Chromium and Selenium Concentration in Cancer

Chromium and Selenium Concentration in Cancer The ratio between chromium and selenium concentration among various age groups of cancer group has also been studied and it shown in table 5.48, and it has been observed that all groups of cancer patients present somewhat similar ratio of chromium and selenium concentration in their blood. Moreover, the concentration balance of chromium and selenium has conspicuously been disturbed as it illustrated in table 5.49. For instance, the breast cancer mortalities in various countries were studied and ascertained a direct correlation with the estimated dietary intake of zinc, chromium and cadmium and inversely proportional to the concentration of selenium (238). The summary of stage wise distribution for chromium and selenium has been illustrated in Table 5.50 and it observed that all four stages of cancer patients present a sort of consistency in chromium and selenium proportion in the blood of cancer patients as shown in Table 5.51. In view of this fact, it may be elucidated that the demarcation among various stages of cancer is arbitrary division and this periphery does not present any association of stages with the distribution-ratio of chromium and selenium in the blood of cancer patients. However, the reduction of 0.064 Â µg ml-1 of selenium concentration in the blood of cancer patients corresponds to more than 52 % decrease as compared to the selenium level in the blood of control group. These variations in concentration may be the result of the disease of cancer however the type of cancer does not influence the levels of selenium in the blood of cancer patients. However, the significant decrease in selenium concentration in whole blood and plasma has been observed in another study where the tannery workers were exposed to chromium compounds and have shown a considerably lower selenium concentration in their blood and they excreted lower amount of selenium in their urine as compared to the worker those were not exposed to the chromium. It may confirm the point of view that chromium and selenium have some kind of interaction and biological selenides are formed with chromium and in due course of time they accumulate in some organs. It was also demonstrated that the tannery workers who were exposed to air with high concentrations of chromium compounds at their workplace exhibited significantly higher erythrocyte and plasma GSH-Px activity than workers of other departments (239). Therefore, higher level of selenium stipulates the main function of selenium is to induce and maintain the enzyme glutathione peroxidase, which prevents cellular damage by catabolizing organic peroxides (240) The enzyme, SeGSH-Px, catalyzes the oxidation-reduction reaction between reduced glutathione and peroxide. Therefore, the pathological lesions lured with selenium deficiency are considered to be caused by peroxidative damage that is the product of depressed SeGSH-Px activity (241-242). However, once chromium absorbed and retained in biological tissue chromium compounds occur as chromium (III). Glutathione and cysteine seem to be the most important cofactors for the intracellular reduction of chromium (VI) (243). The absorption of metal in the human body is a complex process and depends on various factors including dietary components. About 40% of ingested metal is absorbed in the small intestine (244). Furthermore, a variety of neurodegnerative diseases such as Alzheimer’s, Parkinson’s, Creutzfeldt-Jakob, and neuronal damage caused by stroke and ischemia may be associated with pathological disruption of metal trafficking (245-247). Chromium is potentially toxic and carcinogenic at higher doses. All chromates that exhibit oxidation state (VI) can aggressively enter the cell through channels that are specified for the transfer of isoelectric and isostructural anions, such as SO4-2 and PO4-2. However, the insoluble chromates are engrossed by cells through phagocytosis. As soon as the chromates get inside the cell they are competent enough to generate free radicals immediately. Yet, in the presence of cellular reductants the chromium inside the cell can cause a broad series of DNA lesions such as DNA- protein crosslink, Cr-DNA adducts, DNA-DNA cross links, and oxidative damages. The glutathione quickly reacts with chromium (VI) and forms a complex and generate chromium (V) and chromium (III) through slow reduction of chromium (VI) inside the cell. The chromium (V) and chromium (III) species exhibit the tendency to alter the DNA conformation. The reduction of chromium (VI) can be commenced through GSH, or in the pre sence of other reducing agents. The chromium (V) and chromium (III) can react with H2O2 through Fenton reaction and produce hydroxyl radical (OH) that has the potential to damage DNA. There are evidents that interacellular reduction of chromium (VI) results in extensive formation of Cr-DNA adducts, among which chromium (III) – mediated DNA cross-link of glutathione, cysteine, histidine and ascorbate represent an important group of DNA modifications. Therefore, Cr- DNA adducts are responsible for both the mutagenicity and genotoxicity of chromium. The chromium (VI) is considered as carcinogen for lungs cancer for human (248). Numerous epidemiological studies have been performed for more than 100 years on workers exposed to chromium in order to determine its level of carcinogenicity. Altogether, these studies indicate that exposed individuals have approximately 2- 80 fold increased relative risk of developing lungs cancer (226). On the other hand, an inverse association between serum selenium level and cancer risk is biologically possible. The results of the study indicated that the treatment with selenium improved GPx levels. GPx detoxifies H2O2by reducing it to water. It also protects cytosolic organelles from oxidative damage by preventing lipid peroxidation. Selenium could reduce oxidative stress through antioxidant selenoproteins such as glutathione peroxidase, selenoprotein P, and thioredoxin reductase. (249-250). There are numerous promising possibilities