Multiple Sclerosis (MS): Causes, Symptoms and Treatments

Multiple Sclerosis (MS): Causes, Symptoms and Treatments Multiple sclerosis 1. Introduction: Neurology deals with complex and rare disorders. One of the most common neurodegenerative disorders is multiple sclerosis.[1] Multiple sclerosis is a disorder of central nervous system. It is characterized by demyelination, mononuclear cell inflammation and axonal injury. Axonal injury is rarely observed.[2] MS sclerosis is generally categorized under autoimmune disorders. Its causes are unknown.[3] Genetic as well as environmental factors play an important role in development of MS.[1] Elvin Cabalt was the first person to recognize the immune mediated infflamatory response in central nervous system of MS patients. He also found that oligoclonal immunoglobulins are present in cerebrospinal fluid of MS patients.[3]MS affects young adults more than any other age group.[4] It affects females more than males. 2.5 million individuals are affected with MS amongst which 70% are females.MS affects. The incidence of occurrence of MS in individuals varies amongst different regions. It affects northern European population more than the Asian and African population.[5] There is no much sensitive and specific diagnostic test or method for diagnosis of multiple sclerosis.[6] 2. pathological process in MS: Inflammation gliosis Oligodendrocyte axonal toxicity axonal and neuronal Toxicity and axonal loss loss Remyelination Central adaptation and plasticity Ref 1. 3. Classification Multiple sclerosis: Multiple sclerosis can be classified as symptomic multiple sclerosis and asymptomic multiple sclerosis. Symptoms are not seen in case of asymptomic MS whereas symptoms are seen in case of symptomic Sclerosis.[2] symptomic multiple sclerosis can be further classified as 1. Relapsing MS: Relapses are the most important features for diagnosis of multiple sclerosis. Relapses may produce complete i.e permanent or temporary loss of function.[8] 2. Primary progressive MS : Primary progressive multiple sclerosis occurs most probably after the age of35. It involves spinal cord atrophy and difficulty in walking. MRI of brain shows less damage as compared to secondary progressive MS.[9] Primary progressive MS can be differentiated from relapsing-remitting MS by Magnetic resonance spectroscopic imaging(MRSI)[10] 3. Secondary progressive MS : secondary progressive MS is more severe than primary progressive MS. Cerebrospinal fluid of patients with secondary progressive multiple sclerosis shows increased level oligoclonal immunoglobulins(most probably IgG)[9].Patients with secondary progressive MS also have increased level of uric acid in their body.[11] 4. progressive relapsing MS: 5. Transitional MS.[7] The relative proportion of all the types of MS was studied in American population. The observations are as follows: Type % individuals suffering RRMS 55% SSMS 31% PPMS 9% PRMS 5% 4. Causes of multiple sclerosis: The exact cause of the disease i.e multiple sclerosis is still unknown.[3] It is generally thought that multiple sclerosis is initiated by an autoimmune response against myelin sheath and mononuclear cells of nervous system.[2]Both genetic as well as environmental factors are involved in the development of multiple sclerosis.[1] Genetic factors: The involvement of genetic factors in development of MS is confirmed by the fact that 10-12% of the people suffering from MS also have their family members suffering from this disorder. The incidence of occurrence of MS in case of monozygotic twins(28%) also confirms the involvement of genetic factors in development of MS.[7] However there are many cases where only one of the monozygotic twins is suffering from MS, this supports the involvement of environmental factors in development of MS.[2]multiple sclerosis do not show Mendelian pattern of inheritance. This is may be because number of genes involved in the development of MS are more than multiple.[12] The important genetic susceptibility locus involved in development of MS resides in the HLA-DRB gene. Presence of this haplotype increases the risk of development of MS 2-4 times more than the normal individuals[2]. Environmental factors: There are many environmental factors involved in the development of MS. Deficiency of vitamin D: Low levels of vitamin D are thought to be involved in the development of MS.[13]the amount of vitamin D present in individuals system will depend on the amount of sunlight reaching that area. So we can say that latitude also plays an important role in development of MS.[12] Smoking: Cigarette smoking increases the risk of development of MS[2]. It has proven by the survey in Northern America that more than 50% of patients suffering from MS are smokers.