Anti-depressants are commonly used to treat major depression and post-traumatic stress disorder. 17% of women experience major depression during pregnancy, where up to 10% of pregnant women use antidepressants. 20% these women use Prozac (fluoxetine) to treat major depressive symptoms, which crosses the placental barrier and is present in breast milk. Little is known about how exposure to developmental fluoxetine affects adulthood behaviors such as agonistic and submissive behaviors, especially in females. Furthermore, the effects of developmental fluoxetine exposure on aggression and avoidance in Syrian hamsters have not been studied. Therefore, we explored how prenatal and perinatal exposure to fluoxetine affects adulthood aggression and avoidance in male and female Syrian hamsters. Dams were given fluoxetine via drinking water 7 days prior impregnation. Fluoxetine administration continue until offspring reached postnatal day (PD) 12. The offspring were weaned and group-housed at PD 25 and single-housed at PD 60. Animals were handled one week prior to behavioral testing. The following week, animals were tested for aggression in a neutral arena with a non-aggressive stimulus hamster of the same sex. Another group of hamsters were tested for avoidance behavior in a neutral arena 24 hours after social defeat. Duration of aggression and avoidance were quantified. There was no main effect of sex or drug nor was there an interaction. Therefore, we reject our hypothesis of prenatal and perinatal exposure to fluoxetine will affect aggression and avoidance in male and female Syrian hamsters. These findings may be due to a ceiling effect in Syrian hamsters, where the subtle effects of developmental fluoxetine exposure were not observable.

published_or_final_version / Anatomy / Doctoral / Doctor of Philosophy

published_or_final_version / Anatomy / Doctoral / Doctor of Philosophy

Syrian hamsters are a useful model for offensive aggression because males and females spontaneously engage in agonistic bouts. In hamsters, there is a large sex difference on aggression in the serotonin (5-HT) pathways. Male aggression is inhibited and female aggression increases with injections of a 5-HT agonist into the anterior hypothalamus (AH), but little is known if similar effects are seen in adult hamsters with repeated systemic administration of the selective serotonin reuptake inhibitor (SSRI), fluoxetine (FLX), which is one of the few approved pharmacological treatments for mood disorders in children and adolescents. The goal of this study is to determine if repeated intraperitoneal injections of FLX over 30 days in adolescent male and female hamsters has an effect on offensive aggression similar to site specific alterations of the 5-HT system in the AH. Our data suggest that systemic administration of FLX as adolescents over 30 days does not affect offensive aggression in males or females as adults.

Thesis (Ph.D.)--Boston University / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / Recent experimental work has indicated that the thymus in late fetal and early neonatal life plays a major role in the development of mechanisms of immunity. To date, however, no study of the ultrastructure of the prenatal thymus has been reported in the literature, and histochemical and cytochemical studies of this early period are fragmentary. Therefore, in an effort to extend present knowledge of thymic differentiation and function during its early development, the thymus in the golden hamster (Mesocricetus auratus) was studied by selected histochemical methods and by electron microscopy from 9 1/2 days post coitum through 24 hours post partum. Histochemical techniques for the light microscopy included the periodic acid-Schiff technique with salivary digestion control for glycogen, the methyl green-pyronin technique as an indicator for protein synthesis, the sudan black B technique for determination of total unbound lipid, the Nile blue and oil r ed 0 techniques for deter mination of neutral lipid, and the Elftman t echnique for determination of phospholipid. Material was prepared for electron microscopy by fixation for one hour in l% osmium tetroxide (Millonig, 1963), dehydration in graded acetones followed by propylene oxide, and embedding in Maraglas epoxy resin (Freeman and Spurlock, 1962). Grids prepared from these specimens were stained either with 1% phosphotungstic acid in 95% alcohol, or with lead citrate (Reynolds, 1963). They were scanned with either an R.C.A. EMU 2-B electron microscope or a Siemens Elmiskop I. [TRUNCATED] / 2031-01-01

Chinese hamster ovary (CHO) cell lines are frequently used as hosts for the production of recombinant therapeutics, such as monoclonal antibodies (MAbs), due to their ability to perform correct post-translational modifications. A major issue for use of CHO cells lines for the production of recombinant proteins is the selection of cell lines that do not retain stable protein expression during long-term culture (LTC). Instability of expression impairs process yields, effective usage of time and money, and regulatory approval. Protein production is complex and is influenced by cell growth, transcription, translation, protein folding and post-translational processing and secretory events, which may interact to determine stability of expression during prolonged culture. This thesis aims to identify features associated with stability/instability of recombinant protein expression and methods to improve protein production, with the addition of chemically defined (CD) feed and chemicals. Two exemplar CHO cell lines, which secrete the same recombinant antibody were characterised in response to LTC, feed and DMSO addition. Both cell lines (3.90 and 51.69) exhibited unstable protein production over LTC, with a loss in final antibody titres and specific productivity (Qp). The instability observed within the exemplar cell lines was not due to decreased recombinant gene copy numbers or mRNA expression but was associated with lower viable cell densities, increased ER stress (GADD153 and spliced XBP-1 [XBP-1(s)]) and enhanced rates of lactate utilisation (observed during the decline phase of batch culture). Improvement of recombinant protein expression in response to feed or DMSO addition was associated with lower expression of ER stress markers (ATF4, XBP-1(s) and GADD153 at mRNA level and GADD153 at protein level) and alterations to the metabolic activity of the cultures (prevention of alanine and lactate re-utilisation, and greater glucose utilisation between the stationary and decline phase of batch culture).Although feed or DMSO addition improved recombinant protein production, these additions did not reverse the appearance or progression of instability for cells after LTC. ER stress expression was not abolished as a consequence of feed or DMSO addition. Expression of stress markers at earlier time points may be the factor that limits antibody production and secretion. The consequences of the presence of feed and DMSO addition on ER stress markers and antibody production serves to highlight approaches that may be utilised for engineering more productive or stable protein production phenotypes in parental cell lines.

