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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
161

Role of Mast cells in HPV-induced skin cancer

Ghouse, Shanawaz Mohammed 10 August 2017 (has links)
Mast cells (MCs) are long-lived immune cells, which were reported to play an important role in initiating innate and adaptive immune responses against various infections. MCs accumulate in high numbers in the stroma and at the invasion front of various human cancers, suggesting a possible contribution by MCs to tumour growth. Experimental studies using crosses of MC-deficient Kit-mutant mouse strains with mouse models of epithelial cancers have provided evidence for important MC tumour-promoting functions. However, the complex alterations of the immune system that characterize Kit-mutant mice in addition to their MC deficiency, limit the interpretation of these findings. Numerous key observations made in Kit mutant mice were not reproduced in novel, Kit-independent mouse models of MC deficiency. Thus, the impact of MCs on tumour biology remains unclear. The aim of this study is to clarify the contribution of MCs to the biology of Human papilloma virus (HPV)-induced skin cancer in a Kit-independent mouse model of MC deficiency. In K14-HPV16 transgenic mice, HPV oncogenes are constitutively expressed in the epidermis resulting in epidermal hyperplasia with 100% penetrance and squamous cell carcinoma in about 50% of the animals. A cross to a Kit-mutant line suggested that MCs are important tumour promoters in this model. We crossed K14-HPV16 mice to M5Cre R-DTA line, in which MCs are constitutively depleted with high efficiency and selectivity. Unexpectedly, the loss of MCs neither affected keratinocyte proliferation indices nor altered keratinocyte apoptosis at any stage of HPV-induced neoplasia. Furthermore, the loss of MCs did not result in any detectable changes in composition and gene expression of the inflammatory hematopoietic cell infiltrate in the tumour stroma. This shows that, contrary to current belief, MCs have no important function in orchestrating the tumour micro milieu. In keeping with this finding, MC deficiency resulted in no detectable difference in the incidence growth or grading of SSC in K14-HPV16 transgenic mice. Collectively, these results show that, despite their high density in HPV-induced neoplasia, MC have no role in cancerogenesis or neoplastic progression in the K14-HPV16 mouse model. Our findings also emphasize the importance of novel Kitindependent mouse models in the investigation of MC in vivo functions.
162

Same-day vs. next-day reconstruction following Mohs micrographic surgery: a comparative study

Zingas, Louis P. 07 December 2020 (has links)
BACKGROUND: Skin cancer is the most common malignant neoplasm, with more than 5.4 million cases diagnosed annually in the United States. Treatment varies based on the type of neoplasm, its location, as well as primary vs. recurrent lesions. Nonetheless, surgical treatment remains the gold standard. Mohs micrographic surgery (MMS) is a commonly used surgical technique in the excision of such neoplasms. The technique of MMS allows for the precise removal of skin cancers while offering the highest cure rates with maximal preservation of surrounding tissue. Repairs of MMS defects are often done the same day if performed by the resecting Mohs surgeon. However, for more complicated reconstructive procedures, repairs are often performed by a separate reconstructive surgeon. When this occurs, MMS repairs may be delayed and performed on a different day due to a variety of factors such as surgical scheduling conflicts and patient tolerance. Researchers are urgently trying to explore the implications and postoperative complications of delayed MMS as compared to same day MMS. OBJECTIVE: This study compares same-day vs. next day eyelid reconstruction following MMS with attention to postoperative complications. Our aim is to investigate whether or not a delay in closure is associated with an increase in postoperative complications. METHODS: We performed a retrospective chart review of patients who underwent eyelid reconstruction following MMS from January 2008 to December 2018, by a single private practice oculoplastic surgeon. The timing of each patient’s reconstruction along with age, sex, comorbidities, such as diabetes, current smoking status, previous radiation therapy, anticoagulation treatment, and occurrence of postoperative complications were recorded. The specific location of the defect was recorded as well. The timing of reconstruction was classified as same-day or next-day reconstruction. No reconstructions took place more than 48 hours after tumor excision. The complications included in our analysis were: hematoma, wound infection, flap necrosis, dehiscence, and ectropion. Statistical significance was determined by Pearson’s chi-squared analysis. RESULTS: A total of 485 procedures were performed on 390 patients. 334 (69%) of those procedures were same-day reconstructions, while 151 (31%) of those procedures were next-day reconstructions. 19 (5.7%) of the 334 same-day reconstructions and 9 (5.9%) of the 151 next-day reconstructions were associated with complications (p=0.905). Therefore, a total of 28 (5.8%) procedures were associated with complications. More women (54%) than men (46%) underwent reconstruction. Multivariate logistic regression showed that males had a 1.274-fold higher risk of developing complication post reconstruction. Current smokers had a 1.054-fold higher risk of developing complications post reconstruction. CONCLUSIONS: There is no statistically significant difference in the postoperative complication rate when comparing same-day vs. next-day eyelid reconstruction following Mohs micrographic surgery.
163

A Randomized Trial of a Dissonance-Induction Intervention to Decrease Tanning Behaviors among College Females

