Clinical Activity and Exploratory Resistance Mechanism of Milademetan, an MDM2 Inhibitor, in Intimal Sarcoma with MDM2 Amplification: An Open-Label Phase Ib/II Study.

Intimal sarcoma is an extremely rare, life-threatening malignant neoplasm. Murine double minute 2 (MDM2) amplification is observed in >70% of intimal sarcomas. Milademetan, an MDM2 inhibitor, may provide clinical benefit in this patient population. We conducted a phase Ib/II study in patients with MDM2-amplified, wild-type TP53 intimal sarcoma as a substudy of a large nationwide registry for rare cancers in Japan. Milademetan (260 mg) was administered orally once daily for 3 days every 14 days, twice in a 28-day cycle. Of 11 patients enrolled, 10 were included in the efficacy analysis. Two patients (20%) showed durable responses for >15 months. Antitumor activity correlated with TWIST1 amplification (P = 0.028) and negatively with CDKN2A loss (P = 0.071). Acquired TP53 mutations were detected in sequential liquid biopsies as a novel exploratory resistance mechanism to milademetan. These results suggest that milademetan could be a potential therapeutic strategy for intimal sarcoma. SIGNIFICANCE: Strategies to optimize outcomes could include the use of new biomarkers (TWIST1 amplification and CDKN2A loss) to select patients with MDM2-amplified intimal sarcoma who might benefit from milademetan and combination with other targeted treatments. Sequential liquid biopsy of TP53 can be used to evaluate disease status during treatment with milademetan. See related commentary by Italiano, p. 1765. This article is highlighted in the In This Issue feature, p. 1749.

Pulmonary cancers across different histotypes share hybrid tuft cell/ionocyte-like molecular features and potentially druggable vulnerabilities.

Tuft cells are chemosensory epithelial cells in the respiratory tract and several other organs. Recent studies revealed tuft cell-like gene expression signatures in some pulmonary adenocarcinomas, squamous cell carcinomas (SQCC), small cell carcinomas (SCLC), and large cell neuroendocrine carcinomas (LCNEC). Identification of their similarities could inform shared druggable vulnerabilities. Clinicopathological features of tuft cell-like (tcl) subsets in various lung cancer histotypes were studied in two independent tumor cohorts using immunohistochemistry (n = 674 and 70). Findings were confirmed, and additional characteristics were explored using public datasets (RNA seq and immunohistochemical data) (n = 555). Drug susceptibilities of tuft cell-like SCLC cell lines were also investigated. By immunohistochemistry, 10-20% of SCLC and LCNEC, and approximately 2% of SQCC expressed POU2F3, the master regulator of tuft cells. These tuft cell-like tumors exhibited "lineage ambiguity" as they co-expressed NCAM1, a marker for neuroendocrine differentiation, and KRT5, a marker for squamous differentiation. In addition, tuft cell-like tumors co-expressed BCL2 and KIT, and tuft cell-like SCLC and LCNEC, but not SQCC, also highly expressed MYC. Data from public datasets confirmed these features and revealed that tuft cell-like SCLC and LCNEC co-clustered on hierarchical clustering. Furthermore, only tuft cell-like subsets among pulmonary cancers significantly expressed FOXI1, the master regulator of ionocytes, suggesting their bidirectional but immature differentiation status. Clinically, tuft cell-like SCLC and LCNEC had a similar prognosis. Experimentally, tuft cell-like SCLC cell lines were susceptible to PARP and BCL2 co-inhibition, indicating synergistic effects. Taken together, pulmonary tuft cell-like cancers maintain histotype-related clinicopathologic characteristics despite overlapping unique molecular features. From a therapeutic perspective, identification of tuft cell-like LCNECs might be crucial given their close kinship with tuft cell-like SCLC.

Application of ultrasound in a case of eosinophilic fasciitis mimicking stiff-person syndrome.

Eosinophilic fasciitis (EF) is a rare disorder characterized by muscle stiffness mimicking other neuromuscular diseases. The diagnosis of EF is made on the basis of typical skin lesions. We report a case of a 36-year-old male patient with suspected stiff-person syndrome (SPS), who presented with progressive limb muscle stiffness and limited mobility of both wrists without obvious skin changes. Ultrasound revealed fascial thickening of bilateral upper and lower limb muscles and enlargement of hypoechoic tissues around the flexor digitorum tendons of the wrist. Skin and fascia biopsy confirmed the diagnosis of EF. Prednisolone therapy resulted in the improvement of muscle stiffness and tightness. Our findings suggest the need to consider connective tissue diseases such as EF in a patient with atypical features of SPS. Ultrasound is helpful for visualizing the causes of muscle stiffness and joint contractures in EF patients.

