patients had postoperative hepatic failure; in those 2 patients, the GSA-RL was 0.127 and 0.133, respectively, but these patients recovered well. Among those having di- and tri-segmentectomy, 5 patients experienced postoperative hepatic failure, in all subjects the GSA-RL was <0.15. Two patients died of postoperative liver failure 1 to 2 months after the operation. We concluded that GSA-RL is useful to select the procedure for hepatectomy in living donors and that GSA-RL should be >0.15 (mg/min/50 kg body weight) to avoid postoperative hepatic failure.

Functional hepatic regeneration following hepatectomy using galactosyl-human serum albumin liver scintigraphy

In extended hepatectomy and liver transplantation, accurate estimation of functional hepatic regeneration is more important than volumetric regeneration. We investigated the usefulness of measuring the functional hepatic volume by 99m-technetium galactosyl-human serum albumin scintigraphy (GSA). Extended hepatectomy was performed in 32 patients. These patients were divided into subgroups with or without chronic hepatitis or cirrhosis. Functional hepatic volume GSA scintigraphy (GSA-LV) and determination of hepatic volume by CT (CT-LV) measurements were performed preoperatively, at 2 and 4 weeks and at 3 and 6 months after surgery. The preoperative GSA-LV values were significantly correlated with the hepatocyte volume and the 15-minute retention rate of indocyanine green (ICGR15). Similarly, the hepatocyte volume correlated well with the CT-LV and ICGR15. However, the CT-LV correlated only with the ICGR15. Recovery of the GSA-LV was delayed, and about 90% of the volumetric and functional regeneration was observed within 6 months after the hepatectomy. In contrast, the CT-LV in patients with normal liver remnants returned to approximately 90% of the initial volume within 1 month after the hepatectomy, whereas patients with injured livers regeneration showed gradual recovery to approximately 80% of the preoperative value by 6 months after hepatectomy. We conclude that measurement of functional hepatic volume using the GSA-LV is useful to evaluate hepatic function based on hepatocyte volume.

Fibronectin suppresses apoptosis and protects mice from endotoxic shock

Multiple-organ failure related to septicemia is a common cause of early mortality after liver transplantation. Endotoxemia following living donor hepatectomy may be a cause of postoperative death. Plasma fibronectin (Fn) exerts a broad range of biological effects on cellular adhesion, motility, differentiation, apoptosis, hemostasis, wound healing, reticuloendothelial system function, and ischemic injury. We studied the therapeutic effect of plasma Fn in mice after an intraperitoneal injection of lipopolysaccharide (LPS) and d-galactosamine (GalN). Female Balb/c mice received simultaneous intraperitoneal injection of LPS (50 microg/kg) and GalN (400 mg/kg). Thirty minutes prior to GalN/LPS administration, plasma Fn or bovine serum albumin was given intravenously. A single administration of plasma Fn (500 mg/kg) protected in dose-dependent fashion against lethal shock after GalN/LPS challenge. Plasma Fn significantly reduced the serum tumor necrosis factor-alpha, interferon-gamma, and interleukin-6 levels and significantly increased the serum interleukin-10 levels after GalN/LPS administration. Furthermore, plasma Fn significantly inhibited liver necrosis at 9 hours after GalN/LPS injection. The fraction of apoptotic-positive cells in these plasma Fn-treated mice was significantly lower than in the control group. These results support the protective treatment of endotoxin-induced liver injury by plasma Fn.

Pirfenidone protects endotoxin-induced liver injury after hepatic ischemia in rats

BACKGROUND

Pirfenidone (PFD), an experimental antifibrotic agent, was investigated for its effects on endotoxin-induced liver injury after hepatic ischemia-reperfusion.

METHODS

Male Sprague-Dawley rats were subjected to 30 minutes of partial hepatic ischemia, followed by reperfusion for 24 hours. Lipopolysaccharide (LPS) was injected at 30 minutes of reperfusion. PFD (300 mg/kg) or its vehicle (0.5% carboxymethylcellulose) was given orally following LPS administration.

RESULTS

PFD prevented the increase in activities of serum alanine transaminase, aspartate transaminase, and lactate dehydrogenase after reperfusion. PFD inhibited the increase of cytokine-induced neutrophil chemoattractant in serum and liver tissue. The number of neutrophils infiltrating the liver was significantly lower in the PFD-treated group than the control group.

CONCLUSION

These results indicate that PFD prevents endotoxin-induced liver injury after hepatic ischemia-reperfusion, in part through the decrease of neutrophil infiltration to the liver.

