- Guinea pig b the 56 year experiment pdf
- Navigation menu
- Guinea Pig B: The 56 Year Experiment
- Animal use in pharmacology education and research: The changing scenario
- 2019 FIFA Women's World Cup
- The Second World War: The Guinea Pig Club
- 50 Fun Facts About Guinea Pigs for Kids
- Item Preview
Scurvy is a disease resulting from a lack of vitamin C ascorbic acid. It takes at least a month of little to no vitamin C in the diet before symptoms occur. Treatment is with vitamin C supplements taken by mouth. Scurvy currently is rare.
Guinea pig b the 56 year experiment pdf
Early symptoms are malaise and lethargy. After one to three months, patients develop shortness of breath and bone pain. Myalgias may occur because of reduced carnitine production. Other symptoms include skin changes with roughness, easy bruising and petechiae , gum disease , loosening of teeth, poor wound healing, and emotional changes which may appear before any physical changes.
In the late stages, jaundice , generalised edema , oliguria , neuropathy , fever, convulsions, and eventual death are frequently seen. A child presenting a "scorbutic tongue" due to vitamin C deficiency.
Photo of the chest cage with pectus excavatum and scorbutic rosaries. Scurvy, including subclinical scurvy, is caused by a deficiency of dietary vitamin C since humans are unable to metabolically make this chemical. Provided diet contains sufficient vitamin C, the lack of working L-gulonolactone oxidase GULO enzyme has no significance, and in modern Western societies, scurvy is rarely present in adults, although infants and elderly people are affected.
Human breast milk contains sufficient vitamin C, if the mother has an adequate intake. Commercial milk is pasteurized, a heating process that destroys the natural vitamin C content of the milk. Scurvy is one of the accompanying diseases of malnutrition other such micronutrient deficiencies are beriberi or pellagra and thus is still widespread in areas of the world depending on external food aid.
Vitamins are essential to the production and use of enzymes that are involved in ongoing processes throughout the human body. In the synthesis of collagen , ascorbic acid is required as a cofactor for prolyl hydroxylase and lysyl hydroxylase. These two enzymes are responsible for the hydroxylation of the proline and lysine amino acids in collagen.
Hydroxyproline and hydroxylysine are important for stabilizing collagen by cross-linking the propeptides in collagen. Collagen is a primary structural protein in the human body, necessary for healthy blood vessels, muscle, skin, bone, cartilage, and other connective tissues. Defective connective tissue leads to fragile capillaries, resulting in abnormal bleeding, bruising, and internal hemorrhaging. Collagen is an important part of bone, so bone formation is also affected.
Teeth loosen, bones break more easily, and once-healed breaks may recur. Untreated scurvy is invariably fatal.
Diagnosis typically is based on physical signs, X-rays , and improvement after treatment. Scurvy can be prevented by a diet that includes vitamin C-rich foods such as amla , bell peppers sweet peppers , blackcurrants , broccoli , chili peppers , guava , kiwifruit , and parsley.
Guinea Pig B: The 56 Year Experiment
Other sources rich in vitamin C are fruits such as lemons , limes , oranges , papaya , and strawberries. It is also found in vegetables, such as brussels sprouts , cabbage , potatoes , and spinach.
Some fruits and vegetables not high in vitamin C may be pickled in lemon juice , which is high in vitamin C. Though redundant in the presence of a balanced diet,  various nutritional supplements are available, which provide ascorbic acid well in excess of that required to prevent scurvy. Some animal products, including liver , muktuk whale skin , oysters , and parts of the central nervous system, including the adrenal medulla , brain, and spinal cord, contain large amounts of vitamin C, and can even be used to treat scurvy.
Fresh meat from animals which make their own vitamin C which most animals do contains enough vitamin C to prevent scurvy, and even partly treat it.
Animal use in pharmacology education and research: The changing scenario
In some cases notably French soldiers eating fresh horse meat , it was discovered that meat alone, even partly cooked meat, could alleviate scurvy. Conversely, in other cases, a meat-only diet could cause scurvy.
