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Biomedical subjects

T Takeuchi

Publications and source records attributed to T Takeuchi.

At least 379 records · Page 21Linked to original sources

[A case of simple coarctation].

We report a successful surgical repair of the simple coarctation of a 80-day-old girl by extended end-to-end aortic arch reconstruction. She was admitted to our hospital at the age of 4 days because of poor pulsation of femoral arteries. The systolic blood pressure gradient between the arm and the leg was 30 mmHg. Echocardiography on admission revealed a simple coarctation and patent foramen ovale, with the mildly impaired left ventricular contraction (left ventricular fractional shortening was 23%). Although aortography demonstrated an isolated interrupted segment at the aortic isthmus with collaterals (type A classification of Celoria-Patton), the tubular connection between the distal arch and the descending aorta, of which intralumen was obstructed with abundant ductal tissues, was found at operation. The obstruction of the lumen of aortic isthmus in our case, which was originally patent, might be caused by ductal closure and present as a simple coarctation.

Aortic Coarctation↗

[Portal and pulmonary hypertension in a patient with MCTD].

A 42-year-old woman with mixed connective tissue disease (MCTD) died due to the rupture of esophageal varices. The autopsy revealed fresh thrombi in the main trunk of the portal vein. Microscopic examination disclosed wide-spread periportal fibrosis and stenosis of peripheral portal veins without remodeling of hepatic lobular architecture, which was compatible to idiopathic portal hypertension (IPH). Anti-phospholipid antibody was negative. Accordingly it is likely that portal vein thrombosis developed secondary to IPH. In the literature 6 (37.5%) of 16 collagen vascular disease patients with IPH died, and three of them were due to rupture of esophageal varices. Therefore IPH should be considered to be one of the most important complications affecting its grave prognosis in patients with collagen vascular disease. The patient also had had pulmonary hypertension (PH) when the diagnosis of portal hypertension was made. In the literature we found 5 collagen vascular disease patients with both PH and IPH like this case. The most outstanding common clinical feature among these 6 patients was Raynaud's phenomenon associated with positive anti-RNP antibody. Moreover 5 of 6 cases including this case simultaneously developed both PH and IPH. The clinical course of these patients suggests there may be a common pathogenetic factor for these two lesions. A possible candidate involved in the pathogenesis of PH and IPH may be endothelin, one of the vasoactive substances, since its receptor is said to be expressed abundantly in pulmonary and portal vasculatures. However, further investigation is necessary to elucidate the mechanism of PH and IPH in collagen vascular diseases.

Adult↗

[Bacillus Calmette-Guerin intravesical instillation treatment for carcinoma in situ of the bladder. Gifu BCG Instillation Therapy Research Group].

We performed a retrospective long-term study to evaluate the efficacy of intravesical instillation of Tokyo 172 strain Bacillus Calmette-Guerin (BCG) on carcinoma in situ (CIS) of the bladder. Between 1989 and 1998, 42 patients with CIS of bladder underwent intravesical instillation of BCG. In the follow-up period from 6 to 116 months (mean: 37.3 months), the efficacy rate of intravesical BCG instillation for CIS of the bladder was 81.0%. Two patients died from the bladder cancer. The non-recurrence rate in patients with grade 2 carcinoma (19 cases) was not significantly different from that in those with grade 3 carcinoma (23 cases). However, the recurrence rate in patients with secondary CIS (15 cases) was significantly higher than in those with primary CIS (27 cases). The recurrence of CIS was observed in 7 of 42 cases. In 6 of 7 patients, CIS recurred within one year after treatment. Total cystectomy was performed in 10 of 42 patients, and pathological findings of muscle layer invasion were detected in 8 patients. Although side effects occurred in 33 patients (77.5%), no clinically significant side effects were observed. Our results suggest that intravesical BCG therapy may be useful for the treatment of CIS of the bladder.

Adjuvants, Immunologic↗

[Pheochromocytoma of the urinary bladder: a case report].