[12] Surgery: It has been observed that, individuals history of surgery may increase the risk of development of MS as compared to other individuals.[14]There is significant association between tonsillectomy , appendectomy and development of MS[1,14] Obesity: obesity during during young adulthood may be associated in the development of MS[2] Infection with certain viruses and bacteria : infection with certain viruses have been proven to increase the risk of development of MS{1,4,15]These viruses include Epstein Barr Virus,Herpes,Hepititis B virus and Chlamydia pneumonia[2,14] Latitude effect: It has been observed that as we go away from the latitude the percentage of individuals suffering through MS increases.[5] 5. Symptoms of multiple sclerosis: Early symptoms: Blurred vision Weakness in the arm or leg Tinging Loss of balance Thinking problems[1,4,16] Common symptoms: Tremor and ataxia: This has been observed in 75% of the patients suffering from MS. It is caused due to the degeneration of myelin sheath.[17] Bladder problems: people suffering through multiple sclerosis many times face bladder problems such as frequent urination, involuntary sphincter muscles.[16] Dizziness[1,3] Sexual trouble: Patients may have difficulty in having sexual intercourse.[1] Fatigue[1,3,4,16] Unusual sensation: patients may feel unusual sensations like itching, tearing , burning etc[16] Speech problems: people suffering through MS may sometimes develop speech problems. Swallowing problems: People with advanced stage of MS develop swallowing problems. It is important to know that the clinical symptoms of two different individuals suffering through MS differ from each other. 6. Diagnosis of Multiple sclerosis: The clinical symptoms of MS match with other common neurological disorders therefore it is difficult to diagnose MS at its early stage.[3]migraine may sometimes coexist with MS in case of females[6]therefore sensitive techniques are required for incorrect diagnosis MS .[6] some of the diagnosis methods are as fpllows: Magnetic Resonance Imaging: This is the most commonly used method for diagnosis of MS[3].MRI can detect presence of characteristic lesions of MS present in periventricular,infratentorial and juxtracortical region of the brain.[17]one of the limitations of MRI is that it cannot diagnose MS lesions in the early stage.[1] If a period of 3 months has elapse between the first MRI scan and the second MRI scan then the presence of progressive lesions is sufficient to dignose MS.[3] IT should be noted by all the physicians and radiologist that the diagnostic imaging crieteria is most effective when combined with standardise MRI protocols published by International Consortium of Multiple Sclerosis centres .[17] Presence of oligoclonal immunoglobulins: presence of oligoclonal IgG in the cerebrospinal fluid indicates the presence of MS lesions.[4] The presence of oligoclonal immunoglobulins is detected by electrophoresis. the bands obtained after electrophoresis can be isolated for further analysis.[1] Alkaline phosphatase method and peroxidase method for detecting presence of oligoclinal antibodies: It has been found that the alkaline phosphatase method is more sensitive than the peroxidase method for detecting the presence of oligoclonal bands.[18] Fluorescence Activated Cell Sorting: the is the advanced method of diagnosis of MS. The cerebrospinal fluid of suspected individuals is checked by FACS. These samples are checked for the presence of cell surface markers such as CD4, CD25, CD20, CD40, CD25,CCR6 and CD45. It has been observed that B-cells/monocytes (CD20/CD14) ratio differs between MS patients and patients suffering through common inflammatory disease. Biomarkers used for diagnosis: Differential microRNA expression: microRNA’s are differentially expressed in MS patients. microRNA145 is the potential diagnostic biomarker. [18] Myelin Binding Protein (MBP): MBP is basically found in myelin sheath of a neuron. Presence of MBP in the surrounding cerebrospinal fluid indicates the presence of neurodegenerative disorder such as MS[2] Neurospecific enolase: increased level of this enzyme in cerebrospinal fluid may indicate presence of MS. This enzyme is found in the cytosol of the neurons.[1] Inflammatory markers: Glial Fibrillary acidic Protein: This protein is the major component of intermediate filaments of glial cells.[19] It increases when glial cells are associated with astrocytes. This can be used as potential biomarker for diagnosis of MS[9] Biomarkers for remyelination and repair: These biomarkers are not been systematically evaluated. Potential candidates for this type of biomarkers include Neuronal cell adhesion factors(NCAF)[20] Marker for astrocyte activation and gliosis: S-100 is a calcium binding protein found in astrocytes and Schwann cells. Its presence in CSF indicates the presence of neurodegenerative disorder.[19] 7. Treatment of MS: 1. Use of anti-CD20 antibodies: Rituximab is used to treat mostly the patients suffering from primary and relapsing remmiting MS.[20]

