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Biomedical subjects

J Nagata

Publications and source records attributed to J Nagata.

At least 37 records · Page 2Linked to original sources
PubMed1999

Immunohistochemical evaluation of the marbled state in childhood hypoxic encephalopathy.

We have immunohistochemically analyzed the marbled state in 8 cases of perinatal hypoxic ischemic encephalopathy and 4 cases of infantile hypoxic encephalopathy, using antibodies against calbindin-D28k (CaBD), glial fibrillary acidic protein (GFAP), methionine-enkephalin (MEnk), myelin basic protein (MBP), neurofilament (NF), parvalbumin (PV), substance-P (SuP) and synaptophysin (SP). The marbled state was found in the thalamus in 11 cases, whose age at death was over 10 years. Four cases demonstrated the marbled state in the cerebral cortex, in addition to the striatum and/or the thalamus. The abnormally myelinated fibers in the marbled state were stained with both Kluver-Barrera and Holzer stainings; however, they were partly immunopositive for MBP and completely immunonegative for GFAP, CaBD, MEnk, PV, SuP and SP, although some of the neurons and/or fibers showed immunoreactivities for those calcium-binding proteins and/or neurotransmitters. The axons were visualized in the abnormally myelinated fibers by Bodian staining and/or anti-NF immunostainings in the cerebral cortex and striatum but not in the thalamus. GFAP-positive astrocytes did not show any continuity with the abnormally myelinated fibers. These histological features were seen in the cerebral cortex, striatum and thalamus. Difference of the etiology did not affect the histological features with the exception of anti-PV staining, in which PV-immunopositive neurons were observed only in aged subjects with infantile hypoxic encephalopathy, and seemed to be more severely affected by hypoxic stress during the perinatal period than the early infantile period. These data suggest that the site of lesion or the length of survival period after brain injury might influence the formation of the marbled state rather than the etiology. And the direct relationship between the abnormally myelinated fiber and astrocytic process was not verified.

Adolescent↗
PubMed1999

Percutaneous bowel drainage for jaundice due to afferent loop obstruction following pancreatoduodenectomy: report of a case.

A case of jaundice due to an obstruction of the afferent loop following a pancreatoduodenectomy is presented. The dilated loop of the jejunum was drained percutaneously with a 12-F gastrostomy tube. Localized peritonitis around the puncture site was managed conservatively and the obstructive jaundice improved. The treatment strategy for this type of jaundice is discussed.

Afferent Loop Syndrome↗
PubMed1999

Increased heterogeneity of chromosome 17 aneuploidy in endometriosis.

OBJECTIVE: Endometriosis is a complex gynecologic disorder that may display features similar to malignancy, including aggressive growth and localized invasion of the myometrium or spread to various organs outside the uterus. Molecular studies of cancer have demonstrated that genomic instability involving chromosome 17 plays a role in the development and progression of various tumor types. These involve gain and/or loss, deletions, and mutations of candidate tumor suppressor genes (eg, BRCA1 and p53 ) on chromosome 17. STUDY DESIGN: We used a 2-color fluorescence in situ hybridization method for analysis of endometriotic and normal archival tissue. Centromere-specific and locus-specific p53 probes localized to chromosome 17 were selected to study 8 patients with late-stage (severe) endometriosis. Single cells localized to endometriotic lesions or normal endometrial glands were analyzed and identified as normal or abnormal on the basis of the distribution of fluorescence in situ hybridization signals. RESULTS: Overall, chromosome 17 aneuploidy was significantly greater (P <.05) in the endometriosis specimens (mean of 65%) than in normal endometrial cells (mean of 25%). No significant difference (P =.1071) in the distribution of fluorescence in situ hybridization signals was observed among the 5 normal endometrial specimens. However, significant differences (P <. 0001) were observed between the 8 endometriosis tissue specimens. CONCLUSION: We found increased heterogeneity of chromosome 17 aneuploidy in endometriosis. These findings support a multistep pathway involving somatic genetic alterations in the development and progression of this common disease.

