Structural Basis for the Different Mechanical Behaviors of Two Chemically Analogous, Carbohydrate-Derived Thermosets.

Two renewable, structurally analogous monomers, isosorbide undecenoate (IU) and glucarodilactone undecenoate (GDLU) reacted with pentaerythritol tetrakis(3-mercaptopropionate) (PETT) via thiol-ene photopolymerization to form IU-PETT and GDLU-PETT thermosets. Despite their chemical similarity, uniaxial tensile testing showed that GDLU-PETT exhibited a strain-hardening behavior and is significantly tougher than IU-PETT. To understand this observation, in situ tensile testing and wide-angle X-ray scattering experiments (WAXS) were conducted.

Effects of long-term dietary administration of estrogen receptor-beta agonist diarylpropionitrile on ovariectomized female ICR (CD-1) mice.

Diarylpropionitrile (DPN) is an estrogen receptor-β-specific agonist that has been linked to neuroprotection, preserving cognitive function with age, the suppression of anxiety-like behaviors, inhibition of cancer growth, and other positive properties. We hypothesized that DPN may have pro-longevity properties. DPN was administered via feed at a dose corresponding to approximately 3 mg/kg/day to ovariectomized female mice beginning at 7 months of age.

Sustainable Polyesters Derived from Glucose and Castor Oil: Building Block Structure Impacts Properties.

Using the glucose derivatives isosorbide and glucarodilactone along with a castor oil derivative, 10-undecenoyl chloride, two monomers were synthesized: glucarodilactone undecenoate (GDLU) and isosorbide undecenoate (IU). These monomers were polymerized via acyclic diene metathesis (ADMET) polymerization to yield two homopolymers, P(GDLU) and P(IU), and two copolymers, P(GDLUIU) and P(GDLUIU), of similar number-averaged molecular weight and relative composition (51 and 61 kDa, = 1.8 and 1.

Role of cytoprotectants and nitric oxide inhibition in nonsteroidal anti-inflammatory drug-induced gastroduodenal injury in the rat.

Background And Purpose: Nonsteroidal anti-inflammatory drugs (NSAIDs) induce gastroduodenal injury and ulceration. The pathogenesis is uncertain, although reductions in cytoprotective prostaglandins and nitric oxide (NO) have been proposed. The effects of several cytoprotective agents on inhibition of gastroduodenal ulcerogenesis induced by CI-987, a novel NSAID, were evaluated in Wistar rats.

Reference values for young normal Sprague-Dawley rats: weight gain, hematology and clinical chemistry.

1. Arterial blood from 63 male (315-500 g) and 60 female (210-290 g) healthy Sprague-Dawley rats was analyzed for 16 hematological and 22 clinical chemistry parameters. 2.

Biochemical effects of Pembina Cardium crude oil exposure in cattle.

Crude oil pollution at drilling sites located within or in close proximity to agricultural pasture lands poses serious health risks to cattle raised on these lands. To investigate the clinical and systemic biochemical effects, cattle (8/group) were administered single oral doses of Pembina Cardium crude oil (PCCO) at 16.7, 33.

Cytotoxic effects of hydrogen sulfide on pulmonary alveolar macrophages in rats.

Respiratory rates (basal and zymosan-stimulated) and cell viability were monitored in pulmonary alveolar macrophages (PAM) from rats exposed to 0, 70, 280, and 560 mg/m3 (0, 50, 200, and 400 ppm) hydrogen sulfide (H2S) gas for 4 h. Zymosan-stimulated respiratory rates were markedly reduced in PAM collected from rats exposed to 280 and 560 mg/m3 H2S; however, their basal respiratory rates were not affected. Significant decrease in cell viability was also observed in samples from 560 mg/m3 H2S-treated rats, but it remained high and unchanged in other treatments.

Effects of hydrogen sulfide exposure on lung mitochondrial respiratory chain enzymes in rats.

Fischer-344 rats were exposed for 4 hr to various concentrations of hydrogen sulfide (H2S) gas and killed either immediately or at 1, 24, or 48 hr after exposure. Mitochondrial fractions from lung tissues were assayed for the activities of respiratory chain enzymes. Exposure of rats to a low concentration (10 ppm) of H2S caused no significant changes in the activities of lung mitochondrial enzymes.

Effects of dichlorvos on blood cholinesterase activities of cattle.

Inhibitory effects of dichlorvos (2,2-dichlorovinyl dimethyl phosphate, DDVP) [corrected] on erythrocyte acetylcholinesterase (AChE) and plasma cholinesterase (ChE) activities of steers were characterized after treatments in vitro and in vivo (cutaneous application). The rates of in vitro inhibition were markedly influenced by DDVP concentration and incubation time. The activities of inhibited enzymes failed to reactivate spontaneously and had little response to treatment with 2-pyridine aldoxime methiodide (2-PAM).

Induction of hepatic cytochrome P-450 and xenobiotic metabolizing enzymes in rats gavaged with an Alberta crude oil.

