Crystal structure of ricin toxin A chain complexed with a highly potent pterin-based small-molecular inhibitor

Ricin toxin A chain (RTA), from Ricinus communis, is a deadly protein that inactivates ribosomes by degrading an adenine residue at position 4324 in 28S rRNA. Recently, we have demonstrated that pterin-7-carboxamides with peptide pendants were potent RTA inhibitors. Among these, N-(pterin-7-carbonyl)glycyl-L-tyrosine (7PCGY) is the most potent RTA inhibitor as a small organic molecule. However, despite this fascinating inhibitory activity, the mode of interaction of 7PCGY with RTA remains elusive. This study aimed to elucidate the factors responsible for the high RTA inhibitory activity of 7PCGY based on X-ray crystallographic analysis. Herein, we report the successfully resolved X-ray crystal structure of 7PCGY/RTA complexes, revealing that the interaction between the phenolic hydroxy group in 7PCGY and Asn78 of RTA through a hydrogen bonding and the conformational change of Tyr80 and Asn122 are responsible for the high RTA inhibitory activity of 7PCGY.

Impact of the lateral skeletal stability following bilateral sagittal split ramus osteotomy for mandibular asymmetry

This study evaluated the stability of bilateral sagittal split ramus osteotomy (BSSRO) associated with positional plagiocephaly and temporal and masseter muscles using posteroanterior cephalogram analysis and three-dimensional computed tomography (3D-CT). This retrospective cohort study included 31 patients who underwent BSSRO for mandibular asymmetry. The cranial vault asymmetry index (CVAI) and the cephalic index were used as indicators of positional plagiocephaly. The distance from the vertical reference line to the menton (Me) was measured on posteroanterior cephalograms immediately and 1 year after surgery, and postoperative stability was assessed. Temporal and masseter muscles were constructed from 3D-CT data and their volumes were measured. Simple regression analysis showed a significant correlation between postoperative changes in the vertical reference line to the Me and the CVAI (R = 0.56, p = 0.001), the amount of surgical movement in the vertical reference line to the Me (R = 0.41, p = 0.023), and the variable temporal muscle volume (R = 0.27, p = 0.028). There was no significant correlation between postoperative changes in the vertical reference line to the Me and the cephalic index (R = 0.093, p = 0.62) and variable masseter muscle volume (R = 0.16, p = 0.38). According to multivariate analysis, CVAI (p = 0.003) and amount of surgical movement in the vertical reference line to the Me (p = 0.014) were significant predictors of postoperative change in the vertical reference line to the Me. Positional plagiocephaly and amount of surgical movement influence lateral skeletal stability following BSSRO for mandibular asymmetry.

Mycorrhizal specificity differences in epiphytic habitat: three epiphytic orchids harbor distinct ecological and physiological specificity

Orchidaceae has diversified in tree canopies and accounts for 68% of vascular epiphytes. Differences in mycorrhizal communities among epiphytic orchids can reduce species competition for mycorrhizal fungi and contribute to niche partitioning, which may be a crucial driver of the unusual species diversification among orchids. Mycorrhizal specificity-the range of fungi allowing mycorrhizal partnerships-was evaluated by assessment of mycorrhizal communities in the field (ecological specificity) and symbiotic cultures in the laboratory (physiological specificity) for three epiphytic orchids inhabiting Japan. Mycorrhizal communities were assessed with co-existing individuals growing within 10 cm of each other, revealing that ecological specificity varied widely among the three species, ranging from dominance by a single Ceratobasidiaceae fungus to diverse mycobionts across the Ceratobasidiaceae and Tulasnellaceae. In vitro seed germination tests revealed clear differences in physiological specificity among the three orchids, and that the primary mycorrhizal partners contributed to seed germination. In vitro compatibility ranges of three orchids strongly reflect the mycorrhizal community composition of wild populations. This suggests that differences in in situ mycorrhizal communities are not strongly driven by environmental factors, but are primarily due to physiological differences among orchid species. This study shows that the symbiotic strategy among the epiphytic orchid species varies from specialized to generalized association, which may contribute to biotic niche partitioning.

Development of a Machine Learning Model to Evaluate Changes during Radiotherapy in Cervical Cancer Tumor Cells

PURPOSE/OBJECTIVE(S)

Radiotherapy is considered the standard treatment for advanced cervical cancer. It is known that irradiation changes the morphology of tumor cells during the treatment, though its clinical significance is unknown. Recently, the usefulness of machine learning using medical images has been reported, as also as pathological images. The purpose of this study is to create a classification model for cervical tumor biopsy treated with radiotherapy, visualized on whole slide images using machine learning, in an attempt to explore the clinical significance of morphology changes during radiotherapy.

MATERIALS/METHODS

Cervical cancer patients who underwent radical irradiation with both pre- and mid-treatment biopsy from April 1, 2013, to December 1, 2020, were retrospectively analyzed. Tumor biopsies were Hematoxylin and eosin stained and digitized to whole slide images (WSIs). WSI s were divided into tiles of 224 × 224 pixels and converted into feature vectors using a pre-trained convolutional neural network (densenet121). A training and test dataset were divided 1:1 on a patient basis, and the model was trained to classify "pre-treatment" and "mid-treatment", and its accuracy was evaluated. The probability obtained from the classification model was defined as the radiation change index (RCI), and its color map was projected on the WSI for visualization. Survival analysis was performed to examine the clinical significance of the RCI values.

