PubMed Health⌕ Search

Biomedical subjects

S Kusuda

Publications and source records attributed to S Kusuda.

36 records · Page 2Linked to original sources
PubMed1996

Truncation at the C-terminus of the DAX-1 protein impairs its biological actions in patients with X-linked adrenal hypoplasia congenita.

The DAX-1 [DSS (dosage-sensitive sex)-AHC critical region in the X, gene 1] gene has been reported to be responsible for X-linked adrenal hypoplasia congenita (AHC) and hypogonadotropic hypogonadism. However, the function and structure of the DAX-1 protein have not been characterized. In this study, molecular analysis of the DAX-1 gene from 6 patients with AHC, including 2 siblings, identified 5 novel mutations with 3 nonsense mutations and 2 frameshift mutations. Case 1 had a nonsense mutation at position 395 (Q395X). Cases 2 and 3, who were siblings, had a nonsense mutation at position 91 (Y91X). Case 4 had a 2-base deletion (AT) at nucleotides 1610 and 1611 and a 1-base insertion (G) resulting in a premature stop codon at position 462 (1610-1611 del AT ins G). Case 5 had a nonsense mutation at position 271 (Y271X). Case 6 had a 1-base deletion (C) at nucleotide 1169, which induced a frame shift and a premature stop codon at position 371 (1169 del C). All mutated DAX-1 proteins had truncated C-terminal domains. In addition, reverse transcription-PCR and direct sequencing characterized the mutant messenger ribonucleic acid in testis from case 1. Our results suggest that these 5 novel mutations are responsible for X-linked AHC and that the C-terminus of the DAX-1 protein, especially the terminal 11 amino acids, is necessary for normal adrenal cortical embryogenesis.

Adolescent↗
PubMed1996

[Unusual hepatic fibrosis in three cases of Down syndrome].

We report three infants with Down syndrome who had hepatic fibrosis, which is rare in this syndrome. Liver specimens were obtained by biopsy or autopsy. In one patient, the peripheral blood contained blastoid cells, a typical hematological feature of the transiently abnormal myelopoiesis of Down syndrome. Ascites and hepatosplenomegaly were found in all patients. The intralobular hepatic fibrosis was pericellular and perisinusoidal, and the narrowing of the central veins resembled that in venoocclusive disease of the liver. We found some megakaryocytes in the liver, which were stained for von Willebrand factor and platelet glycoprotein IIb/IIIa. In one specimen, collagen type IV and alpha smooth muscle actin were stained by immunohistochemical methods, so the fibrosis in this case was probably caused by cells such as Ito cells derived from myofibroblasts. Overall, the findings suggest that megakaryocytes in the liver of these three patients produce collagen-stimulating cytokines such as transforming growth factor beta, and that Ito cells were involved in the hepatic fibrosis we observed.

Collagen↗
PubMed1995

Screening for PIT1 abnormality by PCR direct sequencing method.

PIT1 abnormality is defined as a genetic abnormality in the PIT1 gene, which encodes a pituitary specific transcription factor Pit-1/GHF-1.PIT1 abnormality has been reported in several patients displaying either complete or incomplete deficiency of thyrotropin (TSH), growth hormone (GH), and prolactin (PRL) in either familial or sporadic cases. To see if there are abnormalities in the PIT1 gene in patients with incomplete TSH, GH, and PRL deficiency, we utilized a PCR direct sequencing method to determine the Pit-1/GHF-1 coding sequence. A total of 15 patients, 1 patient from a family with TSH and GH deficiency, 3 patients with TSH, GH, and PRL deficiency, and 11 patients treated with both human GH (hGH) and thyroid hormone were studied. In one patient of combined pituitary hormone deficiency, the Arg-271-Trp mutation was detected. Since both of the parents did not harbor this mutation, it is a de novo germ line mutation. No mutation was detected in the other patients, showing that PIT1 abnormality is not a frequent cause of GH deficiency.

Base Sequence↗
PubMed1995

Exanthem subitum (roseola infantum) with vesicular lesions.

We report a 7-month-old boy who developed vesicular lesions during the course of exanthem subitum. Human herpesvirus-6 (HHV-6) DNA was detected both in the skin lesions and in the throat, by polymerase chain reaction. IgG and IgM antibodies against HHV-6 were 1:10 and < 1:10, respectively on the tenth day of the illness, and > 1:640 and 1:10 on the twenty-second day, respectively. These results suggest that this was primary HHV-6 infection.

Antibodies, Viral↗
PubMed1995

Perinatal medical support in the area surrounding the Hanshin-Awaji earthquake.