Chait, Sari R 27 August 2009 (has links)
Sun exposure is implicated in the majority of skin cancer cases so it is important to identify interventions that successfully decrease young people's tanning behaviors and increase their sun protection behaviors. Research suggests that interventions that focus on the more immediate appearance related effects of tanning, rather than on future health risks, may be more effective in altering UV-related behaviors. Dissonance induction is a strategy that has been used to successfully alter other health-related behaviors. This study sought to determine if a dissonance induction intervention might be similarly successful in changing UV-related behaviors. The study yielded mixed findings. Relative to a healthy lifestyle control condition, the tanning condition resulted in a decrease in intentions to tan indoors and in actual number of hours spent sunbathing. The tanning condition also resulted in an increase in intentions to use sunscreen on the body. However, compared to a psycho-educational control condition, both groups seemed to have been equally successful and unsuccessful on different measures of UV-related behaviors and intentions. The findings of this study suggest that a dissonance induction intervention for tanning may be successful, but that it requires further study. Despite the mixed findings, this study serves as an important step in the search for successful interventions for decreasing tanning behaviors and increasing sun-protection behaviors.
164

Surgical Treatment and Reconstruction of Nasal Defects According to the Aesthetic Subunits Principles

Núñez-Castañeda, José Miguel, Chang-Grozo, Silvana Lucia 01 January 2021 (has links)
El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / The aim of this study was to determine the prevalence of nasal skin cancer, its location by facial aesthetic subunits and the type of reconstructive procedures performed for each nasal subunit after excision for nasal skin tumors. Observational cross-sectional study of all consecutive patients with the diagnosis of skin tumor located in the nasal unit, treated from 2018 to 2019 by the department of head and neck surgery of a general hospital. 60 patients were treated with nasal skin tumors excisions. A total of 52 patients (86,6%) had basal cell skin cancer, 7 (11,6%) had squamous cell skin cancer and 1 (1,6%) had melanoma. Fifty-nine patients (98.33%) presented a primary tumor and just 1 case (1,66%) recived a previous surgical treatment. Regardless of the type of tumor, the tip subunit was the most often involved with 29 (48,33%) cases in total. Despite of the nasal aesthetic subunit affected, the most frequent type of procedure used for reconstruction was the rotation or advancement flap, based on aesthetic nasal subunits, which was performed in 39 cases (65%). Nasal reconstruction after skin cancer can be very complex, especially since all patients have high expectations about the results. In order to achieve good results, there is a necessity for careful analysis of the defect, correct planning and excellent technical execution of the procedures Frequently, staged procedures will be needed to achieve an optimal result. / Revisión por pares
165

Results of a Social Media Campaign to Prevent Indoor Tanning by Teens: A Randomized Controlled Trial

Buller, David B., Pagoto, Sherry, Baker, Katie, Walkosz, Barbara J., Hillhouse, Joel, Henry, Kimberly L., Berteletti, Julia, Bibeau, Jessica 01 June 2021 (has links)
Indoor tanning (IT) increases risk of developing skin cancer. A social media campaign to reduce mother's permissiveness toward their teenage daughters IT was evaluated. Mothers (N = 869) of daughters aged 14–17 in 34 states without bans on IT by minors were enrolled in a randomized trial with assessments at baseline and 12-months follow-up in 2017–19. A year-long adolescent health campaign was delivered to all mothers. The intervention group received posts on preventing IT and the control group, posts about preventing prescription drug misuse. Daughters (n = 469; 54.0%) completed the assessments at baseline and 12 months. At 12-month follow-up, intervention-group mothers were less permissive of IT by daughters (unadjusted means = 1.70 [95% CI: 1.59, 1.80] v. 1.85 [1.73, 1.97] [5-point Likert scale], b = -0.152), reported more communication about avoiding IT with daughters (4.09 [3.84, 4.35] v. 3.42 [3.16, 3.68] [sum of 7 yes/no items], b = 0.213), and had lower intentions to indoor tan (1.41 [1.28, 1.55] v. 1.60 [1.43, 1.76] [7-point likelihood scale], b = -0.221) than control-group mothers. Daughters confirmed intervention-group mothers communicated about IT (3.81 [3.49, 4.14] v. 3.20 [2.87, 3.53] [sum of 7 yes/no items], b = 0.237) and shared IT posts (unadjusted percentages = 52.4% v. 36.4%, b = 0.438) more than control-group mothers. No differences were found in IT behavior, self-efficacy to refuse permission, and negative attitudes toward IT. A social media campaign may be an effective strategy to convince mothers to withhold permission for IT, which may help increase the effectiveness of state laws designed to reduce IT by minors by requiring parental permission.
166

An Examination of Psychological Variables Relevant to Artificial Tanning Tendencies

Hillhouse, Joel, Turrisi, Robert, Holwiski, Frank, McVeigh, Scott 01 January 1999 (has links)
Cognitions relevant to tanning salon decision making were studied using Jaccard's Theory of Alternative Behavior. Questionnaires were administered assessing tanning salon use, attitudes toward tanning salon use, attitudes toward reasonable behavioral alternatives, and cognitive variables underlying these variables. Tanning salon use reports were very high in this sample. The results support the notion that young people make decisions regarding using tanning salons based on the behavioral alternatives available to them. Specifically, subjects with stronger preferences for using clothing to enhance appearance were less likely to use tanning salons. Furthermore, the multivariate approach used clearly delineates the specific cognitive beliefs and orientations that might be targeted to change these attitudes. The relevance of these findings to skin cancer prevention is discussed.
167

