京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第19587号 / 医博第4094号 / 新制||医||1014(附属図書館) / 32623 / 京都大学大学院医学研究科医学専攻 / (主査)教授 松原 和夫, 教授 妹尾 浩, 教授 浅野 雅秀 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

No description available.

Drug-induced pancreatitis is a condition characterized by sudden inflammation of the pancreas that can be mild or severe but usually subsides. Signs and symptoms consist of abdominal pain, nausea/vomiting, low-grade fever and pain radiating to the lower back. The incidence of acute drug-induced pancreatitis is approximately 2% but in patients that have disease states that predispose them to the development of pancreatitis, such as malignancy, hypercalcemia, tumor lysis syndrome, and immunosuppression it is found to be much higher. Conditions that should be considered in the differential diagnosis are cholelithiasis, hyperlipidemia, pancreatic tumor and alcoholism. Additionally, several medications have been reported to have an association with inducing pancreatitis. The focused medications are cyclophosphamide, vincristine and prednisone. All three of these drugs come with a probable association of medications that can induce pancreatitis. Having risk factors and potential drugs that could induce pancreatitis make it challenging to pinpoint the cause. A 79-year-old male presented to the hospital with generalized weakness and altered mental status lasting approximately 5 days. A clinical diagnosis of angioimmunoblastic T-cell lymphoma was made and chemotherapy was started during the stay. CVP (cyclophosphamide, vincristine, and prednisone) chemotherapy was given along with a rasburicase for potential tumor lysis syndrome. All labs were within normal limits prior to chemotherapy except for calcium, which was 10.9mg/dL and 12.42mg/dL after correction for the albumin being 2.1gm/dL. The following day the patient complained of severe abdominal pain and had mild abdominal distention. A diagnosis of pancreatitis was made after labs revealed: amylase >600 U/L, corrected calcium 12.04mg/dL, glucose 260mg/dL, a bump in BUN from 34 to 50mg/dL and a normal lipid panel. The patient also had a CT scan that revealed cholelithiasis. Subsequently the chemotherapy was stopped and normal saline was given at 50mL/hr due to his heart failure with reduced ejection fraction. Upon discontinuation of the chemotherapy, the patients abdominal pain resolved within 2 days and labs started to return to normal. Labs revealed: corrected calcium 10.5mg/dL, glucose 98mg/dL and BUN 40mg/dL. The chemotherapy agent was switched to intrathecal methotrexate, in which the patient had no trouble tolerating and the abdominal pain never returned. Ultimately, the patient developed worsening heart failure and 20 days later expired. The complexity of pinpointing conditions, risk factors, or drug causes for pancreatitis is outlined in this case. This patient had several risk factors for developing pancreatitis such as malignancy and hypercalcemia but didn’t have any signs/symptoms. After CVP chemotherapy was started, the signs/symptoms matched the labs and clinical diagnosis but cholelithiasis revealed. Once the chemotherapy was stopped all signs/symptoms subsided and labs returned to normal. The most likely cause was the chemotherapy due to the timeline from initiation of therapy to the onset of pancreatitis symptoms but this case is extremely complex due to other conditions and risk factors.

Background: The aim of this study was to compare the direct impact of different agents for immunosuppressive therapy on mouse fibroblasts as a possible cause of drug-induced gingival overgrowth (DIGO). Methods: 3T3 mouse fibroblasts were cultivated in cell-specific media (2 × 104 cells/mL) and treated for 6, 24, 48 and 72 h with one of three immunosuppressive drugs (IsDs): cyclosporin a (CsA), tacrolimus (TaC) and sirolimus (SiR). Different concentrations (10–750 ng/mL) were used to mimic serum levels under active immunosuppressive therapy conditions. Cell population characteristics (cell number, viability and morphology) were assessed using computer-assisted cell analysis. Expression of pro-collagen type I carboxy-terminal propeptide (PICP) was identified using an ELISA assay. Results: The influence of IsDs on the biological status of 3T3 fibroblasts was time- and dose-dependent. Comparing CsA and TaC, the total cell amount was enhanced using concentrations in the range of 10–150 ng/mL (p > 0.05). In contrast, treatment with SiR resulted in a decrease in the average cell number (p < 0.01). PICP and cell diameter of fibroblasts were not susceptible to IsD treatment (p > 0.05). Conclusions: Our results revealed time-dependent effects of IsDs, with distinct influences on cell number. The cell morphology and the PICP balance of the investigated fibroblast cell line remained unaffected. Hence, the potential role of IsDs is not a unilateral mechanism of action but rather a multifactorial process.

