Biomedical subjects

E Fujimoto

Publications and source records attributed to E Fujimoto.

At least 19 recordsLinked to original sources

PubMed1995

Prevalence of fatty liver in Japanese children and relationship to obesity. An epidemiological ultrasonographic survey.

The prevalence of fatty liver in children is unknown and its relationship to obesity is poorly defined. The present study of 810 northern Japanese children (4-12 years old) determined the prevalence of fatty liver in the pediatric population and its relationship to obesity. Diagnosis of fatty liver was based on established real-time ultrasonographic criteria. The overall prevalence of fatty liver was 2.6% and was higher for boys (3.4%) than for girls (1.8%), although not statistically significant (P = 0.15). Fatty liver was found in children as young as 6 years of age. There was no significant association between the prevalence of fatty liver and height (physical growth). There was a strong positive correlation between fatty liver prevalence and established obesity indices: Rohrer's Index--chi 2 linear trend = 59.2, P < 0.0001; body mass index--chi 2 linear trend = 91.6, P < 0.0001; and age-gender-adjusted Japanese standard index of weight for height--chi 2 linear trend = 93.2, P < 0.0001. However, direct measurement of abdominal subcutaneous fat thickness by ultrasonography was the best predictor of fatty liver: chi 2 linear trend = 159, P < 0.0001. These results indicate that fatty liver may develop very early in life, and there is a direct relationship between degree of obesity and fatty liver in children.

Body Height↗

PubMed1992

Conformational changes in the foot protein of the sarcoplasmic reticulum assessed by site-directed fluorescent labeling.

Ca2+ release from sarcoplasmic reticulum during excitation--contraction coupling is likely to be mediated by conformational changes in the foot protein moiety of the triadic vesicles. As a preparative step toward the studies of dynamic conformational changes in the foot protein moiety, we have developed a new method that permits specific labeling of the foot protein moiety of the isolated membranes with a fluorophore. A novel fluorescent cleavable photoaffinity cross-linking reagent, sulfosuccinimidyl 3-((2-(7-azido-4-methylcoumarin-3-acetamido)ethyl)dithio)propionate (SAED), was conjugated with site-directing carriers, polylysine (Ca(2+)-release inducer) and neomycin (Ca(2+)-release blocker). The conjugates were allowed to bind to polylysine- and neomycin-binding sites of the heavy fraction of SR (HSR). After photolysis, the cross-linked reagent was cleaved by reduction and the fluorescently labeled HSR was separated from the carriers by centrifugation. These procedures led to specific incorporation of the methylcoumarin acetate (MCA) into the foot protein. Polylysine and neomycin bound to different sites of the foot protein, since neomycin, at release-blocking concentrations, did not interfere with polylysine binding. The fluorescence intensity of the foot protein labeled with the carrier, neomycin, showed biphasic changes as a function of ryanodine concentration (increasing up to 1 microM ryanodine and decreasing above it), while with the carrier polylysine, ryanodine induced no change in fluorescence intensity. In contrast, the fluorescence intensity of the foot protein labeled with each of the two carriers, neomycin and polylysine, showed almost identical calcium dependence (first increasing from 0.1 microM to about 3.0 microM calcium concentration, and then decreasing at higher calcium concentrations).(ABSTRACT TRUNCATED AT 250 WORDS)

Affinity Labels↗

PubMed1992

Traumatic degeneration of transected myelinated fibers of the mouse sciatic nerve.