After natural disaster, perinatal medical care must usually be provided from outside the disaster area, because most of the medical efforts inside the area focus on patients without special needs. This study reviews the emergency perinatal medical response after the great Hanshin-Awaji earthquake. In the present study, we summarize records of telephone calls and reports from the Neonatal Mutual Cooperative System (NMCS). The day of the earthquake, very little information was available to or from the disaster area. The day after the earthquake, Osaka City General Hospital (OCGH) and Osaka Medical Center and Research Institute for Maternal and Child Health were established as key facilities, and OCGH served as a center through which information passed to and from the disaster area. Most telephone calls to OCGH were placed on the second day after the earthquake by pregnant women concerned about their deliveries. Many high-risk pregnancies and newborn infants were transferred out of the disaster area over the next month. This analysis shows that although the emergency response was very rapid in this instance, the operation may be significantly improved in disasters of this magnitude: (i) if a communication mechanism able to serve a large volume is established; (ii) if helicopter transport was easily available; and (iii) if key facilities to handle communications were previously established so as to be available immediately.

Child Health Services↗
PubMed1994

Terminal differentiation of facial epidermis of the aged: immunohistochemical studies.

In old age, the epidermis tends to become dry and flaky, especially on the lower legs. However, this does not occur on the face, although long-term ultraviolet light irradiation has important effects on the differentiation of facial keratinocytes. Therefore, the differentiation of the epidermal cells of the facial skin in the young and the aged was immunohistochemically examined using antibodies against four differentiation products: filaggrin, involucrin, cystatin A (CTA) and carbonic anhydrase-like protein. The results showed that there was no difference in the amounts of the above three proteins in facial skin between the young and the aged with the exception of CTA. The amount of CTA was much greater in the facial skin of the aged. However, there was a striking decrease of filaggrin content in the skin of the lower leg in the aged. One of the reasons why no scaly skin is found on the face in the aged may be the fact that especially filaggrin does not decrease with aging.

Adult↗
PubMed1992

Measurement of growth promoting activity in human milk using a fetal small intestinal cell line.

To evaluate the effect of the growth promoting activity in human milk on intestinal cells, a bioassay method was established using a fetal intestinal cell line (FHS 74 Int, ATCC CCL 241), since the developing intestine is considered to be a target organ for the growth factors present in human milk. Human milk had a growth promoting activity on the cultured human fetal intestinal cells. The activity level was very high in colostrum and decreased gradually during lactation, while formula products had no activity. The epidermal growth factor (EGF) concentration in human milk was significantly correlated with the growth promoting activity measured by bioassay. Thus, EGF may be the main growth factor for the proliferation of intestinal cells. These results suggest that human milk may stimulate the proliferation of intestinal cells in newborn infants, especially in very-low-birth-weight infants, and accelerate the maturation of the intestinal portion of the digestive system.

Cell Line↗
PubMed1988

Characterization of ovarian gonadotropin receptor. Monomer and associated form of the receptor.

We have purified luteinizing hormone/human choriogonadotropin (hCG) receptor from rat ovary by sequential affinity column on wheat germ lectin-Sepharose and hCG-Sepharose chromatography. The purified receptor, previously identified as a single protein on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) (Kusuda, S., and Dufau, M.L. (1986) J. Biol. Chem. 261, 16161-16168), was further characterized by radioiodination with 1,3,4,6-tetrachloro-3 alpha, 6 alpha-diphenylglycouril, and column chromatography on wheat germ lectin-Sepharose. Autoradiography of SDS-PAGE analysis under reducing conditions showed a single radiolabeled band of Mr = 80,000. The radioiodinated receptors treated with peptide:N-glycosidase F migrated at Mr = 54,000. Treatment with neuraminidase alone caused only a minor reduction in molecular weight, and subsequent treatment with endo-alpha-N-acetyl-D-galactosaminidase had little further effect on the receptor. When the radioiodinated receptor was analyzed by fast protein liquid chromatography, a single broad peak was eluted with Mr of approximately 350,000. The higher Mr of radioiodinated receptors than that of native receptors (Mr = 190,000 dimeric form) could be due to the aggregation of labeled molecules. These complexes dissociated into the monomeric form in the presence of SDS. To determine whether the monomers can bind hormone, the purified unlabeled receptors resolved with SDS were electroblotted to nitrocellulose membranes and incubated with 125I-hCG. Autoradiograms of the blots showed a band of monomer (Mr = 78,000) as well as one of dimer (Mr approximately 150,000). These studies have demonstrated that the luteinizing hormone/hCG receptors are predominantly N-linked glycosylated and suggest that the native receptor is a dimer of identical hormone binding subunits associated by noncovalent interactions. Although the individual subunits can bind hormone, it is conceivable that the dimeric form is necessary for signal transduction.

Animals↗
PubMed1987

Purification and characterization of Leydig cell luteinizing hormone receptor.

