Biomedical subjects

H Honda

Publications and source records attributed to H Honda.

At least 19 recordsLinked to original sources

PubMed1992

Limitations of current preoperative liver imaging techniques for intrahepatic metastatic nodules of hepatocellular carcinoma.

To determine the limitations of the latest techniques in preoperative liver imaging for hepatocellular carcinoma, 20 patients with histologically proven intrahepatic metastatic tumors were studied. In 32 masses, we were able to assess the relationship between these intrahepatic metastatic tumors and the findings of preoperative imaging individually. Six intrahepatic metastatic tumors not exceeding 5 mm in diameter were missed in all the imaging examinations. The detection rate was 60% in 13 intrahepatic metastatic tumors of 5 to 10 mm, 77% in 10 intrahepatic metastatic tumors of 10 to 20 mm and 100% in 3 intrahepatic metastatic tumors exceeding 20 mm. In total, computed tomographic imaging during arterial portography demonstrated the highest rate of detection (40%) of all the studies performed. Magnetic resonance imaging, which was recently introduced, was rather disappointing (31%) in this series. In two patients, intrahepatic metastatic tumors were only histologically confirmed. Our study suggests a low rate of detection of intrahepatic metastatic tumors with current preoperative imaging modalities. For improvement of prognosis after hepatectomy for hepatocellular carcinoma adjuvant therapy and extended hepatectomy seem necessary if the functional capacity of the remaining liver permits.

Aged↗

PubMed1992

Isolation and characterization of macrophages from rat embryonic muscle culture.

We have previously described the wide distribution of resident macrophages in normal rat skeletal muscle. In this study, we investigated the characteristics of the macrophages that occur in rat embryo muscle cultures. We showed that cells of monocyte-macrophage lineage are present in primary muscle cultures of rat embryos (18 days in gestation) and that these cells form morphologically and phenotypically heterogeneous populations, based on their reaction with monoclonal antibodies ED1, ED2, ED3, and OX43. Constitutively Ia+ cells with dendritic appearance were also observed. Furthermore, we established the procedure for isolation of macrophages from the primary muscle cultures. The isolated cells, mostly ED1+, expressed class I and CD4 antigens and bore complement (C3) receptors on their surfaces. The fact that cell of monocyte-macrophage lineage occur in the embryonic muscle suggests that during embryogenesis these cells may enter the developing muscle and give rise to a population of tissue-associated macrophages.

Animals↗

PubMed1992

Characteristic findings of hepatocellular carcinoma: an evaluation with comparative study of US, CT, and MRI.

The sensitivity, specificity, and accuracy of ultrasonography (US), dynamic incremented computed tomography (CT) with delayed phase imaging, and magnetic resonance imaging (MRI) with or without Gd-DTPA were studied for detecting the characteristic appearances of hepatocellular carcinomas (HCC): fibrous capsules, fibrous septa, and mosaic appearances. Results were prospectively evaluated in 30 patients who subsequently underwent hepatic lobectomies or segmentectomies. Pathologic evaluations of the resected liver specimens demonstrated fibrous capsules in 20 tumors (66.7%), fibrous septa in 13 tumors (43.3%), and mosaic appearances in 19 tumors (63.3%). The accuracies for fibrous capsules were 71.4% (20 of 28) for US, 81.5% (22 of 27) for CT, and 92.3% (24 of 26) for MRI. The accuracies for fibrous septa were 57.1% (16 of 28) for US, 59.3% (16 of 27) for CT, and 73.1% (19 of 26) for MRI. The accuracies for mosaic appearances were 71.4% (20 of 28) for US, 51.9% (14 of 27) for CT, and 69.2% (18 of 26) for MRI. Gd-DTPA administered MRI showed higher accuracies than did conventional MRI for all manifestations. In conclusion, the fibrous capsules of HCCs were readily detected by CT and MRI. Gd-DTPA administration demonstrated an advantage in clarifying fibrous capsules, as well as fibrous septa and mosaic appearances.