A 49-year-old man was hospitalized with the chief complaint of coagulation in urine. The patient was not hypertensive. Cystoscopic examination showed a submucosal tumor in the left lateral wall of the bladder. A transurethral sonogram revealed a low echoic nodule. Transurethral resection of the tumor in the urinary bladder was performed. The histopathological diagnosis indicated pheochromocytoma. Blood pressure was stable. After operation, the patient's course was uneventful, and there has been no recurrence for one year after surgery. This patient is the 52nd patient with pheochromocytoma of the urinary bladder reported in the Japanese literature.

Follow-Up Studies↗

A comparison of human spermatozoa immunolabeling features using xenogenic reagents for centrosomal proteins.

The centrosome is an organelle essential to proper chromosomal migration and normal cell growth. In the human, the centrosome is comprised of two centrioles and the pericentriolar cytosol; its control of embryo cleavage processes derives from its role as a locus for spindle organisation. At fertilisation, it is the human sperm centrosome that is responsible for ordering these processes, as the oocyte appears not to contain working centrosomal structures. Abnormalities in fertilisation or early embryo cleavage could be related to impaired sperm centrosome structure or function in some cases. While potential future treatments of infertility due to a defective centrosome could involve use of a donor centrosome to restore normal cell development, such an approach would depend on accurate localisation of this organelle for subsequent transplantation. To locate centrosomal components in the heads and tails of human spermatozoa, labeling was performed on intact spermatozoa using antibodies of known specificity to highly-conserved centrosomal elements. Following general mapping of immunofluorescent signals, unlabeled sperm were dissected to form head/tail sperm fragments which were then separately tested. Distribution of centrosomal proteins in head and tail fragments was assayed for each separation method. Three reagents were compared: 1) rabbit anti-mitotic spindle protein (anti-MSP) antibody, 2) rabbit polyclonal centriole-specific antibodies, and 3) mouse monoclonal anti-MPM-2 (a centrosome phospoprotein) antibody. Of these, anti-MPM-2 antibody appeared to be the most reliable, labeling centrosomal elements in 63% (n = 1,386) of treated spermatozoa. Sequential utilization of n-butylamine to effect head/tail separation followed by anti-MPM-2 antibody labeling was a satisfactory method of centrosome localisation. Microextraction of centrosomes and pericentriolar matrix identified by this method awaits further testing.

Affinity Labels↗

Regulation of human leukocyte antigen expression in human conjunctival epithelium.

PURPOSE: To demonstrate that interferon-gamma (IFN-gamma) is the key cytokine responsible for the upregulation of HLA-DR antigen in conjunctival epithelial cells of Sjogren syndrome (SS) patients. METHODS: Flow cytometry of conjunctival epithelial cells from SS and non-SS dry eye patients was performed for the quantification of HLA-DR surface expression. With a conjunctival epithelial cell line (ChWK), HLA-DR regulation by various cytokines was evaluated, and confocal immunocytochemical and western blot analyses were performed to evaluate the activation of nuclear factorkappa B (NF-kappaB) and signal transducers and activators of transcription 1 and 3 (STAT1 and STAT3, respectively). RESULTS: HLA-DR expression was upregulated in conjunctival epithelial cells of SS patients but not in non-SS dry eye patient or healthy control subject. IFN-gamma was the only cytokine that effectively upregulated HLA-DR expression in ChWK, which was synergistically enhanced by tumor necrosis factor-alpha (TNF-alpha). IFN-gamma induced the nuclear translocation of NF-kappaB, but did not activate STAT1 or STAT3 in ChWK. CONCLUSIONS: Upregulation of HLA-DR antigen in the conjunctival epithelium of SS patients may be regulated by IFN-gamma through the activation of NF-kappaB.

Adult↗

Cloning and bacterial expression of adenosine-5'-triphosphate sulfurylase from the enteric protozoan parasite Entamoeba histolytica.

