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Biomedical subjects

M Fukuzawa

Publications and source records attributed to M Fukuzawa.

At least 91 records · Page 5Linked to original sources
PubMed1996

In situ detection of DNA fragmentation and expression of bcl-2 in human neuroblastoma: relation to apoptosis and spontaneous regression.

UNLABELLED: Spontaneous regression occurs in some cases of neuroblastoma, especially stage IVS. The incidence of neuroblastoma has been reported to be increasing since the mass screening program was introduced in Japan. This would indicate that the screening is detecting regressing tumors. However, the mechanism of regression is still unknown. To evaluate the hypothesis that the regression might be related to apoptosis, the authors examined apoptosis by in situ end-labeling of fragmented DNA and expression of the apoptosis-suppressing protein bcl-2. MATERIALS AND METHODS: One hundred eighteen neuroblastoma cases were available for examination. Eighty (67.8%) were detected by the mass screening program. Serial sections were cut from paraffin-embedded tumors. A modified TdT-mediated dUTP nick end-labeling (TUNEL) method was performed to detect apoptosis. Immunohistochemical analysis was performed to detect bcl-2 expression. RESULTS: In cases under 1 year of age or with a favorable clinical stage, the incidence of apoptosis was significantly high. Expression of bcl-2 was associated with N-myc amplification and unfavorable histology (Shimada classification). Tumors in patients under 1 year of age often had areas where cellularity was markedly decreased, and apoptosis was often observed while bcl-2 expression was reduced. In such cases, there was a negative correlation between occurrence of apoptosis and bcl-2 expression. This suggests that apoptosis may be related to spontaneous regression in neuroblastoma.

Age Factors↗
PubMed1996

Molecular cloning and characterization of the cDNA for discoidin II of Dictyostelium discoideum.

By using monoclonal antibodies directed against discoidin II, we have isolated cDNA clones from axenically grown Ax-2 cells. One cDNA clone (D2) contained a 1.2-kb insert encoding the entire discoidin II protein, which is composed of 257 amino acid residues and has a calculated molecular mass of 28,574. The amino acid sequences, determined by Edman degradation of six tryptic peptides of discoidin II, were identical to those deduced from the cDNA sequence. The protein bears no resemblance to any proteins in the data banks, except that its sequence is 49% identical with the amino acid sequence of discoidin I. Discoidin II shares with discoidin I both a carbohydrate-binding site and an Art-Gly-Asp (RGD) sequence, which has been found in fibronectin in mammalian cells. With the onset of aggregation (8 h of development), a 1.3-kb discoidin II mRNA begins to accumulate. A similar pattern of regulation occurs at the protein level.

Amino Acid Sequence↗
PubMed1996

A case of von Recklinghausen's disease with bilateral pheochromocytoma-malignant peripheral nerve sheath tumors of the adrenal and gastrointestinal autonomic nerve tumors.

A 48-year-old man with neurofibromatosis type 1 presented with chest pain, paroxysmal hypertension, tachycardia, and progressive respiratory insufficiency. Clinical investigation displayed calcified tumors in the anterior mediastinum and pararenal region. Histological examination at autopsy revealed composite tumors consisting of pheochromocytoma and malignant peripheral nerve sheath tumor (MPNST) at two sites: the left adrenal gland and the region surrounding the inferior vena cava, probably corresponding to the right adrenal gland. The MPNST component showed a varied histological appearance, including hyalinized bands with polygonal cells, a cartilaginous and myxoid stroma, a hemangiopericytomatous architecture, and a fibrosarcomatous structure, which suggested osteosarcoma, chondrosarcoma, angiosarcoma, and fibrosarcoma, respectively. In addition, based on the ultrastructural findings, the gastrointestinal tract was involved with mesenchymal tumors showing neurogenic differentiation. These lesions suggest the divergent cellular differentiation of neural crest-derived cells to mesenchymal elements as well as neuroectodermal neoplasms.

Adrenal Gland Neoplasms↗
PubMed1996

Effectiveness of shakuyaku-kanzo-to in neuroleptic-induced hyperprolactinemia: a preliminary report.

