Neuroinvasiveness of the MR766 strain of Zika virus in IFNAR-/- mice maps to prM residues conserved amongst African genotype viruses

Zika virus (ZIKV) strains are classified into the African and Asian genotypes. The higher virulence of the African MR766 strain, which has been used extensively in ZIKV research, in adult IFNα/β receptor knockout (IFNAR-/-) mice is widely viewed as an artifact associated with mouse adaptation due to at least 146 passages in wild-type suckling mouse brains. To gain insights into the molecular determinants of MR766's virulence, a series of genes from MR766 were swapped with those from the Asian genotype PRVABC59 isolate, which is less virulent in IFNAR-/- mice. MR766 causes 100% lethal infection in IFNAR-/- mice, but when the prM gene of MR766 was replaced with that of PRVABC59, the chimera MR/PR(prM) showed 0% lethal infection. The reduced virulence was associated with reduced neuroinvasiveness, with MR766 brain titers ≈3 logs higher than those of MR/PR(prM) after subcutaneous infection, but was not significantly different in brain titers of MR766 and MR/PR(prM) after intracranial inoculation. MR/PR(prM) also showed reduced transcytosis when compared with MR766 in vitro. The high neuroinvasiveness of MR766 in IFNAR-/- mice could be linked to the 10 amino acids that differ between the prM proteins of MR766 and PRVABC59, with 5 of these changes affecting positive charge and hydrophobicity on the exposed surface of the prM protein. These 10 amino acids are highly conserved amongst African ZIKV isolates, irrespective of suckling mouse passage, arguing that the high virulence of MR766 in adult IFNAR-/- mice is not the result of mouse adaptation.

Notch-Hes1 signaling activation in Caroli disease and polycystic liver disease

The Notch signaling pathway plays a key role in the morphogenesis of the biliary tree, but its involvement in cystic biliary diseases, such as Caroli disease (CD) and polycystic liver disease (PLD), has yet to be determined. Immunostaining was performed using liver sections of CD and PLD, and the results were compared with those of congenital hepatic fibrosis (CHF) and von Meyenburg complex (VMC). The expression of Notch receptor 1 (Notch1) was increased in the nuclei of biliary epithelial cells in all cases of CD and PLD, whereas it remained at a low level in CHF and VMC. In addition, Notch2 and Notch3 were preferably expressed in the nuclei of biliary epithelial cells of PLD. Accordingly, the Notch effector Hes1 was highly expressed in biliary epithelial cells of CD and PLD, and the cell proliferative activity was significantly higher in CD and PLD. The expression of the Notch ligand Delta-like 1 was significantly increased in biliary epithelial cells of CD and PLD, which may be causally associated with the nuclear overexpression of Notch1 and Hes1. These results indicate that aberrant activation of the Notch-Hes1 signaling pathway may be responsible for the progression of biliary cystogenesis in CD and PLD.

Multi-Instrument Characterization of Magnetospheric Cold Plasma Dynamics in the June 22, 2015 Geomagnetic Storm

We present a comparison of magnetospheric plasma mass/electron density observations during an 11-day interval which includes the geomagnetic storm of June 22, 2015. For this study we used: Equatorial plasma mass density derived from geomagnetic field line resonances (FLRs) detected by Van Allen Probes and at the ground-based magnetometer networks EMMA and CARISMA; in situ electron density inferred by the Neural-network-based Upper hybrid Resonance Determination algorithm applied to plasma wave Van Allen Probes measurements. The combined observations at L ∼ 4, MLT ∼ 16 of the two longitudinally separated magnetometer networks show a temporal pattern very similar to that of the in situ observations: A density decrease by an order of magnitude about 1 day after the Dst minimum, a partial recovery a few hours later, and a new strong decrease soon after. The observations are consistent with the position of the measurement points with respect to the plasmasphere boundary as derived by a plasmapause test particle simulation. A comparison between plasma mass densities derived from ground and in situ FLR observations during favorable conjunctions shows a good agreement. We find however, for L < ∼3, the spacecraft measurements to be higher than the corresponding ground observations with increasing deviation with decreasing L, which might be related to the rapid outbound spacecraft motion in that region. A statistical analysis of the average ion mass using simultaneous spacecraft measurements of mass and electron density indicates values close to 1 amu in plasmasphere and higher values (∼2-3 amu) in plasmatrough.

