A Cluster of Paragonimiasis with Delayed Diagnosis Due to Difficulty Distinguishing Symptoms from Post-COVID-19 Respiratory Symptoms: A Report of Five Cases.

Paragonimiasis caused by trematodes belonging to the genus Paragonimus is often accompanied by chronic respiratory symptoms such as cough, the accumulation of sputum, hemoptysis, and chest pain. Prolonged symptoms, including respiratory symptoms, after coronavirus disease 2019 infection (COVID-19) are collectively called post-COVID-19 conditions. Paragonimiasis and COVID-19 may cause similar respiratory symptoms. We encountered five cases of paragonimiasis in patients in Japan for whom diagnoses were delayed due to the initial characterization of the respiratory symptoms as a post-COVID-19 condition. The patients had consumed homemade drunken freshwater crabs together. One to three weeks after consuming the crabs, four of the five patients were diagnosed with probable COVID-19. The major symptoms reported included cough, dyspnea, and chest pain. The major imaging findings were pleural effusion, pneumothorax, and nodular lesions of the lung. All the patients were diagnosed with paragonimiasis based on a serum antibody test and peripheral blood eosinophilia (560-15,610 cells/µL) and were treated successfully with 75 mg/kg/day praziquantel for 3 days. Before diagnosing a post-COVID-19 condition, it is necessary to consider whether other diseases, including paragonimiasis, may explain the symptoms. Further, chest radiographic or blood tests should be performed in patients with persistent respiratory symptoms after being infected with COVID-19 to avoid overlooking the possibility of infection.

Midlateral medullary infarction presenting with isolated thermoanaesthesia: a case report.

BACKGROUND: A small lateral medullary lesion could produce isolated impairment of temperature sensation without concomitant impaired pain sensation. However, only one such case has ever been reported, and there are no reports on subjective symptoms and detailed somatosensory testing. CASE PRESENTATION: Herein, we report the case of a 53-year-old female patient presenting with impaired temperature sensation on the left half of her body, from the neck down, following a small infarction of the right midlateral medulla. The chronological changes in the patient's introspection regarding impairment of thermoception and the results of detailed somatosensory tests, including thermal sense, are shown in this report. CONCLUSIONS: Thorough somatosensory tests, personal descriptions of symptoms, and electrophysiological quantification of similar cases are needed to improve our understanding of the neurological separation of the sensations of pain and temperature at the medullary level.

Osteochondral regeneration of the femoral medial condyle by using a scaffold-free 3D construct of synovial membrane-derived mesenchymal stem cells in horses.

BACKGROUND: Medical interventions for subchondral bone cysts in horses have been extensively studied. This study investigated the regeneration of articular cartilage and subchondral bone with scaffold-free three-dimensional (3D) constructs of equine synovial membrane-derived mesenchymal stem cells (SM-MSCs) isolated from three ponies and expanded until over 1.0 × 107 cells at passage 2 (P2). RESULTS: SM-MSCs were strongly positive for CD11a/CD18, CD44, and major histocompatibility complex (MHC) class I; moderately positive for CD90, CD105, and MHC class II; and negative for CD34 and CD45 on flow cytometry and differentiated into osteogenic, chondrogenic, and adipogenic lineages in the tri-lineage differentiation assay. After culturing SM-MSCs until P3, we prepared a construct (diameter, 6.3 mm; height, 5.0 mm) comprising approximately 1920 spheroids containing 3.0 × 104 cells each. This construct was confirmed to be positive for type I collagen and negative for type II collagen, Alcian blue, and Safranin-O upon histological analysis and was subsequently implanted into an osteochondral defect (diameter, 6.8 mm; depth, 5.0 mm) at the right femoral medial condyle. The contralateral (left femoral) defect served as the control. At 3 and 6 months after surgery, the radiolucent volume (RV, mm3) of the defects was calculated based on multiplanar reconstruction of computed tomography (CT) images. Magnetic resonance (MR) images were evaluated using a modified two-dimensional MR observation of cartilage repair tissue (MOCART) grading system, while macroscopic (gross) and microscopic histological characteristics were scored according to the International Cartilage Repair Society (ICRS) scale. Compared to the control sites, the implanted defects showed lower RV percentages, better total MOCART scores, higher average gross scores, and higher average histological scores. CONCLUSIONS: Implantation of a scaffold-free 3D-construct of SM-MSCs into an osteochondral defect could regenerate the original structure of the cartilage and subchondral bone over 6 months post-surgery in horses, indicating the potential of this technique in treating equine subchondral bone cysts.