Bias in Epidemiological Research

Epidemiology is the study of the factors associated with different types of diseases for example, how often does the disease occur, how is the disease transmitted, ways in which the disease can be prevented. There are two main types of epidemiology: descriptive epidemiology and analytical epidemiology. Descriptive epidemiology is concerned with the frequency and distribution of risk factors in a population and it makes it possible for one to assess the way the disease has spread. Analytical epidemiology aims to study the causes and risks involved with the disease and the preventive measures.This is according to Pinchinat, S, & Ponton Sanchez (2006) Observation epidemiological studies In this case the epidemiologist does not carry out any actual experiment or in other words does not take part in any active role in the research. The epidemiologist simply makes observations on what is happening based on an already existing situation without administering any treatments for example if on e wanted to compare the exposure of PCBs exposure to occurrence of cancer over a 20 year period, he would not be required to give any form of treatment only to observe the available case available according to epidemiology home page.Experimental epidemiological studies In contrast to observational studies here the epidemiologist will be required to do the actual experiments or play an active role by administering the treatment to subjects and then observing the effects of the treatment. For example an epidemiologist can perform a clinical trial of a new drug on willing subjects and then observe the changes in subjects based on epidemiology home page. There are different types of biases associated with epidemiological research.According to Eric’s Notebook, bias arises when an estimated value deviates from the original or true value. The case studies given in the assignment are going to provide a basis for the discussion of various types of biases and the effects of the biases on the measures of association. Based on CES-Research-bias & confounding, different types of biases will be discussed. Case 1 This case might show both selection and measurement biases.Selection because the epidemiologist might select the children non-randomly in which case the results could be overestimated or underestimated in that if he over picked children who are not exposed to the chemical then his or her result will be underestimated and vice versa. The results will show a bias in measurement if the epidemiologist measures the outcome inaccurately in which case the results will either be over or underestimated. Case 2 This case could show measurement and analytical biases. Analytical bias is evidenced when patients give false information for example about having less sexual partners.This would lead to over or underestimation of the results. Measurement bias would occur if the epidemiologist collected the wrong data from the studies. This also would lead to over or underestima tion of the results. Case 3 This case will show two kinds of biases; measurement bias because the epidemiologist may collect inaccurate data and analytical bias because of not following up the outcome. All this would lead to either under or overestimation of data. Case 4 Measurement and analytical biases could occur in this case.Incase of analytical bias the results could remain unchanged or underestimated and in case of measurement bias it could either be under or overestimated. Word count: 551 References Aschengran, A, & Seage, G. R, (2008). Essentials of epidemiology in public health, (2nd Ed. ). Sudbury, MA: Jones and Bartlett. CEM-Research- Bias & confounding is a site that provides essential information on research bias on epidemiology. file:///c:/biasconfound. html Checkoway, H, Pearce, N, Kriebel, D. (2004) Research methods in occupational epidemiology.Epidemiology Home Page is a website that gives an introduction to epidemiology File:///c:/epi1. html. Ibrahim, A. M. (2001) Eric Notebook: Selection Bias. Department of veterans’ affairs, epidemiologic research, and information center at Durham, NC. http://eric. unc. edu/notebooks/issue8/eric_notebook_8. pdf Pinchinat, S, & Ponton-Sanchez, A, (2006): Analytic and descriptive epidemiology. Biostatem SARL. File:///c:/epidemiology. htm Study Types in Epidemiology http://www. nwcphp. org/training/courses-exercise/courses/study-types-in-epi

Real Estate Bubble in China: the Present and the Future

