Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 255
Filter
1.
QJM ; 116(2): 141, 2023 02 24.
Article in English | MEDLINE | ID: mdl-36255263
2.
3.
J Laryngol Otol ; 135(9): 773-778, 2021 Sep.
Article in English | MEDLINE | ID: mdl-33928889

ABSTRACT

OBJECTIVE: Severe acute respiratory syndrome coronavirus-2 uses angiotensin-converting enzyme-2 as a primary receptor for invasion. This study investigated angiotensin-converting enzyme-2 expression in the sinonasal mucosa of patients with chronic rhinosinusitis, as this could be linked to a susceptibility to severe acute respiratory syndrome coronavirus-2 infection. METHODS: Ethmoid sinus specimens were obtained from 27 patients with eosinophilic chronic rhinosinusitis, 18 with non-eosinophilic chronic rhinosinusitis and 18 controls. The angiotensin-converting enzyme-2 and other inflammatory cytokine and chemokine messenger RNA levels were assessed by quantitative reverse transcription polymerase chain reaction. Angiotensin-converting enzyme-2 positive cells were examined immunohistologically. RESULTS: The eosinophilic chronic rhinosinusitis patients showed a significant decrease in angiotensin-converting enzyme-2 messenger RNA expression. In the chronic rhinosinusitis patients, angiotensin-converting enzyme-2 messenger RNA levels were positively correlated with tumour necrosis factor-α and interleukin-1ß (r = 0.4971 and r = 0.3082, respectively), and negatively correlated with eotaxin-3 (r = -0.2938). Angiotensin-converting enzyme-2 immunoreactivity was mainly localised in the ciliated epithelial cells. CONCLUSION: Eosinophilic chronic rhinosinusitis patients with type 2 inflammation showed decreased angiotensin-converting enzyme-2 expression in their sinus mucosa. Angiotensin-converting enzyme-2 regulation was positively related to pro-inflammatory cytokines, especially tumour necrosis factor-α production, in chronic rhinosinusitis patients.


Subject(s)
Angiotensin-Converting Enzyme 2/metabolism , Nasal Mucosa/enzymology , Rhinitis/enzymology , Sinusitis/enzymology , Adult , COVID-19/etiology , Chronic Disease , Cross-Sectional Studies , Female , Humans , Male , Middle Aged , Nasal Mucosa/metabolism , Nasal Mucosa/virology , Reverse Transcriptase Polymerase Chain Reaction , Rhinitis/complications , Rhinitis/metabolism , SARS-CoV-2/metabolism , Sinusitis/complications , Sinusitis/metabolism
4.
Ecotoxicol Environ Saf ; 160: 316-327, 2018 Sep 30.
Article in English | MEDLINE | ID: mdl-29857236

ABSTRACT

Environmental contaminant exposure can pose significant risks to human health. Therefore, evaluating the impact of this exposure is of great importance; however, it is often difficult because both the molecular mechanism of disease and the mode of action of the contaminants are complex. We used network biology techniques to quantitatively assess the impact of environmental contaminants on the human interactome and diseases with a particular focus on seven major contaminant categories: persistent organic pollutants (POPs), dioxins, polycyclic aromatic hydrocarbons (PAHs), pesticides, perfluorochemicals (PFCs), metals, and pharmaceutical and personal care products (PPCPs). We integrated publicly available data on toxicogenomics, the diseasome, protein-protein interactions (PPIs), and gene essentiality and found that a few contaminants were targeted to many genes, and a few genes were targeted by many contaminants. The contaminant targets were hub proteins in the human PPI network, whereas the target proteins in most categories did not contain abundant essential proteins. Generally, contaminant targets and disease-associated proteins were closely associated with the PPI network, and the closeness of the associations depended on the disease type and chemical category. Network biology techniques were used to identify environmental contaminants with broad effects on the human interactome and contaminant-sensitive biomarkers. Moreover, this method enabled us to quantify the relationship between environmental contaminants and human diseases, which was supported by epidemiological and experimental evidence. These methods and findings have facilitated the elucidation of the complex relationship between environmental exposure and adverse health outcomes.


