Nosocomial outbreak of SARS-CoV-2 in a hospital ward during the Omicron variant-dominant wave with a review of the relevant literature.

Clusters of nosocomial coronavirus disease 2019 (COVID-19) were reported globally during the recent pandemic. Unfortunately, these clusters negatively impacted inpatient morbidity, mortality, and hospital functions. Using epidemiological data and whole genome sequencing (WGS) of SARS-CoV-2, the present study investigated an outbreak of COVID-19 at a university hospital. Eight inpatients and 13 healthcare workers tested positive for SARS-CoV-2 during a one-month period. Whole genome sequencing (WGS) of the virus in 11 patients revealed that two variants of concern belonging to the Omicron sublineages, BA.2.3 and BA1.1.2, had caused the outbreak during a time when the proportion of the Omicron lineage in the community was changing. When variants of concern are undergoing mutation, a response to the outbreak should be made with multiple variants in mind, even in the absence of epidemiological data showing close contact or other potential vectors of infection, and awareness about infection prevention and control should be raised to safeguard patient safety.

Identification and characterization of dystrophin-locus-derived testis-specific protein: A testis-specific gene within the intronic region of the rat dystrophin gene.

The mammalian X chromosome exhibits enrichment in genes associated with germ cell development. Previously, we generated a rat model of Becker muscular dystrophy (BMD) characterized by an in-frame mutation in the dystrophin gene, situated on the X chromosome and responsible for encoding a protein crucial for muscle integrity. Male BMD rats are infertile owing to the absence of normal spermatids in the epididymis. Within the seminiferous tubules of BMD rats, elongated spermatids displayed abnormal morphology. To elucidate the cause of infertility, we identified a putative gene containing an open reading frame situated in the intronic region between exons 6 and 7 of the dystrophin gene, specifically deleted in male BMD rats. This identified gene, along with its encoded protein, exhibited specific detection within the testes, exclusively localized in round to elongated spermatids during spermiogenesis. Consequently, we designated the encoded protein as dystrophin-locus-derived testis-specific protein (DTSP). Given the absence of DTSP in the testes of BMD rats, we hypothesized that the loss of DTSP contributes to the infertility observed in male BMD rats.

Myeloid/natural killer (NK) cell precursor acute leukemia as a distinct leukemia type.

Myeloid/natural killer (NK) cell precursor acute leukemia (MNKPL) has been described on the basis of its unique immunophenotype and clinical phenotype. However, there is no consensus on the characteristics for identifying this disease type because of its rarity and lack of defined distinctive molecular characteristics. In this study, multiomics analysis revealed that MNKPL is distinct from acute myeloid leukemia, T cell acute lymphoblastic leukemia, and mixed-phenotype acute leukemia (MPAL), and NOTCH1 and RUNX3 activation and BCL11B down-regulation are hallmarks of MNKPL. Although NK cells have been classically considered to be lymphoid lineage-derived, the results of our single-cell analysis using MNKPL cells suggest that NK cells and myeloid cells share common progenitor cells. Treatment outcomes for MNKPL are unsatisfactory, even when hematopoietic cell transplantation is performed. Multiomics analysis and in vitro drug sensitivity assays revealed increased sensitivity to l-asparaginase and reduced levels of asparagine synthetase (ASNS), supporting the clinically observed effectiveness of l-asparaginase.

Viral load of SARS-CoV-2 Omicron BA.5 is lower than that of BA.2 despite the higher infectivity of BA.5.

