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Biomedical subjects

S Kodama

Publications and source records attributed to S Kodama.

At least 199 records · Page 11Linked to original sources
PubMed1990

Differential expression of human leukocyte antigen-A, -B, and -C locus specific genes in trophoblast and embryonic cells.

Research on the escape mechanism of the fetoplacental unit has focused on the placental trophoblast, which is though to play an important role in the survival of the fetus. There are two major findings in the present study: (a) The expression of human leukocyte antigen (HLA)-A, -B, and -C locus specific genes is greatly reduced in trophoblast cells compared to embryonic cells by Northern blot analysis using locus specific oligonucleotide probes. This is true even though the transcripts detected by a complementary DNA probe, which contains a very conserved sequence present in all members of the HLA gene family, are equally abundant in trophoblast and embryonic cells. (b) When trophoblast cells or embryonic cells are cocultured with peripheral blood lymphocytes from the corresponding female in the presence of recombinant interleukin 2, allogeneic cytotoxic T lymphocytes are generated only in cultures with embryonic cells, and trophoblast cells express the resistance to lysis by the allogeneic cytotoxic T lymphocytes. These results strongly suggest that the reduction in expression of transplantation antigens (HLA-A, -B, and -C) might address the question why maternal tissue does not reject trophoblast cells.

Base Sequence↗
PubMed1990

[A case of systemic lupus erythematosus with subarachnoid hemorrhage due to ruptured aneurysm].

A case of systemic lupus erythematosus (SLE) with subarachnoid hemorrhage due to a ruptured intracranial aneurysm is reported. A 31-year-old woman who had been treated with steroid for SLE was admitted to our department with severe headache, and nausea. CT scan showed subarachnoid hemorrhage and the left carotid angiogram revealed a small aneurysm at the supraclinoid portion of the left internal carotid artery. She had no neurological deficit. Hematological examination on admission showed disseminated intravascular coagulation (DIC), therefore, we decided to perform an intentionally delayed operation. In the meantime we treated the patient for DIC with FOY and methylprednisolone. The operation was performed after two weeks, when DIC had been eliminated completely. Postoperative hematological examination showed severe thrombocytopenia. We considered that SLE had come to the fore again, so we used Danazol in company with FOY and steroid. It seemed that Danazol was very effective for her. She was discharged about two months after admission with no problem. Cerebral apoplexy, such as cerebral infarction and cerebral hemorrhage, has often been seen in SLE, but subarachnoid hemorrhage due to a ruptured aneurysm is very rare. We could find only five reports of this phenomenon. Their prognoses were all, unfortunately, poor. It should be born in mind for therapy that a patient in SLE has a tendency to bleed. It seems that repeated hematological examinations and quick and proper management are important. We think that the aneurysmal formation in SLE is due to lupus vasculitis or the fragility of blood vessels due to a long use of Steroid.

Adult↗
PubMed1990

[A power spectral analysis of the EEG in the newborns. I. Developmental changes of normal babies].

Power spectral analysis of the EEG at the neonatal period was performed in 50 premature babies and 36 mature babies. The gestational age ranged from 26 to 40 weeks, and birth weight from 762 g to 3,232 g. All EEGs were recorded when the babies reached to 37-41 weeks of conceptional age, and analyzed using fast Fourier transformation. The relative power in active sleep was evaluated in this study. The percent power of the delta 1 band ranging from 0.5 to 2.0 Hz decreased immediately with increasing conceptional age, while that of the delta 2 (2.2-3.8 Hz), theta 1 (4.0-5.4 Hz) and theta 2 (5.6-7.8) increased with conceptional age. However, no significant change was recognized in the alpha (8.0-12.8 Hz) and beta 13.0-29.8 Hz). These results suggest that the development of the EEG depends on the post conceptional age. The percent power of delta 1 to beta bands was compared among the frontal, central, parietal and occipital regions. The development of EEG in the central region was prominent among other 3 regions in EEG development. The EEGs of premature babies were compared to those of mature babies at the same conceptional age. The percent power of premature babies was higher at the delta 1 band, whereas lower at the delta 2, theta 1 and theta 2 bands than that of mature babies. The data showed that premature babies were more immature than age-matched mature babies in the development of EEGs.

Brain↗
PubMed1990

[A power spectral analysis of the EEG in the newborns. II. The power spectral changes of the infants with neonatal asphyxia].

Power spectral analysis of the EEG at the neonatal period was performed in 33 babies with an Apgar score of 6 or less 1 minute after delivery. Their gestational ages ranged from 27 to 40 weeks, and birth weight from 1,013 g to 4,416 g. They were followed up until 18 months of age. All EEGs were recorded when the babies reached to 37-41 weeks of conceptional age, and analyzed using fast Fourier transformation. The percent power in active sleep was evaluated in this study. The abnormal EEG patterns in infants with neurological damage was classified into the following groups: (1) Increase of the percent power of the delta 1 band, (2) Decrease of the percent of the power of the delta 1. On the other hand, the EEG patterns at the neonatal period in infants with normal development who suffered from neonatal asphyxia were similar to those of age-matched controls. These results suggest one of the most important factors deciding the prognosis of the brain damage is the presence of a normal percent pattern. In conclusion, power spectral analysis of EEG at the neonatal period is useful in predicting the outcome of brain damage if it is used with visual inspection.