We investigated the efficacy of Shakuyaku-kanzo-to (TJ-68) in neuroleptic-induced hyperprolactinemia in 11 treated schizophrenic patients. The mean plasma prolactin level decreased significantly from 28.9 +/- 14.5 ng/mL at baseline to 22.0 +/- 15.2 ng/mL at 4 weeks. Potassium levels did not change significantly. Neither the exacerbation of psychosis nor other adverse effects occurred.

Adult↗
PubMed1996

Inhibition of theophylline metabolism by aciclovir.

We report a case of side effects caused by the increase in plasma theophylline concentration after coadministration of aciclovir had been started during theophylline therapy. Interaction between theophylline and aciclovir has not previously been reported. Therefore, a study of the pharmacokinetic and metabolic interactions between theophylline and aciclovir was carried out in five healthy male volunteers. All subjects received a single oral dose of 320 mg theophylline (aminophylline, 400 mg) after they had taken oral aciclovir 800 mg five times daily for two consecutive days. The area under the curve from 0 to infinity of theophylline (AUC0-infinity) after coadministration of aciclovir was increased from 189.9 +/- 18.2 to 274.9 +/- 34.3 micrograms.h/ml (p < 0.01), and total body clearance was decreased from 28.4 +/- 2.9 to 19.8 +/- 2.5 ml/h/kg (p < 0.01). Further, there was a significant increase in urinary theophylline and decreases in urinary 1,3-dimethyluric acid and 1-methyluric acid after coadministration of aciclovir. The decrease in total body clearance is likely to have resulted from inhibition of metabolism via the oxidation pathway. The results indicated that with aciclovir therapy lower doses of theophylline might be necessary and careful monitoring of plasma concentrations was essential.

Acyclovir↗
PubMed1995

Unfavorable DNA ploidy and Ha-ras p21 findings in neuroblastomas detected through mass screening.

BACKGROUND: Urinary mass screening has been available for 6-month-old infants throughout Japan since 1985. It is still controversial as to whether the program contributes to the detection of unfavorable neuroblastomas destined to present clinically when a patient reaches an older age. DNA diploidy and tetraploidy, low expression of Ha-ras p21, and an amplified N-myc gene status relate to an unfavorable prognosis. The authors examined these biologic indicators in neuroblastomas detected by urinary mass screening. PATIENTS AND METHODS: Seventy-eight neuroblastomas detected by mass screening were studied for DNA ploidy using DNA flow cytometry, Ha-ras p21 expression using immunostaining, and N-myc gene copy number using slot-blot or Southern blot hybridization methods. RESULTS: Of 73 tumors with analyzable DNA flow cytometric results, 18 (24.7%) had diploidy (n = 7) or tetraploidy (n = 11). Twenty-eight (40.0%) of 70 tumors examined showed low-to-absent expression of Ha-ras p21. DNA diploid and tetraploid status correlated significantly with the low-to-absent expression of Ha-ras p21 (P = 0.00021). Fourteen (20.0%) of the 70 patients had both of these two unfavorable prognostic markers. N-myc amplification was not detected in 41 of 41 tumors studied. All 78 patients were alive 8-92 months after completion of treatment. CONCLUSIONS: At least 20.0% of neuroblastomas detected by mass screening have unfavorable biologic prognostic markers. These patients may benefit from early detection and immediate treatment. However, the biologic features associated with a poor prognosis are not predictive of poor outcome in individual patients, and, therefore, should not be used to justify more intensive therapies.

Aneuploidy↗
PubMed1995

Enhanced formation of isoamyl alcohol in Zygosaccharomyces rouxii due to elimination of feedback inhibition of alpha-isopropylmalate synthase.

Mutants of the 'miso' yeast, Zygosaccharomyces rouxii, that produced a large amount of isoamyl alcohol, an important flavour in miso fermentation, were isolated from 5,5,5-trifluoro-DL-leucine-resistant mutants, an analogue of L-leucine. One of the mutants, M21-10, produced a three-fold higher level of isoamyl alcohol than the wild-type strain MY21 in miso fermentation. The activity of alpha-isopropylamalate synthase, one of the enzymes used for L-leucine synthesis, in the mutant M21-10 was not inhibited by the addition of L-leucine, a feedback inhibitor.

