Search PubMed⌕ Search

Biomedical subjects

T Kanda

Publications and source records attributed to T Kanda.

At least 253 records · Page 14Linked to original sources
PubMed1998

The somatostatin analog, octreotide, inhibits in vitro outgrowth of smooth muscle cells from canine coronary and carotid atherosclerotic plaque tissues.

Restenosis is caused by excessive neointima formation resulting from smooth muscle cell (SMC) proliferation and migration from the arterial media into the subendothelial space, stimulated by growth factors. A long-acting somatostatin analog, octreotide, activates protein tyrosine phosphatases and can inhibit the stimulatory effects of growth factors. In this study, we evaluated the effect of octreotide on SMC outgrowth from in vitro explants of both coronary and carotid arterial tissues in a canine endothelium-injury model. After 6 days of culture, SMC grew out of 33.3% and 58.3% of the explants from the injured canine carotid and coronary arterial tissues, respectively. In contrast, SMC outgrowth was not observed from any of the explants from normal canine carotid arterial tissue. Octreotide completely inhibited SMC outgrowth from injured canine carotid arterial tissue at a concentration of 10(-6) M. This agent also inhibited SMC outgrowth from injured canine coronary arterial tissue by 57% and 71% of the control value at concentrations of 10(-8) M and 10(-6) M, respectively. We conclude that our explant cell-culture model may prove to be valuable for assessing the effect of agents designed to reduce intimal proliferation, and that the use of the somatostatin analog octreotide in clinical settings may modify the high incidence of restenosis after coronary interventions by reducing SMC proliferation.

Animals↗
PubMed1998

[Trial of new intraocular lens power calculation following phototherapeutic keratectomy].

We reviewed the SRK-II method and introduce a new equation to calculate the intraocular lens (IOL) power for eyes which underwent laser phototherapeutic keratectomy (PTK). The Gullstrand series was used to determine the power and the radius of curvature of planoconvex IOLs which alter the focal point from the cornea to reach the conjugate point on the retina. The radius of anterior corneal curvature (R), axial length (AXL), predicted postoperative anterior chamber depth (ACD), and lens thickness (LT) were employed in the following formula to calculate the IOL refractive power: K = R/7.7, DC = 337. 5/R, VC = 1,000/DC*1.336 where VC is the posterior vertex focal length. A1 = -(VC-ACD), B1 = AXL-0.5* K-ACD-0. 103 LT, S = 1/A1 + 1/B1; this determined the diopter (D) of IOL in liquid to be (D) = 1,000/(1/S)* 1.336. In eyes which underwent PTK, the keratometric value prior to cataract surgery was not applied. Instead, R' defined as R-dT, where R is the radius of corneal curvature prior to PTK and dT the amount of corneal tissue removed, was introduced. Further, the corneal thickness before cataract surgery (CT') was defined as CT-dT where CT is the corneal thickness prior to PTK. Although it is important to select a lens that has an acurate predicted anterior chamber depth, the new equation appears to be more useful than the SRK-II formula.

Cataract Extraction↗
PubMed1998

Detection of left ventricular enlargement by electrocariography.

Cardiomegaly is one of the commonest findings encountered in daily clinical practice, and its differential diagnosis is a common clinical problem. There are many electrocardiological (ECG) criteria known for left ventricular hypertrophy (LVH), but its limitations have also been suggested. We evaluated 102 patients fulfilling the ECG criteria of precordial and limb lead for LVH with echocardiographic findings as a gold standard. Among these 102 patients, the echocardiogram revealed 38 subjects with LVH, 26 subjects with left ventricular dilatation (LVD), 7 subjects with both findings, and 31 subjects with neither findings. Precordial criteria such as SV1+RV5 or RV6 > 30 mm, SV1 or SV2+RV5 > 35 mm, R+S > 40 mm, SV1 or SV2+RV5 or RV6 > 35 mm, SV2+RV4 or RV5 > 35 mm, high in sensitivity and low in specificity for LVD and LVH, are appropriate for screening LVD and LVH. Cornell limb lead criterion, SV3+RaVL > 28 mm (male), SV3+RaVL > 20 mm (female), high in sensitivity and specificity only for LVH, is the best elecrocardiographic criterion to evaluate LVH. Precordial and limb lead criteria such as R> 13 mm, RaVL > 12 mm, RaVF > 20 mm, onset of intrinsicoid deflection in V5 or V6> 0.05 sec, left axis deviation -30 degrees to -90 degrees, low in sensitivity, and high in specificity, are useful to rule out LVH and/or LVD. Our findings suggest LVD and LVH can be evaluated by ECG, but similar sensitivity and specificity for both LVH and LVD makes separation of LVH from LVD unattainable.

