Biomedical subjects

H Kawano

Publications and source records attributed to H Kawano.

At least 109 records · Page 6Linked to original sources

PubMed2000

[Hemodynamic assessment of the Carpentier-Edwards pericardial valve compared with the St. Jude Medical valve in the aortic position using dobutamine-stress echocardiography].

To assess the hemodynamic performance of the prosthetic valve in the aortic position, we examined dobutamine-stress echocardiography (DSE) to the patients underwent AVR with CEP valve or SJM valve. In 23 mm size, there were no significant differences between CEP group and SJM group in Peak velocity of the aortic jet (PV), peak pressure gradient (PPG) and effective orifice area (EOA). On the other hand, in 21 mm size, PV and PPG of the CEP group were significantly lower than those of the SJM group after DSE. The EOA of the CEP group was significantly larger than that of the SJM group after DSE. Our results suggest that the hemodynamic function of the CEP valve is superior to that of the SJM valve especially in small aortic annuli.

Aged↗

PubMed2000

A case report of surgical treatment of quadricuspid aortic valve associated with regurgitation.

A case of a 65-year-old woman who had a quadricuspid aortic valve associated with aortic regurgitation is reported. The patient had severe aortic regurgitation and four equally divided aortic cusps. The valve abnormality was detected by a transesophageal echo and an aortography. The incomplete aortic valve was excised and replaced by a St. Jude Medical prosthesis. Although this case had no coronary abnormality, a coronary displacement is often reported in quadricuspid aortic valve cases. In order to perform an operation safely, accurate information which is obtained by a non-invasive examination of the transesoph-ageal echo is quite valuable as it can indicate the need for further preoperative examinations of the coronary arteries.

Aged↗

PubMed2000

[Primary pulmonary cryptococcosis with endobronchial lesion].

A 19-year old man was admitted to our hospital with fever and productive cough. Chest X-ray films revealed multiple nodular shadows accompanied by a fusing tendency in the right middle field. A diagnosis of bacterial pneumonia was indicated, and the patient was treated with antibiotics. However, because this failed to resolve the nodular shadows, bronchofibroscopy was performed. Examination with a fiberoptic bronchoscope revealed an elevated lesion in the truncus intermedius. Histopathologic examination of a specimen obtained by transbronchial biopsy revealed cryptococcal organisms with the infiltration of monocytes. These findings yielded a diagnosis of pulmonary cryptococcosis with endobronchial lesion. After 6 months of treatment with fluconazole, the multiple nodular shadows disappeared. Comparison of bronchoscopic findings before and after fluconazole treatment clearly demonstrated the efficacy of the therapy.

Adult↗

PubMed2000

[Porencephaly].

Explore the source record for details and available documents.

Brain↗

PubMed2000

[A small cell lung cancer shadow resembling beads on chest radiographs].

We present a case of small cell lung cancer whose shadow resembles bead son chest radiographs. An 81-year-old woman who had been receiving treatment from her doctor for pulmonary emphysema and chronic respiratory failure consulted our department because a small nodular shadow had been detected radiographically in the right lower lung field. The bead-like shadows in the radiographs and tomograms extended from the periphery of the right lower lobe to the pulmonary hilum. This case of small cell lung cancer appeared in chest radiographs to have an unusual shape.

Aged↗

PubMed1999

TRH increases cerebrospinal fluid concentration of kynurenine.

We have analyzed changes in cerebrospinal fluid (CSF) concentrations of monoamine-related substances to clarify the mechanism of the antiepileptic action of thyrotropin-releasing hormone (TRH). TRH-tartrate was administered to 14 patients with intractable epilepsy. Before and 2 weeks after TRH administration, CSF was collected and analyzed for tryptophan and tyrosine metabolites. Among monoamine-related substances, only CSF concentrations of kynurenine were increased after TRH therapy. Considering the fact that kynurenic acid acts as antagonist on the NMDA receptor complex, the results of this study may explain at least one of the mechanisms of the effectiveness of TRH therapy for intractable epilepsy.

Adolescent↗

PubMed1999

Galectin-1 regulates initial axonal growth in peripheral nerves after axotomy.

