DOCK2 regulates MRGPRX2/B2-mediated mast cell degranulation and drug-induced anaphylaxis.

BACKGROUND: Drug-induced anaphylaxis is triggered by the direct stimulation of mast cells (MCs) via Mas-related G protein-coupled receptor X2 (MRGPRX2; mouse ortholog MRGPRB2). However, the precise mechanism that links MRGPRX2/B2 to MC degranulation is poorly understood. Dedicator of cytokinesis 2 (DOCK2) is a Rac activator predominantly expressed in hematopoietic cells. Although DOCK2 regulates migration and activation of leukocytes, its role in MCs remains unknown. OBJECTIVE: We aimed to elucidate whether-and if so, how-DOCK2 is involved in MRGPRX2/B2-mediated MC degranulation and anaphylaxis. METHODS: Induction of drug-induced systemic and cutaneous anaphylaxis was compared between wild-type and DOCK2-deficient mice. In addition, genetic or pharmacologic inactivation of DOCK2 in human and murine MCs was used to reveal its role in MRGPRX2/B2-mediated signal transduction and degranulation. RESULTS: Induction of MC degranulation and anaphylaxis by compound 48/80 and ciprofloxacin was severely attenuated in the absence of DOCK2. Although calcium influx and phosphorylation of several signaling molecules were unaffected, MRGPRB2-mediated Rac activation and phosphorylation of p21-activated kinase 1 (PAK1) were impaired in DOCK2-deficient MCs. Similar results were obtained when mice or MCs were treated with small-molecule inhibitors that bind to the catalytic domain of DOCK2 and inhibit Rac activation. CONCLUSION: DOCK2 regulates MRGPRX2/B2-mediated MC degranulation through Rac activation and PAK1 phosphorylation, thereby indicating that the DOCK2-Rac-PAK1 axis could be a target for preventing drug-induced anaphylaxis.

Phase I study of alvocidib plus cytarabine/mitoxantrone or cytarabine/daunorubicin for acute myeloid leukemia in Japan.

Therapeutic improvements are needed for patients with acute myeloid leukemia (AML), particularly those who have relapsed or who have treatment-refractory (R/R) AML or newly diagnosed patients with poor prognostic factors. Alvocidib (DSP-2033), a potent cyclin-dependent kinase 9 inhibitor, has previously demonstrated promising clinical activity for the treatment of AML. In this multicenter, open-label, uncontrolled, 3 + 3 phase I study, we investigated the safety and tolerability of alvocidib administered in combination with either cytarabine and mitoxantrone (ACM) for R/R AML or cytarabine/daunorubicin (A + 7 + 3) for newly diagnosed AML. Alvocidib was administered to all patients as a 30-min intravenous (i.v.) bolus (30 mg/m2 /d), followed by a continuous i.v. infusion over 4 h on days 1-3 (60 mg/m2 /d). A total of 10 patients were enrolled: six received ACM (at two dose levels of cytarabine and mitoxantrone) and four received A + 7 + 3. Alvocidib was tolerated and no dose-limiting toxicities were observed. All patients experienced adverse events, of which diarrhea was the most frequent (100%); hematologic events were also common. Alvocidib concentration peaked at the end of dosing (4.5 h after start of administration), plasma accumulation after repeated dosing was minimal and urinary excretion was negligible. The rate of complete remission/complete remission with incomplete hematologic recovery was 66.7% with the ACM regimen in R/R AML, including four complete remission (median duration 13.6 months), and 75% (three complete remission) with the A + 7 + 3 regimen. Further development of alvocidib in hematologic malignancies is warranted. The trial is registered with Clinicaltrials.gov, NCT03563560.

DOCK8 deficiency causes a skewing to type 2 immunity in the gut with expansion of group 2 innate lymphoid cells.

