Development of a transformer model for predicting the prognosis of patients with hepatocellular carcinoma after radiofrequency ablation

INTRODUCTION

Radiofrequency ablation (RFA) is a widely accepted, minimally invasive treatment modality for patients with hepatocellular carcinoma (HCC). Accurate prognosis prediction is important to identify patients at high risk for cancer progression/recurrence after RFA. Recently, state-of-the-art transformer models showing improved performance over existing deep learning-based models have been developed in several fields. This study was aimed at developing and validating a transformer model to predict the overall survival in HCC patients with treated by RFA.

METHODS

We enrolled a total of 1778 treatment-naïve HCC patients treated by RFA as the first-line treatment. We developed a transformer-based machine learning model to predict the overall survival in the HCC patients treated by RFA and compared its predictive performance with that of a deep learning-based model. Model performance was evaluated by determining the Harrel's c-index and validated externally by the split-sample method.

RESULTS

The Harrel's c-index of the transformer-based model was 0.69, indicating its better discrimination performance than that of the deep learning model (Harrel's c-index, 0.60) in the external validation cohort. The transformer model showed a high discriminative ability for stratifying the external validation cohort into two or three different risk groups (p < 0.001 for both risk groupings). The model also enabled output of a personalized cumulative recurrence prediction curve for each patient.

CONCLUSIONS

We developed a novel transformer model for personalized prediction of the overall survival in HCC patients after RFA treatment. The current model may offer a personalized survival prediction schema for patients with HCC undergoing RFA treatment.

Energy dissipation of a sphere rolling up a granular slope: Slip and deformation of the granular surface

We experimentally investigate the dynamics of a sphere rolling up a granular slope. During the rolling-up motion, the sphere experiences slipping and penetration (groove formation) on the surface of the granular layer. The former relates to the stuck motion of the rolling sphere, and the latter causes energy dissipation due to the deformation of the granular surface. To characterize these phenomena, we measured the motion of a sphere rolling up a granular slope of angle α. The initial velocity v_{0}, initial angular velocity ω_{0}, angle of slope α, and density of the sphere ρ_{s} were varied. As a result, the penetration depth can be scaled solely by the density ratio between the sphere and granular layer. By considering the rotational equation of motion, we estimate the friction due to the slips. Besides, by considering energy conservation, we define and estimate the friction due to groove formation. Moreover, the translational friction is proportional to the penetration depth. Using these results, we can quantitatively predict the sphere's motion including stuck behavior.

Clinical utility of postablation liver tumor biopsy and possibility of gene mutation analysis

AIM

Radiofrequency ablation (RFA) is regarded as a first-line treatment for hepatocellular carcinoma (HCC) at an early stage. When treated with RFA, tumor biopsy may not be performed due to the risk of neoplastic seeding. We previously revealed that the risk of neoplastic seeding is significantly reduced by performing biopsies after RFA. In this study, we investigated the possibility of pathological evaluation and gene mutation analysis of post-RFA tumor specimens.

METHODS

Radiofrequency ablation was undertaken on diethylnitrosamine-induced mouse liver tumor, and tumor samples with or without RFA were subjected to whole exome sequencing. Post-RFA human liver tumor specimens were used for detection of TERT promoter mutations and pathological assessment.

RESULTS

The average somatic mutation rate, sites of mutation, and small indels and base transition patterns were comparable between the nontreated and post-RFA tumors. We identified 684 sites of nonsynonymous somatic substitutions in the nontreated tumor and 704 sites of nonsynonymous somatic substitutions in the post-RFA tumor, with approximately 85% in common. In the human post-RFA samples, the TERT promoter mutations were successfully detected in 40% of the cases. Pathological evaluation was possible with post-RFA specimens, and in one case, the diagnosis of adenocarcinoma was made.

CONCLUSION

Our findings suggest that post-RFA liver tumor biopsy is a useful and safe method for obtaining tumor samples that can be used for gene mutation analysis and for pathological assessment.

Abstract 4244: Black soybean seed coat extract suppress intestinal tumorigenesis in APCmin mice

Background: Colorectal cancer (CRC) is a major cause of cancer-related deaths in Japan and worldwide. Since CRC has been reported to have close relationship with diet, it seems significant to identify dietary constituents that might suppress occurrence of CRC. Recently, an epidemiological investigation for cancer incidence in Japan revealed that consumptions of black soybeans seem to reduce incidence of several cancers, especially colorectal cancer. Black soybeans coat extract (BE) is known to contain rich procyanidins which have many beneficial physiological activities such as anticancer effects. Therefore, we hypothesized that BE may have inhibitory effects to intestinal tumorigenesis and investigated using APCmin/+ mice models.

