Incidence of Bowel Wall Swelling Induced by Iodine-Contrast Media and Its Association With Gastrointestinal Manifestation.

PURPOSE: The aim of this study was to investigate the incidence of bowel wall swelling after iodine-contrast media injection and its relationship with gastrointestinal symptoms. METHODS: The incidence of bowel wall swelling was examined in 75 patients who showed adverse reactions to iodine-contrast media (AR[+] group) and 75 controls without adverse reactions (AR[-] group). Bowel wall swelling was identified if there was increased wall thickness on postcontrast computed tomography when compared with precontrast computed tomography. Swelling less than 2-fold of the original wall thickness was defined as grade 1 bowel angioedema, and swelling more than 2-fold was defined as grade 2. RESULTS: The incidence of bowel wall swelling was significantly higher in the AR(+) group (26.6%) than in the AR(-) group (10.6%) ( P = 0.01). Grade 1 bowel wall swelling was observed in 12.0% and 10.7% of AR(+) and AR(-) groups, respectively, whereas grade 2 was observed in 14.7% and 0%, respectively. Bowel wall swelling was observed in the duodenum and jejunum but not in the stomach, ileum, or colon in any patient in either group. In the AR(+) group, nausea and/or vomiting was observed in 15 patients, among whom bowel wall swelling was observed in 9 patients (60%). The frequency of nausea and/or vomiting was significantly higher in the patients with bowel wall swelling (45.0%, 9/20) compared with those without (10.9%, 6/55). CONCLUSION: Bowel wall swelling was more frequent and severe in patients with adverse reactions to iodine-contrast media than those without and was associated with nausea and/or vomiting.

Analysis of echolocation behavior of bats in "echo space" using acoustic simulation.

BACKGROUND: Echolocating bats use echo information to perceive space, control their behavior, and adjust flight navigation strategies in various environments. However, the echolocation behavior of bats, including echo information, has not been thoroughly investigated as it is technically difficult to measure all the echoes that reach the bats during flight, even with the conventional telemetry microphones currently in use. Therefore, we attempted to reproduce the echoes received at the location of bats during flight by combining acoustic simulation and behavioral experiments with acoustic measurements. By using acoustic simulation, echoes can be reproduced as temporal waveforms (including diffracted waves and multiple reflections), and detailed echo analysis is possible even in complex obstacle environments. RESULTS: We visualized the spatiotemporal changes in the echo incidence points detected by bats during flight, which enabled us to investigate the "echo space" revealed through echolocation for the first time. We then hypothesized that by observing the differences in the "echo space" before and after spatial learning, the bats' attentional position would change. To test this hypothesis, we examined how the distribution of visualized echoes concentrated at the obstacle edges after the bats became more familiar with their environment. The echo incidence points appeared near the edge even when the pulse direction was not toward the edge. Furthermore, it was found that the echo direction correlated with the turn rate of the bat's flight path, revealing for the first time the relationship between the echo direction and the bat's flight path. CONCLUSIONS: We were able to clarify for the first time how echoes space affects echolocation behavior in bats by combining acoustic simulations and behavioral experiments.

Simulation of ultrasonically induced electrical potentials in bone.

Low-intensity pulsed ultrasound treatment is known to shorten the healing period of bone fractures by 30%-40%, but the initial mechanism of the healing process remains unknown. One possible mechanism is related to the piezoelectricity of bone. However, the complex geometry of bones results in inherent challenges to evaluating electric fields induced therein. Therefore, in this study, we investigate the piezoelectric responses of bones by using simulations to study the wave propagation and induced potentials in bone, according to the piezoelectric finite-difference time-domain (PE-FDTD) method. First, we verify the suitability of the PE-FDTD method by comparing the simulated electric field results with the experimental data obtained by an ultrasound receiver using bone as the piezoelectric element. Next, ultrasound irradiation into a real bone model (the radius of a 66-year-old woman) is simulated at different incident angles. At normal incidence and off-axis incidence (45°), the maximum electric field strength was 4.3 and 5.6 mV/cm, respectively. We also present evidence of significant shear wave contribution to the induced potential. The results of this study confirm the existence of ultrasonically induced potentials in heterogenous bones with complex shapes, equal in magnitude to potentials generated in electrically stimulated bone healing.

Effect of bat pinna on sensing using acoustic finite difference time domain simulation.

