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Biomedical subjects

S Yagi

Publications and source records attributed to S Yagi.

At least 91 records · Page 5Linked to original sources
PubMed1998

Rotavirus encephalitis mimicking afebrile benign convulsions in infants.

A 2-year-old-boy had rotavirus gastroenteritis and demonstrated afebrile partial seizures with secondary generalization. The presence of rotavirus genome and anti-rotavirus IgG was detected in the cerebrospinal fluid. The genotype of VP4 was P8 and that of VP7 was G4. The imaging analysis by computed tomography and single photon emission computed tomography implied encephalitis. The seizures were well controlled by standard antiepileptic therapy, and the child experienced normal development with neither physical nor neurologic sequelae, which appeared to mimic benign infantile partial epilepsy.

Child, Preschool↗
PubMed1998

Identification of a commonly deleted region at 17p13.3 in leukemia and lymphoma associated with 17p abnormality.

Fluorescence in situ hybridization (FISH) was performed in 17 myeloid leukemia patients and seven lymphoid leukemia/ lymphoma patients who exhibited chromosomal abnormalities on the short arm of chromosome 17, in order to detect a commonly deleted region on chromosome band 17p13. Twenty-four leukemia/lymphoma patients studied cytogenetically at our institution over a period of 10 years had detectable 17p abnormalities such as translocation (six patients), addition (11 patients) and deletion of 17p13 (seven patients). A 17p abnormality was the only abnormality present in three patients. Most of the patients had additional complex cytogenetic abnormalities. The diagnosis was acute myeloid leukemia (AML) in 10 patients, two each with chronic myeloid leukemia (CML), acute lymphoblastic leukemia (ALL), chronic lymphocytic leukemia (CLL) and myelodysplastic syndrome (MDS) and the remaining three with malignant lymphoma (ML). Seven cosmid probes (D17S34, cCI17-624, cCI17-453, D17S379, cCI17-636, cCI17-732 and TP53) which mapped on 17p13 were used to analyze the allelic deletion. Eighty percent (19 out of 24) of the informative leukemia patients exhibited allelic loss in 17p13.3 at cC17-624. The smallest region of an overlapping deletion was observed on chromosome band 17p13.3 between cCI17-624 and cCI17-453. Patients with translocation involving 17p also showed deletion at cCI17-624 and cCI17-453. We hypothesize that this region contains a novel tumor suppressor gene(s) that is involved in leukemogenesis.

Adult↗
PubMed1998

Clinical experiences of percutaneous cardiopulmonary support: its effectiveness and limit.

In recent years, several types of centrifugal pumps have been widely used as the main pumps for cardiopulmonary bypass (CPB) and postcardiotomy cardiac support. From April 1990 to March 1997, a percutaneous cardiopulmonary support (PCPS) system was used in 20 patients with an average age of 58 years (13 males and 7 females). They comprised 11 ischemic, 6 valvular, 2 aortic, and 1 congenital heart disease patients. Our PCPS system consists of a centrifugal pump (BioMedicus BP-80), an oxygenator, and a reservoir. The entire blood contacting surface, including that of the thin wall cannulas, is coated by heparin bonded materials. As a result of this new technology, this system can be used for the long term without systemic heparinization. No major critical thrombi were revealed inside the pumps or circuits. Of the 20 patients, 7 (35%) (Group 1) could be weaned from PCPS, and the remaining 13 (Group 2) could not. In Group 1 although 2 patients suffered from renal failure and pneumonia, respectively, both were discharged from our hospital. The long-term survival rate was 35%. In Group 2 cerebral vascular damage was recognized in 3 patients, renal failure in 4, multiple system organ failure in 4, bleeding in 2, arrhythmia in 1, and leg ischemia in 2. Pulse pressure was significantly elevated due to the recovery of the native heart in Group 1, 2 days after support. However, in Group 2, it did not elevate, and the left ventricular ejection fraction was less than 30%, associated with high left atrial pressure. In conclusion, this heparin coated PCPS system was very simple and easy to control. It demonstrated long-term biocompatibility and was very effective in recovering deteriorated cardiac function. Quicker application of this system can play an important role in preventing severe complications and obtaining better clinical results. If long-term support is necessary, a ventricular assist device (VAD), which is more powerful, durable, and biocompatible, has to be applied instead of PCPS.

