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Biomedical subjects

Y Harada

Publications and source records attributed to Y Harada.

At least 91 records · Page 5Linked to original sources
PubMed2000

Expression of the otx gene in the ciliary bands during sea cucumber embryogenesis.

The Otx gene encodes a homeodomain transcription factor that has a highly conserved role in brain formation of both flies and vertebrates. To deduce evolutionary relationship of the chordate central nervous system to the larval or adult nervous system of nonchordate deuterostomes, we characterized the expression of the Otx gene (Sj-Otx) throughout the entire embryonic and larval development of the sea cucumber Stichopus japonicus. Sj-Otx transcripts were detected in fertilized eggs and in the posterior part of the archenteron of gastrulae. However, the expression was downregulated as embryos developed into auricularia larvae. Sj-Otx was expressed again in the ciliary bands of late auricularia larvae, just before metamorphosis to doliolaria larvae. The expression domain corresponded to the domains moving to the mouth during metamorphosis and sinking into the buccal cavity, but not to the five transverse ciliary bands of the doliolaria. The expression gradually disappeared during further development and was not detected in juveniles. These results indicate that the gene responsible for chordate brain formation is expressed in the ciliary bands of auricularia larvae.

Amino Acid Sequence↗
PubMed2000

Integrative effects of nitric oxide and endothelium-derived hyperpolarizing factor induced by acetylcholine and bradykinin in rat hindquarter perfusion.

We investigated the roles of endothelium-derived vasodilative factors in rat hindquarter perfusion using a system for the direct measurement of nitric oxide (NO). Acetylcholine (ACh) induced the dose-dependent release of NO with a concomitant decrease in perfusion pressure. Under the influence of N(G)-monomethyl-l-arginine (l-NMMA), NO release in response to ACh was blocked, while the perfusion pressure still decreased. In the presence of tetraethylammonium (TEA), the decrease in perfusion pressure in response to ACh was attenuated compared to the control value. The decrease in perfusion pressure in response to ACh was almost abolished in the presence of both l-NMMA and TEA or with deendothelialization. Bradykinin (BK) also induced NO release and biphasic effects on the perfusion pressure. The perfusion pressure decreased with a lower concentration of BK and increased with a higher concentration. l-NMMA and TEA each abolished the decrease in perfusion pressure induced by BK. Furthermore, in the presence of both l-NMMA and TEA, the perfusion pressure actually increased in response to BK. These results suggest that ACh and BK induce vasodilation through NO release and a potassium channel dependent mechanism via endothelium.

Acetylcholine↗
PubMed2000

Externally Supported, Noncoated, Knitted Dacron Graft and Gelatin-Coated Knitted Dacron Graft with Rings for Peripheral Arterial Reconstruction.

During the last 14 years, externally supported noncoated knitted Dacron grafts (EXS) and gelatin-coated knitted Dacron grafts with rings (GEL) were used in 176 patients for femoropopliteal bypass (F-P), femorofemoral bypass (F-F) and axillofemoral bypass (Ax-F). In the EXS group, 58 F-P above knee (ak), 42 below knee (bk), 25 F-F, and 19 Ax-F surgeries were performed. Twenty-three F-Pak, 5 F-Pbk, 26 F-F, and 8 Ax-F surgeries were performed in the GEL group. In the F-Pak, primary patency at 5 and 9 years was 75.5 and 53% for the EXS and that at 3 and 5 years was 75.0 and 60.0% for the GEL (n.s.). In the F-Pbk, primary patency at 5 and 10 years was 60.5 and 29.5% for the EXS, while patency at 1 year was 11.1% for the GEL (P < 0.05). In both the EXS and the GEL groups, the F-Pak surgery showed better outcomes than the F-Pbk surgery. The outcomes of the F-P grafts implanted into the legs with claudication were better than those performed for the limb salvage cases. Primary patency of the F-F and the Ax-F showed no differences and there were also no differences between the graft types. For F-Pak surgery, the EXS is the graft of choice. The GEL is not suitable for F-Pbk surgery. For F-F and Ax-F reconstruction, both the EXS and the GEL are acceptable.

Journal Article↗
PubMed2000

A proposal for the histopathological diagnosis of ductal carcinoma in situ of the breast.