Dedicator of cytokinesis 8 (DOCK8) is a guanine nucleotide exchange factor (GEF) for Cdc42. In humans, homozygous or compound heterozygous deletions in DOCK8 cause a combined immunodeficiency characterized by various allergic diseases including food allergies. Although group 2 innate lymphoid cells (ILC2s) contribute to the development of allergic inflammation by producing interleukin (IL)-5 and IL-13, the role of ILC2s in DOCK8 deficiency has not been fully explored. With the use of cytometry by time-of-flight (CyTOF), we performed high-dimensional phenotyping of intestinal immune cells and found that DOCK8-deficient (Dock8-/-) mice exhibited expansion of ILC2s and other leukocytes associated with type 2 immunity in the small intestine. Moreover, IL-5- and IL-13-producing cells markedly increased in Dock8-/- mice, and the majority of them were lineage-negative cells, most likely ILC2s. Intestinal ILC2s expanded when DOCK8 expression was selectively deleted in hematopoietic cells. Importantly, intestinal ILC2 expansion was also observed in Dock8VAGR mice having mutations in the catalytic center of DOCK8, thereby failing to activate Cdc42. Our findings indicate that DOCK8 is a negative regulator of intestinal ILC2s to inhibit their expansion via Cdc42 activation, and that deletion of DOCK8 causes a skewing to type 2 immunity in the gut.

Association Between Functional Movement Screen Scores and Injuries in Male College Basketball Players.

CONTEXT: The functional movement screen (FMS) is an assessment tool for movement dysfunction, which is used to reduce the risk of injury. Although the relationship between the FMS composite score and injuries has been extensively studied, the association between FMS scores and injuries in only college basketball players remains unknown. OBJECTIVE: To examine the relationship between the FMS score and injuries in basketball players. DESIGN: Cross-sectional study. SETTING: University research laboratory. PARTICIPANTS: Eighty-one male college basketball players (average age 20.1 [1.3] y) participated. MAIN OUTCOME MEASURES: The FMS composite score was calculated from 7 movement tests. The incidence of injuries over a 1-year period prior to the test day was determined based on a questionnaire. Individuals were categorized into 2 groups: injury (with a serious basketball-related injury resulting in the loss of practice and game time for at least 4 wk) and noninjury groups. Mann-Whitney U and chi-square tests were used to evaluate group differences in the composite FMS and 7 movement scores, respectively. Furthermore, the scores significant on univariate analyses were submitted to a multivariate logistic analysis, adjusting for participant characteristics. RESULTS: The composite FMS scores of the 2 groups were not significantly different (P = .38). Among the 7 tasks, only the deep squat and hurdle step showed significant group differences (P = .03 and P = .001, respectively). The multivariate logistic analysis revealed that deep squat (odds ratio, 6.48; 95% confidence interval, 1.23-34.01; P = .03) and hurdle step scores (odds ratio, 25.80; 95% confidence interval, 1.81-368.73; P = .02) were significantly associated with injuries, even after adjustment for participant characteristics. CONCLUSIONS: Deep squat and hurdle step scores may be associated with injuries in basketball players. Further research should be conducted to confirm that these 2 scores can predict the incidence of injuries in basketball players.

Effect of Capacitive and Resistive electric transfer on haemoglobin saturation and tissue temperature.

PURPOSE: This study aims to evaluate the effects of Capacitive and Resistive electric transfer (CRet) and hotpack (HP) on haemoglobin saturation and tissue temperature. MATERIALS AND METHODS: The participants were 13 healthy males (mean age 24.5 ± 3.0). They underwent three interventions on different days: (1) CRet (CRet group), (2) HP (HP group) and (3) CRet without power (sham group). The intervention and measurement were applied at the lower paraspinal muscle. Indiba® active ProRecovery HCR902 was used in the CRet group, and the moist heat method was used in the HP group. Oxygenated, deoxygenated and total haemoglobin (oxy-Hb, deoxy-Hb, total-Hb) counts were measured before and after the 15-min interventions, together with the temperature at the skin surface, and at depths of 10 mm and 20 mm (ST, 10mmDT and 20mmDT, respectively). The haemoglobin saturation and tissue temperature were measured until 30 min after the intervention and were collected at 5-min intervals. Statistical analysis was performed for each index by using the Mann-Whitney U test for comparisons between all groups at each time point. RESULTS: Total-Hb and oxy-Hb were significantly higher in the CRet group than in the HP group continuously for 30 min after the intervention. The 10mmDT and 20mmDT were significantly higher in the CRet group than in the HP group from 10- to 30 min after intervention. CONCLUSIONS: The effect on haemoglobin saturation was higher in the CRet group than in the HP group. In addition, the CRet intervention warmed deep tissue more effectively than HP intervention.

Impact of spillover from white matter by partial volume effect on quantification of amyloid deposition with [11C]PiB PET.

