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Biomedical subjects

Y Kondo

Publications and source records attributed to Y Kondo.

At least 235 records · Page 13Linked to original sources
PubMed1998

Allelic loss of chromosome 13q14.3 in human oral cancer: correlation with lymph node metastasis.

To evaluate the role of chromosome 13 deletions in oral squamous cell carcinoma (SCC) progression and to define the precise localization of putative tumor suppressor genes, we studied tumors from 34 unrelated patients with oral SCC by the polymerase chain reaction (PCR)-loss of heterozygosity (LOH) assay, using 18 different polymorphic loci. Chromosome 13q allelic losses (LOH) were observed in 67.6% at 1 or more loci. These results enabled the identification of a putative minimal region of deletion mapped at 13q14.3. The commonly deleted region is located close, but telomeric to the RB1 locus. We also examined the same samples for inactivation of the RB1 gene by immunohistochemical analysis of paraffin-embedded samples, but no significant variation in RB protein expression was detected. In addition, we also performed PCR-single-strand conformational polymorphism (SSCP) analysis to detect any mutation of the RB1 gene using 52 primer pairs, which covers all exons of this gene. We found no mutations of the RB1 gene in our samples. Interestingly, we found significant correlation between LOH of 13q14.3 and lymph node metastasis. Our results indicate that LOH of 13q is a common event in oncogenesis and/or progression of oral SCC, and also suggest the existence of a new suppressor gene near D13S273-D13S176 loci which may play a role in these events.

Carcinoma, Squamous Cell↗
PubMed1998

FADD gene therapy for malignant gliomas in vitro and in vivo.

Fas/APO-1 (CD95), a cell surface cytokine receptor, triggers apoptotic cell death by specific agonist antibody, suggesting that Fas/APO-1 may be a promising target for treatment of tumors. In this study, we show that treatment with anti-Fas antibody effectively induced apoptosis in malignant glioma cell lines with high expression of Fas/APO-1 (n = 3). Malignant glioma cells with low or undetectable expression of Fas/APO-1 (n = 6), however, were resistant to Fas/APO-1-dependent cytotoxicity. The purpose of this study, therefore, was to determine whether resistant tumors could be made susceptible to apoptosis. FADD/MORT1 constitutes a novel protein that associates specifically with the cytoplasmic death domain of Fas/APO-1 and induces apoptosis. We investigated whether overexpression of FADD would induce apoptosis in malignant glioma cells without activating Fas/APO-1. Results indicated that about 85% of malignant glioma cells, regardless of Fas/APO-1 expression levels, underwent apoptosis after transient transfection with FADD expression vector. To further improve gene transfer of FADD into malignant glioma cells, we constructed a retroviral vector containing the FADD gene. The retroviral transfer of FADD gene significantly enhanced the transduction efficiency and effectively inhibited both in vitro and in vivo survival of malignant glioma cells through induction of apoptosis. These findings suggest that the FADD gene is a novel and useful tool for the treatment of malignant gliomas.

Adaptor Proteins, Signal Transducing↗
PubMed1998

Hovetrichosides C-G, five new glycosides of two auronols, two neolignans, and a phenylpropanoid from the bark of Hovenia trichocarea.

