Head injuries caused by contact with teeth during sports and exercise activities in Japanese schools during the period 2012-2018.

BACKGROUND/AIM: During sports activities, teeth-related contact can cause injury to both ally and opponent players, which can lead to potential infections and aesthetic problems. However, the extent of such injuries remains unclear. This study aimed to clarify the frequency and situation of head injuries caused by teeth (HICBT) occurring under the supervision of schools in Japan. MATERIAL AND METHODS: HICBT records were extracted from the Japan Sport Council data on head injuries occurring reported during the 7-year period from 2012 to 2018 under the supervision of schools in Japan. RESULTS: Of the total 463,527 head injury cases during the study period, 4495 cases (approximately 1%) were HICBT. Of the HICBT cases, 3650 (81.20%) were related to sports and athletic activity. Such injuries were reported to occur most often during basketball with a rate of 57.07% and 50.43%; soccer/futsal was the next most common sport with a rate of 13.38% and 24.01% in junior high school and high school students. Tag games were responsible for a similar number of HICBT cases at 22.73% and 39.03% in kindergartens and elementary school students. CONCLUSIONS: A total of 4495 cases of HICBT were identified, accounting for about 1% of all head injuries under the supervision of schools in Japan during the study period. This result reminds us that our teeth could be the weapon against the players during sports events. HICBTs occurring during basketball and soccer/futsal, in which mouthguards are not mandatory, were conspicuous among junior and senior high school students. Active use of mouthguards in various sports will protect players as well as their teammates and opponents. Sports dentists should encourage the revision of rules, such as mandating the use of mouthguards, in popular sports with a high incidence of HICBT, such as basketball and soccer/futsal.

Improving light-cured intermediate resin for hard and space mouthguard using a glass fiber.

BACKGROUND/AIMS: A light-cured intermediate material is useful for fabricating a hard insert and a buffer space mouthguard (H&SMG). However, it requires improvement in its mechanical properties and shock-absorbing capacity. The aim of this study was to evaluate the mechanical properties of two prototype light-cured intermediate materials reinforced with glass fibers, and the impact absorption capacity and durability of H&SMGs made with the prototype intermediate materials. MATERIALS AND METHODS: Two prototype materials containing long and microlength glass fibers in a light-cured intermediate material, Innerframe LC®, for H&SMG, were fabricated and tested. A three-point bending test was performed for evaluation of the mechanical properties. In addition, a shock absorption test was conducted using a customized pendulum impact testing machine to evaluate the H&SMGs' impact absorption capacity and durability. RESULTS: Long and microlength glass fibers significantly improved flexural modulus and strength. H&SMGs made with these two glass fiber-containing materials had high impact absorption capacity against both low and high impact forces, while the mouthguards made with long glass fiber materials had the best results. CONCLUSION: Long and microlength glass fibers with the prototype materials improved the mechanical properties of Innerframe LC® and the impact absorption capacity and durability of H&SMGs. H&SMGs made with the long glass fiber prototype materials had the best performance.

Jaw-Clenching Intensity Effects on Masseter Oxygen Dynamics and Fatigue: A NIRS Oximetry Study.

The purpose of this study was to clarify the effects of jaw-clenching intensity on masseter muscle oxygen dynamics during clenching and recovery and masseter muscle fatigue using the spatially resolved method of near-infrared spectroscopy. Pulse rate, mean power frequency from electromyography in the masseter and visual analogue scale for masseter fatigue were also examined as related items. The 25% and 50% maximum voluntary contractions were determined using electromyography before the experiment and used as visual feedback on the screen. Twenty-three healthy adult male subjects volunteered for this study. Clenching decreased oxygen and oxygenated haemoglobin, and increased deoxygenated haemoglobin in the masseter muscle. The higher the intensity of clenching, the more prominent the effect. The oxygen dynamics tended to return to normal after clenching, but the change was slower with higher clenching intensity. Pulse rate increased with clenching, and the increment was more prominent with higher clenching intensity. Clenching caused a shift of mean power frequency to a lower range, an increase in subjective fatigue, an early appearance of a breakpoint appearance time and a prolongation of a 1/2 recovery time. All of these effects were more evident with increasing clenching intensity. In conclusion, clenching intensity influenced the oxygen dynamics of the masseter muscle and fatigue state during clenching and recovery. The higher the intensity, the greater the impact.

