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Biomedical subjects

Y Kawachi

Publications and source records attributed to Y Kawachi.

At least 73 records · Page 4Linked to original sources
PubMed1996

Inverted transitional cell carcinoma of the ureter.

An inverted urothelial tumor (transitional cell carcinoma, inverted type, grade 1), consisting of a large (3.5 x 1.2 x 1.2 cm) tumor with stalk (0.3 cm in diameter) and surrounding broad base polypoid foci (0.5 x 0.6 x 0.5 cm altogether), was found in the lower segment of the left ureter of a 59-year-old man. He has taken oral anticancer drugs and kanpo medicine as a follow-up for 61 months, and is now free of disease. Differential diagnosis, inverted urothelial papilloma and carcinoma, and adequate treatment are discussed.

Carcinoma, Transitional Cell↗
PubMed1996

Effectiveness and limitations of the fallback I algorithm for transient supraventricular tachyarrhythmias in DDD pacing.

To examine the function of the fallback I algorithm (Chorus I, Ela Medical Inc., Montrouge, France), which automatically changes the DDD mode to VDI during transient supraventricular tachyarrhythmias to prevent high-rate tracking of the venticule, a total of 45 patients who were preoperatively diagnosed with sick-sinus syndrome (SSS) (Group 1; n = 19) or with advanced or complete atrioventricular block (AVB) (Group 2; n = 26) were followed up and analyzed. Mean follow-up times (mean +/- SD) were 22.4 +/- 9.7 and 12.4 +/- 10.9 months, respectively. Each of the groups was further divided into subgroups according to the preoperative existence of of paroxysmal atrial fibrillation (PAF) or paroxysmal supraventricular tachyarrhythmia (PSVT). During follow-up, the fallback started through a given cycle of ventricular pacing at a upper-rate limit (URL) to avoid a continuous high-rate tracking during the arrhythmias specifically in the patients with PSVT (0/4) (p = 0.0004). The fallback, however, sometimes started in the patients who had AVB not associated with either PAF or PSVT (4/21) during normal exercise because the fallback algorithm did not distinguish a normal P wave from the abnormal atrial waves. To further clarify the behavior of the fallback, a treadmill test was conducted in 25 of the 45 patients. The fallback start was observed in 12 of the 17 patients with AVB (Group 2). In such patients, the use of a long fallback delay and/or a high URL setting prevented the fallback starts during normal exercise. These results suggest that, in DDD pacing, the algorithm in Chorus I is useful in patients with SSS or AVB to avoid highrate tracking of the ventricle during transient supraventricular tachyarrhythmias, but special care must be taken to avoid the fallback starts during the normal exercise in AVB patients.

Adult↗
PubMed1996

Use of automatic mode change between DDD and AAI to facilitate native atrioventricular conduction in patients with sick sinus syndrome or transient atrioventricular block.

The benefits of the automatic DDD (DDD/AMC) mode in the Chorus II pacemaker (Chorus 6234; Ela Medical Inc.), which automatically switches the modes between DDD and AAI to respect spontaneous AV conduction as much as possible in AAI while preserving safety pacing in DDD during paroxysmal AV block (AVB) only, remain unproven. This study examined the functions of the DDD/AMC mode in 12 patients with sick sinus syndrome (SSS; n = 10) or paroxysmal complete AVB (n = 2). A short-term (24 hours) comparative study between simple DDD mode and the DDD/AMC mode was performed in 8 of the 12 patients, and a medium-term (55.2 +/- 54.6 days) follow-up of the DDD/AMC mode was completed in all 12 patients. A comparative pair of 24-hour surface Holter ECGs was obtained in 6 of the 8 patients in the short-term study. Telemetry and built-in Holter histograms were collected in the outpatient clinic in all 12 patients. Although the percentage atrial pacing of the telemetry increased from 59.2 +/- 35.4 in DDD to 70.4 +/- 31.8 in DDD/AMC (P < 0.009; n = 8), the percentage ventricular pacing decreased from 64.6 +/- 37.7 in DDD to 36.2 +/- 43.1 in DDD/AMC (P < 0.027) in the short-term study. In particular, the reduction of percentage ventricular pacing to < 10% was observed in four patients with SSS not associated with > or = first-degree (1 degree) AVB on preoperative ECGs. Between the two modes a significant difference in arrhythmic events was not observed by the 24-hour surface Holter ECGS taken from the six patients in the short-term study. AAI-DDD switching associated with automatic modulation of AV delay and AV hysteresis occurred in all patients in the medium-term study. From the medium-term study, the total AV delay (AV delay plus AV hysteresis) exceeded 300 ms in 6 of the 12 patients in DDD/AMC, and usually became longest during nighttime. From the short- or medium-term study in the 12 patients, two patients preferred the DDD/AMC mode while one preferred the DDD mode. These results suggest that the DDD/AMC mode is useful, at least in SSS patients without > or = 1 degree AVB, by reducing the percentage ventricular pacing.