High non-specific uptake of [11C]Pittsburgh compound B ([11C]PiB) in white matter and signal spillover from white matter, due to partial volume effects, confound radioactivity measured in positron emission tomography (PET) with [11C]PiB. We aimed to reveal the partial volume effect in absolute values of kinetic parameters for [11C]PiB, in terms of spillover from white matter. Dynamic data acquired in [11C]PiB PET scans with five healthy volunteers and eight patients with Alzheimer's disease were corrected with region-based and voxel-based partial volume corrections. Binding potential (BPND) was estimated using the two-tissue compartment model analysis with a plasma input function. Partial volume corrections significantly decreased cortical BPND values. The degree of decrease in healthy volunteers (-52.7±5.8%) was larger than that in Alzheimer's disease patients (-11.9±4.2%). The simulation demonstrated that white matter spillover signals due to the partial volume effect resulted in an overestimation of cortical BPND, with a greater degree of overestimation for lower BPND values. Thus, an overestimation due to partial volume effects is more severe in healthy volunteers than in Alzheimer's disease patients. Partial volume corrections may be useful for accurately quantifying Aß deposition in cortical regions.

Association between floating toe and toe grip strength in school age children: a cross-sectional study.

[Purpose] This study investigated the association between floating toe and toe grip strength. [Subjects and Methods] A total of 635 Japanese children aged 9-11 years participated in this study. Floating toe was evaluated using footprint images, while toe grip strength was measured using a toe grip dynamometer. All 1,270 feet were classified into a floating toe group and a normal toe group according to visual evaluation of the footprint images. Intergroup differences in toe grip strength were analyzed using the unpaired t-test and logistic regression analysis adjusted for age, gender, and Rohrer Index. [Results] There were 512 feet (40.3%) in the floating toe group. Mean toe grip strength of the feet with floating toe was significantly lower than that of normal feet (floating toe group, 12.9 ± 3.7 kg; normal toe group, 13.6 ± 4.1 kg). In addition, lower toe grip strength was associated with floating toe on logistic regression analysis after adjustment for age, gender, and Rohrer Index (odds ratio, 0.954; 95% confidence interval, 0.925-0.984). [Conclusion] This study revealed that lower toe grip strength was significantly associated with floating toe. Therefore, increasing toe grip strength may play a role in preventing floating toe in school age children.

Visualization of small brain nuclei with a high-spatial resolution, clinically available whole-body PET scanner.

OBJECTIVE: To verify the visibility of physiological 18F-fluorodeoxyglucose (18F-FDG) uptake in nuclei in and around the brainstem by a whole-body (WB) silicon photomultiplier positron emission tomography (SiPM-PET) scanner with point-spread function (PSF) reconstruction using various iteration numbers. METHODS: Ten healthy subjects (5 men, 5 women; mean age, 56.0 ± 5.0 years) who underwent 18F-FDG PET/CT using a WB SiPM-PET scanner and magnetic resonance imaging (MRI) of the brain including a spin-echo three-dimensional sampling perfection with application-optimized contrasts using different flip angle evolutions fluid-attenuated inversion recovery (3D-FLAIR) and a 3D-T1 magnetization-prepared rapid gradient-echo (T1-MPRAGE) images were enrolled. Each acquired PET image was reconstructed using ordered-subset expectation maximization (OSEM) with iteration numbers of 4, 16, 64, and 256 (subset 5 fixed) + time-of-flight (TOF) + PSF. The reconstructed PET images and 3D-FLAIR images for each subject were registered to individual T1-MPRAGE volumes using normalized mutual information criteria. For each MR-coregistered individual PET image, the pattern of FDG uptake in the inferior olivary nuclei (ION), dentate nuclei (DN), midbrain raphe nuclei (MRN), inferior colliculi (IC), mammillary bodies (MB), red nuclei (RN), subthalamic nuclei (STN), lateral geniculate nuclei (LGN), medial geniculate nuclei (MGN), and superior colliculi (SC) was visually classified into the following three categories: good, clearly distinguishable FDG accumulation; fair, obscure contour of FDG accumulation; poor, FDG accumulation indistinguishable from surrounding uptake. RESULTS: Among individual 18F-FDG PET images with OSEM iterations of 4, 16, 64, and 256 + TOF + PSF, the iteration numbers that showed the best visibility in each structure were as follows: ION, MRN, LGN, MGN, and SC, iteration 64; DN, iteration 16; IC, iterations 16, 64, and 256; MB, iterations 64 and 256; and RN and STN, iterations 16 and 64, respectively. Of the four iterations, the 18F-FDG PET image of iteration 64 visualized FDG accumulation in small structures in and around the brainstem most clearly (good, 98 structures; fair, 2 structures). CONCLUSIONS: A clinically available WB SiPM-PET scanner is useful for visualizing physiological FDG uptake in small brain nuclei, using a sufficiently high number of iterations for OSEM with TOF and PSF reconstructions.

