Biomedical subjects

A Shibata

Publications and source records attributed to A Shibata.

At least 163 records · Page 9Linked to original sources

PubMed1995

Radiofrequency current caused slowing of non-reentrant idiopathic right ventricular tachycardia originating from a wide arrhythmogenic area.

Radiofrequency catheter ablation was attempted in a patient with non-reentrant idiopathic right ventricular tachycardia (VT). Endocardial mapping indicated that the VT originated in the outflow tract of the right ventricle; however, an electrogram with an almost the identical activation time was recorded from an area extending to 1.0 x 2.0 cm. Each application of radiofrequency current within the area terminated VT, but a progressively slower VT with the same QRS configuration was induced until the area was covered by separate radiofrequency lesions. A progressive prolongation of VT cycle length might be related to a residual arrhythmogenic myocardium. Termination and slowing of the VT rate can be a hallmark of efficacy of each radiofrequency lesion.

Arrhythmias, Cardiac↗

PubMed1995

Correlation between isolated negative U waves and the grade of coronary artery spasm.

The relation between isolated negative U waves and the severity of induced coronary artery spasm was investigated in 24 patients with variant angina to determine the grade of myocardial ischemia during the appearance of isolated negative U waves. Coronary artery spasm was induced by injections of either incremental doses of acetylcholine or ergonovine into the left coronary artery. Coronary spasm was quantified into 4 grades: Grade 0 = complete perfusion, Grade 1 = partial perfusion, Grade 2 = penetration without perfusion, and Grade 3 = no perfusion. Induction with acetylcholine was discontinued when a coronary spasm of Grade > or = 2 was induced. Electrocardiogram in leads V1 to V6 and systemic blood pressure were recorded continuously. Provocations of coronary spasm with at least 2 doses of acetylcholine could be performed in 15 patients. All acetylcholine-induced coronary spasms of Grade < or = 1 disappeared spontaneously within 3 min. Negative U waves developed in 19 (79%) patients, in whom 37 trials with acetylcholine or ergonovine injection were performed. Isolated negative U waves were detected in 10 trials, negative U waves and ST depression in 8 trials, and negative U waves and ST elevation in 14 trials. The induced coronary spasms associated with isolated negative U waves were of Grade 1 in 9 of the 10 trials. In contrast, all of the coronary spasms associated with negative U waves and ST elevation had a Grade of > or = 2. In conclusion, the coronary angiographic finding associated with isolated negative U waves is coronary spasm with delayed filling of the distal coronary artery, with opacification of the entire coronary bed.

Acetylcholine↗

PubMed1995

Urinary excretion rate of ceruloplasmin in non-insulin-dependent diabetic patients with different stages of nephropathy.

The level of ceruloplasmin, which is a more negatively charged protein than albumin, was measured by an immunoradiometric assay in timed overnight urine and serum samples from patients with non-insulin-dependent diabetes mellitus and healthy controls. None of the plasma proteins examined showed any cross-reactivity in this assay. A linear correlation was seen between the ceruloplasmin level and the serial dilution of the sample. Western blot analysis using concentrated urine samples showed that the molecular weight of ceruloplasmin in the urine sample was the same as that of ceruloplasmin in the serum and standard samples. These findings indicated that the substance detected by this assay was truly ceruloplasmin. The urinary ceruloplasmin excretion rate (CER) and clearance of ceruloplasmin increased in parallel with the progression of albuminuria. The highest CER was found in macroalbuminuric patients, followed by micro- and normoalbuminuric patients and the healthy control subjects, the differences between the groups being significant. In view of the fact that the isoelectric point of ceruloplasmin (4.4) is more acidic than that of albumin, the present findings suggested that an enhanced CER was due either to the alteration of charge selectivity in the glomerular basement membrane with unaltered tubular function or to a defect of the non-discriminatory pores (shunt pathway) with unaltered tubular function.

Adult↗

PubMed1995

Nicorandil suppresses a hump on the monophasic action potential and torsade de pointes in a patient with idiopathic long QT syndrome.