The signals that prompt the axons to send out processes in peripheral nerves after axotomy are not well understood. Here, we report that galectin-1 can play an important role in this initial stage. We developed an in vitro nerve regeneration model that allows us to monitor the initial axon and support cell outgrowth from the proximal nerve stump, which is comparable to the initial stages of nerve repair. We isolated a factor secreted from COS1 cells that enhanced axonal regeneration, and we identified the factor as galectin-1. Recombinant human galectin-1 (rhGAL-1) showed the same activity at low concentrations (50 pg/ml) that are two orders of magnitude lower than those of lectin activity. A similarly low concentration was also effective in in vivo experiments of axonal regeneration with migrating reactive Schwann cells to a grafted silicone tube after transection of adult rat peripheral nerve. Moreover, the application of functional anti-rhGAL-1 antibody strongly inhibited the regeneration in vivo as well as in vitro. The same effect of rhGAL-1 was confirmed in crush/freeze experiments of the adult mouse sciatic nerve. Because galectin-1 is expressed in the regenerating sciatic nerves as well as in both sensory neurons and motor neurons, we suggest that galectin-1 may regulate initial repair after axotomy. This high activity of the factor applied under nonreducing conditions suggests that galectin-1 may work as a cytokine, not as a lectin.

Animals↗

PubMed1999

Circulating levels of secretory type II phospholipase A(2) predict coronary events in patients with coronary artery disease.

Background-The circulating levels of secretory nonpancreatic type II phospholipase A(2) (sPLA(2)) are increased in various chronic inflammatory diseases and the increase in the levels correlates with the disease severity. sPLA(2) may possibly play a role in atherogenesis and is highly expressed in atherosclerotic arterial walls that are known to have inflammatory features. Thus, this study prospectively examined whether circulating levels of sPLA(2) may have a significant risk and prognostic values in patients with coronary artery disease (CAD). Methods and Results-Plasma levels of sPLA(2) were measured in 142 patients with CAD and in 93 control subjects by a radioimmunoassay. The sPLA(2) levels had a significant and positive relations with serum levels of C-reactive protein, a marker of systemic inflammation, and with the number of the traditional coronary risk factors associated with individuals. Multivariate logistic regression analysis showed that higher levels of sPLA(2) (>246 ng/dL; 75th percentile of sPLA(2) distribution in controls) were a significant and independent risk factor for the presence of CAD. In multivariate Cox hazard analysis, the higher levels of sPLA(2) were a significant predictor of developing coronary events (ie, coronary revascularization, myocardial infarction, coronary death) during a 2-year follow-up period in patients with CAD independent of other risk factors, including CRP levels, an established inflammatory predictor. Conclusions-The increase in circulating levels of sPLA(2) is a significant risk factor for the presence of CAD and predicts clinical coronary events independent of other risk factors in patients with CAD; these results may reflect possible relation of sPLA(2) levels with inflammatory activity in atherosclerotic arteries.

Aged↗

PubMed1999

Remnant lipoprotein levels in fasting serum predict coronary events in patients with coronary artery disease.

BACKGROUND: Remnant lipoproteins are atherogenic, but assays of remnants have not been available in routine clinical laboratories because of the lack of practical and validated methods. A simple and reliable method for such an assay, using an immunochemical approach, has recently been developed. This study prospectively examined whether remnant lipoprotein levels in fasting serum, measured by our method, may have prognostic value in patients with coronary artery disease (CAD). METHODS AND RESULTS: Remnant lipoprotein levels in fasting serum were measured in 135 patients with CAD by an immunoaffinity mixed gel containing anti-apolipoprotein (apo) A-1 and anti-apoB-100 monoclonal antibodies. Patients were followed up for </=36 months until occurrence of 1 of the following clinical coronary events: recurrent or refractory angina pectoris requiring coronary revascularization, nonfatal myocardial infarction, or cardiac death. Kaplan-Meier analysis demonstrated a significantly higher probability of developing coronary events in patients with the highest tertile of remnant levels (>5.1 mg cholesterol/dL; 75th percentile of distribution of remnant levels) than in those with the lowest tertile of remnant levels (</=3.3 mg cholesterol/dL; 50th percentile of the distribution). Higher levels of remnants were a significant and independent predictor of developing coronary events in multivariate Cox hazard analysis including the following covariates: extent of coronary artery stenosis, age, sex, smoking, hypertension, diabetes mellitus, hypercholesterolemia, low HDL cholesterol, and hypertriglyceridemia. CONCLUSIONS: Higher levels of remnant lipoproteins in fasting serum predict future coronary events in patients with CAD independently of other risk factors. Thus, measurement of fasting remnant levels, assessed by the current immunoseparation method, may be helpful in assessment of CAD risk.

