pH-Dependent Drug Delivery Systems

Gastric carcinoma, or stomach cancer, is a major disease in the world today. Although it only accounts for about 2% of all cancer cases in the United States, it is much more prevalent in nations such as Korea, Japan, Great Britain, South America, and Iceland. While the most common treatment for gastric carcinoma is surgery, there are chemotherapeutic alternatives including the application of doxorubicin, also known as Adriamycin?. However, as with nearly all chemotherapy drugs, doxorubicin causes dose-dependent toxicity that results in severe biological side effects and, potentially, death. Many of the adverse effects of doxorubicin may be attributed to the fact that it is normally administered intravenously; thus, although the drug?s target is the stomach, the doxorubicin is systemically rampant. Hence, we have developed a delivery system for doxorubicin that we hope will limit the drug?s action to the stomach alone. We begin with a means for encasing the doxorubicin inside two types of hydrogels whose diffusive properties vary depending on temperature and pH levels, such that diffusion may be maximized in the stomach and minimized at all other locations inside the gastrointestinal tract. This original design was modeled as a 1-D radial line to represent the spherical shape of the pill. After investigation, another design involving a hollowed out hemisphere was modeled and tested. Results comparison shows that the second design scheme is superior to the first both in outward drug flux and in the amount of drug able to be delivered. Ultimately, results of the study showed that pH-dependent drug release can be attained at a steady and reliable rate, with significantly greater rates of release inside the stomach. However, we were unable to attain a clinically adequate amount of total doxorubicin release with our model designs. Still, it may be possible to achieve medically useful results with pH-dependent drug delivery systems given certain technological improvements in the future

The visible and speaking shewes that bring vice into detestation : homiletic propaganda and Barnabe Barnes\u27 The divils charter.

Dept. of English Language, Literature, and Creative Writing. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1973 .R59. Source: Masters Abstracts International, Volume: 40-07, page: . Thesis (M.A.)--University of Windsor (Canada), 1973

Compliance to Bleach Disinfection Protocols among Injecting Drug Users in Miami

Bleach cleansing of injection equipment has been recommended to reduce the risk of human immunodeficiency virus (HIV) transmission associated with the reuse of injection equipment by injecting drug users (IDUs). We evaluated the recall and performance of the most commonly recommended bleach cleansing procedure of two complete fillings of the syringe with bleach, followed by two complete fillings with rinse water, and not putting used bleach and water back into source containers. IDUs were taught this procedure on enrollment in an HIV prevention demonstration project in Dade County, Florida. During follow-up session 6-12 months after initial training, the knowledge and ability of IDUs to perform bleach cleansing were assessed by trained observers using a standardized method. In 1988-90, we assessed the knowledge and ability of 450 IDUs to perform the bleach cleansing procedure taught at enrollment. More than 90% of IDUs assessed performed the basic steps. However, only 43.1% completely filled the syringe with bleach and only 35.8% completely filled the syringe with bleach at least twice. Substantial proportions of IDUs did not perform all the steps of the previously taught bleach cleansing procedure. Compliance decreased as the number of steps required was increased. This limited compliance may make bleach cleansing less effective and suggests that some IDUs may fail to adequately disinfect injection equipment and therefore sterile needles and syringes are safer than bleach-cleansed ones. Compliance testing can help assess the effectiveness of HIV prevention programs. © 1994 Raven Press, Ltd., New York

Accuracy of epidemiological inferences based on publicly available information: retrospective comparative analysis of line lists of human cases infected with influenza A(H7N9) in China

