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Biomedical subjects

J Taguchi

Publications and source records attributed to J Taguchi.

At least 55 records · Page 3Linked to original sources
PubMed1998

Increased aggregation of human platelets produced by advanced glycation end products in vitro.

Advanced glyco-oxidation end products (AGEs) generate oxygen free radicals that potentiate the development of atherosclerosis. Thus, AGEs may potentiate the aggregation of human platelets through oxidative stress. AGE-bovine serum albumin (BSA) and AGE-poly-L-lysine were evaluated for aggregation of human platelets. Superoxide in platelet-rich plasma (PRP) was measured using lucigenin-derived chemiluminescence. The platelet aggregation induced by ADP or U46619 was potentiated by preincubation with AGE-BSA, by 40% and by 59%, P < .05, respectively, vs BSA. Aggregation was increased by AGEs in a dose-dependent manner. The production of superoxide was significantly greater in PRP incubated with AGE-BSA vs BSA. The other Maillard reaction products, such as Amadori-, pentosidine-, and carboxymethyl lysine (CML)-BSA had no effect. Superoxide dismutase or indomethacin abolished the enhancing effect of AGEs on the platelet aggregation. AGEs potentiate platelet aggregation possibly with superoxide anions and prostanoids. AGE-induced potentiation of platelet aggregation may be involved in the development of atherosclerosis.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
PubMed1998

Interleukin-13 receptor alpha' but not alpha chain: a functional component of interleukin-4 receptors.

In hematopoietic cells, interleukin-2 receptor (IL-2R) gamma chain (termed gammac) is shown to be a component of the IL-4R system, whereas in nonhematopoietic cells, gammac is absent and it is not a component of the IL-4R system. Here, we show that the IL-13R alpha' chain (termed IL-13Ralpha') but not the IL-13R alpha chain (termed IL-13Ralpha) can substitute for gammac and, thus, IL-13Ralpha' forms a novel component of the IL-4R system. This conclusion was drawn on the basis of chemical cross-linking, immunoprecipitation, the ability of IL-13Ralpha' but not IL-13Ralpha to augment IL-4 binding affinity, and the requirement of IL-13Ralpha' for IL-4-induced STAT6 activation in Chinese hamster ovary (CHO) cells transfected with various receptor subunits. Cotransfection of IL-4 receptor p140 (termed IL-4Rbeta) with gammac or IL-13Ralpha' increased IL-4 binding affinity and allowed for STAT6 activation in response to IL-4. However, cotransfection of all three chains did not further increase IL-4 binding or alter the extent of STAT6 activation suggesting that all three chains together do not seem to participate in IL-4 function. Instead, IL-4Rbeta heterodimerizes with gammac or IL-13Ralpha' and mediates STAT6 activation. Cotransfection of IL-4Rbeta with IL-13Ralpha neither increased IL-4 binding affinity nor allowed for STAT6 activation in response to IL-4 indicating that IL-13Ralpha does not convert binding affinity nor transmit signals for IL-4. Because IL-4 phosphorylates JAK1 and JAK2 tyrosine kinases in nonhematopoietic cells, we investigated whether JAK1 and JAK2 are required for IL-4-induced STAT6 activation in various transfectants. Cotransfection experiments with different chains of IL-4R and kinase-deficient JAK1 and JAK2 mutants in CHO cells showed that JAK1 and JAK2 are required for optimal activation of STAT6 in the alpha' beta transfectant but only partially in the beta gammac transfectant. Taken together, our results show that IL-13Ralpha' is a novel functional component of the IL-4R system and that JAK1 and JAK2 mediate IL-4-induced optimal activation of STAT6 in nonhematopoietic cells.

Animals↗
PubMed1998

Novel guide catheter for left coronary intervention via a right upper limb approach.

We designed a novel guide catheter specifically for interventions to the left coronary artery via a right upper limb approach. The catheter has a novel first loop design which utilizes the angle between the right subclavian and innominate arteries for support. The first loop introduces the catheter into the correct position and generates powerful and coaxial back-up power. We report successful implantation of Palmaz-Schatz stents in five cases using this 6 Fr. catheter.

Aged↗
PubMed1998

White matter astrocytes produce hepatocyte growth factor activator inhibitor in human brain tissues.