that may be presented as an account for the observed variations for selenium in whole blood levels associated with malignant disease, as compared to healthy and control group (251). It includes chemotherapeutic-induce necrosis, which could release selenium from tissues into the circulation, preferential sequestration by tumor cells (252-253) and alteration of properties of proteins, especially enzymes, at elevated concentration of selenium in tissues (254-255). Furthermore, the possibility of depression in activities of specific enzymes with loss of vital enzyme activity, and impaired tissue function resulting from a selenium-deficient state (256). The depletion of selenium in the blood of cancer patients may suggest its reciprocal accumulation in the malignant tissues in view of the studies (257-261) who have reported higher concentration of selenium in the cancerous and neighboring tissues cells. Availability of excessive selenium in the cancerous cells may be expected to facilitate the synthesis of selenoproteins e.g. Trx, TrxR etc. which are known to provide protection to the tissue cells against the oxidative stress, carcinogens, and help to reduce cancerous cell growth. The results of recent studies (262-264) regarding the diversified multiple functions of selenoproteins has generated tremendous interest in the understanding and elucidation of mechanisms that triggers the role of these proteins from anti-apoptosis in the normal cells to pro-apoptosis in malignant cells. There are numerous studies (265-267), who have proposed different mechanisms to explain the inhibiting effect of selenium on malignant neoplasm; for examp le modulation of cellular division rate, decrease in formation of carcinogenic metabolites or cellular protection by an antioxidant system. It is generally believed that due to the anti oxidative characteristics of selenoproteins, these proteins can protect the cells and DNA from oxidative damage; in addition, these proteins can react with carcinogens directly to save cells and DNA from their lethal actions. It has been suggested (263), that nitrative inactivation of Trx plays a proapoptotic role if the reactive nitrogen species are increased; and antinitrating treatment may have therapeutic value in those diseases, such as myocardial ischemia/ reperfusion, in which pathological apoptosis is increased. The situation is reversed in malignant tissue cells where apoptosis is beneficial for the inhibition of the cell growth. Therefore, in view of the aforementioned studies, it is possible that the pathological conditions in which production of nitrogen species is increased that may favo r the inactivation of Trx and therefore enhance the apoptotic role of this selenoprotein. A kinetic study of the reaction of NO and O2 in aqueous solutions, based on pH indicator, has been performed by using stopped-flow spectrometry. The results of these studies have shown that at physiological concentrations of O2 and NO, the auto- oxidation of NO does not limit its diffusion from the site of production in endothelial cells to a spatially removed target molecule such as guanylate cyclase in myocytes and platelets. A Trx interacting protein Txnip has been reported (31), which inhibit the antiapoptotic activity of Trx where as NO suppresses the expression of Trxnip and enhances the Trx activity, therefore perhaps the oxidative character of Trx in malignant cells as reported in the above mentioned studies may well be interpreted as the inhibition of its antioxidant activity. In different studies (267-268) it has been suggested on the basis of their results that selenite induces apopt osis by producing superoxide ions which activate p53, a well known protein involved in carcinogenesis, which in turn support apoptosis. A key role has been assigned (269), to Trx-2, located in mitochondria, in interaction with electron transport chain, determining tumor necrosis ROS generation, NF- kB activation and apoptosis. Intestines are the main sits where selenium absorption is measured at maximum. In liver selenium joins many other amino acids and generate selenocysteine and selenoproteins. Selenoproteins consist of active form of selenium and are transferred to all over the body. Kidney and liver, however, have higher concentration of selenoproteins. It is reported that a small quantity of selenoproteins are also exist in blood and serum. Furthermore, being a part of selenoproteins the selenium is an essential part of glutathione peroxidae as well that is the reason selenium is believed to be an antioxidant (36). Glutathione plays a role of a protector in the body of an organism and ensnare the balance of free radicals, peroxides and preserves the redox status of the cell (270). In addition, glutathione perxidase provides defense mechanism against free radicals that may cause destruction of cell membrane. The free radicals are generated when hydrogen peroxide produced in the mitochondria of the cell during the regular metabolism. The stress is a foremost cause of excessive production of hydrogen peroxide that sequentially create a disproportion in free radicals inside the cells. Chemical structure of cell membrane comes under the attack of free radicals and gives away their loosely bounded electrons to the free radicals. Consequently, a chemical structure of cell membrane turns into a reactive entity and begins to instigate an electron from adjacent structure and this chain reaction serves to damage the cell membrane causing the cell to die. Proactive role as a safeguard of glutathione peroxidase quickly transform hydrogen peroxide into water a way before it could generate harmful reactive species called free radicals. Another study highlights defense mechanism of vitamin E in which glutathione peroxidase and vitamin E follow a similar pathway in order to discontinue the chain reaction by engaging the free radicals within the cell membrane. Therefore, it is an effective combination of selenium and vitamin E that can control the production of free radicals and prevent the damage of cell membranes as well as DNA and other cellular structures (270).

