Cocaine known as coke, is a strong stimulant used as a recreational drug. It is snorted, inhaled as smoke, or dissolved and injected into a vein. Mental effects may include loss of contact with reality, an intense feeling of happiness, or agitation. Physical symptoms may include a fast heart rate and large pupils. High doses can result in high blood pressure or body temperature. Effects begin within seconds to last between five and ninety minutes. Cocaine has a small number of accepted medical uses such as numbing and decreasing bleeding during nasal surgery. Cocaine is addictive due to its effect on the reward pathway in the brain. After a short period of use, there is a high risk, its use increases the risk of stroke, myocardial infarction, lung problems in those who smoke it, blood infections, sudden cardiac death. Cocaine sold on the street is mixed with local anesthetics, quinine, or sugar, which can result in additional toxicity. Following repeated doses a person may have decreased ability to feel pleasure and be physically tired.
Cocaine acts by inhibiting the reuptake of serotonin and dopamine. This results in greater concentrations of these three neurotransmitters in the brain, it can cross the blood–brain barrier and may lead to the breakdown of the barrier. Cocaine is a occurring substance found in the coca plant, grown in South America. In 2013, 419 kilograms were produced legally, it is estimated. With further processing crack cocaine can be produced from cocaine. Cocaine is the second most used illegal drug globally, after cannabis. Between 14 and 21 million people use the drug each year. Use is highest in North America followed by South America. Between one and three percent of people in the developed world have used cocaine at some point in their life. In 2013, cocaine use directly resulted in 4,300 deaths, up from 2,400 in 1990; the leaves of the coca plant have been used by Peruvians since ancient times. Cocaine was first isolated from the leaves in 1860. Since 1961, the international Single Convention on Narcotic Drugs has required countries to make recreational use of cocaine a crime.
Topical cocaine can be used as a local numbing agent to help with painful procedures in the mouth or nose. Cocaine is now predominantly used for lacrimal duct surgery; the major disadvantages of this use are cocaine's potential for cardiovascular toxicity and pupil dilation. Medicinal use of cocaine has decreased as other synthetic local anesthetics such as benzocaine, proparacaine and tetracaine are now used more often. If vasoconstriction is desired for a procedure, the anesthetic is combined with a vasoconstrictor such as phenylephrine or epinephrine; some ENT specialists use cocaine within the practice when performing procedures such as nasal cauterization. In this scenario dissolved cocaine is soaked into a ball of cotton wool, placed in the nostril for the 10–15 minutes before the procedure, thus performing the dual role of both numbing the area to be cauterized, vasoconstriction; when used this way, some of the used cocaine may be absorbed through oral or nasal mucosa and give systemic effects.
An alternative method of administration for ENT surgery is mixed with adrenaline and sodium bicarbonate, as Moffett's solution. Cocaine is a powerful nervous system stimulant, its effects can last from 30 minutes to an hour. The duration of cocaine's effects depends on the route of administration. Cocaine can be in the form of fine white powder, bitter to the taste; when inhaled or injected, it causes a numbing effect. Crack cocaine is a smokeable form of cocaine made into small "rocks" by processing cocaine with sodium bicarbonate and water. Crack cocaine is referred to. Cocaine use leads to increases in alertness, feelings of well-being and euphoria, increased energy and motor activity, increased feelings of competence and sexuality. Coca leaves are mixed with an alkaline substance and chewed into a wad, retained in the mouth between gum and cheek and sucked of its juices; the juices are absorbed by the mucous membrane of the inner cheek and by the gastrointestinal tract when swallowed. Alternatively, coca leaves can be consumed like tea.
Ingesting coca leaves is an inefficient means of administering cocaine. Because cocaine is hydrolyzed and rendered inactive in the acidic stomach, it is not absorbed when ingested alone. Only when mixed with a alkaline substance can it be absorbed into the bloodstream through the stomach; the efficiency of absorption of orally administered cocaine is limited by two additional factors. First, the drug is catabolized by the liver. Second, capillaries in the mouth and esophagus constrict after contact with the drug, reducing the surface area over which the drug can be absorbed. Cocaine metabolites can be detected in the urine of subjects that have sipped one cup of coca leaf infusion. Orally administered cocaine takes 30 minutes to enter the bloodstream. Only a third of an oral dose is absorbed, although absorption has been shown to reach 60% in controlled settings. Given the slow rate of absorption, maximum physiological and psychotropic effects are attained 60 minutes after cocaine is administered by ingestion.