Inhibitory effect of polysulfide, an endogenous sulfur compound, on oxidative stress-induced TRPA1 activation

Polysulfide (PS), an endogenous sulfur compound, generated by oxidation of hydrogen sulfide, has a stimulatory action on the nociceptive TRPA1 channel. TRPA1 is also activated by reactive oxygen species such as hydrogen peroxide (H₂O₂) produced during inflammation. Here, we examined the effect of PS on H₂O₂-induced responses in native and heterologously expressed TRPA1 using a cell-based calcium assay. We also carried out behavioral experiments in vivo. In mouse sensory neurons, H₂O₂ elicited early TRPA1-dependent and late TRPA1-independent increases of [Ca²⁺]_i. The former was suppressed by the pretreatment with PS. In cells heterologously expressed TRPA1, PS suppressed [Ca²⁺]_i responses to H₂O₂. Simultaneous measurement of [Ca²⁺]_i and the intracellular PS level revealed that scavenging effect of PS was not related to the inhibitory effect. Removal of extracellular Ca²⁺, a calmodulin inhibitor and dithiothreitol attenuated the inhibitory effect of PS. Pretreatment with PS diminished nociceptive behaviors induced by H₂O₂. The present data suggest that PS suppresses oxidative stress-induced TRPA1 activation due to cysteine modification and Ca²⁺/calmodulin signaling. Thus, endogenous sulfurs may have regulatory roles in nociception via functional changes in TRPA1 under inflammatory conditions.

Diversity in cell differentiation, histology, phenotype and vasculature of mass-forming intrahepatic cholangiocarcinomas

AIMS

Mass-forming intrahepatic cholangiocarcinomas (MF-iCCAs), involving small bile ducts, bile ductules or canals of Hering, remain treated as a single entity. We aimed to examine the diversity in histology, phenotype and tumour vasculature of MF-iCCAs.

METHODS AND RESULTS

Based on morphology and immunophenotype, we classified MF-iCCAs into small bile duct (SBD), cholangiolocarcinoma (CLC), ductal plate malformation (DPM) and hepatocellular carcinoma (HCC)-like subtypes. Genetic correlations among the histological subtypes were examined by multi-region tumour sequencing. Vasculatures and other clinicopathological features were compared among tumour groups with various proportions of the histological subtypes in 62 MF-iCCAs. Cases of pure SBD, CLC, DPM and HCC-like subtypes numbered 18 (29%), seven (11.3%), none (0%) and two (3%), respectively; the remaining 35 (56.4%) cases comprised several components. Genetic alterations, isocitrate dehydrogenase (IDH)1/2, KRAS, TP53, polybromo-1 (PBRM1) and BRCA1-associated protein 1 (BAP1), were shared among SBD, CLC, DPM and hepatoid components within a tumour. We uncovered distinct vascularisation mechanisms among SBD, CLC and DPM subtypes with a prominent vessel co-option in CLC tumours. iCCA with a DPM pattern had the highest vascular densities (mean microvascular density,140/mm² ; arterial vessel density, 18.3/mm² ). Increased CLC component was correlated with longer overall survival time (r = 0.44, P = 0.006). Pure SBD tumours had a lower 5-year overall survival rate compared with MF-iCCA with CLC pattern (30.5 versus 72.4%, P = 0.011).

CONCLUSIONS

MF-iCCAs comprise four histological subtypes. Given their sharing some driver gene alterations, indicating they can have a common cell origin, SBD, CLC and DPM subtypes, however, differ in cell differentiation, histology, phenotype or tumour vasculature.

A multicenter cohort study of osimertinib compared with afatinib as first-line treatment for EGFR-mutated non-small-cell lung cancer from practical dataset: CJLSG1903

Background

FLAURA, the prospective trial of osimertinib as a first-line therapy compared with first-generation epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs), did not show superior survival benefit for osimertinib in either the subgroup of Asians or the subgroup with the L858R mutation. In addition, the superiority of osimertinib compared with second-generation EGFR-TKI is thus far unclear.