BACKGROUND: Sublineage BA.5 of the SARS-CoV-2 Omicron variant rapidly spread and replaced BA.2 in July 2022 in Tokyo. A high viral load can be a possible cause of high transmissibility. METHODS AND RESULTS: The copy numbers of SARS-CoV-2 in nasopharyngeal swab samples obtained from all patients visiting the hospital where this research was conducted were measured using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Viral genotypes were determined using PCR-based melting curve analysis. Next, whole-genome sequencing was performed using approximately one fifth of the samples to verify the viral genotypes determined using PCR. Then, the copy numbers of the BA.1, BA.2, and BA.5 cases were compared. Contrary to expectations, the copy numbers of the BA.5 cases (median 4.7 × 104 copies/µL, n = 291) were significantly (p = .001) lower than those of BA.2 cases (median 1.1 × 105 copies/µL, n = 184). There was no significant difference (p = .44) between the BA.5 and BA.1 cases (median, 3.3 × 104 copies/µL; n = 215). CONCLUSION: The results presented here suggest that the increased infectivity of BA.5 is not caused by higher viral loads, but presumably by other factors such as increased affinity to human cell receptors or immune escape due to its L452R mutation.

Macroglossia and less advanced dystrophic change in the tongue muscle of the Duchenne muscular dystrophy rat.

BACKGROUND: Duchenne muscular dystrophy (DMD) is an X-linked muscle disease caused by a complete lack of dystrophin, which stabilizes the plasma membrane of myofibers. The orofacial function is affected in an advanced stage of DMD and this often leads to an eating disorder such as dysphagia. Dysphagia is caused by multiple etiologies including decreased mastication and swallowing. Therefore, preventing the functional declines of mastication and swallowing in DMD is important to improve the patient's quality of life. In the present study, using a rat model of DMD we generated previously, we performed analyses on the masseter and tongue muscles, both are required for proper eating function. METHODS: Age-related changes of the masseter and tongue muscle of DMD rats were analyzed morphometrically, histologically, and immunohistochemically. Also, transcription of cellular senescent markers, and utrophin (Utrn), a functional analog of dystrophin, was examined. RESULTS: The masseter muscle of DMD rats showed progressive dystrophic changes as observed in their hindlimb muscle, accompanied by increased transcription of p16 and p19. On the other hand, the tongue of DMD rats showed macroglossia due to hypertrophy of myofibers with less dystrophic changes. Proliferative activity was preserved in the satellite cells from the tongue muscle but was perturbed severely in those from the masseter muscle. While Utrn transcription was increased in the masseter muscle of DMD rats compared to WT rats, probably due to a compensatory mechanism, its level in the tongue muscle was comparable between WT and DMD rats and was similar to that in the masseter muscle of DMD rats. CONCLUSIONS: Muscular dystrophy is less advanced in the tongue muscle compared to the masseter muscle in the DMD rat.

In utero transplantation of myoblasts and adipose-derived mesenchymal stem cells to murine models of Duchenne muscular dystrophy does not lead to engraftment and frequently results in fetal death.

Introduction: Duchenne muscular dystrophy (DMD) is a progressive disease that leads to damage of muscle and myocardium due to genetic abnormalities in the dystrophin gene. In utero cell transplantation that might facilitate allogenic transplantation is worth considering to treat this disease. Methods: We performed allogeneic in utero transplantation of GFP-positive myoblasts and adipose-derived mesenchymal stem cells into murine DMD model animals. The transplantation route in this study was fetal intraperitoneal transplantation and transplacental transplantation. Transplanted animals were examined at 4-weeks old by immunofluorescence staining and RT-qPCR. Results: No GFP-positive cells were found by immunofluorescence staining of skeletal muscle and no GFP mRNA was detected by RT-qPCR in any animal, transplantation method and cell type. Compared with previous reports, myoblast transplantation exhibited an equivalent mortality rate, but adipose-derived stem cell (ASC) transplantation produced a higher mortality rate. Conclusions: In utero transplantation of myoblasts or ASCs to murine models of DMD does not lead to engraftment and, in ASC transplantation primarily, frequently results in fetal death.

Human metapneumovirus M2-2 protein inhibits RIG-I signaling by preventing TRIM25-mediated RIG-I ubiquitination.

