Cluster analysis of long COVID in Japan and association of its trajectory of symptoms and quality of life.

BACKGROUND: Multiple prolonged symptoms observed in patients who recovered from COVID-19 are defined as long COVID. Although diverse phenotypic combinations are possible, they remain unclear. This study aimed to perform a cluster analysis of long COVID in Japan and clarify the association between its characteristics and background factors and quality of life (QOL). METHODS: This multicentre prospective cohort study collected various symptoms and QOL after COVID-19 from January 2020 to February 2021. This study included 935 patients aged ≥18 years with COVID-19 at 26 participating medical facilities. Hierarchical cluster analysis was performed using 24 long COVID symptom at 3 months after diagnosis. RESULTS: Participants were divided into the following five clusters: numerous symptoms across multiple organs (cluster 1, n=54); no or minor symptoms (cluster 2, n=546); taste and olfactory disorders (cluster 3, n=76); fatigue, psychoneurotic symptoms and dyspnoea (low prevalence of cough and sputum) (cluster 4, n=207) and fatigue and dyspnoea (high prevalence of cough and sputum) (cluster 5, n=52). Cluster 1 included elderly patients with severe symptoms, while cluster 3 included young female with mild symptoms. No significant differences were observed in the comorbidities. Cluster 1 showed the most impaired QOL, followed by clusters 4 and 5; these changes as well as the composition of symptoms were observed over 1 year. CONCLUSIONS: We identified patients with long COVID with diverse characteristics into five clusters. Future analysis of these different pathologies could result in individualised treatment of long COVID. TRIAL REGISTRATION NUMBER: The study protocol is registered at UMIN clinical trials registry (UMIN000042299).

Expression of the Wolbachia male-killing factor Oscar impairs dosage compensation in lepidopteran embryos.

Wolbachia are intracellular bacteria in insects that can manipulate the sexual development and reproduction by male killing or other methods. We have recently identified a Wolbachia protein named Oscar that acts as a male-killing factor for lepidopteran insects. Oscar interacts with the Masculinizer (Masc) protein, which is required for both masculinization and dosage compensation (DC) in lepidopteran insects. Embryonic expression of Oscar inhibits masculinization and causes male killing in two lepidopteran species, Ostrinia furnacalis and Bombyx mori. However, it remains unknown whether Oscar-induced male killing is caused by a failure of DC. Here, we performed a transcriptome analysis of Oscar complementary RNA-injected O. furnacalis and B. mori embryos, and found that Oscar primarily targets the Masc protein, resulting in male killing by interfering with DC in lepidopteran insects.

Higher-order topological heat conduction on a lattice for detection of corner states.

A heat conduction equation on a lattice composed of nodes and bonds is formulated assuming the Fourier law and the energy conservation law. Based on this equation, we propose a higher-order topological heat conduction model on the breathing kagome lattice. We show that the temperature measurement at a corner node can detect the corner state which causes rapid heat conduction toward the heat bath, and that several-nodes measurement can determine the precise energy of the corner states.

Masculinizer is not post-transcriptionally regulated by female-specific piRNAs during sex determination in the Asian corn borer, Ostrinia furnacalis.

Lepidopteran insects are heterogametic in females, although most insect species are heterogametic in males. In a lepidopteran model species, the silkworm Bombyx mori (Bombycoidea), the uppermost sex determinant Feminizer (Fem) has been identified on the female-specific W chromosome. Fem is a precursor of PIWI-interacting small RNA (piRNA). Fem piRNA forms a complex with Siwi, one of the two B. mori PIWI-clade Argonaute proteins. In female embryos, Fem piRNA-Siwi complex cleaves the mRNA of the male-determining gene Masculinizer (Masc), directing the female-determining pathway. In male embryos, Masc activates the male-determining pathway in the absence of Fem piRNA. Recently, W chromosome-derived piRNAs complementary to Masc mRNA have also been identified in the diamondback moth Plutella xylostella (Yponomeutoidea), indicating the convergent evolution of piRNA-dependent sex determination in Lepidoptera. Here, we show that this is not the case in the Asian corn borer, Ostrinia furnacalis (Pyraloidea). Although our previous studies demonstrated that O. furnacalis Masc (OfMasc) has a masculinizing function in the embryonic stage, the expression level of OfMasc was indistinguishable between the sexes at the timing of sex determination. Deep sequencing analysis identified no female-specific small RNAs mapped onto OfMasc mRNA. Embryonic knockdown of two PIWI genes did not affect the expression level of OfMasc in either sex. These results demonstrated that piRNA-dependent reduction of Masc mRNA in female embryos is not a common strategy of sex determination, which suggests the possibility of divergent evolution of sex determinants across the order Lepidoptera.

