A far-ultraviolet-driven photoevaporation flow observed in a protoplanetary disk

Most low-mass stars form in stellar clusters that also contain massive stars, which are sources of far-ultraviolet (FUV) radiation. Theoretical models predict that this FUV radiation produces photodissociation regions (PDRs) on the surfaces of protoplanetary disks around low-mass stars, which affects planet formation within the disks. We report James Webb Space Telescope and Atacama Large Millimeter Array observations of a FUV-irradiated protoplanetary disk in the Orion Nebula. Emission lines are detected from the PDR; modeling their kinematics and excitation allowed us to constrain the physical conditions within the gas. We quantified the mass-loss rate induced by the FUV irradiation and found that it is sufficient to remove gas from the disk in less than a million years. This is rapid enough to affect giant planet formation in the disk.

Formation of the methyl cation by photochemistry in a protoplanetary disk

Forty years ago, it was proposed that gas-phase organic chemistry in the interstellar medium can be initiated by the methyl cation CH3+ (refs. 1-3), but so far it has not been observed outside the Solar System4,5. Alternative routes involving processes on grain surfaces have been invoked6,7. Here we report James Webb Space Telescope observations of CH3+ in a protoplanetary disk in the Orion star-forming region. We find that gas-phase organic chemistry is activated by ultraviolet irradiation.

Allogeneic Stem Cell Transplantation for Trisomy 8-Positive Myelodysplastic Syndrome or Myelodysplastic/Myeloproliferative Disease with Refractory Behçet's Disease, Case Report and the Review of Literature

We had two cases of trisomy 8-positive myelodysplastic syndrome (MDS) with incomplete Behçet's disease (BD) in which the remissions of both diseases were maintained by allogeneic stem cell transplantation (allo-SCT). Among MDS with BD patients, sometimes it is difficult to control the symptoms of BD with standard therapies, such as corticosteroids and TNF inhibitors. Although there should be careful consideration regarding indications for transplantation, our two cases, in which refractory BD was completely controlled by allo-SCT, suggest that allo-SCT can be one of the treatment options for higher risk MDS with BD patients.

[HIV-negative plasmablastic lymphoma sustaining long-term response after autologous peripheral blood stem cell transplantation]

The patient is a 34-year-old HIV antibody-negative female with normal immunocompetence. The patient was referred to the hospital of the current study due to diarrhea and abdominal pain, which developed in May 2014. On conducting computed tomography (CT), remarkable wall thickening was noted in the terminal ilium over the ascending colon, suggesting a malignant tumor. However, making a definite diagnosis by lower gastrointestinal endoscopic biopsy and left hemicolectomy was not possible. The dense proliferation of plasma cell-like cells and plasmablasts was noted; CD20, CD19, CD79a, CD3, CD4, and Epstein-Barr virus-encoded miRNAs (EBER) were negative and CD138 was positive on immunostaining. Based on the aforementioned data, the patient was diagnosed with plasmablastic lymphoma (PBL). High-dose chemotherapy combined with autologous peripheral blood stem cell transplantation (PBSCT) was performed in the first remission period after the completion of four cycles of hyper CVAD/MTX-AraC alternating therapy. Remission was confirmed by FDG-PET/CT 3 months after autologous PBSCT. No signs of recurrence have been observed in 6 years after the transplantation. Although no standard treatment for PBL has been established, autologous peripheral blood stem cell transplantation combined with high-dose chemotherapy during the first remission period may be a beneficial treatment option.

[Treatment for acute leukemia showing PCR-positivity of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) at initial diagnosis: a case report and review of literature]

The novel coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is rapidly spreading across the world. We encountered two patients with COVID-19 who underwent treatment for acute leukemia at initial diagnosis. Both the patients received conventional induction therapy without the exacerbation of COVID-19. Although the impact of SARS-CoV-2 on the treatment of leukemia is unclear, our treatment experience suggests that there is no major contraindication to standard chemotherapy for acute leukemia in patients with COVID-19. As COVID-19 continues to be a threat worldwide, further evaluations of large cohorts are needed for future treatment decisions for acute leukemia with COVID-19.