Adult↗
PubMed1996

[Mixed warm and cold antibody type autoimmune hemolytic anemia associated with systemic lupus erythematosus].

A 56-year-old woman developed mixed warm and cold antibody type autoimmune hemolytic anemia (mixed AIHA) associated with systemic lupus erythematosus. The patient was admitted to our hospital for acrocyanosis and shortness of breath. High fever and jaundice were observed. Urinalysis revealed protein and hemoglobin, and the sediment contained granular and hyaline casts. Her erythrocytes agglutinated markedly at room temperature. Her hemoglobin was 5.6 g/dl and reticulocyts were 19.3%. Total bilirubin, GOT and LDH were elevated, while haptoglobin and complements were abnormally reduced. Polyclonal increase of immunoglobulin, ANA and anti-Sm antibody were detected. The direct antiglobulin test was positive; IgG1, IgG3 and C3d were detected on the red cell surface. The cold agglutinin (CA) titer was 4096, showing anti-I blood group specificity, and was still active at 30 degrees C. Upon administration of prednisolone gradual increase of hemoglobin and decrease of reticulocytes were observed, indicating the healing of hemolysis. CA disappeared but the direct antiglobulin test remained positive. Mixed AIHA has been defined as the presence of both warm and cold antibodies. In addition, the presence of symptoms of cold agglutinin disease, or low-titer and high thermal amplitude CA might be necessary for the diagnosis of mixed AIHA.

Anemia, Hemolytic, Autoimmune↗
PubMed1996

Successful twenty-four-hour canine lung preservation with lazaroid U74500A.

BACKGROUND: Lipid peroxidation is known to contribute to ischemia-reperfusion injury. U74500A is a 21-aminosteroid (lazaroid) that prevents lipid peroxidation without corticoid side effects. We examined the effect of U74500A on lung preservation using a canine orthotopic single left lung transplantation model. METHODS: Twelve adult mongrel dogs underwent left lung allotransplantation. The lungs of the donor dogs were flushed with University of Wisconsin solution (50 ml/kg). Six donor dogs were pretreated with U74500A (5 mg/kg intravenously) before preservation (group L, n = 6), whereas those dogs without pretreatment served as controls (group C, n = 6). Allografts were stored in University of Wisconsin solution for 24 hours at 1 degrees C. Left single lung transplantations were performed by means of standard technique. Before reperfusion, recipients in group L received another dose of U74500A. Arterial blood gas analysis and hemodynamic measurements were made by occluding the right pulmonary artery to evaluate the transplanted left lung function at a inspired oxygen fraction of 1.0. Serum lipid peroxide level was measured after 2 hours of reperfusion. RESULTS: Arterial oxygen tension, arterial carbon dioxide tension, and left pulmonary vascular resistance at 6 hours after reperfusion were significantly better in group L than in group C (arterial oxygen tension: 510 +/- 66 and 219 +/- 149 mm Hg; arterial carbon dioxide tension: 47 +/- 16 and 68 +/- 14 mm Hg; left pulmonary vascular resistance: 2412 +/- 826 and 3904 +/- 1251 dyn center dot sec/cm5, group L and group C, respectively). Serum lipid peroxide level was significantly lower in group L (0.25 +/- 0.24 nmol/ml) than in group C (0.92 +/- 0.53). CONCLUSIONS: The administration of U74500A prevented lipid peroxidation and preserved pulmonary allograft function after 24 hours of ischemia.