Subject(s)
Environmental Pollutants/toxicity , Cosmetics/toxicity , Dioxins/toxicity , Disease , Drug-Related Side Effects and Adverse Reactions , Environmental Exposure , Humans , Hydrocarbons, Fluorinated/toxicity , Metals/toxicity , Pesticides/toxicity , Polycyclic Aromatic Hydrocarbons/toxicity , Protein Interaction Maps
5.
Diabet Med ; 34(4): 586-589, 2017 04.
Article in English | MEDLINE | ID: mdl-27859559

ABSTRACT

AIM: To examine the contribution of the FUT2 gene and ABO blood type to the development of Type 1 diabetes in Japanese children. METHODS: We analysed FUT2 variants and ABO genotypes in a total of 531 Japanese children diagnosed with Type 1 diabetes and 448 control subjects. The possible association of FUT2 variants and ABO genotypes with the onset of Type 1 diabetes was statistically examined. RESULTS: The se2 genotype (c.385A>T) of the FUT2 gene was found to confer susceptibility to Type 1A diabetes in a recessive effects model [odds ratio for se2/se2, 1.68 (95% CI 1.20-2.35); corrected P value = 0.0075]. CONCLUSIONS: The FUT2 gene contributed to the development of Type 1 diabetes in the present cohort of Japanese children.


Subject(s)
Diabetes Mellitus, Type 1/genetics , Fucosyltransferases/genetics , ABO Blood-Group System/genetics , Asian People/genetics , Case-Control Studies , Genetic Predisposition to Disease , Humans , Japan , Galactoside 2-alpha-L-fucosyltransferase
6.
Diabet Med ; 33(12): 1717-1722, 2016 12.
Article in English | MEDLINE | ID: mdl-27352912

ABSTRACT

AIMS: The aim of this study was to clarify the significance of previously reported susceptibility variants in the development of autoimmune Type 1 diabetes in non-white children. Tested variants included rs2290400, which has been linked to Type 1 diabetes only in one study on white people. Haplotypes at 17q12-q21 encompassing rs2290400 are known to determine the susceptibility of early-onset asthma by affecting the expression of flanking genes. METHODS: We genotyped 63 variants in 428 Japanese people with childhood-onset autoimmune Type 1 diabetes and 457 individuals without diabetes. Possible association between variants and age at diabetes onset was examined using age-specific quantitative trait locus analysis and ordered-subset regression analysis. RESULTS: Ten variants, including rs2290400 in GSDMB, were more frequent among the people with Type 1 diabetes than those without diabetes. Of these, rs689 in INS and rs231775 in CTLA4 yielded particularly high odds ratios of 5.58 (corrected P value 0.001; 95% CI 2.15-14.47) and 1.64 (corrected P value 5.3 × 10-5 ; 95% CI 1.34-2.01), respectively. Age-specific effects on diabetes susceptibility were suggested for rs2290400; heterozygosity of the risk alleles was associated with relatively early onset of diabetes, and the allele was linked to the phenotype exclusively in the subgroup of age at onset ≤ 5.0 years. CONCLUSIONS: The results indicate that rs2290400 in GSDMB and polymorphisms in INS and CTLA4 are associated with the risk of Type 1 diabetes in Japanese children. Importantly, cis-regulatory haplotypes at 17q12-q21 encompassing rs2290400 probably determine the risk of autoimmune Type 1 diabetes predominantly in early childhood.