Electrocardiography↗
PubMed1997

Isolation and culture of bovine endothelial cells of endoneurial origin.

Penetration of immunoglobulins and/or migration of activated lymphocytes into peripheral nervous system (PNS) parenchyma are the initial key steps to develop immunological disorders of PNS including Guillain-Barré syndrome, IgM neuropathy and chronic inflammatory demyelinating polyradiculoneuropathy. Hence, it is important to know the cellular property of endothelial cells of endoneurial tissue origin (PnMEC) because these cells constitute the bulk of the blood-nerve barrier (BNB). For this purpose, we developed a method to isolate and culture pure populations of PnMECs from bovine cauda equina. PnMECs were identified by their cobblestone appearance, immunoreactivity against Factor VIII/von Willebrand factor (vWF) antigen, and positive uptake of DiI-Ac-LDL. The glucose transporter type 1 (GLUT1) expression of these cells was rapidly down-regulated in vitro. Other than GM3(NeuAc) and GM3(NeuGc) as major glycosphingolipids, PnMECs comprise GM1, GD1a, GD1b and GT1b, which are shared by PNS parenchyma, and sialyl lactosaminyl paragloboside (SLPG) as minor species. Because bovine PnMECs proliferate rapidly and a large mass of cells could be obtained, this method should contribute to the biochemical analysis of surface molecules in PnMECs that might play a key role in the formation of BNB as well as in pathological conditions involving the PNS.

Animals↗
PubMed1997

Stretch-induced hypertrophic growth of cardiocytes and processing of brain-type natriuretic peptide are controlled by proprotein-processing endoprotease furin.

When hypertrophic growth is induced in neonatal rat cardiocytes by stretching, the cardiocytes express high levels of brain-type natriuretic peptide (BNP) and the proprotein-processing enzyme furin. A BNP precursor, gammaBNP, possesses a furin-cleavable Arg-X-X-Arg motif, which is cleaved when gammaBNP is processed to form BNP-45. The Arg-X-X-Arg motif is found in many precursors of growth factors and growth-related proteins. To determine if furin converts gammaBNP to BNP-45 as well as other unidentified growth-promoting protein precursors to their active form that may induce hypertrophic growth in cardiocytes, we used two protease inhibitor systems, synthetic peptidyl chloromethyl ketones (CMK) (dec-Arg-Val-Lys-Arg-CMK and dec-Phe-Ala-Lys-Arg-CMK; where dec is decanoyl) and vaccinia vector-integrated native and variant alpha1-antitrypsins. The furin-specific inhibitors, dec-Arg-Val-Lys-Arg-CMK and variant alpha1-antitrypsin with the inhibitory determinant Arg-X-X-Arg, suppressed the stretch-induced hypertrophic growth of cardiocytes as well as the processing of gammaBNP to BNP-45. The other serine protease inhibitors and variant alpha1-antitrypsin against elastase, or thrombin, however, neither suppressed the hypertrophic growth nor prevented the processing of gammaBNP to BNP-45. Thus, we suggest that furin catalyzes the conversion of gammaBNP to BNP-45 as well as growth-promoting proproteins to their active form, which might induce hypertrophic growth in cardiocytes.

Animals↗
PubMed1997

Characterization of the cloned promoter of the human initiation factor 4AI gene.