Patients and methods

We reviewed the clinical data of all consecutive patients who were treated with osimertinib or afatinib as first-line therapy between May 2016 and October 2019 from 15 institutions in Japan. We defined the groups based on first-line EGFR-TKI as the afatinib group and the osimertinib group. Outcomes included time to discontinuation of any EGFR-TKI (TD-TKI), overall survival (OS), and time to treatment failure, with propensity score analysis carried out as an exploratory analysis in the survival and subgroup analyses.

Results

A total of 554 patients were enrolled. Data on 326 patients in the osimertinib group, and 224 patients in the afatinib group were analyzed. TD-TKI adjusted by propensity score in the afatinib and osimertinib groups was 18.6 months (95% confidence interval 15.8 to 22.0) and 20.5 months (95% confidence interval 13.8 to not reached), respectively, without significant difference (P = 0.204). OS adjusted by propensity score favored the afatinib group with a significant difference (P = 0.018). Subgroup analysis with propensity score showed that patients with L858R and without brain metastasis had superior survival benefit with afatinib compared with osimertinib (P < 0.001).

Conclusions

TD-TKI in the afatinib group was not significantly prolonged compared with the osimertinib group in the practical data. In the exploratory analysis of patients with L858R-mutated non-small-cell lung cancer without brain metastasis, afatinib showed more benefit in OS over osimertinib.

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The large-scale practical data of 550 patients who were treated with osimertinib or afatinib as first-line therapy were analyzed.

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The superiority of osimertinib compared with afatinib could not be demonstrated in all populations.

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Osimertinib therapy showed effectiveness in patients with brain metastasis.

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Afatinib therapy showed potential benefit in patients with L858R mutation and without brain metastasis.

Infratentorial onset of progressive multifocal leukoencephalopathy in a patient with systematic lupus erythematosus complicated with lymphoma: a case report

Progressive multifocal leukoencephalopathy (PML) is a rare opportunistic infection of the central nervous system caused by reactivation of JC virus (JCV). Typical PML shows confluent, bilateral but asymmetric, subcortical lesions in the supratentorial white matter on magnetic resonance imaging (MRI). We report here a 50-year-old woman with systemic lupus erythematosus complicated with lymphoma who developed PML with atypical brain MRI findings limited to the infratentorial area at presentation. She presented with numbness on the right side of the face, including her tongue, clumsiness of the right hand, and gait disturbance, after completion of remission induction therapy for lymphoma, including rituximab. Brain MRI demonstrated a solitary lesion limited to the cerebellum and brainstem, but a definitive diagnosis could not be made from cerebrospinal fluid study or tentative histologic evaluation of brain biopsy specimens. Despite methylprednisolone pulse therapy, her neurological deficits progressively worsened. One month later, in-depth analysis of her cerebrospinal fluid and brain biopsy specimens confirmed the presence of JCV. Eventually, the localised unilateral crescent-shaped cerebellar lesions on MRI expanded to the contralateral cerebellum, middle cerebellar hemisphere, pons, and midbrain and finally developed multifocal invasion into the white matter of the cerebral hemispheres. Our case suggests that PML could first present with a solitary infratentorial lesion in immunocompromised patients.

Non-cardiovascular disorders in a contemporary cardiovascular intensive care unit in Japan

BACKGROUND

In the modern US cardiovascular intensive care unit (CICU), the incidence of non-cardiovascular disorders has increased and non-cardiovascular disorders are associated with an increase in morbidity and mortality. In Japan, however, data regarding the association between non-cardiovascular disorders and outcomes in the CICU are limited.

METHODS

This study examined 490 consecutive admissions to a closed CICU at the Nippon Medical School Hospital from January to December 2017. Characteristics, diagnoses, treatments, and outcomes of admitted patients were identified.

