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T Kamiya

Publications and source records attributed to T Kamiya.

At least 91 records · Page 5Linked to original sources
PubMed1998

Hemolysis complicating coil occlusion of patent ductus arteriosus.

We report on 5 patients who developed hemolysis (the Hemolysis group) following coil occlusion for PDA, and compare their data to 66 cases which were not complicated by hemolysis despite residual leak (the No Hemolysis group). A significant leak with a heart murmur was more frequent in the Hemolysis group than in the No Hemolysis group. The ratio of the sum of the loop diameter of coils to the minimal diameter of the ductus (C/D) in those who developed persistent hemolysis that needed a second intervention (2.2+/-0.4) was significantly smaller than in the No Hemolysis group (3.1+/-1.1). Persistent hemolysis can occur if a significant residual shunt remains after implantation of coils with small C/D. As this complication may be avoided by complete closure or, if not complete, a minimal leak, we should be careful to make residual leaks as small as possible by the use of multiple coils.

Anemia, Hemolytic↗
PubMed1998

Genomic organization and mutational analysis of HERG, a gene responsible for familial long QT syndrome.

Familial long QT syndrome (LQTS) is characterized by prolonged ventricular repolarization. Clinical symptoms include recurrent syncopal attacks, and sudden death may occur as a result of ventricular tachyarrhythmias. Three genes responsible for this syndrome (KVLQT1, HERG, and SCN5A) have been identified so far, and mutations have been reported on the basis of partially characterized genomic organization. To optimize the search for HERG mutations, we have determined the genomic structure of HERG and investigated mutations in LQTS families. Human genomic clones containing the HERG gene were isolated from a human genomic library by using reverse-transcribed polymerase chain reaction (RT-PCR) products from this gene as probes. We determined exon/intron boundaries and flanking intronic sequences by using primers synthesized on the basis of the HERG cDNA sequence available in the DNA database. HERG was shown to consist of 15 exons spanning approximately 19 kb on chromosome 7q35. Subsequently, we synthesized oligonucleotide primers to cover the entire coding region and searched for mutations in 36 Japanese LQTS families. When genomic DNA from each proband was examined by the PCR/single-strand conformation polymorphism technique followed by direct DNA sequencing, five novel mutations were detected. Each mutation was present in affected relatives of the respective proband. This work should increase the efficiency of screening mutations associated with HERG.

Amino Acid Sequence↗
PubMed1998

Effects of trimebutine maleate on gastric motility in patients with gastric ulcer.

The effects of trimebutine maleate (TM), a prokinetic drug, on gastrointestinal motility in patients with gastric ulcer were investigated. Twenty patients with active gastric ulcers were allocated to two groups; 10 patients received a proton pump inhibitor alone (PPI group), given orally, and 10 patients received oral TM in combination with a PPI (PPI + TM group), each for a period of 8 weeks. Electrogastrography (EGG) and gastric emptying were measured before and after the treatment period. During the active ulcer stage, tachygastria (more than 0.06 Hz) or bradygastria (less than 0.04 Hz) in the EGG frequency were observed in 9 patients either before or after meals. During the healed ulcer stage, tachygastria or bradygastria was observed in 4 of 10 patients in the PPI group, while in the PPI + TM group, 1 patient had tachygastria and none had bradygastria. Postprandial dip (PD) was observed in 3 of the 20 patients during the active stage, while after treatment, PD was observed in 3 patients in the PPI group and in 6 patients in the PPI + TM group, respectively. Gastric emptying in the PPI group did not show any change between before and after treatment, while that in the PPI + TM group improved significantly after treatment. These results suggest that TM may have an ameliorative effect on abnormal gastric motility in patients with gastric ulcer.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1998

A simplified model of hypoxic injury in primary cultured rat hepatocytes.

