Search

Abstract The objective of this study was to evaluate the intramammary distribution of MRI-detected mass and focus lesions that were difficult to identify with conventional B-mode ultrasound (US) alone. Consecutive patients with lesions detected with MRI but not second-look conventional B-mode US were enrolled between May 2015 and June 2023. Following an additional supine MRI examination, we performed third-look US using real-time virtual sonography (RVS), an MRI/US image fusion technique. We divided the distribution of MRI-detected mammary gland lesions as follows: center of the mammary gland versus other (superficial fascia, deep fascia, and atrophic mammary gland). We were able to detect 27 (84%) of 32 MRI-detected lesions using third-look US with RVS. Of these 27 lesions, 5 (19%) were in the center of the mammary gland and 22 (81%) were located in other areas. We were able to biopsy all 27 lesions; 8 (30%) were malignant and 19 (70%) were benign. Histopathologically, three malignant lesions were invasive ductal carcinoma (IDC; luminal A), one was IDC (luminal B), and four were ductal carcinoma in situ (low-grade). Malignant lesions were found in all areas. During this study period, 132 MRI-detected lesions were identified and 43 (33%) were located in the center of the mammary gland and 87 (64%) were in other areas. Also, we were able to detect 105 of 137 MRI-detected lesions by second-look conventional-B mode US and 38 (36%) were located in the center of the mammary gland and 67 (64%) were in other areas. In this study, 81% of the lesions identified using third-look US with RVS and 64% lesions detected by second-look conventional-B mode US were located outside the center of the mammary gland. We consider that adequate attention should be paid to the whole mammary gland when we perform third-look US using MRI/US fusion technique.

Background: Nonepisodic angioedema with eosinophilia (NEAE) is a condition marked by angioedema and significant eosinophilia and often linked with atopic dermatitis. It predominantly affects young Asian women and occurs more frequently in the autumn and winter. Despite over 100 reported cases, its etiology and pathogenesis remain unclear. Case presentation: A 23-year-old Japanese female florist presented with acute arm swelling following rose-thorn pricks to her hands and fingers in spring. One week later, she developed progressive symmetrical non-pitting edema in her lower legs and a 3 kg weight gain without any rash. She had a history of oral allergy syndrome to apples and pears for which allergen-specific IgE were previously detected. Blood tests showed significant eosinophilia (14,930 cells/μL) and elevated thymus and activation-regulated chemokine (TARC) levels (12,864 pg/mL). Thyroid disease, autoimmune disorders, and hematologic malignancies were ruled out. Normal cardiac markers and a whole-body computed tomography excluded visceral organ involvement. She was diagnosed with NEAE and treated with oral prednisolone, which resolved the edema within 10 days. Prednisolone was tapered gradually on an outpatient basis without recurrence. Conclusion: A review of the literature indicates that NEAE triggered by subcutaneous antigen exposure may not follow the typical age or seasonal patterns. Direct subcutaneous antigen exposure, including rose-thorn pricks, can trigger NEAE. Clinicians should consider NEAE in atypical presentations and thoroughly investigate preceding episodes.

The B20 type chiral magnet FeGe exhibits the formation of skyrmion-lattice (SkL) phases in the vicinity of the magnetic ordering temperature. The SkL is a magnetic superlattice composed of vortex-type topological spin objects, and it has experimentally been known that its formation requires the existence of an intermediate (IM) phase between SkL and the paramagnetic (PM) phases. We take interest in how the crystal lattice experiences the formation of these topological spin texture. In this study, we observed the so-called spin–orbit coupling induced magnetostriction related to these topological spin texture formation, in addition to the ac magnetization anomalies. The temperature and magnetic field dependences of the lattice parameter reflected the transformation of phases, such as helimagnetic (HM), SkL, IM, conical (CM), and PM phases. In the PM region, a phase characterized as gaseous skyrmions was detected similarly to the case of the same B20 type MnSi. Furthermore, the HM, CM, and IM phases were also divided into two regions. Thus, the precise phase diagram near T c was reconstructed from the prospect of the magnetostriction such that we demonstrated that the stabilization of skyrmions needs a finite magnetic field. [ABSTRACT FROM AUTHOR]

