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Biomedical subjects

T Fujimoto

Publications and source records attributed to T Fujimoto.

At least 109 records · Page 6Linked to original sources
PubMed2000

[Avascular necrosis of the femoral head caused by steroid treatment in neurosurgery].

Steroid induced avascular necrosis of the femoral head is a well known disease, but, there are few reports about the disease in neurosurgical patients. In the neurosurgical field, the use of steroids has become prevalent since the 1960's. Recently, the adverse effect of steroids and the limitation of its effect have been highlighted, but its use against neurosurgical diseases is still a common treatment to prevent cerebral edema or to counteract hypo-pituitarism caused by hypophyseal lesions. We reviewed 250 patients of avascular necrosis treated between 1985 and 1997 in our institute. Within these patients, 11 (4.4%) were treated with steroid during neurosurgical treatment. Six patients were treated for brain tumors near hypophyseal lesions, and 5 patients were treated for head injury or cerebro-vascular disease. It is concluded that total steroid dose over 5000 mg such as hydrocortisone may become a high risk for causing avascular necrosis of the femoral had in neurosurgical disease, and it may occur even with the supplemental steroid treatment against hypo-pituitarism. The onset is usually 2 or 3 years after the neurosurgical treatment, when neurosurgical care is no longer needed. Therefore, it tends to be ignored in the neurosurgical field. The treatments against avascular necrosis of the femoral head were femoral head osteotomy or conservative management, and good results were obtained. Early diagnosis and early treatment is essential. Further consideration concerning steroid treatment in neurosurgical patients may be required.

Anti-Inflammatory Agents↗
PubMed2000

[Anesthetic management of the elderly patients with femoral neck fracture by sevoflurane and femoral nerve block].

Fracture of the femoral neck (FNF) is a significant cause of morbidity and mortality in the elderly, and the elderly with FNF are often high-risk patients for anesthesia. We studied 15 patients above 80 years of age with severe physical status (ASA III-IV). After femoral nerve block (for the pain of fracture) and lateral femoral cutaneous nerve block (for the cutting pain), surgical procedure was performed under general anesthesia by laryngeal mask airway under spontaneous ventilation. After the operation, morphine 2 mg was administered subcutaneously. In our experience, the majority of 15 patients cardiovascular status of remained stable, except one patient who needed ephedrine for hypotension and another patient who needed diclofenac sodium for post-operative pain relief.

Aged↗
PubMed2000

Cell biology of caveolae and its implication for clinical medicine.

Caveolae are small invaginations of the plasma membrane found in many cell types, and caveolins are integral membrane proteins that form the framework of caveolae. In the past several years, research on caveolae has developed explosively, and caveolae and/or caveolins have been shown to play many important roles in cell physiology: in particular, they are thought to be related to signal transduction, cholesterol transport, endocytosis and tumor suppression. On the other hand, some studies have suggested that another membrane domain called rafts is also involved in the same processes, and some confusion remains concerning the relationship between these two domains. Abnormalities in caveolae and/or caveolins have been found in various diseases, including cancer, atherosclerosis, muscular dystrophy and the Alzheimer's disease, which may make this domain a new focus for pharmacological research. This review will focus on the cell biology of caveolae, caveolins and rafts, and then summarize the implications of these findings for clinical studies.

Animals↗
PubMed2000

All B cells are progeny of endothelial cells: a new perspective.

We present here a speculative view of embryonic hematopoiesis. We do this with the hope of finding directions for future study, keeping in mind that our model may diverge from the real situation. However, we want to emphasize that previous models have neglected the possibility that endothelial cells (EC) represent a progenitor of hematopoietic cells (HPC). Emerging evidence, including our own, and previous histological studies argue for the presence of hemogenic EC. We discuss seemingly contradictory points of view of embryonic hematopoiesis, such as the origin of lymphogenic progenitors, and have shown that they may be resolved more satisfactorily by introducing this notion. Obviously, a good model should be a testable one, so we are currently developing experimental systems to demonstrate that all B cells are, indeed, the progeny of EC.

Animals↗
PubMed2000

[Prognostic significance of chromosome analysis in childhood acute lymphoblastic leukemia. Children's Cancer and Leukemia Study Group (CCLSG)].

