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Biomedical subjects

T Takagi

Publications and source records attributed to T Takagi.

At least 487 records · Page 27Linked to original sources

Changes in plasma atrial natriuretic peptide during hemodialysis: mechanism of elevated levels in patients with chronic renal failure.

An elevated plasma atrial natriuretic peptide (ANP) concentration was observed in patients with chronic renal failure, and it was significantly (P < 0.01) decreased by hemodialysis with or without fluid removal. The ANP concentration was decreased by dialysis without fluid removal and the decrease was significantly (P < 0.01) correlated with the pre-dialysis value. The decrease in this peptide during fluid removal without diffusion was significantly (P < 0.05) correlated with the decrease in the circulating plasma volume measured by dye dilution. The decrease in the ANP level was therefore considered to be related to a fall in right atrial pressure caused by the decline in the circulating plasma volume. The circulating plasma volume, osmotic pressure, and blood pressure were not changed by hemodialysis without fluid removal. Moreover, the filtrate concentration of ANP (mean: 5.5 pg/ml) during fluid removal without dialysis was only about 8% of the plasma level, so filtration of ANP from the dialyzer was negligible. The decrease in ANP during hemodialysis without fluid removal may therefore have been caused by the removal of or a change in the level of substances, for example electrolytes, epinephrine, and uremic toxins. In addition to volume expansion, such a substance(s) might influence plasma ANP levels in patients with chronic renal failure.

Adult↗

Erythroderma and marked atypical lymphocytosis mimicking cutaneous T-cell lymphoma probably caused by phenobarbital.

A 56-year-old man had been treated with phenobarbital seven weeks prior to admission. One month after initiation of administration of phenobarbital, fever, skin rash and lymphadenopathy occurred. Nine days later, marked atypical lymphocytosis, eosinophilia and hepatic injury was noticed. The histology of the biopsied skin was indistinguishable from lymphoma. CHOP-therapy was started but the patient was followed without further treatment because of polyclonal T-lymphocytosis. Afterward, clinical and hematologic improvement ensued and he has been well until now, 52 months later. The marked T-lymphocytosis observed in this case is probably a lymphoid leukemoid reaction secondary to hypersensitivity to phenobarbital.

Dermatitis, Exfoliative↗

Characteristics of histamine receptors in human cerebral arteries.

Histamine and 2,2-pyridylethylamine, an H1-receptor agonist, (both 10(-8)-10(-3) M) caused contraction of human cerebral artery preparations in the absence of active tension, while dimaprit, an H2-receptor agonist, caused vasorelaxation. The histamine-induced vasoconstriction was blocked non-competitively by tripelennamine, an H1-receptor antagonist. In the presence of cimetidine, an H2-receptor antagonist, histamine-induced contraction was enhanced. The histamine-induced contraction was not affected by phentolamine or propranolol, but abolished by nifedipine. In prostaglandin F2 alpha-precontracted arteries, histamine and dimaprit caused relaxation, while 2,2-pyridylethylamine had no apparent effect. Histamine-induced relaxation was much greater in the presence than in the absence of an H1-antagonist. The vasorelaxation induced by histamine in the presence of an H1-antagonist was also inhibited by an H2-antagonist. Histamine caused no apparent relaxation in precontracted preparations without endothelium. The present results provide further evidence that histamine causes either vasocontraction or vasodilation in human cerebral arteries, and suggest that vasocontraction and vasorelaxation are due to the activation of H1- and H2-receptors, respectively. The relaxation induced by histamine may also be related to the endothelium-derived relaxing factors released from endothelial cells.

Aged↗

Acute obstructive hydrocephalus caused by a migrating intraventricular calculus. Case report.

A 10-year-old boy presented with acute obstructive hydrocephalus caused by the impaction of a calculus on the cerebral aqueduct. The calculus migrated from the third ventricle to the fourth ventricle after ventricular drainage and right ventriculoperitoneal shunt placement had been performed. The nature and origin of the calculus could not be determined, although its release from the choroid plexus in the lateral ventricle is highly possible.

