Longitudinal changes in 18 F-THK5351 positron emission tomography in corticobasal syndrome

BACKGROUND AND PURPOSE

Corticobasal syndrome (CBS) is pathologically characterized by tau deposits in neuronal and glial cells and by reactive astrogliosis. In several neurodegenerative disorders, ¹⁸ F-THK5351 has been observed to bind to reactive astrocytes expressing monoamine oxidase B. In this study, the aim was to investigate the progression of disease-related pathology in the brains of patients with CBS using positron emission tomography with ¹⁸ F-THK5351.

METHODS

Baseline and 1-year follow-up imaging were acquired using magnetic resonance imaging and positron emission tomography with ¹⁸ F-THK5351 in 10 subjects: five patients with CBS and five age-matched normal controls (NCs).

RESULTS

The 1-year follow-up scan images revealed that ¹⁸ F-THK5351 retention had significantly increased in the superior parietal gyrus of the patients with CBS compared with the NCs. The median increases in ¹⁸ F-THK5351 accumulation in the patients with CBS were 6.53% in the superior parietal gyrus, 4.34% in the precentral gyrus and 4.33% in the postcentral gyrus. In contrast, there was no significant increase in the regional ¹⁸ F-THK5351 retention in the NCs.

CONCLUSIONS

Longitudinal increases in ¹⁸ F-THK5351 binding can be detected over a short interval in the cortical sites of patients with CBS. A monoamine oxidase B binding radiotracer could be useful in monitoring the progression of astrogliosis in CBS.

Therapeutic efficacy of plasma exchange in NMO-IgG-positive patients with neuromyelitis optica

Neuromyelitis optica (NMO) is an inflammatory demyelinating disease of the central nervous system (CNS) with a poor prognosis in terms of the optic-spinal function. Recently, a serum autoantibody (NMO-IgG) binding to the blood–brain barrier region was detected exclusively in patients with NMO and its high risk group. We treated six NMO-IgG-positive patients (all female; age 21–67 years old, median 41; three with optic neuritis and three with myelitis) who were unresponsive to high-dose intravenous methylprednisolone (HIMP), with plasma exchange (PE) (three to five exchanges, 2–3 L each). Three of the patients(one with optic neuritis and two with myelitis) showed definite functional improvement following PE. The clinical improvement started to appear after one or two exchanges, while there was little or no improvement in the other three patients. Such quick clinical responses to PE suggest a pathogenetic role of humoral immune factors in NMO, although delayed responses to the corticosteroid therapy might have contributed to the therapeutic efficacy, in part. Further clinical and in vitro studies are needed to determine whether the removal of NMO-IgG is directly relevant to the therapeutic efficacy. PE may hasten the functional recovery from corticosteroid-resistant relapses in some NMO-IgG-positive patients with NMO.

Complement-dependent and -independent aquaporin 4-antibody-mediated cytotoxicity in human astrocytes: Pathogenetic implications in neuromyelitis optica

Background

Neuromyelitis optica (NMO) is an inflammatory disease caused by the aquaporin (AQP)-4-antibody. Pathological studies on NMO have revealed extensive astrocytic damage, as evidenced by the loss of AQP4 and glial fibrillary acidic protein (GFAP), specifically in perivascular regions with immunoglobulin and complement depositions, although other pathological patterns, such as a loss of AQP4 without astrocyte destruction and clasmatodendrosis, have also been observed. Previous studies have shown that complement-dependent antibody-mediated astrocyte lysis is likely a major pathomechanism in NMO. However, there are also data to suggest antibody-mediated astrocyte dysfunction in the absence of complement. Thus, the importance of complement inhibitory proteins in complement-dependent AQP4-antibody-mediated astrocyte lysis in NMO is unclear. In most of the previous studies, the complement and target cells (astrocytes or AQP4-transfected cells) were derived from different species; however, the complement inhibitory proteins that are expressed on the cell surface cannot protect themselves against complement-dependent cytolysis unless the complements and complement inhibitory proteins are from the same species. To resolve these issues, we studied human astrocytes in primary culture treated with AQP4-antibody in the presence or absence of human complement and examined the effect of complement inhibitory proteins using small interfering RNA (siRNA).

Methods

Purified IgG (10 mg/mL) was obtained from 5 patients with AQP4-antibody-positive NMO, 3 patients with multiple sclerosis (MS), and 3 healthy controls. Confluent human astrocytes transfected with Venus-M1-AQP4-cDNA were incubated with IgG (5% volume). After washing, we cultured the cells with human complements with or without heat inactivation. We observed time-lapse morphological and immunohistochemical changes using a fluorescence microscope. We also evaluated cytotoxicity using a propidium iodide (PI) kit and the lactate dehydrogenase (LDH) assay.

