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Biomedical subjects

K Matsuo

Publications and source records attributed to K Matsuo.

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

Apoptosis in murine hair follicles during catagen regression.

Catagen hair follicle involution has been reported to involve apoptosis, although the precise mechanism has not been satisfactorily resolved. Previous studies have involved solely morphological or electron microscopical methods. We report here studies on murine hair follicles during the first postnatal hair cycle conducted using the terminal deoxy-nucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) method. Electrophoresis of DNA isolated from the hair follicles of the same animals was carried out in order to confirm the systematic fragmentation of DNA that typifies apoptosis. On day 10, when all the follicles were growing, there was no evidence of staining with TUNEL in the hair bulbs. Electrophoresis similarly did not show characteristic DNA ladders. By day 15, a few positive cells were observed in the hair bulbs and the numbers had increased by day 17 when many positive cells were seen, especially in the lower portions of the follicles. Electrophoresis demonstrated DNA ladders on days 15, 16 and 17, although the DNA ladder on day 15 was less prominent than that on day 17. These studies confirmed that apoptosis, as identified by techniques that measure DNA fragmentation, occurs in the lower regions of hair follicles towards the end of catagen.

Age Factors↗
PubMed1998

Hypoxia and endothelin-1 induce VEGF production in human vascular smooth muscle cells.

Vascular endothelial growth factor/vascular permeability factor (VEGF/VPF) is a secreted mitogen for vascular endothelial cells, and it promotes vascular permeability and neovascularization in vivo. We investigated the mechanisms by which low oxygen tension modulates the expression of VEGF in human aortic vascular smooth muscle cells (h-SMC) in vitro. Moreover, we measured VEGF levels in the cultured medium with or without endothelin-1 (ET-1) using a newly developed, highly sensitive, enzyme-linked immunosorbent assay. Hypoxia resulted in a substantial induction of VEGF transcripts at 3 and 24 hr. VEGF levels were significantly higher when h-SMC were cultured in medium containing ET-1 than when cultured in medium without ET-1. In conclusion, hypoxia and ET-1 constitute potent stimuli for VEGF production in h-SMC.

Cell Hypoxia↗
PubMed1998

Serum and tissue vascular endothelial growth factor levels in hydatidiform mole.

Using a specific and sensitive enzyme immunoassay for vascular endothelial growth factor (VEGF), we measured the circulating levels of VEGF in patients with hydatidiform mole as well as in maternal serum during normal pregnancy. VEGF levels in maternal serum were elevated at 7 weeks and then fell to a plateau. Serum VEGF levels were increased in patients with hydatidiform mole above the normal pregnant levels, while no differences were seen related to the development of persistent trophoblastic disease. By semi-quantitative RT-PCR in molar tissue for VEGF and placenta growth factor, a member of VEGF family, neither of the mRNA levels have no relation to the development of persistent trophoblastic disease. These observations suggest serum VEGF levels will be of value as a new circulating marker of hydatidiform mole.

Endothelial Growth Factors↗
PubMed1998

Anterior capsule contraction and intraocular lens dislocation after implant surgery in eyes with retinitis pigmentosa.

OBJECTIVE: The purpose of the study was to investigate the extent of anterior capsule contraction, intraocular lens (IOL) decentration, and tilt after implant surgery in eyes with retinitis pigmentosa (RP). DESIGN: A case-control study. PARTICIPANTS: Forty-seven eyes from 47 patients with typical RP and 47 control eyes from 47 age-matched healthy patients were studied. INTERVENTION: Phacoemulsification surgery with polymethylmethacrylate IOL implantation with continuous curvilinear capsulorrhexis was performed. MAIN OUTCOME MEASURES: The area of the anterior capsule opening obtained with capsulorrhexis and the amount of the decentration and tilt of the IOL were measured using a Scheimpflug photography system at 1 week and 1, 3, 6, 9, and 12 months after surgery. RESULTS: The mean area in the RP group was found to be significantly smaller than that in the control group at 1 month after surgery and later (P < 0.0001). The percent area reduction in the RP group at 6 months was 45.2 +/- 25.8% and 4.6 +/- 13.5% in the control group. Both the decentration length and tilt angle were also greater in the RP group than in the control group. Fourteen (29.8%) of the 47 RP eyes had undergone a neodymium:YAG (Nd:YAG) laser anterior capsulotomy at 12 months after surgery, whereas none of the control eyes had undergone an Nd:YAG. CONCLUSIONS: Anterior capsule contraction in the RP eyes was more extensive than in the control eyes, leading to a high Nd:YAG laser anterior capsulotomy rate. Both lens decentration and tilt also were greater in the RP eyes than in the control eyes.

