[Long-Term Survival with Distal Pancreatectomy and Postoperative Chemotherapy in a Patient of Pancreatic Invasive Ductal Adenocarcinoma of the Tail with Peritoneal Dissemination].

A 68-year-old man was referred to our hospital for detailed examination of the pancreatic tail tumor. The tumor was diagnosed as the pancreatic invasive ductal adenocarcinoma and the distal pancreatectomy was scheduled. During surgery, a 2 mm white nodule was observed on the posterior wall of the stomach. Intraoperative frozen section showed no obvious malignant findings, suggesting leiomyoma or gastrointestinal stromal tumor. Distal pancreatectomy with D2 lymphadenectomy was completed as planned. However, this nodule was later confirmed by permanent pathological specimen to be peritoneal dissemination of pancreatic cancer and final diagnosis was invasive ductal carcinoma of pancreatic tail, pT3, pN1a, M1 (PER), pStage Ⅳ. He received chemotherapy for 17 months. Although liver metastasis was appeared 26 months after surgery, the disease is still being controlled with chemotherapy at 33 months.

Evaluation of Spatial Resolution of Virtual Monochromatic Imaging In Vitro: Effect of Energy Level and Contrast.

OBJECTIVE: Our aim was to evaluate effects of the energy level and contrast on the spatial resolution of virtual monochromatic imaging (VMI). METHODS: With 2 types of computed tomographic (CT) scanners (Discovery CT750 HD and Revolution CT), we scanned an elliptical cylinder acrylic phantom with 20- or 40-fold dilutions of contrast medium and obtained VMI data sets at 40, 50, 60, and 70 keV. We evaluated the effects of energy levels and contrast on modulation transfer function (MTF) and the effect of energy levels on noise power spectra (NPS). RESULTS: With both CT scanners, MTF decreased significantly as the energy level decreased. The effect of the dilution of contrast media on MTF varied with CT scanners. With both scanners, NPS curves demonstrate uniform increase in NPS across the entire spatial frequency as the energy levels decreased. CONCLUSIONS: The energy level and contrast can affect the spatial resolution of VMIs.

Clinical improvement in a patient with severe coronavirus disease 2019 after administration of hydroxychloroquine and continuous hemodiafiltlation with nafamostat mesylate.

The number of people infected with severe acute respiratory syndrome coronavirus 2 is increasing globally, and some patients have a fatal clinical course. In light of this situation, the World Health Organization (WHO) declared coronavirus disease 2019 (COVID-19) a pandemic on March 11, 2020. While clinical studies and basic research on a treatment for COVID-19 are ongoing around the world, no treatment has yet been proven to be effective. Several clinical studies have demonstrated the efficacy of chloroquine phosphate and nafamostat mesylate with COVID-19. Here, we report the case of a Japanese patient with COVID-19 with severe respiratory failure who improved following the administration of hydroxychloroquine and continuous hemodiafiltlation with nafamostat mesylate. Hence, hydroxychloroquine with nafamostat mesylate might be a treatment option for severe COVID-19.

Reg3α and Reg3ß Expressions Followed by JAK2/STAT3 Activation Play a Pivotal Role in the Acceleration of Liver Hypertrophy in a Rat ALPPS Model.

To explore the underlying mechanism of rapid liver hypertrophy by liver partition in associating liver partition and portal vein ligation for staged hepatectomy (ALPPS), liver partition at different sites was investigated. Increased inflammatory cytokines owing to the liver partition have been reportedly responsible. If this were true, rapid liver hypertrophy should be achieved regardless of where the liver was split. A male Sprague-Dawley rat model was created, in which a liver split was placed inside the portal vein ligated lobe (PiLL), in addition to the ALPPS and portal vein ligation (PVL) models. Liver regeneration rate, inflammatory cytokine levels, activation status of the Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) pathway and expressions of regenerating islet-derived (Reg)3α and Reg3ß were investigated. The liver regeneration rate was significantly higher in the ALPPS group than in the PiLL group, whereas inflammatory cytokine levels were nearly equal. Additional volume increase in ALPPS group over PVL and PiLL groups was JAK2/STAT3-dependent. Reg3α and Reg3ß expressions were observed only in the ALPPS group. An increase in inflammatory cytokines was not enough to describe the mechanism of rapid liver hypertrophy in ALPPS. Expressions of Reg3α and Reg3ß could play an important role in conjunction with an activation of the JAK2/STAT3 pathway.