Analysis Of Economic Performance Of Canada Economics Essay

Canada is among the top 10 trading states in the universe and its economic system is dominated by service sector. It is one of the wealthiest states and it ‘s a member of administration of economic cooperation and development ( OECD ) and G-8. The impressive growing of Canada ‘s fabrication, excavation and service sections have transformed the North American state from an agricultural economic system to a extremely industrial and modern economic system ( canada economic construction ) . Canada ‘s biggest trading spouse is USA, 80 % of its exports are to USA and imports 65 % from USA ( canada economic system ) . Canada has experienced a high economic growing, even when a planetary economic crisis was impacting most economic systems of universe ( canada economic study ) The purposes and aims of this study are to measure the economic public presentation of Canada. The study discusses about the macroeconomic indexs and balance of payments from 2006 boulder clay today. The study besides discusses about the future positions of Canada. Gross Domestic Product can be defined as â€Å" the sum of goods and services produced by a state over clip † . Canada ‘s economic system is really extremely developed. Foreign Trade is the foundation of Canadian economic system. Foreign Trade is responsible for approximately 45 % of Canada ‘s Gross Domestic Product. Canada is one of those states that are a major exporter of energy ( merchandising economic system 2010 ) . Canada ‘s existent GDP has grown by 0.8 % in the last one-fourth of 2010, led by exports. All major subdivisions increased their end product in the last one-fourth of 2010, except the fabrication industry. The largest sector lending to the GDP growing was the excavation and oil and gas sector. Canada has seen so many ups and downs during the recession period. But 2009 has been the worst twelvemonth for Canada in footings of economic growing as the GDP fell to -2.46 % . But Canada being a major exporter of so many merchandises has somehow gained back its place as GDP rose to 3.07 % . Canada is one state in the universe that has seen a budget excess when the recession was striking so many economic systems severely. But finally in 2009-2010, Canada ‘s excess started shriveling and the state for the first clip in last six old ages witnessed a shortage. Although, Canada was in excess for so many old ages still the % alteration in the figures as seen from the graph below was really less. The excess growing in 2009 was merely 0.15 % as compared to the old twelvemonth where the growing was 1.96 % .In 2010 the state faced a shortage and the growing rate went down to -0.03. Exchange rate is the monetary value of one national currency such as Canadian dollar expressed in footings of in another currency, illustration US dollar or basket of currencies ( Bank of canda ) . Canada has flexible exchange rate system this can be shown from the undermentioned line graph. In 2006 it was 0.88 which increased boulder clay 2008 and because of recession during 2009 it decreased. Motion in Canadian dollar shows how domestic and external factors co relate with each other. These factors play an of import function at different points of clip. The factors are economic public presentation, involvement rates, rising prices rates, Canada ‘s public debt, trade and current history balance etc ( Bank of canda ) . Canada Balance Of PaymentsCurrent HistoryThe balance of payments can be defined as â€Å" the economic dealing of the state ‘s occupants with the remainder of the universe â€Å" ( fxwords ) and the Trade is the â€Å" difference between the exports and imports ( fxwords ) . â€Å" Canada has been in a trade shortage since past few old ages ( 2005-2009 ) because it has imported more than it exported. But in 2010, state ‘s exports increased and finally it the trade balance started lifting ( from -27231 to -23309 ) . The above graphs are similar beacause there is a strong relationship between the trade balance and the current history balance. When the trade balance is diminishing the current balance is besides diminishing and vice-versa. This means they are straight relative to each other.2. Capital and Financial AccountCanada ‘s balance on capital and fiscal history has shown a uninterrupted betterment as the figures went up from -22768 in 2006 to 55546 in 2010. When a state has a positive capital and fiscal history, it has more debits than credits. It is said that a state should non hold any restraints on capital motion because it attracts more Foreign Direct Investment.In Canada stock exchange volumes and capital market deregulating are encouraged by Portfolio Foreign Investments and the investors diversify their portfolio hazard by puting in more than one market ( investopedia ) . Canada is a state full of natural resources, engineering and many other agencies of production. Even Bankss and other fiscal establishments are stable in this state. Canada has been a state of low involvement rate and low rising prices rate. This is the ground why the state has developed more than any other state even after go throughing a bad stage of fiscal crisis ( economic system ticker 2008 ) .Future GDP EstimatesThere has been an addition in the GDP growing in the first one-fourth of 2011.The state has overcome with the recession at a faster rate than any other state. At the terminal of 2009, Canada was in the figure 10 place for universe rankings. Forecasters expect that by the stopping point of 2015, Numberss will make $ 1,971.44 billion in US dollars. Because the economic system of Canada is a mixture of many things and with this state being one of the most critical of all providers of agricultural merchandises, it is expected that the economic system will stay strong ( econ omic system ticker 2008 ) .

