Biomedical subjects

H Hamada

Publications and source records attributed to H Hamada.

At least 217 records · Page 12Linked to original sources

PubMed1999

Adjuvant immunotherapy using fibroblasts genetically engineered to secrete interleukin 12 prevents recurrence after surgical resection of established tumors in a murine adenocarcinoma model.

BACKGROUND: To explore effective therapeutic strategy against cancer of the gastrointestinal tract, tumor vaccination using fibroblasts secreting interleukin-12 (IL-12) was developed as an adjuvant therapy against murine tumor after surgical resection. METHODS: Initially, IL-12 was genetically engineered into fibroblasts (IL-12/3T3 cells), and then we evaluated in vivo and in vitro antitumor effects. In the vaccination model, irradiated C-26 tumor mass was reinoculated intradermally with IL-12/3T3 cells in mice as a tumor vaccine to examine how much it suppresses tumor recurrence. RESULTS: IL-12/3T3 cells producing 7.2 ng/10(6) cells/24 h murine IL-12 in vitro exerted dose-dependent potent tumor suppression when coinoculated with C-26 cells in vivo. Specific immunity was also acquired in 63% of mice in vivo. In the vaccination model, protective immunity was developed in 70% of mice that were inoculated with irradiated tumor mass and IL-12/3T3 cells. In addition, local recurrence was not observed in vaccinated mice, although 44% of control mice had recurrence. CONCLUSIONS: Coinoculation of genetically engineered fibroblasts secreting IL-12 with irradiated tumor mass was proved to be an effective tumor vaccine. This system of vaccination is easily applicable to clinical situations, particularly to human gastrointestinal tract cancers.

Adenocarcinoma↗

PubMed1999

[Reno-sigmoid fistula in a tuberculous pelvic ectopic kidney].

Renocolic fistulas are rare lesions, generally involving the ascending and descending colon. The authors report a case of reno-sigmoid fistula occurring in a tuberculous pelvic ectopic kidney. Nephrectomy with segmental sigmoid resection was completed by antituberculous treatment for 9 months. The patient presents a good general condition with normal renal function and normal intestinal transit with a follow-up of 19 months.

Aged↗

PubMed1999

[Survey of combined spinal-epidural anesthesia in Japan--analysis of questionnaire from 148 hospitals].

Combined spinal-epidural anesthesia (CSEA) offers theoretic advantages especially for lower abdominal and limb surgery, because it produces the rapid onset of anesthesia and the proper muscle relaxation, with the option to extend the blockade with an epidural catheter. Whereas it is not known whether this anesthetic method is commonly used in clinical practice in Japan. We analyzed questionnaires on CSEA obtained form 148 hospitals. It was revealed that most anesthesiologists in Japan preferred general anesthesia with epidural block for lower abdominal surgery to CSEA. For lower limb surgery longer than 2 hrs, CSEA was employed in 57 hospitals (39%). CSEA was mainly used for orthopedics, obstetrics and gynecology and urology. Double needle double interspace method was commonly used rather than needle through needle method. In general, CSEA was not a widely performed anesthetic technic in Japan. CSEA should contribute to reduction of the incidence of postoperative nausea and vomiting caused by general anesthetics, and produce pre-emptive analgesia. We hope CSEA to be a common anesthetic procedure, although some disadvantages exist in training system for junior staff, national health insurance scheme and available local anesthetics in Japan.

Abdomen↗

PubMed1999

[Squamous cell carcinoma in an augmentation of the ilial bladder for tuberculosis].

The development of cancer on the ileal graft after augmentation ileocystoplasty benign bladder disease is a little known complication. The authors report a case of squamous cell carcinoma in the ileal bladder occurring 31 years after augmentation ileocystoplasty for tuberculous bladder, in a 60-year-old patient. The ileal bladder was resected and a new augmentation ileocystoplasty was performed. The postoperative course was uneventful. Histological examination of the operative specimen showed infiltration of all of the intestinal wall. The patient died one year after, in a context of peritoneal carcinomatosis.

Carcinoma, Squamous Cell↗

PubMed1999

Synthesis of Giant Zeolite Crystals by a Bulk-Material Dissolution Technique.

