Intestinal Clostridium species lower host susceptibility to enterohemorrhagic Escherichia coli O157:H7 infection

Susceptibility to enterohemorrhagic Escherichia coli (EHEC) infection varies among humans. The intestinal microbiota seems to play an essential role in host defense against EHEC; thus, we hypothesized that indigenous bacteria, such as Clostridium ramosum and Clostridium perfringens, could influence the susceptibility to EHEC infection. To evaluate the effect of indigenous bacteria on EHEC infection, germ-free mice were precolonized with each indigenous bacterium, and then infected with EHEC O157:H7. Precolonization with C. ramosum or C. perfringens completely prevented death from EHEC infection througout a test period. Precolonization with C. ramosum also reduced the level of secreted Shiga toxin (Stx) 2 and prevented histopathological changes in the kidneys in a similar way to precolonization with Bifidobacterium longum, which is used as a model for preventing EHEC infection. In contrast, the mice precolonized with C. perfringens showed mild renal injuries. When evaluated using an in vitro co-culturing system, again C. ramosum inhibited the growth and Stx production of EHEC more potently than C. perfringens. These results indicate that C. ramosum and C. perfringens suppressed EHEC infection; however, the extent of their preventive effects differed. Therefore, the susceptibility to EHEC infection and its severity can depend on the functional bacteria present in the intestinal microbiota of individuals.

Assignment of Dental Hygienists Improves Outcomes in Japanese Rehabilitation Wards: A Retrospective Cohort Study

OBJECTIVES

To clarify the effectiveness of ward-assigned dental hygienists (DHs) on rehabilitation outcomes in rehabilitation wards.

DESIGN

Retrospective cohort study.

SETTING

The registry data from the Japanese Rehabilitation Nutrition Database.

PARTICIPANTS

656 patients with hip fracture or stroke admitted to convalescent rehabilitation wards.

MEASUREMENTS

The main outcome measures were the Functional Independence Measure (FIM), the Food Intake Level Scale (FILS), and the home discharge rate. Patients were divided into two groups based on the ward setting: with an assigned DH (DH group) and without an assigned DH (NDH group). Clinical characteristics and outcomes were compered between the groups. Between-facility differences were adjusted by generalized estimating equation. We performed post-hoc power analysis to confirm that there were enough samples included in this study to detect a significant difference.

RESULTS

Of 656 patients (mean age, 77 years; 57.1% female; 65.5% stroke) from 10 facilities, 454 patients (69.2%) from 4 facilities were in the DH group. FIM score at discharge (107 vs 90, P<0.001), percentage improvement in FILS score from admission to discharge (44.5% vs 22.8%, P<0.001) and home discharge rate (72.5% vs 61.4%, P<0.001) were significantly higher in the DH group than in the NDH group. After multivariate analysis, the FIM score at discharge (P=0.007), FILS score at discharge (P=0.024), and home discharge rate (P=0.007) were significantly higher in the DH group than in the NDH group.

CONCLUSIONS

ADL and swallowing function were significantly improved at discharge and the home discharge rate was higher among patients in rehabilitation wards with DHs. Having a ward-assigned DH may lead to better rehabilitation outcomes in rehabilitation wards.

THE BUILT ENVIRONMENT INFLUENCED THE INCIDENCE OF FALLS IN OLDER ADULTS LIVING IN THE UNDERSERVED COMMUNITY

The built environment is commonly cited as a facilitator to local walking. Although health promotion programs targeting physical activity are available, few studies have investigated the associations of the perceived neighborhoods with the incidence of falls in the minority communities. Hence, the purpose of this preliminary study was to understand whether the perceived built environment influenced the fall experiences in older adults living in the underserved community. The preliminary cross-sectional survey was conducted at the regional health clinic in Flint, MI. Descriptive statistics and analysis of variance (ANOVA) were performed using SAS v8.4. The eligibility criteria included over 65 years old and Flint residents. Of 132 participants, the mean age was 69.75 (SD=5.00). The majority were female (68%), African Americans (80%), single, divorced or widowed (80%), and &gt; GED (84%). The ANOVAs supported that “had fallen in the past year” was associated with “stores are within easy walking distance,” “easy to walk to a transit stop” and “there is a dirt strip that separates the streets from the sidewalks.” The fall experience was more likely to associate with the sedentary lifestyle and the comorbidities such as diabetes, fatigues, muscle spasms, and chronic pain. To summarize, the built environment increased the incidence of falls in the past year. Those who had fallen had poor health conditions. Further studies are needed for older adults to engage in physical activity. It is essential to develop the age-friendly support systems and accommodations to local walking in this community.

