Dna Digestion and Electrophoresis - 728 Words

DNA DIGESTION AND ELECTROPHORESIS In this experiment we will be doing a process called as DNA digestion or also known as restriction digest. A restriction digest is a procedure used in molecular biology to prepare DNA for analysis or other processing. It is sometimes termed DNA fragmentation, scientists Hartl and Jones describe it this way: This enzymatic technique can be used for cleaving DNA molecules at specific sites, ensuring that all DNA fragments that contain a particular sequence have the same size; furthermore, each fragment that contains the desired sequence has the sequence located at exactly the same position within the fragment. The cleavage method makes use of an important class of DNA-cleaving enzymes isolated primarily†¦show more content†¦One of the most important reaction conditions which varies between different restriction enzymes is the salt concentration. Enzyme buffers are specifically formulated to provide the salt concentration for optimal enzyme activity. It is important, therefore, that the correct buffer solution is used for a particular restriction enzyme. [3] For this experiment we also made use of agarose gel electrophoresis, which takes a lot of time. Electrophoresis may be the main technique for molecular separation in todays cell biology laboratory. In spite of the many physical arrangments for the apparatus, and regardless of the medium through which molecules are allowed to migrate, all electrophoretic separations depend upon the charge distribution of the molecules being separated. Electrophoresis can be one dimensional or two dimensional. One dimensional electrophoresis is used for most routine protein and nucleic acid separations. Two dimensional separation of proteins is used for finger printing , and when properly constructed can be extremely accurate in resolving all of the proteins present within a cell. The support medium for electrophoresis can be formed into a gel within a tube or it can be layered into flat sheets. The tubes are used for easy one dimensional separations, while the sheets have a larger surface area and are better for two- dimensional separations. In electrophoresis, proteins are separated on the basis ofShow MoreRelatedIsolation, Restriction Digestion, And Electrophoresis Of Plasmid Dna1827 Words   |  8 PagesIsolation, restriction digestion, and gel electrophoresis of plasmid DNA Prathyusha Gudapati, BIOL 304, spring 2015. Abstract The purpose of the experiment was to isolate plasmid DNA, followed by restriction digestion using restriction endonucleases and then visualizing the digested fragments after subjecting to gel electrophoresis. Plasmid DNA (pSP72 DNA) was isolated from Escherichia coli KAM32 (E.coli) cultures using the QIA prep miniprep kit and then subjected to restriction digestion by EcoRI and HindIIIRead MoreMethods Of Restriction Mapping Site Essay730 Words   |  3 Pages Discussion In this experiment two methods of restriction mapping site were used i.e. double digestion method and the comparison of fragment pattern to a known sequence. In the double digestion method, the fragments produced by the enzyme Hind III andXhoI independently and concurrently were compared so that it can produce an estimation of relative postion of cleavage site The drawback of restriction mapping is that the technique cannot be directly used for eukaroyotes because of difficulties associatedRead MoreRestriction Enzyme, Alkaline Phosphatase Digestion And Gel Electrophoresis1195 Words   |  5 PagesMMR Report 1.3 Restriction Enzyme, Alkaline phosphatase Digestion †¨and Gel Electrophoresis By Naga Srilekha Somu Chemistry - 429 Spring 2016 Western Illinois University Materials and Equipment: Pure plasmid pET28a, amplified 2-alcohol dehydrogenase gene (a PCR product), 10x bovine serum albumin, 10x neutralization buffer, EcoRI, nuclease free water, pET28a plasmid digested with EcoRI, calf intestinal alkaline phosphatase, agarose gel (1% agarose + 0.3ÃŽ ¼L ethidium bromide), 1x TAE bufferRead MoreA Research Study On Scar Markers1635 Words   |  7 PagesSCAR markers are PCR based primers that represent genomic DNA fragments at genetically defined loci, that are identified by PCR amplification using sequence specific oligonuceotide primers (Paran and Michelmore, 1993; Me Dermott et al., 1994). Inception of SCARs involves cloning the amplified products of arbitrary marker techniques and then sequencing the 2 ends of the cloned products. The sequence s therefore used to design specific primer pairs of 15-30 bp which will amplify single major bandsRead MoreEssay on Using PCR and Gel Electrophoresis to Determine Genotype583 Words   |  3 PagesUsing PCR and Gel Electrophoresi s to Determine Genotype In certain situations, it is necessary to identify DNA retreived from a sample. When there is a small sample in need of identification, Polymerase Chain Reactions are used to multiply the DNA in the sample in to many identical samples. The DNA retrieved from the reaction can then be imported into an aparatus using gel electrophoresis to compare the sample of