Search PubMed⌕ Search

Biomedical subjects

T Kojima

Publications and source records attributed to T Kojima.

At least 451 records · Page 25Linked to original sources
PubMed1995

[Carrier detection and prenatal diagnosis for hemophilia A using the inversion analysis of the factor VIII gene].

Hemophilia A is an X-linked hemorrhagic disorder caused by heterogeneous mutations in the factor VIII gene. Recently, it was reported that approximately 50% of the cases of severe hemophilia A may be caused by a common inversion in the factor VIII gene. In this study, we analyzed 33 Japanese patients with severe hemophilia A for the presence of this inversion mutation using the non-RI Southern blotting, and detected inversion mutations of the factor VIII gene in 12 patients (36.4%). We also showed that the inversion analysis of the factor VIII gene was useful for carrier detection and prenatal diagnosis in a hemophilia A family, which we had not been able to diagnose by the analysis of restriction fragment length polymorphisms (RFLPs) of the factor VIII gene. The detection of inversion mutations in the factor VIII gene using non-RI Southern blotting analysis appears to be very useful for the genetic counseling for severe hemophilia A.

Adult↗
PubMed1995

Effects of hypothalamic paraventricular nucleus: electrical stimulation produce marked analgesia in rats.

The effect of the electrical simulation induced analgesia (ESIA) on the hypothalamic paraventricular nucleus (PVN) was investigated by the paw pressure test, which was used to avoid any tissue damage to the paw of Wistar-SPF/VAF male rats. A stimulating electrode was chronically implanted in the parvocellular (PVN-prv) or magnocellular (PVN-mgn) divisions of the PVN. The ESIA was examined at least 10 days after surgery. The electrical stimulation of the PVN markedly showed analgesia (ESIA), but stimulation of most locations outside the PVN did not produce ESIA. Stimulation threshold for the ESIA was lower from PVN-prv than from PVN-mgn, but neither region was affected by naloxone administration (10 mg/kg, i.p.). These results indicate that the PVN is a part of the pain inhibitory system in the CNS, and show that PVN-ESIA might not be mediated either by opioids or by neuropeptides such as vasopressin.

Analgesia↗
PubMed1994

Induction of a mirror-image duplication of anterior wing structures by localized hedgehog expression in the anterior compartment of Drosophila melanogaster wing imaginal discs.

The segment polarity gene hedgehog (hh) encodes a secretory protein involved in cell-cell communication in Drosophila melanogaster. The hh gene is expressed in the posterior compartment and is essential for the establishment and maintenance of the anterior/posterior-compartment boundary of each embryonic parasegment [Ingham, P.W., Nature 366 (1993) 560-562]. To clarify possible hh functions in adult appendage formation, we isolated a fly line (h9D) associated with a wing malformation from among fly lines with an hh transgene whose expression is under the control of trapped enhancers. In h9D flies, the ectopic expression of hh occurred in the anterior edge of wing pouch in the wing disc. This abnormal hh expression resulted in not only a mirror-image duplication and ectopic outgrowth in the anterior wing compartment, but also the ectopic expression of patched and decapentaplegic, strongly suggesting that the hh product serves as a morphogen or an inducer essential for wing development, including the proximal/distal axis formation.

Animals↗
PubMed1994

DNA typing of the D1S8 (MS32) locus by rapid detection minisatellite variant repeat (MVR) mapping using polymerase chain reaction (PCR) assay.

The typing of the D1S8 (MS32) locus using the minisatellite variant repeat (MVR) polymerase chain reaction (PCR) method was performed by visualising amplified DNA stained with ethidium bromide. The results from rapid detection MVR-PCR were compared with those from the original MVR-PCR using Southern blot hybridisation with a 32P-labelled probe. With genomic DNA extracted from blood samples of 40 healthy unrelated Japanese individuals, the first 41 codes, on average, were correctly determined by rapid detection MVR-PCR without band intensity information, compared with at least 60 codes typed by the original MVR-PCR. The rapid detection MVR-PCR method was applied to bloodstains to simulate forensic samples. On average, 39 code positions could be determined from DNA extracted from 3-month-old bloodstains of six persons. Rapid detection MVR-PCR is more convenient than the original MVR-PCR, furnishes much information with regard to personal identification, and should be applicable to forensic fields.

Alleles↗
PubMed1994

Chemoprevention of spontaneous endometrial cancer in female Donryu rats by dietary indole-3-carbinol.