A Wolbachia factor for male killing in lepidopteran insects.

Bacterial symbionts, such as Wolbachia species, can manipulate the sexual development and reproduction of their insect hosts. For example, Wolbachia infection induces male-specific death in the Asian corn borer Ostrinia furnacalis by targeting the host factor Masculinizer (Masc), an essential protein for masculinization and dosage compensation in lepidopteran insects. Here we identify a Wolbachia protein, designated Oscar, which interacts with Masc via its ankyrin repeats. Embryonic expression of Oscar inhibits Masc-induced masculinization and leads to male killing in two lepidopteran insects, O. furnacalis and the silkworm Bombyx mori. Our study identifies a mechanism by which Wolbachia induce male killing of host progeny.

Edge states of a diffusion equation in one dimension: Rapid heat conduction to the heat bath.

We propose a one-dimensional diffusion equation (heat equation) for systems in which the diffusion constant (thermal diffusivity) varies alternately with a spatial period a. We solve the time evolution of the field (temperature) profile from a given initial distribution, by diagonalizing the Hamiltonian, i.e., the Laplacian with alternating diffusion constants, and expanding the temperature profile by its eigenstates. We show that there are basically phases with or without edge states. The edge states affect the heat conduction around heat baths. In particular, rapid heat transfer to heat baths would be observed in a short-time regime, which is estimated to be t<10^{-2}s for the a∼10^{-3}m system and t<1s for the a∼10^{-2}m system composed of two kinds of familiar metals such as titanium, zirconium, and aluminium, gold, etc. We also discuss the effective lattice model which simplifies the calculation of edge states up to high energy. It is suggested that these high-energy edge states also contribute to very rapid heat conduction in a very short-time regime.

Comparison of Rapid Antigen Tests for COVID-19.

Reverse transcription-quantitative PCR (RT-qPCR)-based tests are widely used to diagnose coronavirus disease 2019 (COVID-19). As a result that these tests cannot be done in local clinics where RT-qPCR testing capability is lacking, rapid antigen tests (RATs) for COVID-19 based on lateral flow immunoassays are used for rapid diagnosis. However, their sensitivity compared with each other and with RT-qPCR and infectious virus isolation has not been examined. Here, we compared the sensitivity among four RATs by using severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) isolates and several types of COVID-19 patient specimens and compared their sensitivity with that of RT-qPCR and infectious virus isolation. Although the RATs read the samples containing large amounts of virus as positive, even the most sensitive RAT read the samples containing small amounts of virus as negative. Moreover, all RATs tested failed to detect viral antigens in several specimens from which the virus was isolated. The current RATs will likely miss some COVID-19 patients who are shedding infectious SARS-CoV-2.

Correlation among sarcopenia, malnutrition and activities of daily living in patients with vertebral compression fractures: a comparison based on admission and discharge parameters evaluating these conditions.

[Purpose] Sarcopenia may be associated with malnutrition in patients with vertebral compression fractures which may affect a patient's functional prognosis. This study investigated the association between sarcopenia, malnutrition, and activities of daily living at the time of hospital discharge in patients with vertebral compression fractures. [Participants and Methods] The study included 36 patients who were hospitalized with vertebral compression fractures. Sarcopenia was assessed by measuring grip strength and calf circumference. The nutritional status was assessed at the time of hospital admission and at discharge using the Mini Nutritional Assessment Short Form screening tool. Activities of daily living were assessed using the Barthel Index. [Results] The prevalence of sarcopenia at the time of admission was 47.2%. The Barthel Index and Mini Nutritional Assessment Short Form scores in patients with sarcopenia at the time of admission were significantly lower at discharge than to those in patients without sarcopenia. Overall, at discharge, weight and calf circumference decreased significantly with a consequent increase in the prevalence of sarcopenia (55.6%). Multivariate analysis showed that the Mini Nutritional Assessment Short Form score, calf circumference loss, and age affected the Barthel Index at discharge. [Conclusion] Patients with vertebral compression fractures often show sarcopenia and malnutrition, which are conditions that may be exacerbated during hospitalization. These conditions can subsequently affect a patient's activities of daily living; thus, nutritional rehabilitation is important in patients with vertebral compression fractures, as demonstrated in this study.