Subject(s)
Chromosomes, Human, Pair 17/genetics , Diabetes Mellitus, Type 1/genetics , Haplotypes/genetics , Polymorphism, Single Nucleotide/genetics , Adolescent , Adult , Age of Onset , Aged , Alleles , Child , Child, Preschool , Female , Gene Frequency/genetics , Genetic Predisposition to Disease/genetics , Humans , Infant , Japan/ethnology , Male , Middle Aged , Young Adult
7.
J Perinatol ; 35(11): 965-9, 2015 Nov.
Article in English | MEDLINE | ID: mdl-26355942

ABSTRACT

OBJECTIVE: The aim of this study was to identify the best sedation/analgesia protocol for laser photocoagulation (PC) of retinopathy of prematurity (ROP). STUDY DESIGN: This multicenter observational study included five hospitals, each using a specific sedation/analgesia protocol: local anesthesia with oxybuprocaine hydrochloride (Group L); intravenous pentazocine (Group P); intravenous fentanyl (Group F); air, oxygen and sevoflurane (AOS) inhalation (Group I). The groups were compared for pain responses, vital signs and adverse events. RESULTS: Heart rates and systemic blood pressures were elevated by PC in Groups L and P and Groups L, P and F, respectively. Moreover, poor analgesic efficacy was recognized in Groups L, P and F. In contrast, Group I experienced hypothermia, enteral feeding intolerance and apnea more frequently. CONCLUSION: From the viewpoint of sedation/pain relief, AOS anesthesia should be the best protocol. However, considering all the various factors together, the most reasonable one can be varied based on the patient's condition and hospital.


Subject(s)
Conscious Sedation/methods , Infant, Premature , Light Coagulation/methods , Pain Measurement , Retinopathy of Prematurity/surgery , Administration, Inhalation , Cohort Studies , Female , Fentanyl/administration & dosage , Humans , Infant, Newborn , Infusions, Intravenous , Japan , Laser Therapy/methods , Male , Methyl Ethers/administration & dosage , Pentazocine/administration & dosage , Prospective Studies , Retinopathy of Prematurity/diagnosis , Risk Assessment , Severity of Illness Index , Sevoflurane , Treatment Outcome
8.
Int J STD AIDS ; 26(11): 821-30, 2015 Oct.
Article in English | MEDLINE | ID: mdl-25332224

ABSTRACT

A retrospective analysis of 86 HIV-1 vertically-infected Vietnamese children with a follow-up period >24 months after initiating antiretroviral therapy (ART) was performed from 2008 to 2012, to assess the outcome of first-line ART in resource-limited settings. Of the 86 children, 68 (79.1%) were treated successfully (plasma HIV-1 viral load [VL] <1000 copies/ml), and 63 (73.3%) had full viral suppression (VL <400 copies/ml) after 24 months of ART. No significant difference between successfully treated patients and failure groups was observed in VL, CD4(+) T-cell count or clinical stage at baseline; age at ART start; or ART regimen. All 14 children with VL >5000 copies/ml, one of four children with VL 1000-5000 copies/ml and none with VL <1000 copies/ml developed reverse transcriptase inhibitor (RTI)-resistance mutations by 24 months of ART. Y181C and M184V/I were the most dominant non-nucleoside and nucleoside RTI-resistance mutations, respectively (13/15, 86.7%). These findings suggest that VL testing after 24 months of ART can be used to efficiently differentiate ART failures among HIV-1 vertically-infected children in resource-limited settings.


Subject(s)
Anti-HIV Agents/therapeutic use , HIV Infections/drug therapy , HIV-1/drug effects , Reverse Transcriptase Inhibitors/therapeutic use , Viral Load/drug effects , CD4 Lymphocyte Count , Child , Child, Preschool , Drug Resistance, Viral , Female , Follow-Up Studies , Humans , Infant , Infectious Disease Transmission, Vertical , Male , Retrospective Studies , Treatment Failure , Treatment Outcome , Vietnam
9.
AJNR Am J Neuroradiol ; 35(11): 2136-9, 2014.
Article in English | MEDLINE | ID: mdl-24994831

