A rare case of liver regenerative and non-neoplastic lesion resembling a well-differentiated hepatocellular carcinoma

BACKGROUND

Nodular regenerative hyperplasia (NRH) is a rare disease that presents pathologically as diffuse hepatic nodules without fibrous septa. It is believed to be caused by vasculopathy against a background of various systemic diseases, such as hematologic, autoimmune, and drug-induced diseases, with various symptoms. In spite of the recent imaging advances, various atypical cases of nodular lesions are observed in daily clinical practice. Cases that do not completely meet these criteria are referred to as -like or -similar lesions in clinical situations, making it difficult to understand their pathogenesis. We present a case in which two hepatic nodular lesions were noted and difficult to differentiate from malignancy preoperatively. The lesions were laparoscopically resected and a pathological diagnosis with non-neoplastic liver regenerative nodules resembling NRH was made.

CASE PRESENTATION

A 49-year-old man with no alcohol or drug intake and no past medical history was identified as having liver tumors on screening examination without any symptoms. Contrast-enhanced computed tomography (CT) showed two hepatic tumors; approximately 2-cm tumors at S7 and S8. Gadolinium-ethoxybenzyl-diethylenetriamine-pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) revealed fat inclusions in their contents. Ethoxybenzyl (EOB) uptake was also observed during the hepatobiliary phase. Based on preoperative examinations, we suspected well-differentiated hepatocellular carcinoma (HCC) and performed laparoscopic S7/8 partial resection for these lesions. Macroscopically, the resected specimens showed a non-cirrhotic yellowish-cut surface containing brownish, ill-defined lesions with irregular borders. Microscopically, these lesions showed zonal necrosis, congestion, and aggregation of hemosiderin-laden macrophages around the central vein. In these areas, the fatty deposition of hepatocytes was lower than that in the surrounding background hepatocytes. Histopathologically, neither neoplastic nor hyperplastic lesions were observed, and he was diagnosed as regenerative hepatic change with centrilobular necrosis.

CONCLUSIONS

Considering the pathological results, these lesions were thought to be a type of NRH-like lesion with possible hepatic vessel disorder. However, the lesion's cause and classification was difficult to determine. The accumulation of these regenerative changes accompanying fatty liver is needed to clarify the mechanism and its clinical significance.

Pilsicainide Toxicity-Induced Brugada-Like ST Segment Elevation and Increased Pacing Voltage Threshold

Pilsicainide is a class Ic antiarrhythmic agent that exhibits fully selective sodium channel blockade. In Japan, it is one of the most prescribed medicines for rhythm control in atrial fibrillation. Pilsicainide is mainly excreted by the kidney. Therefore, the plasma concentration of pilsicainide is likely to be increased in patients with renal insufficiency. In this case report, a 90-year-old woman presented with generalized fatigue and loss of appetite. Her ECG showed marked bradycardia and coved-type ST-segment elevation similar to that of the Brugada type 1 pattern. Owing to dehydration, her renal function indices worsened compared with those measured four months prior. The plasma pilsicainide concentration was elevated to 2.67 µg/mL (therapeutic range: 0.20-0.90 µg/mL), indicating pilsicainide toxicity. A transvenous temporary pacemaker was placed; however, the pacing voltage threshold was increased at several sites within the right ventricle. Pilsicainide administration was immediately discontinued. On day 2 of admission, ventricular backup pacing was no longer required, and there was an improvement in renal function and heart failure symptoms, such as pulmonary edema and cardiomegaly. The ECG changes improved alongside the renal function and as the plasma concentration of pilsicainide decreased. In conclusion, elevated plasma concentrations of pilsicainide can induce life-threatening arrhythmias and pacing failure. Therefore, clinicians should prescribe pilsicainide cautiously, particularly in older patients.

Prognostic Impact of Lymphocyte-to-C-Reactive Protein Ratio in Patients Who Underwent Surgical Resection for Pancreatic Cancer

BACKGROUND

Increasing evidence indicates that increased systemic inflammation is correlated with poorer cancer-specific survival in various cancer types. This study aimed to evaluate the prognostic value of various combinations of inflammatory factors in patients who underwent surgical resection for pancreatic cancer (PC).

METHODS

We retrospectively analyzed 97 consecutive patients with PC who underwent pancreatectomy. We assessed the predictive impact for recurrence using a combination of 5 inflammatory markers and focused on the lymphocyte-C-reactive protein ratio (LCR) to elucidate its prognostic and predictive value for recurrence-free survival (RFS) and overall survival (OS) in univariate and multivariate analyses using the Cox proportional hazards model.

RESULTS

Low preoperative LCR was correlated with low serum hemoglobin, low serum albumin concentration, high frequency of microscopic vascular invasion, and high frequency of microscopic perineural invasion. The low LCR group had significantly worse RFS and OS. Lower preoperative LCR was an independent predictor of shorter RFS and OS in this cohort.

DISCUSSION

Preoperative LCR is a novel and convenient prognostic marker for patients with PC. Patients with low LCR may require more favorable intensive therapy.

Successful multidisciplinary treatment with complete response to atezolizumab plus bevacizumab in a 90-year-old patient with hepatocellular carcinoma recurrence

Atezolizumab plus bevacizumab is the first-line regimen in Japan for hepatocellular carcinoma following the results of the IMbrave 150 trial. However, the safety and efficiency of atezolizumab plus bevacizumab in older patients, especially in the oldest-old patients aged over 80 years, have not been thoroughly studied and is still controversial. Eighteen months ago, a 90-year-old woman underwent a laparoscopic hepatectomy (S6) for her primary hepatocellular carcinoma (S6, 2 cm). Nine months after the first surgery, she received transcatheter arterial chemoembolization treatment for solitary hepatocellular carcinoma recurrence (S8, 2 cm). The subsequent recurrence (S3, 1 cm; S5, 2 cm; S8, 1 cm) was uncovered by radiological assessment 1 year after transcatheter arterial chemoembolization treatment. We then initiated chemotherapy treatment with lenvatinib at 8 mg daily. Despite reducing the lenvatinib dosage, the adverse event of severe fatigue and asitia did not resolve; therefore, the regimen of atezolizumab + bevacizumab combination therapy was changed to be started. After the first 2 months, tumor regression was observed on computed tomography; the patient tolerated the atezolizumab + bevacizumab combination regimen over 8 months for 10 cycles without any adverse effects. She finally showed a complete response; no recurrence developed 1 year after the complete response. Therefore, older adult patients may benefit highly from atezolizumab plus bevacizumab with appropriate patient selection.

