The utilisation of near-infrared Raman spectroscopy for the discrimination of cancers and pre-cancers from normal tissue in the acro-digestive tract has been evaluated. A commercially available Raman microspectrometer has been modified to provide optimum throughput, sensitivity and fluorescence suppression for epithelial tissue measurements. Laser excitation at 830nm was demonstrated to be optimum. High quality (SN ratio 15-20) NIR-Raman spectra have been acquired from oesophageal and laryngeal tissues in time scales under 30 seconds. Pathological groupings covering the full range of normal and neoplastic tissues in the organs of interest have been studied. Both fresh (snap frozen) and formalin fixed tissue samples were investigated, firstly to indicate whether tissue-types can be distinguished in vivo and secondly to demonstrate the use of Raman spectroscopy as a tool for classification in the pathology lab. Results using multivariate statistical techniques to distinguish between spectra from specimens exhibiting different tissue pathologies have been extremely promising. Cross-validation of the spectral predictive models has shown that three groups of larynx tissue can be separated with sensitivities and specificities of between 86 and 90% and 87 and 95% respectively. Oesophageal prediction models have demonstrated sensitivities and specificities of 84 to 97% and 93 to 98% respectively for a three-group consensus model and 73 to 100% and 92 to 100% for an eight-group consensus model. Epithelial tissues including stomach, tonsil, endometrium, bladder and prostate have been studied to identify further tissues where Raman spectroscopy may be employed for detection of disease. Spectra were similar to those obtained from oesophagus and larynx, although sufficiently different for distinct discriminant models to be required. This work has demonstrated the generic nature of Raman spectroscopy for the detection and classification of cancers and pre-cancerous lesions in many tissues. The evidence provided by this study indicates that utilisation of Raman spectroscopy for non-invasive detection and classification of disease is a distinct possibility. Potential difficulties in the transferability from in vitro to in vivo have been evaluated and no significant barriers have been observed. However, further in vivo probe development and optimisation will be required before 'optical biopsy' with Raman spectroscopy can become a reality.

DISSERTATION SUBMITTED IN FINAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE MASTERS OF TECHNOLOGIAE IN NURSING IN THE FACULTY OF HEALTH AND WELLNESS SCIENCES AT THE CAPE PENINSULA UNIVERSITY OF TECHNOLOGY 2015 / Beliefs and awareness towards prostate cancer screening among men is very crucial for early detection and management of the condition. From various literatures reviewed, prostate cancer is the second leading cause of death amongst men. In Nigeria, it is the most common male cancer and may be as high as that seen in African Americans in the United State. In most developing countries e.g Benin Republic, Gambia, Senegal, Ghana, and Nigeria, access to health care and prostate cancer screening methods for early detection is limited. AIM: The aim of the study is to assess the knowledge, belief and attitude of male students in the Benson Idahosa University, Benin City, Nigeria towards prostate cancer screening in order to curb the high incidence and death rate resulting from this disease. POPULATION: The study populations will be Faculty of Social and management Science students of range 18-35 years at Benson Idahosa University, Benin-City, Nigeria. SAMPLE: All students will be selected from the number of male students that are registered in the Faculty of Social Science. METHODOLOGY: This design selected for this study is qualitative cross-sectional. METHOD OF DATA COLLECTION: Interviews and questionnaires will be used as tool for data collection. KEY FINDINGS: The students had never received information from their health care provider about prostate cancer. Very few were able to identify the possible symptoms of prostate cancer. There is low level of knowledge about prostate cancer screening and they do not know what abnormal prostate specific antigen (PSA) is. Majority of the participants gained informed knowledge about prostate cancer screening for the first time from this study. The students have a pronounced negative attitude towards prostate cancer screening. Lack of awareness about cancer screening programs is also identified as a major barrier why many Nigerian men do not go for screening. The level of education has a positive influence to prostate cancer and screening. Prostate cancer screening is not a taboo to Bini culture. CONCLUSIONS: The findings of this study revealed that there is low level of knowledge about prostate cancer among male university students in Benin-City, Nigeria. RECOMMENDATIONS: Initiation of cancer teachings in schools, churches, and traditional gatherings. Demonstrations with the use posters in public places about prostate cancer menace and screening should be 3 encouraged. There should be implementation of policy that every male student from age 30 be involved in health education and promotion programs for prostate cancer. KEYWORDS: male, University students, knowledge of prostate cancer, beliefs and attitude towards screening for prostate cancer, Prostate cancer screening

The utilisation of near-infraredR aman spectroscopyfo r the discrimination of cancersa nd pre-cancers from normal tissue in the acro-digestive tract has been evaluated. A commercially available Raman microspectrometehr as been modified to provide optimum throughput, sensitivity and fluorescence suppression for epithelial tissue measurements. Laser excitation at 830nmw as demonstratedto be optimum. High quality (SN ratio 15-20) NIR-Raman spectrah ave been acquired from oesophageaal nd laryngeal tissues in time scales under 30 seconds. Pathological groupings covering the full range of normal and neoplastic tissues in the organs of interest have been studied. Both fresh (snap frozen) and formalin fixed tissue samples were investigated,f irstly to indicate whether tissue-typesc an be distinguishedi n vivo and secondlyt o demonstrateth e use of Raman spectroscopya s a tool for classificationi n the pathology lab. Results using multivariate statistical techniques to distinguish between spectra from specimens exhibiting different tissue pathologies have been extremely promising. Crossvalidation of the spectral predictive models has shown that three groups of larynx tissue can be separated with sensitivities and specificities of between 86 and 90% and 87 and 95% respectively. Oesophageal prediction models have demonstrated sensitivities and specificities of 84 to 97% and 93 to 98% respectively for a three-group consensus model and 73 to 100% and 92 to 100% for an eight-groupc onsensusm odel. Epithelial tissues including stomach, tonsil, endometrium, bladder and prostate have been studiedt o identify further tissuesw hereR amans pectroscopym ay be employedf or detection of disease.S pectraw ere similar to those obtainedf rom oesophagusa nd larynx, although sufficiently different for distinct discriminant models to be required. This work has demonstratedth e genericn atureo f Ramans pectroscopyfo r the detectiona nd classification of cancersa nd pre-cancerousle sionsi n many tissues.T he evidencep rovided by this study indicatest hat utilisation of Ramans pectroscopyfo r non-invasived etectiona nd classification of diseaseis a distinct possibility. Potentiald ifficulties in the transferabilityf rom in vitro to in vivo have been evaluated and no significant barriers have been observed. However, further in vivo probe development and optimisation will be required before 'optical biopsy' with Ramans pectroscopyc anb ecomea reality.

