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Biomedical subjects

A Ishida

Publications and source records attributed to A Ishida.

At least 145 records · Page 8Linked to original sources
PubMed1997

[A case report of malignant schwannoma of the chest wall].

We described a very rare case of malignant schwannoma of the chest wall, which was surgically resected. The patient, a 40-year-old woman, came to our hospital because of an abnormal shadow in the right chest wall of an X-ray film without any symptoms. Computed tomography revealed a solid tumor attached to the posteroinferior aspect of the intrathoracic chest wall. The tumor was a 2.5 x 2.1 cm, mass originating from the seventh intercostal nerve without pulmonary adhesion, and the patient underwent en bloc resection of the tumor. The pathological diagnosis was malignant schwannoma. The postoperative course was uneventful, and the patient, eight years after the operation is now doing well without local recurrence or distant metastasis. We reviewed seven cases of this type of tumor reported in the Japanese literature.

Adult↗
PubMed1997

[Recurrent intrathoracic dissemination of thymoma with myasthenia gravis: a case report].

A 48-year-old man was readmitted to our hospital with a chief complaint of left anterior chest mass. He had a past history of thymo-thymomectomy six years earlier. On chest CT examination, multiple tumor shadows were noted within the left thoracic cavity. All visible tumors were resected. His postoperative course was favorable, and no signs of recurrence have been recognized on CT to date (three years and six months postoperatively). However, in view of the possible recurrence of the present disease after a long period, strict observation of the course of the disease is necessary.

Humans↗
PubMed1997

[Blood cyst of the pulmonary valve in an adult--a case report].

Blood cysts of the heart valves are commonly reported at postmortem examination of infants but are rare seen in older children and adults. A 42-year-old woman was referred to our hospital for cardiac evaluation because of dyspnea on exertion and heart murmur. There was no history of cyanosis or cardiac failure. Cardiac catheterization revealed valvular pulmonary stenosis and atrial septal defect. Right ventricular angiography showed the circular filling defect 0.7 x 0.7 cm in size at the suprapulmonary valve. However, this preoperative abnormal finding was diagnosed as a blood cyst after surgery. At operation a blood cyst originating from the right cusp of the pulmonary valve was found and resected, and was followed by commissurotomy of the pulmonary valve and direct closure of the atrial septal defect. Her postoperative course was uneventful.

Adult↗
PubMed1997

Time series analysis of the course of Menière's disease.

Subjective symptoms of Menière's disease (vertiginous attacks, nonparoxysmal dizziness, tinnitus, hearing loss, headache, stiff neck, nausea etc.) were graded respectively according to severity (0-3 or 0-5) and were recorded daily by affected patients. These recordings, from 20 cases of Menière's disease, were collected and analysed by an original program of time series analysis including autocorrelation, cross-correlation, daily sum of inner ear related factors and general factors, and their moving average. Cluster occurrence of dizzy spells in the active stage and a marked cross-correlation between inner ear factors and general factors were found to constitute a characteristic pattern in Menière's disease in relation to its pathophysiology. Time series analysis was also useful for clinical decision-making, such as evaluation of the effect of treatment, and estimation of prognosis.

Anti-Inflammatory Agents↗
PubMed1997

[The efficacy of leukodepleted platelet transfusion].

The use of leukopoor blood cellular products is now considered as being a simple and efficacious method to prevent unfavorable transfusion complications such as nonhemolytic febrile transfusion reaction and HLA-alloimmunization which are induced by contaminated leukocytes. Several prospective studies demonstrated that leukocyte depletion by filtration has been found to be effective to prevent HLA alloimmunization and/or platelet transfusion refractoriness, although cost effectiveness of the filter use still remains unclear. Lueukodepletion is also efficient in preventing CMV infection in patients undergoing stem cell transplantation, and its efficacy is readily comparable to CMV seronegative blood products. With more efficient and reliable filters (4th generation filters) having been developed recently, the clinical application of leukodepletion filters in transfusion medicine may be considerably widened.

Cell Separation↗
PubMed1997

The diagnosis and management of splanchnic artery aneurysms. Report of 8 cases.