Retinoic acid-inducible gene I (RIG-I) is a receptor that senses viral RNA and interacts with mitochondrial antiviral signaling (MAVS) protein, leading to the production of type I interferons and inflammatory cytokines to establish an antiviral state. This signaling axis is initiated by the K63-linked RIG-I ubiquitination, mediated by E3 ubiquitin ligases such as TRIM25. However, many viruses, including several members of the family Paramyxoviridae and human respiratory syncytial virus (HRSV), a member of the family Pneumoviridae, escape the immune system by targeting RIG-I/TRIM25 signaling. In this study, we screened human metapneumovirus (HMPV) open reading frames (ORFs) for their ability to block RIG-I signaling reconstituted in HEK293T cells by transfection with TRIM25 and RIG-I CARD (an N-terminal CARD domain that is constitutively active in RIG-I signaling). HMPV M2-2 was the most potent inhibitor of RIG-I/TRIM25-mediated interferon (IFN)-ß activation. M2-2 silencing induced the activation of transcription factors (IRF and NF-kB) downstream of RIG-I signaling in A549 cells. Moreover, M2-2 inhibited RIG-I ubiquitination and CARD-dependent interactions with MAVS. Immunoprecipitation revealed that M2-2 forms a stable complex with RIG-I CARD/TRIM25 via direct interaction with the SPRY domain of TRIM25. Similarly, HRSV NS1 also formed a stable complex with RIG-I CARD/TRIM25 and inhibited RIG-I ubiquitination. Notably, the inhibitory actions of HMPV M2-2 and HRSV NS1 are similar to those of V proteins of several members of the Paramyxoviridae family. In this study, we have identified a novel mechanism of immune escape by HMPV, similar to that of Pneumoviridae and Paramyxoviridae family members.

Potential role of HTLV-1 Tax-specific cytotoxic t lymphocytes expressing a unique t-cell receptor to promote inflammation of the central nervous system in myelopathy associated with HTLV-1.

Human T-lymphotropic virus 1 (HTLV-1) infection causes two serious diseases: adult T-cell leukemia/lymphoma (ATL) and HTLV-1-associated myelopathy (HAM). Immunological studies have revealed that HTLV-1 Tax-specific CD8+ cytotoxic T-cells (Tax-CTLs) in asymptomatic carriers (ACs) and ATL patients play an important role in the elimination of HTLV-1-infected host cells, whereas Tax-CTLs in HAM patients trigger an excessive immune response against HTLV-1-infected host cells infiltrating the central nervous system (CNS), leading to local inflammation. Our previous evaluation of HTLV-1 Tax301-309 (SFHSLHLLF)-specific Tax-CTLs (Tax301-309-CTLs) revealed that a unique T-cell receptor (TCR) containing amino acid (AA)-sequence motif PDR, was shared among HLA-A*24:02+ ACs and ATL patients and behaved as an eliminator by strong activity against HTLV-1. However, it remains unclear whether PDR+Tax301-309-CTLs also exist in HLA-A*24:02+ HAM patients and are involved in the pathogenesis of HAM. In the present study, by high-throughput TCR repertoire analysis technology, we revealed TCR repertoires of Tax301-309-CTLs in peripheral blood (PB) of HLA-A*24:02+ HAM patients were skewed, and a unique TCR-motif PDR was conserved in HAM patients (10 of 11 cases). The remaining case dominantly expressed (-DR, P-R, and PD-), which differed by one AA from PDR. Overall, TCRs with unique AA-sequence motifs PDR, or (-DR, P-R, and PD-) accounted for a total of 0.3-98.1% of Tax301-309-CTLs repertoires of HLA-A*24:02+ HAM patients. Moreover, TCR repertoire analysis of T-cells in the cerebrospinal fluid (CSF) from four HAM patients demonstrated the possibility that PDR+Tax301-309-CTLs and (-DR, P-R, and PD-)+Tax301-309-CTLs efficiently migrated and accumulated in the CSF of HAM patients fostering increased inflammation, although we observed no clear significant correlation between the frequencies of them in PB and the levels of CSF neopterin, a known disease activity biomarker of HAM. Furthermore, to better understand the potential function of PDR+Tax301-309-CTLs, we performed immune profiling by single-cell RNA-sequencing of Tax301-309-CTLs, and the result showed that PDR+Tax301-309-CTLs up-regulated the gene expression of natural killer cell marker KLRB1 (CD161), which may be associated with T-cell activation and highly cytotoxic potential of memory T-cells. These findings indicated that unique and shared PDR+Tax301-309-CTLs have a potential role in promoting local inflammation within the CNS of HAM patients.