Animals↗
PubMed1996

[Reevaluation of administration dosage in parenteral iron therapy].

Concerning parenteral iron therapy in iron deficiency anemia, Nakao's formula has been used to calculate the total amount of iron to be given, based on 80 ml/kg of circulating blood volume and 17 mg/kg of storage iron in healthy Japanese. Recent studies using radionuclide and radioimmunoassay revealed 65 ml/kg as the circulating blood volume and 500 mg as storage iron. From these data, the total amount of iron can be calculated from the following formula; 3.4 (16-X) x 65 x body weigh/100 + 500 mg (B) where 3.4 is the conversion factor for grams of hemoglobin to mg iron and X is the hemoglobin value before treatment. Parenteral iron therapy was performed in 15 patients with iron deficiency anemia using a total dose of iron calculated by the above the formula (B). The results were effective, and no decrease of hemoglobin was seen except in cases with continuous bleeding. In such cases, iron doses depending upon the amount of continuous bleeding should be added to the total amounts obtained from formula (B).

Adult↗
PubMed1996

Autoantibodies to bullous pemphigoid and epidermolysis bullosa acquisita antigens in an infant.

We describe a 1-year-old boy with multiple tense blisters on the skin, who showed circulating autoantibodies directed to both bullous pemphigoid and epidermolysis bullosa acquisita antigens. The patient's serum IgG antibodies bound to the 290-kDa epidermolysis bullosa acquisita antigen with immunoblot analysis of human dermal extracts. Immunoblot analysis also demonstrated that the patient's serum autoantibodies were reactive with recombinant NC16a domain of the 180-kDa bullous pemphigoid antigen. This study confirmed the presence of circulating autoantibodies directed to both bullous pemphigoid antigen and epidermolysis bullosa acquisita antigen.

Autoantibodies↗
PubMed1996

[CD2 and CD8 expression in acute promyelocytic leukemia].

A 34-year-old man was admitted to our hospital for a headache in March, 1995. The patient's hemoglobin was 7.5 g/dl, platelet count was 1.8 x 10(4)/microliter and white blood cell (WBC) count was 12,400/microliters with 99% myeloblasts. Myeloblasts were agranular or hypogranular but electron microscopy revealed microgranules in cytoplasm, and a few faggots were observed. The bone marrow was hyperplastic due to myeloblasts and chromosomal abnormality was recognized: 46, XY, t(15; 17) (q22; q12). PML-RAR alpha with intron 3 breakpoint of the PML locus, and rearrangements of the T-cell receptor beta and gamma genes were detected. These cells were positive for CD2 (63%), CD8 (47%), CD13 (87%) and CD33 (99%). Microgranular variant type of acute promyelocytic leukemia (APL) was diagnosed. Disseminated intravascular coagulation (DIC) was also present. The patient was treated with enocitabine, daunorubicin, 6-mercaptopurine, dalteparin sodium, anti-thrombin III concentrates and gabexate mesilate with prophylactic frozen transfusions of fresh plasma and platelet transfusions for 5 days, but WBC count did not decrease and DIC did not improve. The patient died of cerebral hemorrhage 7 days after diagnosis of APL. APL with CD8 expression has never been reported. We suggest that therapy should be modified in this type of APL and conclusions concerning the most appropriate therapeutic strategy will depend on the results of treatment of similar cases in the future.

Adult↗
PubMed1995

Relationships between intermediate TCR cells and NK1.1+ T cells in various immune organs. NK1.1+ T cells are present within a population of intermediate TCR cells.

