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Biomedical subjects

J Okamura

Publications and source records attributed to J Okamura.

At least 37 records · Page 2Linked to original sources
PubMed2000

The usefulness, indications, and complications of laparoscopy-assisted colectomy in comparison with those of open colectomy for colorectal carcinoma.

The technique of laparoscopy-assisted colectomy (LAC) was developed for benign and malignant diseases of the colon and rectum; however, its feasibility and the associated clinical outcome remain unclear. We reviewed 45 patients who underwent LAC (LAC group) and 62 patients who underwent traditional open surgery (Open group) for colorectal carcinoma in our hospital, and compared the clinical data between the two groups in an effort to determine whether LAC is really minimally invasive and if it enhances the quality of life. So that the backgrounds of the patients in both groups were almost the same, we only compared data of patients with colorectal carcinoma of stages 0, I, and II. The duration of surgery in the Open group was significantly shorter for all procedures except sigmoid resection, but the blood loss was not significantly different between any of the procedures except for right colectomy. The time to the first passing of flatus and restarting oral intake, length of hospital stay, and duration of epidural analgesia were significantly shorter in the LAC group. The morbidity and mortality rates in the LAC group were almost the same as those in the Open group at 29.5% and 3.3% versus 22.6% and 1.6%, respectively. However, five major complications of LAC for advanced colorectal carcinomas might be prevented by performing an open procedure. In conclusion, LAC is a safe and minimally invasive surgical technique following which we can expect a faster recovery; however, patients with advanced colorectal carcinomas must be carefully selected for this operation.

Adenocarcinoma↗
PubMed2000

Thymus-independent expansion of T lymphocytes in children after allogeneic bone marrow transplantation.

The contribution of the thymus-dependent pathway and thymus-independent pathways for T cell regeneration after BMT in children is still unclear. We analyzed the kinetics of T cell regenerative pathways after allogeneic BMT. The number of CD4+CD45RA+ T cells, a thymus-dependent population, was very low until 3 months after BMT. The numbers of CD28- T cells and CD8+ T cells expressing CD8alpha/alpha homodimer (CD8alpha/alpha+ T cells), a thymus-independent population, increased shortly after BMT, beyond the levels of healthy children in some patients. The numbers of Vgamma9+Vdelta2+ and Valpha24+ T cells, which represent populations of extrathymic development, were less than 200/microl during the 6 months after BMT. There was a significant inverse correlation between the percentages of CD4+CD45RA+ and CD28-T cells at 1 month, and a positive correlation between the percentages of CD28- and CD8alpha/alpha+ T cells at 2 and 3 months after BMT. The mean age at BMT was higher in patients with a high level of CD8alpha/alpha+ T cells than in those without an increase in these cells, suggesting the influence of thymic function on the regenerative pathways. These results suggest that the thymus-independent pathway is the dominant source of T cells even in children shortly after allogeneic BMT.

Acute Disease↗
PubMed2000

An effective chemotherapeutic regimen for acute myeloid leukemia and myelodysplastic syndrome in children with Down's syndrome.

In recent pediatric collaborative studies of acute myeloid leukemia (AML), patients with Down's syndrome (DS) have better outcome than other patients when they were treated according to their intensive AML protocols. This may be attributed to enhanced sensitivity of DS AML cells to selected chemotherapeutic agents. We evaluated a less intensive chemotherapeutic regimen which was specifically designed for children with AML-DS. Remission induction chemotherapy consisted of daunorubicin (25 mg/m2/day for 2 days), cytosine arabinoside (100 mg/m2/day for 7 days), and etoposide (150 mg/m2/day for 3 days). Patients received one to seven courses of consolidation therapy of the same regimen. Thirty-three patients were enrolled on the study and their clinical, hematologic and immunophenotypic features were analyzed. Of the 33 patients, all were younger than 4 years and diagnosed as having acute megakaryoblastic leukemia or myelodysplastic syndrome. All patients achieved a complete remission and estimated 8 year event-free survival rate was 80+/-7%. Three patients relapsed and two died due to cardiac toxicity and one due to septic shock. The results of our study showed that patients with AML-DS constitute a unique biologic subgroup and should be treated according to a less intensive protocol designed for AML-DS.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2000

Improved survival for patients with advanced neuroblastoma after high-dose combined chemotherapy based in part on N-myc amplification.