The Anaeropack system for cell culture, which was originally designed for the growth of anaerobic bacteria, was used to produce a hypoxic atmosphere for cultured hepatocytes. We measured changes in the oxygen and carbon dioxide concentrations and the atmospheric temperature in an airtight jar. We also measured changes in the pH of the medium during hypoxia to assess the accuracy of this system. Moreover, we used three durations (2, 3, and 4 h) of hypoxia and 8 h of reoxygenation in cultured rat hepatocytes, and then measured the lactate dehydrogenase (LDH), ketone body concentration (acetoacetate + beta-hydroxybutyrate), and the ketone body ratio (KBR: acetoacetate/beta-hydroxybutyrate) in the medium in order to assess the suitability of this system as a model for reperfusion following liver ischemia. The oxygen concentration dropped to 1% or less within 1 h. The concentration of carbon dioxide rose to about 5% at 30 min after the induction of the hypoxic conditions, and was maintained at this level for 5 h. No effect of the reaction heat produced by the oxygen absorbent in the jar was recognized. The extent of cell injury produced by changing the hypoxic parameters was satisfactorily reflected by the KBR, the ketone body concentration, and the LDH activity released into the medium. Because this model can duplicate the conditions of the hepatocytes during revascularization following ischemic liver, and the Anaeropack system for cell culture is easy to manipulate, it seems suitable for the experimental study of hypoxic injury and revascularization in vitro.

Animals↗
PubMed1998

Effects of administration of monoclonal antibodies (anti-CD4 or anti-CD8) on the development of autoimmune diseases in (NZW x BXSB)F1 mice.

(NZW x BXSB)F1 (W/BF1) mice spontaneously develop autoimmune diseases, characterized by lymphadenopathy, lupus nephritis, and immune thrombocytopenia associated with various autoantibodies such as anti-DNA, anti-platelet and anti-cardiolipin antibodies (Abs). In the present study, we investigate the effects of administration of monoclonal Abs (anti-CD4 or anti-CD8 mAb) on the development of autoimmune diseases in W/BF1 mice. MAb was administered from the age of 7 weeks. Prolongation of survival rate and reduction of severity of autoimmune diseases were observed after treatment with anti-CD4 mAb. However, anti-CD8 mAb treatment accelerated the diseases. Serum levels of IFN-gamma and IL-10 in old W/BF1 mice were significantly high, whereas IL-4 levels were low in comparison with those of young W/BF1 mice; the expression of mRNA of IFN-gamma, IL-4 or IL-10 in CD4+ T cells of old W/BF1 mice was parallel to the serum levels of each cytokine. These observations suggest that CD4+ cells are involved in the development of autoimmune diseases in W/BF1 mice, and that CD8+ cells have a suppressive effect on the development of autoimmune diseases in W/BF1 mice.

Age Factors↗
PubMed1998

Change of antigenic and neutralizing specificity in substitutional epitope peptides of hemophilia B inhibitor.

We have previously described the epitope mapping and functional neutralization of three factor IX inhibitors in hemophilia B (HB-1, 3, and 7) by synthetic peptides (13). However, A concentration of synthetic peptide of about 1000 times the concentration of factor IX in plasma was essential to neutralize the purified antibodies. We now report that substitutional synthetic peptides of epitope are able to neutralize the factor IX inhibitor with a lower concentration. Using two major epitope peptides, 156Val-Asn-Ser-Thr-Glu-Ala-Glu-Thr-Ile164 and 168Ile-Thr-Gln-Ser-Thr-Gln-Ser-Phe-Asn176, we designed changes of antigenicity using the systematic substitution of different amino acids at each residue of the epitope peptides and neutralization rate of factor IX inhibitors by a lower concentration of substitutional synthetic peptides conjugated with bovine serum albumin (BSA). Twenty-five substitutional peptides for HB-1, twenty substitutional peptides for HB-3 and forty-four substitutional peptides for HB-7 reacted stronger than the native sequences. One of the peptides, 1.0 microM of 156Val-Asn-Ser-Thr-Glu-Tyr-Glu-Thr-Ile164 conjugated with BSA, neutralized 26.5% of inhibitor in HB-1's plasma maximally. Our data show that high antigenicity peptides conjugated with BSA ranging in concentration from 0.1 microM to 1.0 microM are able to neutralize factor IX inhibitors in plasma and there is a possibility of peptide neutralization inhibitor therapy.