We analyzed the prognostic significance of chromosomal findings in children with acute lymphoblastic leukemia (ALL), treated according to the Children's Cancer and Leukemia Study Group protocols between 1987 and 1993. Patients were classified into 5 groups according to chromosome number. The patients with a hyperdiploid(> 50) karyotype(13%) had the best prognosis [4-year event-free survival (EFS): 83 +/- 6%], while those with a pseudodiploid karyotype (24%) had the worst prognosis(4-year EFS: 52 +/- 6%) (log-rank, p = 0.03). However, multivariate analysis revealed that the ploidy classification had no prognostic significance in terms of EFS. When patients were classified according to chromosome abnormalities, those with any type of translocation had a worse outcome (4-year EFS: 33 +/- 9%) than those with hyperdiploidy(> 50), normal diploidy, and other abnormalities(log-rank, p < 0.0001). Multivariate analysis revealed that chromosome abnormalities were an independent prognostic factor (relative risk 3.98; p < 0.0001). Patients with t(1; 19) had an EFS similar to that of patients with chromosome abnormalities other than translocations or normal diploidy. We conclude that chromosomal findings have prognostic significance, although some chromosome abnormalities lost their statistical significance after modern intensified chemotherapy. Childhood ALL should be further stratified according to chromosome classification.

Child↗
PubMed2000

[Treatment and prognosis of children with relapsed non-Hodgkin's lymphoma--a report from CCLSG-NHL 890 Study. Children's Cancer and Leukemia Study Group (CCLSG)].

To address the issue of salvageability in relapsed children with NHL who had all received the same frontline therapy, we retrospectively studied the treatment response and the outcome of 27 children who relapsed following the CCLSG-NHL890 protocol. The reinduction rates and 3-year survival rates (mean +/- SD) were as follows: lymphoblastic lymphoma (LB, n = 9), 44% & 17 +/- 14%; leukemia lymphoma syndrome (LLS, n = 8), 25% & 0%; large cell lymphoma (LC, n = 3) 100% & 67 +/- 27%; Burkitt's lymphoma (B, n = 7) 0% & 0%. Thus, the salvageability of LC lymphoma was good, but the outcome of Burkitt's lymphoma was very poor. CCLSG-NHL960 protocol for LB lymphomas and intensive multiagent regimens for LC lymphomas produced favorable response rates, but the effect of the high-dose Ara-C regimen for Burkitt's lymphoma was not determined. The initial stages of the disease seemed to be associated with the patient outcome: the outcome of the patients in stage IV was inferior to that of patients in stages II or III. Other clinical variables, such as relapse sites, relapse time and BM rescue did not affect the patients' outcome.

Adolescent↗
PubMed1999

Tyrosine phosphorylation of caveolin-1 in the endothelium.

Caveolin-1, a scaffolding protein of caveolae, is known to be tyrosine-phosphorylated by Src kinases. Recently we generated a specific antibody to caveolin-1 phosphorylated at tyrosine-14 (PY14) (R. Nomura and T. Fujimoto, 1999, Mol. Biol. Cell 10, 975-986). In the present study, by applying PY14 to sections of normal rat tissues, we found that tyrosine phosphorylation of caveolin-1 occurred in limited locations, including the endothelium of the continuous capillaries and small venules. Cultured endothelial cells were not labeled by PY14 under a standard culture condition, but became positively labeled when exposed to oxidative stresses and/or tyrosine phosphatase inhibitors. The reaction was prohibited by pretreating the cells with herbimycin A or genistein. Vasoactive reagents or physical stimuli did not cause the phosphorylation. Concomitant with the tyrosine phosphorylation, the number of invaginated caveolae decreased drastically, and vesicles labeled intensely for caveolin-1 appeared in the cytoplasm; the average diameter of the vesicles was larger than that of caveolae. The result implies that tyrosine phosphorylation of caveolin-1 occurs at tyrosine-14 in the normal rat endothelium in vivo and may induce caveolar vesiculation and/or fusion.

Animals↗
PubMed1999

Requirements for signal delivery through CD44: analysis using CD44-Fas chimeric proteins.

