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Biomedical subjects

T Furukawa

Publications and source records attributed to T Furukawa.

At least 235 records · Page 13Linked to original sources
PubMed1998

Social support and adjustment to a novel social environment.

The present article aims to examine the ways in which social support may affect the adaptation of individuals to a novel social environment. A distinctive feature of this research was the assessment of social support both before and after entering a completely new network of social relationships. A cohort of international exchange high school students (N = 242) was administered a battery of self-report questionnaires dealing with personality traits, perceived social support, coping behaviors and emotional distress before leaving Japan and six months after living with a host family in a foreign community. Perceived social support abroad contributed to less emotional distress. This health-promoting effect of social support was found to be mediated by adaptive coping behaviours, and was not due to confounding by personality traits. Perceived social support at home was predictive of more emotional distress abroad. Subjects who reported high levels of social support at home were particularly vulnerable when they entered the completely new environment and found that such support was no longer available.

Adaptation, Psychological↗
PubMed1998

[Expression of angiotensin type-2 receptors in rat brain during the cell injury].

The present study examined changes in angiotensin type-2(AT2) receptor mRNA level after global brain ischemia or during glutamate neurotoxicity in cultured cortical cells in rats. The AT2 mRNA level increased by three-fold in both the cortex and hippocampus, which are known to be sensitive to ischemic injury, 3 hr after ischemia. The day 10-14 cortical neurons were exposed to glutamate at a toxic concentration of 100 microM for 15 min. AT2 receptor mRNA was then increased 2-fold after exposure to glutamate, while the maximum increase was observed in a dose-dependent manner 3 hr after glutamate stimulation. AT2 receptor binding also increased 3-12 hr after glutamate exposure. The increase in the mRNA level was antagonized by N-nitro L-arginine methyl-ester, a nitric oxide synthase inhibitor. The hemoglobin, a nitric oxide trap, also inhibited the increase in the mRNA level. These results suggest that the increase in the mRNA level is associated with the nitric oxide synthesis by glutamate exposure. The viability of cortical cells after glutamate stimulation was partially restored by the antisense oligonucleotide for the AT2 receptor. The present results thus suggest the AT2 receptor may in some way be related to one of the processes in cell injury.

Animals↗
PubMed1998

A quantitative evaluation of the effects of sex and age on the positivity of family history of hypertension.

The purpose of this study was to call attention to a potential bias or misclassification resulting from disregarding sex and age of family members in assessing family history of hypertension. Family history of hypertension was obtained among 23,803 family members through a questionnaire survey of 2,316 high school students. From the obtained data sex- and age-specific proportion of a positive history of hypertension was calculated. The effects of sex and age on a positive history was assessed by the logistic regression analysis of the family history. Below age 70 the odds ratios for sex difference were at least 1.24 (p < 0.05) and odds ratios for age difference were at least 1.05 (p < 0.05). This indicated that below age 70 male members had a positive history at least 1.24 times more frequently than females of the same age, and that a positive history increased by at least (1.05)y, where y was age difference by year. Above age 70 the odds ratios for sex and age differences were small. A potential bias or misclassification resulting from sex and age difference can be substantial below age 70. Some measures to control for sex and age of family members are required in assessing the family history.

Adult↗
PubMed1998

[Historical outlook on cytomegalovirus research].

In historical point of view, cytomegalovirus (CMV) research could be divided into two phases, before and after discovery of the virus from a baby with severe jaundice. CMV is an ubiquitous virus which makes it difficult to diagnose CMV diseases. Therefore criteria for definite CMV disease has been proposed by the expert committee. Basic research is concentrating on analysis of functional map of the sequences, which helps to develop more genetically engineered vaccine and clarify the mechanism of latency of CMV. I hope increased awareness of CMV disease in organ transplantation advances the development of both chemotherapy and preventive method in near future.

Antiviral Agents↗
PubMed1998

Hematopoietic cytokine-dependent differentiation to eosinophils and neutrophils in a newly established acute promyelocytic leukemia cell line with t(15;17).