Acute Disease↗

N-terminal amino acid sequences of 440 kDa hemoglobins of the deep-sea tube worms, Lamellibrachia sp.1, Lamellibrachia sp.2 and slender vestimentifera gen. sp.1 evolutionary relationship with annelid hemoglobins.

The deep-sea tube worm Lamellibrachia, belonging to the phylum Vestimentifera, contains two types of extracellular hemoglobins, a 3,000 kDa hemoglobin and a 440 kDa hemoglobin. The latter hemoglobin is composed of four heme-containing chains with molecular masses of 16-18 kDa. We have collected Lamellibrachia sp.1, Lamellibrachia sp.2 and Slender vestimentifera gen. sp.1 from the deep-sea cold-seep or hydrothermal areas at a depth of 1100-1400 m. The four constituent chains of the 440 kDa hemoglobin were isolated from each of the three tube worms by reverse-phase chromatography, and the N-terminal amino acid sequences of 16-44 residues were determined by automated protein sequencer. The amino acid sequences of the homologous chains showed high homology (76-85%), suggesting that they are closely related. The sequences also showed 45-49% homology with annelid hemoglobins. A phylogenetic tree constructed from hemoglobin sequences showed that the tube worm Lamellibrachia, the polychaete Tylorrhynchus and the oligochaete Lumbricus diverged from a common ancestor at almost the same time, about 450 million years before present.

Amino Acid Sequence↗

[Regional phacomatosis with cerebral AVMs and cavernous hemangioma of the skull--report of a case].

We report the coexistence of multiple arteriovenous malformations (AVMs) and hemangioma of the skull in a 38-year-old man with associated varicose veins in his scalp. The patient also had hypotrophy of all right limb tissues with skin pigmentation and syndactyly of both feet. CT scans revealed intraventricular hemorrhage and a hemangioma of the skull at the posterior fossa. Because of the location of the arteriovenous malformations, surgical evacuation and resection were not attempted. The hemangioma was totally removed to decompress the posterior fossa. A few cases of regional phacomatosis with intracranial AVMs have been reported, but we could not find a report of the coexistence of intracranial multiple AVMs and hemangioma of the skull with associated varicose veins of the scalp and skeletal hypotrophy. We discuss on the etiology of the coexistence of regional phacomatosis and hemangioma and on the difference between our case and typical regional phacomatosis.

Adult↗

[Alternating CHOP-MEVP chemotherapy for advanced-stage, intermediate- and high-grade non-Hodgkin's lymphomas].

Twenty-one patients with advanced-stage, intermediate- and high-grade non-Hodgkin's lymphomas were treated with alternating CHOP-MEVP chemotherapy. CHOP therapy consisted of CPA 650 mg/m2, ADM 45 mg/m2, VCR 1.4 mg/m2 and Pred 40 mg/m2 (po). MEVP therapy consisted of MIT 10 mg/m2 (iv) VDS 2 mg/m2 (iv) on day 1, etoposide 200 mg/m2 (po) on days 1-3, and Pred 40 mg/m2 (po) on days 1-5. Three courses of CHOP therapy and MEVP therapy were alternatively administered every three weeks. CR was achieved in 15 (71.4%) of 21 patients. Survival rate and relapse-free rate at 2 years for all 21 patients were 61.9% and 30.9%, respectively. Toxicity was generally tolerable except for CMV interstitial pneumonitis in a patient with IBL-like T-cell lymphoma and secondary leukemia in a patient with T-cell lymphoma. Chemotherapy of higher dose intensity is required to improve the relapse-free survival rate in these subsets of lymphoma.

Adult↗

[Initial anthracycline-based chemotherapy without radiotherapy in patients older than 70 years with localized lymphoma arising from Waldeyer's ring].