No description available.

<p dir="ltr">Torsades de pointes (TdP) is a life-threatening polymorphic ventricular tachycardia associated with QT interval prolongation. Female sex and age > 65 years are risk factors for QT prolongation and TdP, possibly due to the effect of sex hormones. Progesterone shortens QT interval, while estrogen lengthens QT interval in females. Preclinical and clinical evidence indicates that progesterone has protective effects against drug-induced QT interval prolongation. J-Tpeak (JTp) and Tpeak-Tend (Tpe) intervals are biomarkers of early and late repolarization. Population pharmacokinetic/pharmacodynamic (PK/PD) models can be used to describe exposure-response relationships and identify sources of variability. In this study, data were pooled from four clinical trials with similar study design investigating the effect of progesterone on ibutilide-induced ventricular repolarization lengthening in healthy premenopausal women during menses or ovulation phase and healthy postmenopausal women. A nonlinear mixed effect model of ibutilide - QTc interval was first developed with preliminary data from 33 subjects. The model was then updated with new data from a total of 52 subjects, assessing the effect of progesterone on drug-induced QTc interval lengthening and identifying sources of variability through covariate analysis. Finally, two PK/PD models of ibutilide - baseline corrected JTpc (ΔJTpc) interval and Tpe (ΔTpe) interval were developed to assess the effect of progestogen on ibutilide-induced early and late repolarization lengthening. Progesterone showed protective effect against ibutilide-induced QTc interval lengthening, mainly through the shortening of pre-ibutilide baseline QTc interval. Body weight, age, race, hypertension, electrocardiogram (ECG) type and estradiol concentration were not significant covariates. Progesterone attenuates ibutilide-induced lengthening of late ventricular repolarization but did not show significant effect on ibutilide-induced early repolarization lengthening. Higher estradiol concentration was related to higher ibutilide-induced early repolarization lengthening. Black race was related to lower ibutilide-induced late repolarization lengthening.</p>

Yang Lei. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 141-148). / Abstracts in English and Chinese. / Acknowledgements --- p.i / Abstract --- p.ii / Abstract (Chinese Version) --- p.iv / Table of Contents --- p.vi / List of Abbreviations --- p.xii / List of Figures --- p.xiii / List of Tables --- p.xviii / Chapter Chapter 1 --- Literature review --- p.1 / Chapter 1.1 --- Carbon tetrachloride (CC14) --- p.1 / Chapter 1.2 --- Major uses of CC14 --- p.1 / Chapter 1.3 --- Potential human exposure pathways to CC14 --- p.2 / Chapter 1.4 --- Toxicity of CC14 --- p.3 / Chapter 1.5 --- Mechanism of CCl4-induced hepatotoxicity --- p.5 / Chapter 1.6 --- Role of CYP2E1 involved in CCl4-induced hepatotoxicity --- p.7 / Chapter 1.7 --- Definite proof of the involvement of CYP2E1 in CCl4-induced hepatotoxicity by CYP2El-null mouse in vivo model --- p.10 / Chapter 1.8 --- Identification of CYP2E1 -dependent genes involved in CCl4-induced hepatotoxicity by fluorescent differential display (FDD) --- p.11 / Chapter 1.9 --- Objectives of the study --- p.14 / Chapter Chapter 2 --- Materials and methods --- p.16 / Chapter 2.1 --- Animals and treatments --- p.16 / Chapter 2.1.1 --- Materials --- p.16 / Chapter 2.1.2 --- Methods --- p.16 / Chapter 2.2 --- Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) analyses --- p.17 / Chapter 2.2.1 --- Materials --- p.17 / Chapter 2.2.2 --- Methods --- p.17 / Chapter 2.2.2.1 --- Serum preparation --- p.17 / Chapter 2.2.2.2 --- Activity determination --- p.18 / Chapter 2.3 --- Tail-genotyping by PCR --- p.18 / Chapter 2.3.1 --- Materials --- p.18 / Chapter 2.3.2 --- Methods --- p.20 / Chapter 2.3.2.1 --- Preparation of genomic DNA from mouse tail --- p.20 / Chapter 2.3.2.2 --- PCR reaction --- p.20 / Chapter 2.4 --- Total RNA isolation --- p.21 / Chapter 2.4.1 --- Materials --- p.21 / Chapter 2.4.2 --- Methods --- p.21 / Chapter 2.5 --- DNase I treatment --- p.23 / Chapter 2.5.1 --- Materials --- p.23 / Chapter 2.5.2 --- Methods --- p.23 / Chapter 2.6 --- Reverse transcnption of mRNA and amplification by fluorescent PCR amplification --- p.26 / Chapter 2.6.1 --- Materials --- p.27 / Chapter 2.6.2 --- Methods --- p.27 / Chapter 2.7 --- Fluorescent differential display (FDD) --- p.28 / Chapter 2.7.1 --- Materials --- p.28 / Chapter 2.7.2 --- Methods --- p.28 / Chapter 2.8 --- Excision of differentially expressed cDNA fragments --- p.29 / Chapter 2.8.1 --- Materials --- p.29 / Chapter 2.8.2 --- Methods --- p.29 / Chapter 2.9 --- Reamplification of differentially expressed cDNA fragments --- p.34 / Chapter 2.9.1 --- Materials --- p.34 / Chapter 2.9.2 --- Methods --- p.34 / Chapter 2.10 --- Subcloning of reamplified cDNA fragments --- p.36 / Chapter 2.10.1 --- Materials --- p.36 / Chapter 2.10.2 --- Methods --- p.37 / Chapter 2.11 --- Purification of plasmid DNA from recombinant clones --- p.39 / Chapter 2.11.1 --- Materials --- p.39 / Chapter 2.11.2 --- Methods --- p.39 / Chapter 2.12 --- DNA sequencing of differentially expressed cDNA fragments --- p.40 / Chapter 2.12.1 --- Materials --- p.40 / Chapter 2.12.2 --- Methods --- p.40 / Chapter 2.12.3 --- BLAST search against the GenBank DNA databases --- p.41 / Chapter 2.13 --- Northern blot analysis of differentially expressed cDNA fragments --- p.41 / Chapter 2.13.1 --- Formaldehyde gel electrophoresis of total RNA --- p.41 / Chapter 2.13.1.1 --- Materials --- p.42 / Chapter 2.13.1.2 --- Methods --- p.42 / Chapter 2.13.2 --- Preparation of cDNA probes for hybridization --- p.42 / Chapter 2.13.2.1 --- EcoRI digestion of cDNA inserts from plasmid DNA --- p.42 / Chapter 2.13.2.1.1 --- Materials --- p.42 / Chapter 2.13.2.1.2 --- Methods --- p.43 / Chapter 2.13.2.2 --- Purification of DNA from agarose gel --- p.43 / Chapter 2.13.2.2.1 --- Materials --- p.43 / Chapter 2.13.2.2.2 --- Methods --- p.43 / Chapter 2.13.2.3 --- DIG labeling of cDNA --- p.44 / Chapter 2.13.2.3.1 --- Materials --- p.44 / Chapter 2.13.2.3.2 --- Methods --- p.44 / Chapter 2.13.3 --- Hybridization --- p.45 / Chapter 2.13.3.1 --- Materials --- p.45 / Chapter 2.13.3.2 --- Methods --- p.45 / Chapter Chapter 3 --- Results --- p.47 / Chapter 3.1 --- Liver morphology --- p.47 / Chapter 3.2 --- Serum ALT and AST activities --- p.47 / Chapter 3.3 --- Tail-genotyping by PCR --- p.51 / Chapter 3.4 --- DNase I treatment --- p.51 / Chapter 3.5 --- FDD RT-PCR and excision of differentially expressed cDNA fragments --- p.51 / Chapter 3.6 --- Reamplification of excised cDNA fragments --- p.61 / Chapter 3.7 --- Subcloning of reamplified cDNA fragments --- p.61 / Chapter 3.8 --- DNA sequencing of subcloned cDNA fragments --- p.69 / Chapter 3.9 --- Confirmation of differentially expressed patterns by Northern blot analysis --- p.106 / Chapter 3.10 --- Temporal expression of differentially expressed genes --- p.113 / Chapter 3.11 --- Tissue distribution of differentially expressed genes --- p.117 / Chapter Chapter 4 --- Discussion --- p.125 / Chapter 4.1 --- Liver morphology and serum ALT and AST activities --- p.126 / Chapter 4.2 --- Identification of CYP2E1 -dependent genes involved in CCl4-induced hepatotoxicity --- p.127 / Chapter 4.3 --- Functional roles of the identified differentially expressed genes --- p.129 / Chapter 4.3.1 --- Fragment B4 --- p.129 / Chapter 4.3.2 --- Fragment C12 --- p.130 / Chapter 4.3.3 --- Fragment B13 --- p.131 / Chapter 4.3.4 --- Fragment A5 --- p.132 / Chapter 4.4 --- Temporal expression of differentially expressed genes --- p.133 / Chapter 4.4.1 --- Fragment B4 --- p.133 / Chapter 4.4.2 --- Fragment C12 --- p.134 / Chapter 4.4.3 --- Fragment B13 --- p.134 / Chapter 4.4.4 --- Fragment A5 --- p.135 / Chapter 4.5 --- Tissue distribution of differentially expressed genes --- p.136 / Chapter 4.5.1 --- Fragment B4 --- p.136 / Chapter 4.5.2 --- Fragment C12 --- p.136 / Chapter 4.5.3 --- Fragment B13 --- p.137 / Chapter 4.5.4 --- Fragment A5 --- p.137 / Chapter 4.5.5 --- Roles of the identified genes involved in CCl4-induced hepatotoxicity --- p.138 / Chapter 4.6 --- Normalization of Northern blot analysis --- p.13 8 / Chapter 4.7 --- Limitations of FDD technique to identify differentially expressed genes --- p.138 / Chapter 4.8 --- Future studies --- p.139 / Chapter 4.8.1 --- Investigation of the differential expression patterns of the identified genes in acetaminophen-induced liver injury --- p.139 / Chapter 4.8.2 --- Dot blot analysis --- p.140 / Chapter 4.8.3 --- DNA microarray --- p.140 / References --- p.141

Minimizing anti-cancer drug toxicity is a major challenge for the pharmaceutical industry. Toxicity is most frequently due to either the direct interaction of the drug on previously unidentified targets or its conversion to metabolites by drug metabolizing enzymes (e.g. CYP450 enzymes) that cause cellular, tissue or organ damage. Pharmacoproteomics is beginning to take a central role in studying changes in protein expression corresponding to drug administration, the results of which, inform about the mode of action, toxicity, and resistance in pre-clinical and clinical stages of drug development. The main aim of this research is to apply comparative proteomics studies on livers from male and female mice xenograft models treated with major anti-cancer drugs (5-flourouracil, paclitaxel, cisplatin, and doxorubicin) and CYP inducer, TCPOBOP, to investigate their effect on protein expression profiles (proteome). Within this thesis, an attention is paid to optimise a highly validated proteomics workflow for biomarker identification. Proteins were extracted from liver microsomes of mice treated in two separate sets; Set A – male (5-fluoruracil, doxorubicin, cisplatin and untreated) or Set B – female (5-fluoruracil, paclitaxel, TCPOBOP and untreated) using cryo-pulverization and sonication method. The extracts were digested with trypsin ii and the resulting peptides labelled with 4-plex iTRAQ reagents. The labelled peptides were subjected for separation in two-dimensions by iso-electric focusing (IEF) and RP-HPLC techniques before analysis by mass spectrometry and database searching for protein identification. Set A and Set B resulted in identification and quantification of 1146 and 1743 proteins, respectively. Moreover, Set A and Set B recovered 26 and 34 cytochrome P450 isoforms, respectively. The microsomal changes after drug treatments were quite similar. However, more changes were observed in the male set. Up-regulation of MUPs showed the greatest distinction in the protein expression patterns in the treated samples comparing to the untreated controls. In Set A, 5-fluoruracil and cisplatin increased the expression of three isoforms (MUP1, 2, and 6), whereas doxorubicin has increased the expression of four isoforms (MUP1, 2, 3, and 6). On the other side, only TCPOBOP in Set B has increased the expression of two isoforms (MUP1 and 6). Our findings showed that the expression of MUP, normally involved in binding and excretion of pheromones, have drug- and sex-specific differences. The mechanism and significance of MUP up-regulation are ambiguous. Therefore, the impact of each therapeutic agent on MUP and xenobiotic enzymes will be discussed.