The practicality of the finite-difference time-domain (FDTD) method was confirmed by comparing head-related transfer functions obtained from a three-dimensional (3D) digital model of a bat (Rhinolophus ferrumequinum nippon) head with acoustic experiments using a 3D printed physical model. Furthermore, we simulated the auditory directionality using a 3D digital model that was modified based on the pinna movement of a bat during echolocation and found that the alternating movements of the left and right pinna result in a binaural sound pressure difference for vertical sources. Using the FDTD method, suitable for simulating acoustics in large spaces, we could analyze in detail the binaural echoes that bats receive and the acoustic cues they use for echolocation.

Reconstruction of echoes reaching bats in flight from arbitrary targets by acoustic simulation.

Echolocating bats perceive their environment by emitting ultrasonic pulses and listening to echoes that are reflected back from their surroundings. Behavioral decisions of bats are mainly dependent on echo information, and acoustical analysis of echoes is useful for understanding their behavioral decisions. To date, echoes have been measured using a telemetry microphone mounted on the bat's head; however, due to technical difficulties, it was not enough to measure all the echoes reaching the bats in flight. In this paper, we propose an approach to reconstruct the echoes of bats in flight using finite-difference time-domain (FDTD) method simulations based on the measured flight path, speed, and sound information from behavioral experiments. As a result, echoes from any target in flight can be correctly reconstructed, including the Doppler effect. We also analyzed the spatiotemporal transition among attended walls for Doppler shift compensation (DSC) during circling flight in the context of DSC behavior and found that the bats switch their attention to different walls and focus on the wall ahead of them in the direction of flight.

Simulation of pulsed ultrasonic diffraction in viscous fluids using transmission line matrix method.

Ultrasonic fields propagating in viscous media undergo changes in shape due to diffraction, attenuation, and dispersion. Until now, some implementations in the transmission line matrix (TLM) method has been developed to simulate either diffraction or attenuation but never both. In this work, the quadratic frequency dependence of the absorption coefficient as well as the dispersive effect of a viscous fluid are introduced in the TLM method. The idea is to decompose the emitted wave into its components at different frequencies using Fourier transform. Then, dispersion and attenuation effects are considered for each wave component separately before superposing them to get the required acoustic response. This is possible because each one of them is characterized by a constant absorption coefficient and propagates at a single speed. This TLM model has been applied to the diffracted ultrasonic field by a circular transducer radiating a short pulse in a viscous fluid. The obtained waveforms are interpreted in terms of plane and edge waves. A study of the influence of the most important parameters on the waveform of the detected ultrasonic pulses is performed. The numerical results obtained highlight the attenuation effect on the waves' shapes and the influence of the dispersion on their arrival times.

M1 macrophage infiltrations and histological changes in the liver after portal vein embolization using fibrinogen and OK432 in the rat.

The mechanism of anti-tumor effect of transarterial Immuno-Embolization (TIE) using OK-432 has not been well elucidated. In this study, we aimed to investigate the tissue injury and immune response after portal venous embolization (PVE) with/without OK-432. Embolic materials (L group: lipiodol, LF group: lipiodol+fibrinogen, LO group: lipiodol+OK-432, LFO group: lipiodol+fibrinogen+OK-432) were administered via the right portal vein in Wistar rats. The histological findings in LFO group demonstrated liver damage with severe architectural changes. The concentrations of CD68(+) cells were observed in a time-dependent manner; it was significantly increased in the LO group on day 1 and in the LFO group on day 3. CD68(+)CD163(-) macrophages significantly increased in the LFO group on day 7 (P<0.05). In conclusion, PVE with fibrinogen and OK-432 markedly increased the CD68(+)CD163(-) infiltrating macrophages around the peri-portal area in the liver. This novel technique could be applied as immune-enhanced chemo-embolization of liver tumors.

[Pancreatic Adenosquamous Carcinoma That Developed after Resection of IPMA in the Pancreatic Tail].

Pancreatic adenosquamous carcinoma coexisting with intraductal papillary mucinous neoplasm(IPMN)is extremely rare. We report a rare case of pancreatic adenosquamous carcinoma that developed after resection of intraductal papillary mucinous adenoma(IPMA). A 67-year-old man was suspected of having a pancreatic cystic lesion. MRCP demonstrated a cystic lesion measuring 25mm in the pancreatic tail, which had an enhanced nodule. We therefore diagnosed branch duct type IPMN of the pancreas. Although pancreatic juice cytology did not indicate malignancy, we performed laparoscope-assisted distal pancreatectomy. The reason why the IPMN lesion had an enhanced nodule. The histopathological diagnosis was IPMA without malignancy. One year and 5 months after surgery, blood analysis showed an elevated tumor marker level, and abdominal CT demonstrated a pancreatic head tumor with lymphadenopathy. EUS-FNA was performed and the patient was diagnosed with pancreatic adenosquamous carcinoma based on immunohistochemical staining. We administered chemotherapy with gemcitabine and S-1. After 3 courses of this chemotherapy, the size of the pancreatic tumor and the tumor marker level decreased. The patient achieved a partial response. He is still receiving chemotherapy after 7 courses.