Adenosine A2a Receptor Stimulation Attenuates Ischemia-Reperfusion Injury and Improves Survival in A Porcine Model of DCD Liver Transplantation.

Orthotopic liver transplantation (OLT) using allografts from donation after circulatory death (DCD) is potentially associated with compromised clinical outcomes due to ischemia-reperfusion injury (IRI)-induced organ damage and graft-related complications. The aim of this study was to provide in vivo data on the effects of adenosine A2a receptor stimulation in a clinically relevant large animal model of DCD liver transplantation. Cardiac arrest was induced in German Landrace pigs (n = 10; 20-25 kg). After 30 min of warm ischemia, the donor liver was retrieved following a cold flush with 3 L of histidine-tryptophan-ketoglutarate-HTK solution. Animals of the treatment group (n = 5/group) received a standard dose of the selective adenosine receptor agonist CGS 21680 added to the cold flush. All grafts were stored for 4.5 h at 4 °C in HTK-solution before OLT. Hepatocellular injury, apoptosis, protein kinase A-PKA activity, graft microcirculation, liver function, and animal survival were assessed. Compared to untreated livers, adenosine A2a receptor stimulation resulted in improved tissue microcirculation (103% ± 5% vs. 38% ± 4% compared to baseline; p < 0.05), accelerated functional recovery of the graft (indocyanine green-plasma disappearance rate (ICG-PDR) of 75% ± 18% vs. 40% ± 30% after 3 h), increased PKA activity ratio (56% ± 3% vs. 32% ± 3%; p < 0.001 after 1 h), and consequently reduced tissue necrosis and apoptosis. The potent protective effects were clinically manifested in significantly improved survival in the treatment group after 72 h (100% vs. 40%; p = 0.04). The ex vivo administration of adenosine A2a receptor agonist during the back-table flush mitigates IRI-mediated tissue damage and improves functional graft recovery and survival in a large animal model of DCD liver transplantation.

Comparison of full-iodine conventional CT and half-iodine virtual monochromatic imaging: advantages and disadvantages.

PURPOSE: To compare image quality of abdominal arteries between full-iodine-dose conventional CT and half-iodine-dose virtual monochromatic imaging (VMI). MATERIALS AND METHODS: We retrospectively evaluated images of 21 patients (10 men, 11 women; mean age, 73.9 years) who underwent both full-iodine (600 mg/kg) conventional CT and half-iodine (300 mg/kg) VMI. For each patient, we measured and compared CT attenuation and the contrast-to-noise ratio (CNR) of the aorta, celiac artery, and superior mesenteric artery (SMA). We also compared CT dose index (CTDI). Two board-certified diagnostic radiologists evaluated visualisation of the main trunks and branches of the celiac artery and SMA in maximum-intensity-projection images. We evaluated spatial resolution of the two scans using an acrylic phantom. RESULTS: The two scans demonstrated no significant difference in CT attenuation of the aorta, celiac artery, and SMA, but CNRs of the aorta and celiac artery were significantly higher in VMI (p = 0.011 and 0.030, respectively). CTDI was significantly higher in VMI (p = 0.024). There was no significant difference in visualisation of the main trunk of the celiac artery and SMA, but visualisation of the gastroduodenal artery, pancreatic arcade, branch of the SMA, marginal arteries, and vasa recta was significantly better in the conventional scan (p < 0.001). The calculated modular transfer function (MTF) suggested decreased spatial resolution of the half-iodine VMI. CONCLUSION: Large-vessel depiction and CNRs were comparable between full-iodine conventional CT and half-iodine VMI images, but VMI did not permit clear visualisation of small arteries and required a larger radiation dose. KEY POINTS: ・Reducing the dose of iodine contrast medium is essential for chronic kidney disease patients to prevent contrast-induced nephropathy. ・In virtual monochromatic images at low keV, contrast of relatively large vessels is maintained even with reduced iodine load, but visibility of small vessels is impaired with decreased spatial resolution. ・We should be aware about the advantages and disadvantages associated with virtual monochromatic imaging with reduced iodine dose.

