Biomedical subjects

M Kanoh

Publications and source records attributed to M Kanoh.

At least 19 recordsLinked to original sources

PubMed1998

Role of apoptosis in the disappearance of infiltrated and proliferated interstitial cells after myocardial infarction.

Myocardial infarction (MI) progresses from the acute death of myocytes and the infiltration of inflammatory cells into granulation, followed by scars. During the healing process, the myocardial interstitial cell population in the infarcted tissues increases markedly and then decreases. We postulated that apoptosis is responsible for this process. Twenty-four male Japanese white rabbits underwent a 30-minute occlusion of the left coronary artery followed by reperfusion for 2 days, 2 weeks, or 4 weeks (n=8 each). The histological features consisted of dead cardiomyocytes and marked leukocyte infiltration at 2 days after MI and granulation consisting of numerous alpha-smooth muscle actin-positive myofibroblasts, macrophage antigen-positive macrophages, and neovascularization at 2 weeks. At 4 weeks, the cellularity decreased markedly, and scars were evident. Interstitial cells with positive nick end labeling were significantly more frequent at the light microscopic level in the 2-day MI samples (5.3+/-3.6% in the center and 6.9+/-3.3% in the periphery of the infarct region) than in the 2-week (2.5+/-1.0%) and 4-week (0.5+/-0.5%) samples. DNA electrophoresis showed a clear ladder in tissues from the ischemic areas at 2 days after MI but not at 2 and 4 weeks after MI. Ultrastructurally, typical apoptotic figures, including apoptotic bodies and condensed nuclei without ruptured plasma membranes, were detected in leukocytes from all hearts with 2-day MI and in myofibroblasts, endothelial cells, and macrophages from all hearts with 2-week MI. In the electron microscopic in situ nick end labeling, immunogold particles intensely labeled the condensed chromatin of the typical apoptotic nuclei. These particles were also accumulated on nuclei of the interstitial cells showing homogeneous density but not definite condensation as typical apoptotic nuclei, suggesting an early stage of apoptosis. Thus, apoptosis plays an important role in the disappearance of both the infiltrated leukocytes and the proliferated interstitial cells after MI. This finding may have therapeutic implications for postinfarct ventricular remodeling through apoptosis handling during the healing stage of MI.

Animals↗

PubMed1998

[Postoperative infections related to pacing wires, pulmonary arterial catheters, and drainage tubes temporarily inserted during open-heart surgery].

Bacterial examinations of temporary pacing wires (P-wires), pulmonary arterial (P-A) catheters, and drainage tubes temporarily inserted during open-heart surgery were performed in 213 patients. Bacteria were detected in 19 (2.8%) of 672 specimens gathered from the subject patients, with coagulase-negative Staphylococcus (CNS) being most frequently observed. P-wires accounted for 17 out of 19 of the culture-positive specimens, and 7 of the P-wires remained in place for more than two weeks. The frequency of infection with the P-wires was significantly higher than with the P-A catheters or drainage tubes. The period of time that the P-wire was left in place significantly longer than for P-A catheter or drainage tube. There was, however, no statistically significant difference between the culture-positive and negative groups in respect to age, detention periods, operation times, CPB times, or length of ICU stay. As a result of these findings, we have concluded that P-wires should be removed as soon as possible following surgery, and in any case, a meticulous care should be taken to prevent transcutaneous infection.

Adolescent↗

PubMed1996

[Intraventricular arachnoid cyst--on the origin of intraventricular arachnoid cysts].