CD44 is a transmembrane glycoprotein involved in various cell adhesion events, including lymphocyte migration, early hemopoiesis, and tumor metastasis. To examine the requirements of CD44 for signal delivery through the extracellular domain, we constructed a chimeric CD44 protein fused to the intracellular domain of Fas on its C-terminus. In cells expressing the CD44-Fas fusion protein, apoptosis could be induced by treatment with certain anti-CD44 mAbs alone, especially those recognizing the epitope group d, which has been previously shown to play a role in ligand binding, indicating that ligation of a specific region of the CD44 extracellular domain results in signal delivery. Of note was that appropriate ligation of the epitope h also resulted in the generation of apoptotic signal, although this region was not thought to be involved in ligand binding. In contrast, the so-called blocking anti-CD44 mAbs (epitope group f) that can abrogate the binding of hyaluronate (HA) failed to induce apoptosis even after further cross-linking with the secondary Ab, indicating that a mere mAb-induced oligomerization of the chimeric proteins is insufficient for signal generation. However, these blocking mAbs were instead capable of inhibiting apoptosis induced by nonblocking mAb (epitope group h). Furthermore, a chimeric protein bearing a mutation in the HA binding domain and hence lacking the ability to recognize HA was incapable of mediating the mAb-induced apoptosis, suggesting that the functional integrity of the HA binding domain is crucial to the signal generation in CD44.

Animals↗
PubMed1999

Cross-linking of plasmalemmal cholesterol in lymphocytes induces capping, membrane shedding, and endocytosis through coated pits.

By use of a nicked and biotinylated perfringolysin O (BCtheta), which binds to cholesterol specifically, we studied consequences of cross-linking cholesterol in lymphocytes. When bound with BCtheta and then with labeled avidin or streptavidin, capping occurred in most cells within 30 min at 37 degrees C. It was inhibited by cytochalasin D or NaN3, but not by nocodazole. When BCtheta-cholesterol was capped, Thy-1 and transferrin receptor, a GPI-anchored protein and a transmembrane protein, respectively, remained evenly distributed. By fluorescence and electron microscopy, a cluster of small vesicles bound with BCtheta were observed in the cap. They were then shed in the medium or internalized through coated pits. The result indicates that cross-linking of cholesterol in lymphocytes induces capping, but does not affect distribution of membrane proteins, and that the capped cholesterol molecules are either shed as vesicles or endocytosed.

Animals↗
PubMed1999

Incidence and distribution pattern of pelvic and paraaortic lymph node metastasis in patients with Stages IB, IIA, and IIB cervical carcinoma treated with radical hysterectomy.

BACKGROUND: The incidence and distribution pattern of retroperitoneal lymph node metastasis in patients with cervical carcinoma should be investigated based on data from systematic pelvic lymph node (PLN) and paraaortic lymph node (PAN) dissection, so that a basis can be established for determining the site of selective lymph node dissection or sampling. METHODS: A total of 208 patients with Stages IB, IIA, and IIB cervical carcinoma who underwent radical hysterectomy and systematic pelvic and PAN dissection were investigated for lymph node metastasis and histopathologic risk factors for lymph node metastasis. RESULTS: Fifty-three patients (25.5%) had lymph node metastasis. The obturator lymph nodes were most frequently involved, with a rate of 18.8% (39/208). Forty-nine of 53 node-positive patients had lymph node metastasis in the obturator, internal iliac, or common iliac lymph nodes. Of 26 solitary lymph node metastases confined to one node group, 18 were in the obturator, 3 in the internal iliac, 3 in the parametrial, and 2 in the common iliac lymph nodes. A multiple logistic regression analysis revealed that deep cervical stromal invasion and lymph-vascular space invasion were related to PLN metastasis. It was also shown that metastasis to bilateral PLNs (excluding the common iliac lymph nodes) as well as metastasis to the common iliac lymph nodes were significantly related to PAN metastasis. CONCLUSIONS: The results of this study suggest that the obturator lymph nodes can be sentinel lymph nodes of cervical carcinoma. PAN metastasis appears to occur secondarily to wide-spread PLN metastasis. These results provide a basis for determining the site of selective lymph node dissection and for estimating the existence of PAN metastasis from the pattern of metastasis in PLN in patients with cervical carcinoma.

Adult↗
PubMed1999

Ibudilast, a phosphodiesterase inhibitor, ameliorates experimental autoimmune encephalomyelitis in Dark August rats.