We have purified the testicular luteinizing hormone (LH/human choriogonadotropin (hCG)) receptor by sequential affinity chromatography on hCG-Sepharose. The purified LH/hCG receptor was identified as a single protein of Mr = 90,000 +/- 2,000 on sodium dodecyl sulfate-gel electrophoresis (SDS-PAGE), showed high affinity binding for hCG, and a binding capacity of 3.8 nmol/mg of protein. Electrophoretically blotted receptor retained the ability to bind 125I-hCG on nitrocellulose membrane, and the Mr of radioactive band was consistent with that revealed by silver staining. Autoradiography after SDS-PAGE analysis of cross-linked purified receptor-hCG complex showed Mr = 145,000 and Mr = 105,000 bands. These results are consistent with a Mr value for the receptor of 90,000 after accounting for contribution by the intact hormone or its alpha-subunit. Analysis of the free receptor by fast protein liquid chromatography on Superose 12 revealed a single peak of binding activity for 125I-hCG which eluted in the position of Mr = 200,000-240,000 in the presence of Triton X-100. Since a single protein species is observed under reducing or nonreducing conditions in SDS-PAGE, the receptor could exist in the membrane as a dimeric form composed of subunits Mr = 90,000 associated through noncovalent interactions. The pure receptor can be phosphorylated in vitro by the catalytic subunit of cAMP-dependent protein kinase (approximately 0.3 mol of phosphate/mol of receptor). This phosphorylation does not affect the binding characteristics of the receptor. The method described is simple and allows rapid purification of microgram amounts of biological active Leydig cell LH/hCG receptor for structural, functional, and immunological studies.

Animals↗
PubMed1987

Purification and characterization of ovarian LH/hCG and prolactin receptors.

We have purified the luteinizing hormone (LH)/human choriogonadotropin (hCG) receptor to homogeneity by sequential affinity column on wheat germ lectin-Sepharose and hCG-Sepharose. The method was designed to allow also the purification of lactogen receptor from the initial starting material. Comparable purification of lactogen receptor can be attained using Con A-Sepharose as initial step. The purified LH/hCG receptor was identified as a single protein of Mr = 75,000 on SDS gel electrophoresis. The lactogen receptor is composed of two dissimilar active subunits of Mr 88,000 and 40,000, the latter probably being an integral part of the larger form. Comparison of Mr's derived from SDS gels with those from fast performance liquid chromatography suggested that the native LH holoreceptor is present in a dimeric form, while the lactogen receptor seems to be composed of aggregates that could represent dimeric or trimeric forms of holoreceptor Mr 80,000. Cross-linking studies performed after binding of hCG (radiolabeled in the individual subunits) to the purified LH/hCG receptor indicated that the hCG alpha-subunit undergoes predominant interaction with the receptor molecule. The influence of the beta-subunit in this interaction seems to occur mainly through its association with the alpha-subunit, presumably by conferring specificity to the alpha-subunit for its interaction with the receptor. The alpha-subunit, which is identical within species, has an important role in the receptor binding interaction and biological activity of glycoprotein hormones.

Animals↗
PubMed1986

Purification and characterization of the rat ovarian receptor for luteinizing hormone. Structural studies of subunit interaction.

We have purified the luteinizing hormone (LH)/human choriogonadotropin (hCG) receptor by sequential affinity column on wheat germ lectin-Sepharose and hCG-Sepharose. The method was designed to allow also the purification of lactogen receptor from the initial starting material. The purified LH/hCG receptor retained full binding affinity and was identified as a single protein of Mr = 73,000 +/- 3,000 on sodium dodecyl sulfate-gel electrophoresis. Cross-linking studies performed after binding of hCG to the purified LH/hCG receptor indicated that the hCG alpha-subunit undergoes predominant interaction with the receptor molecule. The influence of the beta-subunit in this interaction seems to occur mainly through its association with the alpha-subunit, presumably by conferring specificity to the alpha-subunit for its hormonal interaction with the receptor. The technique described in this study is simple and allows rapid purification of microgram amounts of biologically active receptor suitable for further molecular characterization, microsequencing, and functional reconstitution studies.

Amino Acids↗
PubMed1984

Semiautomated enzyme immunoassay of thyrotropin as a mass screening test for neonatal hypothyroidism.

A sensitive, simple, and rapid semiautomated sandwich enzyme immunoassay (EIA) was developed for measuring thyrotropin in dried blood samples on filter paper for use in screening for neonatal hypothyroidism. Good correlation was found between values for thyrotropin determined by this method and those determined by radioimmunoassay (RIA) (r=0.94). In pilot tests on 17,160 newborn infants in the general population, five cases of primary hypothyroidism were detected by both EIA and RIA. The recall rate was slightly highter in EIA than in RIA.

Autoanalysis↗
PubMedDate not supplied

Adrenoleukodystrophy: new CT findings.

Three cases of adrenoleukodystrophy are presented with sequential findings by computed tomography (CT). In two cases, CT confirmed not only the findings of several previous reports of a caudocranial direction of low-density white matter and contrast enhancement at the periphery of affected regions during the active demyelinating process, but also two other unusual features: (1) calcification in the affected white matter along the trigones of the lateral ventricles and (2) development of a mass effect during the active demyelinating period. Calcification alone without low-density white matter was the initial CT presentation in one case. Periventricular calcification may be specific for adrenoleukodystrophy in the appropriate clinical setting.

Adrenoleukodystrophy↗