ABSTRACT

BACKGROUND AND PURPOSE: The risk factors of early hemorrhagic complications after endovascular coiling are not well-known. We identified the factors affecting early hemorrhagic complications, defined as any expansion or appearance of hemorrhage shown by head CT in the initial 48 hours after coiling. MATERIALS AND METHODS: We retrospectively reviewed a series of 93 patients who underwent coiling for a ruptured saccular aneurysm between 2006 and 2012 at our hospital. RESULTS: Five patients showed early hemorrhagic complications, and all involved an expansion of the existing intracerebral hematoma immediately after coiling. The associated risk factors were accompanying intracerebral hemorrhage at onset (P < .001), postoperative antiplatelet therapy (P < .001), and thromboembolic complications (P = .044). In the accompanying intracerebral hemorrhage group, the associated risk factors were postoperative antiplatelet therapy (P = .044) and earlier initiation of coiling (9.8 ± 6.5 versus 28.1 ± 24.0 hours, P = .023). Early hemorrhagic complications were significant risk factors for worse clinical outcome (modified Rankin Scale, 2.02 ± 2.21 versus 4.4 ± 2.30, P = .022). None of the 93 patients showed further hemorrhage after the initial 48 hours after coiling. CONCLUSIONS: The accompanying intracerebral hemorrhage at onset, thromboembolic complications, postoperative antiplatelet therapy, and earlier initiation of coiling were the risk factors for early hemorrhagic complications.


Subject(s)
Aneurysm, Ruptured/therapy , Embolization, Therapeutic/adverse effects , Endovascular Procedures/adverse effects , Intracranial Aneurysm/surgery , Intracranial Aneurysm/therapy , Postoperative Complications/etiology , Adult , Aged , Blood Vessel Prosthesis , Cerebral Hemorrhage/epidemiology , Cerebral Hemorrhage/etiology , Embolization, Therapeutic/methods , Endovascular Procedures/instrumentation , Female , Hematoma/epidemiology , Hematoma/etiology , Humans , Male , Middle Aged , Postoperative Complications/epidemiology , Retrospective Studies , Risk Factors
10.
Neuropediatrics ; 41(6): 241-5, 2010 Dec.
Article in English | MEDLINE | ID: mdl-21445813

ABSTRACT

OBJECTIVE: Our aim was to clarify the relationship between amplitude-integrated electroencephalographic (aEEG) findings before 24 h of age in preterm infants and neurodevelopmental outcome. DESIGN: 12 infants born between 27 and 32 weeks of gestation were eligible. The recordings of aEEG and conventional EEG were started within 12 h after birth. The background aEEG findings were evaluated and classified. Additionally, we evaluated the absence or presence of changes on the lower border of the aEEG. RESULTS: All infants had discontinuous normal voltage background on aEEG, corresponding to decreased or normal continuity on conventional EEG. Cyclicity on aEEG was seen in 8 of 12 infants within 24 h of age, and all of these infants had favourable outcomes. Cyclicity on aEEG was not recognized in 4 infants. 3 of the 4 infants with absent cyclicity had abnormal neurodevelopmental outcomes at 12 months. One of these infants had intraventricular haemorrhage (grade 2) with delayed development, and 2 had cystic periventricular leukomalacia followed by spastic diplegia. CONCLUSION: Absent cyclicity on aEEG within 24 h of age was associated with poor outcome in preterm infants.


Subject(s)
Brain Injuries/physiopathology , Brain/physiopathology , Cerebral Hemorrhage/physiopathology , Infant, Premature/physiology , Leukomalacia, Periventricular/physiopathology , Electroencephalography , Gestational Age , Humans , Infant, Newborn
11.
Dig Liver Dis ; 39(5): 422-9, 2007 May.
Article in English | MEDLINE | ID: mdl-17379587