We recently established an acute promyelocytic leukemia (APL) cell line (HT93) that has the capacity to differentiate into neutrophils and eosinophils in response to all-trans retinoic acid (ATRA) and human hematopoietic cytokines. The cells had a myeloblastic morphology, were positive for surface CD33, CD34, and CD56, and showed the following karyotypes: 46, XY, t(1;12)(q25;p13), 2q+, t(4;6)(q12;q13), and t(15;17)(q22;q11). When the cells were cultured with ATRA, they showed nuclear segmentation and developed secondary granules consisting in part of neutrophils and eosinophils. In the presence of ATRA and granulocyte colony-stimulating factor (G-CSF), the cells showed polymorphonuclear neutrophil differentiation accompanied by expression of surface CD11b, CD15, CD10, positive activity for neutrophil alkaline phosphatase (NAP), and NAP mRNA expression. In cultures with ATRA and granulocyte-macrophage colony-stimulating factor (GM-CSF), IL (interleukin)-3, or IL-5, HT93 showed remarkable eosinophil maturation at day 8 as determined by luxol fast blue staining, in addition to expression of eosinophil peroxidase and major basic protein. These results indicate that HT93 is an APL cell line with the ability to differentiate into neutrophils and eosinophils, and that these lineages are dependent on the CSF added. HT 93 should prove to be a useful model in analyzing the effects of hematopoietic cytokines on proliferation, differentiation, and maturation of hematopoietic progenitors.

Alkaline Phosphatase↗
PubMed1998

[Efficacy of combination of ondansetron injection and tablet in CAF-induced emesis in breast cancer patients].

Efficacy of combination of ondansetron injection and tablet on CAF (cyclophosphamide, adriamycin, 5-fluorouracil) induced emesis were investigated in 10 breast cancer patients (33 courses). Complete suppression rate of nausea or vomiting were approximately 75%, approximately 90% respectively for every treatment day. According to judgement criteria, antiemetic rate of approximately 100% was achieved during the study period. As to food intake of each treatment day, in approximately 70% of treatment courses was assessed as '(patient was) able to eat most of the meal'. Trend in emetic episodes and food intake in each patient receiving several courses of CAF therapy were evaluated. As a result, those patients experiencing nausea or vomiting or had effect on their food intake, were found to be in the similar condition in the following course (s) of CAF. No adverse drug reaction nor clinical laboratory test abnormalities due to ondansetron was observed. In this investigation, combination of ondansetron injection and tablet was shown to sufficiently suppress CAF-induced nausea and vomiting, and their efficacy was confirmed. Still, the study suggested that number of emetic episodes or degree of anorexia differs according to each individual. Therefore we regard additional administration of ondansetron or concomitant use of steroids should be considered when necessary.

Administration, Oral↗
PubMed1998

The BAX gene, the promoter of apoptosis, is mutated in genetically unstable cancers of the colorectum, stomach, and endometrium.

Disruption of the DNA mismatch repair system, characterized by microsatellite instability (MI), plays an important role in the course of human carcinogenesis by increasing the rate of mutations of genes associated with cancers. However, it is not clear which genes are the target genes for mutation in the course of carcinogenesis. Microsatellites within the coding region of the transforming growth factor beta receptor type II (RII) and insulin-like growth factor II receptor (IGF-IIR) genes were reported to be targets for mutation during the course of carcinogenesis in MI+ tumors. Recently, somatic mutations were found in a poly(G)8 tract in the BCL-2-associated X protein (BAX) gene, one of the essential players in apoptosis, in some MI+ tumors. We examined mutations of BAX in MI+ cancers of various organs and found frameshift mutations at the poly(G)8 tract in 5 of 15 (33%) gastric cancers, 3 of 26 (12%) endometrial cancers, and 9 of 22 (41 %) colorectal cancers. In contrast, no such mutations were found in pancreatic cancer. These results suggest that mutations of BAX play an important role in the course of carcinogenesis in the stomach, colorectum, and endometrium.

