Consistent increase in the prevalence and female ratio of multiple sclerosis over 15 years in northern Japan.

BACKGROUND AND PURPOSE: The prevalence of multiple sclerosis (MS) is considered to be lower in East Asia than in Western countries. An increasing trend has been reported globally for the prevalence of MS. We investigated the changes in the prevalence and clinical characteristics of MS in the Tokachi province of Hokkaido, northern Japan from 2001 to 2016. METHODS: Prevalence was determined on 31 March 2016. Data-processing sheets were collected from all MS-related institutions in Tokachi province. We applied Poser's diagnostic criteria for MS as used in our previous three studies. Cases of neuromyelitis optica spectrum disorders were excluded. RESULTS: In 2016, the crude MS prevalence was 18.6/100 000 (95% confidence interval, 14.3-23.8) in northern Japan. Over the last 15 years, the prevalence of MS in the same area was 8.1, 12.6 and 16.2 in 2001, 2006 and 2011, respectively. The female:male ratio was 3.57, which increased from 2.63 in 2001. The ratios of primary progressive, relapsing-remitting and secondary progressive MS types were 2%, 84% and 14%, respectively. CONCLUSION: Our results demonstrated a consistent increase in MS prevalence among the northern Japanese population, particularly in females, and relatively lower rates of progressive MS in northern Japan than in Western countries.

Impact of screening with thyroid ultrasonography in myasthenia gravis patients.

OBJECTIVES: This study was conducted to screen thyroid abnormality evaluated with ultrasonography (US) in patients with myasthenia gravis (MG) and investigate further when malignancy is suspected. METHODS: Thyroid screening using US was conducted in 162 patients with MG. In cases where malignancy was suspected, further investigations were performed. RESULTS: Abnormal US findings were detected in 125 of 162 patients with MG (72 patients with nodules, 74 patients with cysts, 27 patients with diffuse findings such as enlargement, atrophy, a hypoechoic pattern or a heterogenous echoic pattern, and 28 patients with calcification). From among these 125 subjects, 30 patients underwent further examinations such as needle aspiration cytology. As a result, six patients (3.7% of 162 cases) were positive for papillary carcinoma. The size of the carcinoma in three patients was <10 mm, yet the stage of thyroid carcinomas was high (stage III or IVa) in all six cases. CONCLUSIONS: Our data suggest that the prevalence of thyroid carcinoma in cases of MG may be higher than that of the general population. Furthermore, in patients with MG, there is a possibility that the stage of the carcinoma is higher even when the carcinoma is of a very small size. Patients with MG, when diagnosed, should be advised to undergo US screening of the thyroid because most cases of thyroid carcinoma are highly curable.

Relationship between Barkhof criteria and the clinical features of multiple sclerosis in northern Japan.

We previously reported that the prevalence of multiple sclerosis (MS) in the Tokachi Province of Hokkaido increased from 8.6 to 13.1 per 100,000 individuals between 2001 and 2006. Here, we study the frequency of MS patients who fulfill the Barkhof criteria and identified their common features. All 47 subjects in our previous study, who fulfilled Poser's criteria, were included in this study. Of these, 33 satisfied the Barkhof criteria. In 2006, 9.2 per 100,000 MS patients fulfilled the Barkhof criteria; the percentage of patients who fulfilled these criteria was significantly higher among patients born after 1960 than among those born before 1960 (84.3% and 40.0%, respectively). The proportion of patients with conventional MS (C-MS) who fulfilled the Barkhof criteria was higher than that of patients with opticospinal MS (OS-MS) who fulfilled these criteria (93.9% and 71.4%, respectively). Longitudinally extensive spinal cord lesions (LESCLs) were not associated with the brain lesions defined in the Barkhof criteria (Barkhof brain lesions). In Tokachi Province, the increased percentage of MS patients who fulfill the Barkhof criteria was associated with increased C-MS incidence and an increase in the proportion of C-MS patients with Barkhof brain lesions among people born after 1960.

Effect of high fat diet on NKT cell function and NKT cell-mediated regulation of Th1 responses.