BACKGROUND/PURPOSE: In spite of many different kinds of chemotherapy for neuroblastoma, the prognosis for advanced neuroblastoma remains unsatisfactory. In particular, the outcome of advanced neuroblastoma with high copies of the N-myc gene tend to be poor. Therefore, the new high-dosage combined chemotherapy regimens for advanced neuroblastoma based in part on the N-myc amplification status has been utilized in the Kyushu area of Japan since 1991. This study aims to investigate whether these new regimens based in part on N-myc amplification have improved the survival rate of stage III and stage IV patients in comparison with the old regimens. METHODS: Between 1983 and 1995, 77 patients over 1 year of age and with stage III or IV neuroblastoma were registered in the Kyushu Area. Between 1983 and 1990, 49 patients received 1 of 2 combined chemotherapy regimens consisting of cyclophosphamide, cisplatin plus VM-26, and Adriamycin plus DTIC. Since 1991, two new regimens (New A1 and A3) have been administered based on the N-myc amplification status in a total of 28 patients. The New A1 regimen, which consists of cyclophosphamide, cisplatin, Adriamycin, and VP-16 has been administered in cases of less than 10 copies of N-myc, whereas the A3 regimen, consisting of a higher dose of cyclophosphamide, cisplatin, Adriamycin, and VP-16, has been administered in cases of more than 10 copies of N-myc. The survival rate was then compared between the old regimens and the new regimens. RESULTS: The 3-year survival rate (61.5%) for patients treated by the new regimens was significantly higher than that (32.7%) for patients treated by the old regimens (P <.01). Regarding the 24 cases of more than 10 copies of N-myc, the 3-year survival rate (35.9%) of the 13 patients treated by the A3 regimen was higher than that (0%) of the 11 patients treated by the old regimens (P <.05). However, in the 19 stage IV patients treated by the new regimens, the 3-year survival rate (11.1%) of the 9 cases of more than 10 copies was significantly lower than that (77.8%) of the 10 cases of less than 10 copies of N-myc (P <.01). CONCLUSIONS: These results suggest that high-dose combined chemotherapy based in part on the N-myc amplification status significantly improved the prognosis of patients with advanced neuroblastoma. However, stage IV patients with N-myc amplification still require a more effective treatment modality.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2000

The characteristics of mediastinal neuroblastoma.

The prognosis of mediastinal neuroblastoma has been reported to be better than for other neuroblastomas. The reason for this is however not clear. Furthermore, a comparison between mediastinal neuroblastoma and the other neuroblastomas has been rarely reported so far. In this study, the characteristics of mediastinal neuroblastoma (84 cases) are investigated and compared with those of other neuroblastomas (440 cases). Regarding clinical factors, the age distribution and the rate of cases detected at mass screening were similar in both groups. According to Evan's staging system, the rates of early stage (I, II) were 62% in the mediastinal neuroblastoma and 38% in the other neuroblastomas (p<0.001). Regarding the biological prognostic factors, a favorable histology based on Shimada's classification was found in 100% (35/35) of the mediastinal neuroblastoma cases and in 85% (112/132) of the other neuroblastoma cases (p<0.05). With regard to N-myc amplification, all of the examined 42 cases in mediastinal neuroblastoma had a N-copy number of less than 10 copies, while 32 of the examined 263 cases (12%) in the other neuroblastomas had an amplification of N-myc of more than 10 copies (p<0.05). The 5-year survival rates were 78% in the mediastinal neuroblastoma and 59% in the other neuroblastomas, respectively. Of the cases who underwent an incomplete resection of primary tumors in localized neuroblastoma, the 5-year survival rate of the mediastinal neuroblastoma cases was significantly more favorable than that of the other neuroblastomas. The majority of mediastinal neuroblastoma cases showed an early stage and favorable prognostic factors. It is likely that the clinical and biological prognostic factors of the tumor are therefore more closely correlated with the outcome of mediastinal neuroblastoma rather than the degree of the surgical resection. Regarding the treatment for mediastinal neuroblastoma, it is most important to evaluate the biology of the tumor after surgical resection.

