[A Case of Solitary Inguinal Lymph Node Metastasis 15 Years after Colorectal Cancer Surgery]

The patient is a 69-year-old man. 17 years ago, a colectomy was performed for colorectal cancer, and a disseminated nodule was found during the operation, so the disseminated nodule was also resected. After the surgery, 12 courses of FOLFOX4 were administered, and there was no recurrence thereafter. He was diagnosed with hepatocellular carcinoma 12 years after the colectomy and underwent liver resection. Fifteen years after the colectomy, a mass shadow appeared in the right inguinal region, and inguinal lymph node metastasis of hepatocellular carcinoma or colorectal cancer was suspected. In the same year, he underwent the tumor resection and histopathological diagnosis revealed colon cancer inguinal lymph node metastasis. After the lymph node resection, he has been followed up for 2 years with no recurrence of colorectal cancer. It is extremely rare to have a solitary inguinal lymph node recurrence 15 years after colon surgery.

Design of soft x-ray varied-line-spacing (VLS) high-dispersion laminar-type grating coated with super-mirror-type (SMT) multilayer for flat-field spectrograph in a region of 2-4 keV

A soft x-ray varied-line-spacing (VLS) laminar-type spherical grating with a super-mirror-type (SMT) multilayer was designed for a soft x-ray high resolution flat-field spectrograph in a region of 2-4 keV. The effective groove density of the designed VLS grating is 3200 lines/mm, and the local groove density varies from 2700 to 3866 lines/mm. The geometrical imaging property was evaluated by numerical calculations. The resolving power estimated by means of ray tracing was up to ∼103. For the evaluation of diffraction efficiency, the SMT multilayer structure designed for 3200 lines/mm in our previous work, Koike et al., Rev. Sci. Instrum. 94, 045109 (2023), was employed, and the numerical calculation was performed considering the local groove density of VLS grooves and the local incidence angle being affected by the curvature of the spherical surface and the geometrical relation between the source and incidence point on the grating. The results showed that the SMT multilayer-coated grating exhibited about an order of magnitude higher diffraction efficiency compared with an Au-coated grating.

Proof-of-Principle Experiment for Testing Strong-Field Quantum Electrodynamics with Exotic Atoms: High Precision X-Ray Spectroscopy of Muonic Neon

To test bound-state quantum electrodynamics (BSQED) in the strong-field regime, we have performed high precision x-ray spectroscopy of the 5g-4f and 5f- 4d transitions (BSQED contribution of 2.4 and 5.2 eV, respectively) of muonic neon atoms in the low-pressure gas phase without bound electrons. Muonic atoms have been recently proposed as an alternative to few-electron high-Z ions for BSQED tests by focusing on circular Rydberg states where nuclear contributions are negligibly small. We determined the 5g_{9/2}- 4f_{7/2} transition energy to be 6297.08±0.04(stat)±0.13(syst)  eV using superconducting transition-edge sensor microcalorimeters (5.2-5.5 eV FWHM resolution), which agrees well with the most advanced BSQED theoretical prediction of 6297.26 eV.

A Case of Traumatic Medial Longitudinal Fasciculus Syndrome Whose Causal Lesion Was Detected by Thin-Section MRI with Susceptibility-Weighted Imaging

The aim of the study was to report a case of traumatic medial longitudinal fasciculus (MLF) syndrome diagnosed with brain magnetic resonance imaging (MRI) after a head injury. A 71-year-old male complained of diplopia after he was bruised the back of his head when he was hit by a bicycle and fell down. He showed failure of adduction in the right eye, and mild nystagmus was found in the left eye when looking to the left. Convergence was intact. A low-intensity area was found at the middle right site in the lower part of the midbrain using thin-section MRI with susceptibility-weighted imaging (SWI), which suggested a hemorrhage. From the present history, characteristic abnormality of eye movement, and MRI imaging, he was diagnosed with traumatic MLF syndrome. His symptom was resolved, and the eye movement was improved in 2 weeks. A hemorrhage that occurs in the brainstem may be a cause of traumatic MLF syndrome which could be detected by thin-slice MRI with SWI.

Deexcitation Dynamics of Muonic Atoms Revealed by High-Precision Spectroscopy of Electronic K X Rays

We observed electronic K x rays emitted from muonic iron atoms using superconducting transition-edge sensor microcalorimeters. The energy resolution of 5.2 eV in FWHM allowed us to observe the asymmetric broad profile of the electronic characteristic Kα and Kβ x rays together with the hypersatellite K^{h}α x rays around 6 keV. This signature reflects the time-dependent screening of the nuclear charge by the negative muon and the L-shell electrons, accompanied by electron side feeding. Assisted by a simulation, these data clearly reveal the electronic K- and L-shell hole production and their temporal evolution on the 10-20 fs scale during the muon cascade process.