Verification of the effectiveness of fucosylated haptoglobin as a pancreatic cancer marker in clinical diagnosis.

BACKGROUND: Fucosylated haptoglobin detected by Pholiota squarrosa lectin (PhoSL) that had specificity for fucose α1-6 was reported as an effective biomarker for several gastrointestinal diseases. The aim of this study was to verify Fucosylated haptoglobin detected by Pholiota squarrosa lectin (PhoSL-HP) as a pancreatic cancer (PC) marker using a new method of PhoSL-ELISA. METHODS: PhoSL-HP in sera from 98 PC patients and 158 non-PC samples including 32 intraductal papillary mucinous neoplasm (IPMN) patients, 21 chronic pancreatitis (CP) patients and 105 non-pancreatic disease controls (NPDC) were measured. We compared sensitivities, specificities and areas under the curves (AUC) of PhoSL-HP, CA19-9 and CEA as single markers. We also evaluated PhoSL-HP as combination marker by comparing AUC of CA19-9 combined with PhoSL-HP or CEA. RESULTS: The sensitivities of PhoSL-HP, CA19-9 and CEA for PC were 58%, 76% and 42%, respectively. Although the specificity of PhoSL-HP for NPDC was inferior to both of CA19-9 and CEA, that for pancreatic diseases was higher than both of CA19-9 and CEA. Combined CA19-9 with PhoSL-HP, the AUC was significantly higher at 0.880 than single use of CA19-9 at 0.825 in case of distinguishing PC from other pancreatic diseases. In contrast, the AUC of CA19-9 was not elevated significantly when combined with CEA. CONCLUSION: PhoSL-HP would be a useful marker for PC and have sufficient complementarity for CA19-9.

Effect of Vinyl Acetate, Glass Fibers Contents, and Buffer Space on EVA's Mechanical Property and Shock Absorption Ability.

OBJECTIVES: The aim of the study was to evaluate the mechanical properties and impact absorption capacity of prototype materials comprising ethylene vinyl acetate (EVA) of different hardness reinforced using different amounts of glass fibers (GFs), considering a buffer space. MATERIALS AND METHODS: Six prototype materials were made by adding E-GFs (5 and 10 wt%) to EVA with vinyl acetate (VA) contents of 9.4 wt% ("hard" or HA) and 27.5 wt% ("soft" or SO). Durometer hardness and tensile strength tests were performed to evaluate the mechanical properties of the materials. Moreover, an impact test was conducted using a customized pendulum impact tester to assess the impact absorption capacity (with or without a buffer space) of the specimens. RESULTS: The mechanical properties of the prototypes, namely, durometer hardness, Young's modulus, and tensile strength, were significantly higher in the HA group than in the SO group, regardless of the presence or added amount of GFs. The addition of GFs, particularly in a large amount (10 wt%), significantly increased these values. In terms of the impact absorption capacity, the original hardness of the EVA material, that is, its VA content, had a more substantial effect than the presence or absence of GFs and the added amount of GFs. Interestingly, the HA specimens with the buffer space exhibited significantly higher impact absorption capacities than the SO specimens. Meanwhile, the SO specimens without the buffer space exhibited significantly higher impact absorption capacities than the HA specimens. Moreover, regardless of the sample material and impact distance, the buffer space significantly improved impact absorption. In particular, with the buffer space, the impact absorption capacity increased with the added amount of GFs. CONCLUSION: The basic mechanical properties, including durometer hardness, Young's modulus, and tensile strength, of the EVA prototype were significantly increased by reducing the amount of VA regardless of the presence or added amount of GFs. Adding GFs, particularly in large amounts, significantly increased the values of aforementioned mechanical properties. Impact absorption was significantly affected by the hardness of the original EVA material and enhanced by the addition of the buffer space. The HA specimen had a high shock absorption capacity with the buffer space, and the SO specimen had a high shock absorption capacity without the buffer space. With the buffer space, impact absorption improved with the amount of added GFs.