Materials and Methods: APCmin/+ male mice in the C57BL/6 genetic background were obtained from Jackson Laboratories. APCmin/+ genotypes of each mouse were confirmed by polymerase chain reaction analysis (PCR) using DNA extracted from the tip of mouse tails. Mice were weighed weekly once and monitored regularly for any signs of weight loss. APC min/+ mice at 4 weeks of age were randomly divided into three groups with 5 mice, and fed by either AIN-76A diet, AIN-76A diet containing 0.05% or 0.05% BE for 8 weeks. At 12 weeks of age, intestines were removed from each mouse and then sliced longitudinally. The small intestine was cut into three equally parts: proximal, middle, and distal. Numbers and sizes of intestinal polyps in each portion were evaluated under Video-Zoom-microscope XV-440. Intestinal polyps were categorized by size into 1-2 mm, 2-3 mm and &gt;3 mm. Other parts of the intestines were placed in 10% phosphate-buffered formalin for histopathology and immunohistochemical (PCNA, β-catenin, and MUC2) analyses.

Results: Numbers of polyps in mice fed with containing 0.05% or 0.5% BE diet were significantly smaller than in mice fed without BE (P &lt; 0.05). As for size of polyps, the number of polyps of 1 to 3 mm in size was decreased in mice with BE, however, there were no significant difference for numbers of polyps more than 3 mm in size regarding diets with or without BE. With 0.05% BE diet, reduction rates for occurrence of polyps were 81% for proximal, 48% for middle, and 47% for distal positions, while in with 0.5% BE diet, those reduction rates were 71% for proximal, 59% for middle, and 58% for distal positions, respectively. From these results, the BE, either 0.05% or 0.05% concentration, showed inhibitory effects for tumorigeneses in the small intestine of APC min/+ mice. In histological analyses, the BE was induced higher expression of MUC2-positive cells in normal intestinal lesions and lower expression of β-catenin in tumor sites

Conclusions: The BE showed inhibitory effects in occurrence and growth of intestinal polyps in APCmin/+ mice models. With further evaluation of mechanisms, the BE could be a promising nutrition for prevention of CRC in human.

Citation Format: Yasuyuki Shimizu, Shunta Hirano, Yoko Yamashita, Tsuyoshi Fukumoto, Naritoshi Mukumoto, Ai Nakaoka, Namiko Hoshi, Takeaki Ishihara, Daisuke Miyawaki, Ashida Hitoshi, Ryohei Sasaki. Black soybean seed coat extract suppress intestinal tumorigenesis in APCmin mice. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4244.

Steroid administration for ischemic complications after radiofrequency ablation: A retrospective study

AIM

The aim of this study was to evaluate the effects of steroids on ischemic complications after radiofrequency ablation.

METHODS

A total of 58 patients with ischemic complications were divided into two groups according to corticosteroid use or non-use.

RESULTS

A total of 13 patients who were administered steroids had a shorter duration of fever than those who were not administered steroids (median 6.0 vs. 2.0 days; p < 0.001). Linear regression analysis showed that steroid administration was associated with a reduction of 3.9 days in the duration of fever (p = 0.008).

CONCLUSIONS

Steroid administration for ischemic complications after radiofrequency ablation may reduce the risk of fatal outcomes by blocking systemic inflammatory reactions.

Improved prognosis of hepatitis C-related hepatocellular carcinoma in the era of direct-acting antivirals

The prognostic impact of direct‐acting antivirals (DAAs) on patients with hepatitis C‐related hepatocellular carcinoma (C‐HCC) is still unclear. This study aimed to evaluate the prognosis of C‐HCC in the DAA era. We enrolled 1237 consecutive patients with treatment‐naive C‐HCC who underwent radical radiofrequency ablation between 1999 and 2019. We also enrolled 350 patients with nonviral HCC as controls. We divided these patients into three groups according to the year of initial treatment: 1999–2005 (cohort 1), 2006–2013 (cohort 2), and 2014–2019 (cohort 3). The use of antiviral agents and their effect in patients with C‐HCC was investigated. Overall survival was evaluated for each cohort using the Kaplan‐Meier method and a multivariable Cox proportional hazards regression model. Sustained virologic response (SVR) was achieved in 52 (10%), 157 (26%), and 102 (74%) patients with C‐HCC in cohorts 1–3, respectively. The 3‐ and 5‐year survival rates of patients with C‐HCC were 82% and 59% in cohort 1; 80% and 64% in cohort 2; and 86% and 78% in cohort 3, respectively (p = 0.003). Multivariable analysis adjusted for age, liver function, and tumor extension showed that the prognosis of C‐HCC improved in cohort 3 compared to cohort 1 (adjusted hazard ratio [aHR], 0.49; 95% confidence interval [CI], 0.32–0.73; p < 0.001), whereas the prognosis of nonviral HCC did not improve significantly (aHR, 0.96; 95% CI, 0.59–1.57; p = 0.88). The prognosis of C‐HCC drastically improved with the advent of DAAs.