[A Case of Intra-Abdominal Desmoid Tumor with Acute Abdominal Pain]

A 70-year-old man was admitted to our hospital with acute abdominal pain. Abdominal CT showed a 6-cm-sized tumor near the third portion of the duodenum, and a duodenal GIST was suspected. Although the abdominal pain was intense and the tumor was suspected to be ruptured, the vital signs were stable; therefore, we initially planned to perform an elective surgery. However, because the pain could not be controlled, the surgery was performed on the 6th day of hospitalization. The tumor appeared to be a duodenal GIST because it was pulling the third portion of the duodenum inwards. It had a strong tendency to infiltrate the surrounding organs; therefore, forced resection of the right colon, which is the surrounding organ, was performed. Pathological findings showed that the resected specimen was a desmoid tumor and the surgical margins were negative. The postoperative course 1 year after surgery was favorable, and no tumor recurrence occurred. We report a case of desmoid tumor, which caused acute abdominal pain.

[Pancreatic Head Cancer Invading the Ascending Part of the Duodenum with Difficulty in Diagnosis-A Case Report]

A 61-year-old man visited our hospital because of nausea and vomiting. Abdominal CT revealed a severe stenosis of the ascending part of the duodenum but no evidence of tumors in the duodenum or pancreas. Upper gastrointestinal endoscopy showed severe stenosis of the ascending part of the duodenum with an ulcerative lesion. A biopsy of the site showed no evidence of malignancy. Nevertheless, duodenal and/or pancreatic cancer(s)could have caused the stenosis; therefore, we decided to perform an operation for the diagnosis and treatment of the obstruction. The surgery revealed severe stenosis of the ascending part of the duodenum with scar tissue. We performed subtotal stomach-preserving pancreaticoduodenectomy. Pathological findings showed pancreatic head cancer invading the ascending part of the duodenum. In this case, the diagnosis was difficult to make preoperatively because of the lack of an obvious neoplastic lesion. We believe duodenal invasion by pancreatic cancer without recognizing any tumor mass on CT is rare.

[Strategies of Treatment for Obstructive Colorectal Cancer and Compared with Non-Obstructive Cancer]

The aim of this study was assessment of the laparoscopic surgery after using ileus tube(trans-anal or trans-nasal)for obstructive colorectal cancer compared with non-obstructive cancer.

METHOD

Between April 2010 and March 2019, 129 patients underwent laparoscopic colorectal surgery. 97 patients were non-obstructive colorectal cancer(group N)and 32 patients were obstructive colorectal cancer(group O). Differences between the groups were analyzed using the Mann- Whitney's U-test, as appropriate.

RESULT

In group O, the length of hospital stay was significantly long. There were no significant differences between-group differences in the operation time, estimated blood loss, the rate of conversion to open surgery and postoperative complications.

CONCLUSION

The laparoscopic colorectal surgery is feasible in patients treated with using ileus tube for obstructive colorectal cancer.

Liquid Chromatographic Determination of Fumonisins B1, B2, and B3 in Corn: AOAC–IUPAC Collaborative Study

A liquid chromatographic (LC) method for simultaneous determination of fumonisins B1 (FB1), B2 (FB2), and B3 (FB3) in corn was subjected to a collaborative study involving 12 participants from 10 countries, in which the accuracy and reproducibility characteristics of the method were established. Mean analyte recoveries from corn ranged from 81.1 to 84.2% for FB1 (at a spiking range of 500 to 8000 ng/g), from 75.9 to 81.9% for FB2 (at a spiking range of 200 to 3200 ng/g), and from 75.8 to 86.8% for FB3 (at a spiking range of 100 to 1600 ng/g). The valid data were statistically evaluated after exclusion of outliers. Relative standard deviations for within-laboratory repeatability ranged from 5.8 to 13.2% for FB1, from 7.2 to 17.5% for FB2, and from 8.0 to 17.2% for FB3. Relative standard deviations for between-laboratory reproducibility varied from 13.9 to 22.2% for FB1, from 15.8 to 26.7% for FB2, and from 19.5 to 24.9% for FB3. HORRAT ratios, calculated for the individual toxin analogues, ranged from 0.75 to 1.73. The LC method for determination of fumonisins B1, B2, and B3 in corn (at concentrations of 800–12800 ng total fumonisins/g) has been adopted by AOAC INTERNATIONAL.

Risk Factors for Atrial Fibrillation Recurrence After Cox Maze IV Performed Without Pre-exclusion

BACKGROUND

New guidelines from The Society of Thoracic Surgeons recommend adding surgical ablation as a concomitant procedure for class I indications. We performed the maze procedure for all patients who experienced atrial fibrillation (AF) before cardiac surgery, without surgeon pre-exclusion.