Protein synthesis initiation factor 4AI (eIF-4AI) is ubiquitously expressed in eucaryotic cells. We characterized the eIF-4AI gene promoter cloned from human fibroblasts. The minimal promoter, localized to a region in the 5'-noncoding region adjacent to the first exon, consisted of approximately 300 base pairs (bp), 80% of which were identical with those in the corresponding mouse promoter. The minimal promoter contained TATA and CAAT motifs and consensus sequences binding to SP1 (three sites) and AP2 (one site). Deletion analyses of the promoter revealed that a 24-bp region near 5'-end of the minimal promoter was essential for the efficient transcription, although the AP2 site in the region was dispensable. A fluorescence polarization assay suggested that the plus strand of the 24-bp region, despite the lack of known consensus sequences binding to transcription factors except for AP2, bound to unknown nuclear protein(s) in a sequence specific manner.

Animals↗
PubMed1997

Co-elevation of brain natriuretic peptide and proprotein-processing endoprotease furin after myocardial infarction in rats.

We investigated the expression of the yeast Kex2 family endoproteases furin and PACE4, and brain natriuretic peptide (BNP) in the atrium and ventricle after infarction as well as the conversion of the BNP precursor gammaBNP to BNP-45. In a rat heart failure model, plasma BNP rose in two phases--first at day 3, and again at day 14. BNP mRNA, as measured by Northern blot analysis, increased strongly at day 3, then at days 14 and 28 less strongly in the atrium, and in the ventricle it increased weakly at day 3, then strongly at days 14 and 28. Furin mRNA showed the same pattern of expression as that of BNP message, whereas PACE4 message stayed unchanged after the infarction. Both furin and BNP were immunostained in the myocardium adjacent to the infarcted tissue. We suggest that after myocardial infarction, furin is co-expressed with BNP in both the atrium and ventricle, and that furin may be responsible for the conversion of gammaBNP to BNP-45.

Animals↗
PubMed1997

Identification of catechin oligomers from apple (Malus pumila cv. Fuji) in matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and fast-atom bombardment mass spectrometry.

Molecular size information for polymerized catechin larger than the decamer in unripe apple was obtained by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and by fast-atom bombardment mass spectrometry. Matrix-assisted laser desorption/ionization time of flight mass spectrometry provided evidence for the pentadecamer using trans-3-indoleacrylic acid as the matrix in the presence of silver ion. Even in the absence of silver ion, the dodecamer and undecamer were observed in the positive- and negative-ion modes, respectively. Fast-atom bombardment mass spectrometry also afforded evidence for the undecamer in both positive- and negative-ion modes.

Catechin↗
PubMed1997

Friedreich-like ataxia with retinitis pigmentosa caused by the His101Gln mutation of the alpha-tocopherol transfer protein gene.

The alpha-tocopherol transfer protein (alpha-TTP) is a cytosolic liver protein that is presumed to function in the intracellular transport of alpha-tocopherol, the most biologically active form of vitamin E. We studied 4 unrelated patients with autosomal recessive Friedreich-like ataxia who had isolated vitamin E deficiency. A point mutation was identified in all of them at position 101 of the gene for alpha-TTP, where histidine (CAT) was replaced with glutamine (CAG). Three of the 4 patients developed retinitis pigmentosa subsequent to the onset of ataxia. Neurological symptoms included ataxia, dysarthria, hyporeflexia, and decreased proprioceptive and vibratory sensations. Electrophysiological and pathological examinations showed that the cardinal sites affected were the central axons of dorsal root ganglion cells and the retina, with minor involvement of the peripheral sensory nerve, optic nerve, and pyramidal tract. The vitamin E tolerance test performed showed that the absorption of vitamin E was normal but that its decrease from the serum was accelerated. Oral administration of vitamin E appeared to halt the progression of visual and neurological symptoms. We propose a new treatable syndrome of Friedreich-like ataxia and retinitis pigmentosa caused by a defect in the alpha-TTP gene.

Aged↗
PubMed1997

Detection of GBV-C RNA in patients with non-A-E fulminant hepatitis by reverse-transcription polymerase chain reaction.