Apoptosis↗
PubMed1998

Allogeneic peripheral blood stem cell transplantation for standard-risk leukemia. A multicenter pilot study: Japanese experience. Japan Blood Cell Transplantation Study Group.

A multicenter phase II study of allogeneic peripheral blood stem cell transplantation (allo-PBSCT) was conducted. Twenty-two patients (median age, 36 years) with standard-risk leukemia were transplanted with G-CSF-mobilized PBSC from an HLA-identical sibling donor, and received cyclosporine and methotrexate for GVHD prevention. Median days to ANC >500/microl and platelets >50,000/microl were 12 (9-20) and 16 (11-32), respectively. Grade II-IV acute GVHD developed in 6/21 (29%) and extensive chronic GVHD in 12/20 (60%). These observations indicate that allo-PBSCT is characterized by rapid hematologic engraftment, no increase of acute GVHD and an increased risk of chronic GVHD, and can be used as an alternative to allogeneic bone marrow transplantation.

Adolescent↗
PubMed1998

[Long-term results and quality of life of hemi-Kock orthotopic ileal neobladder after radical cystectomy].

We analyzed the long-term results and the quality of life in patients who received orthotopic lower urinary tract reconstruction using the Kock ileal neobladder. Between July 1990 and October 1993, 37 consecutive patients including 2 females received orthotopic hemi-Kock neobladder after radical cystectomy. In these patients, we analyzed the urinary continence, complications and urethral recurrence, and performed a questionnaire survey by mail. Good continence all day had been achieved in 71% of the patients 4 years after surgery. The rate of the pouch-related complications requiring reoperation was 27%. There was no urethral recurrence. Compared with preoperative conditions, 42% were not satisfied with urination. In these dissatisfied patients, the need to use pads in the daytime, sensation of residual urine and weak urine stream were significantly more frequent than in satisfied patients. In summary, the rate of complications was higher than that of other methods. However, the Kock orthotopic ileal neobladder is a stable procedure providing good function over the long-term.

Adult↗
PubMed1998

[Basic principles and historical consideration of MR cholangiopancreatography].

Basic principle of MR cholangiopancreatography (MRCP) is heavily T2-weighted imaging (hydrography) to use bile and pancreatic juice as "natural contrast medium". Firstly developed sequence for MRCP was a CE-FAST sequence, which employed time-reversed FID signal. The current most popular sequences for MRCP are single-shot fast spin-echo sequences, which are divided into three types (2D single slice, 2D mutiple slice and 3D methods). The advantage of 2D single slice method is conveniently obtained projection imaging within a few seconds of examination time. Both 2D multiple slice and 3D methods consists of a MIP image and a series of source images. The MIP image creates global images of pancreatico-biliary system. The source images provide detailed evaluation of various anatomical structures and abnormalities. By using these sequences properly, MRCP can yield valuable informations of pancreatico-biliary diseases non-invasively.

Biliary Tract↗
PubMed1998

[Elimination of artifacts in MRCP: technical consideration].

Artifacts of MR cholangiopancreatography (MRCP) include fluid-filled gastrointestinal tracts, respiratory motion artifacts, spasm of Oddi's sphincter, vascular compression of bile ducts, overlapping of various anatomical structures and bright signal of surrounding fatty tissue. In this article, various technical considerations to eliminate these artifacts were described for the better imaging analysis of MRCP. The use of high-concentration ferric ammonium citrate (Ferriseltz) is recommended to reduce bright signal of fluid-filled gastrointestinal tracts. In case of long breathhold sequences, O2-inhalation study is useful to eliminate respiratory motion artifacts. Careful attention should be paid to the spasm of Oddi's sphincter and the vascular compression of bile ducts to avoid erroneous interpretation of MRCP findings.

Arteries↗
PubMed1998

Expression patterns of costimulatory molecules on cells derived from human hematological malignancies.