Adult↗

PubMed1999

Pax-6 is required for thalamocortical pathway formation in fetal rats.

Pax-6, a transcription regulatory factor, has been demonstrated to play important roles in eye, nose, and brain development by analyzing mice, rats, and humans with a Pax-6 gene mutation. We examined the role of Pax-6 with special attention to the formation of efferent and afferent pathways of the cerebral cortex by using the rat Small eye (rSey2), which has a mutation in the Pax-6 gene. In rSey2/rSey2 fetuses, cortical efferent axons develop with normal trajectory, at least within the cortical anlage, when examined with immunohistochemistry of the neuronal cell adhesion molecule TAG-1 and 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI) labeling from the cortical surface. A remarkable disorder was found in the trajectory of dorsal thalamic axons by immunostaining of the neurofilament and the neural cell adhesion molecule L1 and DiI labeling from the dorsal thalamus. In normal rat fetuses, dorsal thalamic axons curved laterally in the ventral thalamus without invading a Pax-6-immunoreactive cell cluster in the ventral part of the ventral thalamus. These axons then coursed up to the cortical anlage, passing just dorsal to another Pax-6-immunoreactive cell cluster in the amygdaloid region. In contrast, in rSey2/rSey2 fetuses, dorsal thalamic axons extended downward to converge in the ventrolateral corner of the ventral thalamus and fanned out in the amygdaloid region without reaching the cortical anlage. These results suggest that Pax-6-expressing cell clusters along the thalamocortical pathway (ventral part of the ventral thalamus and amygdala) are responsible for the determination of the axonal pathfinding of the thalamocortical pathway.

Afferent Pathways↗

PubMed1999

Catecholaminergic and neuropeptide Y-immunoreactive synaptic inputs onto median preoptic nucleus neurons projecting to the ventrolateral medullary catecholaminergic area in the rat.

Median preoptic nucleus (POMe) neurons are innervated by catecholaminergic and neuropeptide Y (NPY)-immunoreactive nerve terminals originating from the catecholamine area of the ventrolateral medulla (VLM). The possibility that such POMe neurons project to the VLM catecholamine area was investigated in the rat. Immunoelectron microscopy revealed synaptic contacts of tyrosine hydroxylase- and NPY-immunoreactive axon terminals onto POMe neurons retrogradely labeled from the VLM catecholamine area, suggesting the existence of bidirectional connections between these two regions.

Animals↗

PubMed1999

Synaptic contacts between nerve terminals originating from the ventrolateral medullary catecholaminergic area and median preoptic neurons projecting to the paraventricular hypothalamic nucleus.

A significant role of catecholaminergic projection to the median preoptic nucleus (POMe) which activates vasopressin-producing cells of the paraventricular hypothalamic nucleus (PVN) has been suggested. We investigated the existence of the synaptic contacts between catecholaminergic fibers from the ventrolateral medulla and the POMe neurons projecting to the PVN. Rats received a retrograde tracer in the PVN and subsequently an anterograde tracer into the catecholaminergic area of the ventrolateral medulla at the level of the area postrema. In the POMe, anterogradely labeled nerve terminals were found to make axo-somatic and axo-dendritic synaptic contacts onto retrogradely labeled neurons. Additional studies in which a retrograde tracer was injected into the POMe revealed that almost all retrogradely labeled neurons in the ventrolateral medulla at the level of the area postrema were immunoreactive to tyrosine hydroxylase, suggesting that projection to the POMe from the ventrolateral medulla is largely limited to catecholamine neurons. These results provide, for the first time, direct evidence that catecholaminergic inputs from the ventrolateral medulla affect POMe neurons projecting to the PVN by way of direct synaptic contact.

Animals↗

PubMed1999

Clear cell chondrosarcoma of the pelvis in a skeletally immature patient.