Diet is one of the important factors that modulate immune responses. In the present study, we have examined the capacity of dietary lipids to modify immune responses in mice and we have investigated the contribution of glycolipid-reactive natural killer T (NKT) cells in this process. Mice fed, high fat diet (HFD; 21.2% fat, 0.20% cholesterol) for 3 weeks, as compared with mice fed standard fat diet (SFD; 4.3% fat, 0.03% cholesterol), showed significantly reduced interferon-gamma production in sera at 6 or 12 h after intraperitoneal injection of an NKT cell ligand, alpha-galactosylceramide. In contrast, production of interleukin-13 was significantly higher at 2 and 6 h in HFD fed mice compared with mice on SFD. No difference was detected in the serum interleukin-4 levels between these two groups of animals. The proportion of NKT cells in spleen and liver was reduced in mice fed HFD compared with those on SFD. In addition, activation of NKT cells assessed by up-regulation of CD69 was suppressed specifically in liver from mice fed HFD. Recall responses of conventional T cells and delayed-type hypersensitivity (Th1 type) against ovalbumin were significantly suppressed in mice fed HFD in comparison with those fed SFD. This suppression was not observed in CD1d-/- mice, suggesting that NKT cells in mice fed HFD played a role in suppressing Th1 responses. Taken together, our findings suggest a critical link between NKT cells, dietary lipid and adaptive immune responses.

Prostaglandin E1 protects cultured spinal neurons against the effects of nitric oxide toxicity.

The effects of prostaglandin (PG) E(1) on NO neurotoxicity were examined using rat cultured spinal neurons. Rat cultured spinal neurons exposed to the NO donor, 2,2'-(hydroxynitrosohydrazono) bis-ethanamine (NOC18), showed neurotoxic effects that were accompanied by apoptotic nuclear change, free radical generation, a reduction in glutathione, and mitochondrial dysfunction. PGE(1), at concentrations of 1-100 nM, protected cultured spinal neurons from NO toxicity by reversing the oxidative and pro-apoptotic properties elicited by NOC18 exposure. The administration of PGE(1) increased the intracellular cyclic AMP (cAMP) levels in cultured spinal neurons. In addition, reverse transcriptase-polymerase chain reaction (RT-PCR) analysis confirmed the existence of EP4, a cAMP-elevating PGE receptor, in cultured spinal neurons. The protective effects of PGE(1) against NO neurotoxicity was partially blocked by an inhibitor of MEK [the mitogen-activated protein kinase (MAPK)/extracellular-signal-regulated kinase (ERK) kinase], suggesting that the MAPK/ERK pathway may play a significant role in the activity of PGE(1). PGE(1) up-regulated the expression of the anti-apoptotic protein, Bcl-2, as determined by Western blot analysis. PGE(1) also induced the expression of thioredoxin in cultured spinal neurons. Our data indicate that PGE(1) exerts a protective action against NO neurotoxicity in cultured spinal neurons, and suggests a therapeutic potential of PGE(1) against spinal cord disease, such as amyotrophic lateral sclerosis.

Amelioration of experimental autoimmune encephalomyelitis in C57BL/6 mice by an agonist of peroxisome proliferator-activated receptor-gamma.

Peroxisome proliferator-activated receptor-gamma (PPAR-gamma), a member of the nuclear hormone receptor superfamily, plays a critical role in adipocyte differentiation and glucose homeostasis. It has been implicated that PPAR-gamma functions as a regulator of cellular proliferation and inflammatory responses. In the present study, we examined whether troglitazone, a selective PPAR-gamma agonists, ameliorated experimental autoimmune encephalomyelitis (EAE) induced by administration of myelin oligodendrocyte glycoprotein (MOG) peptide 35-55 in C57BL/6 mice. We found that troglitazone attenuated the inflammation and decreased the clinical symptoms. It was suggested that the amelioration was attributed to the attenuation of pro-inflammatory cytokine gene expressions.

Genetic polymorphisms of IL-1beta and IL-1 receptor antagonist in association with multiple sclerosis in Japanese patients.