DNA to other samples. In our experiment we learned the how to replicate tinyRead MoreOptimization of Asymmetric PCR for Generation of a Single Stranded DNA Library690 Words   |  3 PagesAptamers are short DNA or RNA oligonucleotides with high, specific affinity to a special target. The name was originated from aptus that means to fit and meros that shows the polymer identity of oligonucleotides (1, 2). Aptamer characteristics provide prominent potential applications in multiple fields.These nucleic acid ligands are completely generated through in vitro process for a wide range of targets from small molecules and ions to large proteins and cells and even whole organism or tissueRead More1.3.1 response Essay624 Words   |  3 Pagesï » ¿ Activity 1.3.1: Student Response Sheet PART A- Restriction Enzymes Restriction enzymes are a tool that allows us to pinpoint human identity down to single differences in our DNA. Work through the following simulation so you can see these molecular scissors in action. Find out more about restriction enzymes by viewing the animation and reading the article listed below. DolanDNALearningCenter: Restriction Enzymes http://www.dnalc.org/ddnalc/resources/restriction.html Access ExcellenceRead MorePlant Viruses : A Large, Unique Family Of Plants Viruses1458 Words   |  6 Pagesworld. [1, 2] Geminiviruses consist of four genera, Mastrevirus, Curtovirus, Begomovirus, and Topocuvirus based on host ranges, vector specificities, and genome organizations. Characteristics of geminiviruses include their circular, single-stranded DNA genome and geminate-shaped virus particles. These viruses-- exhibit both prokaryotic and eukaryotic features-- replicate in the nuclei of the host cell and depend on host machineries for transcription [1]. The majority of the Old World begomovirusesRead MorePcr Rflp Report : Pcr1166 Words   |  5 PagesPCR-RFLP Report PCR What is it: The Polymerase Chain Reaction is a method that uses the capability of DNA polymerase to synthesize to new DNA strands which are matching to the template strand. A primer needs to be added to the first nucleotide due to the fact that DNA polymerase only can add a nucleotide only onto a 3 -OH group that already exists. Because of this condition, we are able to define a chosen region of template sequence which we can then generate millions to billions of copies. ThisRead MoreSite Directed Mutagenesis ( Sdm ) Technique942 Words   |  4 PagesSite-directed mutagenesis (SDM) technique is commonly used to induce desired change in DNA plasmid sequence by mutation, insertion or deletion with oligonucleotide primers (1). This SDM usually cooperate with ploymerase chain reaction (PCR) as to amplify the concentration of mutated template (2). PCR, a temperature-based cycle reaction, is completed with three initial steps including denaturing the DNA template, anneal the mutated oligonucleotide primers and elongating the mutated primer with ploymerase

Truman s Decision On The Dropping Of The Atomic Bomb

Aldrin Ubaldo HIS 218-03 Atomic Bomb Paper Presidents Harry Truman’s decision on the dropping of the atomic bomb was the best decision he could make because having another land invasion similar to D-Day of June 1944 would risk more resources and soldiers’ lives on either side. Paul Fussell article states that in PFC E. B. Sledge memoir With the Old Breed at Pelieu and Okinawa. As the U.S military fights closely to the mainland of Japan, the fighting in the surrounding islands in Iwo Jima and Okinawa was getting more vicious than in previous fights and that having a new land invasion would be a â€Å"ghastly bloodletting† and would shock the American public and the world ( Fussell, pg. 16). The Japanese were ruthless fighters and would never give up and would die for their country. It was said that every Japanese soldier, woman and children would fight from coast to coast (Fussell pg. 17). The Japanese code bushido meaning â€Å"the way of the warrior† meant that surrendering was absolutely dishono rable to the Emperor and the country and most soldiers would prefer to take their own lives rather than surrender to the enemy (Correll Enola Gay). The Japanese were prepared to take as much casualties as possible with an estimation of commitment of 2.3 million troops (Correll Enola Gay). Yes the atomic bomb would kill thousands of civilians but these civilians may have been trained to commit suicide runs against the allies if an invasion was put through (Fussell pg. 17). With theShow MoreRelatedTruman and Atomic Bombs649 Words   |  3 Pagesto take a side and then write an editorial on Harry S Truman’s decision to order the dropping of the atom bomb. HARRY S TRUMAN amp; THE DECISION TO ORDER THE DROPPING OF THE ATOMIC BOMB Boom! Boom! Seventy thousands Japanese citizens were perished instantly after the first atomic bomb was dropped in Hiroshima on August 6, 1945. Japanese still refused to surrender to Allied forces. On August 9, 1945, with the dropping of the second atomic bomb in Nagasaki, where eighty thousands people were vaporizedRead MoreThe Dropping Of The Atomic Bomb1207 Words   |  5 