Four methods were investigated to determine their suitability for use in a CF screening programme for the province of British Columbia. A fecal trypsin method which measured trypsin activity by incubating dry stool samples on filter paper cards with the substrate p-tosyl-arginine methyl ester (TAME) and a pH sensitive dye was shown to be non-specific and therefore unsatisfactory. An attempt to combine a fecal albumin screen with a more specific quantitative immunodiffusion technique for albumin and alpha-1 antitrypsin was unsuccessful. A meconium albumin assay using the Boehringer-Mannheim Corporation (BMC) test-strip and a more specific fecal trypsin assay which uses the substrate benzoyl-arginine-p-nitroanilide (BAPNA) were incorporated into two pilot projects at Children's Hospital in Vancouver. The BMC test-strip was simple to use, reliable and inexpensive. Of 8,891 infants tested, 3 positives were diagnosed as suffering from cystic fibrosis and 1 CF patient tested negative. False positives were obtained on 1.3% of infants. The incidence of CF as determined by this screen was 1 in 2000. The meconium albumin screen was satisfactory as a local pilot project but the disadvantages of testing the unstable meconium specimens make the screen unsuitable for a province-wide application. The BAPNA fecal trypsin method devised by Crossley was used to test 4085 dry stool specimens collected in the hospital and at home. Out of a total number of 190 positive results, none was diagnosed as having CF, giving a false positive rate of 5.0% for the hospital collected specimens and 3.4% for the specimens collected at home. The false positive rate in the hospital collected specimens was due mostly to the large proportion of young infants (under 3 days). The false positive rate of the home collected specimens appeared to be due mostly to the thinner spread of stool sample on the card. Because the quantity of stool sample per test was significantly lower in the home than the hospital collected specimens a new cut-off point for the home collected specimens was considered. Its application/ however did not lower the false positive rate sufficiently. As a result, the high incidence of false positives and the difficulties encountered as a result of this incidence also makes the fecal trypsin screen unsuitable for the province of B.C. Difficulties encountered during the follow-up of positive results obtained in the two pilot projects are discussed and recommendations are made regarding the efficient and adequate implementation of a follow-up system. / Medicine, Faculty of / Pathology and Laboratory Medicine, Department of / Graduate

A community health unit in a British Columbia suburb established a screening clinic for 3-year-olds modelled on similar programs already operating in nearby localities. The purpose of the study was to describe this new screening clinic: to report on the procedures employed, the personnel involved, the characteristics of the clientele, and the types, incidence, and disposition of problems detected amongst the children brought to the clinic. The study population consisted of the 47 children and their parents who were the clients of the clinic during its first three months. The research instruments were original questionnaires and forms devised to obtain sociological and health history information. The forms were completed during a home visit and by a telephone interview with each family. The data are arranged in frequency tables and percentages calculated where appropriate. A few variables are cross-tabulated to add descriptive depth to the study. The families in the study were from the middle and upper-middle class segment of society. They had frequently used other health resources in the community. The mothers' main concerns were about speech and language development and behavior problems of their children. Twenty-four children were referred by the clinic staff for 39 problems requiring retesting, further investigation, or intervention. Twelve of these referrals were for problems of vision, 10 for behavior, 6 for speech and language, 3 each for hearing, nutrition, and dental health, and 2 for physical developmental delay. The children cooperated enthusiastically in the test procedures and their parents found the clinic to be reassuring and a valuable learning experience. The parents were willing to comply with the referrals, but some delays in the follow-up procedures were noted, due to the newness of the clinic. The screening clinic for 3-year-olds appears to be filling a previously unmet need in the community. Community health workers involved in planning and promoting new services should find the detailed descriptions of the procedures and of the clientele of the clinic useful to them. The extensive bibliography provides a background of published material on the rationale and result of a variety of methods of screening. Comparison with similar clinics in other areas will be impossible until terminology used, test procedures employed, and methods of reporting results are standardized. Meanwhile, the clinic staff should continue to maintain statistical evidence of the results obtained and to evaluate the procedures used in its program. / Applied Science, Faculty of / Nursing, School of / Graduate

Please read the abstract in the section 00front of this document / Dissertation (MSc (Chemical Pathology))--University of Pretoria, 2005. / Chemical Pathology / unrestricted

The goal of this dissertation is to examine the utility of screening for common mental disorders in primary care in low and middle income countries. Screening for common mental disorders in primary care is often considered as an important step in addressing the mental health treatment gap in low and middle income countries. Nevertheless, there is insufficient evidence to support routine mental health screening in primary care in these countries. Even in high income countries, there is a lack of consensus on the effectiveness of routine mental health screening in primary care, especially screening for depression. Challenges to screening include the high rates of false positive diagnosis, poor evidence on outcomes for people identified by screening, and potential harms due to screening. The specific aims of this dissertation are to: 1) synthesize evidence from low and middle income countries on the current practices of screening for common mental disorders in primary care and the use of screening instruments; 2) understand the significance of a positive screen for common mental disorder in primary care, specifically the distribution and the stability of ICD-10 diagnosis for screened positive patients, their clinical course over a period of one year, and the factors associated with the clinical course; 3) examine the factors associated with antidepressant prescriptions for patients screened positive for common mental disorders in primary care and evaluate the appropriateness of antidepressant prescriptions following screening. Based on our review of literature, evidence to support routine screening for common mental disorders in primary care in low and middle-income countries is inadequate. We highlight concerns about the fidelity with which screening is implemented, especially the flawed use of screening instruments. Introducing depression screening and physician notification in these settings seldom results in improved access to care or appropriate care. The majority of patients identified by screening in primary care have contextual, and probably non-pathological psychological distress (see page iii, for definition of key terms) which is often temporary and self-limiting. Patients with persistent distress symptoms identified by repeated screening, and those with moderate to severe depression may benefit from screening in the presence of evidence based stepped care interventions that are easily accessible and acceptable. Although, the long term effects of these interventions and the sustainability of such primary care based programs in low and middle income countries are uncertain. Our analysis of data from a cluster randomized control trial in India confirmed that a significant proportion of patients screened positive for common mental disorders in primary care has psychological distress that is temporary and self-limiting. However, a smaller, albeit important share of patients also experienced psychological distress that persisted throughout one-year follow-up. Persistent distress was predicted by psychosocial and economic disadvantage. Thus, psychosocial support systems and structural interventions have a larger role to play in addressing psychological distress. We found poor diagnostic stability for ICD-10 based diagnoses, and the most stable and prevalent diagnosis was mixed anxiety and depressive disorder. Further, we found that antidepressants are widely prescribed following screening especially for women and older adults. While many patients with moderate to severe depression could benefit from antidepressants, it is problematic that a significant proportion of patients with less severe disorders also received anti-depressant prescription despite the availability of non-pharmacological treatment options. In summary, there is a lack of empirical evidence to support routine screening for common mental disorders in primary care in low and middle income countries as an effective strategy to identify those in need of treatment; instead screening could lead to over diagnosis and inappropriate antidepressant prescriptions. To address psychological distress in primary care and the unmet need for treatment in low and middle income countries, there is an urgent need to focus on locally driven and culturally relevant approaches to case finding and intervention.