Amino Acid Sequence↗
PubMed1998

Hair follicle elongation in organ culture of skin from newborn and adult mice.

By means of skin organ culture, some biological characteristics of hair follicle elongation were examined. When skin sections from 6-day-old C3H mice were cultured, spontaneous elongation of hair follicles was maintained. Without insulin, hair follicle elongation was poorly maintained irrespective of the presence of serum at 20%. Insulin could be replaced by IGF-I at 100 ng/ml. During in vitro elongation of hair follicles, bromodeoxyuridine was incorporated into germinal epithelial cells around dermal papillae. Skin sections from 4-week-old C3H mice did not show hair follicle elongation in complete medium. However, when 0.5 mM minoxidil was added to the medium, concentration dependent thickening and elongation of hair follicles was observed. In contrast, in vitro elongation of newborn pelage hair follicles was not enhanced by minoxidil. These results suggest that this system with the use of skin sections from 4-week-old C3H mice would be a potential in vitro model of human androgenic alopecia in which the anagen phase is suppressed but the suppression is partially released by minoxidil.

Aging↗
PubMed1998

Study of immunoelectron microscopic localization of cathepsin K in osteoclasts and other bone cells in the mouse femur.

The localization of cathepsin K protein in mouse osteoclasts was examined by immunolight and immunoelectron microscopy using the avidin-biotin-peroxidase complex method with anti-cathepsin K (mouse) antibody. With light microscopy, a strong immunoreaction for cathepsin K was found extracellularly along the bone and cartilage resorption lacunae and detected intracellularly in vesicles, granules, and vacuoles throughout the cytoplasm of multinuclear osteoclasts and chondroclasts attached to the surface of the bone or cartilage. Mononuclear cells, probably preosteoclasts, some distance from the bone also contained a few cathepsin K-positive vesicles and granules. Cathepsin K was sometimes found in the cisternal spaces of the rough endoplasmic reticulum and vesicles of the Golgi apparatus with electron microscopy of the basolateral region of the osteoclasts. Cathepsin K-positive vesicles and granules as lysosomal compartments were present in various stages of fusion with vacuoles as endosomal compartments that contained fragmented cathepsin K-negative fibril-like structures. Some of the vacuoles (endolysosomes), which seemed to be formed by this process of fusion, contained cathepsin K-positive vesicles and fibril-like structures that did not show the regular cross striation of type I collagen fibrils. In the apical region of the osteoclasts, cathepsin K-positive vesicles and pits had already fused with or were in the process of fusing with the ampullar extracellular spaces. There were large deposits of cathepsin K on fragmented fibril-like structures without regular cross striation in the extracellular spaces, as well as on and between the cytoplasmic processes of the ruffled border. There were also extensive deposits of cathepsin K on the type I collagen fibrils with cross striation in the bone resorption lacunae. Osteoblasts and osteocytes were negative for cathepsin K. In the immunocytochemical controls, no immunoreaction was found in the osteoclasts or preosteoclasts, or on the collagen fibrils in the resorption lacunae. The results indicate that cathepsin K is produced in mature osteoclasts attached to the bone and secreted into the bone resorption lacunae. The findings suggest that cathepsin K participates in the extracellular degradation of collagen fibrils in the resorption lacunae and in the subsequent degradation of the fragmented fibrils in the endolysosomes. It is also suggested that cathepsin K degrades the organic cartilage matrix.

Animals↗
PubMed1998

Genes for thrombopoietin and c-mpl are not responsible for familial thrombocythaemia: a case study.