Effect of pirfenidone on induction of chemokines in rat hepatocytes

BACKGROUND

Hepatic ischemia-reperfusion results in a neutrophil-dependent liver injury. The process of neutrophil recruitment and activation in this injury is at least partially dependent on the induction of chemokines, such as cytokine-induced neutrophil chemoattractant (CINC) and macrophage inflammatory protein-2 (MIP-2) in rats. In the liver, parenchymal cells (hepatocytes), in addition to nonparenchymal cells such as Kupffer cells, have been reported to produce chemokines in the regulation of hepatic inflammation. Pirfenidone (PFD) is a new experimental drug used as an antifibrotic agent. Studies were performed to determine whether PFD influences the production of CINC and MIP-2 stimulated by interleukin (IL)-1beta in a primary culture model of rat hepatocytes.

METHODS

Primary cultures of rat hepatocytes were treated with IL-1beta in the presence and absence of PFD. The protein and mRNA of CINC and MIP-2 were analyzed using enzyme-linked immunosorbent assays and Northern blots.

RESULTS

IL-1beta increased the release of CINC and MIP-2 into culture media in a dose- and time-dependent manner. PFD inhibited both CINC and MIP-2 release in dose-dependent fashion. However, PFD had no effect on the levels of CINC mRNA induced by IL-1beta.

CONCLUSION

These results suggest that PFD inhibits the production of CINC and MIP-2 by IL-1beta at a posttranscriptional step in hepatocytes.

Clinicopathologic evaluation after resection for ductal adenocarcinoma of the pancreas: a retrospective, single-institution experience

INTRODUCTION

Between April 1992 and December 2000, 167 patients with pancreatic carcinoma were evaluated and treated in our department. One hundred eight patients (64.7%) with pancreatic carcinoma underwent pancreatectomy. Of these patients, 94 had histologically proven ductal adenocarcinoma. The overall postoperative mortality rate was 3.2% (3 patients), and the morbidity rate was 35.1% (33 patients). The estimated 1-, 2-, 3-, and 5-year survival rates were 43.6%, 28.7%, 21.8%, and 12.9%, respectively. There were only six long-term survivors who survived >5 years after surgery. METHODOLOGY AND AIMS: Institutional experience with 94 consecutive patients with ductal adenocarcinoma who underwent pancreatectomy was reviewed to clarify the influence of 29 prognostic factors (5 host, 17 tumor, and 7 treatment factors). Special reference was made to determine whether these significant factors have an effect on long-term survival. Univariate and multivariate models were used to analyze the effect of prognostic factors on survival.

RESULTS

Univariate analysis indicated that blood loss, operative time, postoperative complications, histopathologic lymphatic and venous permeation, lymph node metastasis, conclusive stage, conclusive curability, resection margins, serosal invasion, size of tumor, retroperitoneal invasion, major arterial invasion, and mode of histologic infiltration were associated with significantly longer survival (p < 0.05). By Cox proportional hazards survival analysis, the most powerful predictors of outcome were venous permeation, lymph node metastasis, tumor diameter, and conclusive curability. The longest-term survivor had the most advanced stage (stage IV(b)) of disease and curability C. No long-term survivors had all of the good prognostic factors (according to multivariate analysis).

CONCLUSIONS

The prognosis after surgical resection of pancreatic carcinoma mostly depends on tumor factors. In this study, it was difficult to identify the determinants of long-term survival in patients with resectable tumors.

Prevention of pleural effusion following hepatectomy using argon beam coagulation

BACKGROUND

Postoperative pleural effusion occurs frequently after hepatectomy. The value of the argon beam coagulator (ABC) for the prevention of pleural effusion after hepatectomy in patients with hepatocellular carcinoma was studied.

METHODS

Sixty patients were divided randomly into two groups: an ABC group (n = 28), in which the cut surface of the hepatic ligaments and bare area of the retroperitoneum were cauterized using an ABC, and a control group (n = 32) in which the ABC was not applied. Patient characteristics, preoperative and postoperative liver function, and postoperative pleural effusion were compared between the two groups.

RESULTS

There were no significant differences between the two groups with respect to histological findings, clinical stage, type of resection, operative data, and preoperative and postoperative laboratory data. One of 28 patients in the ABC group and nine of 32 patients in the control group had pleural effusion. The incidence was significantly lower in the ABC group than in the control group (P = 0.01). Pleurocentesis was needed in two of the ten patients and thoracic drainage in four patients.

CONCLUSION

Application of an ABC to the cut surface of the hepatic ligaments and bare area of retroperitoneum after liver mobilization may prevent postoperative pleural effusion.