METHODS

We retrospectively analyzed 83 patients, aged 71 ± 11 years (22% >80 years), who underwent Cox maze IV for persistent AF between 2014 and 2017. The mean AF duration (AFD) was 6.9 ± 8.6 years and European System for Cardiac Operative Risk Evaluation II was 7.2 ± 6.8.

RESULTS

The 30-day mortality was 2.4%. During follow-up (mean, 675 days), the 1-, 2-, and 3-year survival rates were 92%, 86%, and 82%, respectively. No strokes were observed despite a mean CHA₂DS₂-VAS_C (Congestive heart failure, Hypertension, Age [≥65 = 1 point, ≥75 = 2 points], Diabetes, and Stroke/transient ischemic attack [2 points], vascular disease, Sex [female = 1 point]) score of 4.1 (expected stroke rate, 4%/y). Twelve patients required a new pacemaker; 56 of 73 survivors (77%) remained AF free. Multivariate logistic regression identified preoperative AFD, f wave size, and mean heart rate per Holter as important risk factors for AF recurrence, with AFD as the most important: 98% of patients with AFD less than 5 years remained AF free. Although the AF-free rate with the AFD of 5 or more years was only 55%, their symptoms improved without heart failure readmission. Concomitant atrial plication was performed more frequently in the group with AFD for 5 or more years, with greater atrial volume reduction and appreciable increases in stroke volume.

CONCLUSIONS

The Cox maze IV procedure performed without pre-exclusion showed reasonable survival rates. Although AF recurred in patients with longer AFD, they fared well with substantial increases in stroke volume. Concomitant atrial volume reduction may have contributed to these additional benefits.

Scoring System to Predict pt2 in Gallbladder Cancer Based on Carcinoembryonic Antigen and Tumor Diameter

BACKGROUND AND AIMS

T2 gallbladder cancer requires lymph node dissection for curative resection, whereas simple cholecystectomy is adequate to treat T1 gallbladder cancer. Hence, this study aimed to develop an accurate scoring system to preoperatively predict pT2 in gallbladder cancer.

MATERIAL AND METHODS

We retrospectively assessed data from 57 patients with suspected gallbladder cancer who underwent curative resection between September 2003 and May 2017. Six with apparent invasion of adjacent organs on preoperative images were excluded. We evaluated preoperative computed tomography, magnetic resonance and endoscopic ultrasonographic images, blood biochemistry, and the maximum standard uptake value in fluorodeoxyglucose-positron emission tomography images. We analyzed whether correlations between preoperative findings and the depth of tumor invasion could predict pT2.

RESULTS

The pathological diagnosis was gallbladder cancer in 30 (58.8%) patients, of whom 21 (69.9%) had pT2 or worse. Multivariate analyses selected carcinoembryonic antigen and tumor diameter as independent predictors of pT2 or worse (odds ratios = 1.741 and 1.098, respectively; 95% confidence intervals = 1.004-3.020 and 1.008-1.197, respectively). A regression formula was created using carcinoembryonic antigen and tumor diameter to calculate pT2 predictive scores. The area under the receiver operating characteristics curve of the pT2 predictive score was 0.873.

CONCLUSION

We created a scoring system to predict pT2 in gallbladder cancer using carcinoembryonic antigen and tumor diameter. The present findings suggested that carcinoembryonic antigen is important for the preoperative evaluation of gallbladder cancer.

New precise measurements of muonium hyperfine structure at J-PARC MUSE

High precision measurements of the ground state hyperfine structure (HFS) of muonium is a stringent tool for testing bound-state quantum electrodynamics (QED) theory, determining fundamental constants of the muon magnetic moment and mass, and searches for new physics. Muonium is the most suitable system to test QED because both theoretical and experimental values can be precisely determined. Previous measurements were performed decades ago at LAMPF with uncertainties mostly dominated by statistical errors. At the J-PARC Muon Science Facility (MUSE), the MuSEUM collaboration is planning complementary measurements of muonium HFS both at zero and high magnetic field. The new high-intensity muon beam that will soon be available at H-Line will provide an opportunity to improve the precision of these measurements by one order of magnitude. An overview of the different aspects of these new muonium HFS measurements, the current status of the preparation for high-field measurements, and the latest results at zero field are presented.

Isomeric 26Al beam production with CRIB

We performed an experiment to measure proton resonant elastic scattering of a mixed 26m,gAl beam with a thick target in inverse kinematics by using CNS RI beam sep-arator, located at RIKEN Nishina Center. It aimed to search for strong proton resonances and determine level properties of low spin-parity states in 27Si. Diagnosis of the 26mAl purity of the beam by annihilation radiation are discussed.

