Direct observations of energy transfer from resonant electrons to whistler-mode waves in magnetosheath of Earth

Electromagnetic whistler-mode waves in space plasmas play critical roles in collisionless energy transfer between the electrons and the electromagnetic field. Although resonant interactions have been considered as the likely generation process of the waves, observational identification has been extremely difficult due to the short time scale of resonant electron dynamics. Here we show strong nongyrotropy, which rotate with the wave, of cyclotron resonant electrons as direct evidence for the locally ongoing secular energy transfer from the resonant electrons to the whistler-mode waves using ultra-high temporal resolution data obtained by NASA’s Magnetospheric Multiscale (MMS) mission in the magnetosheath. The nongyrotropic electrons carry a resonant current, which is the energy source of the wave as predicted by the nonlinear wave growth theory. This result proves the nonlinear wave growth theory, and furthermore demonstrates that the degree of nongyrotropy, which cannot be predicted even by that nonlinear theory, can be studied by observations.

Excitation of whistler-mode waves by cyclotron instability is considered as the likely generation process of the waves. Here, the authors show direct observational evidence for locally ongoing secular energy transfer from the resonant electrons to the whistler-mode waves in Earth’s magnetosheath.

Enhancement ofAcinetobacterbaumanniibiofilm growth by cephem antibiotics via enrichment of protein and extracellular DNAin thebiofilm matrices

AIMS

To determine the effects of subinhibitory concentrations of eight cephem and carbapenem antibiotics on thebiofilm formation ofAcinetobacterbaumanniicells and examine itseffect on pre-established biofilms.

METHODS AND RESULTS

Effects of antibiotics on biofilm formation were assayed using microtiter plates with polystyrene peg-lids.Cefmetazole, ceftriaxone, ceftazidime, and cefpirome increased the biomass of pre-established biofilms on pegs in the range of their sub-minimum inhibitory concentrations, whereas none increased biofilm formation by planktonic cells. Carbapenems had a negative effect.The constituents of antibiotic-induced biofilms were analyzed. Ceftriaxoneor ceftazidimetreatment markedly increased the matrix constituent amounts in the biofilms (carbohydrate, 2.7-fold; protein, 8.9-12.7-fold; lipid, 3.3-3.6-fold; DNA, 9.1-12.2-fold; outer membrane vesicles, 2.7-3.8-fold; and viable cells,6.8-10.1-fold).The antibiotic-enhanced biofilmshad increased outer membrane protein A and were resistant to the anti-biofilm effect of azithromycin.

CONCLUSIONS

Some cephems increased the biomass of pre-established biofilms in the ranges of their sub-minimum inhibitory concentrations.The antibiotic-enhanced biofilmspossessed more virulent characteristics than normal biofilms.

SIGNIFICANCE AND IMPACT OF THE STUDY

Incomplete administration of certain cephems followingbiofilm-related Ac.baumannii infectionscould adversely cause exacerbated and chronic clinical results.

Collaborative Research Activities of the Arase and Van Allen Probes

This paper presents the highlights of joint observations of the inner magnetosphere by the Arase spacecraft, the Van Allen Probes spacecraft, and ground-based experiments integrated into spacecraft programs. The concurrent operation of the two missions in 2017-2019 facilitated the separation of the spatial and temporal structures of dynamic phenomena occurring in the inner magnetosphere. Because the orbital inclination angle of Arase is larger than that of Van Allen Probes, Arase collected observations at higher L -shells up to L ∼ 10 . After March 2017, similar variations in plasma and waves were detected by Van Allen Probes and Arase. We describe plasma wave observations at longitudinally separated locations in space and geomagnetically-conjugate locations in space and on the ground. The results of instrument intercalibrations between the two missions are also presented. Arase continued its normal operation after the scientific operation of Van Allen Probes completed in October 2019. The combined Van Allen Probes (2012-2019) and Arase (2017-present) observations will cover a full solar cycle. This will be the first comprehensive long-term observation of the inner magnetosphere and radiation belts.