Result

AQP4-antibody alone caused clustering and degradation followed by endocytosis of membraneous AQP4, thereby resulting in decreased cellular adherence and the shrinkage of astrocytic processes. However, these changes were partially reversed by the removal of IgG in culture. In contrast, following the application of AQP4-antibody and non-heated human complements, the cell bodies and nuclei started to swell. At 3 h, most of the astrocytes had lost mobility and adherence and were eventually destroyed or had swollen and were then destroyed. In addition, the remaining adherent cells were mostly PI-positive, indicating necrosis. Astrocyte lysis caused by rabbit complement occurred much faster than did cell lysis with human complement. However, the cell lysis was significantly enhanced by the transfection of astrocytes with siRNA against human CD55 and CD59, which are major complement inhibitory proteins on the astrocyte membrane. AQP4-antibody-negative IgG in MS or control did not induce such changes.

Conclusion

Taken together, these findings suggest that both complement-dependent and complement-independent AQP4-antibody-mediated astrocytopathies may operate in NMO, potentially contributing to diverse pathological patterns. Our results also suggest that the effect of complement inhibitory proteins should be considered when evaluating AQP4-antibody-mediated cytotoxicity in AQP4-expressing cells.

Features of anti-aquaporin 4 antibody-seronegative Thai patients with neuromyelitis optica spectrum disorders: a comparison with seropositive cases

OBJECTIVE

The aim of this study is to investigate the unique features of seronegative neuromyelitis optica spectrum disorders (NMOSD) in Thailand.

BACKGROUND

It remains unknown whether seronegative NMOSD patients possess clinical and paraclinical features that are distinct from those with seropositivity.

METHODS

In a Thai cohort of idiopathic inflammatory CNS disorders (n=122), 52 patients fulfilled the Wingerchuk 2007 criteria for NMOSD. We determined anti-AQP4 antibody statuses using three different assays (an in-house cell-based assay [CBA], a commercially available CBA and a tissue-based indirect immunofluorescence [IIF] assay).

RESULTS

Among the NMOSD patients, the percentage of seropositive cases was 54.5% based on the in-house and commercial CBAs and 30.8% based on the IIF assay. Using the in-house CBA, seronegative NMOSD patients exhibited distinct features compared with seropositive patients, such as a lack of female preponderance (F/M=1.2 vs. 6.0), frequent simultaneous bilateral optic involvement (33.3% vs. 0.04%), a lower annual relapse rate (0.4 ± 0.3 vs. 0.7 ± 0.6), fewer spinal cord lesions (1.0 ± 4.3 vs. 1.4 ± 0.6), and lower CSF cell counts (20 ± 72 vs. 80 ± 285). Use of the commercial CBA yielded essentially similar results, but some of these differences were not significant using IIF.

CONCLUSIONS

Sensitive anti-AQP4 antibody assays reveal features of seronegative NMOSD patients that differ from those of seropositive patients from Thailand.

Brainstem manifestations in neuromyelitis optica: a multicenter study of 258 patients

BACKGROUND

Neuromyelitis optica (NMO) is a severe autoimmune disease of the central nervous system characterized by spinal cord and optic nerve involvement. Brainstem manifestations have recently been described.

OBJECTIVE

To evaluate the time of occurrence, the frequency and the characteristics of brainstem symptoms in a cohort of patients with NMO according to the ethnic background and the serologic status for anti-aquaporin-4 antibodies (AQP4-abs).

METHODS

We performed a multicenter study of 258 patients with NMO according to the 2006 Wingerchuk criteria and we evaluated prospectively the frequency, the date of onset and the duration of various brainstem signs in this population.

RESULTS

Brainstem signs were observed in 81 patients (31.4%). The most frequently observed signs were vomiting (33.1%), hiccups (22.3%), oculomotor dysfunction (19.8%), pruritus (12.4%), followed by hearing loss (2.5%), facial palsy (2.5%), vertigo or vestibular ataxia (1.7%), trigeminal neuralgia (2.5%) and other cranial nerve signs (3.3%). They were inaugural in 44 patients (54.3%). The prevalence was higher in the non-Caucasian population (36.6%) than in the Caucasian population (26%) (p<0.05) and was higher in AQP4-ab-seropositive patients (32.7%) than in seronegative patients (26%) (not significant).

CONCLUSIONS

This study confirms the high frequency of brainstem symptoms in NMO with a majority of vomiting and hiccups. The prevalence of these manifestations was higher in the non Caucasian population.

Tumor-cytotoxicity of nitric-oxide produced from alveolar macrophages directly stimulated with tumor-cells

Macrophages activated by lipopolysaccharide or interferon-gamma have been shown to be cytotoxic to tumor cells by releasing nitric oxide. Here, we report that unstimulated rat alveolar macrophages cultured with certain tumor cells produce nitric oxide and are cytotoxic to these tumor cells. Alveolar macrophages were taken from BUF/Mna rats, which were known to produce spontaneous thymoma, and cultured with syngeneic BUF/Mna-derived thymoma cells. They were killed by syngeneic or allogeneic alveolar macrophages and this killing was partially abolished by addition of N(G)-monomethyl-L-arginine. X-ray irradiated, mitomycin C-treated or membranous fragments of BUF/Mna-derived thymoma cells directly stimulated rat alveolar macrophages to produce nitric oxide.