[Postoperative Inguinal Hernia after Robot-Assisted Radical Prostatectomy with Prevention Technique Using Spermatic Cord Isolation].

We retrospectivelyevaluated postoperative inguinal hernias (PIHs) after robot-assisted radical prostatectomy(RARP) with a technique for preventing hernias byspermatic cord isolation. Among the RARPs performed from 2016 to 2018, 191 cases were evaluated 12 or more months after surgery. In all the cases, the peritoneum was isolated from the spermatic cord by5 cm or more as a hernia prevention technique during RARP. We compared the background factors between PIH-positive and PIH-negative groups. The PIH-positive group had a significantlylower bodymass index (BMI) than the PIH-negative group (20.6 kg/m2 vs 23.8 kg/m2, p＝0.0079), but there were no significant differences in other background factors. When patients were classified into three groups byBMI, low (＜21.9 kg/m2), intermediate (21.9 to 25.5 kg/m2), and high (＞25.5 kg/m2), the rate of PIH was 8.5% for the low group, 2.1% for the intermediate group, and 0% for the high group. Our findings suggest that incidences of inguinal hernias after the preventive technique of spermatic cord isolation in RARP, and the BMIs tended to be low in the hernia cases.

Osteochondral Regeneration Using Adipose Tissue-Derived Mesenchymal Stem Cells.

Osteoarthritis (OA) is a major joint disease that promotes locomotor deficiency during the middle- to old-age, with the associated disability potentially decreasing quality of life. Recently, surgical strategies to reconstruct both articular cartilage and subchondral bone for OA have been diligently investigated for restoring joint structure and function. Adipose tissue-derived mesenchymal stem cells (AT-MSCs), which maintain pluripotency and self-proliferation ability, have recently received attention as a useful tool to regenerate osteocartilage for OA. In this review, several studies were described related to AT-MSC spheroids, with scaffold and scaffold-free three-dimensional (3D) constructs produced using "mold" or "Kenzan" methods for osteochondral regeneration. First, several examples of articular cartilage regeneration using AT-MSCs were introduced. Second, studies of osteochondral regeneration (not only cartilage but also subchondral bone) using AT-MSCs were described. Third, examples were presented wherein spheroids were produced using AT-MSCs for cartilage regeneration. Fourth, osteochondral regeneration following autologous implantation of AT-MSC scaffold-free 3D constructs, fabricated using the "mold" or "Kenzan" method, was considered. Finally, prospects of osteochondral regeneration by scaffold-free 3D constructs using AT-MSC spheroids were discussed.

[Outcomes of Laparoscopic Radical Prostatectomies by a Single Surgeon Alternating Operating Position].

The clinical outcome of laparoscopic radical prostatectomy (LRP) was retrospectively investigated taking into consideration the surgeon's position during the procedure. The study cohort included 184 consecutive patients who had undergone LRP performed by a single surgeon from February 2013 to July 2018. During the study period,the surgeon stood alternately on either the left or right side of the patient. The D'Amico risk classification was low,intermediate and high in 26 (14.1%),45 (24.5%) and 113 (61.4%) patients,respectively. Mean surgical duration was 203.5 minutes and mean estimated blood loss was 437.6 ml. Nerve sparing (NS) was implemented in 82 (44. 6%) patients. The mean period of having an indwelling urethral catheter was 5. 0 days. Perioperative Clavien-Dindo degree ≥IIIa complications occurred in three (1.6%) patients. Except for cases with presurgical hormonal treatment,surgical margins were positive in 41 (22.3%) patients,among whom 23 (17.4%) had pT2 disease. The 5-year biochemical recurrence-free survival rate was 81.4%,and 84.8% of patients regained urinary continence at 12 months after surgery. Where the surgeon stood during LRP was not associated with significant differences in any parameter. However,the margin positive rate was higher on the side away from where the surgeon stood than the side closer to the surgeon (70.7% vs 29.3%). In conclusion,the position of the surgeon during LRP does not influence the outcome.

[Infected Pelvic Lymphocele after Robot-Assisted Radical Prostatectomy].