In vivo masculinizing function of the Ostrinia furnacalis Masculinizer gene.

The Masculinizer gene (Masc) encodes a CCCH tandem zinc finger protein essential for masculinization and dosage compensation in the silkworm Bombyx mori. Previously we identified a Masc orthologue from the crambid Ostrinia furnacalis (OfMasc) and observed its masculinizing activity in the B. mori cultured cell line BmN-4. However, the role of OfMasc in masculinization of O. furnacalis has not been assessed. In this study, we unexpectedly discovered that all of the male larvae that escaped from Wolbachia-induced embryonic male-killing by OfMasc cRNA injection expressed the female-type splicing variants of O. furnacalis doublesex (Ofdsx). To clarify the role of OfMasc in the masculinization process in vivo, we established a system to monitor both sex chromosome- and dsx splicing-based sexes from a single O. furnacalis embryo. Using this system, we investigated the effects of OfMasc knockdown in early embryos on Ofdsx splicing and found that depletion of OfMasc mRNA in male embryos induced the production of the female-type splicing variants of Ofdsx. This result indicates that OfMasc is required for masculinization in O. furnacalis, and that the Masc protein possesses masculinizing activity in an insect species that is phylogenetically distant from Bombycidae.

The 23-valent pneumococcal polysaccharide vaccine in patients with rheumatoid arthritis: a double-blinded, randomized, placebo-controlled trial.

BACKGROUND: Pneumococcal pneumonia is the most frequent form of pneumonia. We herein assessed the effectiveness of the 23-valent pneumococcal polysaccharide vaccine (PPSV23) in the prevention of pneumonia overall in rheumatoid arthritis (RA) patients at risk for infections. We hypothesized that PPSV23 vaccination is superior in preventing pneumococcal pneumonia compared with placebo in RA patients. METHODS: A prospective, multicenter, double-blinded, randomized, placebo-controlled (1:1) trial was conducted across departments of rheumatology in Japanese National Hospital Organization hospitals. RA patients (n = 900) who had been treated with biological or immunosuppressive agents were randomly assigned PPSV23 or placebo (sodium chloride). The primary endpoints were the incidences of all-cause pneumonia and pneumococcal pneumonia. The secondary endpoint was death from pneumococcal pneumonia, all-cause pneumonia, or other causes. Cox regression models were used to estimate the risk of pneumonia overall for the placebo group compared with the vaccine group. RESULTS: Seventeen (3.7%) of 464 patients in the vaccine group and 15 (3.4%) of 436 patients in the placebo group developed pneumonia. There was no difference in the rates of pneumonia between the two study groups. The overall rate of pneumonia was 21.8 per 1000 person-years for patients with RA. The presence of interstitial pneumonia (hazard ratio: 3.601, 95% confidence interval: 1.547-8.380) was associated with an increased risk of pneumonia in RA patients. CONCLUSION: PPSV23 does not prevent against pneumonia overall in RA patients at relative risk for infections. Our results also confirm that the presence of interstitial lung disease is associated with pneumonia in Japanese patients with RA. TRIAL REGISTRATION: UMIN-CTR UMIN000009566 . Registered 17 December 2012.

Effect of abatacept on the immunogenicity of 23-valent pneumococcal polysaccharide vaccination (PPSV23) in rheumatoid arthritis patients.