Re-oxygenation Improves Hypoxia-induced Pulp Cell Arrest

Dental pulp cells can be exposed to hypoxia during severe inflammation or restorative procedures, though their response to hypoxia is not well-understood. We hypothesized that hypoxia has effects on the growth of pulp cells in vitro. When the cells were exposed to hypoxia for 48 hr, cell growth was suppressed, and cell death was detected by Hoechst staining. Western blot analysis revealed that phosphorylation of retinoblastoma protein was inhibited in cells exposed to hypoxia. Analyses of the molecules involved in retinoblastoma protein phosphorylation revealed that hypoxia suppressed cyclin D2 and activated p21CIP1/WAF1. Further, hypoxia-exposed pulp cells showed improvement of cell viability, cell-cycle progression, and expression of cyclin D2 with re-oxygenation. These findings indicate that hypoxia-induced cell cycle arrest in pulp cells is reversible, while cyclin D2 may play an essential role in the improvement of cell proliferation with re-oxygenation.

REPEATED INTRANODAL LYMPHANGIOGRAPHY FOR THE TREATMENT OF LYMPHATIC LEAKAGE

Treatment of patients with chylous or non-chylous lymphatic leakage can be difficult. An approach using therapeutic lymphangiography can reduce the lymphatic leakage, but it seldom stops the leakage immediately and subsequent conservative treatment is necessary. We report three cases in which intranodal lymphangiography was performed multiple times to inhibit lymphatic leakage. In each case, the lymph node was punctured under ultrasound guidance using a 23-gauge needle and lipiodol was injected manually at a rate of 1 ml/3 min. The procedure was repeated twice in two cases of gastrointestinal carcinoma and four times in one case of lymphoma. In all three cases, the postoperative lymphatic leakage stopped after the repeated intranodal lymphangiography.

Computed diffusion-weighted MRI for prostate cancer detection: the influence of the combinations of b-values

OBJECTIVE

To evaluate the influence of the combinations of b-values on computed diffusion-weighted images (cDWIs) for prostate cancer (PCa) detection at b = 2000 s mm(-2).

METHODS

Diffusion-weighted imaging (DWIs) for 31 patients with PCa (65.2 ± 7.1 years) were obtained pre-operatively at different b-values (0, 100, 500, 1000 and 2000 s mm(-2)) on a 3-T MRI. cDWIs at b = 2000 were generated by using six b-value combinations: 0-100 s mm(-2) (cDWI0-100); 0-500 s mm(-2) (cDWI0-500); 100-500 s mm(-2) (cDWI100-500); 0-1000 s mm(-2) (cDWI0-1000); 100-1000 s mm(-2) (cDWI100-1000); and 500-1000 s mm(-2) (cDWI500-1000). These cDWIs and measured DWIs with b = 2000 s mm(-2) (mDWI2000) were evaluated in this setting. To assess image quality for each DWI, contrast ratios (CRs) of cancerous and non-cancerous lesions were evaluated. To compare the detectability of PCa for each DWI, receiver operating characteristic analysis was used.

RESULTS

CRs of all cDWIs were significantly higher than those of mDWI2000 (p < 0.05). Areas under the curve of cDWI0-100 (0.62) and cDWI0-500 (0.65) were significantly smaller (p < 0.05) than those of others (cDWI100-500, 0.72; cDWI0-1000, 0.73; cDWI100-1000, 0.71; cDWI500-1000, 0.74; mDWI2000, 0.72).

CONCLUSION

The combinations of b-values influenced image quality and diagnostic ability of cDWIs for PCa detection. The combinations of b ≥ 100 and b ≥ 500 s mm(-2), as well as b = 0 and b = 1000 s mm(-2), were optimal in this study.

ADVANCES IN KNOWLEDGE

For generating the useful cDWI for PCa detection, radiologists should take care of the combination of b-values when including low b-values.

Type 2 diabetes reduces the proliferation and survival of oligodendrocyte progenitor cells in ishchemic white matter lesions

Diabetes mellitus (DM) is a major risk factor for stroke and it exacerbates tissue damage after ischemic insult. Diabetes is one of the important causes of the progression of white matter lesion, however, the pathological mechanisms remain unclear. The present study evaluated the influences of type 2 DM on ischemic subcortical white matter injury and the recruitment of oligodendrocyte progenitor cells (OPCs) under chronic cerebral hypoperfusion using type 2 diabetic (db/db) mice. After bilateral common carotid artery stenosis (BCAS), the rarefaction in the white matter was more severe in db/db mice than in db/+ mice, and the number of glutathione S-transferase-pi (GST-pi)-positive mature oligodendrocytes (OLG) was lower in db/db mice than in db/+ mice at 4 and 8 weeks after ischemia. There were no significant differences in the number of single-stranded DNA (ssDNA)-positive apoptotic cells in the deep white matter between the db/db and db/+ mice. We found a transient increase in the platelet-derived growth factor receptor-α (PDGFRα)-positive OPCs in white matter lesions after ischemia. However, significantly fewer PDGFRα-positive OPCs were detected in db/db than db/+ mice from 4weeks after BCAS. The number of Ki67-positive proliferating cells in the deep white matter was significantly lower in db/db mice than in db/+ mice from 4 to 8weeks after BCAS. Most of the Ki67-positive cells were PDGFRα-positive OPCs. Finally, we assessed the survival of 5-bromo-2'-deoxyuridine (BrdU)-positive proliferating cells in ischemic white matter, and found significantly poorer survival of BrdU/PDGFRα-positive OPCs or BrdU/GST-pi-positive OLGs in the db/db mice compared to the db/+ mice in the white matter after BCAS. Our findings suggest that the type 2 DM mice exhibited more severe white matter injury 8 weeks after chronic ischemia. Decreased proliferation and survival of OPCs may play an important role in the progression of white matter lesions after ischemia in diabetics.