Comparison of Motion Artifacts on CT Images Obtained in the Ultrafast Scan Mode and Conventional Scan Mode for Unconscious Patients in the Emergency Department.

OBJECTIVE. The purpose of this study was to investigate whether, in the evaluation of unconscious patients in the emergency department, a new-generation CT scanner that acquires images in ultrafast scan mode (large coverage, fast rotation, high helical pitch) would reduce motion artifacts on whole-body CT images in comparison with those on images obtained with a conventional CT scanner. MATERIALS AND METHODS. Images of a total of 60 unconscious patients presenting to the emergency department were evaluated retrospectively. Of the 60 patients, 30 underwent CT with a new-generation scanner that acquires images in the ultrafast mode, and 30 underwent CT with a conventional scanner. Two radiologists independently evaluated motion artifacts in the aorta, lung, diaphragm, liver, and kidneys. The motion artifacts were graded in severity on a 4-point scale. A value of p < 0.05 was considered to indicate a statistically significant difference. RESULTS. Interobserver agreement on motion artifact ratings was good (κ = 0.80-0.93). Images obtained with the new-generation CT scanner showed a significant reduction in motion artifacts in the aortic root (p = 0.0003), lower lungs (p = 0.011), diaphragm (p = 0.0047), liver (p = 0.0026), and kidneys (p = 0.019). However, there were no significant differences between the two groups with respect to motion artifacts of the aortic arch, thoracic descending aorta, abdominal aorta, and upper lungs. CONCLUSION. CT images obtained in the ultrafast scan mode in the evaluation of unconscious patients had a significant reduction in motion artifacts. The ultrafast technique is expected to be useful for diagnostic CT in the emergency department.

Hepatic Stellate Cells Play a Functional Role in Exacerbating Ischemia-Reperfusion Injury in Rat Liver.

PURPOSE: The involvement of hepatic stellate cells (HSCs) with ischemia-reperfusion (I/R) injury in rat liver was examined using gliotoxin, which is known to induce HSC apoptosis. METHODS: Male Sprague-Dawley rats were used. HSC was represented by a glial fibrillary acidic protein (GFAP)-positive cell. Liver ischemia was produced by cross-clamping the hepatoduodenal ligament. The degree of I/R injury was evaluated by a release of aminotransferases. Sinusoidal diameter and sinusoidal perfusion rates were examined using intravital fluorescence microscopy. RESULTS: Gliotoxin significantly decreased the number of GFAP-positive cells 48 h after dosing (2.50 ± 0.19% [mean ± SD] in the nontreated group vs. 1.91 ± 0.46% in the gliotoxin-treated group). Liver damage was significantly suppressed by the pretreatment with gliotoxin. Sinusoidal diameters in zone 3 were wider in the gliotoxin group (10.25 ± 0.35 µm) than in the nontreated group (8.21 ± 0.50 µm). The sinusoidal perfusion rate was maintained as well in the gliotoxin group as in normal livers, even after I/R. CONCLUSIONS: Pretreatment with gliotoxin significantly reduced the number of HSCs in the liver and further suppressed liver injury following I/R. It is strongly suggested that HSCs play a functional role in exacerbating the degree of I/R injury of the liver.

[Advanced Adrenocortical Carcinoma with Vena Caval Tumor Thrombus Treated with Extended Surgery and Subsequent Chemotherapy].

A 36-year-old female was referred to our hospital for a giant abdominal mass found by ultrasound examination. A computed tomographic scan showed a large retroperitoneal mass measuring 11 cm in diameter suspected to be liver invasion,a right atrial and inferior vena cava (IVC) tumor thrombus with obstruction of hepatic vein junction of IVC,and small lung metastases. She was diagnosed with cT4N0M1 adrenocortical carcinoma (ACC) by a needle biopsy and radiographic examination. Right adrenalectomy and thrombectomy were successfully performed without cardiac arrest and without liver dissection. The operative time was 485 minutes,and the estimated blood loss was 7,533 ml. No major peri- or postoperative complications were observed. For the residual lung mass,a first line combination chemotherapy with etoposide,doxorubicin,cisplatin and mitotane followed by a second line chemotherapy with gemcitabine and capecitabine were administered. She has been alive with disease for 45 months under mitotane treatment against residual lung metastases. In conclusion,extended surgery could be successfully performed for advanced ACC with right atrium and IVC tumor thrombus. Although careful planning is needed for successful surgery,combination therapy with extended surgery and subsequent systematic chemotherapy may provide a substantial benefit in patients with advanced ACC.