Viral load of SARS-CoV-2 Omicron is not high despite its high infectivity.

Patients infected with the Omicron variant of severe acute respiratory syndrome coronavirus 2 has increased worldwide since the beginning of 2022 and the variant has spread more rapidly than the Delta variant, which spread in the summer of 2021. It is important to clarify the cause of the strong transmissibility of the Omicron variant to control its spread. In 694 patients with coronavirus disease 2019, the copy numbers of virus in nasopharyngeal swab-soaked samples and the viral genotypes were examined using quantitative polymerase chain reaction (PCR) and PCR-based melting curve analysis, respectively. Whole-genome sequencing was also performed to verify the viral genotyping data. There was no significant difference (p = 0.052) in the copy numbers between the Delta variant cases (median 1.5 × 105 copies/µl, n = 174) and Omicron variant cases (median 1.2 × 105 copies/µl, n = 328). During this study, Omicron BA.1 cases (median 1.1 ×105 copies/µl, n = 275) began to be replaced by BA.2 cases (median 2.3 × 105 copies/µl, n = 53), and there was no significant difference between the two groups (p = 0.33). Our results suggest that increased infectivity of the Omicron variant and its derivative BA.2 is not caused by higher viral loads but by other factors, such as increased affinity to cell receptors or immune escape.

SeV C Protein Plays a Role in Restricting Macrophage Phagocytosis by Limiting the Generation of Intracellular Double-Stranded RNA.

Macrophages play a central role in the innate immune response to respiratory viral infections through pro-inflammatory factor secretion and phagocytosis. However, as a countermeasure, viral pathogens have evolved virulence factors to antagonize macrophage function. In our recent in vitro analyses of murine macrophage cell lines, Sendai virus (SeV) accessory protein C inhibited the secretion of pro-inflammatory factors, and C gene-knockout SeV (SeVΔC) caused drastic morphological changes in RAW264.7 macrophages, similar to those observed after stimulation with Lipid A, a well-known activator of actin-rich membrane ruffle formation and phagocytosis. Hence, we sought to determine whether the C protein limits phagocytosis in SeV-infected macrophages through the suppression of membrane ruffling. Phagocytosis assays indicated an upregulation of phagocytosis in both SeVΔC-infected and Lipid A-stimulated macrophages, but not in SeV WT-infected cells. Further, the observed membrane ruffling was associated with phagocytosis. RIG-I is essential for Lipid A-induced phagocytosis; its deficiency inhibited SeVΔC-stimulated phagocytosis and ruffling, confirming the essential role of RIG-I. Moreover, treatment with interferon (IFN)-ß stimulation and neutralizing antibodies against IFN-ß suggested that SeVΔC-induced phagocytosis and ruffling occurred in an IFN-ß-independent manner. A newly isolated SeVΔC strain that does not generate dsRNA further highlighted the importance of dsRNA in the induction of phagocytosis and ruffling. Taken together, the current results suggest that SeV C protein might limit phagocytosis-associated membrane ruffling in an RIG-I-mediated but IFN-independent manner via limiting the generation of intracellular dsRNA.

Sendai virus C protein affects macrophage function, which plays a critical role in modulating disease severity during Sendai virus infection in mice.

