Biomedical subjects

Yutaka Hayashi

Publications and source records attributed to Yutaka Hayashi.

At least 19 recordsLinked to original sources

PubMed2006

Living-related intestinal transplantation for a patient with hypoganglionosis.

A 14-yr-old boy with total parenteral nutrition-dependent short-bowel syndrome associated with hypoganglionosis underwent the LR-IT by using a 150 cm segment of distal ileum taken from a healthy donor. The graft vessels were connected to infrarenal aorta and inferior vena cava. The immunosuppressive regimen consisted of daclizumab, tacrolimus, and steroid. The graft surveillance for ACR was accomplished using zoom endoscopy and mucosal biopsy. The blood trough level of tacrolimus was maintained between 20 and 25 ng/mL for the first 2 months, followed by 15-20 ng/mL thereafter. The 50 mg of daclizumab was administered on the day of operation, and same dosage was repeated at 2-wk intervals. The first ACR occurred on POD-9 and was progressive, and required a 14-day course of OKT-3 injection. After the treatment with OKT-3, the graft recovered from the ACR, and began to function well enough to discontinue the intravenous nutrition on POD-55. No infectious complication has occurred. The patient was discharged in POD-112, and currently tolerates full oral intake without requiring intravenous nutritional or fluid supplementation. The donor was discharged without any complications. The LR-IT could successfully be performed with minimal risk to the donor, and it can be a treatment of choice for patients with short-gut syndrome associated with hypoganglionosis.

Adolescent↗

PubMed2006

Biosynthesis of a natural polyketide-isoprenoid hybrid compound, furaquinocin A: identification and heterologous expression of the gene cluster.

Furaquinocin (FQ) A, produced by Streptomyces sp. strain KO-3988, is a natural polyketide-isoprenoid hybrid compound that exhibits a potent antitumor activity. As a first step toward understanding the biosynthetic machinery of this unique and pharmaceutically useful compound, we have cloned an FQ A biosynthetic gene cluster by taking advantage of the fact that an isoprenoid biosynthetic gene cluster generally exists in flanking regions of the mevalonate (MV) pathway gene cluster in actinomycetes. Interestingly, Streptomyces sp. strain KO-3988 was the first example of a microorganism equipped with two distinct mevalonate pathway gene clusters. We were able to localize a 25-kb DNA region that harbored FQ A biosynthetic genes (fur genes) in both the upstream and downstream regions of one of the MV pathway gene clusters (MV2) by using heterologous expression in Streptomyces lividans TK23. This was the first example of a gene cluster responsible for the biosynthesis of a polyketide-isoprenoid hybrid compound. We have also confirmed that four genes responsible for viguiepinol [3-hydroxypimara-9(11),15-diene] biosynthesis exist in the upstream region of the other MV pathway gene cluster (MV1), which had previously been cloned from strain KO-3988. This was the first example of prokaryotic enzymes with these biosynthetic functions. By phylogenetic analysis, these two MV pathway clusters were identified as probably being independently distributed in strain KO-3988 (orthologs), rather than one cluster being generated by the duplication of the other cluster (paralogs).

Amino Acid Sequence↗

PubMed2005

Gastrointestinal stromal tumor in a child and review of the literature.

Gastrointestinal stromal tumors (GIST) are c-KIT positive neoplasm that occur predominantly in adults. A 13-year-old boy who presented with massive gastrointestinal hemorrhage was subsequently diagnosed with GIST of the stomach. The tumor originated from the lesser curvature with a narrow base and no infiltration into surrounding organs. Two metastatic lesions in the liver were also found. Total excision of the gastric lesion was performed followed by adjuvant imatinib mesylate chemotherapy. He has had no signs of recurrence during 8 months of follow-up. GIST in children are rare and their behavior is notoriously difficult to predict. We report our experience and review the literature.

Adolescent↗

PubMed2005

Dynamic MR imaging for diagnosis of lesions adjacent to pituitary gland.

In this study, we evaluated the usefulness of dynamic studies for the preoperative diagnosis of tumor lesions adjacent to the pituitary gland. We examined 13 tumors. We obtained pre- and post-contrast thin slice T1-weighted images of the sellar regions. FSE sequences were used for dynamic study. The capability to distinguish the tumor from the pituitary gland and additional information obtained from the dynamic study were evaluated. Two meningiomas were identified more clearly on the dynamic than on the delayed study. In two cavernous hemangiomas, the peripheral nodular stains gradually increased during the dynamic study. For the preoperative evaluation of lesions adjacent to the pituitary gland, the dynamic study can often identify the lesions more clearly and may provide additional information.

