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Biomedical subjects

T Wada

Publications and source records attributed to T Wada.

At least 253 records · Page 14Linked to original sources
PubMed1999

Encephalopathy in suckling mice infected with Kasba (Chuzan) virus.

Kasba (Chuzan) virus (an orbivirus), strain K-47, produced encephalopathy with severe necrosis in suckling mice inoculated intracerebrally. On day 3 after inoculation with 10(3)TCID50, the mice showed severe focal encephalomalacia and meningitis. On day 4, necrosis had spread to the midbrain, cerebellum and spinal cord. From one day after inoculation, virus was recovered from the brain and the titre rose over the next 3 days. Immunohistochemical examination demonstrated viral antigens in the cytoplasm of both degenerate and intact neurons, and ependymal cells in or around necrotic lesions. The study indicated that the virus has an affinity for immature nerve cells in the brains of suckling mice and causes primary encephalomalacia. Since the lesions resembled those of the hydranencephaly-cerebellar hypoplasia syndrome in calves (Chuzan disease), the system described should prove useful in studies on pathogenesis.

Animals↗
PubMed1999

A cephalometric study of the relationship between the level of velopharyngeal closure and the palatal plane in patients with repaired cleft palate and controls without clefts.

To find out whether the palatal plane is a useful indicator for evaluating the level of velopharyngeal closure, we did a cross-sectional study from early childhood to puberty of the vertical relationship between the palatal plane and the level of velarpharyngeal contact during velopharyngeal functioning in 61 patients with repaired cleft palate (unilateral cleft lip and palate = cleft group) and 82 controls without clefts (control group). Measurements on the vertical dimension were derived from a coordinate system and landmarks on lateral cephalograms, and the significance of differences in measurements was analysed using Student's t-test. Changes in the points of velarpharyngeal contact in relation to the palatal plane with growth showed a consistent tendency though differed between the two groups. In the control group, the PPW (point where palatal plane extension intersects the posterior pharyngeal wall) was maintained at a level that did not differ significantly from the level of midpoint of velarpharyngeal contact during phonation of /a/, and was maintained at a level that did not differ significantly from the level of the inferior point of velarpharyngeal contact. In the cleft group, however, it was maintained at a level that was slightly higher than the superior point of velarpharyngeal contact both during phonation of /a/ and during blowing. These results suggest that the palatal plane is useful as an indicator for evaluating the level of velopharyngeal closure.

Adolescent↗
PubMed1999

A cephalometric study of the stability of the base of the pharyngeal flap following a modified 'unified velopharyngoplasty procedure'.

A cephalometric study was conducted on 12 patients with repaired cleft palate to evaluate the stability in level and length of the base attachment of the velopharyngeal complex following pharyngeal flap surgery by a modified velopharyngoplasty. Complete velopharyngeal closure and normal articulation with a speech appliance were confirmed in all patients prior to pharyngeal flap surgery, which was performed on patients 10 years of age and above. Cephalometric radiographs were taken immediately, 1 year, 2 years and 3 years postoperatively. Cephalometric analysis revealed that although the level and length of the base of the velopharyngeal complex showed changes during the first postoperative year, they remained stable when compared with the palatal plane during the last two years. This indicated therefore that the base of a velopharyngoplasty should be attached at the same level of the palatal plane, namely the level of velopharyngeal closure, and that the procedure appeared useful in producing a stable velopharyngeal complex.

Adolescent↗
PubMed1999

Differential effects of palmitate on glucose uptake in rat-1 fibroblasts and 3T3-L1 adipocytes.