2-Isopropylmalate Synthase↗
PubMed1995

Reduced expression of c-Fos in female NOD mouse thymocytes and up-regulation with human lymphotoxin.

Previously we reported that the administration of human (h) lymphotoxin (h-LT) markedly protected NOD mice from insulin-dependent diabetes mellitus (IDDM) partly by affecting the generation phase of anti-islet effector cells, probably in the thymus. In this study, we investigated the effect of h-LT on the signal transduction of the mouse thymocytes by observing c-Fos expression in the thymocytes by using a flow cytometer. The intensity of c-Fos expression in whole thymocytes was significantly lower in the female NOD with a high incidence of diabetes than that in the male NOD mice with a low incidence of diabetes and than that in normal mice (P < 0.0001). The low c-Fos expression in the female NOD thymocytes was most prominent in CD3low thymocytes. c-Jun expression of the CD3low thymocytes was also lower in the female NOD mice. Administrations of h-LT, h-TNF, and h-IL-2, which has been reported to prevent IDDM in NOD mice by systemic administration, significantly up-regulated c-Fos expression in CD3low thymocytes. From these results, it is assumed that a relationship may exist between the high diabetes incidence and the defective c-Fos expression in female NOD mice and between the prevention of IDDM and the amelioration of the defective c-Fos expression with h-LT in female NOD mice.

Animals↗
PubMed1995

Analysis of action mechanism of lymphotoxin in prevention of cyclophosphamide-induced diabetes in NOD mice.

Recently we reported that lymphotoxin (LT) administration protected non-obese diabetic (NOD) mice and BB rats from insulin-dependent diabetes mellitus. In this study we analysed the protection mechanism of LT by using cyclophosphamide (CY)-induced autoimmune diabetes in NOD mice. Pre-administration of 500 or 1000 U of LT three times a week between the age of 4 and 11-13 weeks before CY-treatment strongly inhibited CY-induced diabetes. This inhibition was reproduced by LT pre-administration at an earlier age (4 to 7 weeks) but not at a later age (8 to 11 or 10 to 12 wks). LT post-administration (100 U daily or 500 U twice a week) after CY-treatment at 14 weeks of age also strongly inhibited CY-induced diabetes. Spleen cell transfer was carried out using various combinations of donors and recipients. Spleen cell transfer from the non-diabetic mice, which were LT pre-administered between the age of 4 and 13 wks, to CY-treated mice did not significantly inhibit CY-induced diabetes, while transfer of the cells from the similarly treated mice to irradiated recipients did induce diabetes although the onset of diabetes was significantly delayed. Diabetes was not transferred by spleen cells from diabetic mice to LT pre-administered and CY-treated mice. LT administration did not change subpopulations and adhesion molecule expressions of the spleen lymphocyte. Taken together, these results suggest that LT protects NOD mice from CY-induced diabetes by making the mice resistant to autoimmune diabetes and possibly by suppressing anti-islet effector cells, but not by inducing adoptively transferable suppressor cells, although the precise mechanisms still remain to be elucidated.

Animals↗
PubMed1995

Improved detection of medically important fungi by immunoperoxidase staining with polyclonal antibodies.

This study was performed to identify pathological fungi of eight species [Aspergillus fumigatus, Candida albicans, Torulopsis (Candida) glabrata, Cryptococcus neoformans, Fusarium anthophilum, Rhizopus oryzae, Sporothrix schenckii and Trichosporon beigelii] in formalin-fixed, paraffin-embedded tissue sections by indirect immunoperoxidase staining. Mature albino rabbits were immunized with formalin-killed organisms. Antibodies were prepared by precipitation. Immunoperoxidase staining was applied to the paraffin-embedded tissue sections of experimentally infected mice and human autopsy and surgical specimens. Although the cell walls of each fungus stained clearly, many cross-reactivities appeared. However, it was possible to obtain specificity for the eight species by absorption and dilution of the antisera.