Scott's Antarctic expedition used lightly fried seal meat and liver, whereby complete recovery from incipient scurvy was reported to have taken less than two weeks. Hippocrates documented scurvy as a disease,   and Egyptians have recorded its symptoms as early as BCE. In the 13th century, the Crusaders frequently suffered from scurvy. The Portuguese planted fruit trees and vegetables in Saint Helena , a stopping point for homebound voyages from Asia, and left their sick, who had scurvy and other ailments, to be taken home by the next ship if they recovered.
In , one of the pilots of Cabral 's fleet bound for India noted that in Malindi , its king offered the expedition fresh supplies such as lambs, chickens, and ducks, along with lemons and oranges, due to which "some of our ill were cured of scurvy". Unfortunately, these travel accounts did not stop further maritime tragedies caused by scurvy, first because of the lack of communication between travelers and those responsible for their health, and because fruits and vegetables could not be kept for long on ships.
In , the French explorer Jacques Cartier , exploring the St. Lawrence River , used the local natives' knowledge to save his men who were dying of scurvy.
In February , Captain James Lancaster , while sailing to Sumatra , landed on the northern coast to specifically obtain lemons and oranges for his crew to stop scurvy. One ship's crew received routine doses of lemon juice while the other three ships did not receive any such treatment. As a result, members of the non-treated ships started to contract scurvy, with many dying as a result.
During the Age of Exploration between and , it has been estimated that scurvy killed at least two million sailors. In , Admiral Sir Richard Hawkins advocated drinking orange and lemon juice as a means of preventing scurvy. He repeated the experience of mariners that the cure for scurvy was fresh food or, if not available, oranges, lemons, limes, and tamarinds.
Even on dry land, in Europe, until the late middle ages, scurvy was common in late winter, when few green vegetables, fruits and root vegetables were available.
2019 FIFA Women's World Cup
This gradually improved with the introduction from the Americas of potatoes; by , scurvy was virtually unheard of in Scotland, where it had previously been endemic. A handwritten book by Mrs.
Ebot Mitchell, discovered in a house in Hasfield, Gloucestershire , contains a "Recp. In , the Leiden -based physician Johann Bachstrom published a book on scurvy in which he stated, "scurvy is solely owing to a total abstinence from fresh vegetable food, and greens; which is alone the primary cause of the disease", and urged the use of fresh fruit and vegetables as a cure.
However, it was not until that James Lind formally demonstrated that scurvy could be treated by supplementing the diet with citrus fruit, in one of the first controlled clinical experiments reported in the history of medicine. In A Treatise on the Scurvy   Lind explained the details of his clinical trial and concluded "the results of all my experiments was, that oranges and lemons were the most effectual remedies for this distemper at sea.
Unfortunately, the experiment and its results occupied only a few paragraphs in a work that was long and complex and had little impact. Lind himself never actively promoted lemon juice as a single 'cure'. He shared medical opinion at the time that scurvy had multiple causes — notably hard work, bad water, and the consumption of salt meat in a damp atmosphere which inhibited healthful perspiration and normal excretion — and therefore required multiple solutions.
Unfortunately this process destroyed the vitamin C and was therefore unsuccessful. During the 18th century, disease killed more British sailors than enemy action. It was mainly by scurvy that George Anson , in his celebrated voyage of —, lost nearly two-thirds of his crew 1, out of 2, within the first 10 months of the voyage.
Although throughout this period sailors and naval surgeons were increasingly convinced that citrus fruits could cure scurvy, the classically trained physicians who ran the medical establishment dismissed this evidence as mere anecdote which did not conform to current theories of disease. Literature championing the cause of citrus juice, therefore, had no practical impact.
The Second World War: The Guinea Pig Club
Medical theory was based on the assumption that scurvy was a disease of internal putrefaction brought on by faulty digestion caused by the hardships of life at sea and the naval diet.
Although this basic idea was given different emphases by successive theorists, the remedies they advocated and which the navy accepted amounted to little more than the consumption of 'fizzy drinks' to activate the digestive system, the most extreme of which was the regular consumption of 'elixir of vitriol' — sulphuric acid taken with spirits and barley water, and laced with spices.