Indole-3-carbinol (I3C) present in cruciferous vegetables has been found to inhibit chemically induced neoplasms in forestomach, mammary gland, liver, and tongue in rodents. I3C is also known to induce estradiol 2-hydroxylase and reduce estrogenic activity. The current study was conducted to examine the possible inhibiting effect of I3C on spontaneous occurrence of endometrial adenocarcinoma in female Donryu rats. The high incidence of endometrial cancer in this strain of rats might be related to increased estrogen/progesterone ratio with aging. A total of 141 female Donryu rats were divided into four groups. Group 1 was given a basal diet alone throughout the study. Starting at 6 weeks of age, groups 2-4 were respectively given the diets containing 200, 500, and 1000 ppm I3C for the entire experimental period (660 days). At the termination of the experiment, the incidences of preneoplastic lesions and neoplasms in the endometrium were estimated. Also, estradiol 2-hydroxylation activity in the liver was assayed in rats fed I3C at these doses for 3 weeks. The incidences of endometrial adenocarcinoma in rats fed I3C [8 of 32 rats (25%) in group 2, 5 of 32 rats (16%) in group 3, and 5 of 35 rats (14%) in group 4] were respectively smaller than that in group 1 (12 of 32 rats, 38%). The incidence of uterine adenocarcinoma in group 4 was significantly lower than that in group 1 (P < 0.05). Dietary I3C also decreased the frequency of preneoplastic endometrial lesions (31% in groups 2-4 versus 44% in group 1). I3C exposure also inhibited the incidence of mammary fibroadenoma. Biochemical assay for estradiol 2-hydroxylation revealed that feeding of I3C significantly increased estradiol 2-hydroxylation (nmol/mg protein) compared to rats treated without I3C [0.34 +/- 0.04 in group 2, 0.53 +/- 0.13 in group 3, and 0.58 +/- 0.11 in group 4 versus 0.28 +/- 0.02 in group 1; P < 0.02, P < 0.003, and P < 0.001, respectively]. These results suggest that dietary I3C inhibits spontaneous occurrence of endometrial adenocarcinoma as well as preneoplastic lesions in Donryu rats. This chemopreventive effect of I3C may be due to its induction of estradiol 2-hydroxylation.

Adenocarcinoma↗
PubMed1994

Impaired human tissue factor-mediated activity in blood clotting factor VIINagoya (Arg304-->Trp). Evidence that a region in the catalytic domain of factor VII is important for the association with tissue factor.

A 37-year-old man was found to have an inherited abnormal factor VII (FVII) (designated FVIINagoya) that has a lower FVII procoagulant activity when tested in a one-stage assay using rabbit, simian, or human tissue factor (TF), but surprisingly has a nearly normal activity using bovine TF. DNA sequence analysis of the propositus' FVII gene revealed a C to T mutation that results in a novel amino acid substitution of Arg304 to Trp. Restriction enzyme analysis of the amplified fragment obtained from each family member demonstrated that the patient is homozygous for the point mutation, and the mother and sister of the patient are heterozygous for this mutation. To elucidate the abnormality in FVIINagoya, we compared the recombinant mutant FVII with normal FVII. In the presence of human TF, kinetic analyses demonstrated that the apparent Km values of FVIINagoya for factor Xa-mediated FVII activation and for FVIIa-mediated factor X (FX) activation were 3.6- and 4.5-fold higher than those of normal FVII, respectively. The ligand binding assay to human TF also showed that FVIINagoya had a 5.2-fold larger apparent Kd than normal. In the presence of bovine TF, however, these values showed no difference between normal and mutant FVII. These findings indicate that the major abnormality in FVIINagoya is not a catalytic dysfunction but an impaired complex-formation of human TF.FVII.FX, suggesting the importance of Arg304 in the interaction with human TF.

Adult↗
PubMed1994

A novel cytokine exhibiting megakaryocyte potentiating activity from a human pancreatic tumor cell line HPC-Y5.

Sixty-four kinds of cell lines were examined for their ability to produce megakaryocyte potentiating activity by means of conditioned media obtained from a protein-free culture system. Six human tumor cell lines were shown to produce this activity, and the cell line HPC-Y5, established from human pancreatic cancer, was shown to have the highest level of activity. The megakaryocyte potentiating factor (MPF) was purified from an HPC-Y5 conditioned medium by a combination of ion-exchange chromatography, gel filtration and reverse-phase HPLC. The purified MPF showed a megakaryocyte potentiating activity almost equal to human interleukin-6 in the presence of murine interleukin-3 in a colony formation assay with mouse bone marrow cells. The apparent molecular weight of MPF is 32,000 when determined by SDS-polyacrylamide gel electrophoresis. Glycopeptidase F digestion, and amino sugar analysis of the factor demonstrated that MPF is a glycoprotein carrying at least one N-linked sugar chain. The N-terminal amino acid sequence of MPF was determined to be Leu-Ala-Gly-Glu-Thr-Gly-Gln-Glu-Ala-Ala-Pro-Leu- Asp-Gly-Val-Leu-Ala-Asn. The same or homologous amino acid sequence has not been found in known proteins, demonstrating that MPF is a novel cytokine that has megakaryocyte potentiating activity in the murine assay system.