Two 2-hydroxy-2-benzylcoumaranone glycosides, 2,4, 6-trihydroxy-2-[(4'-hydroxyphenyl) methyl]-3(2H)-benzofuranone-4-yl-beta-D-glucopyranoside (maesopsin 4-O-glucoside) (1) and 2,4,6-trihydroxy-2-[(4'-hydroxyphenyl) methyl]-3(2H)-benzofuranone-4-yl-beta-D-glucopyranosido-4'-y l-alpha-L -rhamnopyranoside (maesopsin 4-O-glucosido 4'-O-rhamnoside) (2), two neolignan glycosides, 2R-(E)-2, 3-dihydro-2-(4'-hydroxy-3'-methoxylphenyl)-5-(3"-hydroxy-1"-pro pen yl) -7-methoxy-3-benzofuranmethanol-4'-yl-beta-D-glucopyranosyl-(1-->3 )-[ beta-D-glucopyranosyl-(l-->2)]-beta-d-glucopyranoside (3) and (threo) 1-(4'-hydroxy-3'-methoxy)-2-(4"-hydroxymethyl-2", 6"-dimethoxyphenoxy)-propane-1,3-diol-4'-yl-beta-d-glucopynosid e (4), and a phenylpropanoid glycoside, 3-methoxy-5-(2'-propenyl)-1, 2-benzenediol-1-yl-beta-D-apiofuranosyl-(1-->6)-beta-D- glucopyransodie (5) were isolated from the bark of Hovenia trichocarea. Compounds 1-5 were named hovetricosides C-G, respectively, and their structures were established by extensive NMR experiments and chemical methods. Also obtained in this investigation were the known compounds acanthoside B, kelampayoside A, shashenoside I, and 3,4, 5-trimethoxyphenol-1-O-beta-D-xylopyranosyl-(1-->6)-beta-D- glucopyranoside.

Carbohydrate Sequence↗
PubMed1998

Targeted therapy of human malignant glioma in a mouse model by 2-5A antisense directed against telomerase RNA.

Telomerase is the RNA-protein complex which elongates telomeric DNA (TTAGGG)n and appears to play an important role in cellular immortalization. The almost exclusive expression of telomerase in tumor cells, and not in most normal cells, offers an exciting opportunity for therapy by inhibiting its function. Here, we have investigated the effect of inhibition of telomerase on the growth and survival of human malignant glioma cells in vitro and in vivo by using a 19-mer antisense oligonucleotide against human telomerase RNA linked to a 2',5'-oligoadenylate (2-5A). 2-5A antisense functions by activating the endoribonuclease, RNase L, resulting in the degradation of single stranded, targeted RNA. We have shown that the 2-5A antisense treatment effectively suppressed tumor cell growth and survival in vitro. Furthermore, treatment of tumors grown in nude mice with the antisense oligonucleotide inhibited survival of the tumor cells. TUNEL assays suggest that this effect is mediated through the induction of apoptosis. Targeting telomerase RNA with 2-5A antisense, therefore, may represent an effective and novel approach for treatment of a broad range of cancers.

Animals↗
PubMed1998

Effect of intestinal Lactobacillus starter cultures on the behaviour of Staphylococcus aureus in fermented sausage.

The effects of Lactobacillus strains isolated from intestinal tracts for starter cultures of fermented sausage on the growth rate and enterotoxin production of Staphylococcus aureus were studied at two fermentation temperatures of 20 degrees C and 35 degrees C. Initial inoculated populations in the sausage batter were approx. 10(4) cfu/g for S. aureus and 10(7) cfu/g for the Lactobacillus strain as a starter culture. Samples of sausage were taken during fermentation and analyzed for pH and microbial populations. In control lots without inoculation of Lactobacillus strains, staphylococcal enterotoxin was detected during fermentation at each temperature. Of three intestinal Lactobacillus strains, L. rhamnosus FERM P-15120 and L. paracasei subsp. paracasei FERM P-15121 inhibited the growth and enterotoxin production of S. aureus in sausages during fermentation at both temperatures, although L. acidophilus FERM P-15119 could not satisfactorily suppress them. The effect of the two selected strains in meat fermentation (i.e., fermentation time, acid production, inhibition of S. aureus) was the same as that of a commercial L. sake starter culture for fermented sausage. These results suggest the intestinal Lactobacillus strains selected in this study could be utilized as a starter culture to produce new fermented meat products that are microbiologically safe.

Colony Count, Microbial↗
PubMed1998

Inhibition of telomerase increases the susceptibility of human malignant glioblastoma cells to cisplatin-induced apoptosis.