INTRODUCTION: Patients with rheumatoid arthritis (RA) treated with abatacept (ABT) are at increased risk for vaccine-preventable infections. The aim of the present study is to evaluate the humoral response to 23-valent pneumococcal polysaccharide (PPSV23) vaccination in RA patients receiving ABT. METHODS: The immunogenicity study was nested within a randomized, double-blind placebo-controlled study, designed to evaluate the efficacy of the PPSV23. PPSV23 was given to 111 RA patients, who were classified into three groups: RA control (n = 35), methotrexate (MTX) alone (n = 55), and ABT (n = 21). Before and 4-6 weeks after vaccination, we measured the patients' concentrations of antibodies against pneumococcal serotypes 6B and 23F using an enzyme-linked immunosorbent assay and determined their antibody functionality using a multiplexed opsonophagocytic killing assay, reported as the opsonization index (OI). RESULTS: The pneumococcal serotype-specific IgG concentrations and OIs were both significantly increased in all treatment groups in response to PPSV23 vaccination. In the ABT group, the IgG responses for the 6B serotype were lower compared with those in the MTX alone or control groups, whereas the OI responses were similar to those in the other two groups. In a subgroup analysis, the pneumococcal serotype-specific IgG responses were significantly lower in both serotypes (6B and 23F) in the ABT/MTX group; however, the OI responses in the ABT group were not different from the control group. There was no association between the pneumococcal serotype-specific IgG and OI responses for the 6B serotype in patients receiving ABT in contrast to the control or MTX alone patients. No severe adverse effects were observed in any of the treatment groups. CONCLUSIONS: OI responses indicate antibody functionality rather than simply their amount, so the similarity of these measurements between all three groups suggests that RA patients receiving ABT still benefit from receiving the PPSV23 vaccination, even though they produce less IgG in response to it. The results suggest an influence of ABT on the humoral response to PPSV23 vaccination under MTX treatment; however, preserved opsonin responses are expected in RA patients treated with ABT plus MTX. TRIAL REGISTRATION: University Hospital Medical Information Network Clinical Trials Registry: UMIN000009566. Registered 12 December 2012.

Opsonic and Antibody Responses to Pneumococcal Polysaccharide in Rheumatoid Arthritis Patients Receiving Golimumab Plus Methotrexate.

Vaccination against Streptococcus pneumoniae is recommended for rheumatoid arthritis (RA) patients receiving immunosuppressive treatments. The objective of this study was to evaluate the humoral response to 23-valent pneumococcal polysaccharide vaccination (PPSV23) in RA patients receiving methotrexate (MTX) alone or in combination with a tumor necrosis factor inhibitor, golimumab (GOM).PPSV23 was given to 114 RA patients, who were classified into three groups: RA control (n = 35), MTX alone (n = 55), and GOM + MTX (n = 24). Before and 4 to 6 weeks after vaccination, concentrations of antibodies against pneumococcal serotypes 6B and 23F were measured using an enzyme-linked immunosorbent assay and antibody functionality was determined using a multiplexed opsonophagocytic killing assay, reported as the opsonization index (OI).The IgG concentrations and OIs were both significantly increased in all treatment groups in response to PPSV23 vaccination. In the GOM + MTX group, the IgG responses were lower than those in the MTX alone or control groups, whereas the OI responses were similar to those in the other 2 groups. Furthermore, discrepancies between the IgG and OI responses were found in GOM + MTX group. No severe adverse effect was observed in any treatment groups.OI responses indicate that antibody functionality rather than antibody quantity is important. The similarity of these measurements between all 3 groups suggests that RA patients receiving MTX + GOM still benefit from receiving the PPSV23 vaccination, even though they produce less IgG in response to it. These results can help clinicians to better schedule and evaluate pneumococcal vaccination for RA patients.

The Endosymbiotic Bacterium Wolbachia Selectively Kills Male Hosts by Targeting the Masculinizing Gene.