Coexistence of osteoporosis and atherosclerosis in pheochromocytoma: new insights into its long-term management

Osteoporosis and atherosclerosis frequently coexist in patients with pheochromocytoma. The presence of osteoporosis may predict that of atherosclerosis and vice versa in patients with PHEO. These findings have implications for the long-term management of the pheochromocytoma and its potential chronic complications.

INTRODUCTION

Pheochromocytoma (PHEO), a catecholamine-producing tumor, is often found incidentally, and it may be present for years before it is diagnosed. However, long-term exposure to catecholamines excess may induce chronic complications, such as osteoporosis and atherosclerosis. We aimed to evaluate concomitant osteoporosis and atherosclerosis in patients with PHEO.

METHODS

Fifty-one patients with PHEO and 51 patients with a non-functional adrenal tumor were compared radiographically for the prevalence of vertebral fracture (VF), a typical osteoporotic fracture, and abdominal aortic calcification (AAC).

RESULTS

In patients with PHEO, the prevalence of AAC was higher in those with VF (58%) than in those without (6%, p < 0.001). AAC was associated with VF after adjusting for age and sex (odds ratio, 1.53; 95% confidence interval, 1.07-2.46; p = 0.003) in patients with PHEO. The degree of catecholamine excess correlated with the presence of VF and AAC (p = 0.007). The prevalence of VF was higher in patients with PHEO (37%) than those with non-functional AT (12%, p = 0.005), but the prevalence of AAC was comparable between the two groups (25% and 19%, p = 0.636). VF and AAC more frequently coexisted in patients with PHEO (22%) than in those with non-functional AT (2%, p = 0.003).

CONCLUSION

This study represents the first demonstration that osteoporosis and atherosclerosis frequently coexist in patients with PHEO. The presence of osteoporosis may predict that of atherosclerosis and vice versa in patients with PHEO. These findings have implications for the long-term management of the PHEO and its potential chronic complications.

[A case of granulocyte-colony stimulating factor-producing gallbladder adenosquamous carcinoma with rapidly-growing recurrence of liver metastasis in early postoperative period]

An 82-year-old male with a gallbladder mass was diagnosed with gallbladder carcinoma through various examinations. Cholecystectomy, gallbladder bed resection, and lymph node dissection were performed. The histological examination revealed a gallbladder adenosquamous carcinoma, and this tumor showed positive staining for granulocyte-colony stimulating factor (G-CSF). Recurrence of multiple liver metastases was detected on 25th day postoperatively. Unfortunately, the patient died on 97th day postoperatively. Here, we report a case of G-CSF-producing adenosquamous carcinoma of the gallbladder with rapid recurrence of liver metastases in the early postoperative period.

A patient with cystic duct remnant calculus treated by laparoscopic surgery combined with near-infrared fluorescence cholangiography

BACKGROUND

The recurrence of symptoms present before cholecystectomy may be caused by a cystic duct remnant. The resolution of cystic duct remnant syndrome may require surgical resection, but identification of the duct remnant during laparoscopic surgery may be difficult because of adhesions following the previous procedure. Open surgery, which is more invasive than laparoscopic surgery, is frequently chosen to avoid bile duct injury.

CASE PRESENTATION

The patient was a 24-year-old woman with previous laparoscopic cholecystectomy for chronic cholecystitis and repeated attacks of biliary colic. The postoperative course was uneventful, but computed tomography revealed a remnant cystic duct calculus. Ten months after surgery, the patient returned to our department for right hypochondriac pain. Laparoscopic remnant cystic duct resection was performed with intraoperative near-infrared (NIR) fluorescence cholangiography to visualize the common bile duct and remnant cystic duct. The postoperative course was uneventful and the patient was discharged on day 3 after surgery. At the 6-month follow-up, she had no recurrence of pain.

CONCLUSION

Laparoscopic surgery with NIR cholangiography is a safe and effective alternative for the removal of a cystic duct remnant calculus after cholecystectomy.

Improved liver function in patients with cirrhosis due to chronic hepatitis C virus who achieve sustained virologic response is not accompanied by increased liver volume

Background

Serum albumin level improves in patients with chronic hepatitis C virus (HCV) infection who achieve sustained virologic response (SVR) with antiviral therapy. However, it remains controversial whether liver volume increases along with SVR.