Penetration of MeV electrons into the mesosphere accompanying pulsating aurorae

Pulsating aurorae (PsA) are caused by the intermittent precipitations of magnetospheric electrons (energies of a few keV to a few tens of keV) through wave-particle interactions, thereby depositing most of their energy at altitudes ~ 100 km. However, the maximum energy of precipitated electrons and its impacts on the atmosphere are unknown. Herein, we report unique observations by the European Incoherent Scatter (EISCAT) radar showing electron precipitations ranging from a few hundred keV to a few MeV during a PsA associated with a weak geomagnetic storm. Simultaneously, the Arase spacecraft has observed intense whistler-mode chorus waves at the conjugate location along magnetic field lines. A computer simulation based on the EISCAT observations shows immediate catalytic ozone depletion at the mesospheric altitudes. Since PsA occurs frequently, often in daily basis, and extends its impact over large MLT areas, we anticipate that the PsA possesses a significant forcing to the mesospheric ozone chemistry in high latitudes through high energy electron precipitations. Therefore, the generation of PsA results in the depletion of mesospheric ozone through high-energy electron precipitations caused by whistler-mode chorus waves, which are similar to the well-known effect due to solar energetic protons triggered by solar flares.

A new multi-tracer pellet injection for a simultaneous study of low- and mid/high-Z impurities in high-temperature plasmas

A new multi-tracer technique in the Tracer-Encapsulated Solid Pellet (TESPEL) method has been developed in order to acquire simultaneously the information about the behaviors of various impurities, i.e., to study concurrently the behaviors of low- and mid/high-Z impurities in magnetically confined high-temperature plasmas. In this new technique, an inorganic compound (for example, lithium titanate, Li₂TiO₃) is proposed to be used as a tracer embedded in the core of the TESPEL, instead of pure elements. The results of the proof-of-principle experiment clearly demonstrate the applicability of the new multi-tracer technique in the TESPEL method for the simultaneous study of behaviors of low- and mid/high-Z impurities in high-temperature plasmas.

Electronic and spin structures of CaMn4Ox clusters in the S0 state of the oxygen evolving complex of photosystem II. Domain-based local pair natural orbital (DLPNO) coupled-cluster (CC) calculations using optimized geometries and natural orbitals (UNO) by hybrid density functional theory (HDFT) calculations

Domain-based local pair natural orbital (DLPNO) coupled cluster single and double (CCSD) with triple perturbation (T) correction methods were performed to elucidate the relative stabilities of ten different intermediate structures of the CaMn4Ox cluster in the S0 state of the oxygen evolving complex (OEC) of photosystem II (PSII). Full geometry optimizations of all the S0 intermediates were performed by the UB3LYP-D3/Def2-TZVP methods, providing the assumed geometrical structures and starting natural orbitals (UNO) for DLPNO-CCSD(T)/Def2TZVP calculations. The effective exchange integrals (J) for the spin Hamiltonian models for the ten intermediates were obtained by the UB3LYP/Def2-TZVP calculations followed by the general spin projections. DLPNO-CCSD(T) calculations followed by the CBS extrapolation procedure elucidated that the (II, III, IV, IV) and (III, III, III, IV) valence states in the CaMn4O5 cluster of the OEC of the PS II were nearly degenerated in energy in the S0 state, indicating an important role of dynamical electron correlation effects for the valence and spin fluctuations in strongly correlated electron systems (SCESs) consisting of 3d transition metals.

Clinical risk predictors for bradycardia, supraventricular tachycardia and epilepsy necessitating therapy in patients with unexplained syncope monitored by insertable cardiac monitor

Background

Insertable cardiac monitors (ICMs) allow for lengthy monitoring of cardiac rhythm and improve diagnostic yield in patients with unexplained syncope. In most cardiac syncope cases, sick sinus syndrome, atrioventricular block, and paroxysmal supraventricular tachycardia (SVT) are detected using ICMs. On the other hand, epileptic seizures are sometimes diagnosed as unexplained syncope because in these situations, the loss of consciousness is a similar manifestation. Thus, the population of patients with unexplained syncope monitored by ICMs includes epileptic patients. Clinical risk factors for bradycardia, SVT and epilepsy that necessitate therapy in patients with unexplained syncope are not well known. If these risks can be clarified, clinicians could provide more specific targeted monitoring.

