Biomedical subjects

H Kawano

Publications and source records attributed to H Kawano.

At least 55 records · Page 3Linked to original sources

PubMed2001

Characterization of mucins in human middle ear and Eustachian tube.

Mucins are important glycoproteins in the mucociliary transport system of the middle ear and Eustachian tube. Little is known about mucin expression within this system under physiological and pathological conditions. This study demonstrated the expression of MUC5B, MUC5AC, MUC4, and MUC1 in the human Eustachian tube, whereas only MUC5B mucin expression was demonstrated in noninflamed middle ears. MUC5B and MUC4 mucin genes were upregulated 4.2- and 6-fold, respectively, in middle ears with chronic otitis media (COM) or mucoid otitis media (MOM). This upregulation of mucin genes was accompanied by an increase of MUC5B- and MUC4-producing cells in the middle ear mucosa. Electron microscopy of the secretions from COM and MOM showed the presence of chainlike polymeric mucin. These data indicate that the epithelium of the middle ear and Eustachian tube expresses distinct mucin profiles and that MUC5B and MUC4 mucins are highly produced and secreted in the diseased middle ear. These mucins may form thick mucous effusion in the middle ear cavity and compromise the function of the middle ear.

Aged↗

PubMed2001

The relationship of left ventricular mass to endothelium-dependent vasodilation of the brachial artery in patients with hypertension.

Although echocardiographically determined left ventricular mass and geometry predict cardiovascular morbid events in patients with hypertension, the mechanisms underlying this relation are unclear. There is considerable evidence that endothelium-dependent vasodilation is impaired in patients with hypertension. Thus, endothelial dysfunction may contribute to the mechanism that causes cardiovascular morbid events. This study was designed to examine the relationship between left ventricular geometry and endothelial function in patients with hypertension. The percentage increase in brachial arterial diameter during reactive hyperemia was examined by a high-resolution ultrasound technique in 49 patients with hypertension and 64 normotensive subjects. Patients with hypertension had an impairment of the percentage increase in brachial arterial diameter during reactive hyperemia and an increase in thiobarbituric acid-reactive substances (TBARS) compared to normotensive subjects (percentage increase in diameter 5.6 +/- 3.0 vs. 8.0 +/- 2.5%, p < 0.001; TBARS levels 6.1 +/- 1.3 vs. 5.3 +/- 1.0 nmol/ml, p < 0.001). In patients with hypertension, there was a significant correlation between the left ventricular mass index and the percentage increase in brachial arterial diameter during reactive hyperemia (r = -0.583, p < 0.001), and the percentage increase in brachial arterial diameter during reactive hyperemia varied with the pattern of left ventricular geometry (normal ventricular geometry: 7.7 +/- 2.6%; concentric remodeling: 5.2 +/- 2.3%; eccentric hypertrophy: 4.2 +/- 1.8%; concentric hypertrophy: 2.9 +/- 2.6%). We conclude that (1) flow-mediated endothelium-dependent vasodilation in the brachial artery is impaired in patients with hypertension, (2) a relationship exists between the left ventricular mass index and flow-mediated endothelium-dependent vasodilation in the brachial artery in patients with hypertension and (3) increased oxidative stress may play a role in the endothelial dysfunction in patients with hypertension.

Adult↗

PubMed2001

Serotonergic heterotypic sprouting in the unilaterally dopamine-depleted mouse neostriatum.

The effects of unilateral 6-hydroxydopamine (6-OHDA) treatment on striatal serotonin neurons in 12-day-old mice were studied using immunohistochemistry. The unilateral 6-OHDA lesions were evaluated with tyrosine hydroxylase (TH) immunohistochemistry. The majority of the TH-immunoreactive structures disappeared from the substantia nigra and neostriatum on the 6-OHDA lesioned side. However, the density of serotonin fibers was markedly increased throughout the 6-OHDA-depleted neostriatum 1 year later. These results suggest that serotonergic heterotypic sprouting may be permanent.

Age Factors↗

PubMed2001

Adrenomedullin inhibits angiotensin II-induced expression of tissue factor and plasminogen activator inhibitor-1 in cultured rat aortic endothelial cells.

