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Biomedical subjects

T Matsuzaka

Publications and source records attributed to T Matsuzaka.

At least 19 recordsLinked to original sources
PubMed2001

Severe hypercholesterolemia, hypertriglyceridemia, and atherosclerosis in mice lacking both leptin and the low density lipoprotein receptor.

Leptin-deficient mice (ob/ob) are an excellent murine model for obesity, insulin resistance, and diabetes, all of which are components of a multiple risk factor syndrome that, along with hypercholesterolemia, precipitates a potential high risk for atherosclerosis. In the current study, we show an unexpectedly severe hyperlipidemia in ob/ob mice on a background of low density lipoprotein receptor (LDLR) deficiency (-/-). Doubly mutant mice (LDLR-/-;ob/ob) exhibited striking elevations in both total plasma cholesterol (TC) and triglyceride (TG) levels (1715 +/- 87 and 1016 +/- 172 mg/dl, respectively), at age 3-4 months, resulting in extensive atherosclerotic lesions throughout the aorta by 6 months. Lipoprotein analyses revealed the elevated TC and TG levels to be due to a large increase in an apoB-containing broad-beta remnant lipoprotein fraction. While fasting, diet restriction, and low level leptin treatment significantly lowered TG levels, they caused only slight changes in TC levels. Hepatic cholesterol and triglyceride contents as well as mRNA levels of cholesterologenic and lipogenic enzymes suggest that leptin deficiency increased hepatic triglyceride production but did not change cholesterol production in ob/ob mice regardless of their LDLR genotype. These data provide evidence that the hypertriglyceridemia and hypercholesterolemia in the doubly mutant mice are caused by distinct mechanisms and point to the possibility that leptin might have some impact on plasma cholesterol metabolism, possibly through an LDLR-independent pathway. This model will be an excellent tool for future studies on the relationship between impaired fuel metabolism, increased plasma remnant lipoproteins, diabetes, and atherosclerosis.

Animals↗
PubMed2001

Epidemiological and clinical studies of West syndrome in Nagasaki Prefecture, Japan.

Recent advances in diagnostic and therapeutic techniques may have changed incidence and etiologies of West syndrome (WS). We performed a retrospective epidemiological study of WS that occurred in 47 children in Nagasaki Prefecture during a recent 10-year period from 1989 to 1998. The incidence of WS was 3.1/10,000 live births. Thirty-nine patients (83%) had symptomatic WS, in which the prenatal causes were most frequent, followed by low-birth weight (LBW) infants, perinatal and postnatal. Such high frequency of LBW may have been due to a relative increase in survivors of premature babies because of recent advances in perinatal care. The brain computerized tomography/magnetic resonance imaging performed in 41 patients revealed congenital brain malformation (10 patients), destructive brain disorders (13 patients), and no structural abnormalities (18 patients). The seizure outcome was worse in the symptomatic WS than in the cryptogenic WS. The developmental outcome was very poor in both symptomatic and cryptogenic WS. The mean developmental quotient (DQ) in all patients was 25, and only four patients (11%) had a normal DQ (>70). DQ was lower in patients with developmental delay before the onset of WS, symptomatic group, relapse and/or persistence of seizure. Developmental delay seen in WS patients seems to be related to the two major factors, that is, underlying brain abnormalities and the persistent seizures as a result of the former. Therefore, every effort should be made to control seizures, including medical and early surgical treatment, as well as prevention of brain damage through perinatal care.

Age Distribution↗
PubMed2001

Identification of liver X receptor-retinoid X receptor as an activator of the sterol regulatory element-binding protein 1c gene promoter.