The patient was a 71-year-old female with Torsade de Pointes (TdP) associated with idiopathic long QT syndrome. TdP and polymorphic nonsustained VT were frequently observed at bedside and an electrophysiologic study was performed. The QT (and QTU) interval was abnormally prolonged, and alteration of the QT interval was also recorded on the electrocardiogram. Monophasic action potential (MAP) from the right ventricle showed a hump on the falling limb of the MAP following a long RR interval of more than 1.0 sec. Intravenous administration of nicorandil (2 mg) resulted in disappearance of the hump, and ventricular arrhythmia was no longer observed. The QT interval at a PP interval of 720 msec was slightly shortened. She was treated with a DDD-pacemaker and given nicorandil. No recurrence of TdP was observed during the follow-up period of 8 months. This drug might be effective in patients with idiopathic long QT syndrome.

Action Potentials↗

PubMed1995

A radioimmunometric assay for urinary alpha 2-macroglobulin.

To measure urinary alpha 2-macroglobulin levels, a sensitive radioimmunometric assay was established. The least detectable level of this assay was 225 pg/ml. A linear correlation between alpha 2-macroglobulin levels and serial dilution of urine samples was found. Western blot analysis and study on column chromatography revealed that the molecular weight of alpha 2-macroglobulin in urine was identical to that of serum alpha 2-macroglobulin. The findings suggested that urinary substance detected by the present assay was truly alpha 2-macroglobulin. Timed overnight urine samples from 49 diabetic patients with retinopathy and 20 healthy controls were measured by the present assay. Patients were classified as Albustix-negative and Albustix-positive patients. The highest urinary alpha 2-macroglobulin excretion rates (alpha 2-MER) was found in Albustix-positive patients followed by Albustix-negative patients and the healthy controls. In view of the fact that the stroke radius of alpha 2-macroglobulin (88A) is larger than that of the restrictive pore (56A), the present finding suggests that leakage of alpha 2-macroglobulin in urine may be induced by defect of non-discriminatory pores in the glomerular basement membrane proposed by Deen and colleagues.

Adult↗

PubMed1995

Do the effects of blood pressure control on the progression of diabetic nephropathy depend on disease stage?

To determine whether the control of blood pressure has a consistent effect on the progression of diabetic nephropathy with macroalbuminuria in diabetic patients with differing serum levels of creatinine, we evaluated the relationship between mean blood pressure and the yearly rate of increase in serum creatinine concentration in two groups: one with macroalbuminuria and a serum creatinine concentration less than 2 mg/100 ml (group 1), and the other with macroalbuminuria and a serum creatinine concentration of 2 mg/100 ml or more (group 2). Both groups showed a positive relationship between the mean blood pressure and the yearly rate of increase in serum creatinine concentration. However, when the yearly rate of increase in serum creatinine concentration was compared in patients from both groups with matched mean blood pressures of less than 100 mmHg, it was greater in patients of group 2 than in patients of group 1. Thus, although a beneficial effect of blood pressure control on the progression of diabetic nephropathy was found in both groups, the effect was less in patients with macroalbuminuria and a serum creatinine concentration of 2 mg/100 ml or more when mean blood pressure was controlled at less than 100 mmHg.

Adult↗

PubMed1995

Multinucleated giant cells undergoing apoptosis in experimental autoimmune myocarditis.

This study used an experimentally induced myocarditis model in rats to demonstrate the formation and fate of multinucleated giant cells which are known to occur in different kinds of inflammatory lesions. Multinucleated giant cells were frequently recognized in the inflammatory foci, being intermingled with numerous ED1-positive inflammatory macrophages rich in phagosomes. The giant cells reacted with the ED1 antibody but not with ED2, and ultrastructurally resembled the inflammatory macrophages. Multinucleated giant cells possessing less than 5 nuclei in an ultrathin section were rich in phagosomes, whereas those with more nuclei contained numerous lipid droplets and only few phagosomes in their cytoplasm. Light microscopic observation of hematoxylin-eosin stained sections revealed that some multinucleated giant cells displayed variously sized dark bodies which likely corresponded to condensed and fragmented nuclear chromatin. Such multinucleated giant cells were positively stained with the TUNEL method. Under the electron microscope, all nuclei in one multinucleated giant cell showed an eccentric mass of homogeneously condensed chromatin. These observations suggest that multinucleated giant cells are formed by aggregation and also likely by fusion of inflammatory macrophages; gradually loosing the phagocytotic activity characteristic of the latter cells, they then die by apoptosis.