PagesThe dropping of the atomic bombs in Japan was a very helpful source for the United States during the WWII. President Truman, took the responsibility of dropping and creation of the atomic bomb. For the reason that The United States was seeking revenge on Japan for the attack at Pearl Harbor. The atomic bomb caused a high number of innocent Japanese deaths and also awful sickness. The atomic bombs left a big impact in the Japanese empire; also effected the Japanese at the time of the atomic bomb andRead MoreThe Atomic Bomb Was A Revolutionary Invention1528 Words   |  7 Pagesreached its peak with the US dropping atomic bombs on Hiroshima and Nagasaki in August of 1945. The atomic bomb was a revolutionary invention that raised many questions, most comprehensively, why? Why did we drop the atomic bombs? This question regarding the motivations behind dropping the atomic bomb has been mostly buried by the actual event. While Truman himself stated in an August 1945 radio address and further emphasized in his 1955 memoirs that the atomic bombs were dropped in order to â€Å"shortenRead MoreEssay Pres, Truman Atomic Bomb Decision1421 Words   |  6 PagesPresident Trumans Decision to drop the Atomic Bomb on Hiroshima and Nagasaki During World War II the war in Europe ended after the unconditional German surrender at General Eisenhowers Headquarters in Reims, France, May 7, 1945. After the unconditional German surrender in Europe the war shifted to Asia and the Pacific. As the war continued against Japan the Allied forces captured islands such as Iwo Jima and Okinaawa close to Japan brought the Japanese homeland within range of naval and airRead MoreThe Atomic Bomb Of Truman s Diary Entry From The Potsdam Conference867 Words   |  4 Pagesmilitary advisors, President Truman had several people s opinions in mind, with many opinions present it made the decision on whether to or not to drop the bomb difficult to decide for the president. Many can agree or disagree with what would have happened if Truman hadn’t had ordered the first atomic bomb dropped. If the bomb hadn’t been dropped, there is no telling on what would have happened in the war with Japan. President Harry S. Truman s intentions of the atomic bomb were to bring an end to theRead MorePresident Truman And The Dropping Of The Atomic Bomb1280 Words   |  6 PagesThroughout history there have been many important decisions made by our presidents that have affected our country for the better and for the worse. Even though people claim that they could have made better judgement calls than what have been decided, no one knows exactly what circumstances the president is under when the decisions have to be made. In the case of President Harry Truman and the dropping of the atomic bomb, many speculators say that it was a great way to resolve the war with Japan whileRead MoreDropping The Bomb Of Hiroshima And Nagasaki During World War II921 Words   |  4 PagesDropping the Bomb In 1945 America committed an act that some consider to be one of the most destructive acts in the world. It has been questioned why America would execute the devastating dropping of the bombs, nicknamed fat man and little boy, on Hiroshima and Nagasaki during World War two. One of the first and probably main factors for dropping the bombs was to end World War two as soon as possible. The cost of the war was steadily increasing and Truman wanted keep the cost as low as possibleRead MoreAtomic Bombs And Its Effects On Japan1369 Words   |  6 PagesCan you imagine how many atomic bombs that have killed many Japanese during, World War II in Japan? On August 6, 1945, a new weapon with a significant explosive power known as the atomic bombs just has been dropped on Japan. The dropping of this weapon on Hiroshima and Nagasaki there were 262,020 civilians were killed. The United States to chose the atomic bomb in order for Japan to surrender and end the war quickly. Likewise, President Truman as the duty as president and Commander in Chief to protectRead MoreThe Dropping Of The Atomic Bomb853 Words   |  4 Pagesall have diverse opinions on the dropping of the atomic bomb. Varying from, it should be dropped to bring an end to the war with Japan, to it is i nhumane to use such a power weapon on the Japanese military. Having so many diverse opinions on the newest found weapon, made the decision difficult for President Truman. There is no found proof that the war would have ended shortly after if it hadn’t been dropped. It was an uncertain factor on what would happen if the bomb wasn’t dropped, as well as whatRead MoreThe Atomic Bomb : A Significant Period Of Time That Molds The United States980 Words   |  4 PagesThe Atomic Bomb in Japan President Truman, decision over booming Japan is a significant period of time that molds the United States. The crucial decision that was made on August of 1945, brought World War II to an end. While bringing the WWII to an end, it attracted a lot of debates over the use of the atomic bombs in the war. Even though the WWII has ended decades ago debates still lingers to this point. Having people in both sides of the debates, makes people wonder if the use of the first atomic