Aneuploidy↗
PubMed1999

Pathological study on sibling autopsy cases of the late infantile form of neuronal ceroid lipofuscinosis.

We report autopsy cases of two brothers with the late infantile form of neuronal ceroid lipofuscinosis (LINCL) and examine apoptotic cell death in autopsied brains. Both patients showed psychomotor developmental delay, cerebellar ataxia, convulsions, visual disturbance and myoclonus, and they became bedridden around the age of 6-7 years. Macular changes, mimicking cherry-red spots, were observed on funduscopy, but conjunctival biopsy failed to disclose storage materials. In these cases, the autopsies demonstrated severe atrophy with neuronal loss and gliosis throughout the brain and spinal cord, except the hypothalamic neurons and motor neurons in the brain-stem and spinal cord, and autofluorescent lipofuscin-like materials of two types, fine granular deposits and coarse round bodies, were stored in the remaining neurons and glial cells, and in the epithelial cells of various visceral organs. Immunostaining for mitochondrial subunit C visualized the fine granular deposits but not the coarse round bodies. The nuclei of neurons and glia cells were stained by in situ nick end labeling, which was more pronounced in the younger case, although the expression of both bcl-2 and bcl-x was not significantly altered in these cases. It is suggested that immunohistochemistry for subunit C may be useful for diagnosis of NCL, and further investigations are necessary to clarify the relationship between LINCL and apoptosis, especially in severely affected cases.

Atrophy↗
PubMed1998

Megalencephaly, hydrocephalus and cortical dysplasia in severe dwarfism mimicking leprechaunism.

This report concerns an autopsy case of megalencephaly exhibiting a unique combination of physical and brain malformations. A 4-year-old boy had a peculiar face, a severe reduction of subcutaneous adipose tissue, severe growth failure and frequent hypoglycemic episodes. These clinical features were compatible with leprechaunism; however, the absence of hyperinsulinemia and insulin resistance prevented the diagnosis of leprechaunism. The autopsy disclosed complex cardiac and brain malformations. Although hydrocephalus coexisted, the brain weight after complete removal of the cerebrospinal fluid was 2260 g, which was greater than the average brain weight of normal Japanese children of the same age. The neuronal density in the cerebral cortex was decreased, while the surface area of the cerebral cortex and white matter were greater than those in an age-matched control. There was cortical dysplasia in the frontal and parietal lobes. Endocrine tests and immunohistochemical analysis of the brain did not demonstrate any abnormalities in the hypothalamus-pituitary system. Megalencephaly can be associated with dwarfism, and this case is important for consideration of the interrelationship between neuronal proliferation and physical growth.

Brain↗
PubMed1998

Genetic variation and population structure of the Japanese sika deer (Cervus nippon) in Hokkaido Island, based on mitochondrial D-loop sequences.

Mitochondrial DNA (mtDNA) D-loop region sequences (602 bp) from 141 samples of the sika deer Cervus nippon collected from Hokkaido Island of Japan were investigated to elucidate population genetic structure. All animals possessed seven repeat units (38 or 39 bp each) in the sequences. Comparison of the 602-bp sequences showed four sites of transitional mutations (A<-->G or C<-->T). Based on combination of the substitutions, six D-loop haplotypes (a-f types) were identified in the Hokkaido population, suggesting the occurrence of at least six maternal lineages. Distribution maps of the haplotypes constructed using the Geographic Information System showed that the distribution of the major three types differed from haplotype to haplotype. In particular, distribution of the major three types (a-, b-, and c-types) almost overlapped with three main areas of coniferous forests in Hokkaido. These results suggest that expansion of the sika deer population could have occurred through the habitat of coniferous forests after the historical bottleneck in Hokkaido.

Animals↗
PubMed1997

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.

Adolescent↗
PubMed1997

Apolipoprotein A-1 of Japanese quail: cDNA sequence and modulation of tissue expression by cholesterol feeding.