Multicenter phase II trial of trastuzumab deruxtecan for HER2-positive unresectable or recurrent biliary tract cancer: HERB trial.

Trastuzumab deruxtecan (DS-8201) is an antibody-drug conjugate composed of a humanized monoclonal anti-HER2 antibody, a cleavable tetrapeptide-based linker and a potent topoisomerase I inhibitor. The drug's efficacy has been proven in HER2-positive breast and gastric cancers. The rate of HER2 positivity in biliary tract cancer (BTC) has been reported to be 5-20%, and case reports and clinical trials have suggested that HER2 inhibitors might be active in HER2-positive BTC. Here we describe the rationale and design of the phase II HERB trial that will evaluate the efficacy and safety of trastuzumab deruxtecan in patients with HER2-expressing unresectable or recurrent BTC. The primary end point will be the centrally assessed objective response rate in HER2-positive patients.

Trastuzumab deruxtecan (DS-8201) is a new drug against HER2, a receptor on cell membranes that has sensitivity to targeted inhibitors. The drug's efficacy has been proven in HER2-positive breast and gastric cancers. Some studies have suggested that HER2 inhibitors might be active in HER2-positive biliary tract cancers. This article describes the design of a new clinical trial. The HERB trial is designed to evaluate the efficacy and safety of trastuzumab deruxtecan in patients with HER2-expressing biliary tract cancers. Clinical trial registration: JMA-IIA00423.

Complex hereditary peripheral neuropathies caused by novel variants in mitochondrial-related nuclear genes.

Mitochondrial disorders are a group of clinically and genetically heterogeneous multisystem disorders and peripheral neuropathy is frequently described in the context of mutations in mitochondrial-related nuclear genes. This study aimed to identify the causative mutations in mitochondrial-related nuclear genes in suspected hereditary peripheral neuropathy patients. We enrolled a large Japanese cohort of clinically suspected hereditary peripheral neuropathy patients who were mutation negative in the prescreening of the known Charcot-Marie-Tooth disease-causing genes. We performed whole-exome sequencing on 247 patients with autosomal recessive or sporadic inheritance for further analysis of 167 mitochondrial-related nuclear genes. We detected novel bi-allelic likely pathogenic/pathogenic variants in four patients, from four mitochondrial-related nuclear genes: pyruvate dehydrogenase beta-polypeptide (PDHB), mitochondrial poly(A) polymerase (MTPAP), hydroxyacyl-CoA dehydrogenase/3-ketoacyl-CoA thiolase/enoyl-CoA hydratase, beta subunit (HADHB), and succinate-CoA ligase ADP-forming beta subunit (SUCLA2). All these patients showed sensory and motor axonal polyneuropathy, combined with central nervous system or multisystem involvements. The pathological analysis of skeletal muscles revealed mild neurogenic changes without significant mitochondrial abnormalities. Targeted screening of mitochondria-related nuclear genes should be considered for patients with complex hereditary axonal polyneuropathy, accompanied by central nervous system dysfunctions, or with unexplainable multisystem disorders.

Intrathymic Plasmablasts Are Affected in Patients With Myasthenia Gravis With Active Disease.

BACKGROUND AND OBJECTIVES: To investigate intrathymic B lymphopoiesis in patients with myasthenia gravis (MG) and explore thymus pathology associated with clinical impact. METHODS: Thymic lymphocytes from 15 young patients without MG, 22 adult patients without MG, 14 patients with MG without thymoma, and 11 patients with MG with thymoma were subjected to flow cytometry analysis of T follicular helper (Tfh), naive B, memory B, plasmablasts, CD19+B220high thymic B cells, B-cell activating factor receptor, and C-X-C chemokine receptor 5 (CXCR5). Peripheral blood mononuclear cells of 16 healthy subjects and 21 untreated patients with MG were also analyzed. Immunologic values were compared, and correlations between relevant values and clinical parameters were evaluated. RESULTS: The frequencies of circulating and intrathymic plasmablasts were significantly higher in patients with MG than controls. On the other hand, the frequency of CD19+B220high thymic B cells was not increased in MG thymus. We observed a significant increase in CXCR5 expression on plasmablasts in MG thymus and an increased frequency of intrathymic plasmablasts that was correlated with preoperative disease activity. The frequency of intrathymic Tfh cells was significantly lower in patients who received immunosuppressive (IS) therapy than those without IS therapy. However, there was no significant difference in the frequency of intrathymic plasmablasts irrespective of IS therapy. DISCUSSION: Our findings confirmed a correlation between increased frequency of intrathymic plasmablasts and disease activity before thymectomy. We postulate that activated intrathymic plasmablasts endow pathogenic capacity in MG.