Animals↗
PubMed1995

Immunohistochemical analysis of proliferating cell nuclear antigen expression in human neuroblastoma.

Proliferative cell nuclear antigen (PCNA) is a cell-cycle-related nuclear protein that is maximally elevated in late G1 and S phase of proliferating cells. In this study, PCNA was identified immunohistochemically using paraffin section in 67 human neuroblastomas. Percentage of the PCNA-positive nuclei (PCNA index: PCI) ranged from 0% to 75%. There were significant relations between the PCNA expression and mitotic karyorrhexis index (MKI), histological classification, cell concentration, tumor weight, clinical stage, local invasion, lymph node metastasis, liver metastasis, or DNA ploidy. PCI was significantly low in patients who received aggressive chemotherapy before surgery. Patients with PCI higher than 30% showed a worse survival rate compared with those with PCI lower than 10% (P < .01). High PCI significantly related with poor survival, so that PCI may be an independent prognostic factor in neuroblastoma. Although further studies are required, PCNA immunostaining may be useful for assessing proliferating activity and for providing prognostic information in human neuroblastoma.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1995

Purification and characterization of a lipase from Aspergillus oryzae.

A lipase from Aspergillus oryzae was purified by ammonium sulfate fractionation, anion exchange chromatography, hydrophobic interaction chromatography, and anion exchange chromatography. The purified enzyme was a monomeric protein with a molecular mass of 41 kDa estimated by SDS-PAGE and 39 kDa by gel filtration. The optimum pH at 30 degrees C and optimum temperature at pH 7.0 were 7.0 and 30 degrees C, respectively. The enzyme was stable over a pH range of 6-9 at 25 degrees C for 18 h, and up to 30 degrees C at pH 7.0 for 3 h. Ag+, Fe3+, Hg2+, Cu2+, and Zn2+ inhibited the enzyme activity severely. The enzyme was a lipase that hydrolyzed monoacylglycerols and diacylglycerols, but did not hydrolyze triacylglycerols. The N-terminal amino acid sequence of the enzyme was highly homologous with that of the mono- and diacylglycerol lipase from Penicillium camembertii U-150.

Amino Acid Sequence↗
PubMed1994

Low frequency of the p53 gene mutations in neuroblastoma.

BACKGROUND: The p53 gene frequently is affected by point mutations, rearrangements, or deletions that contribute to the genesis or progression of a wide variety of human adult solid tumors; however, to the authors' knowledge, this gene alteration has not been analyzed in neuroblastoma. METHODS: Genomic DNA samples from 20 children with neuroblastoma, including 16 patients with advanced disease, were screened for the presence of mutations in exons 5-9 of the p53 gene, where over 90% of mutations have been reported to be located in human cancer. The screening technique employed polymerase chain reaction/single-strand conformation polymorphism analysis followed by direct DNA sequencing. RESULTS: Heterozygous mutations were detected in 2 of the 20 cases. A silent mutation (T to G transversion) at codon 172 and a missense mutation (G to T transversion) at codon 259 were found in patients with Stage II and Stage IV disease, respectively. Thus, p53 mutations were found to occur in neuroblastoma, but at a low frequency (2 of 20). CONCLUSIONS: Our data suggest that in a minority of neuroblastomas, p53 gene mutations may play a contributing role in tumorigenesis, but other genes presumably play a major role in this tumor.

Child↗
PubMed1994

Inhibition with N-acetylcysteine of enhanced production of tumor necrosis factor in streptozotocin-induced diabetic rats.