Purpose

We aimed to identify these predictors.

Methods

We retrospectively reviewed medical records of consecutive patients who received ICMs to monitor unexplained syncope in three medical facilities. We performed Cox's stepwise logistic regression analysis to identify significant independent risk factors for bradycardia, SVT, and epilepsy.

Results

One hundred thirty-two patients received ICMs to monitor unexplained syncope. During the 17-month follow-up period, 19 patients (10 patients had sick sinus syndrome and 9 had atrioventricular block) needed pacemaker for bradycardia; 8 patients (3 had atrial flutter, 4 had atrial tachycardia, and 1 had paroxysmal atrial fibrillation) needed catheter ablation for SVT; and 9 patients needed antiepileptic agents from the neurologist.Stepwise logistic regression analysis indicated that syncope during effort (odds ratio [OR] = 3.41; 95% confidence interval [CI], 1.21 to 9.6; p=0.02) was an independent risk factor for bradycardia. Palpitation before syncope (OR = 9.46; 95% CI, 1.78 to 50.10; p=0.008) and history of atrial fibrillation (OR = 10.1; 95% CI, 1.96 to 52.45; p=0.006) were identified as significant independent prognostic factors for SVT. Syncope while supine (OR = 11.7; 95% CI, 1.72 to 79.7; p=0.01) or driving (OR = 15.6; 95% CI, 2.10 to 115.3; p=0.007) was an independent factor for epileptic seizure.

Conclusions

ICMs are useful devices for diagnosing unexplained syncope. Palpitation, atrial fibrillation and syncope during effort were independent risk factors for bradycardia and for SVT. Syncope while supine or driving was an independent risk factor for epilepsy. We should carefully follow up of patients with these risk factors.

Funding Acknowledgement

Type of funding source: None

Oxygen torus and its coincidence with EMIC wave in the deep inner magnetosphere: Van Allen Probe B and Arase observations

We investigate the longitudinal structure of the oxygen torus in the inner magnetosphere for a specific event found on 12 September 2017, using simultaneous observations from the Van Allen Probe B and Arase satellites. It is found that Probe B observed a clear enhancement in the average plasma mass (M) up to 3-4 amu at L = 3.3-3.6 and magnetic local time (MLT) = 9.0 h. In the afternoon sector at MLT ~ 16.0 h, both Probe B and Arase found no clear enhancements in M. This result suggests that the oxygen torus does not extend over all MLT but is skewed toward the dawn. Since a similar result has been reported for another event of the oxygen torus in a previous study, a crescent-shaped torus or a pinched torus centered around dawn may be a general feature of the O+ density enhancement in the inner magnetosphere. We newly find that an electromagnetic ion cyclotron (EMIC) wave in the H+ band appeared coincidently with the oxygen torus. From the lower cutoff frequency of the EMIC wave, the ion composition of the oxygen torus is estimated to be 80.6% H+, 3.4% He+, and 16.0% O+. According to the linearized dispersion relation for EMIC waves, both He+ and O+ ions inhibit EMIC wave growth and the stabilizing effect is stronger for He+ than O+. Therefore, when the H+ fraction or M is constant, the denser O+ ions are naturally accompanied by the more tenuous He+ ions, resulting in a weaker stabilizing effect (i.e., larger growth rate). From the Probe B observations, we find that the growth rate becomes larger in the oxygen torus than in the adjacent regions in the plasma trough and the plasmasphere.

Nationwide survey on cerebral amyloid angiopathy in Japan

BACKGROUND AND PURPOSE

A nationwide survey was conducted to understand the epidemiology of cerebral amyloid angiopathy-related intracerebral hemorrhage (CAA-related ICH) and cerebral amyloid angiopathy-related inflammation/vasculitis (CAA-ri) in Japan.

METHODS

To estimate the total number and clinical features of patients with CAA-related ICH and CAA-ri between January 2012 and December 2014 and to analyze their clinical features, questionnaires were sent to randomly selected hospitals in Japan.