BACKGROUND: As the incidence of ductal carcinoma in situ (DCIS) is increasing, it is necessary to make a guideline for the pathological examination and diagnosis of DCIS, by creating criteria based on clinical and biological aspects of the disease. METHOD: We collected biopsy specimens originally diagnosed as benign lesions, from patients who subsequently developed invasive carcinoma in the ipsilateral breast. The histology of the biopsy specimens was re-evaluated principally according to the 1995 Philadelphia Consensus on DCIS. Histopathological agreement on each biopsy specimen was made by the JBCS Study Group members under a multiviewer microscope. In the course of making conclusive agreements among the pathologists, we developed a consensus for the histopathological diagnosis of DCIS, especially non-comedo types. RESULTS: DCIS is defined as a carcinoma of ductal epithelial origin, without any evidence of stromal invasion. It is necessary to note the methods of pathologic examination required to diagnose DCIS. Stromal invasion is an important prognostic factor, and should be diagnosed with caution. Classification of proliferative ductal lesions as benign or malignant (DCIS), the subtype of DCIS (nuclear grade, architecture, and necrosis), and the histological grading of DCIS are proposed and recommended. CONCLUSION: Although we have made a new proposal according to current concepts, there are still several unresolved problems. Thus further examination and modification will be necessary in the future.

Breast Neoplasms↗
PubMed2000

Human papillomavirus type 33 DNA in breast cancer in Chinese.

BACKGROUND: The association between human papillomavirus (HPV) and anogenital tumors, especially cervical cancer, is well documented. However, it remains unclear whether there is also a correlation between HPV infection and human breast cancer. METHODS: We used PCR and Southern blot hybridization to analyze HPV-related DNA specimens from 32 cases of invasive ductal carcinoma operated upon in the Shanghai region of China. RESULTS: DNA derived from HPV33 was detected in 14 cases (43.8%). No HPV16 or HPV18 DNA was detected in any of the cases in this study. This is the first report demonstrating a correlation between HPV33 infection and breast cancer. CONCLUSIONS: Our results suggest that HPV33 infection may be involved in the pathogenesis of breast cancer in Chinese.

Adult↗
PubMed2000

Characterization of a hemichordate fork head/HNF-3 gene expression.

Based on anatomical and developmental similarities, hemichordates are thought to be most closely related to chordates. However, so far very few developmental genes have been characterized from hemichordates. To gain molecular insight into the developmental mechanisms involved in the origin and evolution of chordates, we investigated the expression of a fork head/HNF-3 (PfHNF3) gene in the acorn worm embryo. Chordate fork head genes are implicated in the formation of endoderm, notochord and floor plate. We found that a PfHNF3 transcript was first detected at the early blastula stage; the signal of in situ hybridization was found in the vegetal plate cells, invaginating endoderm and then in the archenteron. By the late gastrula and into the early tornaria larva stages, an intense signal remained in the anterior region of the archenteron, while the expression in the other regions of archenteron decreased. The intense signal was retained in the pharynx of the tornaria larva. A comparison of the pattern of PfHNF3 with that of HNF-3 genes of sea urchin, ascidian, amphioxus and vertebrate suggests a possible acquisition of new functions of the gene during deuterostome evolution.

Amino Acid Sequence↗
PubMed2000

Giant schwannoma of the back.

We treated a patient with giant schwannoma of the back. The tumor measured 35 x 25 x 12 cm and weighted 1840 g. Histological diagnosis was benign schwannoma. To our knowledge, there is no previous report of such a large schwannoma of the back.

Humans↗
PubMed2000

Effect of surgical stress on endogenous morphine and cytokine levels in the plasma after laparoscopoic or open cholecystectomy.

BACKGROUND: Endogenous morphine in the brain leads to various biological responses after surgery. The aim of this study was to determine whether morphine levels in the plasma would be enhanced by open laparotomy rather than by laparoscopic procedures. METHODS: We compared 19 patients who underwent laparoscopic cholecystectomy with five patients who underwent resection of the gallbladder by open laparotomy. Morphine levels in the plasma were measured by an electrochemical detection system. RESULTS: Postoperative endogenous morphine levels were higher with open laparotomy than with the laparoscopic technique (three h after surgery: open, 200 +/- 52.6 fmol/ml vs laparoscopy, 17.6 +/- 3.7, p < 0.01). This morphine elevation accounted for higher levels of cytokine, greater pain scores, and longer duration of fasting in open laparotomized patients than in laparoscopic cholecystectomy patients. Stress hormone levels in the plasma were also higher with open laparotomy than with laparoscopy. CONCLUSION: Morphine synthesis was enhanced by open laparotomy, resulting in greater biological response postoperatively than that seen with laparoscopic cholecystectomy.