Aged↗

PubMed1992

Unusual renal oncocytomas: pathologic and CT correlations.

The unusual features of nine oncocytomas in five patients are reported herein. These include multiplicity in two, bilaterality in two, calcification in one, and association with renal cell carcinomas in three patients. Radiologists should be aware of these findings for this benign renal neoplasm.

Adenoma↗

PubMed1992

Propagation of force and the induced bending displacement along eukaryotic flagellar axoneme.

The mechanical forces responsible for inducing the bending movement of eukaryotic flagellar axonemes have components that propagate at velocities different from those for the displacement of the medium. These forces are subject to the Third Law of Mechanics which states the null-conservation of acting and reacting forces. Experimental demonstration of the propagating internal tensile force along the axoneme, when not accompanied by simultaneous bending displacement, demonstrates that the active force for the bending of the flagellar axoneme is part of the process of counterbalancing the corresponding reactive force to the ATP hydrolysis underlying the force generation.

Adenosine Triphosphate↗

PubMed1992

Fistuloscopy for the management of postoperative intra-abdominal abscesses.

A new technique of fistuloscopy for evaluation and treatment of postoperative intra-abdominal abscesses is described which was used in 8 patients in whom drainage of abscesses following surgery was insufficient. A cholangiofiberscope was introduced into the fistula canal produced by the postoperative drainage. Fistuloscopy was combined with fistulography in all cases to delineate the extent of the inflammatory process. The guidewire was then placed under visual control through the endoscope followed by re-introduction of the drainage tube until a position most effective for pus drainage was achieved. Following this procedure, fever resolved in all 8 patients. Fistuloscopy is recommended to achieve sufficient drainage of intra-abdominal abscesses in those cases where percutaneous ultrasound- or CT-guided drainage fails to lead to significant clinical improvement.

Abscess↗

PubMed1992

Shortening of N1 and P3 latencies in event-related potentials observed coincidentally with clinical improvement during nootropic medication in a demented patient: specific effect of nicergoline.

Event-related potentials, measured eight times in a patient in the early stages of dementia, demonstrated that clinical symptoms, especially loss of motivation, improved coincidentally with a shortening of reaction time, N1 latency, and P3 latency during nicergoline medication among three nootropics prescribed. Such a longitudinal study design was considered to be useful for quantifying and objectively comparing effects of various nootropics noninvasively.

Aged↗

PubMed1992

Ca2+ release from isolated sarcoplasmic reticulum of guinea-pig psoas muscle induced by K(+)-channel blockers.

A Ca(2+)-sensitive electrode was used to measure the Ca2+ concentration of the medium containing the heavy fraction of the fragmented sarcoplasmic reticulum (SR) prepared from guinea-pig psoas muscle. Among K(+)-channel blockers tested, 4-aminopyridine (4-AP), tetraethylammonium (TEA) and charybdotoxin elicited Ca2+ release from the SR, but apamin and glibenclamide did not. These results suggest that a reduction of SR K+ conductance leads to Ca2+ release from the SR.

4-Aminopyridine↗

PubMed1992

Improvement of simultaneous detection of antibodies to Gag and envelope antigens of human T-lymphotropic virus type I by western immunoblot assay.

To determine seropositivity for human T-lymphotropic virus type I (HTLV-I), we attempted to improve the detection system that uses antibody to HTLV-I Env in Western immunoblotting (WB) by adding an envelope glycoprotein (gp46) purified from the culture fluid of HTLV-I-producing cells by immunoaffinity chromatography and gel chromatography. In this WB, 177 of 179 serum samples showing seropositivity in an indirect immunofluorescence assay showed positive reactions to the gp46 envelope antigen as well as to p19, p24, and p53 Gag antigens. The remaining two samples showed negative reactions to p24. False-positive results were not found for 533 indirect immunofluorescence assay-negative serum samples, although one band to p19 or p24 was observed in 46 of the 533 samples. These 46 samples did not react to p53 and gp46, suggesting that these samples belonged to the indeterminate group in accordance with the criteria proposed by the World Health Organization. Therefore, this improved WB can be used for the confirmation of seropositivity.