Adrenomedullin (AM) is a potent vasodilating peptide having a variety of pharmacological properties mainly in respect to vascular pathophysiology. We have previously demonstrated that angiotensin II (Ang II) or natriuretic peptides have influence on the expression of tissue factor (TF) and plasminogen activator inhibitor-1 (PAI-1) in vascular endothelial cells. The aim of this study was to elucidate the effects of AM on TF and PAI-1 mRNA and protein expression in endothelial cells. As a result, AM inhibited Ang II-induced TF and PAI-1 mRNA expression in a dose- and time-dependent manner. Because the expression of TF and PAI-1 mRNA induced by Ang II was attenuated by the increase of intracellular concentrations of cAMP by forskolin and 8-bromo-cAMP and because AM increased the intracellular level of cAMP in rat aortic endothelial cells, it was indicated that the inhibitory effect of AM on the expressions of TF and PAI-1 was mainly mediated by the cAMP-dependent signal transduction. Furthermore, the inhibitory effect of AM on TF and PAI-1 expression was partly attenuated by an NO synthase inhibitor, N(G)-nitro-L-arginine methyl ester. In conclusion, AM is shown to contribute to the regulation of blood coagulation and fibrinolysis by vascular endothelial cells mainly via the cAMP pathway.

8-Bromo Cyclic Adenosine Monophosphate↗

PubMed2001

Parenchymal hyperdensity on computed tomography after intra-arterial reperfusion therapy for acute middle cerebral artery occlusion: incidence and clinical significance.

BACKGROUND AND PURPOSE: The purpose of the present study was to assess the incidence and clinical significance of the intraparenchymal hyperdense areas on the posttherapeutic CT scan just after intra-arterial reperfusion therapy. METHODS: Seventy-seven patients with acute middle cerebral artery occlusion were studied prospectively with post-therapeutic CT. Hyperdense areas were classified into three groups: those in the lentiform nucleus, insular cortex and cerebral cortex. We investigated the incidence of hyperdense areas and hemorrhagic transformations and assessed whether location of hyperdense areas may play a role in the incidence of hemorrhagic transformations. We also evaluated correlation between early CT signs and hyperdense areas. RESULTS: Forty-five hyperdense areas were seen in 37 of the 77 patients (48.1%): 19 of the 45 (42.2%) were confirmed to be hematomas themselves, 6 (13.4%) showed later conversion to petechial hemorrhages, and 20 (44.4%) showed rapid disappearance without hemorrhagic transformations. Eleven of the 37 patients (29.7%) had neurological worsening due to massive hematoma (symptomatic hemorrhage), whereas none of the 40 patients without hyperdense areas had symptomatic hemorrhage. The incidence of hemorrhage among hyperdense areas was significantly lower in the insular cortex than in the other 2 regions (P<0.01). On the other hand, hyperdense areas in the lentiform nucleus had a significantly higher incidence of neurological worsening (P<0.05). There was a significant correlation between early CT signs and hyperdense areas (P<0.0001). CONCLUSIONS: The presence of hyperdense areas was a significant risk factor for severe hemorrhagic transformations, although only 29.7% of patients with hyperdense areas had symptomatic hemorrhage. On the contrary, the absence of hyperdense areas was a reliable negative predictor for symptomatic hemorrhage.

Acute Disease↗

PubMed2001

Developmental changes in cerebrospinal fluid concentrations of monoamine-related substances in patients with dentatorubral-pallidoluysian atrophy.

Using a Coulochem electrode array system, we investigated the developmental changes of monoamine-related substances in patients with dentatorubral-pallidoluysian atrophy. The patterns observed in the developmental changes of tryptophan, tyrosine, homovanillic acid (HVA), 3-O-methyldopa, and 3-methoxy4-hydroxyphenyl glycol (MHPG) in patients with dentatorubral-pallidoluysian atrophy are quite different from those in control subjects. These abnormal developmental changes in monoamine-related substances may be implicated in age-related differences in clinical symptoms of dentatorubral-pallidoluysian atrophy.

Adolescent↗

PubMed2001

Triple valve replacement with bileaflet mechanical valves: is the mechanical valve the proper choice for the tricuspid position?

