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Biomedical subjects

J Goto

Publications and source records attributed to J Goto.

At least 55 records · Page 3Linked to original sources
PubMed2000

Maternal blood coagulation factor XIII is associated with the development of cytotrophoblastic shell.

We analysed the early implantation tissues of normal women and of a patient with congenital factor XIII deficiency in order to study the role of maternal subunit A of factor XIII (XIIIA) in the development of extravillous cytotrophoblast. The patient had received adequate administration of factor XIIIA concentrate only up to 7 weeks of gestation (wG). Her pregnancy was maintained until the latter half of 8 wG, but was terminated by intrauterine fetal death at 9 wG. Immunohistochemical staining of cytokeratin, XIIIA and subunit S of factor XIII was performed in the early implantation tissues of normal women and of this patient. Numerous well-formed cytotrophoblastic shells and Nitabuch's layers were detected in implantation tissues at 7-8 wG in normal women, and XIIIA was present in the intercellular space in well-formed cytotrophoblastic shells, while the cytotrophoblastic shells and Nitabuch's layers in this patient's implantation tissue were poorly-formed. Furthermore, XIIIA was not detected around them. It is suggested that when the maternal plasma activity of factor XIII is low, the concentration of XIIIA at the placental bed is also low, leading to the insufficient formation of cytotrophoblastic shell and therefore an increased probability of miscarriage in patients with congenital factor XIII deficiency.

Adult↗
PubMed2000

Two novel nodal-related genes initiate early inductive events in Xenopus Nieuwkoop center.

In vertebrates, Nodal-related protein plays crucial roles in mesoderm and endoderm induction. Here we describe two novel Xenopus nodal-related genes, Xnr5 and Xnr6, which are first zygotically expressed at the mid-blastula transition, in the dorsal-vegetal region including the Nieuwkoop center. Xnr5 and Xnr6 were isolated by expression screening of a library enriched with immediate-early-type transcripts, and are strong inducers of both mesoderm and endoderm. They also induce the other nodal-related genes in the animal cap. In embryos, cerberus-short (nodal-specific inhibitor) can inhibit Xnr1 and Xnr2 express to the same extent goosecoid, but not Xnr5 and Xnr6 transcription. Xnr5 and Xnr6 are regulated completely cell autonomously, differently from other Xnrs in the cell-dissociated embryos. The expression of Xnr5 and Xnr6 is regulated by maternal VegT and (beta)-catenin, but does not require TGF-(beta) signaling. Therefore, expression of Xnr5 and Xnr6 is controlled by different mechanisms from other Xnr family genes.

Amino Acid Sequence↗
PubMed2000

Morphometric evaluation of the human cervical motoneurons.

Morphometric analysis of the human cervical large motoneurons in the anterior horn was performed in 7 male cadavers with the help of an image-analyzer and the use of a new tissue preparation method which minimizes shrinkage. This method makes it possible to precisely evaluate the size of cervical motoneurons at each level. Our study revealed a difference in number, average area and total area of the motoneurons between C1-C3 and C4-C7 levels. This results can be of importance in setting standard values for the understanding of morphological and functional correlations.

Adult↗
PubMed2000

Gender dimorphism of axons in the human lateral corticospinal tract.

Axons in the lateral corticospinal tract (LCST) were analyzed morphometrically on 37 cadavers (24 males and 13 females). The results revealed gender differences at the first lumbar cord level. Whereas the shape of the axons showed small differences (they were slightly more circular in males than in females), significant differences regarding the average area and diameter were found for the first time: these showed significant reduction with age in the case of males, but not in the case of females.

Adult↗
PubMed2000

Sexual dimorphism of the human cerebral pallium.

Sexual dimorphism was found regarding the cortico-medullary volume ratio in human brains throughout the age range, without the need for statistical analysis. After measurement of the areas of the whole pallium, cerebral cortex and cerebral medullary substance in 10 mm thick slices with the help of an image-analyzer, the total volume of the brain was calculated by integrating the volumes of each slice. The sexual dimorphism found in the cortico-medullary volume ratio may be of importance to understand sex differences, to solve questions related to various activities, functions, behaviours and responses, or to evaluate various pathologic conditions including non-physiological cerebral atrophy.