Myasthenia gravis and neuromyelitis optica spectrum disorder: a multicenter study of 16 patients

OBJECTIVE

To describe 16 patients with a coincidence of 2 rare diseases: aquaporin-4 antibody (AQP4-Ab)-mediated neuromyelitis optica spectrum disorder (AQP4-NMOSD) and acetylcholine receptor antibody (AChR-Ab)-mediated myasthenia gravis (AChR-MG).

METHODS

The clinical details and antibody results of 16 patients with AChR-MG and AQP4-NMOSD were analyzed retrospectively.

RESULTS

All had early-onset AChR-MG, the majority with mild generalized disease, and a high proportion achieved remission. Fifteen were female; 11 were Caucasian. In 14/16, the MG preceded NMOSD (median interval: 16 years) and 11 of these had had a thymectomy although 1 only after NMOSD onset. In 4/5 patients tested, AQP4-Abs were detectable between 4 and 16 years prior to disease onset, including 2 patients with detectable AQP4-Abs prior to thymectomy. AChR-Abs decreased and the AQP4-Ab levels increased over time in concordance with the relevant disease. AChR-Abs were detectable at NMOSD onset in the one sample available from 1 of the 2 patients with NMOSD before MG.

CONCLUSIONS

Although both conditions are rare, the association of MG and NMOSD occurs much more frequently than by chance and the MG appears to follow a benign course. AChR-Abs or AQP4-Abs may be present years before onset of the relevant disease and the antibody titers against AQP4 and AChR tend to change in opposite directions. Although most cases had MG prior to NMOSD onset, and had undergone thymectomy, NMOSD can occur first and in patients who have not had their thymus removed.

AQP4 antibody-positive Thai cases: clinical features and diagnostic problems

OBJECTIVE

To evaluate the prevalence of aquaporin-4 (AQP4) antibody in Thai patients with idiopathic inflammatory demyelinating CNS diseases (IIDCDs) and to analyze the significance of the autoantibody to distinguish neuromyelitis optica (NMO) and other NMO spectrum disorders (ONMOSDs) from other IIDCDs, especially multiple sclerosis (MS).

METHODS

We retrospectively evaluated 135 consecutive patients with IIDCDs seen at the MS clinic at Siriraj Hospital, Bangkok, Thailand, and classified them into NMO, ONMOSDs, optic-spinal MS (OSMS), classic MS (CMS), and clinically isolated syndrome (CIS) groups in this order with accepted diagnostic criteria. The patients' coded sera were tested separately for AQP4 antibody. Then the relations between the clinical diagnosis and the AQP4 antibody serologic status were analyzed.

RESULTS

Among the 135 patients, 53 (39.3%) were AQP4 antibody-positive. Although the AQP4 antibody-positive group had features of NMO, such as female predominance, long cord lesions (>3 vertebral bodies), and CSF pleocytosis, only 18 patients (33% of 54) fully met Wingerchuk 2006 criteria except for AQP4 antibody-seropositive status. We also detected some AQP4 antibody-positive patients in the OSMS (4 of 7), CMS (11 of 46), and CIS (1 of 16) groups. These patients had been misdiagnosed with MS because they often had brain lesions and never underwent spinal cord MRI examination or lacked long cord lesions.

CONCLUSIONS

AQP4 antibody was highly prevalent (almost 40%) in Thai patients with IIDCDs. Moreover, only one-third of AQP4 antibody-positive patients fully met Wingerchuk 2006 criteria, and many were misdiagnosed with MS. A sensitive AQP4 antibody assay is required in this region because the therapy for NMO is different from that for MS.

Pain in neuromyelitis optica and its effect on quality of life: a cross-sectional study

OBJECTIVE

To assess the features of pain and its impact on the health-related quality of life (HRQOL) in neuromyelitis optica (NMO).

METHODS

We analyzed 37 patients with NMO or NMO spectrum disorders seen at the Department of Neurology, Tohoku University Hospital, Sendai, Japan, during the period from November 2008 to February 2009. A total of 35 of them were aquaporin-4 antibody-positive. We used Short Form Brief Pain Inventory (BPI) to assess pain and Short Form 36-item (SF-36) health survey to evaluate the HRQOL. Fifty-one patients with multiple sclerosis (MS) were also studied for comparison.

RESULTS

Pain in NMO (83.8%) was far more common than in MS (47.1%). The Pain Severity Index score in BPI was significantly higher in NMO than in MS, and patients' daily life assessed by BPI was highly interfered by pain in NMO as compared with MS. Pain involving the trunk and both legs was much more frequent in NMO than in MS. SF-36 scores in NMO were lower than MS, especially in bodily pain.

CONCLUSION

Our study showed that pain in NMO is more frequent and severe than in MS and that pain has a grave impact on NMO patients' daily life and HRQOL. Therapy to relieve pain is expected to improve their HRQOL.

Occurrence of acute large and edematous callosal lesions in neuromyelitis optica

BACKGROUND

The corpus callosum is commonly involved in multiple sclerosis (MS), but the characteristics of callosal lesions in neuromyelitis optica (NMO) are unknown.ObjectiveTo reveal the features of callosal lesions in NMO in comparison to MS.