Malignant glioblastomas grow very rapidly and are generally resistant to either DNA-damaging drugs or gamma-irradiation. If tumor cells could be made more susceptible to cell death with treatments, this would clearly represent a significant improvement in the success of treatment. Recently, telomerase has become a focus of interest among oncologists as a target for treating cancer cells. Telomerase elongates telomeric DNA repeats (TTAGGG)n and is important in protecting and replicating DNA. The vast majority of tumor cells, indeed, express telomerase activity whereas normal somatic cells, except for a few cells, do not. Since telomerase is essential for protecting DNA, we may be able to make tumors more sensitive to treatments with DNA-damaging drugs by inhibiting telomerase activity. In this study, we used cis-diamminedichloroplatinum (cisplatin)-sensitive U87-MG cells and cisplatin-resistant U251-MG of human malignant glioblastoma cell lines. U87-MG cells did not express telomerase activity, whereas telomerase was highly detected in U251-MG cells. Interestingly, inhibition of telomerase with an antisense telomerase expression vector not only decreased telomerase activity but also increased susceptibility to cisplatin-induced apoptotic cell death in U251-MG cells. These findings suggest that treatment with antisense telomerase may represent a new chemosensitisation for tumors resistant to anticancer drugs.

Apoptosis↗
PubMed1998

Indomethacin inhibits delayed DNA fragmentation of hippocampal CA1 pyramidal neurons after transient forebrain ischemia in gerbils.

Recent studies have shown a close association between reactive oxygen species and DNA fragmentation and that delayed neuronal death after transient forebrain ischemia manifests as DNA fragmentation-like apoptosis. We examined the effect of indomethacin on ischemic-induced delayed hippocampal neuronal death in gerbils using the TUNEL staining method, since indomethacin is neuroprotective in a variety of degenerative processes, such as Alzheimer's disease. Indomethacin (5 mg/kg, i.p.), administered 5 min before the ischemic insult, significantly decreased the number of TUNEL-positive hippocampal CA1 pyramidal neurons and delayed the appearance of TUNEL-positive neurons. Our results indicate that indomethacin is effective in inhibiting DNA fragmentation after transient forebrain ischemia.

Animals↗
PubMed1998

Pergolide scavenges both hydroxyl and nitric oxide free radicals in vitro and inhibits lipid peroxidation in different regions of the rat brain.

The free radical hypothesis for the pathogenesis and/or progression of Parkinson's disease (PD) has gained wide acceptance in recent years. Although it is clear that dopamine (DA) agonists cannot completely replace levodopa therapy, they can be beneficial early in the course of PD by reducing the accumulation of DA which undergoes auto-oxidation and generates cytotoxic free radicals. In the present study we demonstrate that pergolide, a widely used DA agonist, has free radical scavenging and antioxidant activities. Using a direct detection system for nitric oxide radical (NO.) by electron spin resonance (ESR) spectrometry in an in vitro .NO-generating system, we examined the quenching effects of pergolide on the amount of NO. generated. Pergolide dose-dependently scavenged NO.. In the competition assay, the IC50 value for pergolide was estimated to be about 30 microM. Pergolide also dose-dependently attenuated the hydroxyl radical (.OH) signal in an in vitro FeSO4-H2O2 ESR system with an approximate IC50 value of 300 microM. Furthermore, this agent significantly inhibited phospholipid peroxidation of rat brain homogenates in in vitro experiments and after repeated administration (0.5 mg/kg/24 h, i.p. for 7 days). Our findings suggest a neuroprotective role for pergolide on dopaminergic neurons due to its free radical scavenging and antioxidant properties.

Animals↗
PubMed1998

Growth dependency of a new human pancreatic cancer cell line, YAPC, on autocrine interleukin-1alpha stimulation.

We established a new human pancreatic cancer cell line from the malignant ascites of a patient with pancreatic cancer and called it YAPC. Cytogenetic and morphological analysis indicated that this cell line is monoclonal and of human origin. YAPC cells grow in nude mice, resulting in the formation of a tumor with some functional characteristics of the original tumor. The cells secreted a large amount of inflammatory cytokines including interleukin-1alpha(IL-1alpha), IL-6 and IL-8 in the culture medium. Removal of serum from the culture medium did not change the growth rate of YAPC cells, but the removal of the conditioned medium arrested their proliferation under the serum-free conditions. Exogenous IL-1alpha but neither IL-6 nor IL-8 stimulated DNA synthesis of the cells and accelerated the progress of cell cycle from G1 to the S phase. Anti-IL-1alpha antibody prevented growth of the cells in a dose-dependent fashion. In this pancreatic cancer cell line cell growth is dependent on IL-1alpha in an autocrine fashion. This line may be a useful model for studying growth regulation mechanisms of pancreatic cancer.

