Cutaneous Leishmaniasis And Pathogenesis Biology Essay

Cutaneous Leishmaniasis And Pathogenesis Biology Essay Leishmaniasis is a tropical, protozoan disease caused exclusively by intracellular parasites belonging to the genus Leishmania. Leishmaniasis is a worldwide problem and due to the various species of Leishmania, can manifest in humans as 3 main clinical forms: Cutaneous Leishmaniasis, Mucocutaneous Leishmaniasis, or Visceral Leishmaniasis. Consequently, the severity of the infection and symptoms differ from self healing infections that produce significant scars to the fatal infections. Pathogenesis Leishmaniasis is transmitted by the bite of female insect vector sand flies of the species Phlebotomus in the Old World and Luzomyia in the New World (Figure 1). The life cycle for all Leishmania species is relatively simple and similar (Figure 2). When the sand fly takes a blood meal, it inoculates the source with the 2-3 mm long parasite. At this stage, the Leishmania parasite is known as a promastigote as it contains a singular flagellum. Promastigotes are injected into the host skin, after which they attach themselves to the hosts macrophages, and are induced by phagocytosis. These white blood cells are present at the inoculation site because of the hosts natural immune response to the sand fly bite. Once inside the macrophages, the promastigotes transform into their non-flagellate form, known as amastigotes. From here the amastigotes reproduce by binary fission and continue to proliferate within the white blood cells until the cell bursts. The parasites are then free to infect and invade other reticulo-endothelial cells, which share the same fate and are destroyed due to the reproduction of amastigotes within. The amastigotes and infected macrophages enter the blood circulation. The life cycle of Leishmania is continued when a female sand fly feeds on the infected hosts blood and the amastigotes are taken up by the sand flies. Amastigotes transform into promastigotes, which proliferate by binary fission in the midgut of the sand fly over a period of 4-25 days (WHO, 2010). Hereafter, the promastigotes migrate to the fly proboscis or mouthparts, where the parasite can infect a new host during feeding (Murray et al, 2009) and thus the Leishmania lifecycle is continued. Mammals are more often reservoirs for infection. As well as humans; dogs, rodents, wolves and foxes are examples of common reservoirs (Neuber, 2008) and thus, can suffer from leishmaniasis diseases too. Figure 2: The life cycle of Leishmania. Adapted from Chappuis et al (2007). Figure 1: A Sand fly vector of Leishmania parasites. Extracted from Neuber (2008). Epidemiology Leishmaniasis is endemic in 88 countries, 72 of which are developing countries. An estimated 12 million people are infected with leishmaniasis and 70,000 people die each year (Reithinger et al, 2007). There are currently about 350 million people worldwide that are at risk and threatened by leishmaniasis because they live within 40Â ° north and south of the equator (Jones et al., 2005; Neuber, 2008) and according to the World Health Organisation (2010), there are an estimated 1-2 million new cases each year. There are approximately 20 species of Leishmania which are pathogenic for humans (Chappuis et al., 2007). These species vary in their geographical location and have an effect on the leishmaniasis which manifests (Table 1). Cutaneous leishmaniasis is the most common form of leishmaniasis and is endemic in over 70 countries worldwide (Figure 3). It is found throughout Africa and the Middle East in Afghanistan, Algeria, Iran, Iraq, Kabul, Pakistan, Saudi Arabia, Syria; however, more particularly in South America, in Brazil and Peru (Reithinger et al, 2007; Murray et al, 2009). Over 90% mucocutaneous leishmaniasis often occurs in Bolivia, Brazil and Peru and the majority (over 90%) of visceral leishmaniasis cases, the most dangerous form, is localised to 6 countries; Bangladesh, Brazil, Ethiopia, India, Nepal and Sudan. There are an estimated 500,000 new cases of visceral leishmaniasis each year (WHO, 2010; Chappuis et al., 2007). Figure 3: Geographical distribution of Cutaneous Leishmaniasis. Extracted from Reithinger et al (2007). Main Clinical Presentation Leishmania Parasite Main Geographical Distribution Cutaneous Leishmaniasis L. tropica* Africa, Asia, Middle East, Mediterranean area Cutaneous Leishmaniasis L. major* Middle East, Africa Cutaneous Leishmaniasis L. aethiopia* Ethiopia, Kenya Cutaneous Leishmaniasis L. amazonesis ^ South America (Brazil, Venezuela) Cutaneous Leishmaniasis L .columbiensis ^ Northern South America (Columbia, Panama) Cutaneous Leishmaniasis L. garnhami ^ South America (Venezuela) Cutaneous Leishmaniasis L. peruviana ^ Peru, Panama, Costa Rica, Columbia Cutaneous Leishmaniasis L. venezuelensis ^ Northern South America (Venezuela) Mucocutaneous Leishmaniasis L. braziliensis ^ Central and South America Visceral Leishmaniasis L. donovani* Africa, Asia Visceral Leishmaniasis L. infantum (L. chagasi) Europe, north Africa, Central and South America, Mediterranean area Table 1: Overview of clinical presentation and geographical distribution of species of Leishmaniasis that cause human disease. L. = Leishmania. * Leishmania species of the Old World. ^ Leishmania species of the New world. Data adapted from Reithinger et al (2007), Neuber (2008) and Murray et al (2009). Clinical Presentation Cutaneous Leishmaniasis Cutaneous leishmaniasis is a localised reaction at the inoculation site, which tends to be uncovered areas such as the face, hands and lower legs. Between 2 weeks and 2 months after the sand flys bite, a red papule forms. The area begins to swell and become irritated and after 3-4 weeks, flat ulcers form which eventually harden and form crusted margins. The volcano-like lesions that form can heal without treatment; however, sufferers are commonly left with significant, disfiguring scars. Mucocutaneous Leishmaniasis Mucocutaneous leishmaniasis, also known as espundia, is most often caused by Leishmania viannia braziliensis and has a similar incubation time as cutaneous leishmaniasis. However, this form