Sendai virus (SeV) accessory protein C limits the generation of double-stranded RNAs, defective interfering RNAs, or both, during viral transcription and replication, thereby limiting interferon-ß production. Our recent in vitro analyses on murine macrophage cell lines demonstrated that this protein also contributes to restricting macrophage function, including the production of nitric oxide (NO) and inflammatory cytokines in addition to interferon-ß, in infected macrophages. This study showed that depletion of airway macrophages by clodronate-loaded liposomes led to the development of severe viral pneumonia in recombinant C gene-knockout SeV (SeV∆C)-infected mice, but did not modulate disease severity in wild-type SeV-infected mice. Furthermore, the severe disease observed in macrophage-depleted, SeV∆C-infected mice was associated with exacerbated virus replication in the lungs, leading to severe airway inflammation and pulmonary edema, indicating lung injury. These results suggested that the antimacrophage activity of SeV C protein might play a critical role in modulating lung injury and associated diseases caused by SeV.

Preclinical bioequivalence study of E.coli-derived rhBMP-2/ß-TCP and autogenous bone in a canine guided-bone regeneration model.

PURPOSE: Bone morphogenetic protein (BMP)-2 is a potent growth factor that is widely used in the orthopedic and dental fields for bone regeneration. However, recombinant human BMP-2 (rhBMP-2) products have not been legally approved in Japan. Recently, our research group succeeded in producing GMP-grade rhBMP-2 using the E. coli system (E-rhBMP-2) at the industrial level and developed E-rhBMP-2 adsorbed onto ß-TCP (E-rhBMP-2/ß-TCP) as an alternative material to autogenous bone grafts. Previous studies on the toxicity, pharmacokinetics, and optimal doses of E-rhBMP-2 have confirmed its safety and efficiency. However, comparative studies with standard treatment therapies are still necessary before clinical application in humans. Therefore, in this preclinical study, we compared the bone regeneration ability of E-rhBMP-2/ß-TCP and autogenous bone grafts in a canine guided-bone regeneration model. METHODS: Following extraction of the maxillary third premolar, box-type bone defects (10 mmL × 4 mmW × 9 mmH) were created in the extraction socket area and transplanted with E-rhBMP-2/ß-TCP or autogenous bone graft in a canine. After 8 weeks, micro-CT and histological analyses were performed. RESULTS: Transplantation of both E-rhBMP-2/ß-TCP and autogenous bone graft significantly promoted bone formation compared to the non-transplantation control group. The bone formation ability of E-rhBMP-2/ß-TCP was equal to that of the autogenous bone graft. Histological analysis showed that excessive infiltration of inflammatory cells and residual ß-TCP particles mostly were not observed in the E-rhBMP-2/ß-TCP transplantation group. CONCLUSION: This preclinical study demonstrated that E-rhBMP-2/ß-TCP and autogenous bone have equal potential to promote bone regeneration.

Viral loads and profile of the patients infected with SARS-CoV-2 Delta, Alpha, or R.1 variants in Tokyo.

The rapid spread of the Delta variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) became a serious concern worldwide in summer 2021. We examined the copy number and variant types of all SARS-CoV-2-positive patients who visited our hospital from February to August 2021 using polymerase chain reaction (PCR) tests. Whole genome sequencing was performed for some samples. The R.1 variant (B.1.1.316) was responsible for most infections in March, replacing the previous variant (B.1.1.214); the Alpha (B.1.1.7) variant caused most infections in April and May; and the Delta variant (B.1.617.2) was the most prevalent in July and August. There was no significant difference in the copy numbers among the previous variant cases (n = 29, median 3.0 × 104 copies/µl), R.1 variant cases (n = 28, 2.1 × 105 copies/µl), Alpha variant cases (n = 125, 4.1 × 105 copies/µl), and Delta variant cases (n = 106, 2.4 × 105 copies/µl). Patients with Delta variant infection were significantly younger than those infected with R.1 and the previous variants, possibly because many elderly individuals in Tokyo were vaccinated between May and August. There was no significant difference in mortality among the four groups. Our results suggest that the increased infectivity of Delta variant may be caused by factors other than the higher viral loads. Clarifying these factors is important to control the spread of Delta variant infection.

Arterial and Venous Thrombosis Complicated in COVID-19: A Retrospective Single Center Analysis in Japan.

