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Biomedical subjects

Y Kaneda

Publications and source records attributed to Y Kaneda.

At least 289 records · Page 16Linked to original sources
PubMed1997

Epidemiologic survey of Blastocystis hominis infection in Japan.

The incidence of Blastocystis hominis in a healthy population was determined by fecal examination of 6,422 Japanese and 54 resident non-Japanese who visited the St. Luke's International Hospital Health Screening Center for a routine medical check-up during a one-year period. Of the enrolled subjects, 30 Japanese (0.5%) and four non-Japanese (7.4%) had B. hominis in their stools. These individuals were asymptomatic except for one who reported flatus and one who reported mild abdominal discomfort. Statistical analysis indicated that the prevalence in the Japanese was lower than in the non-Japanese, and lower than the prevalence reported for other countries. Colonoscopic observations on seven B. hominis-positive individuals did not reveal pathogenic intestinal lesions. Several months after the first examination, 23 of the B. hominis-positive individuals, including three non-Japanese, were re-examined. Although they had not been treated with anti-B. hominis drugs, 10 individuals were now B. hominis-negative (by stool examination) and eight were passing fewer organisms. The remaining five individuals were still discharging large numbers of B. hominis. These B. hominis-positive individuals had no reported symptoms despite passing numerous organisms. Therefore, it seems that infection with B. hominis rarely gives rise to clinical symptoms. In no instance was invasion of host tissues by the organisms detected.

Adult↗
PubMed1997

PEGylation of interleukin-6 effectively increases its thrombopoietic potency.

The in vivo thrombopoietic activity of polyethylene glycol-modified interleukin-6 (MPEG-IL-6), in which 54% of the 14 lysine amino groups of IL-6 were coupled with PEG, was compared to that of native IL-6. Native IL-6 and MPEG-IL-6, which showed about 51% of the specific bioactivity of native IL-6, were administered subcutaneously to mice every 2 days for 7 days. Native IL-6 increased not only the peripheral platelet count, but also the plasma-IgG1 level in a dose-dependent manner. MPEG-IL-6 showed about 500 times higher thrombopoietic potency than native IL-6. Further, in comparison to native IL-6, MPEG-IL-6 did not enhance IgG1 production as much as it enhanced platelet production. MPEG-IL-6 significantly stimulated platelet recovery in mice treated with 5-fluorouracil, whereas the administration of native IL-6 had a negligible effect. The plasma half-life of MPEG-IL-6 was about 100-fold longer than that of native IL-6. The decrease in the plasma clearance of MPEG-IL-6 was thought to be due, in part, to the shielding of the proteolytic sites in the IL-6 molecule by the PEG chain. The uptake of IL-6 by the reticuloendothelial system, such as the liver and spleen, was markedly limited by PEGylation. The PEGylation of IL-6 markedly enhanced the blood-residency of IL-6, resulting in effective augmentation of its thrombopoietic activity and a marked decrease in its side-effects. These findings suggest that MPEG-IL-6 may be a potential candidate for thrombopoietic agent.

Animals↗
PubMed1997

[Development of in vivo gene transfer methods towards future gene therapy].

More than 100 protocols have been proposed for human gene therapy in the United States, but no effective results have been reported in the gene therapy field. This failure in gene therapy mainly results from the lack of effective gene transfer vectors. As far as somatic gene therapy is concerned, it will be very hard to control systemic disorders even after a much more powerful vector system is developed. However, local disorders will be able to be better regulated by gene therapy. In this regard, cardiovascular diseases will be suitable and promising targets for future gene therapy. Fusigenic viral-liposome, called HVJ-liposome, seems to be an effective tool for gene therapy. In this system, genes, oligonucleotides and proteins can be directly introduced into the cytoplasm by virus-cell fusion. Using HVJ-liposome, restenosis after angioplasty was successfully prevented in rat carotid artery by the introduction of either antisense oligonucleotides against cell-cycle controlling factor or double-stranded oligonucleotides containing E2F binding sites as a decoy. Constitutive nitric oxide synthase gene was also effective in inhibiting of neointima formation in rat carotid artery. These results indicate the possibility of gene therapy to prevent restenosis after angioplasty. We present here novel targets for future gene therapy.