RESULTS

The most common primary diagnosis was acute coronary syndrome (50.4%), followed by acute heart failure (20.0%), arrhythmia (6.7%), and non-cardiovascular diseases (3.7%). The mortality rate and median length of stay (LOS) in the CICU were 4.7% and 4 (interquartile range, 2-8) days, respectively. Of all patients, 42.2% (n = 207) developed non-cardiovascular complications such as acute respiratory failure, acute kidney injury, or sepsis during CICU stay. Multivariate logistic regression analysis revealed that acute respiratory failure and sepsis were significantly associated with mortality in the CICU (odds ratio, 11.014 and 25.678, respectively; both p<0.05). The multiple linear regression analysis showed that acute kidney injury was significantly associated with LOS in the CICU (β=0.144, p = 0.002).

CONCLUSIONS

Approximately half of patients admitted to the CICU had non-cardiovascular disorders including non-cardiovascular disease and non-cardiovascular complications, which were significantly associated with mortality and LOS in the CICU.

Safety Evaluation of Initial CT-P6 Administration for 30 min during the Switch from Reference Trastuzumab in Maintenance Infusion: A Multicenter Observational Study

CT-P6 is a biosimilar of trastuzumab and is recommended to be administered for 30-90 min in subsequent maintenance infusions to prevent infusion-related reactions (IRRs). We administered CT-P6 for 30 min as the first injection and as an alternative to reference trastuzumab in the maintenance infusion and evaluated the safety of the administration. A total of 140 patients with breast or gastric cancer, who received a switch from tri-weekly reference trastuzumab to CT-P6 for 30 min in maintenance infusions, were retrospectively evaluated. Premedication was administered prior to an infusion of CT-P6 and a cytotoxic agent. However, premedication was not provided when CT-P6 was co-administered with pertuzumab or administered alone. The primary endpoint was the incidence of IRRs. The secondary endpoint was the incidence of diarrhea and skin toxicity. Ninety-five percent of the patients had breast cancer, and 44.3% had advance-stage cancer. The treatment included CT-P6 alone (17.9%) or with cytotoxic agents (23.6%), antihormonal drugs (25.7%), and pertuzumab (62.9%). Median administration time of trastuzumab at the switch was 13 administrations (range 2-140). Premedication was administered to 20.7% patients. One patient (0.7%) experienced grade 3 IRR. The frequency of diarrhea in the reference trastuzumab group and the CT-P6 group was 7.1 and 6.4%, respectively, and that of skin toxicity was 6.4 and 5.0%, respectively, without differences. In conclusion, we first demonstrated that an initial CT-P6 administration for 30 min during the switch from reference trastuzumab in maintenance infusion is an acceptable administration method.

A case of Epstein-Barr virus-associated lymphoepithelioma-like carcinoma of the colon

Lymphoepithelioma-like carcinoma is a poorly differentiated carcinoma with prominent lymphoid infiltration occurring in various organs but is exceedingly rare in the colorectal region. This malignancy is frequently associated with Epstein-Barr virus (EBV). Here we report a case of EBV-associated lymphoepithelioma-like carcinoma of the cecum in an 84-year-old male who presented with occult blood. In situ hybridization for EBV-encoded small RNAs (EBER) in an endoscopic submucosal dissection specimen showed that the tumor consisted of EBER-negative well-differentiated tubular adenocarcinoma and EBER-positive lymphoepithelioma-like carcinoma. Real-time PCR detected 7.16 copies of the EBV genome per cell in a sample microdissected from the latter component. Genotyping analysis demonstrated EBV genotype 1, and viral protein/transcript expression in the tumor showed EBV latency I. Expression of Ephrin receptor A2, a recently reported receptor for EBV, was demonstrated in the tumor cells by immunohistochemistry. To our knowledge, this is the first report of lymphoepithelioma-like carcinoma in the colorectal region showing a definite association with EBV infection.

A Pilot Study Analyzing the Clinical Utility of Comprehensive Genomic Profiling Using Plasma Cell-Free DNA for Solid Tumor Patients in Japan (PROFILE Study)

BACKGROUND

The clinical utility of plasma cell-free DNA in precision cancer medicine has not been established. A pilot study was conducted to investigate the clinical utility of comprehensive genomic profiling by liquid biopsy in a Japanese population.

METHODS

In this PROFILE study, 102 patients with advanced solid tumors who showed progression with standard systemic therapy underwent liquid biopsy between August 2017 and February 2020. Liquid biopsy was performed using Guardant360.