causes more devastating disfigurement to disease sufferers as the parasites metastasise towards to the mucosal membranes and destroy them and nearby unrelated tissue structures also (Murray et al, 2009). This form is more commonly seen after a primary infection of cutaneous leishmaniasis, where the lesions have eventually healed. Untreated lesions can transform into mucocutaneous forms and year later the oral and nasal mucosas become infected. Inflammation of the nose, mouth, oropharynx and trachea cause sever mutilation and facial disfigurement. Death can sometimes arise as mucosal lesions do not self-heal and prolonged infection compromises both immune and respiratory systems. Visceral Leishmaniasis Visceral leishmaniasis, also known as, kala-azar, dumdum fever or black fever, is the most severe form of leishmaniasis, and if left untreated, those infected will die. It is the most dangerous because parasites leave the skin and colonise the entire reticulo-endothelial system (Neuber, 2008) and spread to internal organs. Incubation period may be from several weeks to a year and can present as a rapidly fatal disease or as an asymptomatic, self-limiting infection (Murray et al, 2009). As the parasites proliferate and destroy the hosts cells, sufferers present with a marked enlargement of the liver, spleen lymph nodes as well as fatigue, weight loss, fever chills, severe anaemia and kidney damage. Death is caused by haemorrhage, complications relating to anaemia or a weakened immune system which cannot deal with bacterial co-infections (Chappuis et al, 2007). As is the case with all forms of leishmaniasis, the chances of the sufferer developing a secondary infection, such as a bacterial infection, are very high and doing so, can complicate the disease further and may lead to death. To add: one photo for each CL, ML and VL. Canine Leishmaniasis Leishmania infantum not only cause severe disease in humans, but in dogs also. Millions of dogs in Europe, Asia, North Africa, and South America are affected by the parasite. There are some clinical manifestations of the disease in dogs which re similar to that of humans including cutaneous alterations, enlargement of lymph nodes, liver and spleen, weight loss and glomerulopathy. As well as this, ocular lesions, epistaxis (nose bleeds), onycogryphosis (abnormal curving of claws) and lameness (disability in walking) are classic symptoms found in infected dogs (Maia and Campino, 2008). As with visceral leishmaniasis, canine leishmaniasis may also present as an asymptomatic infection, thus delaying necessary treatment. Diagnosis Due to the clinical presentations of the disease, a diagnosis can be made; however, for a definitive diagnosis the Leishmania parasite must be detected to confirm the diagnosis. Parasitological techniques are routinely used and involve demonstrating promastigotes in a direct examination of tissue aspirates, or detecting amastigotes in biopsy specimens, which are then, examined using a microscope. Serological techniques to diagnose leishmaniasis are based upon indirectly identifying specific host humoural and cell-mediated responses after inoculation of the parasite. Diagnostic methods include direct agglutination test (DAT), the immunofluorescence antibody test (IFAT), the enzyme-linked immunosorbent assay (ELISA), immunoblotting and antigen detection. Molecular techniques involve detecting leishmanial DNA or RNA have been beneficial in not only diagnosis, but species identification also. The molecular techniques include using various versions of polymerase chain reactions (PCR) to amplify species specific parasite sequences, DNA probes, monoclonal antibodies (MAbs) and isoenzyme electrophoresis. Treatment All forms of leishmaniasis should be treated due to their mortality and morbidity consequences. Drugs are available to treat the disease and choice for all forms is the pentavalent antimonial compound sodium stibogluconate (Pentostam). Cutaneous leishmaniasis is also treated with injections of other antimonial compounds, such as fluconazole and litefosine, directly into the infected lesions (* Figure). Miltefosine has also proven to be an effective treatment for visceral leishmaniasis (Murray et al, 2009). However, as with all drug treatments, the development of drug resistance is a huge issue and over use of this drug in previous years could lead to Leishmania species becoming resistant. As well as this, there are considerable side effects associated with most drugs (Neuber, 2008). A safe and effective vaccine against the various species is urgently required particularly in endemic areas; however, there is currently no vaccine available although work to develop one is still ongoing. (To add: * Figure of such treatment) Social and Economical Implications Leishmaniasis is found in developing countries or the poorer regions of a country and thus commonly affects the poorest of the poor. Having such a disease can cause many problems in the lives of those infected and their families as they become poorer due to the direct and high costs of diagnosis and treatment of the disease, and the indirect costs such as loss of income (Chappuis et al, 2007). Another impact of the disease is the social and psychological stigma associated with leishmaniasis, because of the disfigurement and significant scarring caused. Thus, even after the disease has been treated or self-healed, patients must deal with a constant reminder of what they had to endure. Cheap, rapid and accurate diagnostic methods are needed to allow all those infected, especially the poor, to get the medical attention they need, and to also allow treatment to start as soon as possible thus ensuring symptoms may not be as detrimental. Project Aims The aim of this project is to compare the different methods for diagnosis of leishmaniasis in humans and dogs. These methods will be critically analysed in order to test the following hypothesis: A Leishmania infection can be detected unequivocally. In doing so, the necessary requirements for a correct diagnosis for those who live in endemic areas and for those whom leishmaniasis is a threat, will also be discussed.