RESULTS

In the first survey, 2348 of 4657 departments responded to the questionnaire (response rate 50.4%). The total numbers of reported patients with CAA-related ICH and CAA-ri were 1338 and 61, respectively, and their total numbers in Japan were estimated to be 5900 [95% confidence interval (CI) 4800-7100] and 170 (95% CI 110-220), respectively. The crude prevalence rates were 4.64 and 0.13 per 100 000 population, respectively. The clinical information of 474 patients with CAA-related ICH obtained in the second survey was as follows: (i) the average age of onset was 78.4 years; (ii) the prevalence increased with age; (iii) the disease was common in women; and (iv) hematoma most frequently occurred in the frontal lobe. Sixteen patients with CAA-ri for whom data were collected in the second survey had the following characteristics: (i) median age of onset was 75 years; (ii) cognitive impairment and headache were the most frequent initial manifestations; and (iii) focal neurological signs, such as motor paresis and visual disturbance, were frequently observed during the clinical course.

CONCLUSIONS

The numbers of patients with CAA-related ICH and CAA-ri in Japan were estimated.

The Space Physics Environment Data Analysis System (SPEDAS)

With the advent of the Heliophysics/Geospace System Observatory (H/GSO), a complement of multi-spacecraft missions and ground-based observatories to study the space environment, data retrieval, analysis, and visualization of space physics data can be daunting. The Space Physics Environment Data Analysis System (SPEDAS), a grass-roots software development platform (www.spedas.org), is now officially supported by NASA Heliophysics as part of its data environment infrastructure. It serves more than a dozen space missions and ground observatories and can integrate the full complement of past and upcoming space physics missions with minimal resources, following clear, simple, and well-proven guidelines. Free, modular and configurable to the needs of individual missions, it works in both command-line (ideal for experienced users) and Graphical User Interface (GUI) mode (reducing the learning curve for first-time users). Both options have "crib-sheets," user-command sequences in ASCII format that can facilitate record-and-repeat actions, especially for complex operations and plotting. Crib-sheets enhance scientific interactions, as users can move rapidly and accurately from exchanges of technical information on data processing to efficient discussions regarding data interpretation and science. SPEDAS can readily query and ingest all International Solar Terrestrial Physics (ISTP)-compatible products from the Space Physics Data Facility (SPDF), enabling access to a vast collection of historic and current mission data. The planned incorporation of Heliophysics Application Programmer's Interface (HAPI) standards will facilitate data ingestion from distributed datasets that adhere to these standards. Although SPEDAS is currently Interactive Data Language (IDL)-based (and interfaces to Java-based tools such as Autoplot), efforts are under-way to expand it further to work with python (first as an interface tool and potentially even receiving an under-the-hood replacement). We review the SPEDAS development history, goals, and current implementation. We explain its "modes of use" with examples geared for users and outline its technical implementation and requirements with software developers in mind. We also describe SPEDAS personnel and software management, interfaces with other organizations, resources and support structure available to the community, and future development plans.

ELECTRONIC SUPPLEMENTARY MATERIAL

The online version of this article (10.1007/s11214-018-0576-4) contains supplementary material, which is available to authorized users.

Direct measurements of two-way wave-particle energy transfer in a collisionless space plasma

Particle acceleration by plasma waves and spontaneous wave generation are fundamental energy and momentum exchange processes in collisionless plasmas. Such wave-particle interactions occur ubiquitously in space. We present ultrafast measurements in Earth's magnetosphere by the Magnetospheric Multiscale spacecraft that enabled quantitative evaluation of energy transfer in interactions associated with electromagnetic ion cyclotron waves. The observed ion distributions are not symmetric around the magnetic field direction but are in phase with the plasma wave fields. The wave-ion phase relations demonstrate that a cyclotron resonance transferred energy from hot protons to waves, which in turn nonresonantly accelerated cold He⁺ to energies up to ~2 kilo-electron volts. These observations provide direct quantitative evidence for collisionless energy transfer in plasmas between distinct particle populations via wave-particle interactions.