RESULTS

Of the 102 patients, 56 were women, and the median age was 65 years. Regarding the types of cancer, 31 were hepatobiliary and pancreatic cancer, 17 were gastrointestinal cancer, and 13 were breast cancer. Frequently altered genes were TP53 (53.9%, 46/102), KRAS (25.5%, 26/102), PIK3CA (19.6%, 20/102), and EGFR (17.6%, 18/102). At least one genetic aberration was detected in 92 patients (90.2%). Actionable mutation was discovered in 88 patients (86.3%), and 67 patients (65.7%) were clinical trial candidates. Of the 102 patients, 22 (21.6%) were able to receive biomarker-matched therapy. Their best responses were as follows: 1 complete response, 3 partial responses, 7 stable diseases, and 11 progressive diseases. Additionally, the treated patients were divided on the basis of matching scores (≥ 50% vs. < 50%). The patients were divided into high and low groups. The high group had a higher disease control rate (DCR) of 75% compared with 20% in the low group (P = 0.010).

CONCLUSIONS

The results indicate that liquid biopsy is useful for identifying actionable mutations associated with the clinical response of selected patients.

Esophageal pressure monitoring for airway management during catheter ablation of atrial fibrillation

Background

Respiratory management during catheter ablation of atrial fibrillation (AF) is important for the efficacy and safety of the procedure. Obstructive apnea due to an upper airway obstruction might cause serious complications including air embolisms and cardiac tamponade. However, real time monitoring of upper airway obstructions during catheter ablation has not been established. The purpose of the present study was to evaluate esophageal pressure monitoring for respiratory management during catheter ablation of AF.

Methods and Results

Twenty-four consecutive patients (20 men and 4 women; mean age, 61 ± 13 years) with AF who underwent esophageal pressure monitoring during catheter ablation of AF were retrospectively analyzed. The patients were divided into 2 groups. One was the obstructive apnea (OA) group (n = 17), which required airway management tools including nasal airways and/or non-invasive positive airway pressure (NPPV) and the other was the control group (n = 7), which did not require airway management. Esophageal pressure measurements were obtained in all patients, and the OA group exhibited a substantial negative esophageal pressure as compared to the control group (−41.48 ± 19.58 vs. −12.42 ± 5.77 mmHg, p < 0.001). Airway management in the OA group immediately improved the negative esophageal pressure and returned to a normal range (−41.48 ± 19.58 vs. −16 ± 8.1 mmHg, 0 < 0.001) along with a recovery from desaturation.

Conclusions

Esophageal pressure monitoring was a simple and effective method for the evaluation and management of obstructive apnea during AF catheter ablation.

Gastrointestinal bleeding increases the risk of subsequent cardiovascular events in patients with acute cardiovascular diseases requiring intensive care

Gastrointestinal (GI) bleeding worsens the outcomes of critically ill patients in the intensive care unit (ICU). Owing to a lack of corresponding data, we aimed to investigate whether GI bleeding during cardiovascular-ICU (C-ICU) admission in acute cardiovascular (CV) disease patients is a risk factor for subsequent CV events. Totally, 492 consecutive C-ICU patients (40.9% acute coronary syndrome, 22.8% heart failure) were grouped into GI bleeding (n = 27; 12 upper GI and 15 lower GI) and non-GI bleeding (n = 465) groups. Thirty-nine patients died or developed CV events during hospitalization, and 453 were followed up from the date of C-ICU discharge to evaluate subsequent major adverse CV events. The GI bleeding group had a higher Acute Physiology and Chronic Health Evaluation II score (20.2 ± 8.2 vs. 15.1 ± 6.8, p < 0.001), higher frequency of mechanical ventilator use (29.6% vs. 13.1%, p = 0.039), and longer C-ICU admission duration (8 [5–16] days vs. 5 [3–8] days, p < 0.001) than the non-GI bleeding group. The in-hospital mortality rate did not differ between the groups. Of those who were followed-up, CV events after C-ICU discharge were identified in 34.6% and 14.3% of patients in the GI and non-GI bleeding groups, respectively, during a median follow-up period of 228 days (log rank, p < 0.001). GI bleeding was an independent risk factor for subsequent CV events (adjusted hazard ratio: 2.23, 95% confidence interval: 1.06–4.71; p = 0.035). GI bleeding during C-ICU admission was independently associated with subsequent CV events in such settings.

