Discrimination of Frailty Phenotype by KinectTM-Based Stepping Parameters.

Background: Frailty increases the risk of falling, hospitalization, and premature death, necessitating practical early-detection tools. Objectives: To examine the discriminative ability of KinectTM-based stepping parameters for identifying frailty phenotype. Design: Population-based cross-sectional study. Setting: Eighteen neighborhoods near Tokyo Metropolitan Institute for Geriatrics and Gerontology, Itabashi, Tokyo, Japan. Participants: In total, 563 community-dwelling older adults aged ≥75 years without mobility limitations, neurological disease, or dementia were included. Measurements: Step number (SN) and knee total movement distance (KMD) during a 20-s stepping test were evaluated using the KinectTM infrared depth sensor. Results: The number (%) of participants with frailty were 51 (9.1). The area under the receiver operating characteristic curves (95% confidence interval) of a parameter consisting of SN and KMD for frailty was 0.72 (0.64, 0.79). Conclusions: Stepping parameters evaluated using KinectTM provided acceptable ability in identifying frailty phenotype, making it a practical screening tool in primary care and home settings.

Duration of COVID-19 PCR positivity for Omicron vs earlier variants.

There have been reports that the Omicron variant of SARS-CoV-2 is milder and may resolve more quickly than earlier variants of SARS-CoV-2, like the Delta variant. Due to a dearth of studies on duration of PCR positivity for the Omicron variant, we studied this question in a cohort of routinely tested employees that work in a large laboratory. We found that there was no difference in duration of PCR positivity among those infected with the Omicron variant of SARS-CoV-2 versus earlier variants of SARS-CoV-2. That suggests in a clinical study that the increased infectiousness of Omicron might likely be due to factors related to viral and host cell interactions, rather than viral load or duration of infectivity, which has been suggested in immune escape studies.

Incidence of SARS-CoV-2 infection among previously infected or vaccinated employees.

INTRODUCTION: We aimed to determine the incidence of SARS-CoV-2 infection among individuals with a previous SARS-CoV-2 infection versus vaccinated individuals. METHODS: In March 2020, a SARS-CoV-2 testing company began routinely screening its workforce for SARS-CoV-2 with a PCR test. On December 15, 2020, vaccination with either the BNT162b2 or mRNA-1273 vaccines became available. Routine screening has continued through July 2021. We compared the incidence of SARS-CoV-2 infection between people who were SARS-CoV-2 naïve and unvaccinated, people with prior COVID-19 without vaccination, and people vaccinated without prior COVID-19. Incidence in 100 person-years with 95% confidence intervals (95% CIs) was calculated with the Poisson Exact equation. The incidence rate ratio (IRR), the ratio of confirmed COVID-19 cases per 100 person-years of follow-up with 95% CIs, was used as a measure of association between groups. Analyses were performed on StataSE. RESULTS: The median age of employees was 29.0 years (interquartile range: 23.6, 39.9). During the observation period, 258 SARS-CoV-2 incident infections were identified. The naïve, unvaccinated group had a SARS-CoV-2 incidence of 25.9 per 100 person-years (95% CI: 22.8-29.3). The previously infected, unvaccinated group had an incidence of 0 per 100 person-years (95% CI: 0-5.0). The vaccinated group had an incidence of 1.6 per 100 person-years (95% CI: 0.04-4.2). CONCLUSION: We found a strong association between prior SARS-CoV-2 infection and/or vaccination for SARS-CoV-2 with either the BNT162b2 or mRNA-1273 vaccines and the reduced incidence of SARS-CoV-2 infection when compared with those naïve and/or unvaccinated to SARS-CoV-2.

A Systematic Review of the Protective Effect of Prior SARS-CoV-2 Infection on Repeat Infection.