Child, Preschool↗
PubMed2000

Treatment of childhood acute myelogenous leukemia with allogeneic and autologous stem cell transplantation during the first remission: a report from the Kyushu-Yamaguchi Children's Cancer Study group in Japan.

A total of 64 newly diagnosed acute myelogenous leukemia patients (except FAB M3 and/or Down syndrome) under 18 years of age were consecutively enrolled into the study. Patients having an HLA-identical sibling (allo group) were assigned to undergo allogeneic bone marrow transplantation (allo BMT) in the first complete remission (CR). Others (non-allo group) were assigned to undergo autologous peripheral blood stem cell transplantation (PBSCT) or autologous BMT (auto BMT). Conditioning regimen was busulfan + melphalan for all transplantation. Of 64 patients (allo group 24; non-allo group 40), 59 (92.2%) achieved a CR. Eighteen relapses occurred (allo group 4; non-allo group 14) and 6 died during the first CR. The 5-year event-free survival (EFS) rate was 53.3 +/- 6.4% at a median follow-up period of 45 months. The 5-year EFS rates of allo and non-allo groups were 70.8 +/- 9.3% and 43.0 +/- 8.1%, respectively (p = .08). The EFS rates at 5 years post-transplant for allo BMT from an HLA-identical sibling (n = 18), PBSCT (11), and auto BMT (6) were 88.1 +/- 7.9%, 41.6 +/- 19.7%, and 83.3 +/- 15.2%, respectively. The outcome of allo BMT was superior to that of autograft. Auto BMT rather than PBSCT might contribute to a long-term survival in case of no available HLA-identical siblings.

Adolescent↗
PubMed2000

[Evaluation of hepatic resection following hepatic arterial infusion chemotherapy for colorectal liver metastases].

We evaluated the significance of hepatectomy following hepatic arterial infusion (HAI) chemotherapy for colorectal liver metastases. The prognosis of 4 cases with initially resectable tumors was discouraging, indicating no benefit of preoperative HAI for resectable tumors. The 2- and 3-year survival of patients who underwent hepatectomy after downstaging by HAI of originally unresectable metastases were 100% and 67%, respectively, suggesting that hepatectomy combined with HAI is a promising modality for those patients. However, it seems that the control of extrahepatic disease and decision making for the timing for surgical therapy are issues requiring improvement.

Aged↗
PubMed2000

[Malignant islet cell tumor of the pancreas with multiple liver metastases effectively treated by transcatheter arterial embolization with degradable starch microspheres--a case report].

A 57-year-old woman underwent distal pancreatectomy for malignant islet cell tumor of the pancreas in 1991. One year later, multiple liver metastases appeared. Although three transcatheter arterial embolizations (TAE) with spongel and nine ethanol injections were performed over seven years, the tumors were growing gradually. Therefore, TAE with degradable starch microspheres (DSM) was selected. Under angiography, TAE of the left hepatic artery was done using 900 mg of DSM following injection of Farumorubicin (20 mg), Lipiodol (3 ml) and cisplatin (90 mg). The tumors in the embolized hepatic area were remarkably decreased in size, and satisfactory local control was obtained. Thereafter, TAE with DSM was carried out twice, and she is still living with outpatient treatment. Thus, it is suggested that TAE with DSM could be a promising, alternative therapeutic modality for liver metastases from malignant islet cell tumor of the pancreas.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1999

Bilateral basal ganglial necrosis after allogeneic bone marrow transplantation in a child with Kostmann syndrome.

A 6-year-old girl underwent allogeneic BMT from a matched sibling donor for the treatment of Kostmann syndrome. She suddenly became drowsy on day 30 after BMT, and lost consciousness 2 days later. Cranial CT scan showed symmetrical lesions suggesting bilateral necrosis in the basal ganglia. Clinical and laboratory investigations failed to reveal any evidence of neurometabolic disease.

