Loss of the dentate nucleus neurons is associated with torpedo formation: a morphometric study in progressive supranuclear palsy and dentatorubro-pallidoluysian atrophy

Cerebellar torpedoes can be induced by direct damage to Purkinje cell axons. This raises the possibility that the loss of dentate nucleus neurons (DNNs) may also cause torpedo formation through synaptic detachment between DNNs and Purkinje cell axon terminals. To investigate this possibility, we conducted a morphometric study with an image analyzer in progressive supranuclear palsy (PSP) and dentatorubro-pallidoluysian atrophy (DRPLA). Using horizontal and sagittal sections of the cerebellar hemispheres containing the greatest proportion of the dentate nucleus, we determined the line densities of torpedoes, Purkinje cells, and DNNs. In PSP and DRPLA, the densities of DNNs were significantly lower, and the densities of torpedoes much greater than in controls, while those of Purkinje cells were normal in both diseases. In addition, the torpedo densities in PSP and DRPLA showed a strong negative correlation with the DNN densities. Thus, this study clearly demonstrated that torpedoes are formed in association with the loss of DNNs, suggesting that they may occur in consequence of synaptic disconnection of Purkinje cells from DNNs.

Expression of cyclooxygenase genes and involvement of endogenous prostaglandin during osteogenesis in the rat tibial bone marrow cavity

Many researchers have demonstrated that the administration of prostaglandins (PGs), especially PGE2, increases the bone volume in vivo. It is still not clear how endogenous PG is associated with such bone formation. Cyclooxygenase (COX), which acts in the synthesis of PG from arachidonic acid, has been recently revealed to have two subtypes, a constitutive type (COX-1) and an inducible one (COX-2). We examined the expression of each COX subtype during osteogenesis with the established model of the rat tibial medullary cavity in which osteogenesis can be induced by the injection of colchicine. The expression of both COX-1 and COX-2 genes was enhanced after colchicine injection in the early stage before the start of bone formation. Only the COX-2 gene expression was elevated again later during the beginning of bone formation. Furthermore, the daily administration of indomethacin, COX inhibitor, could reduce the bone mass induced by colchicine in the rat tibiae. These data indicate that endogenous PGs are associated with osteogenesis in this model. Moreover, the present study suggests that COX-2 and COX-1 would both be involved in the early stage of osteogenesis, and COX-2 is likely to be more associated with the maturation of osteoblasts in the later stage.

Molecular cloning and functional characterization of murine cDNA encoding transcription factor NFATc

Transcription factors of the NFAT (nuclear factor of activated T cells) family play important roles in immune and inflammatory responses by regulating the expression of genes encoding cytokines and immunoregulatory proteins. Here we describe cloning and characterization of full-length cDNA encoding murine (m) NFATc which predicts that the protein has all the conserved structural motifs of NFAT family members, including the rel homology domain, the NFAT homology domain and the nuclear translocation signals. mNFATc complexed with AP-1 bound specifically to the murine IL-2 NFAT recognition sequence and activated transcription from the co-transfected IL-2 promoter in COS-7 cells. Northern blot analysis showed that the cDNA probe hybridized with a 4.5 kb transcript which is highly inducible in murine T cells. By Northern and in situ hybridization, mNFATc transcript was detected from the early stage of development. In the mouse embryo, mNFATc transcript was strongly expressed in thymus, lung and submandibular gland and weakly in skeletal muscle and heart suggesting that mNFATc may have a role both in embryogenesis and in mature T cells.

Surgical treatment of epilepsy from schizencephaly with fused lips

BACKGROUND

Surgical treatment of schizencephaly with fused lips has been reported in few cases. In all of the previously reported cases, temporal lobectomy was selected as a major surgical treatment, except for one case with cortical resection. We present a case of direct resection of dysplastic walls of the schizencephalic cleft and the surrounding epileptic area.

CASE

This 20-year-old college student with medication-resistant epilepsy was surgically treated by subpial cortical resection of the epileptogenic area around a schizencephalic cleft. Magnetic resonance imaging showed an unilateral schizencephalic cleft with fused lips in the right parietal lobe. Pathologic examination demonstrated dysplastic neurons in the epileptogenic cortex. Intraoperative electrocorticography clearly detected epileptiform discharges around the cleft, and the epileptogenic lesion was completely resected. He has been seizure-free for 1 year since the operation and he has no neurologic deficits.

CONCLUSION

Subpial resection of the dysplastic cortex surrounding the cleft under the guide of electrocorticography is an effective and minimally invasive procedure for the treatment of schizencephaly.