We systematically reviewed studies to estimate the risk of SARS-CoV-2 reinfection among those previously infected with SARS-CoV-2. For this systematic review, we searched scientific publications on PubMed and MedRxiv, a pre-print server, through August 18, 2021. Eligible studies were retrieved on August 18, 2021. The following search term was used on PubMed: ((("Cohort Studies"[Majr]) AND ("COVID-19"[Mesh] OR "SARS-CoV-2"[Mesh])) OR "Reinfection"[Majr]) OR "Reinfection"[Mesh]. The following search term was used on MedRxiv: "Cohort Studies" AND "COVID-19" OR "SARS-CoV-2" AND "Reinfection". The search terms were broad to encompass all applicable studies. There were no restrictions on the date of publication. Studies that did not describe cohorts with estimates of the risk of SARS-CoV-2 reinfection among those with previous infection were excluded. Studies that included vaccinated participants were either excluded or limited to sub-groups of non-vaccinated individuals. To identify relevant studies with appropriate control groups, we developed the following criteria for studies to be included in the systematic analysis: (1) baseline polymerase chain reaction (PCR) testing, (2) a uninfected comparison group, (3) longitudinal follow-up, (4) a cohort of human participants, i.e. not a case report or case series, and (5) outcome determined by PCR. The review was conducted following PRISMA guidelines. We assessed for selection, information, and analysis bias, per PRISMA guidelines. We identified 1,392 reports. Of those, 10 studies were eligible for our systematic review. The weighted average risk reduction against reinfection was 90.4% with a standard deviation of 7.7% (p-value: <0.01). Protection against SARS-CoV-2 reinfection was observed for up to 10 months. Studies had potential information, selection, and analysis biases. The protective effect of prior SARS-CoV-2 infection on re-infection is high and similar to the protective effect of vaccination. More research is needed to characterize the duration of protection and the impact of different SARS-CoV-2 variants.

Self-Collected Oral Fluid and Nasal Swabs Demonstrate Comparable Sensitivity to Clinician Collected Nasopharyngeal Swabs for Coronavirus Disease 2019 Detection.

We compared self-collected oral fluid swab specimens with and without clinician supervision, clinician-supervised self-collected anterior nasal swab specimens, and clinician-collected nasopharyngeal swab specimens for the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Supervised oral fluid and nasal swab specimens performed similarly to clinician-collected nasopharyngeal swab specimens. No sample type could detect SARS-CoV-2 infections amongst all positive participants.

Cytokine expression in Treponema pallidum infection.

BACKGROUND: Current syphilis tests cannot distinguish between active and past syphilis among patients with serofast rapid plasma reagin (RPR) titers. We investigated whether cytokine profiles might provide insight in the differentiation of active and treated syphilis. METHODS: We collected quarterly serum samples from participants at risk for incident syphilis in a prospective cohort study of men and male-to-female transgender women. We defined incident syphilis as a new RPR titer ≥ 1:8 or a fourfold increase from a prior RPR titer and a positive Treponema pallidum particle agglutination assay. We measured cytokine expression using a 63-multiplex bead-based Luminex assay (eBiosciences/Affymetrix, San Diego, California, USA). We used tertile bins and Chi square tests to identify differences in proportions of cytokines between samples from patients with active and treated syphilis. We constructed a network of cytokine profiles from those findings. We used R software (R version 3.4.1, R, Vienna, Austria) to fit models. RESULTS: We identified 20 pairs of cytokines (out of 1953 possible pairs) that differed between active and treated syphilis. From those, we identified three cytokine networks of interest: an Eotaxin-Rantes-Leptin network, a Mig-IL1ra-Trail-CD40L network, and an IL12p40-IL12p70 network. CONCLUSIONS: Differences in cytokine profiles are present among men and male-to-female transgender women with active and treated syphilis. Cytokine assays may be a potentially useful tool for identifying active syphilis among patients with serologic syphilis reactivity.

Exercise and/or Dietary Varieties and Incidence of Frailty in Community-Dwelling Older Women: A 2-Year Cohort Study.