RESULTS

A total of eighty-four patients were analyzed, and the median observation period was 3.2 years. 184 WSIs were obtained, and 2203407 tiles were generated. The classification model was trained using 2500 tiles for each "pre-treatment" and "mid-treatment". The accuracy of the classification model was 70.8 %, with an AUC of 0.77 for the ROC curve. The probability obtained from the classification model was defined as RCI, with 0 being "pre-treatment" and 1 being "mid-treatment", and the mean RCI of "pre-treatment" and "mid-treatment" were 0.38 and 0.61, respectively. When the RCIs were visualized with a color map, the areas considered to be "pre-treatment" were consistent with a viable tumor component, and the areas considered to be "mid-treatment" were consistent with fibrosis supposed to cause by irradiation. To evaluate the clinical significance of RCI, we divide the clinical cohort into two groups with a threshold mean RCI of 0.4 in the pre-treatment biopsy. The disease-free survival was 91 months and 47 months in the RCI<0.4 and RCI≥0.4 groups, respectively.

CONCLUSION

We created a model to classify tissues before and during radiotherapy and successfully visualized it on slide images. The low RCI group before treatment had a better prognosis than the high RCI group, suggesting that the tumor morphologic features obtained by machine learning may be useful for prognosis prediction. Further studies are planned to develop a model that can accurately predict prognosis.

Optimization of a fast deuterium diagnostic method based on visible energetic 3He spectroscopy for high electron density plasmas

Fast ions play a crucial role in plasma heating, and their behavior in the plasma must be accurately understood. A diagnostics method based on charge exchange emission from the n = 4 - 3 transition (λ0 = 468.6 nm) of energetic 3He produced by the deuteron-deuteron reaction has been proposed as a for fast deuterons with energies in the order of MeV. The proposed method has the following advantages: No beam emission interferes with the spectra, the direction of the measuring line of sight, and the injection angle of the diagnostic beam can be freely determined. In previous studies, due to competing bremsstrahlung, it was expected that the proposed method will not be practical in the case of high electron density operation. This paper makes the proposed method available for measurement even at high electron densities by optimizing the measurement line of sight direction and the diagnostic beam incidence angle. This allows an electron density five times larger than the range of applications shown in previous studies. This result will contribute to measure of DT alpha in ITER.

Structure of pyridoxal 5'-phosphate-bound D-threonine aldolase from Chlamydomonas reinhardtii

D-Threonine aldolase (DTA) is a pyridoxal-5'-phosphate-dependent enzyme which catalyzes the reversible aldol reaction of glycine with a corresponding aldehyde to yield the D-form β-hydroxy-α-amino acid. This study produced and investigated the crystal structure of DTA from Chlamydomonas reinhardtii (CrDTA) at 1.85 Å resolution. To our knowledge, this is the first report on the crystal structure of eukaryotic DTA. Compared with the structure of bacterial DTA, CrDTA has a similar arrangement of active-site residues. On the other hand, we speculated that some non-conserved residues alter the affinity for substrates and inhibitors. The structure of CrDTA could provide insights into the structural framework for structure-guided protein engineering studies to modify reaction selectivity.

Enhanced Material Assimilation in a Toroidal Plasma Using Mixed H_{2}+Ne Pellet Injection and Implications to ITER

The ablation and assimilation of cryogenic pure H_{2} and mixed H_{2}+Ne pellets, which are foreseen to be used by the ITER tokamak for mitigating thermal and electromagnetic loads of major disruptions, are observed by spatially and temporally resolved measurements. It is experimentally demonstrated that a small fraction (here ≈5%) of neon added to hydrogenic pellets enhances the core density assimilation with reduced outward transport for the low magnetic-field side injection. This is consistent with theoretical expectations that line radiation increased by doped neon in dense plasmoids suppresses the plasmoid pressure and reduces the E[over →]×B[over →] transport of the ablated material.

Pterin-based small molecule inhibitor capable of binding to the secondary pocket in the active site of ricin-toxin A chain

The Ricin toxin A chain (RTA), which depurinates an adenine base at a specific region of the ribosome leading to death, has two adjacent specificity pockets in its active site. Based on this structural information, many attempts have been made to develop small-molecule RTA inhibitors that simultaneously block the two pockets. However, no attempt has been successful. In the present study, we synthesized pterin-7-carboxamides with tripeptide pendants and found that one of them interacts with both pockets simultaneously to exhibit good RTA inhibitory activity. X-ray crystallographic analysis of the RTA crystal with the new inhibitor revealed that the conformational change of Tyr80 is an important factor that allows the inhibitors to plug the two pockets simultaneously.

Intraosseous carcinoma of the anterior maxilla identified as the occult primary tumour of carcinoma of unknown primary

Carcinoma of unknown primary (CUP) is defined as lymph node metastasis without a detectable origin until after the initial treatment has been performed. The most common occult primary site in the head and neck, as revealed by a review of the published literature, is the oropharynx. An occult primary site in the oral region is extremely rare. We report a rare case of head and neck CUP (HNCUP) in a 69-year-old female patient, wherein the occult primary lesion was a primary intraosseous carcinoma (PIOC) invading the anterior maxilla. During the course of the initial diagnostic workup, no primary lesion could be identified; however, cervical lymph node metastasis to left levels IB and IIA were observed in the patient. A neck dissection followed by adjuvant radiotherapy was performed. However, the PIOC of the anterior maxilla was identified 6 months after neck treatment and was confirmed as the occult primary tumour of the HNCUP. This case is quite rare and required a comprehensive workup to guide optimal treatment. Careful follow-up or active biopsy should be considered if osteolytic changes are observed in the jaw.