While the onset of these effects is slow, the effects are sustained for approxima
Daptomycin is a lipopeptide antibiotic used in the treatment of systemic and life-threatening infections caused by Gram-positive organisms. It is a occurring compound found in the soil saprotroph Streptomyces roseosporus, its distinct mechanism of action makes it useful in treating infections caused by multiple drug-resistant bacteria. It is marketed in the United States under the trade name Cubicin by Cubist Pharmaceuticals. Daptomycin designated as LY 146032, was discovered by researchers at Eli Lilly and Company in the late 1980s. LY 146032 showed promise in phase I/II clinical trials for treatment of infection caused by Gram-positive organisms. Lilly ceased development because high-dose therapy was associated with adverse effects on skeletal muscle, including myalgia and potential myositis; the rights to LY 146032 were acquired by Cubist Pharmaceuticals in 1997, which following U. S. Food and Drug Administration approval in September 2003 for use in people older than 18 years, began marketing the drug under the trade name Cubicin.
Cubicin is marketed in the EU and in several other countries by Novartis following its purchase of Chiron Corporation, the previous licensee. Daptomycin has a distinct mechanism of action, disrupting multiple aspects of bacterial cell membrane function, it inserts into the cell membrane in a phosphatidylglycerol-dependent fashion, where it aggregates. The aggregation of daptomycin alters the curvature of the membrane, which creates holes that leak ions; this causes rapid depolarization, resulting in a loss of membrane potential leading to inhibition of protein, DNA, RNA synthesis, which results in bacterial cell death. It has been proposed that the formation of spherical micelles by Daptomycin may affect the mode of action. Daptomycin is bactericidal against Gram-positive bacteria only, it has proven in vitro activity against enterococci, streptococci and stationary-phase Borrelia burgdorferi persisters. Daptomycin resistance is still uncommon, but has been reported in GRE, starting in Korea in 2005, in Europe in 2010, in Taiwan 2011, in the USA, where nine cases have been reported from 2007 to 2011.
Daptomycin resistance emerged in five of the six cases. The mechanism of resistance is unknown. A 4 million year-old strain of Paenibacillus isolated from soil samples in Lechuguilla Cave was found to be resistant to daptomycin. Daptomycin is approved for use in adults in the United States for skin and skin structure infections caused by Gram-positive infections, S. aureus bacteraemia, right-sided S. aureus endocarditis. It binds avidly to pulmonary surfactant. There seems to be a difference in working daptomycin on hematogenous pneumonia. Daptomycin has been shown to be non-inferior to standard therapies in the treatment of bacteraemia and right-sided endocarditis caused by S. aureus. A study in Detroit, Michigan compared 53 patients treated for suspected MRSA skin or soft tissue infection with daptomycin against vancomycin, showing faster recovery with daptomycin. In phase III clinical trials, limited data showed daptomycin to be associated with poor outcomes in patients with left-sided endocarditis.
Daptomycin has not been studied in patients with prosthetic valve meningitis. In skin and soft tissue infections, 4 mg/kg daptomycin is given intravenously once daily. For S. aureus bacteraemia or right-sided endocarditis, the approved dose is 6 mg/kg given intravenously once daily. Daptomycin is given every 48 hours in patients with renal impairment with a creatinine clearance of less than 30 ml/min. No information is available on dosing in people less than 18 years of age. Daptomycin is supplied as a sterile, preservative-free, pale yellow to light brown, lyophilised 500- or 350-mg cake that must be reconstituted with normal saline prior to use. Daptomycin is applicable as 2-min injection. Common adverse drug reactions associated with daptomycin therapy include: Cardiovascular: low blood pressure, high blood pressure, swelling Central nervous system: insomnia Dermatological: rash Gastrointestinal: diarrhea, abdominal pain Hematological: eosinophilia Respiratory: dyspnea Other: injection site reactions, hypersensitivityLess common, but serious adverse events reported in the literature include Hepatotoxicity: elevated transaminases Nephrotoxicity: acute kidney injury from rhabdomyolysisAlso and rhabdomyolysis have been reported in patients taking statins, but whether this is due to the statin or whether daptomycin potentiates this effect is unknown.
