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Biomedical subjects

Y Honda

Publications and source records attributed to Y Honda.

At least 361 records · Page 20Linked to original sources
PubMed1996

[Evaluation of left ventricular volume and ejection fraction using three-dimensional transesophageal echocardiography].

Left ventricular (LV) volume and ejection fraction (EF) derived from three-dimensional echocardiography using a multiplane transesophageal probe (3D-TEE) were compared with LV volume and EF obtained from left ventriculography (LVG) in 14 patients (mean age: 61 years). Left ventricular volumes were calculated using a summation of disks algorithm based on multiple reconstructed short-axis cross-sections from 3D data. Left ventricular volume (end-diastole and end-systole) and EF from 3D-TEE were compared with those from LVG using linear regression analysis. Three-dimensional TEE demonstrated excellent correlations with LVG for measuring LV volume (r = 0.97, SEE = 11 ml) and EF (r = 0.95, SEE-4%), respectively. Three-dimensional TEE is useful for the measurement of LV volume and EF in the clinical setting.

Echocardiography, Transesophageal↗
PubMed1996

[Phasic flow velocity characteristics of the right coronary artery in patients with aortic stenosis: a Doppler guide wire study].

This study investigated the characteristics of the phasic flow velocity pattern of the right coronary artery and the relationship to hemodynamic parameters in patients with aortic stenosis. Coronary flow velocities were recorded at the proximal (segment 1) and the distal (segment 4PD) portion of the right coronary artery using a Doppler guide wire (0.014-in, 15 MHz) in 10 patients with aortic stenosis and 8 control subjects with normal coronary arteries. The diastolic to systolic peak velocity ratio at both the proximal and distal portion were significantly greater in patients with aortic stenosis than in control subjects. Systolic flow reversal was not seen in the right coronary artery in control subjects, but it was observed in 5 patients (50%) at the proximal portion and in 10 patients (100%) at the distal portion. Peak velocity of flow reversal at the distal portion showed a significant correlation with mean pressure gradient across the aortic valve (y = -1.3x + 37.3, r = 0.71, p = 0.02). Systolic flow reversal is characteristic in the right coronary artery, especially at the distal portion, in patients with aortic stenosis. This may be related to the pressure difference across the aortic valve through the posterior descending artery.

Aged↗
PubMed1996

[Value and limitations of valve resistance in assessing prosthetic aortic valve function: clinical study using dobutamine stress doppler echocardiography].

Hemodynamic resistance may be a useful index for the severity of valvular aortic stenosis, but little is known about the utility of valve resistance in assessing the prosthetic aortic valve function. This study investigated whether valve resistance is useful in assessing prosthetic valve function in 13 patients with normally functioning CarboMedics prosthetic aortic valves. Transvalvular pressure gradient, effective orifice area and valve resistance derived from two-dimensional and Doppler echocardiography were calculated before and after dobutamine infusion. Dobutamine was infused incrementally (3-12 micrograms/kg/min) under echocardiographic imaging. Transvalvular pressure gradient (24 +/- 7-->53 +/- 18 mmHg, p < 0.01) and valve resistance (102 +/- 32-->140 +/- 57 dynes.sec.cm-5, p < 0.01) significantly increased after dobutamine infusion. However, effective orifice area did not increase significantly (1.1 +/- 0.5-->1.2 +/- 0.5 cm2). These findings indicate that transvalvular pressure gradient and valve resistance are flow-dependent and should be treated with caution when assessing prosthetic valve function.

Adult↗
PubMed1996

[Two cases of clear cell tumor of the lung].

We report two cases of benign clear cell tumor of the lung, which were found as well-circumscribed lesions on chest X-ray films without any symptoms, and removed surgically. Light microscopy showed proliferation of clear cells filled with glycogen in both cases. Immunohistochemical examination performed in a case suggested that the tumor cells might be associated to a derivation from neural and/or smooth muscle cells, because of positive staining for NSE and SMA. In another case, the tumor formed a necrotic cavity, which could be detected by the preoperative MRI examination. This report might introduce a note of caution for the pathologic and radiographic diversity of this disease.

Adult↗
PubMed1996

Carcinoembryonic antigen and related antigens expressed on keratinocytes in inflammatory dermatoses.