Objectives: Pharyngeal follicles similar to those seen in influenza have been observed in patients with coronavirus disease 2019 (COVID-19), suggesting their potential as early-stage diagnostic markers. In this study, we examined the diagnostic potential of pharyngeal follicles for COVID-19, particularly the Omicron variant and its subtypes, to obtain basic data for AI-based diagnostic imaging tools. Methods: A cross-sectional study was conducted from July 21, 2022, to March 31, 2023, at the Tokyo Shinagawa Hospital's fever clinic. Participants aged ≥15 years who underwent real-time polymerase chain reaction testing for COVID-19 and pharyngeal examinations were included. Demographic details, symptom onset, throat pain, and vaccination status were also recorded. Pharyngeal structures were categorized into four groups: follicles, buds, mixed, or absent. Results: Of the 1223 participants, 829 (67.8%) tested positive for COVID-19. Among those who tested positive, 73.6% (95% CI: 70.6%-76.6%) had follicular structures, compared to 52.8% (95% CI: 47.9%-57.7%) of those who tested negative (P = 1.0 × 10−12). Overall, 818 participants exhibited follicular structures (439 with follicles, 281 with buds, and 98 with mixed structures), while 405 lacked any follicular structures. Regression analysis identified throat pain and follicular structures as significant COVID-19 predictors (95% confidence intervals: 2.49-4.85 and 1.43-2.59, respectively). Mixed follicles were identified as a potentially characteristic feature of COVID-19. Conclusion: Pharyngeal follicular structures demonstrated high sensitivity for early COVID-19 diagnosis.

Abstract Background and Aim Increased liver fibrosis scores (LFS), such as fibrosis‐4 index (FIB‐4) or non‐alcoholic fatty liver disease fibrosis score (NFS), and fatty liver are known risk factors for severe coronavirus disease 2019 (COVID‐19). The purpose of this study was to identify the best scores, which predict the prognosis of COVID‐19. Methods Participants comprised consecutive Japanese COVID‐19 patients admitted to our hospital between February 14, 2020, and April 14, 2021. Multivariate logistic regression analysis was performed to evaluate the relationships between LFS (FIB‐4, NFS, aspartate aminotransferase‐to‐platelet ratio index [APRI], BARD score, and hepatic steatosis index [HSI]) or fatty liver on computed tomography (CT), and severity of COVID‐19. Results Of the 415 patients (mean age, 59 years), 177 patients (42.7%) needed oxygen therapy, 90 patients (21.7%) worsened to severe COVID‐19, and 45 patients (10.8%) died during admission. Multivariate logistic regression analysis showed that increased FIB‐4 and NFS were risk factors for death, severe COVID‐19, and oxygen demand; that increased BARD was a risk factor for severe COVID‐19 and oxygen demand; and that increased APRI and HSI were not risk factors for any status of COVID‐19. Furthermore, increased NFS or BARD and fatty liver were independent risk factors for severe COVID‐19 and oxygen demand. Conclusions This study showed that FIB‐4 and NFS were the best liver fibrosis scores that predicted worse prognosis for COVID‐19, and that increased NFS or BARD and fatty liver evident on CT represented independent risk factors for severe COVID‐19 and oxygen demand.

Background: Our investigation focused whether infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) before or after receiving the mRNA COVID-19 vaccine can increase immune protection. And we also investigated relationship of infection acquired. Methods: Three shots of the mRNA coronavirus disease 2019 (COVID-19) vaccine BNT162b2 were administered to 736 healthcare workers at Tokyo Shinagawa Hospital. Serum samples were collected before the first shot (P1), at one month (P2), and at six months (P3) after the second shot and at one month after the third shot (P4). The presence of infection was assessed using IgG against the nucleocapsid (IgG (N) and RBD in the spike protein of SARS-CoV-2. We defined infection before P2 as natural infection (NI) and infection between P2 and P3 as breakthrough infection (BI) and compared susceptibility to further infection between the NI (−) and NI (+) groups and between BI (−) and BI (+) groups. Events in 485 participants who had a complete dataset of IgG (N) and IgG (RBD) from P1 to P4 were analyzed. Results: The presence of SARS-CoV-2 infection before P2 were examined by examining the titers of IgG (N)P1, IgG (N) P2, and IgG (RBD) P1 that exceeded the cutoff values. Consequently, 35 participants (7.22 %) were categorized into the NI (+) group, whereas 450 (92.8 %) were categorized into the NI (−) group. Between P2 and P3, the NI (−) group showed a higher rate of SARS-CoV-2 infection than the NI (+) group; however, there was no significant difference in the infection rate between P3 and P4. The infection rate was significantly lower in the BI (+) group than in the BI (−) group. Pre-primary vaccination infection significantly increased IgG (RBD) levels between P1 and P3. Post-primary vaccination infection significantly increased IgG (RBD) levels between P3 and P4. Conclusions: Infection with SARS-CoV-2 before or after receiving the mRNA COVID-19 vaccine can increase immune protection; however, the duration of this effect may be limited.