A phosphodiesterase inhibitor (PDEI), Ibudilast, which has been in wide use for the management of bronchial asthma and cerebrovascular disease in Japan, was tested for its clinical efficacy on experimental autoimmune encephalomyelitis (EAE) in Dark August rats. The severity of acute EAE was significantly ameliorated by prophylactic oral treatment with Ibudilast (10 mg/kg per day) starting on the day of immunization, although it did not modify the course of the disease when it was given after the onset of the first clinical sign of EAE. Histologically, inflammatory cell infiltration in the lumbar spinal cord was significantly reduced in Ibudilast-treated animals as compared to control animals. Ibudilast mildly suppressed MBP-induced proliferation of T cells in regional lymph nodes, the secretion of interferon-gamma from T cells activated by MBP in CFA, and the secretion of tumor necrosis factor-alpha from macrophages. While the in vitro studies did not suggest difference between Ibudilast and other PDEIs such as rolipram, the clinical dose of Ibudilast is approximately 200-fold higher than that of rolipram and the effective dose of Ibudilast was relatively close to what has been therapeutically used in patients. Thus, Ibudilast may be a candidate for clinical use for patients with multiple sclerosis. 1999 Elsevier Science B.V. All rights reserved.

Administration, Oral↗
PubMed1999

Elevated levels of interleukin-12 and interferon-gamma in patients with human T lymphotropic virus type I-associated myelopathy.

The levels of interleukin-12 (IL-12) (p70 heterodimer), total IL-12 (p70 heterodimer plus p40 chains), interferon-gamma (IFN-gamma) as Th1 cytokine, and those of interleukin-4 (IL-4) and interleukin-10 (IL-10) as Th2 cytokines in sera and cerebrospinal fluid (CSF) from 22 patients with human T lymphotropic virus type I (HTLV-I)-associated myelopathy (HAM) were compared with those of 22 patients with other neurological diseases (OND), including nine anti-HTLV-I-seropositive carriers. Both serum IL-12 (total and p70 heterodimer) and CSF IFN-gamma, measured by the enzyme-linked immunosorbent assay (ELISA), were significantly elevated in patients with HAM as compared to the patients with OND, including the anti-HTLV-I-seropositive carriers. Serum IFN-gamma also was significantly elevated in the HAM patients as compared to the controls. There was no significant difference in the CSF levels of IL-12 (total and p70 heterodimer) between the HAM patients and controls, whereas, for the Th2 cytokines IL-4 was detected in the CSF of four anti-HTLV-I-seropositive carriers of the 13 control patients but not in any of the patients with HAM. No significant difference was found in the serum levels of IL-4 and IL-10, nor in the CSF levels of IL-10 in the patients with HAM and in the controls. These findings indicate that in patients with HAM, the immunological balance of helper T lymphocytes between Th1 and Th2 is toward Th1 in the periphery and that Th1-mediated immunological status in the central nervous system is involved in the pathogenesis of HAM.

Adult↗
PubMed1999

Arterial tonometry in the measurement of the effects of innocuous mechanical stimulation of the neck on heart rate and blood pressure.

Arterial tonometry was used to continuously monitor the effects on heart rate and blood pressure of a series of innocuous mechanical stimuli applied to the neck in conscious humans. The stimuli used were derived from procedures commonly employed in clinical examination and physical therapy of the neck. In alert subjects, the stimuli used generally caused small and sometimes statistically significant decreases in heart rate, systolic pressure and diastolic pressure. In alert subjects, statistically significant decreases in systolic and diastolic pressure were particularly associated with stimuli which involved full rotation of the neck. In the course of the prolonged series of stimuli, some subjects slept or reported being on the verge of sleep. In these subjects, the same stimuli produced mixed effects on heart rate and increases in systolic and diastolic pressure which were significantly different from the effects obtained in fully alert subjects.

Adult↗
PubMed1999

Expression of alpha4-integrin defines the earliest precursor of hematopoietic cell lineage diverged from endothelial cells.