[A case of two re-resections for peritoneal recurrence of pancreatic cancer].

A 63-year-old man underwent subtotal stomach-preserving pancreaticoduodenectomy and intraoperative radiation therapy for pancreatic head cancer (Stage IVa, JPS). Subsequently, he received adjuvant chemotherapy including gemcitabine (GEM). A peritoneal recurrence appeared adjacent to the right colon and the lower pole of the right kidney. He received chemotherapy including S-1 and GEM+S-1. Since the recurrent lesions were localized, he underwent resection for the recurrence lesions 2 years and 9 months after surgery. The resection was R1, and re-recurrence appeared in the lower pole of the right kidney. After chemotherapy and chemoradiotherapy, he underwent re-resection for the recurrence 4 years and 3 months after the first surgery. Three months after re-resection, multiple liver metastases appeared in the bilateral lobes. Reoperation can be one of the multidisciplinary management options for local recurrence of pancreatic cancer under specific conditions.

Discrimination of object information by bat echolocation deciphered from acoustic simulations.

High-precision visual sensing has been achieved by combining cameras with deep learning. However, an unresolved challenge involves identifying information that remains elusive for optical sensors, such as occlusion spots hidden behind objects. Compared to light, sound waves have longer wavelengths and can, therefore, collect information on occlusion spots. In this study, we investigated whether bats could perform advanced sound sensing using echolocation to acquire a target's occlusion information. We conducted a two-alternative forced choice test on Pipistrellus abramus with five different targets, including targets with high visual similarity from the front, but different backend geometries, i.e. occlusion spots or textures. Subsequently, the echo impulse responses produced by these targets, which were difficult to obtain with real measurements, were computed using three-dimensional acoustic simulations to provide a detailed analysis consisting of the acoustic cues that the bats obtained through echolocation. Our findings demonstrated that bats could effectively discern differences in target occlusion spot structure and texture through echolocation. Furthermore, the discrimination performance was related to the differences in the logarithmic spectral distortion of the occlusion-related components in the simulated echo impulse responses. This suggested that the bats obtained occlusion information through echolocation, highlighting the advantages of utilizing broadband ultrasound for sensing.

Cyst-like extension of hepatic subcapsular bleeding caused by ruptured hepatocellular carcinoma into the bursa omentalis.

An 81-year-old man, who experienced upper abdominal pain after shoveling snow, was admitted to a local hospital where a computed tomography (CT) showed a cystic lesion adjoining the pancreas. He was transferred to our department for detailed investigations and treatment. On ultrasonography, a tumor of the caudate lobe of the liver, with which the cystic lesion was continuous, was seen. The tumor of the caudate lobe of the liver was enhanced in the early phase of the CT but was washed out in the delayed phase. Subsequently, T(1)-weighted and T(2)-weighted magnetic resonance imaging (MRI) images showed a low intensity and a high intensity, respectively. Because the cystic lesion was continuous with the tumor of the caudate lobe of the liver, its CT value was higher than that of water, and both the T(1)-weighted and T(2)-weighted MRI images showed a high intensity, which was attributed to a hematoma. Examination of the image suggested that rupture of a hepatocellular carcinoma (HCC) might have caused intracavitary hemorrhage. After the HCC was treated by transcatheter arterial embolization therapy, the patient was discharged. Subsequently, tumor enlargement was confirmed, and surgical removal of the tumor was conducted at the hospital where the patient had originally presented. On histology, moderately differentiated HCC was diagnosed, but the cyst-like lesion was confirmed to be a hepatic subcapsular hematoma extending into the bursa omentalis. Although ruptured HCC often causes intraperitoneal bleeding, this rare case showed a cyst-like imaging finding in the form of a subcapsular hematoma within the bursa omentalis.

Sequential magnetic resonance imaging for evaluation of Kupffer cell function.