Prognostic Impact of the Preoperative Systemic Inflammation Score in Patients With Pancreatic Ductal Adenocarcinoma

BACKGROUD

The systemic inflammation score (SIS), which is based on the preoperative lymphocyte-to-monocyte ratio (LMR) and serum albumin (Alb) level, is a prognostic indicator for several cancer types. However, the prognostic significance of the SIS in pancreatic ductal adenocarcinoma (PDAC) remains unknown.

METHODS

Seventy-eight patients who underwent radical surgery for PDAC were categorized as follows: SIS 0 (LMR ≥3.51 and Alb ≥4.0 g/dl), n = 26; SIS 1 (LMR <3.51 or Alb <4.0 g/dl), n = 29 and SIS 2 (LMR <3.51 and Alb <4.0 g/dl), n=23.

RESULTS

The tumour size sequentially increased in SIS 0, 1 and 2 groups. A higher SIS was associated with increased vascular invasion, perineural invasion and surgical margin positivity rate. Recurrence-free survival (RFS) rates between the SIS 1 and 2 groups showed no significant difference However, patients of the SIS 1 and 2 groups had poorer outcomes than those of the SIS 0 group for RFS. Overall survival (OS) rates between the SIS 1 and 2 groups also showed no significant difference. However, patients of the SIS 1 and 2 groups had poorer outcomes than those of the SIS 0 group for OS. The SIS was an independent prognostic factor for RFS and OS.

DISCUSSION

The SIS is a simplified prognostic factor for patients with PDAC.

Clinical Characteristics of the Patient With Unmeasurable Ankle-Brachial Index in Endovascular Treatment

Introduction Ankle-brachial index (ABI) is an important indicator to diagnose lower extremity arterial disease (LEAD). However, patients with unmeasurable ABI are sometimes excluded from the analysis and their clinical characteristics are poorly understood. Methods One hundred twenty-two consecutive Japanese subjects (mean age, 72 years), who underwent successful endovascular treatment (EVT) for lower extremity arteries at our hospital were retrospectively studied. Results Of the 122 patients, 23 (19%) patients presented an unmeasurable ABI before EVT. Five of 23 (22%) had still an unmeasurable ABI one day after EVT. Comorbidities including hypertension, diabetes, dyslipidemia, hemodialysis, smoking, ischemic heart disease, atrial fibrillation, and past-EVT history were not different between ABI measurable and unmeasurable patients. However, patients with unmeasurable ABI presented a significantly higher degree of Rutherford category and a smaller number of tibial vessel runoff than patients with measurable ABI before EVT (p<0.05 and p<0.01, respectively). There was no difference in the lesion site between the two groups. The event rate including all-cause mortality, re-EVT, lower limb amputation, and bypass surgery did not differ between two groups four years after EVT. ABI after four years of initial EVT did not differ between pre-EVT measurable and unmeasurable patients (0.96 vs. 0.84, p=0.48). Conclusions Patients with unmeasurable ABI before EVT were characterized by higher degree of Rutherford categorization and a small number of tibial vessel runoff, but there was no significant difference in outcomes during the follow-up period.

Novel case of laparoscopically resected gastric adenocarcinoma concurrent with lanthanum deposition

A 73-year-old man taking lanthanum carbonate for hemodialysis showed progressing gastric mucosal changes with lanthanum deposition. Regular examination revealed concurrent gastric carcinoma. The extent and depth of its invasion were ambiguous because of the surrounding lanthanum deposition. Furthermore, there could be other potent carcinomas, and curative laparoscopic gastrectomy was performed.

Subcutaneous-implantable cardioverter defibrillator lead dislodgement in a juvenile catecholamine-induced polymorphic ventricular tachycardia patient

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a relatively rare inherited arrhythmic disease that causes sudden cardiac death, and is caused by mutations in the cardiac ryanodine receptor (RyR2) or sarcoplasmic reticulum protein calsequestrin 2 gene (CASQ2). A 16-year-old man was diagnosed with CPVT and was implanted with a Subcutaneous-implantable Cardioverter Defibrillator (S-ICD), but defibrillation electrode detachment occurred early after placement. We suspected that a two-incision technique was the possible cause. We also report on changes in surface ECG in remote monitoring of the device. TAKE HOME MESSAGE  Although two-incision techniques are becoming the mainstream method of S-ICD implantation, we should consider that the three-incision technique may be advantageous in highly active patients. Remote monitoring may also be useful for early detection of S-ICD dislodgement.

Delayed laparoscopic cholecystectomy for a patient with coronavirus disease 2019 who developed gangrenous cholecystitis: a case report

Background

Gangrenous cholecystitis has a high risk of perforation and sepsis; therefore, cholecystectomy in the early stage of the disease is recommended. However, during the novel coronavirus disease 2019 (COVID-19) pandemic, the management of emergent surgeries changed to avoid contagion exposure among medical workers and poor postoperative outcomes.

Case presentation

A 56-year-old man presented to our hospital with abdominal pain. Computed tomography revealed intraluminal membranes, an irregular or absent wall, and an abscess of the gallbladder, indicating acute gangrenous cholecystitis. Early laparoscopic cholecystectomy seemed to be indicated; however, a COVID-19 antigen test was positive despite no obvious pneumonia on chest computed tomography and no symptoms. After discussion among the multidisciplinary team, antibiotic therapy was started and percutaneous transhepatic gallbladder drainage (PTGBD) was planned for the following day because the patient’s vital signs were stable and his abdominal pain was localized. Fortunately, the antibiotic therapy was very effective, and PTGBD was not needed. The cholecystitis improved and the patient was discharged from the hospital on day 10. One month later, laparoscopic delayed cholecystectomy was performed after confirming a negative COVID-19 polymerase chain reaction test result. The postoperative course was uneventful, and the patient was discharged on postoperative day 2 in satisfactory condition.

Conclusion

We have reported a case of acute gangrenous cholecystitis in a patient with asymptomatic COVID-19 disease. This report can help to determine treatment strategies for patients with gangrenous cholecystitis during future pandemics.

Urine osmolality predicts worsening renal function and poor prognosis in acute decompensated heart failure

Background/Purpose

Worsening renal function (WRF) can sometimes occur in the patients with acute decompensated heart failure (ADHF) and increase the risk of morbidity and mortality (1). In a previous study, it was reported that fractional excretion of sodium (FENa) reflects net sodium reabsorption from nephron segments and predicts WRF during treating ADHF (2). On the other hand, recently the new drugs which approach urine concentration mechanism and affect urine osmolality (U-OSM), such as tolvaptan and sodium-glucose cotransporter-2 inhibitor, have begun to be widely used as treatment of heart failure. Thus, we focused on U-OSM, which reflects not only sodium handling but also water excretion controlled by the collecting duct, and evaluated the association between WRF and U-OSM. Moreover, previous studies have demonstrated that FENa, fractional excretion of urea nitrogen and transtubular potassium concentration gradient are markers for long-term prognosis in patients with ADHF (3–5). Therefore, we also studied whether U-OSM can predict prognosis in ADHF.