Alzheimer’s disease and related dementias (ADRD) are among the leading causes of disability and mortality among the older population worldwide and a costly public health issue, yet there is still no treatment for prevention or cure. Clinical trials are available, but successful recruitment has been a longstanding challenge. One strategy to improve recruitment is conducting eligibility prescreening, a resource-intensive process where clinical research staff manually go through electronic health records to identify potentially eligible patients. Natural language processing (NLP), an informatics approach used to extract relevant data from various structured and unstructured data types, may improve eligibility prescreening for ADRD clinical trials. Guided by the Fit between Individuals, Task, and Technology framework, this dissertation research aims to optimize eligibility prescreening for ADRD clinical research by evaluating the sociotechnical factors influencing the adoption of NLP-driven tools. A systematic review of the literature was done to identify NLP systems that have been used for eligibility prescreening in clinical research. Following this, three NLP-driven tools were evaluated in ADRD clinical research eligibility prescreening: Criteria2Query, i2b2, and Leaf. We conducted an iterative mixed-methods usability evaluation with twenty clinical research staff using a cognitive walkthrough with a think-aloud protocol, Post-Study System Usability Questionnaire, and a directed deductive content analysis. Moreover, we conducted a cognitive task analysis with sixty clinical research staff to assess the impact of cognitive complexity on the usability of NLP systems and identify the sociotechnical gaps and cognitive support needed in using NLP systems for ADRD clinical research eligibility prescreening. The results show that understanding the role of NLP systems in improving eligibility prescreening is critical to the advancement of clinical research recruitment. All three systems are generally usable and accepted by a group of clinical research staff. The cognitive walkthrough and a think-aloud protocol informed iterative system refinement, resulting in high system usability. Cognitive complexity has no significant effect on system usability; however, the system, order of evaluation, job position, and computer literacy are associated with system usability. Key recommendations for system development and implementation include improving system intuitiveness and overall user experience through comprehensive consideration of user needs and task completion requirements; and implementing a focused training on database query to improve clinical research staff’s aptitude in eligibility prescreening and advance workforce competency. Finally, this study contributes to our understanding of the conduct of electronic eligibility prescreening for ADRD clinical research by clinical research staff. Findings from this study highlighted the importance of leveraging human-computer collaboration in conducting eligibility prescreening using NLP-driven tools, which provide an opportunity to identify and enroll participants of diverse backgrounds who are eligible for ADRD clinical research and accelerate treatment development.

研究背景： / 2009年起，中國政府發起並資助了一項覆蓋全國31個省221個鄉村、針對100萬名農村婦女的細胞學及肉眼觀察宮頸癌篩查試點項目。國家及地方政府需要對可行的篩查策略進行衛生經濟學評估，為下一步擴大規模的篩查提供政策依據。 / 研究目標： / 應用人群特異性Markov模型，對巴氏塗片及肉眼觀察的宮頸癌篩查策略進行成本效果及成本效用兩方面的衛生經濟學評估，進而為中國農村婦女宮頸癌篩查政策的制定提供依據。 / 研究方法： / 本論文工作建立了Markov人群動態擬合模型，該模型能夠整合與中國農村宮頸癌流行情況相吻合的成本及健康狀況的數據，進而用於擬合20年內35-59歲中國農村婦女在有/無篩查幹預下的成本、效用和效果。本文分析的八個備選篩查策略包括：採用醋酸染色肉眼觀察（VIA）或傳統細胞學（巴氏塗片）分別進行10年，5年，3年及1年一次的篩查。 / 本文從社會學角度出發，成本數據涵蓋篩查、診斷及治療過程中產生的直接及間接成本。模型在結構上綜合了已被廣泛認可的宮頸癌自然發展史模型，以及宮頸癌及其癌前病變（CIN）在中國農村進行篩查和治療的標準臨床路徑。模型輸入參數盡可能地使用了能夠反映中國農村婦女人群特異性的數據。通過對比國家報告數據與模型預測結果，本文從全死因死亡率、宮頸癌死亡率及宮頸癌發病率三個方面驗證了模型的可信度。 / 模型的結局變量包括：累計成本、累計生命年(LYs)、累計質量調整生命年(QALYs)、預期宮頸癌死亡率及發病率降低百分比(%)、CIN 相對風險、宮頸浸潤癌相對風險，增量成本效用比(ICUR, 表述為每挽救一個質量調整生命年消耗的成本)及增量成本效果比(ICER, 表述為每挽救一個生命年消耗的成本)等。與無篩查幹預相比，我們界定ICUR及ICER小於三倍人均國內生產總值（76,824元，2009年)的優勢策略為‘具有成本效益’的選擇，並將其中ICUR和ICER最低的策略，定義為‘最具成本效益’的策略，將具有最大健康效益的策略（挽救最多質量調整生命年或生命年的策略），定義為‘最有效’的策略。同時，我們對可能影響決策的不確定因素進行了敏感性分析。 / 結果： / 與無篩查幹預相比，肉眼觀察及巴氏塗片篩查均能夠減少宮頸癌患病例數，進而顯示出一定的健康效益。較短的篩查間隔具有更高的健康效益。模型預測在不同的篩查策略幹預下，宮頸癌死亡率和發病率分別有望降低6.67-31.95%和5.12-24.71%，預期CIN發病相對風險為0.89-0.98，預期宮頸癌發病相對風險為0.73-0.95。篩查幹預對健康的保護作用在本研究中得到了證實。 / 成本效用分析顯示，10年一次的肉眼觀察策略最具成本效益，其次為5年一次、3年一次、1年一次的肉眼觀察篩查策略及1年一次的巴氏塗片篩查策略。與無篩查幹預相比，如上策略每挽救一個質量調整生命年消耗的成本為11,921至26,069元（1,892-4,138美元，2012年）。同時成本效果分析也顯示，10年一次的肉眼觀察策略最具成本效益，其次為5年一次的肉眼觀察策略及5年一次的巴氏塗片篩查策略。同樣與無篩查幹預相比，如上策略每挽救一個生命年消耗的成本為37,211至68,226元（5,906-18,830美元，2012年）。 / 對於某一既定策略，相應的ICUR和ICER受當地經濟狀況相關因素的影響最大，這些因素包括治療成本、篩查成本和成本貼現率。從檢測技術水平上看，肉眼觀察對分析結果的影響小於巴氏塗片，原因是前者敏感度範圍較小。篩查覆蓋率、初篩陽性隨訪率、診斷陽性治療率也都與相應的ICUR和ICER呈負相關性。敏感性分析結果顯示本文中模型對於健康結局的預測，及相關的衛生經濟學分析，受自然史模型中HPV感染和CIN之間轉移概率的不確定性的影響最大。HPV感染與CIN間的進展和逆轉概率是該項模型研究的核心參數。 / 結論： / 本文中成本效用和成本效果分析均顯示，相較於傳統的細胞學篩查策略，採用間隔時間較長（10年或5年）的肉眼觀察篩查策略，對一般發病地區的35-59歲的農村婦女來說，是更具‘成本效益’的選擇。對於宮頸癌高發地區，其篩查頻率可以提高到1年一次。1年一次的巴氏塗片篩查策略，是最有效的篩查策略，可以挽救最多的生命。但採用該策略時，應在財政預算允許的前提下，確保篩查技術和項目完成的質量。 / 篩查項目的高覆蓋率，對篩查陽性患者良好的隨訪和診治，初篩檢測技術平均水平以上的表現，以及較低的篩查和治療成本是確保篩查項目具備成本效益優勢的核心因素。本文完成的成本效用及成本效果分析，能夠為公共衛生決策提供重要的輔助作用。 / Background: / A Chinese government-sponsored cytology/visual inspection pilot cervical cancer screening program covered 10 million rural women in 221 counties of 31 provinces was initiated in 2009. Both the local and national governments in China need health economic evaluations of feasible strategies so as to make better policies for the next-step enlarging screening. / Objectives: / To perform health economic evaluations of Pap smear and visual inspection cervical cancer screening strategies using population-specific Markov modeling cost-utility (CUA) and cost-effectiveness (CEA) analyses, in order to assist screening policy making for women in rural China. / Methods: / Markov simulation models were developed to synthesize the evidence on costs and health outcomes related to cervical cancer epidemiology in rural China, and applied to predict the long-term utility, effectiveness and costs for hypothetical cohorts of 35-59 years old rural Chinese women, with or without the presence of screening over 20 years. The eight alternative screening strategies assessed were visual inspection with acetic acid (VIA) or traditional