Between July 1982 and November 1992 twenty-six patients older than 70 years with localized stage of non-Hodgkin's lymphoma (NHL) arising from Waldeyer's ring were treated with initial chemotherapy consisting of anthracycline-based combination chemotherapies without regional radiotherapy in Saitama Cancer Center and Chiba Cancer Center. Patients with stage I-II were eligible for this study. There were 9 men and 17 women, ranging in age from 70 to 86 years with a median age of 77. Eight patients were aged over 80. The initial chemotherapy consisted of 400 mg/m2 of cyclophosphamide iv on day 1, either 40 mg/m2 of adriamycin or 40 mg/m2 of epirubicin iv on day 1, 2.0 mg/m2 of vindesine iv on day 1 and 40 mg/m2 of prednisolone po for 5 days. This combination chemotherapy was repeated every 4 weeks and given 6-10 cycles. There were 4 cass of stage I disease and 22 cases of stage II disease. Histologic subtypes were follicular large (1 case), diffuse large (16 cases), diffuse mixed (4 cases), and diffuse medium (4 cases). A complete response was obtained in 23 (88%) of the 26 patients. The median courses of chemotherapies in complete responders were 6 (range, 2-10). There were 7 recurrences among the 23 responders. The complete response was well sustained with an actuarial relapse-free survival of 59% at 5 years. To date 9 patients expired, four after a recurrence, four under complete remission and the remaining one without attaining CR. The survival curve of all patients became flat at 56 months and was well sustained with an actuarial survival of 34%.

Aged↗

Ultrastructure of calcified muscle fibres at the implantation site of demineralized bone matrix gelatin.

To clarify the mechanism of calcification during new bone formation induced by demineralized bone matrix gelatin (BMG), BMG was implanted into the skeletal muscle of Sprague-Dawley (SD) rats and histological changes were examined 1,2,3,5,7 and 10 days later. From day 2 after implantation, calcification was observed in muscle fibres near the implanted BMG. Calcification of the BMG ('acellular mineral deposition') was first seen on day 3 and in both, calcification increased. The calcification of muscle fibre was first seen in the sarcoplasmic reticulum (SR) and then in mitochondria or lipid droplet-like structures of satellite cells. The muscle mineral deposition occurred without osteogenic cells and matrix vesicles in the same way as 'acellular mineral deposition'.

Animals↗

[A fatal case of a hepatitis B virus carrier with fulminant hepatic failure after cytotoxic chemotherapy for malignant lymphoma].

A 48-year-old woman with malignant lymphoma, who was diagnosed as a hepatitis B virus (HBV) carrier because of positive HBs antigen, was admitted to Chiba Cancer Center Hospital. Complete remission was achieved by two courses of combination chemotherapy, but fulminant hepatitis developed after withdrawal of chemotherapy and she died of hepatic failure. Retrospective analysis of viral DNA disclosed a mutation in the precore region of HBV-DNA in her serum. We consider that the precoremutant virus was associated with the pathogenesis of severe hepatic failure after withdrawal of cytotoxic chemotherapy.

Antineoplastic Combined Chemotherapy Protocols↗

Technetium-99m(V)dimercaptosuccinic acid uptake in intra-abdominal massive deposit of amyloid protein.

Technetium-99m(V)dimercaptosuccinic acid (DMSA) scintigraphy was performed in two patients with pathologically confirmed primary amyloidosis. Both patients had tumor-like deposits of AL-type amyloid in the abdomen. Marked uptake of the tracer by the amyloid deposits was noted. Technetium-99m-(V)DMSA scintigraphy appears to be useful in detecting the distribution of amyloid deposits and in determining the appropriate site for biopsy.

Abdomen↗

A comparative study of CHOP versus MEVP (mitoxantrone, etoposide, vindesine, prednisolone) therapy for intermediate-grade and high-grade non-Hodgkin's lymphoma: a prospective randomized study.