Ciliate protozoa in the rumen of sassaby antelope, Damaliscus lunatus lunatus, including the description of a new species and form

Composition of rumen ciliate fauna in five Zambian, sassaby antelopes was determined. Six genera, 18 species, and four forms were identified. One new species and form, belonging to the subfamily Diplodiniinae, were found, then labeled Ostracodinium damaliscus n. sp. and Diplodinium bubalidis f. aspinosum n. f., respectively. Only ophryoscolecid species were present while isotrichids were absent. Twelve of 18 total species are commonly found in African antelopes. Three of those 12 species, Entodinium fyferi, Enoploplastron garstangi and Opisthotrichum janus, are only found in African antelopes. Percentage composition was low in the genera Enoploplastron, Eudiplodinium and Entodinium, and high in the genus Opisthotrichum. The average density of ciliates was 3.1 x 10(5)/ml of rumen fluid, and the average number of ciliate species per host was 17.2.

The advantage of gastrectomized patients in management of their chronic hepatitis C

Because the majority of patients with chronic hepatitis C do not respond to interferon, alternative treatments need to be established. Several lines of evidence suggest that iron depletion is beneficial for such patients. Thus, gastrectomized patients with a reduced capacity for iron absorption might have an advantage in treatment of their liver damage over patients with intact gastrointestinal tracts. Four male gastrectomized patients had post-transfusion chronic hepatitis C. The iron load in three patients was adjusted below 10 ng/ml of serum ferritin level by phlebotomy. Subsequent interferon treatment for the four patients without iron load cleared circulating hepatitis C virus RNA in one patient only. However, serum ferritin concentrations were stabilized at low levels without maintenance phlebotomy, and sustained normalization of serum liver enzyme activities was obtained in all four patients. Similar treatments were done for 10 male patients with intact gastrointestinal tracts. The amount of removed iron from these patients was more than that from gastrectomized patients. Interferon also failed to clear circulating hepatitis C virus RNA except in one case. Low ferritin levels and sustained normalization of liver enzymes were seen in three patients. A transient elevation of ferritin levels with low enzyme activities was seen in two patients. Relapsing hepatitis was seen in five of the seven patients who needed maintenance phlebotomy due to a rebound in serum ferritin levels, probably because of active iron absorption from the intestine. Our data suggest that depletion of cytotoxic iron is a key to managing patients with chronic hepatitis C.

Coexistence of ganglioglioma and cortical dysplasia in a patient with intractable epilepsy--case report

An 8-year-old girl presented with coexistence of ganglioglioma and cortical dysplasia manifesting as intractable epilepsy. Preoperative computed tomography demonstrated a small calcified lesion in the left frontal lobe which was not diagnosed as ganglioglioma. Magnetic resonance imaging also failed to demonstrate positive evidence of ganglioglioma or cortical dysplasia. A calcified tumor and the surrounding epileptogenic areas were resected under electrocorticography (ECoG) guidance. Histological examination revealed coexistence of ganglioglioma and cortical dysplasia. The patient became seizure-free after surgery. Resection of the ganglioglioma together with the adjacent epileptogenic area under intraoperative ECoG guidance is important to achieve a successful surgical result in patients with ganglioglioma.

[A case of pulmonary arteriovenous fistula presenting as multiple brain abscesses after a sustained period without treatment]

A 64-year-old man was admitted to our hospital with multiple brain abscesses accompanied by pulmonary arteriovenous fistula (PAVF). He had been diagnosed with PAVF eight years previously, but had refused any treatment despite a developing exertional dyspnea. Rendu-Osler-Weber disease was diagnosed as well because the patient exhibited teleangiectasis of the nasopharyngeal mucosa and persistent gastro-intestinal bleeding. Despite administration of antibiotics and corticosteroids the abscesses perforated into the lateral ventricle. The natural history of this rare disease is still incompletely understood. Thus, the time at which treatment should be commenced remains unclear. However the natural course of PAVF is unsatisfactory, and it appears that treatment by surgery and/or embolization should be considered in all cases.

Amphistin, a new melanogenesis inhibitor, produced by an actinomycete

A new melanogenesis inhibitor, named amphistin, was isolated from the fermentation broth of an actinomycete strain KP-3052. Amphistin was purified from the culture filtrate by the combination of cation exchange, gel filtration, and aminosilyl silica gel chromatographic methods. The structure of amphistin was elucidated as gamma-(beta-histidinoalanino)homoalanine by NMR experiments including 1H-15N HMBC experiment and other spectroscopic analyses. Amphistin inhibited the melanogenesis of B16 melanoma cells at concentration of 6.8 microM.