Measurement of Vascular Diameter in Computed Tomography Angiography With Reduced Iodine Load: Comparison of Virtual Monochromatic Imaging in Dual-Energy Computed Tomography and Conventional Polychromatic Scan In Vitro.

OBJECTIVES: The aim of this study was to compare accuracy of measurement between virtual monochromatic imaging (VMI) in dual-energy computed tomography and conventional polychromatic 120-kVp computed tomographic scan in vascular models containing various densities of contrast material. METHODS: We evaluated measured diameters of 12 models of vessels of 4 inner diameters containing high, intermediate, and low densities of contrast material using software automation. RESULTS: Measurement errors with 70-keV VMI were significantly larger than or comparable to errors with 120-kVp scan for all models, and those with 50-keV VMI were significantly smaller than errors with 120-kVp scan for low-density models and larger for high-density models. CONCLUSIONS: Acquisition of images by VMI at low energy facilitates accurate measurement of diameters of poorly enhanced vessels with reduced iodine load but can increase measurement errors in other situations by decreasing spatial resolution, so VMI should be applied carefully to evaluate vessel diameter.

[Outcome of Resection of Inferior Vena Cava Superior to the Renal Vein in Renal Cell Carcinoma with Vena Caval Tumor Thrombus].

Surgical management with radical nephrectomy and thrombectomy has often been performed in renal cell carcinoma (RCC) with tumor thrombus infiltrating the inferior vena cava (IVC). We retrospectively reviewed the outcomes of IVC resection without venous reconstruction in patients with RCC and IVC thrombus at our institution. Eight patients with right RCC underwent radical nephrectomy and IVC resection superior to the level of the renal vein without venous reconstruction from August 2005 to February 2015. Thoracotomy, liver mobilization, and extracorporeal circulation were performed based on the IVC thrombus level. We assessed surgical outcomes, perioperative complications, and survival. At presentation, four patients had level IIIa IVC thrombus, three had level IIIb IVC thrombus, and one had level IV IVC thrombus. Perioperative imaging showed that three of the four patients who underwent neoadjuvant molecular targeting therapy achieved down-staging of the tumor thrombus level. The median operative time was 406 min, and the median estimated blood loss was 3,135 ml. With regard to IVC resectionassociated perioperative complications, one patient needed extracorporeal circulation with IVC ligation and Pringle maneuver owing to low blood pressure. Another patient underwent temporary hemodialysis for 8 days after surgery. There were no perioperative deaths, and none of the patients required permanent hemodialysis. Three patients survived the mean observation period of 25 months, including one patient with no recurrence. Three patients achieved long-term survival of more than 2 years. IVC resection without venous reconstruction may be a feasible option for patients with RCC and IVC tumor thrombus. Further study is needed to determine the most appropriate candidates for this procedure.

Severe acute interstitial lung disease in a patient with anaplastic lymphoma kinase rearrangement-positive non-small cell lung cancer treated with alectinib.

Alectinib, the second generation anaplastic lymphoma kinase (ALK) inhibitor, has significant potency in patients with ALK rearrangement positive non-small cell lung cancer (NSCLC), and its toxicity is generally well tolerable. We report a patient who developed severe acute interstitial lung disease after alectinib treatment. An 86-year-old woman with stage IV lung adenocarcinoma positive for rearrangement of ALK gene was treated with alectinib. On the 215th day after initiation of alectinib administration, she was admitted to our hospital with the symptom of progressive dyspnea. Computed tomography (CT) revealed diffuse ground glass opacities and consolidations in both lungs, and analysis of bronchoalveolar lavage fluid revealed pronounced lymphocytosis. There was no evidence of infection or other specific causes of her condition, and she was therefore diagnosed with interstitial lung disease induced by alectinib. Her CT findings and respiratory condition improved after steroid pulse therapy. As far as we are aware, this is the first reported case of alectinib-induced severe interstitial lung disease (ILD). We should be aware of the possibility of such a severe adverse event and should therefore carefully monitor patients treated with this drug.

