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.

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%.

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.

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.

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.

Expression of drebrin E in migrating neuroblasts in adult rat brain: coincidence between drebrin E disappearance from cell body and cessation of migration.

Migrating neuroblasts in the adult brain form the rostral migratory stream (RMS) from the lateral ventricle to the olfactory bulb (OB) and then differentiate in the OB. In this study, we immunohistochemically analyzed drebrin expression in the RMS of the adult rat brain. Although drebrin is concentrated in dendritic spines of mature neurons, drebrin-immunopositive (DIP) cell bodies were observed in the RMS. The polysialated form of a neural cell adhesion molecule (PSA-NCAM) was detected in DIP cells. K(i)-67, a marker of proliferating cells, was also detected in a subset of DIP cells; however, neither glial fibrillary acidic protein, nestin nor vimentin was detected in DIP cells. These results indicate that DIP cells in the RMS are migrating neuroblasts. An image subtraction method, based on using anti-pan-drebrin and anti-drebrin A antibodies, demonstrated that DIP migrating neuroblasts are immunopositive for drebrin E but not for drebrin A (E+A-). Furthermore, olfactory bulbectomy increased the number of cells with drebrin E+A- signals in the RMS, indicating that these cells migrate along the RMS. Drebrin E+A- cells were also found in the subgranular layer of the dentate gyrus and in the piriform cortex. Thus, detection of drebrin E+A- signals is useful for identifying migrating neuroblasts in the adult brain. In the OB, drebrin E+A- signals were observed in the cell bodies of migrating neuroblasts in the core region; however, only fibrous and punctate drebrin E+A- signals were observed in postmigratory neuroblasts at the outer layers. These data demonstrate that the disappearance of drebrin E+A- signals from the cell body coincides with the cessation of neuronal migration. The disappearance of drebrin E from the cell body may be a molecular switch for the cessation of migration in newly generated neuroblasts.

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.

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.

Different profiles of Ca2+ responses to endothelin-1 and PDGF in liver myofibroblasts during the process of cell differentiation.

BACKGROUND AND PURPOSE: Hepatic stellate cells play an important role in liver fibrosis but little is known about liver myofibroblasts located around the central vein and in the portal area. In this study, intracellular Ca(2+) concentration ([Ca(2+)](i)) was measured to assess the response to endothelin-1 (ET-1), platelet derived growth factor (PDGF) and ATP in rat liver myofibroblasts. EXPERIMENTAL APPROACH: Rat liver myofibroblasts were compared in 'quiescent' (cultured on Matrigel-coated dishes) and 'activated' (cultured on non-coated plastic dishes) conditions. [Ca(2+)](i) was measured with the fluorescent dye fura-2 and mRNA for ET-1, PDGF and their receptors by RT-PCR. KEY RESULTS: ET-1 increased [Ca(2+)](i) in quiescent cells but not in activated cells, whereas PDGF-BB increased [Ca(2+)](i) in activated cells but not in quiescent cells. However, there was no difference between responses to ATP in quiescent or activated cells. ET-1 (in quiescent cells), PDGF-BB (in activated cells) and ATP (in both cells) all induced transient increases in [Ca(2+)](i) in the absence of extracellular Ca(2+) (with EGTA), indicating the involvement of Ca(2+) release from intracellular Ca(2+) stores. The sustained increase in [Ca(2+)](i) in the presence of external Ca(2+) in activated cells (ATP and PDGF) was significantly reduced by nicardipine, a L-type Ca(2+) channel blocker, but not in quiescent cells (ATP and ET-1). CONCLUSIONS AND IMPLICATIONS: The different pharmacological profiles of [Ca(2+)](i)-response in quiescent and activated myofibroblasts suggest that ET-1 and PDGF contribute differently to myofibroblast activation during the process of liver fibrosis.

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.

Influence of micrometastasis on N stage in gastric cancer and clinical application.