The concern over whether China is experiencing a real estate bubble has increased, especially after Dubai crisis happened. The construction area of both residential and commercial properties has increased by almost 6 times since year of 2000. China has enjoyed a sharp increase in property price since 2006. Especially, after 2009, due to the large stimulus package, majority of the money went to construction and real estate industry. It further pushed up the property price, leading to a lot families became the â€Å"slave of the property† who were struggled to pay the mortgage. Not only the high price has affected most people‘s lives in China, it could also greatly affect Chinese economy and even the global economy. Domestically, the prosperity of real estate industry is fuelled by local investment and easy band loan. According to MSN Money, there is an increase of 38. 2% from 2010 in property market , mainly from developers and speculators. The scale of loans goes to property market is even more scary, up to $1. 3 trillion. People have compared the real estate bubble of China to the United States. The question is will Chinese property bubble has the similar effect? Fortunately, the difference between China and the United States are quite striking. The factors lead to the collapse of property market in United States will unlikely to happen. In China, a country with high saving rate, people used to buy property in cash 4 or 5 years ago. Even in the heyday of residential mortgages, the loan is not as easy as in the U. S. Down payment amount is much higher than in the U. S. A decline of 20 to 30 % in prices will not let the bubble burst in China. In conclusion, the burst of real estate bubble is not easy in China and, if happened, will have limited effect to the world economy. In this paper, I will try to present the whole picture of Chinese real estate market from the current situation to how it evolves, and will touch on the future as well. This will be achieved with the help of some data and the explanations of ratios. Section II: A Real Estate Bubble in China? The first question needs to be answered is that is there a real estate bubble in China? Since government tries to avoid this sensitive word â€Å"bubble†, and data are not reliable. People have to figure them out and estimate how large the bubble is. Bubble is believed to exist in many major cities of China. For example, in Beijing, real estate prices rose by 350% to 900 % only in 7 years from 2003 to 2010(Figure 1). Other indicators of real estate bubble have reached an alarming status in China in many major cities, including Beijing, Shanghai , Nanjing , Hangzhou and so on. The even striking fact in China is that you can hear stories about â€Å"empty cities† very often. China has the second largest mall empty in southeast China, and modern empty city in Ordos. These are only the cases that you know and easy to identify. However, more empty streets or blocks are in the cities, waiting for people to move in. Ghost City Ordos: the famous empty city in China is Ordos, which is located in the north part of China. Ordos is the second richest city in China, followed by Shanghai, even richer in term s of per capita than Beijing. The city is rich because of abundant natural resources. One –sixth of China‘s coal reserve, one –third of it is natural gap reserves. The GDP has increased at 25% per year, much higher than the national level. With such a huge amount of money, local government wants to attract more people to stay in Ordos. This is how the empty city comes from. The new city was designed to accommodate 300, 000 people, with a capacity of holding 1 million people. Currently, you can hardly see any people on the street, even though most of the properties have been sold out. Surprisingly, the city is still under construction. The local government still believes that they can fill in the new city soon. Unfortunately, the stories about empty cities have been repeated on and on in China. This has been interpreted as a sign of over investment and real estate bubble. In the case, the apartments have all been sold out, even though nobody moves in. ecause most people believe that property will grow definitely. For investment purpose, most of them prefer to buy one. This kind of behavior has contributed to the high vacancy rate in China, High Vacancy Rate: since official data are not reliable, the concrete number of vacancy rate is not available from official sources. The reason for this has been that government officials said that, they don't know what vacancy rate means. Obviously, government is trying to avoid knowing the fact. Somehow, people have provided a rough estimate on the vacancy rate. They are using how many electric meters that have no readings for 6 months as an indicator of vacancy rate. Overall, we got a number of 65. 