Acute Kidney Injury↗
PubMed1998

Endoscopic treatment of refractory filarial chyluria: a preliminary report.

PURPOSE: We report our experiences treating 5 patients who had filarial chyluria using an endoscopic approach. MATERIALS AND METHODS: Two men and 3 women 47 to 83 years old with chyluria were treated with endoscopic coagulation using guide tube methods. Intrarenal pelvic instillation of silver nitrate was not effective in 4 patients and catheterization was impossible in 1. RESULTS: The responsible lesion was successfully coagulated in all 5 patients. Because the lesion was in the ruptured portion of the caliceal fornix, we thought that chyluria had arisen in the fragile portion of the fornix (fistulization). After endoscopic treatment there was no recurrence in any patient. CONCLUSIONS: Endoscopy is effective and minimally invasive therapy for filarial chyluria.

Aged↗
PubMed1998

Factors determining drug residence in skin during transdermal absorption: studies on beta-blocking agents.

The factors determining drug residence in skin during penetration across rat abdominal skin were investigated using five beta-blocking agents with different lipophilicities as model drugs in vivo and in vitro. The amount of beta-blocking agent in the skin at steady state correlated well with lipophilicity. The distribution of beta-blocking agents to the stratum corneum and the contribution of intercellular lipids in the stratum corneum to their skin distribution were also correlated with their lipophilicity, suggesting that the stratum corneum, especially intercellular lipids in the stratum corneum, would be responsible for the residence of beta-blocking agents in the skin. Furthermore, cholesterol-3-sulfate, palmitic acid, stearic acid and oleic acid were found to interact with the beta-blocking agents, which are cationized under the physiological condition, and were assumed to play an important role in the skin accumulation. On the other hand, the binding to keratinocyte was so small that keratinocyte might have little effect on the skin accumulation of the beta-blocking agents. Drug transport from the stratum corneum to viable skin was suggested to be regulated by the lipophilicity of these agents. To investigate the residence of these drugs in viable skin, in vitro transport studies using stripped skin were performed. The transport rate constant across viable skin to receptor cells (k23) was inversely correlated with the lipophilicity of the drugs. The elimination rate constants from viable skin (k(vs)) obtained in the in vivo study were much smaller than the values of k23 obtained in the in vitro study, and they were inversely correlated with the binding to cytosol components of viable skin but not the lipophilicity. The viable skin-to-muscle concentration ratio of these drugs, obtained at the beta-phase of the plasma concentration-time curve after intravenous administration, was also inversely correlated with the binding to the cytosol components of viable skin. These results suggest that k(vs) reflects the transport from viable skin to muscle rather than to blood circulation and that the binding of drugs to cytosol components in viable skin would be one of the important factors determining the residence in viable skin.

Administration, Cutaneous↗
PubMed1998

Left atrial myxoma with an atrial septal defect: a case report and review of the literature.

We report a case of a 49 year-old Japanese woman with a left atrial myxoma complicated by an atrial septal defect diagnosed intraoperatively, which was classified as in secundum defect and was 28x110 mm in diameter. The tumor, which was attached by a pedicle to the posterior wall of the left atrium near the posterior commissure of the mitral valve, was removed together with a small portion of the left atrial wall. The postoperative course was uneventful. The pathologic findings were consistent with the diagnosis of myxoma. Since the defect was functionally canceled by the myxoma, the diagnosis of an atrial septal defect was not confirmed preoperatively even by color Doppler echocardiography and cardiac catheterization. Tumor embolization is one of the critical complications of myxoma. Fortunately, she didn't suffer from either systemic or pulmonary emboli. During surgery of myxoma with atrial septal defect, careful manipulation is needed, especially at caval cannulation so as not to damage the tumor directly. In the cases with atrial septal defect or patent foramen ovale, myxomas are generally situated on the interatrial septum. However, in this case the tumor was located on the posterior wall of the left atrium.

Cardiac Catheterization↗
PubMed1998

[Cervical epidural hematoma caused by cervical twisting after epidural anesthesia: a case report].