The Benefits of Integrating Computers into the Early Childhood Classroom :: Teaching Education

The Advantages of Integrating Computers into the Early Childhood Classroom Each year, new technologies hold the promise to alter the way we think and learn. Computers are prevalent everywhere, and they are making their way into school systems around the country (Roberts, Carter, Friel, and Miller, 1988). It is obvious that there is a demand for technological instruction in high school and college. However, the question of if computers should be implemented into early childhood classrooms is still prudent. With computers all around us, it is inevitable that children will be exposed to them, and they will eventually be facilitated into their daily lives. The purpose of this research paper is to explore the advantages, disadvantages, and methods of integrating computers into the early childhood classroom. How Computers Effect Young Children Early childhood experiences should maximize young children’s overall growth and development. Their eyes should be opened to the wonderment of learning and the pleasures of discovery. Computers can by an important tool to optimize young children’s potential, and help aid the learning process (Scoter 2001). Before deciding to introduce children to computers, it is important to address the potential benefits and dangers the machines have on youths. Potential Dangers Some people believe that computers should not have a place in early childhood classrooms. They speculate that computers will rob children of their childhood, replace other activities, reduce creativity, and lead to social isolation. It is feared that computers will force them to learn what they are not ready to learn. The machines are often viewed as one more thing to rush young children through their vital childhood years (Scoter, 2001). Whether computers will rob children of their childhood totally depends on how they are used. If children are forced to use computers for lengthy periods of time with drill software, computers could very well rob them of their childhood. On the other hand, if computers are used in appropriate ways that meet children’s development level, they can benefit young children, and teach them what they are ready to learn (NAEYC, 2001). It is also believed that computers will replace other childhood activities, such as building with blocks, painting pictures, or playing â€Å"house†. Exposure to computers may hinder children’s developing understanding of the real world. In reality, this does not occur. Whenever something new, whether it is a paint set or a computer, is first introduced into a classroom, all the children want to use it.