The purpose of this report is to describe the clinical characteristics and surgical technique for splanchnic artery aneurysms. Over the past 10 years we have surgically resected 8 cases of splanchnic artery aneurysms including 2 cases involving the superior mesenteric artery, 3 involving the renal artery, 1 involving the hepatic artery and 2 involving the splenic artery. Diagnosis was established preoperatively in all patients by splanchnic angiography. Surgical treatment for splanchnic artery aneurysms is indicated in any symptomatic patient, in all symptomatic patients with suspected renal aneurysmal expansion and in patients who have renal aneurysms occurring with functionally important renal stenosis, usually associated with hypertension, in all patients with surgical accessible hepatic artery aneurysms, in all patients who have superior mesenteric artery aneurysms having a high tendency to rupture, and in all patients with an asymptomatic splenic artery aneurysms 1.5 cm or larger in diameter. Although splanchnic artery aneurysms are uncommon and asymptomatic, we recommend that splanchnic arteries should be treated surgically because of their tendency to rupture or organ failure.

Adult↗
PubMed1996

Crkl is constitutively tyrosine phosphorylated in platelets from chronic myelogenous leukemia patients and inducibly phosphorylated in normal platelets stimulated by thrombopoietin.

Platelet functions such as aggregation and clot retraction are often abnormal in chronic mylogenous leukemia (CML) patients. However, the molecular mechanisms of these altered functions are unknown. As expression of the p210bcr-abl oncogene product, a constitutively active tyrosine kinase, is known to have an essential role in the pathogenesis of CML and tyrosine phosphorylation is intimately involved in various aspects of platelet activation, we examined the pattern of protein tyrosine phosphorylation in platelets from 15 CML patients by immunoblotting with a monoclonal antiphosphotyrosine antibody (4G10). Before and after stimulation with thrombin, the only consistent difference between normal and CML platelets was the presence of a tyrosine phosphorylated protein with a relative molecular weight of 39 kD. This tyrosine phosphorylated protein was identified as crid, an SH2, SH3 containing adapter protein. Thus, as previously demonstrated for neutrophils from CML patients, tyrosine phosphorylation of p39crkl persists in mature platelets. No tyrosine phosphorylation of crid was detected following stimulation with thrombin in normal platelets. However, crkl became incorporated into the Triton X-100 insoluble residue following thrombin stimulation in a manner dependent on platelet aggregation. Further, we found that crkl is an endogenous substrate for calpain, a protease that may be involved in postaggregation signaling processes. This suggests that crkl may be involved in the reorganization of the cytoskeleton during normal platelet aggregation and its tyrosine phosphorylation in CML platelets may contribute to the abnormal platelet function in CML patients. Finally, we found that thrombopoietin induces tyrosine phosphorylation of crk1 in normal platelets and FDCP cells genetically engineered to express human c-Mpl. This suggests that crk1 can be phosphorylated by a kinase other than p210bcr-abl and that crk1 may have a role in signaling by thrombopoietin.

Adaptor Proteins, Signal Transducing↗
PubMed1996

Effect of anoxia on striatal monoamine metabolism in immature rat brain compared with that of hypoxia: an in vivo microdialysis study.

We examined in 5-day-old rats the effects of either anoxia or 8% hypoxia on extracellular monoamines such as dopamine (DA), 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), norepinephrine (NE), 5-hydroxytryptamine (5-HT), and 5-hydroxyindole-3-acetic acid (5-HIAA) using in vivo microdialysis and subsequent HPLC. After stabilization 64 animals were exposed to 100% nitrogen for 16 min and 40 animals to 8% oxygen for 128 min. Both anoxia and hypoxia produced acute increase in the striatal extracellular DA (anoxia: P < 0.001, hypoxia: P < 0.01). Especially in anoxia, DA levels increased transiently to 2000-times the basal levels and 6-times higher than those in hypoxia. NE also increased in both anoxia and hypoxia. DOPAC and HVA decreased during hypoxia (P < 0.01 and P < 0.001, respectively), while those in anoxia were unchanged. In anoxia, decrease tendency of their levels were in short duration and that of 5-HIAA was followed by gradual increase (P < 0.001). These data demonstrated that brief exposure to anoxia or hypoxia had significant influence on striatal monoamine metabolism in immature brain and the pattern of change of monoamine in anoxia was different from that in hypoxia.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1996

Effects of cardiac output on Doppler transmitral and transtricuspid flow velocity patterns in very low birth weight infants.

