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Biomedical subjects

T Yamane

Publications and source records attributed to T Yamane.

At least 127 records · Page 7Linked to original sources

Clinical significance of simultaneous measurement of reticulated platelets and large platelets in idiopathic thrombocytopenic purpura.

Frequencies of reticulated platelets (RP) and large platelets (LP) among circulating platelets can now be simultaneously determined using the R-3000 automated reticulocyte counter (Sysmex, Kobe, Japan) equipped with special software. We measured frequencies of RP and LP in patients with idiopathic thrombocytopenic purpura (ITP. acute type n = 5; chronic type n = 39), and healthy normal controls (n = 20). In ITP patients, the platelet-associated IgG (PAIgG) level was also determined. Both RP and LP were significantly higher in chronic ITP patients than those in normal volunteers, and interestingly, the LP in acute ITP was significantly lower than that in chronic ITP although there was no significant difference in RP between acute and chronic ITP. Furthermore, we analyzed the changes in both RP and LP during the clinical course of ITP to monitor the therapeutic effect in 2 patients. An elevation of RP with a steep slope prior to a decrease in the platelet count level was observed. The RP significantly correlated with the PAIgG level. Simultaneous measurement of RP and LP may be helpful for the diagnosis of chronic ITP, for the differentiation of acute from chronic type and for the control of the efficacy of management in ITP, since RP seems to reflect the disease activity of ITP.

Female↗

A practical quick staining method using hydrochloric acid-fast metachromatic dye for megakaryocytes.

A specific stain using violet polymethine dye (VPM stain) for megakaryocytes was first developed by Kass (1995). We have modified this method for practical use in bone marrow specimens. The modified VPM stain labels megakaryocytes very well, while other marrow cells are poorly colorized. This staining procedure was more stable, and its color intensity was finer and clearer than the original. Using this stain, morphologic classification of megakaryocytes in bone marrow specimens from 11 normal and 8 myelodysplastic syndrome (MDS) patients was performed. Many megakaryocytes observed in MDS patients were juvenile compared with normal subjects according to their morphology. Blasts from acute megakaryoblastic leukemia (M7) and from a megakaryoblastic cell line (Mo7e) were also clearly stained with our method. This staining method is practical and very useful for rapid identification of megakaryocyte distribution and morphology.

Bone Marrow Examination↗

Avoidance of solidification of sesame oil at low temperature by self-interesterification with immobilized lipase.

To reduce the freezing point of sesame oil, the lipase-catalyzed interesterification of sesame oil in a solvent free system was studied. The lipase was immobilized on Celite and refined sesame oil was used as the only substrate for the reaction. After interesterification, the oil did not solidify at 0 degrees C even after 24 h, and even longer storage at 2-4 degrees C did not result in solidification. The change of physical behavior was investigated with a differential scanning calorimeter and X-ray diffraction, and reduction in the thermodynamic and crystallographic stability of the interesterified oil was demonstrated. The change in triacylglycerol species composition after the reaction was analyzed, showing that content of trisaturated acylglycerol was decreased.

Calorimetry, Differential Scanning↗

Electrophysiologically guided ablation of the pulmonary veins for the curative treatment of atrial fibrillation.

Catheter ablation of triggers that induce paroxysms of atrial fibrillation (AF) is an emerging curative therapy for this most common of supraventricular arrhythmias. In a series of 225 consecutive patients with multidrug resistant AF, 96% of triggering foci originated from one or several pulmonary veins (PV) independent of ambient ectopy or structural heart disease. This article describes an ablation procedure that is guided by activation mapping tailored to each individual PV, including criteria to define an arrhythmogenic PV, the use of provocative manoeuvres, the role of circumferential mapping catheters to provide information on the extent, distribution and activation of PV muscle as well as the monitoring of distal PV potentials (PVP) during ablation. Radiofrequency ablation to eliminate distal PVPs is performed by targeting the proximal PVP during sinus rhythm (right PV) or left atrial pacing (left PV). This end-point predicts a successful outcome more often than acute ectopy suppression. Complete elimination of AF is presently achieved in 70% of the patients, resulting in the elimination of antiarrhythmic treatment and suspension of anticoagulant treatment. It is anticipated that continued technological development will improve and facilitate this technique of curative treatment of AF.

Atrial Fibrillation↗

Leptin receptor and leukemia.

The receptor for leptin, the gene product of the obese gene, is expressed in hematopoietic stem cells. Leptin stimulates normal myeloid and erythroid development, and is secreted from bone marrow adipocytes, which occupy most of the marrow cavity in humans. Leptin might thus play an important role in the control of the expansion and differentiation of primitive hematopoietic cells through paracrine interaction in the bone marrow microenvironment. Leukemic cells of some patients with acute myeloblastic leukemia, acute lymphoblastic leukemia, and chronic myeloid leukemia (CML) also express the leptin receptor. In cases of CML, higher expression of leptin receptor is observed during blast crisis than in chronic phase. Leptin alone and in combination with other cytokines has stimulative effects on proliferation of leukemia cells as well as anti-apoptotic effects. These findings suggest the possibility that leptin plays roles in the pathophysiology of leukemia.