A case of cervical epidural hematoma caused by cervical twisting after epidural anesthesia was reported. A 41-year-old man who had had anterior fusion of C5 - 7 using a plate due to cervical spondylosis fifteen months before admission, had undergone epidural anesthesia through the C7/T1 interspace without difficulty for shoulder pain in a pain clinic. Two hours after injection, he complained of severe pain in his neck and both shoulders just after cervical twisting as was his custom. Within minutes he noted paresis of his left extremities. Neurological examination on admission revealed left side dominant tetraparesis and loss of pain and temperature sensations below the level of T4 on his right side. Laboratory data analysis and coagulation tests were normal. CT scans and MRI demonstrated an epidural hematoma with a small amount of air extending from C3 to the upper margin of C7. Four hours after the onset, a laminoplasty was performed from C3 to C7 with total removal of the hematoma. No bleeding site or any vascular abnormality was found to account for the hematoma formation. He was discharged with good recovery after operation. Most of the reported epidural hematomas associated with epidural anesthesia were related to coagulopathy, anticoagulant therapy or difficult puncture. On review of the literature, this is the first case of spinal epidural hematoma cause by cervical twisting after spinal anesthesia and which was without impaired coagulation or difficult spinal puncture. Cervical epidural hematoma should be considered as a possible complication in patients with pain or neurological deficits after some cervical manipulations.

Adult↗
PubMed1998

Macroscopic aspects of cloth-covered Starr-Edwards prostheses at reoperation: what the precursory valve teaches us.

BACKGROUND AND AIMS OF THE STUDY: Cloth-covered Starr-Edwards ball valves were the first choice in prosthetic substitution at the authors' institution between June 1968 and March 1977. This study investigated, retrospectively, macroscopic aspects of the prostheses at reoperation. METHODS: Among 59 survivors who underwent isolated aortic or mitral valve replacement, 12 required reoperation for valve dysfunction (five aortic valve replacements, seven mitral valve replacements). Reoperation was necessitated by valvular endocarditis, paravalvular leak, hemolysis, thromboembolism, orifice stenosis attributable to pannus, and inappropriate sizing related to growth and thrombus. The mean time to reoperation was 11.7 +/- 6.2 years after initial surgery (range: 2 years 4 months to 21 years 8 months). RESULTS: Marked cloth wear was observed in all aortic prostheses, but only slight wear in mitral valves. Pannus formation was observed around the orifice in both aortic and mitral prostheses, but strut cloth was not extensively covered by autologous tissue. In mitral valves, strut cloth was only slightly worn and less loose than that of the aortic valve. These changes notably affected prosthetic valve function, the most significant problem in mitral prostheses being thrombus (four of seven valves). CONCLUSIONS: Pannus formation and thrombus caused by the reaction of the patient's tissues remain major problems in the use of artificial valves, and require further work for their improvement.

Adolescent↗
PubMed1998

Post-operative effects of olprinone after coronary artery bypass grafting.

The aim of this study was to test the effects of olprinone after coronary artery bypass grafting (CABG). In order to prevent hypotension caused by olprinone, low doses of catecolamines were used concomitantly. Total 22 elective CABG cases were evaluated. In all cases, moderate hypothermia and cardioplegic cardiac arrest were performed. In 10 cases, continuous intravenous 0.1 microg/kg/min of olprinone, 3 microg/kg/min of dobutamine (DOB) and dopamine (DOA) as the initial doses, were used concomitantly (Group I). As a control, the same initial doses of catecolamine (DOB and DOA) of Group I were administered in another 12 patients (Group II). When the pump flow of cardiopulmonary bypass (CPB) was decreased to half, these drugs were administered in both groups. Hemodynamics were recorded before CPB, just after the operation and 3, 6, 12, 24, 48, and 72 hours after the operation. Three hours after the operation, both mean aortic pressure (AoP) and pulmonary artery pressures (PAP) of Group I demonstrated significantly lower values than those of Group II. Cardiac index (CI) of Group I showed significantly higher values than that of Group II until 6 hours after surgery. The systemic vascular resistance index (SVRI) of Group I indicated a significantly lower value than that of Group II until 24 hours after the operation. Pulmonary capillary wedge pressure (PCWP) of Group I demonstrated a significantly lower value than that of Group II. There were no significant differences in urine output, oxygen delivery (DO2) and oxygen consumption (VO2) between both groups. Olprinone increased CI and decreased SVRI, and it showed easy weaning from CPB, demonstrating excellent hemodynamics after CABG. These results suggested that this new phosphodiesterase inhibitor may be effective for not only weaning from CPB but also post-cardiotomy cardiogenic shock.