BACKGROUND/AIMS: Kupffer cells play an important role in liver regeneration and depression of their function is associated with poor outcome. However, there is no clinically safe and reliable method for evaluating Kupffer cell function. METHODOLOGY: We used magnetic resonance imaging following injection of superparamagnetic iron oxide, which is trapped by Kupffer cells, to evaluate Kupffer cell function in 14 patients, including 6 with normal liver and 8 with obstructive jaundice T1-weighed signal intensity of the liver parenchyma was examined every 4 minutes for 60 min after superparamagnetic iron oxide injection. RESULTS: Signal intensity values gradually decreased in both groups after accumulation of iron in the liver. Serum iron levels equally and significantly increased in both groups. In contrast, the values of relative enhancement, percentage of signal intensity of precontrast to postcontrast, between 8-20 minutes after superparamagnetic iron oxide injection were significantly higher in obstructive jaundice group than in the control, indicating Kupffer cell dysfunction in obstructive jaundiced liver. CONCLUSIONS: These results indicate that chronological magnetic resonance imaging with superparamagnetic iron oxide is a suitable method for assessment of Kupffer cell function in patients with obstructive jaundice.

Traffic of infused bone marrow cells after genetically-labeled syngeneic bone marrow transplantation following lethal irradiation in mice.

UNLABELLED: Bone marrow (BM) cells are considered the source of stem cells for various organs. However, how quickly BM cells can penetrate and constitute lymphoid organs remains elusive. In the present study, we addressed this issue in a model using genetically-labeled syngeneic BM transplantation (BMT). METHODS: Donor BM cells were obtained from "green mice", transgenic mice with enhanced GFP. Lethally irradiated C57BL/6 mice were infused with 1 x 10(6) BM cells from the green mice through the tail vein. BM chimerism was analyzed by FACS and the presence of donor BM cells in thoracoabdominal organs was assessed by fluorescence microscopy. The commitment of BM cells was examined by immunohistochemical staining using epithelium-, macrophage-, B and T-lymphocyte, and endothelium-specific antibodies. RESULTS: BM chimerism reached 40+/- 18.5%, 82.6 +/- 23.4%, and 72 +/- 18% (mean +/- SD) at 1, 4, and 12 wks after BMT, respectively. GFP-positive cells were detected in all organs in the course of chimeric formation. Most GFP-positive cells were T and B lymphocytes in lymphoid systems including spleen, thymus, mesenteric lymph nodes and microvilli, and some were positive for macrophage and endothelial cell markers. CONCLUSIONS: Our results indicate that BM-derived cells migrate rapidly into various thoracoabdominal organs after BMT, and that lymphoid tissues are predominantly replaced with infused BM in lethally-irradiated mice. This confirmed the previous finding by others and suggests high interest of this model for further studies to characterize kinetics and roles of infused cells.

A Molecularly Modulated Mode-Locked Laser.

A mode-locked laser operating at a frequency over 10 THz is reported, which is three orders of magnitude greater than a standard mode-locked laser. The system used molecules with a Raman gain as an amplifier, while coherent molecular motions were used for optical modulation. Molecules in a high-finesse optical cavity modulated a continuous-wave beam to produce a train of ultrashort optical pulses at a repetition rate corresponding to the frequency of molecular motion. Phase-locking was achieved by an appropriate compensation of the total dispersion of the optical cavity. Thus, the oscillating multiple longitudinal modes were all coupled under phase-matching conditions of parametric four-wave mixing.

Continuous-wave phase-matched molecular optical modulator.

In optical modulation, the highest available modulation rate is basically limited to the GHz frequency range at best. This is because optical modulation is often performed using electro-optic or acousto-optic effects that require application of an external signal to solid-state nonlinear optical materials. Here we describe optical modulation of continuous-wave radiation at frequencies exceeding 10 THz based on ultrafast variation of molecule polarizability arising from coherent molecular motion. The optical modulation efficiency is extensively enhanced by fulfilling phase-matching conditions with the help of dispersion control of the optical cavity, generating sidebands with a highest ratio of 7.3 × 10(-3). These results will pave the way for development of versatile optical modulation-based techniques in a wide range of research fields in optical sciences, such as mode-locked lasers operating in the THz range.

Role of intratumoral infiltrating macrophages after transarterial immunoembolization for hepatocellular carcinoma.