KRAS-Mutated, Estrogen Receptor-Positive Low-Grade Serous Ovarian Cancer: Unraveling an Exceptional Response Mystery

We report on a woman with aggressive estrogen receptor‐positive, KRAS‐mutated ovarian cancer who achieved a remarkable response to combination therapy with the MEK inhibitor (trametinib) and the aromatase inhibitor (letrozole), even though the disease had failed to respond to a combination of a PI3K inhibitor and different MEK inhibitor, as well as to trametinib and the estrogen modulator, tamoxifen, and to letrozole by itself. The mechanism of action for exceptional response was elucidated by in vitro experiments that demonstrated that the fact that tamoxifen can have an agonistic effect in addition to antagonist activity, whereas letrozole results only in estrogen depletion was crucial to the response achieved when letrozole was combined with an MEK inhibitor. Our current observations indicate that subtle variations in mechanisms of action of outwardly similar regimens may have a major impact on outcome and that such translational knowledge is critical for optimizing a precision medicine strategy.

Key Points

This report describes the remarkable response of a patient with KRAS‐mutated, estrogen receptor‐positive low‐grade serous ovarian cancer treated with trametinib (MEK inhibitor) and letrozole (aromatase inhibitor), despite prior progression on similar agents including tamoxifen (estrogen modulator).

In vitro investigation revealed that tamoxifen can have agonistic in addition to antagonistic effects, which could be the reason for the patient not responding to the combination of trametinib and tamoxifen.

The current observations suggest that drugs with different mechanisms of action targeting the same receptor may have markedly different anticancer activity when used in combinations.

This article reports the case of a patient with aggressive estrogen receptor‐positive, KRAS‐mutated ovarian cancer who achieved a remarkable response to combination therapy with the MEK inhibitor trametinib and the aromatase inhibitor letrozole, despite earlier failures of treatment with other combination inhibitor treatment. This article focuses on the possibility that subtle variations in mechanisms of action of outwardly similar regimens may have major effects on patient outcomes.

Anti-USAG-1 therapy for tooth regeneration through enhanced BMP signaling

Uterine sensitization-associated gene-1 (USAG-1) deficiency leads to enhanced bone morphogenetic protein (BMP) signaling, leading to supernumerary teeth formation. Furthermore, antibodies interfering with binding of USAG-1 to BMP, but not lipoprotein receptor-related protein 5/6 (LRP5/6), accelerate tooth development. Since USAG-1 inhibits Wnt and BMP signals, the essential factors for tooth development, via direct binding to BMP and Wnt coreceptor LRP5/6, we hypothesized that USAG-1 plays key regulatory roles in suppressing tooth development. However, the involvement of USAG-1 in various types of congenital tooth agenesis remains unknown. Here, we show that blocking USAG-1 function through USAG-1 knockout or anti-USAG-1 antibody administration relieves congenital tooth agenesis caused by various genetic abnormalities in mice. Our results demonstrate that USAG-1 controls the number of teeth by inhibiting development of potential tooth germs in wild-type or mutant mice missing teeth. Anti-USAG-1 antibody administration is, therefore, a promising approach for tooth regeneration therapy.

Lung Pathology of Mutually Exclusive Co-infection with SARS-CoV-2 and Streptococcus pneumoniae

Postmortem lung pathology of a patient in Japan with severe acute respiratory syndrome coronavirus 2 infection showed diffuse alveolar damage as well as bronchopneumonia caused by Streptococcus pneumoniae infection. The distribution of each pathogen and the accompanying histopathology suggested the infections progressed in a mutually exclusive manner within the lung, resulting in fatal respiratory failure.