Evaluation Of Work In Progress †Blue Remembered Hills Essay

For the past term and a half I have been studying Blue Remembered Hills as part of my Drama Coursework and a couple of weeks ago I performed an extract from the play with three fellow students. I will be writing about my Work In Progress and how well we worked together as a group to make our performance successful. To do this I will be focusing on the rehearsal process and the final performance. The Rehearsals. The rehearsals went very well, with steady progress throughout each session. The main strengths were the whole groups ability to pick up words, stage directions and changes quickly, for example when we decided to use a domino effect for our entrance. This effect was put in close to the end of our whole rehearsal process but we never had any problems with it and no one forgot it either. We also had all our lines learnt by the fourth lesson which meant we could get on with focusing on our stage directions and character analysis. Our main weaknesses were our character analysis, for example one of our group members found it hard to perform as his character because his personality was very different to his characters and his volume was a slight issue as well. I also found it hard to perform as my character because at the beginning I would let the status slip slightly at the wrong moment and I wasn’t seen as the bully anymore, I would also have to be careful about my pitch because I was playing a boy and sometimes my voice would come off girly and high pitched. One of our main problems was that some of us had other commitments like work or clubs that made it hard to organise lunchtime or after school rehearsals this affected our rehearsal process because when we managed to organise a rehearsal it had to be a short one or someone might have forgotten or not been able to make it, so it was hard for our teacher to asses our work and give us feedback if there was someone missing. We over came our problem by working extra hard in our lesson time so we could pay off for it that way. We also tried to work outside a lot so it could help us imagine our surroundings and the sort of things a seven year old would do outside. I found my strengths were my ability to incorporate ideas into our work and give constructive criticism. I don’t feel there was a directors role because we all had ideas and were able to give each other advice on their character build up. I felt I was able to help the group improve practise by asking for line reruns and workshops to improve our overall characters. My main weakness was character analysis (as above) mainly because, as a group, we didn’t do enough character analysis and this could have helped me. I feel my contribution benefited the rehearsal process because I could keep the group focused on a task and I was a good team player. I fell I could have helped others in my group more without feeling I was going to offend them because it affects the whole group dynamics if one person is unsure and it shouldn’t have to be a hindrance. The demands of working in a group are to not mess around or waste time, because you have to put as much effort in as your group members otherwise it isn’t fair, and you are putting the whole group in jeopardy and therefore are not able to make a satisfactory performance. The Performance In our final performance the domino effect worked really well as opening the scene because it gave us all the energy we needed to open the scene as seven year old boys. The thing that didn’t work well was the dirt on the floor, the sticks were fine, it was just the debris and mud on the floor that didn’t work. We put it there to make the scene more site-specific but it was unnecessary because we didn’t need to use it as a prop and had to sweep it up afterwards as well!! Our strengths as a group was our ability to stay in character even when we weren’t speaking because this helped to keep the energy levels high and keep the performance interesting. As an individual performance my strengths were my volume and diction because I felt I carried my words out so everyone could hear me. My weaknesses were my body language and pitch because I would often slip out of my characters voice and body language. For example when I am fighting with John I would lead from my chest which isn’t manly. I felt our group created a performance that clearly expressed a theme suited to our target audience. We achieved this by developing skills which enabled us to broaden our minds and act as seven year olds. I was able to play my character because: My voice was mainly boyish and I was able to pull off bully mannerisms; My body language was like a seven year old because instead of sitting I would squat, or I would fold my arms to show stroppiness when someone does something I don’t like; My facial expressions suited the mood I was in or the situation that was happening, like when the atmosphere dropped when everyone looked at the squirrel in guilt I changed my facial expression to look uncomfortable or guilty; My gestures were large and clumsy like that of a child like when we were trying to get the squirrel out of the tree I would wave my stick or hurl stones at it; And my interactions with others on stage were that of a higher status character and sometimes very nasty because I was a bully and carried the higher status, likely after my fight with John I stuck my tongue out at him and made other nasty gestures towards him. Overall I felt that my performance and our overall work in progress was a success and we worked very well as a group to make our performance successful.