Basal Ganglia↗
PubMed1999

Treatment of infant acute lymphoblastic leukemia in Japan. Childhood Leukemia Study Group of the Ministry of Health and Welfare (Kouseisho).

Although current chemotherapeutic regimens cure as many as 70% of children with acute lymphoblastic leukemia (ALL), infants continue to show a poor outcome. In this paper, we describe the outcome in 37 ALL infants treated between 1989 and 1995 in Japan. Patients had characteristic findings of infant ALL, including hyperleukocytosis > 100 x 10(9)/l (15/37, 41%), blast cells with a CD10-negative phenotype (30/37, 81%), and 11q23/MLL involvement (21/37, 57%). Seven were treated according to Aggressive Treatment Research Group protocol, 15 according to the Ministry of Health and Welfare protocol, and 15 according to protocols of other institutions. The 3-year overall event-free survival (EFS) was 33%. The EFS was 13% for infants aged < 26 weeks at diagnosis and 43% for infants aged > 26 weeks. Infants who had blast cells with CD10 negative phenotype with 11q23/MLL involvement were also associated with poor prognosis. However, infants with CD10 positive blasts without 11q23/MLL involvement had a better outcome (EFS 75%). These results suggest that intensive chemotherapy is effective for patients with good prognostic factors, but for infants with poor prognostic factors a more aggressive approach such as stem cell transplantation might be necessary.

Female↗
PubMed1998

Mass screening for neuroblastoma at 6 months of age: difficult to justify.

BACKGROUND/PURPOSE: A statistical analysis of the mass screening for neuroblastoma in Japan based on a population study rarely has been reported. This study aims to evaluate retrospectively the effectiveness of mass screening at 6 months of age using the available population data. METHODS: The data on the neuroblastoma cases registered by the Committee for Pediatric Solid Malignant Tumors in the Kyushu area were analyzed based on both screened and unscreened populations in the Kyushu area. RESULTS: From 1988 to 1992, the cumulative incidence of neuroblastoma in children less than 5 years of age was 82 in 484,599 for screened children, and 11 in 92,966 for unscreened children, respectively. Fourteen of the 82 screened patients had negative findings at 6 months of age (MS-negative cases). No significant difference was observed in the cumulative mortality rates from neuroblastoma in children younger than 5 years of age between the screened children and the unscreened children. Six of seven patients who died among the screened children were MS-negative cases with stage III or IV disease. In addition, no significant difference was found in the cumulative mortality rates from the neuroblastoma cases in patients less than 5 years of age between the children screened from 1988 to 1992 (7 of 484,599) and all children from 1980 to 1984 (14 of 668,084). CONCLUSIONS: These findings suggests that the majority of the patients detected by mass screening had a favorable prognosis, and, mass screening in Japan for children less than 6 months of age was not observed to reduce the incidence and mortality from neuroblastoma. Therefore, mass screening at 6 months of age was not found to improve substantially the prognosis of patients with unfavorable neuroblastoma identified over 1 year of age, which is the primary purpose of such mass screening for neuroblastoma.

Evaluation Studies as Topic↗
PubMed1998

Unrelated umbilical cord-blood stem cell transplantation: a report from Kanagawa Cord Blood Bank, Japan.

Umbilical cord-blood (CB) has been used as a source of hematopoietic stem cells in pediatric patients with sibling donors. As a result of the success with CB transplantation from sibling donors, pilot programs for the banking of unrelated donor CB were initiated in the organization of Kanagawa Cord Blood Bank, Japan in 1995. As of December 1997, unrelated donor CB was used to reconstitute hematopoiesis in seven patients aged 0.7-12.8 years, weighing 7-36 kg with high-risk leukemia (n = 5), myelodysplastic syndrome (n = 1), and immunodeficiency syndrome (n = 1). Engraftment of CB was achieved in six patients. The absolute neutrophil count reached 500/microliter in a median of 27 days; a platelet count of 20,000/microliter was reached by a median of 64 days in three patients who could be evaluated. Five patients are currently surviving. Grade I GVHD developed in three patients and grade III in one patient; no GVHD developed in three patients. Although only a small number of patients have been studied and the period of observation is too short to determine long-term survival, HLA-matched or HLA-mismatched CB from unrelated donors can provide an alternative source of hematopoietic reconstitution for clinical transplantation.