METHODS

We retrospectively reviewed the medical records and the brain magnetic resonance imaging films of 56 patients with MS and 22 patients with NMO.

RESULTS

In MS, 36 (64.3%) of 56 patients had callosal lesions, but only four patients had acute lesions. All such acute lesions were small, isolated and non-edematous, and the intensity was homotonic. Chronic lesions were observed in 34 patients with MS, and 32 (94%) of them presented small lesions located at the callosal lower margin ("hemi-oval pattern"). Meanwhile, four (18.2%) patients with NMO had callosal lesions, and three of them had acute lesions. Those acute lesions were multiple, large edematous ones with heterogeneous intensity ("marbled pattern"). In the chronic stage, the lesions shrank or disappeared.

CONCLUSIONS

Acute large, edematous callosal lesions occasionally occur in NMO. Similar to longitudinally extensive transverse myelitis, such callosal lesions may reflect severe edematous inflammation in NMO, and may provide additional evidence that the pathogenesis in NMO is different from that in MS.

Intractable hiccup and nausea in neuromyelitis optica with anti-aquaporin-4 antibody: a herald of acute exacerbations

BACKGROUND

Intractable hiccup and nausea (IHN) are unique symptoms in neuromyelitis optica (NMO). Recent studies have strongly suggested that the pathogenesis of NMO is closely associated with anti-aquaporin-4 (AQP4) antibody. However, clinical implications of IHN and the relationship with anti-AQP4 antibody remain unknown.

METHODS

The past medical records of 35 patients with seropositivity for anti-AQP4 antibody were reviewed. We also followed the titres of anti-AQP4 antibody in a patient with NMO, who had newly developed IHN.

RESULTS

Of the 35 patients, 15 patients (43%) had episodes of IHN. There was a total of 35 episodes of IHN in these 15 patients and, of the 35 episodes, hiccup was seen in 23 episodes (66%) and nausea was seen in 28 episodes (80%). The IHN frequently preceded (54%) or accompanied (29%) myelitis or optic neuritis. The IHN was often preceded by an episode of viral infection. The titres of anti-AQP4 antibody were remarkably increased when the intractable hiccup appeared in a case.

CONCLUSIONS

IHN could be a clinical marker for the early phase of an exacerbation. Careful observation may be needed when INH is seen in patients with NMO, and the early initiation of the treatment could prevent subsequent neurological damage.

Modulation of dendritic cell development by immunoglobulin G in control subjects and multiple sclerosis patients

Intravenous immunoglobulin (IVIg) preparations are reportedly effective in inhibiting the relapse of multiple sclerosis (MS), but few reports have investigated the effect of IVIg on dendritic cells (DCs), which are thought to be involved in such relapses. In the system that uses monokines to differentiate DCs from peripheral blood monocytes (Mo-DCs), we investigated the effect of immunoglobulin G (IgG) on these antigen-presenting cells. Using monocytes derived from healthy volunteers, IgG partially inhibited the expression of CD1a, a marker of immature DCs (imDCs), and CD40 and CD80, which are markers associated with T cell activation. In contrast, IgG enhanced the expression of CD83, a marker of mature DCs (mDCs). Furthermore, IgG markedly inhibited the expression of CD49d [very late activation antigen (VLA)-4 alpha4-integrin], the adhesion molecule required for mDCs to cross the blood-brain barrier. We obtained similar results on all the aforementioned cell surface molecules investigated in both healthy controls and MS patients. In addition, IgG treatment of cells from both healthy controls and MS patients inhibited the production of interleukin (IL)-12, a cytokine associated with mDC differentiation, but did not inhibit the production of IL-10. These results suggested the possibility that IgG treatment, apart from its known ability to regulate inflammation, may help to prevent relapses of MS by controlling DC maturation, consequently inhibiting invasion of immune cells into the central nervous system and affecting the cytokine profile.

Low-dose corticosteroids reduce relapses in neuromyelitis optica: a retrospective analysis

Neuromyelitis optica (NMO) is a relapsing neurologic disease characterized by severe optic neuritis and transverse myelitis. A disease-modifying therapy for NMO has not been established. We retrospectively analysed the effect of low-dose corticosteroid (CS) monotherapy on the annual relapse rate in nine patients with NMO. We divided the clinical course in each patient into two periods; the CS Period in which CS was administered, and the No CS Period in which CS was not administered. Periods related to other immunological therapies, such as high-dose methylprednisolone, immunosuppressants, interferon-beta, and plasma exchange, were excluded. As a result, the annual relapse rate during the CS Periods [median, 0.49 (range, 0—1.31)] was found to be significantly lower than that during the No CS Periods [1.48 (0.65—5.54)]. As for the dose of CS, relapses occurred significantly more frequently with `10 mg/day or less' than with `over 10 mg/day' (odds ratio: 8.75). The results of the present study suggest a beneficial effect of low-dose CS monotherapy in reducing relapses in NMO. Multiple Sclerosis 2007; 13: 968—974. http://msj.sagepub.com

Loss of aquaporin 4 in lesions of neuromyelitis optica: distinction from multiple sclerosis