Methods

A total of 157 patients admitted to our hospital because of a primary diagnosis of ADHF from February 2020 through July 2021 were retrospectively reviewed. U-OSM in the spot urinary samples were examined within 72 hours after admission. U-OSM was calculated based on the following validated formula (6): U-OSM = 1.07 × {2 × [urine sodium (mEq/L)] + [urine urea nitrogen (mg/dL)]/2.8 + [urine creatinine (mg/dl)] × 2/3} + 16.2. The primary outcome was the occurrence of WRF during hospitalization. WRF was defined as increased serum creatinine ≥0.3 mg/dL from baseline (7). The secondary outcome was the occurrence of ADHF readmission and all-cause death within 180 days after discharge.

Results

Primary Outcome. WRF developed in 46% of all patients. In the patients that developed WRF during hospitalization, U-OSM was significantly lower than in the patients without WRF (366±106 mOsm/L versus 430±128 mOsm/L; P&lt;0.001). Receiver operating characteristic curve analysis revealed the optimal cutoff values of U-OSM was 403 mOsm/L (AUC 0.64; 95% CI: 0.56–0.72; P&lt;0.001) to predict the WRF (Figure 1). On multivariable logistic regression analysis, U-OSM (OR, 1.99, 95% CI: 1.27–3.12; p=0.003) and serum creatinine (OR, 1.00, 95% CI: 0.99–1.00; P=0.009) were independent predictors of WRF.

Secondary Outcome. There were 34 patients (22%) readmitted and 9 patients (6%) died within 180 days after discharge. ROC curve analysis revealed the optimal cutoff values of U-OSM as 349 mOsm/L (C-statistic 0.74; 95% CI: 0.65–0.83; P&lt;0.001) to predict ADHF readmission and all-cause death within 180 days (Figure 2A). On Kaplan-Meier analysis, the secondary outcome was significantly higher in patients with U-OSM&lt;349 mOsm/L (u-OSM≥349, 57%, U-OSM&lt;349, 43%; HR, 0.99; 95% CI: 0.99–1.00, P&lt;0.001) (Figure 2B).

Conclusion

U-OSM on admission may be a predictor of WRF and a prognostic marker in ADHF patients.

Funding Acknowledgement

Type of funding sources: None.

Synchronous gallbladder metastasis originating from residual gastric cancer: a case report and the review of literature

Background

Gastric cancer rarely metastasizes to the gallbladder. Furthermore, there has never been a case report of simultaneous gallbladder metastasis from residual gastric cancer. Here, we report a case of synchronous gallbladder metastasis originating from a residual gastric cancer.

Case presentation

A 67-year-old man underwent a follow-up upper endoscopy 18 months after a partial gastrectomy for gastric cancer; an ulcerative lesion was found in the remnant stomach at the gastrojejunal anastomosis. A biopsy revealed gastric signet-ring cell carcinoma (SRCC). A full-body examination revealed no abnormalities other than gallstones in the gallbladder. With a diagnosis of residual gastric cancer (cT2N0M0 cStage I), the patient underwent open total gastrectomy and cholecystectomy. Macroscopic findings of the resected specimen revealed thickening of the gallbladder wall; however, no obvious neoplastic lesions were found on the mucosal surface of the gallbladder. The pathological findings showed that the SRCC had invaded the submucosa of the gastrojejunostomy site with a high degree of lymphatic invasion and lymph node metastases. SRCCs were also found in the lymphatic vessels of the gallbladder wall. These findings suggested the possibility of gallbladder metastasis through lymphatic vessels. The patient and his family members refused postoperative chemotherapy. Ten months after the operation, the patient experienced respiratory failure due to lymphangitis carcinomatosa and died.

Conclusions

At present, it is difficult to determine whether resection of the gallbladder contributes to an improved prognosis of gastric cancer patients. However, reports in such cases demonstrate that gallbladder metastasis could be a poor predictor of prognosis for gastric cancer.

A case of successful conversion surgery for locally advanced pancreatic cancer with synchronous triple cancer of the lung and esophagus: a case report

Background

The number of reports of multiple primary cancer (MPC) is increasing because of the advancement in diagnostic imaging technology. However, the treatment strategy for MPCs involving pancreatic cancer is controversial because of the extremely poor prognosis. We herein report a patient with synchronous triple cancer involving the pancreas, esophagus, and lung who underwent conversion surgery after intensive chemotherapy for unresectable locally advanced pancreatic cancer.

Case presentation

A 59-year-old man was admitted to our hospital with epigastric pain, anorexia, and weight loss. Computed tomography and upper gastrointestinal endoscopy revealed that the patient had synchronous triple cancer of the pancreas, esophagus, and lung. While the esophageal and lung cancer were relatively non-progressive, the pancreatic tail cancer had invaded the aorta, celiac axis, and left kidney, and the patient was diagnosed with unresectable locally advanced disease. Because the described lesion could have been the prognostic determinant for this patient, we initiated intensive chemotherapy (gemcitabine plus nab-paclitaxel) for pancreatic cancer. After six courses of chemotherapy, the tumor size shrank remarkably and no invasion to the aorta or celiac axis was observed. No significant changes were observed in the esophageal and lung cancers; endoscopic submucosal dissection could be still a curative treatment for the esophageal cancer. Therefore, we performed curative resection for pancreatic cancer (distal pancreatomy, splenectomy, and left nephrectomy; ypT3N0cM0, ypStage IIA, UICC 8th). Pathologically, complete resection was achieved. The patient then underwent endoscopic submucosal dissection for early esophageal cancer (pT1a[M]-LPM) and video-assisted thoracoscopic right upper lobectomy in combination with right lower partial resection for early lung cancer (pT2aN0M0, pStage IB, UICC 8th). Eight months after pancreatic cancer surgery, the patient is alive and has no sign of recurrence; as a result of the successful treatment, the patient has a good quality of life.

Conclusions

Treatment of MPC is challenging, especially for cases with unresectable tumors. Although synchronous triple cancer can involve unresectable pancreatic cancer, radical resection may be possible after careful assessment of the appropriate treatment strategy and downstaging of unresectable tumors.

Indocyanine green fluorescence to ensure perfusion in middle segment-preserving pancreatectomy: a case report

Background

Middle segment-preserving pancreatectomy (MSPP) is an alternative to total pancreatectomy that allows for the preservation of the endocrine and exocrine functions of the pancreas. However, maintaining perfusion to the pancreatic remnant is of critical importance. We describe the first case to our knowledge in which indocyanine green (ICG) fluorescence was used to confirm perfusion to the pancreatic remnant during MSPP.