Blotting, Western↗

PubMed1992

Effects of mechanical vibration on left ventricular diastolic properties during global ischemia.

To examine the effect of mechanical vibration on ventricular relaxation and diastolic chamber stiffness under global ischemia, we studied eight coronary perfused, isolated, isovolumic canine left ventricles (LV). To produce varying degrees of impaired relaxation, graded coronary flow reduction and paced tachycardia were imposed. A mechanical 50-Hz, 2-mm-amplitude vibration was applied during diastole and was turned off during systole. Without diastolic vibration, the relaxation time constant of LV pressure (tau) increased with the severity of ischemia. The chamber stiffness index (K) from the diastolic pressure-volume relationship showed a slight increase during ischemia; tau decreased with diastolic vibration. The change in tau with vibration increased with ischemia and was dependent on vibration amplitude but not heart rate. The ratio of tau to the diastolic interval (DI, the time from peak negative rate of LV pressure change to end diastole) always decreased with vibration and was linearly correlated with K (r = 0.93; P less than 0.01). K decreased with vibration when tau/DI was greater than 0.3. We conclude that diastolic vibration improves impaired relaxation and chamber stiffness under myocardial ischemia.

Analysis of Variance↗

PubMed1992

Effect of xamoterol in Shy-Drager syndrome.

BACKGROUND: Xamoterol, a cardioselective beta 1-adrenoceptor partial agonist, has been reported to be effective on postural hypotension. We investigated the effect of xamoterol in five patients with Shy-Drager syndrome (SDS) in relation to their prevailing sympathetic nerve activity and sensitivity of beta-adrenoceptors and the change in circadian variation of blood pressure. METHODS AND RESULTS: Ambulatory blood pressure over 24 hours was monitored by noninvasive sphygmomanometer (model 5200, Spacelab). Plasma norepinephrine levels of SDS patients were significantly lower than that of normal subjects (n = 5) both at rest (54 +/- 15 versus 178 +/- 83 pg/ml) and after 10-minute standing (74 +/- 24 versus 318 +/- 143 pg/ml). Infusion of isoproterenol (0.02 micrograms/kg/min) produced a mild rise of systolic blood pressure and tachycardia in normal subjects but resulted in marked hypotension and tachycardia in SDS subjects. After xamoterol administration (200 mg b.i.d.), systolic blood pressure and heart rate were significantly increased in the averages during the day; however, increases were more pronounced at night. In two of the five patients, the improvement in dizziness was large enough to enable them to increase their daily activities. CONCLUSIONS: Our observations suggest that 1) beta 1-selective, high intrinsic sympathomimetic activity of xamoterol increases blood pressure and heart rate in patients with SDS as a consequence of their prevailing beta 1-adrenoceptor hypersensitive state, and 2) blood pressure monitoring over 24 hours appears to have important advantages in evaluating the therapeutic effects on postural hypotension.

Adrenergic beta-Agonists↗

PubMed1992

Diastolic vibration improves systolic function in cases of incomplete relaxation.

BACKGROUND: Incomplete relaxation of the left ventricle (LV) affects LV filling, but the subsequent effect on LV systolic function remains unclear. We attempted to improve relaxation by applying oscillatory mechanical perturbation during diastole (diastolic vibration) and examined the extent to which systolic function improved. METHODS AND RESULTS: Using 10 open-chest canine preparations, pacing tachycardia and administration of propranolol were imposed to induce various levels of incomplete relaxation. Myocardial length perturbation was induced with an oscillator attached to the LV surface (50 Hz, 1-mm amplitude) and was restricted to the period from the beginning of isovolumic relaxation to end diastole. At resting heart rates, diastolic vibration caused an immediate decrease in the time constant (T) of LV pressure fall without any influence on heart rate, LV peak systolic pressure (peak LVP), stroke volume (SV), LV peak positive dP/dt, and total systemic vascular resistance. With pacing tachycardia, diastolic vibration increased both peak LVP and SV at 160 beats per minute (before) and 120 beats per minute (after propranolol), simultaneously decreasing both T and LV diastolic pressures and increasing end-diastolic segment length. The increase in peak LVP and SV caused by diastolic vibration correlated with the T/diastolic interval (r = 0.82), the assumed index of severity of incomplete relaxation. CONCLUSIONS: These results suggest that diastolic vibration accelerates the LV relaxation rate and that this increased relaxation improves systolic function through the Frank-Starling mechanism.