Modification of LSC spectra of 125I by high atomic number elements

The ¹²⁵I pulse-height spectra via a liquid scintillation counter (LSC) displayed notable variations. The counting efficiencies of higher and lower energy peaks increased and decreased, respectively, with the enhancement of the amount of high atomic numbered elements within the cocktails. This tendency was ascribed to the increasing probability of the interaction of photons with the scintillation cocktail. Moreover, it was noted that the shape of a ¹²⁵I spectrum strongly depends on the amount of high atomic numbered elements.

Development of a new tracer-encapsulated solid pellet injection system for more precise control of tracer-impurity-deposit location in LHD

A new tracer-encapsulated solid pellet (TESPEL) injection system has been developed additionally for the LHD heliotron. This system has three-dimensionally bended guide tubes, which allows us to inject the TESPEL obliquely on a poloidal cross-section of the LHD plasma. Consequently, this system enables us to control a tracer-impurity-deposited location more precisely. Moreover, this system can make it possible for the tracer impurity to be deposited even only inside the ergodic region (outside a last closed flux surface of the LHD plasma). A stereoscopic fast camera system has been also developed for capturing a three-dimensional TESPEL trajectory.

Urinary podocalyxin levels were associated with urinary albumin levels among patients with diabetes

Diabetic nephropathy has dramatically increased worldwide. In this study, we measured urinary podocalyxin in 240 patients with diabetes. The relationship between urinary podocalyxin and clinical parameters and the effects of dipeptidyl peptidase-4 inhibitors (DPP4i) and alpha-glucosidase inhibitor (a-GI) on urinary podocalyxin levels were examined. Urinary podocalyxin levels were significantly higher in patients with microalbuminuria than in those with normoalbuminuria. Urinary podocalyxin levels were also significantly related to albumin-to-creatinine ratio. Neither DPP4i nor α-GI ameliorated the increase in urinary podocalyxin levels. Our results indicated that urinary podocalyxin will be not only an early marker but also a treatment target for DN.

Generalized approximate spin projection calculations of effective exchange integrals of the CaMn4O5 cluster in the S1 and S3 states of the oxygen evolving complex of photosystem II

Full geometry optimizations followed by the vibrational analysis were performed for eight spin configurations of the CaMn4O4X(H2O)3Y (X = O, OH; Y = H2O, OH) cluster in the S1 and S3 states of the oxygen evolution complex (OEC) of photosystem II (PSII). The energy gaps among these configurations obtained by vertical, adiabatic and adiabatic plus zero-point-energy (ZPE) correction procedures have been used for computation of the effective exchange integrals (J) in the spin Hamiltonian model. The J values are calculated by the (1) analytical method and the (2) generalized approximate spin projection (AP) method that eliminates the spin contamination errors of UB3LYP solutions. Using J values derived from these methods, exact diagonalization of the spin Hamiltonian matrix was carried out, yielding excitation energies and spin densities of the ground and lower-excited states of the cluster. The obtained results for the right (R)- and left (L)-opened structures in the S1 and S3 states are found to be consistent with available optical and magnetic experimental results. Implications of the computational results are discussed in relation to (a) the necessity of the exact diagonalization for computations of reliable energy levels, (b) magneto-structural correlations in the CaMn4O5 cluster of the OEC of PSII, (c) structural symmetry breaking in the S1 and S3 states, and (d) the right- and left-handed scenarios for the O-O bond formation for water oxidation.

Multiple liver metastases of pancreatic solid pseudopapillary tumor treated with resection following chemotherapy and transcatheter arterial embolization: A case report