Keung Hoi Yee. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 151-174). / Abstracts in English and Chinese. / Acknowledgement --- p.I / Abstract --- p.II / 摘要 --- p.V / Content --- p.VII / List of tables --- p.XIII / List of figures --- p.XIV / Abbreviations --- p.XVII / Chapter Chapter 1 --- General Introduction --- p.1 / Chapter 1.1 --- Biology of Pleurotus tuber-regiun (Ptr) --- p.1 / Chapter 1.1.1 --- Ptr grown in the wild --- p.1 / Chapter 1.1.2 --- Cultivation of Ptr --- p.2 / Chapter 1.2 --- Functional food and pharmaceutical application of Ptr sclerotium --- p.3 / Chapter 1.2.1 --- Traditional food and medicinal uses of Ptr sclerotium --- p.3 / Chapter 1.2.2 --- Nutritional value and chemical composition --- p.4 / Chapter 1.2.3 --- Anti-tumor activity --- p.7 / Chapter 1.2.4 --- Anti-viral activity --- p.8 / Chapter 1.2.5 --- Immunologic function --- p.8 / Chapter 1.2.6 --- Pharmaceutical application --- p.9 / Chapter Chapter 2 --- Toxicological evaluation on Ptr sclerotium --- p.11 / Chapter 2.1 --- Introduction --- p.11 / Chapter 2.1.1 --- Toxicological concern of Ptr sclerotium --- p.11 / Chapter 2.1.2 --- Toxicological study --- p.12 / Chapter 2.1.3 --- Biochemical methods for toxicological evaluation --- p.14 / Chapter 2.1.3.1 --- Serum enzyme activities --- p.15 / Chapter 2.1.3.2 --- Other serum analytes --- p.17 / Chapter 2.1.4 --- Histopathological study --- p.20 / Chapter 2.1.5 --- Acute toxicity --- p.21 / Chapter 2.1.6 --- Sub-acute and sub-chronic toxicity --- p.23 / Chapter 2.1.7 --- Objectives --- p.26 / Chapter 2.2 --- Materials and Methods --- p.27 / Chapter 2.2.1 --- Sample materials and chemicals --- p.27 / Chapter 2.2.2 --- Acute toxicity test --- p.27 / Chapter 2.2.2.1 --- Diet and animals --- p.27 / Chapter 2.2.2.2 --- Experimental design --- p.28 / Chapter 2.2.2.3 --- Calculation of sclerotium intake dose --- p.29 / Chapter 2.2.2.4 --- Biochemical assays --- p.30 / Chapter 2.2.2.5 --- Histopathological examination --- p.31 / Chapter 2.2.3 --- Sub-acute and sub-chronic toxicity tests --- p.32 / Chapter 2.2.3.1 --- Diet Preparation --- p.32 / Chapter 2.2.3.2 --- Experimental design --- p.32 / Chapter 2.2.3.3 --- Biochemical assays --- p.36 / Chapter 2.2.3.4 --- Organ weight --- p.40 / Chapter 2.2.3.5 --- Histopathological examination --- p.41 / Chapter 2.2.4 --- Statistical analyses --- p.41 / Chapter 2.3 --- Results and Discussion --- p.42 / Chapter 2.3.1 --- Acute toxicity test --- p.42 / Chapter 2.3.1.1 --- Food consumption --- p.43 / Chapter 2.3.1.2 --- Serum transaminase activities --- p.44 / Chapter 2.3.1.3 --- Histopathology --- p.45 / Chapter 2.3.1.4 --- NOAEL --- p.45 / Chapter 2.3.2 --- Sub-acute toxicity test --- p.50 / Chapter 2.3.2.1 --- Body weight gain --- p.50 / Chapter 2.3.2.2 --- Biochemical assays --- p.51 / Chapter 2.3.2.3 --- Organ per body weight and histopathology --- p.52 / Chapter 2.3.2.4 --- Effects of Ptr sclerotial diets --- p.53 / Chapter 2.3.3 --- Sub-chronic toxicity test --- p.59 / Chapter 2.3.3.1 --- Food and energy consumption --- p.59 / Chapter 2.3.3.2 --- Biochemical assays --- p.63 / Chapter 2.3.3.3 --- Organ per body weight --- p.67 / Chapter 2.3.3.4 --- Body weight increase --- p.75 / Chapter 2.3.3.5 --- NOAEL --- p.80 / Chapter 2.4 --- Summary --- p.81 / Chapter Chapter 3 --- Hepatoprotection of Ptr sclerotium --- p.82 / Chapter 3.1 --- Introduction --- p.82 / Chapter 3.1.1 --- Hepatotoxicity --- p.82 / Chapter 3.1.2 --- Potential hepatoprotection effect of Ptr sclerotium --- p.83 / Chapter 3.1.3 --- Toxicity of CC14 --- p.85 / Chapter 3.1.4 --- Toxicity of AFB! --- p.89 / Chapter 3.1.5 --- Bioactivity of chlorophyllin --- p.92 / Chapter 3.1.6 --- Comet assay --- p.93 / Chapter 3.1.7 --- Objectives --- p.98 / Chapter 3.2 --- Materials and Methods --- p.99 / Chapter 3.2.1 --- Sample materials and chemicals --- p.99 / Chapter 3.2.2 --- Curative and preventive