Apolipoprotein (apo) A-1 cDNA was amplified by the reverse-transcriptase-polymerase chain reaction (RT-PCR). Primers were synthesized according to the nucleotide sequence of chicken apo A-1, and the identity of apo A-1 cDNA was confirmed by comparing with the N-terminal amino acid sequence. The open reading frame of apo A-1 cDNA consists of 795 nucleotides, and it is capable of coding a polypeptide of 264 amino acids. A comparison between quail and chicken apo A-1 revealed 94.5% homology in the nucleotide sequence and 91.7% homology in the amino acid sequence. There was a similar 11- or 22-amino acid repeat in quail apo A-1 as was the case for chicken apo A-1. Apo A-1 mRNA was evaluated to be 1.4 k in length and was expressed in various tissues of Japanese quail: the liver, small intestine, lung, kidney, heart, and muscle. A quantitative evaluation, however, revealed that the liver and small intestine were the major organs for apo A-1 synthesis, accounting for more than 90% of the total expression of apo A-1 mRNA. Besides apo A-1 mRNA (1.4 k in length), a transcript of 4.1 k was detected in all the tissues examined, with a magnitude ranging from 5 to 10% of the apo A-1 mRNA level. The effect of cholesterol level on the expression of apo A-1 mRNA was studied to address the physiological significance of apo A-1 in the liver, small intestine, and muscle. The level of cholesterol in the liver and breast muscle was increased by feeding with cholesterol and reached a saturation level at day 7. There was also a temporal rise of cholesterol level at day 7 in the small intestine. Dietary cholesterol increased the expression of apo A-1 mRNA two fold in both the liver and small intestine. This was not the case for breast muscle, in which the expression of apo A-1 mRNA was not modulated by the cholesterol level.

Amino Acid Sequence↗
PubMed1997

Lipoprotein and apoprotein profiles of hyperlipidemic atherosclerosis-prone Japanese quail.

The purpose of this study was to characterize the lipoprotein and apoprotein profiles of hyperlipidemic atherosclerosis-prone (HAP) Japanese quail. HAP and commercially available (CA) Japanese quail were fed either a semi-purified diet containing 1% cholesterol or a cholesterol-free diet for two weeks. The lipoproteins of CA and HAP quail fed cholesterol-free diet were composed of two fractions: densities ranging from 1.02 to 1.09 and from 1.09 to 1.21. The lipoprotein distribution patterns obtained from both strains showed an HDL-predominant pattern. A protein of 26 kDa was the major apoprotein in the entire density range of the lipoprotein class. Marked increases in the cholesterol ester levels were observed in the lower density fractions (1.006 < d < 1.055: chylomicron and VLDL fractions) of the cholesterol-fed quail, accounting for 46% of the total lipids in CA quail and 54% in HAP quail. In addition, the presence of a protein of 470 kDa was exclusively observed in the lower density fractions (1.006 < d < 1.055) of the cholesterol-fed HAP quail. The fatty-acid compositions of the chylomicron and VLDL fractions were affected by the dietary cholesterol in both strains: a decrease in concentration of 16: 0 and increase in 18: 0 (weight %). However, cholesterol feeding had no effect on the level of cholesterol, chemical composition or fatty-acid composition of the HDL fractions in either strain. Although the lipoprotein and apoprotein profiles of HAP quail showed resemblances to those of the CA quail, expression of the 470 kDa protein in the lipoproteins (d < 1.055) appeared to be pronounced in HAP quail. The relevance of these lipoprotein and apoprotein profiles to the genesis of atherosclerosis was discussed in this study.

Animals↗
PubMed1996

Accumulation of 1-o-alkyl-2,3-diacylglycerols in cultured rat keratinocytes.