Renal pelvic plasmacytoid subtype urothelial carcinoma accompanied with solitary mammary metastasis.

A 72-year-old female was referred to our institution for further evaluation of right renal tumor detected during work-up for macroscopic hematuria in other hospital. CT urography performed at our institution suggested renal pelvic tumor. Voiding cytology was atypical. CT also revealed a small mass in the right mammary gland. Percutaneous needle biopsies were performed on the right mammary gland and renal mass, leading to a pathological diagnosis of UC with plasmacytoid subtype, suggesting metastasis from the renal pelvic UC to the mammary gland. She had a favorable response to four cycles of dose-dense MVAC therapy; therefore, we performed nephroureterectomy. One month after nephroureterectomy, new intraperitoneal metastatic lesions were observed and pembrolizumab therapy was started. After seven doses of pembrolizumab, CT revealed a marked size reduction of intraperitoneal metastases and the mammary metastasis remained small.

Exploratory mass cytometry analysis reveals immunophenotypes of cancer treatment-related pneumonitis.

Anticancer treatments can result in various adverse effects, including infections due to immune suppression/dysregulation and drug-induced toxicity in the lung. One of the major opportunistic infections is Pneumocystis jirovecii pneumonia (PCP), which can cause severe respiratory complications and high mortality rates. Cytotoxic drugs and immune-checkpoint inhibitors (ICIs) can induce interstitial lung diseases (ILDs). Nonetheless, the differentiation of these diseases can be difficult, and the pathogenic mechanisms of such diseases are not yet fully understood. To better comprehend the immunophenotypes, we conducted an exploratory mass cytometry analysis of immune cell subsets in bronchoalveolar lavage fluid from patients with PCP, cytotoxic drug-induced ILD (DI-ILD), and ICI-associated ILD (ICI-ILD) using two panels containing 64 markers. In PCP, we observed an expansion of the CD16+ T cell population, with the highest CD16+ T proportion in a fatal case. In ICI-ILD, we found an increase in CD57+ CD8+ T cells expressing immune checkpoints (TIGIT+ LAG3+ TIM-3+ PD-1+), FCRL5+ B cells, and CCR2+ CCR5+ CD14+ monocytes. These findings uncover the diverse immunophenotypes and possible pathomechanisms of cancer treatment-related pneumonitis.

Characterization of titanium particles treated with N2 plasma using a barrel-plasma-treatment system.

Metallic titanium (Ti) particles treated with N2 plasma via the barrel-plasma-treatment system were thoroughly evaluated, to investigate changes in physical and chemical properties resulting from the treatment. The color of the Ti particles changed from gray to uniform brown upon plasma-treatment, indicating good surface uniformity. Depth profiling using X-ray photoelectron spectroscopy showed that the nitrogen implanted by plasma-treatment formed Ti-N bonds at or near the surface of the particles, resulting in the formation of a stoichiometric TiN layer. It was determined from cross-sectional transmission electron microscopy and nanobeam diffraction measurements that the resulting TiN layer had two different structures. Nanoindentation data showed that the surface of a treated sample was about five times harder than that of untreated particles.

Association between forefoot pain and sesamoid rotation angle determined using a weight-bearing plantar ultrasound imaging device.