Evidence of a sophisticatedly heterogeneous population of human umbilical vein endothelial cells

Induction and promotion of angiogenesis play a role in a diverse range of physiologic and pathophysiologic processes that are especially relevant to the field of regenerative medicine. For assessing vasculogenesis and neo-angiogenesis, identifying angiogenic factors, angiocrine factors, and vascular niche, facilitating tissue-repair and tumor growth, efficiently generating induced pluripotent stem cells, and coculturing with organ-specific stem cells, isolation and characterization of the subpopulation of human umbilical vein endothelial cells (HUVECs) and their endothelial progenitor cells (EPCs) are needed. In this study, primary HUVECs were collected from fresh umbilical cords and fractionated and characterized with the use of flow cytometry. Clonal colony assay showed that endothelial colony-forming units in culture frequently existed in fresh HUVECs. Antigenic profiling demonstrated that undifferentiated EPCs in HUVECs had normal endothelial marker CD31 with a subpopulation of cells positive for hematopoietic stem cell marker CD34 and c-Kit. With continuing passages, EPC markers CD34 and vascular endothelial growth factor receptor 2 expression decreased dramatically. Moreover, a distinct subpopulation with different proliferative capability and angiogenesis from the early-passage HUVECs was shown. In conclusion, it is possible to isolate accurately and to enrich EPCs or hematoangioblast-like cells from a heterogeneous population of HUVECs, and to explore the differential process with flow cytometry for further investigations.

Evaluation of genetic introgression from domesticated pigs into the Ryukyu wild boar population on Iriomote Island in Japan

We evaluated genetic introgression from domesticated pigs into the Ryukyu wild boar (RWB) population on Iriomote Island based on their genetic structure and diversity. We used a combination of mitochondrial DNA D-loop region (596 bp) polymorphisms and 23 microsatellite markers. RWBs (n = 130) were collected from 18 locations on Iriomote Island and compared with 66 reference samples of European and Asian domestic pigs. We identified six distinct haplotypes, involving 22 single nucleotide polymorphisms (including one insertion) in the RWB population. The phylogenetic tree had two branches: the RWB group and domestic lineage. Fourteen of 130 RWBs (10.8%) belonged to the European domestic lineage, including 11 RWBs from the Panari Islands, northwest of Iriomote Main Island (IMI). The heterozygosity values, total number of alleles, number of effective alleles and polymorphism information content of the RWB groups were lower than those of the European domestic groups. The RWB population on IMI had a lower heterozygous deficiency index (FIS = 0.059) than did the other populations, which indicates that this population was more inbred. There was a large genetic distance (FST = 0.560) between RWBs on IMI and the Meishan populations. Structure analysis using the 23 microsatellite markers revealed that 16 RWBs had an admixture pattern between RWB and domesticated pig breeds. These results suggest that gene flow may have occurred from domestic pigs to RWBs and demonstrate that there was low genetic variation in the IMI population.

Visceral fat accumulation is associated with cerebral small vessel disease

BACKGROUND AND PURPOSE

Obesity is associated with the risk of coronary artery disease and stroke. Visceral fat plays a significant role in the atherogenic effects of obesity. Whether visceral fat accumulation, as measured by computed tomography (CT), is an independent risk factor for the presence of cerebral small vessel disease (SVD) was investigated.

METHODS

This study comprised 506 Japanese subjects 35-74 years of age (mean 55.3 years) without a history of symptomatic cerebrovascular disease who underwent health screening tests, including brain magnetic resonance imaging, carotid echography and measurements of the visceral fat area (VFA) and subcutaneous fat area (SFA) on abdominal CT. Visceral fat accumulation was defined as VFA ≥ 100 cm(2) . Logistic regression analysis was performed to examine the associations between visceral fat accumulation and cerebral SVD such as white matter lesions (WMLs) and silent lacunar infarction (SLI).