Recent Developments in Therapeutic Peptides for the Glucagon-like Peptide 1 and 2 Receptors

Glucagon-like peptide 1 (GLP-1) and glucagon-like peptide 2 (GLP-2) are proglucagon derived peptides that are released from gut endocrine cells in response to nutrient intake. These molecules are rapidly inactivated by the action of dipeptidyl peptidase IV (DPP-4) which limits their use as therapeutic agents. The recent emergence of three-dimensional structures of GPCRs such as GLP-1R and glucagon receptor has helped to drive the rational design of innovative peptide molecules that hold promise as novel peptide therapeutics. One emerging area is the discovery of multifunctional molecules that act at two or more pharmacological systems to enhance therapeutic efficacy. In addition, drug discovery efforts are also focusing on strategies to improve patient convenience through alternative routes of peptide delivery. These novel strategies highlight the broad utility of peptide-based therapeutics in human disease settings where unmet needs still exist.

Enhanced intrinsic photovoltaic effect in tungsten disulfide nanotubes

The photovoltaic effect in traditional p-n junctions-where a p-type material (with an excess of holes) abuts an n-type material (with an excess of electrons)-involves the light-induced creation of electron-hole pairs and their subsequent separation, generating a current. This photovoltaic effect is particularly important for environmentally benign energy harvesting, and its efficiency has been increased dramatically, almost reaching the theoretical limit¹. Further progress is anticipated by making use of the bulk photovoltaic effect (BPVE)², which does not require a junction and occurs only in crystals with broken inversion symmetry³. However, the practical implementation of the BPVE is hampered by its low efficiency in existing materials^4-10. Semiconductors with reduced dimensionality² or a smaller bandgap^4,5 have been suggested to be more efficient. Transition-metal dichalcogenides (TMDs) are exemplary small-bandgap, two-dimensional semiconductors^11,12 in which various effects have been observed by breaking the inversion symmetry inherent in their bulk crystals^13-15, but the BPVE has not been investigated. Here we report the discovery of the BPVE in devices based on tungsten disulfide, a member of the TMD family. We find that systematically reducing the crystal symmetry beyond mere broken inversion symmetry-moving from a two-dimensional monolayer to a nanotube with polar properties-greatly enhances the BPVE. The photocurrent density thus generated is orders of magnitude larger than that of other BPVE materials. Our findings highlight not only the potential of TMD-based nanomaterials, but also more generally the importance of crystal symmetry reduction in enhancing the efficiency of converting solar to electric power.

Intestinal Bacteria as Powerful Trapping Lifeforms for the Elimination of Radioactive Cesium

In March 2011, an accident at the Fukushima Daiichi Nuclear Power Plant led to major problems, including the release of radionuclides such as Cesium (Cs)-137 into the environment. Ever since this accident, Cs-137 in foods has become a serious problem. In this study, we determined the concentration of Cs-137 in the feces, urine, and ruminal contents of cattle and demonstrated the possibility of its elimination from the body by intestinal bacteria. The results revealed a high Cs-137 concentration in the feces; in fact, this concentration was higher than that in skeletal muscles and other samples from several animals. Furthermore, intestinal bacteria were able to trap Cs-137, showing an uptake ratio within the range of 38–81% in vitro. This uptake appeared to be mediated through the sodium–potassium (Na⁺-K⁺) ion pump in the bacterial cell membrane. This inference was drawn based on the fact that the uptake ratio of Cs-137 was decreased in media with high potassium concentration. In addition, it was demonstrated that intestinal bacteria hindered the trapping of Cs-137 by the animal. Cattle feces showed high concentration of Cs-137 and intestinal bacteria trapped Cs-137. This study is the first report showing that intestinal bacteria contribute to the elimination of Cs-137 from the body.

Effects of Wolbachia/Cardinium Infection on the Mitochondrial Phylogeny of Oligonychus castaneae (Acari: Tetranychidae)