Neuromyelitis optica (NMO) is an inflammatory and necrotizing disease clinically characterized by selective involvement of the optic nerves and spinal cord. There has been a long controversy as to whether NMO is a variant of multiple sclerosis (MS) or a distinct disease. Recently, an NMO-specific antibody (NMO-IgG) was found in the sera from patients with NMO, and its target antigen was identified as aquaporin 4 (AQP4) water channel protein, mainly expressed in astroglial foot processes. However, the pathogenetic role of the AQP4 in NMO remains unknown. We did an immunohistopathological study on the distribution of AQP4, glial fibrillary acidic protein (GFAP), myelin basic protein (MBP), activated complement C9neo and immunoglobulins in the spinal cord lesions and medulla oblongata of NMO (n = 12), MS (n = 6), brain and spinal infarction (n = 7) and normal control (n = 8). The most striking finding was that AQP4 immunoreactivity was lost in 60 out of a total of 67 acute and chronic NMO lesions (90%), but not in MS plaques. The extensive loss of AQP4 accompanied by decreased GFAP staining was evident, especially in the active perivascular lesions, where immunoglobulins and activated complements were deposited. Interestingly, in those NMO lesions, MBP-stained myelinated fibres were relatively preserved despite the loss of AQP4 and GFAP staining. The areas surrounding the lesions in NMO had enhanced expression of AQP4 and GFAP, which reflected reactive gliosis. In contrast, AQP4 immunoreactivity was well preserved and rather strongly stained in the demyelinating MS plaques, and infarcts were also stained for AQP4 from the very acute phase of necrosis to the chronic stage of astrogliosis. In normal controls, AQP4 was diffusely expressed in the entire tissue sections, but the staining in the spinal cord was stronger in the central grey matter than in the white matter. The present study demonstrated that the immunoreactivities of AQP4 and GFAP were consistently lost from the early stage of the lesions in NMO, notably in the perivascular regions with complement and immunoglobulin deposition. These features in NMO were distinct from those of MS and infarction as well as normal controls, and suggest that astrocytic impairment associated with the loss of AQP4 and humoral immunity may be important in the pathogenesis of NMO lesions.

High CSF neurofilament heavy chain levels in neuromyelitis optica

The neurofilament heavy chain (NfHSMI35), a biomarker of axonal damage in the CSF, was measured in patients with neuromyelitis optica (NMO) and multiple sclerosis (MS). Significantly high CSF NfHSMI35 levels (>0.73 ng/mL) were found in 6 of 24 (25%) of the patients with NMO but none of the patients with MS (0/24). This finding suggests that axonal damage is more severe in NMO than in MS.

Clinical and laboratory features of neuromyelitis optica with oligoclonal IgG bands

Of 23 neuromyelitis optica (NMO) cases, we found two cases with oligoclonal IgG bands (OBs). Both patients were positive for NMO-IgG. Their common features were long disease duration and co-existing autoimmune diseases (myasthenia gravis and sicca syndrome). Although OBs are mostly negative in NMO, which distinguishes it from multiple sclerosis (MS), they can be positive by long-standing autoimmunity, which may not be directly related to NMO. Multiple Sclerosis 2007; 13: 332-335. http://msj.sagepub.com

Clinical and MRI features of Japanese patients with multiple sclerosis positive for NMO-IgG

This study investigates the relation between the serological status of NMO (neuromyelitis optica)-IgG and the clinical and MRI features in Japanese patients with multiple sclerosis. Serum NMO-IgG was tested in 35 Japanese patients diagnosed with multiple sclerosis, including 19 with the optic-spinal form of multiple sclerosis (OSMS), three with the spinal form of multiple sclerosis (SMS), and 13 with the conventional form of multiple sclerosis (CMS), which affects the brain. NMO-IgG was detected in 14 patients, 12 with OSMS and 2 with CMS. In these patients, longitudinally extensive (> 3 vertebral segments) spinal cord lesions (93% v 57%) and permanent, complete blindness (no perception of light) in at least one eye (50% v 0%) were the noticeable features as compared with NMO-IgG-negative OSMS. The two patients having CMS with NMO-IgG had unusual brain lesions, but in other respects had features suggesting OSMS. NMO-IgG was detected in more than half the number of patients with OSMS and in some patients with CMS. This newly discovered serum autoantibody was markedly associated with longitudinally extensive spinal cord lesions and with complete blindness, suggesting severe optic-spinal disease.

Relevance of callosal and periventricular MRI lesions to oligoclonal bands in multiple sclerosis

OBJECTIVES

To evaluate the association between callosal or periventricular lesions, and the presence of oligoclonal IgG bands (OB) or the IgG index in Japanese patients with multiple sclerosis (MS).

MATERIALS AND METHODS

Brain magnetic resonance imaging (MRI) was studied in 34 Japanese clinically definite MS cases. Sagittal 2-mm fast fluid-attenuated inversion-recovery (FLAIR) imaging was added to the routine MRI studies.

RESULTS

Among the 34 patients, 20 (59%) were OB positive. Among the 20 patients with OB-positive MS, 17 (85%) had callosal lesions, although only two (14%) of 14 OB-negative MS patients had callosal lesions. The periventricular lesion area was significantly larger in the OB-positive patients compared with the OB-negative patients.