Experiments to date have revealed a population of T cells that carry intermediate (int) levels of TCR (or CD3) and express IL-2R beta-chain (IL-2R beta) in mouse liver. Such int TCR cells also reside in other immune organs, although in low numbers. On the other hand, NK1.1+ T cells with int TCR do reside in the thymus and other peripheral organs. To determine the relationship of two types of cells, we characterized int CD3 cells and NK1.1+ T cells throughout the organs in terms of the phenotype, V beta repertoire, and morphology. Although both IL-2R beta+ T cells and NK1.1+ T cells are classified as int CD3 cells, NK1.1+ T cells are present within int CD3 cells. The majority of int CD3 cells in the liver and thymus were NK1.1+, whereas the minority of such cells in the spleen, lymph nodes, and bone marrow were NK1.1+. Among int CD3 cells, double-negative (DN) CD4-8- cells and/or CD4+ were abundant in NK1.1+ subset, whereas CD8+ cells were generally abundant in NK1.1- subset. Self-reactive V beta+ clones estimated by the M1s system were distributed to both NK1.1+ and NK1.1- subsets. High CD3 cells in the thymus and other organs contained neither DN cells nor forbidden clones. Int CD3 cells had the morphology of granular or agranular lymphocytes carrying perforin. Among int CD3 cells, NK1.1+ subset had a higher level of perforin-positive cells than NK1.1- subset. These results clearly demonstrate the relationship between int TCR cells and NK1.1+ T cells in various organs.

Animals↗
PubMed1995

Self-reactive T cell clones in a restricted population of interleukin-2 receptor beta+ cells expressing intermediate levels of the T cell receptor in the liver and other immune organs.

T cells expressing high levels of the T cell receptor (TCRhigh) differentiate in the major intrathymic pathway and then distribute to the peripheral immune organs, whereas T cells expressing intermediate levels of the TCR (TCRint) differentiate in both extrathymic pathways and an alternative intrathymic pathway and localize in unique sites, including the liver and thymic medulla. Since TCRint cells constitutively express interleukin-2 receptor beta-chain (IL-2R beta), two-color staining for CD3 (or TCR) and IL-2R beta clearly distinguished IL-2R beta+ CD3int (or TCRint) cells from IL-2R beta-, CD3high cells. CD3int cells may be considered to be primordial T cells based on their phenotype, morphology and other functional properties. In this study, using anti-V beta mAb in conjunction with the endogenous superantigen Mls, the distribution of self-reactive clones among T cells generated in all of the above pathways was investigated in mice. Self-reactive T cell clones were confined to IL-2R beta+, CD3int cells, in all of the organs tested. A significant proportion of self-reactive clones was never identified among CD3high cells in the thymus and peripheral immune organs in either young (8 week old) or old (50 week old) mice. Possibly reflecting their self-reactivity, CD3int cells, but neither NK cells nor CD3high cells had a potent cytotoxic effect against a syngeneic hepatoma in the presence of anti-CD3 mAb. These results raise the possibility that CD3int cells seen in the liver and thymus might belong to a similar primordial lineage of T cells, and that self-reactive clones are not generated through the major intrathymic pathway, but only through extrathymic pathways and an alternative intrathymic pathway.

Age Factors↗
PubMed1995

Supportive cellular elements for hepatic T cell differentiation: T cells expressing intermediate levels of the T cell receptor are cytotoxic against syngeneic hepatoma, and are lost after hepatocyte damage.