Adult↗

PubMed2005

CT arteriography for orbital tumors: diagnostic and surgical value.

The aim of this study is to investigate the efficacy of dynamic computed tomography (CT) during selective angiography (CT-arteriography) of orbital tumors in the evaluation of intratumoral vascular anatomy, feeding artery territory, and histological diagnosis. Among 35 consecutive cases with various orbital lesions, those cases showing tumor staining or pooling of the contrast medium on digital subtraction angiography (DSA) were evaluated by CT-arteriography (n = 14). The information obtained by CT-arteriography was compared with that provided by enhanced MRI (n = 31) and dynamic MRI (n = 21), in which the contrast medium was injected intravenously. In addition to the visualization of fine vascular anatomy, CT-arteriography emphasized areas of nodular enhancement and non-enhancing cystic/necrotic components as well as the intratumoral feeding arteries. Patterns of CT-arteriography were categorized into three subgroups: homogeneous enhancement (benign lymphoid lesion), partial enhancement (schwannomas and carcinomas), and patchy multinodular enhancement (specific for cavernous angiomas). In addition, CT-arteriography with selective arterial catheterization clearly delineated the feeding artery territories. CT-arteriography, with a minimal dose of contrast medium, can offer significant advantages over intravenously injected dynamic neuroimaging, and provides additional valuable preoperative information about the orbital tumor under investigation.

Adult↗

PubMed2005

Psychosocial liaison-consultation for the children who have undergone repair of imperforate anus and Hirschsprung disease.

OBJECTIVE: The aim of this study was to investigate the psychological status of Japanese children with congenital anorectal malformation and their mothers to develop appropriate psychiatric interventions. METHOD: The subjects comprised 50 children with congenital anorectal malformation aged 0 to 16 years and their mothers. The psychology of children aged 7 to 16 years was investigated by Kovacs' Children's Depression Inventory (CDI). The psychology of their mothers was assessed by Spielberger's State-Trait Anxiety Index (STAI) and Zung's Self-rating Depression Scale (SDS). RESULTS: Depression was more marked in the children aged 12 to 16 years than in those aged 7 to 11 years according to the CDI. The mothers of preschool children showed higher levels of anxiety and depression than those of school-aged children, according to the STAI and SDS. Significant correlations between the CDI score of the children and the STAI or SDS score of the mothers were observed only among children aged 7 to 11 years. CONCLUSIONS: The frequency of depression and anxiety among children with congenital anorectal malformation and that among their mothers was associated with the age of the child. Long-term postoperative psychosocial support for the children and their mothers may be required, taking into account the age of the child.

Adolescent↗

PubMed2005

Thoracoscopic removal of neurogenic mediastinal tumors in children.

PURPOSE: The aim of this study was to evaluate the feasibility and advantages of thoracoscopic removal of neurogenic mediastinal tumors (NMTs) in children. METHODS: From January 1998 to December 2001, 6 patients, ages 1.1 to 6.8 years (mean, 3.5 years), underwent thoracoscopic removal of NMT. A retrospective study was done to assess the type of anesthesia, conversions to standard thoracotomy, operative time, complications, and the current status of each patient. RESULTS: General anesthesia using a Fogarty catheter as an ipsilateral bronchial blocker was utilized. Four 5-mm ports were placed in all patients. All NMTs were successfully removed without a need to convert to standard thoracotomy. The tumor was captured in an extraction bag, fragmented, and then removed through the trocar site, which had been enlarged up to 2.0-2.5 cm in each case. Pathologic diagnosis was neuroblastoma in 1 patient, ganglioneuroblastoma in 2, and ganglioneuroma in 3 patients. The mean operative time was 230 minutes. There was no need for transfusion and no serious complication related to this approach. All patients are alive at the time of writing, without any evidence of tumor recurrence. CONCLUSION: All tumors were successfully removed. Thoracoscopic surgery is a feasible, safe, and effective technique in the treatment for children with NMT.

Child↗

PubMed2005

Social adaptation of children with congenital fecal dysfunction: from the viewpoint of the mother-child relationship.

Excretory dysfunction associated with congenital anal anomalies (a generic term that includes anal atresia and Hirschsprung's disease) is presumed to greatly affect the psychology of the affected children. In this study, we conducted a survey on the psychological status of children with excretory dysfunction, and investigated the relationship between the affected children and their families in addition to their social life. Four children with fecal dysfunction due to a congenital anal anomaly and their mothers were interviewed. The results of psychological tests in the children and mothers along with our findings in the interviews with the children and mothers, were included in the data analysis. We found that regardless of the degree of excretory dysfunction, the child's state of mind was influenced by whether the mother exhibited warmth or criticism towards her child and whether there was a support system for the mother and child. We suggest that psychiatric consultation is necessary for these children.