Opportunistic use of a Foley catheter to provide a common electrocautery with a water-irrigating channel for hepatic parenchymal transection.

High-tech surgical energy devices that are used during a single surgery have increased in number and the expense for such disposable units is by no means negligible. We developed a handmade water-irrigating monopolar electrocautery using a Foley catheter to perform liver parenchymal transection. A commonly used 20-24 Fr Foley catheter was cut at a length of about 8 cm. The shaft of the 5 mm ball electrode measuring 13.5 cm in length was then inlaid into the urine drainage channel. The target tissues were cauterized without making an eschar, thereby preventing the adhesion of the electrode to the tissues. A ball electrode with our handmade water irrigation sheath can be made in only a few minutes at a very low cost, using common medical supplies and yielding satisfactory effects comparable to the use of specialized high-tech devices.

Nrf2 activation protects the liver from ischemia/reperfusion injury in mice.

OBJECTIVE: To investigate the role of Nrf2 in the pathogenesis of hepatic ischemia-reperfusion (I/R) injury. BACKGROUND: Hepatic I/R injury is a serious complication that leads to liver failure after liver surgery. NF-E2-related factor 2 (Nrf2) is a transcription factor that plays a critical role in protecting cells against oxidative stress. Therefore, it is suggested that Nrf2 activation protects the liver from I/R injury. METHODS: Wild-type and Nrf2-deficient mice were treated with 15-deoxy-Δ(12,14)-prostaglandin J2 (15d-PGJ2), or a vehicle. Subsequently, these mice were subjected to 60-minute hepatic 70% ischemia, followed by reperfusion. Liver and blood samples were collected to evaluate liver injury and mRNA expressions. RESULTS: After hepatic I/R, Nrf2-deficient livers exhibited enhanced tissue damage; impaired GSTm1, NQO1, and GCLc inductions; disturbed redox state; and aggravated tumor necrosis factor α mRNA expression in comparison with wild-type livers. 15d-PGJ2 treatment protected the livers of wild-type mice from I/R injury via increased expressions of GSTm1, NQO1, and GCLc; maintained redox status; and decreased tumor necrosis factor α induction. These effects induced by 15d-PGJ2 were not seen in the livers of Nrf2(-/-) mice and were not annulled by peroxisome proliferator-activated receptor γ antagonist in Nrf2(+/+) mice, suggesting that the protective effect of 15d-PGJ2 is mediated by Nrf2-dependent antioxidant response. CONCLUSIONS: Nrf2 plays a critical role in the mechanism of hepatic I/R injury and would be a new therapeutic target for preventing hepatic I/R injury during liver surgery.

Prognosis analysis of sarcomatous intrahepatic cholangiocarcinoma from a review of the literature.

BACKGROUND: Sarcomatous intrahepatic cholangiocarcinoma (ICC) is a rare histological variant of ICC. The prognosis of sarcomatous ICC is poorly understood. METHODS: We analyzed the prognosis of sarcomatous ICC by reviewing the previous reports and our own case. RESULTS: Only 15 cases of sarcomatous ICC have been reported in the English-language literature so far. Median survival time of patients with sarcomatous ICC with and without surgery was 11 and 3 months, respectively. Survival rate of patients operated on for sarcomatous ICC was similar to that of patients with ordinary ICC without surgery in the early postoperative period. In the long-term view, however, the prognosis for the patients with sarcomatous ICC receiving surgery was better than that for the patients with ordinary ICC without surgery. CONCLUSION: Although the prognosis for the patients with sarcomatous ICC was poor even after curative resection, surgery would be justified as the primary treatment for sarcomatous ICC.

High-dose corticosteroid therapy for erlotinib-induced interstitial lung disease in Japanese patient with advanced pancreatic cancer.