BACKGROUND: Preoperative transarterial immunoembolization (TIE) for hepatocellular carcinoma (HCC) is effective for preventing recurrence. We aimed to investigate the intratumoral and peritumoral M1 macrophage-induced immune response following TIE treatment. METHODS: We compared 13 patients treated with TIE between 2003 and 2009 (TIE group) and 13 patients treated with surgery alone during the same period of time at our institute (control group) using an immunohistological study with CD68 and CD163 antibodies. RESULTS: No significant differences in clinicopathological characteristics, except for surgical time, were observed between the two groups. The 3-year recurrence-free survival outcome of the TIE group was quite different from that of the control group (100% vs. 38.5%, P = 0.034). In the histological investigation, lytic necrosis and coagulation necrosis of the main tumor along with the presence of multinuclear giant cells were observed in 10 of the 13 patients in the TIE group. The immunohistological study showed that not only the numbers of intratumoral CD68(+) cells, but also the numbers of intratumoral and peritumoral CD8(+) cells were significantly increased in the TIE group. CONCLUSIONS: The suppression of tumor recurrence induced by preoperative TIE might be induced by intratumoral M1 macrophages that are activated by OK-432 and fibrinogen.

Appearance of rectal varices in extrahepatic portal obstruction after treatment for esophago-gastric varices: a case report.

We report a case of rectal varices that developed after endoscopic injection sclerotherapy (EIS) and Hassab's operation for esophageal varices with extrahepatic portal obstruction. A 54-year-old woman was admitted to our hospital in September 1997 for treatment of hematochezia. Emergent colonoscopy revealed tortuous rectal varices with a white plug. Angiography revealed that rectal varices were provided with backward blood flow by the inferior mesenteric vein due to extrahepatic portal obstruction. In this case, previous treatment, EIS and Hassab's operation, for esophago-gastric varices might have inhibited the development of collaterals apart from surface of gastrointestinal tract, such as para-esophageal collateral veins or spleno-renal shunt. Since the thrombus in the extrahepatic portal vein causes strong pressure on inferior mesenteric vein which is connected to the inferior vena cava via the inferior rectal vein, rectal varices might be developed. In this case, it was considered that rectal varices were not treated enough by endoscopic therapy because of regurgitant hyper blood flow against portal venous pressure. Therefore, rectal transection was performed. After the treatment, the patient suffered no further episodes of bleeding from rectal varices.

Remnant left lobe torsion causing hepatic venous outflow obstruction after hepatic right lobectomy for giant hepatocellular carcinoma: report of a case.

We report the case of a 67-year-old man with remnant left liver torsion causing acute hepatic venous outflow obstruction after right hepatectomy for giant hepatocellular carcinoma, which was successfully treated with surgery. After the primary surgery, he developed significant liver dysfunction and renal failure. Doppler ultrasonography disclosed gradual reduction of hepatic perfusion. Abdominal computed tomography revealed that the swollen remnant liver was dislocated in the right subphrenic space. After surgical repositioning of the left lobe into its anatomical position, the hepatic congestion immediately disappeared, and the hemodynamic parameters improved. The falciform and round ligaments were fixed to the anterior abdominal wall to keep the remnant liver in the anatomical position. His postoperative course was uneventful. Doppler ultrasonography was useful to assess hepatic perfusion for screening of acute hepatic venous outflow obstruction and abdominal computed tomography is definitive for diagnosis. Fixation of remnant liver may be effective for preventing hepatic venous outflow obstruction after right hepatectomy, particularly for giant tumor.

Increased IL-17 production correlates with immunosuppression involving myeloid-derived suppressor cells and nutritional impairment in patients with various gastrointestinal cancers.

Although a causal relationship between inflammation and innate immunity of cancer is more widely accepted today, many of the precise cell mechanisms mediating this relationship have not been elucidated. Th17 cells, which produce the proinflammatory cytokine interleukin 17 (IL-17), have been recognized as one of the key factors in the regulation of inflammatory bowel disease and rheumatoid arthritis. This study demonstrated that, in patients with various types of gastrointestinal cancer, IL-17 production was correlated with myeloid-derived suppressor cell (MDSC) levels and with markers for nutritional impairment, immune suppression and chronic inflammation. IL-17 was significantly higher in patients with various types of gastrointestinal cancer compared to normal volunteers. In addition, IL-17 levels were significantly correlated with neutrophil counts and the neutrophil/lymphocyte ratio (NLR) and significantly inversely correlated with cell-mediated immune response indicators [lymphocyte phytohemagglutinin (PHA)-blastogenesis and IL-12 induction] and patient nutritional status (prealbumin levels). Circulating MDSC levels were significantly correlated with IL-17 production. These results suggest that, in human gastrointestinal cancers, chronic inflammation involving IL-17 may be an important mechanism contributing to disease progression through enhancement of immune suppression or cachexia. Controlling the activation of Th17 cells may prove to be a valuable strategy for the treatment of gastrointestinal cancer patients.