Due to the limited data available, the manufacturer recommends that statins be temporarily discontinued while the patient is receiving daptomycin therapy. Creatine kinase levels are checked while individuals undergo daptomycin therapy. In July 2010, the FDA issued a warning that daptomycin could cause life-threatening eosinophilic pneumonia; the FDA said it had identified seven confirmed cases of eosinophilic pneumonia between 2004 and 2010 and an additional 36 possible cases. The seven confirmed victims were all older than 60 and symptoms appeared within two weeks of initiation of therapy. Daptomycin is a cyclic lipopeptide antibiotic produced by Streptomyces roseosporus. Daptomycin consists of 13 amino acids, 10 of which are arranged in a cyclic fashion, three on an exocyclic tail. Two nonproteinogenic amino acids exist in the lipopeptide, the unusual amino acid L-kynurenine, only known to daptomycin, L-3-methylglutamic acid; the N-terminus of the exocycl
A firefighter is a rescuer extensively trained in firefighting to extinguish hazardous fires that threaten life and the environment as well as to rescue people and animals from dangerous situations. The complexity of modern, industrialized life has created an increase in the skills needed in firefighting technology; the fire service known in some countries as the fire brigade or fire department, is one of the three main emergency services. From urban areas to aboard ships, firefighters have become ubiquitous around the world; the skills required for safe operations are practiced during training evaluations throughout a firefighter's career. Initial firefighting skills are taught through local, regional or state-approved fire academies or training courses. Depending on the requirements of a department, additional skills and certifications such as technical rescue and pre-hospital medicine may be acquired at this time. Firefighters work with other emergency response agencies such as the police and emergency medical service.
A firefighter's role may overlap with both. Fire investigators or fire marshals investigate the cause of a fire. If the fire was caused by arson or negligence, their work will overlap with law enforcement. Firefighters frequently provide some degree of emergency medical service, in addition to working with full-time paramedics; the basic tasks of firefighters include: fire suppression, fire prevention, basic first aid, investigations. Firefighting is further broken down into skills which include: size-up, ventilation and rescue, containment, mop up and overhaul. A fire burns due to the presence of three elements: fuel and heat — referred to as the fire triangle. Sometimes it is known as the fire tetrahedron if a fourth element is added: a chemical chain reaction which can help sustain certain types of fire; the aim of firefighting is to deprive the fire of at least one of those elements. Most this is done by dousing the fire with water, though some fires require other methods such as foam. Firefighters are equipped with a wide variety of equipment for this purpose that include: ladder trucks, pumper trucks, tanker trucks, fire hose, fire extinguishers.
While sometimes fires can be limited to small areas of a structure, wider collateral damage due to smoke and burning embers is common. Utility shutoff is an early priority for arriving fire crews. Specific procedures and equipment are needed at a property where hazardous materials are being used or stored. Structure fires may be attacked with "exterior" resources, or both. Interior crews, using the "two in, two out" rule, may extend fire hose lines inside the building, find the fire and cool it with water. Exterior crews may direct water into windows and other openings, or against any nearby fuels exposed to the initial fire. Hose streams directed into the interior through exterior wall apertures may conflict and jeopardize interior fire attack crews. See Fire suppression for other techniques. Buildings that are made of flammable materials such as wood are different from fire-resistant building materials such as concrete. A "fire-resistant" building is designed to limit fire to a small area or floor.
Other floors can be safe by preventing smoke damage. All buildings on fire must be evacuated, regardless of fire rating; some fire fighting tactics may appear to be destructive, but serve specific needs. For example, during ventilation firefighters are forced to either open holes in the roof or floors of a structure, or open windows and walls to remove smoke and heated gases from the interior of the structure; such ventilation methods are used to improve interior visibility to locate victims more quickly. Ventilation helps to preserve the life of trapped or unconscious individuals as it releases the poisonous gases from inside the structure. Vertical ventilation is vital to firefighter safety in the event of a flashover or backdraft scenario. Releasing the flammable gases through the roof eliminates the possibility of a backdraft, the removal of heat can reduce the possibility of a flashover. Flashovers, due to their intense heat and explosive temperaments, are fatal to firefighter personnel. Precautionary methods, such as smashing a window, reveal backdraft situations before the firefighter enters the structure and is met with the circumstance head-on.