Anterior Chamber↗
PubMed1998

Protection of chickens with or without maternal antibodies against both Marek's and Newcastle diseases by one-time vaccination with recombinant vaccine of Marek's disease virus type 1.

We constructed a stable recombinant Marek's disease virus type 1 (rMDV1) expressing the fusion protein (F) of Newcastle disease virus (NDV) by inserting the coding sequence within the US10 gene of MDV1 by homologous recombination and designated this as rMDV1-US10L(F). The NDV-F protein was significantly expressed under control of the SV40 late promoter in cultured cells infected with the rMDV1. To examine the protective efficacy of the rMDV1, specific pathogen-free (SPF) chickens were vaccinated with rMDV1 at one-day-old. Almost all birds (> 95%) were protected from NDV challenge via intramuscular, ocular, intranasal and intratrachial routes at 4 weeks after vaccination. The rMDV1 showed 100% protection against virulent MDV1 challenge in SPF chickens. Antibody responses against NDV-F and MDV1 antigens were observed at least up to 11 weeks after immunization. When the sera from chickens vaccinated with the rMDV1 were examined for the presence of anti-NDV-F antibody on the day of NDV challenge, the vaccinated bird group which did not survive from NDV challenge were found to show lower antibody titers than the surviving group. The rMDV1 also provided sufficient protection against NDV and MDV1 challenges in commercial chickens with maternal antibodies against NDV-F and MDV1 antigens.

Animals↗
PubMed1998

Comparison of the ability of viral protein-expressing plasmid DNAs to protect against influenza.

The ability of plasmid DNA encoding various influenza viral proteins from the A/PR/8/34 (H1N1) virus to protect against influenza was compared in BALB/c mice. The plasmid DNA encoded hemagglutinin (HA), neuraminidase (NA), matrix protein (M1), nucleoprotein (NP) or nonstructural protein (NS1) in a chicken beta-actin-based expression vector (pCAGGS). Each DNA was inoculated twice 3 weeks apart at a dose of 1 microgram per mouse by particle-mediated DNA transfer to the epidermis (gene gun). Seven days after a second immunization, mice were challenged with the homologous virus and the ability of each DNA to protect mice from influenza was evaluated by decreased lung virus titers and increased survival. Mice, given HA- or NA-expressing DNA, induced a high level of specific antibody response and protected well against the challenge virus. On the other hand, mice given M1-, NP-, or NS1-DNA failed to provide protection, although M1- and NP-DNAs did induce detectable antibody responses. These results indicate that both HA- and NA-expressing DNAs for the surface glycoproteins are most protective against influenza from among the various viral protein-expressing DNAs used here.

Animals↗
PubMed1998

A follow-up of rhabdomyosarcoma of the infratemporal fossa region in adults based on the magnetic resonance imaging findings: case reports.

Two adult patients with rhabdomyosarcoma of the infratemporal fossa region were evaluated by computed tomography and magnetic resonance imaging both before and after treatment. Successful treatment accompanied by reduction of the tumor mass as a result of chemotherapy was demonstrated in one patient. In the other patient a subsequent increase in the tumor mass was documented. Information on not only the size but also the internal architecture of the tumor may be useful when tumor response to therapy is being investigated. Magnetic resonance imaging is recommended as a method for outcomes evaluation in adult rhabdomyosarcoma cases.

Adult↗
PubMed1998

Effects of tibolone (Org OD14) treatment for 3 months on ovariectomy-induced osteopenia in 8-month-old rats on a low-calcium diet: preventive testing for 3 months.