4 million apartments. It is estimated that the vacancy rate is as high as 36%. With such a high vacancy rate, people are wondering how large the real estate bubble in China will be. James S. Chanos, one of the first foresee the collapse of Enron and earn large profit from hedge fund, gave the answer, it will be Dubai times 1000. A growing number of economists and hedge funds managers have been believed that Chinese economy is a big bubble. Others argue that China is definitely not a bubble, the development is real. There is overheating in some area, but infrastructure construction is still necessary to a country like China with such a huge population. Still, a lot people live in area without roads. The demand of properties is still more than the supply of apartments, due to the urbanization and economic growth. The pent up demand from city dwellers for better living condition, in the future, will convert to real development in economy. Even in 2009, when residential property prices enjoy a high fluctuation, the construction area has increased by 40. 7%, largely due to the central government‘s stimulus financial package. Figure 4 Section III , What are the forces that push up the price? In China, it is more than market demand and supply that determine the price . Local government, individual investors, and central banks are also involved, which make the issue more complicated. Recent years’ increase in property price has created an impression that real estate market will keep growing in the future. Unfortunately, this is also the belief in the U.  S. real estate market which, ultimately, results in economic recession. Thus, almost everybody bet on the future of real estate market. In this section, I will analyze both the market reasons and social factors that contribute to present situation in China. In terms of market demand, the demand for property comes from two kinds of groups. One is from the new migrants from rural places in China. Another is from local residences who want better living condition. Due to the urbanization process and economic growth in recent years, the demand will increase in the long term. This has been part of the reason why investors bet on the market growth. At the same time, governments and real estate developers have made an effort to supply enough apartments to meet the increasing demand. According to Macroeconomic principle , it seems that these have been enough to explain the fact. In an emerging country, political issues are unavoidable in any sense. Land sales have become an essential resource of local government’s revenue which means high property price shares the burden of high land-use right. In China, people don't buy land instead they are renting land for a certain amount of time. Normally, it is 70 years. In this sense, you are renting the land or buy the right to use the land for 70 years. Because of the conflict of interest, local governments are not enthusiastic in applying the central government’s price control policies. In order to facilitate the transaction, local governments even requires very low upfront. Question concerning this will be further mentioned in the next part. It has shown that in Beijing and Hangzhou, land sales have accounted for more than 30% of tax revenue. Thus , local authority has less incentive to tackle the problem. Only average home buyers bear the cost of high property price. Individual investors and state-owned companies made things worse as well. Since state-owned companies normally have much solid financial foundations than private companies, they are more likely to win the land sales bid. It was shown in Beijing that 82 % of land auctions are won by SOEs. These large firms are owned by central government, so in turn, if SOEs didn't win the auction or real estate market suffer a big crisis , both the SOEs and central authority will be affected. This has encourage local government to cooperate with SOEs. For individuals, they store apartments, waiting for a moment when real estate price goes even higher. Earning quick money is all their purpose. High vacancy rate can explain the situation. Section IV, How Real Estate bubble will affect China’s economy? Unlike other industries, real estate industry affects not only the industry itself but also social safety, political stability and financial stability in China. There are mainly two types of risk that will threaten the development of China’s economy, namely, loose mortgage policy for individuals and corporate. Mortgage loans are relatively new to Chinese residence. Most people pay cash to buy property instead of real estate loans. However, it grows almost 50% per year. The proportion of mortgage loans in nominal GDP has increased by 5 % in just one year. When big fluctuation of property price happens, it is likely