In an attempt to identify transcription factors which activate sterol-regulatory element-binding protein 1c (SREBP-1c) transcription, we screened an expression cDNA library from adipose tissue of SREBP-1 knockout mice using a reporter gene containing the 2.6-kb mouse SREBP-1 gene promoter. We cloned and identified the oxysterol receptors liver X receptor (LXRalpha) and LXRbeta as strong activators of the mouse SREBP-1c promoter. In the transfection studies, expression of either LXRalpha or -beta activated the SREBP-1c promoter-luciferase gene in a dose-dependent manner. Deletion and mutation studies, as well as gel mobility shift assays, located an LXR response element complex consisting of two new LXR-binding motifs which showed high similarity to an LXR response element recently found in the ABC1 gene promoter, a reverse cholesterol transporter. Addition of an LXR ligand, 22(R)-hydroxycholesterol, increased the promoter activity. Coexpression of retinoid X receptor (RXR), a heterodimeric partner, and its ligand 9-cis-retinoic acid also synergistically activated the SREBP-1c promoter. In HepG2 cells, SREBP-1c mRNA and precursor protein levels were induced by treatment with 22(R)-hydroxycholesterol and 9-cis-retinoic acid, confirming that endogenous LXR-RXR activation can induce endogenous SREBP-1c expression. The activation of SREBP-1c by LXR is associated with a slight increase in nuclear SREBP-1c, resulting in activation of the gene for fatty acid synthase, one of its downstream genes, as measured by the luciferase assay. These data demonstrate that LXR-RXR can modify the expression of genes for lipogenic enzymes by regulating SREBP-1c expression, providing a novel link between fatty acid and cholesterol metabolism.

Alitretinoin↗
PubMed2001

[Epidemiological and clinical study of West syndrome in Nagasaki Prefecture, Japan].

To determine the occurrence, outcome, and prognostic factors of West syndrome (WS), we performed a retrospective epidemiological study of WS occurred in 47 children (26 boys and 21 girls) in Nagasaki prefecture during a recent 10-year period from 1989 to 1998. The incidence of WS was 3.1/10,000 live births. The mean age at onset of spasm is 6.3 months (range: 2 to 12 months). Thirty-nine patients (83%) had symptomatic WS, in which the prenatal causes (patients) were most frequent, followed by low-birth weight infants (patients), perinatal (patients) and postnatal (patients). The brain CT was performed in 37 patients, and revealed congenital brain malformations (9 patients), destructive brain disorders (12 patients), and no structural abnormalities (16 patients). The seizure outcome was worse in the symptomatic WS than in the cryptogenic WS; seizure/disappeared in 39% of the former and in 75% of the latter/developmental delay before the onset of WS, relapse of WS and persistence of seizures were associated with poor seizure outcomes. Among the remaining seizures at the time of this surveillance, a tonic seizure was most frequently observed, followed by the partial seizures. Lennox-Gastaut syndrome was observed in 2 patients only. Epileptic discharge in the latest interictal EEG were diffuse in 4.3%, focal or multifocal in 60.7%, and absent in 35%, suggesting that many patients with WS had cortical epileptogenic foci. The developmental outcome was very poor in both the symptomatic and cryptogenic WS. The mean DQ in all the patients was 25, and only 4 patients (11%) had a normal DQ (> 75). DQ was lower in patients with congenital brain malformations than in those with destructive brain disorders.

Brain↗
PubMed2001

Developmental assessment-based surgical intervention for intractable epilepsies in infants and young children.

PURPOSE: To define the most appropriate time for surgery for medically intractable epilepsies in infants and young children. METHODS: First we examined retrospectively the changes in developmental quotients (DQs) during the clinical course and the clinical factors affecting the DQ in 39 consecutive patients younger than 15 years, who underwent surgical treatment for intractable epilepsy. Second, we examined prospectively five new patients for early detection of developmental arrest or regression by periodic developmental assessments and whether this could lead to early surgical intervention, eventually resulting in minimal developmental defects. RESULTS: Retrospective studies revealed that the DQ progressively decreased with age and that the reduction of DQ was related to continuing frequent seizures in many patients. The prospective studies demonstrated that periodic developmental assessments could detect the reduction of DQ at 5 months or later after onset of frequent seizures in three patients. In two other patients, operations were performed before reduction of DQs, and their postoperative DQ levels were normal. The post-operative recovery of DQ was complete in one patient whose operation was performed 3 months after reduction of DQ, whereas it was incomplete in two others whose operations were carried out at 12 and 14 months after reduction, respectively. Furthermore, three patients with normal developmental outcome had shorter periods between the onset of frequent seizures and the operation (< or = 7 months) than those of two patients with developmental delay (> or = 17 months). CONCLUSIONS: To minimize the developmental defects, periodic developmental assessments should be initiated when frequent seizures have occurred, and surgery should be considered as soon as possible when DQ reduction is recognized.