Subclinical hyperthyroidism (SHyper) is defined as normal levels of free thyroxine (fT4) and free triiodothyronine (fT3) with suppressed levels of TSH. Previous studies have reported the individual pathophysiology of endogenous SHyper patients and athyreotic patients receiving TSH suppression therapy with levothyroxine; however, apparently no studies have compared the two conditions. Five-hundred-forty untreated endogenous SHyper patients and 1,024 patients receiving TSH suppression therapy who underwent total thyroidectomy for papillary thyroid carcinoma were sampled. Thyroid hormone profiles and peripheral indices related to thyrotoxicosis were investigated in endogenous SHyper patients, athyreotic patients receiving TSH suppression therapy, and healthy participants. Endogenous SHyper patients showed significantly higher thyroid hormone levels (fT4 [p < 0.001] and fT3 [p < 0.001]), and peripheral indices showed a significant tendency towards thyrotoxicosis (strong TSH suppression: alkaline phosphatase [ALP, p < 0.001], creatinine [Cre, p < 0.001], pulse rate [p < 0.05]; and mild TSH suppression: Cre [p < 0.05]) than healthy participants. In contrast, athyreotic patients receiving TSH suppression therapy showed a significant tendency towards thyrotoxicosis than healthy participants only when TSH was strongly suppressed (fT3 [p < 0.001] and Cre [p < 0.001]). Endogenous SHyper patients showed significantly higher fT3 levels (p < 0.001) than athyreotic patients receiving TSH suppression therapy; however, there was a significant tendency towards thyrotoxicosis only when TSH was strongly suppressed (ALP [p < 0.05] and pulse rate [p < 0.05]). The effects of endogenous SHyper and TSH suppression therapy on target organ function are different. Although the serum thyroid hormone profile is similar to that of the thyrotoxic state, athyreotic patients receiving TSH suppression therapy with mildly suppressed serum TSH levels are not thyrotoxic.

This paper proposes a novel algorithm to accurately calculate the coordinates of homoclinic points observed in discrete-time dynamical systems. The proposed method is based on the particle swarm optimization method. Compared with the current methods, the proposed methodology has the advantages of not requiring the careful selection of the initial conditions and not requiring information related to the derivative of the objective function. It is shown that the proposed method can successfully obtain the homoclinic points of a system, even if the system parameters are close to those that describe the homoclinic bifurcation sets of the system; this is achieved via the construction of an efficient objective function that depends on the Euclidean distance between the points in each manifold. We apply the developed method to two- and three-dimensional discrete-time dynamical systems and demonstrate the validity of the algorithm via the numerical work. The reliability of the proposed algorithm was achieved by evaluating a metric based on the success rate of the method.

Abstract Aim The aim of this study was to investigate genetic alterations within breast cancer in the setting of recurrent or de novo stage IV disease. Patients and methods : This study included 22 patients with recurrent breast cancer (n = 19) and inoperable de novo stage IV breast cancer (n = 3). For next generation sequencing, FoundationOneCDx (F1CDx) (Foundation Medicine Inc., Cambridge, MA, USA) was performed in 21 patients and FoundationOneLiquid CDx was performed in 1 patient. Results Median age was 62.9 years (range, 33.4–82.1). Pathological diagnoses of specimens included invasive ductal carcinoma (n = 19), invasive lobular carcinoma (n = 2), and invasive micropapillary carcinoma (n = 1). F1CDx detected a median of 4.5 variants (range, 1–11). The most commonly altered gene were PIK3CA (n = 9), followed by TP53 (n = 7), MYC (n = 4), PTEN (n = 3), and CDH1 (n = 3). For hormone receptor-positive patients with PIK3CA mutations, hormonal treatment plus a phosphoinositide 3-kinase inhibitor was recommended as the treatment of choice. Patients in the hormone receptor-negative and no human epidermal growth factor receptor 2 expression group had significantly higher tumor mutational burden than patients in the hormone receptor-positive group. A BRCA2 reversion mutation was revealed by F1CDx in a patient with a deleterious germline BRCA2 mutation during poly ADP ribose polymerase inhibitor treatment. Conclusion Guidance on tailored precision therapy with consideration of genomic mutations was possible for some patients with information provided by F1CDx. Clinicians should consider using F1CDx at turning points in the course of the disease.