Conformational change in ricin toxin A-Chain: A critical factor for inhibitor binding to the secondary pocket

Ricin toxin A-chain (RTA), a toxic protein from Ricinus communis, inactivates ribosomes to induce toxicity. The active site of RTA consists of two binding pockets. Many studies have focused on developing RTA inhibitors that can simultaneously bind to these critical pockets; however, almost all the inhibitors developed so far interact with only one pocket. In the present study, we discovered that pterin-7-carboxamides with aromatic l-amino acid pendants interacted with the active site of the enzyme in a 2-to-1 mode, where one inhibitor molecule bound to the primary pocket and the second one entered the secondary pocket in the active site of RTA. X-ray crystallographic analysis of inhibitor/RTA complexes revealed that the conformational changes of Tyr80 and Asn122 in RTA were critical for triggering the entry of inhibitor molecules into the secondary pocket of the RTA active site.

Deep modeling of plasma and neutral fluctuations from gas puff turbulence imaging

The role of turbulence in setting boundary plasma conditions is presently a key uncertainty in projecting to fusion energy reactors. To robustly diagnose edge turbulence, we develop and demonstrate a technique to translate brightness measurements of HeI line radiation into local plasma fluctuations via a novel integrated deep learning framework that combines neutral transport physics and collisional radiative theory for the 3³D - 2³P transition in atomic helium with unbounded correlation constraints between the electron density and temperature. The tenets for experimental validity are reviewed, illustrating that this turbulence analysis for ionized gases is transferable to both magnetized and unmagnetized environments with arbitrary geometries. Based on fast camera data on the Alcator C-Mod tokamak, we present the first two-dimensional time-dependent experimental measurements of the turbulent electron density, electron temperature, and neutral density, revealing shadowing effects in a fusion plasma using a single spectral line.

Na+/K+ ATPase α1 and β3 subunits are localized to the basolateral membrane of trophectoderm cells in human blastocysts

STUDY QUESTION

Is there a relation between specific Na+/K+ ATPase isoform expression and localization in human blastocysts and the developmental behavior of the embryo?

SUMMARY ANSWER

Na+/K+ ATPase α1, β1 and β3 are the main isoforms expressed in human blastocysts and no association was found between the expression level of their respective mRNAs and the rate of blastocyst expansion.

WHAT IS KNOWN ALREADY

In mouse embryos, Na+/K+ ATPase α1 and β1 are expressed in the basolateral membrane of trophectoderm (TE) cells and are believed to be involved in blastocoel formation (cavitation).

STUDY DESIGN, SIZE, DURATION

A total of 20 surplus embryos from 11 patients who underwent IVF and embryo transfer at a university hospital between 2009 and 2018 were analyzed.

PARTICIPANTS/MATERIALS, SETTING, METHODS

After freezing and thawing Day 5 human blastocysts, their developmental behavior was observed for 24 h using time-lapse imaging, and the expression of Na+/K+ ATPase isoforms was examined using quantitative RT-PCR (RT-qPCR). The expressed isoforms were then localized in blastocysts using fluorescent immunostaining.

MAIN RESULTS AND THE ROLE OF CHANCE

RT-qPCR results demonstrated the expression of Na+/K+ ATPase α1, β1 and β3 isoforms in human blastocysts. Isoforms α1 and β3 were localized to the basolateral membrane of TE cells, and β1 was localized between TE cells. A high level of β3 mRNA expression correlated with easier hatching (P = 0.0261).

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

The expression of mRNA and the localization of proteins of interest were verified, but we have not been able to perform functional analysis.

WIDER IMPLICATIONS OF THE FINDINGS

Of the various Na+/K+ ATPase isoforms, expression levels of the α1, β1 and β3 mRNAs were clearly higher than other isoforms in human blastocysts. Since α1 and β3 were localized to the basolateral membrane via fluorescent immunostaining, we believe that these subunits contribute to the dilation of the blastocoel. The β1 isoform is localized between TE cells and may be involved in tight junction formation, as previously reported in mouse embryos.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by the JSPS KAKENHI (https://www.jsps.go.jp/english/index.html), grant number 17K11215. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The authors have no conflicts of interest.

Lyotropic liquid crystal-based transcutaneous peptide delivery system: Evaluation of skin permeability and potential for transcutaneous vaccination

Transcutaneous drug delivery is a promising method in terms of drug repositioning and reformulation because of its non-invasive and easy-to-use features. To overcome the skin barrier, which is the biggest challenge in transcutaneous drug delivery, a number of techniques, such as microemulsion, solid-in-oil dispersions and liposomes, have been studied extensively. However, the low viscosity of these formulations limits drug retention on the skin and reduces patient acceptability. Although viscosity can be increased by adding a thickening reagent, such an addition often alters formulation nanostructures and drug solubility, and importantly, decreases skin permeability. In this study, a gel-like lyotropic liquid crystal (LLC) was used as a tool to enhance skin permeability. In particular, we prepared 1-monolinolein (ML)-based LLCs with different water contents. All LLCs significantly enhanced skin permeation of a peptide drug, an epitope peptide of melanoma, despite their high viscoelasticity. Fourier transform infra-red spectroscopic analysis of the skin surface treated with the LLCs revealed that the gyroid geometry more strongly interacted with the lamellar structure inside the stratum corneum (SC) than the diamond geometry. Finally, as the result of the in vivo tumor challenge experiment using B16F10 melanoma-bearing mice, the LLC with the gyroid geometry showed stronger vaccine effect against tumor than a subcutaneous injection. Collectively, ML-based LLCs, especially with the gyroid geometry, are a promising strategy to deliver biomacromolecules into skin. STATEMENT OF SIGNIFICANCE: Transcutaneous drug delivery is a promising method for drug repositioning and reformulation because of its non-invasive and easy-to-use features. To overcome the skin barrier, which is the biggest challenge in transcutaneous drug delivery, we used a gel-like lyotropic liquid crystal (LLC) as a novel tool to enhance skin permeability. In this paper, we demonstrated that an LLC with a specific liquid crystalline structure has the highest skin permeation enhancement effect for a peptide antigen as a model drug. Moreover, the peptide antigen-loaded LLC showed a vaccine effect that was comparable to a subcutaneous injection in vivo. This study provides a basis for designing a transcutaneous delivery system of peptide drugs with LLC.