Angioplasty↗
PubMed1997

[Lymph node dissection during a video-assisted lobectomy is inferior to that in a standard lobectomy].

The indications for a video-assisted lobectomy are currently ill-defined. Clinicians recommend based on the extent of lymph node involvement. Fifty-nine patients with clinical stage I non-small cell lung cancer underwent lobectomies with systemic lymph node dissections through a standard thoracotomy (Group C), and 26 patients underwent lobectomies with lymph node dissections using the video-assisted procedure (Group V). The number of dissected lymph nodes at all node levels were compared between the two groups. There was no significant difference between groups in the total number of dissected lymph nodes in patients with right lung cancer. The number of dissected hilar and interlobar lymph nodes, however, was less in Group V than that in Group C (hilar: 1.2 +/- 0.4 vs. 2.8 +/- 0.6, interlobar: 1.1 +/- 0.4 vs. 2.1 +/- 0.4). The total number of dissected lymph nodes in patients with left lung cancer was significantly less in Group V than that in Group C (18.5 +/- 0.3 vs. 28.7 +/- 2.4). In addition, the number of dissected lymph nodes in pratracheal, pretracheal, tracheobronchial, subcarinal, hilar, and interlobar lymph nodes were significantly less in the group V than those in Group C. Although there was no significant difference in the actual survival rates between the groups in this preliminary study, a sufficiently small number of dissected lymph nodes in the video-assisted lobectomy may have resulted in inaccurate staging and poor prognosis in these patients.

Aged↗
PubMed1997

Visual evoked potential and electroencephalogram of healthy females during the menstrual cycle.

Flash visual evoked potential (VEP) and electroencephalogram (EEG) changes during the menstrual cycle were studied using healthy females having regular menstruation, with 21 at the follicular phase (FP) and 23 at the luteal phase (LP). The following results were obtained. (1) The waveforms of Group Mean VEPs of both groups had approximately similar triphasic contours, consisting of 16 components of P 1-N 8 up to 500 msec of latency. (2) Latencies tended to be longer in LP. (3) Interpeak amplitudes tended to be larger in LP, and one VEP interpeak amplitude (P 5-N 7) of long latency component was significantly larger at LP after eliminating the effect of body height by ANCOVA for 2 CH. (4) Quantitative analysis of EEGs between FP and LP resulted in a tendency for increased alpha, and decreased beta power % at LP. Since estrogen increases the VEP amplitude, and decreases the VEP latency and the alpha activity of EEGs, the large VEP amplitude, the tendency for prolonged VEP latency, and the tendency for increased alpha power % at LP observed in this study indicate that the VEP amplitude at LP reflects the effect of estrogen, and that the VEP latency and EEGs at LP reflect the effect of progesterone.

Adult↗
PubMed1996

Analysis of nuclear localization of laminin binding protein precursor p40 (LBP/p40).

We isolated a monoclonal antibody M108, which recognized 40 kDa protein (p40) in the cytoplasm, the perinuclear region in interphase and the perichromosomal region during mitosis. As reported previously, it was revealed from the immunofluorescent observation and the biochemical analyses that the nuclear p40 was associated both with the nuclear envelope and the chromatin DNA in interphase nuclei. In this report, we isolated the p40 from cytoplasmic particles, and identified it by extensive microsequencing as LBP/p40, which was considered to be a precursor of laminin binding protein p67 (LBP/p67). Epitope-tagged LBP/p40 was expressed in cultured cells, and the protein was localized in the nucleus as well as in the cytoplasm. Further analysis showed that the nuclear LBP/p40 was tightly associated with the nuclear structures.

Animals↗
PubMed1996

Fusigenic viral liposome for gene therapy in cardiovascular diseases.