Adrenocorticotropic Hormone↗
PubMed2000

Effects of hyaluronan on the healing of rabbit meniscus injured in the peripheral region.

The effect of hyaluronan (hyaluronic acid; HA) on the healing of rabbit meniscus injured in the peripheral region was assessed. A longitudinal tear was created in the peripheral region of the medial meniscus in 20 mature New Zealand white rabbits. One week after surgery, HA was injected into the left knee joint once a week for 5 weeks (HA group), while saline was injected into the right knee (control group). Six and 12 weeks after surgery, gross morphology, histology, and biochemical evaluations were performed. On gross morphological examination, there was evidence of meniscal healing in both groups, but the healing rate of the HA group was significantly higher than that of the control group at 12 weeks. Histologically, meniscal healing started at the tibial portion of the meniscal injury at 6 weeks in both groups, then advanced in the direction of the femoral surface at 12 weeks in the HA group. Biochemically, water and glycosaminoglycan contents did not differ significantly between the two groups. Hyaluronan maintained the healing process of the injured menisci, especially in the femoral surface, up to 12 weeks after injury.

Adjuvants, Immunologic↗
PubMed2000

Sustained hemostatic abnormality in patients with steroid-induced osteonecrosis in the early period after high-dose corticosteroid therapy.

To determine whether the development of steroid-induced osteonecrosis in collagen disease patients was related to hemostatic abnormality after corticosteroid administration, we examined levels of thrombin-antithrombin III complex (TAT) and plasmin-alpha2-plasmin inhibitor complex (PIC) in 32 patients who were treated with high-dose corticosteroid. All were prospectively followed for osteonecrosis, with serial magnetic resonance imaging (MRI), for at least 12 months from the beginning of corticosteroid therapy. MRI was performed on bilateral hips and knees. Of the 32 patients, 17 (53.1%) had osteonecrosis in the hip or knee. Osteonecrosis was detected on MRI at an average 3.1 months after the start of high-dose corticosteroid therapy. PIC levels were significantly higher in the group of 17 patients with osteonecrosis (ON group) than in the group of 15 patients without osteonecrosis (non-ON group) (P < 0.0001). The difference in PIC levels was most prominent 20 days after the start of the high-dose corticosteroid therapy. Moreover, the number of osteonecrotic joints was significantly correlated with PIC levels (P < 0.0001). The sustained hemostatic abnormality after corticosteroid therapy in the ON group suggests that microvascular coagulation participates in the development of osteonecrosis.

Adolescent↗
PubMed2000

Soluble Fas in serum from patients with renal cell carcinoma.

OBJECTIVES: Fas/APO- 1 is an apoptosis-signaling cell-surface receptor belonging to the tumor necrosis factor receptor family. The Fas-Fas ligand system plays an important role in cytotoxic T-lymphocyte-mediated or natural killer cell-mediated cytotoxicity against tumor cells. Soluble Fas (sFas), generated by alternative splicing, has been reported to antagonize the interaction of cell-surface Fas with Fas ligand. This study examined the level of sFas in the serum of patients with renal cell carcinoma (RCC) and investigated the correlation between the sFas level and clinicopathologic parameters of RCC. METHODS: Using reverse transcriptase-polymerase chain reaction, we examined the production of sFas messenger RNA (mRNA) from the cultured human RCC cell lines ACHN and OUR-10 and from surgical specimens. We also measured sFas levels in the serum of 31 patients with RCC before and after nephrectomy using an sFas-specific enzyme-linked immunosorbent assay. RESULTS: mRNA of sFas was identified both in cultured ACHN cells and human RCC tissues, although mRNA of wild-type Fas was exclusively predominant. The level of sFas in the serum of patients with RCC was significantly higher than that of normal controls, but sFas was not detectable in the supernatant of cultured renal cancer cells. Preoperative and postoperative serum sFas levels did not clearly correlate with the patients' age or sex or with histologic stage, grade, or cell type of RCC. The serum sFas level in patients with RCC correlated with tumor size. In 24 of the 31 cases, radical nephrectomy reduced the serum sFas level within 3 months. CONCLUSIONS: Our results suggest that the elevated serum sFas level in patients with RCC might not be derived from the tumor itself but might reflect an immune response to the tumor burden. Serum sFas may be a useful indicator of tumor burden in patients with RCC.