Carcinoembryonic antigen (CEA) is recognized as being important not only as a tumour marker, but also as a cell adhesion molecule in the metastasis of malignant tumour cells, and in the development of inflammatory disorders in some organs. However, the role played by this antigen in inflammatory dermatoses has not been studied previously. To investigate the expression of CEA in inflamed skin, we performed immunohistochemical studies to detect the antigen in both frozen and formalin-fixed, paraffin-embedded biopsy specimens of inflammatory dermatoses, using five different monoclonal antibodies and one polyclonal antibody against human CEA or CEA-related molecules. CEA and CEA-related antigens were expressed by epidermal keratinocytes and by some infiltrating inflammatory cells in inflamed skin. The expression was observed primarily in the upper part of the malpighian layers of the epidermis. On the basis of the distribution of this expression, we suggest an additional role for CEA-related molecules, differing from their roles as tumour markers and adhesion molecules, namely that these molecules may be associated with the state of differentiation of epidermal keratinocytes. Unexpected expression of CEA-related antigens was seen on normal follicular keratinocytes. Thus, it is conceivable that CEA-related antigen may also play a role in the biology of hair follicles.

Antigens, Surface↗
PubMed1996

[The influence of endoscopic injection sclerotherapy (EIS) on respiro-circulatory condition in patients with portal hypertension--the effect of oxygen administration].

We studied the influence of EIS on the respiro-circulatory condition of patients with portal hypertension. Subjects were fifty patients with portal hypertension who were successfully injected more than 5.0 ml of sclerotant into varices. A prospective randomized controlled trial was proposed to elucidate the effect of prophylactic administration of pure oxygen. Twenty-five patients inhaled pure oxygen (O2), remaining twenty-five patients did not during EIS. Respiro-circulatory function of patients was evaluated by monitoring O2 saturation, pulse rate and blood pressure during EIS. PaO2 was measured before and after EIS in seven patients without O2. EIS by the 5% ethanolamine oleate with iopamidol (EOI) was performed under X-ray monitoring. O2 saturation in patients without O2 inhalation was lowered, whereas that in patients with O2 inhalation was stable during EIS. O2 saturation during injection of EOI and after EIS in patients without O2 inhalation was significantly lower than that in patients with O2 inhalation. Pulse rate was significantly lower and a rise in blood pressure was smaller in patients given O2. No significant differences of PaO2 was noted before and after EIS. In conclusion, the monitoring of O2 saturation, pulse rate and blood pressure is necessary during EIS. Prophylactic administration of pure oxygen may be useful for prevention of hypoxic state and respiro-circulatory stabilization during EIS.

Adult↗
PubMed1996

Protective effect of the novel cerebrovascular-selective calcium antagonist (+/-)-(E)-1-(3-fluoro-6, 11-dihydrodibenz[b,e]-oxepine-11-yl)-4-(3-phenyl-2-propenyl)-piperazine dimaleate on ischemic brain damage after permanent middle cerebral artery occlusion in rats.

In this study the effect of post-ischemic treatment of AJ-3941 ((+/-)-(E)-1-(3-fluoro-6,11-dihydrodibenz [b,e]-oxepine-11-yl)-4-(3-phenyl-2-propenyl)-piperazine dimaleate, CAS 143110-70-7) a cerebrovascular-selective calcium antagonist, on brain infarction and edema in a rat model of focal cerebral ischemia with permanent middle cerebral artery occlusion (MCAo) was evaluated. Brain infarct size was determined at 24 h after MCAo by measuring 2,3,5-triphenyltetrazolium chloride-negative stained area of the serial brain sections. Post-ischemic treatment of AJ-3941 (3 mg/kg p.o.), 10 min and 3 h after the insult, significantly reduced brain infarct size by 44-80%, compared to vehicle control. The reducing effect was observed both in the cortical and subcortical regions. Three days after MCAo, contents of water and Na+ in the ipsilateral hemisphere significantly increased comparing with those in control rats. Post-ischemic treatment with AJ-3941 (3 and 10 mg/kg twice daily p.o. for 2 days) markedly inhibited the increase in water content and suppressed the increase in Na+ content. In the contralateral hemisphere, these contents showed no significant differences between vehicle-treated group and either control (non-operated) or AJ-3941-treated group. AJ-3941 had only minimum effect on body temperature and physiological parameters, such as blood pressure, blood gases and glucose, even when the maximum dose used (10 mg/kg) was repeatedly administered. These results indicate that post-ischemic treatment with AJ-3941 may ameliorate the brain infarction and edema after permanent focal cerebral ischemia, and they also suggest that AJ-3941 has a beneficial effect in the treatment of ischemic cerebral damage.

