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Biomedical subjects

M Mizuguchi

Publications and source records attributed to M Mizuguchi.

At least 37 records · Page 2Linked to original sources
PubMed2000

Rapid immunologic diagnosis of classic late infantile neuronal ceroid lipofuscinosis.

OBJECTIVE: To establish a new method for rapid diagnosis of late infantile neuronal ceroid lipofuscinosis (LINCL, CLN2) using specific polyclonal antibodies against the CLN2 gene product. METHODS: Cells and tissues were obtained from five patients with LINCL, two with variant type NCL, three with other lysosomal storage diseases, and eight control subjects. Two antibodies were raised against N- and C-terminal peptide fragments of the normal product of the CLN2 gene. The authors examined the possibility of diagnosis of LINCL with immunostaining and immunoblotting using specific antibodies made of the recently identified defective gene in LINCL. RESULTS: Immunoreactivity with these antibodies showed the absence or marked reduction of CLN2 immunoreactivity in the lymphocytes, lymphoblasts, and fibroblasts of all five patients with LINCL examined. CONCLUSIONS: These results indicate the usefulness of this diagnostic method based on the changes in CLN2 immunoreactivity. This relatively simple, specific, and cost-effective method is a promising diagnostic tool for this disease, although additional studies are necessary.

Aminopeptidases↗
PubMed2000

Cold denaturation of alpha-lactalbumin.

We have investigated the thermal unfolding of bovine alpha-lactalbumin by means of circular dichroism spectroscopy in the far- and near-ultraviolet regions, and shown that the native alpha-lactalbumin undergoes heat and cold denaturation. The guanidine hydrochloride-induced unfolding of alpha-lactalbumin was also investigated by circular dichroism spectroscopy at various temperatures from 261 to 318 K. It is shown that the population of the molten globule state is strongly dependent on temperature and that the molten globule state does not accumulate during the guanidine hydrochloride-induced unfolding transition at 261 K. Our results indicate that the molten globule state of alpha-lactalbumin undergoes cold denaturation as the native alpha-lactalbumin does, and that the heat capacity change of unfolding from the molten globule to the unfolded state is positive and significant. The present results further support the idea that the molten globule and the unfolded states do not belong to the same thermodynamic state, and that the native, molten globule and unfolded states are sufficient for interpreting the guanidine hydrochloride-induced unfolding behavior of alpha-lactalbumin.

Animals↗
PubMed2000

Cerebellar degeneration in hereditary dentatorubral-pallidoluysian atrophy and Machado-Joseph disease.

We examined the mechanism of cerebellar degeneration in brains obtained at autopsy from six cases of hereditary dentatorubral-pallidoluysian atrophy (DRPLA) and six cases of Machado-Joseph disease (MJD), using terminal deoxynucleotidyltransferase-mediated in situ nick end labeling (TUNEL) and immunohistochemistry for apoptosis-related proteins, neurotrophin receptors and glutamate transporters. In three subjects with DRPLA, who developed dementia and cerebellar ataxia at over 50 years of age, the number of Purkinje cells was mildly reduced, TUNEL-positive cells were observed in the molecular layer of the cerebellar cortex, and immunoreactivities for calbindin D28K and excitatory amino acid transporter-1 (EAAT1) were altered in the molecular layer. In addition, all cases of DRPLA showed a reduction of immunoreactivity for EAAT1 in the dentate nucleus. In MJD, augmentation of Bcl-x expression by the Purkinje cells, and increases in Trk B- and GFAP-immunopositive glial cells in the granular layer were observed in half of the cases, whereas immunoreactivity for EAAT-1 was preserved both in the cerebellar cortex and dentate nucleus. One case of MJD showed TUNEL-positive granular cells in the cerebellar cortex. Age-matched control subjects did not show TUNEL-positive cells or immunohistochemical changes in the cerebellum. There were neither TUNEL-positive cells nor alteration of the in situ expression of apoptosis-related proteins in the dentate nucleus in either variant of hereditary spinocerebellar degeneration, although both exhibited grumose degeneration in the dentate nucleus. These findings indicate that latent degeneration in the cerebellar cortex may occur in DRPLA and MJD, in addition to the dentate change, which is the cardinal feature in the neuropathology of these two diseases. The lesion of Purkinje cells and their processes in the molecular layer associated with altered glutamate transport may be important in DRPLA, while the significance of the abnormalities observed in some MJD cases, which might be related to apoptotic mechanism, remains unclear.