OBJECTIVE: Exercise and dietary habits rich in variety may reduce the risk of frailty incident, but such association remains unexamined. This study aimed to examine the longitudinal associations between exercise and/or dietary varieties and incidence of frailty in older women. DESIGN: A 2-year population-based prospective cohort study. SETTING AND PARTICIPANTS: Six hundred and four community-dwelling older Japanese women aged ≥75 years with non-frailty at baseline survey. MEASUREMENTS: Frailty was assessed using Fried's frailty criteria composed of shrinking, weakness, slowness, low activity, and exhaustion at both baseline and follow-up surveys. Frailty incident was defined as the presence of ≥3 components at the follow-up survey. At baseline, information about exercise and dietary habits were obtained from all participants through a face-to-face interview. Participants were grouped into two categories, high (≥2) and low (<2) exercise varieties, assessed by the number of participations in 17 exercise types. By dietary variety, assessed using Dietary Variety Score (range, 0 to 10), participants were grouped into two, high (≥4 points) and low (<4 points) dietary varieties. Binary logistic regression analyses were applied to obtain adjusted odds ratios (ORs) and 95% confident intervals (CIs) of the incidence of frailty in the 4 groups (low-exercise and low-dietary varieties [low EV + low DV] as reference; low-exercise and high-dietary varieties [low EV + high DV]; high-exercise and low-dietary varieties [high EV + low DV]; and high-exercise and high-dietary varieties [high EV + high DV]). RESULTS: Frailty incidence rate was 9.3% over the 2-year follow-up period. Incidence rates of frailty in the 4 groups were as follows: 23.7%, 10.1%, 6.5%, and 7.7% in the low EV + low DV, low EV + high DV, high EV + low DV, and high EV + high DV groups, respectively. After adjustment for covariates, only the high EV + high DV group was associated with a significantly lower OR (0.38; 95% CI 0.15-0.92) of frailty incidence compared with the low EV + low DV group. CONCLUSION: Higher variety of exercise and diet was significantly associated with lower incidence of frailty. Thus, the combination of variety-rich exercise and dietary program may be useful in preventing the incidence of frailty in older women.

Drebrin A regulates hippocampal LTP and hippocampus-dependent fear learning in adult mice.

Structural plasticity of dendritic spines, which underlies higher brain functions including learning and memory, is dynamically regulated by the actin cytoskeleton and its associated proteins. Drebrin A is an F-actin-binding protein preferentially expressed in the brain and localized in the dendritic spines of mature neurons. Isoform conversion from drebrin E to drebrin A and accumulation of the latter in dendritic spines occurs during synapse maturation. We have previously demonstrated that drebrin A plays a pivotal role in spine morphogenesis and plasticity. However, it is unclear whether drebrin A plays a specific role in processes required for structural plasticity, and whether drebrin E can substitute in this role. To answer these questions, we analyzed mutant mice (named DAKO mice), in which isoform conversion from drebrin E to drebrin A is disrupted. In DAKO mouse brain, drebrin E continues to be expressed throughout life instead of drebrin A. Electrophysiological studies using hippocampal slices revealed that long-term potentiation of CA1 synapses was impaired in adult DAKO mice, but not in adolescents. In parallel with this age-dependent impairment, DAKO mice exhibited impaired hippocampus-dependent fear learning in an age-dependent manner; the impairment was evident in adult mice, but not in adolescents. In addition, histological investigation revealed that the spine length of the apical dendrite of CA1 pyramidal cells was significantly longer in adult DAKO mice than in wild-type mice. Our data indicate that the roles of drebrin E and drebrin A in brain function are different from each other, that the isoform conversion of drebrin is critical, and that drebrin A is indispensable for normal synaptic plasticity and hippocampus-dependent fear memory in the adult brain.

Laboratory Evaluation of a Dual-Path Platform Assay for Rapid Point-of-Care HIV and Syphilis Testing.

We assessed the laboratory performance of the Chembio dual-path platform HIV-syphilis rapid immunodiagnostic test and electronic reader for detection of HIV and Treponema pallidum antibodies in 450 previously characterized serum specimens. For visual or electronic reader HIV antibody detection, the sensitivity was 100% and the specificity was 98.7%. For visual T. pallidum antibody detection, the test sensitivity was 94.7% and the specificity was 100.0%; with the electronic reader, the sensitivity was 94.7% and the specificity was 99.7%.

Engineering of pseudoislets: effect on insulin secretion activity by cell number, cell population, and microchannel networks.