Animals↗

PubMed1992

Ventricular contractility evaluated by mechanical perturbation of the myocardium--experimental and clinical approach adopting small amplitude vibration input.

Small amplitude mechanical vibration has been reported to depress the function of the isolated left ventricle in an amplitude dependent manner. We examined, 1) contractility and preload dependency of the magnitude of functional depression (VID) by applying 50 Hz, 2 mm amplitude vibration to the epicardium of the canine left ventricle and 2) whether VID is present in the failing human ventricle. The magnitude of VID was independent of preload in the physiological range of LV volume showing peak LV pressure greater than 75 mmHg, and VID was correlated with Emax at each inotropic state. In the in-situ condition, VID appeared only in the failing condition with a sensitive increase at a mild level of heart failure. In a study during routine cardiac catheterization (n = 27), the presence of VID has been demonstrated in the human ventricle (n = 18). The magnitude of VID was correlated with ejection fraction (EF) as, VID in peak LV pressure (mmHg) = 80.6 - 110 x EF, r = 0.84, p less than 0.01 in patients with EF less than or equal to 0.7 (n = 14). Therefore, we concluded that VID could be a clinical tool for evaluation of mild heart failure.

Animals↗

PubMed1992

[Effects of ambroxol HCl on the guinea pig tracheal mucous secretion and the rat pulmonary surfactant secretion].

The effects of orally administered ambroxol HCl (ambroxol) on guinea pig tracheal mucous secretion and rat pulmonary surfactant secretion were investigated histologically and biochemically. Ambroxol significantly increased the number of active goblet cells in guinea pig tracheal epithelium and total mucopolysaccharide level. Moreover, ambroxol significantly increased the neutral mucopolysaccharide level and PAS-positive substance in the guinea pig tracheal submucosal glands. Ambroxol did not show a significant effect on the content of the total phosphatidylcholine in rat lung lavage fluid, while ambroxol significantly increased the ratio of disaturated phosphatidylcholine to total phosphatidylcholine. From these results, it is suggested that ambroxol increases both the tracheal mucous secretion, especially the neutral mucopolysaccharide, and pulmonary surfactant secretion and these effects reflect part of the expectorant mechanism of the drug.

Ambroxol↗

PubMed1992

Virus-associated demyelination in the pathogenesis of Bell's palsy.

We examined the cerebrospinal fluid findings, including the activity of the myelin-associated enzyme 2',3'-cyclic nucleotide 3'-phosphohydrolase (CNP), and virus serology in patients with Bell's palsy. Eighty-nine of 164 patients showed hematological and/or serological evidence of an inflammatory reaction. Examinations of the CSF disclosed an elevated total protein level and pleocytosis in 33% and 10% of the 91 patients, respectively. The activity of CNP was significantly elevated in the patient group (15.5 +/- 3.8 nmol/h/ml) as compared with the control (13.2 +/- 1.3 nmol/h/ml) (p < 0.01), suggesting the presence of intrathecal myelin breakdown. Furthermore, there was an association between antibodies against herpes simplex virus (HSV) and elevated CNP activity. The inflammatory alterations and accompanying spinal fluid abnormalities, together with the high frequency of HSV antibodies suggest that HSV-associated demyelination may play a pathogenetic role in Bell's palsy.