Pathogens are known to manipulate the reproduction and development of their hosts for their own benefit. Wolbachia is an endosymbiotic bacterium that infects a wide range of insect species. Wolbachia is known as an example of a parasite that manipulates the sex of its host's progeny. Infection of Ostrinia moths by Wolbachia causes the production of all-female progeny, however, the mechanism of how Wolbachia accomplishes this male-specific killing is unknown. Here we show for the first time that Wolbachia targets the host masculinizing gene of Ostrinia to accomplish male-killing. We found that Wolbachia-infected O. furnacalis embryos do not express the male-specific splice variant of doublesex, a gene which acts at the downstream end of the sex differentiation cascade, throughout embryonic development. Transcriptome analysis revealed that Wolbachia infection markedly reduces the mRNA level of Masc, a gene that encodes a protein required for both masculinization and dosage compensation in the silkworm Bombyx mori. Detailed bioinformatic analysis also elucidated that dosage compensation of Z-linked genes fails in Wolbachia-infected O. furnacalis embryos, a phenomenon that is extremely similar to that observed in Masc mRNA-depleted male embryos of B. mori. Finally, injection of in vitro transcribed Masc cRNA into Wolbachia-infected embryos rescued male progeny. Our results show that Wolbachia-induced male-killing is caused by a failure of dosage compensation via repression of the host masculinizing gene. Our study also shows a novel strategy by which a pathogen hijacks the host sex determination cascade.

Pneumococcal polysaccharide vaccination in rheumatoid arthritis patients receiving tacrolimus.

INTRODUCTION: In rheumatoid arthritis (RA) patients receiving immunosuppressive treatments, vaccination against Streptococcus pneumoniae is recommended. The objective of the study was to evaluate the effects of tacrolimus (TAC) on immune response following administration of a 23-valent pneumococcal polysaccharide vaccine (PPSV23) in patients with established RA. METHODS: Patients with RA (n = 133) were vaccinated with PPSV23. Patients were classified into TAC (n = 29), methotrexate (MTX) (n = 55), control (n = 35), and TAC/MTX (n = 14) treatment groups. We measured the concentrations of pneumococcal serotypes 6B and 23F by using an enzyme-linked immunosorbent assay and determined antibody functionality by using a multiplexed opsonophagocytic killing assay, reported as the opsonization index (OI), before and 4 to 6 weeks after vaccination. A positive antibody response was defined as at least a twofold increase in the IgG concentration or as at least a 10-fold increase in the OI. RESULTS: IgG concentrations and OIs were significantly increased in all treatment groups after PPSV23 vaccination. The TAC treatment group appears to respond in a manner similar to that of the RA control group in terms of 6B and 23F serotype concentration and function. In contrast, the MTX group had the lowest immune response. Patients who received a combination of TAC and MTX (TAC/MTX) also had a diminished immune response compared with those who received TAC alone. CONCLUSIONS: TAC monotherapy does not appear to impair PPSV23 immunogenicity in patients with RA, whereas antibody production and function may be reduced when TAC is used with MTX. Thus, PPSV23 administration during ongoing TAC treatment should be encouraged for infection-prone TAC-treated patients with rheumatic diseases. TRIAL REGISTRATION: University Hospital Medical Information Network Clinical Trials Registry: UMIN000009566. Registered 12 December 2012.

A simple rule for quadrupedal gait generation determined by leg loading feedback: a modeling study.

We discovered a specific rule for generating typical quadrupedal gaits (the order of the movement of four legs) through a simulated quadrupedal locomotion, in which unprogrammed gaits (diagonal/lateral sequence walks, left/right-lead canters, and left/right-lead transverse gallops) spontaneously emerged because of leg loading feedbacks to the CPGs hard-wired to produce a default trot. Additionally, all gaits transitioned according to speed, as seen in animals. We have therefore hypothesized that various gaits derive from a trot because of posture control through leg loading feedback. The body tilt on the two support legs of each diagonal pair during trotting was classified into three types (level, tilted up, or tilted down) according to speed. The load difference between the two legs led to the phase difference between their CPGs via the loading feedbacks, resulting in nine gaits (3(2): three tilts to the power of two diagonal pairs) including the aforementioned.

Analysis of the gait generation principle by a simulated quadruped model with a CPG incorporating vestibular modulation.