Tau immunoreactivity in glial cytoplasmic inclusions in multiple system atrophy

In order to clarify the manner and significance of tau expression in glial cytoplasmic inclusions (GCIs), ubiquitinated oligodendroglial abnormal structures in multiple system atrophy (MSA), an immunohistochemical study was carried out in the lesions of the pontine nuclei of 10 cases of MSA using antibodies against various epitope locations of tau protein. As a result, tau-2 was constantly but weakly positive in ubiquitinated GCIs in each case (from 28.6 to 66.7%). However, tau-2-immunoreactivity in GCIs was not correlated to the density of ubiquitin-positive GCIs or preserved pontine neurons. Antibodies against tau proteins of N-terminal or C-terminal failed to label GCIs, although a few number of GCIs were occasionally positive for tau-1 after dephosphorylation. In comparison with the knowledge on tau-immunoreactivity of coiled bodies (CBs) in oligodendroglia in progressive supranuclear palsy (PSP) or corticobasal degeneration, GCIs are quite different from CBs which have a wide range of epitope location of tau proteins, including N-terminal and C-terminal. This study suggests that expression of tau proteins in GCIs is not related to the essential neurodegenerative process in MSA but induced by non-specific stress in oligodendroglia, unlike CB in various 'tau diseases' such as PSP.

Morphologic difference of neuropil threads in Alzheimer's disease, corticobasal degeneration and progressive supranuclear palsy: a morphometric study

Using Gallyas-Braak's silver stain, neuropil threads (NTs) in Alzheimer's disease (AD), corticobasal degeneration (CBD) and progressive supranuclear palsy (PSP) were analyzed morphologically and morphometrically. The NT density was highest in the cerebral cortical layer V in AD and CBD, and in the subcortical white matter in PSP. An overlaid, two-dimensional, camera lucida drawing revealed differences in the fine profile of NTs among these three disease groups. The differences were confirmed by computerized feature analysis which revealed differences in maximum length, breadth, Feret's angle and orientation of the NTs. Unlike a previous assumption that all NTs have a similar appearance, our study revealed that NTs in AD, CBD and PSP were distinctively different with respect to their morphology.

Protective protein in the bovine lysosomal beta-galactosidase complex

Cathepsin A [EC 3.4.16.1], so called protective protein, occurs as an enzyme complex with lysosomal beta-galactosidase [3.2.1.23] and is involved in the stable enzymic expression of lysosomal sialidase [3.2.1.18]. In this study we investigated the enzymatic properties of cathepsin A in the bovine beta-galactosidase complex and how it is involved in the molecular multiplicities of the beta-galactosidase and sialidase complexes. Bovine protective protein homologous to the human protein had a molecular weight of 48 kDa on SDS-PAGE and cathepsin A activity optimum around pH 6.0. It hydrolyzed dipeptide substrates composed of hydrophobic amino acids much faster than any other type of substrate tested. This specificity was found to be conserved from human to a non-mammal, chicken. Immunoprecipitation using an anti beta-galactosidase antibody demonstrated that cathepsin A is a component of both the sialidase and beta-galactosidase complexes. The over 700 kDa sialidase complex depolymerized by a brief incubation at pH 7.5 and the sialidase was inactivated irreversibly via formation of an enzyme active smaller species of sialidase. The 669 kDa beta-galactosidase complex dissociated reversibly into a 120 kDa beta-galactosidase and a 170 kDa cathepsin A, but the 120 kDa beta-galactosidase, free from the cathepsin A, formed a 260 kDa aggregate under the same conditions. Inactivation of cathepsin A by heat treatment did not affect its complex forming activity. The 170 kDa protective protein dissociated into a 50 kDa one at pH 7.5, which no longer formed the complex. These findings indicate that the 170 kDa protective protein could be the minimum unit required for in vitro reconstitution of the complex, and that its complex forming activity is carried in a heat-stable domain. Both beta-galactosidase and cathepsin A activities were labile under the dissociated condition, indicating that it physiologically stabilizes not only beta-galactosidase but also itself by forming the complex.