We report on a case of clear cell chondrosarcoma (CCCS) of the left iliac bone in a 12-year-old skeletally immature boy. Radiographic examination revealed an aggressive osteolytic lesion with areas of mineralization. Fluid-fluid levels were seen on T2-weighted MR images. Laboratory data showed slight elevation of serum alkaline phosphatase. The biopsy specimen showed histological features of CCCS with some resemblance to osteosarcoma, such as prominent irregular osteoid formation among clear tumor cells. Surgical treatment was accomplished without pre- or post-operative chemotherapy. Because of the patient's age, elevated serum alkaline phosphatase, and histopathology with prominent osteoid production, this case could be confused with osteosarcoma. Although CCCS is an extremely rare bone tumor in children, it is important to be aware that it may arise in a skeletally immature patient. CCCS, unlike osteosarcoma, is not treated with neo-adjuvant chemotherapy.

Bone Neoplasms↗

PubMed1999

Giant trichoblastoma mimicking malignancy.

We report a case of giant trichoblastoma, a rare benign hair germ tumor. A 73-year-old man presented with a soft-tissue mass on his upper arm. Magnetic resonance imaging analysis revealed an unique mosaic pattern on T2-weighted images. Needle biopsy disclosed a keratinizing tumor suggesting squamous cell carcinoma. The size of the tumor was 9.5 x 7 x 9.5 cm, one of the largest trichoblastomas ever reported. The rarity and gigantic size of the tumor, together with its misleading clinical features, prompted us to report our case.

Aged↗

PubMed1999

Motor innervation by enteric nerve fibers containing both nitric oxide synthase and galanin immunoreactivities in the striated muscle of the rat esophagus.

The relationship between nitric oxide synthase (NOS)- and galanin-immunoreactive nerve terminals and the origin of NOS-immunoreactive nerve terminals on the motor endplates in the striated muscles of the rat esophagus was investigated. Double immunohistochemical staining revealed a dual innervation of motor endplates by calcitonin gene-related peptide (CGRP)-immunoreactive axons and by axons that were immunoreactive for both NOS and galanin. On average, 91% of NOS terminals were galanin immunoreactive. NOS-immunoreactive fibers were revealed at 67% of endplates, identified by the presence of CGRP terminals. The left vagus and superior laryngeal nerve were cut and 15 days allowed for terminals to degenerate. This caused a significant loss of CGRP fibers, but did not affect the density of innervation of the striated muscle by NOS-immunoreactive fibers. Thus the NOS/galanin fibers are deduced to originate from ganglia in the esophageal wall. This is supported by our observation of numerous NOS-immunoreactive nerve cell bodies in the myenteric ganglia of the esophagus, 74% of which were galanin immunoreactive. There were no CGRP-immunoreactive nerve cell bodies in the wall of the esophagus.

Animals↗

PubMed1999

Improvement of endothelial vasomotor dysfunction by treatment with alpha-tocopherol in patients with high remnant lipoproteins levels.

OBJECTIVES: This study sought to examine whether oral intake of alpha-tocopherol, an antioxidant, could improve endothelium-dependent vasorelaxation in patients with high remnant lipoproteins levels. BACKGROUND: Remnant lipoproteins are known to be atherogenic and impair endothelium-dependent arterial relaxation, but the underlying mechanisms remain unclear. Oxidative stress is a common feature of various risk factors for atherosclerosis. METHODS: Flow-mediated vasodilation of the brachial artery during reactive hyperemia was examined by high resolution ultrasound technique before and at the end of 4 weeks treatment with oral administration of alpha-tocopherol acetate (300 IU/day) or placebo, which was randomly assigned, in 40 patients with high serum levels of remnants and in 30 patients with low remnants levels in the fasting state (>75th percentile and <25th percentile, respectively, of the distribution of remnants levels in 150 consecutive hospitalized patients). RESULTS: Before treatment, flow-mediated vasodilation was lower in patients with high remnants levels than in those with low levels (4.1 +/- 0.3% vs. 6.0 +/- 0.5%, p < 0.01). Treatment with alpha-tocopherol but not with placebo significantly increased flow-mediated dilation in patients with high remnants levels (7.5 +/- 0.4% after alpha-tocopherol vs. 4.2 +/- 0.4% after placebo, p < 0.01). In patients with low remnants levels, alpha-tocopherol was not effective. The beneficial effect with alpha-tocopherol in high remnants patients was associated with decrease in plasma levels of thiobarbituric acid reactive substances, an indicator of lipid peroxidation (6.6 +/- 0.3 nmol/ml before alpha-tocopherol vs. 4.6 +/- 0.3 after alpha-tocopherol, p < 0.05). CONCLUSIONS: Alpha-tocopherol improved impairment of endothelium-dependent vasodilation in patients with high remnants levels. The increase in oxidative stress may at least partly contribute to endothelial vasomotor dysfunction, in patients with high remnants levels.