The aim of this study is to clarify the incidences of infected pelvic lymphocele (IPL) after robot-assisted radical prostatectomy (RARP). From 2016 to 2017, we evaluated 173 consecutive patients who underwent RARP. The transperitoneal approach was used for the RARPs. Limited lymph node dissection was performed in the pelvic lymphoceles region surrounding the obturator nerve. Patients with IPL were defined as those with infected pelvic lymphoceles classified as Clavien-Dindo (CD) classification system grade II or greater and a fever over 38 degrees Celsius. All other cases were defined as nonIPL. IPL was observed in 5 cases (2.9%) that were classified as CD grade II in 2 cases, IIIa in 2 cases, and IVa in 1 case. The most severe case (CD grade IVa) required temporary dialysis for acute renal failure during conservative treatment. While the dissected lymph nodes in the IPL group were sificantly greater than those in the nonlPL group (20.8 ± 7.1 vs 10.3 ± 6.0, P = 0.0298) and the preoperative prostate specific antigen in the IPL group was significantly higher than that in the nonIPL group (15.6 ± 21.7 ng/ml vs 9.0 ± 6.1 ng/ml, P = 0.0359), there were no significant differences in the other background factors between the two groups. In the multivariate analysis, the number of dissected lymph nodes was an independent predictive factor for IPL. While the incidences of IPL after RARP were low, the number of dissected lymph nodes was related to IPL.

[Second Transurethral Resection (TUR) for Bladder Cancer Diagnosed with High Grade pT1 by Initial TUR Under Narrow Band Imaging].

We evaluated 52 consecutive cases of patients undergoing second transurethral resections (TUR) for non-muscle invasive bladder cancer (NMIBC) in which the patients were diagnosed with high grade pT1 by the initial TUR under narrow band imaging (NBI). The initial TUR under NBI (NBI-TUR) was performed : Systematic intravesical observation under white light imaging (WLI) and NBI was followed by a multiple site biopsy (MSB), after which lesions detected in positive findings were resected completely under NBI. The tumor detection rates under WLI and NBI were calculated separately and compared with endoscopic findings and MSB samples. The second TUR was performed as a resection that included the surrounding mucosa and muscle layer of the initial NBI-TUR scar under WLI observation, 4-8 weeks after the initial NBI-TUR. The patients were divided into two groups : The residual cancer lesion-positive group (NBIR positive), and the residual cancer lesion-negative group (NBIR negative). The tumor detection rate under NBI was more sensitive compared with that under WLI in the initial NBI-TUR (89.4% vs 59.1% p< 0.0001), and the residual cancer detection rate in the 2nd TUR reached 34.6% (18/52). There was no significant difference in the background factors between the NBIR positive and NBIR negative. While the number of cancer lesions detected under NBI was significantly higher than that under WLI in the NMIBCdiagnosed high grade pT1, the rate of cancer lesions that were difficult to identify in the initial NBI-TUR was still high. These findings demonstrate the limitations of the mono-therapeutic effect of NBI-TUR.

[Robot-Assisted Partial Nephrectomy for Renal Tumor ≤7 cm in Diameter].

The aim of this study was to compare the perioperative results of robot-assisted partial nephrectomy (RAPN) with those of laparoscopic partial nephrectomy (LPN) for cT1 renal tumors. From August 2015 to March 2018, 63 consecutive cases undergoing LPN and RAPN (30 cases of LPN and 33 cases of RAPN) for renal tumors ≤7cm in diameter (cTla: 42 cases and cT1b: 21 cases) were evaluated. The trifecta was defined on the basis of the following three criteria: ischemic time less than 25 minutes, no positive surgical margin, and no perioperative complications within four weeks postoperative. The background factors were compared between the two groups. There were no cases requiring changes in the operation methods. There was no significant difference in age, body mass index, gender, or tumor side between the two groups. While the mean tumor diameter and mean RENAL nephrometry score (RNS) were 32.6 mm and 7.3, respectively, there were no differences between the two groups. The warm ischemic time of RAPN was significantly shorter than that of LPN (12.7 min vs 19.9 min, P = 0.0007), and the estimated blood loss of RAPN was less than that of LPN (58.6 ml vs 160.3 ml, P = 0.0005). While there was no apparent tumor damage, tumor exposure on the resection surface was observed in two cases. Perioperative complications were observed in four cases. The trifecta achievement rate of RAPN and that of LPN was 93.9% (31 cases) and 66.7% (20 cases), respectively. The initial perioperative results of RAPN were comparable with those of LPN for cT1 renal tumors.

A pilot study of regenerative therapy by implanting synovium-derived mesenchymal stromal cells in equine osteochondral defect models.