Hepatocyte growth factor (HGF) is a potent mitogen for mature hepatocytes and also has multifunctional effects on some other cells in various organs. A HGF activator (HGFA) has been identified as a key enzyme that regulates the activity of HGF in vivo. Our previous studies have shown that brain astrocytes produce both proteins. Recently, HGFA inhibitor-1 (HAI-1), a novel Kunitz-type serine protease inhibitor, has been isolated. We examined HAI-1 immunolabeling in the brains of neurologically normal persons and patients with Alzheimer's disease (AD) and cerebral infarction. Furthermore, we identified the expression of the mRNA for HAI-1 by in situ hybridization histochemistry. The HAI-1 antibody stained astrocytes in the white matter of all brain tissues and was present in plasma. In AD, the intensity of HAI-1 immunolabeling was less than in the other cases. Expression of the mRNA for HAI-1 was also seen in astrocytes. The intensity of the signal for HAI-1 mRNA was similar in AD and normal control brains. These results suggest that, in human brain, secreted pro-HGF from astrocytes may be activated by HGFA and inhibited by HAI-1 on or near the astrocytic cell surface and that rapid HAI-1 consumption may occur in the white matter in AD.

Animals↗
PubMed1998

Diagnostic value of hemostatic parameters in bone marrow transplant-associated thrombotic microangiopathy.

We investigated hemostatic parameters in a prospective study of 16 patients who received bone marrow transplants (BMT). We found a significant rise in the levels of fibrinogen, plasmin-alpha2 antiplasmin inhibitor complex, tissue-plasminogen activator.plasminogen activator inhibitor complex (t-PA.PAI), von Willebrand factor antigen, and thrombomodulin on day 14 after transplant compared with values before transplant. Protein C and thrombin-antithrombin III levels did not change significantly. No significant changes in prothrombin time ratio, activated partial thromboplastin time, or protein S were detected. Patients who had grades II-IV graft-versus-host disease (GVHD) (n = 6) showed a significantly higher level of t-PA.PAI on day 14 compared with those with grades 0-I GVHD (n = 10) (P = 0.0062). Three patients with grades II-IV GVHD developed thrombotic microangiopathy (TMA) on days 19, 19 and 62. In these patients, we noted significantly lower levels of fibrinogen (P = 0.0383), and significantly higher levels of t-PA.PAI (P = 0.0008) and thrombomodulin (P = 0.0001) on day 14 compared with those patients who did not develop TMA. These results suggest that prothrombotic states and endothelial damage may be caused by the conditioning regimen and/or acute GVHD during BMT; thrombomodulin values on day 14 post BMT may be useful in surveillance for TMA because of endothelial cell injury.

Adolescent↗
PubMed1998

Human parvovirus B19 capsid antigen in granulocytes in parvovirus-B19-induced pancytopenia after bone marrow transplantation.

A patient with refractory anemia with an excess of blasts in transformation developed pancytopenia and a concurrent interstitial pneumonia 110 days after allogeneic bone marrow transplantation. Bone marrow examination showed 0.4% giant proerythroblasts and 86.2% granulocytes, some of them large with a bizarre configuration and the others of normal size. Serum folate level was found low, 0.6 ng/ml. Immunocytochemistry with a B19-specific monoclonal antibody MAB8292 revealed B19 capsid antigen only in erythroblasts and large, bizarre granulocytes, but not in granulocytes of normal size. In situ hybridization of bone marrow cells using digoxigenin-labeled DNA probes detecting parvovirus B19 also demonstrated positive signals in 8.5% of marrow cells. Parvovirus B19 DNA was isolated from the serum and the bronchoalveolar lavage fluid of this patient by the polymerase chain reaction. These findings suggest that neutropenia may be caused by an involvement with parvovirus B19 though a deficiency of folic acid may have in part contributed to the genesis of neutropenia in the patient. The relevance of parvovirus B19 to the interstitial pneumonia remains unclear.

Adult↗
PubMed1998

A quantitative method for determination of endothelial mRNA expression in vivo: induction of platelet-derived growth factor by endotoxin.