Case presentation

A 79-year-old man with diabetes mellitus was referred to our hospital for treatment of a pancreatic tumor. Computed tomography revealed a hypovascular mass in the uncus of the pancreas and dilatation of the main pancreatic duct, measuring 13 mm in the tail of the pancreas. He was diagnosed with cancer of the pancreatic uncus via endoscopic ultrasound and fine-needle aspiration revealed a mixed-type intraductal papillary mucinous neoplasm (IPMN), along with high-risk stigmata in the tail of the pancreas. We performed MSPP and the length of the pancreatic remnant was 4.6 cm. The dorsal pancreatic artery was preserved and perfusion to the pancreatic remnant was confirmed by ICG fluorescence. Histopathological examination showed a pancreatic ductal adenocarcinoma in the uncus (pT1cN1M0, pStage 2B) and IPMN in the tail of the pancreas. The postoperative course was complicated by a grade B pancreatic fistula, but this was successfully treated with conservative management. The patient was transferred to a hospital 33 days after surgery. Insulin administration was necessary, but C-peptide was detectable and blood glucose was relatively well-controlled. He did not exhibit any exocrine dysfunction when pancreatic enzyme supplementation was administered.

Conclusion

ICG fluorescence can be used to evaluate perfusion to the pancreatic remnant during MSPP.

Estimation of genetic parameter for feed efficiency and resilience traits in three pig breeds

Recently, automatic feeders have become popular for collecting daily feed intake data in the pig industry, making it possible to evaluate genetic effects on feed efficiency and resilience traits, expressed as day-to-day fluctuations in feeding records. This study aimed to understand the influence of genetic factors on feed efficiency traits, including residual intake and BW gain (RIG), and resilience traits, as well as to compare the differences in genetic parameter estimates among three purebred pig breeds. A total of 6 103 pigs from three breeds (Large White: 1 193 pigs, Landrace: 3 010 pigs, and Duroc: 1 900 pigs) were raised in a specific pathogen-free environment. The growth and feed intake records during the testing period were obtained using automatic feeders, and the average daily gain (ADG) and average feed intake (AFI) were calculated. Feed conversion ratio (FCR), residual feed intake (RFI), residual gain, and RIG were calculated as feed efficiency traits, and the log-transformed variance of deviation for the daily feed intake (LnVar_FI), daily occupation time (LnVar_OC), and the daily number of visits to the feeder (LnVar_VT) was calculated as resilience traits. After estimating the genetic parameters for each breed, a meta-analysis was performed to obtain the weighted mean of heritability estimates (h_m²) and genetic correlation estimates (GC_m) for the three breeds. The h_m² were moderate and ranged from 0.31 to 0.39 for feed efficiency traits and 0.31 to 0.40 for resilience traits, and there were no significant differences in heritability estimates among the three breeds except for AFI, RFI, and RIG. For feed efficiency traits, the FCR and RIG showed favourably moderate GC_m with AFI (0.29 and -0.33, respectively) and ADG (-0.39 and 0.31, respectively). For resilience traits, the LnVar_FI and LnVar_VT showed favourably low to moderate GC_m with FCR (0.33 and 0.28, respectively) and RIG (-0.37 and 0.28, respectively), and there were no genetic relationships of LnVar_OC with FCR and RIG (the absolute value of GC_m was 0.01). There was no significant difference in the genetic correlation estimates among the three breeds for feed efficiency and resilience traits. Our results suggest that feed efficiency and resilience traits were heritable, and resilience traits showed favourable or no genetic correlation with feed efficiency traits. In addition, the influence of genetic factors on feed efficiency and resilience traits could be the same among breeds.

Recurrent intraductal papillary neoplasm of the bile duct due to intraductal dissemination: a case report and literature review

Background

Intraductal papillary neoplasm of the bile duct (IPNB) is a subtype of biliary tumor. The 5-year survival rate of patients with IPNB who underwent curative resection is 81%. However, IPNB is known to often recur in other parts of the bile duct. Nevertheless, its mechanism remains poorly understood. Herein, we report the case of a patient with recurrent IPNB, which was considered to be attributed to intraductal dissemination in the common bile duct at 12 months after curative resection. We also made a review of the existing literature.

Case presentation

A 69-year-old man was referred to our hospital for the evaluation and dilation of an intrahepatic bile duct (IHBD) mass. Computed tomography (CT) findings confirmed a mass in the left hepatic duct. Left trisectionectomy, extrahepatic bile duct resection with biliary reconstruction, and regional lymph node dissection were performed. Intraoperative examination of the resection margin at the common bile duct and posterior segmental branch of the hepatic duct was negative for the presence of malignant cells. Histologically, the tumor showed intraductal papillary growth of the mucinous epithelium and was diagnosed as non-invasive IPNB. It had a papillary structure with atypical epithelial cells lined up along the neoplastic fibrovascular stalks. Immunohistochemically, this was as a gastric-type lesion. At 12 postoperative months, CT revealed a 1.5-cm mass in the lower remnant common bile duct. We performed subtotal stomach-preserving pancreaticoduodenectomy. The tumor exhibited papillary growth and was microscopically and immunohistochemically similar to the first tumor. At approximately 16 months after the patient’s second discharge, CT showed an abdominal mass at the superior mesenteric plexus, which was diagnosed as recurrent IPNB. Chemotherapy is ongoing, and the patient is still alive. In this case, as described in many previous reports, IPNB recurred below the primary lesion in the bile duct.

Conclusion

Based on our review of previous reports on IPNB recurrence, intraductal dissemination was considered one of the mechanisms underlying recurrence after multicentric development. Considering the high frequency and oncological conversion of recurrence in IPNB, regular follow-up examination is essential to achieve better prognosis in patients with recurrent IPNB.

Lethal multiple colon necrosis and perforation due to fulminant amoebic colitis: a surgical case report and literature review

Background

Amoebiasis caused by the protozoan species Entamoeba histolytica rarely develops into fulminant amoebic colitis (FAC), but when it does, it shows an aggressive clinical course including colonic perforation, necrotizing colitis, and high mortality. Surgical treatment for FAC patients should be carried out urgently. However, even after surgery, the mortality rate can be 40–50%. Although FAC is one of the most unfavorable surgical diseases with a poor prognosis, there are a few reports on the perioperative diagnosis and management of FAC based on autopsy findings. We herein report the surgical case of a 64-year-old man who developed multiple colon necrosis and perforation due to FAC. A detailed autopsy revealed FAC as the cause of death. Additionally, we reviewed the existing literature on FAC patients who underwent surgery and followed their perioperative diagnosis and management.