Abstract Low-temperature neutron diffraction experiments at $$P= 8$$ P = 8 GPa have been conducted to investigate the magnetic structures of metallic Holmium at high pressures by employing a long d-spacing high-flux diffractometer and a Paris-Edinburgh press cell inside a cryostat. We find that at $$P=8$$ P = 8 GPa and $$T=5$$ T = 5 K, no nuclear symmetry change is observed, keeping therefore the hexagonal closed packed (hcp) symmetry at high pressure. Our neutron diffraction data confirm that the ferromagnetic state does not exist. The magnetic structure corresponding to the helimagnetic order, which survives down to 5 K, is fully described by the magnetic superspace group formalism. These results are consistent with those previously published using magnetization experiments.

Abstract Background Invasive lobular carcinoma (ILC) sometimes presents with unique clinical, pathologic, and radiographic features. In this case report, we describe a patient with ILC, whose initial presentation consisted with symptoms secondary to bone-marrow dissemination. In addition, the breast primary was revealed only by magnetic resonance imaging (MRI) followed by real-time virtual sonography (RVS). Case presentation A 51-year-old woman presented to our outpatient clinic with dyspnea on exertion. She had severe anemia (hemoglobin, 5.3 g/dL) and thrombocytopenia (platelet count, 31 × 103/mL). Bone-marrow biopsy was performed to evaluate hematopoietic function. The pathologic diagnosis was bone-marrow carcinomatosis due to metastatic breast cancer. Initial mammography followed by ultrasonography (US) failed to detect the primary tumor. On MRI, a non-mass-enhancement lesion was observed. While second-look US also did not detect the lesion, it was clearly visualized with RVS. We were finally able to biopsy the breast lesion. The pathologic diagnosis was ILC positive for both estrogen receptor and progesterone receptor, with 1 + immunohistochemical staining for human epidermal growth factor receptor 2. This case of ILC was characterized by bone-marrow metastasis. Due to decreased cell adhesion, the risk of bone-marrow metastasis is higher in ILC than in invasive ductal carcinoma, the most prevalent type of breast cancer. Biopsy of the primary lesion, which was initially only detected with MRI, was successfully performed with clear visualization during RVS, which is based on the fusion of MRI and US images. Conclusion In this case report and literature review, we describe the unique clinical characteristics of ILC and a strategy for identifying primary lesions that are initially only visualized with MRI.

Takano et al. show that heterologous booster by SARS-CoV-2 recombinant spike protein vaccine recalls a more sustained and broader anti-spike receptor-binding domain antibody response compared to homologous booster by mRNA vaccine.

Chiral helimagnetism was investigated in transition-metal intercalated dichalcogenide single crystals of MnTa3S6. Small-angle neutron scattering (SANS) experiments revealed the presence of harmonic chiral helimagnetic order, which was successfully detected as a pair of satellite peaks in the SANS pattern. The magnetization data are also supportive of the presence of chiral soliton lattice (CSL) phase in MnTa3S6. The observed features are summarized in the phase diagram of MnTa3S6, which is in strong contrast with that observed in other dichalcogenides such as CrNb3S6 and CrTa3S6. The presence of the remanent state provides tunable capability of the number of chiral solitons at zero magnetic field in the CSL system, which may be useful for memory device applications.

The formation of chiral magnetic soliton lattice (CSL) is investigated in monoaxial chiral dichalcogenide CrTa3S6 crystals in terms of a surface barrier, which prevents the penetration of chiral solitons into the system and is an intrinsic origin of hysteresis for the continuous phase transition of nucleation-type, as discussed in the system of quantized vortices in type-II superconductors. The magnetoresistance (MR) was examined with microfabricated platelet samples in different dimensions with regard to the c-axis direction of the crystal. The CSL formation was confirmed by the discrete MR changes, reflecting the number of chiral solitons, as well as by the presence of a surface barrier, recognized as a fixed ratio of critical magnetic fields during the hysteresis field cycle. We also argue the influence of the surface barrier in bulk CrTa3S6 crystals.