Anal Canal↗

PubMed2005

Concentrations of copper and zinc in liver and serum samples in biliary atresia patients at different stages of traditional surgeries.

Many patients with biliary atresia (BA) have impaired metabolism of copper (Cu) and zinc (Zn) because of the obstruction of bile ducts. An excessive Cu accumulation is cytotoxic and results in fibrosis in hepatic tissues. Since Zn works antagonistically to Cu, lower Zn concentrations may deteriorate liver damage. In the 1980's, we performed a series of surgeries on BA patients for the construction and alteration of the bile flow route, which is the major excretion route for Cu. We obtained liver and serum samples at each surgery, and measured Cu and Zn concentrations by inductively coupled plasma atomic emission spectrometry. Hepatic Cu concentration decreased with the improvement of cholestasis after the establishment of bile excretion. Conversely, when cholestasis persisted or recurred, increases in hepatic and serum Cu concentrations were noted. Hepatic Zn concentration was lower than previously reported normal values. High hepatic and serum Cu concentrations due to persistent or recurrent cholestasis and low hepatic Zn concentration may deteriorate hepatic fibrosis and liver cirrhosis.

Biliary Atresia↗

PubMed2005

Correlation of gamma-catenin expression with good prognosis in medulloblastomas.

OBJECT: Medulloblastoma is a malignant cerebellar tumor of childhood and is difficult to cure due to frequent cerebrospinal fluid dissemination. Amplification of the c-myc gene (4%) and messenger (mRNA) overexpression (50%) are known to be adverse prognostic indicators. Because mRNA overexpression cannot be explained by gene amplification alone, mechanisms other than gene amplification are postulated. Molecules on the Wnt signal pathway in primary tumors were examined. METHODS: Immunohistochemical and cytogenetic examinations of beta- and gamma-catenin, c-myc, N-myc, and cyclin D1 in 24 primary medulloblastomas were conducted, and their clinical relevance was evaluated. Cytoplasmic/membranous staining of beta- and gamma-catenin was detected in 19 (79%) and nine (37%) cases, respectively, and nuclear expression of cyclin D1 and c-myc was detected in six (25%) and 21 (83%) cases, respectively. The expression levels of gamma-catenin in Western blot analysis and immunohistochemistry were similar. By differential polymerase chain reaction, c-myc and N-myc were amplified separately in two large cell/anaplastic medulloblastomas. No cyclin D1 amplification, or beta- or gamma-catenin mutations were found. Kaplan-Meier analysis revealed no dissemination at diagnosis (Chang Grade M0) and gamma-catenin expression was correlated with good prognosis (p = 0.0002 and 0.003, respectively). Expression of gamma-catenin was also significant in the M0 group (p = 0.022). Expression of cyclin D1 showed a trend toward adverse outcome (p = 0.057) and all patients in whom cyclin D1 expression was found died of disease. CONCLUSIONS: Expression of gamma-catenin is of great prognostic value and its immunohistochemistry may be useful for further stratification of treatment. Cyclin D expression may have the potential to be an adverse prognostic indicator.

Adolescent↗

PubMed2004

Frequent gene amplification and overexpression of decoy receptor 3 in glioblastoma.

The decoy receptor 3 (DcR3) gene is amplified at high frequency in human lung, colon, and liver cancers. DcR3 has been demonstrated to produce a secreted member of the tumor necrosis factor receptor superfamily that negatively regulates Fas-mediated apoptosis. In this study we examined DcR3 gene amplification, DcR3 mRNA expression, and DcR3 protein expression in 46 human astrocytic brain tumors by quantitative genomic PCR, quantitative reverse transcription-PCR, and immunohistochemistry, respectively. The DcR3 gene amplification was detected in none of 6 (0%) low-grade astrocytomas, 1 of 16 (6%) anaplastic astrocytomas, and 6 of 24 ( 25%) glioblastomas. Six of 7 (86%) cases with gene amplification exhibited both mRNA overexpression and/or protein overexpression, suggesting that DcR3 mRNA and protein were expressed more abundantly in the cases with gene amplification. We thus concluded that high DcR3 mRNA expression and protein expression may be positively related to the gene amplification in astrocytic brain tumors, especially glioblastomas. Further, we speculated that the DcR3 gene amplification with overexpression may be responsible for malignant features in glioblastomas.