Aged↗
PubMed1998

Congenital coronary artery fistula treated surgically in the right atrium and the atrial septum.

Various surgical techniques have been employed according to the type of the coronary fistula. In this case, preoperative examinations by aortography and MRI revealed a coronary artery fistula which originated from a site just proximal of the RCA, ran through the interatrial septum and drained into the posterior wall of right atrium. The ratio of pulmonary to systemic blood flow (Qp/Qs) was 1. 95. During surgery, we were not able to ligate or divide the fistula on the cardiac surface because the fistulous vessel originated from the posterior aspect of the proximal RCA. After establishing a cardiopulmonary bypass, the opening of the fistula in the right atrium was closed with an autologous pericardium patch, the surface of the interatrial septum was incised and the fistula was identified. The conduit was then divided and closed in the atrial septum. The postoperative course was uneventful. This approach is able to interrupt the fistula safely without interfering with normal coronary flow. Closure of the outlet and division of the fistula itself is a recommendable method to insure interruption of fistulous communication.

Adult↗
PubMed1997

Slow cycling of unphosphorylated myosin is inhibited by calponin, thus keeping smooth muscle relaxed.

A key unanswered question in smooth muscle biology is whether phosphorylation of the myosin regulatory light chain (RLC) is sufficient for regulation of contraction, or if thin-filament-based regulatory systems also contribute to this process. To address this issue, the endogenous RLC was extracted from single smooth muscle cells and replaced with either a thiophosphorylated RLC or a mutant RLC (T18A/S19A) that cannot be phosphorylated by myosin light chain kinase. The actin-binding protein calponin was also extracted. Following photolysis of caged ATP, cells without calponin that contained a nonphosphorylatable RLC shortened at 30% of the velocity and produced 65% of the isometric force of cells reconstituted with the thiophosphorylated RLC. The contraction of cells reconstituted with nonphosphorylatable RLC was, however, specifically suppressed in cells that contained calponin. These results indicate that calponin is required to maintain cells in a relaxed state, and that in the absence of this inhibition, dephosphorylated cross-bridges can slowly cycle and generate force. These findings thus provide a possible framework for understanding the development of latch contraction, a widely studied but poorly understood feature of smooth muscle.

Animals↗
PubMed1997

Thromboxane inhibition potentiates antihypertensive effects of alpha 1 adrenoceptor antagonists in the rat.

We investigated the influence of the vascular and renal thromboxane system on the antihypertensive effects of the alpha 1 adrenoceptor antagonist (alpha 1 blocker) bunazosin in spontaneously hypertensive rats (SHR). SHR were treated for 2 weeks with the alpha 1, blocker bunazosin (0.5 mg/kg body weight/day). The systolic blood pressure immediately declined with bunazosin treatment, and then rose toward the level observed in untreated SHR. This antihypertensive effect was accompanied by a decrease in the ratio of prostacyclin to thromboxane A2 in the vascular wall and the kidney. A subdepressor dose of the thromboxane synthase inhibitor OKY-046 lessened the thromboxane generation during bunazosin treatment, and synergistically potentiated the antihypertensive action of the alpha 1 blocker. Such synergy was also observed between OKY-046 and prazosin, an alternative alpha 1 blocker, but not with amosulalol, an alpha 1 blocker having no quinazoline moiety. alpha 1 blockers with a quinazoline moiety dose-dependently stimulate thromboxane generation in cultured smooth muscle cells from SHR. These data indicate that alpha 1 blockers enhance thromboxane generation in the arterial wall and kidney, thereby contributing to the lessening of the antihypertensive effects observed during alpha 1 blocker treatment.

Adrenergic alpha-Antagonists↗
PubMed1997

Effects of alcohol intake on organ injuries in normotensive and hypertensive human subjects.