Gastrointestinal stromal tumour lacking mutations in the KIT and PDGFRA genes in a cat

Molecular subtyping in gastrointestinal stromal tumours is a useful method for predicting the efficacy of treatment using tyrosine kinase inhibitors in humans. However, owing to the paucity of reports on mutational analyses, the association between genetic mutations and the therapeutic response to tyrosine kinase inhibitors remains unclear in feline gastrointestinal stromal tumours. In this report, we describe the case of a cat with a gastrointestinal stromal tumour which was unresponsive to tyrosine kinase inhibitors. A mutational analysis revealed that the cat lacked mutations in both the KIT and platelet-derived growth factor receptor-alpha (PDGFRA) genes. Our findings are consistent with the fact that KIT/PDGFRA wild-type gastrointestinal stromal tumours are less responsive to tyrosine kinase inhibitors in humans. This signifies the need for further evaluation and possibly individualised treatment for gastrointestinal stromal tumours in cats on the basis of mutational analyses.

Fast deuteron diagnostics using visible light spectra of 3He produced by deuteron-deuteron reaction in deuterium plasmas

The fast deuteron (non-Maxwellian component) diagnostic method, which is based on the higher resolution optical spectroscopic measurement, has been developed as a powerful tool. Owing to a decrease in the D-H charge-exchange cross section, the diagnostic ability of conventional optical diagnostic methods should be improved for ∼MeV energy deuterons. Because the ³He-H charge-exchange cross section is much larger than that of D-H in the ∼MeV energy range, the visible light (VIS) spectrum of ³He produced by the dueteron-dueteron (DD) reaction may be a useful tool. Although the density of ³He is small because it is produced via the DD reaction, improvement of the emissivity of the VIS spectrum of ³He can be expected by using a high-energy beam. We evaluate the VIS spectrum of ³He for the cases when a fast deuteron tail is formed and not formed in the ITER-like beam injected deuterium plasma. Even when the beam energy is in the MeV energy range, a large change appears in the half width at half maximum of the VIS spectrum. The emissivity of the VIS spectrum of ³He and the emissivity of bremsstrahlung are compared, and the measurable VIS spectrum is obtained. It is shown that the VIS spectrum of ³He is a useful tool for the MeV beam deuteron tail diagnostics.

Neck Location on the Outer Convexity is a Predictor of Incomplete Occlusion in Treatment with the Pipeline Embolization Device: Clinical and Angiographic Outcomes

BACKGROUND AND PURPOSE

With the increasing use of the Pipeline Embolization Device for the treatment of aneurysms, predictors of clinical and angiographic outcomes are needed. This study aimed to identify predictors of incomplete occlusion at last angiographic follow-up.

MATERIALS AND METHODS

In our retrospective, single-center cohort study, 105 ICA aneurysms in 89 subjects were treated with Pipeline Embolization Devices. Patients were followed per standardized protocol. Clinical and angiographic outcomes were analyzed. We introduced a new morphologic classification based on the included angle of the parent artery against the neck location: outer convexity type (included angle,  <160°), inner convexity type (included angle,  >200°), and lateral wall type (160° ≤ included angle  ≤200°). This classification reflects the metal coverage rate and flow dynamics.

RESULTS

Imaging data were acquired in 95.3% of aneurysms persistent at 6 months. Complete occlusion was achieved in 70.5%, and incomplete occlusion, in 29.5% at last follow-up. Multivariable regression analysis revealed that 60 years of age or older (OR, 5.70; P = .001), aneurysms with the branching artery from the dome (OR, 10.56; P = .002), fusiform aneurysms (OR, 10.2; P = .009), and outer convexity-type saccular aneurysms (versus inner convexity type: OR, 30.3; P < .001; versus lateral wall type: OR, 9.71; P = .001) were independently associated with a higher rate of incomplete occlusion at the last follow-up. No permanent neurologic deficits or rupture were observed in the follow-up period.

CONCLUSIONS

The aneurysm neck located on the outer convexity is a new, incomplete occlusion predictor, joining older age, fusiform aneurysms, and aneurysms with the branching artery from the dome. No permanent neurologic deficits or rupture was observed in the follow-up, even with incomplete occlusion.

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.

X-ray structure analysis of a unique D-amino-acid oxidase from the thermophilic fungus Rasamsonia emersonii strain YA

D-Amino-acid oxidases (DAAOs) catalyze the oxidative deamination of neutral and basic D-amino acids. The DAAO from the thermophilic fungus Rasamsonia emersonii strain YA (ReDAAO) has a high thermal stability and a unique broad substrate specificity that includes the acidic D-amino acid D-Glu as well as various neutral and basic D-amino acids. In this study, ReDAAO was crystallized by the hanging-drop vapor-diffusion method and its crystal structure was determined at a resolution of 2.00 Å. The crystal structure of the enzyme revealed that unlike other DAAOs, ReDAAO forms a homotetramer and contains an intramolecular disulfide bond (Cys230-Cys285), suggesting that this disulfide bond is involved in the higher thermal stability of ReDAAO. Moreover, the structure of the active site and its vicinity in ReDAAO indicates that Arg97, Lys99, Lys114 and Ser231 are candidates for recognizing the side chain of D-Glu.