Adult↗
PubMed2000

Sexual dimorphism of the motoneurons in the human spinal cord.

There have been few morphometric studies on the size of the motoneurons of the human spinal cord. The purpose of the present study is to report the differences in the size of the motoneurons between males and females in the human spinal cord. We examined numbers and transverse cell body areas of the motoneurons of the anterior horn using 16 male and 21 female human spinal cords at levels C5 and L3. The sizes of the motoneurons were larger in males than in females, but their numbers were practically the same. These results can be of great importance in setting standard values for the understanding of morphological and functional correlations.

Aged↗
PubMed1999

Ultrasensitive determination of NE-100, a novel sigma ligand, in human plasma by liquid chromatography and electrospray ionization tandem mass spectrometry combined with a column-switching technique.

For the highly sensitive and selective determination of NE-100, a novel sigma ligand, at levels of low picogram per milliliter of human plasma, a method with excellent reliability employing liquid chromatography (LC)-electrospray ionization (ESI) tandem mass spectrometry (MS-MS) combined with a column-switching technique has been developed. The method involves the use of a stable isotope labeled compound as the internal standard (I.S.), liquid-solid extraction of a plasma specimen with a C8 cartridge, automated on-line clean-up on a short trapping column, subsequent separation on a micro-bore C18 column and detection with ESI-MS-MS using m/z 356 ([M+H]+) as a precursor ion and m/z 105 as a product ion in a selected reaction monitoring mode. The detection and the quantification limits of NE-100 in plasma were 0.5 pg/ml with a signal-to-noise ratio (S/N) of 3 and 2.3 pg/ml, respectively, with an S/N of 21. The good linearity of the calibration graph was obtained in the range of 2.3 to approximately 907.0 pg/ml with excellent reliability. The developed method was applied to the determination of NE-100 in plasma obtained from the clinical trail.

Anisoles↗
PubMed1999

Rapid aggregate formation of the huntingtin N-terminal fragment carrying an expanded polyglutamine tract.

Huntington's disease (HD) is caused by an expansion of the CAG repeat in the HD gene. The repeat is translated to the polyglutamine tract as huntingtin, the product of HD gene. Several studies showed that the expansion of polyglutamine tract leads to formation of cytoplasminc and/or intranuclear aggregates in vivo or in vitro. To understand the molecular mechanism of the aggregate formation, we studied the transient expression of HD exon 1-GFP fusion proteins in COS-7 cells. The fusion protein carrying 77 glutamine repeats aggregated in a time-dependent manner, while the fusion protein carrying 25 glutamine tract remained to be distributed diffusely in the cytoplasm even 72 hours after transfection. Initially, fluorescent signals were diffusely distributed in the COS-7 cells that were transfected with the construct containing the 77 CAG repeats. Approximately 40 hours later after the transfection, large aggregates grew very rapidly in those cells and the diffuse cytoplasmic fluorescence faded out. This process was completed within 40 minutes from the appearance of small aggregates in the perinuclear regions. The addition of cycloheximide reduced the frequencies of aggregate formation. A possibility was discussed that the aggregate formation was via nucleation. The focal concentration of mutated proteins in neurons may trigger the aggregate formation.

Animals↗
PubMed1999

Characterization of cholyl-adenylate in rat liver microsomes by liquid chromatography/electrospray ionization-mass spectrometry.

The cholyl-adenylate, covalently bound 3alpha, 7alpha, 12alpha-trihydroxy-5beta-cholanoic acid (cholic acid) with adenosine 5'-monophosphate having an acid anhydride linkage, has been characterized by means of liquid chromatography/mass spectrometry in an incubation mixture with a rat liver microsomal fraction. The authentic specimen of cholyl-adenylate was synthesized using the carbodiimide method and the structure was confirmed by MS and nuclear magnetic resonance spectroscopy. After incubation of cholic acid with a hepatic microsomal fraction in the presence of adenosine 5'-triphosphate, bile acids were extracted and purified by solid-phase extraction on a Sep-Pak C18 cartridge and then subjected to a LC/MS analysis, where cholyl-adenylate and a CoA thioester of cholic acid (cholyl-CoA) were monitored with characteristic negative ions of m/z 736 and 577, respectively. Cholyl-adenylate was definitely characterized and preferential biotransformation into the acyl-adenylate prior to formation of cholyl-CoA was noted. The nonenzymatic formation of taurine-conjugated cholic acid by incubation of cholyl-adenylate with taurine in a buffer solution was also demonstrated.