Animals↗

PubMed1995

Pneumatosis cystoides intestinalis after chemotherapy for hematological malignancies: report of 4 cases.

Pneumatosis cystoides intestinalis (PCI) is known to be a relatively rare condition which is characterized by gas cysts in the gastrointestinal mucosa. We treated four cases of PCI accompanied by hematological malignancies during chemotherapy treatment. All cases suffered from abdominal discomfort. Abdominal X-ray films revealed gas cysts in the intestine. PCI was observed during leukocytopenic states, and three cases had septicemia. Etoposide was administered to three cases, and prednisolone to all cases. It is considered that PCI sometimes occurs in patients with hematological malignancies during a period of leukocytopenia, and may be caused by intestinal mucosal damage due to myelosuppressive agents and immunosuppression from prednisolone.

Adult↗

PubMed1995

Exercise-induced angina with intermittent ST-segment elevation.

A 59-year-old man was admitted for evaluation of mild exertional angina in the morning. During graded treadmill exercise stress testing, the patient had reproducibly intermittent chest pains associated with ST-segment elevations in leads II, III and aVF. A baseline coronary angiogram showed a coronary narrowing of 90% in the middle segment of the right coronary artery. The coronary narrowing was immediately resolved by an intracoronary injection of nitroglycerin. This was a very rare case of variant angina with intermittent ST-segment elevations and chest pains which were reproducibly demonstrated during exercise and the recovery phase of treadmill testing.

Angina Pectoris↗

PubMed1995

Effects of long-term treatment with recombinant human granulocyte-macrophage colony-stimulating factor in patients with myelodysplastic syndrome.

We examined the effects of long-term treatment with recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) in 61 patients with myelodysplastic syndrome (MDS). Patients were randomly assigned to receive daily subcutaneous injection of 60 micrograms/m2, 125 micrograms/m2 or 250 micrograms/m2 for 8 weeks. A significant increase in granulocyte counts including neutrophils and eosinophils was shown from one week after the start of the treatment in all three dose groups. The increase in granulocyte counts reached a plateau at the 4th week and was sustained during the treatment period. However, no consistent change in other cell lineages including monocytes, lymphocytes, reticulocytes and platelets were observed. Nevertheless peak-levels of these cells were significantly higher than the pre-treatment levels. In higher dose groups, the number of patients developing infections was reduced. There was no significant difference in the incidence of adverse events among the 3 dose groups, and the toxicity was generally well-tolerated. These observations indicate that treatment with rhGM-CSF can be of potential therapeutic benefit to patients with MDS.

Adolescent↗

PubMed1995

[Continuation of complete remission by oral administration of cytarabine ocfosfate in a patient with M0, who achieved remission by small doses of cytosine arabinoside with G-CSF].

A 70-year-old male was admitted to our hospital because of leukocytosis. The laboratory examination revealed leukocytosis (44,500/microliters) with blasts (99%) in the peripheral blood. Myeloperoxidase staining of the leukemia cells was negative, but the surface phenotype was CD13- and CD33-positive, and negative for all lymphoid antigens. Peroxidase staining using the electron microscope was positive. Thus, the patient was diagnosed as acute myeloblastic leukemia (M0), according to the FAB classification. Although the therapy regimens commonly used for ANLL were effective for some cases with M0, the regimens mainly for ALL were more effective for the others. Thus we cannot determine what is the most effective regimen for M0. Since the patient had many complications, he was treated with low-dose AraC instead of combination chemotherapy. After the beginning of treatment, he became febrile and we added G-CSF to Ara-C. One month later, the patient achieved complete remission without severe infection. After four courses of consolidation therapy, the patient was discharged. He has been maintained in remission for more than 3 years and 8 months with only 5-day oral administration of cytarabine ocfosfate every four weeks.