Background: Thrombosis is a characteristic complication in coronavirus disease 2019 (COVID-19). Since coagulopathy has been observed over the entire clinical course, thrombosis might be a clue to understanding the specific pathology in COVID-19. Currently, there is limited epidemiological data of COVID-19-associated thrombosis in the Japanese population and none regarding variant strains of SARS-CoV-2. Here, we elucidate the risk factors and the pattern of thrombosis in COVID-19 patients. Methods: The patients consecutively admitted to Tokyo Medical and Dental University Hospital with COVID-19 were retrospectively analyzed. SARS-CoV-2 variants of concern/interest (VOC/VOI) carrying the spike protein mutants E484K, N501Y, or L452R were identified by PCR-based analysis. All thrombotic events were diagnosed by clinical symptoms, ultrasonography, and/or radiological tests. Results: Among the 516 patients, 32 patients experienced 42 thromboembolic events. Advanced age, severe respiratory conditions, and several abnormal laboratory markers were associated with the development of thrombosis. While thrombotic events occurred in 13% of the patients with a severe respiratory condition, those events still occurred in 2.5% of the patients who did not require oxygen therapy. Elevated D-dimer and ferritin levels on admission were independent risk factors of thrombosis (adjusted odds ratio 9.39 and 3.11, 95% confidence interval 2.08-42.3, and 1.06-9.17, respectively). Of the thrombotic events, 22 were venous, whereas 20 were arterial. While patients with thrombosis received anticoagulation and antiinflammatory therapies with a higher proportion, the mortality rate, organ dysfunctions, and bleeding complications in these patients were higher than those without thrombosis. The incidence of thrombosis in COVID-19 became less frequent over time, such as during the replacement of the earlier strains of SARS-CoV-2 by VOC/VOI and during increased use of anticoagulatory therapeutics. Conclusion: This study elucidated that elevated D-dimer and ferritin levels are useful biomarkers of thrombosis in COVID-19 patients. The comparable incidence of arterial thrombosis with venous thrombosis and the development of thrombosis in less severe patients required further considerations for the management of Japanese patients with COVID-19. Further studies would be required to identify high-risk populations and establish appropriate interventions for thrombotic complications in COVID-19.

Sitafloxacin reduces tumor necrosis factor alpha (TNFα) converting enzyme (TACE) phosphorylation and activity to inhibit TNFα release from lipopolysaccharide-stimulated THP-1 cells.

Sepsis is a systemic reaction to an infection and resulting in excessive production of inflammatory cytokines and chemokines. It sometimes results in septic shock. The present study aimed to identify quinolone antibiotics that can reduce tumor necrosis factor alpha (TNFα) production and to elucidate mechanisms underlying inhibition of TNFα production. We identified quinolone antibiotics reduced TNFα production in lipopolysaccharide (LPS)-stimulated THP-1 cells. Sitafloxacin (STFX) is a broad-spectrum antibiotic of the quinolone class. STFX effectively suppressed TNFα production in LPS-stimulated THP-1 cells in a dose-dependent manner and increased extracellular signal-regulated kinase (ERK) phosphorylation. The percentage of intracellular TNFα increased in LPS-stimulated cells with STFX compared with that in LPS-stimulated cells. TNFα converting enzyme (TACE) released TNFα from the cells, and STFX suppressed TACE phosphorylation and activity. To conclude, one of the mechanisms underlying inhibition of TNFα production in LPS-stimulated THP-1 cells treated with STFX is the inhibition of TNFα release from cells via the suppression of TACE phosphorylation and activity. STFX may kill bacteria and suppress inflammation. Therefore, it can be effective for sepsis treatment.

Suppression of Bone Necrosis around Tooth Extraction Socket in a MRONJ-like Mouse Model by E-rhBMP-2 Containing Artificial Bone Graft Administration.