Abstract Background Coronavirus disease 2019 (COVID-19) was previously thought to have a low reinfection rate, but there are concerns that the reinfection rate will increase with the emergence and spread of mutant variants. This report describes the case of a 36-year-old, non-immunosuppressed man who was infected twice by two different variants of COVID-19 within a relatively short period. Case presentation A 36-year-old Japanese man with no comorbidities was infected with the E484K variant (R.1 lineage) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Symptoms were mild and improved with symptomatic treatment alone. About four months later he presented to another outpatient department with high fever and headache. We diagnosed him as infected with the Alpha variant (B.1.1.7) of SARS-CoV-2 based on SARS-CoV-2 real-time reverse transcription polymerase chain reaction testing (RT-PCR). The patient was hospitalized with high fever. The patient received treatment in the form of anti-inflammatory therapy with corticosteroid and antibacterial chemotherapy. The patient improved without developing severe disease. Conclusion Concerns have been raised that the reinfection rate of COVID-19 will increase with the emergence of mutant variants. Particularly in mild cases, adequate amounts of neutralizing antibodies may not be produced, and reinfection may thus occur. Continued attention to sufficient infection control is thus essential.

Abstract Background The purpose of this study was to evaluate the clinical performance of Digital Breast Tomosynthesis guided vacuum-assisted biopsy (DBT-VAB) for microcalcifications in the breast. Methods Retrospective review of 131 mammography-guided VABs at our institution were performed. All of the targets were calcification lesion suspicious for cancer. 45 consecutive stereotactic vacuum-assisted biopsies (ST-VABs) and 86 consecutive DBT-VABs were compared. Written informed consent was obtained. Tissue sampling methods and materials were the same with both systems. Student’s t-test was used to compare procedure time and the Fisher’s exact test was used to compare success rate, complications, and histopathologic findings for the 2 methods. Results The tissue sampling success rate was 95.6% for ST-VAB (43/45) and 97.7% (84/86) for DBT-VAB. Time for positioning (10.6 ± 6.4 vs. 6.7 ± 5.3 min), time for biopsy (33.4 ± 13.1 vs. 22.5 ± 13.1 min), and overall procedure time (66.6 ± 16.6 min vs. 54.5 ± 13.0 min) were substantially shorter with DBT-VAB (P

Abstract Background Dual ectopic thyroid, a very rare condition, is defined as the simultaneous presence of ectopic thyroid tissue in two abnormal locations. Here, we report the surgical management of a patient with dual ectopic thyroid. Case presentation The patient was a 12-year-old boy with right para-midline swelling for 2 months. On physical examination of the upper anterior neck, there was a 4 cm × 3 cm mass that was soft, mobile, smooth, and painless. Blood examination showed euthyroidism. Neck ultrasonography showed a well-circumscribed multilocular cyst. We followed up by observation only because the patient had no local symptoms or malignancy. After 2 years, the mass gradually enlarged, so we performed surgery to improve cosmetic outcomes. Preoperative neck CT revealed both a high-density solid mass at the base of the tongue and a central low-density region surrounded by a high-density area at the pretracheal region below the hyoid. The infrahyoid mass was surgically removed, and the sublingual mass was left intact. Pathological findings showed the growth of multiple-size follicles, leading to a diagnosis of adenomatous goiter. Postoperative 123−I scintigraphy showed radioactive iodine uptake in the sublingual lesion, but none in the normal thyroid bed despite the extirpation of thyroid tissue. Postoperative thyroid hormone replacement was started for subclinical hypothyroidism. One year postoperatively, the patient became euthyroid. Conclusion Surgical excision was used to manage a symptomatic cervical infrahyoid mass related to dual ectopic thyroid. Postoperatively, thyroid hormone replacement was required both to prevent enlargement of the remaining sublingual thyroid and to maintain adequate thyroid hormone levels.

The production of Cu-alloy-based components using laser powder bed fusion (L-PBF) is hindered by the low laser absorptivity and high thermal conductivity of these alloys. In this study, we developed a trace alloying method to fabricate strong and ductile CuCrZr alloys using l-PBF. The laser absorptivity and flowability of the CuCrZr powders were enhanced by the trace Zr alloying because of the existence of surface oxide scales, resulting in the production of dense l-PBF builds. The surface oxides or in-situ oxidation generated irregular Zr/Cr oxide nanoparticles, which were distributed throughout the build structure. The subsequent hot isostatic pressing, solution treatment, and aging multisteps resulted in the homogeneous precipitation of submicron Cr particles, which formed coherent interfaces with the Cu matrix. Consequently, a CuCrZr alloy with a high strength and ductility of 287 MPa and 42%, respectively, was successfully prepared owing to the enhanced l-PBF processability and effective precipitation strengthening. The findings of this study suggest that high-performance Cu alloys can be designed and manufactured for various applications by combining the l-PBF and traditional metallurgical processes.