ABSTRACT

BACKGROUND: The effectiveness of leukocytapheresis against ulcerative colitis has been reported. However, the efficacy of this therapy for steroid-resistant ulcerative colitis patients has hardly been examined. AIMS: The aims of this study are to evaluate the efficacy of leukocytapheresis for steroid-resistant ulcerative colitis patients and to identify clinical factors that predict the efficacy of this therapy for these patients. METHODS: Clinical factors of 71 steroid-resistant ulcerative colitis patients who underwent leukocytapheresis analysed. RESULTS: Of those analysed, 53 (75%) patients showed an initial response to leukocytapheresis. Among cases with initial response, however, only 19 (27%) patients maintained remission for more than 6 months. Steroid-dependent course (Odds ratio =5.53, 95% confidence interval; 1.24-24.73) and a high C-reactive protein degree (Odds ratio=1.6, confidence interval; 1.09-2.35) were predictors of initial response to leukocytapheresis. Rapid response, which means remission induction within three leukocytapheresis sessions, was the only predictor of maintenance of remission for more than 6 months after successful leukocytapheresis therapy (odds ratio=8.01, confidence interval; 1.08-59.37). CONCLUSIONS: Leukocytapheresis was effective for steroid-resistant ulcerative colitis patients. However, relapse was frequently observed within short periods after the initial response to this therapy. Patients without a rapid response should be treated with alternative or additional therapies.


Subject(s)
Colitis, Ulcerative/therapy , Leukapheresis , Adolescent , Adult , Aged , Child , Female , Humans , Male , Middle Aged , Predictive Value of Tests , Steroids/therapeutic use , Treatment Outcome
12.
Chemotherapy ; 52(6): 271-8, 2006.
Article in English | MEDLINE | ID: mdl-16988503

ABSTRACT

BACKGROUND: AmBisome is a small unilamellar vesicle containing amphotericin B. AmBisome is generally unable to pass through the blood-brain barrier, but the distribution of AmBisome in the brain is increased by inflammation, and in consequence, AmBisome exhibits activity against fungal meningitis. We investigated the influence of the progression of cryptococcal meningitis on the brain penetration and efficacy of AmBisome. METHOD: Mice were infected intracerebroventricularly with Cryptococcus neoformans 4 h or 5 days prior to a single dose treatment. RESULTS: The brain tissue level and efficacy of AmBisome when administered 5 days after infection were greater than 4 h after infection. An immunohistochemical study showed that AmBisome-derived amphotericin B was localized at the infected site in the subarachnoid space. When AmBisome was compared with Fungizone at the maximum tolerated dose, 10 mg/kg AmBisome exhibited greater efficacy than 1 mg/kg Fungizone in both regimens. CONCLUSION: The brain penetration of AmBisome was enhanced by the progression of cryptococcal meningitis and correlated with the in vivo activity.


Subject(s)
Amphotericin B/pharmacology , Antifungal Agents/pharmacology , Brain/drug effects , Brain/pathology , Meningitis, Cryptococcal/drug therapy , Amphotericin B/administration & dosage , Amphotericin B/blood , Animals , Antifungal Agents/administration & dosage , Antifungal Agents/blood , Biomarkers/blood , Brain/metabolism , Brain/microbiology , Cryptococcus neoformans/drug effects , Cryptococcus neoformans/isolation & purification , Disease Models, Animal , Disease Progression , Immunohistochemistry , Male , Maximum Tolerated Dose , Meningitis, Cryptococcal/microbiology , Meningitis, Cryptococcal/mortality , Mice , Survival Analysis , Time Factors , Treatment Outcome
13.
Xenobiotica ; 33(1): 43-55, 2003 Jan.
Article in English | MEDLINE | ID: mdl-12519693