1. This cross-sectional study examined the influence of alcohol intake on organ injuries in normotensive and hypertensive subjects. 2. A total of 514 normotensive subjects and 302 never-treated hypertensive subjects were screened from 4557 men who entered the health check programme of our institute during the period 1990 to 1994. According to the daily alcohol consumption data reported by a self-administered questionnaire, the normotensive and hypertensive subjects were both classified into four categories; very light and non- (0-10 ml of ethanol), light (11-29 ml), moderate (30-58 ml) and heavy (> or = 59 ml) drinker groups. In these four pairs of groups, organ injuries in the heart, kidney and optic fundus were evaluated and serum lipids were measured. 3. Although the blood pressure levels were similar among the four groups of hypertensive subjects, the electrocardiographic findings of left ventricular hypertrophy were significantly more common among the moderate and heavy drinkers but not in the light drinkers compared with the very light and non-drinkers (very light and non-drinkers 25%, light drinkers 23%, moderate drinkers 38%, heavy drinkers 40%; P = 0.026). The alcohol intake increased the serum level of high-density lipoprotein cholesterol in a dose-dependent manner without changing the total cholesterol level; however, the serum gamma-glutamyl transpeptidase and triacylglycerol levels were increased in the moderate and heavy drinkers. Urinary albumin excretion and fundoscopic lesions were not associated with the drinking habit in either the normotensive or hypertensive subjects. 4. These data suggest that habitual alcohol consumption exceeding 29 ml per day facilitates the development of left ventricular hypertrophy in hypertensive patients. Among the hypertensive subjects, light drinkers consuming 11 to 29 ml of ethanol daily showed preferable profiles in terms of organ injuries and risks of cardiovascular diseases.

Alcohol Drinking↗
PubMed1997

Effect of benidipine on microvascular remodeling and coronary flow reserve in two-kidney, one clip Goldblatt hypertension.

OBJECTIVE: To determine whether chronic treatment with benidipine, a calcium antagonist, leads not only to regression of left ventricular hypertrophy, but also to an improvement in coronary flow reserve and microvascular remodeling. DESIGN AND METHODS: Two-kidney, one clip Goldblatt hypertensive rats were assigned either to a benidipine-treatment group or to a group without treatment after their kidneys had been clipped for 4 weeks. Benidipine was administered to rats in the treatment group for 6 weeks. At the end of the treatment, the systemic hemodynamics and coronary blood flow were determined in conscious unrestrained rats by using nonradioactive colored microspheres injected through the left atrium. The coronary blood flow was determined in rats of both groups with the rats at rest and after near-maximal vasodilatation induced by carbochrome. For evaluation of the microvascular remodeling capillary density, the wall : lumen ratio of arterioles and perivascular fibrosis were quantified by using an image analyzer after fixation of heart tissue. RESULTS: Benidipine treatment lowered the blood pressure significantly with a decrease in total peripheral resistance, and the left ventricular mass decreased markedly compared with that of untreated hypertensive rats. The coronary flow reserve of the untreated hypertensive rats was lower than that of the controls, but benidipine treatment improved the coronary flow reserve. We found a significant decrease in capillary density, and significant increases in wall : lumen ratio and perivascular fibrosis in untreated hypertensive rats. These changes in microvasculature were improved by benidipine treatment. CONCLUSION: Taken together, these results suggest that benidipine exerts favorable effects as an antihypertensive drug by reversing cardiac hypertrophy and improving the coronary flow reserve and microvascular remodeling.

Animals↗
PubMed1997

Relation between the initial portion of the signal-averaged QRS complex and cardiac function and infarct size in patients with myocardial infarction.

We analyzed signal-averaged electrocardiograms (ECG) obtained in 50 patients with recent myocardial infarction (RMI: 25 anterior and 25 inferior) and 20 normal subjects to determine the relationship between the initial portion of the signal-averaged QRS complex and cardiac function and infarct size. We examined (1) the root mean square voltage (RMS10-40, microV), (2) the integration (A10-40, microV.msec) at 10-msec intervals over the first 40 msec of the signal-averaged QRS complex, and (3) the intervals (T) of the magnitude of the signal-averaged ECG achieved at 10-microV intervals over the first 40 microV (T10-40, msec). The mean RMS10-40 (p < 0.01) and A10-40 (A10, p < 0.05; A20-40, p < 0.01) were significantly lower and the T10-40 (p < 0.01) was significantly longer in RMI patients than in normal subjects. The RMS10-40 (p < 0.01) and A10-40 (p < 0.05) were significantly lower and the T10-40 (T10.20, p < 0.01; T30.40, p < 0.05) was significantly longer in patients with anterior RMI patients than in patients with inferior RMI. The A30 was correlated with the ejection fraction and total creatine kinase (CK) release in all patients (r = 0.73, and -0.78, respectively, p < 0.001). These results suggest that the A30 may be an important predictor of ventricular dysfunction and infarct size in patients with RMI.

Adult↗