Cryptorchidism is a male congenital disorder with an unspecified, multifactorial etiology. This review evaluated the strength of select factors in the development of cryptorchidism to better understand its etiology. The strength of relationship between factors and their respective functions during testicular descent was evaluated. Factors evaluated in the causal pathway include the signaling mechanisms Desert Hedgehog (DHH), Insulin-like Hormone 3 (INSL3) and Platelet-Derived Growth Factor (PDGF), as well as sex hormone regulation (androgen: estrogen ratio, aromatase expression). Articles supporting a factor in testicular descent were evaluated and scored. These scores were summed to create the “Step Score” for each step in the causal pathway. An arrow system was developed which ranked the strength of each pathway step as either “weak”, “moderate” or “strong”. Thus, step scores and the strength of factors in the pathological pathway were determined: DHH (15-moderate), PDGF (10-weak), INSL3 (24-strong) and Androgen: Estrogen ratio, Aromatase (23-strong). The pathological pathway produced by this review represents a literature based perspective of the research regarding cryptorchidism etiology. Literature indicates that prenatal exposure to endocrine disrupting chemicals in animals and humans may lead to abnormal genital development. Recently, prenatal maternal cigarette smoke was demonstrated to be a risk factor for cryptorchidism. This controversial finding was explored in the context of endocrine disrupting chemicals. However, literature has provided very little evidence in support of this hypothesis and more research is needed to better evaluate prenatal maternal smoking as a risk factor for undescended testis.

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<p>Cigarette smoking is a lifestyle behaviour associated with adverse reproductive health effects including premature exhaustion of the follicle population and premature menopause; however, the mechanisms mediating its effects on follicle loss are largely unexplored. Therefore, this thesis was undertaken to examine the effect of cigarette smoke (CS), at concentrations representative of human exposure, on follicle loss in mouse ovaries and determine the underlying mechanisms mediating their loss. CS contains over 4,000 chemicals, many of which result in reactive oxygen species (ROS) generation, which can cause cell death. In the first study, we hypothesized that follicles exposed to CS would be lost via apoptosis in a selective stage-dependent manner. Although apoptosis is a cell death pathway through which follicles are thought to die, the studies herein found no changes in apoptosis, despite increased follicle loss. Given these findings, we hypothesized that an alternative cell death mechanism was responsible. At the time, the relevance of autophagy, a novel ovarian cell death pathway, to granulosa cell death and toxicant-induced changes in ovarian function were unknown. We further demonstrated increased oxidative stress, decreased antioxidant expression, and autophagy in treated ovaries. Finally, we tested the hypothesis that CS exposure results in dysregulation of mitochondrial repair mechanisms, leading to follicle loss via autophagy-mediated granulosa cell death. We demonstrated that CS exposure activates autophagy and alters mitochondrial dynamics. Taken together, these studies provide evidence that CS causes significant follicle loss, decreases the cell’s ability to cope with ROS disrupting mitochondrial repair mechanisms, leading to autophagy-mediated follicle loss.</p> / Doctor of Philosophy (PhD)

In undertaking this study the investigator had the following purposes: 1. To determine the percentage of the college women of the study who are cigarette smokers. 2. To determine the percentage of the college men of the study who are cigarette smokers. 3. To determine the carious habits of the students who participated in the study in regard to cigarette smoking. 4. To determine the students' reasons for smoking cigarettes. 5. To determine the opinions and attitudes of the students of the study in regard to cigarette smoking. 6. To compare the women students with the men students of the study in regard to cigarette smoking on the basis of the data obtained.

MPH / Department of Public Health / Background: Globally, cigarette smoking is causing preventable deaths in developing countries affecting especially the youth. Historically, cigarette smoking is known to be more common among adults but is also becoming common among students. Purpose: The study aimed to investigate factors contributing to cigarette smoking and its health consequences amongst students of the University of Venda in South Africa. Methodology: A quantitative approach using a descriptive cross- sectional design was adopted. Convenience sampling was used to randomly select 428 respondents. A self-reporting questionnaire with closed ended questions was administered to respondents between the ages of 17-40 years who suited the inclusion criteria. Permission to conduct the research was obtained from the Ethics Committee of the University of Venda. Data were analysed using SPSS version 23 and presented in the form of tables and charts. Pearson’s chi squares were used to test significant relationships between variables and smoking status. Results: A total of 407 students participated in the study. Of the 407, 208 (51%) of respondents were female students. The mean age of the study population was 24 years. Of these 407, 175(43%) reported being smokers 232 (57%) were nonsmokers. More smokers were observed among the male respondents and registered for first and second years. There was a significant relationship between age, gender, religion, school of affiliation, amount of pocket money and smoking status (P-value=0.05).The results showed that the majority of the respondents285 (70%) agreed to the belief that students smoked cigarettes due to availability of cigarettes at every corner of the campus, 281 (79%) peer influenced by friends 289 (71%) family members who smoke, and 313 (76.8%)increase social interaction. The majority of the students were knowledgeable about health consequences caused by smoking. Nonsmoking students were more knowledgeable about harmful effects of smoking as compared to smokers (P=0.00. Conclusion: The study concludes that students smokes cigarettes due to being a friend with someone who smokes, being in new a environment, stress, depression, observation of other students smoking, no signage prohibiting smoking and lack of knowledge regarding health / NRF