A more durable mechanical valve may be a better choice for the tricuspid position than a bioprosthesis when the patient already has mechanical prosthesis in the left side of the heart. Eleven cases of triple valve replacement (total follow-up period, 49.5 patient years), all with mechanical valves, are reviewed to assess optimal valve selection. Nine patients had undergone a total of 12 previous cardiac surgeries. Three patients died in hospital (27.3%), but there were no late deaths among the survivors. Two cases of valve thrombosis in the tricuspid position occurred (linearized incidence: 4.04%/patient years) and 1 of these required reoperation. Because of this high incidence of valve thrombosis, the bileaflet mechanical valve is not considered to be the best choice. Even if mechanical valves are implanted in the left side of the heart, a bioprosthesis may be a better choice at the tricuspid position.

Adult↗

PubMed2001

Glycogen storage disease associated with left ventricular aneurysm in an elderly patient.

Glycogen storage disease (GSD) types II, III, IV, and V may be associated with cardiomyopathy, but, with the exception of type III GSD, adult cases are extremely rare. A 62-year-old man was found to have GSD and a concomitant left ventricular aneurysm. He had been comparatively well until the age of 62 years, although he had suffered a cerebral infarction at the age of 35 years. The damage caused by glycogen deposition was strictly confined to the myocardium. Left ventriculography revealed a left ventricular aneurysm in the apex. The serial change on electrocardiogram, as well as the findings of the echocardiogram and of cardiac catheterization, resembled those of the dilated phase of hypertrophic cardiomyopathy. However, a left ventricular endomyocardial biopsy specimen revealed central vacuolar degeneration of myocytes with depositions of glycogen. The GSD type remains unknown in the present patient, because the activity of debranching enzyme (type III) measured from the skeletal muscle specimen was normal, whereas that of acid maltase (type II) was slightly low. It is possible that there is a specific malfunction of the acid maltase of the myocardium in the present patient.

Glycogen Storage Disease↗

PubMed2001

The right ventricular outflow tract as an unusual location for an implantable defibrillator electrode in a patient with arrhythmogenic right ventricular dysplasia.

A 41-year-old woman with arrhythmogenic right ventricular dysplasia (ARVD) underwent the implantation of an implantable cardioverter-defibrillator (ICD), in which the defibrillator electrode was unusually located in the right ventricular (RV) outflow tract. Although fractionated electrograms were demonstrated in the RV apex, which is the usual site for ICD electrodes, normal electrograms were recorded in the RV outflow tract during an electrophysiologic study. An electrode with a screw-in tip was used to fix the implant in the RV outflow tract and obtain successful defibrillation. If normal electrograms are recorded in the RV outflow tract, the site may prove to be an alternative location for an ICD electrode even for ARVD patients.

Adult↗

PubMed2001

Isolation of a thermophilic poly-L-lactide degrading bacterium from compost and its enzymatic characterization.

Thermophilic poly-L-lactide-degrading bacteria were isolated from a garbage fermentor. One of the isolates, strain PL21, was identified as Bacillus smithii based on its physiological properties, sugar assimilation pattern, and partial 16S rDNA sequence. The degradation activity of poly-L-lactide exibited by the culture fluid was parallel to the esterase activity, and the purified enzyme was active against various fatty acid esters and poly-L-lactide, at 60 degrees C and pH 5.

Journal Article↗

PubMed2001

Arginine-vasopressin neurons in the rat hypothalamus produce neurokinin B and co-express the tachykinin NK-3 receptor and angiotensin II type 1 receptor.

Secretion of arginine-vasopressin (AVP) from the hypothalamic paraventricular (PVN) and supraoptic (SON) nuclei is induced by neurokinin B (NKB) and angiotensin. To characterize the mechanisms by which this occurs, we used immunohistochemical techniques to assess the ability of AVP-producing neurons to express NKB, NKB receptor (NK-3 receptor) and angiotensin II type 1 receptor (AT-1 receptor). Double fluorescence immunohistochemistry indicated that AVP-immunoreactive cell bodies in the PVN and SON, as well as their axon varicosities in the posterior pituitary, co-express NKB. Almost all AVP-neuron perikarya also expressed both the NK-3 receptor and AT-1 receptor. Thus, AVP-producing neurons in the PVN and SON, which are regulated by NKB, are themselves a source of NKB. Furthermore, the regulation of AVP release by these neurons by NKB and angiotensin II is mediated by the NK-3 receptor and the AT-1 receptor, respectively.