The underlying molecular basis for familial thrombocythaemia (FT). an extremely rare form of primary thrombocythaemia which occurs in an autosomal dominant manner, is currently unknown. We have investigated a family with FT and clarified whether we could detect alteration(s) in the genes coding for c-mpl and its ligand, thrombopoietin (TPO). There was no difference in platelet c-mpl mRNA expression levels between the affected and non-affected individuals in the family. Nucleotide sequence analysis of the c-mpl cDNA for the proband revealed no abnormality. We identified an intragenic tetranucleotide short tandem repeat system in the TPO gene and found non-linkage between the TPO locus and the FT phenotype. We conclude that genes for c-mpl and TPO are not responsible for thrombocythaemia in our FT family.

Adult↗
PubMed1998

Proanthocyanidins from grape seeds promote proliferation of mouse hair follicle cells in vitro and convert hair cycle in vivo.

For the purpose of discovering natural products which possess hair growing activity, we examined about 1000 kinds of plant extracts concerning growth-promoting activity with respect to hair follicle cells. After an extensive search, we discovered that proanthocyanidins extracted from grape seeds promote proliferation of hair follicle cells isolated from mice by about 230% relative to controls (100%); and that proanthocyanidins possess remarkable hair-cycle-converting activity from the telogen phase to the anagen phase in C3H mice in vivo test systems. The profile of the active fraction of the proanthocyanidins was elucidated by thiolytic degradation and tannase hydrolysis. We found that the constitutive monomers were epicatechin and catechin; and that the degree of polymerization was 3.5. We demonstrated the possibility of using the proanthocyanidins extracted from grape seeds as agents inducing hair growth.

Animals↗
PubMed1998

Fluorescence microscopic demonstration of cathepsin K activity as the major lysosomal cysteine proteinase in osteoclasts.

The enzyme activity of lysosomal cysteine proteinases in vital rabbit osteoclasts and mouse osteoclast-like cells was visualized with Z-Leu-Arg-4-methoxy-beta-naphthylamide (Z-LR-MNA) as the enzyme substrate. The MNA liberated by proteolysis forms a fluorescent insoluble Schiff-base product in the presence of 5-nitrosalicylaldehyde. Many small fluorescent particles, endproducts of the Z-LR-MNA hydrolysis, were observed in proximity to the bone surface underneath the actively resorbing osteoclasts, as well as in the cytoplasm. The Z-LR-MNA hydrolase activity was markedly diminished by bafilomycin A1 and chloroquine treatment. Moreover, the activity was completely inhibited by cysteine proteinase inhibitors such as leupeptin and E-64d, but not by other classes of proteinase inhibitors. About 60% of the hydrolase activity in mouse osteoclast-like cells was immunoabsorbed by anti-cathepsin K antibody-coupled Sepharose CL-4B beads, and about 10% of the activity was absorbed with the anti-cathepsin L antibody-coupled beads. Thus, the majority of the Z-LR-MNA hydrolase activity in osteoclasts was derived from cathepsin K. In contrast, using the same substrate in the assay, no detectable cathepsin K activity was observed in mouse peritoneal macrophages. The abundant cathepsin K activity in osteoclasts would therefore indicate a significant role of this enzyme in bone matrix degradation.

Amino Acid Sequence↗
PubMed1998

Surface marker patterns of T cells and expression of interleukin-2 receptor in measles infection.

The surface marker patterns of T cells of Ghanaian children during measles infection were studied and an attempt was made to demonstrate T cell activation and viability in vitro after activation in vivo by measles virus. The frequencies of CD4+ and CD8+ naive T cells in measles patients were high while their memory T cells were remarkably reduced with no sign of proliferation even at the acute phase of the illness. The reduction of memory T cells was prolonged during the convalescent phase (2 months after onset). The anti-CD3 monoclonal antibody-induced expression of interleukin-2 receptor alpha chain (IL-2R/CD25) was significantly suppressed; however, the addition of phorbol 12-myristate 13-acetate or ionomycin caused a remarkable recovery of CD25 expression. On simple culture, an appreciable proportion of T cells from measles patients died rapidly in contrast with only a few T cells from healthy controls doing so. The suppression of CD25 expression was still demonstrated during the convalescent phase of the disease. Taken together these results suggest unresponsiveness and activation-induced cell death of T cells during severe measles infection in Ghanaian children. Furthermore the prolonged abnormalities of T cells (i.e. decreased memory T cells and inhibition of CD25 expression during the convalescent phase) might be related to post-measles infection immunosuppressive status.