Explaining the Variations in Isotopic Ratios in Meteoritic Amino Acids

Measurements of the isotopic abundances in meteoritic amino acids have found enhancements of ²H/H, ¹⁵N/¹⁴N, and ¹³C/¹²C in the amino acids in the meteorites studied. We show that they are consistent with the processing of the constituents of the meteorites by electron antineutrinos that would be expected from a core-collapse supernova or neutron-star merger. Using theoretical electron antineutrino cross-sections, we are able to predict these isotopic ratio variations depending on the time-integrated antineutrino flux at the site where the amino acids were processed.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection after allogeneic stem cell transplantation

This is the first report of a case of COVID‐19 after allogeneic stem cell transplantation. Our case suggests that COVID‐19 may exist without characteristic CT images, especially in immunocompromised hosts, such as patients after transplantation.

Connections Between Nuclear Physics and the Origin of Life - Examining the Origin of Biomolecular Chirality

The discovery of bio-molecules in meteorites with an excess of one chiral state has created one of the biggest questions in astrobiology today. That is, what is the origin of bio-molecular homochirality? Studies of this question are highly interdisciplinary, and while several phenomenological models exist, we examine the relationship between fundamental symmetries at the particle level and the macroscopic formation of bio-molecules. A model has been developed which couples fundamental interactions with the formation of molecular chirality. In this magneto-chiral model atomic nuclei bound in amino acids interact via the weak interaction in stellar environments. Nuclei are coupled to the molecular geometry (chirality) via the shielding tensor, the same interaction responsible for NMR identification. Associated with this is the fact that isotopic abundances vary from solar system values. Interactions with leptons can selectively destroy one chiral state over the other while changing isotopic values. Possible sites are proposed in which this model may exist.

Amino Acid Chiral Selection Via Weak Interactions in Stellar Environments: Implications for the Origin of Life

Magnetochiral phenomena may be responsible for the selection of chiral states of biomolecules in meteoric environments. For example, the Supernova Amino Acid Processing (SNAAP) Model was proposed previously as a possible mode of magnetochiral selection of amino acids by way of the weak interaction in strong magnetic fields. In earlier work, this model was shown to produce an enantiomeric excess (ee) as high as 0.014% for alanine. In this paper we present the results of molecular quantum chemistry calculations from which ees are determined for the α-amino acids plus isovaline and norvaline, which were found to have positive ees in meteorites. Calculations are performed for both isolated and aqueous states. In some cases, the aqueous state was found to produce larger ees reaching values as high as a few percent under plausible conditions.

Selection of Amino Acid Chirality via Neutrino Interactions with 14N in Crossed Electric and Magnetic Fields

Previous work has suggested that the chirality of the amino acids could be established in the magnetic field of a nascent neutron star from a core-collapse supernova or massive collapsar. The magnetic field would orient the 14N nuclei, and the alignment of its nuclear spin with respect to those of the electron antineutrinos emitted from the collapsing star would determine the probability of destruction of the 14N nuclei by interactions with the antineutrinos. Subsequent work estimated the bulk polarization of the 14N nuclei in large rotating meteoroids in such an environment. The present work adds a crucial piece of this model by describing the details by which the selective 14N nuclear destruction would produce molecular chiral selectivity. The effects of the neutrino-induced interactions on the 14N nuclei bound in amino acids polarized in strong magnetic fields are studied. It is shown that electric fields in the reference frame of the nuclei modify the magnetic field at the nucleus, creating nuclear magnetizations that are asymmetric in chirality. The antineutrino cross sections depend on this magnetization, creating a selective destructive effect. The environmental conditions and sites in which such a selection mechanism could occur are discussed. Selective destruction of D-enantiomers results in enantiomeric excesses which may be sufficient to drive subsequent autocatalysis necessary to produce the few-percent enantiomeric excesses found in meteorites and subsequent homochirality. Molecular quantum chemical calculations were performed for alanine, and the chirality-dependent effects studied were included. A preference for left-handed molecules was found, and enantiomeric excesses as high as 0.02% were estimated for molecules in the electromagnetic conditions expected from a core-collapse supernova. Key Words: Amino acids-Supernovae-Antineutrinos-Enantiomeric excess-Chirality. Astrobiology 18, 190-206.

