Neuronal degeneration and cognitive impairment can be prevented via the normalization of mitochondrial dynamics.

Neuronal cells possess a certain degree of plasticity to recover from cell damage. When the stress levels are higher than their plasticity capabilities, neuronal degeneration is triggered. However, the factors correlated to the plasticity capabilities need to be investigated. In this study, we generated a novel mouse model that able to express in an inducible manner a dominant-negative form of MFN2, a mitochondrial fusion factor. We then compared the phenotype of the mice continuously expressing the mutated MFN2 with that of the mice only transiently expressing it. Remarkably, the phenotypes of the group transiently expressing mutant MFN2 could be divided into 3 types: equivalent to what was observed in the continuous expression group, intermediate between the continuous expression group and the control group, and equivalent to the control group. In particular, in the continuous expression group, we observed remarkable hyperactivity and marked cognitive impairments, which were not seen, or were very mild in the transient expression group. These results indicate that abnormal mitochondrial dynamics lead to stress, triggering neuron degeneration; therefore, the neurodegeneration progression can be prevented via the normalization of the mitochondrial dynamics. Since the availability of mouse models suitable for the reproduction of both neurodegeneration and recovery at least partially is very limited, our mouse model can be a useful tool to investigate neuronal plasticity mechanisms and neurodegeneration.

Rituximab maintenance therapy for patients with antineutrophil cytoplasmic antibody-associated vasculitis in Japan.

OBJECTIVES: We examined the efficacy and safety of rituximab (RTX) maintenance therapy for patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) in Japan. METHODS: We conducted a retrospective study using a multi-center cohort database of vasculitis patients. All maintenance treatment courses were divided into three groups: a RTX group, a group treated with other immunosuppressant drugs (IS) and a group receiving glucocorticoid monotherapy (GC). The primary endpoint was the comparison of relapse-free survival after 1 year. We also analyzed the occurrence of severe adverse events (SAEs) to assess safety. RESULTS: We included 123 courses of 107 patients (RTX n = 14, IS n = 64, GC n = 45). Twelve of 14 in the RTX group patients were diagnosed with granulomatosis with polyangiitis (GPA). The relapse-free survival of RTX maintenance therapy was comparable to that in the other groups (p = .122). After 1 year of treatment, the RTX group was administered lower steroid doses and one-third of them could withdraw corticosteroid. The overall incidence of SAE was 0.54/patient-year in the RTX group, 0.39/patient-year in the IS group and 0.34/patient-year in the GC group. CONCLUSION: RTX maintenance therapy could be effective and safe in Japanese GPA patients.

Discovery of Self-Assembling Small Molecules as Vaccine Adjuvants.

Immune potentiators, termed adjuvants, trigger early innate immune responses to ensure the generation of robust and long-lasting adaptive immune responses of vaccines. Presented here is a study that takes advantage of a self-assembling small-molecule library for the development of a novel vaccine adjuvant. Cell-based screening of the library and subsequent structural optimization led to the discovery of a simple, chemically tractable deoxycholate derivative (molecule 6, also named cholicamide) whose well-defined nanoassembly potently elicits innate immune responses in macrophages and dendritic cells. Functional and mechanistic analyses indicate that the virus-like assembly enters the cells and stimulates the innate immune response through Toll-like receptor 7 (TLR7), an endosomal TLR that detects single-stranded viral RNA. As an influenza vaccine adjuvant in mice, molecule 6 was as potent as Alum, a clinically used adjuvant. The studies described here pave the way for a new approach to discovering and designing self-assembling small-molecule adjuvants against pathogens, including emerging viruses.

Acquired Expression of Mutant Mitofusin 2 Causes Progressive Neurodegeneration and Abnormal Behavior.

