Bryant & Stratton College (BSC) is a private for-profit college with campuses in New York, Ohio, Virginia, and Wisconsin, as well as an online campus. Founded in 1854, the college offers associate degree programs at all campuses and bachelor's degree programs at some campuses. The college is approved by the New York State Board of Regents and accredited by the Middle States Commission on Higher Education.
Most study designs evaluate the effect of one independent study variable and one dependent response variable. This approach can effectively show how a single variable can impact a study endpoint. However, the patient response can be impacted by multiple variables, and the effect of one variable can be dependent upon another. Factorial study design allows for the assessment of the effect of multiple independent variables on an outcome using one experiment rather than performing multiple experiments with individual independent variables. This approach results in more efficient assessment of the impact of multiple variables in a single clinical study. This can result in significant cost savings relative to performing multiple studies. Factorial studies also allow for the evaluation of interactions between study variables. Most prospective study designs evaluate the effect of one independent variable on an outcome but do not assess whether the status of other measurable variables modulates this effect. Directly testing for interactions using a factorial study design allows the investigator to assess whether the effect of one study variable on the outcome is modified by another study variable.
To design and execute a successful translational research protocol, investigators should employ a systematic approach from study inception to study completion. Relying on forms and templates from trusted sources increases the likelihood of success at each step in the research process from design and execution to analysis and publication. This chapter aims to outline how forms and templates can be incorporated throughout the research process and directs readers to helpful resources to develop a successful study.
In the present study, effects of transient hypothyroidism (from birth to 30 days) and persistent hypothyroidism (from birth to 90 days) on testicular antioxidant defence system of mature rats were compared in order to know the role of hypothyroidism induced oxidative stress in testicular development and maturation. Rats were made hypothyroid by feeding lactating mothers and adult rats with 0.05% 6-n-propyl thiouracil (PTU) in drinking water. PTU treatment for 30 days or for 90 days to rats from birth resulted in a decrease in body weight at the age of 90 days in comparison to the controls. The testicular germ cell counts were significantly decreased in persistent hypothyroid rats whereas they were increased in the transient hypothyroid rats. However, a significant reduction in the number of live sperms in epididymis of both 30 day and 90-day PTU treated rats was noticed on 90 days of age. Mitochondrial lipid peroxidation (LPx) levels were decreased in transient hypothyroidism whereas LPx and protein carbonylation were elevated during persistent hypothyroidism in the testis. Reduced testicular superoxide dismutase (SOD), catalase and glutathione reductase (GR) and glutathione peroxidase (GPx) activities were marked during transient hypothyroidism. In contrast, an elevation in SOD (PMF) and catalase activities with a significant decline in GPx and GR activities was found following persistent hypothyroidism. Marked histological changes were observed in the testis of both experimental groups. These results suggest a direct regulatory role of thyroid hormone on testicular physiology and antioxidant defence system during development and maturation.