Arachnoid cysts very rarely occur within the ventricular system, where no arachnoid tissue exists. We present three cases of intraventricular arachnoid cyst with special reference to its origin. The first patient was a 5-year-old boy who complained of headaches and enlargement of his head. A CT scan revealed obstructive hydrocephalus and a large cystic lesion in the right lateral ventricle. The symptoms resolved after fenestration of the cyst and cystoperitoneal shunt. The second patient was a 49-year-old woman who complained of headache and numbness in her left upper extremity. A CT scan and MRI revealed a large cyst in the trigone of the right lateral ventricle. Fenestration of the cyst wall and cystoperitoneal shunt were performed relieving her complaints. The third patient was a 42-year-old man who complained of frequent seizures and dizziness. A CT scan and MRI demonstrated a moderate size cystic mass in the inferior horn of the right lateral ventricle. The symptoms were improved by partial resection of the cyst wall. Immunohistochemical studies and light microscopy confirmed that the cyst walls were composed of arachnoid membrane, implying that the cysts were arachnoid cysts. CT and MRI in these three cases showed widening of the choroidal fissure bordering the cyst wall, occasionally involving a part of the protruding cyst wall. On enhanced CT and MRI, the choroid plexus in the trigone of ipsilateral lateral ventricle was displaced anterolaterally, implying that the cysts had grown from outside the choroid plexus. Postoperative MRI demonstrated the shrunken cyst wall attached to the choroidal fissure. The surgical findings in case 3 also showed that the cyst wall was attached firmly to the choroid plexus. These findings appeared to indicate that the intraventricular arachnoid cyst originated from the arachnoid layer drawn into the choroidal fissure with choroidal vascular mesenchyme.

Adult↗

PubMed1995

Complement activation by cross-linked B cell-membrane IgM.

The B cell membrane IgM (mIgM) occurs in a monomeric form incapable of activating C. However, when cross-linked by a polyvalent ligand, mIgM may activate C by assuming a polymeric structure like secreted IgM. This possibility was tested with CR2- lymphoma cells, which did not activate C spontaneously. When CR2-deficient mIgM(lambda)+ Ramos cells were treated with F(ab')2 goat anti-lambda, then exposed to human serum, a marked C3 deposition took place, as examined by the flow cytometry. Similarly, C3 deposition on mIgM(kappa)+, mIgD(kappa)+ P32 cells was induced by F(ab')2 of either anti-kappa or anti-mu. Anti-delta was without effect, but the C3 deposition resulting from anti-kappa was markedly enhanced after mIgD was modulated by anti-delta. The mIgM-cross-linked cells bound C1q, and C3 deposition on these cells was abrogated by depletion of C1q, but not Factor B nor D, from serum. The C1-binding step of the mIgM-mediated C activation was inhibited by monomeric Fab' of polyclonal anti-mu containing a blocking Ab to the hemolytic activity of human IgM Forssman Ab. A large proportion of C3 deposits on mIgM-cross-linked cells was found to be associated with mIgM in the form of C3dg or C3d. These results demonstrate that cross-linked mIgM indeed triggers the classical pathway of C.

B-Lymphocytes↗

PubMed1995

Immunochemical crossreactivity between globulins from buckwheat and indigo seeds.

Immunochemical relationships between salt-soluble proteins (albumins plus globulins) from buckwheat and indigo seeds were shown by immunoblot and immunodiffusion analyses using rabbit antisera raised against buckwheat globulins. These antigenic crossreactivities were roughly consistent with their polypeptide components judged by two-dimensional electrophoresis and SDS-PAGE analyses.

Animals↗

PubMed1995

[Rupture of dissecting aortic aneurysm associated with the right-sided aortic arch and anomalous course of the left brachiocephalic vein--a case report].

A case of ruptured dissecting aortic aneurysm (DeBakey IIIb) associated with the right sided aortic arch and anomalous course of the left branchiocephalic vein was reported. A sixty-nine-year-old female suddenly had the severe back pain and soon fell into shock. The diagnosis of a ruptured dissecting aortic aneurysm associated with the right sided aortic was obtained on CT scanning. CT films also showed the left brachiocephalic vein behind the ascending aorta. Emergency operation was performed through median sternotomy and left thoracotomy. The descending aorta, forming an aneurysm with the aberrant subclavian artery, prominently protruded far to the left, and was located behind the trachea and the esophagus. Extra-anatomical bypass grafting was performed between the ascending aorta and the distal descending aorta. The patient eventually died of multiple organ failure on the 11th day after operation. These findings were confirmed by autopsy. A rare vascular anomaly with aortic dissection was reported, and a surgical approach to that lesion was discussed.

Aged↗

PubMed1995

A case of Fabry's disease with granulomatous interstitial nephritis.