Monetary Union essays

Monetary Union essays PE 116 Movement Education Kevin Juon Date 4-21-99 The word gymnastics came from the Greeks. The Greeks used this word to describe any type of physical activity. Exercise was an important part of their education process, sort of like what is in place today. They used exercise in order to beautify the body, promote health, comfort, strength, and vigor. The Romans took the Greeks beliefs on exercise, and used them in training their military forces. After the Romans, exercising virtually dropped off the face of the Earth until Johann Basedow (1723-1790) opened a school in 1774. Then once again, it became part of education. Today, hundreds of years after the Greeks, many people exercise for these same reasons they did. The Spartans also exercised, and one of the things they did were balancing activities. This was most likely important to the Spartans for different reasons, for example, it would help them during battle to be able to keep their balance. Schools today also use the balance beam even though it is not because they want the kids to be prepared for battle. The balance beam will help the kids acquire the balance needed in many activities they will perform as kids, Many types of gymnastics help balance, but there is no single activity that requires balance like the balance beam. The balance beam is able to be used for all different skill levels because the height of the beam can be adjusted. The teacher of a class is able to have the kids first try the exercise trying to stay on a piece of tape that was put on the floor. Then they could have the kids try it on a bleacher, it is a higher up, but is also wider than a regulation balance beam. Finally, once the kids get the hang of it, they can have them try the exercises on the balance beam. A direct result of the balance beam use, is the development and good use of the muscles in the feet ...

Back to Space

Back to Space I found President Bush's "State of the Union Address" was very interesting. As he talked about his new space plans about NASA. As I got to thinking about his new plan, I found myself wondering what is out there in the universe? Should we really be spending so much money on space activities?There are many good reasons why we should send people to mars and moon. Our universe is very complex and mysterious. The more we learn about it the better off we will be. Like what the wise man, Francis Bacon, once said "Knowledge is Power." Many people wonder what is out there. Maybe sending people to mars and moon could answer some of our questions. NASA has had problems in the past, but they have helped us learn so much about space. We have already had the rover on mars for sometime now. The rover has helped us find out many interesting facts.English: President George W. Bush delivers his Sta...Space program all over the world should share information about the finding on the universe. I know th e chinese have just put their 1st astronaut up in space a month or so ago. It may draw conflict with NASA. I think they should just all work together. We all live on one planet.There is some controversy why we shouldn't send people to Mars. For example, the space shuttle Colombia that crashed and killed seven astronauts. What makes them think that something like this won't happen again? Money is also a very big issue. American is in a lot of debt right now. Is spending all this money going to mars a good idea? Think of the Americans we will be putting in danger.Overall I strongly agree with President Bush, and his idea of putting people on mars and moon. We could learn...