Animals↗
PubMed1996

Predicting risk of embolization during anticoagulation for left atrial thrombus by transesophageal echocardiography: a case report.

A 75-year-old woman was admitted with transient left hemiparesis accompanied by diminished level of consciousness in September 1994. Holter electrocardiography showed transient atrial fibrillation, and transesophageal echocardiography (TEE) revealed an atrial septal aneurysm, spontaneous echo contrast, and a thrombus in the left atrial appendage. The patient received anticoagulant treatment with warfarin, and follow-up TEE showed thrombus resolution. However, after the warfarin was discontinued, symptoms recurred in October 1995 and TEE showed a club-like left atrial thrombus (21 x 40 mm) originating in the left atrial appendage and extending to the center of the left atrium. Follow-up TEE after warfarin therapy showed resolution at the neck of the thrombus but the head threatened detachment. The thrombus was subsequently excised surgically. Follow-up TEE was critical for detecting the risk of significant embolization during anticoagulant therapy.

Aged↗
PubMed1996

Visualization of leukocyte dynamics in the choroid with indocyanine green.

PURPOSE: To report a method to evaluate leukocyte dynamics in the choroidal circulation with indocyanine green (ICG) angiography. METHODS: Nonpigmented and pigmented rats were administered ICG solution intravenously. The fundus image was obtained with a scanning laser ophthalmoscope and recorded on magnetic tapes at a video rate (30 frames/second). The images were analyzed with a personal computer-based image analysis system. RESULTS: On ICG angiography, hyperfluorescent dots were seen moving along the choroidal vessels and in the retinal vessels several minutes after injection. These fluorescent dots were thought to be circulating leukocytes stained with ICG. The micrographs of blood smears after ICG injection showed intense fluorescence of leukocytes. Computer-assisted image analysis allowed tracing of these fluorescent dots using a frame-by frame method. CONCLUSIONS: Results of this study indicated that ICG can be used for vital staining of leukocytes and that it is possible to evaluate leukocyte movement in the choroidal circulation in vivo in rats.

Animals↗
PubMed1996

[A case suspected of early active pulmonary tuberculosis detected by CT with the onset of episcleritis].

A 56-year-old female with the chief complaint of conjunctival injection was referred to our hospital after treatments with oral and topical corticosteroid under the diagnosis of episcleritis without any therapeutic efficacy. Possible causes of the episcleritis such as collagen vascular disease were not found, but a chest CT revealed centrilobular nodules, branching linear lesions and bronchial wall thickening which were not detected in a plain X-ray picture. We suspected pulmonary tuberculosis and tuberculous episcleritis based on these CT findings, strongly positive tuberculine skin test result and a history of contact with a smear positive tuberculosis patient. The pulmonary lesion disappeared and the episcleritis healed after the treatment with systemic antituberculous agents.

Female↗
PubMed1996

[Novel method for lower-half body perfusion at circulatory arrest].

It is generally accepted that patients with thoracic aortic aneurysma (TAA) require surgical reconstruction in the open distal anastomosis method. However, the optimal treatment of those with TAA remains controversial, as some of the postoperative complications are spinal-cord injury, rhabdomyolysis, MNMS and so forth caused by ischemia of lower-half body. Therefore the new Y connector with a one-way valve is useful for open distal anastomosis to avoid ischemia of the lower-half body. Through the branch of the Y connector between the femoral artery cannula and the arterial line, the occlusion balloon catheter is inserted and inflated at the descending aorta for perfusion of lower-half body. This procedure is safer and faster to perform than the conventional methodology in which a puncture is inserted, and a balloon catheter may be used only on the side of blood supply, thus making it possible to minimize the aggression of the patient.

Aortic Aneurysm, Thoracic↗
PubMed1996

Sweat duct milia--immunohistological analysis of structure and three-dimensional reconstruction.