Tibolone (Org OD14), (7alpha, 17alpha)-17-hydroxy-7-methyl-19-norpregn-5(10)-en-20-yn++ +-3-one, is a synthetic steroid with weak estrogenic, progestational, and androgenic properties. We investigated the prophylactic effects of tibolone on bone loss, bone strength, and plasma and urinary parameters in 8-month-old ovariectomized rats on a low-Ca diet. Oral administration of tibolone (0.03-3 mg/kg/day) was started immediately after ovariectomy (ovx) and continued for 3 months. Bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry. Oral administration of tibolone (1 or 3 mg/kg/day) significantly prevented a decrease in BMD and bone ash density (bone ash weight/volume) of the global femur, and BMDs in the femoral distal and proximal regions. Also in the lumbar vertebrae, the ovx-induced reduction in BMD was prevented by tibolone (1 and 3 mg/kg/ day) treatment, resulting in a significantly higher lumbar vertebral (L-2) bone compression strength compared to the ovx control group. Neither ovx alone nor supplemented with tibolone affected the BMD or bending strength of the femoral mid-diaphysial region. Tibolone (0.03-3 mg/kg/day) significantly reduced the ovx-induced increases in serum osteocalcin level. Furthermore, tibolone inhibited an increase in the urinary hydroxyproline/creatinine, pyridinoline/creatinine, and deoxypyridinoline/creatinine ratios induced by ovx. Tibolone also reduced body weight gain and serum cholesterol level, as has been reported for estrogen. These findings indicate that tibolone prevents reduction in bone mass associated with osteopenia by reducing increased trabecular bone resorption induced by a combination of ovx and a low-Ca diet.

Administration, Oral↗
PubMed1998

Serum vascular endothelial growth factor levels in various liver diseases.

The clinical significance of circulating vascular endothelial growth factor (VEGF) in patients with various liver diseases was investigated. Twenty-one patients with acute hepatitis (AH), 40 with chronic hepatitis (CH), 34 with cirrhosis (LC), 16 with fulminant hepatitis (FH), 10 with primary biliary cirrhosis (PBC), 12 with autoimmune hepatitis (AIH), and 120 healthy individuals were included. Serum VEGF levels were measured by a chemiluminescence enzyme-linked immunosorbent assay. The mean values of serum VEGF levels in the patients with AH, CH, LC, FH, AIH, PBC, and control were 172.7, 58.0, 44.1, 37.3, 49.7, 74.9, and 65.0 pg/ml, respectively. The patients with AH had a level of serum VEGF significantly higher than that of the control group (P < 0.001). The serum VEGF levels in survivors of FH were significantly increased, but not in the nonsurvivors in the recovery phase compared with the levels on admission (P < 0.05). In the LC patients, serum VEGF levels were significantly lower than those of the control group (P < 0.05). These findings suggest that serum VEGF level may be associated with hepatocyte regeneration grade.

Acute Disease↗
PubMed1998

Increase in serum vascular endothelial growth factor levels during altitude training.

The present study was performed to evaluate the effects of physical exercise at altitudes on serum vascular endothelial growth factor (VEGF) levels. Eight subjects underwent intensive swimming training for 21 days at 1886 m. After altitude training commenced, red blood cell (RBC) counts and erythropoietin levels increased, but both haemoglobin and haematocrit levels did not change significantly. The serum level of VEGF, measured by means of a highly sensitive chemiluminescence (ELISA), showed a transient decrease 10 days after start of the altitude training, thereafter increasing significantly to reach a peak level 19 days later, rising from 23.0 +/- 5.3 to 46.0 +/- 14.6 pg mL-1 (P < 0.05 vs. before). On return to low altitude in Japan, the level of VEGF decreased, and 1 month later had returned to initial levels. Endurance training at altitudes increases serum VEGF levels; this could be an adaptive reaction to hypoxic conditions. This result suggests that VEGF may provide a new physiological parameter for hypoxic stress imposed by high altitude training.

Adult↗
PubMed1998

A monoarthritis model in rabbits induced by repeated intra-articular injections of lipopolysaccharide.