2',3'-Cyclic Nucleotide 3'-Phosphodiesterase↗

PubMed1992

Differential diagnosis of hepatic tumors (hepatoma, hemangioma, and metastasis) with CT: value of two-phase incremental imaging.

Two-phase dynamic incremental CT is a technique in which CT scans are obtained 45 sec and 6 min after commencing the rapid bolus injection of contrast medium. We analyzed the contrast enhancement patterns of three types of hepatic tumors (72 hepatomas, 39 hemangiomas, and 28 metastases) in 139 patients to determine if any differences in the patterns are useful in the differential diagnosis of these lesions. Dynamic incremental CT scanning was performed after 100 ml of iodinated contrast material was administered i.v. with a power injector at a rate of 2 ml/sec. A 1-sec scanning time was used with a 1.6-sec inter-scan delay, which allowed table motion between scans. CT scans (eight to 16 sections) were obtained 45-110 sec (early phase) and 6-7 min (delayed phase) after commencing the injection of contrast medium. The enhancement patterns of hepatomas were as follows: 32% were totally hyperdense in the early phase and totally hypodense in the delayed phase, while 24% were totally hypodense in both phases. Most of the hepatomas (88%) appeared as totally hypodense lesions in the delayed phase. In the case of hemangiomas, 56% were peripherally hyperdense in the early phase; in the delayed phase, 36% were isodense and 31% were totally hyperdense. Most hemangiomas (85%) were not totally hypodense in the early phase, and no hemangioma was totally hypodense in both phases. In the early phase, 61% of metastases were hypodense. In the delayed phase, 57% were hypodense. Metastases most commonly were totally hypodense in both phases (43%). We conclude that contrast enhancement patterns of hepatomas, hemangiomas, and metastases seen on two-phase dynamic incremental CT scans are useful in the differential diagnosis of these tumors.

Carcinoma, Hepatocellular↗

PubMed1992

Modified hemoglobin solution as possible perfusate relevant to organ transplantation.

A modified hemoglobin solution ( - conjugate solution, PHP solution) has very interesting characteristics such as oxygen-carrying property without corpuscular components. Experimental use of the PHP solution has shown promising possibilities as a perfusate relevant to organ transplantations. 1) Elongation of warm ischemic time in canine kidneys: Dogs survived even with the unilateral kidneys which had been exposed up to 4.5 hour warm ischemia and, thereafter, perfused with the PHP solution. 2) Elongation of perfusion preservation period of canine livers: Dogs survived with the transplanted livers which had been perfused for 48 hours with the PHP solution. 3) Successful perfusion of rat small intestine: Lewis rat intestines perfused and preserved for 12 hours with the PHP solution showed a higher survival rate compared with those with Collins or UW solution. 4) Removal of antibodies: By exchange transfusion with a total of 30-60 ml of the PHP solution, a Lewis rat hematocrit lowered to 5% while IgG went down to nil from 8970 mg/dl, IgA to 28 mg/dl from 118 mg/dl and IgM to 190 mg/dl from 897 mg/dl. This technique is expected to be applicable for removal of the naturally existing antibodies in xenotransplantation.

Animals↗

PubMed1992

Saccades to targets in three-dimensional space: dependence of saccadic latency on target location.

The latency of saccadic movements to targets appearing at various positions in three-dimensional visual space was measured in four experiments. The first experiment confirmed that latencies of saccades to visual targets are greater in the lower visual field and showed that the increase is not influenced by the vertical starting position of the eye in the orbit, nor by a time gap between the fixation offset and the target onset. A hypothesis that this visual field difference was caused by a link between downward saccades and convergence movements was tested by recording saccade latencies when the targets were in a different depth plane from that of the original fixation. We did not find any direct support for the vergence involvement hypothesis, although the lower/upper visual field effect was shown to decrease consistently in monocular viewing. It was also shown that saccades to targets positioned in a different depth plane have longer latencies. In a final experiment, the visual field effect was shown to depend on the egocentric rather than the gravitational vertical.

Adult↗