How to do repeat hepatectomy for remnant liver recurrence using diaphragmatic incision for right liver mobilization.

In addition to difficulties with parenchymal resection reflecting anatomic disorientation arising from rotation of the liver remnant that accompanies regeneration, repeat resections typically involve difficult and protracted lysis of adhesions. We describe our technique for facilitating right liver mobilization even in the presence of severe adhesions. Lysis of dense retroperitoneal adhesions posterior to the right liver can be performed safely by incising the diaphragm to facilitate manipulations to mobilize the right liver.

Modification of ALPPS to avoid ischemia and congestion after stage 1: a case report.

BACKGROUND: Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) has been advocated for treating advanced liver tumors, but the devascularized ischemic area resulting from liver parenchymal division can become a nidus for sepsis. We present a patient who underwent ALPPS modified to avoid ischemia and congestion after liver partitioning during stage 1. CASE PRESENTATION: ALPPS was carried out for a patient with multiple bilobar liver metastases from rectosigmoid colon cancer. The 2-stage treatment included 3 partial resections within the left lateral section and parenchymal division at the umbilical fissure with right portal vein ligation as stage 1, followed by right trisectionectomy as stage 2. During parenchymal division at the umbilical fissure, Segment 4 portal pedicles and the middle hepatic vein had to be resected at their roots. To safely accomplish this, combined resection of Segment 4 and the drainage area of the middle hepatic vein was performed after parenchymal partition, aiming to avoid ischemia and congestion within the remnant liver. Successful stage 2 hepatectomy followed later. No ischemia or congestion occurred during stage 1 or 2. CONCLUSIONS: During ALPPS, ischemia and congestion after stage 1 must be avoided to reduce morbidity and mortality. The modification described here should reduce likelihood of severe postoperative complications.

Analysis of gene expression profiles in fatal hepatic failure after hepatectomy in mice.

BACKGROUND: We developed 90%-hepatectomized mice that were the fatal model, and analyzed the gene expression profiles using a complementary DNA (cDNA) microarray to clarify the mechanisms of hepatic failure after excessive hepatectomy. MATERIALS AND METHODS: Ribonucleic acid (RNA)s from the remnant hepatic tissue of 70%- and 90%-hepatectomized mice were labeled with fluorescent dyes, and hybridized to the Riken set of 39,168 full-length enriched mouse cDNA arrays. The gene expression profiles in 90%- and 70%-hepatectomized mice were analyzed by scanning date for fluorescent dye signals. RESULTS: The down-regulated genes in 90%-hepatectomized mice were genes activating extracellular matrix (ECM) remodeling (matrix metalloproteinases, laminins, and integrins), genes related to cytokines (tumor necrosis factor α converting enzyme, and Janus kinase 3) that were related to the priming, genes related to growth factor (heparin-binding epidermal growth factor-like growth factor and others), and genes promoting cell cycle progression (cyclin D1, D2, and E2) that were related to the progression of hepatocytes. The up-regulated genes were genes inhibiting ECM remodeling [plasminogen activator inhibitors (PAIs)]. CONCLUSIONS: Hepatic failure after hepatectomy was characterized by the inhibition of hepatic cell cycle priming and progression both induced by ECM remodeling in liver regeneration. Particularly, the overexpression of PAIs was thought to play the major role in the first step of inhibition of ECM remodeling.

Pathogenesis in ABO incompatible liver transplantation: a clinicohistological evaluation of four patients.

The aim of this study was to clarify the pathogenesis of antibody-mediated rejection (AMR) of ABO-incompatible liver transplantation (ABO-I-LT). We investigated, within one month of surgery, the clinical courses of 10 patients who received ABO-I-LT. We encountered four cases of AMR, which were classified into two groups according to the stage of the AMR: early (within the first 14 postoperative days [PODs]) or late (after the 14th POD). There were three patients in the early stage, and one patient in the late stage. Three early-stage AMR patients had both hyperbilirubinemia and thrombocytopenia within one month after LDLT, but the one late-stage AMR patient had neither. On liver biopsy, hemorrhagic infiltration was seen more frequently in the early-stage AMR patients than in the patient with late-stage AMR. Plasma exchange combined with a large amount of gamma-globulin bolus infusion therapy was effective in the three early-stage patients, but the late-stage AMR was controlled by antibiotic treatment. This study showed that the early-stage AMR resulted from the antigen-antibody reaction of ABO-blood-group antigens, while the late-stage AMR may have been caused by an infection.