Neurons have high plasticity in developmental and juvenile stages that decreases in adulthood. Mitochondrial dynamics are highly important in neurons to maintain normal function. To compare dependency on mitochondrial dynamics in juvenile and adult stages, we generated a mouse model capable of selective timing of the expression of a mutant of the mitochondrial fusion factor Mitofusin 2 (MFN2). Mutant expression in the juvenile stage had lethal effects. Contrastingly, abnormalities did not manifest until 150 d after mutant expression during adulthood. After this silent 150 d period, progressive neurodegeneration, abnormal behaviors, and learning and memory deficits similar to those seen in human neurodegenerative diseases were observed. This indicates that abnormal neuronal mitochondrial dynamics seriously affect survival during early life stages and can also significantly damage brain function after maturation. Our findings highlight the need to consider the timing of disease onset in mimicking human neurodegenerative diseases.SIGNIFICANCE STATEMENT To compare the dependency on mitochondrial dynamics in neurons in juvenile and adult stages, we generated a mouse model expressing a mutant of the mitochondrial fusion factor MFN2 in an arbitrary timing. Juvenile expression of the mutant showed acute and severe phenotypes and had lethal effects; however, post-adult expression induced delayed but progressive phenotypes resembling those found in human neurodegenerative diseases. Our results indicate that abnormal neuronal mitochondrial dynamics seriously affect survival during early life stages and can also significantly damage brain function after maturation. This strongly suggests that the timing of expression should be considered when establishing an animal model that closely resembles human neurodegenerative diseases.

Demonstration of on-chip quantum dot microcavity lasers in a molecularly engineered annular groove.

The on-chip quantum dot (QD) microcavity laser engineered on an annular groove made of fused silica was demonstrated based on the external quasi-cavity configuration. By incorporating an appropriate dose of polymer into QD film, the spectral purity of the lasing spectrum was significantly enhanced. In contrast to the dye microcavity laser embedded on the same trench profile, a QD laser possesses a lifetime that is over 10 times longer. We have introduced a unique two-step quantum gain deposition process that has remarkably reduced the wavelength drifts of laser emissions in an aqueous environment by approximately 400%. The reconfigurable cavity platform in combination with an appropriately engineered quantum gain medium embedded onto it promises to enable photostable chip-scale coherent light sources for various photonic, chemical, and biochemical sensing applications.

Organic-inorganic hybrid microdisk laser with dye and silica mixed doping prepared by ink-jet printing method.

We developed an ink-jet printing method for fabricating inorganic microdisks at room temperature, which is much lower than the melting point of solid-state inorganic oxide, and have fabricated an organic-inorganic hybrid microdisk laser. Silica was used as the inorganic disk material, and microdisk-shaped aggregates were formed by the ink-jet printing method using a solution in which nanosilica particles were dispersed in propylene glycol monomethylether (PGME) solvent. Then, a microdisk capable of laser oscillation was also prepared by preliminarily adding the laser dye rhodamine 6G to the ink to form a mixed organic material. The structural evaluation of the printed microdisk was first conducted using an optical microscope, a scanning electron microscope (SEM), and an atomic force microscope (AFM). The results of laser oscillation evaluation by optical excitation showed that the printed microdisk sufficiently functions as an optical resonator with a low optical loss. In these evaluations, excellent values such as a surface roughness of 5.83 nm from root mean square (R. M. S.) which is one forth smaller than the particle diameter, and a laser oscillation threshold of 4.76 µJ/mm2 at a wavelength of 601.4 nm were obtained. To the best of our knowledge, this is the first time that an inorganic microdisk has been fabricated at room temperature to realize an organic-inorganic hybrid microdisk laser.

Demonstration of versatile whispering-gallery micro-lasers for remote refractive index sensing.

We developed chip-scale remote refractive index sensors based on Rhodamine 6G (R6G)-doped polymer micro-ring lasers. The chemical, temperature, and mechanical sturdiness of the fused-silica host guaranteed a flexible deployment of dye-doped polymers for refractive index sensing. The introduction of the dye as gain medium demonstrated the feasibility of remote sensing based on the free-space optics measurement setup. Compared to the R6G-doped TZ-001, the lasing behavior of R6G-doped SU-8 polymer micro-ring laser under an aqueous environment had a narrower spectrum linewidth, producing the minimum detectable refractive index change of 4 × 10-4 RIU. The maximum bulk refractive index sensitivity (BRIS) of 75 nm/RIU was obtained for SU-8 laser-based refractive index sensors. The economical, rapid, and simple realization of polymeric micro-scale whispering-gallery-mode (WGM) laser-based refractive index sensors will further expand pathways of static and dynamic remote environmental, chemical, biological, and bio-chemical sensing.