The present study was undertaken to identify the chemical structure of neutral lipid accumulated in cultured rat keratinocytes and to address their metabolism. Neutral lipid of similar mobility with alkyldiacylglycerol was isolated from cultured rat keratinocytes by thin layer chromatography. The long-chain diols derived from the neutral lipids were identified as 1-alkylglycerol based on the mass spectra of their nicotinylidene derivatives. Thus these neutral lipids were identified as 1-o-alkyl-2,3-diacylglycerols (ADAG). Addition of rat serum elevated the level of ADAG with increasing trend of linoleic acid concentration in this fraction. [14C]Acetate added to the confluent plates was incorporated into alkyl- and acyl-chains of ADAG with incubation in 24 h, and remained un-metabolized up to 72 h. This, however, is not the case for the label incorporation into phospholipid and triacylglycerol. Radioactivities of these two lipid fractions appeared to reach the maximum in 24 h, and thereafter decreased to 72 h with a similar decay curve. Incorporation of [14C]acetate into phospholipid and ADAG was significantly depressed, and that into triacylglycerol and free cholesterol was increased by the supplementation of the medium with rat serum. In concomitance with the accumulation of ADAG, the concentration of ethanolamine-plasmalogen increased in the cultured keratinocytes. The results of the present study first showed the elevated level of ether lipid synthesis in the proliferating primary culture of rat keratinocytes.

Acetates↗
PubMed1996

Septo-optic dysplasia with cerebellar hypoplasia in Cornelia de Lange syndrome.

Little is known about the neuropathology of Cornelia de Lange syndrome. We report a unique type of cerebral malformation combined with Cornelia de Lange syndrome in a 5-year-old female child. At autopsy, the optic systems, hypothalamic nuclei, corpus callosum and cerebellar vermis were hypoplastic, and the septum pellucidum, fornix and anterior commissure were rudimentary. The brain had malformative features of septo-optic dysplasia combined with commissural dysplasia and cerebellar vermian hypoplasia. This case suggests an interrelationship between Cornelia de Lange syndrome and midline development of the brain.

Brain↗
PubMed1996

Age-related changes in branched-chain fatty acid concentration of the skin surface lipid from hairless mouse.

Age-related changes in branched chain fatty acid (BCFA) concentration were studied with the skin surface lipid from hairless mice. A large proportion of BCFA was present in the cholesterol ester (CE) and wax diester (WDE) fraction of the skin surface lipid from hairless mice. The concentration of iso-series BCFA was highest at infancy and decreased with advancing age in both CE and WDE fraction. The concentration of anteiso-series BCFA appeared to be constant throughout the experiment.

Age Factors↗
PubMed1996

Effect of dietary cholesterol on the activities of key enzymes of cholesterol metabolism in hyperlipidemia- and atherosclerosis-prone Japanese quail.

The hyperlipidemia- and atherosclerosis-prone (HAP) Japanese quail is a strain developed for the study of atherosclerosis by genetic selection from the commercially available (CA) Japanese quail. To delineate the characteristics of cholesterol metabolism in this strain, concentrations of serum lipids as well as hepatic enzyme activities were compared between HAP and CA quail. The hepatic enzymes studied are involved in the key step reaction in cholesterol metabolism: HMG-CoA reductase, ACAT, and cholesterol 7 alpha-hydroxylase. The animals were fed ad libitum with either 1% cholesterol or cholesterol-free semipurified diet for 28 days. Although a significant increase (p < 0.01) in serum cholesterol was observed in both strains on elapse of cholesterol feeding, formation of atheroma was seen exclusively in HAP quail of the cholesterol-fed group. The serum and liver cholesterol levels of HAP quail fed the cholesterol diet were significantly higher (p < 0.01) than those of CA quail. No significant differences were seen in the rate of cholesterol biosynthesis (HMG-CoA reductase activity), cholesterol ester formation (ACAT activity) and cholesterol catabolism (7 alpha-hydroxylase activity) between CA and HAP quail. Furthermore, the fecal excretions of acidic and neutral sterol showed no significant difference between strains. Although the formation of atheroma in HAP quail may be presumably due to the contribution of the marked increase in serum cholesterol level, the rate of cholesterol catabolism and synthesis in HAP quail compared well with those of CA quail. These observations suggest that the retarded rate of cholesterol biosynthesis or catabolism is not responsible for hypercholesterolemia in HAP quail.