SAT0208 INCIDENCES OF ADVERSE EFFECTS AND DISEASE FLARE DUE TO PNEUMOCYSTIS PNEUMONIA PROPHYLAXIS WITH TRIMETHOPRIM/SULFAMETHOXAZOLE IN SYSTEMIC LUPUS ERYTHEMATOSUS PATIENTS

Background:

Methods of preventing pneumocystis pneumonia (PCP) in systemic lupus erythematosus (SLE) are controversial. Previous studies have verified the efficacy and safety of trimethoprim/sulfamethoxazole (TMP-SMX) in patients with rheumatic diseases1. However, as for SLE, some clinicians advise against prescribing TMP-SMX because sulfa allergy is reportedly more common in SLE than in other rheumatic diseases2, 3. Anecdotally, sulfonamides may also worsen SLE itself, but few data are available on lupus flares related to sulfonamides3.

Objectives:

This study aimed to assess the incidences of adverse effects and disease flare due to PCP prophylaxis with TMP-SMX in SLE patients.

Methods:

SLE patients seen at our hospital between September 2010 and April 2018 who received TMP-SMX as a PCP prophylaxis were enrolled. The clinical manifestations, treatment course, adverse drug reactions, and occurrence of lupus flares were retrospectively assessed from the medical records. The Naranjo adverse drug reaction probability scale4 was used to determine whether the reactions were induced by SMX-TMP. According to the British Isles Lupus Assessment Group (BILAG) 2004 index, a severe flare of lupus was defined as a development of a new grade A manifestation, and a moderate flare as a development of grade B manifestation following grade C, D or E. Two board-certificated rheumatologists reviewed the medical records in a blinded fashion to determine the reason for the flare, with disagreement resolved by consensus.

Results:

In total, 188 SLE patients were enrolled; of these, 117 (62.2%) had no adverse events and were able to continue taking SMX-TMP as needed. Seventy-one patients (37.8%) stopped SMX-TMP due to suspected adverse drug reactions, including fever, rash, liver function disorder, and cytopenia. The Naranjo scale indicated “definite” in 4, “probable” in 39, and “possible” in 28. Eighteen-patients restarted the SMX-TMP and 9 patients could continue the prophylaxis without adverse effects. Five patients were hospitalized to treat the adverse events: 3 with drug rash (concomitant use of hydroxychloroquine in 2), 1 with hypersensitivity (concomitant use of azathioprine) and 1 with hyponatremia, respectively.

Lupus flares occurred in 10 patients (5.3%) within one month after the start of the the SMX-TMP prophylaxis. Macrophage activation syndrome (MAS) or neuropsychiatric SLE occurred in 9 of them. Of 188 cases, 2 patients (1.1%) developed a new onset of MAS during the stable clinical course as the flare, which was considered due to SMX-TMP. Confounding factors, including high disease activity and the reduction of glucocorticoids, were identified in other 8 flares.

Conclusion:

PCP prophylaxis with SMX-TMP was tolerable in most SLE patients. However, a small number of SLE patients developed severe adverse effects or disease flares due to the SMX-TMP.

References:

[1]Park JW, et al. Annals of the Rheumatic Diseases 2018;77:644-649.

[2]Suyama Y, et al. Modern Rheumatology 2016;26:557-61

[3]Petri M, et al. Journal of Rheumatology 1992;19:265-9

[4]Naranjo CA, et al. Clinical Pharmacology and Therapeutics 1981;30:239-45

Disclosure of Interests:

None declared

Mechanism of eukaryotic serine racemase-catalyzed serine dehydration

Eukaryotic serine racemase (SR) is a pyridoxal 5'-phosphate enzyme belonging to the Fold-type II group, which catalyzes serine racemization and is responsible for the synthesis of D-Ser, a co-agonist of the N-methyl-d-aspartate receptor. In addition to racemization, SR catalyzes the dehydration of D- and L-Ser to pyruvate and ammonia. The bifuctionality of SR is thought to be important for D-Ser homeostasis. SR catalyzes the racemization of D- and L-Ser with almost the same efficiency. In contrast, the rate of L-Ser dehydration catalyzed by SR is much higher than that of D-Ser dehydration. This has caused the argument that SR does not catalyze the direct D-Ser dehydration and that D-Ser is first converted to L-Ser, then dehydrated. In this study, we investigated the substrate and solvent isotope effect of dehydration of D- and L-Ser catalyzed by SR from Dictyostelium discoideum (DdSR) and demonstrated that the enzyme catalyzes direct D-Ser dehydration. Kinetic studies of dehydration of four Thr isomers catalyzed by D. discoideum and mouse SRs suggest that SR discriminates the substrate configuration at C3 but not at C2. This is probably the reason for the difference in efficiency between L- and D-Ser dehydration catalyzed by SR.

Patient care experience with utilization of isolation precautions: systematic literature review and meta-analysis

BACKGROUND

Use of isolation precautions (IP) may represent a trade-off between reduced transmission of infectious pathogens and reduced patient satisfaction with their care.

OBJECTIVE

To perform a systematic literature review and meta-analysis to identify if and how IPs impact patients' care experiences.