ATP-Binding Cassette Transporters↗
PubMed2000

Ectopic expression of telencephalin in brains with holoprosencephaly.

Telencephalin (TLN), a telencephalon-specific glycoprotein, is exclusively expressed in neurons of the mammalian telencephalon. In the normally developing human brain, TLN immunoreactivity appeared and increased from 35 gestational weeks (GW) in the temporal cortex, and reached adult level at 5 months of postnatal age, being strong in the molecular layer, and weak in the external and internal granular layers. TLN expression corresponded with the development of neuronal dendrites and synapses. In brains with holoprosencephaly TLN immunoreactivity was already strong from as early as 28 GW. Staining was weak in the molecular layer, but strong in the external sparse and middle cellular layers in most cases. Notably, TLN was abundant in the glomerular structures in the internal pyramidal and multiform layers of fetal brains with alobar holoprosencephaly, which disappeared with increasing age. These results indicate premature and ectopic development of the dendrites and synaptic network in holoprosencephaly.

Adolescent↗
PubMed2000

The developmental and aging changes of Down's syndrome cell adhesion molecule expression in normal and Down's syndrome brains.

We studied the expression of Down's syndrome cell adhesion molecule (DSCAM) in Down's syndrome (DS) and control brains, using antisera against peptide fragments of DSCAM. On Western blots of human, mouse and rat brain homogenates, the antisera recognized a product at approximately 200 kDa. In the brain of a 2-year-old patient with DS, Western blotting revealed an overexpression of DSCAM compared to an age-matched control. Immunohistochemistry demonstrated DSCAM in the cerebral and cerebellar white matter of both control and DS subjects, in accordance with the temporal and spatial sequence of myelination. In DS brains, immunoreactivity for DSCAM, compared to that for controls, was enhanced in the Purkinje cells at all ages, and in the cortical neurons during adulthood. In demented DS patients, DSCAM immunoreactivity was observed in the core and periphery of senile plaques. The pattern of DSCAM expression suggests that it may play a role as an adhesion molecule regulating myelination. The overexpression of DSCAM may also play a role in the mental retardation and the precocious dementia of DS patients, although the mechanism of neuronal dysfunction is undetermined.

Adolescent↗
PubMed2000

Simultaneous loss of hamartin and tuberin from the cerebrum, kidney and heart with tuberous sclerosis.

Tuberous sclerosis (TSC) is caused by a mutation in either the TSC1 or TSC2 gene. The clinical manifestations of mutations of the two genes are hardly distinguishable, for reasons as yet unknown. In this study, we examined the expression of the products of these genes, hamartin and tuberin, in control and TSC tissues. Western blotting disclosed that hamartin and tuberin are both abundant in the cerebral gray matter and that they have similar subcellular distributions and developmental patterns of expression. Immunohistochemical localizations of hamartin and tuberin were also similar, with high levels of expression being localized to the cerebral neurons and glial cells, renal uriniferous and collecting tubules, and cardiac muscles. In the cerebrum with TSC, both hamartin and tuberin were simultaneously reduced in the cortical tubers and subependymal giant cell astrocytomas, and from the normal-appearing cortex. The renal angiomyolipomas and cardiac rhabdomyomas also showed a loss of both the proteins. These results provide evidence for the co-localization and interaction of hamartin and tuberin in vivo, and suggest that a mutation in one TSC gene may secondarily affect the expression of the other in some TSC lesions.

Adolescent↗
PubMed2000

A novel migration-related gene product, doublecortin, in neuronal migration disorder of fetuses and infants with Zellweger syndrome.

Immunohistochemical expression of doublecortin (DCX), KIAA0369 (KIA) and LIS1 proteins as well as nestin and vimentin in the cerebral cortices of six patients with Zellweger syndrome (ZS), aged 19 gestational weeks (GW) to 8 months, was compared with that in nine controls, aged 12 GW to 8 months. DCX immunoreactivity was apparently reduced in ZS, particularly in the cortical plate of fetuses, and in the subependymal foci of heterotopic neurons of the infants. Reduced expression of DCX in ZS was confirmed by Western blot analysis. On the other hand, neuronal expression of nestin was high in the cortical plate, migrating cells of the white matter and germinal cells in the ventricular zone in fetuses with ZS. Immunoreactivities for KIA, LIS1 and vimentin in ZS were comparable to those of controls. Reduced expression of DCX may be responsible for the neuronal migration disorder, and increased expression of nestin may be another evidence for delayed neuronal maturation in ZS.