We studied effects of cardiac output on Doppler transmitral and transtricuspid flow velocities in 24 appropriate for gestational age premature infants. We measured peak flow velocity of early diastole (peak E) and atrial contraction (peak A), ratio of peak flow velocity of early diastole to atrial contraction (peak E/A), total flow velocity-time integral, the first third filling fraction, peak filling rate normalized to stroke volume, and deceleration time (DT). Cardiac output was calculated as the product of the aortic flow velocity-time integral, aortic valve area, and heart rate. The cardiac output increased significantly with advancing gestational age and body weight (r = 0.78 and 0.86, P < 0.01, respectively). With increasing cardiac output, the transmitral as well as transtricuspid peak E, peak E/A, and total flow velocity-time integral increased significantly without any change in the peak filling rate normalized to stroke volume, peak A, and deceleration time. The transmitral as well as transtricuspid peak E did not correlate with the heart rate. Although these results do not establish whether changes in ventricular relaxation process or in cardiac output is responsible for the progressive increase in the peak E and peak E/A. Unchanged peak filling rate normalized to stroke volume of the left and right ventricles suggest that changes in cardiac output with maturity is, in fact, one of the important contributory factors. This evidence should be borne in mind in interpreting ventricular diastolic filling as an index of ventricular diastolic function in premature infants.

Blood Flow Velocity↗
PubMed1996

Electrophysiologic comparison between incessant and paroxysmal tachycardia in patients with permanent form of junctional reciprocating tachycardia.

To clarify the differences between the incessant and paroxysmal types of the permanent form of junctional reciprocating tachycardia, we performed electrophysiologic studies in 11 patients with long RP' tachycardia using a slowly conducting accessory pathway as the retrograde conduction, and concluded that the short AH intervals during sinus rhythm and tachycardia are very important factors in the development of incessant tachycardia.

Adolescent↗
PubMed1996

Evidence that autophosphorylation at Thr-286/Thr-287 is required for full activation of calmodulin-dependent protein kinase II.

Calmodulin-dependent protein kinase II (CaM-kinase II) undergoes a very rapid autophosphorylation at Thr-286/Thr-287 in the presence of Ca2+/calmodulin and ATP/Mg2+, and this has greatly hampered studies on the role of the autophosphorylation in the regulation of the enzyme activity, because it has been difficult to measure the activity of the non-autophosphorylated enzyme in the presence of Ca2+/calmodulin. In the present study, this difficulty was overcome by using adenosine 5'-O-(3-thiotriphosphate) (ATP gamma S) in place of ATP. When the enzyme was assayed with 2 microM ATP gamma S and 200 microM syntide-2 at 5 degrees C in the presence of Ca2+/calmodulin, the linear reaction rate of thiophosphorylation of syntide-2 was much slower than that of the enzyme which had previously undergone autothiophosphorylation. Under the limiting assay conditions, thiophosphorylation of the enzyme did not occur significantly during assay. Using this assay condition, activation by autothiophosphorylation was examined. When CaM-kinase II was autothiophosphorylated at 5 degrees C, the concomitant stimulation of both activities in the presence and absence of Ca2+/calmodulin was observed. The activity of the recombinant wild-type enzyme in the presence of Ca2+/calmodulin as well as in its absence was also markedly activated upon autothiophosphorylation, whereas those of the recombinant mutated enzyme, whose Thr-287 was replaced by Ala, was not activated at all. These results provide strong support for the contention that CaM-kinase II initially possesses a basal low level of the total activity and that the initial rapid autophosphorylation on Thr-286/Thr-287 results in full activation of the enzyme.

Adenosine Triphosphate↗
PubMed1996

A novel homozygous mutation of the myelin Po gene producing Dejerine-Sottas disease (hereditary motor and sensory neuropathy type III).

We have previously reported that heterozygosity for myelin Po gene mutations were associated with Charcot-Marie-Tooth disease type 1B (CMT1B) or Dejerine-Sottas disease. We investigated the Po gene in a family with clinical Dejerine-Sottas disease and found two children were homozygous for a deletion of Phe 64. The parents were heterozygous first cousins with subclinical CMT1B and slow nerve conduction velocities. These results suggest that the effect of homozygous Phe 64 deletion on impairment of myelination is dosage-dependent. Clinical phenotype and/or myelin impairment may be determined both by the type of mutation and by the dosage of mutated gene.

Base Sequence↗
PubMed1996

Phorbol ester inhibits the phosphorylation of the retinoblastoma protein without suppressing cyclin D-associated kinase in vascular smooth muscle cells.