Amino Acid Sequence↗
PubMed1994

Experimental study of cryopreserved allogeneic transfer of vessel: preliminary report.

It has long been known that the antigenicity of tissues is depressed when they are kept at a very low temperature. In this study, Lewis rats and Brown Norway (B.N.) rats were used because these species are significantly dissimilar at the major histocompatibility complex (MHC) Femoral arteries were harvested from Lewis rats, frozen while lowering the temperature in a stepwise fashion to -70 degrees C. After three weeks of cryogenic storage, the arteries were transplanted into Lewis and B.N. rats. At various times from the first to the twelfth week after surgery, grafted vessels were observed, and pathological and electron microscopic studies were carried out. The vessels were found to be in good condition at the end of the 12 week observation period. These results strongly suggest that prolonged cryopreservation of vessels makes allotransplantation without immunosuppression possible.

Animals↗
PubMed1994

Sequential changes in intercellular junctions between hepatocytes during the course of acute liver injury and restoration after thioacetamide treatment.

Sequential changes of gap junctions (GJs), tight junctions (TJs) and desmosomes (DSs) between hepatocytes during restorative proliferation were studied in rats after a single intraperitoneal administration of 200 mg/kg thioacetamide (TAA). Antibody against connexin 32 was used to demonstrate GJs; simultaneously the changes in TJs and DSs were studied using antibodies against 7H6 protein and desmoplakins. Propidium iodide and bromodeoxyuridine were used to recognize necrotic and proliferative cells. GJs were evenly distributed in early necrotic hepatocytes at 16 h after TAA treatment, then disappeared from necrotic and surrounding cells at 24 h. At 48 h, GJs had disappeared completely from hepatocytes in whole liver lobules, while many hepatocytes were heavily labelled with BrdU. At 72 h, GJs reappeared, firstly in perinecrotic areas. At 96 h after treatment, when the injured areas had disappeared and restorative proliferation ceased, GJs were distributed evenly throughout the lobules. Immunohistochemical observation of GJs in centrilobular, perinecrotic and periportal areas after TAA-induced hepatic necrosis was confirmed by counting the number of connexin-32-positive spots in the respective areas. TJs and DSs disappeared from necrotic cells at 24 h, but then increased between 24 and 48 h in perinecrotic areas, though the increased intensity of these junctions was more evident at 48 h. At 72 h, localization of TJs and DSs returned to normal. These results suggest that during the course of acute hepatic injury, GJs (cell-cell communication) behave differently from other intercellular junctions.

Animals↗
PubMed1994

Changes in nasal airway resistance and secretory response in the guinea pig after nasal challenge with capsaicin and histamine.

We studied serial changes of nasal airway resistance (NAR) and secretory response after topical stimulation with either capsaicin or histamine, since both are known to stimulate a chemosensitive sensory C-fiber ending. After topical capsaicin stimulation, a dose-related increase of NAR was noted, with a peak response occurring at 10-20 min. These NAR responses were completely abolished following systemic pretreatment with capsaicin. However, they were not affected by atropine, diphenhydramine or hexamethonium pretreatment. After topical histamine stimulation, an atropine-resistant increase of NAR was found and continued more than 120 min. The early phase of this response was significantly suppressed by the systemic pretreatment with capsaicin. A secretory response also occurred after topical capsaicin stimulation and continued for 30 min. This secretory response was almost completely blocked by atropine, hexamethonium or systemic capsaicin pretreatment and was partially suppressed by diphenhydramine pretreatment. These findings suggest that sensory C-fiber stimulation can induce both atropine-resistant vascular reflexes and atropine-sensitive secretory reflexes, and that these reflexes might play an important role during the early phase after nasal stimulation.

Administration, Intranasal↗
PubMed1994

A rapid method for detecting barbiturates in serum using EI-SIM.