Asphyxia Neonatorum↗
PubMed1989

Target antigen of islet cell antibody in Japanese insulin-dependent diabetes mellitus.

The target antigens of islet cell antibody (ICA) have not been clarified. We tried to modify the antigen in human pancreatic tissues and characterize the ICA with immunohistochemical methods. Human pancreatic tissues were treated with periodate (A), borohydride (B), neuraminidase (C), methanol (D), chloroform-methanol (E), or protease (F) to modify the antigens, and stained by an immunofluorescent method using ICA-positive sera from five Japanese insulin-dependent diabetes mellitus (IDDM) patients. In all sera the fluorescence of islets disappeared or waned after A, C, D, and E, and did not change after F. The disappearance or loss of fluorescence induced by A was recovered after B. It is, therefore, suggested that one of the antigens of ICA in Japanese IDDM patients is the sialic acid residue of glycolipid.

Adolescent↗
PubMed1989

A sandwich enzyme immunoassay for collagenase inhibitor using monoclonal antibodies.

A sandwich enzyme immunoassay for collagenase inhibitor was set up with a pair of monoclonal antibodies prepared against bovine dental pulp collagenase inhibitor. Two different combinations of the antibodies were found to be applicable to the immunoassay; one was for the determination of both bovine and human collagenase inhibitors, but the other was only for the bovine one. Minimum sensitivity was 1 pg/tube (3 pg/ml) for bovine collagenase inhibitor and 1.5 pg/tube (5 pg/ml) for human inhibitor. The levels of collagenase inhibitor in several normal human body fluids were measured by the immunoassay, and the values obtained were as follows: serum, 183 +/- 30 ng/ml (mean +/- SD); platelet-poor plasma, 68 +/- 13; cerebrospinal fluid, 60 +/- 13; amniotic fluid, 1,780 +/- 969; tear fluid, 418 +/- 145; mixed saliva, 316 +/- 166; urine, 7 +/- 8.

Animals↗
PubMed1989

Effects of ergocalciferol supplementation on the concentration of vitamin D and its metabolites in human milk.

The effect of maternal ergocalciferol (vitamin D2) supplementation on the concentrations of vitamin D, 25-hydroxyvitamin D (25-OH-D), 24R,25-dihydroxyvitamin D [24,25-(OH)2D], and 1 alpha,25-dihydroxyvitamin D [1,25-(OH)2D] in their milk was studied. Vitamin D2, D3, 25-OH-D2 and 25-OH-D3 were simultaneously determined by high performance liquid chromatography, and the determination of 24,25-(OH)2D and 1,25-(OH)2D was performed by competitive protein binding assay and radioreceptor assay, respectively, after separation of the D2 and D3 compounds. After healthy lactating mothers had received a daily oral dose of vitamin D2 (1,200 IU/d) for 4 wk, the concentrations of vitamin D2, D3 and the metabolites were determined in their plasma and milk. Although the plasma levels of 25-OH-D2 were significantly increased, the increase in milk was relatively small. On the other hand, the increase of vitamin D2 levels in milk was greater than that of 25-OH-D2 in milk after supplementation. The levels of 1,25-(OH)2D in milk was lower after 5 wk of lactation than after 1 wk of lactation, regardless of maternal vitamin D2 supplementation. When total antirachitic activities in milk were calculated, only a very slight increase was observed as a result of supplementation.

24,25-Dihydroxyvitamin D 3↗
PubMed1989

Purification and characterization of recombinant human interleukin 5 expressed in Chinese hamster ovary cells.

Recombinant human interleukin 5 (rhIL-5) expressed in Chinese hamster ovary cells was purified and characterized. Molecular heterogeneity was observed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Two major components of Mr around 40,000 were detected under non-reducing conditions. However, under reducing conditions, the Mr of rhIL-5 was determined to be 22,000 and 20,000. After treatment with endoglycosidase F, a band with an apparent Mr of 18,000 was observed. Treatment of rhIL-5 with 2-mercaptoethanol followed by N-ethylmaleimide resulted in its dissociation into a monomeric form. This alkylated rhIL-5 was biologically less active than intact rhIL-5. These results suggest that rhIL-5 exists as a dimer, and that the heterogeneity of rhIL-5 is mainly due to the difference in the content of carbohydrate. Moreover, the formation of disulfide bond(s) might be important for the biological activity of rhIL-5.

Amino Acid Sequence↗
PubMed1989

Supplementary thyroxine therapy in patients with hypothyroidism induced by long-term anticonvulsant therapy.