Adolescent↗

PubMed2004

Expression profiling and differential screening between hepatoblastomas and the corresponding normal livers: identification of high expression of the PLK1 oncogene as a poor-prognostic indicator of hepatoblastomas.

Hepatoblastoma is one of the most common malignant liver tumors in young children. Recent evidences have suggested that the abnormalities in Wnt signaling pathway, as seen in frequent mutation of the beta-catenin gene, may play a role in the genesis of hepatoblastoma. However, the precise mechanism to cause the tumor has been elusive. To identify novel hepatoblastoma-related genes for unveiling the molecular mechanism of the tumorigenesis, a large-scale cloning of cDNAs and differential screening of their expression between hepatoblastomas and the corresponding normal livers were performed. We constructed four full-length-enriched cDNA libraries using an oligo-capping method from the primary tissues which included two hepatoblastomas with high levels of alpha-fetoprotein (AFP), a hepatoblastoma without production of AFP, and a normal liver tissue corresponded to the tumor. Among the 10,431 cDNAs randomly picked up and successfully sequenced, 847 (8.1%) were the genes with unknown function. Of interest, the expression profile among the two subsets of hepatoblastoma and a normal liver was extremely different. A semiquantitative RT-PCR analysis showed that 86 out of 1188 genes tested were differentially expressed between hepatoblastomas and the corresponding normal livers, but that only 11 of those were expressed at high levels in the tumors. Notably, PLK1 oncogene was expressed at very high levels in hepatoblastomas as compared to the normal infant's livers. Quantitative real-time RT-PCR analysis for the PLK1 mRNA levels in 74 primary hepatoblastomas and 29 corresponding nontumorous livers indicated that the patients with hepatoblastoma with high expression of PLK1 represented significantly poorer outcome than those with its low expression (5-year survival rate: 55.9 vs 87.0%, respectively, p=0.042), suggesting that the level of PLK1 expression is a novel marker to predict the prognosis of hepatoblastoma. Thus, the differentially expressed genes we have identified may become a useful tool to develop new diagnostic as well as therapeutic strategies of hepatoblastoma.

Cell Cycle Proteins↗

PubMed2004

Biliary atresia with associated complicated anorectal and urogenital malformations.

We report on a girl with biliary atresia (BA) who also suffered with anorectal agenesis without fistula and complicated urogenital malformation. The outcome of patients with these severe anomalies is poor, but she has survived without liver and/or renal transplantation for more than 3 years. A careful treatment plan for each anomaly in addition to prevention of cholangitis and urinary tract infection is indispensable for managing these complicated anomalies.

Abnormalities, Multiple↗

PubMed2004

Molecular genetic analysis of deep-seated glioblastomas.

Glioblastoma can be divided into genetic subsets. The most prominent criterion for dividing glioblastomas into subsets is the dichotomy between TP53 mutation and EGFR amplification, two genetic alterations that almost never coincide in the same tumor. Approximately one third of glioblastomas have TP53 mutations, one third have EGFR amplification, and one third have neither. When viewed in terms of tumor progression, secondary glioblastomas have a much higher incidence of TP53 mutations than do primary glioblastomas. When viewed in terms of the age of tumor onset, glioblastomas in young adults are likely to have TP53 mutations. However, no correlations have yet been found between the tumor locations and the genetic subsets. In this study, we evaluated the associations between the glioblastoma sites and the genetic subsets defined by the presence of the TP53 mutation or EGFR amplification in nine deep-seated glioblastomas of the thalamus and basal ganglia. All nine tumors were clinically defined as primary glioblastomas. Our investigation revealed that all tumors had TP53 mutations and none had EGFR amplifications. These findings suggest that glioblastomas deep-seated in the thalamus and basal ganglia can be grouped into a subset of glioblastomas with TP53 mutations, akin to the subsets of secondary and younger adult glioblastomas. The locations where the glioblastomas originate may be associated with the genetic features.

Adult↗

PubMed2004

Autologous amnion graft for repair of myelomeningocele: technical note and clinical implication.

OBJECTIVE AND IMPORTANCE: Amniotic membrane can be used as autologous reconstruction graft material when aseptically obtained. We introduce here a novel repair technique using autologous amnion graft, and report a case presentation of myelomeningocele successfully treated with this graft material. TECHNIQUE: Amniotic membrane, which was composed of amnion and chorion, was aseptically harvested at cesarean section. Removing chorionic tissue, amnion containing monolayer of amniotic epithelial cells and underlining fibrous tissue was isolated. After the procedure of reconstruction of neural and meningeal elements, the membrane was placed as onlay autograft over the reconstructed neural structure followed by suture of undermined skin flap without any myocutaneous flap transfer technique or fascial transposition from paraspinal muscles. RESULTS: The postoperative healing process of the wound was excellent. CONCLUSION: Autograft of amniotic tissue has no risks of rejection, foreign body reaction, or transmission of slow virus infection to reconstruct the lesion of newborn patient. Amnion autograft would be a biologic rationale to promote wound healing, being applied as a part of a variety of pediatric neurosurgical procedure.