Non-esterified fatty acids are thought to be one of the causes for insulin resistance. However, the molecular mechanism of fatty acid-induced insulin resistance is not clearly known. In this study, we first examined the effect of palmitate on insulin signaling in 3T3-L1 adipocytes. We found that 1h treatment with 1 mmol/l palmitate had no effect on insulin binding, tyrosine phosphorylation of insulin receptors, 185 kDa proteins and Shc, and PI3 kinase activity in 3T3-L1 adipocytes. Then, the effects of palmitate on MAP kinase activity and glucose uptake in fully differentiated 3T3-L1 adipocytes were compared with those in poorly differentiated 3T3-L1 cells and in HIRc-B cells. Palmitate treatment had no effect on MAP kinase activity in fully differentiated 3T3-L1 adipocytes, while it inhibited MAP kinase in poorly differentiated 3T3-L1 cells and HIRc-B cells. Glucose transport in 3T3-L1 adipocytes treated with palmitate for 1 h, 4 h and 16 h was higher than that in control cells, but palmitate treatment caused a rightward shift of the insulin-dose responsive curve for glucose uptake in HIRc-B cells. Palmitate treatment did not significantly affect basal and insulin-stimulated GLUT4 translocation. When the cells were treated with PD98059, a specific MEK inhibitor, insulin-stimulated glucose uptake was not affected in 3T3-L1 adipocytes, while it was almost completely inhibited in HIRc-B cells. These results suggest the primary effect of palmitate on adipocytes may not involve insulin resistance of adipocytes themselves.

3T3 Cells↗
PubMed1999

Effect of nitric oxide synthase inhibitor on cochlear dysfunction induced by transient local anoxia.

To evaluate whether nitric oxide (NO) plays a role in the mechanism of generation of cochlear dysfunction induced by anoxia and reperfusion, the effects of a nitric oxide synthase (NOS) inhibitor, N-nitro-L-arginine, were examined using 71 albino guinea pigs. Transient cochlear anoxia of different duration (15, 30 or 60 min) was induced by pressing the labyrinthine artery and compound action potential (CAP) was measured before and 4 h after anoxia. N-nitro-L-arginine (1-30 mg/kg) administered intraperitoneally 1 h before the onset of anoxia alleviated the cochlear dysfunction when the anoxic period was 15 or 30 min. No beneficial effect was observed, however, in the 60-min anoxia. These results indicate that NO contributes to the generation of anoxia-induced cochlear dysfunction and that NOS inhibitor has a protective effect on the cochlear injury induced by anoxia of moderate duration.

Action Potentials↗
PubMed1999

The therapeutic effect of bovine lactoferrin in the host infected with Helicobacter pylori.

BACKGROUND: It remains unclarified whether bovine lactoferrin (bLF) can exert a therapeutic effect on the host infected with Helicobacter pylori. METHODS: Germfree BALB/c mice were orally inoculated with H. pylori to induce infection. Three weeks after infection the mice were given bLF orally once daily for 2 or 4 weeks and were then killed to examine the bacterial number in the stomach and the serum antibody titer to H. pylori. To count the number of epithelium-bound H. pylori, the resected stomach was agitated in phosphate-buffered saline to remove non-bound H. pylori before bacterial enumeration. RESULTS: The administration of 10 mg bLF for 3 to 4 weeks decreased the number of H. pylori in the stomach to one-tenth and also exerted a significant inhibitory effect on the attachment of H. pylori to the stomach. As a result, the serum antibody titer to H. pylori, whose level is presumed to represent the size of the immune response by the host, thereby reflecting the degree of bacterial attack, decreased to an undetectable level. CONCLUSIONS: These findings suggest that bLF exerts an inhibitory effect on colonizing H. pylori by detaching the bacterium from the gastric epithelium and by exerting a direct anti-bacterial effect.

Animals↗
PubMed1999

Recognition control of the nucleic acid model through conformational switching of nucleobase induced by borate ester formation of cis-2',3'-diol.

A novel nucleic acid model that possessed 5'-amino-5'-deoxyuridine at alpha- and gamma-position of L-glutamic acid through amide linkage using 5'-amino group was synthesized and the conformation and the hybridization properties were studied. The complex of alpha-PRNA with complementary DNA/RNA was more stable than the corresponding natural duplex in the absence of borate. Its recognition ability was however lost when borax was added to the solution.