Firefighter safety is the number one priority. Whenever possible, property is moved into the middle of a room and covered with a salvage cover, a heavy cloth-like tarp. Various steps such as retrieving and protecting valuables found during suppression or overhaul and boarding windows and roofs can divert or prevent post-fire runoff. Wildfires require a unique set of tactics. In many countries such as Australia and the United States, these duties are carried out by local volunteer firefighters. Wildfires have some ecological role in allowing new plants to grow, therefore in some cases they will be left to burn. Priorities in fighting wildfires include preventing the loss of life and property.. Firefighters rescue people from dangerous situations such as crashed vehicles, structural collapses, trench collapses and tunnel emergencies and ice emergencies, elevator emergencies, energized electrical line emergencies, industrial accidents. In less common circumstances, Firefighters rescue victims from hazardous materials emergencies as well as steep cliffs and high rises - The latter is referred to as High Angle Rescue, or Rope Rescue
September 11 attacks
The September 11 attacks were a series of four coordinated terrorist attacks by the Islamic terrorist group al-Qaeda against the United States on the morning of Tuesday, September 11, 2001. The attacks killed 2,996 people, injured over 6,000 others, caused at least $10 billion in infrastructure and property damage. Additional people died of 9/11-related cancer and respiratory diseases in the months and years following the attacks. Four passenger airliners operated by two major U. S. passenger air carriers —all of which departed from airports in the northeastern United States bound for California—were hijacked by 19 al-Qaeda terrorists. Two of the planes, American Airlines Flight 11 and United Airlines Flight 175, were crashed into the North and South towers of the World Trade Center complex in Lower Manhattan. Within an hour and 42 minutes, both 110-story towers collapsed. Debris and the resulting fires caused a partial or complete collapse of all other buildings in the World Trade Center complex, including the 47-story 7 World Trade Center tower, as well as significant damage to ten other large surrounding structures.
A third plane, American Airlines Flight 77, was crashed into the Pentagon in Arlington County, which led to a partial collapse of the building's west side. The fourth plane, United Airlines Flight 93, was flown toward Washington, D. C. but crashed into a field in Stonycreek Township near Shanksville, after its passengers thwarted the hijackers. 9/11 is the single deadliest terrorist attack in human history and the single deadliest incident for firefighters and law enforcement officers in the history of the United States, with 343 and 72 killed, respectively. Suspicion fell on al-Qaeda; the United States responded by launching the War on Terror and invaded Afghanistan to depose the Taliban, which had failed to comply with U. S. demands to extradite Osama bin expel al-Qaeda from Afghanistan. Many countries strengthened their anti-terrorism legislation and expanded the powers of law enforcement and intelligence agencies to prevent terrorist attacks. Although Osama bin Laden, al-Qaeda's leader denied any involvement, in 2004 he claimed responsibility for the attacks.
Al-Qaeda and bin Laden cited U. S. support of Israel, the presence of U. S. troops in Saudi Arabia, sanctions against Iraq as motives. After evading capture for a decade, bin Laden was located in Pakistan and killed by SEAL Team Six of the U. S. Navy in May 2011; the destruction of the World Trade Center and nearby infrastructure harmed the economy of Lower Manhattan and had a significant effect on global markets, which resulted in the closing of Wall Street until September 17 and the civilian airspace in the U. S. and Canada until September 13. Many closings and cancellations followed, out of respect or fear of further attacks. Cleanup of the World Trade Center site was completed in May 2002, the Pentagon was repaired within a year. On November 18, 2006, construction of One World Trade Center began at the World Trade Center site; the building was opened on November 3, 2014. Numerous memorials have been constructed, including the National September 11 Memorial & Museum in New York City, the Pentagon Memorial in Arlington County and the Flight 93 National Memorial in a field in Stonycreek Township near Shanksville, Pennsylvania.
Although not confirmed, there is evidence of alleged Saudi Arabian involvement in the attacks. Given as main evidence in these charges are the contents of the 28 redacted pages of the December 2002 Joint Inquiry into Intelligence Community Activities before and after the Terrorist Attacks of September 11, 2001 conducted by the Senate Select Committee on Intelligence and the House Permanent Select Committee on Intelligence; these 28 pages contain information regarding the material and financial assistance given to the hijackers and their affiliates leading up to the attacks by the Saudi Arabian government. The origins of al-Qaeda can be traced to 1979. Osama bin Laden helped organize Arab mujahideen to resist the Soviets. Under the guidance of Ayman al-Zawahiri, bin Laden became more radical. In 1996, bin Laden issued his first fatwā. In a second fatwā in 1998, bin Laden outlined his objections to American foreign policy with respect to Israel, as well as the continued presence of American troops in Saudi Arabia after the Gulf War.