Antigens, Surface↗
PubMed1998

Coronary risk factors in acute Kawasaki disease: correlation of serum immunoglobulin levels with coronary complications.

BACKGROUND: To determine the usefulness of the IgG z-score (age and sex-standardized serum IgG level) before intravenous gamma globulin therapy (IVGG) in predicting the occurrence or severity of coronary complications in Kawasaki disease (KD). METHODS: A case-control study of clinical and laboratory findings with 88 children in the early stage of acute KD who received IVGG (100 or 200 mg/kg for 2-5 days) therapy. Of these, 20 cases had persistent coronary arterial lesions (small aneurysm, moderate aneurysm or large aneurysm persisting more than 1 month). The controls comprised 68 children with no coronary aneurysms or transient small aneurysm only observed within 1 month after the onset of KD. The association between serum levels of immunoglobulin G (IgG). IgM, IgA as well as other coronary risk factors previously reported and the occurrence of the coronary arterial lesions was evaluated using logistic regression analysis. RESULTS: After adjustment for age, gender, total IVGG dose before the 9th illness day and other traditional coronary risk factors, the odds ratio for the persistent coronary aneurysm associated with lower serum IgG z-score (< -0.7485 vs > or = -0.7485), was 30.3 (95% confidence interval, 3.8-243.2). Furthermore, the serum IgG z-score was inversely correlated with the severity of the coronary arterial lesion. CONCLUSIONS: The IgG z-score before IVGG therapy in the early stage of KD provides useful information on the risk factors for persistent coronary aneurysm and is a novel, additional indicator for therapy to prevent the coronary complications in acute KD.

Case-Control Studies↗
PubMed1998

Cavitary pulmonary metastases of gallbladder cancer.

We report a case of multiple cavitary pulmonary metastases of gallbladder cancer. Radiologically, every cavity displayed a very thin wall containing only air inside. The postmortem histopathological examination showed that: (1) the cavities were surrounded by normal alveoli; (2) these walls were composed mostly of adenocarcinoma cells; (3) necrotic or mucous substance was sparse in the cavity space; (4) cancer cells infiltrated along the surface of the alveolar septa, and (5) the morphology of the cancer cells of the gallbladder and the lung was the same. It seemed likely that the thin-walled cavities in the lung might result from central breakdown of the tumor and subsequent expectoration of debris through the connected airways.

Adenocarcinoma↗
PubMed1998

Transcatheter occlusion of patent ductus arteriosus with a new detachable coil system (DuctOcclud): a multicenter clinical trial.

A multicenter clinical trial of DuctOcclud, a new detachable coil for transcatheter occlusion of patent ductus arteriosus (PDA), was conducted. DuctOcclud was used in 35 patients (12 male and 23 female) for transcatheter occlusion of PDA between January, 1996, and April, 1997. The age of the patients ranged from 0.5 to 27.2 years (median 7.6 years) and weight from 6.3 to 70.0 kg (median 23.0 kg). The smallest diameter of PDA was 2.0+/-0.7 mm (range 1.0-3.3 mm). Pulmonary-systemic flow ratio (Qp/Qs) was 1.3+/-0.3 (range 1.0-2.2). The coils were successfully implanted in 32 (91%) patients. Of 31 patients who were followed 6 months after the procedure, 26 (84%) had no residual shunt and 5 (16%) had trivial residual shunt. One patient had infective endocarditis 1 month after the procedure but recovered completely. There were no incidences of coil embolization, hemolysis, late coil migration, or pulmonary artery stenosis. We conclude that DuctOcclud is a safe and effective device of transcatheter occlusion of PDA.

Adolescent↗