Manufactured nanoparticles (NPs) are a class of small ( ≤ 100 nm) materials that are being used for a variety of purposes, including industrial lubricants, food additives, antibacterial agents, as well as delivery systems for drug and gene therapies. Their unique characteristics due to their small size as well as their parent materials allow them to be exploited in convenience applications; however, some of these properties also allow them to interact with and invade biological systems. Few studies have been performed to determine the potential harm that NPs can inflict on reproductive and developmental processes in organisms. In this study, Drosophila melanogaster and CD-1 mice were orally exposed to varying doses of titanium dioxide (TiO2) NPs, silver (Ag) NPs, or hydroxyl-functionalized carbon nanotubes (fCNTs) and Drosophila were also exposed to microparticles (MPs) as a control for particle size. The subsequent effect of these materials on reproduction and development were evaluated. Strikingly, each type of NP studied negatively affected either reproduction or development in one or both of the two model systems. TiO2 NPs significantly negative effected both CD-1 mouse development (100 mg/kg or 1000 mg/kg) as well as Drosophila female fecundity (0.005%-0.5% w/v). Ag NPs significantly reduced mouse fetus viability after prenatal exposure to10 mg/kg. Ag NPs also significantly decreased the developmental success of Drosophila when they were directly exposed to these NPs (0.05% - 0.5% w/v) compared to both the vehicle and MP controls. fCNTs significantly increased the presence of morphological defects, resorptions and skeletal abnormalities in CD-1 mice, but had little effect on Drosophila. We speculate that the differences seen in the effects of NP types may be partially due to differences in reproductive physiology as well as each organism’s ability to internalize these NPs. Whereas the differing response of each organism to a NP type was likely due in part to varying durations of exposure. Since NPs are a popular commodity in today’s consumer world, the research presented here accentuates the need for further studies on the detrimental effects that these particles may have on a variety of developing organisms and on female reproductive health. / Thesis (Master, Environmental Studies) -- Queen's University, 2010-09-20 17:57:59.343

Nitrous oxide (N2O) oxidizes vitamin B12. disrupting deoxyribonucleic acid (DNA) synthesis. Occupational exposures to subanesthetic levels of the gas have been documented that may result in suppressed proliferative cell activities. Male CD-I mice were exposed to 0, 50, 500, and 5000 parts of N2O per million parts of air (ppm) for 6 hr/day, 5 days/week for 2 and 13 weeks. Splenic lymphocytes were assayed for responsiveness to mitogens and for the ability to produce interleukin-2 (lL-2) . Tritiated-thymidine ([3H]-TdR) uptake was measured in CD-I splenic lymphocytes cultured in a mixed-lymphocyte culture (MLC). Cytolytic cell activity was measured by 51chromium release assay. Antibody-mediated immunocompetency was determined for sheep red blood cell (SRBC)-sensitized animals by plaque-forming cell (PFC) assay and sera anti-SRBC antibody titer. Deoxyuridine suppression tests (dUdRST) were performed on bone marrow cells. Serum adrenocorticotropic hormone and corticosterone levels were determined. There was significantly decreased splenic lymphocyte uptake of [3H)-TdR by cells cultured with mitogenic substances and in MLC following 2-week animal exposures to 5000 ppm. After 13-week exposures, the animals' splenic lymphocytes showed decreased [3H]-TdR uptake following low N20 dosing and nonsignificantly increased responsiveness at the higher gas exposures in both the blastogenic and MLC assays. Compared to control animals, the 5000- ppm-exposure group had significantly depressed PFC activity and circulating anti-SRBC immunoglobulin M levels following 13-week gas exposures, and all three subchronic exposure groups demonstrated both decreased liver weights and leukopenia. Bone marrow activity at these dosing levels was dose-responsively depressed following subchronic gas exposures.No hormonal effect appears to be attributable to N20 exposure.

<p>Using a conditioning paradigm and an automated olfactometer, I investigated the olfactory sensitivity of five CD-1 mice for seven aromatic aldehydes. With two of the stimuli (3-phenylpropanal and canthoxal), the animals discriminated concentrations as low as 10 ppb (parts per billion) from the odorless solvent and with four of the stimuli (helional, cyclamal, lilial and lyral) they discriminated concentrations as low as 1 ppb, with single individuals even scoring better. All five animals yielded the by far lowest threshold value with bourgeonal and discriminated a concentration of 0.1 ppq (parts per quadrillion) from the odorless solvent. The detection threshold values for aromatic aldehydes were found to be affected by the type of functional groups and oxygen moiety attached to the benzene ring. A comparison of the present data with those obtained in other species found no clear correlation between olfactory sensitivity and the size of the olfactory receptor repertoire.</p>

Previous studies showed that early exposure to soy isoflavones resulted in improved bone mineral density (BMD) and bone quality that resulted in stronger bones in CD-1 mice. This study investigated whether the benefits to bone health are transferred to second generation (F2) females and if there are any adverse effects on reproductive health. First generation (F1) female CD-1 mice received subcutaneous injections of the isoflavones daidzein (DAI) and genistein (GEN) or corn oil from postnatal day (PND) 1 to 10 or 21. F1 and F2 treated-females experienced earlier pubertal onset and lengthened anogenital distance but only F1 had reduced fertility, histological abnormalities in the uterus and ovaries, and altered estrous cycling. F2 had higher BMD and stronger bones at 4 months of age. In conclusion, early life exposure to soy isoflavones compromise reproductive function but confer a transgenerational benefit to bone development in CD-1 mice.