Methods

Patients with chronic HCV infection with a history of hepatocellular carcinoma (HCC) who achieved SVR with anti-HCV treatment from March 2003 to November 2017 were enrolled. Patients were followed up with periodic computed tomography (CT) scans to detect HCC recurrence. Patients who underwent treatment for HCC recurrence within 1 year after initiation of anti-HCV treatment were excluded. Laboratory data, including alanine aminotransferase (ALT) level, serum albumin level, and platelet count, were collected at baseline and timepoints after treatment initiation. Liver volume was evaluated at baseline and 24 and 48 weeks after treatment initiation using a CT volume analyzer. A linear mixed-effects model was applied to analyze the chronologic change in liver volume. The correlations between changes in ALT level, albumin level, and liver volume were also evaluated.

Results

Of 108 enrolled patients, 78 had cirrhosis. Serum albumin level continued to increase through 48 weeks after treatment initiation. A significant increase in liver volume was observed only in patients without cirrhosis (P = 0.005). There was a significant correlation between ALT level decrease and albumin level increase (P = 0.018).

Conclusions

Improved liver albumin production with SVR was contributed by improved liver cell function rather than increased liver volume in patients with cirrhosis.

Total tumour volume as a prognostic factor in patients with resectable colorectal cancer liver metastases

Background

Although total tumour volume (TTV) may have prognostic value for hepatic resection in certain solid cancers, its importance in colorectal liver metastases (CRLM) remains unexplored. This study investigated its prognostic value in patients with resectable CRLM.

Method

This was a retrospective review of patients who underwent hepatic resection for CRLM between 2008 and 2017 in a single institution. TTV was measured from CT images using three‐dimensional construction software; cut‐off values were determined using receiver operating characteristic (ROC) curve analyses. Potential prognostic factors, overall survival (OS) and recurrence‐free survival (RFS) were determined using multivariable and Kaplan–Meier analyses.

Results

Some 94 patients were included. TTV cut‐off values for OS and RFS were 100 and 10 ml respectively. Right colonic primary tumours, primary lymph node metastasis and bilobar liver metastasis were included in the multivariable analysis of OS; a TTV of 100 ml or above was independently associated with poorer OS (hazard ratio (HR) 6·34, 95 per cent c.i. 2·08 to 17·90; P = 0·002). Right colonic primary tumours and primary lymph node metastasis were included in the RFS analysis; a TTV of 10 ml or more independently predicted poorer RFS (HR 1·90, 1·12 to 3·57; P = 0·017). The 5‐year OS rate for a TTV of 100 ml or more was 41 per cent, compared with 67 per cent for a TTV below 100 ml (P = 0·006). Corresponding RFS rates with TTV of 10 ml or more, or less than 10 ml, were 14 and 58 per cent respectively (P = 0·009). A TTV of at least 100 ml conferred a higher rate of unresectable initial recurrences (12 of 15, 80 per cent) after initial hepatic resection.

Conclusion

TTV was associated with RFS and OS after initial hepatic resection for CRLM; TTV of 100 ml or above was associated with a higher rate of unresectable recurrence.

[A Case of Primary Anal Fistula Cancer with Extensive Intrapelvic Spreading That Was Successfully Treated with Bevacizumab plus mFOLFOX6]

The patient was a 68-year-old man who had an anal fistula for>10 years. He was referred to our institution after visiting a local physician with left femoral pain as the main complaint and received a diagnosis of high inflammatory response. We then found discharge of pus in the perianal region during a medical examination. We also found an extensive intrapelvic tumor during a computed tomography(CT)/magnetic resonance imaging examination. In addition, the level ofa tumor marker and inflammatory response were high. To control the inflammation, we performed seton drainage and sigmoid colostomy. On the basis of the pathological findings from the mucus component, we confirmed a diagnosis of fistula cancer. Considering that the progressive lesion had extensively spread, we decided to initiate chemotherapy alone because ofthe absence ofan indication for radiotherapy. We administered bevacizumab plus mFOLFOX6, and partial response was observed on a CT scan. We could control the progression ofthe disease for>6 months. The present case suggests that bevacizumab plus mFOLFOX6 can be an effective regimen for unresectable advanced fistula cancers.

Biomechanical Diagnosis of Atherosclerosis by Ultrasound

Setting: Atherosclerosis causes structural changes in artery walls that alter their physical properties. The stiffness parameteris one quantitative index of the elastic properties of large arteries.can be calculated from the measurements of blood pressure and arterial diameter. We examined whether quantitatively evaluates common carotid atherosclerosis. Methods: We measured the common carotid artery inner diameter and its pulsatile change with an ultrasonic instrument. The subjects were healthy persons, patients with atherosclesrosis risk factors, patients with myocardial infarctions, and patients with cerebral infarction. Results: Thein healthy persons aged 40-59 years was 11.2. β was 13.2 in patients with atherosclerosis risk factors, 13.4 in patients with myocardial infarction, and 13.5 in patients with cerebral infarctions. These data in each patient group were significantly higher than those in healthy subjects. Conclusions: This diagnostic method is inexpensive, noninvasive and easily performed.shows promise as a useful diagnostic indicator of atherosclerosis.