Effects of edge inclination angles on whispering-gallery modes in printable wedge microdisk lasers.

The ink-jet technique was developed to print the wedge polymer microdisk lasers. The characterization of these lasers was implemented using a free-space optics measurement setup. It was found that disks of larger edge inclination angles have a larger free spectral range (FSR) and a lower resonance wavelength difference between the fundamental transverse electric (TE) and transverse magnetic (TM) whispering-gallery modes (WGMs). This behavior was also confirmed with simulations based on the modified Oxborrow's model with perfectly matched layers (PMLs), which was adopted to accurately calculate the eigenfrequencies, electric field distributions, and quality parameters of modes in the axisymmetric microdisk resonators. Combined with the nearly equivalent quality factor (Q-factor) and finesse factor (F-factor) variations, the correlations between the TE and left adjacent TM modes were theoretically demonstrated. When the edge inclination angle is varied, the distinguishable mode distribution facilitates the precise estimation of a resonance wavelength shift. Therefore, the flexible and efficient nature of wedge polymer microdisk lasers extends their potential applications in precision sensing technology.

Synthesis of Branched Trehalose Glycolipids and Their Mincle Agonist Activity.

The macrophage inducible C-type lectin (Mincle) is a pattern recognition receptor that recognizes trehalose dimycolate (TDM), and trehalose dibehenate (TDB) and related trehalose diesters, and thus represents a promising target for the development of vaccine adjuvants based on the trehalose glycolipid scaffold. To this end, we report on the synthesis of a series of long-chain α-branched, ß-modified trehalose monoesters and diesters to explore how glycolipid structure affects signaling through Mincle. Key steps in our synthetic strategy include a Fráter-Seebach α-alkylation to install the C20 aliphatic lipid on a malic acid derivative, and the formation of a ß,γ-epoxide as an intermediate from which modifications to the ß-position of the lipid can be made. Biological evaluation of the derivatives using nuclear factor of activated T cells (NFAT)-green fluorescent protein (GFP) reporter cell lines expressing mMincle or hMincle revealed that the hMincle agonist activity of all diesters was superior to that of the current lead trehalose glycolipid adjuvant TDB, while the activity of several monoesters was similar to that of their diester counterparts for mMincle, but all showed reduced hMincle agonist activity. Taken together, diesters 2d-g are thus potent Mincle agonists and promising vaccine adjuvants.

[A Case of Multiple Venous Thromboses Associated with Acute Cytomegalovirus Infection].

A previously healthy 44-year-old male presented with fever, abdominal pain, liver dysfunction and lymphadenopathy. He was diagnosed as having acute cytomegalovirus (CMV) infection with elevated CMV-IgG and IgM, and observed with supportive therapy. He was admitted to our hospital with prolonged fever lasting for a month. Enhanced CT revealed multiple thromboses in the right pulmonary artery and superior mesenteric vein. Follow-up CT after one week revealed new-onset thromboses in the left pulmonary artery and common iliac vein. Screening tests for thrombophilia were negative. His symptoms were improved with anticoagulant therapy with intravenous heparin, followed by oral warfarin. He was discharged on admission day 28 with good condition. Follow-up CT after 6 months revealed complete resolution of the thromboses. Anticoagulant therapy was stopped after 9 months, and he has been well without recurrence. Though vascular thrombosis is a rare complication, we must be alert to the signs and symptoms of thrombosis in patients with acute CMV infection.

Nanoparticle-polymer composite volume holographic gratings dispersed with ultrahigh-refractive-index hyperbranched polymer as organic nanoparticles.

We report on volume holographic recording at a wavelength of 532 nm in photopolymerizable polymer nanocomposites that are incorporated with new hyperbranched polymers (HBPs) acting as transporting organic nanoparticles. Since HBPs possess an ultrahigh index of refraction of 1.82 due to the inclusion of triazine and aromatic ring units, high-contrast transmission volume holographic gratings with refractive index modulation amplitudes as large as 2.2×10(-2) are recorded. This value enables us to realize a 10 µm thick transmission volume grating with the diffraction efficiency near 100% in the green.