Previous studies showed that early exposure to soy isoflavones resulted in improved bone mineral density (BMD) and bone quality that resulted in stronger bones in CD-1 mice. This study investigated whether the benefits to bone health are transferred to second generation (F2) females and if there are any adverse effects on reproductive health. First generation (F1) female CD-1 mice received subcutaneous injections of the isoflavones daidzein (DAI) and genistein (GEN) or corn oil from postnatal day (PND) 1 to 10 or 21. F1 and F2 treated-females experienced earlier pubertal onset and lengthened anogenital distance but only F1 had reduced fertility, histological abnormalities in the uterus and ovaries, and altered estrous cycling. F2 had higher BMD and stronger bones at 4 months of age. In conclusion, early life exposure to soy isoflavones compromise reproductive function but confer a transgenerational benefit to bone development in CD-1 mice.

No description available.

―Green‖ odors comprise a group of eight structurally related aliphatic alkenals and alkenols which are characteristic for the odor of a wide variety of plant materials. Using an automated olfactometer, the olfactory detection thresholds for ―green‖ odors were determined in six CD-1 mice and compared with that of spider monkeys and human subjects. Detection threshold values for alcoholic ‖green‖ odors (cis-3-hexen-1-ol, trans-3-hexen-1-ol, trans-2-hexen-1-ol and 1-hexanol) ranged from 8.1 x 109 to 8.1 x 1011 molecules/cm3 and for aldehydic ‖green‖ odors (cis-3-hexenal, trans-3-hexenal, trans-2-hexenal and n-hexanal) , from 8.1 x 107 to 8.1 x 1011 molecules/ cm3 . Detection threshold values of ―green‖ odor with double bond ranged from 8.1 x 107 to 8.1 x 1011 molecules/cm3 and for ―green‖ odor without double bond ranged from 8.1 x 108 to 8.1 x 1011 molecules/cm3. Detection threshold value of cis- configured ―green‖ odors ranged from 8.1 x 108 to 8.1 x 1011 molecules/ cm3 and for trans- configured ―green‖ odors threshold value ranged from 8.1 x 107 to 8.1 x 1011 molecules/ cm3. Trans-2-hexenal with a double bond at C-2 position in its molecular structure yielded the lowest detection threshold value when compared the other ―green‖ odors (8.1 x 107 to 8.1 x 109 molecules /cm3) which shows not only the presence of double bond plays a major role in detection but the position of the double bond present. A comparison between the present data and data from the other species showed that CD-1 mice displayed lower detection thresholds for all ‖green‖ odors than human subjects and spider monkeys except for the cis-3-hexen-1-ol odor. These findings suggest that the differences in the threshold values between ―green‖ odors are due to the difference in the molecular structure like the presence of double bond and the position of double bond.

Using a conditioning paradigm and an automated olfactometer, I investigated the olfactory sensitivity of five CD-1 mice for seven aromatic aldehydes. With two of the stimuli (3-phenylpropanal and canthoxal), the animals discriminated concentrations as low as 10 ppb (parts per billion) from the odorless solvent and with four of the stimuli (helional, cyclamal, lilial and lyral) they discriminated concentrations as low as 1 ppb, with single individuals even scoring better. All five animals yielded the by far lowest threshold value with bourgeonal and discriminated a concentration of 0.1 ppq (parts per quadrillion) from the odorless solvent. The detection threshold values for aromatic aldehydes were found to be affected by the type of functional groups and oxygen moiety attached to the benzene ring. A comparison of the present data with those obtained in other species found no clear correlation between olfactory sensitivity and the size of the olfactory receptor repertoire.

The olfactory sensitivity of five male CD-1 mice (Mus musculus) for six amino acids was determined using an operant conditioning paradigm. All animals significantly distinguished dilutions as low as 0.01 mM L-cysteine, 3.3 mM L-methionine, 10 mM L-proline, 0.03 mM D-cysteine, 0.3 mM D-methionine and 10 mM D-proline from the odorless solvent, with individual animals displaying even lower detection thresholds. Among the three different L-forms of the amino acids the mice were most sensitive for cysteine and least sensitive for proline, and among the three D-forms the animals displayed a lower sensitivity for D-proline compared to D-cysteine and D-methionine. A comparison between the present data and results obtained with other species showed that the CD-1 mice displayed a higher sensitivity than human subjects and spider monkeys with three (L-Cysteine, D-cysteine and L-proline) of the six amino acids. Results from this report support the idea that the number of functional olfactory receptor genes is not suitable to predict a species’ olfactory sensitivity.

Vitamin D is important for bone development with immunomodulatory effects. This study investigated whether feeding CD-1 and interleukin 10 (IL-10) knockout (KO) dams low (25 IU/kg diet) or high (5,000 IU/kg diet) vitamin D affected bone health of dams as well as their offspring. Offspring were weaned to 1 of the 2 diets and followed to young adulthood. Unlike CD-1 dams, IL-10 KO dams experienced greater femur strength with high vitamin D. CD-1 male offspring had reduced femur neck strength and female offspring had smaller, weaker femurs, and weaker lumbar vertebra 2 (LV2) with high maternal vitamin D. IL-10 KO male offspring had larger femurs and female offspring had stronger femurs when weaned to high vitamin D. Low vitamin D did not adversely impact bone health but the optimal level of dietary vitamin D seems to differ between healthy and inflammatory states.