Brora Scottish Cashmere Article Example | Topics and Well Written Essays - 1000 words

Brora Scottish Cashmere - Article Example It is a privilege to be writing an article on this personally beloved, globally renowned Cashmere brand. Victoria Stapleton who is the founder, owner and creative director at Brora, was brought up in the North of England, which is home to the Scottish cashmere industry. Having lived so close to the hub of the cashmere industry Victoria often found herself in the mills, as she â€Å"spent many childhood hours browsing mill shops and feeling the delicious quality of their cashmere†. In 1990 when her family got involved with ‘Hunters of Brora’, a 100 year old tweed mill, Victoria jumped at the opportunity to get involved and was soon managing the mills retail venture. Having been brought up in an entrepreneurial family she knew that she wanted to have her own business one day. The experience of working in a mill and gaining knowledge of how a business is run â€Å"†¦sowed the seeds for the founding of Brora†. Victoria began her entrepreneurial career by o pening a retail outlet in London and now, Brora has expanded its outlets all over the UK, the most recent being opened in Cambridge, Covent Garden and Westbourne Grove in London. Brora is a retail company that strongly follows the philosophy of ‘Buy British’. ... e clothing manufactured by the company is produced in mills which are situated in the UK, using only the finest raw materials and carefully selected yarn from selected herds. Being a private and democratically run company not only builds a strong relationship with the customers that Brora caters to but also with the suppliers and employees that are associated with the company. Brora has a strong culture of workmanship & camaraderie within the company. People who work there don’t often leave, primarily because the company is socially responsible towards its workers. There is a true-to-the-word democratic process involved in all core decision making efforts and this practice of mutual consultation is not only confined to the insides of the organization, in fact every customer is treated as part of the family. Brora claims that every customer is a friend & thus, should be treated like one, â€Å"The Company is run personally and democratically and this ethos extends to our custo mer, who becomes a good friend with whom Brora has a relationship, built on honesty & trust.† The clothing collection at Brora offers a variety of beautiful and luxurious products for women, men, children and babies, all available in a various materials for everyone in the family. The company is dedicated to producing affordable clothing for every age group, where each collection is dynamic with a wide variety of colors and designs to choose from. No matter what piece of clothing or accessories you choose, it will give you a luxurious and stylish aura. It is vividly evident that each clothing collection is a result of Victoria’s love for the arts and the natural beauty of the Scottish landscape, which offers her a vivid palette to work with; â€Å"When I want a focused day of inspiration, I do love

Should Physician-assisted suicide be legal Essay

Should Physician-assisted suicide be legal - Essay Example The issue of legalisation of physician-assisted suicide at national and international levels has for a long time continued to trigger debate among people in the society and has resulted in diverse perspectives: while in some countries physician-assisted suicide is legal, in others, there is a great struggle between various groups to legalise it and allow people to carry it out when need arises. Those who support and those who oppose the legalisation of physician-assisted suicide argue on their justifications not only according to their thinking but also with consideration of the ethical perspectives (Lachman, 2010). Legalisation of physician-assisted suicide is not a simple decision to make because it involves contradicting perspectives against and for considering the effects it has on the lives of the affected individuals. The rights that people have prevent them from killing others even with any justification and support from any organisation as far as the choice and authorisation are not from the affected individual. ... In this respect, no person has the right to terminate the life of another person because the right to live does not offer any provision for a special case in which a person has to end the life of another. The right to live does not imply in any way the duty of any medical practitioner to induce suicide to a patient in whatever condition he or she may be, but rather the duty to protect life (Jeffrey, 2009). According to some proponents of legalising physician-assisted suicide, it would lessen the pain of the affected as well as their family members so that they contain it with ease. In this way, legalising physician-assisted suicide will allow suffering people to make consultations with the family members before they take the action and before parting because they will be able to set time for it. This would allow them to reduce the negative implications of the suffering individual and come up with a solution that will have benefits for the suffering and those ones who relate to them ( Lachman, 2010). Some people who support legalisation of physician-assisted suicide argue that individuals that are suffering have their own choices and they can decide to die with dignity rather than suffer from pain until death, which may take long to happen. This means that a person has a choice to make on the way he or she can end his life in circumstances that place him or her in a condition of suffering and without comfort, with minimal chances of surviving. As such, the suffering will need their right of choice to end his or her life be respected by the government bodies or other organisations which may have an opinion about the suicide (Jeffrey, 2009). Legalising physician-assisted suicide will help the patients with a terminal illness