Embryonic stem cells can differentiate in vitro into hematopoietic cells through two intermediate stages; the first being FLK1(+) E-cadherin- proximal lateral mesoderm and the second being CD45(-) VE-cadherin+ endothelial cells. To further dissect the CD45(-) VE-cadherin+ cells, we have examined distribution of alpha4-integrin on this cell population, because alpha4-integrin is the molecule expressed on hematopoietic stem cells. During culture of FLK1(+) E-cadherin- cells, CD45(-) VE-cadherin+ alpha4-integrin- cells differentiate first, followed by alpha4-integrin+ cells appearing in both CD45(-) VE-cadherin+ and CD45(-) VE-cadherin- cell populations. In the CD45(-) VE-cadherin+ cell population, alpha4-integrin+ subset but not alpha4-integrin- subset had the potential to differentiate to hematopoietic lineage cells, whereas endothelial cell progenitors were present in both subsets. The CD45(-) VE-cadherin- alpha4-integrin+ cells also showed hematopoietic potential. Reverse transcription-polymerase chain reaction analyses showed that differential expression of the Gata2 and Myb genes correlated with the potential of the alpha4-integrin+ cells to give rise to hematopoietic cell differentiation. Hematopoietic CD45(-) VE-cadherin+ alpha4-integrin+ cells were also present in the yolk sac and embryonic body proper of 9.5 day postcoitum mouse embryos. Our results suggest that the expression of alpha4-integrin is a marker of the earliest precursor of hematopoietic cell lineage that was diverged from endothelial progenitors.

Animals↗
PubMed1999

Improvement in CNS protective treatment in non-high-risk childhood acute lymphoblastic leukemia: report from the Japanese Children's Cancer and Leukemia Study Group.

BACKGROUND: Prevention of central nervous system (CNS) leukemia by early introduction of therapy to this sanctuary site is an essential component of modern treatment strategy for acute lymphoblastic leukemia (ALL). However, the optimal form of preventive CNS therapy remains debatable. PROCEDURE: To address this issue, we evaluated the efficacy of CNS preventive therapy for 572 children with ALL who achieved complete remission in the Children's Cancer and Leukemia Study Group (CCLSG) ALL874 (1987-1990) and ALL911 (1991-1993) studies. They received risk-directed therapy based on age and leukocyte count. In the ALL 874 study, the non-high-risk (low-risk [LR] + intermediate risk [IR]) patients were randomly assigned to the conventional cranial irradiation (CRT) regimen (L874A and I874A) and the high-dose methotrexate (HDMTX) regimen without CRT (L874B and I874B). The former patients received 18-Gy CRT plus 3 doses of intrathecal (i.t.) MTX and the latter patients received 3 courses of HDMTX at 2 g/m2 plus 13 doses of ITMTX (L874B) or 4 courses of HDMTX at 4.5 g/m2 plus 1 dose of ITMTX (I874B). RESULTS: The 7-year probabilities (+/- SE) of CNS relapse-free survival were 97.3% +/- 2.6% (L874A, n = 41) vs. 90.3% +/- 5.3% (L874B, n = 39) (P = 0.25) in the LR patients, and 100% (I874A, n = 55) vs. 78.5% +/- 6.5% (I874B, n = 54) (P = 0.002) in the IR patients. The corresponding disease-free survival (DFS) rates were 79.4% +/- 6.5% vs. 74.4% +/- 7.3% (P = 0.62) in the LR group and 63.3% +/- 6.8% vs. 58.3% +/- 7.2% (P = 0.66) in the IR group. Thus, the HDMTX regimen could not provide better protection of CNS relapse as compared with the CRT regimen, although their overall efficacy was not significantly different. In the ALL 911 study, intensive systemic chemotherapy with extended i,t, injections of MTX plus cytarabine achieved a high CNS relapse-free survival (98% +/- 1.9% at 7 years) and a favorable DFS (85.5% +/- 5% at 7 years) in the IR patients. The patients in the high-risk (HR) group in both ALL874 and ALL911 studies received the 18-Gy or 24-Gy CRT with intensive systemic chemotherapy. Their 7-year probabilities of CNS relapse-free survival ranged from 88% to 95%, among which the T-ALL patients had a risk of CNS leukemia, which was 3-4 times higher compared with B-precursor ALL patients. CONCLUSIONS: These results indicate that long-term intrathecal CNS prophylaxis as well as appropriate systemic therapy for the non-high-risk patients can provide protection against CNS relapse equivalent to that provided by cranial irradiation.

Adolescent↗