We attempted to develop a monoarthritis model using repeated intra-articular injections of high-dose Lipopolysaccharide (LPS). Furthermore, the effect of dexamethasone on this arthritis model by intra-articular administration was studied to examine whether the model can be used to screen anti-rheumatic drugs in a short time. Arthritis was induced by one, two or three intra-articular injections of LPS (5-50 micrograms/joint) at 4-day intervals into the knee joint. The rabbits were sacrificed at 7 days following the last injection of LPS. Three intra-articular injections of LPS at 50 micrograms/joint resulted in persistent joint swelling. Hyperplasia of synovium with some discolouration was macroscopically observed. Infiltration of mononuclear cells and lymphoid follicles were histologically observed as the synovial lesions. Concerning the articular bone/cartilage, trabecular destruction of gastrocnemius sesamoid bone and severe loss of safranin-O staining of articular cartilage were observed. Immunohistochemical analysis revealed that inflammatory cells and lymphoid follicles in the synovial lesions consisted predominantly of CD4+ T cells, with few CD8+ T cells. Treatment with dexamethasone markedly reduced the joint swelling and the articular destruction. The results suggest that this arthritis model in rabbits can be utilized to screen anti-rheumatic drugs as a model of rheumatoid arthritis.

Animals↗
PubMed1998

Aortitis syndrome (Takayasu's arteritis) with cataract and elevated serum level of vascular endothelial growth factor.

The aortitis syndrome is a chronic inflammatory process that affects the aorta and its primary branches. Patients with aortitis syndrome exhibit various ocular changes. We present a patient in whom cataract was the initial objective finding. The serum concentration of vascular endothelial growth factor, a cytokine that affects neovascularization, and vasopermeability, was elevated before the initiation of prednisolone treatment. Cataract should be considered as a possible characteristic initial finding in patients with aortitis syndrome. Vascular endothelial growth factor may be involved in the progression of aortitis syndrome.

Adult↗
PubMed1998

Vascular endothelial growth factor in patients with rheumatoid arthritis.

To examine the role of vascular endothelial growth factor (VEGF), an endothelial cell specific growth factor, in rheumatoid arthritis (RA), serum concentration of VEGF was examined in patients with RA, osteoarthritis (OA), systemic lupus erythematosus (SLE), systemic sclerosis (SS) and control subjects. Serum C-reactive protein (CRP) level, erythrocyte sedimentation rate, white blood cell count and rheumatoid factor titer were also determined in patients with RA. The serum concentration of VEGF was significantly higher in patients with RA than in controls (p < 0.01), and patients with OA (p < 0.05), SLE (p < 0.05), and SS (p < 0.05). The serum concentration of VEGF correlated with serum levels of CRP (r = 0.698, p < 0.0001). The serum concentration of VEGF before treatment was significantly higher than that after treatment in patients with RA who experienced clinical remission (p < 0.05). Our data suggest that VEGF is involved in the pathogenesis of RA and that measurement of serum concentration of VEGF is a noninvasive, useful method for monitoring the disease activity of RA.

Adolescent↗
PubMed1998

Radiofrequency catheter ablation of concealed atrioventricular accessory pathways using a "simultaneous pacing method".

The retrograde atrial potential at a successful ablation site is usually obscured by the wide and large ventricular potential during atrioventricular reentrant tachycardia or ventricular pacing, which makes it difficult to determine the appropriate ablation site for a concealed accessory pathway. A pacing maneuver named the "simultaneous pacing method" is proposed herein to differentiate the retrograde atrial potential from the ventricular potential for a successful ablation of the concealed accessory pathway. Catheter ablation was performed in 12 patients with a single left free-wall concealed accessory pathway. The atrial insertion site was determined by the simultaneous pacing method in six patients (group I) and by ventricular pacing in six patients (group II). In the simultaneous pacing method, electrograms recorded during ventricular pacing in the earliest retrograde atrial activation site are a fusion of the ventricular potential and the following retrograde atrial potential. When atrial and ventricular pacings are performed simultaneously (simultaneous pacing), the end portion of the electrograms recorded at the same site is solely the ventricular component, because atrial is activated earlier. The atrial potential can be confirmed during ventricular pacing in comparison with the electrograms during the "simultaneous pacing." Radiofrequency catheter ablation was successful in eliminating conduction through the accessory pathway in all 12 patients. The radiofrequency applications in group I were significantly fewer than those in group II (1.7 +/- 1.0 in group I, 5.3 +/- 3.2 in group II, P < 0.05). The total procedure time in group I was significantly shorter than in group II (57.8 +/- 15.7 vs 106.7 +/- 41.6 mins in group II, respectively, P < 0.05). The fluoroscopy time in group I was significantly shorter than in group II (54.0 +/- 7.9 vs 81.3 +/- 26.3 mins, respectively, P < 0.05). We were able to determine the atrial insertion site of accessory pathways by the simultaneous pacing method. The simultaneous pacing method was useful in eliminating concealed left free-wall accessory pathways.