Effective Prevention of Carotid Artery Atherosclerosis by Following this Motto for Healthy Habits: “Give Up One, Reduce Two, and Increase Three”

Objectives: Lifestyle has a major influence on the development and progression of atherosclerosis. Our motto for healthy habits is “give up one, reduce two, and increase three”. The one thing that is to be given up is smoking. The two things that are to be reduced are intake of food and alcohol. The three things that are to be increased are exercise, rest and enjoyable activities. We assessed correlation between these six-health habits and plaque score indicating degree of atherosclerosis in the carotid artery.

Methods: Subjects were divided into unfavorable (practicing zero to three habits) and optimal (practicing four to six habits) healthy habits groups.

Results: Plaque score was significantly higher in the unfavorable group (7.6 ± 5.8) than in the optimal group (4.9 ± 4.2) (P<0.001).

Conclusions: The healthy habits that significantly contributed to prevention of atherosclerosis were quitting smoking and increasing rest and enjoyable activities.

Quality of life following esophagectomy with three-field lymphadenectomy for carcinoma, focusing on its relationship to vocal cord palsy

To clarify the quality of life of patients who underwent esophagectomy for carcinoma by right thoracotomy, laparotomy and cervical anastomosis, 116 patients who were cancer free at the time of mailing a questionnaire were analyzed. A significant decrease in vital capacity for 3 years postoperatively, as well as in the percentage of ideal body weight, between 3 and 5 years were observed in 57 patients with three-field lymphadenectomy. Patients' quality of life undergoing three-field dissection was worse than those with less radical lymphadenectomy (59 cases) in terms of the performance status and difficulty in talking at 60 months or more postoperatively. Around 20% of all patients reported severe hoarseness due to permanent recurrent nerve paralysis, resulting in poor quantity of food intake at 24 months or less postoperatively and restricted daily activity and difficulty in talking at 60 months or more after the operation. When a patient suffers from vocal cord insufficiency caused by permanent paralysis of the recurrent nerve, early treatment before discharge from the hospital should be performed to improve the quality of life of such a patient.

Pancreatic volume is one of the independent prognostic factors for resectable pancreatic ductal adenocarcinomas

BACKGROUND

It is well known that pancreatic ductal adenocarcinoma (PDAC) is accompanied with pancreatic atrophy and fibrosis. We previously reported the correlation between pancreatic volume and body surface area (BSA) and significant reduction of BSA-adjusted pancreatic volume in pancreatic cancer patients. We evaluated potential correlation between BSA-adjusted pancreatic volume and PDAC prognosis.

METHODS

The study subjects were 48 pancreatic cancer patients received pancreatectomy at our department from June 2006 to September 2012. Pancreatic volumetry was retrospectively performed using the images obtained from multidetector computed tomography before the surgery. BSA-adjusted pancreatic volumes were calculated and analyzed for potential correlation with the prognosis.

RESULTS

Average BSA-adjusted pancreatic volume among 48 cases was 35.4 ± 11.9 ml/m(2) . Types of surgery included 24 cases with pancreaticoduodenectomy and 24 cases with distal pancreatectomy. The cases with BSA-adjusted pancreatic volume less than 40 ml/m(2) had significantly poorer prognosis compared to the cases of 40 ml/m(2) and greater (3-year survival rate: 32.4% vs. 64.3%). Statistical analysis identified four prognosis factors, i.e. BSA-adjusted pancreatic volume less than 40 ml/m(2) , postoperative adjuvant chemotherapy, lymph node metastasis and lymphatic invasion.

CONCLUSIONS

This study demonstrated BSA-adjusted pancreatic volume as a prognosis factor for PDAC and the volume of 40 ml/m(2) is considered to be the cutoff value.

Three-day regimen of oseltamivir for postexposure prophylaxis of influenza in wards

Inpatients who had been in close contact with patients with influenza were given oseltamivir [75mg capsules once daily for adults or 2mg/kg (maximum of 75mg) once daily for children] for three days as postexposure prophylaxis (PEP). The index patients with influenza were prescribed a neuraminidase inhibitor and were discharged immediately or transferred to isolation rooms. The protective efficacy of oseltamivir for three days was 93% overall [95% confidence interval (CI) 53-99%; P=0.023] and 94% for influenza A (95% CI 61-99%; P=0.017), which is comparable to that of seven- to 10-day regimens of oseltamivir as PEP.