Case presentation

A 64-year-old man presented with anorexia, diarrhea, and altered consciousness on arrival to our hospital. Computed tomography revealed a large mass in the upper right lobe of his lung, and the patient was admitted for close investigation. Bloody diarrhea, lower abdominal pain, and hypotension were observed soon after admission. Urgent abdominal contrast-enhanced computed tomography scan revealed extensive intestinal ischemia, intestinal pneumatosis, and free intra-abdominal gas. The preoperative diagnosis was bowel necrosis and perforation with intussusception of the small intestinal tumor. Emergency subtotal colectomy and enterectomy were performed soon after the contrast-enhanced computed tomography. He was taken to an intensive care unit after surgery. However, he could not recover from sepsis and died with disseminated intravascular coagulation and multiple organ failure on the 10th-day post-surgery. A histopathological examination of the resected colon showed transmural necrosis and massive amoebae invasion. He was diagnosed with FAC. An autopsy revealed that he had developed pulmonary large cell carcinoma with small intestinal metastasis. The death was caused by intestinal ischemia, necrosis and the perforation of the residual bowel caused by amoebae invasion.

Conclusions

Since FAC is a lethal disease with a high mortality rate and antibiotic therapies except metronidazole are ineffective, preoperative serological testing and perioperative metronidazole therapy in FAC patients can dramatically improve their survival rates.

Not Only Hypoxia- but Radiation-Induced Epithelial-Mesenchymal Transition Is Modulated by Hypoxia-Inducible Factor 1 in A549 Lung Cancer Cells

Hypoxia leads to post-treatment metastasis and recurrences of cancer via the epithelial-mesenchymal transition (EMT). Radiotherapy itself may also contribute to the acquisition of EMT phenotypes. Despite extensive studies on the EMT driven by either hypoxia or radiation stimuli, the molecular mechanisms characterizing these EMT events remain unclear. Thus, we aimed to evaluate the differences in the molecular pathways between hypoxia-induced EMT (Hypo-EMT) and radiation-induced EMT (R-EMT). Further, we investigated the therapeutic effects of HIF-1α inhibitor (LW6) on Hypo-EMT and R-EMT cells. A549 cells, lung adenocarcinoma cell line, acquired enhanced wound-healing activity under both hypoxia and irradiation. Localization of E-cadherin was altered from the cell membrane to the cytoplasm in both hypoxia and irradiated conditions. Of note, the expression levels of vimentin, one of the major EMT markers, was enhanced in irradiated cells, while it decreased under hypoxia condition. Importantly, LW6 significantly blocked EMT-related malignant phenotypes in both Hypo-EMT cells and R-EMT cells with concomitant re-location of E-cadherin onto the cell membrane. Moreover, LW6 deflected stress responsive signalling, JNK, activated sustainably under hypoxic condition, and the blockage of JNK impaired EMT phenotypes. Together, this work demonstrated the molecular events underlying Hypo-EMT and R-EMT, and highlighted HIF-1α as a therapeutic target not only in Hypo- EMT, but also in R-EMT.

Primary anorectal malignant melanoma with laparoscopic abdominoperineal resection: a case study and review of the relevant literature

ARMM is a disease with a poor prognosis. ARMM is often diagnosed at an advanced stage, and the 5-year survival rate of ARMM is < 20%. Although the number of case reports on ARMM is gradually increasing, the optimal treatment strategy for ARMM remains controversial. We report the case of an 81-year-old woman who had experienced bloody stool for 6 months before her diagnosis and who had been initially diagnosed with hemorrhoids. The pathological diagnosis of a biopsy specimen was malignant melanoma. Other examinations showed no evidence of lymph node or distant metastasis. Based on these results, laparoscopic abdominoperineal resection was performed. Three months later on her first follow-up examination, distant metastasis to the lung and liver was detected. Immunotherapy using Nivolumab was initiated to treat the recurrent disease. We reviewed the characteristics of a total of 1834 ARMM patients described in previous reports on ARMM for which the full text was available on PubMed. We experienced a case of ARMM. The prognosis of ARMM is still poor, regardless of the surgical procedure. Previous studies and our case report suggest that systemic therapy, such as immunotherapy using an anti-PD-1 ligand may be more important than reinforcement of local control for improving the prognosis of ARMM patients.

Impact of technically qualified surgeons on laparoscopic colorectal resection outcomes: results of a propensity score-matching analysis

Background

The Endoscopic Surgical Skill Qualification System (ESSQS) was introduced in Japan to improve the quality of laparoscopic surgery. This cohort study investigated the short‐ and long‐term postoperative outcomes of colorectal cancer laparoscopic procedures performed by or with qualified surgeons compared with outcomes for unqualified surgeons.

Methods

All laparoscopic colorectal resections performed from 2010 to 2013 in 11 Japanese hospitals were reviewed retrospectively. The procedures were categorized as performed by surgeons with or without the ESSQS qualification and patients' clinical, pathological and surgical features were used to match subgroups using propensity scoring. Outcome measures included postoperative and long‐term results.

Results

Overall, 1428 procedures were analysed; 586 procedures were performed with ESSQS‐qualified surgeons and 842 were done by ESSQS‐unqualified surgeons. Upon matching, two cohorts of 426 patients were selected for comparison of short‐term results. A prevalence of rectal resection (50·3 versus 40·5 per cent; P < 0·001) and shorter duration of surgery (230 versus 238 min; P = 0·045) was reported for the ESSQS group. Intraoperative and postoperative complication and reoperation rates were significantly lower in the ESSQS group than in the non‐ESSQS group (1·2 versus 3·6 per cent, P = 0·014; 4·6 versus 7·5 per cent, P = 0·025; 1·9 versus 3·9 per cent, P = 0·023, respectively). These findings were confirmed after propensity score matching. Cox regression analysis found that non‐attendance of ESSQS‐qualified surgeons (hazard ratio 12·30, 95 per cent c.i. 1·28 to 119·10; P = 0·038) was independently associated with local recurrence in patients with stage II disease.

Conclusion

Laparoscopic colorectal procedures performed with ESSQS‐qualified surgeons showed improved postoperative results. Further studies are needed to investigate the impact of the qualification on long‐term oncological outcomes.