Administration, Oral↗

PubMed1995

Localization of porcine cardiac myosin epitopes that induce experimental autoimmune myocarditis.

Porcine cardiac myosin induced severe myocarditis in Lewis rats, similar to that seen after immunization with human or rat cardiac myosin. We investigated the localization of pathogenic epitopes by using porcine cardiac myosin. Subfragment-1 (S-1) and the rod were obtained by alpha-chymotryptic digestion. The rod was further fragmented by using cyanogen bromide cleavage. Three subfragments of S-1 were prepared by tryptic digestion. All Lewis rats immunized with the rod exhibited severe myocarditis, and the immunization of the cyanogen bromide-cleaved peptide equivalent to human beta-cardiac myosin heavy chain RDCB9 (residues 1070 to 1165) induced moderate myocarditis. Although none of the rats immunized with the whole S-1 exhibited any myocardial lesions, moderate inflammatory cardiac lesions were detectable in rats immunized with the tryptic digests of S-1. Our results indicate that the myocardiogenic epitopes in Lewis rats are located in the RDCB9 (residues 1070 to 1165) of the cardiac myosin rod and that a cryptic minor epitope may reside in S-1.

Amino Acid Sequence↗

PubMed1995

[Bence Jones type multiple myeloma showing diffuse infiltration to the dura mater by myeloma cells].

A 62-year-old man with aleukemic Bence Jones type multiple myeloma who developed neurologic abnormalities is reported. After admission, consciousness disturbance appeared and a lumbar puncture obtained M-protein. Though brain CT showed no abnormal findings except a punched out lesion of the temporal bone, MRI disclosed remarkable enhancement of the dura mater. Meningeal involvement by myeloma cells without leukemic blood picture is very rare though it is common in other lymphoproliferative disorders such as acute lymphocyte leukemia and malignant lymphoma. We report a case of BJ type multiple myeloma with meningeal involvement due to diffuse infiltration to the dura mater and discuss a possible mechanism of meningeal involvement in this patient.

Bence Jones Protein↗

PubMed1995

FK506 treatment of graft-versus-host disease developing or exacerbating during prophylaxis and therapy with cyclosporin and/or other immunosuppressants. Japanese FK506 BMT Study Group.

A phase II study of the efficacy and safety of FK506, a new potent immunosuppressant, has been conducted in 49 patients with GVHD after allogeneic BMT. Eighteen patients with acute GVHD and 31 with chronic GVHD entered the study. FK506 was administered at an initial dose of 0.05 mg/kg i.v. or 0.15 mg/kg orally twice a day to those whose GVHD had become uncontrollable with cyclosporin and/or other immunosuppressants. The response to FK506 was evaluated in 13 patients with acute and 26 with chronic GVHD. A marked response was observed in 5 and a good response in 2 of 13 patients with acute GVHD. For those with chronic GVHD, the response was marked in 2 patients, good in 10 and poor in 8. The most common adverse effects were renal toxicity (53.1%), followed by nausea and vomiting (30.6%) and a feeding of warmth (18.4%). There was a correlation between renal toxicity and whole blood levels of FK506. The dose should be adjusted to keep a trough level between 15 and 25 ng/ml. FK506 is promising in the treatment of both acute and chronic GVHD, even if it is intractable with other immunosuppressants, and may be most effective if administered early in the course of GVHD.

Acute Disease↗

PubMed1995

[Circularity index of left ventricular shape in the assessment of heart disease].