In the present study, we have investigated the association of specific polymorphisms of the interleukin (IL)-1beta and IL-1 receptor antagonist (ra) gene with both the susceptibility to and the clinical characteristics of multiple sclerosis (MS) in Japanese patients. We collected and analyzed DNA from 98 MS patients and 104 healthy controls for distribution of IL-1beta or IL-1ra polymorphisms. Our results show no significant differences in the distribution of the polymorphisms between MS patients and controls. Furthermore, no association was observed between IL-1beta or IL-1ra polymorphisms and clinical characteristics, such as age at disease onset, clinical course and severity. Together, our findings suggest that IL-1beta or IL-1ra gene polymorphisms may not be relevant in the susceptibility to MS or the clinical characteristics of Japanese patients with MS.

Reverse seroconversion of hepatitis B virus after hematopoietic stem cell transplantation.

Hepatitis B virus (HBV) reactivation in patients previously positive for hepatitis B surface antibody (HBsAb), so-called reverse seroconversion, has been considered to be a rare complication after hematopoietic stem cell transplantation (HSCT). We experienced two patients who developed reverse seroconversion among nine who were HBsAb positive and Hepatitis B core antibody (HBcAb) positive before HSCT; one after autologous bone marrow transplantation (BMT) and another after allogeneic peripheral blood stem cell transplantation (PBSCT). We reviewed the literature and considered that reverse seroconversion of HBV after HSCT is not uncommon among HBsAb positive recipients. The use of corticosteroids, the lack of HBsAb in donor, and a decrease in serum HBsAb and HBcAb levels may predict reverse seroconversion after HSCT.

Estrogen receptor gene polymorphism in Japanese patients with multiple sclerosis.

Estrogen has been reported to have immunosuppressive functions, and to inhibit the progression of experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS). Since estrogen shows its biological effects via estrogen receptors (ER), we investigate the possible role of ER genes (ERG) in the pathogenesis of MS. PvuII and XbaI polymorphisms in ERG were detected by PCR-RFLP from the DNA of 79 conventional MS patients and 73 healthy controls. The [P] allele in the profiles in PvuII was significantly more prevalent in MS patients than in the controls (P<0.0005). In the study of XbaI polymorphism, the onset age of MS patients with the Xx genotype was earlier than that of the xx genotype group (mean age+/-S.D.; 22.60+/-8.04, and 27.49+/-9.14, respectively) (P<0.05) by ANOVA followed by Fisher's PLSD. Although the Xx genotype group tended to earlier onset age than the XX genotype group (29.60+/-11.10), this difference did not reach. On the basis of these results, PvuII polymorphism might be associated with susceptibility to MS, and XbaI polymorphism with onset age of MS. ERG polymorphism should be further studied in other populations to improve strategies for treatment of MS.

Macrophage migration inhibitory factor in the cerebrospinal fluid of patients with conventional and optic-spinal forms of multiple sclerosis and neuro-Behçet's disease.

Macrophage migration inhibitory factor (MIF) is becoming increasingly recognized as an important regulator of immune and inflammatory responses. It is released by activated T lymphocytes and macrophages and up-regulates the proinflammatory activity of these cells. MIF is required for antigen- and mitogen-driven T cell activation, and stimulates macrophages to release cytokines and nitric oxide. On the basis of the recent suggestion that pharmacological modulation of MIF production and neutralization of its activity may have important implications for treatment of a variety of autoimmune or inflammatory conditions, we determined the level of MIF in the cerebrospinal fluid (CSF) of patients with conventional-form multiple sclerosis (C-MS) and optic-spinal form multiple sclerosis (OpS-MS), and neuro-Behçet's disease (NBD). As control, the CSF of patients with non-inflammatory neurological diseases (NIND) was used. The concentration of MIF in CSF samples was significantly elevated in relapsed cases of C-MS (4.13+/-1.07 ng/ml) (mean+/-S.D.) compared with control samples (2.38+/-0.60 ng/ml) (P<0.0001), whereas MIF in the CSF of C-MS patients in remission was not elevated (2.65+/-0.67 ng/ml). The concentration of MIF in the CSF of OpS-MS patients in relapse (5.53+/-1.74 ng/ml) was higher than that of patients with C-MS in relapse (P<0.05). In NBD patients, the concentration of MIF in CSF was significantly elevated (7.47+/-5.61 ng/ml) compared with control samples (P<0.01) and correlated well with cell count in these samples (r=0.910, P<0.005). These results suggest that MIF may play a pivotal role in immune-mediated diseases of the central nervous system, and that MIF may be useful in the study of differences between C-MS and OpS-MS.