Gene expression during liver regeneration after partial hepatectomy in mice lacking type 1 tumor necrosis factor receptor.

BACKGROUND: To investigate the function of tumor necrosis factor-alpha (TNF-alpha) during hepatocyte proliferation, we studied liver regeneration following partial hepatectomy in mice lacking type 1 TNF receptor (TNFR-1). MATERIALS AND METHODS: TNFR-1 knockout (KO) and wild-type mice were subjected to partial (two-thirds) hepatectomy. Liver regeneration was evaluated by assessing liver weights and Ki67 immunohistochemistry. Riken complementary DNA microarray analysis was performed for liver samples from mice undergoing partial hepatectomy to better compare different mouse partial hepatectomy models (TNFR-1 KO mice, KO group; and wild-type mice, W group). RESULTS: Liver weight was regained after 14 days in the KO group, and after 7 days in the W group. Genes including lipopolysaccharide, toll-like receptor 4 precursor, mitogen-activated protein kinase kinase kinase 4, mitogen-activated protein kinase kinase kinase kinase 4, and mitogen-activated protein kinase 8-interacting protein were up-regulated in the KO group. As for the cell-cycle-regulated genes, the levels of cyclin D1, nuclear factor-kappa B light chain, and TNF receptor super family membrane 1a were down-regulated in the KO group. Microarray analysis showed decreased activities of the hexokinase- and phospho-fructokinase-related glycolytic pathways in the KO group. CONCLUSIONS: These results contribute to the better understanding of the mechanisms of liver regeneration after partial hepatectomy in TNFR-1 KO mice.

Transfection of NF-kappaB decoy oligodeoxynucleotides into macrophages reduces murine fatal liver failure after excessive hepatectomy.

BACKGROUND: Macrophages play an important role in the initiation of hypercytokinemia, which is involved in the development of liver failure after excessive hepatectomy. This study was aimed at evaluating whether the selective suppression of nuclear factor kappa B (NF-kappaB) in macrophages by decoy oligodeoxynucleotides (ODN) could prevent liver failure after excessive hepatectomy. MATERIALS AND METHODS: Ninety percent hepatectomy was performed in 8-wk-old mice. NF-kappaB/decoy/ODN was transfected into the liver by the hemagglutinating virus of Japan-liposome method. The survival rate, serum levels of interleukin (IL)-1beta IL-6, and tumor necrosis factor-alpha, and the histological findings in the remnant liver were compared between the 90%-hepatectomized mice transfected with the decoy ODN (decoy group) and the 90%-hepatectomized mice injected with saline (control group). RESULT: The control group mice died within 48 h of the operation, while the survival rate in the decoy group at 48 h after the operation was 35%, and at 2 wk, 15%. The serum levels of all cytokines were significantly lower in the decoy group than in the control group. The number of terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling-positive cells in the remnant liver was smaller in the decoy group. CONCLUSION: Transfection of NF-kappaB/decoy/ODN reduces fatal liver failure in mice after excessive hepatectomy by suppressing hypercytokinemia, but offers only a low rate of survival.

The proangiogenic factor ephrin-A1 is up-regulated in radioresistant murine tumor by irradiation.

