Eye diseases

Eye diseases 1. Introduction 1.1 Glaucoma Eye disease such as glaucoma, cataracts, age-related macular degeneration and diabetic retinopathy are some of the common causes of reduced vision and blindness (Short, 2008). Glaucoma is a progressive eye disease where the damage of optic nerves resulted in visual field loss. In the year of 2010, it is estimated that 60.5 million people will be diagnosed with glaucoma, and by 2020, the number would be increased to 79.6 million (Quigley and Broman, 2005). According to International Glaucoma Association, some of the risk factors that contribute to the development of glaucoma are advanced age, race, long or short sighted, and genetic predisposition. Damage of the optic nerves in glaucoma is often due to elevated intraocular pressure (IOP) which occurs when there is an imbalance of aqueous humor production and drainage in the eye. This clear fluid produced by the ciliary body flows into the posterior chamber and exit through trabecular meshwork at the open angle where the cornea and iri s meet (1). Blocked drainage channel restricts the flow of aqueous humor out of the anterior chamber. This causes the pressure in eye to be increased to an abnormal level, thus damaging the optic nerves. Optic nerve plays an important role in transmitting impulses from the light sensitive tissue layer, the retina to the brain, where the visual information is interpreted. Therefore, early detection and treatment could prevent permanent and irreversible blindness from glaucoma. There are several classifications of glaucoma, the most common types are primary open-angle glaucoma (POAG) and primary angle-closure glaucoma (PACG). The difference between these two types is the present of physical obstruction in the drainage channel in one and its absence in the other. As for the former type, an increase in IOP is caused by blockage of the drainage channel where the aqueous humor drains out (1) (Coleman,1999). This process occurs very gradually and often patient does not notice any early signs of sight loss such as blind spots, or patches of vision loss until severe damaged has been done to the optic nerves, thus causing blindness. Different ethnic group was shown to have different glaucoma prevalence. The African population was shown to be more prevalent to suffer from POAG in the study demonstrated by Ntim-Amponsah et al. (2004). The standardised age-specific glaucoma prevalence for that ethic group was 7.7% while the Caucasians have an overall lower prevalence than that. It was suggested by Herndon et al. (2004) that the blacks have an overall thinner central corneal compared to the Caucasians and this might contribute to the progression of POAG. As explained by Coleman (1999), in primary angle-closure glaucoma (PACG), the angle between the iris and lens is very narrow. When the iris dilates, the iris-lens contact prevents the flow of aqueous humor into the anterior chamber. The continuous secretion of aqueous humor creates a pressure which pushes the iris forward onto the trabecular meshwork, closing the angle (1). This rapid onset causes sudden build-up of intraocular pressure leading to short-term loss of vision. Severe eye pain, blurred vision, headache, nausea, vomiting and halos around lights are among the symptoms observed in this eye disease. Asian was shown to have a higher prevalence of PACG compared to the Western population. Some of the studies concluded that Chinese are at a higher risk of suffering from PACG. This is related to the geometry of the anterior chamber where Chinese has a smaller corneal or a shallower anterior chamber, thus implying that there is a higher risk of developing angle closure and therefo re PACG (Wang et al., 2002). 1.2 Pharmacological therapy of glaucoma The goal in treating glaucoma is to delay the progression by giving immediate therapy for early stage glaucoma patient to prevent further loss of vision. Treatment aims to reduce IOP by either increasing the aqueous humor drainage or reducing the aqueous humor secretion rate. Several classes of drugs are used in the treatment of glaucoma, namely beta-adrenergic antagonists (beta-blockers), selective alpha2-adrenoceptor antagonist, carbonic anhydrase inhibitors and prostaglandin analogues. The choice of treatment depends on the effectiveness and side-effects of the drug, co-mobility and cost of treatment. Beta-blockers are one for the first line drug used in treatment of glaucoma but newer medications are increasingly being used as first choice of glaucoma therapy. The exact mechanism of beta-blocker in reducing IOP is not known, but it was suggested that beta-blocker reduces the aqueous humor production by blocking the beta2-receptor on the non-ciliary body epithelium. On