Bin Laden used Islamic texts to exhort Muslims to attack Americans until the stated grievances are reversed. Muslim legal scholars "have throughout Islamic history unanimously agreed that the jihad is an individual duty if the enemy destroys the Muslim countries", according to bin Laden. Bin Laden orchestrated the attacks and denied involvement but recanted his false statements. Al Jazeera broadcast a statement by bin Laden on September 16, 2001, stating, "I stress that I have not carried out this act, which appears to have been carried out by individuals with their own motivation." In November 2001, U. S. forces recovered a videotape from a destroyed house in Afghanistan. In the video, bin Laden admits foreknowledge of the attacks. On December 27, 2001, a second bin Laden video was released. In the video, he said: It has become clear that the West in general and America in particular have an unspeakable hatred for Islam.... It is the hatred of crusaders. Terrorism against America deserves to be praised because it was a response to injustice, aimed at forcing America to stop its support for Israel, which kills our people....
Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group on the periodic table, a reactive nonmetal, an oxidizing agent that forms oxides with most elements as well as with other compounds. By mass, oxygen is the third-most abundant element in the universe, after helium. At standard temperature and pressure, two atoms of the element bind to form dioxygen, a colorless and odorless diatomic gas with the formula O2. Diatomic oxygen gas constitutes 20.8% of the Earth's atmosphere. As compounds including oxides, the element makes up half of the Earth's crust. Dioxygen is used in cellular respiration and many major classes of organic molecules in living organisms contain oxygen, such as proteins, nucleic acids and fats, as do the major constituent inorganic compounds of animal shells and bone. Most of the mass of living organisms is oxygen as a component of water, the major constituent of lifeforms. Oxygen is continuously replenished in Earth's atmosphere by photosynthesis, which uses the energy of sunlight to produce oxygen from water and carbon dioxide.
Oxygen is too chemically reactive to remain a free element in air without being continuously replenished by the photosynthetic action of living organisms. Another form of oxygen, ozone absorbs ultraviolet UVB radiation and the high-altitude ozone layer helps protect the biosphere from ultraviolet radiation. However, ozone present at the surface is a byproduct of thus a pollutant. Oxygen was isolated by Michael Sendivogius before 1604, but it is believed that the element was discovered independently by Carl Wilhelm Scheele, in Uppsala, in 1773 or earlier, Joseph Priestley in Wiltshire, in 1774. Priority is given for Priestley because his work was published first. Priestley, called oxygen "dephlogisticated air", did not recognize it as a chemical element; the name oxygen was coined in 1777 by Antoine Lavoisier, who first recognized oxygen as a chemical element and characterized the role it plays in combustion. Common uses of oxygen include production of steel and textiles, brazing and cutting of steels and other metals, rocket propellant, oxygen therapy, life support systems in aircraft, submarines and diving.
One of the first known experiments on the relationship between combustion and air was conducted by the 2nd century BCE Greek writer on mechanics, Philo of Byzantium. In his work Pneumatica, Philo observed that inverting a vessel over a burning candle and surrounding the vessel's neck with water resulted in some water rising into the neck. Philo incorrectly surmised that parts of the air in the vessel were converted into the classical element fire and thus were able to escape through pores in the glass. Many centuries Leonardo da Vinci built on Philo's work by observing that a portion of air is consumed during combustion and respiration. In the late 17th century, Robert Boyle proved. English chemist John Mayow refined this work by showing that fire requires only a part of air that he called spiritus nitroaereus. In one experiment, he found that placing either a mouse or a lit candle in a closed container over water caused the water to rise and replace one-fourteenth of the air's volume before extinguishing the subjects.
From this he surmised that nitroaereus is consumed in both combustion. Mayow observed that antimony increased in weight when heated, inferred that the nitroaereus must have combined with it, he thought that the lungs separate nitroaereus from air and pass it into the blood and that animal heat and muscle movement result from the reaction of nitroaereus with certain substances in the body. Accounts of these and other experiments and ideas were published in 1668 in his work Tractatus duo in the tract "De respiratione". Robert Hooke, Ole Borch, Mikhail Lomonosov, Pierre Bayen all produced oxygen in experiments in the 17th and the 18th century but none of them recognized it as a chemical element; this may have been in part due to the prevalence of the philosophy of combustion and corrosion called the phlogiston theory, the favored explanation of those processes. Established in 1667 by the German alchemist J. J. Becher, modified by the chemist Georg Ernst Stahl by 1731, phlogiston theory stated that all combustible materials were made of two parts.