Effect of antioxidant supplementation on skeletal muscle and metabolic profile in aging mice.

Aging induces drastic changes in muscle mass and function (sarcopenia); however, the detailed mechanisms underlying sarcopenia remain poorly understood. Recent studies suggested that age-related increases in oxidative stress induce muscle atrophy. In this study, we investigated the effect of 6-month supplementation of antioxidants, specifically piceatannol (PIC) and enzymatically modified isoquercitrin (EMIQ), on age-related physiological changes, including skeletal muscle weight and quality, in 25-month-old (OLD) mice, compared to in 4-month-old (young, YNG) C57BL/6J mice. Muscle weight corrected by body weight significantly declined in OLD mice, compared to in YNG mice. The control OLD mice also showed changes in the expression of genes related to muscle fiber type, reduced locomotor activity, and increased oxidative stress markers in blood. Consistent with the muscle weight and quality changes, whole-body fat oxidation during sedentary conditions and exercise periods in control OLD mice was significantly lower than that in YNG mice. Interestingly, compared to the control OLD mice, the PIC- or EMIQ-fed OLD mice showed higher fat oxidation. Furthermore, EMIQ, but not PIC, increased locomotor activity, the expression of genes encoding antioxidant enzymes, and suppressed the carbonylated protein in the skeletal muscle of OLD mice. These results suggested that chronic antioxidant intake could alleviate aging-related muscle function changes.

Prediction of improvement after extended thymectomy in non-thymomatous myasthenia gravis patients.

BACKGROUND: It is popularly believed that myasthenia gravis (MG) patients show acetylcholine receptor antibody (AChRAb) production associated with the thymus (germinal centers, approximately 80%). It has been suggested that thymectomy can remove the area of autoantibody production. This study aimed to determine whether the solid volume of the thymus calculated using three-dimensional (3D) imaging could be used to predict the efficacy of thymectomy. Additionally, the study assessed the relationships of the solid volume with germinal centers, change in the serum AChRAb level, postoperative MG improvement, and prednisolone (PSL) dose reduction extent. METHODS: This retrospective study included 12 consecutive non-thymomatous MG patients (9 female and 3 male patients), who underwent extended thymectomy at our institution over the last 10 years. The mean patient age was 43.3 ± 14.2 years (range, 12-59 years). The study assessed the number of germinal centers per unit area, change in the serum AChRAb level, postoperative MG improvement, PSL dose reduction extent, and solid volume of the thymus. RESULTS: The number of germinal centers per unit area was significantly correlated with the solid volume of the thymus. The PSL dose reduction extent tended to be correlated with the solid volume. CONCLUSIONS: Our findings suggest that the solid volume of the thymus can possibly predict steroid dose reduction. Additionally, the solid volume of the thymus in 3D images is the most important indicator for predicting the efficacy of extended thymectomy.

The updated retrospective questionnaire study of sporadic inclusion body myositis in Japan.

BACKGROUND: Sporadic inclusion body myositis (sIBM) is the most prevalent muscle disease in elderly people, affecting the daily activities. sIBM is progressive with unknown cause and without effective treatment. In 2015, sIBM was classified as an intractable disease by the Japanese government, and the treatment cost was partly covered by the government. This study aimed to examine the changes in the number of patients with sIBM over the last 10 years and to elucidate the cross-sectional profile of Japanese patients with sIBM. METHODS: The number of sIBM patients was estimated through a reply-paid postcard questionnaire for attending physicians. Only patients diagnosed as "definite" or "probable" sIBM by clinical and biopsy sIBM criteria were included in this study (Lancet Neurol 6:620-631, 2007, Neuromuscul Disord 23:1044-1055, 2013). Additionally, a registered self-administered questionnaire was also sent to 106 patients who agreed to reply via their attending physician, between November 2016 and March 2017. RESULTS: The number of patients diagnosed with sIBM for each 5-year period was 286 and 384 in 2011 and 2016, respectively. Inability to stand-up, cane-dependent gait, inability to open a plastic bottle, choking on food ingestion, and being wheelchair-bound should be included as sIBM milestones. Eight patients were positive for anti-hepatitis C virus antibody; three of them were administered interferon before sIBM onset. Steroids were administered to 33 patients (31.1%) and intravenous immunoglobulin to 46 patients (43.4%). From 2016 to 2017, total of 70 patients applied for the designated incurable disease medical expenses subsidy program. Although the treatment cost was partly covered by the government, many patients expressed psychological/mental and financial anxieties. CONCLUSIONS: We determined the cross-sectional profile of Japanese patients with sIBM. Continuous support and prospective surveys are warranted.

