Biomedical subjects

Hiroyuki Ishiguro

Publications and source records attributed to Hiroyuki Ishiguro.

6 recordsLinked to original sources

PubMed2006

Allogeneic haematopoietic cell transplantation from alternative donors with a conditioning regimen of low-dose irradiation, fludarabine and cyclophosphamide in Fanconi anaemia.

A pilot study was undertaken using a fludarabine-based conditioning regimen to improve haematopoietic cell transplantation (HCT) from alternative donors in 27 Fanconi anaemia (FA) patients. Patients were conditioned with 150-180 mg/m2 of fludarabine, 40 mg/kg of cyclophosphamide, 5-10 mg/kg of antithymocyte globulin, and 300-450 cGy of thoracoabdominal/total body irradiation. One patient who received unrelated cord blood transplantation failed to engraft, another patient died of sepsis. The 1-year overall survival was 96.3% (95% CI, 89-100). This conditioning regimen exerted an immunosuppressive effect that enabled durable engraftment in alternative donor HCT without severe toxicity.

Child↗

PubMed2004

Changes in thyroid function after bone marrow transplant in young patients.

BACKGROUND: Changes in thyroid function among young patients who received bone marrow transplantation (BMT) were evaluated. METHODS: The study included 91 patients (50 males) who underwent BMT from 1985 to 1995 at the age of 0.6-21 years. Sixty patients had neoplastic disease such as leukemia or lymphoma, and the remainder had non-neoplastic diseases. Preconditioning regimen for BMT included 12 Gy of fractionated-total body irradiation (TBI) for patients with neoplastic disease and 3-8 Gy of irradiation for the remaining patients, in addition to chemotherapy. Evaluation of thyroid function was performed by serial assessment of basal serum FT4, FT3, TSH concentrations as well as by TRH test. RESULTS: No patient had overt hypothyroidism or elevated basal TSH concentrations (>10 mU/L). However, 6 (7%) of patients experienced exaggerated peak TSH response to TRH stimulation several years after BMT. In 33 patients whose thyroid status was evaluated before, within 3 months, and 1 year after BMT, serum FT3 concentrations as well as peak TSH response to TRH stimulation significantly decreased immediately after BMT (<3 months) and normalized within 1 year. However, serum FT4 concentrations did not change significantly. One patient developed primary hypothyroidism and another developed follicular adenoma of the thyroid 5 and 12 years after BMT, respectively. CONCLUSION: Short-term changes in thyroid function after BMT can indicate euthyroid sick syndrome rather than tertiary hypothyroidism. It must be noted that overt hypothyroidism may occur several years after BMT, hence long-term follow-up of thyroid function is warranted.

Adolescent↗

PubMed2004

Long-term follow-up of thyroid function in patients who received bone marrow transplantation during childhood and adolescence.

An increasing number of long-term surviving bone marrow transplant (BMT) recipients have recovered from their primary disease but are at risk of developing failure of endocrine organs. We investigated 147 patients who underwent allogeneic BMT. Thyroid function was evaluated by serial measurement of basal TSH and free T4 levels as well as by TRH provocative test. Thyroid ultrasound examination was performed for evaluation of thyroid tumor after BMT. Five patients were found to have overt thyroid dysfunction (hypothyroidism in four patients and hyperthyroidism in one patient). Twenty-three patients in the under 9-yr-old group at BMT and 16 patients in the over 10-yr-old group at BMT had subclinical compensated hypothyroidism. Younger age at BMT was the strongest factor for developing thyroid dysfunction, compared with older age (P < 0.001). Only in patients with subclinical compensated hypothyroidism did median basal and peak TSH increase to the upper half of the normal range by 8 yr after BMT and then returned slightly to the middle of the normal range spontaneously. These results suggest that thyroid dysfunction in long-term BMT survivors depends on age at BMT, with a greater risk among younger patients, indicating the need for life-long surveillance.

Adenoma↗

PubMed2003

Macrophage apolipoprotein A-I expression protects against atherosclerosis in ApoE-deficient mice and up-regulates ABC transporters.