The fine structure of sweat duct milia and the pathomechanism in their aetiology are still unknown. To examine the relationship and connection of milia to the sweat ducts as well as to the overlying epidermis, nine sweat duct milia, six incomplete and three complete, were studied by three-dimensional reconstruction (3DR) analysis based on photomicrographs obtained after histological and immunohistochemical staining with antibodies against carcinoembryonic antigen (CEA), cancer antigen (CA 50) and human cytokeratin 19 (CK 19). In both incomplete and complete milia, an eccrine duct expressing the antigens penetrated into the cyst wall at the centre of its base, formed a circular path within the wall, and opened into the inner cavity. The eccrine duct was mature in eight milia and immature in one. In the cyst wall, CA 50 and CK 19 were detected throughout the entire cyst except for the most apical portion of incomplete milia, where the cyst wall fused with the overlying epidermis which did not express any of the antigens. CEA was distributed mainly in the basal half of the milia. The finding that the path of the eccrine duct within the cyst wall is circular conflicts with the currently accepted concept of simple penetration of the eccrine duct into the wall, suggesting an acrosyringeal origin of the milia. An incomplete milium is the result of fusion between cells derived from an eccrine duct and those derived from the surrounding epidermis, while the formation of a complete milium does not involve this fusion.

Aged↗
PubMed1996

Ocular hypotensive mechanism of intravitreally injected brain natriuretic peptide in rabbit.

PURPOSE: To determine whether brain natriuretic peptide (BNP) affects intraocular pressure (IOP), aqueous humor dynamics, and cyclic guanosine monophosphate (cGMP) concentration in the aqueous humor of the rabbit eye. METHODS: Twenty microliters of 10(-4) M and 10(-5) M (2 nmol, 0.2 nmol) BNP or atrial natriuretic peptide (ANP) were injected intravitreally into rabbit eyes, after which the IOP was measured using a pneumatonometer. Aqueous humor dynamics were studied at approximately 6 hours after the intravitreal injection of 2 nmol BNP. Aqueous humor flow was measured by fluorophotometry, and outflow facility was measured by the two-level constant pressure perfusion method, whereas uveoscleral outflow was measured by the fluorescein isothiocyanate-dextran perfusion method. The concentration of cGMP in the aqueous humor at 6 hours after injection of 2 or 0.2 nmol BNP also was measured by enzyme immunoassay. RESULTS: Intravitreal administration of BNP or of ANP caused a decrease in IOP, with a maximum effect at approximately 6 hours after the injection. Total outflow facility in eyes treated with 2 nmol BNP increased by 29%, although the aqueous humor flow and uveoscleral outflow did not show significant changes. The concentration of cGMP in the aqueous humor increased significantly in BNP-treated eyes. CONCLUSIONS: Intravitreal injection of BNP into rabbit eyes reduced IOP because of an increase in the outflow facility. Brain natriuretic peptide also increased the concentration of cGMP in the aqueous humor. It is probable that BNP-activated guanylate cyclase induced an upregulation of cGMP in the aqueous humor.

Animals↗
PubMed1996

In vivo gene transfer into the retina mediated by a novel liposome system.

PURPOSE: To determine whether a reporter gene can be introduced into rat and mouse retinas in vivo using the authors' novel liposome system. METHODS: Cytomegalovirus-promoted LacZ genes and nonhistone nuclear protein, high mobility group 1 (HMG1), were coencapsulated in liposomes by agitation and sonication. The liposomes were then coated with the envelope of inactivated hemagglutinating virus of Japan (HVJ; Sendai virus) by fusion (HVJ liposome). The HVJ liposome solution was injected into the vitreous cavity of adult Sprague-Dawley rats (n = 30) or the subretinal space of adult CD-1 mice (n = 42). LacZ expression was assessed by beta-galactosidase assay. RESULTS: LacZ expression was demonstrated in the photoreceptors as long as 30 days after intravitreal and subretinal injections. beta-Gal activity was observed also in neurons and glial cells in the ganglion cell layer of the intravitreally injected rats and, although at lower intensity, in the retinal pigment epithelium of both animals. No inflammation or toxic effects secondary to the HVJ liposomes were detected on histologic examination. CONCLUSIONS: In vivo transfer and expression of a reporter gene into adult mammalian retina can be achieved using HVJ liposomes. This method offers a promise as a nonviral system for in vivo gene transfer into adult mammalian neural retina.

Animals↗
PubMed1996

In vivo quantification of leukocyte behavior in the retina during endotoxin-induced uveitis.