SAKE: first-principles electron transport calculation code

We developed and implemented a numerical code called SAKE, which stands for (simulation code for atomistic Kohn-Sham equation). We developed it for first-principle electron transport calculations based on density-functional theory and non-equilibrium Green's function formalism. First, we present the central calculation parts of the formalism of the electronic states and transport properties for open and non-equilibrium systems. We show specific computational techniques, such as the use of a complex contour integration for charge density from the density matrix, which is compared with the calculation method of summing the residues of the Fermi-Dirac distribution, as well as the efficient achievement of the self-consistent procedures. Thereafter, for applications of the present computation code, SAKE, we present first-principle calculation results of three different systems. We first analyze electronic structures of polythiophene molecular wires, compare summation techniques for the density matrix. We show thermoelectric properties of an n-type antiferromagnetic semiconductor CuFeS2 as a second application. The electrical conductance, electrical thermal conductance, and the Seebeck coefficients with carrier doping are examined, and the analytical form of the Seebeck coefficient is briefly described. For the third application, we analyze the electron transport properties of polyaniline molecular wires under structural deformations, i.e. rotations around the transport direction. The thermally averaged current-voltage characteristics are also analyzed. The results show that the current decreases as the temperature increases which are determined based on the competition between the thermal energy and the electronic energy, which increases with the rotation angle.

P6355The behavior of atrial fibrillation in patients with heart failure hospitalization

Background

Relationship between atrial fibrillation (AF) and heart failure (HF) is often compared with proverbial question of which came first, the chicken or the egg. Some patients showing AF at the HF admission result in restoration of sinus rhythm (SR) at discharge. It is not well elucidated that the restoration into SR during hospitalization can render the preventive effect for rehospitalization.

Purpose

To investigate the impact of restoration into SR during hospitalization for readmission rate of the HF patients showing AF.

Methods

We enrolled consecutive 640 HF patients hospitalized from January 2015 to December 2015. Patients data were retrospectively investigated from medical record. Patients showing atrial fibrillation on admission but unrecognized ever were defined as “incident AF”; patients with AF diagnosed before admission were defined as “prevalent AF”. Primary endpoint was a composite of death from cardiovascular disease or hospitalization for worsening heart failure. Secondary endpoints were death from cardiovascular disease, unplanned hospitalization related to heart failure, and any hospitalization.

Results

During mean follow up of 19 months, 139 patients (22%) were categorized as incident AF and 145 patients (23%) were categorized as prevalent AF. Among 239 patients showing AF on admission, 44 patients were discharged in SR (39 patients in incident AF and 5 patients in prevalent AF). Among incident AF patients, the primary composite end point occurred in significantly fewer in those who discharged in SR (19% vs. 42% at 1-year; 23% vs. 53% at 2-year follow-up, p=0.005). To compare the risk factors related to readmission due to HF with the cox proportional-hazards model, AF only during hospitalization [Hazard Ratio (HR)=0.37, p<0.01] and prevalent AF (HR=1.67, p=0.04) was significantly associated. There was no significant difference depending on LVEF.

Conclusion

Newly diagnosed AF with restoration to SR during hospitalization was a good marker to forecast future prognosis.

Comparison of computed tomography imaging analyses for evaluation after chemotherapy in patients with colorectal cancer: a retrospective pooled analysis of six phase II clinical trials

BACKGROUND

There are several methods for analyzing computed tomography (CT) images to evaluate chemotherapy efficacy in clinical studies. However, the optimal analysis method for each drug is still under debate. We conducted a pooled analysis using data from six phase II studies to evaluate four analysis methods in colorectal cancers (CRCs): morphological responses (MRs), early tumor shrinkage (ETS), depth of response (DpR), and response evaluation criteria in solid tumors (RECIST) ver.1.1.

METHODS

We included 249 patients in this analysis. Pretreatments and findings of subsequent CT imaging were analyzed based on the MR, ETS, DpR, and RECIST ver.1.1. Differences in overall survival (OS) between the responders and non-responders according to each method were evaluated using survival analysis.

RESULTS

The responders had significantly better hazard ratios (HRs) for OS, in terms of DpR (≥ median), ETS, objective response rate (ORR) [complete response (CR) + partial response (PR)], and disease control rate [CR + PR + stable disease (SD)]. Patients with right-sided colon cancers showed better HRs for DpR, but not for ETS and ORR. Contrastingly, patients with left-sided CRCs had better HRs for ETS, DpR, and ORR. MR was not associated with outcomes in this study, even in cases where bevacizumab was used. In patients with liver metastasis, ETS, DpR, and ORR showed better HRs, but not in those with lung metastasis.

CONCLUSION

Early tumor shrinkage and DpR might be predictive markers only in left-sided CRCs with liver metastasis. Each imaging analysis has a different value based on the primary and metastatic sites.

Successful multidisciplinary treatment including repeated metastasectomy for recurrent squamous cell esophageal carcinoma: a case report

Background

Recurrences after radical esophagectomy are common. The prognosis for recurrent esophageal cancer is generally poor. Recurrences usually occur between 1 and 3 years of surgery, with the duration of median survival after recurrence ranging from 5 to 10 months. The number of sites and involved organs vary among patients. Consequently, a standard therapeutic strategy has not been established, and the role of surgery in the management of recurrence is unclear.

Case presentation

A 67-year-old man presented with dysphagia 6 months previously and was diagnosed with esophageal squamous cell carcinoma (ESCC) in the upper thoracic region (T2M0M0, stage IB), for which he underwent thoracoscopy-assisted esophagectomy and lymphadenectomy. Adjuvant chemotherapy was not prescribed. Three years after the operation, he developed a solitary metastasis in the left lung, requiring segmentectomy followed by chemotherapy with combined cisplatin (CDDP) and 5-fluorouracil (5-FU). The following year, a metastatic lesion was recognized in the right lung, invading the chest wall, for which he underwent partial lobectomy with local chest wall resection. Multiple mediastinal and abdominal lymph node (LN) metastases were detected in the right lung a year later, which necessitated chemoradiation to a dose of 50.4 Gy with concomitant CDDP and 5-FU. Post-treatment computed tomography (CT) showed a good response. Positron emission tomography (PET)-CT revealed a reduction in the metastatic LNs with no fluoro-deoxy-glucose (FDG) uptake. The following year, metastases were detected in the left cervical LNs. Owing to the limited extent of metastases, resection was followed by chemoradiation to a dose of 50 Gy with CDDP and 5-FU. The following year, metastases were detected in the mediastinal LNs; chemotherapy was administered with nedaplatin and docetaxel. The follow-up CT and PET-CT demonstrated complete disappearance of the tumor, and the patient is currently surviving without recurrence for 11 years from the first curative operation.

Conclusions

This case demonstrates that aggressive multidisciplinary treatment including surgery and radiation to achieve local control could be a meaningful treatment strategy in cases with limited and slowly occurring recurrences.