To improve the efficiency of liposome-mediated DNA transfer as a tool for gene therapy, we have developed a fusigenic liposome vector based on principles of viral cell fusion. The fusion proteins of hemagglutinating virus of Japan (HVJ; also Sendai virus) are complexed with liposomes that encapsulate oligodeoxynucleotide or plasmid DNA. Subsequent fusion of HVJ-liposomes with plasma membranes introduces the DNA directly into the cytoplasm. In addition, a DNA-binding nuclear protein is incorporated into the HVJ-liposome particle to enhance plasmid transgene expression. The fusigenic viral liposome vector has proven to be efficient for the intracellular introduction of oligodeoxynucleotide, as well as intact genes up to 100 kbp, both in vitro and in vivo. Many animal tissues have been found to be suitable targets for fusigenic viral liposome DNA transfer. In the cardiovascular system, we have documented successful cytostatic gene therapy in models of vascular proliferative disease using antisense oligodeoxynucleotides against cell cycle genes, double-stranded oligodeoxynucleotides as "decoys" to trap the transcription factor E2F, and expression of a transgene encoding the constitutive endothelial cell form of nitric oxide synthase. Similar strategies are also effective for the genetic engineering of vein grafts and for the treatment of a mouse model of immune-mediated glomerular disease.

Animals↗
PubMed1996

Sustained transgene expression by transfection of renin gene into liver of neonates.

Although transfection of renin gene into adult liver resulted in increased blood pressure (BP) for 1 week, sustained transgene expression must be considered to produce a continuous hypertensive animal. We hypothesized that gene transfer into neonatal rats would result in long-term transgene expression, given with highly replicating hepatocytes in neonates. Initially, chloramphenicol acetyltransferase (CAT) vector was transfected into the liver of 1-day-old rats. Immunohistochemical staining showed positive staining of CAT throughout the liver. Therefore, we transfected renin vector to study biological effects. At 2, but not 4 and 8, weeks, a significant increase in plasma angiotensin II concentration was observed in rats transfected with renin vector. Expression of renin mRNA in the liver transfected with renin vector could be detected at least up to 6 weeks, while no significant changes in BP were observed. These results demonstrated that in vivo gene transfer into the neonatal liver resulted in sustained transgene expression, suggesting the potential use of in vivo gene transfer as a tool to produce a novel model.

Aging↗
PubMed1996

Autocrine-paracrine effects of overexpression of hepatocyte growth factor gene on growth of endothelial cells.

Although hepatocyte growth factor (HGF) is synthesized in vascular cells, it is not known whether locally synthesized HGF acts similarly to exogenously added HGF. Therefore, we transfected cultured cells with human HGF vector and examined the effects on growth of vascular cells. Endothelial cells (EC) transfected with HGF vector synthesized and secreted high levels of HGF, and also showed significantly higher number. Addition of conditioned medium from vascular smooth muscle cells (VSMC) or EC transfected with HGF vector to nontransfected EC resulted in a significant increase in cell number, which was abolished by anti-HGF antibody. Co-culture of HGF-transfected VSMC with EC showed that HGF released from VSMC or EC stimulated EC growth. These results demonstrate that endogenously produced HGF by transfection of human HGF vector can exert autocrine and paracrine stimulatory effects on EC growth, but not VSMC growth, suggesting the role of local HGF system in cardiovascular disease.

Animals↗
PubMed1996

Transient introduction of a foreign gene into healing rat patellar ligament.

We investigated the in vivo introduction of a reporter gene into healing rat patellar ligaments using the hemagglutinating virus of Japan (HVJ)-liposome-mediated gene transfer method. The mid-portion of the medial half of the patellar ligament was cut transversely with a scalpel in 14-wk-old male Wistar rats. A HVJ-liposome suspension containing beta-galactosidase (beta-gal) cDNA was injected directly into the injured site and pooled in the fascial pocket covering the injured site 3 d postoperatively. Thereafter, beta-gal-labeled cells were observed in the wound site accounting for 3% of the wound cells on the first day, 2% on the third, 7% on the seventh, 6% on the 14th, 2% on the 28th, and 0.2% on the 56th day after injection. The beta-gal-labeled cells were initially localized in and adjacent to the wound site, but they were observed spreading into the ligament substance away from the wound on the seventh day after injection. On day 28, beta-gal-labeled cells were observed throughout the length of the ligament substance. With double-labeling for marker antigens for monocyte/macrophage (ED-1) and for collagen I aminopropeptide (pN collagen I), it was revealed that fibroblastic (pN collagen I-positive) cells accounted for 63% and monocyte/macrophage lineage cells for 32% of the beta-gal-labeled cells in the day 7 wound. On day 28, they formed 58 and 35% of the beta-gal-labeled cells in the wound, respectively. Thus, we succeeded in introducing the beta-gal gene into healing rat patellar ligament. Moreover, labeling of the transfected cells made it possible to identify a biological event, namely that the cells in and around the wound site infiltrate into the uninjured ligament substance and come to populate the whole length of the ligament substance as repair progresses. These results suggest that ligament healing may involve not only the repair of the wound site itself but also extensive cellular infiltration of ligament substance adjacent to the wound.