RESULTS

The prevalence of WMLs and SLI but not carotid plaque were significantly higher in subjects with VFA ≥ 100 cm(2) than those with VFA < 100 cm(2) . A VFA ≥ 100 cm(2) was associated with WMLs and SLI independent of age, cardiovascular risk factors and other measurements of obesity, such as waist circumference and body mass index. A large waist circumference was independently associated with SLI. SFA, the combination of VFA and SFA, and body mass index were not associated with WMLs or SLI.

CONCLUSIONS

Visceral fat accumulation was independently associated with the presence of cerebral SVD in subjects without a history of symptomatic cerebrovascular disease.

Virulence genes and antimicrobial susceptibility in Pasteurella multocida isolates from calves

A total of 378 isolates of Pasteurella multocida from clinically healthy and diseased calves were characterised for their susceptibility to 9 antimicrobial agents and screened by PCR for the presence of antimicrobial resistance genes and 22 genes virulence-associated, including capsule biosynthesis genes. Of the 378 isolates, 102 (27.0%) were resistant to at least one of the 9 tested antimicrobial agents. Resistance to oxytetracycline (21.7%) was the most frequently observed phenotype among the isolates. The tet(H) gene were the primary determinant detected. The resistance rates for thiamphenicol, ampicillin, kanamycin and florfenicol were 13.2%, 5.8%, 9.0% and 0.5%, respectively. Cefazolin, ceftiofur, cefquinome and enrofloxacin were effective antimicrobial agents, with no resistant isolates emerging over the course of the investigation. Most isolates were identified as capsular type A, only 6.3% belonged to capsular type D and no other capsular type was identified. Four of the virulence-associated genes (pfhA, tadD, tbpA and HAS) exhibited associations to the capsular type, and three (pfhA, tbpA and hgbB) were associated with the disease status of the animals. These virulence genes have been considered as epidemiological markers and are hypothesised to have a strong positive association with the outcome of disease in cattle.

Thoracoscopic hepatectomy for malignant liver tumor

BACKGROUND

Anatomical position of the liver poses a difficulty in approaching the lesions using a laparoscopic approach.

METHODS

The patient was a 79-year-old man with a surgical history of laparoscopic sigmoidectomy for colon cancer and posterior segmentectomy of the liver for metastatic liver tumor. On admission, he presented with another liver tumor (diameter, 1.5 cm) in the dome of segment VIII. Because of the high possibility of severe adhesion around the liver and difficulty of approaching the lesion from the abdomen, we selected the transthoracic approach rather than the abdominal approach; the patient consented to this procedure. The patient was placed in the left-lateral position under general anesthesia with single-lung ventilation. We placed three trocars into the right thoracic space. The intrathoracic space was observed using a flexible-tip rigid scope (Olympus, Tokyo, Japan). The tumor was detected by inserting a flexible laparoscopic ultrasound probe (Hitachi Aloka, Ltd., Tokyo, Japan) through the diaphragm; the diaphragm was dissected immediately above the tumor using a harmonic scalpel (Ethicon Endo-Surgery, Inc., Cornelia, GA). The liver surface was precoagulated using a low-voltage monopolar coagulator with a ball-shaped tip (Amco Inc., Tokyo, Japan) with the electrosurgical unit VIO300D (Erbe Elektromedizin, Tuebingen, Germany). The parenchyma was first sealed using BiClamp LAP forceps (Erbe Elektromedizin) and divided using the harmonic scalpel. The specimen was extracted using a retrieval bag. After complete hemostasis was achieved, the diaphragm was closed by continuous suturing.

RESULTS

The operation lasted for 310 min and estimated blood loss was 10 mL. The patient was discharged on postoperative day 4.

CONCLUSIONS

Although the duration of TH was long because of the narrow thoracic cavity space, TH was performed without any problems. As a rule, we should select TH for lesions located in the dorsal segment VII/VIII, with severe adhesion around the liver.

A new classification system for branch artery perfusion patterns in acute aortic dissection for examining the effects of central aortic repair

OBJECTIVES

We developed a new classification system for branch perfusion patterns in acute aortic dissection and used it to retrospectively evaluate the perfusion status of whole aortic branches and to examine the effects of central aortic repair.

METHODS

Thirty-four consecutive patients with acute type A aortic dissection underwent emergent surgery at our institution between August 2008 and December 2011. A retrospective review of pre- and postoperative computed tomographic angiography was performed. Branch perfusion patterns were categorized into three classes: Class I, dissection involving but not extending into the branch; Class II, dissection extending into the branch and Class III, dissection causing ostial avulsion.