1-Alkyl-2-acetylglycerophosphocholine Esterase↗
PubMed2000

Acute disseminated encephalomyelitis after live rubella vaccination.

We report here a case involving a 14-year-old boy who developed acute disseminated encephalomyelitis following live rubella vaccination. The patient became febrile and began to experience nuchal pain 16 days after the immunization. By 22 days after immunization, he experienced difficulty in walking. By 24 days, he had developed tetraparesis with retention of urine, and total sensory loss below the Th1 dermatomal level. He was febrile at this point and showed nuchal rigidity and Lhermitte's sign. Cerebrospinal fluid examination revealed elevated cell counts, protein level, and myelin basic protein. T2-weighted magnetic resonance imaging detected high intensity lesions in the bilateral cerebral white matter and cervical spinal cord. Following the administration of intravenous corticosteroids, the patient's clinical symptoms improved rapidly.

Adolescent↗
PubMed2000

Effects of high-dose intravenous corticosteroid therapy in Landau-Kleffner syndrome.

Two children with Landau-Kleffner syndrome were successfully treated with antiepileptic drugs and a high-dose intravenous corticosteroid. A combination of valproate and a benzodiazepine (clonazepam or diazepam) ameliorated epileptic seizures and electroencephalographic spikes and waves, but speech disturbances persisted. Both patients were treated with an intravenous infusion of high-dose methylprednisolone sodium succinate (20 mg/kg daily) for 3 consecutive days. This infusion was repeated three times with a 4-day interval between treatments, which resulted in a rapid improvement in speech ability. After intravenous therapy, prednisolone was given orally (2 mg/kg daily for 1 month, then gradually withdrawn), which maintained the clinical improvement in speech.

Administration, Oral↗
PubMed2000

Bronchoprotective effects of atrial natriuretic peptide against propranolol-induced bronchoconstriction after allergic reaction in guinea pigs.

OBJECTIVE: To study the effects of intravenous atrial natriuretic peptide (ANP) on antigen-induced bronchoconstriction, propranolol-induced bronchoconstriction (PIB) after antigen challenge, and histamine-induced bronchoconstriction in guinea pigs. METHODS: Allergic bronchoconstriction was evoked by inhalation of ovalbumin (OA) and PIB was caused when 10 mg/mL of propranolol was inhaled 20 min after OA challenge in passively sensitized and artificially ventilated guinea pigs. 25, 50, 100 and 200 microg/mL of histamine were inhaled for 20 s at 5-min intervals in non-sensitized guinea pigs. RESULTS: Pretreatment with ANP in doses of 0.1 and 1.0 nmol/kg injected intravenously 15 min after antigen challenge reduced PIB in a dose-dependent manner, and 5 min before antigen challenge significantly attenuated PIB but not antigen-induced bronchoconstriction. Intravenous ANP significantly reduced bronchial responses to increasing concentrations of inhaled histamine in a dose-dependent manner. CONCLUSION: These results suggest that ANP possesses protective effects against propranolol-induced and histamine-induced bronchoconstriction, albeit by a non-specific mechanism in guinea pig in vivo.

Allergens↗
PubMed2000

Novel cerebral lesions in the Eker rat model of tuberous sclerosis: cortical tuber and anaplastic ganglioglioma.

The Eker rat is a model for human tuberous sclerosis (TSC) caused by a mutation in the Tsc2 gene. We describe here histological and immunohistochemical findings of the brain lesions in Eker rats, with emphasis on 2 novel lesions found in this study: a cortical tuber and an anaplastic ganglioglioma. The rat cortical tuber resembled those of humans, and further confirmed the value of this animal model as a tool for investigating the molecular pathology of tuberous sclerosis. On the other hand, the rat anaplastic ganglioglioma had features of a malignant neoplasm that are absent from human subependymal giant cell astrocytomas.

Animals↗
PubMed2000

Fukutin protein is expressed in neurons of the normal developing human brain but is reduced in Fukuyama-type congenital muscular dystrophy brain.