ICT A case of Knowledge and Critical Thinking

Questions: 1. Briefly describe the business processes supported by a Supply Chain Management (SCM) information system. In a global business like Emerson what are the advantages and disadvantages of using a SCM information system? With Emersons many divisions using different suppliers, what would be the benefits of using a single SCM information system for all of its divisions? 2. Global companies like Emerson have suppliers, manufacturing, distribution, and retail operations. List and briefly describe the technologies and devices (used for input, output, and communication) that are used with SCM information systems. Choose two different input devices and discuss the advantages and disadvantages of each. Discuss the benefits that they provide to the business? 3. Consider that you have to implement a new SCM information system for Emerson. Describe each of the different implementation options. Discuss the advantages and disadvantages of the different implementation options. Make a recommendation and justify? 4. Modern SCM information systems and with the use of other technologies have supported businesses in improving environmental sustainability by reducing carbon emissions. Research and find an example. Briefly describe the system and how it works and how carbon emissions where reduced. Discuss what decision making is performed and how does the SCM information system contribute to the decision making. Discuss the advantages and disadvantages to the business? Answers: 1. Before understanding the various business processes supported by a supply chain management, it is important to understand the concept of SCM. Supply chain can be defined as interlinked set of business procedures and business providers, through which flow of goods and information related to it is managed, initiating from point of design till the delivery of the product or service to the end consumer. A simplistic view of supply chain management is displayed below: Figure 1: Overview of SCM In this context, there are several business processes which are supported by a SCM (Handfield Nichols, 2009). This can be understood by example of Emerson case study as well. It can be clearly understood from the case study, that following business processes are supported: Sales Production Logistics Purchasing Above mentioned are the core processes which supports the SCM. A hierarchy of the business processes in a company like Emerson has been displayed below: Figure 2: Business process hierarchy Hence, from above diagram it can be understood, that how several business processes and their sub-processes supports the SCM (Bowersox et al, 2002). In a global business like Emerson, use of supply chain information system has its own share of advantages as well as disadvantages as follows: Advantages Use of SCM information system can help company like Emerson to generate and analyse information related to demand, supply, inventory and shipment and other aspects in real time. SCM information system helps in increasing the manufacturing throughput or in other words, productions at all levels of organisation. Through use of SCM information system, organisations can generate better return on assets. Internet based SCM, take the advantage a step further, as it helps in connecting all the suppliers and other related entities through a common link over information network. SCM information helps in improving the responsiveness and efficiency of the business. Disadvantages Inability to implement the SCM information system can rapidly increase the cost of implementation, further increasing the operational cost of the business. There can be issues such as increase in the lead time in the procurement processes, as in many cases real time update of inventory can trigger this situation, between supplier and the buyer. Implementation of SCM information system can be capital intensive for the business, as it might require assigning human, financial, and material resources to fulfil the requirements of SCM in the business. Considering the case, where different divisions in Emerson, are coordinating with different suppliers to fulfil their requirement, in such case, single SCM information system can be of tremendous benefit (Gunasekaran Ngai, 2004, pp.269-295). Firstly, it will enable to provide a consolidate view of entire supply chain management within organisation. Hence, instead of segregated view through the supply chain, Emerson can have better control over its supply chain, and will enable it manage its relationship with suppliers in a better way. SCM information system will also enable Emerson to save operational cost which it used to spend due to breakup of supply chain at multiple levels, leading to operational inefficiency, redundancies and delay in supplies and procurement of materials required for manufacturing. 