Adult↗

PubMed2004

Development of an implantable artificial anal sphincter using a shape memory alloy.

BACKGROUND/PURPOSE: The authors created a new artificial anal sphincter using a shape memory alloy (AS-SMA) to treat fecal incontinence and evaluated its validity. METHODS: AS-SMA consists of 2 Ti-Ni plates to sandwich the intestine and generates a pressure of 55 mm Hg at its resting position. With the electric power supply, the 2 metals bend to form an almondlike shape making a maximum gap of 33 mm between each other at the temperature of 55 degrees C. The device was attached to the colostomy in a piglet and was operated several times a day for 1 month. Fecal continence, bowel movements, and general condition of the piglet were recorded. After the experiment, tissue damage around the device was investigated. RESULTS: Fecal continence was obtained while the device was in the resting position. When it was operated, bowel movements were observed. The bowel movements to operations ratio was 82:105 (78%). During the experiment, the animal had neither abdominal distension nor vomiting. At the autopsy, there was mild inflammation and shallow burns around the device. No compression injury was detected. CONCLUSIONS: AS-SMA achieved fecal continence of the colostomy. With reduction of the associated side effects, it would be a potential substitute for an impaired anal sphincter.

Alloys↗

PubMed2004

An experimental study on the utility of a 3-mm ultrasonically activated trocar system.

BACKGROUND/PURPOSE: A prototype of a 3-mm ultrasonically activated trocar system supplied by Olympus Corporation was evaluated experimentally in terms of its utility and safety. METHODS: Three piglets with an average weight of 12 kg were used. A pneumoperitoneum was created by Hasson's technique. Eleven punctures were made with a disposable conical 3-mm trocar (CT), 9 punctures with a 3-mm radially expanding trocar (ET), and 13 punctures with a 3-mm ultrasonically activated trocar (UT) under laparoscopic control. The authors recorded the time for abdominal penetration, the severity of the peritoneal tenting, the presence of elevated abdominal pressure of 5 mm Hg or more at the penetration, and the maximal force applied to the trocar to remove from the abdominal wall. RESULTS: The average times for penetration were 11.8, 9.4, and 3.8 seconds with CT, ET, and UT, respectively (P < .05, CT v. UT, ET v. UT). The average maximal forces at the trocar removal were 10.52, 21.17, and 21.24 N with CT, ET, and UT, respectively (P < .05, CT v. ET, CT v. UT). Elevation of abdominal pressure of 5 mm Hg or more was recorded in CT and ET but not in UT. Peritoneal tenting was the most severe in ET and minimal in UT. No complication related to the UT system was found. CONCLUSIONS: The 3-mm UT is a simple and safe device and is expected to become commercially available.

Animals↗

PubMed2004

Cholangitis as a late complication in long-term survivors after surgery for biliary atresia.

BACKGROUND/PURPOSE: A retrospective review was performed to assess the utility of diagnostic imaging (DI), efficacy of treatment, and outcome of late cholangitis in long-term survivors after surgery for biliary atresia. METHODS: Sixty-one patients surviving without liver transplantation (LTx) for more than 20 years were divided into 2 groups depending on whether cholangitis developed after age 20. Clinical factors including the type of obstruction, the age at the initial operation, and the early complication with cholangitis were compared between the 2 groups. DI such as computed tomography scan and magnetic resonance imaging, clinical courses after treatment of cholangitis, and current status of the patients were also evaluated. RESULTS: Thirteen patients had cholangitis after age 20. There was no statistical difference in the clinical factors studied between the 2 groups. Abnormal DI findings including dilatation of intrahepatic bile ducts and hepatic fibrosis were seen in 10 patients with late cholangitis. One patient died, and 2 ultimately underwent LTx. The remaining 10 patients including 4 with normal or near-normal liver function have survived without LTx. CONCLUSIONS: Although the majority of the patients had potential predisposing factors for cholangitis such as dilatation of intrahepatic bile ducts, a few patients unexpectedly had cholangitis without such abnormal findings after an excellent, long-term postoperative course.

Adult↗