Large-vessel vasculitis possibly induced by BRAF and MEK inhibitors for BRAF V600E positive lung adenocarcinoma.

The combination therapy of v-Raf murine sarcoma viral oncogene homolog B1 (BRAF) and mitogen-activated protein kinase kinase (MEK) inhibitors is approved for treating patients with BRAF V600E-positive tumours, including melanoma and lung cancer. Several case reports indicated autoimmune side effects associated with the use of BRAF and MEK inhibitors. Still, the effects of these drugs on the immune system were not fully elucidated. Here, we report a patient with large-vessel vasculitis diagnosed after initiation of treatment with dabrafenib and trametinib for BRAF V600E-positive metastatic lung adenocarcinoma. She was a never-smoker woman in her early 70s who presented with a chronic cough and was diagnosed with BRAF V600E-positive metastatic lung adenocarcinoma by transbronchial lung biopsy. She was successfully treated with prednisolone and methotrexate while BRAF and MEK inhibitors were continued. We should be careful about autoimmune diseases using BRAF and MEK inhibitors.

Efficacy and safety of abatacept in patients with rheumatoid arthritis with previous malignancy.

Background: Abatacept (ABT) is known to lower infection risk than other biologics and is effective and safe in elderly patients with rheumatoid arthritis (RA). However, there were inconsistent reports on the impact of ABT on malignancies which are more common in the elderly and strongly related to prognosis. Objectives: This study aimed to evaluate the efficacy and safety of ABT in patients with RA with previous malignancy in clinical practice. Design: A multicenter, retrospective study. Methods: Patients who received ABT for RA in two hospitals in Yokohama until May 2022 were included in this study. The patients were divided into two groups according to the presence or absence of a history of malignancy (no previous malignancy: NP group, previous malignancy: PM group). The collected parameters were compared between the groups using propensity score matching. Results: In this study, 312 patients were included, of whom 73 had previous malignancies when starting ABT. The age at ABT initiation was significantly higher in the PM group, the rate of methotrexate use was significantly lower in the PM group, and the Steinbrocker stage was significantly higher in the PM group. After matching these 3 factors, 68 patients were selected from each group. No significant differences in the ABT continuation rate, and malignancy incidence were observed between the two groups after ABT initiation. In addition to these factors, when matched for smoking history, interstitial lung disease, disease duration, sex, and inflammatory status, which are known risk factors for malignancy in RA, 40 patients were selected from each group. No significant differences in the ABT continuation rate, and malignancy incidence were observed between the two groups after ABT initiation. Conclusion: In our clinical practice, ABT was as effective and safe in patients with a history of malignancy as in those without.

Direct evaluation of cohesin-mediated sister kinetochore associations at meiosis I in fission yeast.

Kinetochores drive chromosome segregation by mediating chromosome interactions with the spindle. In higher eukaryotes, sister kinetochores are separately positioned on opposite sides of sister centromeres during mitosis, but associate with each other during meiosis I. Kinetochore association facilitates the attachment of sister chromatids to the same pole, enabling the segregation of homologous chromosomes toward opposite poles. In the fission yeast, Schizosaccharomyces pombe, Rec8-containing meiotic cohesin is suggested to establish kinetochore associations by mediating cohesion of the centromere cores. However, cohesin-mediated kinetochore associations on intact chromosomes have never been demonstrated directly. In the present study, we describe a novel method for the direct evaluation of kinetochore associations on intact chromosomes in live S. pombe cells, and demonstrate that sister kinetochores and the centromere cores are positioned separately on mitotic chromosomes but associate with each other on meiosis I chromosomes. Furthermore, we demonstrate that kinetochore association depends on meiotic cohesin and the cohesin regulators Moa1 and Mrc1, and requires mating-pheromone signaling for its establishment. These results confirm cohesin-mediated kinetochore association and its regulatory mechanisms, along with the usefulness of the developed method for its analysis. This article has an associated First Person interview with the first author of the paper.

Initial hydroxychloroquine monotherapy in systemic lupus erythematosus: report of three cases.