2. Technology has played major role in improving the efficiency and productivity of existing organisations. In this regard SCM information systems has played major role, especially for organisations in manufacturing segment. An integrated supply chain model is displayed below: Figure 3: Integrated supply chain model In a supply chain model there are various input as well as output channels from where there is in-flow and out-flow of information which takes place continuously. This information can be related to scenarios such as, punching in of a purchase order, generation of PO, PO being extracted by supplier, and then supplying the requested material to the supplier, resulting into update of the inventory (Lee et al, 2004, pp.1875-1886). In order to facilitate such processes in a SCM information system, there are various technologies and devices which are used such as: EDI (electronic data interchange): This has been mentioned in the case study of Emerson as well. EDI as a technology enables transactions and information exchanges in a supply chain information system. EDI is defined as computer to computer exchange of structured data which enables automatic processing of information (Thomas Griffin, 1996, pp.1-15). Bar Coding and scanner: Bar codes can be defined as representation of a number or code in a format which can be read by a machine like bar code scanner. Every bar code helps in encapsulating various information about the item. Bar codes are generally used across the supply chain to identify and track goods (Stock Lambert, 2001). Inventory management systems: These information systems, enable end-to-end management of the information related to inventory. Such systems basically work in a circular process, which includes stages such as purchase tracking, inventory monitoring, and re-ordering (Cooper Ellram, 1993, pp.13-24). Transportation management systems: This information system mainly helps in providing visibility to the supplier and the buyer about the shipments and the orders. Such systems also helps in scheduling related issues (Cooper et al, 1997, pp. 1-14). Two different input devices are: Bar coding and scanner: Bar codes as discussed in above section specifies name of the product along with other information such as manufacturer etc. its advantages are: It eliminates human error which might happen due to incorrect information input in database. Reduces training time for the employee, as barcode scanner is a handheld or desktop devices which hardly requires any special training to be used. Inventory control improves, as barcodes helps in precise tracking of inventory. Promotes better decision making, as data is obtained rapidly and accurately. Speech recognition: Speech recognition is another popular and upcoming way of hands-free data entry in a supply chain operations. Unlike other devices which required keying in data, speech recognition provides the individual at any point in SCM to input the data based on voice, which has enabled in saving lot of efforts and time for organisations. Advantages of such input technology is: Speech recognition based data entry eliminates any possible case of human error due entering due to typing issue. Such technology, helps in boosting the overall productivity of the employee as he can perform other tasks in parallel as well. Can be beneficial for disabled person who are present in the supply chain operations. Input devices provide numerous benefits to the business like Emerson. Firstly, it helps in automation of the input process in the supply chain operations, hence reducing the margin of error which might come up due to incorrect information. Secondly, such devices helps in better monitoring and tracking of the inventory, as all the information related to inventory is updated within seconds and real time, which might not be possible in case of manual process (Lambert Cooper, 2000, pp.65-83). 3. In order to implement a SCM information system, there can be various approaches which can selected for Emerson. However before selection of an approach it is important to focus on following aspects associated with the organisation: Size of the organisation Geographical spread of the organisation Number of people who are expected to use the system Timeline by which the system is expected to be live for use There are two possible approach are: Big bang approach: under which complete organisation will be covered for the rollout of the SCM information system. Hence each and every location where Emerson has its operations will be covered, and there will be a global rollout of the entire SCM information system. Phased approach: Under this approach of implementation. Instead of going for a global rollout of SCM information system, focus will be on rollout in a phased approach. Which means, that either few specific locations can be selected where SCM information system will be rolled out, followed by other locations. After analysis of the two possible implementation approach for SCM information system, it can be said that Emerson as an organisation is spread across globe with complex business process in the organisation facilitating day-to-day transactions (Holland, 2005, pp. 117-133). Also there are thousands of users spread across globe who will be potential users