Borates↗
PubMed1999

Synthesis of nucleotide antibiotics having N-acyl phosphoramidate linkages.

This paper reports the synthesis of nucleotide antibiotics having N-acyl phosphoramidate linkages. The key reaction, the construction of the N-acyl phosphoramidate linkage was achieved by the reaction of nucleoside 5'-phosphoramidite derivatives with carboxamide derivatives in the presence of 5-(3,5-dinitrophenyl)-1H-tetrazole as a very effective activator. By use of this activator, Phosmidosine was synthesized by condensation of an appropriately protected 8-oxoadenosine 5'-O-phosphoramidite derivative with an N-protected prolinamide derivative. In the case of Agrocin 84, the two P-N bonds were constructed progressively. The N-acyl phosphoramidate linkage at the 5'-position of the ribose moiety was similarly synthesized. After phosphorylation of the amino group of the adenine moiety, a fully protected Agrocin 84 derivative, which would be converted to Agrocin 84, was successfully synthesized.

Adenine Nucleotides↗
PubMed1999

Synthesis and properties of oligonucleotides containing 2'-O-methyl-2-thiouridine.

New methods to synthesize 2'-O-methyl-2-thiouridine and its phosphoramidite building block for incorporation into oligonucleotides were developed. Oligonucleotides containing 2'-O-methyl-2-thiouridine were expected to be favorable as antisense agents in several respects, i.e., nuclease resistance, stable RNA duplex formation, and exact base recognition. Therefore, to make them clear, we synthesized oligonucleotides having 2'-O-methyl-2-thiouridine and analyzed their properties in detail.

Indicators and Reagents↗
PubMed1999

Eotaxin contributes to renal interstitial eosinophilia.

BACKGROUND: A potent eosinophil chemotactic cytokine, human eotaxin, is directly chemotactic for eosinophils. Therefore, the specific expression of eotaxin in tissue might play a crucial role in tissue eosinophilia. However, the precise molecular mechanism of the recruitment and activation of eosinophils in human renal diseases remains to be investigated. We evaluated the role of eotaxin in the pathogenesis of human diffuse interstitial nephritis with marked infiltration of eosinophils. METHODS: In this study, we examined 20 healthy volunteers. 56 patients with primary or secondary glomerular diseases and two hypereosinophilic syndrome patients without renal involvement. Urinary and serum eotaxin levels were determined by an enzyme-linked immunosorbent assay. We also detected the presence of eotaxin protein immunohistochemically. RESULTS: On the one hand, urinary levels of eotaxin were significantly higher before the initiation of glucocorticoid administration in the patient with interstitial nephritis with marked infiltration of eosinophils. On the other hand, urinary eotaxin levels were not detected in any patients with nephrotic syndrome, interstitial nephritis without eosinophils, hypereosinophilic syndrome without renal involvement or other renal diseases. Serum eotaxin levels were not detected in any of the patients. Therefore, the detection of eotaxin in the urine was specific for renal interstitial eosinophilia. Moreover, endothelial cells, infiltrating mononuclear cells and renal epithelial cells in the tubulointerstitial lesions were immunostained with specific anti-eotaxin antibodies. Furthermore, the elevated urinary levels of eotaxin decreased dramatically during glucocorticoid-induced convalescence. HYPOTHESIS: We hypothesize that in situ expression of eotaxin may provide a new mechanism to explain the renal interstitial eosinophil infiltration.

Adolescent↗
PubMed1999

The short- and long-term outcomes of membranous nephropathy treated with intravenous immune globulin therapy. Kanazawa Study Group for Renal Diseases and Hypertension.