Traumatic degeneration of myelinated fibers was studied by electron microscopy over 5 days following transection of mouse sciatic nerve. Special attention was paid to the mechanism which separates the degenerating part, while preserving the viable part of the axon. Immediately after transection, the opened end of the proximal stump revealed extensive subcellular changes including the disorganization of neurofilaments, and disruption of mitochondria and axonal endoplasmic reticulum (SER). Subsequently, vesicles of round and tubular profiles filled up the whole area of the stump end, and proximal to it appeared a neurofilament-predominant area characterized by randomly oriented neurofilaments and normally appearing mitochondria and SER. Characteristic membranous demarcations occurred in early periods at the border between the vesicle accumulation and the neurofilament-predominant areas, and later also within these areas. The demarcation membranes formed both by invagination of the surface plasma membrane and, probably, by fusion of the large vesicles. These became prominent with time, dividing the axoplasm into compartments of varying sizes, which gradually underwent degeneration and were liberated from the parent axon. Occurrence of autophagic vacuoles was characteristic of the degenerating portions of the parent axon. Thus, by the function of demarcation membranes, the parent axon to be preserved could remain membrane-bound, while the degenerating parts were shed off.

Animals↗

PubMed1991

Separation and characterization of three positional isomers of dimaltosyl-cyclomaltoheptaose (dimaltosyl-beta-cyclodextrin).

A mixture of maltosylcyclomaltoheptaoses (maltosyl-beta-cyclodextrins, G2-beta CDs) was prepared from maltose and beta-cyclodextrin (beta CD) through the reverse action of Klebsiella pneumoniae pullulanase. Three positional isomers of dimaltosyl-beta CD in the mixture were separated by high-performance liquid chromatography on a reversed phase column and a graphitized carbon column. Their molecular weights were measured by fast-atom bombardment mass spectrometry, and the structures were established by methylation analysis, hydrolysis with glucoamylase to the known compounds, three positional isomers of diglucosyl-beta CD, and 13C-nuclear magnetic resonance spectroscopy.

Cyclodextrins↗

PubMed1990

Northern hybridization analysis of VH gene expression in murine monoclonal antibodies directed to cancer-associated ganglioside antigens having various sialic acid linkages.

The expression of the VH genes in 46 murine hybridoma cells that secrete mAb directed to the cancer-associated carbohydrate Ag, especially acidic glycolipids such as gangliosides and sulfated glycoplipids, was analyzed by Northern hybridization of poly(A)+ RNA of hybridoma with cDNA probes for nine VH gene families. Different hybridomas tended to express VH genes of the same family when the cognate Ag had the same or similar carbohydrate structures; i.e., the VH genes of the J558 family (group 1) were preferentially expressed in the mAb directed to various gangliosides that have NeuAc alpha (or NeuGc alpha) 2-3 and/or 2-8 linkage (71%), the most common linkage of sialic acid residues in the gangliosides of higher animals, and the hybridomas directed to sulfated glycolipids also expressed mainly the VH genes of the J558 family (80%). In contrast, the five mAb directed to various gangliosides with NeuAc alpha 2-6 linkage were exclusively encoded by the VH genes of Q52 family (group 2, 100%), and three antibodies directed to gangliosides with a NeuAc alpha 2-9 linkage all expressed genes of J606 family (group 6, 100%). The VH family usage was largely correlated with the linkage of sialic acid residues in the cognate carbohydrate Ag, but was not correlated at all with the difference in the fine specificities toward the core neutral carbohydrate chain, to which the sialic acid residues were attached. These findings suggest that the VH gene family in these anticarbohydrate antibodies is selected, depending primarily on the linkage of the sialic acid residues in carbohydrate Ag; these residues form the immunodominant sugar residue in the respective antigenic determinant.

Animals↗

PubMed1990

[Immunoglobulin genes encoding antibodies directed to oncodevelopmental carbohydrate antigens].