Medication-related osteonecrosis of the jaw (MRONJ) is related to impaired bone healing conditions in the maxillomandibular bone region as a complication of bisphosphonate intake. Although there are several hypotheses for the onset of MRONJ symptoms, one of the possible causes is the inhibition of bone turnover and blood supply leading to bone necrosis. The optimal treatment strategy for MRONJ has not been established either. BMP-2, a member of the TGF-ß superfamily, is well known for regulating bone remodeling and homeostasis prenatally and postnatally. Therefore, the objectives of this study were to evaluate whether cyclophosphamide/zoledronate (CY/ZA) induces necrosis of the bone surrounding the tooth extraction socket, and to examine the therapeutic potential of BMP-2 in combination with the hard osteoinductive biomaterial, ß-tricalcium phosphate (ß-TCP), in the prevention and treatment of alveolar bone loss around the tooth extraction socket in MRONJ-like mice models. First, CY/ZA was intraperitoneally administered for three weeks, and alveolar bone necrosis was evaluated before and after tooth extraction. Next, the effect of BMP-2/ß-TCP was investigated in both MRONJ-like prevention and treatment models. In the prevention model, CY/ZA was continuously administered for four weeks after BMP-2/ß-TCP transplantation. In the treatment model, CY/ZA administration was suspended after transplantation of BMP-2/ß-TCP. The results showed that CY/ZA induced a significant decrease in the number of empty lacunae, a sign of bone necrosis, in the alveolar bone around the tooth extraction socket after tooth extraction. Histological analysis showed a significant decrease in the necrotic alveolar bone around tooth extraction sockets in the BMP-2/ß-TCP transplantation group compared to the non-transplanted control group in both MRONJ-like prevention and treatment models. However, bone mineral density, determined by micro-CT analysis, was significantly higher in the BMP-2/ß-TCP transplanted group than in the control group in the prevention model only. These results clarified that alveolar bone necrosis around tooth extraction sockets can be induced after surgical intervention under CY/ZA administration. In addition, transplantation of BMP-2/ß-TCP reduced the necrotic alveolar bone around the tooth extraction socket. Therefore, a combination of BMP-2/ß-TCP could be an alternative approach for both prevention and treatment of MRONJ-like symptoms.

SARS-CoV-2 R.1 lineage variants that prevailed in Tokyo in March 2021.

The spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants, such as B.1.1.7 and B.1.351, has become a crucial issue worldwide. Therefore, we began testing all patients with COVID-19 for the N501Y and E484K mutations by using polymerase chain reaction (PCR)-based methods. Nasopharyngeal swab samples from 108 patients who visited our hospital between February and April 2021 were analyzed. The samples were analyzed using reverse transcription-PCR with melting curve analysis to detect the N501Y and E484K mutations. A part of the samples was also subjected to whole-genome sequencing (WGS). Clinical parameters such as mortality and admission to the intensive care unit were analyzed to examine the association between increased disease severity and the E484K mutation. The ratio of cases showing the 501N + 484K mutation rapidly increased from 8% in February to 46% in March. WGS revealed that the viruses with 501N + 484K mutation are R.1 lineage variants. Evidence of increased disease severity related to the R.1 variants was not found. We found that the R.1 lineage variants rapidly prevailed in Tokyo in March 2021, which suggests the increased transmissibility of R.1 variants, while they showed no increased severity.

Comparison of physiological functions between neuromedin U-related peptide and neuromedin S-related peptide in the rat central nervous system.

Two novel peptides, neuromedin U precursor-related peptide (NURP) and neuromedin S precursor-related peptide (NSRP), are produced from neuromedin U (NMU) and neuromedin S (NMS) precursors, respectively, as these precursors have multiple consensus sequences for proteolytic processing. Our group has shown previously that one of these two novel peptides, NURP, stimulates body temperature and locomotor activity, but not food intake. However, the physiological function of the other peptide, NSRP, has remained unclear. Therefore, the aim of this study was to characterize differences in the regions of the rat brain targeted by the NMU/NMS peptide family, including NURP and NSRP, and their physiological functions. First, we explored the regions of c-Fos expression after intracerebroventricular (i.c.v.) injection of NURP and NSRP and found that these were fewer than after i.c.v. injection of NMU and NMS in the hypothalamus, possibly because NURP and NSRP cannot activate NMU/NMS receptors. In the ventral subiculum, which is one region of the hippocampus, c-Fos expression was evident only after i.c.v. injection of NURP. We also examined the effects of NSRP on food intake, body temperature and locomotor activity. Like NURP, NSRP increased both body temperature and locomotor activity, but not food intake, indicating that NSRP is also a functional peptide. However, these effects of NSRP were distinctly weaker than those of NURP. These findings suggest differences in the affinity of NURP and/or NSRP for specific receptors, or in their respective biological activities.

