Tetsuro Tsukamoto

Long-term cultured astrocytes inhibit myelin formation, but not axonal growth in the co-cultured nerve tissue.

The chronic demyelinated plaque of multiple sclerosis (MS) is characterised by a loss of oligodendrocytes, astrogliosis, and incomplete or no remyelination which probably results in part from the suppressive effects of gliotic astrocytes on myelin formation. We explanted mouse cerebella on astrocyte cultures which had been maintained for 2 to 12 weeks and assessed the myelination in the cerebellar tissue at 18 days after explanation. Myelination occurred vigorously in the tissue explanted on 2-to 4-week-old astrocytes, but was poorer in the tissue explanted on astrocytes older than 4 weeks. No myelin sheath was formed on 12-week-old astrocytes, although axons developed equally as well as those in the tissues explanted on 2-week-old astrocytes. As astrocytes were maintained longer, they became fibrous and immunostained more deeply with anti-glial fibrillary acidic protein antibody, being analogous to astrogliosis. These findings imply that astrogliosis in chronic demyelinated lesions of MS may potentially block remyelination.

Treatment of multiple sclerosis with anti-measles cow colostrum

Previous virological and immunological studies have suggested that multiple sclerosis (MS) is an auto-immune disease triggered by a virus infection. In order to inhibit the growth of measles virus in the patients jejunum, we obtained an IgA-rich cow colostrum containing anti-measles lactoglobulin resistant to proteases. This colostrum was orally administered to patients with MS to investigate its effect on the course of the disease.Measles-positive antibody colostrum was orally administered every morning to 15 patients with MS at a daily dosage of 100 ml for 30 days. Similarly, measles-negative antibody (< 8) control colostrum was orally administered to 5 patients. As a clinical assessment, disability scores developed by the International Federation of Multiple Sclerosis Societies were used. As a result, of 7 high NT titre (512–5120) anti-measles colostrum recipients 5 patients improved and 2 remained unchanged. Among 8 low NT titre (8–32) anti-measles colostrum recipients 5 patients improved and 3 remained unchanged. However, of 5 negative NT titre (< 8) colostrum recipients 2 patients remained unchanged and 3 worsened. No side-effects were observed in colostrum recipients. These findings suggest the efficacy of orally administered anti-measles colostrum in improving the condition of MS patients (P < 0.05).

Intrathecal synthesis of immunosuppressive acidic protein (IAP) in patients with multiple sclerosis and other inflammatory neurological diseases

Immunosuppressive acidic protein (IAP), an immunosuppressive substance produced mainly by macrophages, has previously been shown to increase in the serum of patients with inflammatory neurological diseases. In this study we assayed the IAP levels in cerebrospinal fluid (CSF) by a passive hemagglutination-inhibition test. CSF-IAP levels increased significantly in patients with multiple sclerosis (MS) during both the active and inactive stages and in patients with Guillain-Barré syndrome (GBS) or Miller Fisher syndrome (MFS) as compared with those of control patients, but not in patients with amyotrophic lateral sclerosis or spinocerebellar degeneration. During the active stage of MS, increased CSF-IAP levels together with the elevated IAP% (CSF-IAP/total CSF protein) and IAP index [(CSF-IAP/serum IAP)/(CSF albumin/serum albumin)] suggested the intrathecal synthesis of IAP. In contrast, in patients with GBS or MFS, increased CSF-IAP levels without elevation of IAP% could be attributed largely to increased total CSF protein levels. In patients with neuro-Behçets disease, CSF-IAP levels and IAP% were elevated during the active stage, but remained normal levels during the inactive stage. Assaying CSF-IAP could provide useful information about inflammatory or immunopathological events within the central nervous system.