Using a quartz glass tube as a bulk silica source under aqueous hydrothermal conditions afforded giant crystals of MFI zeolite about 3 mm in size (see photo). Similar procedures were successfully applied to bulk aluminosilicate ceramics to synthesize large crystals of other zeolites, such as ANA, JBW, CAN, and SOD.

Journal Article↗

PubMed1999

[Propofol anesthesia for a patient with congenital myotonic dystrophy].

We report the anesthetic management for a five year old boy with congenital myotonic dystrophy. The patient was scheduled for bilateral orchiopexy under general anesthesia. Anesthesia was induced with fentanyl 50 micrograms, vecuronium 0.6 mg and propofol 40 mg intravenously to facilitate tracheal intubation. During operation, we monitored train of four ratio (TOF) to confirm effect of muscle relaxation. Anesthesia was maintained with propofol (2 mg.kg-1.hr-1), nitrous oxide and caudal block. At the end of the operation, the patient recovered smoothly from anesthesia and post-operative course was uneventful. Congenital myotonic dystrophy presents many problems for the management of general anesthesia, because of respiratory or circulatory complications. In this case, we were careful not to use drugs which may cause respiratory or circulatory depression. We have demonstrated that anesthesia with propofol is a safe method for the anesthetic management of a patient with this disease.

Anesthesia, General↗

PubMed1999

Transplacental exposure to antipsychotic drugs during pregnancy and megacystis in the fetus.

Urinary retention is an adverse effect of antipsychotic drugs that has not been previously reported in the fetus. We have diagnosed megacystis in a fetus possibly caused by transplacental exposure to the antipsychotic drugs being administered to the mother. Two weeks after the mother stopped taking the drugs, the size of the enlarged fetal urinary bladder returned to normal. Sonographic examination of the neonate revealed an anatomically normal urinary tract, with a normal bladder capacity and urination.

Adult↗

PubMed1999

[Cooperative study of intraarterial preventive chemotherapy after resection of hepatic metastasis from colorectal cancer].

This is a compilation of the results of preventive intraarterial infusion following resection of hepatic metastasis from colorectal cancer at four surgical centers. The cases studied included two groups: A) 76 patients who underwent normal liver resection only, and B) 78 patients who underwent resection with adjuvant chemotherapy. Methods included: 1) WHF, 50 cases; 2) other methods using 5-FU, 18 cases; and 3) intraarterial infusions other than 5-FU, 10 (2 cases, outcome unknown). Survival rates for groups A and B for 1 and 5 years were 71.2, 18.9% and 91.5, 56.2%, respectively, with the rates for the intraarterial infusion group showing far better results. The 1- and 5-year survival rates in terms of infusion methods were: 1) 90.7% and 64.6%; 2) 94.4% and 39.3%; and 3) 90% and 60%, respectively, showing no remarkable differences between methods. Total doses of 5-FU were (a) less than 5 g, 7 patients (b) 5-15 g, 16 patients (c) 15-30 g, 22 patients (d) greater than 30 g, 23 patients. A comparison of 1- and 5-year survival rates shows (a) 85.7% and 17.1%; (b) 66.5% and 44.3%; (c) 100% and 62.7%; (d) 100% and 66.5%, respectively, with doses (c) and (d) showing markedly better results than the (a) dosage. From this we conclude that the group undergoing intraarterial hepatic infusion had a markedly improved prognosis compared to the group not undergoing any type of adjuvant therapy. Also, groups receiving a dosage of 15 g or greater of 5-FU showed prolonged survival rates.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1999

Autosomal recessive hydrocephalus due to congenital stenosis of the aqueduct of sylvius.

Isolated hydrocephalus due to congenital stenosis of the aqueduct of Sylvius is almost always an X-linked recessive inherited condition. We describe a brother and sister with isolated hydrocephalus from congenital aqueductal stenosis. We believe that these two occurrences represent a rare autosomal recessive form of this abnormality. In assessing a first known occurrence of hydrocephalus with stenosis of the aqueduct of Sylvius in a family, the rare possibility of autosomal inheritance must be considered in genetic counselling.