Quantitation of mRNA expression by endothelial cells in vivo has been limited to larger animals from which sufficient amounts of RNA could be isolated for Northern blot analysis. In the present study, we established a technique to isolate endothelial RNA from rat aortas using en face preparations. This RNA was not contaminated with RNA from smooth muscle cells as demonstrated by the absence of smooth muscle alpha-actin RNA. Following lipopolysaccharide (LPS) administration to rats, quantitation of platelet-derived growth factor (PDGF) ligand and receptor mRNA expression was carried out by competitive reverse transcriptase-polymerase chain reaction and normalized to glyceraldehyde-3 phosphate dehydrogenase. The results of the competitive reverse transcriptase-polymerase chain reaction were compared with those obtained by en face in situ hybridization. Aortic endothelium showed a 140-fold increase in PDGF-A mRNA expression 4 hours after LPS injection. Expression levels of this growth factor declined to near base line levels within 36 hours of the LPS injection. A 52-fold increase in PDGF-B mRNA was seen at 12 hours after LPS injection but expression levels were approximately 300-fold lower than for PDGF-A. These data indicate that changes in PDGF expression by endothelium in vivo can greatly exceed those observed in cultured cells. This method should permit study of endothelial gene regulation in a variety of pathological conditions in vivo.

Actins↗
PubMed1997

Genetic polymorphism of 5,10-methylenetetrahydrofolate reductase (MTHFR) as a risk factor for coronary artery disease.

BACKGROUND: Epidemiological studies have identified hyperhomocyst(e)inemia as an independent risk factor for coronary artery disease (CAD). Recently, the alanine/valine (A/V) polymorphism of the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene, one of the key enzymes catalyzing remethylation of homocysteine, has been reported. The VV genotype correlates with increased plasma homocyst(e)ine levels as a result of the reduced activity and increased thermolability of this enzyme. In this study, we examined the distribution of the MTHFR genotypes in Japanese men and the association between the VV genotype and CAD. METHODS AND RESULTS: The diagnoses of CAD of all the studied patients were confirmed by coronary angiography. The MTHFR genotype was analyzed by PCR followed by HinfI digestion. In 778 healthy male subjects, the frequency of the V allele was 0.33, comparable to that in a French Canadian population. In 362 patients with CAD, the VV genotype was significantly more frequent than in control subjects (16% versus 10%, P=.0067). The association of the VV genotype with CAD was further increased in patients with > or = 99% stenotic lesions (18%, P=.0010), whereas no significant association with the VV genotype was observed in patients without a > or = 99% stenosis. When the genotype frequency was compared among patients with different numbers of stenotic coronary arteries, the frequency of the VV genotype was significantly higher in patients with triple-vessel disease (26%) than in patients with single- or double-vessel disease (15% and 14%, respectively). CONCLUSIONS: The VV genotype of MTHFR was also common in the Japanese population and was significantly associated with CAD. The frequency of this genotype in particular was correlated with the severity of disease. The VV genotype associated with a predisposition to increased plasma homocyst(e)ine levels may represent a genetic risk factor for CAD.

5,10-Methylenetetrahydrofolate Reductase (FADH2)↗
PubMed1997

The evidence of clonal evolution with monosomy 7 in aplastic anemia following granulocyte colony-stimulating factor using the polymerase chain reaction.

We present here the case of a Japanese female patient with aplastic anemia who developed monosomy 7 and clonal evolution following a treatment with recombinant human granulocyte colony-stimulating factor (rhG-CSF). At the onset of aplastic anemia, cytogenetic analysis was 46, XX and X-inactivation/methylation analysis revealed a polyclonal pattern. After 4 months of administration of rhG-CSF, she had 45, XX, -7 and a clonal pattern, although there were no morphological evidence of a myelodysplastic syndrome or leukemia. The ratio of monosomy 7 to normal analyzed by fluorescence in situ hybridization decreased after discontinuation of rhG-CSF and there were still no dysplastic changes and/or increased numbers of blasts. These results indicate that the acquisition of monosomy 7 following rhG-CSF treatment dose not always cause clonal evolution to induce hematological malignancies.

Anemia, Aplastic↗
PubMed1997

Torsades de pointes complicating pentamidine therapy of Pneumocystis carinii pneumonia in acute myelogenous leukemia.