Animals↗
PubMed1995

1-O-alkyl-2,3-diacylglycerols in the skin surface lipids of the hairless mouse.

A neutral lipid class was isolated by thin-layer chromatography from the skin surface lipids of the hairless mouse. The fraction migrated faster than triglycerides and had a migration rate similar to that of diacyl alkanediols (diester wax). Upon deacylation, however, the long-chain diols were identified as 1-alkylglycerol ethers based on their chromatographic properties and on the mass spectra of their nicotinylidene derivatives. Thus, the skin lipid fraction was identified as 1-O-alkyl-diacylglycerol. The alkyl moieties were all saturated and even-numbered and ranged in chainlength from C16 to C22 with 1-O-hexadecylglycerol amounting to 34% of the total glycerol ether moieties. The fatty acids derived from this lipid fraction were mostly monoenoic with chainlengths ranging from C16 to C24. The major acyl component was eicosenoic acid (20:1) representing 61% of the total fatty acids.

Acylation↗
PubMed1995

Selective use of L-valine and L-isoleucine for the biosynthesis of branched-chain fatty acids in rat skin.

Iso- and anteiso-fatty acids are detected in more than trace amounts in rat skin surface lipid. The terminal portion of even carbon number iso- and anteiso-fatty acids are synthesized respectively from valine (Val) and isoleucine (Ile) by essentially the same reaction sequences established for straight chain fatty acids. This paper describes the stereospecific biosynthesis of these branched chain fatty acids (BCFAs) and alcohols (BCFALs) in rat skin. Dependence of the concentration of these BCFAs on dietary L-Val and L-Ile was studied. Concentrations of even carbon number iso- and anteiso-fatty acid increased respectively with dietary L-Val and L-Ile. The saturation dose appeared to be 2% for L-Val and 1% for L-Ile. Supplementation of the diet with 2% D-Val, however, did not affect the concentration of even carbon number iso-fatty acid in rat skin surface lipid despite a comparable serum Val level to that of the 2% L-Val group. A similar experiment using 1% DL-Ile found that L-isomer, but not D-isomer, in the circulation was used for the biosynthesis of anteiso-fatty acids. This view was applicable to the incorporation of D-Val and DL-Ile into related BCFALs.

Absorption↗
PubMed1994

Precursor role of branched-chain amino acids in the biosynthesis of iso and anteiso fatty acids in rat skin.

Monoester fraction of rat skin surface lipid has been shown to contain more than trace amounts of branched-long-chain fatty acids (BCFAs) of the iso and anteiso series. These BCFAs are biosynthesized using either branched-chain amino acids (BCAAs) or branched-chain alpha-keto acids (BCKAs), or using both of them as precursor. This study has been carried out to address which precursor, BCAAs or BCKAs in the circulation, are mainly utilized for biosynthesis of BCFAs. Dietary supplement of [14C]-valine and isoleucine-induced sharp rise of serum concentration of these two amino acids and their respective alpha-keto acids, and elevated the levels of related BCFAs and branched-chain fatty alcohols in the monoester fraction. A larger proportion of label in the total skin surface lipid was found in the monoester fraction in which fatty acid and alcohol accounted for approx. 80% of total radioactivity. Incorporation of intravenously administered [14C]-BCAAs and BCKAs into the monoester fraction revealed that BCAAs were far better as precursors than BCKAs for BCFA biosynthesis in rat skin. Among three BCAAs, leucine differed from valine or isoleucine in that this amino acid was primarily utilized for production of straight-chain fatty acids rather than for production of related BCFA.

Amino Acids, Branched-Chain↗