This study aims to understand the principles of gait generation in a quadrupedal model. It is difficult to determine the essence of gait generation simply by observation of the movement of complicated animals composed of brains, nerves, muscles, etc. Therefore, we build a planar quadruped model with simplified nervous system and mechanisms, in order to observe its gaits under simulation. The model is equipped with a mathematical central pattern generator (CPG), consisting of four coupled neural oscillators, basically producing a trot pattern. The model also contains sensory feedback to the CPG, measuring the body tilt (vestibular modulation). This spontaneously gives rise to an unprogrammed lateral walk at low speeds, a transverse gallop while running, in addition to trotting at a medium speed. This is because the body oscillation exhibits a double peak per leg frequency at low speeds, no peak (little oscillation) at medium speeds, and a single peak while running. The body oscillation autonomously adjusts the phase differences between the neural oscillators via the feedback. We assume that the oscillations of the four legs produced by the CPG and the body oscillation varying according to the current speed are synchronized along with the varied phase differences to keep balance during locomotion through postural adaptation via the vestibular modulation, resulting in each gait. We succeeded in determining a single simple principle that accounts for gait transition from walking to trotting to galloping, even without brain control, complicated leg mechanisms, or a flexible trunk.

Exact renormalization group approach to a nonlinear diffusion equation.

The exact renormalization group is applied to a nonlinear diffusion equation with a discontinuous diffusion coefficient. The generating functional of the solution for the initial-value problem of nonlinear diffusion equations is first introduced, and next a regularization scheme is presented. It is shown that the renormalization of an action functional in the generating functional leads to an anomalous diffusion exponent in full order of the perturbation series with respect to a nonlinearity.

Regression of an atherosclerotic coronary artery plaque demonstrated by multislice spiral computed tomography in a patient with stable angina pectoris.

Multislice spiral computed tomography (MSCT) permits direct visualization of not only coronary artery stenosis but also atherosclerotic plaques in patients with coronary artery disease. In this report, we describe a patient with stable angina in whom the regression of the plaque was documented by serial MSCT examinations. In the patient, a 46-year-old man with stable angina, MSCT revealed a stenotic lesion at the proximal portion of the left anterior descending artery. Axial, curved multiplanar reconstruction and cross-sectional images consistently depicted a protruding computed tomography low-signal mass suggesting an atherosclerotic plaque. Intracoronary ultrasound (ICUS) also documented an eccentric soft plaque with an echo-lucent mass suggesting a lipid core. Lipid-lowering therapy with pravastatin was started. Follow-up MSCT performed 7 months later documented an increase in the luminal area while the external vessel area remained unchanged. The regression of the plaque was also confirmed by a follow-up ICUS study. MSCT was thought to be feasible for serial evaluation of the plaque size and texture.

Noninvasive assessment of coronary artery disease by multislice spiral computed tomography using a new retrospectively ECG-gated image reconstruction technique.

The present study was designed to investigate the accuracy of multislice spiral computed tomography (MSCT) in detecting coronary artery disease, compared with coronary angiography (CAG), using a new retrospectively ECG-gated reconstruction method that reduced cardiac motion artifact. The study group comprised 54 consecutive patients undergoing MSCT and CAG. MSCT was performed using a SOMATOM Volume Zoom (4-detector-row, Siemens, Germany) with slice thickness 1.0 mm, pitch 1.5 (table feed: 1.5 mm per rotation) and gantry rotation time 500 ms. Metoprolol (20-60 mg) was administered orally prior to MSCT imaging. ECG-gated image reconstruction was performed with the reconstruction window (250 ms) positioned immediately before atrial contraction in order to reduce the cardiac motion artifact caused by the abrupt diastolic ventricular movement occurring during the rapid filling and atrial contraction periods. Following inspection of the volume rendering images, multiplanar reconstruction images and axial images of the left main coronary artery (LMCA), left anterior descending artery (LAD), left circumflex artery (LCx) and right coronary artery (RCA) were obtained and evaluated for luminal narrowing. The results were compared with those obtained by CAG. Of 216 coronary arteries, 206 (95.4%) were assessable; 10 arteries were excluded from the analysis because of severe calcification (n=4), stents (n=3) or insufficient contrast enhancement (n=3). The sensitivity to detect coronary stenoses >or=50% was 93.5% and the specificity to define luminal narrowing <50% was 97.2%. The positive predictive value and the negative predictive value were 93.5% and 97.2%, respectively. The sensitivity was still satisfactory (80.6%) even when non-assessable arteries were included in the analysis. The new retrospectively ECG-gated reconstruction method for MSCT has excellent diagnostic accuracy in detecting significant coronary artery stenoses.