CONCLUSIONS

The present study clearly demonstrated a strong association between the periventricular lesions and OB in Japanese MS. Certain OB-related immune mechanisms may contribute to the development of callosal and periventricular lesions in MS. OB may be an important factor to understand the pathomechanisms of MS lesions.

Intractable hiccup and nausea with periaqueductal lesions in neuromyelitis optica

Intractable hiccup and nausea (IHN) was found in eight of 47 cases of relapsing neuromyelitis optica (NMO) (17%) but in none of 130 cases of multiple sclerosis (MS). IHN resolved with methylprednisolone. In six cases, MRI detected linear medullary lesions involving the pericanal region, the area postrema, and the nucleus tractus solitarius. Like long and centrally located myelitis, a linear medullary lesion causing IHN may distinguish NMO from MS.

5-aminolaevulinic acid photodynamic therapy in a transgenic mouse model of skin melanoma

Photodynamic therapy (PDT) is widely used to treat preneoplastic skin lesions and non-melanoma skin tumours. Studies analyzing the effects of PDT on malignant melanoma have yielded conflicting results. On the one hand, melanoma cell lines in culture as well as cell lines transplanted into experimental animals were sensitive to PDT. On the other hand, spontaneous melanomas of human patients responded poorly to most PDT regimens tested so far. Here, we analyzed effects of 5-aminolaevulinic acid (5-ALA)-based PDT on melanoma cell lines and on experimental melanomas. To mimic the clinical situation as closely as possible, metallothionein-I/ret (MT-ret) mice, a transgenic model of skin melanoma development, were used. Optimal doses of 5-ALA as well as energy doses and power densities were determined in vitro using a cell line (Mel25) established by us from a melanoma of an MT-ret transgenic mouse as well as commercially available human and mouse melanoma cell lines. Treatment with light irradiation alone had no effect. In combination with 5-ALA, however, this illumination readily induced the death of all mouse and human melanoma cell lines examined. Still, 5-ALA PDT caused only minor focal regressive changes including haemorrhages and fibrosis of MT-ret melanomas in vivo and did not significantly delay tumour growth. These results show that, even though MT-ret melanoma cells are vulnerable to 5-ALA PDT in vitro, malignant MT-ret melanomas in vivo are quite resistant to this type of therapy at doses which are highly effective in vitro.

Epitope analysis of the cerebrospinal fluid IgG in HTLV-I associated myelopathy patients using phage display method

We, for the first time, analyzed the binding motifs of immunoglobulin G (IgG) in the cerebrospinal fluid (CSF) of human T lymphotropic virus type I (HTLV-I)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) patients with a phage library displaying 12-mer random peptides. As a result, the sequences highly homologous to HTLV-I gp46 192-199, 237-243 and 255-261 were the common linear epitopes of high affinity- IgG exclusively detected in both CSF and sera of the patients. These IgG responses were confirmed with corresponding HTLV-I peptides and serum antibody titers significantly correlated with disease severity or duration. Gp46 237-243 has not been detected in previous enzyme-linked immunosorbent assay (ELISA) studies using bound longer peptides, suggesting the usefulness of the phage display method.

Absence of IgG1 response in the cerebrospinal fluid of relapsing neuromyelitis optica

The authors studied immunoglobulin (Ig) G subclasses in the CSF and sera of patients with relapsing neuromyelitis optica (RNMO) and typical multiple sclerosis (MS). Although the total IgG concentrations were elevated in the CSF of patients with RNMO and MS, IgG1% and IgG1 index were significantly elevated only in patients with MS. The absence of the CSF IgG1 responses in the patients with RNMO may suggest less Th1 immunity and may also explain the rarity of oligoclonal IgG bands in patients with this disease.

Sustained activation of c-jun-terminal kinase (JNK) is closely related to arsenic trioxide-induced apoptosis in an acute myeloid leukemia (M2)-derived cell line, NKM-1

High concentrations (greater than 5 microM) of arsenic trioxide (As(2)O(3)) have been reported to be able to induce apoptosis in several malignant cells. We explored cell lines in which apoptosis was induced with a therapeutic concentration (1-2 microM) of As(2)O(3), and found that 1 microM of As(2)O(3) induced apoptosis in the NKM-1 cell line, which was established from a patient with acute myeloid leukemia (M2). Apoptosis induced by 1 microM of As(2)O(3) in NKM-1 cells was accompanied by an increased cellular content of H(2)O(2), a decreased mitochondrial membrane potential (Deltapsim), and activation of caspase-3. C-Jun-terminal kinase (JNK) was activated only in NKM-1 cells and arsenic-sensitive NB4 cells, but not in arsenic-insensitive HL-60 cells. Activation of JNK in NKM-1 was sustained from 6 to 24 h after As(2)O(3) treatment, and preceded changes in cellular H(2)O(2), Deltapsim, and caspase-3 activation. Moreover, addition of a JNK inhibitor reduced the percentage of apoptotic cells after the As(2)O(3) treatment. Taken together, in the M2 cell line NKM-1, 1 microM of As(2)O(3) induced sustained activation of JNK and apoptosis. This finding may provide a basis to select a subgroup other than acute promyelocytic leukemia, which can benefit from As(2)O(3) treatment.