that majority of property owners’ benefit will be affected from two perspectives. First of all, it will mean the shrink of the value of lifetime saving. As property is the largest investment of most families, the decline of price is also the shrink of their wealth. Secondly, households will become more conservative in investing in the future. People will spend less money on consumption and put more money into banks instead. On the other hand, individual and corporate mortgage loans will also pose a threat to the banking system. For individuals, mortgage loans are relatively new. Chinese used to pay cash for their properties. Nowadays, mortgage loans have enjoyed a 50% increase in just one year. When property price declines, the majority of loan owners will have difficulty in paying the mortgage. When it comes in a large scale, private banks can go bankrupt. Due to some negotiation between different groups, real estate developers don't need to pay the full amount of bidding price, instead they only need to pay a small portion to get the right to use the land. To be specific, if a firm wins a bid which worth 5 billion RMB, only one-tenth of the full amount need to be paid initially. What‘s more, firm can get a loan from banks by using the land as a collateral at the amount of 2. 5 billion. It is clear that firms don't take as much risk as we thought and they can use the extra money to invest in biding for more land. Whenever there is market fluctuation or crisis, these firms and banks will definitely have a difficult time. Conclusion: Opinion diverts in interpreting overheating in construction industry. Some believe that China has a real estate bubble and it will burst soon. Others disagree, thinking this is an exaggeration of the problem of overheating investment in real estate industry in some areas. Personally, with the evidence mentioned above, real estate bubble does exist in China. However, the real demand is there as well. Most of the problems come from over investment in some areas. Resource misallocation leads to the unreasonable increase in property value. More market liberalization and less state-owned companies compete in the industry will help solve the problem. The importance of property even relates to marriage. There is an article in New York Times, titled† In China, Money can buy Love†. Owning a property has become the condition for marrying to somebody. If property price jumps dramatically, not only the economy will be affected, but also social well-being.

Paying the Price The Adventures of Eddie Fung Essay

The Chinese Exclusion Act of 1882 was tailored to cripple the immigration of Chinese into the United States, because they were deemed inassimilable and seen as uncivilized, unclean and filthy, creating an anti-Chinese fervor (Zia). This era promoted resentment towards Chinese which further escalated, with the Johnson-Reed Act of 1924 that extended to other Asian groups. Nonetheless, this did not prevent Chinese immigrants from entering the United States. Chinese found loopholes in the law that allowed them to bring their family members as ‘paper sons’. The 1906 earthquake in San Francisco destroyed municipal records, which catalyzed immigration from China by allowing Chinese-men to claim US citizenship and bring their family from China†¦show more content†¦His family would depend on local-markets to provide free or discounted food, such as buying hard bread as opposed to fresh bread. Over the summer he would be sent to a camp, to improve what school-officials ca tegorized as malnutrition. Although he enjoyed the close-knit community of Chinatown he â€Å"Hated the fact that the boundaries of Chinatown were so limited† (Yung 23). Eddie’s father influenced Eddie to be the chaperone in the family despite his age. At an early age he felt as though he had a financial responsibility, which influenced him to get a job as both a shoe-shiner and a paperboy. He describes his family’s structure as the father being the head of the family, and the mother as the heart. This helped create a balance within the family, but caused tension between Eddie and his father’s expectations. Eddie experienced two spheres of education, American school and Chinese school. â€Å"I loved going to American school, but Chinese school was another matter.† (Yung 25) He disliked the limited exposure of Chinese education, and felt that he had been exposed to a wider world in American school, which eventually led him to flunk out of school. This came as a disappointment to Eddie’s father, and added immense pressure to Eddie. The confinement he felt in Chinatown frustrated him, his overprotective mother crippled his adventurous-ambition and the pressure added by his father to lead the family caused him to runaway when at the age of 13. He