Blood Banks↗
PubMed1998

Dehydroepiandrosterone (DHEA) ameliorates the insulin sensitivity in older rats.

To evaluate whether dehydroepiandrosterone (DHEA) ameliorates the decreased insulin sensitivity in older rats, hyperinsulinemic euglycemic clamp studies were performed in rats of various age groups previously treated with DHEA. The glucose metabolic clearance rate (MCR) of the control rats showed a gradual decline with the advancing ages (MCR = 13.05 - 0.027*age (days), r2=0.683, p < 0.01, n = 18). The glucose MCR of the DHEA-treated rats also showed a gradual decline with the aging process (MCR = 12.67 - 0.011*age (days), r2=0.429, p < 0.01, n = 18). However, the MCR of the DHEA-treated rats were significantly higher than that of control rats. As glucose MCR is a parameter which indicates the insulin sensitivity in various tissues, especially in muscles and body composition, was not changed after the injection of DHEA, DHEA is considered to work on muscles to increase insulin sensitivity.

Aging↗
PubMed1998

Donor leukocyte infusion after allogeneic bone marrow transplantation was not effective for relapsed rhabdomyosarcoma.

A 10-year-old boy with metastatic rhabdomyosarcoma had an HLA-identical sibling and received an allogeneic BMT. Recurrence was detected in the BM as the only site of treatment failure 12 months after BMT. Donor leukocyte infusion (DLI) was chosen as salvage therapy. Although sufficient cells (a total of 29.7 x 10(7)/kg) were infused, no signs of acute GVHD nor BM aplasia occurred and the patient died of disease progression 9 months after DLI.

Bone Marrow Transplantation↗
PubMed1998

Infrequent mutations in the PTEN/MMAC1 gene among primary breast cancers.

Recently PTEN/MMAC1, a candidate tumor suppressor gene, was isolated from chromosome 10q23-24 and somatic mutations of this gene were detected in several malignancies including brain, prostate, and breast tumors. To investigate further the potential role of this gene in mammary carcinogenesis, we examined 69 primary breast cancers for mutations in PTEN/MMAC1 by means of polymerase chain reaction single-strand conformation polymorphism and sequencing analysis. We detected only one somatic missense mutation, a change from T to C at codon 59 (TCA to CCA) resulting in substitution of Pro for Ser in the predicted protein. This site is located outside of phosphatase or phosphate-acceptor motifs, but this codon encodes a residue that is conserved in homologous proteins, tensin and auxilin and is likely to be crucial for normal function of PTEN/MMAC1. Among the 69 tumors examined, three low-frequency polymorphisms were found as well, one in the non-coding region of exon 1 and one each in introns 2 and 7. Our results suggested that mutation of the PTEN/MMAC1 gene is not a major factor in the development of most primary breast cancers.

Adult↗
PubMed1998

[Analysis of 18 breast cancer patients with hypercalcemia].

A total of 91 breast cancer patients died of advanced and recurrent breast cancer at the Osaka Teishin Hospital from 1986 to 1996. There were 18 cases (19.8%) among them showing hypercalcemia (serum corrected Ca > or = 11.0 mg/dl). These 18 cases were analyzed to determine the incidence of hypercalcemia and to find a more effective treatment. All these patients had multiple bone metastases during their clinical course, and six patients (33.3%) had pathologic bone fracture just before the occurrence of hypercalcemia. Their common symptoms were general fatigue, gastrointestinal symptoms, renal dysfunction or neurological symptoms. There was no definitive correlation between clinical signs and serum calcium values. Among various therapies, the use of pamidronate disodium (Aredia) in combination with hydration, steroid and calcitonin was found to be the most effective treatment for hypercalcemia. The survival time from the diagnosis of hypercalcemia in the patients undergoing treatment with Aredia was significantly better than without it (p < 0.01). This suggests that Aredia should be effective and useful for advanced breast cancer patients with hypercalcemia.

Adult↗