Carrier Proteins↗

Basic and clinical evaluation of a newly-developed enzymatic bilirubin assay.

An enzymatic bilirubin assay using bilirubin oxidase was evaluated. Its repeatability and linearity were excellent, and excellent correlations were observed between the enzyme and the diazo methods in total and conjugated bilirubin. The coefficient of correlation between the conjugated bilirubin fraction obtained with the diazo method and that of HPLC was 0.424, while this coefficient was 0.580 for the diazo method. A multi-laboratory study using 3 serum specimens revealed lower coefficients of variation for the enzymatic method than for the diazo method. Bilirubinuria specimen showed good accord between total bilirubin and conjugate bilirubin levels for the enzymatic method, not for the diazo method. When 12 newborn baby specimens and 34 pediatric specimens were studied, all exhibited increased concentrations of conjugated bilirubin with the diazo method. In an adult case with prolonged jaundice, the diazo method usually yielded higher conjugated bilirubin values than the enzymatic method. The enzymatic method was then concluded to be superior to the diazo method for conjugated bilirubin determination.

Adult↗

[High-dose chemotherapy with autologous peripheral blood stem cell transplantation for treatment of non-Hodgkin's lymphoma].

Findings for 41 patients with non-Hodgkin's lymphoma (NHL) treated with high-dose chemotherapy (HDC) and/or autologous peripheral blood stem cell transplantation (PBSCT) are reported. Two of the 41 patients were treated with HDC alone without PBSCT. At transplant, 20 patients were in complete remission, while 19 had resistant NHL and had failed to achieve a complete remission (CR) after several courses of conventional chemotherapy. The conditioning regimens used were mainly ACE (cytarabine, cyclophosphamide, etoposide) and MEAC (MCNU, etoposide, cytarabine, cyclophosphamide). The treatment-related mortality rate was 4.9%. Two patients treated with MEAC died from intractable congestive heart failure. Nine of the 19 patients with resistant NHL achieved CR, and at a median follow-up of 26 months (range, 3 to 93 months) the estimated two-year disease-free survival rate for these patients was 44.4%. Four patients in CR at present were in partial remission before HDC and PBSCT. Fifteen of the 20 patients in CR before HDC were transplanted in first CR and 5 in 2nd CR. At a median follow-up of 49 months (range, 3 to 96 months), the estimated 3-year DFS for the group of all patients was 73.7%. Five relapses occurred between 5 and 35 months post-transplantation. In conclusion, HDC and PBSCT as induction therapy was only effective for patients with resistant NHL who responded to conventional chemotherapy, and may improve the survival of patients in CR as consolidation therapy.

Adolescent↗

[Total hematological analysis system as a screening test for hematological malignancy].

Measurement of complete blood cell count and white blood cell differentiation is an essential laboratory test and the most important screening test for hematological malignancy. Recently, several automated blood cell analyzers have been developed to improve accuracy and precision. When flag messages generated in the presence of morphological abnormalities of the samples are displayed, manual revision is necessary. In our laboratory, the manual revision rate has been 35-40%. Therefore blood cell analyzers are useful in screening for abnormalities as well as greatly reducing expensive and time-consuming manual differential procedures. In addition, automated blood cell analyzers can provide several types of useful information including the leukocyte distribution scattergram. However, most such information is not utilized in the clinical field. In the future, a total hematological analysis system will be constructed so that all information provided by automated blood cell analyzer and by manual methods are available.

Blood Cell Count↗

[Mycosis fungoides terminating in acute myelocytic leukemia].

A 57-year-old woman was admitted to our hospital with suspected leukemia in September 1999. In 1990, systemic erythema had occurred, and mycosis fungoides (MF) had been diagnosed by skin biopsy. Interferon-gamma therapy had not been effective, and the erythema had disappeared after treatment with psoralen and ultraviolet A (PUVA) therapy (1.46 J/cm2). The patient had subsequently done well with a course of topical steroids. On admission this time, the WBC count was 1,600/microliter with 6% blasts. The total nucleated cell count in a bone marrow aspirate was 43.1 x 10(4)/microliter, of which 86.2% were peroxidase-positive blasts. Acute myelocytic leukemia (AML) was diagnosed. Chromosomal analysis demonstrated abnormalities of 48, XX, +4, +8, +add(10)(p11), add(11)(q23) in 10 of 20 cells, and 51, idem, +6, +8, +21, +mar in 8 cells with mixed-lineage leukemia gene rearrangement. Therapies (radiation, chemotherapy and PUVA) for MF, and the altered immune response seen in patients with this disease, especially in the more advanced stages, collectively termed cutaneous T-cell lymphoma (CTCL), suggest that such patients may be at increased risk of a second primary malignancy. To our knowledge, AML has been reported in 8 MF patients including the present one. Attention should be given to the possibility of MF terminating in AML.

Female↗

[B precursor lymphoblastic leukemia/lymphoma manifested at onset as hemophagocytic syndrome].