CONTEXT: Erlotinib is a selective epidermal growth factor receptor tyrosine kinase inhibitor used as a target therapy against non-small lung cancer and advanced pancreatic cancer. A regimen of erlotinib plus gemcitabine has been proven to prolong overall survival in the patient with advanced pancreatic cancer. In addition to common adverse effects, such as diarrhea, mucositis and skin rash (acne form eruptions), acute interstitial lung disease (ILD) has been reported as an infrequent but potentially fatal complication. We here report a case of a Japanese patient with erlotinib-induced ILD in whom high-dose corticosteroid therapy was successful. CASE REPORT: A fifty-five-year-old male with cancer of the head of the pancreas with multiple liver metastases started treatment with gemcitabine plus erlotinib. On the 13th day of erlotinib treatment, he had high fever. Chest computed tomography (CT) scan showed a diffuse ground-glass like infiltration of both lungs. He was diagnosed with ILD, and high-dose corticosteroid therapy was started. Two weeks after the introduction of steroid therapy, the reticular shadow faded away on CT. He was successfully treated with corticosteroid for erlotinib-induced acute ILD although he died 6 months after the initiation of chemotherapy owing to disease progression. CONCLUSION: we showed a case of a successfully treated Japanese patient of erlotinib-induced ILD. Because erlotinib-induced ILD would frequently occur in Japanese patients, closer attention to ILD should be paid for Japanese patients than in Western populations. If erlotinib-induced ILD occurs, a high-dose corticosteroid therapy would be a useful option of treatment.

Role of preferential cyclooxygenase-2 inhibition by meloxicam in ischemia/reperfusion injury of the rat liver.

BACKGROUND: Ischemia/reperfusion injury (IRI) is one of the major clinical problems in liver and transplant surgery. Livers subjected to warm ischemia in vivo often show a severe dysfunction and the release of numerous inflammatory cytokines and arachidonic acid metabolites. Cyclooxygenase (COX)-2 is the inducible isoform of an intracellular enzyme that converts arachidonic acid into prostaglandins. The aim of the study was to evaluate the effect of COX-2 inhibition and the role of Kupffer cells in IRI of the liver. METHODS: Male Wistar rats [250- 280 g body weight (BW)] were anesthetized and subjected to 30-min warm ischemia of the liver (Pringle's maneuver) and 60-min reperfusion after median laparotomy. The I/R group received no additional treatment. In the COX-2 inhibitor (COX-2I) group, the animals received 1 mg/kg BW meloxicam prior to operation. Gadolinium chloride (GdCl3) (10 mg/kg BW) was given 24 h prior to operation in the GdCl3 and GdCl3 + COX-2I groups for the selective depletion of Kupffer cells. The GdCl3 + COX-2I group received both GdCl3 and meloxicam treatment prior to operation. Blood and liver samples were obtained at the end of the experiments for further investigations. RESULTS: After 30 min of warm ischemia in vivo, severe hepatocellular damage was observed in the I/R group. These impairments could be significantly prevented by the selective COX-2 inhibition and the depletion of Kupffer cells. Alanine aminotransferase was significantly reduced upon meloxicam and GdCl3 treatment compared to the I/R group: I/R, 3,240 ± 1,262 U/l versus COX-2I, 973 ± 649 U/l, p < 0.001; I/R versus GdCl3, 1,611 ± 600 U/l, p < 0.05, and I/R versus GdCl3 + COX-2I, 1,511 ± 575 U/l, p < 0.01. Plasma levels of tumor necrosis factor alpha (TNF-α) were significantly reduced in the COX-2I treatment group compared to I/R (3.5 ± 1.5 vs. 16.3 ± 11.7 pg/ml, respectively; p < 0.05). Similarly, the amount of TxB2, a marker for COX-2 metabolism, was significantly reduced in the meloxicam treatment groups compared to the I/R group: I/R, 22,500 ± 5,210 pg/ml versus COX-2I, 1,822 ± 938 pg/ml, p < 0.001, and I/R versus GdCl3 + COX-2I, 1,530 ± 907 pg/ml, p < 0.001. All values are given as mean ± SD (n = 6). CONCLUSION: These results suggest that the inhibition of COX-2 suppressed the initiation of an inflammatory cascade by attenuating the release of TNF-α, which is an initiator of the inflammatory reaction in hepatic IRI. Therefore, we conclude that preferential inhibition of COX-2 is a possible therapeutic approach against warm IRI of the liver.

Olfactory homing of chum salmon to stable compositions of amino acids in natal stream water.