Drug interaction between tacrolimus and nilotinib in a patient with chronic myeloid leukemia after renal transplant

Nilotinib, a BCR‐ABL tyrosine kinase inhibitor, is a known inhibitor of CYP3A4 and could increase the concentration of drugs metabolized by CYP3A4. An immunosuppressive drug for nilotinib‐treated patients following transplant should be administered with careful pharmacokinetic monitoring because of its interaction with nilotinib.

[Rapidly progressive hemorrhagic pneumonia caused by Stenotrophomonas maltophilia occurring early after bone marrow transplantation in a patient with myelodysplastic syndrome]

A 44-year-old woman had repeated bacterial infections because of hypoplastic myelodysplastic syndrome; therefore, she underwent allogeneic hematopoietic cell transplantation. Broad spectrum antibiotics were administered because she had bacterial infection and pneumonia 2 weeks before undergoing transplantation. On day19 after transplantation, she suddenly presented with hemoptysis. Stenotrophomonas maltophilia was considered to be the cause of hemorrhagic pneumonia, which required ventilation support, massive transfusion, and catecholamine administration. However, she died 8 h after the onset of hemoptysis. Severe S. maltophilia infections may occur in patients with immunocompromised conditions such as those after allogeneic hematopoietic cell transplantation.

Principal component analysis uncovers cytomegalovirus-associated NK cell activation in Ph+ leukemia patients treated with dasatinib

Dasatinib treatment markedly increases the number of large granular lymphocytes (LGLs) in a proportion of Ph⁺ leukemia patients, which associates with a better prognosis. The lymphocytosis is predominantly observed in cytomegalovirus (CMV)-seropositive patients, yet detectable CMV reactivation exists only in a small fraction of patients. Thus, etiology of the lymphocytosis still remains unclear. Here, we identified NK cells as the dominant LGLs expanding in dasatinib-treated patients, and applied principal component analysis (PCA) to an extensive panel of NK cell markers to explore underlying factors in NK cell activation. PCA displayed phenotypic divergence of NK cells that reflects CMV-associated differentiation and genetic differences, and the divergence was markedly augmented in CMV-seropositive dasatinib-treated patients. Notably, the CMV-associated highly differentiated status of NK cells was already observed at leukemia diagnosis, and was further enhanced after starting dasatinib in virtually all CMV-seropositive patients. Thus, the extensive characterization of NK cells by PCA strongly suggests that CMV is an essential factor in the NK cell activation, which progresses stepwise during leukemia and subsequent dasatinib treatment most likely by subclinical CMV reactivation. This study provides a rationale for the exploitation of CMV-associated NK cell activation for treatment of leukemias.

Possible Involvement of the Rat Hypothalamo-Neurohypophysial/-Spinal Oxytocinergic Pathways in Acute Nociceptive Responses

Oxytocin (OXT)-containing neurosecretory cells in the parvocellular divisions of the paraventricular nucleus (PVN), which project to the medulla and spinal cord, are involved in various physiological functions, such as sensory modulation and autonomic processes. In the present study, we examined OXT expression in the hypothalamo-spinal pathway, as well as the hypothalamo-neurohypophysial system, which includes the magnocellular neurosecretory cells in the PVN and the supraoptic nucleus (SON), after s.c. injection of saline or formalin into the hindpaws of transgenic rats that express the OXT and monomeric red fluorescent protein 1 (mRFP1) fusion gene. (i) The numbers of OXT-mRFP1 neurones that expressed Fos-like immunoreactivity (-IR) and OXT-mRFP1 intensity were increased significantly in the magnocellular/parvocellular PVN and SON after s.c. injection of formalin. (ii) OXT-mRFP1 neurones in the anterior parvocellular PVN, which may project to the dorsal horn of the spinal cord, were activated by s.c. injection of formalin, as indicated by a significant increases of Fos-IR and mRFP1 intensity intensity. (iii) Formalin injection caused a significant transient increase in plasma OXT. (iv) OXT, mRFP1 and corticotrophin-releasing hormone mRNAs in the PVN were significantly increased after s.c. injection of formalin. (v) An intrathecal injection of OXT-saporin induced hypersensitivity in conscious rats. Taken together, these results suggest that the hypothalamo-neurohypophysial/-spinal OXTergic pathways may be involved in acute nociceptive responses in rats.