Protein phosphatase 2A-linked and -unlinked caspase-dependent pathways for downregulation of Akt kinase triggered by 4-hydroxynonenal

We studied the signal pathways for regulation of serine/threonine protein kinase Akt in Jurkat cells that had been treated with 4-hydroxynonenal (HNE) for caspase-dependent apoptosis induction. Treatment of cells with HNE led to a decrease in the level of Akt activity due to the dephosphorylation at Ser473, a major regulatory phosphorylation site. HNE-mediated dephosphorylation of Akt was prevented by a protein phosphatase 2A (PP2A) inhibitor, okadaic acid, and by a caspase-3 inhibitor, DEVD-CHO. HNE treatment resulted in an increase in the total level of PP2A activity, release of active tyrosine-dephosphorylated PP2A from the cytoskeleton and PP2A-Akt association, which were all dependent on caspase-3 activation. These results suggest that the level of PP2A activity is at least in part determined by its tyrosine phosphorylation, which is dually controlled by okadaic acid-sensitive phosphatases and protein-tyrosine kinases. Possibly underlying the mechanism of caspase-mediated activation of PP2A, HNE treatment resulted in downregulation of the activity of Src kinase, as a representative caspase-sensitive kinase to phosphorylate PP2A at tyrosine. In addition, activated caspase-3 partially cleaved Akt at a late stage of the apoptosis. These results indicate the existence of two distinct caspase-dependent signal pathways for downregulation of Akt that works as a mechanism of positive feedback regulation for HNE-triggered apoptotic signals.

A comparative study of Japanese multiple sclerosis patients with and without oligoclonal IgG bands

The cerebrospinal fluid oligodonal IgG bands (OB) are less frequently observed in Japanese multiple sclerosis (MS) patients compared with Caucasian patients. We studied 40 consecutive Japanese MS patients to investigate the differences in the clinical and magnetic resonance imaging (MRI) features of MS between OB-positive patients and OB-negative ones. Among the 40 patients, 22 (55%) patients were OB-positive by either agarose gel electrophoresis (AGE) or isoelectric focusing (IEF), and 18 (45%) patients were OB-negative by both AGE and IEF. There were differences between the two groups only in the clincal forms of MS, but not in terms of gender, onset age, disease duration, or disease severity. In the OB-negative group, nine (50%) of the patients had the optic-spinal form of MS (OS-MS), but only one patient (4.5%) in the OB-positive group had OS-MS. Although most OB-positive patients showed brain MRI lesions typical of MS, 13 (72%) of the OB-negative patients showed no or few brain MRI lesions and the rest of the OB-negative patients showed atypical MS lesions, such as diffuse white matter lesions or large ring-enhanced lesions. Our results suggest that the majority of OB-negative Japanese MS patents show either no or few brain MRI lesions or atypical brain MRI lesions.

Activation of caspase-8 is critical for sensitivity to cytotoxic anti-Fas antibody-induced apoptosis in human ovarian cancer cells

Two ovarian cancer cell lines named NOS4 and SKOV-3 have been shown to have different sensitivities to a cytotoxic anti-Fas antibody, CH-11. Although both cell lines express Fas molecules on the cell surfaces at the same intensities, apoptosis is induced by CH-11 in NOS4 cells but not in SKOV-3 cells. In this study, the different apoptosis-sensitivities of these cells were assessed. Both cell lines express almost the same levels of FADD, RIP, c-FLIP, FAP-1, Bax, Bcl-2 and Bcl-XL. Evidence of caspase-8, caspase-9 and caspase-3 activation and of cleavage of PARP and Bid was obtained in NOS4 cells but not in SKOV-3 cells. When triggered by FasL protein, DNA fragmentation and caspase-8 activation were observed in SKOV-3 cells, though they were not as clear as in NOS4 cells. All the anti-Fas antibody-mediated signals for apoptosis induction in NOS4 cells were completely blocked by a caspase-8-specific inhibitor, Z-IETD-FMK. These results indicate that the different sensitivities to the anti-Fas antibody are solely dependent on the activation of caspase-8, which could be influenced by yet unknown qualitative or quantitative abnormalities in molecules involved in DISC formation.

Glyoxal and methylglyoxal induce lyoxal and methyglyoxal induce aggregation and inactivation of ERK in human endothelial cells

Increased production of glyoxal (GO) and methylglyoxal (MGO) under oxidative stress is harmful to the cells. In this study, we examined the early signaling effect of GO/MGO on cultured human umbilical vein endothelial cells. Both GO and MGO induced tyrosine phosphorylation and aggregation of a number of cellular proteins. Aggregation occurred mainly for cell surface proteins such as Flk-1 and VE-cadherin, but barely for the majority of intracellular proteins. Interestingly, however, GO/MGO caused both aggregation and dephosphorylation of intracellular phospho-ERK for inactivation. This phospho-ERK dephosphorylation was mediated by orthovanadate-sensitive phosphatase activity accompanying chemical recruitment of MKP-1 to the aggregated phospho-ERK. Evidence was provided that GO/MGO upregulated MKP-1 activity that in turn dephosphorylated possibly co-aggregated phospho-ERK efficiently for inactivation. These results together suggest that GO and MGO trigger a novel pathway for chemical reaction-mediated downregulation of ERK.

