Inhibition of tumor-promoting effects by poricoic acids G and H and other lanostane-type triterpenes and cytotoxic activity of poricoic acids A and G from Poria cocos

The structures of two novel 3,4-seco-lanostane-type triterpenes isolated from the sclerotium of Poria cocos were established to be 16alpha-hydroxy-3,4-seco-lanosta-4(28),8,24-triene-3,21-dioic acid (1; poricoic acid G) and 16alpha-hydroxy-3,4-seco-24-methyllanosta-4(28),8,24(24(1))-triene-3,21-dioic acid (2; poricoic acid H) on the basis of spectroscopic methods. These two, and eight other known compounds isolated from the sclerotium, poricoic acid B (3), poricoic acid A (4), tumulosic acid (5), dehydrotumulosic acid (6), 3-epidehydrotumulosic acid (7), polyporenic acid C (8), 25-hydroxy-3-epidehydrotumulosic acid (9), and dehydroabietic acid methyl ester (10), showed potent inhibitory effects on Epstein-Barr virus early antigen (EBV-EA) activation induced by the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA). Evaluation of the cytotoxicity of compounds 1 and 4 against human cancer cell lines revealed that 1 was significantly cytotoxic to leukemia HL-60 cells [GI(50) (concentration that yields 50% growth) value 39.3 nM], although it showed only moderate cytotoxicity to the other cells. Compound 4 exhibited moderate cytotoxicity to all of the cancer cell lines tested.     

Chinese medicine induces neurite outgrowth in PC12 mutant cells incapable of differentiation

During continuous culture of neural PC12 cells, we obtained a drug-hypersensitive PC12 mutant cell that showed high stimulation of neurite outgrowth by various drugs. When several Chinese medicines such as shu-jing-huo-xie-tang and Wu-Ling-San were provided to these PC12 mutant cells, the frequency of nerve growth factor (NGF)-induced neurite outgrowth increased approximately 30-fold compared to NGF alone. Neurite outgrowth induced by NGF in PC12 cells is accompanied by sustained activation of mitogen-activated protein kinase (MAPK); however, these Chinese medicines did not induce MAPK activity. The findings thus indicate that certain Chinese medicines may induce neurite outgrowth by a novel mechanism which is distinct from the NGF-activated pathway in PC12 mutant cells.     

Eosinophilic myelitis associated with atopic diathesis: a combined neuroimaging and histopathological study

Histologically proven eosinophilic myelitis has rarely been reported except in connection with parasitism. To clarify its clinicopathological features, we conducted a nationwide survey of biopsy-proven eosinophilic myelitis of unknown cause throughout Japan. Six such cases were collected and studied immunologically and pathologically. All were young to middle-aged men. All showed a protracted and fluctuating course with mild disability for 3-25 (mean 12.5) months before biopsy. Magnetic resonance imaging revealed localized lesions of T2-high and T1-iso signal intensity with a partial gadolinium enhancement in all cases. Cerebrospinal fluid (CSF) examinations were completely normal except for modest pleocytosis in two cases. Eosinophilia was present in the peripheral blood in two cases but was absent from the CSF of all cases. In spite of the chronic nature of the disease, spinal cord pathology revealed very active lesions with marked cell infiltration consisting mainly of CD8(+) T cells and varying numbers of eosinophils in the perivascular areas and the parenchyma. Both the myelin and axons were severely disrupted in all cases. Moreover, eosinophil cationic protein (ECP), an activated eosinophil product, was heavily deposited in the tissues. All but one case had hyperIgEemia and mite antigen-specific IgE in the sera, and two had accompanying atopic disorders. The present study thus revealed idiopathic eosinophilic myelitis to be a localized and persistent inflammation of the spinal cord, with distinct clinicopathological features, that has a possible link to atopic diathesis.     

An autopsy case of argyrophilic grain dementia with abundant neurofibrillary tangles]

We reported an autopsy case of "senile dementia" showing neuropathologically abundant neurofibrillary tangles(NFT) and argyrophilic grains(AG) without senile plaques. A Japanese woman developed memory disturbance when she was 70 years old. The patient was hospitalized at age 80 and a cranial CT scan revealed bilateral mild atrophy of the temporal lobes and mild enlargement of the lateral ventricle, especially in the inferior horn. She died at the age of 80. Autopsy showed that her brain weighted 1220 g. Numerous NFT were found in the entorhinal (trans-entorhinal) region, subiculm, CA1-CA4, dentate gyrus, amygdala, nucleus basalis of Meynert, substantia nigra, and locus coeruleus. Furthermore, numerous AG were seen in the temporal lobe(T3, T4), amygdala, prominently in the basolateral nuclei. Obvious neuronal loss with gliosis was noted in the temporal lobes, including the hipocampal regions. Few senile plaques was detected in temporal lobe(T4). Sarkosyl-insoluble tau extracted from the temporal lobe consisted predominantly of four-repeat tau isoforms. To our knowledge, this is the first report of argyrophilic grain dementia complicated with tangle only dementia.     