of the proposed SCM information system. In such circumstances, it is logical to opt for phased implementation of the SCM information system. Reason behind opting for phased approach is, that this approach will enable implementation of SCM information system in a controlled manner. Secondly, this approach will allow management to observe and analyse the benefits of first phase of implementation. If some further improvement is required then it can be done, before moving towards the next phase of implementation. This approach will also enable the business to evaluate the overall performance of the SCM information system, and map the exis ting business process with the proposed SCM information system in a seamless manner. Phased approach will allow Emerson management to identify the core business areas where they first want to implement the system, before moving on to other business areas. This pre-planning, understanding of current business processes, identification of gaps and designing of to be processes can be achieved in an efficient manner only through a phased approach, as phased approach will give enough bandwidth to analyse each business process and understand the required outcome expected from the proposed SCM information system. Overall, it can be said that as an organisation Emerson is not suited well for big-bang approach, especially due to scale of operations it has, and number of geographical regions it exists. In such situation, Emerson should opt for a phased implementation of the SCM information system. 4. Modern supply chain management information systems have created far reaching impact on the environment sustainability mainly by reducing the carbon emission drastically at various levels of supply chain. Supply chain are critical links that connects an organisations input to its output. Traditionally, supply chain management has focused on aspects such as just in time delivery, cost reduction, inventory control etc. However over a period of time, role of SCM has become important in environment sustainability, especially its role in increase of carbon emission. The supply chain can be characterised as the production of raw materials, their transfer to and through various processing steps, and finally the final product shipping and receiving. Each step requires a review of combustion/energy emissions, waste disposal emissions, transportation energy costs and emissions, and packaging related emissions. With use of SCM information system this entire lifecycle of procuring material for production and shipping it back has reduced to a large level. This can be understood by example of Emerson as well, which combined the shipments from various suppliers through one container. In such situation it becomes obvious that fuel combustion and carbon emission in a case where two different ships would have carried supply from suppliers would have been much higher as compared to a situation, where a consolidated shipment is being sent, resulting into reduction of carbon emission and improving overall environment sustainability. This has been possible due t o SCM information system, because it has allowed business organisations like Emerson to consolidate its supply chain business processes in a single view, where the organisation has tight control over its inventory, and material being procured from different suppliers. In a way it can be said that SCM information system has helped the organisation by improving the view of overall supply chain, resulting in much better coordination with suppliers, which could not have been possible with traditional way of handling the supply chain. References Handfield, R. B., Nichols, E. L. 2009. Introduction to supply chain management (Vol. 183). Upper Saddle River, NJ: prentice Hall. Bowersox, D. J., Closs, D. J., Cooper, M. B. 2002. Supply chain logistics management (Vol. 2). New York: McGraw-Hill. Gunasekaran, A., Ngai, E. W. 2004. Information systems in supply chain integration and management. European Journal of Operational Research, 159(2), 269-295. Lee, H. L., Padmanabhan, V., Whang, S. 2004. Information distortion in a supply chain: the bullwhip effect. Management science, 50(12_supplement), 1875-1886. Thomas, D. J., Griffin, P. M. 1996. Coordinated supply chain management. European journal of operational research, 94(1), 1-15. Stock, J. R., Lambert, D. M. 2001. Strategic logistics management. Cooper, M. C., Ellram, L. M. 1993. Characteristics of supply chain management and the implications for purchasing and logistics strategy. International Journal of Logistics Management, The, 4(2), 13-24. Cooper, M. C., Lambert, D. M., Pagh, J. D. 1997. Supply chain management: more than a new name for logistics. International Journal of Logistics Management, The, 8(1), 1-14. Lambert, D. M., Cooper, M. C. 2000. Issues in supply chain management. Industrial marketing management, 29(1), 65-83. Holland, C. P. 2005. Cooperative supply chain management: the impact of interorganizational information systems. The Journal of Strategic Information Systems, 4(2), 117-133

Lyme Disease Essays - Medicine, Clinical Medicine, Rheumatology, RTT