Efficient gene-targeting in rat embryonic stem cells by CRISPR/Cas and generation of human kynurenine aminotransferase II (KAT II) knock-in rat.

The relative proportion of kynurenine aminotransferase (KAT) I-IV activities in the brain is similar between humans and rats. Moreover, KAT II is considered to be the main enzyme for kynurenic acid production in the brain. Taken together, human KAT II knock-in (hKAT II KI) rats will become a valuable tool for the evaluation of KAT II targeted drugs as a human mimetic model. Although we initially tried the approach by conventional gene-targeting via embryonic stem cells (ESCs) to generate them, we had to give up the production because of no recombinant ESCs. Accordingly, we developed a method to improve the efficiency of homologous recombination (HR) in ESCs by the combination with the CRISPR/Cas system. Co-electroporation of Cas9 plasmid, single guide RNA plasmid and hKAT II KI vector increased the number of drug-resistant colonies and greatly enhanced the HR efficiency from 0 to 36 %. All the clones which we obtained showed the same sequence as designed. These recombinant clones resulted in chimeras that transmitted the hKAT II KI allele to their offspring. hKAT II KI rats showed no reduction of KATs mRNA expression and the amount of kynurenic acid was similar between the hKAT II KI rats and the wild type in their brains. These results indicate that the methodology presented in this report can overcome the problem encountered in conventional gene-targeting that prevented production of humanized rats.

[Streptococcal Toxic Shock-like Syndrome due to Streptococcus suis Serotype 2 in a Japanese Pig Farmer].

Streptococcus suis is a major swine pathogen. It has recently been recognized as an emerging zoonosis that causes mainly meningitis and sepsis in human. In particular, toxic shock-like syndrome (TSLS) caused by this pathogen has a high mortality rate. However, misidentification of S. suis by conventional biochemical and commercial identification tests is not rare. The patient was a 71-year-old man who worked as a pig farmer who was admitted for fever, oliguria and subcutaneous hemorrhage. He was diagnosed as having septic shock and blood culture was positive for Gram-positive cocci, mainly diplococcus. This pathogen was identified with S. suis with using MALDI-TOF MS analysis, though a commercial Gram-Positive bacteria identification kit revealed viridans streptococci. His clinical features met the diagnostic criteria of TSLS, and ceftriaxone and clindamycin were administered. On admission day 28, he was discharged in good condition.

Nightly biting cycles of malaria vectors in a heterogeneous transmission area of eastern Amazonian Brazil.

BACKGROUND: The biting cycle of anopheline mosquitoes is an important component in the transmission of malaria. Inter- and intraspecific biting patterns of anophelines have been investigated using the number of mosquitoes caught over time to compare general tendencies in host-seeking activity and cumulative catch. In this study, all-night biting catch data from 32 consecutive months of collections in three riverine villages were used to compare biting cycles of the five most abundant vector species using common statistics to quantify variability and deviations of nightly catches from a normal distribution. METHODS: Three communities were selected for study. All-night human landing catches of mosquitoes were made each month in the peridomestic environment of four houses (sites) for nine consecutive days from April 2003 to November 2005. Host-seeking activities of the five most abundant species that were previously captured infected with Plasmodium falciparum, Plasmodium malariae or Plasmodium vivax, were analysed and compared by measuring the amount of variation in numbers biting per unit time (co-efficient of variation, V), the degree to which the numbers of individuals per unit time were asymmetrical (skewness = g1) and the relative peakedness or flatness of the distribution (kurtosis = g2). To analyse variation in V, g1, and g2 within species and villages, we used mixed model nested ANOVAs (PROC GLM in SAS) with independent variables (sources of variation): year, month (year), night (year X month) and collection site (year X month). RESULTS: The biting cycles of the most abundant species, Anopheles darlingi, had the least pronounced biting peaks, the lowest mean V values, and typically non-significant departures from normality in g1 and g2. By contrast, the species with the most sharply defined crepuscular biting peaks, Anopheles marajoara, Anopheles nuneztovari and Anopheles triannulatus, showed high to moderate mean V values and, most commonly, significantly positive skewness (g1) and kurtosis (g2) moments. Anopheles intermedius was usually, but not always, crepuscular in host seeking, and showed moderate mean V values and typically positive skewness and kurtosis. Among sites within villages, significant differences in frequencies of departures from normality (g1 and g2) were detected for An. marajoara and An. darlingi, suggesting that local environments, such as host availability, may affect the shape of biting pattern curves of these two species. CONCLUSIONS: Analyses of co-efficients of variation, skewness and kurtosis facilitated quantitative comparisons of host-seeking activity patterns that differ among species, sites, villages, and dates. The variable and heterogeneous nightly host-seeking behaviours of the five exophilic vector species contribute to the maintenance of stable malaria transmission in these Amazonian villages. The abundances of An. darlingi and An. marajoara, their propensities to seek hosts throughout the night, and their ability to adapt host-seeking behaviour to local environments, contribute to their impact as the most important of these vector species.