cytology (Pap smear) each with ten-year, five-year, three-year and one year screening intervals. / The study was conducted from the societal perspective, thus both directed and non-direct costs related to screening, diagnosis and treatment interventions were considered. The model structures incorporated with the well-accepted the natural history model of cervical cancer and the standard clinical pathway of screening and treatment interventions for precancerous lesions (CIN) and cervical cancer in real practice in rural China. Population-specific data were used as much as possible to be the model inputs. The model estimates were validated by comparison of our predictions of all-cause mortality, cervical cancer mortality and cervical cancer incidence with the national reported data. / Outcome variables included cumulative cost, life years (LYs), quality-adjusted life years (QALYs), predicted reduction(%) in cervical cancer mortality and incidence, relative risk of CIN, relative risk of cervical cancer, incremental cost-utility ratio (ICUR, presented as cost per QALY saved) and incremental cost-effectiveness ratio (ICER, presented as cost per life year saved). Compared with no screening, not-dominated strategies with ICUR and ICER less than three times China’s GDP per capita (76,824 CNY, 2009) were considered to be ‘cost-effective’ options. Among the identified ‘cost-effective’ options, the strategy with lowest ICUR or ICER was defined as the most cost-effective strategy, and the strategy with the highest health benefit (largest QALY saved or life year saved) was defined as the most effective strategy. Sensitivity analyses were conducted to test the effect of uncertainties on decision making. / Results: / All of the VIA and Pap smear screening strategies of showed certain benefits due to the decreased number of women developing cervical cancer, when compared with no screening. A trend for shorter screening interval to have greater benefit was also found. Cervical cancer mortality and incidence were expected to be reduced by 6.67-31.95% and 5.12-24.71% with different screening strategies. And the predicted relative risks of CIN and invasive cervical cancer of 0.89-0.98 and 0.73-0.95, respectively, also demonstrated the protective effect of screenings. / Modeling cost-utility analysis identified ten years VIA screening as the most cost-effective strategy followed by VIA screening with five-, three- and one year interval and Pap smear screening with a one year interval. Compared with no screening, the incremental costs per QALY saved of these strategies ranged from 11,921 to 26,069 Yuan (1,892-4,138 US dollars, 2012). In the meanwhile, modeling cost-effectiveness analysis also identified ten-years VIA screening as the most cost-effective strategy followed by VIA screening with five-year intervals and Pap smear screening with five-year intervals. Compared with no screening, the incremental costs per life year saved of these strategies ranged from 37,211 to 68,226 Yuan (5,906-18,830 US dollars, 2012). / Both ICUR and ICER of a selelected strategy were greatest influnced by factors related to variations in local economies , including treatment cost, screening cost and discounting rate of the cost. The influence of primary test performance of VIA was rather less than that of Pap smear due to the narrower ranges of the VIA sensitivities. Screening coverage, follow-up rate and treatment rate were also negatively associated with ICUR and ICER. Health outcome predictions and health economic analyses were mostly influenced by the uncertainties in HPV infection and CIN transitions in the natural history. Progression and regression probabilities between HPV infection and CIN were considered to be the key parameters of the simulation models. / Conclusions: / Baseline CUA and CEA results suggested that in comparison with traditional cytology screening strategies, organized VIA screening with long intervals (ten or five years) were more cost-effective options than for 35-59 years old women in normal incidence areas of rural China. The VIA screening interval can be shorten to one year in high incidence areas. Pap smear strategy with one year interval can be utilized as the most effective strategy with most lives saved when budget allows and the performances of program and test are ensured. / High coverage of the screening program, good management of screening positives, average or above performance of primary test, and lower screening and treatment costs are key elements for a cost-effective screening program. Cost-utility and cost-effectiveness analyses, such as the one conducted in this thesis study, can be considered important adjuncts to policy decision-making about public health objectives. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Li, Xue. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 388-401). / Abstracts also in Chinese; appendixes includes Chinese. / Abstract of thesis --- p.i / 中文摘要 --- p.v / ACKNOWLEDGEMENTS --- p.viii / TABLE OF CONTENTS --- p.1 / LIST OF TABLES --- p.8 / LIST OF FIGURES --- p.11 / ABBREVIATIONS --- p.12 / Chapter CHAPTER 1 --- INTRODUCTION --- p.14 / Chapter 1.1 --- Epidemiological patterns and disease burden of cervical cancer --- p.14 / Chapter 1.1.1 --- Cervical cancer incidence and mortality worldwide --- p.14 / Chapter 1.1.2 --- Risk factors for cervical cancer --- p.15 / Chapter 1.1.2.1 --- Human Papillomavirus (HPV) --- p.15 / Chapter 1.1.2.2 --- Parity --- p.16 / Chapter 1.1.2.3 --- Smoking --- p.16 / Chapter 1.1.2.4 --- Human Immunodeficiency Virus (HIV) --- p.17 / Chapter 1.1.2.5 --- Contraception --- p.17 / Chapter 1.1.2.6 --- Sexual behavior, nutrition and other factors --- p.18 / Chapter 1.1.3 --- Disease burden of cervical cancer in China --- p.18 / Chapter 1.1.3.1 --- Epidemiology of Cervical Cancer in China --- p.18 / Chapter 1.1.3.2 --- Cervical cancer in different geographic areas of China --- p.20 / Chapter 1.2 --- The need for cost-effectiveness analysis of cervical screening strategies in China --- p.21 / Chapter 1.2.1 --- Cervical cancer prevention in China --- p.21 / Chapter 1.2.2 --- Why do we need a modeling cost-effectiveness analysis? --- p.23 / Chapter 1.3 --- Natural history of cervical cancer --- p.25 / Chapter 1.3.1 --- Terminology --- p.25 / Chapter 1.3.2 --- Natural history of cervical cancer --- p.27 / Chapter 1.4 --- Secondary prevention strategies of cervical cancer --- p.29 / Chapter 1.4.1 --- Screening tests --- p.29 / Chapter 1.4.1.1 --- Cervical cytology --- p.29 / Chapter 1.4.1.2 --- Visual Inspection --- p.32 / Chapter 1.4.1.3 --- HPV testing --- p.36 / Chapter 1.4.2 --- Summary of different screening strategies all over the world --- p.37 / Chapter CHAPTER 2 --- LITERATURE REVIEW --- p.40 / Chapter 2.1 --- Background --- p.40 / Chapter 2.2 --- Objectives of the literature review --- p.41 / Chapter 2.3 --- Search strategies and results --- p.41 / Chapter 2.3.1 --- Search strategies --- p.41 / Chapter 2.3.2 --- Inclusion and exclusion criteria --- p.42 / Chapter 2.4 --- Literature results summary --- p.44 / Chapter 2.4.1 --- Methodology, target population and analytical perspective --- p.44 / Chapter 2.4.2 --- Screening test and program performance --- p.47 / Chapter 2.4.3 --- Cost and utility estimation --- p.49 / Chapter 2.4.4 --- Model parameter sources and validation --- p.53 / Chapter 2.4.5 --- Alternatives and identified cost-effective strategies --- p.58 / Chapter 2.5 --- Conclusions --- p.63 / Chapter CHAPTER 3 --- OBJECTIVES --- p.64 / Chapter 3.1 --- General Objectives --- p.64 / Chapter 3.2 --- Alternative cervical cancer screening strategies in this study --- p.64 / Chapter 3.3 --- Decision rules for recommended cost-effective options --- p.65 / Chapter 3.4 --- Analytical perspective and time horizon --- p.65 / Chapter 3.5 --- Objectives --- p.66 / Chapter 3.6 --- Analytical scenario in this study --- p.66 / Chapter 3.6.1 --- Patterns of cervical screening program delivery in rural China --- p.67 / Chapter 3.6.2 --- Demographic profile of the simulated hypothetical cohort --- p.67 / Chapter 3.6.3 --- Summary of model assumptions --- p.68 / Chapter 3.6.3.1 --- Assumptions related to screening performance and clinical practice --- p.68 / Chapter 3.6.3.2 --- Assumptions related to epidemiological characteristics of cervical cancer --- p.68 / Chapter 3.6.3.3 --- Assumptions related to economic evaluation --- p.69 / Chapter CHAPTER 4 --- METHODOLOGY --- p.70 / Chapter 4.1 --- Alternative strategies in this study --- p.70 / Chapter 4.2 --- Markov Model Developments and Applications --- p.72 / Chapter 4.2.1 --- General introduction of Markov Transition Model --- p.72 / Chapter 4.2.2 --- Structure of Markov models --- p.76 / Chapter 4.2.2.1 --- Natural history model of cervical cancer --- p.76 / Chapter 4.2.2.2 --- Structure of Pap smear and Visual Inspection screening models --- p.82 / Chapter 4.2.2.3 --- Structure of precancerous lesion and invasive cancer treatment models --- p.83 / Chapter 4.2.2.4 --- Interaction of the models --- p.85 / Chapter 4.2.3 --- Demographic profile of the hypothetical cohort --- p.86 / Chapter 4.2.4 --- Probabilities --- p.88 / Chapter 4.2.4.1 --- Identification and converting between rate and probability --- p.89 / Chapter 4.2.4.2 --- Initial probabilities --- p.90 / Chapter 4.2.4.3 --- Transition probabilities --- p.91 / Chapter 4.2.5 --- Screening, diagnosis and treatment characteristics --- p.101 / Chapter 4.2.5.1 --- Screening program characteristics --- p.101 / Chapter 4.2.5.2 --- Diagnosis test performance --- p.104 / Chapter 4.2.5.3 --- Precancerous lesions treatment characteristics --- p.104 / Chapter 4.2.5.4 --- Invasive cancer and treatment characteristics --- p.106 / Chapter 4.2.6 --- Model validation --- p.111 / Chapter 4.3 --- Cost data collection --- p.112 / Chapter 4.3.1 --- Perspective of study --- p.112 / Chapter 4.3.2 --- Selection of study sites --- p.113 / Chapter 4.3.3 --- Screening cost data collection --- p.113 / Chapter 4.3.4 --- Treatment cost data collection --- p.115 / Chapter 4.4 --- Cost-utility analysis and cost-effectiveness analysis --- p.117 / Chapter 4.4.1 --- General introduction of these two analyses --- p.117 / Chapter 4.4.2 --- Utility Estimates --- p.118 / Chapter 4.4.3 --- Screening utility and effectiveness evaluation --- p.120 / Chapter 4.4.4 --- Cost-effectiveness and cost-utility analysis method --- p.122 / Chapter 4.5 --- Time horizon and discounting rate --- p.125 / Chapter 4.6 --- Summary of modeling assumptions --- p.126 / Chapter 4.6.1 --- Assumptions related to screening performance and clinical practice --- p.126 / Chapter 4.6.2 --- Assumptions related to epidemiological characteristics of cervical cancer --- p.127 / Chapter 4.6.3 --- Assumptions related to economic evaluation --- p.128 / Chapter 4.7 --- Sensitivity analysis --- p.128 / Chapter 4.8 --- Ethical approval --- p.129 / Chapter CHAPTER 5 --- RESULTS --- p.130 / Chapter 5.1 --- Model validation --- p.130 / Chapter 5.2 --- Cost analysis results --- p.134 / Chapter 5.2.1 --- Screening costs results --- p.134 / Chapter 5.2.2 --- Treatment cost results --- p.136 / Chapter 5.2.3 --- The proportional costs breakdown for different screening strategies --- p.139 / Chapter 5.3 --- Utility estimation results --- p.141 / Chapter 5.4 --- Cost-utility analysis results --- p.144 / Chapter 5.4.1 --- Baseline analysis --- p.144 / Chapter 5.4.2 --- Influence of screening program performance --- p.148 / Chapter 5.4.2.1 --- Coverage of the screening program --- p.148 / Chapter 5.4.2.2 --- Follow up rate and treatment rate of positives --- p.155 / Chapter 5.4.3 --- Influence of screening test performance --- p.159 / Chapter 5.4.4 --- Influence of costs --- p.165 / Chapter 5.4.4.1 --- Influence of screening costs --- p.165 / Chapter 5.4.4.2 --- Influence of treatment costs --- p.168 / Chapter 5.4.5 --- Influence of discounting --- p.171 / Chapter 5.4.6 --- Summary of factors and their influences on the baseline CUA results --- p.174 / Chapter 5.5 --- Cost-Effectiveness analysis results --- p.180 / Chapter 5.5.1 --- Baseline analysis --- p.180 / Chapter 5.5.1.1 --- Life year saved --- p.181 / Chapter 5.5.1.2 --- Cervical cancer mortality reduction --- p.185 / Chapter 5.5.1.3 --- Cervical cancer incidence reduction --- p.187 / Chapter 5.5.1.4 --- Relative risk of CIN and cervical cancer --- p.189 / Chapter 5.5.1.5 --- Effectiveness summary of alternative screening strategies on the hypothetical 100,000 rural Chinese women --- p.191 / Chapter 5.5.2 --- Factors that influence the CEA results --- p.195 / Chapter 5.5.2.1 --- Best scenario