Synovium-derived mesenchymal stromal cells (SM-MSCs) from seven Thoroughbreds with naturally occurring intra-articular fracture proliferated to over ten million cells by the second passage. Using three experimental Thoroughbreds, columnar osteochondral defects were made arthroscopically at the bilateral distal radius. Five million allogenic SM-MSCs were implanted into the right defect, and another five million were injected into the right radio-carpal joint (implantation site). No SM-MSCs were implanted into the left defect or the same joint (control site). At 3 and 6 weeks after surgery, ten million autologous SM-MSCs were injected into the right joints. Radiolucent volumes of defects calculated by analysis of postmortem CT images 9 weeks after surgery were decreased in implanted sites compared with control sites in all horses. The average scores for ICRS gross and histopathological grading scales in implanted sites were equal to or higher than those of the controls. These results suggest that allogenic implantation and subsequent autologous injection of SM-MSCs might not obstruct subchondral bone formation in defects.

Isolation of equine peripheral blood stem cells from a Japanese native horse.

The sizes of Japanese native horses have drastically decreased, and protection of these populations is important for Japanese horse culture. Social trials as well as scientific attempts are necessary for maintaining the breed. Mesenchymal stem cells (MSCs) have potential as a cell source for various cell therapies. However, there have been no reports on MSCs of Japanese native horses. We aimed to isolate and characterize MSCs from a Japanese native horse, the Noma horse. Plastic-adherent and self-replicating cells were isolated from a Noma horse's peripheral blood (PB). The isolated cells had trilineage potential and a surface antigen of mesenchymal cells, so they fulfilled the minimal criteria of MSCs. Therefore, PB can be one source of MSCs for Japanese native horses.

Characteristics and multipotency of equine dedifferentiated fat cells.

Dedifferentiated fat (DFAT) cells have been shown to be multipotent, similar to mesenchymal stem cells (MSCs). In this study, we aimed to establish and characterize equine DFAT cells. Equine adipocytes were ceiling cultured, and then dedifferentiated into DFAT cells by the seventh day of culture. The number of DFAT cells was increased to over 10 million by the fourth passage. Flow cytometry of DFAT cells showed that the cells were strongly positive for CD44, CD90, and major histocompatibility complex (MHC) class I; moderately positive for CD11a/18, CD105, and MHC class II; and negative for CD34 and CD45. Moreover, DFAT cells were positive for the expression of sex determining region Y-box 2 as a marker of multipotency. Finally, we found that DFAT cells could differentiate into osteogenic, chondrogenic, and adipogenic lineages under specific nutrient conditions. Thus, DFAT cells could have clinical applications in tissue regeneration, similar to MSCs derived from adipose tissue.

A study of the distribution of color Doppler flows in the superficial digital flexor tendon of young Thoroughbreds during their training periods.

Aim of this study was to evaluate the relationships of exercise and tendon injury with Doppler flows appearing in the superficial digital flexor tendon (SDFT) of young Thoroughbreds during training periods. The forelimb SDFTs of 24 one- to two-year-old Thoroughbreds clinically free of any orthopaedic disorders were evaluated using grey-scale (GS) and color Doppler (CD) images during two training periods between December 2013 to April 2015. Twelve horses per year were examined in December, February, and April in training periods that began in September and ended in April. The SDFT was evaluated in 3 longitudinal images of equal lengths (labelled 1, 2, 3 in order from proximal to distal), and 6 transversal images separated by equal lengths (labelled 1A, 1B, 2A, 2B, 3A and 3B in order from proximal to distal) of the metacarpus using both GS and CD. The running (canter and gallop) distance for 1 month before the date of the ultrasonographic examinations was increased in December, February, and April in both of the two training periods. CD flows defined as rhythmically blinking or pulsatory colored signals were found in 56 of 864 (6.4%) transversal CD images, in 28, 12, 13, and 3 images of 1A, 1B, 2A and 2B, respectively, and in 7, 14, and 35 images captured in December, February, and April, respectively. There were no longitudinal or transversal GS images indicating injury in the SDFTs in either of the two training periods. The increase of CD flows in the proximal regions of the SDFT are possibly related to the increase of the running distance during the training periods of the one- to two-year-old Thoroughbreds. Because no injury was diagnosed in the SDFTs by GS images during the training periods, the increase of CD flows in the proximal parts of SDFT is not necessarily predictive of tendon injury in the near future during the training period of young Thoroughbreds.

Creating 3D constructs with cranial neural crest-derived cell lines using a bio-3D printer.