ABSTRACT

1. The use of everted sacs of the small intestine as an enzyme source for studying the metabolism of xenobiotics by cytochrome P450 (P450, CYP) enzymes and UDP-glucuronosyltransferases has been investigated. 2. Most of the drug oxidation activities for testosterone, bufuralol, ethoxyresorufin and 7-ethoxycoumarin resided in the upper part of the everted sacs and in intestinal microsomes. Testosterone 6 beta-hydroxylase activities in the everted sacs were about two times higher than those in the intestinal microsomes. By freezing and thawing treatment, the testosterone 6 beta- and 16 alpha-hydroxylase activities of the everted sacs were considerably decreased, and those of the intestinal microsomes were abolished. 3. Microsomal testosterone 6 beta-hydroxylation, bufuralol 1'-hydroxylation, and pentoxyresorufin and ethoxyresorufin O-dealkylation were inhibited by ketoconazole, quinine, metyrapone and alpha-naphthoflavone respectively. Immunoreactive proteins using anti-CYP2B1 and anti-CYP3A2 antibodies were detected in the upper and middle parts of the rat small intestine. 4. Except for morphine 3-glucuronidation, glucuronidation activities in intestinal microsomes or everted sacs were not dependent on the intestinal region. The lower part of the everted sacs exhibited about 10 times higher morphine-3-glucuronidation activities compared with those of the upper part. The glucuronidation activities of 4-nitrophenol in the everted sacs were 10 times higher than those in microsomes. 5. These results demonstrated that the upper part of rat small intestine serves as the major site for intestinal P450-mediated first-pass metabolism. CYP3A enzymes in rat intestinal microsomes may not be stable but probably play an important role in drug oxidations. The high activity of glucuronidation in the rat small intestine should also be considered in terms of drug metabolism.


Subject(s)
Cytochrome P-450 Enzyme System/metabolism , Glucuronosyltransferase/metabolism , Intestines/enzymology , Microsomes/enzymology , Pharmaceutical Preparations/metabolism , Adrenergic beta-Antagonists/metabolism , Animals , Catalysis , Cytochrome P-450 Enzyme Inhibitors , Enzyme Inhibitors/pharmacology , Ethanolamines/metabolism , Freezing , Glucuronides/metabolism , Glucuronosyltransferase/antagonists & inhibitors , Immunoblotting , Male , Microsomes, Liver/enzymology , Morphine/metabolism , Naphthols/metabolism , Nitrophenols/metabolism , Oxidation-Reduction , Rats , Rats, Wistar , Testosterone/metabolism , Xenobiotics/metabolism
14.
J Membr Biol ; 190(3): 189-96, 2002 Dec 01.
Article in English | MEDLINE | ID: mdl-12533784

ABSTRACT

Cyclic AMP evokes fluid secretion with bicarbonate in exocrine ducts. Clearance of fluorescent dyes from rat parotid intralobular ducts by forskolin was visualized as a fluorescence change in the duct luminal space by optical sectioning under a confocal laser scanning microscope to clarify the secretory function in the ducts. When the isolated rat parotid intralobular duct segments were superfused with membrane-impermeable fluorescent dyes during the experimental period, fluorescent dyes were passively moved into the duct space. Forskolin and isobutylmethylxanthine decreased the fluorescence of anionic dye, sulforhodamine B, and neutral dye, dextran tetramethyl-rhodamine, in the duct space, suggesting that the forskolin-induced clearance of fluorescent dyes might be the result of fluid secretion in the ducts. Methazolamide inhibited a forskolin-induced sustained decrease in duct fluorescence and intracellular acidification. Low concentrations of external Cl?, DIDS, bumetanide and amiloride did not markedly inhibit a forskolin-induced decrease in duct fluorescence. These findings suggest that a major portion of the steady decrease in duct fluorescence by forskolin was related to intracellular HCO3? production, not the uptake mechanism of external Cl?. Glibenclamide, NPPB, DPC and DMA inhibited the forskolin-induced decrease. Forskolin evokes the clearance of fluorescent dyes from duct space possibly due to fluid secretion in rat parotid ducts, associated with secretion through CFTR and DPC-sensitive anion channels of carbonic anhydrase-dependent bicarbonate linked with the Na+/H+ exchange mechanism.