average, no n-selective beta-blockers such as timolol, levobunolol, carteolol and metipranolol lower the IOP by 20-35% while beta1-receptor antagonist, betaxolol lowers it by 15-25%. However, when the pharmacological therapy is unsuccessful, laser or surgery are required to treat this eye disease (Soltau and Zimmerman, 2002). The most widely used ocular hypotensive agent is the non-selective beta-blocker, timolol. Timolol is often used as an adjunct therapy to other difference classes of IOP-lowering agents such as brimonidine, travoprost and acetazolamide. In one of the studies, combination therapy of latanoprost and timolol was proved to be more effective in lowering IOP compared to using lataoprost alone in glaucoma treatment (Olander K, 2004). The maleate salt of timolol is soluble in water and alcohol, and has a pKa of approximately 9 in water at 25Â °C. The current commercially available opthalmic therapies of timolol are timolol maleate topical opthalmic solution and gel-forming ophthalmic solution. Some of the local side effects of topical application of timolol include ocular irritation, burning, pain, itching, erythema and dry eyes. Beta-blocker is contra-indicated in patients who have bronchial asthma, history of chronic obstructive pulmonary disease, sinus bradycardia, heart block, or uncontr olled heart failure. In some cases, exacerbation of reactive airways disease and cardiovascular disease due to the systemic absorption of the non-selective beta-blocker has been reported occasionally in patients receiving topical timolol therapy (McEvoy G K, 2002). After long-term usage of timolol, tolerance might develop in some patients. This has been suggested that there is an up-regulation of beta-receptors in target cells in response to constant exposure of antagonist at the beta-receptors (Fechtner, 2008). 1.3 Drug delivery in treatment of glaucoma There are several approaches in delivering intraocular drugs, among them are topical application, systemic administration, intraocular implants and intravitreal injections. Each of these routes has its own advantages and challenges (Short, 2008). Topical administration is the most widely used route for drug delivery in treating eye diseases. The major challenge of this application to the posterior ocular tissues is poor drug bioavailability resulted from the ocular physiological and anatomical constraints, which include tear fluid turnover rate, nasolacrimal drainage and high efficiency of blood-ocular barrier. It was shown that only 1-5% of the topically applied drugs is absorbed across the cornea and reaches the target intraocular tissues. Furthermore, nasolacrimal drainage contributes to extensive precorneal losses that lead to poor bioavailability. In addition, systemic exposure through nasolacrimal drainage will also cause significant systemic toxicity. Blood-ocular barrier whic h is located at the retinal pigmented epithelium and the endothelium of the retinal vessels is also a major challenge in delivering topical drugs to the target tissues. This barrier limits the penetration of intraocular drugs to the back of the eyes. Unfortunately, systemically administered drugs are also having the same problem in penetrating the barrier. Hence, alternative drug delivery strategies such as intravitreal injections have been investigated and developed to overcome this problem (Tombrain-Tink and Barnstable, 2006). Intravitreal injection is the administration of intraocular drugs to the vitreous cavity of the eye and this route is becoming increasingly popular in treating glaucoma patients. Due to short half-life of drugs in the vitreous, frequent and repeated injections to the eye are needed to maintain the drug concentration at therapeutic level in the vitreous and the retina. Consequently, this procedure leads to complication such as infection, vitreous hemorrhage, and lens or retinal injury. Sustained release formulation has been developed and possible benefits of particulate drug delivery has been investigated and studied to overcome such complications. The particulate drug delivery systems include microparticles and nanoparticles such as liposome, microcapsule, nanocapsules, microspheres and nanospheres. Liposomes, microcapsules and nanocapsules allow encapsulation of the drug molecules while in microspheres and nanospheres, drugs are dispersed in a spherical polymer matrix. These particu lates act as a reservoir to control the release rate during periods of days and sometime even months (Short, 2008; Tombrain-Tink and Barnstable, 2006). 