Evaluation of glucose metabolism after distal pancreatectomy according to the donor criteria of the living donor pancreas transplantation guidelines proposed by the Japanese Pancreas and Islet Transplantation Association

BACKGROUND

Living donor pancreas transplantation (LDPT) reduces the number of deaths of diabetic patients on dialysis and of candidates on the waiting lists and helps to overcome the organ shortage. Stringent criteria must be applied to minimize the risk of metabolic complications for living donors. The Japanese Pancreas and Islet Transplantation Association (JPITA) proposed LDPT guidelines in 2010. In this study, we retrospectively evaluated glucose metabolism of the patients who underwent distal pancreatectomy (DP) according to the donor criteria of the LDPT guidelines proposed by the JPITA.

METHODS

Fifty-two nondiabetic patients who underwent DP were divided into 2 groups according to the donor criteria: indication group (IG, n = 14) who had age ≤ 65, hemoglobin A1c (HbA1c) < 5.9%, and body mass index (BMI) < 25 kg/m(2). The other patients were placed in the no indication group (NG, n = 38). Clinical data and percent resected volume (PRV) of each pancreas as determined by multi-detector row computed tomography volumetry were compared between the 2 groups.

RESULTS

During the follow-up period (median 12 months), 14 patients (27%) developed new-onset diabetes within a median onset time of 10 months (range 3-24 months) postoperatively. No patient in the IG developed new-onset diabetes. On the other hand, 37% of the patients in the NG developed new-onset diabetes. There were significant between-group differences in changes in preoperative serum fasting glucose and HbA1c levels, whereas there were no significant between-group differences in preoperative serum albumin or body weight. Multivariate analysis identified preoperative HbA1c (odds ratio 51.6, P = .002) and PRV (odds ratio 2.07, P = .033) as independent risk factors for new-onset diabetes.

CONCLUSION

Living donor criteria in the LDPT guidelines proposed by the JPITA are appropriate for prevention of glucose metabolic complications in donors. Further long-term follow-up studies of living donors' metabolic function are needed to clarify the safety of the donor.

Functioning pancreas graft with thromboses of splenic and superior mesenteric arteries after simultaneous pancreas-kidney transplantation: a case report

Graft thrombosis is the most common cause of early graft loss after pancreas transplantation. The grafted pancreas is difficult to salvage after complete thrombosis, especially arterial thrombosis, and graft pancreatectomy is required. We describe a patient presenting with a functioning pancreas graft with thromboses of the splenic artery (SA) and superior mesenteric artery (SMA) after simultaneous pancreas-kidney transplantation (SPK). A 37-year-old woman with a 20-year history of type 1 diabetes mellitus underwent SPK. The pancreaticoduodenal graft was implanted in the right iliac fossa with enteric drainage. A Carrel patch was anastomosed to the recipient's right common iliac artery, and the graft gastroduodenal artery was anastomosed to the common hepatic artery using an arterial I-graft. The donor portal vein was anastomosed to the recipient's inferior vena cava. Four days after surgery, graft thromboses were detected by Doppler ultrasound without increases in the serum amylase and blood glucose levels. Contrast enhanced computed tomography revealed thromboses in the SA, splenic vein and SMA. Selective angiography showed that blood flow was interrupted in the SA and SMA. However, pancreatic graft perfusion was maintained by the I-graft in the head of the pancreas and the transverse pancreatic artery in the body and tail of the pancreas. We performed percutaneous direct thrombolysis and adjuvant thrombolytic therapy. However, we had to stop the thrombolytic therapy because of gastrointestinal hemorrhage. Thereafter, the postoperative course was uneventful and the pancreas graft was functioning with a fasting blood glucose level of 75 mg/dL, HbA1c of 5.1%, and serum C-peptide level of 1.9 ng/mL at 30 months post-transplantation.

A polyketide synthase gene, ACRTS2, is responsible for biosynthesis of host-selective ACR-toxin in the rough lemon pathotype of Alternaria alternata

The rough lemon pathotype of Alternaria alternata produces host-selective ACR-toxin and causes Alternaria leaf spot disease of rough lemon (Citrus jambhiri). The structure of ACR-toxin I (MW = 496) consists of a polyketide with an α-dihydropyrone ring in a 19-carbon polyalcohol. Genes responsible for toxin production were localized to a 1.5-Mb chromosome in the genome of the rough lemon pathotype. Sequence analysis of this chromosome revealed an 8,338-bp open reading frame, ACRTS2, that was present only in the genomes of ACR-toxin-producing isolates. ACRTS2 is predicted to encode a putative polyketide synthase of 2,513 amino acids and belongs to the fungal reducing type I polyketide synthases. Typical polyketide functional domains were identified in the predicted amino acid sequence, including β-ketoacyl synthase, acyl transferase, methyl transferase, dehydratase, β-ketoreductase, and phosphopantetheine attachment site domains. Combined use of homologous recombination-mediated gene disruption and RNA silencing allowed examination of the functional role of multiple paralogs in ACR-toxin production. ACRTS2 was found to be essential for ACR-toxin production and pathogenicity of the rough lemon pathotype of A. alternata.