Acyl Coenzyme A↗
PubMed1999

New screening methods for chemicals with hormonal activities using interaction of nuclear hormone receptor with coactivator.

The endocrine system exerts important functions in a multitude of physiological processes including embryogenesis, differentiation, and homeostasis. Xenobiotics may modify natural endocrine function and so affect human health and wildlife. It is necessary, therefore, to understand the degree to which xenobiotics can disrupt endocrine systems. The key targets of endocrine disruptors are nuclear hormone receptors, which bind to steroid hormones and regulate their gene transcription. We have developed relevant assay systems based on the ligand-dependent interaction between nuclear hormone receptor and coactivator. The coactivators used in this study contained CBP, p300, RIP140, SRC1, TIF1, and TIF2. By two hybrid assay in yeast, the interactions of estrogen receptor with RIP140, SRC1, TIF1, and TIF2 were detected and they were completely dependent on the presence of estrogen. Specificity of this assay was assessed by determining the effect of steroids, known estrogen receptor agonists, and phytoestrogens. The pattern of response to chemicals were consistent with estrogenic activity measured by other assay systems, indicating that this assay system is reliable for measuring estrogenic activity. In addition, we carried out in vitro binding studies: GST pull-down assay and surface plasmon resonance analysis. The estrogen receptor also bound to coactivator in response to chemicals depending on their estrogenic activity in vitro. These data demonstrate that the measurement of interaction between steroid hormone receptor and coactivator serves as a useful tool for identifying chemicals that interact with steroid receptors.

Adaptor Proteins, Signal Transducing↗
PubMed1999

Ataxia with isolated vitamin E deficiency: a Japanese family carrying a novel mutation in the alpha-tocopherol transfer protein gene.

We report a Japanese family with ataxia with isolated vitamin E deficiency (AVED). Gene analysis revealed a single nucleotide substitution of T to C at nucleotide position 2 in the alpha-tocopherol transfer protein gene (TTPA). This substitution abolishes the start codon. The proband and his affected sister were homozygous for this mutation, and their serum alpha-tocopherol concentrations were remarkably reduced. Relations between the mutations and clinical features are discussed.

Adult↗
PubMed1999

Experimental vaccine activities of recombinant E1 and E2 glycoproteins and hypervariable region 1 peptides of hepatitis C virus in chimpanzees.

A chimpanzee was immunized with two recombinant envelope glycoproteins E1 and E2 of hepatitis C virus (HCV), strain HCV-N2, and the hypervariable region 1 (HVR1) peptides of a different isolate, HCV-#6, then received an intravenous inoculation of 10 chimpanzee infectious doses of HCV-#6. With high humoral immune response against E1 and E2 but a low response against HVR1, the vaccinee became infected with the HCV. However, after increasing the titer of anti-HVR1 against HCV-#6, the vaccinee showed protection. Neutralization of HCV-#6 with the antiserum from this protected vaccinee was achieved by inoculation of this mixture into another chimpanzee. These results suggest that vaccination with a peptide-vaccine of homologous HVR1 is effective in the chimpanzee.

Amino Acid Sequence↗
PubMed1999

Transgenic mice harboring a full-length human mutant DRPLA gene exhibit age-dependent intergenerational and somatic instabilities of CAG repeats comparable with those in DRPLA patients.

Dentatorubral-pallidoluysian atrophy (DRPLA) is one among an increasing number of hereditary neurodegenerative diseases determined as being caused by unstable expansion of CAG repeats coding for polyglutamine stretches. To investigate the molecular mechanisms underlying CAG repeat instability, we established three transgenic lines each harboring a single copy of a full-length human mutant DRPLA gene carrying a CAG repeat expansion. These transgenic mice exhibited an age-dependent increase (+0.31 per year) in male transmission and an age-dependent contraction (-1.21 per year) in female transmission. Similar tendencies in intergenerational instabilities were also observed in human DRPLA parent-offspring pairs. The intergenerational instabilities of the CAG repeats may be interpreted as being derived from the instability occurring during continuous cell division of spermatogonia in the male, and that occurring during the period of meiotic arrest in the female. The transgenic mice also exhibited an age-dependent increase in the degree of somatic mosaicism which occurred in a cell lineage-dependent manner, with the size range of CAG repeats being smaller in the cerebellum than in other tissues including the cerebrum, consistent with observations in autopsied tissues of DRPLA patients. Thus, the transgenic mice described in this study exhibited age-dependent intergenerational as well as somatic instabilities of expanded CAG repeats comparable with those observed in human DRPLA patients, and are therefore expected to serve as good models for investigating the molecular mechanisms of instabilities of CAG repeats.