Child, Preschool↗
PubMed2000

Walker-Warburg syndrome is genetically distinct from Fukuyama type congenital muscular dystrophy.

A female patient who fulfilled the diagnostic criteria of Walker-Warburg syndrome had muscle biopsy finding of muscular dystrophy. There was normal expression of merosin (laminin alpha2 chain) and dystrophin and only slightly reduced dystrophin-associated glycoprotein expression. On genetic analysis, she had no specific haplotype, the common mutation of 3kb insertion, or point mutations in the Fukuyama-type congenital muscular dystrophy gene, suggesting that the two diseases are not genetically identical.

Alleles↗
PubMed1999

Autosomal dominant onychodystrophy and congenital sensorineural deafness.

The disease "deafness and onychodystrophy" (DOD) is characterized by congenital hearing impairment and dystrophic or absent nails and teeth. The autosomal dominant form of the disorder has been previously reported only in one family. We describe here another family in which three members in three generations (a girl, her mother, and her maternal grandfather) were affected with DOD. Our finding is consistent with an autosomal dominant mode of inheritance and confirms autosomal dominant DOD (DDOD, MIM *124480) as a recognizable clinical entity.

Adult↗
PubMed1999

Quantitative EEG analyses and surgical outcome after corpus callosotomy.

PURPOSE: To clarify the relation between quantitative electroencephalogram (EEG) findings and outcome following corpus callosotomy (CC). METHODS: The degree of bilateral synchrony and morphologic similarity of spike-wave discharges was analyzed by using a cross-correlation analysis and the measurements of amplitude differences between bilateral homologous regions in 22 patients who underwent anterior CCs for intractable symptomatic generalized epilepsies (SGE; 17 patients) and frontal lobe epilepsy (five patients). RESULTS: Interictal generalized synchronous spike-wave (GSSW) bursts in the SGE patients were disrupted and changed to unilateral spike-waves (USWs) in 11 patients and to bilaterally independent spike-waves (BISWs) in six. The USW group had better surgical outcome than the BISW group. Preoperatively, the USW group had significantly lower interhemispheric synchrony (IS) and fewer regional changes in the side leading in time and the side dominant for amplitude, suggesting unilaterally predominant epileptogenesis that triggered the secondary bilateral synchrony. Postoperatively, the BISW group had a more marked reduction in IS because of independent discharges from bilateral epileptogenic areas, and the USW group had a greater amplitude difference because of unilateralized spike-waves. In addition, an excellent surgical outcome was related to (a) the preoperative degree of the morphologic similarity of the bilateral spike-waves (only a small variation during a burst of spike-waves) and the few instances of regional changes in the side leading in time and in the side dominant for amplitude; and (b) to large postoperative amplitude differences. CONCLUSION: Preoperative quantitative EEG analyses enabled us to predict the underlying conditions of epileptogenesis and the surgical outcomes in patients undergoing CC.

Adolescent↗
PubMed1997

[Neurological outcome associated with influenza viral infection].

Several neurological complications associated with Influenza virus infection are known as a febrile convulsion, polyneuritis, meningitis, encephalomyelitis and encephalopathy. Influenza encephalopathy is the most severe complication associated with Influenza. It may be classified into several subtypes according to the clinical symptoms and laboratory data. In this review, Reye's syndrome, acute necrotizing encephalopathy and hemorrhagic shock and encephalopathy syndrome (HSE) are described in detail. The 1995 influenza pandemia in Nagasaki prefecture was markedly neurovirulent and lethal. Twelve cases developed influenza encephalopathy, and the mortality rate between them was 50%. Almost all of them had never be inoculated of influenza vaccine before.