IgA vasculitis following COVID-19 vaccination.

Immunoglobulin A (IgA) vasculitis is generally triggered by infectious causes, but it has also been reported after immunisation with various vaccines. Herein, we report two cases of IgA vasculitis after receiving the first or second dose of the Pfizer-BioNTech BNT16B2b2 mRNA vaccine. Two men, aged 22 and 30 years, developed palpable purpura on the extremities and arthritis. One patient also complained of fever and gastrointestinal symptoms. Laboratory findings revealed mild leucocytosis and slightly elevated C-reactive protein levels, although the platelet count and coagulation profile were within normal levels in both cases. Proteinuria and microhaematuria were seen in one patient. Skin biopsies were performed in both patients and revealed leucocytoclastic vasculitis. The deposits of IgA and C3 were shown in immunofluorescence studies in one patient. Both patients were diagnosed with IgA vasculitis and treated with prednisolone, and their symptoms resolved within 1 week after initiation of treatment. The coronavirus disease 2019 mRNA vaccine could trigger IgA vasculitis; however, a coincidence cannot be ruled out.

Mycobacterial mycolic acids trigger inhibitory receptor Clec12A to suppress host immune responses.

Mycobacteria often cause chronic infection. To establish persistence in the host, mycobacteria need to evade host immune responses. However, the molecular mechanisms underlying the evasion strategy are not fully understood. Here, we demonstrate that mycobacterial cell wall lipids trigger an inhibitory receptor to suppress host immune responses. Mycolic acids are major cell wall components and are essential for survival of mycobacteria. By screening inhibitory receptors that react with mycobacterial lipids, we found that mycolic acids from various mycobacterial species bind to mouse Clec12A, and more potently to human Clec12A. Clec12A is a conserved inhibitory C-type lectin receptor containing immunoreceptor tyrosine-based inhibitory motif (ITIM). Innate immune responses, such as MCP-1 production, and PPD-specific recall T cell responses were augmented in Clec12A-deficient mice after infection. In contrast, human Clec12A transgenic mice were susceptible to infection with M. tuberculosis. These results suggest that mycobacteria dampen host immune responses by hijacking an inhibitory host receptor through their specific and essential lipids, mycolic acids. The blockade of this interaction might provide a therapeutic option for the treatment or prevention of mycobacterial infection.

Community ecology of container mosquitoes (Diptera: Culicidae) in Virginia following invasion by Aedes japonicus.

The success of an invasive species in a new region depends on its interactions with ecologically similar resident species. Invasions by disease vector mosquitoes are important as they may have ecological and epidemiological consequences. Potential interactions of a recent invasive mosquito, Aedes japonicus Theobald, with resident species in Virginia were evaluated by sampling larvae from containers and trapping adults. Distinct species compositions were observed for artificial containers and rock pools, with Ae. albopictus most abundant in the former and Ae. japonicus in the latter. However, these two species were found to co-occur in 21.2% of containers sampled. Among the six mosquito species most common in containers from May through September, 2006, only interspecific associations of Ae. japonicus with Aedes albopictus (Skuse) and Aedes triseriatus (Say) were significant, and both were negative. In addition to differences in habitat preference, mean crowding estimates suggest that interspecific repulsion may contribute to the significant negative associations observed between these species. High relative abundances of late instars and pupae of Ae. japonicus seem to provide this species with a mechanism of evading competition with Ae. albopictus, facilitating their coexistence in artificial containers. Although annual fluctuations were observed, trends in adult populations over a 6-yr period provide no evidence of declines. In summary, this survey of diverse container types and all life stages provided only limited evidence for competitive displacements or reductions of resident container species by Ae. japonicus, as observed elsewhere in its invasive range.