Adult↗
PubMed1999

The role of low molecular weight hyaluronic acid contained in Wharton's jelly in necrotizing funisitis.

The purpose of this research was to study the changes in the molecular weight of hyaluronic acid in Wharton's jelly altered by necrotizing funisitis. Umbilical cords were collected at delivery from 20 newborns without funisitis, 6 newborns with acute funisitis, and 4 newborns with necrotizing funisitis. Agarose gel electrophoresis of Wharton's jelly was performed to analyze the molecular weight of hyaluronic acid (HA). We also investigated the effects of low or high molecular weight HA on the production of interleukin-8 in human umbilical fibroblasts. In Wharton's jelly without funisitis, HA was 1150 +/- 280 kD in preterm newborns, regardless of gestational week at birth, and that in full-term newborns was 1100 +/- 200 kD. When acute funisitis was present, HA was 700 +/- 250 kD, and when necrotizing funisitis was present, HA was 520 +/- 100 kD. The molecular weight of HA was significantly below normal in newborns with necrotizing funisitis. Low molecular weight HA was associated with increased levels of IL-8 in the supernatant of cultured human umbilical fibroblasts in a time- and dose-dependent manner. High molecular weight HA did not induce the production of IL-8 in the same cells. Low molecular weight HA has a potent inflammatory action. The conversion from high to low molecular weight HA in Wharton's jelly may be important in the pathophysiology of necrotizing funisitis.

Birth Weight↗
PubMed1999

Morphometric nerve fiber analysis and aging process of the human vestibular nerve.

Myelinated and unmyelinated nerve fibers of the human vestibular nerve were analyzed with the use of a new staining method that makes it possible to discriminate various structures of the nervous tissue. An image-analyzing digitizer, a microscope with a drawing tube and a personal computer for storing data and performing statistical analyses were employed in this study. We measured the axonal numbers and transverse areas of myelinated vestibular nerve fibers in 20 cadavers, and of unmyelinated fibers in 14 cadavers. The average number of myelinated axons and unmyelinated axons were 20,318 and 2,782, and the average transverse area of their axons were 3.46 and 0.49 micron 2, respectively. The transverse areas of myelinated axons decreased with age, although the numbers of their axons did not change. However, in the case of unmyelinated axons, both the transverse areas and the numbers did not change.

Aged↗
PubMed1999

Sexual dimorphism of the human spinal cord in the aging process.

There have been few morphometric studies on age-related changes in the human spinal cord. The purpose of the present study was to determine the existence of sexual dimorphism of the spinal cord between males and females during the aging process. Spinal cords were removed from cadaver specimens, 26 males and 22 females for anatomic practice, the age at death ranged from 41 to 97 years for males (average, 71.5 years) and from 59 to 92 years for females (average, 76.6 years). Spinal cord segments were embedded in celloidin after secondary fixation and dehydration. Sections were stained with the Luxol fast blue-periodic acid-Schiff-hematoxylin and Klüver-Barrera methods. Morphometric analysis was performed with an electronic optical planimeter and a computer. Each section was enlarged 13.5 times to take a picture. The areas of the transverse section white matter and gray matter of the spinal cord at segments C5 and L3 were measured. Although there was no correlation between the total transverse area of the spinal cord and age either in males or females, we noticed that the area of the gray matter decreased faster in males than in females; while the area of the white matter decreased faster in females than in males. The area ratio of the white matter to the whole segment area of the spinal cord (W/T) at level C5 is larger in males than that in females. Our results suggest that there could be a difference between males and females in changes in the white and gray matters of the spinal cord due to aging.

Adult↗