Distinct Osteogenic Potentials of BMP-2 and FGF-2 in Extramedullary and Medullary Microenvironments.

Bone morphogenetic protein-2 (BMP-2) and fibroblast growth factor-2 (FGF-2) have been regarded as the major cytokines promoting bone formation, however, several studies have reported unexpected results with failure of bone formation or bone resorption of these growth factors. In this study, BMP-2 and FGF-2 adsorbed into atellocollagen sponges were transplanted into bone defects in the bone marrow-scarce calvaria (extramedullary environment) and bone marrow-abundant femur (medullary environment) for analysis of their in vivo effects not only on osteoblasts, osteoclasts but also on bone marrow cells. The results showed that BMP-2 induced high bone formation in the bone marrow-scarce calvaria, but induced bone resorption in the bone marrow-abundant femurs. On the other hand, FGF-2 showed opposite effects compared to those of BMP-2. Analysis of cellular dynamics revealed numerous osteoblasts and osteoclasts present in the newly-formed bone induced by BMP-2 in calvaria, but none were seen in either control or FGF-2-transplanted groups. On the other hand, in the femur, numerous osteoclasts were observed in the vicinity of the BMP-2 pellet, while a great number of osteoblasts were seen near the FGF-2 pellets or in the control group. Of note, FCM analysis showed that both BMP-2 and FGF-2 administrated in the femur did not significantly affect the hematopoietic cell population, indicating a relatively safe application of the two growth factors. Together, these results indicate that BMP-2 could be suitable for application in extramedullary bone regeneration, whereas FGF-2 could be suitable for application in medullary bone regeneration.

Development of a Unique T Cell Receptor Gene-Transferred Tax-Redirected T Cell Immunotherapy for Adult T Cell Leukemia.

Adult T cell leukemia/lymphoma (ATL) is an aggressive peripheral T cell neoplasm caused by infection with human T cell lymphotropic virus type-1 (HTLV-1). Its prognosis remains extremely poor. Tax, the most important regulatory protein for HTLV-1, is associated with the aggressive proliferation of host cells and is also a major target antigen for CD8+ cytotoxic T cells (CTLs). Based on our previous findings that Tax-specific CTLs with a T cell receptor (TCR) containing a unique amino-acid sequence motif exhibit strong HLA-A*24:02-restricted, Tax301-309-specific activity against HTLV-1, we aimed to develop a Tax-redirected T cell immunotherapy for ATL. TCR-ɑ/ß genes were cloned from a previously established CTL clone and transduced into peripheral blood mononuclear cells (PBMCs) of healthy volunteers using a retroviral siTCR vector. Then the cytotoxic efficacy against HTLV-1-infected T cells or primary ATL cells was assessed both in vitro and in vivo. The redirected CTLs (Tax-siCTLs) produced a large amount of cytokines and showed strong killing activity against ATL/HTLV-1-infected T cells in vitro, although they did not have universal activity against ATL cells. Next, in a xenograft mouse model using an HTLV-1-infected T cell line (MT-2), in all mice treated with Tax-siCTLs, the tumor rapidly diminished and finally disappeared without normal tissue damage, although all mice that were untreated or treated with non-gene-modified PBMCs died because of tumor progression. Our findings confirm that Tax-siCTLs can exert strong anti-ATL/HTLV-1 effects without a significant reaction against normal cells and have the potential to be a novel immunotherapy for ATL patients.