RET tyrosine kinase enhances hair growth in association with promotion of melanogenesis

We first demonstrated that c-Ret protein is transiently expressed mainly in the inner and outer root sheaths of hair follicles soon after birth in the skin of normal C57BL/6 and BALB/c mice. A longer-lasting expression of activated RET protein overlapped the c-Ret expression with some preferential expression in the outer root sheath in close association with increase in the number of S-100 protein-containing cells in the area and excess melanogenesis in and around hair bulbs in the skin of RFP-RET-transgenic mice on a C57BL/6 background (RFP-RET/B6). Hair follicles in the skin of the transgenic mice continuously showed histology of the anagen phase, and the recovery period for the hair of the transgenic mice after shaving was shortened. Such growth promotion was not observed in the case of white hairs of RFP-RET-transgenic mice on a BALB/c background. These results suggest that RET works to extend the anagen phase in association with upregulation of melanin production.

Synthesis of a set of di- and tri-sulfated galabioses

Among cell-adhesion molecules, L-selectin recognizes sulfated sLe(x) with relatively low affinity. Here, we aimed at artificial mimics by synthesizing a set of di- and tri-sulfated galabioses, which may surpass the affinity of sulfated sLe(x). As a strategy to obtain 3',6',6-tri-O-sulfogalabioses, regioselective reductive cleavage of 4,6- and 4',6'-di-O-benzylidenegalabioses was employed. Two suitably protected galactose precursors were conjugated to yield alpha and beta anomers (48 and 18%, respectively) by using a pentenyl galactoside donor and iodinium di-sym-collidine perchlorate as the catalyst. For synthesizing the 3',6-di-O-sulfogalabiose, however, a trichloroacetimidate donor was superior (52%) to the pentenyl one (30%).

T-cell-immunity-based inhibitory effects of orally administered herbal medicine juzen-taiho-to on the growth of primarily developed melanocytic tumors in RET-transgenic mice

We examined the effect of oral administration of juzen-taiho-to, one of the most popular herbal medicines in Japan, on primary melanocytic tumor growth in RET-transgenic mice. There was virtually no difference between the lengths of tumor-free stages in the juzen-taiho-to-treated mice and the untreated littermate control mice. The rate of tumor growth in the juzen-taiho-to-treated mice, however, was greatly suppressed during the entire period after the initial tumor development. Correspondingly, the life span of juzen-taiho-to-treated transgenic mice was longer (over 6 mo in mean value) than that of control mice. We partially elucidated the mechanism of the antitumor effect of juzen-taiho-to. The addition of juzen-taiho-to at any of a wide range (50-1600 microg per ml) of concentrations to in vitro cultures of Mel-Ret cells, a malignant melanoma cell line derived from a RET-transgenic mouse, caused neither cell death nor cell cycle arrest directly. The addition of 50-400 microg per ml of juzen-taiho-to to cultures of murine spleen cells, however, promoted their DNA synthesis. More importantly, peritoneal exudate cells from the juzen-taiho-to-treated transgenic mice, in which the ratio and number of T cells were increased, displayed an antitumor immunity against Mel-Ret cells in vitro. Interestingly, the peritoneal-exudate-cell-associated antitumor immunity was further augmented by the addition of 200-400 microg per ml of juzen-taiho-to in vitro. This immunity, which was primarily conveyed by Thy-1+ T cells, was antigen (RET/melanoma) specific and cytotoxic. Amongst various chemical ingredients of juzen-taiho-to examined in this study, glycirrhizin displayed an action, partially replacing that of juzen-taiho-to, in promoting anti-Mel-Ret immunity when supplementarily added in vitro. These results suggest that juzen-taiho-to suppresses once-developed primary melanocytic tumors through potentiation of T-cell-mediated antitumor cytotoxic immunity in vivo.

[Transverse myelopathy with renovascular hypertension caused by fibromuscular dysplasia]

An 18-year-old woman developed subacute transverse myelopathy with renovascular hypertension, hyperlipidemia, and proteinuria. Spinal magnetic resonance imaging(MRI) showed an intra-spinal cord lesion with severe spinal cord swelling at the C 2-Th 2 level. Increased plasma and cerebrospinal fluid interleukin-8(IL-8) levels and the presence of serum antineutrophil cytoplasmic antibody(ANCA) suggested the existence of an ischemic lesion due to vasculitis. Administration of corticosteroids ameliorated the clinical symptoms and MRI findings. Renovascular angiogram revealed the presence of fibromuscular dysplasia(FMD) at the left renal artery but no malformation was found at the cervical arteries. We discussed the possibility of relationships between myelopathy, FMD, IL-8, and ANCA.