Effect of Glutathione Bio-Molecule on Tooth Discoloration Associated with Silver Diammine Fluoride.

This study evaluated the effect of Glutathione (GSH) bio-molecule on the reduction of enamel and dentin discoloration after application of 38% silver diammine fluoride solution (SDF). One hundred and twenty bovine teeth specimens were used. The enamel and dentin specimens were divided into three groups: (1) SDF only (control); (2) SDF followed by application of a potassium iodide solution (KI); and (3) SDF mixed with 20% GSH. Half the specimens were exposed to light and the remainder kept in dark conditions (n = 10) Color changes were measured using a spectrophotometer at the following time intervals: before solution application (baseline) and immediately after application, then 3, 6, 24, 48, 72 h, and 7, 10 and 14 days. SEM/EDS analysis was performed on treated enamel and dentin. Statistical analysis was done using a repeated measures ANOVA test. The spectrophotometer results showed that the SDF group exhibited the greatest color changes under both light exposed and dark conditions, while SDF + GSH group was effective in decreasing the color changes in both light and dark conditions. The SDF + KI group showed an insignificant color changes over time. SEM/EDS analysis showed different patterns for the silver crystal formation in each group (SDF, SDF + GSH, and SDF + KI group). It was concluded GSH can effectively minimize color changes after application of SDF, especially on enamel and to a lesser extent on dentin.

Inhibition of NGLY1 Inactivates the Transcription Factor Nrf1 and Potentiates Proteasome Inhibitor Cytotoxicity.

Proteasome inhibitors are used to treat blood cancers such as multiple myeloma (MM) and mantle cell lymphoma. The efficacy of these drugs is frequently undermined by acquired resistance. One mechanism of proteasome inhibitor resistance may involve the transcription factor Nuclear Factor, Erythroid 2 Like 1 (NFE2L1, also referred to as Nrf1), which responds to proteasome insufficiency or pharmacological inhibition by upregulating proteasome subunit gene expression. This "bounce-back" response is achieved through a unique mechanism. Nrf1 is constitutively translocated into the ER lumen, N-glycosylated, and then targeted for proteasomal degradation via the ER-associated degradation (ERAD) pathway. Proteasome inhibition leads to accumulation of cytosolic Nrf1, which is then processed to form the active transcription factor. Here we show that the cytosolic enzyme N-glycanase 1 (NGLY1, the human PNGase) is essential for Nrf1 activation in response to proteasome inhibition. Chemical or genetic disruption of NGLY1 activity results in the accumulation of misprocessed Nrf1 that is largely excluded from the nucleus. Under these conditions, Nrf1 is inactive in regulating proteasome subunit gene expression in response to proteasome inhibition. Through a small molecule screen, we identified a cell-active NGLY1 inhibitor that disrupts the processing and function of Nrf1. The compound potentiates the cytotoxicity of carfilzomib, a clinically used proteasome inhibitor, against MM and T cell-derived acute lymphoblastic leukemia (T-ALL) cell lines. Thus, NGLY1 inhibition prevents Nrf1 activation and represents a new therapeutic approach for cancers that depend on proteasome homeostasis.

Memory B cell resurgence requires repeated rituximab in myasthenia gravis.

The immunologic effects of rituximab (RTX) in myasthenia gravis (MG) remain to be explored. We aimed to clarify immunologic reactions and their association with response to RTX in MG. Regulatory T cell and B cell profiles of MG patients were monitored. Two patients presenting with generalized MG with anti-acetylcholine receptor antibodies were treated with RTX. The treatment led to sustained clinical improvement, discontinuation of intravenous immunoglobulin or plasma exchange, and reduction of prednisolone and other drugs. One patient was in remission for more than one year, whereas the other patient exhibited deterioration of symptoms within one year. Disease activity was associated with the repopulation of IgD-CD27- and IgD-CD27+ memory B cells. Clinicians should be aware of the possibility that MG ranges in the duration of B cell depletion and additional RTX should be prescribed upon resurgence of memory B cells.