Pentamidine isethionate induced torsades de pointes in a 33-year-old woman with acute myelogenous leukemia. This is the first report of Pentamidine-induced torsades de pointes in Japan for over ten years. On the 4th day of intravenous pentamidine for Pneumocystis carinii pneumonia, asymptomatic sinus bradycardia was noted with QT interval prolongation, and torsades de pointes were revealed on the 8th day. Although torsades de pointes was dissolved with discontinuation of the intravenous pentamidine and administration of magnesium sulfate, sinus bradycardia and prolonged QT interval persisted. Ventricular pacing resulted in no arrhythmia and normalization of the QT interval on the 10th day after discontinuation of pentamidine. Careful monitoring of the electrocardiogram should be carried out during intravenous pentamidine therapy.

Adult↗
PubMed1997

alpha-Fetoprotein-producing rectal carcinoma--a case report.

A case with an alpha-fetoprotein (AFP)-producing carcinoma originating from the rectum is described. A 71-year-old male patient, who underwent a rectectomy for rectal carcinoma, developed space occupying lesions in the liver and a remarkable AFP elevation (220,000 ng/ml) in the 6th month postoperatively, and then expired one year later. Histologically, the rectal carcinoma consisted of well-differentiated adenocarcinomas, and contiguous cancerous cells proliferating in either a medullary or trabecular pattern. In the "trabecular" areas, localization of AFP was confirmed immunohistochemically. Results of concanavalin A or lens culinaris agglutinin affinity chromatography demonstrated that it was between a hepatic type and a yolk sac type, and was considered to be an intestinal type. This could have been an AFP-producing rectal carcinoma, in which the patient experienced liver metastasis at a relatively early postoperative period and died. This shows that AFP-producing rectal carcinomas are highly malignant, biologically, similar to AFP-producing gastric cancers.

Adenocarcinoma↗
PubMed1997

[A case of olfactory neuroblastoma with intracranial, intraorbital extension and multiple metastases].

A 51-year-old man presented with headache, vomiting and exophthalmus. Neurological examination revealed anosmia, papilledema, decrease in visual acuity, and disability in ocular movement. MRI showed a huge mass which occupied the whole nasal cavity and compressed the frontal lobe upwards and the eyes laterally. CT revealed an extensive bony destruction of the frontal base and bilateral orbits. The mass was biopsied transnasally, and was histologically diagnosed as olfactory neuroblastoma. It was highly radiosensitive and disappeared with a local irradiation of 40 Gy. Three months later the patient complained of a pain radiating from the neck to the right arm. MRI demonstrated a metastasis at the vertebral body of C5. Local irradiation of 30 Gy was performed. The metastatic lesion was removed, and a bone graft taken from the iliac bone was transplanted via an anterior cervical approach. Three weeks later, however, a hard mass appeared in the right of his neck and was surgically removed. By histological examination, it was also identified as a metastatic neuroblastoma to the cervical lymph node. A week after the removal of the cervical metastatic lesion, the metastasis extended rapidly to the left cervical and the bilateral hilar lymph nodes of the lungs. Chemotherapy was performed with a total doses of 800mg of cyclophosphamide, 1.5mg of vincristine, 40mg of pirarubicin, and 80mg of cisplatin. The lesions disappeared within 7 days. However, the patient died from disseminated intravascular coagulation 10 months after the onset. Olfactory neuroblastoma is usually an intranasal neoplasm, but it rarely extends intracranially and intraorbitally as is shown in our case. Basically, olfactory neuroblastoma is a relatively slow-growing tumor though it has a tendency to develop local recurrences over long periods even after aggressive primary treatment, and accompanied with distant metastases. However, our patient showed a very short survival time. Invasive extension and multiple metastases occurred during a short period, followed by disseminated intravascular coagulation. Combined chemotherapy at the initial treatment may be recommended in such an extensive case.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1997

[Gene Polymorphism of 5, 10-methylenetetrahydrofolate reductase as a coronary risk factor].