Four P-like elements are required for optimal transcription of the mouse IL-4 gene: involvement of a distinct set of nuclear factor of activated T cells and activator protein-1 family proteins

We previously identified the P sequence as a critical regulatory element of the human IL-4 promoter. In the mouse IL-4 promoter, there are five elements homologous to the human P sequence designated conserved lymphokine element 0 (CLE0), P, P2, P3 and P4. To characterize the role of these P-like elements and their binding factors in the native promoter, we did transient transfection and electrophoretic mobility shift assays (EMSA). Transfection of EL-4 cells with the IL-4 promoter-reporter constructs carrying mutated P-like elements showed that four P-like elements, CLE0, P, P2 and P4, but not P3, were required for optimal activation of the IL-4 promoter. EMSA showed that both constitutive and inducible complexes bound to CLE0, P, P2 and P4, whereas only a constitutive complex bound to P3. In competition and antibody supershift assays in EMSA, complexes formed with P or P2 proved to contain nuclear factor of activated T cells (NFAT) family proteins as major components. Activator protein (AP)-1 family proteins interacted with CLE0, P, P2 and P4. NFAT/AP-1 complex formed only with P and P2. Cross-competition assays among the P-like elements revealed element-specific and common complexes. Six tandem repeats of the P element linked to the SV40 promoter responded to phorbol 12-myristate 13-acetate, while that of other elements did not. It would thus appear that components of each P-like element-binding complexes are not identical and may coordinately contribute to transcriptional activity.

Low epithelial cell proliferation and absence of oncoprotein expression in juvenile polyposis of the stomach, with or without tumors

OBJECTIVES

To assess cell proliferation and analyze oncogenetic abnormalities in cases of juvenile polyposis of the stomach (JPs), with or without coexisting tumors.

METHODS

The Ki-67 labeling indices (KLI) were compared for juvenile polyps and coexisting tumors in three cases of JPs along with values for gastritis, foveolar epithelial hyperplastic polyps, adenomas, and carcinomas. Expression of p53, Bcl-2, and c-ErbB-2 in tumors was examined immunohistochemically, and a search for c-Ki-ras mutations was made by DNA direct sequencing.

RESULTS

The KLI for JPs did not significantly differ between cases, being consistently lower than the values for both hyperplastic polyps and gastritis. The KLI for the papillary tumors and a signet ring cell carcinoma found in association with JPs tended to be lower than those for their conventional counterparts. P53, but not Bcl-2 and c-ErbB-2, was focally expressed in the papillary tumors, whereas all three were absent in the signet ring cell carcinoma, in the JPs. No c-Ki-ras mutations were detected in the papillary tumors.

CONCLUSIONS

The cell proliferation of JPs is relatively low and the polyps can be considered hamartomatous. However, neoplastic change clearly can occur in association with a relative increase in proliferative activity being observed in coexisting tumors. Low cellular proliferative activity and absence of oncogenetic abnormalities in tumors of JPs, compared with their conventional counterpart tumors, suggest that pathways of tumorigenesis and genetic alteration in JPs may be different from those in their conventional counterparts.

Neuropathology of the dentate nucleus in developmental disorders

The dentate nucleus was examined histologically and immunohistochemically in 47 cases of nonprogressive developmental disorders. Neuronal loss and/or atrophy was observed in 13 cases, while mild neuronal lesions, characterized by dendritic swelling and/or the appearance of eosinophilic materials around the neurons, were exhibited in 20 cases. The former change was accompanied by diffuse central nervous system involvement, and the etiology was perinatal hypoxic ischemic encephalopathy, acute encephalopathy, and meningoencephalitis in most cases. On the other hand, most of the patients with kernicterus showed the latter change. Immunohistochemically, the mild neuronal lesions mimicking grumose, degeneration, described in some neurodegenerative diseases, seemed to reflect the changes of Purkinje cell terminals. It is suggested that secondary structural alteration of the dentate neurons in the absence of severe atrophy can occur in nonprogressive developmental disorders.

Apolipoprotein E in progressive supranuclear palsy in Japan

Progressive supranuclear palsy (PSP) is a rare neurodegenerative disease which shows several psychiatric and neurologic symptoms: pseudobulbar palsy, supranuclear ocular palsy, extrapyramidal rigidity, gait ataxia, and dementia. Almost all cases seem to be sporadic; therefore, the elucidation of risk factors is important to clarify the pathological mechanism. Apolipoprotein E4 (ApoE4) is now well established as a risk factor of Alzheimer's disease (AD). Here we report the ApoE allele frequency in PSP, which shares pathological findings such as neurofibrillary tangle (NFT) with AD. NFT is an important sign for the derangement of normal cytoskeletons in degenerating neurons. Although there was no significant increase in epsilon 4 allele frequency in the present series of PSP cases compared with that in the Japanese controls, there was a significant increase in the epsilon 2 allele frequency in PSP compared to controls.