The antiatherogenic effect of high-density lipoprotein (HDL) and its major protein component apolipoprotein A-I (apoA-I) has been largely attributed to their key roles in reverse cholesterol transport (RCT) and cellular cholesterol efflux. Substantial evidence shows that overexpression of human apoA-I reduces atherosclerosis in animal models. However, it is uncertain whether this protection is due to an increase in plasma HDL level or to a local effect in the artery wall. To test the hypothesis that expression of human apoA-I in macrophages can promote RCT in the artery wall, we used a retroviral construct expressing human apoA-I cDNA (MFG-HAI) to transduce ApoE(-/-) bone marrow cells and then transplanted these cells into ApoE(-/-) mice with preexisting atherosclerosis. ApoE(-/-) mice reconstituted with MFG-HAI marrow had a significant reduction (30%) in atherosclerotic lesions in the proximal aorta compared to control mice that received marrow expressing MFG parental virus. Peritoneal macrophages isolated from MFG-HAI mice showed a four- to fivefold increase in mRNA expression levels of both ATP-binding cassette (ABC) A1 and ABCG1 compared to controls. Our data demonstrate that gene transfer-mediated expression of human apoA-I in macrophages can compensate in part for apoE deficiency and delay the progression of atherosclerotic lesions by stimulating ABC-dependent cholesterol efflux and RCT.

ATP-Binding Cassette Transporters↗

PubMed2003

Relation between phenotype of tumor cells and clinicopathology in bovine leukosis.

Thirty-three cases of enzootic bovine leukosis (EBL) and 14 cases of sporadic bovine leukosis (SBL) were examined by immunohistochemistry using 6 monoclonal antibodies against leukocyte differentiation molecules of bovine leukocytes. There were 17 cases of B-1a cell type, 10 cases of B-1b cell type and 6 cases of B-2 cell type in EBL, and 5 cases originating from B cells (B-2 cell type) and 9 cases originating from immature T cells in SBL. The average age for the EBL cases of B-1a cell type was 8.6 years, B-1b cell type was 6.5 years, and of B-2 cell type was 4.5 years. In cases of SBL, immature T cell type patients were younger than B-2 cell type ones. The lymphoma originating from B cells differed from that originating from T cells in morphology. In T cell tumors, the nucleus of tumor cells was round, the edge of the cytoplasm obvious, and tumor cells were sporadically present and proliferated. When compared with T cells, the region among B cells was obscure. But, there was no relation between phenotype and the histologic classification of tumor cells. In EBL, beyond the lymph node, tumors of B-1a and B-1b types had developed in the heart and abomasum, and those of the B-2 type tended to occur in liver. In SBL, B-2 type and T type cells formed tumors in the liver, kidney, thymus, and one case of T-cell type tumor formed on the skin. We would like to propose a new classification of bovine leukosis as EBL, calf type B-cell lymphoma, juvenile T-cell lymphoma and skin type T-cell lymphoma.

Abomasum↗

PubMed2003

Persistence of mild hyperthyrotropinemia after discontinuation of three-year course of low-dose L-thyroxine therapy in infants with borderline hypothyroidism.

Treatment plan for neonates with borderline hypothyroidism (persistent hyperthyrotropinemia with normothyroxinemia) has not been established. In this study, changes in thyroid function after discontinuation of low-dose L-thyroxine (L-T4) supplement in infants with the condition were evaluated. Fourteen infants with hyperthyrotropinemia at neonatal screening had repeated hyperthyrotropinemia (> 8 mU/L) with normothyroxinemia. TSH response was exaggerated at TRH testing. The subjects were treated with low-dose L-T4 (3 to 9 microg/kg/day) for 2.2 to 6 years, and euthyroid status was maintained. After discontinuation of therapy, mild hyperthyrotropinemia persisted up to 24 months, while serum FT4 remained within the lower half of the normal range. TSH response to TRH stimulation, which tended to be exaggerated 1 month after discontinuation, became lower 6 to 12 months later. RAIU and thyroid scintigraphy were normal in all subjects. No patient developed hypothyroxinemia, although mild elevation of TSH lasted rather long after discontinuation of low-dose L-T4 therapy. Administration of L-T4 was not resumed provided the subjects were followed at regular interval. Further long-term investigation is needed to define whether re-administration is necessary or not.

Drug Administration Schedule↗