Animals↗

PubMed2001

Hypertrophic pulmonary osteoarthropathy associated with non-small cell lung cancer demonstrated growth hormone-releasing hormone by immunohistochemical analysis.

Hypertrophic pulmonary osteoarthropathy (HPO) associated with non-small cell lung cancer in a 58-year-old man was accompanied by an elevated serum level of growth hormone (GH). HPO rapidly disappeared after resection of the primary tumor and the elevation of serum GH was resolved. Immunohistochemically the tumor contained growth hormone-releasing hormone (GHRH) but not GH. These findings suggest that the high serum GH level due to ectopic GHRH production in the tumor, was a contributing factor in HPO. This is the second reported case of non-small cell lung cancer which was immunohistochemically positive for GHRH associated with HPO.

Carcinoma, Non-Small-Cell Lung↗

PubMed2001

Increased plasminogen activator inhibitor activity and diabetes predict subsequent coronary events in patients with angina pectoris.

BACKGROUND: Plasminogen activator inhibitor (PAI) is a marker of recurrence of myocardial infarction. Diabetes mellitus is also an important risk factor of coronary artery disease, including myocardial infarction and angina pectoris. AIM: We examined baseline plasma PAI activity levels, clinical variables, and angiographic findings and assessed them as prospective values for subsequent coronary events, such as sudden death, nonfatal myocardial infarction and coronary revascularization by percutaneous transluminal coronary angioplasty or coronary artery bypass surgery during the follow-up period. METHODS: We conducted a prospective study for 4 years of 249 consecutive patients admitted with angina pectoris. Blood samples for PAI were drawn at discharge. RESULTS: In the multivariate Cox proportional hazard model, PAI activity and diabetes mellitus were significant and independent risk factors (the risk increased by 10% in those with a higher PAI concentration and by 70% in diabetic patients). Event-free survival was reduced by higher PAI activity (> or = 8.4 IU/mL) and the presence of diabetes. The patients with higher PAI activity and diabetes had a 4.2-fold risk in comparison with the patients with lower PAI activity and no diabetes. However, patients with lower PAI activity were less likely to have coronary events even when they had diabetes. CONCLUSIONS: Higher PAI activity and diabetes predict subsequent coronary events in patients with angina pectoris. Diabetes has less prognostic value for subsequent coronary events in patients with lower PAI activity.

Angina Pectoris↗

PubMed2001

Homozygous serum amyloid P component-deficiency does not enhance regression of AA amyloid deposits.

Serum amyloid P component (SAP) is a common protein constituent of all types of amyloid deposits. Using SAP-deficient mice generated through gene targeting, we and others have shown that SAP significantly promotes amyloid deposition. It has been speculated that SAP protects amyloid fibrils from degradation by coating their exterior surface. To assess potential ways of treating individuals with amyloidosis, we examined the persistence of splenic AA amyloid fibrils in SAP-deficient and wild-type mice. No enhancement in the rate of regression of splenic AA amyloid was observed in the SAP-deficient mice relative to wild-type mice. These results present, for the first time, evidence that lack of SAP in AA amyloid deposits does not enhance regression of the deposits in vivo and suggest that dissociation of bound SAP from AA amyloid deposits would not significantly accelerate regression of the deposits in vivo.

Amyloidosis↗

PubMed2001

Correlation of early CT signs in the deep middle cerebral artery territories with angiographically confirmed site of arterial occlusion.