Abortion, Therapeutic↗

PubMed1999

Inverse association between coffee drinking and serum uric acid concentrations in middle-aged Japanese males.

Consumption of caffeine-rich beverages, which have diuretic properties, may decrease serum uric acid concentrations. We examined cross-sectionally the relationship of coffee and green tea consumption to serum uric acid concentrations in 2240 male self-defence officials who received a pre-retirement health examination at four hospitals of the Self-Defence Forces between 1993 and 1994. The mean levels of coffee and green tea consumption were 2.3 and 3.1 cups/d respectively. There was a clear inverse relationship between coffee consumption and serum uric acid concentration. When adjusted for hospital only, those consuming less than one cup of coffee daily had a mean serum uric acid concentration of 60 mg/l, while that of those drinking five or more cups of coffee daily was 56 mg/l (P < 0.0001). No such relationship was observed for green tea, another major dietary source of caffeine in Japan. The relationship between coffee consumption and serum uric acid concentration was independent of age, rank in the Self-Defence Forces, BMI, systolic blood pressure, serum creatinine, serum total cholesterol and serum HDL-cholesterol concentrations, smoking status, alcohol use, beer consumption and intake of dairy products. These findings suggest that coffee drinking may be associated with lower concentrations of serum uric acid, and further studies are needed to confirm the association.

Alcohol Drinking↗

PubMed1998

Construction, propagation, and titer estimation of recombinant adenoviruses carrying proapoptotic genes.

Generation of a recombinant adenovirus (Adv) that induces the constitutive expression of an apoptotic gene has been extremely difficult owing to severe apoptotic damage to the host cell. In this study, 293 cells were transduced with the caspase-inhibiting CrmA gene (293-CrmA cells), and used as host cells to generate Adv carrying apoptosis-inducing genes (proapoptotic genes). The 293-CrmA cells proved to be highly efficient for the construction of recombinant Adv carrying genes encoding Fas and Fas ligand. Moreover, the 293-CrmA line produced an ample quantity of these recombinant viruses. Because the conventional 293 plaque formation assay did not reflect the actual number of cells infected with the Adv carrying the proapoptotic gene, a determination of the Adv DNA copy number introduced into target cells was necessary to evaluate the quantity of infective virus. The techniques described here should be widely applicable for the construction of a recombinant Adv, in ample quantity, and for the estimation of the quantity of recombinant Adv produced.

Adenoviridae↗

PubMed1998

Lymphotactin gene-modified bone marrow dendritic cells act as more potent adjuvants for peptide delivery to induce specific antitumor immunity.

Dendritic cells (DC) are regarded as attractive candidates for cancer immunotherapy. Our aim is to improve the therapeutic efficacy of DC-based tumor vaccine by augmenting DC preferential chemotaxis on T cells. Mouse bone marrow-derived DC were transduced with lymphotactin (Lptn) gene by adenovirus vector. The supernatants from Lptn gene-modified DC (Lptn-DC) were capable of attracting CD4+ and CD8+ T cells in a chemotaxis assay, whereas their mock control could not. Lptn expression of Lptn-DC was further confirmed by RT-PCR. Lptn-DC were pulsed with Mut1 peptide and used for vaccination. Immunization with the low dose (1 x 10(4)) of Mut1 peptide-pulsed DC induced weak CTL activity, whereas the same amounts of Mut1 peptide-pulsed Lptn-DC markedly induced specific CTL against 3LL tumor cells. A single immunization with 1 x 10(4) Mut1 peptide-pulsed Lptn-DC could render mice resistant to a 5 x 10(5) 3LL tumor cell challenge completely, but their counterpart could not. The protective immunity induced by Mut1 peptide-pulsed Lptn-DC depends on both CD4+ T cells and CD8+ T cells rather than NK cells in the induction phase and depends on CD8+ T cells rather than CD4+ T cells and NK cells in the effector phase. Moreover, the involvement of CD28/CTLA4 costimulation pathway and IFN-gamma are also necessary. When 3LL tumor-bearing mice were treated with 1 x 10(4) Mut1 peptide-pulsed Lptn-DC, their pulmonary metastases were significantly reduced, whereas the same low dose of Mut1 peptide-pulsed DC had no obvious therapeutic effects. Our data suggest that Lptn-DC are more potent adjuvants for peptide delivery to induce protective and therapeutic antitumor immunity.