Voltage-gated channels involved in taste responses and characterizing taste bud cells in mouse soft palates

Taste bud cells (TBCs) on soft palates differ from those on tongues in innervation and chemosensitivity. We investigated voltage-gated channels involved in the taste responses of TBCs on mouse soft palates under in-situ tight-seal voltage/current-clamp conditions. Under the cell-attached mode, TBCs spontaneously fired action currents, which were blocked by application of 1 microM TTX to TBC basolateral membranes. Firing frequencies increased in response to taste substances applied to TBC receptor membranes. Under the whole-cell clamp mode, as expected, TBCs produced various voltage-gated currents such as TTX-sensitive Na+ currents (INa), outward currents (Iout) including TEA-sensitive and insensitive currents, inward rectifier K+ currents (Iir), and Ca2+ currents including T-type, P/Q-type, and L-type Ca2+ currents. We classified TBCs into three types based on the magnitude of their voltage-gated Na+ currents and membrane capacitance. HEX type (60% of TBCs examined) was significantly larger in Na+ current magnitude and smaller in membrane capacitance than LEX type (23%). NEX type (17%) had no Na+ currents. HEX type was equally distributed within single taste buds, while LEX type was centrally distributed, and NEX type was peripherally distributed. There were correlations between these electrophysiological cell types and morphological cell types determined by three-dimensional reconstruction. The present results show that soft palate taste buds contain TBCs with different electrophysiological properties, and suggest that their co-operation is required in taste transduction.     

Differential development of cation-chloride cotransporters and Cl- homeostasis contributes to differential GABAergic actions between developing rat visual cortex and dorsal lateral geniculate nucleus

A recent study suggested that gamma-aminobutyric acid (GABA) plays differential roles in activity-dependent plasticity between the visual cortex (VC) and the dorsal lateral geniculate nucleus (dLGN). In the present study, to investigate differential GABAergic functions in postnatal visual system development, the development of [Cl(-)](i), cation-Cl(-) cotransporter expression, and the [Ca(2+)](i) responses evoked by GABA were compared between VC and dLGN during the early stages of development. Using rat brain slices from postnatal days (P) 0-17, GABA-evoked [Ca(2+)](i) responses and resting [Cl(-)](i) were measured by means of optical imaging of Ca(2+) and Cl(-), respectively. Changes in the expression of cation-Cl(-) cotransporters (viz. the outwardly-directed K(+)-Cl(-) cotransporter, KCC2, and the inwardly-directed Na(+),K(+)-2Cl(-) cotransporter, NKCC1) were examined in VC and dLGN by in situ hybridization. At birth, the excitatory actions of GABA were powerful in VC, but missing in dLGN (as indicated by neuronal [Ca(2+)](i) transients), and the resting [Cl(-)](i) was significantly higher in VC than in dLGN. Signals for KCC2 mRNA expression were significantly higher in dLGN than in VC at P0. This suggests that extrusion of Cl(-) from neurons is stronger in dLGN than in VC at P0, so that a GABAergic excitatory effect was not observed in dLGN because of more negative equilibrium potential for Cl(-). The present study indicates clear differences in the molecular and physiological bases of Cl(-) homeostasis and GABA actions between the developing VC and dLGN. Such differential GABAergic actions may underlie the distinct mechanisms involved in VC and dLGN development within the visual system.     

Event based and time based prospective memory in Parkinson's disease

BACKGROUND: Patients with Parkinson's disease have been reported to have retrospective memory impairment, while prospective memory, which is memory for actions to be performed in the future, has not yet been investigated. OBJECTIVE: To investigate the prospective memory of patients with Parkinson's disease. METHODS: Twenty Parkinson's disease patients and 20 age matched normal controls were given event based and time based prospective memory tasks. In the event based prospective memory task, the subject was asked to perform an action whenever particular words were presented. In the time based prospective memory task, the subject was asked to perform an action at certain times. RESULTS: The Parkinson's disease patients were impaired on the event based prospective memory task but not on the time based prospective memory task. The impairment of the Parkinson's disease patients on the event based prospective memory task was not the result of their forgetting the content of the prospective memory instructions, but the result of their failure to retrieve it spontaneously when the target words appeared. CONCLUSIONS: These results suggest that event based prospective memory is impaired in patients with Parkinson's disease, presumably relating to frontal lobe dysfunction.     

Changes in serum macrophage-related factors in patients with chronic inflammatory demyelinating polyneuropathy caused by intravenous immunoglobulin therapy

Chronic inflammatory demyelinating polyneuropathy (CIDP) is a slowly progressive or recurrent neuropathy accompanied by infiltration of macrophages in the peripheral nerves. Macrophage colony-stimulating factor (M-CSF) and monocyte chemoattractant protein-1 (MCP-1) are a macrophage-related cytokine and chemokine, respectively. Although, intravenous immunoglobulin (IVIg) infusion therapy has been used for treating CIDP patients, not all CIDP patients have responded to IVIg infusion therapy. To determine the mechanisms of the action of IVIg, we examined serum M-CSF and MCP-1 levels during and after IVIg infusion therapy in 19 CIDP patients treated with IVIg (0.4 g/kg/day for 5 days). Ten of the 19 patients (52.6%) responded to IVIg therapy. Both M-CSF and MCP-1 concentrations in IVIg responders were significantly higher on day 1 postinfusion than those in nonresponders, but decreased to their pretreatment values on day 5 postinfusion. The results suggest that immunomodulation through M-CSF and MCP-1 is involved in the mechanisms underlying the effect of IVIg infusion therapy in CIDP patients.     

Decreased galectin-1 immunoreactivity of the skin in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease involving motor neurons. In addition to motor neuron signs and symptoms, a lack of bedsores has been considered a feature of ALS. Recently, we revealed that galectin-1 is a component of the axonal spheroid, which is an early pathological change of the spinal cord in ALS. To investigate whether galectin-1 is associated with skin changes in ALS, we performed an immunohistochemical investigation using anti-galectin-1 antibodies. The present study revealed that galectin-1 immunoreactivity is reduced in the skin of patients with ALS, suggesting that cutaneous galectin-1 is involved in the pathological process of ALS.