Adult↗
PubMed1998

Retroviral transfer of CPP32beta gene into malignant gliomas in vitro and in vivo.

Malignant gliomas are highly aggressive neoplasms that are very resistant to current therapeutic approaches, including irradiation, chemotherapy, and immunotherapy. To improve the prognosis, it is absolutely essential to explore novel modalities of treatment. Recently, we have demonstrated that interleukin 1beta-converting enzyme (ICE), a mammalian homologue of the Caenorhabditis elegans cell death gene ced-3, induces apoptotic cell death in malignant glioma cells. To date, ICE and ICE-like proteases (the ICE family), such as Ich-1L, CPP32beta, Mch2alpha, and Mch3alpha, have been shown to mediate apoptosis in some cells. The purpose of this study is to determine whether the ICE gene family functions as a useful tool for the treatment of malignant glioma cells through induction of apoptosis. The transient transfection assays showed that CPP32beta and Mch2alpha genes induced apoptotic cell death in malignant glioma cells more effectively than did the ICE, Ich-1L, and Mch3alpha genes. To improve the efficiency of gene transfer into malignant glioma cells, we constructed the retroviral vectors containing the ICE gene family. The retroviral transfer of CPP32beta or Mch2alpha gene effectively induced apoptosis in malignant glioma cells in vitro. Furthermore, treatment of tumors grown in mice with retrovirus containing CPP32beta significantly inhibited growth of the tumors through induction of apoptosis. The retroviral transfer of CPP32beta or Mch2alpha, therefore, may be a novel and promising approach for the treatment of malignant glioma, an invariably fatal tumor.

Animals↗
PubMed1998

African origin of GB virus C/hepatitis G virus.

Ninety-four GB virus C/hepatitis G virus (GBV-C/ HGV) RNA-positive serum samples were obtained from all over the world. We found that all 15 GBV-C/HGV isolates from the Pygmies and the Bantu in the Central African region had a 12-amino acid indel (i.e. insertion or deletion) in the non-structural protein (NS) 5A region. Phylogenetic analyses of the NS5A region, using GBV-A as an outgroup, showed that these 15 isolates had diverged from the common ancestor much earlier than the remaining isolates, indicating an African origin of GBV-C/HGV.

Africa↗
PubMed1998

Basal cell adenocarcinoma of the salivary glands: comparison with basal cell adenoma through assessment of cell proliferation, apoptosis, and expression of p53 and bcl-2.

BACKGROUND: Basal cell adenocarcinoma (BCAC) of the salivary gland is a rare tumor and recently described entity. Eleven cases of BCAC are presented here and compared with basal cell adenoma (BCA) through assessment of cell proliferative activity, apoptosis, and expression of p53, bcl-2, and epidermal growth factor receptor (EGFR) because these two tumors show close similarity in some cytologic and architectural characteristics. METHODS: Formalin fixed, paraffin embedded sections of 11 cases of BCAC and 9 cases of BCA, selected from the authors' files of 1851 primary tumors of the major salivary gland, were examined using immunostaining for Ki-67 (MIB-1), p53, bcl-2, and EGFR. In addition, apoptosis was determined by terminal deoxynucleotidyl transferase-mediated dUTP-digoxigenin nick end labeling. RESULTS: The incidence of BCAC was 0.6% among patients with major salivary gland tumors in the current series. Nine cases of BCAC arose in the parotid gland and two were of submandibular gland origin. Approximately 50% of the patients had recurrences, but no patient developed metastases or died of disease. Vascular involvement (75%), perineural invasion (36%), and necrosis (45%) were common features. Cell proliferative activity, including mitotic count, Ki-67 labeling index (LI), and apoptotic index were significantly higher in BCAC than BCA. More than four mitotic figures per ten high-power fields or a Ki-67 LI > 5% appeared to be limited to cases of BCAC. Considering those cases expressing p53 or EGFR in > 10% of tumor cells as positive, 6 of the 11 BCAC cases were positive for p53 and 3 were positive for EGFR. In contrast, all BCA cases were negative for p53 and EGFR. Although all cases of BCA were strongly positive for bcl-2 (> 50% of tumor cells), 3 of 11 cases of BCAC were completely negative. CONCLUSIONS: BCAC is a rare salivary gland tumor with a relatively high recurrence rate. Examination of cell proliferation, apoptosis, and expression of p53, bcl-2, and EGFR were found to be useful in distinguishing malignant basal cell tumors from their benign counterparts arising in the salivary gland.