While the pre-treatment status of cancer is generally correlated with outcome, little is known about microenvironmental change caused by anti-cancer treatment and how it may affect outcome. For example, treatment may lead to induction of gene expression that promotes resistance to therapy. In the present study, we attempted to find a gene that was both induced by irradiation and associated with radioresistance in tumors. Using single-color oligo-microarrays, we analyzed the gene expression profiles of two murine squamous cell carcinomas, NR-S1, which is highly radioresistant, and SCCVII, which is radiosensitive, after irradiation with 137-Cs gamma rays or carbon ions. Candidate genes were those differentially regulated between NR-S1 and SCCVII after any kind of irradiation. Four genes, Efna1 (Ephrin-A1), Sprr1a (small proline-rich protein 1A), Srgap3 (SLIT-ROBO Rho GTPase activating protein 3) and Xrra1 [RIKEN 2 days neonate thymus thymic cells (NOD) cDNA clone E430023D08 3'], were selected as candidate genes associated with radiotherapy-induced radioresistance. We focused on Efna1, which encodes a ligand for the Eph receptor tyrosine kinase known to be involved in the vascular endothelial growth factor (VEGF) pathway. We used immunohistochemical methods to detect expression of Ephrin-A1, VEGF, and the microvascular marker CD31 in radioresistant NR-S1 tumor cells. Ephrin-A1 was detected in the cytoplasm of NR-S1 tumor cells after irradiation, but not in SCCVII tumor cells. Irradiation of NR-S1 tumor cells also led to significant increases in microvascular density, and up-regulation of VEGF expression. Our results suggest that radiotherapy-induced changes in gene expression related with angiogenesis might also modulate microenvironment and influence responsiveness of tumors.

Prostaglandin E1 prevents liver failure after excessive hepatectomy in the rat by up-regulating Cyclin C, Cyclin D1, and Bclxl.

Prostaglandin E1 (PGE1) has wide-ranging effects on cytoprotection and may play a role in preventing liver failure following excessive hepatectomy. We examined the effect of PGE1 on hepatocyte apoptosis and liver regeneration after 95% hepatectomy in a rat model. PGE1 or vehicle was intravenously administered 30 minutes before and during hepatectomy. The extent of hepatocyte injury was evaluated by serum alanine aminotransferase and aspartate aminotransferase levels. To evaluate hepatocyte apoptosis and liver regeneration, terminal deoxynucleotidyl transferase dUTP nick end labeling staining and Ki67 labeling were performed. The expression levels of Bcl-xL, Bcl-2, Bax, Cyclin C, Cyclin D1, Cyclin E, p21, transforming growth factor-beta, plasminogen activator inhibitor-1, and glyceraldehyde-2-phosphate dehydrogenase mRNA were also examined by reverse transcription-polymerase chain reaction. Survival was improved in the PGE1 group (26.6%), whereas all rats in the vehicle group died within 60 hours. PGE1 significantly suppressed the release of alanine aminotransferase and aspartate aminotransferase at 12 hours postoperatively. Pretreatment with PGE1 significantly increased the Ki67-positive cell count and decreased the terminal deoxynucleotidyl transferase dUTP nick end labeling positive cell count after hepatectomy, and also significantly increased the expression levels of Bcl-xL, Cyclin C, and Cyclin D1. Our results suggest that pretreatment with PGE1 may increase survival following hepatectomy by salvaging the remaining liver tissue, which it does by inhibiting apoptosis and stimulating hepatocyte proliferation.

Validity of hepatic resection of colorectal liver metastases in the elderly (75 years and older).

AIM: To evaluate the validity of surgical therapy for colorectal liver metastases in the elderly patients. PATIENTS AND METHODS: Between 1992 and 2004, 401 patients were diagnosed as having liver metastases from colorectal cancer. These comprised 64 patients aged 75 years or older and 337 patients aged less than 75 years. RESULTS: Two hundred and thirty-two patients (57.9%) underwent potentially curative hepatic resection. Postoperative complications occurred in 29.6% of the older patients and in 23.4% of the younger patients. Mortality was 0% in the older group and 0.5% in the younger group. The overall 5-year survival rates of the older and younger group were 33.2% and 47.9%, respectively (p < 0.01). The proportion of patients who died of other diseases was significantly higher in the older (11.1%) than the younger group (2.0%) (p = 0.04). CONCLUSION: Age cannot be regarded as a medical contraindication for hepatic resection of colorectal liver metastases.

Amphiregulin is a promising prognostic marker for liver metastases of colorectal cancer.