Vitamin D receptor gene polymorphism in multiple sclerosis and the association with HLA class II alleles.

We have previously reported that the association between Bsm I polymorphism, one of the vitamin D receptor genes (VDRG) polymorphism, and multiple sclerosis (MS). In this report, we investigated the further possible role or relevance of VDRG in the pathogenesis of MS. Apa I polymorphism was detected by PCR-RFLP from the DNA of 77 conventional MS patients and 95 healthy controls. The study of the Bsm I and Apa I haplotypes was carried out by employing previously reported Bsm I data. The AA genotype and the [A] allele in the profiles were significantly more prevalent in MS patients than in controls (P=0.0070 and P=0.0321, respectively). In the [A] allele-positive MS patients, the positive rate of DPB1*0501 in HLA was significantly higher than that of the [A] allele-positive controls and that of the [A] allele-negative MS patients even when the corrected P value (P(corr)) was applied (P(corr)=0.0220 and P(corr)=0.0077, respectively). The frequency of DRB1*1501 was higher in the [A] allele-positive patients than in the [A] allele-positive controls and the [A] allele-negative patients (P(uncorr)=0.0431 and P(uncorr)=0.0089, respectively), but the P values did not reach statistical significance after P corrections. The rate of Bsm I and Apa I haplotypes was much higher in bA/bA-positive MS patients than in the controls (P=0.0003), and in the bA positive MS patients, the positive rate of DPB1*0501 was higher than that of the bA-positive controls and that of the bA-negative MS patients (P(corr)=0.0308 and P(corr)=0.0033, respectively). These results indicate that VDRG polymorphism may be associated with susceptibility to MS, and HLA alleles may correlate with risk for MS together with VDRG.

Chronic inflammatory demyelinating polyneuropathy with multiple hypertrophic nerves in intracranial, and intra- and extra-spinal segments.

Hypertrophic nerves have occasionally been seen in chronic inflammatory demyelinating polyneuropathy (CIDP), but most are in the cauda equina. We report a case with CIDP in whom magnetic resonance imaging (MRI) with gadolinium diethylene triamine penta-acetic acid (Gd-DTPA) enhancement demonstrated hypertrophy of various peripheral nerves including multiple cranial nerves. Interestingly, none showed neurological signs corresponding to the lesions, except for clinical signs consistent with CIDP. MRI can be useful for the detection of silent, but abnormal nerve involvement in CIDP.

[Clinical studies of cefodizime in the pediatric field].

Cefodizime (CDZM, THR-221) was evaluated for its pharmacokinetics, safety and efficacy in 30 pediatric patients with bacterial infections. The following results were obtained. 1. The pharmacokinetics of CDZM in 6 children were investigated with a dose level of 20 mg/kg via intravenous injection. Mean serum half-lives (T 1/2 beta) of the drug were 120.9 minutes (HPLC) and 115.6 minutes (bioassay). In 8 hours after administration of CDZM, urinary excretion rates were 74.7% (HPLC) and 75.0% (bioassay). 2. The clinical efficacies of CDZM were studied in 29 pediatric patients, comprising 22 with respiratory tract infections, 2 with urinary tract infections, 2 with enteritis, 2 with lymphadenitis and 1 with gingivitis. The clinical efficacies were excellent in 13, good in 13 and fair in 3, with an efficacy rate of 89.7%. 3. The eradication rate for pathogens identified in 7 pediatric patients was 60% (6/10). The clinical efficacy rate in cases where pathogens were identified was 100% in terms of excellent+ good evaluations. 4. Only one case of mild diarrhea was observed as a side effect associated with CDZM. Laboratory tests revealed abnormal value of slightly elevated eosinophil in 3 cases. The data suggested that CDZM is a safe and effective injectable antibiotic for the treatment of infections in children.