Adenocarcinoma↗
PubMed1998

The therapeutic effect of hypertonic solutions on the changes in the effective circulating plasma volume in acute necrotizing pancreatitis in rats.

While hypovolemia or hypovolemic shock is dominant in the early stage of severe acute pancreatitis, there have been few studies on the effects of hypertonic solutions in the management of this disease. We conducted this study to evaluate the therapeutic effects of hypertonic saline solutions (HS) on the course of severe acute pancreatitis in rats. Pancreatitis was induced in male Wistar rats by injecting a 5% solution of sodium taurocholate into the biliopancreatic duct. The effective circulating plasma volume (ECPV) was measured using radioiodinated [125I]bovine serum albumin. Samples of blood and of ascitic fluid were obtained 3, 6, and 12 h after the onset of pancreatitis. Lactated Ringer's solution (LR) and HS were administered consecutively for 3 h beginning 3 h after the induction of pancreatitis. ECPV was measured 6 h after the onset of pancreatitis. The survival rates were investigated for up to 10 days. The mean ECPV decreased significantly from 24.9 +/- 1.1 ml/kg before disease onset to 11.5 +/- 1.3 ml/kg 6 h postoperatively. LR failed to achieve a normal value for ECPV even following a 150 ml/kg infusion. HS200 and HS300 restored the ECPV to the normal level, and with smaller volumes infused. All rats in the untreated group died within 3 days. LR and HS improved the survival rates, with the infusion of HS200, 100 ml/kg, thus attaining a 45% survival at 10 days.

Analysis of Variance↗
PubMed1998

Primary hyperparathyroidism and acute pancreatitis during pregnancy. Report of a case and a review of the English and Japanese literature.

The simultaneous occurrence of primary hyperparathyroidism (PHPT) and pancreatitis during pregnancy is very rare. We present a case of concurrent PHPT and pancreatitis in pregnancy and review 13 cases reported in the English and Japanese literature. Two maternal and three fetal deaths occurred. Mortality seemed to be related to delayed resection of the parathyroid tumor. Morphologically, severe pancreatitis was only seen in three cases, whereas even edematous or focal pancreatitis caused the same symptoms as clinically severe pancreatitis. Acute pancreatitis should be kept in mind in the differential diagnosis of unexplained nausea and abdominal pain during pregnancy, and hyper-or normocalcemia in the severe form of pancreatitis should be a clue to concurrent PHPT.

Acute Disease↗
PubMed1998

Gallbladder contraction in biliary atresia: a pitfall of ultrasound diagnosis.

In 3 (9 %) of 34 children with biliary atresia, US revealed gallbladder contraction following an oral feed, given on admission, but not with subsequent feeds. Surgery revealed a Kasai type IIIa biliary atresia with a patent communication between the gallbladder and duodenum. We propose that the bile ducts may initially have been patent, but then gradually became obliterated secondary to inflammation. These cases may explain the development of one type of biliary atresia.

Biliary Atresia↗
PubMed1998

Radiological and laboratory features of infantile cortical hyperostosis. A case report.

We describe a boy aged nine months with infantile cortical hyperostosis in association with cystic fibrosis. Symmetrical periosteal thickening was present in the clavicles, ribs, femora, humeri, ulnae and radii. Periosteal hyperostosis of the humerus developed in association with an increase in the levels of serum alkaline phosphatase a month before the appearance of hyperirritability and soft tissue swelling about the hip joints. The condition gradually resolved during the following eight months.

Alkaline Phosphatase↗