tests of Ptr sclerotium against CCl4-induced hepatotoxicity --- p.99 / Chapter 3.2.2.1 --- Animal and diets --- p.99 / Chapter 3.2.2.2 --- Dose-response of CCl4 on rat model --- p.100 / Chapter 3.2.2.3 --- Biochemical assays --- p.100 / Chapter 3.2.2.4 --- Curative hepatoprotection test on Ptr --- p.101 / Chapter 3.2.2.5 --- Preventive hepatoprotection test on Ptr --- p.101 / Chapter 3.2.3 --- Preventive tests of Ptr sclerotium against AFB1-induced hepato- and geno-toxicity --- p.103 / Chapter 3.2.3.1 --- Dose-response of AFB1 on rat model --- p.103 / Chapter 3.2.3.2 --- Preventive test of Ptr against AFB1 --- p.103 / Chapter 3.2.3.3 --- Biochemical assays --- p.105 / Chapter 3.2.3.4 --- Histopathological examination --- p.105 / Chapter 3.2.4 --- Comet assay --- p.106 / Chapter 3.2.4.1 --- Reagent preparations --- p.106 / Chapter 3.2.4.2 --- Procedures --- p.107 / Chapter 3.2.5 --- Statistical analyses --- p.110 / Chapter 3.3 --- Results and Discussion --- p.111 / Chapter 3.3.1 --- Curative and preventive tests of Ptr sclerotium against CCl4-induced hepatotoxicity --- p.112 / Chapter 3.3.1.1 --- Dose-response of CCl4 on rat model --- p.112 / Chapter 3.3.1.2 --- Curative test of Ptr sclerotium against CCl4-induced hepatotoxicity --- p.116 / Chapter 3.3.1.3 --- Preventive test of Ptr sclerotium against CCl4-induced hepatotoxicity --- p.121 / Chapter 3.3.2 --- Preventive tests of Ptr sclerotium against AFB1-induced hepato- and geno-toxicity --- p.126 / Chapter 3.3.2.1 --- Dose-response of AFB1 on rat model --- p.126 / Chapter 3.3.2.2 --- Preventive test of Ptr sclerotium against AFB1-induced geno- and hepatotoxicity --- p.134 / Chapter 3.3.2.3 --- CHL versus 30% Ptr sclerotial diet --- p.137 / Chapter 3.3.3 --- A comparison of the hepatotoxicity of CC14 and AFB1 --- p.142 / Chapter 3.4 --- Summary --- p.147 / Chapter Chapter 4 --- Conclusions and future work --- p.148 / References --- p.151 / Related publication --- p.175

Hydroxyurea was used as a model teratogen to investigate the role of oxidative stress and stress-response pathways in mediating developmental toxicity. When administered to pregnant mice during early organogenesis, hydroxyurea induced fetal death and growth retardation, as well as external and skeletal malformations. The malformed fetuses displayed hindlimb, vertebral column, and tail defects. Hydroxyurea treatment enhanced the production of 4-hydroxynonenal, a lipid peroxidation end product, in malformation sensitive regions of the embryo. Depletion of glutathione, a major cellular antioxidant, specifically enhanced hydroxyurea-induced malformations and elevated the region-specific production of 4--hydroxynonenal protein adducts in the embryo, without affecting the incidence or extent of hydroxyurea-induced fetal death or growth retardation. The major proteins modified by 4-hydroxynonenal were involved in energy metabolism. Thus, oxidative stress is important in the induction of malformations by hydroxyurea. / Exposure to hydroxyurea stimulated the DNA binding activity of activator protein 1 (AP-1), an early response redox-sensitive transcription factor. Activated AP-1 was composed mainly of c-Fos heterodimers. Glutathione depletion did not change the effects of hydroxyurea on AP-1/c-Fos DNA binding activities despite an augmentation of the incidence of embryo malformations. Mitogen-activated protein kinases (MAPKs) activate AP-1 in response to stress by post-transcriptional phosphorylation of AP-1 proteins. Hydroxyurea treatment dramatically enhanced the activation of stress-responsive p38 MAPKs and JNKs (c-Jun N-terminal protein kinases). Selectively blocking p38 MAPKs enhanced the incidence of fetal death, whereas selective inhibition of JNKs specifically elevated the limb defects induced by hydroxyurea. Thus, activation of stress-response pathways impacts on the response of the embryo to a teratogenic insult.