[Clinical study on aztreonam in pediatrics].

Efficacy and safety of aztreonam (AZT) for 31 cases of infections of children were studied with the following results. Clinical efficacy of AZT for 22 respiratory tract infections, 5 urinary tract infections and 2 gastrointestinal infections was "excellent" for 19 cases (65.5%), "good" for 9 cases (31.0%) and "poor" for 1 case (3.4%) with an overall effective rate of 96.6%. Microbiological effect of AZT for 19 isolated strains (15 cases) was 100% in disappearance of the Gram-negative bacteria and 89.5% on the whole. With regard to side effect of AZT in 31 cases, there was a slight elevation of GPT in 1 case and eosinophilia in 2 cases. It was considered from the above results that AZT is a useful and safe antibiotic for infections of children.

[Trigeminal neurinoma in the cavernous sinus revealed by intratumoral hemorrhage: a case report].

A case of trigeminal neurinoma located in the left cavernous sinus and revealed by intratumoral hemorrhage is reported. Preoperatively, magnetic resonance imaging provided the accurate localization of the lesion, allowing precise planning of the surgical approach. The neurinoma inside the cavernous sinus wall was removed successfully, and the patient developed no new neurological deficits except for anesthesia in the 1st division of the trigeminal nerve. The characteristic findings of magnetic resonance imaging of the trigeminal neurinoma in the cavernous sinus are reported.

Structural basis for the altered drug sensitivities of non-small cell lung cancer-associated mutants of human epidermal growth factor receptor.

The epidermal growth factor receptor (EGFR) has an essential role in multiple signaling pathways, including cell proliferation and migration, through extracellular ligand binding and subsequent activation of its intracellular tyrosine kinase (TK) domain. The non-small cell lung cancer (NSCLC)-associated EGFR mutants, L858R and G719S, are constitutively active and oncogenic. They display sensitivity to TK inhibitors, including gefitinib and erlotinib. In contrast, the secondary mutation of the gatekeeper residue, T790M, reportedly confers inhibitor resistance on the oncogenic EGFR mutants. In this study, our biochemical analyses revealed that the introduction of the T790M mutation confers gefitinib resistance on the G719S mutant. The G719S/T790M double mutant has enhanced activity and retains high gefitinib-binding affinity. The T790M mutation increases the ATP affinity of the G719S mutant, explaining the acquired drug resistance of the double mutant. Structural analyses of the G719S/T790M double mutant, as well as the wild type and the G719S and L858R mutants, revealed that the T790M mutation stabilizes the hydrophobic spine of the active EGFR-TK conformation. The Met790 side chain of the G719S/T790M double mutant, in the apo form and gefitinib- and AMPPNP-bound forms, adopts different conformations that explain the accommodation of these ligands. In the L858R mutant structure, the active-site cleft is expanded by the repositioning of Phe723 within the P-loop. Notably, the introduction of the F723A mutation greatly enhanced the gefitinib sensitivity of the wild-type EGFR in vivo, supporting our hypothesis that the expansion of the active-site cleft results in enhanced gefitinib sensitivity. Taken together, our results provide a structural basis for the altered drug sensitivities caused by distinct NSCLC-associated EGFR mutations.

The role of B cells in multiple sclerosis: implications for B-cell-targeted therapy.

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system. Although most studies have emphasized the role of T cells in the pathogenesis of MS, increasing evidence supports the concept that B cells play a key role in the pathogenesis of MS, mainly in association with the deposition of antibodies and the activation of complement. Emerging pathophysiological findings of B-cell, follicle-like structures in the meninges of patients and observations of decreased interleukin (IL)-10 production from naïve B cells in MS have recently been reported. As more knowledge is gained of the pathophysiology of B cells in MS, the mechanisms of B-cell-mediated neuropharmacology of current therapy had been clarified as well. In this article, we review the increasing evidence that points to a link between B cells and MS, and also discuss the potential of B-cell-targeted therapy in MS.