Preventive effect of dietary quercetin on disuse muscle atrophy by targeting mitochondria in denervated mice.

Quercetin is a major dietary flavonoid in fruits and vegetables. We aimed to clarify the preventive effect of dietary quercetin on disuse muscle atrophy and the underlying mechanisms. We established a mouse denervation model by cutting the sciatic nerve in the right leg (SNX surgery) to lack of mobilization in hind-limb. Preintake of a quercetin-mixed diet for 14days before SNX surgery prevented loss of muscle mass and atrophy of muscle fibers in the gastrocnemius muscle (GM). Phosphorylation of Akt, a key phosphorylation pathway of suppression of protein degradation, was activated in the quercetin-mixed diet group with and without SNX surgery. Intake of a quercetin-mixed diet suppressed the generation of hydrogen peroxide originating from mitochondria and elevated mitochondrial peroxisome proliferator-activated receptor-γ coactivator 1α mRNA expression as well as NADH dehydrogenase 4 expression in the GM with SNX surgery. Quercetin and its conjugated metabolites reduced hydrogen peroxide production in the mitochondrial fraction obtained from atrophied muscle. In C2C12 myotubes, quercetin reached the mitochondrial fraction. These findings suggest that dietary quercetin can prevent disuse muscle atrophy by targeting mitochondria in skeletal muscle tissue through protecting mitochondria from decreased biogenesis and reducing mitochondrial hydrogen peroxide release, which can be related to decreased hydrogen peroxide production and/or improvements on antioxidant capacity of mitochondria.

B-cell lymphoma with Mott cell differentiation in a cat.

A 12-year-old, male castrated Domestic Shorthair cat was presented to Animal Medical Center of Gifu Univeristy with anorexia and vomiting. Physical examination revealed an enlarged left tonsil and right mandibular lymph node (approximately 2-3× the normal size), and a submucosal mass on the right side of the epiglottis (1.5 × 2.0 cm). On computed tomography images, an enlarged left tonsil, and enlarged right mandibular, right pharyngeal, and left and right cervical lymph nodes were observed. Cytologic examination of smears of tonsil and lymph nodes revealed numerous medium- to large-sized neoplastic lymphoid cells, approximately half of which contained one or several light-blue homogenous globoid cytoplasmic inclusions (5-10 µm), which stained magenta with periodic acid-Schiff (PAS) stain. Histopathologic examination of the left tonsil revealed diffuse proliferation of medium- to large-sized neoplastic lymphoid cells effacing the original lymphoid architecture. Half of the cells contained one or several eosinophilic globoid cytoplasmic inclusions, which stained magenta with PAS and showed positive immunohistochemical reactions for immunoglobulin M (IgM) and λ light chain. Neoplastic lymphoid cells were also CD20+ , Pax5+ , and MUM1+ , and CD3- . Thus, the neoplastic lymphoid cells expressed a B-cell immunophenotype, and the globoid cytoplasmic inclusions represented an aberrant IgM λ light chain accumulation, similar to Russell bodies. B-cell lymphoma with Mott cell differentiation was diagnosed based on cytologic, histopathologic, and immunohistochemical features. This is the first report of B-cell lymphoma with Mott cell differentiation in a cat.

Late-onset myasthenia gravis is predisposed to become generalized in the elderly.

OBJECTIVE: The continuous increase in the number of patients presenting with late-onset myasthenia gravis (LOMG) underscores the need for a better understanding of the clinical course and the establishment of an optimal therapeutic strategy. We aimed to clarify factors associated with clinical outcomes in LOMG. METHODS: We retrospectively reviewed the clinical profiles of 40 patients with early-onset MG (EOMG) (onset age: 49 years or younger), 30 patients with non-elderly LOMG (onset age: 50-64 years), and 28 patients with elderly LOMG (onset age: 65 years or older) and compared the subgroups according to onset age and thymus status. The evaluated parameters were MGFA classification before treatment, MG-ADL score, complicating diseases, antibody titer, treatment, and MGFA post-intervention status. RESULTS: Elderly LOMG patients showed transition to generalized symptoms at a higher frequency and underwent thymectomy less frequently than EOMG and non-elderly LOMG patients (p < 0.001). The frequencies of crisis and plasmapheresis were significantly lower in thymectomized LOMG patients without thymoma than in thymectomized LOMG patients with thymoma or non-thymectomized LOMG patients (p < 0.01, P < 0.05, respectively). However, the outcome was not significantly different. All of the thymectomized LOMG patients without thymoma presenting with hyperplasia or thymic cyst had a favorable clinical course. CONCLUSIONS: Our study showed that elderly LOMG patients are more prone to severity, suggesting that they require aggressive immunomodulatory therapy.