Extrathymic T cells exist in the liver and are often seen in close contact with Kupffer cells in the hepatic sinusoids. Since selective depletion of Kupffer cells has become possible by using liposome-encapsulated clodronate, it was investigated whether elimination of Kupffer cells influences the level of extrathymic T cells in the liver. Extrathymic T cells were identified as interleukin-2 receptor beta-chain (IL-2R beta) intermediate TCR (TCRint) cells by two-color staining for CD3 or T cell receptor (TCR) and IL-2R beta. The elimination of Kupffer cells did not significantly affect levels of TCRint cells up to 7 days after treatment. We then examined monocyte colony stimulating factor (M-CSF)-deficient op/op mice (low levels of Kupffer cells). Extrathymic T cells both in the liver and spleen of these mice were detected at a level comparable to that of control mice. Since extrathymic T cells in the liver are sometimes located in the parenchymal space, the relationship between extrathymic T cells and hepatocytes was then examined. Electron microscopy revealed that some hepatic T cells adhered directly to hepatocytes. When hepatocytes were damaged by a single injection of CCl4, hepatocyte death and subsequent hepatic fibrosis were induced. Beginning 3 days after injection, CD3int cells, but not other type of cells, decreased prominently. Purified CD3int cells, as well as whole lymphocytes in the liver, were cytotoxic against syngeneic hepatoma. In parallel with the above-mentioned hepatic damage, the cytotoxic activity of lymphocytes against such targets was impaired in the liver. These results suggest that extra-thymic generation of TCRint cells and their acquisition of cytotoxic function are relatively independent of Kupffer cells, but are dependent on hepatocytes.

Animals↗
PubMed1995

Intermediate TCR cells with self-reactive clones are effector cells which induce syngeneic graft-versus-host disease in mice.

It has been established that, even after syngeneic bone marrow transplantation, animals treated with immunosuppressive drugs may suffer from graft-versus-host disease, showing autoimmune-like symptoms. Although the major effector cells are known to be T-cell subsets, detailed characterization of such T cells remains to be investigated. In the present study, we characterized them, especially as to whether they are thymus-derived T cells or extrathymic T cells, and how self-reactive clones were distributed among the above T-cell subsets. BALB/c mice (Mls-1b2a) were irradiated (9 Gy), subjected to bone marrow transplantation, and then treated with cyclosporin A (CsA) for 6 weeks. From 2 weeks after the cessation of CsA, these mice displayed signs of GVH disease. The major target organs included the liver and colon. Two-color staining for CD3 and IL-2R beta was applied to identify CD3-IL-2R beta+ NK cells, CD3-intermediate +IL-2R beta+ cells (i.e., intermediate CD3 or TCR cells of extrathymic origin) and CD3-high+IL-2R beta- cells (i.e., high CD3 cells of thymic origin). It was demonstrated that the major expanding lymphocytes were intermediate TCR cells and that self-reactive clones (V beta 3+ and V beta 11+ cells in this strain of mice) were confined to this population. Interestingly, these self-reactive clones had ability to respond to immobilized anti-V beta 3 and anti-V beta 11 mAbs. Liver MNC in mice with GVH disease which contained the highest proportion of intermediate TCR cells were able to mediate the adoptive transfer of GVH disease to other irradiated (6.5 Gy) mice. Intermediate TCR cells also showed potent cytotoxic activity against syngeneic leukemia cells. These results suggest that intermediate TCR cells are the major effector cells for the induction of syngeneic GVH disease.

Animals↗
PubMed1995

A rare case of large ventricular septal defect with minimal pulmonary vascular obstructive changes in a 41-year-old woman.

We describe a case of large ventricular septal defect (VSD) with minimal obstructive changes in the small pulmonary arteries of a 41-year-old woman. Before cardiac catheterization, some laboratory findings led us to consider that surgical closure of the defect would not be possible. However, because hemodynamic examinations showed only mildly elevated pulmonary vascular resistance, we patch-closed the VSD successfully. The histology of lung specimens showed only minimal obstructive changes in the small pulmonary arteries. Considering the size of the VSD and the age at which we hemodynamically evaluated the patient, the mildness of the pulmonary vascular obstructive changes appeared to be atypical in the natural course of a VSD of this size.

Adult↗
PubMed1995

Left ventricular-coronary sinus shunt through a septal aneurysm after mitral valve re-replacement.