A wide range of invertebrates harbor intracellular endosymbiotic bacteria. Within these endosymbionts, Wolbachia and Cardinium, have been attracting particular attention because these bacteria frequently affect the genetic structure and genetic diversity of their hosts. They cause various reproductive alterations such as cytoplasmic incompatibility, parthenogenesis induction, male-killing, and feminization. Through these alterations, they also affect the maternally inherited organelles of their hosts. Mitochondrial DNA (mtDNA) can be used for molecular phylogenetic analysis of invertebrates. However, in Wolbachia- or Cardinium-infected invertebrates, phylogenetic trees based on mtDNA are often inconsistent with those based on nuclear DNA. In the present study, we determined the Wolbachia/Cardinium infection status of 45 populations of the mite, Oligonychus castaneae Ehara & Gotoh (Acari: Tetranychidae), collected throughout Japan. Then, we compared phylogenetic trees of O. castaneae based on both the cytochrome c oxidase subunit I (COI) gene of mtDNA and the 28S rRNA gene of nuclear DNA to clarify the effects of Wolbachia and/or Cardinium infection. We found 106 Wolbachia-infected individuals and 250 Cardinium-infected individuals in a total of 450 individuals, indicating an infection rate of 79%. No double-infected individuals were observed. In the 28S tree, almost all populations formed a single group. In the COI tree, O. castaneae formed four separate groups that more closely followed Wolbachia/Cardinium infection than geographic distribution. These results strongly suggest that the endosymbionts affected mitochondrial variation of O. castaneae.

Caste-specific microRNA expression in termites: insights into soldier differentiation

Eusocial insects have polyphenic caste systems in which each caste exhibits characteristic morphology and behaviour. In insects, caste systems arose independently in different lineages, such as Isoptera and Hymenoptera. Although partial molecular mechanisms for the development of eusociality in termites have been clarified by the functional analysis of genes and hormones, the contribution of microRNAs (miRNAs) to caste differentiation is unknown. To understand the role of miRNAs in termite caste polyphenism, we performed small RNA sequencing in a subterranean termite (Reticulitermes speratus) and identified the miRNAs that were specifically expressed in the soldier and worker castes. Of the 550 miRNAs annotated in the R. speratus genome, 74 were conserved in insects and 174 were conserved in other termite species. We found that eight miRNAs (mir-1, mir-125, mir-133, mir-2765, mir-87a and three termite-specific miRNAs) are differentially expressed (DE) in soldiers and workers of R. speratus. This differential expression was experimentally verified for five miRNAs by real-time quantitative PCR. Further, four of the eight DE miRNAs in soldier and worker termite castes were also differentially expressed in hymenopteran castes. The finding that Isoptera and Hymenoptera shared several DE miRNAs amongst castes suggests that these miRNAs evolved independently in these phylogenetically distinct lineages.

Ligand chirality can affect histidine protonation of vitamin-D receptor: ab initio molecular orbital calculations in water

Vitamin D is recognized to play important roles in the onset of immunological diseases as well as the regulation of the amount of Ca in the blood. Since these physiological actions caused by active vitamin D are triggered by the specific interaction between the vitamin D receptor (VDR) and active vitamin D, many types of compounds have been developed as potent ligands against VDR. It was found that the binding affinity between VDR and its ligand depends significantly on the chirality of the ligand. However, the reason for the dependence has, thus far, not been elucidated. In the present study, we investigated the specific interactions between VDR and some ligands with different chirality, using ab initio fragment molecular orbital (FMO) calculations. The FMO results reveal that two histidine residues of VDR contribute significantly to the binding between VDR and ligand and that their protonation states can affect the specific interactions between VDR and ligand. We therefore considered other possible protonation states of these histidine residues and determined their most stable states, using the ab initio FMO calculations. The results illustrate the possibility that the difference in the chirality of a ligand can induce the change in protonation states of the histidine residues of VDR existing near the ligand. This finding provides an important warning that the protonation states of histidine residues existing near the ligand should be considered more precisely in the molecular simulations for investigating the specific interactions between protein and ligand.

Radiative cooling of cationic carbon clusters, CN+, N = 8, 10, 13-16

The radiative cooling of highly excited carbon cluster cations of sizes N = 8, 10, 13-16 has been studied in an electrostatic storage ring. The cooling rate constants vary with cluster size from a maximum at N = 8 of 2.6 × 10⁴ s^-1 and a minimum at N = 13 of 4.4 × 10³ s^-1. The high rates indicate that photon emission takes place from electronically excited ions, providing a strong stabilizing cooling of the molecules.

Relationship Between Stress Coping Mechanisms and Depression in Kidney Transplant Recipients

BACKGROUND

It has been reported that transplant recipients are exposed to physical and psychosocial stresses even after transplant surgery and exhibit psychological disorders such as depression.

PURPOSE

In this study, we extracted trends concerning how recipients of kidney transplants cope with stress, and we also examined how they cope with depression and its countermeasures.

METHOD

We administered questionnaire surveys to 109 kidney transplant recipients. These included items on personal attributes, medical information, depression, and stress-coping type scales. Statistical analysis was performed using factor analysis and multiple regression analysis.