Child↗
PubMed1996

Mouse/human sequence divergence in a region with a paternal-specific methylation imprint at the human H19 locus.

We have identified a region with characteristics of a paternal-specific methylation imprint at the human H19 locus. This region, extending from -2.0 kb upstream to the start of transcription, is heavily methylated in sperm and on the paternal allele in somatic cells. This methylation was preserved during pre-implantation. Structural analysis revealed the presence of CpG islands and a large direct repeat with a 400 bp sequence reiterated several times, but no significant sequence homology to the corresponding region of the mouse H19 gene. These findings could suggest a role for secondary DNA structure in genomic imprinting across the species, and they also present a puzzling aspect of the evolution of the H19 regulatory region in human and mouse.

Alleles↗
PubMed1995

Normal age-related conversion of bone marrow in the mandible: MR imaging findings.

OBJECTIVE: The mandible is one of the most common sites for osteomyelitis and other marrow-based diseases. Therefore, knowledge of the normal patterns of marrow distribution could help evaluate marrow-based diseases. The purpose of this study was to assess the age-related normal sequence of conversion from hematopoietic to fatty marrow in the mandible as depicted on MR images. SUBJECTS AND METHODS: We prospectively reviewed T1-weighted MR images of the mandible for the distribution of hematopoietic and fatty marrow. Forty-five subjects 4 months to 25 years old with no known marrow abnormality were examined with the spin-echo technique. Marrow conversion was assessed in the condyle, ramus, angle, and body of the mandible using visual grading based on homogeneity, signal intensity, and a signal-intensity ratio determined by the intensities of the surrounding subcutaneous fat and air. RESULTS: Conversion of hematopoietic to fatty marrow occurred first in the mandibular body, followed by the angle, ramus, and finally the condyle. The marrow in the region distal to the ramus had almost fully converted to fatty marrow by the third decade of life, but the remaining regions contained some hematopoietic marrow. Further substantiating these results, the signal-intensity ratio increased up to about 90% in the angle and 70% in the ramus by the age of 10 years and then leveled off. On the other hand, the signal-intensity ratio in the condyle reached 60% by age 15 and remained unchanged for the following 10 years. CONCLUSION: The normal age-related conversion from hematopoietic to fatty marrow in the mandible follows a well-defined sequence, first seen in the mental region early in childhood, then in the body, the ramus, and finally the condyle.

Adolescent↗
PubMed1993

Relationship between vitamin K dependent coagulation factors and anticoagulants (protein C and protein S) in neonatal vitamin K deficiency.

To determine the relationship between vitamin K dependent coagulation factors and natural anticoagulants, namely protein C and protein S, in various degrees of vitamin K deficiency, plasma values for clotting activity, protein induced by vitamin K absence (PIVKA-II), protein C antigen, gamma-carboxy protein C antigen, and protein S antigen including total and free fractions and activity of protein C were measured in 66 full term and healthy breast fed neonates who did not receive vitamin K supplement at birth. The 66 neonates were divided into a control group (17 cases) and a low group (49 cases) according to their values for clotting activity--that is, > or = 20% or < 20% during the first six days of life--and vitamin K was immediately given when the neonates showed values < 20%. In the low group clotting activity gamma-carboxy protein C, free protein S, and protein C activity was significantly decreased to a minimum on day 2 or 3, and increased in parallel after vitamin K administration. Furthermore, they were positively correlated with one another and inversely cor-correlated with the PIVKA-II concentrations. These findings suggest that simultaneous gamma-carboxylation of coagulation factors and proteins C and S acts to maintain both coagulation and anticoagulation activities in parallel at various concentrations of vitamin K. The breast milk intake in the group with low values of clotting activity was significantly lower than that in the control group during the first three days of life.(ABSTRACT TRUNCATED AT 250 WORDS)

Biomarkers↗