DATA SOURCES

Medline, ClinicalTrials.gov, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Embase, PsychInfo, HSRProj and Cochrane Library databases.

STUDY ELIGIBILITY CRITERIA

Interventional and observational studies published January 1990 to May 2019 were eligible for inclusion.

PARTICIPANTS

Patients admitted to an acute-care facility.

INTERVENTIONS

IPs versus no IPs.

METHODS

Six reviewers screened titles, abstracts and full text. Experience of care reported by patients using the Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) survey was assessed as the outcome for the meta-analysis. Pooled odds ratios were calculated using the random-effects model. Heterogeneity was assessed using the I² value.

RESULTS

After screening 7073 titles and abstracts, 15 independent studies were included in the review. Pooling of unadjusted estimates from the HCAHPS survey demonstrated that IP patients were less likely to give top scores on questions pertaining to respect, communication, receiving assistance and cleanliness compared to the no-IP patients. Patients under IP with longer length of stay appeared to have more negative experiences with the care received during their stay compared to no IP.

CONCLUSIONS

Patients under IP were more likely to be dissatisfied with several aspects of patient care compared to patients not under IP. It is crucial to educate patients and healthcare workers in order to balance successful implementation of IP and patient care experiences, particularly in healthcare settings where it may be beneficial.

Isotope Effect on Energy Confinement Time and Thermal Transport in Neutral-Beam-Heated Stellarator-Heliotron Plasmas

The isotope effect on energy confinement time and thermal transport has been investigated for plasmas confined by a stellarator-heliotron magnetic field. This is the first detailed assessment of an isotope effect in a stellarator heliotron. Hydrogen and deuterium plasmas heated by neutral beam injection on the Large Helical Device have exhibited no significant dependence on the isotope mass in thermal energy confinement time, which is not consistent with the simple gyro-Bohm model. A comparison of thermal diffusivity for dimensionally similar hydrogen and deuterium plasmas in terms of the gyroradius, collisionality, and thermal pressure has clearly shown robust confinement improvement in deuterium to compensate for the unfavorable mass dependence predicted by the gyro-Bohm model.

Post-discharge oral antimicrobial use among hospitalized patients across an integrated national healthcare network

OBJECTIVES

Antimicrobial stewardship programmes have focused on reducing inappropriate inpatient antimicrobial prescribing, but several small studies have found a large portion of antimicrobial exposure occurs immediately after hospital discharge. In this study, we describe the prescribing of oral antimicrobials at hospital discharge across an integrated national healthcare system. At the hospital level, we also compare total inpatient antimicrobial use and post-discharge oral antimicrobial use.

METHODS

This retrospective cross-sectional study used national administrative data to identify all acute-care admissions during 2014-2016 within the Veterans Health Administration (VHA). We evaluated inpatient days of therapy (DOT) and post-discharge DOT, defined as oral outpatient antimicrobials dispensed at the time of hospital discharge. At the hospital level, inpatient DOT/100 admissions were compared with post-discharge DOT/100 admissions using Spearman's rank-order correlation.

RESULTS

There were 1 681 701 acute-care admissions across 122 hospitals, and 335 369 (19.9%) were prescribed an oral antimicrobial at discharge. Fluoroquinolones (38.3%) were the most common post-discharge antimicrobial. At the hospital level, median inpatient antimicrobial use was 331.3 (interquartile range (IQR) 284.9-367.9) DOT/100 admissions and median post-discharge use was 209.5 (IQR 181.5-239.6) DOT/100 admissions. Thirty-nine per cent of the total duration of antimicrobial exposure occurred after discharge. At the hospital-level, the metrics of inpatient DOT/100 admissions and post-discharge DOT/100 admissions were weakly positively correlated with rho=0.44 (p < 0.001).

CONCLUSIONS

A large proportion of antimicrobial exposure among hospitalized patients occurred immediately following discharge. Antimicrobial-prescribing at hospital discharge provides an opportunity for antimicrobial stewardship. Hospital-level stewardship metrics need to include both inpatient and post-discharge antimicrobial-prescribing to provide a comprehensive assessment of hospital-associated antimicrobial use.

The motion and distribution of the gas in the central 300 pc of the galaxy as revealed by spectra of H3. Philos Trans A Math Phys Eng Sci 2019;377:20180400. [PMID: 31378174 DOI: 10.1098/rsta.2018.0400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Spectroscopy of absorption lines of H₃⁺ in the central molecular zone (CMZ) of the Galaxy show that a previously largely unknown component of the interstellar medium there, warm (T∼200 K) and diffuse (n ≲ 10² cm^-3) gas, makes up a large fraction of the volume of the CMZ, and that this gas is moving radially outward from the centre. These discoveries upend the generally accepted understanding that the interstellar environment of the CMZ comprises almost entirely an ultra-hot plasma and dense molecular clouds. The radial momentum associated with the diffuse gas in the CMZ exceeds that of the ejecta of thousands of core-collapse supernovae and implies some extraordinary past activity in the centre, possibly associated with the supermassive black hole, Sgr A*. We speculate that within approximately 10⁶ years, gravity could halt the expansion of the diffuse gas and that contraction towards the centre could then commence. This article is part of a discussion meeting issue 'Advances in hydrogen molecular ions: H₃⁺, H₅⁺ and beyond'.