Background: Appropriate public health responses to infectious disease threats should be based on best-available evidence, which requires timely reliable data for appropriate analysis. During the early stages of epidemics, analysis of ‘line lists’ with detailed information on laboratory-confirmed cases can provide important insights into the epidemiology of a specific disease. The objective of the present study was to investigate the extent to which reliable epidemiologic inferences could be made from publicly-available epidemiologic data of human infection with influenza A(H7N9) virus. Methods: We collated and compared six different line lists of laboratory-confirmed human cases of influenza A(H7N9) virus infection in the 2013 outbreak in China, including the official line list constructed by the Chinese Center for Disease Control and Prevention plus five other line lists by HealthMap, Virginia Tech, Bloomberg News, the University of Hong Kong and FluTrackers, based on publicly-available information. We characterized clinical severity and transmissibility of the outbreak, using line lists available at specific dates to estimate epidemiologic parameters, to replicate real-time inferences on the hospitalization fatality risk, and the impact of live poultry market closure. Results: Demographic information was mostly complete (less than 10% missing for all variables) in different line lists, but there were more missing data on dates of hospitalization, discharge and health status (more than 10% missing for each variable). The estimated onset to hospitalization distributions were similar (median ranged from 4.6 to 5.6 days) for all line lists. Hospital fatality risk was consistently around 20% in the early phase of the epidemic for all line lists and approached the final estimate of 35% afterwards for the official line list only. Most of the line lists estimated >90% reduction in incidence rates after live poultry market closures in Shanghai, Nanjing and Hangzhou. Conclusions: We demonstrated that analysis of publicly-available data on H7N9 permitted reliable assessment of transmissibility and geographical dispersion, while assessment of clinical severity was less straightforward. Our results highlight the potential value in constructing a minimum dataset with standardized format and definition, and regular updates of patient status. Such an approach could be particularly useful for diseases that spread across multiple countries

Managing risk, changing aspirations and household dynamics: implications for wellbeing and adaptation in semi-arid Africa and India

Semi-arid regions across Africa and Asia are characterized by rapidly changing biophysical regimes, structural vulnerabilities, and increasing livelihood precarity. Gender, class, and caste/ethnic identities and relationships, and the specific social, economic and political power, roles and responsibilities they entail, shape the choices and decisions open to individuals and households in managing the risks they face. Unpacking the multiple, intersecting inequalities confronting rural populations in these climate hotspots is therefore vital to understand how risk can be managed in a way that supports effective, inclusive, and sustainable local adaptation. Drawing on empirical evidence from six countries, generated through a mixed methods approach, we examine how changes in household dynamics, structure, and aspirations, shape risk management with implications for household well-being, adaptive capacity, and ultimately sustainable development. The ability of individuals within households, differentiated by age, marital status, or education, to manipulate the very structure of the household and the material and social resources it offers, differentiates risk management strategies such as livelihood diversification, migration, changing agricultural practices and leveraging social support. Our evidence suggests that while greater risks can drive conflictive behavior within households, with women often reporting lower subjective wellbeing, new forms of cooperative behavior are also emerging, especially in peri-urban spaces. Through this study, we identify entry points into enabling sustainable and inclusive adaptation behavior, emphasizing that interventions should work for both women and men by challenging inequitable social and gender norms and renegotiating the domains of work and cooperation to maintain overall household wellbeing

Testing a global standard for quantifying species recovery and assessing conservation impact.

Recognizing the imperative to evaluate species recovery and conservation impact, in 2012 the International Union for Conservation of Nature (IUCN) called for development of a "Green List of Species" (now the IUCN Green Status of Species). A draft Green Status framework for assessing species' progress toward recovery, published in 2018, proposed 2 separate but interlinked components: a standardized method (i.e., measurement against benchmarks of species' viability, functionality, and preimpact distribution) to determine current species recovery status (herein species recovery score) and application of that method to estimate past and potential future impacts of conservation based on 4 metrics (conservation legacy, conservation dependence, conservation gain, and recovery potential). We tested the framework with 181 species representing diverse taxa, life histories, biomes, and IUCN Red List categories (extinction risk). Based on the observed distribution of species' recovery scores, we propose the following species recovery categories: fully recovered, slightly depleted, moderately depleted, largely depleted, critically depleted, extinct in the wild, and indeterminate. Fifty-nine percent of tested species were considered largely or critically depleted. Although there was a negative relationship between extinction risk and species recovery score, variation was considerable. Some species in lower risk categories were assessed as farther from recovery than those at higher risk. This emphasizes that species recovery is conceptually different from extinction risk and reinforces the utility of the IUCN Green Status of Species to more fully understand species conservation status. Although extinction risk did not predict conservation legacy, conservation dependence, or conservation gain, it was positively correlated with recovery potential. Only 1.7% of tested species were categorized as zero across all 4 of these conservation impact metrics, indicating that conservation has, or will, play a role in improving or maintaining species status for the vast majority of these species. Based on our results, we devised an updated assessment framework that introduces the option of using a dynamic baseline to assess future impacts of conservation over the short term to avoid misleading results which were generated in a small number of cases, and redefines short term as 10 years to better align with conservation planning. These changes are reflected in the IUCN Green Status of Species Standard