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Dive into the research topics where Yorikazu Ishikawa is active.

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Featured researches published by Yorikazu Ishikawa.


European Journal of Cancer and Clinical Oncology | 1991

Detection of tyrosine hydroxylase mRNA and minimal neuroblastoma cells by the reverse transcription-polymerase chain reaction

Naito H; Noboru Kuzumaki; Junichi Uchino; Ryoji Kobayashi; Takaaki Shikano; Yorikazu Ishikawa; Shuzo Matsumoto

To facilitate the diagnosis of bone marrow metastasis in neuroblastoma, we have developed a method of amplifying and detecting the tyrosine hydroxylase (TH) mRNA sequence in bone marrow cells using a combination of reverse transcription and the polymerase chain reaction (RT/PCR). By this method, the sequence of TH was detected clearly in the neuroblastoma tissues of all 6 patients and not detected in the bone marrow cells of any of the 9 negative control children. In a reconstitution experiment, 1 neuroblastoma cell per 100,000 normal bone marrow cells could be detected, thus indicating the great sensitivity of this method. Based on these results, this technique may be of value in the diagnosis and treatment follow-up of bone marrow metastasis of neuroblastoma.


Bone Marrow Transplantation | 1999

Neurological complications after stem cell transplantation in childhood

Akihiro Iguchi; Ryouji Kobayashi; Makoto Yoshida; Makoto Kaneda; N Watanabe; Yuko Cho; Hideki Arioka; Naito H; Takaaki Shikano; Yorikazu Ishikawa

We analyzed the incidence of neurological complications in 77 patients receiving stem cell transplantation (SCT), and 12 patients (15.8%) had the following symptoms: convulsions, intracranial hemorrhage, and leukoencephalopathy. Although statistically not significant, neurological complications were seen more frequently in patients after allogeneic transplantation, and in those with acute graft-versus-host disease (GVHD) exceeding grade II. The most significant risk factor for neurological complications was identified as unrelated donor allogenic transplantation (P = 0.016). Complications were categorized into three groups, based on time of onset and symptoms: (1) convulsions during the conditioning period, (2) intracranial hemorrhage during the period of granulocyte recovery, and (3) leukoencephalopathy at around 2 months after SCT. We propose awareness of the risks of neurological complications in each period after SCT so that immediate and effective treatment of patients can be instigated.


Bone Marrow Transplantation | 1998

Electroencephalogram abnormality and high-dose busulfan in conditioning regimens for stem cell transplantation

Ryouji Kobayashi; N Watanabe; Akihiro Iguchi; Yuko Cho; Makoto Yoshida; Hideki Arioka; Naito H; Takaaki Shikano; Yorikazu Ishikawa

High-dose busulfan (BU) is widely used in combined chemotherapy before allogeneic or autologous bone marrow transplantation. Convulsions are reported as a side-effect of high-dose BU. We recorded electroencephalograms (EEGs) before and on the third day of BU administration in 22 patients. Abnormal EEGs were observed on the third day in 13 cases (59%). These patients were older (P < 0.05) and had had larger doses of bu (P < 0.025) than the nine patients with normal eegs. convulsions occurred in two of the 22 patients, one of whom was receiving prophylaxis with phenytoin. gamma aminobutyric acid (gaba), a natural mediator of defense against epileptic activity, concentrations in cerebrospinal fluid measured before and after administration of bu showed no definite changes.


Pediatrics International | 1992

Myelodysplastic syndrome with partial deletion of the long arm of chromosome 5: first report of a case in a child.

Takaaki Shikano; Yorikazu Ishikawa; Michiya Anakura

A childhood case of myelodysplastic syndrome (MDS) with a deletion of the long arm of chromosome 5 (5q‐) is reported. The patient was an 8 year old boy who has recurrent angina. Laboratory evaluation revealed the following: hemoglobin 8.1 gm/dl, white blood cell count 4.9 × 103/l with 3% atypical lymphocytes, and platelet count 17.7 × 104/l. A bone marrow aspirate revealed 20% blast cells and dysmyelopoietic changes involving all three marrow cell lines. Karyotype analysis of marrow cells revealed 46,XY,5q‐ in 100% of the metaphases.


British Journal of Haematology | 1984

Ph1‐positive and Ph1‐negative abnormal cell lines in a child with lymphoblastic lymphoma

Takaaki Shikano; Yasuhiko Kaneko; Yorikazu Ishikawa; Norio Niikawa; Tatsuto Tonooka; Takeo Takeda; Masahiro Kikuchi

Summary. A 7‐year‐old Japanese boy with Ph1‐positive‐lymphoblastic lymphoma is described. The diagnosis was based on biopsied tonsils which were enlarged at the time of admission. On the eighth day after admission an enlarged mediastimal mass was detected on a chest X‐ray film. The lymphoblasts which appeared in the peripheral blood and bone marrow proved to be T‐cells. Chromosome studies on the bone marrow cells revealed two abnormal cell lines; one had a 7; 11 translocation and the other a 7;11 translocation and a 9;22 translocation, forming the Ph1‐chromosome. The latter line with the Ph1 chromosome was considered to have been derived from the former line without the Ph1. Our findings show that the Prochromosome may be a secondary change in the course of karyotypic evolution.