Forefoot pain is a common symptom for several foot problems. This study aimed to determine whether parameters of forefoot structure (hallux valgus angle (HVA), transverse arch height (TAH) and sesamoid rotation angle (SRA)) are associated with forefoot pain. 547 feet of adult women were divided into two groups: without pain (n = 472) and with pain (n = 75). HVA was measured with a goniometer, TAH and SRA were measured using a weight bearing plantar ultrasound imaging device.Associations between forefoot pain and parameters of forefoot structure were analyzed using the Mann-Whitney U test and univariate and multivariate logistic regression analyses. The intra-rater and inter-rater reliability of the ultrasound images were also tested. SRA was significantly greater in the group with pain compared to the group without pain (p = 0.031) but not HVA (p = 0.057) nor TAH (p = 0.117). The association between forefoot pain and SRA was significant (univariate: p = 0.015 and multivariate p = 0.015), but not between HVA nor TAH. The intra-rater and inter-rater reliability were almost perfect (SRA: ICC1,1 = 0.94, ICC2,1 = 0.91 and TAH: ICC1,1 = 0.88, ICC2,1 = 0.81). We conclude that a higher SRA is related to forefoot pain and should be taken into consideration for assessment of patients with forefoot pain.

Altered macrophage phenotypes in a case of autoimmune pulmonary alveolar proteinosis.

Mass cytometry of BALF cells from a pulmonary alveolar proteinosis patient, positive for anti-GM-CSF antibodies, suggests potential impairment in human alveolar macrophage differentiation https://bit.ly/45JHUrz.

Expansion of ST2-expressing macrophages in a patient with bronchiolitis obliterans syndrome.

This case study of a patient with BOS after HSCT found increased ST2+CD64+ macrophages in BALF, a potential therapeutic target for treatment-refractory BOS, and reduced CCR2+CD14+ monocytes compared to other lung disorders https://bit.ly/406Uyy9.

Mass cytometry identifies characteristic immune cell subsets in bronchoalveolar lavage fluid from interstitial lung diseases.

Immune cells have been implicated in interstitial lung diseases (ILDs), although their phenotypes and effector mechanisms remain poorly understood. To better understand these cells, we conducted an exploratory mass cytometry analysis of immune cell subsets in bronchoalveolar lavage fluid (BALF) from patients with idiopathic pulmonary fibrosis (IPF), connective-tissue disease (CTD)-related ILD, and sarcoidosis, using two panels including 64 markers. Among myeloid cells, we observed the expansion of CD14+ CD36hi CD84hiCCR2- monocyte populations in IPF. These CD14+ CD36hi CD84hi CCR2- subsets were also increased in ILDs with a progressive phenotype, particularly in a case of acute exacerbation (AEx) of IPF. Analysis of B cells revealed the presence of cells at various stages of differentiation in BALF, with a higher percentage of IgG memory B cells in CTD-ILDs and a trend toward more FCRL5+ B cells. These FCRL5+ B cells were also present in the patient with AEx-IPF and sarcoidosis with advanced lung lesions. Among T cells, we found increased levels of IL-2R+ TIGIT+ LAG3+ CD4+ T cells in IPF, increased levels of CXCR3+ CD226+ CD4+ T cells in sarcoidosis, and increased levels of PD1+ TIGIT+ CD57+ CD8+ T cells in CTD-ILDs. Together, these findings underscore the diverse immunopathogenesis of ILDs.

Cholesterol sulfate limits neutrophil recruitment and gut inflammation during mucosal injury.

During mucosal injury, intestinal immune cells play a crucial role in eliminating invading bacteria. However, as the excessive accumulation of immune cells promotes inflammation and delays tissue repair, it is essential to identify the mechanism that limits the infiltration of immune cells to the mucosal-luminal interface. Cholesterol sulfate (CS) is the lipid product of the sulfotransferase SULT2B1 and suppresses immune reactions by inhibiting DOCK2-mediated Rac activation. In this study, we aimed to elucidate the physiological role of CS in the intestinal tract. We found that, in the small intestine and colon, CS is predominantly produced in the epithelial cells close to the lumen. While dextran sodium sulfate (DSS)-induced colitis was exacerbated in Sult2b1-deficient mice with increased prevalence of neutrophils, the elimination of either neutrophils or intestinal bacteria in Sult2b1-deficient mice attenuated disease development. Similar results were obtained when the Dock2 was genetically deleted in Sult2b1-deficient mice. In addition, we also show that indomethacin-induced ulcer formation in the small intestine was exacerbated in Sult2b1-deficient mice and was ameliorated by CS administration. Thus, our results uncover that CS acts on inflammatory neutrophils, and prevents excessive gut inflammation by inhibiting the Rac activator DOCK2. The administration of CS may be a novel therapeutic strategy for inflammatory bowel disease and non-steroidal anti-inflammatory drug-induced ulcers.