Neuronal inclusions in the dentate fascia in patients with multiple system atrophy

Ubiquitin-immunoreactive neuronal inclusions in the granular cells in the dentate fascia (UNIDs) of patients with multiple system atrophy (MSA) were examined for immunohistochemical and ultrastructural characterization especially in comparison with those which were recently reported for amyotrophic lateral sclerosis with dementia (ALS-D). Eight of 23 MSA patients had UNIDs which were also identified by Gallyas-Braak impregnation but immunonegative for other antibodies including against tau, neurofilaments, and alphaB crystallin. Ultrastructurally, loosely aggregated fibrils without limiting membrane located around the nucleus, which was confirmed by the results of ubiquitin-immunoelectron microscopy. The formation of UNIDs in MSA and ALS-D was suggested to be caused by different types of degeneration because UNIDs in MSA differ from these in ALS-D in terms of their stainability by Gallyas-Braak impregnation and ultrastructurally. In this study hippocampal involvement in MSA differing from ALS-D was clarified.

Focal cortical dysplasia: appearance on MR images

PURPOSE

To clarify the magnetic resonance (MR) imaging characteristics of focal cortical dysplasia (FCD).

MATERIALS AND METHODS

The authors reviewed the MR images of 14 patients with FCD, which was confirmed with histologic examination.

RESULTS

MR images exhibited FCD in 13 of the 14 patients. All lesions were localized to part of one hemisphere. T2-weighted images showed blurring of the gray matter-white matter junction and abnormal signal intensity in the white matter in 11 patients. T1-weighted images showed blurring of the gray matter-white matter junction in seven patients, broad gyri in nine, thick cortices in nine, abnormal sulci in 10, and focal enlargement of the overlying subarachnoid space or adjacent ventricle in eight. Surgical specimens exhibited disruption of cortical lamination without abnormal gyration in all patients, cytomegalic neurons in the cortex in three, disorganized bizarre glial cells in the cortex in seven, ectopic neurons or bizarre glial cells in the white matter in nine, and blurring of the gray matter-white matter junction in one.

CONCLUSION

Blurring of the gray matter-white matter junction with abnormal signal intensity in the white matter on T2-weighted images is characteristic of FCD. The presence of ectopic neurons and bizarre glial cells, dysmyelination, and a reduction in the number of myelinated fibers might have been responsible for the MR imaging characteristics.

[Proton MR spectroscopy of hyperplastic hematopoietic marrow in aplastic anemia]

The purpose of this study was to compare the findings of magnetic resonance (MR) spectroscopy of hyperplastic hematopoietic marrow with those of normal bone marrow. Twenty-four samples of normal marrow from eight control subjects and 19 samples of hyperplastic marrow in aplastic anemia were examined with a 1.5T MR unit. The former showed low intensity on opposed-phase T1-weighted images, while the latter showed high intensity on both fast STIR and opposed-phase T1-weighted images. MR spectroscopy quantitatively confirmed that the water: fat ratio was increased and the transverse relaxation time of water was changed in hyperplastic bone marrow, compared with normal bone marrow. In summary, MR imaging is able to detect hematopoietic regions among a wide range of bone marrow of aplastic anemia, while MR spectroscopy allowed us to quantitatively analyze the cell population of hyperplastic hematopoietic marrow in aplastic anemia.

Control of NFATx1 nuclear translocation by a calcineurin-regulated inhibitory domain

The nuclear factor of activated T cells (NFAT) regulates cytokine gene expression in T cells through cis-acting elements located in the promoters of several cytokine genes. NFATx1, which is preferentially expressed in the thymus and peripheral blood leukocytes, is one of four members of the NFAT family of transcription factors. We have performed domain analysis of NFATx1 by examining the effects of deletion mutations. We found that NFATx1 DNA binding activity and interaction with AP-1 polypeptides were dependent on its central Rel similarity region and that transcriptional activation was reduced by deletions of either its N-terminal domain or its C-terminal domain, suggesting the presence of intrinsic transcriptional activation motifs in both regions. We also identified a potent inhibitory sequence within its N-terminal domain. We show that the inactivation of the inhibition was dependent on the activity of calcineurin, a calcium-calmodulin-dependent phosphatase. We also show that calcineurin associated with the N-terminal domain of NFATx1 at multiple docking sites and caused a reduction of size, indicative of dephosphorylation, in NFATx1. We have mapped the inhibitory activity to less than 60 residues, containing motifs that are conserved in all NFAT proteins. Finally, we demonstrate that deletion in NFATx1 of the mapped 60 residues leads to its nuclear translocation independent of calcium signaling. Our results support the model proposing that the N-terminal domain confers calcium-signaling dependence on NFATx1 transactivation activity by regulating its intracellular localization through a protein module that associates with calcineurin and is a target of its phosphatase activity.