Left ventricular volume and ejection fraction obtained by cineangiography are useful to evaluate global left ventricular function in humans. Left ventriculography provides evidence of the effect of coronary artery stenosis on regional wall motion in patients with coronary artery disease. Changes in left ventricular shape are also found in various heart diseases. The left ventricular cavity is normally ellipsoid in shape, but becomes flat in hypertrophic cardiomyopathy, globular in dilated cardiomyopathy, and aneurysmal in some patients with myocardial infarction. This study developed a new method to quantify regional and global left ventricular shape. Regional circularity index (RCI) was defined as GD divided by r (GD = distance from each 5-degree endocardial margin to the center of gravity, r = radius of the circle equal to left ventricular area). The global circularity index (GCI) was derived from the sum of magnitude of RCI-1. The end-systolic GCI was related to end-systolic left ventricular wall stress (r = 0.71, p < 0.001). The change in GCI during systole was related to left ventricular ejection fraction (r = 0.79, p < 0.001). In severe cases of dilated cardiomyopathy, the left ventricle became more spherical during ejection. End-systolic left ventricular moment around the minor axis had a good correlation with left ventricular ejection fraction (r = 0.81, p < 0.001). Quantification of regional and global left ventricular shape can be used to estimate left ventricular wall stress from left ventricular shape. Left ventricular shape change during systole and the moment around the left ventricular short axis contributes to left ventricular ejection.

Angiocardiography↗

PubMed1995

[Serial 123I-IMP SPECT in a case of cryptococcal meningoencephalitis].

We performed serial brain perfusion SPECT studies using 123I-IMP in the course of cryptococcal meningoencephalitis. Increased perfusion was detected in the cerebellum coinciding with the appearance of the abnormality on MRI. The perfusion in the lesion was then decreased as the abnormality on MRI disappeared. Cryptococcal meningoencephalitis should be also taken in the differential diagnosis when the inflammatory brain lesion shows increased perfusion.

Aged↗

PubMed1995

[Anemia and hemostatic abnormalities associated with multiple myeloma].

Anemia and bleeding are commonly observed in patients with multiple myeloma (MM). Anemia in MM is multifactorial in origin. Three common causes are marrow replacement by the malignant cells, thereby reducing the available number of BFU-E, chronic renal failure and shortening of the half life of erythrocytes. Some patients with anemia but without renal failure show a good response to erythropoietin (Epo) with full correction of anemia. This indicates that human Epo is a promising therapeutic tool or treating myeloma-associated anemia. The incidence of severe bleeding complications is low, despite the diversity of abnormal hemostatic tests in patients with MM. These patients frequently show abnormal coagulation tests, including thrombin time, fibrin degeneration products, platelet aggregation tests and bleeding time. The most effective therapeutic approach to bleeding is to treat the underlying malignancy. Supplemental to this, plasma exchange is useful.

Anemia↗

PubMed1995

Enhanced elimination of Ph+ chromosome cells in vitro by combined hyperthermia and other drugs (AZT, IFN-alpha, TNF, and quercetin): its application to autologous bone marrow transplantation for CML.

Autologous bone marrow transplantation (ABMT) for chronic myelogenous leukemia (CML) is limited because of the difficulty in purging Ph chromosome positive cells from bone marrow cells (or peripheral blood stem cells). Combining hyperthermia with certain drugs that affect Ph+ cell growth in vivo and in vitro may enhance the killing (apoptosis) of CML cells in vitro. In this study, we chose such drugs (i.e., azidothymidine [AZT], interferon-alpha [IFN-alpha], tumor necrosis factor [TNF], and quercetin) and tested this hypothesis using two CML-derived cell lines in vitro, K562 and KU812, to enhance the killing of CML cells with heat. Our results indicate that the optimal hyperthermic purging effect is achieved by heating at 42 degrees C for 1 hour with IFN-alpha (100 U/mL) and AZT (0.5 microM/L) or with quercetin (50 microM) [corrected], depending on the sensitivity of the CML cells eliminated in vitro. K562 cells were significantly eradicated by a combination of IFN-alpha and AZT, while KU812 cells were significantly inhibited by quercetin at the temperature and drug concentrations above. This combined effect may enhance apoptosis of CML cells in vitro.

Apoptosis↗