A simple and rapid method for analysis of barbiturates in serum has been developed. In order to extract and clean barbiturates in serum, a separation column packed with Extrelut and Florisil was used, and the eluate was directly analyzed by means of electron impact selected ion monitoring (EI-SIM). Selected ions used were base peak ions of 10 barbituartes, and the internal standard used was allobarbital or secobarbital. The calibration curves were linear over the range 0.5-5 ng. Extraction of replicate serum samples containing 20 micrograms/1.5 ml and 5 micrograms/1.5 ml resulted in a recovery of 87.2-105.2% and 81.6-104.6%, respectively, with the exception of phenobarbital, which was 151.9% and 172.1%, respectively. Secobarbital was also analyzed in the serum of 13 patients who had been given secobarbital intravenously. In 3 out of 10 cases, secobarbital levels greater than 1 micrograms/ml were detected more than 72 h after administration. This method seems to have possibilities for clinical use.

Adult↗
PubMed1994

A comparative study usefulness of magnetic resonance imaging in the diagnosis of acute cholecystitis.

The utility of magnetic resonance imaging (MRI) in the diagnosis of acute cholecystitis was evaluated in 72 consecutive individuals (5 healthy, 13 with chronic cholecystitis and silent gallbladder stones, 43 without biliary or diffuse liver disease, and 11 with acute cholecystitis and gallbladder stones) with a 0.5-T superconducting unit. On the T1-weighted (500/20) and less T1-weighted axial spin-echo images (620/25), the liver/gallbladder signal intensity ratio (mean +/- SD) was 2.5 +/- 0.51 (n = 5) and 1.8 +/- 0.29 (n = 8) in acute cholecystitis; 0.9 +/- 0.42 (n = 6) and 1.0 +/- 0.29 (n = 9) in chronic cholecystitis; and 0.9 +/- 0.14 (n = 5) and 0.8 +/- 0.19 (n = 43) in normal gallbladder, respectively. Our results indicate that the liver/gallbladder signal intensity ratio on the T1-weighted image may be a simple and reliable indicator for the diagnosis of acute cholecystitis; we suggest further investigation to confirm these results.

Acute Disease↗
PubMed1994

Extended palmar advancement flap with V-Y closure for finger injuries.

The technique of using volar advancement flaps with V-Y closure to the fingers is described. It is possible to perform volar flap advancements up to 15 mm and use V-Y closures in the distal palm, avoiding a skin graft. This method is based on knowledge of the vascular anatomy of the finger dorsum, to avoid devitalising dorsal skin. This method was applied to 14 fingers of 13 patients including finger amputations, claw nail deformities, and skin defects of the middle phalanx. Favourable results were observed.

Adolescent↗
PubMed1994

Secondary correction of the bilateral cleft lip nose by excision of the columellar forked flap and nasal remodelling with reverse-U flaps: a preliminary report.

Although the forked flap procedure has been widely used as a technique to lengthen the columella in the bilateral cleft lip deformity, often the results are unfavourable. We describe a technique to achieve a more natural shape, in which the unsatisfactory forked flap is excised and the columella is reconstructed by mobilization and rotation of nasal skin, combined with bilateral reverse-U flaps. Five consecutive patients who underwent this secondary correction procedure are presented.

Adolescent↗
PubMed1994

Maturational changes in superoxide anion production of rabbit alveolar macrophages.

We investigated the effect of maturation on the superoxide anion production of rabbit alveolar macrophages by endothelin-1, N-formyl-methionyl-leucyl-phenylalanine, and phorbol 12-myristate 13-acetate. The O2- production by phorbol 12-myristate 13-acetate in young (0.2-0.3 kg) rabbits was as high as that in adult (3.0-3.5 kg) rabbits. However, when alveolar macrophages were stimulated by N-formyl-methionyl-leucyl-phenylalanine or preincubated with endothelin-1 before phorbol 12-myristate 13-acetate stimulation, O2- production of young rabbits was relatively weak compared to adult rabbits. The present data indicate that the ability of O2- production is sufficiently developed with a chemotactic peptide which directly stimulates protein kinase C.

Aging↗
PubMed1994

Meconium-induced lung injury mediated by activation of alveolar macrophages.

To clarify the mechanism of meconium-induced cellular injury, we examined the effect of meconium on the alveolar macrophages (AM) and bronchial epithelial cells (AK-D). Meconium obtained from healthy newborns was added to culture medium of AM and/or AK-D, which were cultured for 1 hour. Superoxide anion production of AM and the expression of intercellular adhesion molecule-1 (ICAM-1) on AK-D stimulated by meconium or oxygen radicals were determined. As a result, superoxide anion production of AM significantly increased when AM was cultured with meconium. Expression of ICAM-1 on AK-D appeared when AK-D was stimulated by hydroxyl radical but did not when AK-D was cultured with meconium. These results suggest that meconium-induced lung injury may occur through an activation of alveolar macrophages and the macrophage-epithelial cell axis may be important for the pathogenesis of meconium aspiration syndrome.

Animals↗