LC50 Determination of tert-Butyl Acetate using a Nose Only Inhalation Exposure in Rats.

tert-Butyl acetate (TBAc) is an organic solvent, which is commonly used in architectural coatings and industrial solvents. It has recently been exempted from the definition of a volatile organic compound (VOC) by the Air Resources Board (ARB) . Since the use of TBAc as a substitute for other VOCs has increased, thus its potential risk in humans has also increased.

Dose-response Effects of Bleomycin on Inflammation and Pulmonary Fibrosis in Mice.

Many studies have reported that bleomycin, anti-cancer drug, induces pulmonary fibrosis as a side effect. However, few investigations have focused on the dose-response effects of bleomycin on pulmonary fibrosis. Therefore, in the present study, we investigated the effects of different doses of bleomycin in male mice.

Standardization of bronchoalveolar lavage method based on suction frequency number and lavage fraction number using rats.

Bronchoalveolar lavage (BAL) is a useful tool in researches and in clinical medicine of lung diseases because the BAL fluid contains biochemical and cytological indicators of the cellular response to infection, drugs, or toxicants. However, the variability among laboratories regarding the technique and the processing of the BAL material limits clinical research. The aim of this study was to determine the suction frequency and lavage fraction number necessary to reduce the variability in lavage using male Sprague-Dawley rats.

A novel mutation in Hr causes abnormal hair follicle morphogenesis in hairpoor mouse, an animal model for Marie Unna Hereditary Hypotrichosis.

Hairpoor mice (Hr(Hp)) were derived through N-ethyl-N-nitrosourea (ENU) mutagenesis. These mice display sparse and short hair in the Hr(Hp)/+ heterozygous state and complete baldness in the Hr(Hp)/Hr(Hp) homozygous state. This phenotype was irreversible and was inherited in an autosomal semidominant manner.

Characteristics of ethylnitrosourea-induced cataracts.

Purpose: This study analyzed genes associated with the morphology and regulation of ethylnitrosourea (ENU)-induced cataract mouse.

Materials And Methods: Immunohistochemistry analysis using anti-crystallins and PCNA antibody revealed that the localization pattern of these specific markers differed between the cataractous and wild-type lens epithelium. Two-dimensional electrophoresis and microarray techniques were used to identify the proteins and genes related to ENU-induced cataract.

Basic Principles of the Validation for Good Laboratory Practice Institutes.

Validation specifies and coordinates all relevant activities to ensure compliance with good laboratory practices (GLP) according to suitable international standards. This includes validation activities of past, present and future for the best possible actions to ensure the integrity of non-clinical laboratory data. Recently, validation has become increasingly important, not only in good manufacturing practice (GMP) institutions but also in GLP facilities.

Recurrent exposure to welding fumes induces insufficient recovery from inflammation.

Previous studies on welding-fume-induced lung fibrosis have indicated that recovery is possible when the degree of exposure is short-term and moderate. However, this study investigated the recovery after recurrent exposure to welding fumes, as welders are invariably re-exposed to welding fumes after recovering from radiographic pneumoconiosis. Thus, to investigate the disease and recovery processes of welding-fume-induced pneumoconiosis in the case of recurrent welding-fume exposure, rats were exposed to manual metal arc-stainless steel (MMA-SS) welding fumes with a total suspended particulate (TSP) concentration of 51.

Point mutation of Hoxd12 in mice.

Purpose: Genes of the HoxD cluster play a major role in vertebrate limb development, and changes that modify the Hoxd12 locus affect other genes also, suggesting that HoxD function is coordinated by a control mechanism involving multiple genes during limb morphogenesis. In this study, mutant phenotypes were produced by treatment of mice with a chemical mutagen, N-ethyl-N-nitrosourea (ENU). We analyzed mutant mice exhibiting the specific microdactyly phenotype and examined the genes affected.

Noninvasive Monitoring of Bleomycin-induced Lung Injury in Rats Using Pulmonary Function Test.

The single intratracheal instillation (ITI) of bleomycin (BLM) is a widely used method for inducing experimental pulmonary fibrosis in rat model. In the present study, pulmonary function tests (PFTs) of tidal volume (V), minute volume (V), and respiratory frequency (F) have been applied to study their possibility as a tool to monitor the progress of BLM-induced lung injury in rat model. Rats were treated with a single ITI of BLM (2.

Study of a BALB/c Mouse Model for Allergic Asthma.

Allergic asthma is a worldwide public health problem and a major socioeconomic burden disease. It is a chronic inflammatory disease marked by airway eosinophilia and goblet cell hyperplasia with mucus hypersecretion. Mouse models have proven as a valuable tool for studying human asthma.

Fine localization of a new cataract locus, Kec, on mouse chromosome 14 and exclusion of candidate genes as the gene that causes cataract in the Kec mouse.

A mouse with cataract, Kec, was generated from N-ethyl-N-nitrosourea (ENU) mutagenesis. Cataract in the Kec mouse was observable at about 5 weeks after birth and this gradually progressed to become completely opaque by 12 weeks. Dissection microscopy revealed that vacuoles with a radial or irregular shape were located primarily in the cortex of the posterior and equatorial regions of the lens.

Pulmonary Toxicity and Recovery from Inhalation of Manual Metal Arc Stainless Steel Welding Fumes in Rats.

The objectives of this study were to examine the lung injury and inflammation caused by manual metal arc stainless steel (MMA-SS) welding fume inhalation and to evaluate the recovery process. Sprague-Dawley rats were exposed to MMA-SS welding fumes for 2 h per day in a whole-body exposure chamber, with a total suspended particulate (TSP) concentration of 51.4 ± 2.

Implications for tooth development on ENU-induced ectodermal dysplasia mice.

Background: In this study, the mutated phenotypes were produced by treatment of chemical mutagen, N-ethyl-N-nitrosourea (ENU). We analyzed the mutated mice showing the specific phenotype of ectodermal dysplasia (ED) and examined the affected gene.

Methods: Phenotypes, including size, bone formation, and craniofacial morphology of ENU-induced ED mice, were focused.

Studies on the Small Body Size Mouse Developed by Mutagen -Ethyl--nitrosourea.

Mutant mouse which show dwarfism has been developed by -ethyl--nitrosourea (ENU) mutagenesis using BALB/c mice. The mutant mouse was inherited as autosomal recessive trait and named Small Body Size (SBS) mouse. The phenotype of SBS mouse was not apparent at birth, but it was possible to distinguish mutant phenotype from normal mice 1 week after birth.

Studies on -Ethyl--nitrosourea Mutagenesis in BALB/c Mice.

N-ethyl-N-nitrosoures (ENU) is effective in inducing hypermorphic mutation as well as hypomorphic and antimorphic mutations. Therefore, this mutagen is used to the production of mutant in the mice. In order to perform an effective ENU mutagenesis using BALB/cAnN mice, determination of optimal dosage and dosage regimen of ENU is necessary.

A novel missense mutation in the mouse hairless gene causes irreversible hair loss: genetic and molecular analyses of Hr m1Enu.

A novel autosomal recessive mutant was produced using N-ethyl-N-nitrosourea mutagenesis. The characteristics of the mutant mice included progressive irreversible hair loss within a month of birth, wrinkled skin, and long curved nails. Linkage analysis revealed that the causative gene is linked to D14Mit193 on chromosome 14.