In order to elucidate the possibility of costimulatory molecules-mediated immuno or immuno-gene therapy for human hematological malignancies, we analyzed 30 hematopoietic cell lines and cells obtained from 48 patients with hematological malignancies for the expression of costimulatory molecules such as CD80 and CD86. The 30 hematopoietic cell lines were composed of 4 cell lines derived from the patients with T-cell acute lymphoblastic leukemia (T-ALL), 3 from Philadelphia chromosome positive ALL (Ph1+ALL), 8 from acute myeloblastic leukemia (AML), 3 from acute promyelocytic leukemia (APL), 8 from chronic myeloid leukemia at blast crisis (CML-BC), 3 from Burkitt's lymphoma and one from follicular cell lymphoma. The expression of CD80 or CD86 was frequent on cell lines derived from the patients with CML-BC or Burkitt's lymphoma, while it was rare on cell lines from T-ALL. Subsequently we analyzed the cells obtained from 48 patients with hematological malignancies, which consisted of 6 samples from patients with ALL, 30 from AML, 2 from CML-BC, 3 from B-cell lymphoma and one from each acute mixed leukemia (AMixL), adult T cell leukemia (ATL), T-cell large granular lymphocytic leukemia (T-LGL leukemia), chronic lymphocytic leukemia (CLL), myelodysplastic syndrome (MDS)-RAEB in T, multiple myeloma (MM) or T-cell lymphoma. Among all the 48 cases, all cases except one case with CLL and two with B cell lymphoma were demonstrated to be negative for CD80 on the neoplastic cells. CD86 and HLA-DR were shown to be expressed in 50% and 88% of total 48 cases respectively. In 30 AML samples, CD86 was positive in 15 cases (50%), which was sharply in contrast with the finding that CD80 was not detected in any AML samples. HLA-DR was expressed in 25 AML samples (83%). We also treated seven human hematopoietic cell lines with IFN-gamma, IL-12 or IL-15 and observed whether these cytokines could induce or enhance the expression of CD40, CD54, CD58 and HLA-DR as well as CD80 and CD86. The present study demonstrated that the expression of CD86 could be upregulated not only by IFN-gamma, but also by IL-12 or IL-15 in some cell lines. These findings suggested the possibility that the absence of CD80 on neoplastic cells may be associated with the lack of efficient anti-tumor immunity in most patients with hematological malignancies and that the immuno or immuno-gene therapy manipulating the expression of costimulatory molecules such as CD80 may be a useful treatment modality for hematological malignancies.

Adult↗
PubMed1997

Cancer cells isolated from malignant pleural and peritoneal effusions inhibit phospholipase A2 activity in human polymorphonuclear leukocytes.

We studied the influence of cancer cells on the LTB4 production by human polymorphonuclear leukocytes (PMN). The cancer cells were isolated from malignant pleural effusion specimens taken from two patients or from a peritoneal effusion specimen of one patient. While human PMN produced LTB4 following stimulation with A23187, the addition of cancer cells inhibited LTB4, 5-HETE and 12-HETE production by PMN in a cell number-dependent manner, while the cancer cell lines also showed a similar inhibition. The addition of lysate of the breast cancer cells also inhibited in a dose-dependent manner the production of LTB4 by PMN following stimulation with A23187. The addition of arachidonic acid completely reversed the inhibition of PMN-LTB4 production by the addition of the breast cancer cell lysates, thus suggesting inhibition at the phospholipase A2 level. The addition of this lysate to the partially purified human cytosolic PLA2 also inhibited the PLA2 activity. In contrast, the addition of lymphoma cells isolated from metastatic lymphnodes did not inhibit the LTB4 production from PMN. Since LTB4 is one of the important chemotactic factors for PMN and monocytes, these findings suggest that the inhibition of the PLA2 activity by the cancer cells thus results in a reduced production of LTB4 from PMN and contributes to a predisposition to develop severe infection in patients with advanced cancer.

Ascitic Fluid↗