Changes in body weight gain and in biochemical parameters of blood and liver were assessed in Sprague-Dawley rats after multiple oral administration of three test doses of an Alberta crude oil (ACO). Rats treated with ACO (1.25-5 ml/kg) did not show statistically significant (p greater than .

The toxicology of detergents, bleaches, antiseptics and disinfectants in small animals.

Small animals are exposed to a variety of household products. The most common route of exposure is oral by direct ingestion or from grooming soiled fur and feet. The majority of household products are complex chemical mixtures.

Histologic and ultrastructural alterations in lungs of rats exposed to sub-lethal concentrations of hydrogen sulfide.

Fischer-344 rats were killed 1, 18, and 42 hr after a single 4-hr exposure to an atmosphere of 0, 116, or 615 mg m-3 of hydrogen sulfide (H2S). Lungs, fixed by the intratracheal route, were examined by light and electron microscopy. Histologic changes were transient and mainly present in rats exposed to 615 mg m-3 H2S.

In vitro and in vivo effects of dichlorvos on blood cholinesterase activities of cattle.

Studies were conducted to ascertain in vitro effects and effects of percutaneous application (in vivo) of dichlorvos (2,2-dichlorovinyl dimethyl phosphate; DDVP) on cholinesterase activities in bovine erythrocytes and plasma. Treatment in vitro of erythrocytes and plasma with DDVP resulted in concentration- and time-dependent inhibition of erythrocyte acetylcholinesterase (AChE) and plasma cholinesterase (ChE) activities. Mean (+/- SD) DDVP concentrations required to cause 50% enzyme inhibition were 15.

Nasal lesions in rats exposed to hydrogen sulfide for four hours.

Fischer-344 rats were exposed for 4 hours to 0, 14, 280, or 560 mg of hydrogen sulfide.m-3 and killed 1, 18, or 44 hours later. We evaluated the nasal epithelial cells and determined the anatomic distribution of lesions.

Biochemical and cytologic alterations in the respiratory tract of rats exposed for 4 hours to hydrogen sulfide.

Fischer-344 rats were killed by exsanguination 1, 20, and 44 hr after a single 4-hr exposure to an atmosphere of 0, 10, 200, and 400 ppm of hydrogen sulfide (H2S). Alterations in the activities of lactate dehydrogenase and alkaline phosphatase, and cytomorphology of epithelial cells in fluids obtained by nasal and bronchoalveolar lavage were used as indicators of cell injury. Changes in the number of leukocytes were used as indicators of inflammatory response, and changes in the concentration of protein were used as indicators of altered vascular permeability.

Profiles of type-II pneumocytes in rats inoculated intratracheally with bacterial lipopolysaccharide.

Ultrastructural and morphometric profiles of type-II pneumocytes (P-II) were investigated in rats killed 18 or 24 hours after a single intratracheal inoculation of bacterial (Escherichia coli) lipopolysaccharide (LPS). Inoculation with LPS induced pulmonary injury and inflammation, as measured by increased lactate dehydrogenase and alkaline phosphatase activities and increased numbers of polymorphonuclear neutrophils in fluid collected by bronchoalveolar lavage. Marked ultrastructural changes and desquamation of a few P-II developed at the time of high activity of lactate dehydrogenase and alkaline phosphatase in bronchoalveolar lavage fluid.

Effects of high dietary sulphur on enzyme activities, selenium concentrations and body weights of cattle.

This study was designed to assess the effects of a moderate increase in dietary sulphur (S) in cattle. Twelve animals were initially fed a basal concentrate (S = 0.2%) and then divided into two groups; one fed basal and the other high S (S = 0.

Effect of sex and age on the activities of lactate dehydrogenase and alkaline phosphatase in the lungs of rats.

Since toxicity studies among different laboratories generally involve rats of different sex and age, this study was conducted to investigate the effect of sex, age and animal to animal variation in the activities of lactate dehydrogenase and alkaline phosphatase from bronchoalveolar lavage fluid, bronchoalveolar cell lysate and lung homogenate. Correlation between numbers of bronchoalveolar cells recovered from lungs and enzyme activity in bronchoalveolar cell lysate or lung homogenate supernatant were also investigated. Male rats showed significantly (p less than 0.

Adiaspiromycosis in striped skunks in Alberta, Canada.

Pulmonary adiaspiromycosis was diagnosed in seven of 25 striped skunks (Mephitis mephitis) in east-central Alberta. The infection varied from mild, where only microscopic lesions were seen, to severe, where gross lesions of grayish-white nodules were observed in the lung parenchyma. Mild lesions were restricted to the lung, while severe lesions extended to the tracheobronchial and mediastinal lymph nodes.

A mouse model for estimation of Pasteurella haemolytica deposition in calf lungs following aerosol exposure.

A method used to calculate the number of Pasteurella haemolytica reaching the lungs of calves during an aerosol exposure is described. This method is based on a linear relationship of bacterial deposition in lungs of mice and calves when exposed to the same bacterial aerosol.