Adenoviridae↗

PubMed1998

Generation of fiber-mutant recombinant adenoviruses for gene therapy of malignant glioma.

Recombinant adenovirus (Adv)-mediated gene transduction is a powerful technology for cancer gene therapy. In this article, we report the generation of a fiber-mutant Adv vector, using the Adv genomic DNA-terminal protein complex (DNA-TPC) cotransfection method. First, a fiber-mutant construct in a plasmid carrying the right-side two-thirds of the human adenovirus type 5 (Ad5) genome (pTR) was cotransfected with Ad5 DNA-TPC, yielding the recombinant Adv with the desired fiber mutation. The DNA-TPC from the mutant Adv was then utilized to produce a second-step recombinant Adv with an expression cassette in the place of E1. By this procedure, we generated a fiber mutant, F/K20, that has a linker and a stretch of 20 lysine residues added at the C terminus of the fiber. By using Adv carrying a reporter lacZ gene (AxCAZ2) with either F/K20 or wild-type fiber (F/wt), we examined the transduction efficiency of F/K20-Adv. No significant difference in the transduction efficiency between F/K20 and F/wt-Adv was observed for a human fibroblast line, WI-38, or various tumor cell lines, including melanoma, prostate, esophageal, and pancreatic cancer lines. In clear contrast, F/K20-Adv showed a remarkably enhanced efficiency in genetic transduction of human glioma cells. In all four human glioma lines tested, the multiplicities of infection (MOIs) for transduction of 50% of the population (ED50) were decreased with F/K20-Adv compared with F/wt-Adv: 7-fold for T98G, 14-fold for U251, 9-fold for U373, and 42-fold for U87 cells. Therefore, we attempted to apply F/K20-Adv for gene therapy of malignant glioma. Glioma cells infected with F/K20-Adv carrying genes for interleukin 2 or interleukin 12 produced a high level of each cytokine at a much lower MOI than did cells infected with F/wt-Adv. Infection with F/K20-Adv carrying the wild-type p53 tumor suppressor gene resulted in an enhanced level of p53 protein expression and an increased incidence of F/K20-Adv in transduction efficiency for malignant glioma, providing promising tools for gene therapy.

Adenoviridae↗

PubMed1998

Local expression of immunoregulatory IL-12p40 gene prolonged syngeneic islet graft survival in diabetic NOD mice.

Local production of immunosuppressive cytokines will be one of the most suitable therapeutic strategies against organ-specific autoimmune diabetes. To establish such a new therapy, we constructed recombinant adenoviral vectors with inserted mIL-12p40 (Ad.IL-12p40) and mIL-10 (Ad.IL-10). Sufficient amounts of IL-12p40 and IL-10 were secreted by relevant adenovirus-transfected nonobese diabetic (NOD) islets. Shortly after transfection, 400 NOD islets transfected with Ad.IL-12p40 or Ad.IL-10 were transplanted under the renal capsule of a newly diabetic NOD mouse. NOD mice with IL-12p40-producing islet grafts kept normoglycemia in all of 14 grafted mice for over 4 wk after transplantation. In contrast, NOD mice with IL-10-producing islet grafts became diabetic in all of six grafted mice within 2 wk af-ter transplantation. Reverse transcription-PCR analysis revealed that local production of IL-12p40 led to the decrease of interferon-gamma and the augmentation of transforming growth factor-beta at the graft site. These results suggest that IL-12 plays an important role in the destruction of islet cells at the inflamed site of autoimmunity. Such a local blockade of IL-12 would be a useful gene therapy for human autoimmune diabetes.

Adenoviridae↗

PubMed1998

Apoptosis by retrovirus- and adenovirus-mediated gene transfer of Fas ligand to glioma cells: implications for gene therapy.