[Infliximab therapy for Crohn's-like gastrointestinal lesions after allogeneic bone marrow transplantation]

A 45-year-old man was diagnosed with t(8;21) positive acute myelogenous leukemia and failed to achieve complete remission (CR) after the first induction chemotherapy. He was then treated with high-dose cytarabine and achieved CR. Molecular relapse was detected during post-remission therapy and he underwent myeloablative bone marrow transplantation from his HLA-matched sibling donor. One year after transplantation, he developed an intractable anal fistula during treatment of chronic GVHD. Colonoscopy showed longitudinal ulcers and cobblestone appearance, and histopathological examination revealed non-caseating epithelioid granuloma. According to these findings, he was diagnosed with Crohn's-like chronic gastrointestinal inflammatory disease. He was treated with enteral nutrition, mesalazine and dose re-escalation of cyclosporine, but these therapies were not effective. Therefore, we decided to treat him with infliximab. After starting treatment with infliximab, his abdominal symptoms and the anal fistula showed prompt improvement. There are few reports regarding the efficacy of infliximab for gastrointestinal chronic GVHD. Our experience suggests that infliximab could be useful for the treatment of Crohn's-like gastrointestinal inflammatory disease.

[Extranodal natural killer/T-cell lymphoma, nasal type developing central nervous system and epididymis involvement immediately after concurrent chemoradiotherapy]

A 66-year-old man showed central nervous system (CNS) and epididymis involvement after concurrent chemoradiotherapy for extranodal natural killer/T-cell lymphoma, nasal type (ENKL). The patient experienced continuous nasal obstruction. CT revealed a mass in the nasal cavity and paranasal sinuses. Biopsy of the nasal cavity mass showed it to be ENKL. Based on bone marrow biopsy and 18F-FDG PET/CT findings, the clinical stage was suspected to be IIE. The sites involved were the nasal cavity, paranasal sinuses, and cervical lymph nodes. We performed concurrent chemoradiotherapy consisting of a 67% dose of DeVIC and involved field radiation therapy towards his head and neck. Head and neck CT confirmed a therapeutic response. After receiving concurrent chemoradiotherapy, the patient complained of perineal discomfort. Ultrasonography revealed swelling of the left epididymis. Left epididymis biopsy showed ENKL involvement and lumbar puncture revealed CNS involvement. The findings of this case suggest that evaluation of CNS involvement might be an essential part of the initial workup for some ENKL patients.

[Successful second cord blood transplantation (CBT) for late graft failure associated with several immune disorders after the initial CBT in a patient with acute myeloid leukemia]

A 64-year-old woman underwent reduced-intensity conditioning cord blood transplantation (RIC-CBT) for refractory acute myeloid leukemia (AML). A 6/6 antigen-level HLA-identical cord blood from a male infant was transfused. After successful engraftment with complete donor chimerism, the patient developed mixed chimera (XX 8.8%) on day 82. Tapering of tacrolimus was started on day 96. Bone marrow chimerism analysis showed a decreasing recipient cell population (XX 2.2%) on day 117 and tacrolimus was discontinued with no clinical signs of GVHD on day 123. However, pancytopenia with agranulocytosis was detected on day 138. She was diagnosed as having secondary graft failure associated with Coombs-positive immune hemolytic anemia and immune thrombocytopenia (ITP). At the same time, the percentage of recipient T cell chimerism in peripheral blood was about 50% and the B cell population showed lambda light chain restriction. On day 180, she received a second RIC-CBT due to lack of improvement of agranulocytosis. A single dose of rituximab was administered on day - 11 before the second CBT to eliminate the activated B cells. Prompt neutrophil engraftment was achieved and both hemolytic anemia and ITP also showed resolution. She is currently well (30 months after the second CBT), showing normal blood cell counts and complete second donor chimerism of marrow cells.