Subject(s)
Bicarbonates/metabolism , Microscopy, Confocal/methods , Parotid Gland/cytology , Parotid Gland/metabolism , Rhodamines/pharmacokinetics , 1-Methyl-3-isobutylxanthine/pharmacology , Animals , Colforsin/pharmacology , Fluorescent Dyes/pharmacokinetics , In Vitro Techniques , Male , Metabolic Clearance Rate , Parotid Gland/drug effects , Rats , Rats, Wistar
16.
Bull Tokyo Dent Coll ; 42(1): 51-5, 2001 Feb.
Article in English | MEDLINE | ID: mdl-11484795

ABSTRACT

This case report describes an ameloblastic fibro-odontoma arising from a calcifying odontogenic cyst (COC) in the mandible of a twenty-three-year old male. The patient was referred to the Department of Oral Surgery, Tokyo Dental College, on March 30th, 2000, complaining of a painful swelling, which had appeared three weeks earlier on his left mandibular molar region. In a pathological view, the lesion was a round cyst the size of a chicken-egg, dark red in color, and surrounded by a thick membrane. The cyst had an epithelium of varying thickness which included many ghost cells and an enamel-like structure on the inside, and a thick wall of connective tissue with an ameloblastic fibro-odontoma on the outside. Enamel organ-like epithelial islands were structured radially in the form of strands with immature dentin. Cytokeratin 19 was strongly immunoreactive in the epithelium of the lesion; osteopontin and osteocalcin reacted in the mesenchymal cells and weakly in the epithelial element of this tumor.


Subject(s)
Mandibular Neoplasms/pathology , Neoplasms, Multiple Primary/pathology , Odontogenic Cyst, Calcifying/pathology , Odontoma/pathology , Adult , Connective Tissue/pathology , Dental Enamel/pathology , Dentin/pathology , Enamel Organ/pathology , Epithelium/pathology , Humans , Keratins/analysis , Male , Mesoderm/pathology , Osteocalcin/analysis , Osteopontin , Phosphoproteins/analysis , Sialoglycoproteins/analysis
17.
J Biochem ; 130(2): 217-25, 2001 Aug.
Article in English | MEDLINE | ID: mdl-11481038

ABSTRACT

We surveyed proteins capable of binding to the cytoplasmic domain of Na(+)/H(+) exchanger (NHE)1 in a rat brain cDNA library with the yeast two-hybrid system. One clone obtained coded for a protein reported previously as a human calcineurin homologous protein (CHP). Since CHP is homologous to the regulatory subunit B of calcineurin, we expected a possible interacting partner of CHP like the catalytic subunit of calcineurin (calcineurin A), and surveyed this putative partner again with the yeast two-hybrid system. A clone thus obtained coded for a kinase, which is basically the same as that reported for human DRAK2. Overexpression of the rat homologue of DRAK2 caused apoptosis-like cell death of NIH3T3 cells, which was dependent on the kinase activity, confirming the previous result for DRAK2. The purified CHP and rat DRAK2 proteins synthesized in Escherichia coli could bind in vitro. CHP and rat DRAK2 expressed in COS-7 cells were found to be localized in the Golgi apparatus and nucleus, respectively. Some of them was also found in the membrane peripheral region. When they were co-expressed in the same cells, most of CHP moved to the nucleus where rat DRAK2 is located, suggesting in vivo interaction of these proteins. However, minor but significant fractions of both proteins were also found in the membrane peripheral region. Rat DRAK2 is expressed highly in thymus, spleen, and testis, where the apoptosis plays an important role in physiology.


Subject(s)
Apoptosis/physiology , Arabidopsis Proteins , Calcium-Binding Proteins/metabolism , Protein Serine-Threonine Kinases/metabolism , Sodium-Hydrogen Exchangers/metabolism , Amino Acid Sequence , Animals , Apoptosis Regulatory Proteins , Base Sequence , Binding Sites , Calcineurin , Cell Line , Cloning, Molecular , Gene Library , Humans , Molecular Sequence Data , Protein Binding , Protein Serine-Threonine Kinases/chemistry , Protein Serine-Threonine Kinases/genetics , Rats , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/metabolism , Tissue Distribution , Two-Hybrid System Techniques
18.
Ind Health ; 39(2): 168-74, 2001 Apr.
Article in English | MEDLINE | ID: mdl-11341547