A 20 year-old male patient was admitted to our department for the treatment of recurrence of fever and pancytopenia developed despite of temporal remission of hemophagocytosis syndrome that had been treated with large doses of methylprednisolone in our hospital. Superficial lymph nodes were not palpable. CT scan and echography revealed neither findings of splenohepatomegalia or enlargement of intraabdominal lymph nodes. Bone marrow aspiration showed an increase of histiocytes, the cells phagocytizing erythrocytes and platelets, and a negative test for peroxidase stain. Analysis of surface antigens showed that 11.3% of cells were blast cells positive for CD10, CD19, CD20, CD34 and TdT. Bone marrow biopsy revealed a localized increase in tumor cells positive for L26, CD10 and negative for UCHL-1. Because of the absence of detectable tumor masses and the difficulty in differentiating between malignant lymphoma and lymphatic leukemia, we diagnosed the condition as B precursor lymphoblastic leukemia/lymphoma. If diagnosed with malignant lymphoma preceded by hemophagocytic syndrome(LAHS), he might have a rare type of LAHS-associated malignant lymphoma since histological examination did not reveal diffuse large cell lymphoma, a condition found in most patients with LAHS-associated malignant lymphoma. Whereas if diagnosed as ALL, he was the first adult patient with ALL with HPS at onset as far as we know. In any of these possibilities, the case was considered rare.

Adult↗

[Clinical cases of acquired coagulation inhibitors].

The acquired coagulation factor inhibitors are classified into alloantibodies, which appear in association with supplementary treatment for congenital coagulation factor deficiency, and autoantibodies, which are spontaneously produced. We report here 2 cases of acquired factor VIII inhibitor and 1 case of factor V inhibitor. Case 1: A 52-year-old woman noted swelling of the right parotid region in March 1988. Though contrast examination was scheduled, she was admitted for detailed examination due to a markedly prolonged coagulation time. An APTT correction test suggested that decreased factor VIII activity was due to the presence of an inhibitor. Since antinuclear antibody and SS-A antibody were positive and infiltration by lymphocytes in the salivary gland acini in a lip biopsy specimen was detected, Sjögren's syndrome was diagnosed. Case 2: A 33-year-old woman had normal delivery of her second child in February 1998. In June 1998, she suffered slight contusion in the left lower limb. The affected site became swollen and painful, making walking difficult. Since both upper limbs became markedly swollen after 1 week, she visited our hospital. Prolonged APTT and a marked decrease in factor VIII activity were observed. Factor VIII inhibitor titer was high at 19 Bethesda units. Case 3: A 64-year-old man had had asymptomatic macroscopic hematuria since the beginning of August 1998 but was placed under observation since no abnormal findings were observed on various imaging tests. However, he was admitted to Osaka City General Medical Center because of vesicular tamponade. Factor V activity was markedly decreased to 1.0%. PT correction test suggested that decreased factor V activity was due to the presence of an inhibitor. The underlying disease could not be determined in this case. In patients with acquired coagulation inhibitors, bleeding symptoms are reported to be mild in many cases, and severe bleeding is rare. However, cases of death without severe bleeding or underlying disease have also been reported, indicating that the prompt diagnosis and treatment of this condition are necessary.

Adult↗

HLA class II alleles in Japanese patients with non-Hodgkin's lymphoma.

The distribution of HLA-DRB1 alleles and DQB1 alleles in 30 Japanese patients with non-Hodgkin's lymphoma (NHL) was analyzed using polymerase chain reaction with the sequence-specific primer (PCR-SSP) method, and the association between the disease and the presence of certain HLA class II alleles was investigated. The frequencies of HLA-DRB1*0803, DRB1*0802 and DRB1*1502 were increased while those of DRB1*1501 and DRB1*0405 were decreased. On the other hand, the incidence of HLA-DQB1 alleles was similar to that in the normal population. However, none of these HLA class II alleles showed significant positive or negative associations with NHL. In addition, when allele frequencies of NHL Japanese patients were compared to Thai patients, only DRB1*0803 was significantly increased in Japanese patients. These results indicate that DRB1*0803 may not contribute to NHL susceptibility in the Japanese population. However, further studies with larger numbers of NHL Japanese patients are needed to confirm our preliminary findings.

Adolescent↗

Single-step single-molecule PCR of DNA with a homo-priming sequence using a single primer and hot-startable DNA polymerase.

We have previously reported that a protein library can be constructed by directly combining PCR amplification of a single DNA molecule and cell-free protein synthesis. To specifically amplify single DNA molecules, however, two-step PCR with nested primers was used. Here we describe a simpler method for single-step amplification of a single molecule. The method involves the use of both hot-startable DNA polymerase and a DNA template that has homo-priming sequences at both ends for amplification using a single primer. These two modifications greatly decreased the possibility of formation and subsequent accumulation, respectively, of primer-dimers that inhibit the amplification of target template. In addition, a high-fidelity DNA polymerase was successfully used, resulting in the significant reduction of the accumulation of mutations during amplification.

Journal Article↗