A 15-year-old boy with proteinuria and hematuria is reviewed in this study. He was first found to have urinary abnormalities at the age of 13 years, and his renal function was exacerbated for a short duration. Renal biopsy was performed to make a histological diagnosis and to establish adequate therapy. Light microscopy showed marked tubulointerstitial inflammation with granulomatous changes, and electron microscopy revealed that numerous osmiophilic inclusions were present in podocytes, mesangial cells, and endothelial cells of the glomeruli and in epithelial cells of the tubules. The alpha-galactosidase activity of lymphocytes from the patient was measured, and the results of this assay indicated that the patient's lymphocytes had a low level of alpha-galactosidase activity. Therefore, the patient was diagnosed as having Fabry's disease with renal dysfunction. This study demonstrated that the onset age of renal insufficiency in Fabry's disease may be earlier than that described previously, and that when granulomatous interstitial nephritis is developed, renal function may deteriorate progressively.

Adolescent↗

PubMed1994

A method for simultaneous detection of fluorescent G-bands and in situ hybridization signals.

Improved techniques for detecting in situ hybridization signals on fluorescent G-bands are described. Prior to hybridization of biotinylated DNA probes, chromosomes with replication G-bands were treated with formaldehyde and denatured with an alkaline solution. These steps preserve chromosome morphology well, and enable us to simultaneously demonstrate fluorescein hybridization signals and G-banded chromosomes stained with propidium iodide. This method is useful for precise chromosomal localization of DNA markers.

Chromosome Banding↗

PubMed1994

[Perforation of the right ventricular wall and extraction into the left thoracic cavity by a permanent endocardial pacemaker lead: a case report].

A 80-year-old woman with right ventricular wall perforation and extraction into the left thoracic cavity by a permanent endocardial pacemaker (PM) lead was presented. The patient underwent an insertion of a permanent endocardial lead into the apex of the right ventricle for the treatment of sick sinus syndrome. The right ventricular perforation of the PM lead was incidentally diagnosed by recognizing it into the left thoracic cavity three months after the operation. Another PM lead could be inserted without removal of the former one.

Aged↗

PubMed1993

Cytidylate cyclase activity is stimulated via activation of a guanine nucleotide-binding protein.

Cytidylate cyclase is a membrane-bound enzyme which catalyzes the biosynthesis of cytidine 3',5'-cyclic monophosphate (cCMP) from CTP. By using a sensitive and specific enzyme immunoassay method, we evaluated the participation of guanine nucleotide-binding protein (G-protein) in the regulation of cytidylate cyclase activity in rat brain and other tissues. AlF4-, an activator of G-proteins, effectively elevated the cyclase activity. The stimulation by GTP gamma S, a nonhydrolyzable GTP analogue, was also observed in time- and concentration-dependent manner during the preincubation and this effect was competitively inhibited by the addition of GDP beta S. However, islet-activating protein and cholera toxin which affected adenylate cyclase activity had no effect on cytidylate cyclase activity. These results indicate that cytidylate cyclase is associated with a certain G-protein and its activity is regulated by the mode different from that of adenylate cyclase.

Adenylyl Cyclases↗

PubMed1992

Down regulation of myelin-specific mRNAs in the mechanism of hypomyelination in the undernourished developing brain.

The expression of myelin-specific protein genes, i.e. myelin proteolipid (PLP), basic (BP), and myelin associated glycoproteins (MAG) was studied in normal and severely undernourished 20-day-old rats. The undernutrition paradigm resulted in reductions of approximately 50, 25 and 65% in body weight, brain weight and brain myelin yield, respectively. The amount of total brain RNA was not significantly altered, although the amount of cyclophilin (CYC) mRNA was increased. In contrast, the steady-state levels of myelin specific mRNAs were significantly decreased by approximately 40, 20 and 40% for PLP, BP and MAG, respectively. In addition, polyadenylation of the PLP transcript was altered, producing an abnormal ratio of the 1.6 kb to the 3.2 kb PLP mRNAs. The results indicate that down-regulation of myelin-specific gene expression is involved in the mechanisms of hypomyelination in hunger disease, although the individual genes are differently altered. Furthermore, undernutrition may have additional effects on the posttranscriptional processing of the transcripts as indicated by the abnormal size distribution of PLP messages.