Astrocytic tumors frequently express Fas/APO-1 (Fas), in sharp contrast to surrounding normal brain cells, providing a potential window through which selective killing of tumor cells could be pursued. To assess this possibility, we transduced Fas into U251, a glioma cell line resistant to anti-Fas antibody-mediated apoptosis, and obtained transfectants with high levels of Fas expression. Anti-Fas antibody showed significantly enhanced cytotoxicity for the transfectants, suggesting that U251 cells maintained an intercellular cascade of Fas-mediated apoptosis. When U251 transfectants with high-level Fas expression were transduced with Fas ligand-encoding gene via retrovirus, they were unaffected by exposure to anti-Fas antibody or Fas ligand adenovirus (Adeno-FL). Thus, retroviral induction of Fas ligand into the glioma cells with high levels of Fas led to the selection of cells that were resistant to Fas-dependent apoptosis. These resistant U251 transfectants were susceptible to FADD adenovirus (Adeno-FADD)-induced apoptosis, indicating that a cascade of death signals was blocked at the steps between Fas ligand and FADD. As for adenoviral transduction of Fas ligand into gliomas, gliomas with a relatively high level of expression of Fas were remarkably sensitive to Adeno-FL-induced apoptosis. Besides, Adeno-FADD induced pronounced apoptosis in all glioma cells. Our data suggest the possibility of using adenovirus-mediated transduction of Fas ligand and FADD genes as a therapeutic approach to target gliomas.

Adenoviridae↗

PubMed1998

Cloning of inv, a gene that controls left/right asymmetry and kidney development.

Most vertebrate internal organs show a distinctive left/right asymmetry. The inv (inversion of embryonic turning) mutation in mice was created previously by random insertional mutagenesis; it produces both a constant reversal of left/right polarity (situs inversus) and cyst formation in the kidneys. Asymmetric expression patterns of the genes nodal and lefty are reversed in the inv mutant, indicating that inv may act early in left/right determination. Here we identify a new gene located at the inv locus. The encoded protein contains 15 consecutive repeats of an Ank/Swi6 motif at its amino terminus. Expression of the gene is the highest in the kidneys and liver among adult tissues, and is seen in presomite-stage embryos. Analysis of the transgenic genome and the structure of the candidate gene indicate that the candidate gene is the only gene that is disrupted in inv mutants. Transgenic introduction of a minigene encoding the candidate protein restores normal left/right asymmetry and kidney development in the inv mutant, confirming the identity of the candidate gene.

Amino Acid Sequence↗

PubMed1998

lefty-1 is required for left-right determination as a regulator of lefty-2 and nodal.

lefty-1, lefty-2, and nodal are expressed on the left side of developing mouse embryos and are implicated in left-right (L-R) determination. The role of lefty-1 was examined by analyzing mutant mice lacking this gene. The lefty-1-deficient mice showed a variety of L-R positional defects in visceral organs. Unexpectedly, however, the most common feature of lefty-1-/- mice was thoracic left isomerism (rather than right isomerism). The lack of lefty-1 resulted in bilateral expression of nodal, lefty-2, and Pitx2 (a homeobox gene normally expressed on the left side). These observations suggest that the role of lefty-1 is to restrict the expression of lefty-2 and nodal to the left side, and that lefty-2 or nodal encodes a signal for "leftness."

Animals↗

PubMed1998

Pitx2, a bicoid-type homeobox gene, is involved in a lefty-signaling pathway in determination of left-right asymmetry.

Signaling molecules such as Activin, Sonic hedgehog, Nodal, Lefty, and Vg1 have been found to be involved in determination of left-right (L-R) asymmetry in the chick, mouse, or frog. However, a common signaling pathway has not yet been identified in vertebrates. We report that Pitx2, a bicoid-type homeobox gene expressed asymmetrically in the left lateral plate mesoderm, may be involved in determination of L-R asymmetry in both mouse and chick. Since Pitx2 appears to be downstream of lefty-1 in the mouse pathway, we examined whether mouse Lefty proteins could affect the expression of Pitx2 in the chick. Our results indicate that a common pathway from lefty-1 to Pitx2 likely exists for determination of L-R asymmetry in vertebrates.

Animals↗