Animals↗
PubMed1996

Fusigenic liposome-mediated DNA transfer into cardiac myocytes.

Current methods of gene transfer into cultured cardiac myocytes have serious limitations, including low efficiency, toxicity or constraints on DNA insert size. The present study examined the effectiveness of hemagglutinating virus of Japan (HVJ) in promoting liposome-mediated DNA transfer into cultured neonatal rat cardiac myocytes. Fluorescein isothiocyanate-labeled oligonucleotides (F-ODN) or plasmid expression vectors encoding SV40 large T antigen (pActSVT) and beta-galactosidase (pAct beta-gal) were complexed with liposomes and the viral protein coat of HVJ. Plasmid vectors were complexed with the nuclear localizing protein HMG-1 prior to HVJ-liposome encapsulation. Neonatal myocytes were transfected by incubation with HVJ-liposome/DNA complexes on culture day 3 or 7. Using F-ODN, we were able to demonstrate significant uptake of DNA (transfection efficiencies of 80-90%) 1 h after transfection that persisted for 1 week in culture. Interestingly, F-ODN were concentrated in the myocyte nuclei for the first 4 days after transfection. Immunohistochemistry showed that 25-30% of myocytes transfected with either pActSVT or pAct beta-Gal expressed plasmid-encoded protein at 72 h whether they were transfected at day 3 or day 7 of culture, while cells transfected with blank vectors did not. Quantitative beta-galactosidase assays confirmed that the use of HVJ significantly enhanced liposome-mediated transfection. Cell toxicity was not apparent. Gene transfer via intracoronary injection also demonstrated the capacity of HVJ to mediate transfection of rabbit cardiac myocytes in vivo, with F-ODN-dependent fluorescence persisting for up to 1 week. We conclude that HVJ/liposome-mediated transfer is efficient for the transfection of both oligonucleotides and plasmids into cardiac myocytes both in vitro and in vivo, and may provide a new tool for the investigation of cardiac myocyte biology and disease.

Animals↗
PubMed1996

Disadvantages of muscle-sparing thoracotomy in patients with lung cancer.

At our institute patients with lung cancer had traditionally undergone lobectomy with mediastinal lymph node dissection using a standard posterolateral approach. The considerable morbidity associated with the standard posterolateral thoracotomy led us to investigate an alternative muscle-sparing approach. A prospective, randomized study of 30 patients with primary lung cancer (stage I or II) was performed to compare the following: operative field size, number of dissected lymph nodes, surgery time, postoperative pain, shoulder range of motion, and pulmonary function test results between patients who underwent either standard thoracotomy (SP group, n = 15) or the muscle-sparing thoracotomy (MS group, n = 15). The procedure should provide enough operative field size to access to mediastinum. Compared with the standard posterior thoracotomy, the muscle-sparing thoracotomy supplied a smaller operative field (218 +/- 31 versus 165 +/- 41 cm2) and required more surgery time (87 +/- 13 minutes) than the standard posterior thoracotomy (66 +/- 12 minutes). There were no significant differences in the number of dissected mediastinal lymph nodes. During the early postoperative days, pain and restriction of shoulder flexion were significantly less in the MS group than in the SP group. There were no significant differences in pulmonary function between the two groups. In terms of the operative field there is a marked disadvantage with the muscle-sparing incision compared with standard thoracotomy. The operative field is significantly smaller than with a standard thoracotomy, requiring more time to dissect the mediastinum; however, the pain is less and shoulder range of motion is superior to what is seen after standard thoracotomy during the early postoperative period. We conclude that there is no overall advantage to using the muscle-sparing incision in patients with lung cancer.