In order to evaluate the real extent of lymph node metastasis (LNM) in gastric cancer, an immunohistochemical (IHC) analysis was performed. We examined 11173 lymph nodes removed from 355 patients with all stages of gastric carcinoma. Tissue preparations were stained with cytokeratin 18, monoclonal antibody against cytokeratin. Micrometastases were found in 2.5% of the lymph nodes and in 31.3% of patients. The incidence of the patients with LNM increased to 9.1% in T(1m) (n = 99), 31.6% in T(1sm) (n = 95, 23.1% in sm1, 34.8% in sm2), 66.7% in T2 (n = 108, 48.8% in mp, 76.5% in ss), 88.1% in T3 (n = 42), and 90.9% in T4 (n = 11) lesions. Upstage was identified in 8.5% of patients: 6.7% in T1 (4.0% in m, 7.7% in sm1, 10.1% in sm2), 14.8% in T2 (20% in mp, 11.8% in ss), 2.4% in T3, and 0% in T4. Factors related to LNM were: tumor size and lymphatic invasion in mucosal lesions; only lymphatic invasion in submucosal lesions; size and depth of tumor, and lymphatic invasion in T2 lesions. In conclusion, the incidence of micrometastasis in regional lymph nodes was higher than we imagined in T1 lesions, more than D1 lymphadenectomy for sm1 and selected cases of mucosal cancer, and D2 lymphadenectomy for sm2 are necessary.

A developmentally regulated member of the sialyltransferase family (ST8Sia II, STX) is a polysialic acid synthase.

We found polysialic acid synthase activity of ST8Sia II (STX) in vitro and in vivo. Previously, we showed that mouse ST8Sia II exhibits alpha 2,3-sialylated N-glycan alpha 2,8-sialyltransferase activity, but the polysialic acid synthase activity of ST8Sia II was not detected at that time [Kojima, N. et al. (1995) FEBS Lett. 360, 1-4]. When fetuin was [14C]sialylated with ST8Sia II and then its N-linked oligosaccharides were analyzed, a part of the N-linked oligosaccharides was eluted in the void volume from a Sephadex G-50 column, and was eluted in the void volume from a Sephadex G-50 column, and was eluted from the DEAE-Toyopearl column at almost the same salt concentration as that where colomic acid was eluted. In addition, a series of 14C-labeled oligo-sialic acids were obtained from the oligosaccharides on partial mild acid hydrolysis. These results indicated that a part of N-linked oligosaccharides of fetuin were polysialylated with ST8Sia II. Transfection of ST8Sia II gene into several cell lines including NIH3T3 led to the expression of polysialic acids on the cell surface. Thus, ST8Sia II can directly synthesize polysialic acid chains on alpha 2,3-sialylated N-linked oligosaccharides of glycoproteins without any initiator sialytransferase.

Enzymatic activity of a developmentally regulated member of the sialyltransferase family (STX): evidence for alpha 2,8-sialyltransferase activity toward N-linked oligosaccharides.

We have detected sialyltransferase activity of recombinant mouse STX, which was cloned from rat brain as a new member of the sialyltransferase family, but sialyltransferase activity of which had not been detected previously [Livingston and Paulson, J. Biol. Chem. (1993) 268, 11504-11507]. The activity of mouse STX was specific toward sialylated glycoproteins. N-Glycanase treatment and linkage-specific sialidase treatment of glycoproteins revealed that STX transfers sialic acids through alpha 2,8-linkages to only N-linked oligosaccharides of glycoproteins. However, polymerase activity for polysialic acid synthesis was not detected for this sialyltransferase. Since this alpha 2,8-sialyltransferase gene is highly restricted in fetal and newborn brain, it may be involved in the polysialylation of glycoproteins, especially of N-CAM.

Abnormal IgG galactosylation and arthritis in MRL-Fas(lpr) or MRL-FasL(gld) mice are under the control of the MRL genetic background.

MRL mice bearing the lpr (Fas) or gld (Fas ligand) mutation, MRL-Fas(lpr) or MRL-FasL(gld), respectively, develop arthritis similar to rheumatoid arthritis, but C3H and C57BL/6 mice bearing such mutations do not. In MRL-Fas(lpr) mice, agalactosylated oligosaccharides in serum IgG increase significantly in comparison to MRL-+/+ mice without arthritis. In this study, an increased level of agalactosylation in IgG, as compared to MRL-+/+, was found in both MRL-Fas(lpr) and MRL-FasL(gld) mice. In contrast, the incidence of IgG without galactose was comparable among C3H-Fas(lpr), C3H-FasL(gld), and C3H-+/+ mice as well as between C57BL/6-Fas(lpr) and C57BL/6-+/+ mice. These results suggest that the increase in agalactosylated IgG and the development of arthritis in MRL-Fas(lpr) and MRL-FasL(gld) mice are controlled by the MRL genetic background.