To evaluate a new combination chemotherapy with mitoxantrone (MXT), etoposide (VP-16), vindesine (VDS), and prednisolone (MEVP therapy) as a front-line chemotherapy for non-Hodgkin's lymphoma (NHL), a prospective randomized study comparing this therapy (28 patients) with CHOP therapy (29 patients) was conducted in 57 patients with intermediate-grade or high-grade NHL with stages II-IV. The MEVP therapy consisted of 10 mg/m2 of MXT intravenously on day 1, 2 mg/m2 of VDS intravenously on day 1, 200 mg/m2 of VP-16 orally on days 1-3, and 40 mg/m2 of prednisolone orally on days 1-5. This regimen was repeated every 3 weeks for up to 10 courses. Complete responses (CR) were achieved in 17 (63.0%) of the 27 evaluable patients treated with MEVP therapy, and in 20 (71.4%) of the 28 evaluable patients treated with CHOP therapy. Relapse-free survival rates and overall survival rates at 3 years were 58.8% and 46.4%, respectively, for the MEVP group and 70.0% and 54.0%, respectively, for the CHOP group. Granulocytopenia was more severer and associated infection episodes were more frequent in the MEVP group. MEVP therapy was effective as a front-line chemotherapy for intermediate- and high-grade NHL, although it was not superior to CHOP therapy in treatment effect and was not less toxic than CHOP.

Adolescent↗

Nucleotide sequence of a complementary DNA for human ST2.

Human ST2 cDNA, a homologue of murine ST2 that is only expressed in growth-stimulated BALB/c-3T3 cells and a member of the primary response gene family induced by growth factors, was isolated from the cDNA library of an activated human helper T cell line, 5C10. Human ST2 has 67.6% identity in a 327 amino acid overlap to murine ST2. Furthermore, as in the case of murine ST2, human ST2 encodes a protein remarkably similar in sequence to the extracellular portion of human interleukin 1 receptor, both types 1 and 2. The expression of ST2 in human lymphocytes could trigger further investigations into its physiological role in humans.

3T3 Cells↗

Role of liver-type glucose transporter (GLUT2) in transport across the basolateral membrane in rat jejunum.

To obtain information on the regulation of glucose transport across the basolateral membrane (BLM) of intestinal epithelial cells, we measured the number of [3H]cytochalasin B binding sites and the level of liver-type glucose transporter (GLUT2) protein in the BLM in the jejunum of rats (i) with diabetes (ii) given a high-carbohydrate diet or (iii) with experimental hyperglycemia (12 h infusion of a high-glucose solution). A glucose uptake and the number of D-glucose inhibitable [3H]cytochalasin B binding sites in BLM vesicles were significantly increased in all three conditions. Western blot analysis showed that the amount of GLUT2 protein in BLM vesicles was increased in rats with diabetes and those given a high-carbohydrate diet, but not in those with experimental hyperglycemia. These results suggest that there is a mechanism for rapid regulation of glucose transport in the BLM that does not depend on change in the amount of GLUT2.

Animals↗

A myoglobin evolved from indoleamine 2,3-dioxygenase.

Hemoglobins and myoglobins are some of the best studied proteins. They are distributed in animals, plants and bacteria, and the characteristic two intron-three exon structure is widely conserved in animal globin genes (Jhiang et al., 1988). To date, all of the hemoglobins and myoglobins are believed to have a common origin, and so they are considered to be homologous. We have isolated a completely new type of myoglobin from the red muscle of the abalone Sulculus diversicolor aquatilis. The myoglobin consists of an unusual 41 kDa polypeptide chain, contains one heme per chain and forms a homodimer under physiological conditions. The cDNA-derived amino acid sequence of Sulculus myoglobin showed no significant homology with any other globins, but, surprisingly, showed high homology (35% identity) with human indoleamine 2,3-dioxygenase, a tryptophan degrading enzyme containing heme. This clearly indicates that Sulculus myoglobin evolved from a gene for indoleamine dioxygenase, but not from a globin gene. Sulculus myoglobin lacks the enzyme activity of indoleamine dioxygenase. However, in the presence of tryptophan, the autoxidation rate of oxymyoglobin was greatly accelerated, suggesting that a tryptophan binding site remains near or in the heme cavity as a relic of the molecular evolution.

Amino Acid Sequence↗