Animals↗

PubMed1992

Cyclic AMP-induced upregulation of proteolipid protein and myelin associated glycoprotein gene expression in C6 cells.

A model culture system of C6 rat glioma cells was used to test the involvement of cAMP in the regulation of the myelin PLP and MAG genes. The treatment of cells with isoproterenol (10(-5) to 10(-8) M) upregulated the expression of the PLP and MAG genes in a concentration-dependent manner. The mRNA for PLP reached a maximum (sevenfold higher than in control cells) after about 12-24 hr, then declined to approximately fourfold over the control level. The response of MAG gene was delayed by at least 36 hr, and the level of MAG mRNA reached a maximum of approximately 48-fold over the control level on the fourth day in culture. The co-administration of propranolol blocked the effect of isoproterenol, whereas 10(-5) M forskolin simulated the effect of isoproterenol, indicating a role of cAMP in the signal transduction cascades leading to upregulation of the myelin genes. However, the dissimilarity in the timing and the extent of upregulation of the PLP and MAG genes by cAMP-stimulating agents indicate the existence of different intracellular mechanisms for the activation of these two genes. Cycloheximide blocked the stimulatory effect of isoproterenol on both the PLP and MAG genes, indicating that the effect of cAMP on the myelin genes is mediated by protein product(s) of other cAMP-response gene(s).

Animals↗

PubMed1992

Retinoic acid-regulated expression of proteolipid protein and myelin-associated glycoprotein genes in C6 glioma cells.

The effect of retinoic acid (RA) on the expression of myelin-specific genes, i.e., proteolipid protein (PLP) and myelin-associated glycoprotein (MAG) in rat glioma C6 cells, was analyzed by Northern blot hybridization. RA-treatment increased the steady-state level of the PLP-specific messages within one day after RA administration and the upregulation reached a maximum on the third day. Concomitantly, the expression of MAG-specific messages in the RA-treated C6 cells dropped below the detectability limit. The expression of the PLP gene was directly related to the RA concentration increasing to approximately 44-fold over the control (untreated cells) level at 10(-6) M RA. The stimulatory effect was vitiated by cycloheximide indicating the involvement of intermediate genes in the PLP gene activation. The total cellular RNA content and the level of cyclophilin mRNA was not changed by the RA-treatment. The present data indicate that RA can be a potent modulator of the myelin-specific gene expression. Furthermore, the reciprocal response of PLP versus MAG genes to RA demonstrates that these two genes utilize different regulatory mechanisms.

Animals↗

PubMed1992

Differential upregulation of PLP and MAG genes in C6 glioma cells by N2A neuroblastoma conditioned medium.

The effect of factors released from N2A neuroblastoma cells on the expression of myelin protein genes in glioma C6 cells, i.e., proteolipid protein (PLP) and myelin-associated glycoprotein (MAG), was studied. Both cells lines were propagated in serum-free DMEM-F10 (1:1) medium. The addition of 50% N2A conditioned medium (N2ACM) stimulated the proliferation of C6 cells by approximately 4.5 fold as compared to control cells. The N2ACM-treated cells formed aggregates indicating increased cell-cell affinity. The exposure of C6 cells to N2ACM transiently stimulated the expression of both the MAG-specific and the PLP-specific messages up to eight and four fold over the control values, respectively. The maximal upregulation of the PLP gene occurred two days after N2ACM administration and preceded that of the MAG gene by two days. The effect of N2ACM was dose-dependent in the range of 12.5 to 50%. The secretion of N2A paracrine factors that stimulated the myelin gene expression was also time-dependent. The optimal conditioning time for the release of the PLP gene-stimulating activity was one day, while the maximal MAG gene-stimulating activity was found in the medium conditioned for 3 days. This cellular system may provide a convenient model for studies on trophic neuronal-glial interaction. Furthermore, the results indicate a difference in the regulatory mechanisms between the PLP and the MAG genes.

Animals↗

PubMed1992

Reduction of cerebral blood flow in chronic schizophrenia: relation to age.