1.4 Microspheres Microspheres of biodegradable polymers such as poly (lactic-co-glycolic) acid (PLGA) are a combination of drug and polymer. PLGA-based microspheres have several advantages over other controlled released drug delivery system. The administration of these microspheres to the body only requires syringes and needles, thus avoiding surgical implants of controlled-release formulations. Besides that, these PLGA are biodegradable and are biocompatible to the tissues, including the brain tissues (Fournier, 2003). Three microencapsulation techniques are being employed in producing PLGA microspheres these days. Solvent evaporation and solvent extraction process is one of the method which includes single emulsion process and double emulsion process. The former process involves oil-in-water emulsification and latter is the most commonly used water-in-oil-in-water (w/o/w) method used to encapsulate water-soluble drugs such as timolol maleate into microspheres. Final emulsions from both processes wi ll undergo solvent removal by extraction or evaporation. The solid microspheres that are produced from these processes will then be filtered or sieved, and finally dried. This technique is widely used because it is easy and does not involve complicated steps. Other methods such as phase separation and spray drying are also being used to encapsulate microspheres. The disadvantage of phase separation is that it needs a careful optimisation of some parameters, such as solvent and polymer type, salt type and concentration in order to obtain any microspheres at all. On the other hand, the limitation of spray drying is that small batches of drug are produced due to loss of product during spray-drying (Jain, 2000). PLGA, a copolymer of lactic acids and glycolic acids is commonly used in the production of controlled-release biomedical devices such as microparticles and nanoparticles. Incorporation of the active substance in polymer matrix allows drug to be released at a slower rate over a prolonged period, thus reducing the frequency of drug administration and hence improving patients compliance. The main target of controlled-release drug delivery is to produce a zero-order release pattern, but this was not achieved very often. Some of the small molecules are associated with undesirable initial burst phase during where drugs on the microsphere surface are being released through rapid diffusion, followed by a slow release or no release. During the initial burst phase, excessive release of potent drugs from the polymer for a prolonged time causes severe side effects. However, during the second phase, only a small fraction of drug will be released from the matrix due to decreased driving force in d rug depletion (Berkland et al., 2002). In the study conducted by Mao et al. (2007), the effect of different preparation of water-in-oil-in water emulsion on the burst release of fluorescein isothiocyanate labeled dextran from the PLGA microspheres was being investigated. It was found that an increase in drug loading, polyvinyl alcohol concentration and homogenisation speed resulted in a decrease in initial burst. This is due the changes in morphology of the by using different preparation techniques. The main mechanism of drug release from microsphere can be divided to two processes, which are drug diffusion from the polymer network and drug release through polymer degradation. Once PLGA is administered to the eyes, water fills into the network of pore by a negative water gradient and the active compound subsequently diffuses out of the co-polymer. However, this gradient will disappear gradually within a period time and thus the drug molecules are released at a slower rate at a later stage. This process is often coupled with the breakage of ester bonds of the polymer by hydrolysis and it can also be autocatalysed by the accumulation of acidic degradation products and hence leading degradation of PLGA-based microsphere. During this process, oligomers at the surface of microsphere escape from the matrix, leaving behind those who are entrapped inside the matrix core. Size of microsphere plays a very important role in manipulating the rate of degradation. In one of the study, it was shown that larger particle size will degrade more rapidly. This is due to the inner core of the polymer is more acidic compared to its external environment (Grizzi et al. ,1995) Effect of several factors such as polymer composition and preparation condition on the drug release patterns were being investigated by several studies. It has been demonstrated by Janoria and Mitra (2007) that different lactide/glycolide ratio resulted in different release rate of a lipophilic prodrug (GCV-monobutyrate) from PLGA-based microsphere. PLGA with higher lactide content (65:35) was found to have higher glass transition temperature than lower lactide content (50:50) of PLGA polymer. This was suggested that the former ratio had slower drug diffusion