A Comparison of the Efficacy of an Appearance-Focused Skin Cancer Intervention Within Indoor Tanner Subgroups Identified by Latent Profile Analysis

Stapleton, Jerod, Turrisi, Rob, Hillhouse, Joel, Robinson, June K., Abar, Beau 01 June 2010 (has links)
The reduction of intentional exposure to ultraviolet (UV) radiation is an important area of skin cancer prevention. Hillhouse et al. (Cancer 113:3257-3266, 2008) have developed an appearance-focused intervention with evidence of efficacy in lowering indoor tanning UV exposure in young women. In the current study, a subgroup approach was used to determine moderators of intervention efficacy. Undergraduate females in two regions of the United States (n = 362) were randomized into an intervention or control condition. Latent profile analysis was used to identify subgroups of indoor tanners based on patterns of indoor tanning motives. Intervention efficacy was examined within each subgroup. We found evidence for 4 subgroups of tanners: knowledgeable-appearance tanners, low-knowledge tanners, low-knowledge, relaxation tanners, and knowledgeable, low-appearance and lowrelaxation tanners. The intervention significantly reduced indoor tanning for the low-knowledge subgroup (34% of the sample). The utility of the subgroup approach in developing targeted behavioral skin cancer interventions is discussed.
168

Preventing Skin Cancer in College Females: Heterogeneous Effects Over Time

Abar, Beau W., Turrisi, Robert, Hillhouse, Joel, Loken, Eric, Stapleton, Jerod, Gunn, Holly 01 November 2010 (has links)
Objectives: To evaluate the effects of an appearance-focused intervention to reduce the risk of skin cancer by decreasing indoor tanning, examine potential heterogeneity in tanning across this time, and correlate the subtypes with predictors collected at baseline. Design: Randomized controlled trial with 379 female college students measured at 6 monthly time points. Main Outcome Measure: Self-reported indoor tanning frequency. Results: The intervention was effective at decreasing tanning over the period between the fall and spring. Longitudinal latent class analysis found 3 patterns of tann1ers among the treatment individuals: abstainers, moderate tanners, and heavy tanners. These classes appeared in both the treatment and control conditions, and the intervention had a harm reduction effect by reducing levels of exposure within the moderate and heavy tanner classes. Participant age and self-reported tanning patterns were found to be predictive of class membership. Conclusions: This research suggests that brief intervention approaches can be effective at reducing risk for skin cancer and illustrates several ways in which these protective effects can be enhanced.
169

Appearance Motives to Tan and Not Tan: Evidence for Validity and Reliability of a New Scale

Cafri, Guy, Thompson, J. Kevin, Roehrig, Megan, Rojas, Ariz, Sperry, Steffanie, Jacobsen, Paul B., Hillhouse, Joel 01 April 2008 (has links)
Background: Risk for skin cancer is increased by UV exposure and decreased by sun protection. Appearance reasons to tan and not tan have consistently been shown to be related to intentions and behaviors to UV exposure and protection. Purpose: This study was designed to determine the factor structure of appearance motives to tan and not tan, evaluate the extent to which this factor structure is gender invariant, test for mean differences in the identified factors, and evaluate internal consistency, temporal stability, and criterion-related validity. Method: Five-hundred eighty-nine females and 335 male college students were used to test confirmatory factor analysis models within and across gender groups, estimate latent mean differences, and use the correlation coefficient and Cronbach's alpha to further evaluate the reliability and validity of the identified factors. Results: A measurement invariant (i.e., factor-loading invariant) model was identified with three higher-order factors: sociocultural influences to tan (lower order factors: media, friends, family, significant others), appearance reasons to tan (general, acne, body shape), and appearance reasons not to tan (skin aging, immediate skin damage). Females had significantly higher means than males on all higher-order factors. All subscales had evidence of internal consistency, temporal stability, and criterion-related validity. Conclusions: This study offers a framework and measurement instrument that has evidence of validity and reliability for evaluating appearance-based motives to tan and not tan.
170

Peer Crowd Identification and Indoor Artificial UV Tanning Behavioral Tendencies

Stapleton, Jerod, Turrisi, Rob, Hillhouse, Joel 01 October 2008 (has links)
In this study, the relation between peer crowd identification and indoor tanning behavioral tendencies was examined. Participants were 174 undergraduate students at a large university in the USA. Results indicated peer crowd identification was significantly associated with indoor artificial UV tanning behavioral tendencies (attitudes, normative beliefs, past year use and intentions) independent of gender and skin type. Participants who identified with the popular peer crowd were at the greatest risk for indoor tanning UV exposure while identification with the brain crowd was protective against such behavior. The findings are discussed in terms of implications for future skin cancer intervention efforts.

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