BACKGROUND: A considerable diversity in prognosis is seen with membranous nephropathy (MN). A recent report showed beneficial effects of immune globulin (Glb) therapy in Heymann nephritis, a rat model of MN. However, the early and late clinical effects of Glb in human MN have remained unclear. METHODS: We studied retrospectively 86 patients with primary MN from 1965 to 1988 who were followed for at least 5 years, or until renal or actual death. Thirty patients were non-randomly treated with 1-3 courses of intravenous immune globulin, 5-10 g/day (100-150 mg/kg/day) for 6 consecutive days. Based on electron microscopic (EM) findings, the patients were divided into two subtypes, i.e. homogeneous type with synchronous electron-dense deposits, and heterogeneous type with various stages of dense deposits, due to their different clinical outcomes. RESULTS: There was no difference in the initial clinicopathological states between Glb (n = 30) and non-Glb group (n = 56) (70 vs. 68% in nephrotic state; 37 vs. 39% in female, 50 vs. 52% in homogeneous type, 50 vs. 48% in heterogeneous type respectively). For the homogeneous type, at 6 months post-treatment, Glb therapy had induced earlier remission as compared to non-Glb treatments with corticosteroid alone or together with cyclophosphamide (57 vs. 10% respectively, P = 0.006). However, there was no significant difference in the early therapeutic effect for the heterogeneous type (13% for Glb vs. 5% for non-Glb in remission after 6 months), or in the final outcome for all groups (18% for Glb vs. 10% for non-Glb in renal death after 15 years). No adverse effects were recorded during or after Glb therapy. CONCLUSIONS: Our results suggest that short-term relatively low-dose intravenous Glb therapy has a beneficial effect in the earlier induction of remission in a subgroup of MN, the homogeneous type with EM findings of synchronous electron-dense deposits, but does not alter the long-term outcome of human MN.

Adolescent↗
PubMed1999

Implication of carbonyl stress in long-term uraemic complications.

Advanced glycation end products (AGEs) are formed during non-enzymatic glycation and oxidation (glycoxidation) reactions. AGEs, such as pentosidine and carboxymethyllysine are increased in plasma proteins and skin collagen of uraemic patients several times more than in normal subjects and non-uraemic diabetic patients. However, AGEs do not differ between diabetics and non-diabetics in uraemic patients. The AGE accumulation in uraemia, therefore, cannot be attributed to hyperglycaemia, nor simply to a decreased removal by glomerular filtration of AGE-modified proteins. Recent evidence has suggested that, in uraemia, the increased carbonyl compounds, derived from both carbohydrates and lipids, modify proteins not only by glycoxidation but also by lipoxidation reactions, leading to the increased production of AGEs and advanced lipoxidation end products (ALEs). Thus, uraemia might be a state of increased carbonyl compounds with potentially damaging proteins ('carbonyl stress'). Carbonyl stress in uraemia appears relevant to long-term complications, such as dialysis-related amyloidosis. The increased AGEs and ALEs in uraemic plasma and tissue proteins may indicate alterations in the non-enzymatic chemistry involving both carbohydrates and lipids in uraemia.

Glycation End Products, Advanced↗
PubMed1999

Cloning of the RNA polymerase alpha subunit gene from Thermus thermophilus HB8 and characterization of the protein.

The region containing the RNA polymerase alpha subunit (RNAPalpha) gene (rpoA) and the ribosomal protein genes of a thermophilic eubacterial strain, Thermus thermophilus (Tt) HB8, was cloned from a genomic DNA library by Southern hybridization. The gene order in this region is rpl36-rps13-rps11-rps4-rpoA-rpl17, which is identical to that in some other eubacteria. The rpoA gene encodes a 315 amino acid residue protein with a molecular weight of 35,013, the amino acid sequence showing 42% identity to that of Escherichia coli (Ec). From the results of comparison of the amino acid sequence and the predicted secondary structure of the C-terminal domain of Tt RNAPalpha (Tt alphaCTD) with those of Ec, the overall folding is expected to be similar. However, amino acid residues Asn268 and Cys269 in Ec alphaCTD, which are essential for its interaction with DNA or regulatory proteins, were replaced by His and Ser, respectively, in Tt alphaCTD. By means of a T7-based expression system in Ec cells, Tt RNAPalpha was overexpressed and purified. The high thermostability of Tt RNAPalpha was demonstrated by the CD spectra.