Many attempts have been made to identify natal stream odors for salmon olfactory homing. It has recently been hypothesized that odors are dissolved free amino acids; however, it is unknown whether these odors change on a seasonal or annual basis. We analyzed dissolved free amino acid (DFAA) concentration and composition of water from the Teshio River in Hokkaido, Japan, where chum salmon (Oncorhynchus keta) returned for spawning, during juvenile downstream migration in spring and adult upstream migration in autumn with a 4-year difference. Among the 19 amino acids found in the Teshio River water, DFAA concentrations fluctuated largely, but 5-7 stable DFAA compositions (mole %) were found between the spring and autumn samples over a 4-year span. Two kinds of artificial stream water (ASW) were prepared using the same DFAA concentration in the Teshio River during the time of juvenile imprinting in spring (jASW) and adult homing in autumn (aASW), after a 4-year period. In behavioral experiments of upstream selective movement in a 2choice test tank, 4-year-old mature male chum salmon captured in the Teshio River showed significant preference for either jASW or aASW when compared to control water, but did not show any preference with respect to jASW or aASW. In electro-olfactogram experiments, adults were able to discriminate between jASW and aASW. Our findings demonstrate that the long-term stability of the DFAA compositions in natal streams may be crucial for olfactory homing in chum salmon.

Expression of aquaporin-3 and -8 mRNAs in the parr and smolt stages of sockeye salmon, Oncorhynchus nerka: effects of cortisol treatment and seawater acclimation.

This study aimed to examine the role of 2 aquaporin (AQP) isoforms (AQP3, and -8) in sockeye salmon (Oncorhynchus nerka) in response to a hyperosmotic challenge from freshwater to seawater (SW) during the parr and smoltification (smolt) stages. AQP3 mRNA was primarily detected in the osmoregulatory organs, such as gills, while AQP8 mRNA was primarily found in the intestine. These results suggested that AQP isoforms play a role in osmoregulation in specific osmoregulatory organs. Similarly, AQP3 mRNA expression in the gills (mean values:1.06 ± 0.05 [parr] and 1.29 ± 0.07 [smolt]) was significantly higher than AQP8 mRNA levels (parr: 0.04 ± 0.003; smolt: 0.14 ± 0.004), and in the intestine, AQP8 mRNA expression (parr: 0.89 ± 0.007; smolt: 1.91 ± 0.03) was significantly higher than AQP3 mRNA levels (parr: 0.24 ± 0.006; smolt: 0.83 ± 0.005); these expression patterns were similar in vivo and in vitro. Additionally, AQP mRNA levels were lower in cortisol treated than in control groups. Therefore, these results suggest that AQPs play important roles in the water absorption mechanisms associated with multiple AQP isoforms, and that cortisol enhances the hypo-osmoregulatory capacity of fish in SW, and also controls the expression of AQPs in a hyperosmotic environment.

Diffusion-weighted MRI for differential diagnosis in gallbladder lesions with special reference to ADC cut-off values.

BACKGROUND/AIMS: We retrospectively evaluated the usefulness of the apparent diffusion coefficient (ADC) measured from high-b value diffusion-weighted imaging (DWI) of magnetic resonance imaging for the differential diagnosis of gallbladder lesions among patients with cancer, adenoma and inflammatory disease. METHODOLOGY: Forty patients with gallbladder lesions (22 patients with cancer, 7 patients with adenoma, and 11 patients with inflammatory disease) were enrolled in this study. All patients underwent high-b value DWI, and the ADC value was measured. The cut-off values were determined by receiver operating characteristic analysis. RESULTS: The ADC values of gallbladder cancers (1.31±0.57x10-3 mm2/s) were smallest and those of adenomas (2.66±0.43x10-3 mm2/s) were largest among the diseases. Inflammatory diseases took a middle position (1.97±0.54x10-3 mm2/s) between them. There were significant differences among the 3 groups of diseases (p<0.05). The cut-off value within ADC values to discriminate cancer from the other diseases was 1.64x10-3 mm2/s (accuracy 87.5%), and that to discriminate adenoma was 2.25x10-3 mm2/s (accuracy 90.0%). CONCLUSIONS: The ADC values measured from high-b value DWI would be useful for the differential diagnosis of gallbladder lesions.