Abstract Background There have been no reports of tracheal intubation for airway obstruction after acute thyroid swelling following fine-needle aspiration (FNA) of the thyroid gland. Case presentation A 58-year-old woman with a 22 mm × 13 mm right hypervascular thyroid nodule underwent FNA once with a 22G needle under ultrasonographic guidance. Shortly after the aspiration, ultrasound revealed hypoechoic swelling with a crack-like pattern. The patient was observed under bed rest in the Fowler position and received intravenous steroids. A computed tomography (CT) scan showed swelling not only of the thyroid but also of the retropharyngeal space, and the patient complained of difficulty swallowing saliva. Laryngeal fiberscopy revealed protrusion of the posterior pharyngeal wall, edematous changes in the mucosa of the pharynx and epiglottis, and retention of saliva. The patient was intubated awake and hydrocortisone was administered every 8 h. She was extubated 3 days after FNA and discharged without any complications. Conclusions When neck swelling is noticed after FNA, ultrasonographic findings are especially important to assess potential causes. If airway obstruction is suspected, CT findings and fiberscope observation of the pharynx provide particularly useful information.

Nonlocal spin polarization phenomena are thoroughly investigated in the devices made of chiral metallic single crystals of CrNb3S6 and NbSi2 as well as of polycrystalline NbSi2. We demonstrate that simultaneous injection of charge currents in the opposite ends of the device with the nonlocal setup induces the switching behavior of spin polarization in a controllable manner. Such a nonlocal spin polarization appears regardless of the difference in the materials and device dimensions, implying that the current injection in the nonlocal configuration splits spin-dependent chemical potentials throughout the chiral crystal even though the current is injected into only a part of the crystal. We show that the proposed model of the spin dependent chemical potentials explains the experimental data successfully. The nonlocal double-injection device may offer significant potential to control the spin polarization to large areas because of the nature of long-range nonlocal spin polarization in chiral materials. [ABSTRACT FROM AUTHOR]

A synthesis of single crystals of chiral dichalcogenides TM3X6 (T: 3d transition metal, M: Nb or Ta, X: S or Se) remains an intriguing issue for the investigation of emergent quantum properties such as chiral helimagnetism. In this study, we investigated a correlation between the quantity of Cr intercalation x and the magnetic property in single crystals of a chromium (Cr) intercalated chiral disulfide CrxNb3S6 in order to optimize the synthesis condition for the intercalation-controlled single crystals. The magnetic properties, including a magnetic transition temperature Tc, take different values depending on the samples. We systematically grew single crystals of CrxNb3S6 with x ranged from 0.89 to 1.03 and found that the amount of the Cr intercalation x is an essential factor in controlling the magnetic properties of the grown crystals. The magnetization anomaly, which appears in the temperature dependence as evidence of the formation of chiral magnetic soliton lattice (CSL), was observed only in a narrow region of x from 0.98 to 1.03. The single crystals with x being 0.98 and 0.99 showed the CSL behavior with the highest Tc of 133 K. These results indicate that the small number of defects on the sites for T ions dramatically affects the quality of the single crystals in the synthesis of TM3S6. We also discuss the importance of synthesizing enantiopure single crystals of chiral dichalcogenides in order to observe chiral physical properties unique to chiral compounds such as magneto-chiral effect and chiral-induced spin selectivity.

Abstract The oral microbiome plays an important role in the human microbial community and in maintaining the health of an individual. Imbalances in the oral microbiome may contribute to oral and systemic diseases. The progression of periodontal disease is closely related to the growth of bacteria, such as Porphyromonas gingivalis, in the oral cavity. However, the pathogen growth mechanism specific to periodontal disease remains unknown. This study aimed to identify bacteria associated with periodontal health by focusing on hemolytic bacteria. Unstimulated saliva samples were collected from ten periodontitis patients and five healthy subjects to detect and identify the presence of hemolytic bacteria. The saliva of healthy subjects contained a higher proportion of G. haemolysans than saliva samples from patients with periodontitis. Growth inhibition assays indicated that the protein components contained in the culture supernatant of G. haemolysans directly suppressed the growth of P. gingivalis. This study shows that the presence of G. haemolysans in saliva is associated with periodontal health and that it inhibits the growth of P. gingivalis in vitro.