Glucocorticoids (GCs) use is associated with increased organ damage in systemic lupus erythematosus (SLE), and the treatment goal is to stop their use. Treatment with hydroxychloroquine (HCQ) without daily GCs may benefit patients by minimising the cumulative dose of GCs, but clinical experience with HCQ monotherapy is limited. To accumulate evidence for initial HCQ monotherapy in SLE, we retrospectively analysed three new SLE patients who visited Yokohama City University Hospital in 2015. The patients were all Japanese females with a mean age of 26.0 ± 5.3 years, high anti-dsDNA antibody titres, no major organ damage, and a mean pre-treatment Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) score of 9.3 ± 3.1. During the mean observation period of 3.8 ± 0.8 years, none of them received daily GCs or immunosuppressants, but one of the three patients were treated with short-term oral GCs and NSAIDs for a skin rash or arthralgia flairs. SLEDAI-2K was reduced to 3.3 ± 1.2. No other new SLE symptoms emerged, and the Systemic Lupus International Collaborating Clinics Damage Index (SDI) of them were maintained at 0. None of the patients developed HCQ-related retinal toxicity. Current experience with initial HCQ monotherapy suggests that such a therapeutic strategy may be useful in managing disease activity and preserving cumulative GCs in SLE patients without organ involvements.

Joint angle based motor point tracking stimulation for surface FES: A Study on biceps brachii.

Functional electrical stimulation (FES) has been an effective treatment option in clinical rehabilitation such as motor function recovery after stroke. The main limitation of FES is the lack of stimulation efficiency in motor unit recruitment compared with voluntary contractions, which may cause the early onset of muscle fatigue. The stimulation efficiency of FES can be improved by optimizing electrode positions to target the motor point (MP). However, the location of MP relative to the skin may shift with the change of muscle geometry during dynamic exercise. Hence, the purpose of this study is to maintain the stimulation efficiency of FES in dynamic exercise by switching the stimulation position to follow the shift of MP. We first measured the shift of the MP of the biceps brachii with respect to the elbow joint angle, and then conducted an experiment to compare four stimulation methods: 2-channel simultaneous stimulation (SS), 2-channel time based shifting stimulation (TSS), 2-channel joint angle based shifting stimulation (JASS), and 3-channel JASS. TSS and JASS were designed as two different MP tracking strategies. The experimental results show that the 3-channel JASS caused the smallest decrease in the maximal elbow angle and the angular velocity. The results also suggest that MP tracking stimulation based on joint angle is effective for the sustainable induction of muscle contraction. Both tracking selectivity and tracking density were shown to be important to improve the stimulation efficiency of FES.

A Taz1- and Microtubule-Dependent Regulatory Relationship between Telomere and Centromere Positions in Bouquet Formation Secures Proper Meiotic Divisions.

During meiotic prophase, telomeres cluster, forming the bouquet chromosome arrangement, and facilitate homologous chromosome pairing. In fission yeast, bouquet formation requires switching of telomere and centromere positions. Centromeres are located at the spindle pole body (SPB) during mitotic interphase, and upon entering meiosis, telomeres cluster at the SPB, followed by centromere detachment from the SPB. Telomere clustering depends on the formation of the microtubule-organizing center at telomeres by the linker of nucleoskeleton and cytoskeleton complex (LINC), while centromere detachment depends on disassembly of kinetochores, which induces meiotic centromere formation. However, how the switching of telomere and centromere positions occurs during bouquet formation is not fully understood. Here, we show that, when impaired telomere interaction with the LINC or microtubule disruption inhibited telomere clustering, kinetochore disassembly-dependent centromere detachment and accompanying meiotic centromere formation were also inhibited. Efficient centromere detachment required telomere clustering-dependent SPB recruitment of a conserved telomere component, Taz1, and microtubules. Furthermore, when artificial SPB recruitment of Taz1 induced centromere detachment in telomere clustering-defective cells, spindle formation was impaired. Thus, detachment of centromeres from the SPB without telomere clustering causes spindle impairment. These findings establish novel regulatory mechanisms, which prevent concurrent detachment of telomeres and centromeres from the SPB during bouquet formation and secure proper meiotic divisions.