Mating disruption by a synthetic sex pheromone in the white grub beetle Dasylepida ishigakiensis (Coleoptera: Scarabaeidae) in the laboratory and sugarcane fields

A serious sugarcane pest, Dasylepida ishigakiensis, remains in the soil during most of its life cycle except for a short period for mating. Mating disruption by an artificial release of the sex pheromone (R)-2-butanol (R2B), therefore, may be a feasible method to control this pest. We examined the effects of artificial release of R2B and its related compounds, (S)-2-butanol (S2B) and the racemic 2-butanol (rac-2B), on the mating success of this beetle both in the laboratory and in the field. In flight tunnel experiments, almost all males orientated towards a R2B-releasing source and 40% of them landed on the source. When the atmosphere was permeated with R2B, the frequency of males landing on the model was significantly reduced. Both rac-2B and S2B were less effective, but substantial reduction in landing success by males was achieved at higher rac-2B concentrations. R2B released from polyethylene dispensers in sugarcane plots greatly reduced not only the proportion of females mated with males but also the number of males caught by R2B-baited traps, indicating that male mate-searching behaviour was strongly affected by the released R2B. Similar inhibitory effects on male behaviour were also observed when tube- or rope-type dispensers released high rac-2B concentrations in the field. These results indicate that it would be highly possible to control D. ishigakiensis through the disruption of the sexual communication by releasing either synthetic R2B or rac-2B.

Risk factors for survival and local recurrence after particle radiotherapy for single small hepatocellular carcinoma

BACKGROUND

Particle radiotherapy is a novel treatment for malignant tumours. The present study aimed to evaluate risk factors for overall survival and local control after particle radiotherapy of single small hepatocellular carcinoma (HCC), and to identify suitable candidates for this treatment.

METHODS

All patients with a single HCC smaller than 5 cm in diameter treated by particle radiotherapy between 2001 and 2008 were identified retrospectively from a prospectively collected database. Clinical outcomes and prognostic factors were analysed.

RESULTS

A total of 150 patients were included. Five-year overall survival and local control rates were 50.9 and 92.3 per cent respectively. Multivariable analysis revealed that several factors, including age and Child-Pugh classification, significantly influenced overall survival. Proximity to the digestive tract and Child-Pugh classification were independent risk factors for local recurrence. Other tumour factors including size, gross classification, previous treatment, macroscopic vascular invasion, and tumour location in relation to the diaphragm and large vessels did not influence local control rate.

CONCLUSION

Particle radiotherapy seems safe and effective, and may be a novel treatment for small HCC. Recurrences are more frequent when the tumour is located close to the gut.

Long-term field trial to control the invasive Argentine ant (Hymenoptera: Formicidae) with synthetic trail pheromone

Previous short-term experiments showed that trail following behavior of the Argentine ant, Linepithema humile (Mayr) (Hymenoptera: Formicidae), can be disrupted by a high concentration of synthetic trail pheromone component (Z)-9-hexadecenal. In this study, a long-term field trial was conducted in 100-m2 plots of house gardens in an urban area of Japan to see whether the control effect on Argentine ants can be obtained by permeating synthetic trail pheromone from dispensers. The dispensers were placed in the experimental plots during the ant's active season (April-November) for 2 yr with monthly renewal. To estimate Argentine ant population density, foraging activity of Argentine ants in the study plots was monitored by monthly bait surveys. Throughout the study period, Argentine ant foraging activity was suppressed in the presence of the dispensers, presumably via trail forming inhibition. In contrast, the level of foraging activity was not different between treatment and no-treatment plots when the dispensers were temporarily removed, suggesting that treatment with pheromone dispensers did not suppress Argentine ant density in the treatment plots. Population decline may be expected with larger-scale treatment that covers a significant portion of the ant colony or with improvement in the potency of the disruptant.