analysis --- p.196 / Chapter 5.5.2.2 --- Worst scenario analysis --- p.201 / Chapter 5.5.2.3 --- Summary of the possible ranges of costs and effectiveness in different scenarios --- p.206 / Chapter 5.6 --- Sensitivity analysis --- p.209 / Chapter 5.6.1 --- Sensitivity analysis of Cost-Utility analysis results --- p.209 / Chapter 5.6.1.1 --- Tornado analysis --- p.209 / Chapter 5.6.1.2 --- One-way sensitivity analysis --- p.213 / Chapter 5.6.2 --- Sensitivity analysis of Cost-Effectiveness analysis results --- p.220 / Chapter 5.6.2.1 --- Tornado analysis --- p.220 / Chapter 5.6.2.2 --- One-way sensitivity --- p.224 / Chapter 5.6.3 --- Summary of sensitivity results --- p.236 / Chapter CHAPTER 6 --- SUMMARY, DISSICUSSION AND CONCLUSIONS --- p.240 / Chapter 6.1 --- Summary of Markov model development and validation --- p.240 / Chapter 6.1.1 --- Category and source summary of input parameters --- p.240 / Chapter 6.1.2 --- Model validation --- p.244 / Chapter 6.2 --- Summary of modeling results --- p.245 / Chapter 6.2.1 --- Summary of Cost-Utility Analysis --- p.245 / Chapter 6.2.1.2 --- Baseline analysis findings --- p.245 / Chapter 6.2.1.2 --- Influential factors on the cost-effective manner of alternative strategies --- p.246 / Chapter 6.2.2 --- Summary of Cost-Effectiveness Analysis --- p.250 / Chapter 6.2.2.1 --- Baseline analysis findings --- p.251 / Chapter 6.2.2.2 --- Possible ranges for cost and effectiveness of alternative strategies under different scenarios --- p.253 / Chapter 6.2.3 --- Summary of CUA and CEA findings --- p.257 / Chapter 6.2.4 --- Summary of sensitivity analysis --- p.259 / Chapter 6.2.4.1 --- Important variables on health outcome predictions --- p.259 / Chapter 6.2.4.2 --- Sensitive variables to the baseline CUA and CEA recommendations --- p.260 / Chapter 6.2.4.3 --- Overview of the sensitivity analysis --- p.263 / Chapter 6.3 --- Discussion --- p.264 / Chapter 6.3.1 --- Alternative strategies of cervical cancer screening in rural China --- p.264 / Chapter 6.3.1.1 --- Target ages --- p.265 / Chapter 6.3.1.2 --- Screening intervals --- p.266 / Chapter 6.3.1.3 --- Feasible primary screening tests --- p.267 / Chapter 6.3.1.4 --- Service delivering patterns --- p.269 / Chapter 6.3.1.5 --- Time horizon of this thesis study --- p.270 / Chapter 6.3.2 --- Transition probability estimation --- p.271 / Chapter 6.3.3 --- Screening and treatment cost estimation --- p.276 / Chapter 6.3.3.1 --- Representativeness of the selected counties --- p.276 / Chapter 6.3.3.2 --- Screening costs of VIA and Pap smear --- p.277 / Chapter 6.3.3.3 --- Treatment costs --- p.279 / Chapter 6.3.4 --- Utility estimation --- p.280 / Chapter 6.3.4.1 --- Instrument selection --- p.280 / Chapter 6.3.4.2 --- Utility estimation between studies --- p.281 / Chapter 6.3.5 --- Baseline cost-utility and cost-effectiveness analyses --- p.283 / Chapter 6.3.6 --- Sensitivity Analysis --- p.284 / Chapter 6.3.7 --- Strengths and limitations --- p.286 / Chapter 6.3.7.1 --- Limitations --- p.286 / Chapter 6.3.7.2 --- Strengths --- p.288 / Chapter 6.4 --- Policy implications --- p.289 / Chapter 6.4.1 --- How to manage a cost-effective cervical cancer screening program? --- p.289 / Chapter 6.4.2 --- How can VIA screening be adopted? --- p.290 / Chapter 6.4.3 --- How can Pap smear screening be adopted? --- p.291 / Chapter 6.4.4 --- Framework for policy decision making --- p.292 / Chapter 6.5 --- Conclusions --- p.295 / Chapter APPENDIX --- p.300 / Chapter Appendix 1-1 --- The 2001 Bethesda System* --- p.300 / Chapter Appendix 1-2 --- The FIGO Staging for cervical cancers* --- p.301 / Chapter Appendix 1-3 --- Cervical Cancer Screening Program in different countries --- p.302 / Chapter Appendix 4-1 --- WHO World Standardized Population Distribution (%) --- p.305 / Chapter Appendix 4-2 --- Summary of transition probabilities literature review --- p.306 / Chapter Appendix 4-3 --- Price Indices from 1978 to 2010 --- p.326 / Chapter Appendix 4-4 --- Screening Cost Questionnaire --- p.327 / Chapter Appendix 4-5 --- Programmatic Cost Survey Questionnaire --- p.339 / Chapter Appendix 4-6 --- Treatment Cost Survey Questionnaire --- p.342 / Chapter Appendix 4-7 --- EQ-5D Algorism (UK) --- p.344 / Chapter Appendix 4-8 --- Chinese Version of EQ5D----HQOL score questionnaire --- p.345 / Chapter Appendix 5-1 --- Calibrated variables and its final settings --- p.348 / Chapter Appendix 5-2 --- Cervical cancer new cases and deaths all over the world in 2008 --- p.349 / Chapter Appendix 5-3 --- Data distribution of CIN2-3 and cervical cancer treatment costs --- p.350 / Chapter Appendix 5-4 --- Relative risk of CIN and cervical cancer by age groups of alternative screening strategies --- p.361 / Chapter Appendix 5-5 --- Influence of discounting rate of life years on the CEA results --- p.363 / Chapter Appendix 5-6 --- Tornado analysis results based on the effect on QALYs predictions --- p.367 / Chapter Appendix 5-7 --- Tornado analysis results based on the effect on life-year predictions --- p.372 / Chapter Appendix 6-1 --- Summary of Markov Model Inputs and Sources --- p.377 / REFERENCE --- p.388

Thesis (PhD (Pathology. Medical Microbiology))--University of Stellenbosch, 2009. / ENGLISH ABSTRACT: Due to modern high-throughput technologies, large numbers of compounds are produced by parallel synthesis and combinatorial chemistry. The pharmaceutical industry therefore requires rapid and accurate methods to screen new drugs leads for membrane permeability potential in the early stages of drug discovery. Around 50 % of all investigational new drugs fail in pre-clinical and clinical phases of development due to inadequate absorption/permeation, distribution, metabolism, excretion and/or unacceptable toxicity. This may be decreased by applying in vitro screening methods early in the discovery process. Reliable in vitro models can be applied to determine permeation of the test compounds, which will help avoid the wasting of valuable resources for the development of drugs that are destined to fail in preclinical and clinical phases due to insufficient permeability properties. It is important to decide as early as possible on the most promising compound and physical formulation for the intended route of administration. With awareness of the increasing importance of