ABSTRACT

We tried to evaluate the carcinogenic risk of man-made mineral fiber based on the mesothelioma incidence in female F344 rats after intraperitoneal administration. Rats (female F344/ Nslc, 5-week-old, n=330) were observed for 2 years after the intraperitoneal administration of 5 to 20 mg of 9 types of the JFM (Japan Fibrous Material Research Association) standard fiber samples (glass wool, rock wool, micro fiber glass, three types of refractory fiber, potassium titanate whisker, silicon carbide whisker, titanium oxide whisker), wollastonite (natural fiber) and UICC chrysotile B. All rats administered 10 mg of silicon carbide whisker had developed peritoneal mesothelioma within a year. The cumulative incidence of peritoneal mesothelioma at the end of the experiment was 85% for 10 mg UICC chrysotile B, 77% for 10 mg of potassium titanate whisker, 70% for 5 mg of silicon carbide whisker, 20% for 5 mg of potassium titanate whisker, 20% for 20 mg of refractory fiber 2 and 10% for 20 mg of refractory fiber 1. Carcinogenicity was estimated 2.4 times for silicon carbide whisker and 0.23 for potassium titanate whisker in comparison with UICC chrysotile B. It has been well documented from several experimental studies that man-made fibers are safer than asbestos because of the different durability in the lung. Present results consistently suggest that man-made fibers with high durability have similar or higher risk as carcinogen than asbestos.


Subject(s)
Mesothelioma/etiology , Mineral Fibers/toxicity , Peritoneal Neoplasms/etiology , Animals , Carcinogens/toxicity , Female , Injections, Intraperitoneal , Mesothelioma/pathology , Peritoneal Neoplasms/pathology , Rats , Rats, Inbred F344 , Risk Assessment
19.
Drug Metab Dispos ; 29(6): 794-7, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11353746

ABSTRACT

Tegafur, an anticancer prodrug, is reported to be bioactivated to 5-fluorouracil (5-FU) by cytochrome P450 (P450) enzymes. Liver microsomal P450 enzymes involved in the biotransformation of tegafur into 5-FU in rats and the effect of tegafur in vivo on P450 levels in rats were investigated. Of 12 cDNA-expressed rat P450 enzymes tested, CYP1A2, CYP3A1, and CYP2C11 had high 5-FU formation rates from 100 microM and 1.0 mM tegafur concentrations. The contributions of CYP1A, CYP2C, and CYP3A enzymes to 5-FU formation in male rat liver microsomes were supported by immunoinhibition studies. 5-FU formation from tegafur, at substrate concentrations of 100 microM and 1.0 mM, was increased by intraperitoneal treatment of tegafur (50 mg/kg for 5 days) as well as by beta-naphthoflavone, phenobarbital, and dexamethasone. Orally administered tegafur (100 mg/kg daily for 20 days) caused the induction of CYP2B (5-fold) and of CYP1A and CYP3A (approximately 2-fold) and of 5-FU formation (approximately 2-fold) in rat liver microsomes. These results suggest that CYP1A and CYP3A enzymes, autoinduced by tegafur, have important roles in 5-FU formation from tegafur in rat liver microsomes. Coadministration of tegafur and P450-inducing drugs could markedly enhance the biotransformation of tegafur into 5-FU via P450 induction.


Subject(s)
Aryl Hydrocarbon Hydroxylases , Cytochrome P-450 CYP1A2/metabolism , Cytochrome P-450 Enzyme System/metabolism , Fluorouracil/pharmacokinetics , Microsomes, Liver/drug effects , Mixed Function Oxygenases/metabolism , Prodrugs/pharmacokinetics , Tegafur/pharmacokinetics , Animals , Biotransformation , Cytochrome P-450 CYP1A2/biosynthesis , Cytochrome P-450 CYP3A , Cytochrome P-450 Enzyme System/biosynthesis , Enzyme Induction , Female , Male , Microsomes, Liver/enzymology , Mixed Function Oxygenases/biosynthesis , Rats , Rats, Wistar , Tegafur/pharmacology
SELECTION OF CITATIONS
SEARCH DETAIL
...