A 33-year-old female was diagnosed with a solid pseudopapillary tumor (SPT) of the pancreas and multiple liver metastases at the Department of Gastroenterological Surgery, Ishikawa Prefectural Central Hospital (Kanazawa, Japan). Distal pancreatectomy and postoperative systemic chemotherapy with gemcitabine (GEM) and S-1, an oral fluoropyrimidine derivative, was administered, however, liver metastases became enlarged and local recurrence occurred. Therefore, the patient was referred to the Department of Gastroenterologic Surgery at the Graduate School of Medicine (Kanazawa, Japan) for hepatic arterial infusion (HAI) chemotherapy. Oral S-1 (80 mg/m²) was administered as well as HAI chemotherapy with GEM (1,000 mg/standard liver volume). Following 18 cycles, tumor sizes were reduced and 18-fluorodeoxyglucose positron emission tomography (¹⁸FDG-PET) examination revealed obvious reduction of tumor FDG uptake. Transarterial tumor embolization (TAE) was performed for the previously unresectable right subphrenic liver tumor, and the other tumors were surgically resected. The resected tumors were diagnosed as liver metastases and a local recurrence of SPT in the postoperative pathological examination, which revealed that the resected tumors were composed of sheets of bland cells, which were positive for CD10, CD56, vimentin, neuron-specific enolase and α-antitrypsin. The postoperative course was uneventful, and the patient is currently under observation at an outpatient clinic; postoperative adjuvant chemotherapy with oral S-1 has continued, and additional TAE is planned. In the future, if the middle segment of the liver becomes enlarged, surgery for the residual right lobe tumor may be possible. This case demonstrates one method of SPT treatment: Preoperative HAI chemotherapy with GEM, plus oral S-1 and TAE. If complete resection can be achieved, the majority of patients with SPT have a favorable prognosis. In patients with unresectable metastases from SPT, it is crucial to conduct systematic multimodal treatment to maximize treatment success.

[A case report of hepatic arterial infusion chemotherapy and RFA for liver metastasis from pancreatic cancer]

A 71-year-old female patient was administered 2 courses of neoadjuvant chemotherapy (GS therapy) for pancreatic body cancer, and underwent pancreatic body and tail resection. She was diagnosed as having T3N0M0, Stage III disease, and adjuvant chemotherapy with gemcitabine was started. However, a solitary 9 mm liver metastasis was found using CT imaging 3 months after the operation. We started hepatic arterial infusion chemotherapy (GEM+5-FU), with additional treatment using RFA after 5 courses, and a CR was achieved. The HAI regimens were changed to GEM+S-1 and a further 18 courses were administered. After HAI, adjuvant chemotherapy (S-1) was continued, but 2 further liver metastases were found. The patient was still alive 4 years after surgery and continued to undergo radiation chemotherapy.

Case Report of an ABO-Incompatible Living-Donor Liver Transplant for a Familial Amyloid Polyneuropathy Patient

Liver transplant is a treatment for familial amyloid polyneuropathy. Few cases of ABO-incompatible living-donor liver transplant for familial amyloid polyneuropathy exist. The outcome of an ABO-incompatible living-donor liver transplant has improved recently, using local infusion therapy and rituximab prophylaxis. Here, we describe a successful ABO-incompatible living-donor liver transplant in a patient with familial amyloid polyneuropathy in whom disease progression ceased at 2 years' follow-up. Additionally, no evidence of acute or chronic rejection, or adverse events of the immunosuppressive therapy, was seen. As a postoperative complication, fatty changes in the grafted liver because of malnutrition or adverse events of corticosteroids were confirmed by a liver biopsy taken early after transplant. The main cause of malnutrition was considered to be gastrointestinal dysfunction caused by familial amyloid polyneuropathy. Therefore, before deterioration of digestive function, liver transplants should be considered for familial amyloid polyneuropathy. This case suggests that an ABO-incompatible living-donor liver transplant may provide greater opportunities for familial amyloid polyneuropathy patients.

Pancreatic body adenocarcinoma with neuroendocrine tumor characteristics: A case report

A 61-year-old female with pancreatic body cancer underwent a distal pancreatectomy. The tumor was a moderately- to poorly-differentiated adenocarcinoma. Tumor growth filled the dilated main pancreatic duct (MPD) and infiltrated the surrounding area. Six months later, metastases to the left diaphragm and MPD of the remnant pancreatic head were detected. Chemoradiotherapy was administered, but the patient succumbed 22 months after surgery. An autopsy demonstrated that a moderately- to poorly-differentiated adenocarcinoma had arisen from the pancreatic head and infiltrated the duodenum and bile duct. Huge liver metastases and multiple peritoneal disseminations were also present. Microscopically, a portion of the tumor had a pseudo-rosette appearance in the adenocarcinoma component, while another section showed characteristics of a neuroendocrine tumor (NET) immunohistochemically. The original surgically-resected tumor also showed NET characteristics immunohistochemically. It is therefore necessary to search for NET components in pancreatic cancer with atypical growth and metastases, even when adenocarcinoma has been diagnosed histologically.