RESULTS

Fifteen out of 109 (13.8%) were found to be high-risk patients for depression based on responses to the questionnaire using the depression scale. We extracted 2 factors of stress-coping type, namely Factor 1, "Directly coping with the problem," of patients who try to directly resolve the problem in a positive manner and Factor 2, "Stress-release while avoiding the problem," for those who relieve their feelings in response to the stress without resolving the problem itself. When multiple regression analysis was conducted with the depression scale as the dependent variable and the stress-coping factor as the independent variable, Factor 1 tended to be associated with reduced depression and Factor 2 with increased depression.

CONCLUSIONS

Results showed that to improve the mental health of those who receive kidney transplants, it is necessary to examine the depression and stress-coping types of such patients at an early stage and carry out education on stress-coping, focusing on resolving the actual problem.

440. The Masqueraders Presenting a Multisystem Disease: Unusual and Atypical Clinical Features of Scrub Typhus in Fukushima, Japan

Background

Scrub typhus (ST) is endemic in Fukushima, where the highest number has been reported from 2006 to 2011 in Japan. Atypical clinical presentation of ST makes the diagnosis difficult followed by treatment delay. Despite fatal but treatable disease with early recognition, the myriad clinical features of ST have been underreported.

Methods

We reviewed the clinical features of adult patients diagnosed as ST from 2008 to 2017 at Ohta Nishinouchi General Hospital, a major teaching hospital in Fukushima, Japan.

Results

Total 55 cases (serotype Karp 24, Irie/Kawasaki 21, Hirano/Kuroki 10) of ST were confirmed by elevated specific IgM and IgG in the paired sera and real-time PCR analysis of eschars. Unusual presentations as the main clinical features of ST are found in 7/55 (13%; Karp 4 and Irie/Kawasaki 3), including cardiovascular (3 cases of paroxysmal atrial fibrillation), neurological (2 cases of syncope and one case of encephalitis) and metabolic/electrolyte disorder (one case of hyponatremia). In terms of atypical clinical features, the cases without triad (fever ≥38.0℃, rash and eschar) were found in 14/55 (25%). The cases of “eschar negative scrub typhus” were found in 6/55 (11%; Karp 1, Irie/Kawasaki 2, Hirano/Kuroki 3). The cases without fever and rash were also found in 6/55 (11%; Karp 2, Irie/Kawasaki 3, Hirano/Kuroki 1) and 4/55 (7%; Karp 2, Irie/Kawasaki 1, Hirano/Kuroki 1), respectively. Severe cases (4/55, 7%) were found with shock and disseminated intravascular coagulation including one fatal case (1/55, 1.8%; Hirano/Kuroki). Besides more than the half of ST cases with triad (30/55; 55%), unusual and atypical presentations were found in 38% (21/55) of the total number of cases.

Conclusion

The diagnosis of ST is a clinical challenge without typical features. In endemic area, unusual and atypical presentation of ST involving multi-system should be noted as the odds-on favorite differential diagnosis.

Disclosures

All authors: No reported disclosures.

EVALUATION OF PATIENT EXPOSURE IN FAST kVp SWITCHING DUAL ENERGY COMPUTED TOMOGRAPHY: PHANTOM STUDY

The aim of this study was to evaluate the suitability of size specific dose estimates (SSDE) to estimate patient dose in Fast kVp switching dual energy CT. An anthropomorphic phantom (RAN-110) was repeatedly scanned (chest, abdomen and the pelvis) using a 64 detector row MDCT (Discovery CT750 HD, GE Healthcare, Milwaukee, WI, USA) with various CT parameters, including Fast kVp switching. Dosimetry was performed using thermo-luminescent dosimeters, positioned both superficially and within the phantom. SSDE was calculated for all slices of the anthropomorphic phantom using both the localiser and axial images. In Fast kVp switching, SSDE underestimated the measured absorbed dose for the chest/abdomen region ~35% at the maximum, but were in closer agreement for the pelvic region about within 10%. In single energy techniques, SSDE could not be applied in the estimation of organ doses, but in Fast kVp switching dual energy techniques, SSDE could be applied for anatomical regions with larger thicknesses.

Emergence of coexisting ordered states in active matter systems

Active systems can produce a far greater variety of ordered patterns than conventional equilibrium systems. In particular, transitions between disorder and either polar- or nematically ordered phases have been predicted and observed in two-dimensional active systems. However, coexistence between phases of different types of order has not been reported. We demonstrate the emergence of dynamic coexistence of ordered states with fluctuating nematic and polar symmetry in an actomyosin motility assay. Combining experiments with agent-based simulations, we identify sufficiently weak interactions that lack a clear alignment symmetry as a prerequisite for coexistence. Thus, the symmetry of macroscopic order becomes an emergent and dynamic property of the active system. These results provide a pathway by which living systems can express different types of order by using identical building blocks.