We investigated the immunoglobulin genes which encode the variable region of the monoclonal antibodies directed to the onco-developmental carbohydrate antigens such SSEA-1, fucosyl SSEA-1, SSEA-3 and SSEA-4. The VH region of these antibodies was preferentially encoded by the gene members of the X24, VH7183 and Q52 families, the families which are known to be located at the 3'-end region of the murine germ line VH gene. This result is interesting particularly when considering that the members of the 3'-end VH families are known to be preferentially expressed in embryonic B lymphocytes by an intrinsic genetic program. The comparative study of the nucleic acid sequences of mRNAs encoding these antibodies and the sequences of the corresponding germ line VH genes disclosed that the sequences encoding the antibodies contain no mutation from the germ line VH genes, or contain only a few somatic mutations, which are thought to be insignificant for the reactivity of the antibodies to the nominal antigens. These results imply that some of the embryonic B lymphocytes that express the unmutated germ line VH genes of the 3'-end families can be reactive with embryonic carbohydrate antigens, albeit rearranged with appropriate D-JH gene segments, and coupled with proper light chains. The VH region of the syngenic monoclonal anti-idiotypic antibodies directed to these anti-carbohydrate antibodies were also encoded preferentially by the members of the 3'-end VH families. We propose here that a part of the virgin embryonic B lymphocytes, which express the antibody encoded by the gene members of the 3'-end VH families at the cell surface, will be stimulated by the embryonic carbohydrate antigens which are abundantly present in the internal milieu of the embryo. The clonally expanded B lymphocytes, in turn, will facilitate the proliferation of other populations of embryonic B lymphocytes expressing the corresponding anti-idiotypic antibodies, which are also encoded by the gene members of the 3'-end VH families. This process will lead to the formation of the primitive immune idiotype network system directed to the embryonic carbohydrate auto-antigens in the embryo, which is rarely exposed to the external antigens.

Animals↗

PubMed1989

[Histological malignancy grading of oral squamous cell carcinomas].

UNLABELLED: A modification of Jakobsson's criteria that determines the mode of cancer invasion (Yamamoto, 1982) has been reported to be useful in predicting the prognosis in patients with an oral squamous cell carcinoma. In this retrospective study, a five-factorial grading system of the histological malignancy (+ the differentiations, the nuclear polymorphism, the mitoses, and the cellular response) was evaluated in relation to clinical course of each patient. RESULT: 75 cases were classified into four grades from Grade 1, the lowest malignancy, to Grade 4, the highest malignancy. The percentage metastases was 10, 24, 54, and 75% for each grade, respectively. The percentage of survival was 75, 75, 35, and 25% for each grade, respectively. From these results, this grading system was seen to have a close-correlation with the clinical course of each patient.

Adult↗

PubMed1989

Histochemical study of the differentiation of microglial cells in the developing human cerebral hemispheres.

Applying nucleoside diphosphatase (NDPase) histochemistry, the appearance and differentiation of microglial cells in the developing human cerebral hemispheres were investigated by light and electron microscopy. In the pallium of the 38 days old human embryo, a few round NDPase-positive cells (round cells) were observed in the expanding zone. Although distinct blood vessels had not yet formed within the wall of the pallium, some cellular elements resembling haemopoietic cells were noticed in the expanding zone. In the 51 days old fetus, blood vessels displaying NDPase activity were seen in the mantle and marginal layers, and some invaded the matrix. Several round NDPase-positive cells were distributed, mainly around the vascular sprouts (primitive blood vessels) in the matrix. In the marginal layer, NDPase-positive cells exhibiting short cytoplasmic processes were encountered (poorly ramifying cells). In the 58, 66 and 82 days old fetuses, the round NDPase-positive cells were seen mainly in the matrix or subcortical layer where vascular sprouts were conspicuous and the poorly ramifying cells were in the subcortical and marginal layers. In the two latter fetuses, NDPase-positive cells showing long highly ramifying cytoplasmic processes (highly ramifying cells) were noted mainly in the marginal layer and sometimes in the subcortical layer. In the 5 months old fetuses, numerous NDPase-positive cells were distributed in the mantle, subcortical and marginal layers, and most of them appeared to belong to the populations of the poorly or highly ramifying cells. On the basis of the ultrastructural features, the round cells and highly ramifying cells were regarded as amoeboid cells and microglial cells, respectively. These findings suggest that at least some amoeboid cells are transformed into microglial cells via the stages of poorly ramifying microglial cells, and also that, in the human cerebral hemispheres, appearance of the microglial elements is closely related with vascularisation, especially in the early developmental stages.

Brain↗

PubMed1988