Adult↗

PubMed1999

Hyperglycemia rapidly suppresses flow-mediated endothelium-dependent vasodilation of brachial artery.

OBJECTIVES: We examined whether endothelial dysfunction occurs when acute hyperglycemia is induced by oral glucose loading. BACKGROUND: Endothelial dysfunction has been shown to occur in patients with diabetes mellitus (DM), and chronic hyperglycemia is implicated as a cause of endothelial dysfunction. However, in many patients with Type 2 DM and in those with impaired glucose tolerance (IGT), fasting blood glucose may be within normal limits, and hyperglycemia occurred only post-prandially. METHODS: With ultrasound technique, we measured flow-mediated endothelium-dependent vasodilation during oral glucose tolerance test in 58 subjects: (17 patients with normal glucose tolerance [NGT], 24 with IGT, and 17 with type 2 DM). In addition, we measured the levels of thiobarbituric acid reactive substances (TBARS) and nitrite/nitrate. RESULTS: Flow-mediated vasodilation decreased after glucose loading (NGT: 7.53+/-0.40, 4.24+/-0.28 and 6.35+/-0.40, in fasting, at 1- and 2-h, respectively, IGT: 6.50+/-0.48, 1.40+/-0.41** and 4.00+/-0.47*, respectively; DM: 4.77+/-0.37, 1.35+/-0.38** and 1.29+/-0.29%**, respectively; *p < 0.01 vs. fasting, **p < 0.005 vs. fasting). The TBARS concentration increased in parallel with plasma glucose level in each group (NGT: 1.43+/-0.07, 2.03+/-0.12 and 1.80+/-0.12, respectively; IGT: 1.65+/-0.11, 2.46+/-0.12** and 1.94+/-0.08*, respectively; DM: 1.73+/-0.07, 2.34+/-0.08** and 2.47+/-0.09** nmol/ml, respectively; *p < 0.05 vs. fasting, **p < 0.01 vs. fasting). Glucose loading did not change nitrite/nitrate concentration in any of the groups. CONCLUSIONS: Hyperglycemia in response to oral glucose loading rapidly suppresses endothelium-dependent vasodilation, probably through increased production of oxygen-derived free radicals. These findings strongly suggest that prolonged and repeated post-prandial hyperglycemia may play an important role in the development and progression of atherosclerosis.

Acute Disease↗

PubMed1999

Down-regulation and redistribution of GPV/GPVf2, a subunit of von Willebrand factor receptor (GPIb/IX/V complex), on the surface membrane of thrombin-stimulated human platelets.

We have studied down-regulation and redistribution of glycoprotein V (GPV) and its fragment GPVf2, a subunit of a receptor for von Willebrand factor (VWF), on the surface membrane of thrombin and thrombin receptor activating peptide (TRAP) stimulated platelets by using a newly developed GPVf2-specific monoclonal antibody (1D9). Immunoelectron-microscopical studies revealed that about 50% each of total GPV and GPIX were expressed on the surface membrane of the resting human platelets, and about 83% of GPlbalpha was expressed on the surface. In thrombin-stimulated platelets, the surface GPIbalpha, GPIX and GPV, after hydrolysis by thrombin, was converted to GPVf2, translocated from the surface to the intraplatelet pool and then again redistributed to the surface. In TRAP-stimulated platelets, GPIbalpha, GPIX and GPV, without conversion to GPVf2, were translocated from the surface to the intraplatelet pool and then returned to the surface. Ristocetin-induced agglutinations of both the thrombin- and TRAP-stimulated platelets were lowered during the decreased surface expressions of GPIbalpha, GPIX and GPV/GPVf2 and then normalized when these GPs were again redistributed onto the surface, indicating that the redistributed GPIb/IX/Vf2 complex on the surface can act as a VWF receptor as efficiently as an intact GPIb/IX/V.

Blood Platelets↗