OBJECTIVES: The development of bio-three-dimensional (bio-3D) printers has led to significant advances in regenerative medicine. Three-dimensional constructs, including spheroids, are maintained by extracellular matrix proteins secreted by cells so that the cells can be cultured in conditions closer to the physiological environment. This study aimed to create a useful 3D construct as a model of the dentin-pulp complex. METHODS: We examined the expression patterns of extracellular matrix proteins and cell proliferation areas in a 3D construct created using O9-1 cells derived from cranial neural crest cells of mice. The 3D construct was created by sticking the spheroid cultures onto a needle array using a bio-3D printer. RESULTS: Cell proliferation areas along with characteristic expression of tenascin C and DMP1 were evaluated. The expression of tenascin C and DMP1 was significantly enhanced in the spheroids compared to that in two-dimensional cultures. Moreover, cell proliferation regions and tenascin C expression were confirmed in the outer layer of spheroids in the embryonic stem cell medium, with insignificant DMP1 expression being observed. Interestingly, in a 3D construct cultured in calcification-induction medium, DMP1 expression was promoted, and DMP1-positive cells existed in the outermost layer without overlapping with tenascin C expression. CONCLUSIONS: The extracellular matrix proteins, tenascin C and DMP1, were expressed in a polarized manner in spheroids and 3D constructs, similar to the findings in the dental papilla. Therefore, these 3D constructs show potential as artificial models for studying odontogenesis.

Survival and soluble immune mediators of immune checkpoint inhibitor-induced interstitial lung disease in patients with non-small cell lung cancer.

BACKGROUND: Immune checkpoint inhibitor-related interstitial lung disease (ICI-ILD) is a serious adverse event frequently observed in patients with non-small cell lung cancer (NSCLC). We investigated the clinical effects and mechanism of action of ICI-ILD in NSCLC patients treated with ICI. METHODS: We retrospectively screened patients with advanced or recurrent NSCLC who received PD-1/PD-L1 inhibitor monotherapy and examined the prognostic impact of ICI-ILD. In addition, we analyzed the levels of 72 different soluble immune mediators in pre-treatment plasma to explore possible mechanisms associated with the development of ICI-ILD. Furthermore, the relationships between soluble immune mediators associated with ICI-ILD development and survival were analyzed. RESULTS: Of 141 patients with NSCLC, 25 (17.7%) developed ICI-ILD. Logistic regression analysis revealed that pre-treatment CXCL9, MMP-1, IL-6, and IL-19 levels were associated with ICI-ILD development. There were no significant differences in progression-free survival (PFS) and overall survival (OS) between patients with or without ICI-ILD. In patients with ICI-ILD, patients with lower grade ICI-ILD had better OS than those with higher-grade ICI-ILD. In ICI-ILD patients, there was a trend for patients with lower-grade ICI-ILD to have better PFS and OS than those with higher-grade ICI-ILD. Among four soluble immune mediators associated with ICI-ILD, a high level of IL-19 was significantly correlated with worse OS and PFS. CONCLUSION: The identified soluble immune mediators, including CXCL9, MMP-1, IL-6, and IL-19, may be useful as biomarkers to associate with ICI-ILD development. Although we did not detect significant differences in PFS and OS between patients with and without ICI-ILD, PFS and OS were longer in those with lower-grade ICI-ILD than in patients with higher-grade ICI-ILD. Among biomarkers, IL-19 may be a causal and prognostic factor for ICI-ILD.

Clinical significance of interstitial lung abnormalities and immune checkpoint inhibitor-induced interstitial lung disease in patients with non-small cell lung cancer.

BACKGROUND: Interstitial lung abnormalities (ILAs) are known to be a risk of drug-induced pneumonitis. However, there are few reports on the relationship between ILAs and immune checkpoint inhibitor-related interstitial lung disease (ICI-ILD). We retrospectively investigated the clinical significance of ILAs in patients with non-small cell lung cancer (NSCLC) receiving ICIs. METHODS: We defined ILAs as nondependent abnormalities affecting more than 5% of any lung zone, including ground-glass or diffuse centrilobular nodularities, traction bronchiectasis, honeycombing, and nonemphysematous cysts. Early-onset ICI-ILD was defined as developing within 3 months after the initiation of ICI administration. RESULTS: Of 264 patients with advanced NSCLC, 57 patients (21.6%) had ILAs (43 fibrotic and 14 nonfibrotic ILAs). The difference between the incidence of ICI-ILD in patients with or without ILAs was not significant. Of 193 patients treated by ICI monotherapy, 18 (9.3%) developed early-onset ICI-ILD. Among patients receiving ICI monotherapy, the incidence of early-onset ICI-ILD was significantly higher in patients with than in patients without nonfibrotic ILAs. CONCLUSION: The presence of nonfibrotic ILAs is a significant risk for early-onset ICI-ILD in patients with NSCLC undergoing ICI monotherapy. Clinicians should be aware of ILAs, especially nonfibrotic ILAs, before administering ICIs to lung cancer patients.