Impact of histone deacetylase 1 and metastasis-associated gene 1 expression in esophageal carcinogenesis

Animal models are important for the development of novel therapies for esophageal cancer. Histone deacetylase 1 (HDAC1)/metastasis-associated gene (MTA1) complexes inhibit p53 acetylation and thus, inhibit p53-induced apoptosis. The aim of the present study was to evaluate HDAC1 and MTA1 expression in esophageal carcinogenesis in rats. The rats underwent a total gastrectomy followed by esophagojejunostomy to induce chronic duodenal content reflux esophagitis. The rats were sacrificed sequentially at 20, 30, 40 and 50 weeks post-surgery and the esophagi were examined. Immunohistochemical analysis was conducted to assess the expression and localization of HDAC1 and MTA1. At 20 weeks post-surgery, squamous proliferative hyperplasia and Barrett’s metaplasia (BM) were observed. While, adenocarcinoma-associated BM and squamous cell carcinoma were observed at 30–50 weeks post-surgery. The nuclear expression of HDAC1 and MTA1 was observed in all of the stages of squamous carcinogenesis and adenocarcinogenesis, although not in the normal esophageal epithelium. The expression of HDAC1 and MTA1 may be involved in duodenoesophageal reflux-induced neoplastic transformation of the esophageal mucosa into cancer cells with squamous and adeno differentiation.

Comparative study of the antitumor activity of Nab-paclitaxel and intraperitoneal solvent-based paclitaxel regarding peritoneal metastasis in gastric cancer

Intraperitoneal (i.p.) chemotherapy with paclitaxel (PTX) has been shown to be a promising treatment strategy for peritoneal metastasis. The present study focused on the comparative evaluation of the therapeutic efficacy of nanoparticle albumin-bound PTX (Nab-PTX) and i.p. administration of the conventional solvent-based PTX (Sb-PTX). We also investigated the difference in antitumor activity depending on the route of administration in the Nab-PTX treatment. Nab-PTX was administered i.p. or intravenously (i.v.) and Sb-PTX was administered i.p. at equitoxic and equal doses to nude mice bearing gastric cancer OCUM-2MD3 cell subcutaneous and peritoneal xenografts. Therapeutic efficacy of Sb-PTX and Nab-PTX was evaluated as inhibition of tumor growth using a peritoneal metastatic model with subcutaneous xenografts. The survival rate was also investigated using mouse peritoneal models. For assessment of subcutaneous tumors, the change in tumor volume was measured, and for assessment of peritoneal tumors, the weight of ascitic fluid and the total peritoneal tumor burden were measured for each individual mouse. At equitoxic doses, treatment with Nab-PTX resulted in a greater reduction in the size of subcutaneous tumors and the weight of ascites and peritoneal burden as compared with i.p. Sb-PTX (p<0.05). Treatment with i.p. and i.v. Nab-PTX also achieved greater survival benefit than i.p. Sb-PTX (p<0.05). In contrast, there was no significant difference in the degree of tumor reduction and the survival time between both drugs at equal doses. With regard to the route of administration, the antitumor efficacy of Nab-PTX after i.v. administration was equivalent to the efficacy after i.p. administration. These results suggest that i.v. Nab-PTX may be another encouraging treatment option that can target peritoneal dissemination in gastric cancer.

Relationship between midgut malrotation and anatomy of the hepatoduodenal ligament: a rare anatomical variation in a deceased donor

INTRODUCTION

Anatomical variations around the hepatoduodenal ligament greatly influence surgical procedures and the difficulty of operations. Here, we report the case of a deceased donor with midgut malrotation (MgM) and anatomical variation. We also present an anatomical comparison between MgM and normal cases.