Background: Carbon monoxide (CO) is a toxic gas, but it is also produced endogenously when haem is degraded. When produced in vivo, CO is believed to have positive biological effects. For example it activates the production of cyclic guanosine mono-phosphate and causes vasodilatation. CO is also believed to have anti-inflammatory properties by binding to Mitogen activated protein (MAP) kinase. Several studies in cells, mice and rats support this opinion regarding both the circulatory as well as the anti-inflammatory properties. However, studies in larger animals regarding circulatory effects have demonstrated contradictory results. The only study in humans regarding anti-inflammatory properties of CO could not demonstrate such effects. Methods: This thesis consists of four different models. In paper I a method for analysis of CO in blood was developed using gas chromatography. In paper II a porcine model was used to investigate the elimination time for CO. The pigs in paper II had a high concentration of CO administered via blood, and CO concentrations were followed over time and kinetically parameters calculated. Circulatory parameters were also measured to evaluate if there were any circulatory changes after CO administration. In paper III CO´s anti-inflammatory properties were investigated in an endotoxin-induced systemic inflammatory model in pigs. Paper III was a randomized study where one group inhaled CO and the other group served as controls. Plasma cytokine concentrations were measured and followed over time as an indication of the inflammatory state. In paper IV, CO concentrations in blood from blood donors at the Blood Centre in Umeå were investigated. The blood donors also completed a questionnaire about age, smoking history and other possible sources for exogenous contamination of CO in the blood. Results and conclusions: In paper I we developed a method suitable for analysis of low concentrations of CO in blood. The half-life of CO at levels of 250 µM in pigs was found to be 60 minutes. CO did not show anti-inflammatory effects after an endotoxin-induced systemic inflammation in pigs. In banked blood CO was present at concentrations up to six times higher than normal concentrations. This could be a risk when transfusing such blood to susceptible patients.

College students and emerging adults have been found to be at risk for smoking cigarettes, drinking to excess, using illicit drugs, driving dangerously, and engaging in risky sexual and delinquent behaviour. Psychosocial correlates (Sensation Seeking, peer behaviour, parent behaviour, and peer and parent anti-substance use messages) from three domains of influence (personality, parent, and peer) were examined together to provide a greater context for the occurrence of such health-risk behaviours. The strongest predictor(s) of each behaviour were identified to better inform intervention practices. Three groups were compared— 1) those who never tried substances, 2) those who tried substances in the past, and 3) those who continue to use substances at present, in a population of emerging adults. Self-report data was gathered from 203 Collèges d'Enseignement Général Et Professionnel (CEGEP) students in the Montreal region. Measures included: Reckless Behaviour Questionnaire, Reckless Driving Measure, Health Behaviour Survey, Sensation Seeking Scale—Form V, and the Marlowe-Crowne Social Desirability Scale. Results revealed that peer behaviour was the most significant predictor of substance use in emerging adults, whereas parent behaviour was only a significant predictor of reckless driving. Sensation Seeking, specifically Disinhibition, was found to predict more global reckless behaviours, including illegal activities, such as stealing or using marijuana (p < .01). Neither peer nor parent anti-substance messages were significantly related to any of the health-risk behaviours measured in this study. It would appear that health-risk behaviours tend to be related to the same underlying factors but to varying degrees. Intervention implications are discussed.

College students and emerging adults have been found to be at risk for smoking cigarettes, drinking to excess, using illicit drugs, driving dangerously, and engaging in risky sexual and delinquent behaviour. Psychosocial correlates (Sensation Seeking, peer behaviour, parent behaviour, and peer and parent anti-substance use messages) from three domains of influence (personality, parent, and peer) were examined together to provide a greater context for the occurrence of such health-risk behaviours. The strongest predictor(s) of each behaviour were identified to better inform intervention practices. Three groups were compared— 1) those who never tried substances, 2) those who tried substances in the past, and 3) those who continue to use substances at present, in a population of emerging adults. Self-report data was gathered from 203 Collèges d'Enseignement Général Et Professionnel (CEGEP) students in the Montreal region. Measures included: Reckless Behaviour Questionnaire, Reckless Driving Measure, Health Behaviour Survey, Sensation Seeking Scale—Form V, and the Marlowe-Crowne Social Desirability Scale. Results revealed that peer behaviour was the most significant predictor of substance use in emerging adults, whereas parent behaviour was only a significant predictor of reckless driving. Sensation Seeking, specifically Disinhibition, was found to predict more global reckless behaviours, including illegal activities, such as stealing or using marijuana (p < .01). Neither peer nor parent anti-substance messages were significantly related to any of the health-risk behaviours measured in this study. It would appear that health-risk behaviours tend to be related to the same underlying factors but to varying degrees. Intervention implications are discussed.