Causes and Effects of Bullying Essay

Bullying is a serious problem in homes, schools and communities. Often dismissed as an adolescent â€Å"rite of passage,† research clearly indicates bullying is learned behavior and detrimental to the academic, physical, social and emotional development of all involved bullies, targets and the bystanders who witness it. Bullying is not only a problem of youth but is one that spans all ages. Despite volumes of research, countless â€Å"anti-bullying† programs and increased by the media, bullying continues to pervade our culture and our schools. It is a complex social issue requiring determination, leadership and courage to address. Although it is a difficult challenge, it cannot be ignored. A wave of recent bullying incidents with tragic outcomes has shed a renewed light on this issue. The advent of technology allowing for impulsive, anonymous and rapid communication, has expanded the opportunities for bullying to a degree that necessitates more innovative and immediate responses than ever before. Most people know that bullying is wrong. Calling someone names has absolutely no beneficial purpose. Moreover, hitting someone makes a bully feel good in the moment while doing permanent damage to the person being victimized. With the Internet, people now have even more opportunities to bully through cyberbullying. This includes sending crude pictures, posting fake web pages, or tweeting slanderous messages. Cyberbullying has subsequently led to a rise in a completely new kind of bullying. One of the effects of bullying is that it can change the victim’s personality. It can cause people who are normally confident and happy to become self-conscious, shy, and unsure. Additionally, victims of bullying may also become sad or depressed. Their confidence might completely disappear, keeping them from trying new things or trusting people. Once a person has been bullied, they may hesitate to participate in situations where he or she might be ridiculed, such as in public speaking or in sports. A bullying victim might even begin to possess previously absent anxious behavior. Despite all the negative effects of bullying, there are even far more serious consequences. People who have been bullied sometimes become so upset, scared, or depressed that they see no worth in themselves and no way out of their torment. There have been countless reports over the past few years of students committing suicide because they were bullied. Meanwhile, there are times when victims see no recourse but to seek revenge by serious acts of violence against the bully and instigators. As a result of bullying, people can lose their ability to love and trust, denying them the chance to experience a quality relationship later in their life. They might find themselves as a submissive partner or they may want to be completely alone. Compounding all of these problems, victims often develop eating disorders, begin to self-injure, or require extensive counseling. Social bullying can also leave people without a supportive group of friends that they can lean on and spend time with.

Immigrant High School dropouts Free Essay Example, 2750 words

Finally, the research identified that increasing rates of compensation to those who are unemployed decreased employment rates. Assessment This research article presents findings that link increasing school dropouts to employment rates. Its main purpose was to establish the potential effect of school dropouts on the economy of the state. The findings reveal that there is no significant contribution of high school dropouts to decreasing levels of employment. Although these findings do not conform to those of other studies, the article is critical in offering a different view of the issue. Reflection The article relied on quantitative analysis to determine the core relation of school dropout and the economic development, which is a critical consideration in my research. Driscoll, A. K. (1999). Risk of High School Dropout among Immigrant and Native Hispanic Youth. International Migration Review, (4). 857. Summary This source focuses on examining the existing relationship between the immigrant population and the alarming school dropout rates exhibited by the Hispanic students. The research conducted by the author utilized NELS: 88 data set in determining the reasons motivating Hispanic students in the 8th grade to drop out of high school. We will write a custom essay sample on Immigrant High School dropouts or any topic specifically for you Only $17.96 $11.86/pageorder now This research study revealed that causes of school dropouts are similar across different populations in the lower levels of education. However, students in the 8th grade were more likely to drop out of school if they lacked sufficient individual and family resources. Moreover, the research identified that family income and remarkable performance were some of the factors that prevented school dropout. Assessment The article serves as a credible source for this research because the research question addressed is related to Hispanic youths, which are part of the immigrant community. The fact that it explains a set of factors that motivate students to drop out of school makes it a comprehensive source, which augments others. Reflection It is intriguing that a similar set of factors determines school dropout in the early years of education. On the other end, the author presents new information that eighth graders were likely to drop out of school if they lacked individual or family resources. Economic stability emerged as a critical factor contributing to school dropouts. Griffin, B. W. (2002). Academic Disidentification, Race, and High School Dropouts. High School Journal, 85(4), 71-81. Summary This article seeks to identify the effect of academic disidentification on the increasing rates of school dropouts.