A gene encoding adenosine-5'-triphosphate sulfurylase (AS) was cloned from the enteric protozoan parasite Entamoeba histolytica by polymerase chain reaction using degenerate oligonucleotide primers corresponding to conserved regions of the protein from a variety of organisms. The deduced amino acid sequence of E. histolytica AS revealed a calculated molecular mass of 47925 Da and an unusual basic pI of 9.38. The amebic protein sequence showed 23-48% identities with AS from bacteria, yeasts, fungi, plants, and animals with the highest identities being to Synechocystis sp. and Bacillus subtilis (48 and 44%, respectively). Four conserved blocks including putative sulfate-binding and phosphate-binding regions were highly conserved in the E. histolytica AS. The upstream region of the AS gene contained three conserved elements reported for other E. histolytica genes. A recombinant E. histolytica AS revealed enzymatic activity, measured in both the forward and reverse directions. Expression of the E. histolytica AS complemented cysteine auxotrophy of the AS-deficient Escherichia coli strains. Genomic hybridization revealed that the AS gene exists as a single copy gene. In the literature, this is the first description of an AS gene in Protozoa.

Amino Acid Sequence↗

Molecular cloning and characterization of the genes encoding two isoforms of cysteine synthase in the enteric protozoan parasite Entamoeba histolytica.

The enteric protozoan parasite Entamoeba histolytica was shown to possess cysteine synthase (CS) activity. The cDNA and genomic clones that encode two isoforms of the E. histolytica CS were isolated and characterized from a clonal strain of E. histolytica by genetic complementation of the cysteine-auxotrophic Escherichia coli NK3 with an E. histolytica cDNA library. The two types of the E. histolytica CS genes differed from each other by three nucleotides, two of which resulted in amino acid substitution. Deduced amino acid sequences of the E. histolytica CS, with a calculated molecular mass of 36721 Da and an isoelectric point of 6.39, exhibited 38-48% identity with CS of bacterial and plant origins. The absence of the amino-terminal transit peptide in the deduced protein sequences and the presence of the CS protein mainly in the supernatant fraction of the amoebic lysate after cellular fractionation suggested that the identified E. histolytica CS genes encoded cytosolic isoforms. Substrate specificity of the recombinant E. histolytica CS was similar to that of plant CS. Phylogenetic analysis indicates that the amoebic CS, first described in Protozoa, does not belong to any families of the CS superfamily, and represents a new family.

Amino Acid Sequence↗

Inhibition of skeletal muscle sarcoplasmic reticulum Ca2+-ATPase by nitric oxide.

The effects of nitric oxide on the activities of thapsigargin-sensitive sarcoplasmic reticulum Ca2+-ATPase (SERCA) and Ca2+ uptake by sarcoplasmic reticulum (SR) membranes prepared from white skeletal muscle of rabbit femoral muscle were studied. Pretreatment of the SR preparations with nitric oxide at concentrations of up to 250 microM for 1 min decreased the SERCA activity concentration dependently, and also decreased their Ca2+ uptake. Both these effects of nitric oxide were reversible. Inhibitors of guanylyl cyclase and protein kinase G (PKG) had no significant effect on the nitric oxide-induced inhibitions of SERCA and Ca2+ uptake. Moreover, dithiothreitol did not reverse the inhibitory effects of nitric oxide on SERCA and Ca2+ uptake. These findings suggest that nitric oxide inhibits SERCA, mainly SERCA 1, of rabbit femoral skeletal muscle by an action independent of the cyclic GMP-PKG system or oxidation of thiols, and probably by a direct action on SERCA protein.

Aminoquinolines↗

Synthesis of anti-rheumatic agent epoxyquinomicin B.

Anti-rheumatic agent (+/-)-epoxyquinomicin B was synthesized for a 22% overall yield in eight steps from commercially available 3-hydroxy-4-nitrobenzaldehyde via the intermediate quinone 6 prepared by selective phenol oxidation of 5 by use of Fremy's salt as the key step.

Antirheumatic Agents↗

Application of a linear alkylbenzene sulfonate biosensor to river water monitoring.

A novel whole cell biosensor was constructed for the detection of anionic surfactants in aquatic environments. The analysis was rapid, convenient and did not require organic reagents. In this report, the application of this sensor to river water samples was investigated when applied to environmental samples; other organic substances present in river water may affect the measurement of linear alkylbenzene sulfonates. In order to deal with this problem, a correction system was developed using whole cells of Trichosporon cutaneum. This system was applied to in situ 24 h continuous monitoring in the Saka river.

Benzenesulfonates↗