in vitro models in the investigations of the permeability properties of drug compounds, this research project was specifically devoted to determine the suitability of our in vitro model to evaluate and predict drug permeability. A continuous flow-through diffusion system was employed to evaluate the permeability of nine different compounds/drugs with different chemical properties, across three biological membranes. The biological membranes chosen for the present study were human vaginal mucosa, human skin tissue and human small intestine mucosa. The continuous flow-through diffusion system was furthermore utilised to investigate the effects of de-epithelialisation of mucosal surfaces, chemical enhancers, temperature, permeant concentration and formulation on the permeability of the test compounds/drugs. The in vitro permeability information and data from the flow-through diffusion model were compared to in vitro and in vivo literature studies and drug profile. An in vitro model that is able to reliably predict in vivo data will shorten the drug development period, economise resources and may potentially lead to improved product quality. In this thesis research results are reported on the permeability of the mentioned biological membranes to the various chemical markers, including anti-HIV (human immunodeficiency virus) drugs. The permeability studies will be discussed in three sections: vaginal mucosa, skin tissue, small intestine mucosa. The results of the vaginal permeability studies showed that the three peptides (MEA- 5, MDY-19 and PCI) readily penetrated the vaginal mucosa. MDY-19 had a higher flux rate than MEA-5, commensurate with its smaller molecular size (weight). The surfactant enhanced the flux rate of MDY-19 approximately 1.3 times and decreased the lag time of the peptide. Removal of the vaginal epithelium increased the flux rates of the peptides across the mucosa and may have implications for a more rapid uptake of these and other microbicides in vivo. The permeability of 1 mM MDY-19 and PCI at 37 °C were significantly (p<0.05) higher than at 20 °C. At 37 °C the AUCs of the overall mean flux values of MDY-19 and PCI increased with concentration according to well-established diffusion theory. The experiments on the permeability of different terbinafine hydrochloride formulations through human skin demonstrated that the terbinafine hydrochloride formulations used in this study, readily diffused into the skin tissue. However, no flux values for any of the terbinafine hydrochloride formulations through the skin into the acceptor fluid were found. The mean terbinafine concentrations in the skin after 24 h exposure to the three commercial, terbinafine hydrochloride formulations were 3.589, 1.590 and 4.219 μg/ml respectively. The mean terbinafine concentration in the skin exposed to the 10 mg/ml PBS/Methanol solution was higher than those from the three commercial formulations. The results of the temperature study demonstrated that an increase of 5 ºC caused a significant increase in flux values of tritiated water across skin. The flux values for tritiated water across skin at 37 ºC were on average double those at a temperature of 32 ºC. The permeability of excised human small intestine mucosa to different oral dosage drugs was investigated over a 24 h period. The four drugs selected were zidovudine, propranolol hydrochloride, didanosine and enalapril maleate. They were selected as representative model compounds of drug classes 1 (high solubility, high permeability) and 3 (high solubility, low permeability) according to the Biopharmaceutics Classification System. The flux rates of the four chosen test drugs were influenced by the length of the experiment. Between the time periods 2-4 h and 4-6 h, zidovudine’s mean flux values across small intestine tissue were respectively 1.8 and 2.0 times higher than didanosine and 2.3 and 2.2 times higher than enalapril. Propranolol’s mean flux values were respectively 1.2 and 1.4 times higher than didanosine and 1.6 higher than enalapril during both the 2-4 and 4-6 h time periods. Between both the time periods 2-4 and 4-6 h AZT’s mean flux values were 1.4 times higher than propranolol and didanosine’s mean flux values were respectively 1.3 and 1.1 times higher than enalapril during the mentioned time periods. Class 1 drugs showed a significantly higher flux rate across the jejunal mucosa compared to the class 3 drugs and these results are in line with their Biopharmaceutics Classification System classification. The in vitro model has proved to be reliable to predict permeability of class 1 and 3 drugs and also showed correlation with human in vivo data. It seems that the in vitro flow-through diffusion model used in the present study have the potential to overcome some of the problems and limitations demonstrated by other in vitro techniques and may potentially serve as a future tool for pharmaceutical companies to predict the diffusion characteristics of new drugs and different formulations, across different biological membranes. Furthermore, it may serve as a prospective method for assessing the bioequivalence of alternative (generic) vehicles or formulations containing the same drug/compound. / AFRIKAANSE OPSOMMING: As gevolg van moderne hoë spoed tegnologie kan groot hoeveelhede middels vervaardig word deur ooreenkomende sintese en kombinasieleer chemie. Die farmaseutiese industrie benodig dus vinnige en akkurate metodes om nuwe geneesmiddels te evalueer t.o.v. membraan deurlaatbaarheid. Hierdie evaluasie moet verkieslik so vroeg moontlik in die geneesmiddel se ontwikkelingsproses geskied. Ongeveer 50 % van alle potensiële geneesmiddels misluk in pre-kliniese en kliniese fases van geneesmiddelontwikkeling. Die mislukte pogings kan toegskryf word aan onvoldoende absorbsie/deurlaatbaarheid, distribusie, metabolisme, ekskresie en/of onaanvaarbare middel toksisiteit. Dit is daarom belangrik om so vroeg moontlik in die geneesmiddelontwikkelingsproses te besluit op die mees belowende middel, asook die geskikte formulasie vir die spesifieke roete van toediening van die middel. Die farmaseutiese industrie benodig tans in vitro modelle met die potensiaal om die deurlaatbaarheid van geneesmiddels te bepaal en te voorspel. Betroubare in vitro modelle kan aangewend word om