PURPOSE: The interaction between leukocytes and vascular endothelial cells plays an important role in various inflammatory disorders. This study evaluated leukocyte behavior in the retina during endotoxin-induced uveitis (EIU) in vivo. METHODS: EIU was induced in female Lewis rats by footpad injection of lipopolysaccharide (LPS). The time-course changes of retinal leukocyte behavior were followed at 1.5, 3, 4.5, 6, 12, 24, 48, 72, and 120 hours after LPS treatment using acridine orange digital fluorography, consisting of high-resolution images from a scanning laser ophthalmoscope and a fluorescent nuclear dye of acridine orange. RESULTS: Major retinal vessels were significantly dilated (P < 0.05) at 4.5 hours after LPS injection. The vasodilation, marked in veins, became maximum at 24 hours and subsided at 72 hours. Leukocytes were observed rolling along the walls of major veins at 4.5 hours. The number of rolling leukocytes gradually increased and reached a peak level of 33.8 +/- 3.4 cells/minute per major vein at 12 hours. Leukocyte rolling was still observed at 72 hours. No rolling of leukocytes was observed along the arterial walls throughout any experiments. The velocities of rolling leukocytes were determined at 6, 12, 24, and 48 hours. The leukocyte rolling velocity at 6 hours was significantly slower (33.3 +/- 2.8 microns/second, P < 0.05) than at the other three times (average, 46.6 microns/second). Cellular infiltration into the vitreous cavity was detected at 24 hours and reached its maximum at 48 hours. CONCLUSIONS: This study demonstrates that it is possible to evaluate EIU by investigating retinal leukocyte behavior and that vasodilation of major retinal vessels and leukocyte-endothelial interactions precede inflammatory cell emigration into the vitreous. This method may be useful to quantify the severity of inflammation in EIU.

Acridine Orange↗
PubMed1996

[Cellular and molecular biology of ischemic retina].

We introduce our studies on the retinal ischemia in light of both pre- and post-Noell viewpoints. For several years now, we have employed in vivo intraretinal microelectrodes for this field of experiments. This series of studies on the cat eye revealed that the sensory retina as well as the retinal pigment epithelium is severely damaged after only a ten-minute stoppage of blood flow. This phenomenon in usually masked in the routine electroretinogram, a mass electrical response of the retina monitored from the ocular surface. Our studies, employing cultured amacrine cells from embryonic rat eyes, revealed that ischemic changes in neural cells are induced by an increase in extracellular glutamate. Among the glutamate analogs, N-methyl-D-aspartate (NMDA) is responsive to this change. An influx of calcium through NMDA receptor channels activates nitric oxide synthase (NOS), inducing intracellular nitric oxide (NO) in selected amacrine cells. Nitric oxide reacts with free radicals in the cell and induces peroxinitrite, which is toxic. This cascade triggered by ischemia is interrupted by extracellular zinc, magnesium, hemoglobin, nitroprusside, s-nitrosocysteine, and some NMDA antagonists. In terms of clinical application, there is a possibility that dihydroxyphenylalanine (DOPA), superoxide dismutase (SOD), and catalase (CAT), as well as vitamins B6 and B12, are important candidates for administration before an ischemic attack for prevention of damage to the retinal neurons. Gene expression of NOS, interleukin (IL)-1, IL-6, tumor necrosing factor (TNF), and transforming growth factor (TGF)-beta in the ischemic retina was investigated in order to discover reaction substances common to ischemic change and inflammation.

Animals↗
PubMed1996

[Surfactant protein A in bronchoalveolar lavage fluid from patients with idiopathic interstitial pneumonia].

We measured the levels of surfactant protein A (SP-A) in bronchoalveolar lavage fluid from patients with idiopathic interstitial pneumonia and from healthy volunteers. The SP-A levels in the patients who were smokers (1.4 +/- 0.2 micrograms/ml) were significantly (p < 0.05) lower than those in the patients who were nonsmokers (3.0 +/- 0.5 micrograms/ml). However, SP-A levels did not differ significantly between patients and volunteers who were smokers, or between patients and volunteers who were nonsmokers. The ratios of SP-A to phospholipid in patients who were smokers and in those who were non-smokers did not differ significantly from those in volunteers who were smokers and volunteers who were non smokers. The total number of alveolar macrophages in bronchoalveolar lavage fluid did not significantly correlate with the level of SP-A, although the percentage of alveolar macrophages correlated negatively (p < 0.05) with the level of SP-A. The low level of SP-A in patients with idiopathic interstitial pneumonia who are smokers may weaken the host defense functions in peripheral airways and may contribute to the poor outcomes in these patients.

Adult↗