through the polymer matrix, hence longer releasing time. On the other hand, an addition of surfactants, polyvinyl alcohol or Triton X-100 to the primary emulsion obtained from the double emulsion solvent evaporation technique resulted in the production of larger particle size, thus slower releasing rate was observed (Bouissou et al., 2006). Besides that, inclusion of additives in the formulation will also affect the release prof ile of microspheres. Kang F R and Singh J (2001) found out that the addition of PEG 1000 and tricaprin increased the porosity of the PLGA, thus changing its surface characteristics. This has lead to a higher initial releasing rate of bovine serum albumin due to rapid diffusion of the protein through the large pores on the surface of microspheres. Different preparation methods effect the morphology and drug distribution of microspheres. A change in the process condition will yield different size distribution and porosity of the microsphere. Some of the critical parameters of determining the microparticles morphology are volume ratio of oil to internal water, homogenisation speed and type of solvents used. Surface morphology of microspheres is shown to be influenced by the volume ratio of oil to internal water in a research conducted by Yang et al. (2000). An increase in size and initial burst of the microspheres was observed by decreasing the volume ratio from 40:1 to 12:1. More porous microparticles were also observed in lower volume ratio. Homogenisation speed was also proved to be important in determining the morphology of microparticles by Sansdrap and Moes (1993). When homogenisation speed was increased, the microparticulate was found to be smaller. Similarly, different organic phase solvent was proved to produce differen t size distribution of particles. Song et al. (2006) showed that partially water-soluble solvents such as ethyl acetate and propylene carbonate produced smaller mean particle size compared to the fully water-soluble solvents, acetone and dichloromethane. Since there are limited studies based on the effect of method parameters on the morphology and drug release profile of timolol maleate encapsulated microsphere, this study aimed to further investigate the effect of volume ratio of oil to internal water, homogenisation speed and type of solvents used. Timolol maleate is encapsulated in PLGA by double-emulsion solvent evaporation method. The surface morphology and particle sizes of the microspheres were being studied using scanning electron microscopy (SEM). On the other hand, the effect on the drug release profile was determined by analysing the released drug sample from the microspheres using ultraviolet spectrophotometer.

Bureaucracy and the Church of God Essay -- Religion

Max Weber, German sociologist, social theorist, and economist, explicated the theory of bureaucracy in which he details the monocratic bureaucracy â€Å"as an ideal form that maximized rationality† (Bolman & Deal, 2008, p. 48). He provided his most complete exposition of theory in his 1922 tome Economy and Society (Casey, 2004). This classic form of bureaucracy is characterized by the following (a) well-defined official functions; (b) specialization of function; (c) clearly defined hierarchy of offices; (d) rules governing performance, which require training to administer; (e) impersonal treatment of clients, in that all are treated equally; (f) merit as the basis of promotion or appointment; (g) compensation based on rank; (h) separation of personal and company assets and interests; (i) discipline and control of daily work; (j) files and record keeping for decisions, acts, and rules (Bolman & Deal, 2008; O’Connor, 2011). There are numerous shorthand versions of We ber’s theory including Harmon and Mayer (1986) in Organization Theory for Public Administration and Heady (2001) in Public Administration: A Comparative Perspective (O’Connor, 2011). The prime directive and raison d’à ªtre of the bureaucracy is to act as a bulwark against the forces of chaos, irrationality, and disorganization that constantly jeopardize an organization (Casey, 2004). In this sense, bureaucracy can be seen as necessary to the survival of groups. It is, however, a term that is vilified in popular culture, used pejoratively even by some researchers, and reviled as nearly blasphemous and certainly anti-democratic by many reform-minded persons. To the Weberian observer, in contrast, bureaucracy is not only as equal to all other organizational forms, but is ... ...e. Bolman, L. G., & Deal, T. E. (2008). Reframing organizations: Artistry, choice, and leadership (4th ed.). San Francisco, CA: Jossey-Bass. Casey, C. (2004). Bureaucracy re-enchanted? Spirit, experts and authority in organizations. Organization, 11, 59-79. doi:10.1177/1350508404039658 Nelson, R. E. (1993). Authority, organization, and societal context in multinational churches. Administrative Science Quarterly, 38(4), 653-682. Retrieved from http://web.edbscohost.com.proxy1.ncu.edu/ehost/pdfviewer/pdfviewer?sid-fd218266-afad-43b7-bfbb-5c53002cd06d%40sessionmgr14&vid=8&hid=19 O’Connor, T. (2011). Theories of bureaucracies. Retrieved from http://drtomoconnor.com/4090/40901lect02.htm Yeakley, R. (2011, February 15). Growth stalls, falls for largest U. S. churches. USA Today. Retrieved from http://www.usatoday.com/news/religion/2011-02-16-church_growth_15_ST_N.htm