PURPOSE: Aberrant activation of epidermal growth factor receptors (EGFR/HER1) by ligand stimulation or heterodimerization with human epidermal growth factor 2 (HER2) is considered to play an important role in the development of colorectal carcinoma. Amphiregulin (AR) is a ligand of EGFR that might be related to the development and progression of gastrointestinal tumors. The aim of this study was to determine the AR, EGFR, and HER2 protein expression levels and to evaluate their prognostic relevance to the clinical course of colorectal cancer. EXPERIMENTAL DESIGN: The AR, EGFR, and HER2 protein levels in primary tumors of colorectal cancer (n = 106) were examined using immunohistochemistry. Metastatic sites in liver specimens (n = 16) were also analyzed in the same manner. RESULTS: Thirteen (81.6%) metastatic lesions of the liver stained positive for AR. Among the primary lesions of colorectal cancer, 58 (54.7%) stained positive for AR, 13 (12.3%) stained positive for EGFR, and 5 (4.7%) stained positive for HER2. When the relationships between each protein expression level and the clinicopathologic factors were examined, only the AR expression level was significantly related to liver metastasis (P = 0.0296). A multivariate analysis of liver metastasis proved that AR expression was an independent prognostic factor of liver metastasis from colorectal cancer (P = 0.0217). CONCLUSIONS: AR expression in primary lesions of colorectal cancer is an important predictive marker of liver metastasis.

Rapid screening assay for KRAS mutations by the modified smart amplification process.

Previously, the smart amplification process version 2 (SMAP-2) was developed to detect mutations from tissue and in crude cell lysates and has been used for rapid diagnosis of specific somatic mutations with single-nucleotide precision. The purpose of this study was to develop a rapid and practical method to detect cancer and metastasis in specimens using the SMAP-2 assay. We developed modified SMAP-2 assays that enabled detection of any change in a single codon using a single assay. Rapid SMAP-2 screening assays are suitable for routine clinical identification of critical amino acid substitutions such as codon 12 mutations in KRAS. Primers bracketing the first two nucleotides of KRAS codon 12 were designed so that all possible alleles would be amplified by the SMAP-2 assay. In combination with the peptide nucleic acid (PNA) with exact homology to the wild-type allele, our assay amplified all mutant alleles except for the wild-type sequence. With this new assay design (termed PNA-clamp SMAP-2), we could detect KRAS mutations within 60 minutes, including sample preparation. We compared results from PNA-clamp SMAP-2 assay, polymerase chain reaction-restriction fragment length polymorphism, and direct sequencing of clinical samples from pancreatic cancer patients and demonstrated perfect concordance. The PNA-clamp SMAP-2 method is a rapid, simple, and highly sensitive detection assay for cancer mutations.

Six consecutive cases of successful adult ABO-incompatible living donor liver transplantation: a proposal for grading the severity of antibody-mediated rejection.

BACKGROUND: The clinical symptoms, histological findings, and treatments for antibody-mediated rejection (AMR), which is the leading cause of graft loss in adult ABO-incompatible liver transplantation (ABO-I-LT), have rarely been discussed. METHODS: We performed adult living donor ABO-I-LT on six patients. We used anti-CD20 monoclonal antibody combined with plasma exchange preoperatively and intraportal or hepatic-arterial infusion, consisting of prostaglandin E1, corticosteroids, and protease inhibitor postoperatively to prevent AMR. Splenectomy was performed in patients 1, 4, 5 and 6 but not in patients 2 and 3. Weekly liver biopsies were performed after ABO-I-LT. When severe AMR was diagnosed, we performed plasma exchange combined with gamma-globulin bolus infusion (PE+IVIG). RESULTS: In patients 1-3, severe jaundice, rapid decreases in platelet counts, and severe coagulopathy were observed in the early postoperative period. Liver biopsies sampled after the onset of these clinical findings were characterized by severe periportal and lobular hemorrhagic and neutrophil infiltration, suggesting that severe AMR occurred. However, after the initiation of PE+IVIG, AMR was remedied in all three patients. In patients 4-6, severe AMR was not observed. Mild AMR characterized by mild portal hemorrhagic infiltration was observed in patient 4, and moderate AMR characterized by moderate periportal and lobular hemorrhagic infiltration was observed in patient 6. Patients 4-6 did not require PE+IVIG and their clinical course was uneventful. CONCLUSION: Given the experience of these six patients, we consider that AMR may be graded based on liver biopsy findings including hemorrhagic infiltration and neutrophil infiltration, as well as clinical findings. All six patients are currently doing well.