Scaffold-free human vascular calcification model using a bio-three-dimensional printer.

Morbidity and mortality rates associated with atherosclerosis-related diseases are increasing. Therefore, developing new research models is important in furthering our understanding of atherosclerosis and investigate novel treatments. Here, we designed novel vascular-like tubular tissues from multicellular spheroids composed of human aortic smooth muscle cells, endothelial cells, and fibroblasts using a bio-3D printer. We also evaluated their potential as a research model for Mönckeberg's medial calcific sclerosis. The tubular tissues were sufficiently strong to be handled 1 week after printing and could still be cultured for 3 weeks. Histological assessment showed that calcified areas appeared in the tubular tissues within 1 week after culture in a medium containing inorganic phosphate (Pi) or calcium chloride as the calcification-stimulating factors. Calcium deposition was confirmed using micro-computed tomography imaging. Real-time quantitative reverse transcription polymerase chain reaction analysis revealed that the expression of osteogenic transcription factors increased in calcified tubular tissues. Furthermore, the administration of Pi and rosuvastatin enhanced tissue calcification. The bio-3D printed vascular-like tubular structures, which are composed of human-derived cells, can serve as a novel research model for Mönckeberg's medial calcific sclerosis.

A Rare Case of Diffuse Bilateral Minute Pulmonary Meningothelial-like Nodules Increasing over the Short Term and Resembling Metastatic Lung Cancer.

A 54-year-old woman was referred to our hospital because computed tomography (CT) revealed multiple lung nodules during a health checkup. The nodules were up to 5 mm in diameter and randomly distributed in both lungs, appearing ring-shaped. No clinical symptoms were present. However, the nodes proliferated, and multiple lung metastases could not be ruled out, so a biopsy was performed to establish a diagnosis. She was diagnosed with minute pulmonary meningothelial-like nodules (MPMNs), and her condition had not deteriorated at the latest follow-up. Although rare, MPMNs can proliferate for a short time, but a biopsy to exclude malignant causes is essential.

A Novel Near-Infrared Fluorescence Probe THK-565 Enables In Vivo Detection of Amyloid Deposits in Alzheimer's Disease Mouse Model.

PURPOSE: Noninvasive imaging of protein aggregates in the brain is critical for the early diagnosis, disease monitoring, and evaluation of the effectiveness of novel therapies for Alzheimer's disease (AD). Near-infrared fluorescence (NIRF) imaging with specific probes is a promising technique for the in vivo detection of protein deposits without radiation exposure. Comprehensive screening of fluorescent compounds identified a novel compound, THK-565, for the in vivo imaging of amyloid-ß (Aß) deposits in the mouse brain. This study assessed whether THK-565 could detect amyloid-ß deposits in vivo in the AD mouse model. PROCEDURES: The fluorescent properties of THK-565 were evaluated in the presence and absence of Aß fibrils. APP knock-in (APP-KI) mice were used as an animal model of AD. In vivo NIRF images were acquired after the intravenous administration of THK-565 and THK-265 in mice. The binding selectivity of THK-565 to Aß was evaluated using brain slices obtained from these mouse models. RESULTS: The fluorescence intensity of the THK-565 solution substantially increased by mixing with Aß fibrils. The maximum emission wavelength of the complex of THK-565 and Aß fibrils was 704 nm, which was within the optical window range. THK-565 selectively bound to amyloid deposits in brain sections of APP-KI mice After the intravenous administration of THK-565, the fluorescence signal in the head of APP-KI mice was significantly higher than that of wild-type mice and higher than that after administration of THK-265. Ex vivo analysis confirmed that the THK-565 signal corresponded to Aß immunostaining in the brain sections of these mice. CONCLUSIONS: A novel NIRF probe, THK-565, enabled the in vivo detection of Aß deposits in the brains of the AD mouse model, suggesting that NIRF imaging with THK-565 could non-invasively assess disease-specific pathology in AD.