ACTTS3 encoding a polyketide synthase is essential for the biosynthesis of ACT-toxin and pathogenicity in the tangerine pathotype of Alternaria alternata

The tangerine pathotype of Alternaria alternata produces host-selective ACT-toxin and causes Alternaria brown spot disease of tangerine and tangerine hybrids. Sequence analysis of a genomic BAC clone identified part of the ACT-toxin TOX (ACTT) gene cluster, and knockout experiments have implicated several open reading frames (ORF) contained within the cluster in the biosynthesis of ACT-toxin. One of the ORF, designated ACTTS3, encoding a putative polyketide synthase, was isolated by rapid amplification of cDNA ends and genomic/reverse transcription-polymerase chain reactions using the specific primers designed from the BAC sequences. The 7,374-bp ORF encodes a polyketide synthase with putative beta-ketoacyl synthase, acyltransferase, methyltransferase, beta-ketoacyl reductase, and phosphopantetheine attachment site domains. Genomic Southern blots demonstrated that ACTTS3 is present on the smallest chromosome in the tangerine pathotype of A. alternata, and the presence of ACTTS3 is highly correlated with ACT-toxin production and pathogenicity. Targeted gene disruption of two copies of ACTTS3 led to a complete loss of ACT-toxin production and pathogenicity. These results indicate that ACTTS3 is an essential gene for ACT-toxin biosynthesis in the tangerine pathotype of A. alternata and is required for pathogenicity of this fungus.

Function of genes encoding acyl-CoA synthetase and enoyl-CoA hydratase for host-selective act-toxin biosynthesis in the tangerine pathotype of Alternaria alternata

The tangerine pathotype of Alternaria alternata produces host-selective ACT-toxin and causes Alternaria brown spot disease. Sequence analysis of a genomic cosmid clone identified a part of the ACTT gene cluster and implicated two genes, ACTT5 encoding an acyl-CoA synthetase and ACTT6 encoding an enoyl-CoA hydratase, in the biosynthesis of ACT-toxin. Genomic Southern blots demonstrated that both genes were present in tangerine pathotype isolates producing ACT-toxin and also in Japanese pear pathotype isolates producing AK-toxin and strawberry pathotype isolates producing AF-toxin. ACT-, AK-, and AF-toxins from these three pathotypes share a common 9,10-epoxy-8-hydroxy-9-methyl-decatrienoic acid moiety. Targeted gene disruption of two copies of ACTT5 significantly reduced ACT-toxin production and virulence. Targeted gene disruption of two copies of ACTT6 led to complete loss of ACT-toxin production and pathogenicity and a putative decatrienoic acid intermediate in ACT-toxin biosynthesis accumulated in mycelial mats. These results indicate that ACTT5 and ACTT6 are essential genes in ACT-toxin biosynthesis in the tangerine pathotype of A. alternata and both are required for full virulence of this fungus.

[Advanced gastric cancer showing complete response to neoadjuvant chemotherapy with CPT-11 and S-1-a case report]

We report a case of advanced gastric cancer that showed a complete histological response to neoadjuvant chemotherapy. The patient, a 56-year-old man, was diagnosed as having advanced gastric cancer with lymph node metastases( cT3 cN1 cH0 cP0 cM0, cStageIIIA). He was initially treated with combined neoadjuvant chemotherapy comprising CPT-11+S-1. S-1(120 mg/day)was administered orally for 21 days, followed by CPT-11(130 mg/body)divon days 1 and 15. The primary lesion and lymph node metastases were diminished by 2 courses of chemotherapy, and no serious toxicities were observed. Distal gastrectomy and lymph node dissection(D2)were performed. Only a small ulcer was observed on the resected stomach. Histological examination of the resected stomach and lymph nodes revealed no remaining viable cancer cells. The patient has been doing well without any recurrence for 1 year since the start of treatment.

Functional analysis of a multicopy host-selective ACT-toxin biosynthesis gene in the tangerine pathotype of Alternaria alternata using RNA silencing

Alternaria brown spot, caused by the tangerine pathotype of Alternaria alternata, is a serious disease of commercially important tangerines and their hybrids. The pathogen produces host-selective ACT toxin, and several genes (named ACTT) responsible for ACT-toxin biosynthesis have been identified. These genes have many paralogs, which are clustered on a small, conditionally dispensable chromosome, making it difficult to disrupt entire functional copies of ACTT genes using homologous recombination-mediated gene disruption. To overcome this problem, we attempted to use RNA silencing, which has never been employed in Alternaria spp., to knock down the functional copies of one ACTT gene with a single silencing event. ACTT2, which encodes a putative hydrolase and is present in multiple copies in the genome, was silenced by transforming the fungus with a plasmid construct expressing hairpin ACTT2 RNAs. The ACTT2 RNA-silenced transformant (S-7-24-2) completely lost ACTT2 transcripts and ACT-toxin production as well as pathogenicity. These results indicated that RNA silencing may be a useful technique for studying the role of ACTT genes responsible for host-selective toxin biosynthesis in A. alternata. Further, this technique may be broadly applicable to the analysis of many genes present in multiple copies in fungal genomes that are difficult to analyze using recombination-mediated knockdowns.