To elucidate the role of protein kinase C in vascular smooth muscle cell proliferation, we examined the effects of phorbol 12-myristate 13-acetate (PMA) on G1 events in human arterial cells. About 15 h after G0 cells were stimulated with fetal bovine serum and basic fibroblast growth factor, [3H]thymidine incorporation started. PMA (10 nM) inhibited the incorporation over 90% when added earlier than 3 h after stimulation, but had no effect when added 12 h or later. PMA inhibited the phosphorylation of the retinoblastoma protein (pRb), which normally began at about 9 h. PMA did not inhibit the gene expression of Cdk2, Cdk3, Cdk4, Cdk5, and cyclins G, C, and D, all of which began at 0-3 h. However, PMA reduced the expression of cyclins E and A, which usually began at 3-9 h and about 15 h, respectively. PMA inhibited the histone H1 kinase activity of Cdk2, which increased from about 9 h, whereas PMA did not inhibit the pRb kinase activities of cyclin D-associated kinase(s) and Cdk4, detectable from 0-3 h. These results suggested that the PMA-induced inhibition of pRb phosphorylation is not mediated by suppressing cyclin D-associated kinase(s) including Cdk4, but involves the suppression of Cdk2 activity that results from the reduced expression of cyclins E and A.

Cell Cycle↗
PubMed1996

Changes in left ventricular volume and systolic function before and after the closure of ductus arteriosus in full-term infants.

Using echocardiographic techniques, the change in left ventricular (LV) volume and its effect on systolic function were studied before and after the closure of ductus arteriosus in 18 full-term infants. Examinations were performed twice in each infant, within 6 h after birth and on day 5, and the patency of the ductus with left-to-right shunt was confirmed at the first examination by Doppler echocardiography. A biplane Simpson's rule method was used for volume measurements. The LV end-diastolic volume, stroke volume, and cardiac output were more than 1.3-fold before the ductal closure, and the ejection fraction showed the similar change. However, the mean normalized systolic ejection rate, an index of contractility, and heart rate showed no significant difference. The Frank-Starling curve was obtained from the relationship between the LV end-diastolic and stroke volumes, and the LV performance was operated at a higher level on that curve when the ductus was open. Our data indicated that LV cardiac output was significantly higher during the patency of the ductus arteriosus and that this high cardiac performance might depend more on the Frank-Starling response to the volume load through the ductus arteriosus than on the increase of LV contractility and heart rate.

Cardiac Output↗
PubMed1996

Infantile choriocarcinoma: a case report with MRI, angiography and bone scintigraphy.

Infantile and maternal choriocarcinoma is a very rare disease. We report a case with the characteristic clinical features of infantile choriocarcinoma: developing anemia, hemorrhagic liver tumors, rapid progression to death and maternal choriocarcinoma. Bone scintigraphy showed increased uptake by the liver tumors. In this case there were two possible primary sites: the placenta of this pregnancy and a hydatidiform mole that had been present 2 years previously.

Angiography↗
PubMed1996

Circulating endogenous thrombopoietin, interleukin-3, interleukin-6 and interleukin-11 levels in patients undergoing allogeneic bone marrow transplantation.

To elucidate the physiologic role of thrombopoietin (TPO) for hematologic reconstitution following allogeneic bone marrow transplantation (BMT), serum TPO levels as well as interleukin-3 (IL-3), IL-6 and IL-11 were serially measured in 55 samples from 3 patients who underwent allogeneic BMT using an enzyme-linked immunosorbent assay (ELISA). The TPO level was higher in the serum taken during marrow aplasia than in the pretransplant serum. The serum TPO levels and platelet counts showed a strong inverse relationship in all patients examined. We also sequentially measured endogenous serum TPO levels before and within 36 h after platelet transfusions. Endogenous serum TPO levels were inversely correlated with platelet mass following platelet transfusions. Serum levels of IL-3 had no apparent correlation with platelet counts and serum levels of IL-11 remained below the detection levels (31.3 pg/ml) in all samples. Serum levels of IL-6 were high during myeloaplasia and more upregulated in the febrile period. These findings support the view that TPO is the central regulator for megakaryopoiesis in vivo and the rationale for its clinical use after allogeneic BMT.

Adult↗
PubMed1996

Doppler echocardiographic findings of indomethacin-induced occlusion of the fetal ductus arteriosus.

We present an unusual case of indomethacin-induced occlusion of the fetal ductus arteriosus, which occurred in one of twins. In fetal echocardiography, the characteristic findings, a to and fro regurgitation pattern at pulmonary valve and postvalvular dilation of the main pulmonary artery, were obtained in addition to right ventricular dilation and hypertrophy, tricuspid regurgitation, right atrium dilation, and pericardial effusion. This fetus developed fetal distress and was delivered by an emergency cesarean section at 35 weeks' gestation. We suggest that these fetal echocardiographic findings may be the end-stage signs of the fetal ductal occlusion as well as the signs for emergent delivery.

Adult↗