BACKGROUND AND PURPOSE: Early CT signs in the deep middle cerebral artery (MCA) territories have been reported to be seen at the initial period of ischemia. We attempted to investigate the incidence of parenchymal hypodensity within 3 hours after ischemic onset among patients with angiographically proved embolic MCA occlusion and to assess the correlation of subtle hypodensity in the deep MCA territories with involvement of the lenticulostriate arteries in the presence of ischemia. METHODS: Fifty CT images obtained within 3 hours after onset of embolic MCA occlusion were retrospectively reviewed by three neurosurgeons who were aware of clinical features. Early CT signs in the deep MCA territories were divided into three grades according to their anatomic location: grade I, normal basal ganglia with hypodensity localized to the insula; grade II, partial obscuration of the posterolateral part of the putamen; and grade III, hypodensity of the entire lentiform nucleus. A grade I CT sign was considered to be a negative finding for lenticulostriate artery involvement, whereas grade II and III CT signs were considered to be positive findings. Site of occlusion and involvement of the lenticulostriate arteries were confirmed by angiography. RESULTS: Thirty-eight (76%) of 50 patients had early CT signs in the deep MCA territories. Sensitivity and specificity of a grade I CT sign indicating absence of lenticulostriate artery involvement in ischemia were 65% and 87%, respectively. On the other hand, sensitivity and specificity of grade II and grade III CT signs for presence of lenticulostriate artery involvement in ischemia were 77% and 100%, respectively. Grade II CT signs resulted from various sites of occlusion, whereas grade III was unequivocally predictive of proximal occlusion to all of the lenticulostriate arteries. CONCLUSION: Involvement of the lenticulostriate arteries may be presumed by precise evaluation of subtle, CT-revealed hypodensity in the deep MCA territories, even within 3 hours of ischemic onset.

Aged↗

PubMed2001

Effects of water deprivation on neurokinin B production by the arginine-vasopressin neurons of hypothalamic paraventricular and supraoptic nuclei.

In order to clarify the role of neurokinin B (NKB), the dynamic changes in NKB expression and synthesis following water deprivation were examined in the arginine-vasopressin (AVP) neurons of hypothalamic paraventricular (PVN) and supraoptic (SON) nuclei. In intact rats, NKB and AVP showed almost the same high level of immunohistochemical reactivity in the magnocellular neurons of the PVN and SON, as well as in the varicose fibers in the median eminence (ME). In contrast, NKB precursor peptide (NKBp) immunoreactivity in the SON and PVN were relatively weak. Five days after water deprivation, AVP and NKB immunoreactivity decreased drastically, while NKBp-immunoreactivity increased in both the PVN and SON magnocellular neurons. Reverse transcription-polymerase chain reaction analysis of control animals revealed high levels of AVP mRNA and substantial amounts of NKB mRNA in the SON. This was contrast to the relatively low levels of AVP mRNA and undetectable levels of NKB mRNA in the PVN. After five days of water deprivation, AVP mRNA in the PVN and NKB mRNA in both the PVN and the SON increased considerably. These results indicate that synthesis and release of NKB, which colocalizes to AVP neurons, are enhanced by water deprivation in the same manner as AVP in the PVN and SON. Thus, NKB seems to be involved in the central control of body fluid levels. The results also suggest that the production rate of NKB under normal conditions in SON dominant.

Animals↗

PubMed2001

[A case of primary pleural leiomyosarcoma].

A 70-year-old man was admitted to our hospital with complaints of chest pain and exertional dyspnea. Chest radiography and computed tomography (CT) revealed right pleural effusion and pleural thickening on admission. The pleural fluid was bloody. Microbiological and cytologic examinations of the fluid were negative. The chest CT revealed progress of pleural thickening after hospitalization. A thoracoscopic pleural biopsy was performed, and the histological finding of the excised specimen was leiomyosarcoma. Because no organ of origin of the leiomyosarcoma, other than the pleura, was detected, this case was diagnosed as a primary pleural leiomyosarcoma. It is thought that leiomyosarcoma originating from the pleura is rare.

Aged↗

PubMed2001

Open heart operation in a patient with hereditary spherocytosis: a case report.

A 9-year-old girl who had ostium secundum atrial septal defect (ASD) and hereditary spherocytosis (HS) is described. The patient had a history of splenectomy for HS and underwent repair of the ASD under cardiopulmonary bypass (CPB), however, no significant or persistent hemolysis was observed during and after CPB. Only 10 patients with HS who underwent cardiac operations using CPB have been reported. The case is presented due to its rarity.

Cardiopulmonary Bypass↗