The effect of age on resting-state cerebral blood flow (CBF) was studied in 40 medicated patients with chronic schizophrenia aged 20 to 57 and 32 age- and sex-matched normal controls, using the regional CBF with the xenon-133 inhalation technique. Global CBF (average of 16 cerebral regions) and the left prefrontal flow ratio (left prefrontal/global CBF) were significantly lower in schizophrenics aged 20-29 than in age-matched controls. Both global CBF and the left prefrontal flow ratio correlated with age in controls, but neither of such correlations was found in schizophrenics. Therefore, the CBF deficits in chronic schizophrenia appear to be unaffected by the aging process.

Adult↗

PubMed1992

[The prevalence and the clinical characteristics of silent myocardial ischemia detected by stress thallium scintigraphy].

The prevalence of silent myocardial ischemia was retrospectively assessed in a group of 100 consecutive patients with angiographically proved coronary artery disease, and diagnostic ECG, by symptom-limited exercise thallium-201 scintigraphy. Twenty-four patients had no evidence of ischemia despite adequate exercise level. So among 76 patients with exercise induced ischemia, only 33 patients (43%) stopped exercise due to anginal pain (symptomatic ischemia: Group 3). And 43 patients with asymptomatic ischemia composed of 23 patients (30%) with ECG change (Group 2B) and 20 patients (26%) without ECG change (Group 2A). Patients background including the history of old myocardial infarction and diabetes mellitus, were similar among Group 2A, 2B, and Group 3. And our major observation was that the extent and severity of quantified SPECT perfusion defects was nearly identical between 3 groups Thus in this study group, there was a rather high prevalence rate of silent ischemia (57%) by exercise thallium-201 criteria. Patients with silent ischemia, associated with positive and negative exercise ECG findings, and those with exercise angina had similar background and comparable amount of jeopardized myocardium.

Aged↗

PubMed1992

[Presence of human epidermal growth factor (hEGF), basic fibroblast growth factor (bFGF) in human aqueous].

Thirty-eight cataract eyes and 15 artificial aphakic or pseudophakic eyes were enrolled in this study to determine levels of human epidermal growth factor (hEGF) and basic fibroblast growth factor (bFGF) in human aqueous, using a radioimmunoassay. Neither hEGF nor bFGF were detected in either congenital cataract eyes or senile cataract eyes without any complication. In cases of senile cataract complicated with glaucoma and traumatic cataract, bFGF range from 0.4 to 0.8 ng/ml whereas hEGF was not detected. In cases of senile cataract with myocardial or brain infarction and anterior subcapsular cataract, bFGF was detected ranging from 0.4 to 1.0 ng/ml and in some of the cases hEGF was detected at a level of 1.0 ng/ml. hEGF was detected at 1.0 ng/ml in some cases of secondary cataract after uveitis, cataract complicated with retinal detachment, cataract after scleral buckling or vitrectomy, and aphakic or pseudophakic eyes after extracapsular cataract extraction or phacoemulsification. These results showed that hEGF and bFGF exist at a level of about 1 ng/ml in human aqueous in some pathological states and it seems possible that proliferation of lens epithelial cells is promoted by the growth factors, with the result that after cataract, anterior capsular opacities and shrinkage become severe.

Adolescent↗

PubMed1991

Effect of culture conditions on PLP and MAG gene expression in rat glioma C6 cells.

The effects of culture conditions on the expression of myelin-specific genes, i.e. proteolipid protein (PLP) and myelin-associated glycoprotein (MAG) in rat glioma C6 cells was studied. Early passage (40-46) cells had higher steady-state level of PLP- and MAG-specific mRNA than late (100) passage cells when grown in defined (serum-free) medium. The PLP gene expression was increased whereas the MAG gene expression was reduced in the presence of 10% fetal calf serum in either passage. The level of both PLP- and MAG-specific messages was also directly related to the cell density indicating cell contact-induced stimulation of the gene expression. Furthermore, the cells apparently secrete factors into the medium, which upregulate the gene expression in autocrine fashion. The results also indicate a dissimilarity of regulatory mechanisms involved in the expression of the PLP and MAG genes.

Animals↗