Hyperhomocysteinemia has been identified as a possible risk factor for coronary artery disease. The association of the alanine/valine (A/V) polymorphism of 5, 10-methylenetetrahydrofolate reductase (MTHFR), one of the key enzymes catalyzing re-methylation of homocysteine, with coronary artery disease was examined in 362 Japanese males with a diagnosis of coronary artery disease confirmed with coronary angiography. The A/V polymorphism was analyzed with PCR followed by Hinf I digestion. The screening of 778 male volunteer controls revealed that the frequency of V allele in Japanese was 0.33, comparable to that in the French Canadian population. The VV genotype, which correlates with increased plasma homocysteine levels due to reduced activity and increased thermolability of this enzyme, was significantly more frequent in patients with coronary artery disease (15.7%, n = 362) than in controls (10.2%, n = 778; p = 0.0067). The association of the VV genotype with coronary artery disease was further increased in patients with > or = 99% stenotic lesion (p = 0.0010). In these patients, the frequency of the VV genotype was significantly higher in patients with triple-vessel disease (26%) than in patients with single- or double-vessel disease (15% and 14%, respectively). The fasting plasma homocysteine levels in VV subjects were higher than those in AV or AA subjects. The VV genotype of MTHFR associated with increased plasma homocysteine levels may represent an important genetic risk factor for coronary artery disease, especially with the occurrence of myocardial infarction.

Adult↗
PubMed1997

[Successful treatment of subdural hematoma with operation in a patient with acute promyelocytic leukemia].

A 51 year-old male admitted with petechiae and headache. Acute promyelocytic leukemia (APL) with disseminated intravascular coagulation (DIC) was diagnosed. He received all-trans retinoic acid (ATRA) with enocitabine and daunomycin for induction chemotherapy, and supportive therapy for DIC. On 2nd day after admission, subacute subdural hematoma was confirmed with CT scan. He had anisocoria and disturbance of consciousness, and was treated with neurosurgical operation for his life saving on the 3rd day. Although DIC was continued at this time, the operation was done without problem. The recurrence of hematoma has not occurred after the operation. Furthermore, the findings of DIC disappeared by the day 6 following induction therapy. He achieved a complete remission including cytogenetic findings on 35th day after administration of ATRA and received 3 times of combination chemotherapy as consolidation therapy. It may be difficult to do neurosurgical treatment in the setting of DIC. However, we should consider whether the indications for surgery operation according to the condition of each patient.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1997

[A case with nasopharyngeal carcinoma extending into the cavernous sinus].

Nasopharyngeal carcinoma is seen frequently in South China, but it is rare in Japan as well as in Western countries. We reported a rare case with intracranial extension at the initial presentation. This 25-year-old Japanese female showed left abducens palsy. MRI revealed an intracavernous mass with homogeneous enhancement connected with the lesion around the epipharynx through the parapharyngeal space. The mass enlarged gradually, followed by left trigeminal palsy. An elevation of the titer of serum EBV Ig-G was noted. She was operated on via the subtemporal approach, which revealed an intracavernous tumor, connected with the infratemporal fossa mass via the enlarged foramen ovale. Histological examination of the surgical specimen revealed lymphoepithelioma. Local irradiation of 60Co of 63 Gy was performed on the cavernous and parapharyngeal tumors and they decreased in size remarkably. However, metastasis to the upper right neck lymph node occurred, and it was removed. Additional irradiation of 45 Gy was performed on her neck. Chemotherapy was not able to be carried out due to leucocytopenia. At present, 2 years after onset, no regrowth of the tumor has been seen. At initial presentation, intracranial extension of nasopharyngeal carcinoma is very rare. Remission may be obtained by a combination of surgery and irradiation even in cases with metastasis.

Adult↗
PubMed1996

Pure red cell aplasia after major ABO-incompatible bone marrow transplantation: two case reports of treatment with recombinant human erythropoietin.

A 34-year-old man with acute myelocytic leukemia (AML: MO) and a 32-year-old woman with AML: M2 developed pure red cell aplasia (PRCA) after receiving a major ABO incompatible bone marrow transplant (BMT). The first patient responded to recombinant human erythropoietin (rhEPO) therapy, while the second did not. The second patient also received methylprednisolone (m-PSL) but developed reticulocytosis and hemolysis after the administration of m-PSL. Plasmapheresis was then performed and the patient promptly recovered from hemolysis and PRCA. We conclude that close attention must be paid when treating PRCA following major ABO-incompatible BMT with rhEPO and m-PSL, as there is always the potential for massive hemolysis.

ABO Blood-Group System↗