Engineered pseudoislets reconstituted from a suspension of pancreatic α and ß cells have the potential to relieve the shortage of donor islets for transplantation in the treatment of type 1 diabetes. However, the methods to fabricate pseudoislets are not well developed. In this study, we attempted to generate pseudoislets, which show a higher potential for glucose-induced insulin secretion, by altering total cell number, adjusting the cell ratio of pancreatic α and ß cells, and fabricating microchannel networks with the use of alginate hydrogel beads. To effectively aggregate α and ß cells and hydrogel beads, we used a previously established rapid aggregation method. When pseudoislets were reconstituted with 8,000 cells in a 1:8 α/ß-cell ratio, we observed that the glucose-induced insulin secretion was enhanced by 3.1 times compared with the pseudoislets formed with ß cells only. In addition, embedding of microchannel networks increased the insulin secretion rate by 4.4 times compared with the pseudoislets without the microstructures. These findings demonstrated that active modification was effective in reconstituting higher functional pseudoislets, which may be useful for islet transplantation.

Engineering of implantable liver tissues.

In this chapter, from the engineering point of view, we introduce the results from our group and related research on three typical configurations of engineered liver tissues; cell sheet-based tissues, sheet-like macroporous scaffold-based tissues, and tissues based on special scaffolds that comprise a flow channel network. The former two do not necessitate in vitro prevascularization and are thus promising in actual human clinical trials for liver diseases that can be recovered by relatively smaller tissue mass. The third approach can implant a much larger mass but is still not yet feasible. In all cases, oxygen supply is the key engineering factor. For the first configuration, direct oxygen supply using an oxygen-permeable polydimethylsiloxane membrane enables various liver cells to exhibit distinct behaviors, complete double layers of mature hepatocytes and fibroblasts, spontaneous thick tissue formation of hepatocarcinoma cells and fetal hepatocytes. Actual oxygen concentration at the cell level can be strictly controlled in this culture system. Using this property, we found that initially low then subsequently high oxygen concentrations were favorable to growth and maturation of fetal cells. For the second configuration, combination of poly-L: -lactic acid 3D scaffolds and appropriate growth factor cocktails provides a suitable microenvironment for the maturation of cells in vitro but the cell growth is limited to a certain distance from the inner surfaces of the macropores. However, implantation to the mesentery leaves of animals allows the cells again to proliferate and pack the remaining spaces of the macroporous structure, suggesting the high feasibility of 3D culture of hepatocyte progenitors for liver tissue-based therapies. For the third configuration, we proposed a design criterion concerning the dimensions of flow channels based on oxygen diffusion and consumption around the channel. Due to the current limitation in the resolution of 3D microfabrication processes, final cell densities were less than one-tenth of those of in vivo liver tissues; cells preferentially grew along the surfaces of the channels and this fact suggested the necessity of improved 3D fabrication technologies with higher resolution. In any case, suitable oxygen supply, meeting the cellular demand at physiological concentrations, was the most important factor that should be considered in engineering liver tissues. This enables cells to utilize aerobic respiration that produces almost 20 times more ATP from the same glucose consumption than anaerobic respiration (glycolysis). This also allows the cells to exhibit their maximum reorganization capability that cannot be observed in conventional anaerobic conditions.

Avidin-biotin-based approach to forming heterotypic cell clusters and cell sheets on a gas-permeable membrane.

Implantation of sheet-like liver tissues is a promising method in hepatocyte-based therapies, because angiogenesis is expected to occur upon implantation from the surrounding tissues. In this context, we introduce here a new methodology for the formation of a functional thick hepatic tissue usable for cell sheet technology. First, we report the formation of composite tissue elements in suspension culture. Composite elements were composed of human hepatoma Hep G2 cells and mouse NIH/3T3 fibroblasts which are important modulators for thick-tissue formation. To overcome the very low attachment and organization capability between different cells in suspension, we synthesized a new cell-to-cell binding molecule based on the avidin-biotin binding system that we previously applied to attach hepatocytes on artificial substrata. This newly synthesized biotin-conjugated biocompatible anchoring molecule was inserted in the plasma membrane of both cell types. NIH/3T3 cells were further conjugated with avidin and incubated with biotin-presenting Hep G2 cells to form highly composite tissue elements. Then, we seeded those elements on highly gas-permeable membranes at their closest packing density to induce the formation of a thick, composite, functional hepatic tissue without any perfusion. This methodology could open a new way to engineer implantable thick liver tissue sheets where different cell types are spatially organized and well supplied with oxygen.

TS-071 is a novel, potent and selective renal sodium-glucose cotransporter 2 (SGLT2) inhibitor with anti-hyperglycaemic activity.