CASE REPORT

The donor, a male in his 60s, was diagnosed with MgM based on preoperative computed tomography. Intraoperatively, the liver graft was harvested from the proper hepatic artery (PHA), but its length was too short for reconstruction. Therefore, the hepatic artery was reconstructed at both the left and right hepatic arteries.

METHODS

The length of the proper hepatic artery (l-PHA) and main trunk of the portal vein (l-PV) was compared between MgM and control groups (n = 9) using computed tomography. The ratio of PHA (r-PHA) and PV (r-PV), which was calculated as the l-PHA or l-PV divided by the patient's height, was also compared.

RESULTS

The r-PV was 1.3% in the MgM group and 1.6% in the control group (P = .09). The r-PHA was 0.23% in the MgM group and 0.92% in the control group (P < .01). Thus, the PHA was significantly shorter in the MgM group. Additionally, anatomical variations of the hepatic artery were confirmed in four cases.

CONCLUSION

Preoperative radiological evaluation is not always adequate for identifying anatomical abnormalities in deceased donors. MgM is a rare but important anomaly because of the possibility of associated anatomical variations of the hepatic artery.

Currarino syndrome in an adult presenting with a presacral abscess: a case report

Introduction

Currarino syndrome (Currarino triad) was described in 1981 as a triad syndrome with a common embryogenesis in infants and with three characteristics: anorectal stenosis, a defect in the sacral bone, and a presacral mass. We describe here an unusual case of Currarino syndrome in an adult presenting with a presacral abscess but no meningitis.

Case presentation

A 32-year-old Japanese man presented with fever, arthralgia and buttock pain. A digital rectal examination showed mild rectal stenosis with local warmth and tenderness in the posterior wall of his rectum. Computed tomography showed a scimitar-shaped deformity of his sacrum and an 8cm presacral mass, which continued to a pedicle of his deformed sacrum. This was diagnosed as Currarino syndrome with a presacral abscess. The abscess was drained by a perianal approach with our patient treated with antibiotics. His symptoms soon disappeared. After three months, an excision was performed through a posterior sagittal approach. His postoperative course was uneventful and he was discharged 10 days after surgery. A histopathological examination revealed an infected epidermoid cyst. He has been free from recurrence as of four years and six months after surgery.

Conclusions

We report a case of Currarino syndrome in an adult who presented with a presacral abscess but no meningitis. Abscess drainage followed by radical surgery resulted in a successful outcome.

En bloc vascular resection for the treatment of borderline resectable pancreatic head carcinoma

Borderline resectable (BR) pancreatic head carcinoma (PhC) is an advanced disease, presenting with infiltration of major vessels. Major vascular resection (VR), particularly arterial resection, to achieve microscopic no residual tumor (R0) is a controversial approach, due to the potential complications. In this study, we aimed to clarify the benefit of en bloc R0 resection with VR for PhC by retrospectively evaluating 78 PhC patients who underwent pancreatoduodenectomy at our institute. The patients were divided into 4 groups as follows: R, resectable (n=20); BR-V, BR involving the superior mesenteric vein or portal vein (PV) (n=28); BR-SMA, BR involving the superior mesenteric artery (n=21); and BR-HA, BR involving the hepatic artery (n=9). In total, 65 patients underwent VR, with 63, 21 and 9 patients undergoing PV, SMA and HA resection, respectively. The R0 rates were as follows: R group, 85%; BR-V, 82%; BR-SMA, 71%; and BR-HA, 33%. The median survival time and 5-year survival rate for R0 resection were 31 months and 25% in the R group, 22 months and 28% in the BR-V group, 17 months and 27% in the BR-SMA group and 10 months and 0% in the BR-HA group, respectively. The prognosis was comparable among the BR-V, BR-SMA and R groups, but was significantly poorer in the BR-HA group. In total, 5 patients (6.4%) died perioperatively (4 from postoperative hemorrhage and 1 from suffocation due to failure of expectoration, without pneumonia or asthma). Of the 4 patients who succumbed to hemorrhage, 3 had undergone arterial resection. Therefore, en bloc resection with major VR for R0 may be suitable for BR-V and BR-SMA PhC patients.