Of 287 patients under long-term therapy with anticonvulsants, 24 with low serum thyroxine and free thyroxine concentrations were prescribed supplementary thyroxine in the present study. In addition, the basal metabolic rate (BMR) was measured in 13 out of 24 patients and in eight of them it was low (under -15%). Serum thyroid hormone concentrations improved after administration of thyroxine. However, improvement of the BMR was not obtained after one month of supplementary therapy. EEG after administration showed an increase in the power spectra of the occipital alpha 2 band (10.0-12.8 Hz) and beta 1 band (13.0-19.8 Hz), and a decrease in that of the theta band (4.0-7.8 Hz). The interpeak latency from wave I to wave V in the ABR was normalized after administration. These results suggest that supplementary therapy with thyroxine may be necessary in patients with hypothyroidism induced by anticonvulsants.

Adolescent↗
PubMed1989

[Immunohistochemical study on the MHC class I antigen expression on squamous cell carcinoma of the uterine cervix].

Immunohistological analysis was performed to detect MHC Class I antigen expression on uterine cervical squamous cell carcinomas of 23 patients using a monoclonal antibody (W6/32) to recognize a monomorphic determinant of HLA-ABC and an antibody (MA2.2) to react only with cells typed as HLA-A2. The results were as follows. 1. In 2 of 23 cases examined, cancer cells lacked reactivity with W6/32, although normal epithelial cells and connective stromal cells surrounding cancer nests were clearly positive for the antibody in all cases. 2. Of the remaining 21 cases, fourteen cases were judged to be HLA-A2 positive, based on the obvious staining of the stromal cells with MA2.2. Of these 14 only 5 carcinomas were positive for HLA-A2, and the cancer cells in the other 9 cases failed to bind MA2.2. These data suggest that in most clinically diagnosed patients, cancer cells do not have their own MHC Class I products on their cell surfaces phenotypically, and this unique property may be related to the biological characteristic that permits cancer cells to survive and proliferate unrestrictedly in vivo, mainly escaping from the immune-surveillance system under cytotoxic T lymphocytes (CTLs), which need to recognize not only cancer-specific (associated) antigen(s) but also the self-MHC Class I products to kill the cancer cells efficiently.

Adult↗
PubMed1988

Cockayne syndrome: magnetic resonance images of the brain in a severe form with early onset.

A 2-year-old boy with an early onset and severe form of Cockayne's syndrome (CS) showed differences from the common CS form, which made the clinical diagnosis difficult. However, the cellular characteristics of CS, that the patient's skin fibroblasts exhibited the hypersensitivity to the lethal effect of 254 nm ultraviolet light (UV) and a defective recovery of post-UV DNA synthesis, but normal level of UV-induced unscheduled DNA synthesis, were observed. The magnetic resonance imaging (MRI) by the inversion-recovery method of the brain at age of 26 months showed atrophy or poor development of high signal images of the white matter. The MRI spin-echo image showed a low signal image of the lenticular nucleus. The T1 and T2 values of the cerebrum (grey matter, white matter, lenticular nucleus and thalamus) were greater than those of the age-matched controls. but similar to infant brains with much free water. Such MRI findings may suggest hypomyelination leading to the severe atrophy of the brain in this CS patient. His severe symptoms progressed rapidly until his death at 35 months due to systemic sepsis and renal dysfunction. Autopsy revealed severe microcephaly, severe atrophy of cerebrum, cerebellum and brain stem, and calcification throughout the brain, especially in the basal ganglia. Myelin staining showed numerous patchy losses of myelination in the cortical white matter.

Atrophy↗
PubMed1988

Ruptured dissecting aneurysm of the vertebral artery revealed by repeat angiography.

A case of subarachnoid hemorrhage caused by the rupture of a dissecting aneurysm of the vertebral artery is reported. The initial angiogram was normal, and repeat angiography carried out 12 days later revealed a dissecting aneurysm of the right vertebral artery. This angiographic change seems to be due to the progression of minimal dissection that was not found at the time of first angiogram.

Aortic Dissection↗
PubMed1987

Establishment and some mutational characteristics of 3T3-like near-diploid mouse cell line.

A stable and nonmalignant near-diploid cell line, designated m5S, has been established by serial in vitro transfers of embryonic skin cells of ICR mouse. The cells are stable in karyotype and growth, display high sensitivity to contact inhibition of cell division, are nontumorigenic in nude mice, and the transformation and mutation may be reproducibly tested. Unlike most of the mouse cell lines, the m5S underwent a unique karyotypic change during establishment and showed high stability in a diploid range, making amenable to the study of mutagenesis. The m5S is nearly unique; it represents the second near-diploid cell line sensitive to postconfluence inhibition of cell division derived from mouse embryo cells to be reported and characterized. These cells are being successfully used for qualitative and quantitative studies of oncogenic transformation as well as mutation to drug resistance by radiation and chemicals.

Animals↗