Lyme Disease The National Organization for Rare Disorders (NORD), P.O. Box 8923, New Fairfield, CT 06812, (203) 746-6518 Lyme Disease Lyme Arthritis General Discussion -------------------------------- ** REMINDER ** The information contained in the Rare Disease Database is provided for educational purposes only. It should not be used for diagnostic or treatment purposes. If you wish to obtain more information about this disorder, please contact your personal physician and/or the agencies listed in the "Resources" section of this report. Lyme disease is a tick-transmitted inflammatory disorder characterized by an early focal skin lesion, and subsequently a growing red area on the skin (erythema chronicum migrans or ECM). The disorder may be followed weeks later by neurological, heart or joint abnormalities. Symptomatology -------------------------------- The first symptom of Lyme disease is a skin lesion. Known as erythema chronicum migrans, or ECM, this usually begins as a red discoloration (macule) or as an elevated round spot (papule). The skin lesion usually appears on an extremity or on the trunk, especially the thigh, buttock or the under arm. This spot expands, often with central clearing, to a diameter as large as 50 cm (c. 12 in.). Approximately 25% of patients with Lyme disease report having been bitten at that site by a tiny tick 3 to 32 days before onset of ECM. The lesion may be warm to touch. Soon after onset nearly half the patients develop multiple smaller lesions without hardened centers. ECM generally lasts for a few weeks. Other types of lesions may subsequently appear during resolution. Former skin lesions may reappear faintly, sometimes before recurrent attacks of arthritis. Lesions of the mucous membranes do not occur in Lyme disease. The most common symptoms accompanying ECM, or preceding it by a few days, may include malaise, fatigue, chills, fever, headache and stiff neck. Less commonly, backache, muscle aches (myalgias), nausea, vomiting, sore throat, swollen lymph glands, and an enlarged spleen may also be present. Most symptoms are characteristically intermittent and changing, but malaise and fatigue may linger for weeks. Arthritis is present in about half of the patients with ECM, occurring within weeks to months following onset and lasting as long as 2 years. Early in the illness, migratory inflammation of many joints (polyarthritis) without joint swelling may occur. Later, longer attacks of swelling and pain in several large joints, especially the knees, typically recur for several years. The knees commonly are much more swollen than painful; they are often hot, but rarely red. Baker's cysts (a cyst in the knee) may form and rupture. Those symptoms accompanying ECM, especially malaise, fatigue and low- grade fever, may also precede or accompany recurrent attacks of arthritis. About 10% of patients develop chronic knee involvement (i.e. unremittent for 6 months or longer). Neurological abnormalities may develop in about 15% of patients with Lyme disease within weeks to months following onset of ECM, often before arthritis occurs. These abnormalities commonly last for months, and usually resolve completely. They include: 1. lymphocytic meningitis or meningoencephalitis 2. jerky involuntary movements (chorea) 3. failure of muscle coordination due to dysfunction of the cerebellum (cerebellar ataxia) 4. cranial neuritis including Bell's palsy (a form of facial paralysis) 5. motor and sensory radiculo-neuritis (symmetric weakness, pain, strange sensations in the extremities, usually occurring first in the legs) 6. injury to single nerves causing diminished nerve response (mononeuritis multiplex) 7. inflammation of the spinal cord (myelitis). Abnormalities in the heart muscle (myocardium) occur in approximately 8% of patients with Lyme disease within weeks of ECM. They may include fluctuating degrees of atrioventricular block and, less commonly, inflammation of the heart sack and heart muscle (myopericarditis) with reduced blood volume ejected from the left ventricle and an enlarged heart (cardiomegaly). When Lyme Disease is contracted during pregnancy, the fetus may or may not be adversely affected, or may contract congenital Lyme Disease. In a study of nineteen pregnant women with Lyme Disease, fourteen had normal pregnancies and normal babies. If Lyme Disease is contracted during pregnancy, possible fetal abnormalities and premature birth can occur. Etiology -------------------------------- Lyme disease is caused by a spirochete bacterium (Borrelia Burgdorferi) transmitted by a small tick called Ixodes dammini. The spirochete is probably injected into the victim's skin or bloodstream at the time of the insect bite. After an incubation period of 3 to 32 days, the organism migrates outward in the skin, is spread through the lymphatic system or is disseminated by the blood to different body organs or other skin sites. Lyme Disease was first described in 1909 in European medical journals. The first outbreak in the United States occurred in the early 1970's in Old lyme, Connecticut.