Positive Psychology Essay

Martin Seligman is considered the father of positive psychology (Friedman & Schustack, 2012). Positive psychology pertains to helping people live happier and healthier lives (Friedman & Schustack, 2012). Seligman and Csikszentmihalyi states that â€Å"positive psychology at the subjective level is about valued [sic] subjective experiences,† such as â€Å"well-being, contentment, satisfaction (in the past), hope and optimism (for the future) and flow and happiness (in the present)† (McNulty & Fincham, 2011, p. 101). Seligman and Csikszentmihalyi are also states that the â€Å"individual level is about positive individual traits† and the capability â€Å"for love and vocation, courage, interpersonal skill, aesthetic sensibility, perseverance, forgiveness, originality, future mindedness, spirituality, high talent and wisdom† (McNulty & Fincham, 2011, p. 101). Finally, Seligman and Csikszentmihalyi state that positive psychology â€Å"at the group level is ab out the civic virtue’s† and† the institutions that move† individual’s â€Å"toward better citizenship† and the â€Å"responsibility, nurturance, altruism, civility, moderation, tolerance and work ethic† (McNulty & Fincham, 2011, p. 101). The chosen article states that the â€Å"field of positive psychology† believes that people have specific â€Å"psychology traits† that are inherited of the individual’s positive mental health (McNulty & Fincham, 2011, p. 101). Studies show that â€Å"forgiveness, optimistic, positive thoughts and kindness† can â€Å"benefit or harm† individuals (McNulty & Fincham, 2011, p. 101). The researchers state that the psychologist should move forward and examine the individual’s traits that may support well-being. The researchers show three approaches to search for a better understanding to positive psychology. First, psychologist need to examine the process of happiness and factors (McNulty & Fincham, 2011). Second, psychologist need to understand, prevent, relieve and understand people who suffer (McNulty & Fincham, 2011). And finally, to study shows that â€Å"short term† and â€Å"long term† effects of psychological traits character istics (McNulty & Fincham, 2011, p. 107). References Friedman, H. S., & Schustack, M. W. (2012). Personality Classic theories and modern research (5th ed.). [Vital source ebook]. Retrieved from Vital Book file McNulty, J. K., & Fincham, F. D. (2011). Beyond positive psychology? Toward a contextual view of psychological processes and well-being. American Psychologist, 67(2), 101-110. http://dx.doi.org/10.1037/a0024572

Abigail Scott Duniway Womens Rights in the West

Dates: October 22, 1834 - October 11, 1915 Occupation: American western pioneer and settler, womens rights activist, womens suffrage activist, newspaper publisher, writer, editor Known for: role in winning womens suffrage in the Northwest,, including Oregon, Washington and Idaho; publishing a pro-womens rights newspaper in Oregon: first woman publisher in Oregon; wrote first book commercially published in Oregon Also known as: Abigail Jane Scott About Abigail Scott Duniway Abigail Scott Duniway was born Abigail Jane Scott in Illinois. At age seventeen she moved with her family to Oregon, in a wagon pulled by oxen, over the Oregon Trail. Her mother and a brother died en route, and her mother was buried near Fort Laramie. The surviving family members settled in Lafayette in Oregon Territory. Marriage Abigail Scott and Benjamin Duniway were married in 1853. They had a daughter and five sons. While working together on their backwoods farm, Abigail wrote and published a novel, Captain Grays Company, in 1859, the first book commercially published in Oregon. In 1862, her husband made a bad financial deal -- without her knowledge -- and lost the farm. Son after that he was injured in an accident, and it fell to Abigail to support the family. Abigail Scott Duniway ran a school for a while, and then opened a millinary and notions shop. She sold the shop and moved the family to Portland in 1871, where her husband got a job with the U.S. Customs Service. Womens Rights Beginning in 1870, Abigail Scott Duniway