Amino Acid Sequence↗
PubMed1999

Endoscopic resection of two granular cell tumours of the oesophagus.

Granular cell tumour of the oesophagus is rare and usually single. It is diagnosed by endoscopic appearance, results of endosonography, and histological examination of biopsy specimens. Although histological examination is required for diagnosis, it is difficult occasionally to obtain tumour samples by forceps because granular cell tumour is usually located in the submucosal layer. We report the case of a Japanese man with two granular cell tumours of the oesophagus. One lesion was diagnosed as a granular cell tumour by histological examination of a biopsy specimen, but the other was not. Endoscopic resection was performed to obtain the diagnosis and treat the lesions since some granular cell tumours are potentially malignant. Both tumours were completely resected endoscopically, and the diagnosis of granular cell tumour could be established by histological examination of resected tissue. Endoscopic resection is thus useful in the diagnosis and treatment of granular cell tumour of the oesophagus.

Adenocarcinoma↗
PubMed1999

Temporal and spatial patterns of accumulation of the transcript of Myo-inositol-1-phosphate synthase and phytin-containing particles during seed development in rice.

Myo-inositol-1-phosphate (I[1]P) synthase (EC 5.5.1.4) catalyzes the reaction from glucose 6-phosphate to I(1)P, the first step of myo-inositol biosynthesis. Among the metabolites of I(1)P is inositol hexakisphosphate, which forms a mixed salt called phytin or phytate, a storage form of phosphate and cations in seeds. We have isolated a rice (Oryza sativa L.) cDNA clone, pRINO1, that is highly homologous to the I(1)P synthase from yeast and plants. Northern analysis of total RNA showed that the transcript accumulated to high levels in embryos but was undetectable in shoots, roots, and flowers. In situ hybridization of developing seeds showed that the transcript first appeared in the apical region of globular-stage embryos 2 d after anthesis (DAA). Strong signals were detected in the scutellum and aleurone layer after 4 DAA. The level of the transcript in these cells increased until 7 DAA, after which time it gradually decreased. Phytin-containing particles called globoids appeared 4 DAA in the scutellum and aleurone layer, coinciding with the localization of the RINO1 transcript. The temporal and spatial patterns of accumulation of the RINO1 transcript and globoids suggest that I(1)P synthase directs phytin biosynthesis in rice seeds.

Amino Acid Sequence↗
PubMed1999

Dacarbazine, nimustine hydrochloride, cisplatin and tamoxifen combination chemotherapy for advanced malignant melanoma.

Melanoma is an uncommon disease in Japan. The incidence, however, has been gradually increasing in the last two decades, as in many other countries worldwide. Ten patients with metastatic malignant melanoma were treated between March of 1997 and April of 1998 in the Department of Dermatology, National Cancer Center Hospital, with a combination chemotherapy consisting of dacarbazine (DTIC), nimustine hydrochloride (ACNU), cisplatin (CDDP), and tamoxifen (TAM). The patients characteristics were as follows: four were males and six females; the age range was 33-70 years; all were Japanese; sites of primary disease: extremities 4, primary unknown 3, nasal cavity 1, anus 1, scalp 1; sites of metastases: lymph nodes 6, pulmonary system 5, skin 2, liver 3, gall bladder 1, adrenal gland 1. The chemotherapy regimen included DTIC 220 mg/m2/i.v. on days 1 through 3, ACNU 60 mg/m2/i.v. on day 1, cisplatin 25 mg/m2/i.v. on days 1 through 3, and tamoxifen 10 mg p.o. twice daily. One patient achieved a complete response and 3 showed partial responses. The response rate was 40%. The four responders included those with metastases to the nodes, lung, and liver. The main toxicities were nausea, vomiting, leucopenia, anemia, and thrombocytopenia. This regimen is a fairly effective combination against metastatic melanoma.

Adult↗