Clinical and echocardiographic characteristics for differentiating between transthyretin-related and light-chain cardiac amyloidoses

Differential diagnosis between transthyretin (TTR) and immunoglobulin light-chain (AL) cardiac amyloidoses is essential due to significantly different prognoses and therapeutic options. Therefore, clinical characteristics of patients with biopsy-proven cardiac amyloidosis were investigated to differentiate TTR from AL amyloidosis. From September 2006 to May 2014, 46 patients were confirmed to have cardiac amyloidosis (TTR, n = 28; AL, n = 18) in our institute. The median age of patients with TTR amyloidosis was 78 years (range 61-90) with 27 (96 %) males, while that of patients with AL amyloidosis was 66 (range 52-76) with 12 (67 %) males. There were no statistically significant differences in echocardiographic findings regarding left ventricular (LV) systolic function or diastolic dysfunction between the two groups. Interestingly, serum brain natriuretic peptide (BNP) levels in patients with AL amyloidosis were significantly higher than those in TTR amyloidosis patients. In contrast, the LV wall was significantly thicker in patients with TTR amyloidosis than in those with AL amyloidosis. Therefore, the ratio of BNP to LV mass index (LVMI) at presentation in AL amyloidosis patients was significantly higher than that in TTR patients (6.7 vs 2.9, p = 0.0006). A BNP-LVMI ratio of less than 3.5 had a diagnostic sensitivity and specificity for TTR amyloidosis of 71 and 83 %, respectively. One-year overall survival was 88.7 % in the patients with TTR amyloidosis and 23.7 % in the patients with AL amyloidosis. Our analysis indicates that the BNP-LVMI ratio, as well as age and sex, may be useful parameters for distinguishing TTR from AL cardiac amyloidosis.

Mixed aliphatic and aromatic composition of evaporating very small grains in NGC 7023 revealed by the 3.4/3.3 μm ratio

CONTEXT

A chemical scenario was proposed for photon-dominated regions (PDRs) according to which UV photons from nearby stars lead to the evaporation of very small grains (VSGs) and the production of gas-phase polycyclic aromatic hydrocarbons (PAHs).

AIMS

Our goal is to achieve better insight into the composition and evolution of evaporating very small grains (eVSGs) and PAHs through analyzing the infrared (IR) aliphatic and aromatic emission bands.

METHODS

We combined spectro-imagery in the near- and mid-IR to study the spatial evolution of the emission bands in the prototypical PDR NGC 7023. We used near-IR spectra obtained with the IRC instrument onboard AKARI to trace the evolution of the 3.3 μm and 3.4 μm bands, which are associated with aromatic and aliphatic C-H bonds on PAHs. The spectral fitting involved an additional broad feature centered at 3.45 μm that is often referred to as the plateau. Mid-IR observations obtained with the IRS instrument onboard the Spitzer Space Telescope were used to distinguish the signatures of eVSGs and neutral and cationic PAHs. We correlated the spatial evolution of all these bands with the intensity of the UV field given in units of the Habing field G0 to explore how their carriers are processed.

RESULTS

The intensity of the 3.45 μm plateau shows an excellent correlation with that of the 3.3 μm aromatic band (correlation coefficient R = 0.95) and a relatively poor correlation with the aliphatic 3.4 μm band (R=0.77). This indicates that the 3.45 μm feature is dominated by the emission from aromatic bonds. We show that the ratio of the 3.4 μm and 3.3 μm band intensity (I3.4/I3.3) decreases by a factor of 4 at the PDR interface from the more UV-shielded layers (G0 ~ 150, I3.4/I3.3 = 0.13) to the more exposed layers (G0 > 1 × 104, I3.4/I3.3 = 0.03). The intensity of the 3.3 μm band relative to the total neutral PAH intensity shows an overall increase with G0, associated with an increase of both the hardness of the UV field and the H abundance. In contrast, the intensity of the 3.4 μm band relative to the total neutral PAH intensity decreases with G0, showing that their carriers are actively destroyed by UV irradiation and are not efficiently regenerated. The transition region between the aliphatic and aromatic material is found to correspond spatially with the transition zone between neutral PAHs and eVSGs.

CONCLUSIONS

We conclude that the photo-processing of eVSGs leads to the production of PAHs with attached aliphatic sidegroups that are revealed by the 3.4 μm emission band. Our analysis provides evidence for the presence of very small grains of mixed aromatic and aliphatic composition in PDRs.