worked for womens rights and womens suffrage in the Pacific Northwest. Her experiences in business helped convince her of the importance of such equality. She founded a newspaper, New Northwest, in 1871, and served as its editor and a writer until she closed the paper in 1887. She published her own serialized novels in the paper as well as advocating for womens rights, including married womens property rights and the right to vote. Among her first projects was managing a speaking tour of the Northwest by suffragist Susan B. Anthony in 1871. Anthony advised her on politics and organizing for womens rights. That same year, Abigail Scott Duniway founded the Oregon State Women Suffrage Association, and in 1873 she organized the Oregon State Equal Suffrage Association, for which she served for a while as president. She traveled around the state, lecturing and advocating for womens rights. She was criticized, attacked verbally and even subjected to physical violence for her positions. In 1884, a womens suffrage referendum was defeated in Oregon, and the Oregon State Equal Suffrage Association fell apart. In 1886, Duniways only daughter, at age 31, died of tuberculosis, with Duniway at her bedside. From 1887 to 1895 Abigail Scott Duniway lived in Idaho, working for suffrage there. A suffrage referendum finally succeeded in Idaho in 1896. Duniway returned to Oregon, and revived the suffrage association in that state, beginning another publication, The Pacific Empire. Like her earlier paper, the Empire advocated for womens rights and included Duniways serialized novels. Duniways position on alcohol was pro-temperance but anti-prohibition, a position which subjected her to attacks both by the business interests supporting alcohol sales and the growing prohibition forces including within the womens rights movement. In 1905, Duniway published a novel, From the West to the West, with the main character moving from Illinois to Oregon. Another woman suffrage referendum failed in 1900. The National American Woman Suffrage Association (NAWSA) organized a suffrage referendum campaign in Oregon for 1906, and Duniway left the state suffrage organization and did not participate. The 1906 referendum failed. Abigail Scott Duniway then returned to the suffrage fight, and organized new referenda in 1908 and 1910, both of which failed. Washington passed suffrage in 1910. For the 1912 Oregon campaign, Duniways health was failing, and she was in a wheelchair, and she was unable to participate much in the work. When that 1912 referendum finally succeeded in granting women the full franchise, the governor asked Abigail Scott Duniway to write the proclamation in recognition of her long role in the struggle. Duniway was the first woman in her county to register to vote, and is credited with being the first woman in the state to actually vote. Later Life Abigail Scott Duniway completed and published her autobiography, Path Breaking, in 1914. She died the following year. Background, Family: Mother: Anne Roelofson (of German, French and English heritage, born in Kentucky)Father: John Tucker Scott (of Scotch-Irish and English heritage, born in Kentucky)Siblings: one of ten children; one brother was Harvey W. Scott who ran another newspaper in Portland, Oregon, in which he publicly opposed womens suffrage Marriage, Children: husband: Benjamin C. Duniway (married August 2, 1853; vocation)children:one daughter, the eldest: Clarafive sons: Willis, Hubert, Wilkie, Clyde, and Ralph Books About Abigail Scott Duniway: Gayle R Bandow. In pursuit of a purpose: Abigail Scott Duniway and the New Northwest. Ruth Barnes Moynihan. Rebel for Rights: Abigail Scott Duniway. Dorothy Nafus Morrison. Ladies Were Not Expected: Abigail Scott Duniway and Womens Rights. Elinor Richey. The Unsinkable Abigail: In forty years of scraping and scrapping for womens rights, Abigail Scott Duniway never lost her nerve or wicked tongue. Debra Shein. Abigail Scott Duniway. Helen K. Smith. The Presumptuous Dreamers: A Sociological History of the Life Times of Abigail Scott Duniway, 1834-1871.Helen K. Smith. Presumptuous Dreamers: A Sociological History of the Life and Times of Abigail Scott Duniway, 1872-1876.Helen K. Smith. Presumptuous Dreamers: A Sociological History of the Life Times of Abigail Scott Duniway, 1877-1912.Jean M. Ward, and Elaine A. Maveety. Yours for Liberty: Selections from Abigail Scott Duniways Suffrage Newspaper by Abigail Scott Duniway. Books by Abigail Scott Duniway: Captain Grays company, or, Crossing the plains and living in Oregon.Path Breaking: An Autobiographical History of the Equal Suffrage Movement in Pacific Coast States.From the West to the West.True Temperance.Edna and John: A Romance of Idaho Flat.David And Anna Matson.