Fukuyama-type congenital muscular dystrophy (FCMD) results from a mutation in a gene on chromosome 9q31, fukutin, and is characterized pathologically by micropolygyria of the cerebral and cerebellar cortices. To elucidate the physiological function of fukutin as well as its pathological role in FCMD, we raised antisera against fukutin protein and observed its expression in developing human brains with or without FCMD. Western blotting using these antibodies demonstrated a 60-kd band in the fetal but not in postnatal cerebral cortex of the controls. This band appeared negligible in the brains of FCMD fetuses. Immunohistochemistry revealed the localization of fukutin in Cajal-Retzius cells, the subpial granular layer, the neuropil of the marginal zone, the cortical plate neurons, and the ventricular neuroepithelium of the fetal cerebrum. In the fetal cerebellum, fukutin immunoreactivity was localized to the external granule cell layer, molecular layer, Purkinje cells, and some internal granular cells. The immunoreactivity in these structures was reduced markedly in postnatal normal brains, as well as in an FCMD cerebrum at 23 gestational weeks. The spatial and temporal pattern of fukutin expression is compatible with its predicted role: the regulation of neuronal migration in the fetal cerebrum and cerebellum.

Adolescent↗
PubMed1999

The molten globule state of a chimera of human alpha-lactalbumin and equine lysozyme.

The molten globule state of equine lysozyme is more stable than that of alpha-lactalbumin and is stabilized by non-specific hydrophobic interactions and native-like hydrophobic interactions. We constructed a chimeric protein which is produced by replacing the flexible loop (residues 105-110) in human alpha-lactalbumin with the helix D (residues 109-114) in equine lysozyme to investigate the possible role of the helix D for the high stability and native-like packing interaction in the molten globule state of equine lysozyme. The stability of the molten globule state formed by the chimeric protein to guanidine hydrochloride-induced unfolding is the same as that of equine lysozyme and is substantially greater than that of human alpha-lactalbumin, although only six residues come from equine lysozyme. Our results also suggest that the non-native interaction in the molten globule state of alpha-lactalbumin changes to the native-like packing interaction due to helix substitution. The solvent-accessibility of the Trp residues in the molten globule state of the chimeric protein is similar to that in the molten globule state of equine lysozyme in which packing interaction around the Trp residues in the native state is partially preserved. Therefore, the helix D in equine lysozyme is one of the contributing factors to the high stability and native-like packing interaction in the molten globule state of equine lysozyme. Our results indicate that the native-like packing interaction can stabilize the rudimentary intermediate which is stabilized by the non-specific hydrophobic interactions.

Acrylamide↗
PubMed1999

Development of telencephalin in the human cerebrum.

Telencephalin (TLN) is a 130kDa, type 1 integral membrane glycoprotein of the immunoglobulin superfamily found in the mammalian central nervous system. TLN shows a molecular structure resembling intercellular adhesion molecules-1 and -3, and binds to the CD11a/CD18 leukocyte integrin. TLN was localized to neuronal dendrites in the telencephalic gray matter: cerebral cortex and basal ganglia. We studied immunohistochemically the expression of TLN in the developing human brain. In the hippocampus, TLN immunoreactivity appeared at 29 gestational weeks (GW), intensified subsequently, and persisted into adulthood. In the temporal cortex, labeling was weak and restricted to the cytoplasm of pyramidal neurons from 35 to 39 GW, but thereafter became diffuse and intense in the cortical layers, especially the molecular layer, by 5 months of postnatal age. The development of TLN was late compared to synaptophysin and microtubule-associated protein 2, suggesting its involvement in the functional maturation of neuronal dendrites and synapses.

Adolescent↗
PubMed1999

Multicenter study of paroxysmal dyskinesias in Japan--clinical and pedigree analysis.

To investigate the clinical features of paroxysmal dyskinesias and carry out a pedigree analysis, we conducted a multicenter survey in Japan. A questionnaire was mailed to 229 medical institutions. A total of 150 patients with paroxysmal kinesigenic choreoathetosis (PKC), including 53 sporadic cases and 97 affected individuals from 32 pedigrees, were identified. The mean age of onset of PKC was 8.8 years, and 80% of the cases were men. Of the 32 pedigrees with familial occurrence, 18 (56%) were compatible with an autosomal-dominant inheritance (AD) with complete penetrance, and seven (22%) had AD with incomplete penetrance; the remaining seven were sibling recurrence cases with apparently healthy parents. In six of seven familial cases with incomplete penetrance, the disease gene was thought to be transmitted by clinically unaffected females. Paroxysmal dystonic choreoathetosis (PDC) was found in five cases, including two sporadic cases and three affected individuals from two pedigrees; the mean age of onset was 0.6 years, and a male predominance was noted (male:female = 4:1). There was one case of paroxysmal hypnogenic dyskinesia and one case of paroxysmal exertion-induced dyskinesia. There is an unexplained male predominance for paroxysmal dyskinesias. When the genetic defect of patients with paroxysmal dyskinesias is identified, the pathophysiology of the disease will become more clear.

Adolescent↗