Significant increase in immunosuppressive acidic protein (IAP) in serum of patients with multiple sclerosis and other inflammatory neurological disorders

IAP, a type of alpha 1-acid glycoprotein, is mainly produced by macrophages when stimulated in the presence of circulating immune complexes or some inflammatory substances. We assayed the serum levels of IAP by a single radial immunodiffusion method. The normal level of IAP is below 500 micrograms/ml (385 +/- 73). In multiple sclerosis patients, however, IAP increased during exacerbation (630 +/- 191) and decreased during the inactive stage (433 +/- 170). Eighty-five percent of patients with neuro-Behcets disease also had high levels of IAP, correlating well with disease activity. In some patients with Guillain-Barré syndrome or Miller Fisher syndrome, IAP increased during the acute phase. In patients with herpes simplex encephalitis, IAP levels remained abnormally high for more than 60 days after onset. The mean value of IAP in patients with amyotrophic lateral sclerosis did not differ from that of normal controls. An increase in IAP in the serum of patients seems to reflect the activity of an inflammatory or immunopathological process.

Vacuolar degeneration in mice infected with a coronavirus JHM‐CC strain

Vacuolar degeneration was constantly induced in the CNS of 4-week-old ICR mice by intracerebral or intranasal inoculation of JHM-CC virus, a small plaque mutant of mouse hepatitis virus (JHM). Most animals showed no symptoms or only mild hindlimb paresis. Irrespective of clinical manifestations, the virus was isolated from the CNS up to days 14 to 16. Viral antigen expression in the CNS tissue was most extensive around days 5 to 7 and became undetectable on day 14. Viral antigens were localized almost exclusively to neurons, and the temporal sequence of viral antigen distribution after intranasal inoculation clearly indicated the virus spread through the olfactory and limbic systems into the brainstem and spinal cord, and possible cell-to cell transmission of the virus within the CNS. Vacuolar changes, most conspicuous in the brainstem and spinal cord, were steadily progressive up to 4 weeks after infection, but became indistinct by 4 months. Although the distribution of vacuolar lesions largely agreed with that of viral antigen-positive cells, the severity of vacuolation did not correlate with that of inflammation. Intramyelinic splitting, periaxonal edema, and swollen neurites were major ultrastructural substrates for vacuolar changes. This model could provide a better understanding of new types of neurologic disorders associated with viral infections, including vacuolar myelopathy in AIDS.

Vacuolar Degeneration Induced by JHM-CC Virus in the CNS of Cyclophosphamide-Treated Mice

The infection with JHM-CC virus (1), a small plaque mutant of neuro-virulent JHM virus, is non-fatal in immunocompetent mice but constantly induces vacuolar degeneration in the brain and spinal cord (2). To elucidate the role of host immune response in pathogenesis of JHM-CC induced vacuolar degeneration in the central nervous system (CNS), the kinetics of virus growth and the temporal sequence of viral antigen distribution were correlated with histopathological changes in cyclophosphamide-treated adult ICR mice.

Difference in Response of Susceptible Mouse Strains to a Small Plaque Mutant (JHM-CC) of Mouse Coronavirus

The JHM-CC virus is a small plaque mutant isolated from the DBT cell culture persistently infected with JHM (1), the most neurotropic strain of mouse Coronavirus (2). This JHM-CC virus had been shown to induce severe vacuolar degeneration in the brainstem and spinal cord of the infected ICR mice (1,3). Since the strain difference of mice in their susceptibility to various strains of mouse coronaviruses including parental JHM virus has been documented (4,5), we compared the kinetics of virus production and neuropathological changes after intracerebral inoculation of the JHM-CC virus in three strains of mice.

Vacuolar Encephalomyelopathy in Mice Induced by Intracerebral Inoculation with a Coronavirus JHM-CC Strain

JHM-CC virus, a mutant strain of mouse hepatitis virus, was isolated by Hirano in 1980 from a DBT cell culture persistently infected with the neurovirulent strain, JHM1. This mutant strain is characterized by formation of smaller plaques on the DBT cells and by lower cell virulence than the original JHM1. Although several murine coronaviruses such as JHM are known to cause demyelinating encephalitis2,4, we found that JHM-CC does not induce primary demyelination, but instead produces characteristic vacuolar degeneration in the brain and spinal cord. In this report we describe the clinical manifestations, neuropathological changes and viral antigen distribution in the central nervous system (CNS) of ICR mice infected intracerebrally with JHM-CC.