GBV-C might be a causative agent of fulminant hepatitis of unknown etiology. Fulminant hepatitis is an indication for liver transplantation. However, in Japan, because of the legal difficulties associated with cadaveric donation, patients with fulminant hepatitis are still treated by plasmapheresis and multiple transfusions of fresh frozen plasma. So, the possibility that GBV-C might be transmitted by transfusions after the onset of fulminant hepatitis is real. Therefore, we have examined the possible role of GBV-C in non-A-E fulminant hepatitis. Nine patients with non-A-E fulminant hepatitis and one with non-A-E late onset hepatic failure were examined. Sera were obtained from the patients at admission before any blood or blood products were given, and again after transfusions. GBV-C RNA was detected by nested reverse transcription polymerase chain reaction with primers based on the reported sequence. GBV-C RNA was negative in all 10 pretransfusion patients with non-A-E fulminant hepatitis or late onset hepatic failure. Then, fresh frozen plasma was transfused to these patients, and four of them became seropositive. GBV-C is unlikely to be a major etiologic agent for non-A-E fulminant hepatitis in Japan.

Adult↗
PubMed1997

Running exercise improves metabolic abnormalities and fat accumulation in sucrose-induced insulin-resistant rats.

Insulin resistance and hyperinsulinemia are observed in rats fed a high sucrose diet. Insulin resistance is thought to be related to abnormal fat distribution. We previously reported the metabolic characteristics and the fat distribution in rats with sucrose-induced insulin resistance. This study was designed to examine the effects of exercise in these rats. The rats were divided into three groups: those receiving a starch-based diet (control), those receiving a high-sucrose diet (sucrose fed), and those receiving a high-sucrose diet and wheel-running exercise (exercised). Animals were killed after 4 weeks or 12 weeks. After 4 weeks, the three groups did not differ with respect to gain in adipose tissues. The portal vein (PV) insulin concentration was significantly increased in the sucrose-fed and the exercised rats compared with the control rats. The inferior vena cava (IVC) glucose concentration and the PV free fatty acid (FFA) were significantly lower in the exercised rats than in the sucrose-fed rats. After 12 weeks, the exercised rats had significantly lower mesenteric fat (MS) and subcutaneous fat (SC) and a lower MS:SC ratio than the sucrose-fed rats. The glucose levels in IVC, PV, and FFA in PV were significantly reduced in the exercised rats as compared with the sucrose-fed rats. These findings suggest that long-term exercise improves insulin resistance by reducing the accumulation of MS as well as SC. It is also suggested that short-term exercise improves glucose metabolism without change of fat accumulation.

Adipose Tissue↗
PubMed1997

Intraoperative blood salvage in abdominal simple total hysterectomy for uterine myoma.

OBJECTIVE: To investigate the safety and usefulness of salvage-type autologous blood transfusion for abdominal simple total hysterectomy for uterine myoma. METHODS: Forty patients with uterine myoma diagnosed histologically were treated by abdominal simple total hysterectomy using an intraoperative blood salvage apparatus. Bacterial contamination in the processed blood was studied. RESULTS: Homologous blood transfusion was unnecessary. There was a positive relationship between bleeding volume and the hemoglobin (g) level in the processed blood. All vaginal swabs were positive for bacteria. Bacterial cultures of all processed blood samples without an antibiotic were positive whereas results were negative in 11 (50%) of the processed blood samples with an antibiotic. There were no significant side effects after reinfusion. CONCLUSION: Salvage-type autologous blood transfusion in abdominal simple total hysterectomy for uterine myoma was safe and its future use is promising.

Adult↗
PubMed1997

Decrease in myocardial polyamine concentration in rats with myocardial infarction.

Cardiac polyamines are thought to protect the myocardium against harmful stimuli and to be regulated by sympathetic nerve activation. In the present study, polyamines concentrations in non-infarcted myocardium were investigated. Myocardial polyamines contents decreased significantly in the non-infarcted regions by day 3 in rats with myocardial infarction compared with sham-operated rats and with the untreated control rats. The cardiac catecholamine concentration decreased by day 1 after myocardial infarction. Myocardial ornithine decarboxylase activity also decreased in the non-infarcted regions; suggesting that the decrease in cardiac polyamines contents relate to an insufficiency of the ornithine decarboxylase activity in rats with myocardial infarction. These results suggest that the decrease in polyamines concentrations after myocardial infarction is associated with functional sympathetic nerve denervation and that the vulnerability of the heart after myocardial infarction may be due to a decrease in polyamine concentrations in the non-infarcted region.