Effect of rice bran fermented with Saccharomyces cerevisiae and Lactobacillus plantarum on gut microbiome of mice fed high-sucrose diet

To clarify the effect of rice bran (RB) and fermented RB (FRB) in a high-sucrose and low-dietary fibre diet on the gut microbiome, the in vitro bile acid-lowering capacity and caecal microbiota of ICR mice fed with 20% RB or FRB diets for two weeks were determined. The caecal microbiome was analysed by 16S rRNA gene amplicon sequencing. The in vitro bile acid-lowering capacity was high for FRB. In mouse experiments, triacylglycerol and total cholesterol were generally lower with FRB, although the faecal frequency was highest in mice fed with RB. The Shannon-Wiener and Simpson's indices for alpha-diversity in the microbiome of mice fed with RB and FRB, were higher than mice fed the control diet. At the phylum level in the caecal microbiome, Firmicutes and Bacteroidetes were high with FRB and RB, respectively. At the operational taxonomic unit level, some bacterial groups related to diabetes and gut toxicity, such as Lachnospiraceae and Enterorhabdus mucosicola, were high for RB but not for FRB diets. These results suggest that FRB, rather than RB, intake improve the intestinal environment and blood lipid condition.

Synthesis and Aldose Reductase Inhibitory Activity of Botryllazine A Derivatives

Aldose reductase (AR) is associated with the onset of diabetic complications. Botryllazine A and its analogues were synthesized and evaluated for human AR inhibitory activity. Analogues possessing aromatic bicyclic systems at the C5 position of the central pyrazine ring exhibited superior AR inhibiting activity relative to the parent botryllazine A. In addition, the benzoyl groups at positions C2 and C3 of the pyrazine ring were dispensable for this improved inhibitory activity. Conversely, a benzoyl group-containing phenolic hydroxyl groups-at either position C2 or C3 of the pyrazine ring was essential for attainment of high inhibitory activity approaching that of sorbinil (a highly effective AR inhibitor).

Correlation Between Splenectomy and Portal Vein Complications in Living Donor Liver Transplantation

OBJECTIVES

In adults undergoing living donor liver transplantation (LDLT), the transplanted livers are partial grafts, and the portal venous pressure is higher than that observed with whole liver grafts. In patients undergoing LDLT concomitant with splenomegaly, portal venous flow is often diverted to collateral vessels, leading to a high risk of portal vein thrombosis. In such cases, occlusion of the collateral veins is important; however, complete occlusion of all collaterals without blocking the blood flow through the splenic artery causes portal hypertension and liver failure. We aimed to examine the effect of performing a splenectomy concomitant with LDLT to reduce portal vein complications.

METHODS

Between 1991 and 2017, we performed 170 LDLT operations, including 83 in adults. For this cohort study, adult cases were divided into 2 groups. Group I was those who underwent LDLT without splenectomy (n = 60); Group II was those who underwent LDLT with splenectomy for the reduction of portal hypertension (n = 23). We investigated the incident rates of complications, including blood loss, lethal portal vein thrombosis (intrahepatic thrombosis), acute rejection, and so on. We also investigated the survival rates in both groups.

RESULTS

The incident rate of lethal portal vein thrombosis in Group II was significantly lower than that observed in Group I (4.4% vs 21.7%, respectively, P = .0363). There were no statistically significant differences observed between the groups with respect to blood loss, survival rates, and other such parameters.

CONCLUSION

LDLT concomitant with splenectomy might effectively reduce the occurrence of portal vein complications in adults.

Effect of Middle Hepatic Vein Tributaries Preserving Technique Until Just Before Graft Retrieval on Donors' Surgical Outcomes in Living Donor Liver Transplantation

BACKGROUND

The technique of preserving the major tributaries of the middle hepatic vein (MHV) (V5 and V8) until just before graft retrieval is beneficial to minimize congestion time of the graft. However, it remains unclear whether this technique exerts a burden on donors in terms of operative time, blood loss, and postoperative hepatic dysfunction. In this study we investigated adverse effects of the MHV tributaries preserving technique until immediately before graft retrieval on donors' surgical outcomes.

METHODS

Data from 71 donors who underwent right hepatectomy without MHV for a liver transplantation at our hospital from January 2002 to August 2016 were retrospectively reviewed. Donors were divided into 3 groups as follows: group 1 (n = 12), no MHV tributary reconstruction; group 2 (n = 33), single MHV tributary reconstruction; group 3 (n = 26), 2 or 3 MHV tributaries reconstruction. Donor operation time, blood loss, proportion of the remnant liver, maximum postoperative total bilirubin, aspartate aminotransferase, alanine transaminase, minimum platelets, prothrombin time, albumin level, number of days in hospital from surgery to discharge, and surgical complications were compared.

RESULTS

Compared with groups 2 and 3, group 1 exhibited shorter average operational time and less average blood loss, but the difference was not significant. Comparisons of all other factors indicated no significant differences.

CONCLUSION

The technique of preserving the major tributaries of the MHV until just immediately before graft retrieval does not appear to impose an apparent burden on donors.