50 Fun Facts About Guinea Pigs for Kids
In , a new variant appeared. Advocated by Dr David MacBride and Sir John Pringle , Surgeon General of the Army and later President of the Royal Society, this idea was that scurvy was the result of a lack of 'fixed air' in the tissues which could be prevented by drinking infusions of malt and wort whose fermentation within the body would stimulate digestion and restore the missing gases.
The others were beer, Sauerkraut and Lind's 'rob'. The list did not include lemons.
Cook did not lose a single man to scurvy, and his report came down in favour of malt and wort, although it is now clear that the reason for the health of his crews on this and other voyages was Cook's regime of shipboard cleanliness, enforced by strict discipline, as well as frequent replenishment of fresh food and greenstuffs. In contact with air, the copper formed compounds that prevented the absorption of vitamins by the intestines.
The first major long distance expedition that experienced virtually no scurvy was that of the Spanish naval officer Alessandro Malaspina , — Only one outbreak occurred, during a day trip across the open sea. Five sailors came down with symptoms, one seriously. After three days at Guam all five were healthy again.
Spain's large empire and many ports of call made it easier to acquire fresh fruit. Although towards the end of the century MacBride's theories were being challenged, the medical establishment in Britain remained wedded to the notion that scurvy was a disease of internal 'putrefaction' and the Sick and Hurt Board, run by administrators, felt obliged to follow its advice.
Within the Royal Navy, however, opinion — strengthened by first-hand experience of the use of lemon juice at the siege of Gibraltar and during Admiral Rodney's expedition to the Caribbean — had become increasingly convinced of its efficacy. This was reinforced by the writings of experts like Gilbert Blane  and Thomas Trotter  and by the reports of up-and-coming naval commanders.
With the coming of war in , the need to eliminate scurvy acquired a new urgency. But the first initiative came not from the medical establishment but from the admirals. Ordered to lead an expedition against Mauritius, Rear Admiral Gardner was uninterested in the wort, malt and elixir of vitriol which were still being issued to ships of the Royal Navy, and demanded that he be supplied with lemons, to counteract scurvy on the voyage.
Members of the Sick and Hurt Board, recently augmented by two practical naval surgeons, supported the request, and the Admiralty ordered that it be done. There was, however, a last minute change of plan. The expedition against Mauritius was cancelled. Then in March , came astonishing news. Suffolk had arrived in India after a four-month voyage without a trace of scurvy and with a crew that was healthier than when it set out.
The effect was immediate.
Fleet commanders clamoured also to be supplied with lemon juice, and by June the Admiralty acknowledged the groundswell of demand in the navy had agreed to a proposal from the Sick and Hurt Board that lemon juice and sugar should in future be issued as a daily ration to the crews of all warships.
It took a few years before the method of distribution to all ships in the fleet had been perfected and the supply of the huge quantities of lemon juice required to be secured, but by , the system was in place and functioning.
This led to a remarkable health improvement among the sailors and consequently played a critical role in gaining the advantage in naval battles against enemies who had yet to introduce the measures. The surgeon-in-chief of Napoleon 's army at the Siege of Alexandria , Baron Dominique-Jean Larrey , wrote in his memoirs that the consumption of horse meat helped the French to curb an epidemic of scurvy.
The meat was cooked but was freshly obtained from young horses bought from Arabs, and was nevertheless effective. This helped to start the 19th-century tradition of horse meat consumption in France. Lauchlin Rose patented a method used to preserve citrus juice without alcohol in , creating a concentrated drink known as Rose's lime juice.
The Merchant Shipping Act of required all ships of the Royal Navy and Merchant Navy to provide a daily lime ration of one pound to sailors to prevent scurvy. The plant Cochlearia officinalis , also known as "common scurvygrass", acquired its common name from the observation that it cured scurvy, and it was taken on board ships in dried bundles or distilled extracts.
Its very bitter taste was usually disguised with herbs and spices; however, this did not prevent scurvygrass drinks and sandwiches from becoming a popular fad in the UK until the middle of the nineteenth century, when citrus fruits became more readily available.