BACKGROUND AND PURPOSE: The renal sodium-glucose cotransporter 2 (SGLT2) plays an important role in the reuptake of filtered glucose in the proximal tubule and therefore may be an attractive target for the treatment of diabetes mellitus. This study characterizes the pharmacological profile of TS-071 ((1S)-1,5-anhydro-1-[5-(4-ethoxybenzyl)-2-methoxy-4-methylphenyl]-1-thio-D-glucitol hydrate), a novel SGLT2 inhibitor in vitro and in vivo. EXPERIMENTAL APPROACH: Inhibition of glucose uptake by TS-071 was studied in CHO-K1 cells stably expressing either human SGLT1 or SGLT2. Single oral dosing studies were performed in rats, mice and dogs to assess the abilities of TS-071 to increase urinary glucose excretion and to lower plasma glucose levels. KEY RESULTS: TS-071 inhibited SGLT2 activity in a concentration-dependent manner and was a potent and highly selective inhibitor of SGLT2. Orally administered TS-071 increased urinary glucose excretion in Zucker fatty rats and beagle dogs at doses of 0.3 and 0.03 mg·kg(-1) respectively. TS-071 improved glucose tolerance in Zucker fatty rats without stimulating insulin secretion and reduced hyperglycaemia in streptozotocin (STZ)-induced diabetic rats and db/db mice at a dose of 0.3 mg·kg(-1). CONCLUSION AND IMPLICATIONS: These data indicate that TS-071 is a potent and selective SGLT2 inhibitor that improves glucose levels in rodent models of type 1 and 2 diabetes and may be useful for the treatment for diabetes mellitus.

Genetic disruption of the alternative splicing of drebrin gene impairs context-dependent fear learning in adulthood.

Dendritic spines are postsynaptic structures at excitatory synapses that play important roles in synaptic transmission and plasticity. Dendritic spine morphology and function are regulated by an actin-based cytoskeletal network. Drebrin A, an adult form of drebrin, is an actin-binding protein in dendritic spines, and its decrease is purportedly concerned with synaptic dysfunction in Alzheimer's disease. Rapid conversion of drebrin E, an embryonic form of drebrin, to drebrin A occurs in parallel with synaptic maturation. To understand the physiological role of drebrin isoform conversion in vivo, we generated knockout mice in which a drebrin A-specific exon was deleted from the drebrin gene. Drebrin A-specific knockout (DAKO) mice expressed drebrin E, which substituted for drebrin A. Subcellular fractionation experiment indicated that cytosolic form of drebrin was increased in the brains of DAKO mice. Furthermore, drebrin accumulation in synaptosomes of DAKO mice was much higher than that of wild-type (WT) mice. DAKO mice were viable and showed no apparent abnormalities in their gross brain morphology and general behaviors. However, DAKO mice were impaired in a context-dependent freezing after fear conditioning. These data indicate that drebrin A plays an indispensable role in some processes of generating fear learning and memory.

Pathologic and immunologic profiles of a limited form of neuromyelitis optica with myelitis.

BACKGROUND: Neuromyelitis optica (NMO) is a demyelinating syndrome characterized by myelitis and optic neuritis. Detection of anti-NMO immunoglobulin G antibody that binds to aquaporin-4 (AQP4) water channels allows the diagnosis of a limited form of NMO in the early stage with myelitis, but not optic neuritis. However, the detailed clinicopathologic features and long-term course of this limited form remain elusive. METHODS: We investigated 8 patients with the limited form of NMO with myelitis in comparison with 9 patients with the definite form. RESULT: All patients with limited and definite form showed uniform relapsing-remitting courses, with no secondary progressive courses. Pathologic findings of biopsy specimens from the limited form were identical to those of autopsy from the definite form, demonstrating extremely active demyelination of plaques, extensive loss of AQP4 immunoreactivity in plaques, and diffuse infiltration by macrophages containing myelin basic proteins with thickened hyalinized blood vessels. Moreover, the definite form at the nadir of relapses displayed significantly higher amounts of the inflammatory cytokines interleukin (IL)-1beta and IL-6 in CSF than the limited form and multiple sclerosis. CONCLUSION: This consistency of pathologic findings and uniformity of courses indicates that aquaporin 4-specific autoantibodies as the initiator of the neuromyelitis optica (NMO) lesion consistently play an important common role in the pathogenicity through the entire course, consisting of both limited and definite forms, and NMO continuously displays homogeneity of pathogenic effector immune mechanisms through terminal stages, whereas multiple sclerosis should be recognized as the heterogeneous 2-stage disease that could switch from inflammatory to degenerative phase. This report is a significant description comparing the pathologic and immunologic data of limited NMO with those of definite NMO.