Adult↗
PubMed1998

Mid-diastolic potential is related to the reentrant circuit in a patient with verapamil-sensitive idiopathic left ventricular tachycardia.

We report a case of verapamil-sensitive idiopathic ventricular tachycardia in which a mid-diastolic potential (MDP) 45 msec preceding the Purkinje potential (P potential) was recorded. Pacing during the tachycardia caused concealed entrainment, and the stimulus-QRS interval was equal to the P potential-QRS interval. The interval between the last pacing stimulus and the next P potential (postpacing interval) was longer than the ventricular tachycardia cycle length, but the MDP was orthodromically activated. These findings suggest that the MDP was on the reentrant circuit and the P potential was not on the reentrant circuit, but a bystander.

Adult↗
PubMed1998

Increased dispersion of repolarization time determined by monophasic action potentials in two patients with familial idiopathic ventricular fibrillation.

INTRODUCTION: The role of increased dispersion of repolarization in the genesis of torsades de pointes in patients with long QT syndrome has been clarified, but its role in the genesis of idiopathic ventricular fibrillation (VF) is not yet known. To investigate the pathogenesis of VF, we recorded monophasic action potentials (MAPs) from two siblings (48- and 36-year-old males) with familial idiopathic VF. METHODS AND RESULTS: The elder brother (patient 1) showed a late r' wave in lead V1 and ST segment elevation in leads V1 through V3. The younger brother (patient 2) had late r' waves and ST segment elevation in leads II, III, and aVF, and the configurations were very similar to those of patient 1. MAPs were recorded from several sites in the right ventricular (RV) and left ventricular (LV) endocardium during constant right atrial pacing. The repolarization time (RT) was defined as the sum of the activation time (AT) and action potential duration (APD) at 90% repolarization. In patient 1, marked prolongation of the AT (140 msec) and the RT (380 msec) was recorded in the RV septum of the outflow tract, and the RT dispersion was markedly increased (125 msec). In contrast, patient 2 showed prolongation of the AT (80 msec) and RT (310 msec), and fractionated electrograms in the RV floor of the inflow tract. The RT dispersion was also increased (80 msec). VF and nonsustained polymorphic ventricular tachycardia were induced by double premature stimulation in patients 1 and 2, respectively. Chronic amiodarone therapy decreased the RT dispersion and suppressed the induction of ventricular tachyarrhythmias in patient 2, although late r' waves and slight ST segment elevation were unmasked in leads V1 and V2. CONCLUSION: Our data suggest that the increased dispersion of the RT, which was due mainly to a localized conduction delay in the RV, created an arrhythmogenic substrate in the two patients with familial idiopathic VF.

Action Potentials↗
PubMed1998

Dynamic changes of 12-lead electrocardiograms in a patient with Brugada syndrome.

We present a patient with Brugada syndrome in whom 12-lead ECGs were recorded just before and after an episode of ventricular fibrillation (VF). A progressive elevation of both the RS-T segment and J waves just preceding and following the VF, and a close relationship between the amplitude of the RS-T segment and the preceding R-R intervals during atrial fibrillation, were documented. These findings support the hypothesis that RS-T elevation and a subsequent VF are related to a transient outward current-mediated spike-and-dome morphology of the epicardial action potential.

Adult↗