We describe a case in which a left ventricular-coronary sinus communication through a dissecting ventricular septal aneurysm developed after a redo mitral valve replacement. The outlet orifice of the communication was located in the side wall of the ostium of the coronary sinus. Both the communication and the aneurysm were successfully dealt with by performing a right atriotomy and by opening the aneurysm from its outlet orifice.

Aged↗
PubMed1995

Simplified Manouguian's aortic annular enlargement for aortic valve replacement.

A simplified Manouguian's aortic annular enlargement for aortic valve replacement with prosthetic valve was performed in a patient with severe aortic stenosis and mild regurgitation by preserving both the anterior mitral leaflet and the left atrial roof intact. This method minimized the operative risk by avoiding injury to the mitral valve, while inserting a possibly two-size-larger prosthetic valve. The inserted prosthetic valve was positioned parallel to the original aortic valve. Moreover, the incision from the top of the commissure between the noncoronary cusp and left coronary cusp through the interventricular fibrous trigone appears to be easily extended into the exact center of the anterior mitral leaflet if further enlargement is required.

Aorta↗
PubMed1995

Preoperative autologous blood donations in pediatric cardiac surgery.

BACKGROUND: Preoperative autologous blood donation is one of the most effective methods to avoid homologous blood transfusion in cardiac operations. However, there have been few reports about the safety and efficacy of autologous blood donation in children. METHODS: Since 1986, we have instituted a blood conservation program including preoperative autologous blood donations in children. Eighty children as young as 3 years old (mean +/- SD, 8.6 +/- 3.9 years) and weighing as little as 12.3 kg (29.2 +/- 14.5 kg) were enrolled in the program, and 735 +/- 388 mL of blood was donated during an average of 3.1 +/- 1.5 phlebotomies before the operations. RESULTS: Two episodes of mild vasovagal reaction were observed in 2 patients as a complication of the phlebotomy. Seventy-six percent of the collected blood was stored by cryopreservation; the remaining 24% was preserved by liquid storage. Seventy-eight of these patients (97.5%) underwent operations using cardiopulmonary bypass. Seventy-five patients (94%) were operated on successfully without the need for a homologous blood transfusion. As for the other 5 patients, 2 received only platelet concentrate. CONCLUSION: Preoperative autologous blood donation is a safe and effective method to avoid homologous blood transfusion in pediatric cardiac operations.

Adolescent↗
PubMed1995

Maldistribution of the cerebral blood flow in retrograde cerebral perfusion.

Retrograde cerebral perfusion (RCP) through a superior vena caval (SVC) cannula has now become a useful alternative for brain protection during aortic arch operations. However, little is still known about its physiological effects, especially regarding the flow distribution in the brain. We studied the cerebral blood flow distribution under hypothermic conditions using mongrel dogs (n = 6, weighing 9.5 to 14 kg). We measured the cerebral tissue blood flow of the cortex with a laser Doppler flowmeter and cerebral tissue blood flow of the medulla using the hydrogen clearance method. The cerebral blood distribution at 28 degrees C with a whole body bypass flow of 100 ml/kg per min and aortic pressure of 88.3 +/- 20.4 mmHg was used as a control. Then the body temperature was decreased to 20 degrees C and the descending aorta was cross-clamped just distal to the origin of the left subclavian artery to establish antegrade cerebral perfusion (ACP). The perfusion flow was decreased to 54.8 +/- 12.4 ml/kg per min so as to make the aortic pressure similar to the control conditions. After measuring the cerebral blood flow distribution in ACP, the perfusion was then switched to RCP through the bilateral internal maxillary vein and the SVC pressure was kept at 40 mmHg. In RCP, the cerebral blood flow of the medulla was quite similar to that in ACP (12.4 ml/min per 100 g versus 15.2 ml/min per 100 g, NS). In contrast, the cerebral blood flow of the cortex significantly decreased to 16% of the flow in ACP (7.8 perfusion units versus 50 perfusion units, P < 0.01). Because of the maldistribution of the cerebral blood flow in RCP, careful attention should be paid to the clinical application of this method.

Animals↗