Animals↗
PubMed1997

GB virus-C RNA in Japanese patients with hepatocellular carcinoma and cirrhosis.

BACKGROUND/AIMS: The involvement of non-B, non-C virus in the incidence of hepatocellular carcinoma (HCC) is not yet known. We have therefore examined the occurrence of GBV-C RNA in such patients. METHODS: One hundred and eleven patients diagnosed as having HCC and 67 patients with cirrhosis without HCC were examined for the prevalence of GBV-C RNA by nested reverse transcription polymerase chain reaction with primers located at the helicase region. Sera were obtained and kept at -20 degrees C until analysis. RESULTS: GBV-C RNA was positive in 11/111 (9.9%) cases with HCC, in 10/74 (13.5%) anti-HCV positive cases, in 1/25 (4%) HBsAg positive cases, and in 0/8 (0%) anti-HCV and HBsAg negative cases. GBV-C RNA was also positive in 7/67 (10.4%) cases with cirrhosis, in only 1/18 (5.6%) anti-HCV and HBsAg negative cases, in 4/33 (12.1%) anti-HCV positive, and in 2/14 (14.3%) HBsAg positive cases. The clinical background of patients with anti-HCV positive HCC who were also positive for GBV-C RNA did not differ from the background of those negative for GBV-C RNA. CONCLUSIONS: GBV-C is unlikely to be a major etiologic agent of non-B, non-C chronic liver diseases and HCC in Japan.

Adult↗
PubMed1997

Distribution of vasoactive intestinal polypeptide immunoreactive nerve fiber in the rat nasal mucosa.

The distribution of vasoactive intestinal polypeptide (VIP)-immunoreactive nerve fiber of the respiratory nasal mucosa of the rat was examined by use of immunohistochemistory with light, laser confocal scanning and electron microscopy. On light microscopy, it was observed that VIP immunoreactive nerve fibers distributed under and within the epithelium in addition to around the blood vessels and glands. The laser confocal scanning microscope revealed the network of VIP-immunoreactive nerve fibers at glands, but it was denser around glands than within glands. The VIP-immunoreactive nerve fibers formed fine varicosities and was distributed below the middle portion of the epithelium. Some fibers were observed as if they were surrounding goblet cells. Electron microscopy showed that the VIP-immunoreactive nerve fibers within the epithelium were terminated as free nerve endings. Some of them were in close contact with goblet cells.

Animals↗
PubMed1997

Distribution of choline acetyltransferase (ChAT) immunoreactive nerve fibers in the nasal mucosa; especially in the respiratory epithelium.

The distribution and morphological construction of cholinergic nerve fibers in the respiratory nasal mucosa of the rat and human were investigated using choline acetyltransferase (ChAT) activities by means of light microscopy, confocal laser scanning microscopy and electron microscopy. It was observed that ChAT-immunoreactive (IR) nerve fibers were distributed to form fine varicosities around the blood vessels and seromucous glands under the epithelium and at the basement membrane and within the epithelium. Electron microscopy showed that the ChAT-IR nerve fibers within the epithelium terminated as free nerve endings. Some of them were in close contact with goblet cells. The distribution of ChAT immunoreactive fibers resembled that of vasoactive intestinal polypeptide-IR nerve fibers.

Animals↗
PubMed1997

Brain atrophy in congenital neuromuscular disease with uniform type 1 fibers.

We report a patient with congenital neuromuscular disease with uniform type 1 fibers. The patient had manifested muscle weakness and running difficulty since early childhood. Ptosis and ophthalmoplegia were evident, in addition to facial and distal weakness. Her serum creatine kinase level was normal, and electromyography revealed low-amplitude and short duration of motor unit potentials. A muscle biopsy specimen demonstrated absolute predominance of type 1 fibers (> 98%) with no diagnostic structures. Her intelligence was borderline (IQ 80), and dilatation of the lateral ventricles was demonstrated by cranial CT. This is the first report of an abnormality in the central nervous system in congenital neuromuscular disease with uniform type 1 fibers.

Atrophy↗