Promotion in solid phase reaction of Pt/SiOx bilayer film by electron-orbital-selective-excitation

A thermally impossible positive free energy reaction can proceed by electron-orbital-selective excitation. When the Si 2p core level is photo-excited in Pt/SiO_x bilayer films, Coulomb repulsion at the final two-hole state localized in the valence band by an interatomic Auger transition induces dissociation of the O atom and formation of a Si–Pt bond. Consequently, Pt₂Si silicide is formed by a positive free energy reaction. Under a single particle excitation of the valence band, low probability of the coexistence of the two-hole state for picosecond order suppresses to allow the reaction to proceed.

A thermally impossible positive free energy reaction can proceed by electron-orbital-selective excitation.

REACTOR PHYSICS EXPERIMENT IN A GRAPHITE-MODERATION SYSTEM FOR HTGR

The Japan Atomic Energy Agency (JAEA) started the Research and Development (R&D) to improve nuclear prediction techniques for High Temperature Gas-cooled Reactors (HTGRs). The objectives are to introduce a generalized bias factor method to avoid full mock-up experiment for the first commercial HTGR and to introduce reactor noise analysis to High Temperature Engineering Test Reactor (HTTR) experiment to observe sub-criticality. To achieve the objectives, the reactor core of graphite-moderation system named B7/4”G2/8”p8EUNU+3/8”p38EU(1) was newly composed in the B-rack of Kyoto University Critical Assembly (KUCA). The core is composed of the fuel assembly, driver fuel assembly, graphite reflector, and polyethylene reflector. The fuel assembly is composed of enriched uranium plate, natural uranium plate and graphite plates to realize the average fuel enrichment of HTTR and it’s spectrum. However, driver fuel assembly is necessary to achieve the criticality with the small-sized core. The core plays a role of the reference core of the bias factor method, and the reactor noise was measured to develop the noise analysis scheme. In this study, the overview of the criticality experiments is reported. The reactor configuration with graphite moderation system is rare case in the KUCA experiments, and this experiment is expected to contribute not only for an HTGR development but also for other types of a reactor in the graphite moderation system such as a molten salt reactor development.

[A Case of Recurrent Hepatocellular Carcinoma Successfully Treated by Radiation Therapy]

We report a case of recurrent hepatocellular carcinoma(HCC)successfully treated by radiation therapy. A 79-year-old woman was diagnosed with HCC and underwent liver resection. Seven months after resection, CT and MRI detected a new HCC, and she had a surgery again. One year after the surgery, CT and MRI detected local recurrence, and she underwent the third operation. Three months after the operation, the third liver recurrence was treated by transcatheter arterial chemoembolization( TACE). Four months later, a new lesion was detected and treated by stereotactic body radiation therapy(SBRT) twice. She remains alive without recurrence 27 months after the last radiation therapy. Very few evidence is reported of radiation therapy for HCC, but this case suggests that radiation therapy provides a benefit for patients with HCC after other treatments.

SARS-CoV-2 D614G variant exhibits efficient replication ex vivo and transmission in vivo

The spike aspartic acid-614 to glycine (D614G) substitution is prevalent in global severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) strains, but its effects on viral pathogenesis and transmissibility remain unclear. We engineered a SARS-CoV-2 variant containing this substitution. The variant exhibits more efficient infection, replication, and competitive fitness in primary human airway epithelial cells but maintains similar morphology and in vitro neutralization properties, compared with the ancestral wild-type virus. Infection of human angiotensin-converting enzyme 2 (ACE2) transgenic mice and Syrian hamsters with both viruses resulted in similar viral titers in respiratory tissues and pulmonary disease. However, the D614G variant transmits significantly faster and displayed increased competitive fitness than the wild-type virus in hamsters. These data show that the D614G substitution enhances SARS-CoV-2 infectivity, competitive fitness, and transmission in primary human cells and animal models.

[A Case of Lynch Syndrome with Seven Cancers in Five Organs]

The case is a woman in her 70s with a history of colon and cervical cancer in her 40s. She had gastric cancer and breast cancer in her 70s. Her eldest son died of colon cancer in his 20s, and her eldest daughter had cervical cancer in her 40s. She was suspected to have Lynch syndrome and a genetic diagnosis was performed and then confirmed. Later she developed gastric cancer and ureteral cancer. We report a case of Lynch syndrome in which she developed seven cancers in five organs, all of which were early stage cancers.