RESULTS

In cervical branches (total 169 branches), 70 branches (41%) presented with Class I patterns, 58 (34%) with Class II and none with Class III. In abdominal branches (total 135 branches), 76 branches (56%) presented with Class I patterns, 12 (9%) with Class II and 18 (13%) with Class III. In common iliac arteries (total 68 arteries), 14 arteries (21%) presented with Class I patterns, 24 (35%) with Class II and none with Class III. After repair, among 21 high-risk cervical branches, 14 branches (67%) showed improvement, 3 (14%) preserved distal perfusion supplied through the patent branch false lumen and 4 (19%) showed no improvement in high-risk perfusion pattern or worsened. Among 22 high-risk abdominal branches, 18 branches (82%) showed improvement, 3 (14%) preserved distal perfusion supplied through the patent branch or aortic false lumen and 1 (5%) showed no improvement in high-risk perfusion pattern.

CONCLUSIONS

To overcome malperfusion syndromes associated with acute aortic dissection, recognition of diverse branch perfusion patterns through a universal classification system is imperative.

Newly designed bioabsorbable substitute for the treatment of diaphragmatic defects

PURPOSE

Earlier studies have investigated the suitability of various materials and autologous grafts for the repair of diaphragmatic defects. Our group investigated the feasibility of using an artificial diaphragm (AD) to repair wide diaphragmatic defects.

METHODS

Twelve pigs were laparotomized and, in each pig, a defect was fashioned by resecting a round 8-cm diameter hole in the left diaphragm. Next, the defect was repaired by implanting an AD. The animals were relaparotomized 8 or 24 weeks after implantation for gross, histological and radiological observation of the implanted sites.

RESULTS

All recipient animals survived until killing for evaluation. Chest X-ray examinations showed no differences between the preoperative diaphragms and the grafted diaphragms at 8 and 24 weeks after implantation. At 8 weeks after implantation, the implanted sites exhibited fibrous adhesions to the liver and lungs without deformities or penetrations. Parts of the surface tissue at the graft sites had a varnished appearance similar to those of the native diaphragm. Histology performed at 8 weeks detected no trace of the ADs in the graft sites; however, numerous inflammatory cells and profuse fibrous connective tissue were observed. At 24 weeks after implantation, no differences were found in the thorax between the areas with the grafts and the unaffected areas. Histology of the graft sites in the thorax confirmed growth of mesothelial cells similar to that observed in the native diaphragm.

CONCLUSIONS

Artificial diaphragms can be a novel substitute for diaphragmatic repair.

Liver resection using a soft-coagulation system without the Pringle maneuver

BACKGROUND/AIMS

The Pringle maneuver is generally performed to reduce the amount of blood loss during hepatic resection. We have developed a method to sufficiently control blood loss during hepatectomy without applying the Pringle maneuver. This study was performed to determine the safety and operative blood loss in hepatectomy performed by this new method.

METHODOLOGY

We performed 102 hepatic resections without the Pringle maneuver. We retrospectively compared the short-term operative outcome between these 102 cases and another 75 hepatic resections performed with the Pringle maneuver. The resections without the Pringle maneuver were performed using a soft-coagulation system.

RESULTS

The median length of the surgery using the soft-coagulation system without the Pringle maneuver was 135 minutes, significantly shorter than the surgical time required for resection with the Pringle maneuver 297 minutes (p<0.001). The median volume of operative blood loss was significantly lower in the non-Pringle-maneuver group (200cc vs. 704cc; p<0.001). Regarding postoperative liver function, AST, ALT, T-Bil and PT, levels were all significantly improved in the non-Pringle-maneuver group (p<0.01).

CONCLUSIONS

Our data suggest that hepatic resection using a soft-coagulation system without the Pringle maneuver is extremely safe and effective in controlling bleeding.

Self-organization of human hepatic organoid by recapitulating organogenesis in vitro

BACKGROUND

Careful orchestration among endodermal epithelial, endothelial, and mesenchymal cells initiate liver organogenesis prior to vascular function. Nonparenchymal endothelial or mesenchymal cells not only form passive conduits, but also establish an organogenic stimulus. Herein, we have evaluated the potential roles of primitive endothelial and mesenchymal cells toward hepatic organization in vitro.

METHODS

To track the cellular movements and localization, we retrovirally transduced enhanced green fluorescence protein and kusabira orange into human fetal liver cells (GFP-hFLCs) and human umbilical vein endothelial cells (KO-HUVECs), respectively. GFP-hFLCs were cocultivated with KO-HUVECs and human mesenchymal stem cells (hMSCs) under conventional two-dimensional (2D) conditions.

RESULTS

Even under 2D culture, fetal liver, endothelial, and mesenchymal cells self-organized into a macroscopically visible three-dimensional (3D) organoid. Time-lapse confocal imaging showed dynamic cellular organizations of GFP-hFLCs and KO-HUVECs. Endothelial cells organized into patterned clusters wrapping fetal liver cells, forming vessel-like lumens inside. Mesenchymal cells supported the generated organoid from outside.