A fatal case of diffuse alveolar hemorrhage complicated by rheumatoid arthritis.

We describe a fatal case of diffuse alveolar hemorrhage (DAH) complicated by rheumatoid arthritis (RA). A female patient was diagnosed with RA two months earlier and was treated with prednisolone and tacrolimus due to abnormalities in chest images. The patient was admitted to Hamanomachi Hospital for exertional dyspnea and was treated for exacerbation of chronic heart failure. Even after treatment for heart failure, exertional dyspnea remained. Chest CT imaging revealed contractile, patchy consolidations and ground-glass opacities (GGO) with a peribronchial distribution, suggesting an organizing pneumonia (OP) pattern. She was then treated with an additional 25 mg/day of prednisolone following a clinical diagnosis of OP. When the prednisolone dose was tapered, chest imaging showed worsening infiltration. A bronchoscopy was conducted, and bronchoalveolar lavage fluid was sanguineous, indicating DAH. Given that additional workup for the other etiology of DAH was negative, DAH was thought to be related to RA. Intensive treatment, including pulse dose methylprednisolone, failed to halt progression of respiratory failure, leading to a fatal outcome. The clinical presentation proved challenging due to its rarity. DAH might be a differential diagnosis in RA patients with consolidations and GGO in chest CT images. We review past cases of RA-associated DAH and assess potential treatment choices for future cases.

Your worst enemy could be your best friend: predator contributions to invasion resistance and persistence of natives.

Native predators are postulated to have an important role in biotic resistance of communities to invasion and community resilience. Effects of predators can be complex, and mechanisms by which predators affect invasion success and impact are understood for only a few well-studied communities. We tested experimentally whether a native predator limits an invasive species' success and impact on a native competitor for a community of aquatic insect larvae in water-filled containers. The native mosquito Aedes triseriatus alone had no significant effect on abundance of the invasive mosquito Aedes albopictus. The native predatory midge Corethrella appendiculata, at low or high density, significantly reduced A. albopictus abundance. This effect was not caused by trait-mediated oviposition avoidance of containers with predators, but instead was a density-mediated effect caused by predator-induced mortality. The presence of this predator significantly reduced survivorship of the native species, but high predator density also significantly increased development rate of the native species when the invader was present, consistent with predator-mediated release from interspecific competition with the invader. Thus, a native predator can indirectly benefit its native prey when a superior competitor invades. This shows the importance of native predators as a component of biodiversity for both biotic resistance to invasion and resilience of a community perturbed by successful invasion.

Diapause influenced oviposition behavior and physical egg hatch cues of Aedes atropalpus (Diptera: Culicidae): traits that may influence successful colonization of riverine rock pools.

Mosquitoes have developed specialized oviposition strategies that allow them to develop in a wide variety of aquatic habitats. Environmentally cued hatching traits may also play an important role in the successful colonization of some larval habitats, but this subject has remained largely unexplored in Culicidae. Aedes atropalpus (Coquillett) is an autogenous rock pool specialist that may maintain unique adaptations for oviposition and egg hatching. We investigated the egg-laying strategies of Ae. atropalpus exposed to standard (non-diapausing) rearing conditions and diapause-inducing conditions and tested the impact of physical agitation on egg hatch rates by exposing floating and submerged eggs to physical agitation treatments. The results of the oviposition experiment indicate that Ae. atropalpus females primarily lay non-diapausing eggs directly onto the water surface and lay diapausing eggs directly on solid surfaces. The egg-hatching experiment demonstrated that physical agitation significantly increases Ae. atropalpus hatch rates. Floating and submerged eggs responded similarly to the agitation treatment. These data suggest that oviposition behaviors based on both egg diapause status and environmentally-cued hatching strategies may be important adaptations for Ae. atropalpus in riverine rock pools.