Role of nitric oxide synthesized by nitric oxide synthase 2 in liver regeneration.

BACKGROUND/AIMS: Nitric oxide synthase 2 (NOS2) is expressed during liver regeneration after a partial hepatectomy (PHx); NOS2 subsequently synthesizes nitric oxide (NO). However, the role of NOS2-synthesized NO in post-PHx liver regeneration remains unclear. We investigated the role of NOS2-synthesized NO in liver regeneration. METHODS: NOS2 knockout (NOS2-KO) mice and control mice were subjected to PHx. Liver mass recovery and serum alanine aminotransferase (ALT) levels were then evaluated. The expressions of Ki-67 and single-strand DNA were also evaluated in remnant liver specimens. Differences in the gene expression profiles of the two groups of remnant liver specimens were analysed using a microarray and were validated using a reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: In NOS2-KO mice, liver regeneration was delayed and apoptosis and serum ALT levels were higher than the levels in the control mice. A microarray study and RT-PCR revealed that heat shock protein 70 family (HSP70 family), haeme oxygenase 1 (Hmox1), neuropilin 1 (Nrp1) and epidermal growth factor receptor (EGFR) were downregulated in NOS2-KO mice. CONCLUSIONS: NOS2-synthesized NO may improve hepatocyte viability through the induction of the HSP70 family and Hmox1 and may sensitize the remnant liver to growth factors through the induction of Nrp1 and EGFR post-PHx.

Outcome of and risk factors for incisional hernia after partial hepatectomy.

INTRODUCTION: This study was conducted to analyze differences among abdominal incisions, and risk factors for incisional hernia after partial hepatectomy. MATERIALS AND METHODS: In 626 posthepatectomy cases, we analyzed retrospectively the distribution regarding the type of incision and assessed risk factors for incisional hernia. RESULTS: Of the patients, 95 (15.2%) had median incisions, 233 (37.2%) had J-shaped incisions, 206 (32.9%) had right transverse incisions with vertical extensions in the midline from the subumbilical region to the xiphoid process (RTVE), and 92 (14.7%) had bilateral transverse incision with a vertical extension to the xiphoid process (a reversed T incision). The respective frequencies of incisional hernia after median, J-shaped, RTVE, and reversed T incisions were 6.3, 4.7, 5.4, and 21.7%, so that the difference between reversed T and other incisions was significant. A diagnosis of "no hernia" required a minimum follow-up of 12 months. The risk factors for incisional hernia were incision type, postoperative ascites, body mass index, repeat hepatectomy, and steroid use in multivariate analysis. CONCLUSION: The incidence of incisional hernia after reversed T incision was significantly higher than after other incisions. If incision extension is necessary, the midline incision should be extended from the subumbilical region.

Retroportal hepaticojejunostomy for extended resection of hilar bile ducts.

High hepatic duct resection sometimes is unavoidable in achieving curative resection of hilar cholangiocarcinoma, as tumor cells can extend further than expected along the bile ducts from the macroscopically evident cancer. In patients undergoing left hemihepatectomy with caudate lobectomy whose bile duct must be severed at the subsegmental bile duct levels, the orifices of the posterior bile ducts would lie behind the right portal vein. Conventional hepaticojejunostomy would be risky in such cases because an anastomosis performed in the usual manner would be subjected to strain. Instead, between 2002 and 2004, three patients underwent retroportal hepaticojejunostomy using a jejunal limb mobilized and positioned behind the hepatoduodenal ligament. Primary tumors were classified as type IV in the Bismuth-Corlette classification. Tension-free hepaticojejunal anastomosis was performed successfully in all three patients; insufficiency of the hepaticojejunostomy did not develop. Neither early nor late complications directly related to this method occurred. Retroportal hepaticojejunostomy, thus, permits more peripheral resection of the hepatic duct while providing a sufficient operative field for safe, tension-free anastomosis. This technique is very useful for patients undergoing left hemihepatectomy requiring high hilar resection of the bile duct.