die deurlaatbaarheid van potensiële geneesmiddels te toets. Sodoende sal die onnodige uitgawes op die ontwikkkeling van geneesmiddels wat in elk geval later gaan faal in pre-kliniese en kliniese fases van geneesmiddelproewe a.g.v. deurlaatbaarheidseienskappe, vermy word. Hierdie navorsingsprojek was dus spesifiek onderneem om die waarde en toepaslikheid van ‘n in vitro deurlopende-vloei perfusie model te ondersoek. Die model se potensiaal om geneesmiddels se deurlaatbaarheid en absorpsie te voorspel was geëvalueer. Die deurlopende-vloei perfusie apparaat was gebruik om die deurlaatbaarheidsvloede van drie verskillende biologiese membrane t.o.v. nege chemiese stowwe (MEA-5, MDY-19, PCI, terbinafien hidrochloried, getritieerde water, zidovudien, propranolol, hidrochloried, didanosien, enalapril maleaat) te bepaal. Die drie biologiese membrane wat gebruik was, was vaginale weefsel, vel en klein intestinale weefsel. Al drie weefsel tipes was van menslike oorsprong. Die deurlopende-vloei perfusie apparaat was ook gebruik om die effek wat verwydering van die mukosa se epiteellaag op deurlaatbaarheidsvloede het, te ondersoek. Verder was navorsing gedoen op die effek van temperatuur en die konsentrasie en formulasie van die toetsmiddels op hulle diffusie vloedwaardes. Daar was ook gekyk na die invloed van ander chemiese stowwe op die toetsmiddels se diffusie vloedwaardes. Die in vitro deurlaatbaarheidsinformasie en -gegewens was vergelyk met ander in vitro en in vivo literatuurstudies en geneesmiddel databasisse. ‘n In vitro model wat in staat is om in vivo resultate betroubaar te voorspel, het die potensiaal om die tyd wat dit neem om geneesmiddels te ontwikkel, te verkort, finansiële uitgawes te besnoei en om geneesmiddelkwaliteit te verseker. In die tesis word dan die resultate gerapporteer van die deurlaatbaarheidsvloede van die verskillende tipes weefsel ten op sigte van verskeie chemiese stowwe, insluitende anti-MIV (menslike immuniteitsgebreksvirus) middels. Die deurlaatbaarheidstudies word bespreek in drie afdelings: vaginale mukosa, vel en klein intestinale mukosa. Die resultate van die deurlaatbaarheidstudies op die vaginale weefsel dui daarop dat die drie peptiede (MEA-5, MDY-19 and PCI) die vaginale mukosa goed penetreer. Soos verwag, het MDY-19 hoër diffusie vloedwaardes as MEA-5 gehad. Dit kan toegeskryf word aan MDY-19 se kleiner molekulere grootte (gewig). Surfaktant het die diffusie vloedwaardes van MDY-19 1.3 keer vergroot en het ook die tyd na vaste vlak verminder. Die verwydering van die vaginale epiteel het die diffusie vloedwaardes van die peptiede verhoog en mag dus dui op die vinniger opname van peptiede en moontlike ander mikrobisiede in vivo, wanneer die belyning van die epiteel onderbreek. Die deurlaatbaarheid van 1 mM MDY-19 en PCI by 37 °C was satisties beduidend (p<0.05) hoer as teem 20 °C. Die area onder die kurwe (AOK) van die gemiddelde vloedwaardes van MDY-19 en PCI by 37 °C, het toegeneem met ‘n toename in die konsentrasie van hierdie peptiede. Die toename vloedwaardes ondersteun dus die alombekende diffusie teorie. Die transdermale diffusie eksperimente van verskillende terbinafien formulasies het getoon dat terbinafien geredelik vrygestel word vanuit hierdie formulasies na die vel. Geen terbinafien vloedwaardes, van enige van die formulasies, was egter gevind in die ontvangselle van die deurlopende-vloei perfusie apparaat nie. Die gemiddelde terbinafien konsentrasies in die vel na 24 h se blootstelling aan drie kommersiële terbinafien hidrochloried formulasies was onderskeidelik 3.589, 1.590 en 4.219 μg/ml. Die gemiddelde terbinafien konsentrasie in die vel wat aan 10 mg/ml PBS/metanol blootgestel was, was hoër as die konsentrasies in die vel wat aan die drie kommersiële formulasies blootgestel was. Die resultate van die temperatuurstudie op vel het aangetoon dat ‘n temperatuur toename van 5 ºC ‘n statisties beduidende toename in vloedwaardes van getritieerde water oor vel veroorsaak. Die vloedwaardes van die getritieerde water oor vel teen ‘n temperatuur van 37 ºC was gemiddeld dubbeld so veel as teen 32 ºC. Die deurlaatbaarheidsvloede van klein intestinale mukosa ten opsigte van verskillende geneesmiddels (wat oraal toegedien word) was ondersoek gedurende ‘n 24 h eksperiment. Die vier geneesmiddels wat gebruik was, was zidovudine, propranolol hidrochloried, didanosien en enalapril maleaat. Hierdie geneesmiddels is verteenwoordigers van die Biofarmaseutiese Klassifikasie Sisteem se klas 1 (hoë oplosbaarheid, hoë deurlaatbaarheid) en klas 3 (hoë oplosbaarheid, lae deurlaatbaarheid) geneesmiddels. Die vloedwaardes van die vier geneesmiddels het gewissel na aanleiding van die tydsverloop in die eksperiment. Zidovudien se gemiddelde vloedwaardes tussen 2-4 en 4-6 h was onderskeidelik 1.8 en 2.0 keer hoër as didanosien se gemiddelde vloedwaardes vir hierdie tyd periodes en onderskeidelik 2.3 en 2.2 keer hoër as enalapril se gemiddelde vloedwaardes. Tydens hierdie selfde periodes was propranolol se gemiddelde vloedwaardes 1.2 en 1.4 keer hoër as didanosien en vir beide periods 1.6 keer hoër as enalapril se gemiddelde vloedwaardes. Gedurende beide genoemde tyd periodes was zidovudien se gemiddelde vloedwaardes 1.4 keer hoer as propranolol en didanosien se gemiddelde vloedwaardes was onderskeidelik 1.3 en 1.1 keer hoër as enalapril tydens 2-4 en 4-6 h. Die klas 1 geneesmiddels het statisties beduidende hoër vloedwaardes gehad as die klas 3 geneesmiddels. Hierdie resultate stem ooreen met die geneesmiddels se Biofarmaseutiese Klassifikasie Sisteem klassifikasie. Dit wil dus voorkom asof die in vitro model wat gebruik was in die studie, gebruik kan word om die deurlaatbaarheidsvloede van klas 1 en 3 te voorspel. Die resultate van hierdie studie stem ooreen met ander in vivo studies. Dit wil voorkom asof die in vitro deurlopende-vloei perfusie apparaat die potensiaal het om sommige van die probleme en tekortkominge van ander in vitro modelle te oorkom en dat dit moontlik die potensiaal het om die diffusie-eienskappe van nuwe geneesmiddels en verskillende formulasies oor verskillende biologiese membrane te voorspel. Die model kan verder moontlik dien as ‘n potensiële toestel om biogelykbaarheid van alternatiewe (generiese) formulasies, wat dieselfde geneesmiddel/chemiese stof bevat, te bepaal.