published_or_final_version / Anatomy / Master / Master of Philosophy

published_or_final_version / Anatomy / Doctoral / Doctor of Philosophy

Phodopus campbelli is a naturally biparental dwarf hamster with males so paternal they will act as midwives during the birth of their litter. The hormonal regulation of parental behaviour has been well established in many species. However, to date, no causal mechanism for the extensive paternal behaviour displayed by male P. campbelli has been discovered. Recently, activity at the progesterone receptor has been shown to inhibit infant-directed behaviour in male mice. Therefore, the first study in this thesis was carried out to determine if antagonism of the progesterone receptor (PR) would enhance infant-directed care behaviour in naïve P. campbelli males. Despite detectable serum progesterone concentration in males, PR antagonism did not alter progesterone concentration, nor did it alter infant-directed behaviour in males with antagonized PR in adulthood. A slight increase in the latency to retrieve a pup seen in males with antagonized PR during adolescence suggests that there may be a developmental effect of PR activity on infant-directed behaviour in adulthood. Neonatal male rats express high levels of PR in brain regions important for parental behaviour. Since hormones can act very early in life to organize adult behaviour, the second study was carried out to determine if progesterone acting much earlier than adolescence is important in the regulation of paternal behaviour in P. campbelli adulthood. Males were treated daily for the first week of life with transdermal progesterone, which increased neonatal serum progesterone concentration fivefold. Despite the significant increase in progesterone (and therefore presumably activity at the PR), male behaviour in three different stages of adulthood (sexually naïve, during the birth of the male’s first litter, and in new fatherhood) towards pups was not altered. Measures of paternal contribution such as pup weight throughout the lactational period were altered by progesterone treatment during the neonatal period, but litter quality was ultimately high in both groups. Therefore, activity at the PR in adulthood, puberty, or during the neonatal period does not inhibit paternal behaviour in the naturally biparental hamster, P. campbelli. Thus, progesterone and its receptor do not organizationally or activationally regulate paternal behaviour in P. campbelli. / Thesis (Master, Biology) -- Queen's University, 2009-09-04 13:23:18.733

Therapeutic monoclonal antibodies (MAb) are produced as secreted complex glycoproteins from mammalian cell systems and represent one of the most important classes of therapeutic medicines for the treatment of a variety of human diseases. Their benefit in health care and high economic impact provide the driving force for the development of improved production levels with the focus of optimizing clinical efficacy. One important issue is the optimization of monoclonal antibody production. A frequent approach used to address this challenge is the engineering of mammalian cell lines to increase antibody production levels through genetic manipulation. Valuable information can then be obtained by monitoring the effects of genetic changes on the biochemistry of the cell associated with MAb production. Global protein expression profiling of mammalian cells used for the production of biopharmaceuticals may reveal key biochemical characteristics associated with MAb-producing cell lines. A better understanding of these characteristics can in turn lead to more rational strategies for cell line and process development. The proposed research relates to a larger NSERC Strategic Network (MAbNet) Grant to develop and establish a novel platform for the large-scale manufacture of specific glycoforms of therapeutic monoclonal antibodies. The efficacy of these recombinant MAbs will be enhanced by the control of their glycosylation profiles. The work presented in this thesis will assist MAbNet in meeting their objectives. Specifically, we use 2D-Differential In-Gel Electrophoresis (2D-DIGE) to quantify protein expression differences between EG2-hFc1-producing Chinese Hamster Ovary cells (CHO-1A7) with its parental cell line (CHO-BRI). Here, we identified 34 unique differentially expressed proteins associated with EG2-hFc1 production that relate to various biological processes including protein processing, carbohydrate metabolism, amino acid metabolism, energy metabolism, apoptosis, and cell proliferation pathways. The majority of identified significant protein expression changes and their associated metabolic processes seem to prioritize energy production in CHO-1A7 cells. Due to the metabolic load of recombinant antibody production, the CHO-1A7 cell line attempts to meet the energy requirements needed for recombinant protein biosynthesis while maintaining cell viability and efficient protein folding mechanisms. A 2-D proteome reference map was also constructed for the CHO-BRI host cell line containing 131 identified protein spots. The map provides information that will further expand our understanding of this particular cell line. It will be a useful tool for studies investigating physiological responses and protein expression patterns of CHO-BRI to genetic and environmental perturbations. The set of identified differentially expressed proteins provides data on the downstream changes in protein expression due to genetic manipulation, and furthermore can provide targets for cell-line specific optimization of antibody production. The work described in this thesis furthers our understanding of antibody production in a specific CHO cell line.