Effect of dentin desensitizers on resin cement bond strengths

Introduction: The crown preparation promotes the exposure of dentin tubules. Thus, to avoid post-operative sensitivity, the first approach involves the use of dentin adhesives, and the second one the use of dentin desensitizers. Objective: This study evaluated the effect of dentin desensitizers on microtensile bond strengths (μTBSs) of a resin cement to dentin. Material and methods: Twenty bovine teeth were prepared until obtaining flat dentin surfaces. A standardized smear layer was created (#600-grit SiC paper). The samples were randomly divided into the following four groups (n = 5): no treatment (Control), treatment with Gluma Desensitizer (Heraeus Kulzer), Super Seal (Phoenix Dental) and Teethmate Desensitizer (Kuraray Noritake Dental). The dentin surfaces were then treated with ED Primer II (Kuraray Noritake Dental). Twenty composite blocks, 4 mm thick (Estenia CeB, Kuraray Noritake Dental) were used. The composite surfaces were abraded with aluminum oxide (50 μm), and then silanized. The composite block was bonded to the dentin surface with a resin cement (Panavia F 2.0, Kuraray Noritake Dental) according to the manufacturer's instructions. After 24-hour storage (37ºC, 100% RH), the bonded samples were cut into beam-shaped microtensile specimens and loaded in tension until failure. Data were analyzed with one-way ANOVA and the Dunnett's test (α = 0.05). An SEM was used to examine the failure modes. Results: The μTBSs (MPa ± SD) were: 24.4 ± 3.2 (Control), 14.0 ± 5.6 (Gluma Desensitizer), 8.6 ± 4.7 (Super Seal), and 34.7 ± 4.6 (Teethmate Desensitizer), in which there were significant differences among the four groups (p < 0.05). The Teethmate Desensitizer group showed the highest μTBS, while the Super Seal group showed the lowest mean of μTBS to dentin. Conclusion: The efficacy of the desensitizers is material-dependent; Gluma Desensitizer and Super Seal decreased the μTBSs, however, Teethmate Desensitizer improved it.

Increased proinflammatory cytokines in sera of patients with multifocal motor neuropathy.

BACKGROUND: Multifocal motor neuropathy (MMN) is characterized by clinical improvement with intravenous immunoglobulin and the frequent detection of anti-ganglioside antibodies. However, the immunological background of the neuronal damage in MMN is still unclear. OBJECTIVE: The aim of this study is to investigate abnormalities in the cytokine and chemokine profiles of MMN patients. METHODS: Sera from 16 patients with MMN, 16 patients with sporadic amyotrophic lateral sclerosis (ALS), and 15 patients with other non-inflammatory neurological diseases (ONDs) were analyzed for 27 cytokines and chemokines using a multiplex bead array. We also checked whether the altered cytokine/chemokine profile in the MMN group differed significantly in the presence or absence of abnormal electrophysiological findings. RESULTS: Serum IL-1Ra, IL-2, G-CSF, TNF-α, and TNFR1 levels were significantly higher in the MMN group than in the ONDs group. Of these, G-CSF and TNF-α also showed significant increases compared to the ALS group. Serum G-CSF and TNF-α levels were significantly higher in MMN patients presenting with focal demyelination including conduction block than in patients without any focal demyelination. CONCLUSIONS: Proinflammatory cytokines may contribute to peripheral nerve demyelination in MMN.

Increased number of Hassall's corpuscles in myasthenia gravis patients with thymic hyperplasia.

The thymus is implicated as an organ that contributes to autoimmunity in myasthenia gravis (MG) patients. Hassall's corpuscles (HCs) are assumed to represent the terminally differentiated stage of medullary thymic epithelial cells (mTECs). By using multicolor immunohistofluorescence analysis, we examined HCs in thymuses that were therapeutically excised from MG (+) and MG (-) patients. We found that the number of HCs per unit area of the thymic medulla was significantly elevated in the thymuses of MG (+) patients with thymic hyperplasia. CCL21 expression increased in the hyperplastic MG thymuses. We speculate that the altered differentiation of mTECs is associated with the thymic hyperplasia and the onset of MG.