We previously reported that the in vivo production of the tumor necrosis factor alpha (TNF) was significantly enhanced after the onset of diabetes in spontaneous type 1 and 2 diabetic animals. In this report we confirmed the enhanced production of TNF in streptozotocin (STZ)-induced diabetes and then attempted to suppress the enhanced TNF production with N-acetylcysteine (NAC), a precursor of glutathione synthesis. The lipopolysaccharide-induced serum TNF activities were significantly enhanced in STZ-induced diabetic rats (6-18 weeks of age) compared with those of nondiabetic rats throughout the 12-week experiment. A single, oral administration of NAC (200 or 1000 mg/kg body wt) significantly suppressed the enhanced TNF production in the diabetic rats compared with that in untreated rats in a dose-dependent manner. On the other hand, in the long-term (6 or 12 weeks) administrations, smaller doses of NAC (50 or 200 mg/kg/day) also significantly inhibited the enhanced production of TNF regardless of the dose of NAC. NAC administration, however, did not suppress the TNF production of nondiabetic rats. The long-term NAC administration affected neither body weight nor levels of serum glucose, fructosamine, albumin, and triglyceride. These results show that NAC administration significantly suppressed the enhanced TNF production in diabetic rats and indicate that NAC might be useful in preventing TNF-mediated pathological conditions in diabetes.

Acetylcysteine↗
PubMed1994

The effect of donor-specific transfusion and cyclosporin A on small bowel transplantation in the rat.

Pre-transplant blood transfusions are given as a means of desensitization to reduce the required dose of cyclosporin A (CsA). In this study, the effect of pretransplant blood transfusion on host survival and T-cell function against alloantigen were investigated. Male Lewis rats (RT1(1)) were used as the recipients in all experiments, and male DA rats (RT1a) were used as the blood and small bowel donors, and as a source of allogeneic stimulator cells. Male BUF rats (RT1b) were used as donors of third party blood, and of allo-stimulator cells in a delayed-type hypersensitivity (DTH) response. In our experimental design, Lewis rats were divided into the following groups according to the type of administration: (1) a donor-specific blood transfusion (DST) 8 days preoperatively and a concurrent 5-day course of CsA at 10 mg/kg per day; (2) a nonspecific third party blood transfusion (NST) and CsA at 10 mg/kg per day from day 8 to day 4 preoperatively; (3) CsA alone from day 8 to day 4 preoperatively; (4) DST alone 8 days preoperatively; or (5) no treatment, being the control group. Postoperative treatment consisted of CsA at 2.5 mg/kg per day for 30 days. Rats conditioned with NST plus CsA, CsA alone, DST alone, and the untreated control rats survived for 7.2 +/- 1.2, 9.0 +/- 2.2, 6.8 +/- 0.4, and 7.4 +/- 1.6 days, respectively. In contrast, the five rats conditioned with DST plus CsA survived for 100 days or more.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

DNA flow cytometric analysis of neuroblastoma: distinction of tetraploidy subset.

Neuroblastoma has several characteristics that differentiate it from other adult malignancies. The ploidy pattern of neuroblastoma has been shown to be related to prognosis. Specifically, a DNA diploidy pattern is associated with a poorer outcome, and an aneuploidy pattern is associated with a better outcome. A tetraploidy pattern has also been identified; however, there is little information regarding this pattern. To examine the properties of neuroblastoma according to these DNA ploidy patterns, the authors performed flow cytometric analysis (retrospectively) for 61 neuroblastoma cases, using paraffin-embedded tissues. Fifty-six of the cases had analyzable results. Calculated DNA indices (DI) ranged from 1.0 to 2.30. The 56 cases were divided into three groups according to DI: diploid (DI = 1.0 to 1.17, n = 19), aneuploid (DI = 1.25 to 1.75, n = 26), and tetraploid (DI = 1.81 to 2.30, n = 11) groups. Compared with the aneuploid group, the diploid group had a stronger correlation with older patient age (> or = 1 year) (P < .01), more advanced clinical stage (III, IV) (P < .01), and poorer prognosis (P < .001). The tetraploid group had properties that were statistically similar to those of the diploid group (P < .05, P < .05, P < .001, respectively). These findings indicate that a subset of DNA tetraploid is present in neuroblastoma, and this subset, which may have clinical and biological characteristics similar to those of the DNA diploid group, should be distinguished from DNA aneuploidy.

Aneuploidy↗