C-reactive protein/albumin ratio is a poor prognostic factor of esophagogastric junction and upper gastric cancer

BACKGROUND AND AIM

The C-reactive protein (CRP)/albumin (Alb) ratio has been reported as a novel prognostic marker in several cancers. The objective of this study was to investigate the prognostic value of the CRP/Alb ratio in patients who underwent surgery for adenocarcinoma of the esophagogastric junction (AEG) and upper gastric cancer (UGC).

METHODS

Data for 144 patients who underwent surgery for AEG and UGC were reviewed. The CRP/Alb ratio, neutrophil-lymphocyte ratio, platelet-lymphocyte ratio, Glasgow Prognostic Score, and controlling nutritional status score were calculated, and the relationship between these biomarkers and postoperative prognosis was analyzed.

RESULTS

The optimal cutoff value of the CRP/Alb ratio was determined to be 0.1. According to the cutoff value of CRP/Alb ratio, patients were divided into two groups (CRP/Alb < 0.1, n = 124; CRP/Alb ≥ 0.1, n = 20). The 5-year recurrence-free survival and overall survival (OS) rates were significantly lower in the patients with the CRP/Alb ratio ≥ 0.1 than in those with the CRP/Alb ratio < 0.1 (recurrence-free survival: 44.9% vs 77.9%, P = 0.0011; OS: 43.4% vs 82.0%, P < 0.0001). In the multivariate analyses, the N-stage, and CRP/Alb ratio ≥ 0.1 were identified as independent predictive factors for OS in patients with AEG and UGC (P = 0.0061 and P = 0.0439, respectively).

CONCLUSIONS

The CRP/Alb ratio was strongly associated with poor prognosis in patients who underwent surgery for AEG and UGC.

Primary amelanotic malignant melanoma of the esophagus: a case report

Background

Primary amelanotic malignant melanoma of esophagus, which is a subtype of primary malignant melanoma of the esophagus (PMME), is a very rare disease with a poor prognosis. We herein report a case of the amelanotic type of PMME.

Case presentation

An 86-year-old woman was admitted to our hospital with symptoms of dysphagia. An endoscopic examination and constructed radiography revealed an elevated and semipedunculated lesion with an ulcer in the lower thoracic esophagus accompanied by another submucosal lesion of the esophagus. She was diagnosed with esophageal squamous cell carcinoma by a preoperative endoscopic biopsy. We performed thoracoscopy- and laparoscopy-assisted subtotal esophagectomy with lymphadenectomy. Based on the surgical specimens, although there were no melanocytes, we made a diagnosis of a malignant melanoma immunohistochemically; the tumor cells were positive for S-100 protein and HMB45 focally and partially for Melan-A.

Conclusion

We experienced a case of primary amelanotic malignant melanoma, and the patient has remained disease-free for 1 year since the surgery. Since the diagnosis of amelanotic type of PMME is difficult, it should be made by the combination of a morphological examination, pathological examination, and immunohistochemistry.

Neoadjuvant Chemoradiotherapy for Patients with cT3/Nearly T4 Esophageal Cancer: Is Sarcopenia Correlated with Postoperative Complications and Prognosis?

BACKGROUND

Since the clinical impact of sarcopenia on multimodal therapy for patients with esophageal cancer is not well understood, this study was conducted to determine the influence of sarcopenia on the efficacy of neoadjuvant chemoradiotherapy (NACRT) for locally advanced esophageal cancer.

METHODS

The skeletal muscle index was quantified at the level of the third lumbar vertebra on computed tomography images, and sarcopenia was defined as a skeletal muscle index that was less than the average for each gender. We compared treatment outcomes in patients with cT3 and nearly T4 thoracic esophageal squamous cell carcinoma between the sarcopenia group (n = 85) and the non-sarcopenia group (n = 72).

RESULTS

The 5-year survival rates were 33.4% in the non-sarcopenia group and 31.5% in the sarcopenia group; these differences were not significant. The prognosis of the patients with sarcopenia was worse than that of the patients without sarcopenia in the surgery-alone group, but there was no difference between patients with and without sarcopenia in the NACRT group.

CONCLUSIONS

NACRT could be a useful option for patients with locally advanced esophageal squamous cell carcinoma, even for those with sarcopenia, without increasing the incidence of morbidity and mortality.

Coherent anti-Stokes Raman scattering rigid endoscope toward robot-assisted surgery

Label-free visualization of nerves and nervous plexuses will improve the preservation of neurological functions in nerve-sparing robot-assisted surgery. We have developed a coherent anti-Stokes Raman scattering (CARS) rigid endoscope to distinguish nerves from other tissues during surgery. The developed endoscope, which has a tube with a diameter of 12 mm and a length of 270 mm, achieved 0.91% image distortion and 8.6% non-uniformity of CARS intensity in the whole field of view (650 μm diameter). We demonstrated CARS imaging of a rat sciatic nerve and visualization of the fine structure of nerve fibers.

Role of Multichance Fission in the Description of Fission-Fragment Mass Distributions at High Energies

Fission-fragment mass distributions were measured for ^{237-240}U, ^{239-242}Np, and ^{241-244}Pu populated in the excitation-energy range from 10 to 60 MeV by multinucleon transfer channels in the reaction ^{18}O+^{238}U at the Japan Atomic Energy Agency tandem facility. Among them, the data for ^{240}U and ^{240,241,242}Np were observed for the first time. It was found that the mass distributions for all the studied nuclides maintain a double-humped shape up to the highest measured energy in contrast to expectations of predominantly symmetric fission due to the washing out of nuclear shell effects. From a comparison with the dynamical calculation based on the fluctuation-dissipation model, this behavior of the mass distributions was unambiguously attributed to the effect of multichance fission.

Chemoradiotherapy for Solitary Skeletal Muscle Metastasis from Oesophageal Cancer: Case Report and Brief Literature Review

BACKGROUND

The incidence of skeletal muscle metastasis from oesophageal cancer is very low, and the treatment strategy has not been established.

CASE REPORT

A 77-year-old man underwent oesophagectomy following neoadjuvant chemotherapy for oesophageal squamous cell carcinoma (CT-pT3 N0 M0, CT-pStage II). Fourteen months after surgery, he became aware of a subcutaneous tumour in his left forearm. Computed tomography and fluorodeoxyglucose positron-emission tomography revealed a 65×75 mm intramuscular nodular lesion with a standardized uptake value of 8.5. Further examination by biopsy strongly suggested this was a solitary metastasis from oesophageal cancer. The patient received chemoradiotherapy with two cycles of 5-fluorouracil combined with cisplatin and radiation. Clinical complete response was confirmed by imaging 7 months after chemoradiation and no recurrence has occurred at 20 months since chemoradiation.