Female↗
PubMed1996

Molecular design of hybrid tumour necrosis factor-alpha. II: The molecular size of polyethylene glycol-modified tumour necrosis factor-alpha affects its anti-tumour potency.

To design hybrid tumour necrosis factor-alpha (TNF-alpha) applicable to systemic anti-tumour therapeutic use, we assessed the relationships among the molecular size of hybrid TNF-alpha, in vitro bioactivity and in vivo anti-tumour potency. Natural human TNF-alpha was covalently modified with polyethylene glycol (PEG) of various number-average molecular weights (Mn = 2000, 5000, 12,000). The in vitro bioactivity of PEG-modified TNF-alpha s decreased with an increase in the degree of PEG modification, irrespective of the molecular weight of PEG. This decrease in the specific bioactivity markedly increased with an increase in the molecular weight of the attached PEG. The in vivo anti-tumour effects of the hybrid TNF-alpha s with a molecular size from 100 to 110 kDa, which had more than 50% of specific bioactivity of native TNF-alpha, were significantly superior to other PEG-TNF-alpha s. These hybrid TNF-alpha s showed over ten times greater anti-tumour effects than native TNF-alpha. Thus, the molecular size, which was determined by the degree of PEG modification and PEG molecular weight, influences the specific activity and anti-tumour effects of hybrid TNF-alpha.

Animals↗
PubMed1996

Inhibition of TGF-beta 1 expression by antisense oligonucleotides suppressed extracellular matrix accumulation in experimental glomerulonephritis.

Overproduction of transforming growth factor-beta 1 (TGF-beta 1) has been implicated in the pathogenesis of fibrotic diseases. TGF-beta 1 plays a crucial role in the accumulation of extracellular matrix (ECM) in human and experimental glomerular diseases. However, it remains unclear whether inhibition of TGF-beta 1 overproduction would suppress TGF-beta 1-induced ECM accumulation. To inhibit the overproduction of TGF-beta 1 in experimental glomerulonephritis induced by anti-Thy 1.1 antibody, we introduced antisense oligodeoxynucleotides (ODN) for TGF-beta 1 into the nephritic kidney by the HVJ-liposome-mediated gene transfer method. Sense, scrambled or reverse ODN were also introduced as controls. Transfected ODN accumulated mainly in the nuclei of mesangial cells in the glomeruli of transfected kidneys. In the antisense ODN-transfected rats, a marked decrease in expression of TGF-beta 1 mRNA was confirmed by Northern analysis. Consequently, the expression of TGF-beta 1 protein in the glomerulus was markedly reduced in the antisense ODN-transfected kidney with a comparable effect in preventing glomerular ECM expansion in experimental glomerulonephritis. In contrast, sense, scrambled and reverse ODNs failed to suppress TGF-beta 1 expression and ECM accumulation. Thus, these results suggested that inhibition of TGF-beta 1 overproduction could suppress progression to glomerulosclerosis.

Animals↗
PubMed1996

Gene therapy by skeletal muscle expression of decorin prevents fibrotic disease in rat kidney.

There are currently no effective therapies for progressive fibrotic diseases. Recent evidence has implicated overproduction of transforming growth factor-beta1 (TGF-beta1) as a major cause of tissue fibrosis. Furthermore, this evidence implies that inhibitors of TGF-beta1 may be clinically useful as antifibrotic agents. The proteoglycan decorin is a known inhibitor of TGF-beta1. In a rat model of glomerulonephritis we have shown that fibrosis is mediated by TGF-beta1. We report here that transfer of decorin cDNA into rat skeletal muscle increases the amount of decorin messenger RNA and protein present in skeletal muscle and decorin present in kidney, where it has a marked therapeutic effect on fibrosis induced by glomerulonephritis. Transfected glomerulonephritic rats showed a significant reduction in levels of glomerular TGF-beta1 mRNA and TGF-beta1 protein, extracellular matrix accumulation and proteinuria. These results demonstrate the potential of gene therapy as a novel treatment for fibrotic diseases caused by TGF-beta1.

Animals↗