Carcinoma, Renal Cell↗
PubMed2000

Development of gap junctional channels and intercellular communication in rat liver during ontogenesis.

BACKGROUND/AIMS: We investigated the expression of connexin (Cx) 32 and 26 subunit proteins of the gap junction (GJ) in the rat liver during ontogenesis to clarify their roles in control of growth and differentiation, and observed their channels in association with development of gap junctional intercellular communication (GJIC). METHODS: The expression of Cx32 and 26 in prenatal and postnatal livers was examined by Western blot and immunofluorescence. GJ channels were investigated not only by double immunofluorescence study but also by immunogold electron microscopy. The spread of lucifer yellow 5 min after its microinjection was examined in the cultured liver tissues. RESULTS: 1) Western blot showed the expression of both Cx from the late stage of gestation and their peak a week after birth. 2) Cx32- or 26-positive plaques were scattered on hepatocytes of the fetal liver and some of them were colocalized; both were increased just after birth. On day 7 after birth, Cx32-positive plaques were present on all hepatocytes within a lobule, and Cx26-positive plaques were distributed in the periportal area. 3) Double-immunogold electron microscopy just after birth showed that most GJ channels were homotypic type of Cx32 or 26, and that few were heterotypic. On day 7 after birth, most channels had the homotypic type of type of Cx32 in the middle and pericentral areas, and there was a heterotypic type of Cx32 and 26 in the periportal area. 4) The dye transfer of lucifer yellow showed a wider spread in the liver tissues on day 7 after birth than on day 1. CONCLUSION: Increased GJ formation and compatibility or incompatibility of GJ channels are closely associated with development of GJIC, and GJIC may develop at cytodifferentiation during ontogenesis.

Animals↗
PubMed2000

The expression of nonchordate deuterostome Brachyury genes in the ascidian Ciona embryo can promote the differentiation of extra notochord cells.

The notochord is a structure present in all chordates and its development requires the transcription of Brachyury. While previous studies have shown that Brachyury is essential for notochord formation in vertebrate embryos, this gene is also expressed during the embryogenesis of nonchordate deuterostomes, hemichordates and echinoderms. Here we report that nonchordate deuterostome Brachyury genes can trigger the differentiation of extra notochord cells when these genes are ectopically expressed in ascidian embryos. The 2.6 kb upstream region of fork head gene (Ci-fkh) of Ciona intestinalis promotes the tissue-specific expression of a reporter gene in endoderm, notochord and nerve cord. By taking advantage of this promoter, we misexpressed the Brachyury gene of ascidian (Ci-Bra), cephalochordate amphioxus (Am(Bb)Bra2), hemichordate acorn worm (PfBra), and echinoderm sea urchin (SpBra), in Ciona embryos. The misexpression of not only the chordate Brachyury, but also the nonchordate deuterostome Brachyury, resulted in the transformation of presumptive endodermal cells into notochord cells. This was confirmed by in situ hybridization experiments using four different notochord-specific probes from Ciona that have different temporal expression patterns. RT-PCR analyses indicated that Ci-Bra was not upregulated by the product of Am(Bb)Bra2, PfBra or SpBra. In situ hybridization showed no ectopic expression of Ci-Bra in the manipulated embryos. These results suggest that the introduction of nonchordate deuterostome Brachyury genes into ascidian embryos can trigger the differentiation of notochord cells in ascidian embryos. Evolutionary alteration in the genetic circuitry, especially downstream of this transcription factor, seems critical for the evolution of notochord and chordate body plan.

Amino Acid Sequence↗
PubMed2000

Highly efficient suicide gene expression in hepatocellular carcinoma cells by epstein-barr virus-based plasmid vectors combined with polyamidoamine dendrimer.