Pediatrics International | 1999

Effective treatment of cyclic thrombocytopenia with cepharanthin

Hideto Furuyama; Yasutsugu Koga; Kazurou Hamasaki; Fumiko Kuroki; Noritomo Itami; Yorikazu Ishikawa

Cyclic thrombocytopenia is an extremely uncommon disease characterized by periodic fluctuation in peripheral platelet counts.1 Although this disease predominantly occurs in women synchronous with menstruation, its etiology is unknown. It is resistant to treatment and its management has not been established.1 In the present report, we describe a 1-year and 7-monthold girl with cyclic thrombocytopenia who was successfully treated with cepharanthin, a biscoclaurine alkaloid, which is mainly used in Japan for allergic disorders, snake bites and for the rescue of bone marrow suppression due to irradiation.


Leukemia & Lymphoma | 1999

Leukoencephalopathy in Childhood Acute Lymphoblastic Leukemia with T(1; 19)

Takaaki Shikano; Ryouji Kobayashi; Yorikazu Ishikawa

To clarify the incidence of leukoencephalopathy in patients with t(1;19) and their clinical characteristics, we studied 239 acute lymphoblastic leukemia (ALL) cases. The 1;19 translocation was found in 20 (8.5%) of the 239 children with ALL. Leukoencephalopathy occurred in 2 (10%) patients with t(1;19) during the early first remission and in one case with t(1;19) at the time of central nervous system (CNS) relapse. Leukoencephalopathy was not found during the early first remission in patients lacking t(1;19), but did develop in 4 patients lacking t(1;19) at the time of CNS relapse. There were no differences in age, sex, leukocyte count, platelet count or serum lactate dehydrogenase level between t(1;19) patients with and without leukoencephalopathy. Our results suggest the incidence of leukoencephalopathy in patients with t(1;19) during the early first remission to be 10%, but we can not predict which patients will develop leukoencephalopathy.


Transplantation Proceedings | 2010

High Susceptibility to Severe Infectious Complications at Reinduction Chemotherapy in Patients Who Relapse After Stem Cell Transplantation

Akihiro Iguchi; Ryouji Kobayashi; Tomonobu Sato; Naito H; Takaaki Shikano; Yorikazu Ishikawa; Kunihiko Kobayashi

Patients who relapse after stem cell transplantation (SCT) usually appear to be liable to severe infectious complications at reinduction chemotherapy compared to patients at the first induction therapy, though this is not statistically substantiated. The aim of this study was to analyze episodes of infectious complications during reinduction chemotherapy among patients who relapsed after SCT compared with those at the first induction chemotherapy. Between February 1988 and March 2004, 145 children received SCT, and 17 (12 with hematologic malignancies and 5 with solid tumors) were enrolled as eligible subjects for this study. Positive blood cultures (sepsis) were present in six patients exclusively at the reinduction therapy but none at the first induction (P = .009). Three of the six patients progressed to septic shock. Moreover, all patients positive for blood cultures were those with hematologic malignancy (P = .007), and every patient with septic shock had received allogenic transplantation. Our results showed that reinduction chemotherapy needs attention for severe infectious complications, particularly among patients with hematologic malignancies receiving allogenic transplantations. Possible immaturity of the reconstructed systemic immune system and/or insufficient recovery of mucosal protective functions in the patients after SCT are discussed in view of their high susceptibility to severe infectious complications.


Pediatric Hematology and Oncology | 1993

Painless and Safe Subcutaneous Catheter for Injection of Various Cytokines in Patients with Hematological Disorders

Yorikazu Ishikawa; Motohiko Okano; Hideki Arioka; Ryoji Kobayashi; Naito H; Yukio Sakiyama

Various cytokines have been used to treat patients with hematological disorders, eg, recombinant granulocyte colony-stimulating factor (G-CSF),1 recombinant granulocyte-macrophage colony-stimulating factor (GM-CSF),2 and erythropoietin (EPO) are given to patients with aplastic anemia (AA). G-CSF and GM-CSF are also used to treat neutropenia in patients with leukemia, lymphoma, and other solid tumors who receive such treatment as intensive chemotherapy.3 Interferon (IFN)-gamma is used to treat patients with chronic granulomatous disease (CGD).4 Generally these cytokines are administered either intravenously or subcutaneously. However, it is difficult to continue intravenous injection for long periods, especially in children. One of the major problems associated with the subcutaneous route is pain. Recently, teflon catheters have been used for daily painless injections of insulin by subcutaneous inplantation into the abdominal wall of diabetic patients.5


Cancer Genetics and Cytogenetics | 1993

Jumping translocations of 1q in Burkitt lymphoma and acute nonlymphocytic leukemia

Takaaki Shikano; Hideki Arioka; Ryoji Kobayashi; Naito H; Yorikazu Ishikawa

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