CONCLUSION

Generation of whole organ architecture remains a great challenge so far. Our preliminary results showed that recapitulation of primitive cellular interactions during organogenesis elicit the intrinsic self-organizing capacity to form hepatic organoids. Future studies to define precise conditions mimicking organogenesis may ultimately lead to the generation of a functional liver for transplantation and for other applications such as drug development.

Generation of functional human vascular network

BACKGROUND

One of the major obstacles in regenerating thick, complex tissues such as the liver is their need for vascularization, which is essential to maintain cell viability during tissue growth and to induce structural organization. Herein, we have described a method to engineer a functional human vascular network.

METHODS

Enhanced green fluorescence protein-labeled human umbilical vein endothelial cells (GFP-HUVECs) were cocultivated with kusabira orange-labeled human mesenchymal stem cells (KO-hMSCs) inside a collagen/fibronectin matrix. Premature vascular network formation was visualized by fluorescence microscopy imaging. Furthermore, constructs prevascularized in vitro were implanted into a transparency window in immunodeficient mice.

RESULTS

Following several days of cultivation, GFP-HUVECs formed vessel-like structures that were stabilized by pericytes differentiated from KO-hMSCs. After implantation in vivo, the patency of human vascular structures was proved by rhodamine dextran infusion. These functional vascular structures remained for over 2 months.

DISCUSSION

Vascularization is the key challenge to organ generation. We successfully generated human vascular networks inside a matrix. Integration of parenchymal cells using our engineering technique should facilitate future efforts to reconstitute vascularized human organ systems in vitro.

Role of natural killer T cells in the mouse colitis-associated colon cancer model

Invariant natural killer T (iNKT) cells are considered innate-like lymphocytes, and regulate the immunity against inflammation and tumorigenesis. However, the impact of iNKT cells in inflammation-associated tumorigenesis remains unclear. In this study, we examined the physiological role of iNKT cells in a mouse colitis-associated colorectal cancer model. C57BL/6 (B6) and Jα18 NKT cell-deficient KO (KO) mice were used. Colitis-associated colorectal cancer was induced by azoxymethane (AOM) and dextran sodium sulfate (DSS). The resulting inflammation and tumours were examined. The surface markers of mononuclear cells from the liver and the colon were assessed by FACS. The levels of IL-13 from the colon were measured by ELISA. α-galactosylceramide (GC), or its close analog OCH, was administered intraperitoneally on the first day of each cycle of DSS-administration. In the AOM/DSS model, hepatic iNKT cells were significantly decreased. In KO mice there were significantly greater numbers of colon tumours and more severe inflammation than in B6 mice. FACS analysis revealed that the population of NK1.1 (+) T cells (non-invariant NKT cells) in the colon was increased when compared to B6 mice. The secretion of IL-13 was increased in the colon of KO mice after AOM/DSS. The number of colon tumours was significantly decreased in the GC-treated group compared to the control group. GC-treatment significantly inhibited IL-13 secretion from the colonic mononuclear cells and the number of colonic NK1.1 (+) T cells was significantly decreased. These results suggest that iNKT cells may play a critical role in the prevention of tumour progression and inflammation in the AOM/DSS model.

A fatal case of severe methemoglobinemia presumably due to chlorate ingestion

A fatal case due to severe methemoglobinemia is presented. A male in his forties was found unconscious in his house and, despite intensive care, death was confirmed approximately 11 hours later. Toxicological analysis using ion chromatography revealed the presence of chlorate in the stomach contents. However, chlorate was not detected in the blood, and no other drugs or ethanol were detected in the blood either. We concluded that the cause of death was presumably due to chlorate poisoning, based on the results of the autopsy and the toxicological examination.

Duct-to-mucosa pancreatojejunostomy for small main pancreatic duct by the parachute technique after pancreatoduodenectomy

A duct-to-mucosa pancreatojejunostomy is technically difficult to perform for a small main pancreatic duct after pancreatoduodenectomy. Our group applied the parachute technique to reconstruct and attach a small pancreatic duct to the jejunal mucosa. This method makes it very easy to position stitches on the posterior row of the anastomosis. It also allows a complete view of every stitch, both inside and outside the pancreatic duct and jejunal wall. Sixteen patients underwent pancreatoduodenectomy followed by duct-to-mucosa pancreatojejunostomy by the parachute technique. Pancreatic fistulae developed in 3 of the patients, but none of the fistulae were severe. The median postoperative hospital stay was 14.5 days, and there were no postoperative deaths during that time. In conclusion, pancreatojejunostomy by the parachute technique is a simple method with a very low risk of pancreatic fistula formation and a considerably shortened postoperative hospital stay. The method is also useful for reconstruction with pancreatojejunostomy after pancreatoduodenectomy.