CONCLUSION

Radiotherapy or chemoradiotherapy can be an alternative locoregional therapy to surgery for solitary skeletal muscle metastasis.

Clinical Results of Accelerated Hypofractionated Radiotherapy for Central-Type Small Lung Tumours

Purpose: We evaluated the efficacy and toxicity of accelerated hypofractionated radiotherapy (AHYPOF-RT) for central-type small lung tumours. Methods: Between November 2006 and January 2015, 40 patients with central-type small lung tumours underwent AHYPOF-RT delivered using 10 MV X-rays and a coplanar 3-field technique. The number of fractions ranged from 24 to 28, with a fraction size of 2.5–3 Gy. A total dose of 69–75 Gy to the isocentre of the planning target volume was administered to each patient. Cumulative survival and local control rates were calculated using the Kaplan–Meier method. Results: The 27 men and 13 women enrolled in the study had a median age of 79 years (range: 60−87 years). The tumour stage was T1a in 9 patients, T1b in 17 patients, and T2a in 14 patients, with a median size of 26.5 cm (range: 11–49 cm). The median follow-up period was 23 months. A complete response was achieved in 3 patients (7.5%), and a partial response, in 17 patients (42.5%). The overall 2-year and 3-year local control rates were 87.3% and 81.8% respectively; the 2-year and 3-year overall survival rates were 78.9% and 66.7% respectively. Grade 3 pneumonitis occurred in 3 patients; no other severe adverse events (≥grade 3) were observed in any patient. Conclusions: Accelerated hypofractionated radiotherapy using a fraction size of 2.5–3 Gy was highly safe and can be a more effective treatment option than conventional radiotherapy for patients with central-type small lung tumours.

IκBNS induces Muc5ac expression in epithelial cells and causes airway hyper-responsiveness in murine asthma models

BACKGROUND

In allergic asthma, environmental allergens including house dust mite (HDM) trigger pattern recognition receptors and activate downstream signaling pathways including NF-κB pathways not only in immune cells but also in airway epithelial cells. Recent studies have shown that NF-κB activation is regulated positively or negatively depending on the cellular context by IκBNS (encoded by the gene Nfkbid), one of atypical IκB proteins, in the nucleus. Therefore, we hypothesized that IκBNS expressed in immune cells or epithelial cells is involved in the regulation of asthmatic responses.

AIM

To determine the roles of IκBNS in HDM-induced asthmatic responses.

METHODS

Roles of IκBNS in HDM-induced airway inflammation and airway hyper-responsiveness (AHR) were examined by using IκBNS-deficient (Nfkbid^-/- ) mice. Roles of IκBNS expressed in hematopoietic cells and nonhematopoietic cells were separately evaluated by bone marrow chimeric mice. Roles of IκBNS expressed in murine tracheal epithelial cells (mTECs) were examined by air-liquid interface culture.

RESULTS

House dust mite-induced airway inflammation and AHR were exacerbated in mice lacking IκBNS in hematopoietic cells. In contrast, HDM-induced airway inflammation was exacerbated, but AHR was attenuated in mice lacking IκBNS in nonhematopoietic cells. The induction of Muc5ac, a representative mucin in asthmatic airways, was reduced in Nfkbid^-/- mTEC, whereas the induction of Spdef, a master regulator of goblet cell metaplasia, was not impaired in Nfkbid^-/- mTEC. Moreover, IκBNS bound to and activated the MUC5AC distal promoter in epithelial cells.

CONCLUSION

IκBNS is involved in inducing Muc5ac expression in lung epithelial cells and causing AHR in HDM-induced asthma models.

Direct administration of 2-Hydroxypropyl-Beta-Cyclodextrin into guinea pig cochleae: Effects on physiological and histological measurements

2-Hydroxypropyl-Beta-Cyclodextrin (HPβCD) can be used to treat Niemann-Pick type C disease, Alzheimer's disease, and atherosclerosis. But, a consequence is that HPβCD can cause hearing loss. HPβCD was recently found to be toxic to outer hair cells (OHCs) in the organ of Corti. Previous studies on the chronic effects of in vivo HPβCD toxicity did not know the intra-cochlear concentration of HPβCD and attributed variable effects on OHCs to indirect drug delivery to the cochlea. We studied the acute effects of known HPβCD concentrations administered directly into intact guinea pig cochleae. Our novel approach injected solutions through pipette sealed into scala tympani in the cochlear apex. Solutions were driven along the length of the cochlear spiral toward the cochlear aqueduct in the base. This method ensured that therapeutic levels were achieved throughout the cochlea, including those regions tuned to mid to low frequencies and code speech vowels and background noise. A wide variety of measurements were made. Results were compared to measurements from ears treated with the HPβCD analog methyl-β-cyclodextrin (MβCD), salicylate that is well known to attenuate the gain of the cochlear amplifier, and injection of artificial perilymph alone (controls). Histological data showed that OHCs appeared normal after treatment with a low dose of HPβCD, and physiological data was consistent with attenuation of cochlear amplifier gain and disruption of non-linearity associated with transferring acoustic sound into neural excitation, an origin of distortion products that are commonly used to objectively assess hearing and hearing loss. A high dose of HPβCD caused sporadic OHC losses and markedly affected all physiologic measurements. MβCD caused virulent destruction of OHCs and physiologic responses. Toxicity of HPβCD to OHC along the cochlear length is variable even when a known intra-cochlear concentration is administered, at least for the duration of our acute studies.

Plutonium, 137Cs and uranium isotopes in Mongolian surface soils

Plutonium (²³⁸Pu and ^239,240Pu), ¹³⁷Cs and plutonium activity ratios (²³⁸Pu/^239,240Pu) as did uranium isotope ratio (²³⁵U/²³⁸U) were measured in surface soil samples collected in southeast Mongolia. The ^239,240Pu and ¹³⁷Cs concentrations in Mongolian surface soils (<53 μm of particle size) ranged from 0.42 ± 0.03 to 3.53 ± 0.09 mBq g^-1 and from 11.6 ± 0.7 to 102 ± 1 mBq g^-1, respectively. The ²³⁸Pu/^239,240Pu activity ratios in the surface soils (0.013-0.06) coincided with that of global fallout. The ²³⁵U/²³⁸U atom ratios in the surface soil show the natural one. There was a good correlation between the ^239,240Pu and ¹³⁷Cs concentrations in the surface soils. We introduce the migration depth to have better understanding of migration behaviors of anthropogenic radionuclides in surface soil. We found a difference of the migration behavior between ^239,240Pu and ¹³⁷Cs from ¹³⁷Cs/^239,240Pu - ¹³⁷Cs plots for the Mongolian and Tsukuba surface soils; plutonium in surface soil is migrated easier than ¹³⁷Cs.