The present study was aimed at devising an efficient nonviral strategy for suicide gene therapy of hepatocellular carcinoma (HCC). To improve the efficiency of DNA delivery and expression, we applied Epstein-Barr virus (EBV)-based plasmid vectors instead of conventional plasmid vectors and combined them with cationic liposome (EBV/lipoplex) or polyamidoamine dendrimer (PAAD) (EBV/polyplex). When the beta-galactosidase gene was transferred to HuH7, PLC/PRF/5, or HLE cells, < or =50-fold higher beta-galactosidase activities were demonstrated in the cells transfected with EBV vector compared with those transfected with conventional plasmid vectors. PAAD-mediated transfection of HCC with pSES.Tk (an EBV-based vector carrying the herpes simplex virus-1 thymidine kinase gene) resulted in a marked reduction in viable cell number by the addition of ganciclovir (GCV). The HCC cells transfected with pSES.Tk/PAAD showed 100- to 1000-fold higher susceptibilities to GCV than those transfected with pS.Tk (a conventional plasmid vector carrying herpes simplex virus-1 thymidine kinase gene)/PAAD. The pSES.Tk-transfected HCC cells were effectively killed by day 9 in culture with a clinically feasible concentration of GCV (25 microM), whereas the pS.Tk-transfected cells survived the culture. These results demonstrate highly efficient suicide gene transfer into various HCC cells by EBV-based plasmid vectors in vitro, suggesting the possible application of this nonviral vector system to gene therapy of HCC.

Antineoplastic Agents↗
PubMed2000

Targeted killing of carcinoembryonic antigen (CEA)-producing cholangiocarcinoma cells by polyamidoamine dendrimer-mediated transfer of an Epstein-Barr virus (EBV)-based plasmid vector carrying the CEA promoter.

The present study reports a novel nonviral method to efficiently and specifically target carcinoembryonic antigen (CEA)-producing cholangiocarcinoma (CC) cells in vitro. Epstein-Barr virus (EBV)-based and conventional plasmid vectors were constructed that possess the beta-galactosidase (beta-gal) or herpes simplex virus-1 (HSV-1) thymidine kinase (Tk) genes as well as tandem repeats of the human genomic sequence -82 to -42 bp from the transcriptional start site of the CEA gene. The plasmids were transfected by means of polyamidoamine dendrimer into CEA-positive (HuCC-T1) or -negative cell lines. Transfection of the conventional plasmid vector with the CEA promoter and beta-gal gene resulted in a very low or undetectable level of marker gene expression even in the CEA-positive cell line. Transferring the HSV-1 Tk gene by conventional plasmid did not affect the susceptibility of HuCC-T1 cells to ganciclovir. In marked contrast, strong beta-gal expression was specifically obtained in HuCC-T1 cells by transfecting the EBV-based plasmid in which the CEA promoter and a ubiquitous promoter (SRalpha) are employed to drive the EBV-encoded nuclear antigen 1 (EBNA1) and beta-gal genes, respectively (pTES.beta). Furthermore, CEA-positive but not -negative tumor cells were rendered highly susceptible to ganciclovir when transfected with the EBV-based vector that carries the CEA promoter-EBNA1 and SRalpha-HSV-1 Tk genes (pTES.Tk). These results strongly suggest that the EBV-based plasmid vector/cationic polymer system (EBV/polyplex) equipped with the CEA promoter provides an efficient nonviral method for the targeted gene therapy of CEA-producing malignancies.

Carcinoembryonic Antigen↗
PubMed2000

Effective suicide gene therapy in vivo by EBV-based plasmid vector coupled with polyamidoamine dendrimer.

This study demonstrates in vivo effectiveness of a nonviral vector system, Epstein-Barr virus (EBV)-based plasmid vector coupled with polyamidoamine (PAMAM) dendrimer (EBV/polyplex), in suicide gene therapy of cancer. The EBV-based vector is a plasmid vector containing EBV nuclear antigen 1 (EBNA1) gene and oriP from EBV genome. HSV-1 tk gene was transferred into Ewing's sarcoma cell lines, A4573 and KP-EWS-YI, by using an EBV-based plasmid vector, pSES.Tk, or a conventional plasmid vector, pS.Tk. Cells transfected with pSES.Tk/dendrimer showed approximately 100 times lower ID50 to ganciclovir (GCV) compared with those transfected with pS. Tk/dendrimer. Intratumoral injection of pSES.Tk/dendrimer but not pS. Tk/dendrimer drastically suppressed the growth of tumors which had generated from A4573 or Huh7 hepatocellular carcinoma (HCC) cells inoculated into severe combined immunodeficiency (SCID) mice. The treatment with pSES.Tk/dendrimer also resulted in significant prolongation of survival of the mice implanted with A4573. These results suggest that the EBV/polyplex system could be useful for in vivo suicide gene therapy of cancer. Gene Therapy (2000) 7, 53-60.

Animals↗