Effect of neutron and γ -ray on charge-coupled device for vacuum/extreme ultraviolet spectroscopy in deuterium discharges of large helical device

A charge-coupled device (CCD) is widely used as a detector of vacuum spectrometers in fusion devices. Recently, a deuterium plasma experiment has been initiated in a Large Helical Device (LHD). Totally 3.7 × 10¹⁸ neutrons have been yielded with energies of 2.45 MeV (D-D) and 14.1 MeV (D-T) during the deuterium experiment over four months. Meanwhile, γ-rays are radiated from plasma facing components and laboratory structural materials in a wide energy range, i.e., 0.01-12.0 MeV, through the neutron capture. It is well known that these neutrons and γ-rays bring serious problems to the CCD system. Then, several CCDs of vacuum ultraviolet/extreme ultraviolet/X-ray spectrometers installed at different locations on LHD for measurements of spectra and spatial profiles of impurity emission lines are examined to study the effect of neutrons and γ-rays. An additional CCD placed in a special shielding box made of 10 cm thick polyethylene contained 10% boron and 1.5 cm thick lead is also used for the detailed analysis. As a result, it is found that the CCD has no damage in the present neutron yield of LHD, while the background noise integrated for all pixels of CCD largely increases, i.e., 1-3 × 10⁸ counts/s. The data analysis of CCD in the shielding box shows that the background noise caused by the γ-ray is smaller than that caused by the neutron, i.e., 41% from γ-rays and 59% from neutrons. It is also found that the noise can be partly removed by an accumulation of CCD frames or software programming.

Predictive performance of a genetic risk score using 11 susceptibility alleles for the incidence of Type 2 diabetes in a general Japanese population: a nested case-control study

AIMS

To assess the predictive ability of a genetic risk score for the incidence of Type 2 diabetes in a general Japanese population.

METHODS

This prospective case-control study, nested within a Japan Public Health Centre-based prospective study, included 466 participants with incident Type 2 diabetes over a 5-year period (cases) and 1361 control participants, as well as 1463 participants with existing diabetes and 1463 control participants. Eleven susceptibility single nucleotide polymorphisms, identified through genome-wide association studies and replicated in Japanese populations, were analysed.

RESULTS

Most single nucleotide polymorphism loci showed directionally consistent associations with diabetes. From the combined samples, one single nucleotide polymorphism (rs2206734 at CDKAL1) reached a genome-wide significance level (odds ratio 1.28, 95% CI 1.18-1.40; P = 1.8 × 10^-8 ). Three single nucleotide polymorphisms (rs2206734 in CDKAL1, rs2383208 in CDKN2A/B, and rs2237892 in KCNQ1) were nominally significantly associated with incident diabetes. Compared with the lowest quintile of the total number of risk alleles, the highest quintile had a higher odds of incident diabetes (odds ratio 2.34, 95% CI 1.59-3.46) after adjusting for conventional risk factors such as age, sex and BMI. The addition to the conventional risk factor-based model of a genetic risk score using the 11 single nucleotide polymorphisms significantly improved predictive performance; the c-statistic increased by 0.021, net reclassification improved by 6.2%, and integrated discrimination improved by 0.003.

CONCLUSIONS

Our prospective findings suggest that the addition of a genetic risk score may provide modest but significant incremental predictive performance beyond that of the conventional risk factor-based model without biochemical markers.

Inhibition of homoserine dehydrogenase by formation of a cysteine-NAD covalent complex

Homoserine dehydrogenase (EC 1.1.1.3, HSD) is an important regulatory enzyme in the aspartate pathway, which mediates synthesis of methionine, threonine and isoleucine from aspartate. Here, HSD from the hyperthermophilic archaeon Sulfolobus tokodaii (StHSD) was found to be inhibited by cysteine, which acted as a competitive inhibitor of homoserine with a Ki of 11 μM and uncompetitive an inhibitor of NAD and NADP with Ki's of 0.55 and 1.2 mM, respectively. Initial velocity and product (NADH) inhibition analyses of homoserine oxidation indicated that StHSD first binds NAD and then homoserine through a sequentially ordered mechanism. This suggests that feedback inhibition of StHSD by cysteine occurs through the formation of an enzyme-NAD-cysteine complex. Structural analysis of StHSD complexed with cysteine and NAD revealed that cysteine situates within the homoserine binding site. The distance between the sulfur atom of cysteine and the C4 atom of the nicotinamide ring was approximately 1.9 Å, close enough to form a covalent bond. The UV absorption-difference spectrum of StHSD with and without cysteine in the presence of NAD, exhibited a peak at 325 nm, which also suggests formation of a covalent bond between cysteine and the nicotinamide ring.

Cytoprotective Effects of Mesenchymal Stem Cells During Liver Transplantation from Donors After Cardiac Death in Rats

BACKGROUND

Liver transplantation from donors after cardiac death (DCD) might increase the pool of available organs. Recently, some investigators reported the potential use of mesenchymal stem cells (MSCs) to improve the outcome of liver transplantation from DCD. The aim of this study was to evaluate the cytoprotective effects and safety of MSC transplantation on liver grafts from DCD.

METHODS

Rats were divided into 4 groups (n = 5) as follows: 1. the heart-beating group, in which liver grafts were retrieved from heart-beating donors; 2. the DCD group, in which liver grafts were retrieved from DCD that had experienced apnea-induced agonal conditions; 3. the MSC-1 group, and 4. the MSC-2 group, in which liver grafts were retrieved as with the DCD group, but were infused MSCs (2.0 × 10⁵ or 1.0 × 10⁶, respectively). The retrieved livers were perfused with oxygenated Krebs-Henseleit bicarbonate buffer (37°C) through the portal vein for 2 hours after 6 hours of cold preservation. Perfusate, bile, and liver tissues were then investigated.

RESULTS

Bile production in the MSC-2 group was significantly improved compared with that in the DCD group. Based on histologic findings, narrowing of the sinusoidal space in the both MSC groups was improved compared with that in the DCD group.

CONCLUSIONS

MSCs could protect the function of liver grafts from warm ischemia-reperfusion injury and improve the viability of DCD liver grafts. In addition, we found that the infusion of 1.0 × 10⁶ MSCs does not obstruct the hepatic sinusoids of grafts from DCD.