Purification and biochemical characterization of a D-galactose binding lectin from Japanese sea hare (Aplysia kurodai) eggs.

A lectin was purified from Japanese sea hare Aplysia kurodai by lactosyl-agarose affinity chromatography. The molecular mass of the lectin was determined to be 56 and 32 kDa by SDS-PAGE under non-reducing and reducing conditions, respectively. It was found to agglutinate trypsinized and glutaraldehyde-fixed rabbit and human erythrocytes in the absence of divalent cations. The lectin exhibited stable thermo-tolerance as it retained hemagglutinating activity for 1 h even at 80 degrees C and showed stability at pH 10. By contrast, it was very sensitive at pH less than 5 and in the presence of the sulfhydryl-group preserving reagent, beta-mercaptoethanol. The hemagglutinating activity by the lectin was specifically inhibited by D-galactose, galacturonic acid, methyl-alpha- and methyl-beta-D-galactopyranoside, lactose, melibiose, and asialofetuin. The association rate constant (k(ass)) and dissociation rate constant (k(diss)) were determined for the lectin to be 4.3 x 10(5) M(-1) x sec(-1) and 2.2 x 10(-3) sec(-1), respectively, using a surface plasmon resonance biosensor. The lectin moderately inhibited cell proliferation in the P388 cell line dose dependently. Interestingly, lectin-treated cells did not show a fragmented DNA ladder as is caused by apoptosis, suggesting that the cell proliferation inhibition was caused by another unknown mechanism.

Restored viability and function of dental pulp cells on poly-methylmethacrylate (PMMA)-based dental resin supplemented with N-acetyl cysteine (NAC).

This study examines cytotoxicity of poly-methylmethacrylate (PMMA)-based dental temporary filling resin to dental pulp cells, and the potential amelioration of the toxicity with an anti-oxidant amino-acid, N-acetyl cysteine (NAC). Dental pulp cells extracted from rat maxillary incisors were cultured on the resin material with or without NAC incorporation, or on the polystyrene. The cultures were supplied with osteoblastic media, containing dexamethasone. Forty five percent of cells on the PMMA dental resin were necrotic at 24h after seeding. However, this percentage was reduced to 27% by incorporating NAC in the resin, which was the level equivalent to that in the culture on polystyrene. The culture on the untreated resin was found to be negative for alkaline phosphate (ALP) activity at days 5 and 10 or von Kossa mineralized nodule formation at day 20. In contrast, some areas of the cultures on NAC-incorporated resin substrates were ALP and von Kossa positive. Collagen I and dentin sialoprotein genes were barely expressed in day 7 culture on the untreated resin. However, those genes were expressed in the culture on the resin with NAC. These results suggest that the decreased cell viability and the nearly completely suppressed odontoblast-like cell phenotype of dental pulp cells cultured on PMMA dental resin can be salvaged to a biologically significant degree by the incorporation of NAC in the resin.

N-acetyl cysteine (NAC)-assisted detoxification of PMMA resin.

Despite its proven cytotoxicity, poly-methyl methacrylate (PMMA) resin is one of the most frequently and extensively used materials in dental practice. This study hypothesized that an anti-oxidant amino acid, N-acetyl cysteine (NAC), has the potential to detoxify this material. Ten percent of the rat dental pulp cells were viable when cultured on the PMMA resin for 24 hours, while over 70% of the cells were viable on the NAC-added resin. Nearly all suppressed alkaline phosphatase activity, matrix mineralizing capability, and odontoblastic gene expression, such as dentin sialoprotein, on the untreated control resin was recovered by NAC in a concentration-dependent manner. A Ca/P ratio of 1.65 was found in the extracellular matrix of cultures on NAC-added resin, while that in the untreated resin culture was 0.70. The addition of NAC to PMMA resin significantly ameliorated its cytotoxicity to the dental pulp cells and restored their odontoblast-like cell phenotype to a biologically significant degree.