One part, called phlogiston, was given off when the substance containing it was burned, while the dephlogisticated part was thought to be its true form, or calx. Combustible materials that leave little residue, such as wood or coal, were thought to be made of phlogiston. Air did not play a role in phlogiston theory, nor were any initial quantitative experiments conducted to test the idea. Polish alchemist and physician Michael Sendivogius in his work De Lapide Philosophorum Tractatus duodecim e naturae fonte et manuali experientia depromti described a substance contained in air, referring to it as'cibus vitae', this substance is identical with oxygen. Sendivogius, during his experiments performed between 1598 and 1604, properly recognized that the substance is equivalent to the gaseous byproduct released by the thermal decomposition of potassium nitrate. In Bugaj’s view, the isolation of oxygen and the proper association of the substance to that part of air, required for life, lends sufficient weight to the discovery of oxygen by Sendivogius.
Paragonimus is a genus of flukes. Some tens of species have been described, but they are difficult to distinguish, so it is not clear how many of the named species may be synonyms; the name Paragonimus is derived from the combination of two Greek words, “para” and “gonimos”. Several of the species are known as lung flukes. In humans some of the species occur as zoonoses; the first intermediate hosts of Paragonimus include at least 54 species of freshwater snails from superfamilies Cerithioidea and Rissooidea. The most prominent species of Paragonimus in human medicine is Paragonimus westermani, an infectious lung fluke originating in eastern Asia. Worldwide, about nine species of Paragonimus are known to cause human paragonimiasis in which many of the species reside in East Asia, West Africa, in North and South America. Species of Paragonimus vary in size; the adult flatworm has an oval shape body with spines covering its thick tegument. Both the oral sucker and acetabulum are muscular; the acetabulum is bigger than the oral sucker – 0.19 mm and 0.12 mm, respectively.
Ovaries are located behind the acetabulum and posterior to the ovary are the testes. The seminal receptacle, the uterus and its metraterm, the thick-walled terminal part, lie between the acetabulum and the ovary; the parasite passes through an aquatic snail and a crustacean. It enters its mammalian definitive hosts. Typical hosts include dogs and humans. Humans contract paragonimiasis when they eat undercooked freshwater crabs or crayfish, that contain live metacercariae. In the intestine, the parasite will move into the abdomen and into the lungs. In the lung, the parasites cross fertilize each other; the cyst ruptures in the lungs and the eggs may be coughed up or swallowed and excreted in the feces. An egg landing in fresh water releases a ciliated miracidium. A successful miracidium swims about until it finds an intermediate host an aquatic snail. A crustacean in turn becomes infected by eating infected snails; the definitive host completes the cycle. Worldwide 20 million people are infected with Paragonimus.
Human infections are most common in regions with many human and animal reservoir hosts plus an abundance of intermediate hosts, such as snails, crabs, or crayfish, where in addition consumption of raw or undercooked seafood is common. Consumption of insufficiently cooked meat from infected land animal hosts, such as wild boar transmits the infection; the domestic cat is a reservoir for a variety of lung flatworms and can transmit the infection to humans. Symptoms of paragonimiasis may include abdominal pain, diarrhea and hives. If the infection remains untreated, the symptoms may diminish or disappear after only few months, but sometimes they last for decades. Paragonimiasis is caused by the body's natural immune response to the worms and eggs that are present and migrating from the intestines to the lungs; as a rule, the parasites begin to cause symptoms about three weeks after ingesting live metacercariae. After about eight weeks, they begin to produce eggs in the lungs; some patients develop brain damage if parasites produce eggs.
The brain damage causes headache and seizures. Untreated cerebral paragonimaisis results in death from increased intracranial pressure. Praziquantel has been used to treat paragonimiasis by separating the tegument. An complete rate of cure may be expected after three days of treatment if there has not been too much permanent damage, such as from intracranial effects. Other medications can be used such as bithionol and triclabendazole with high cure rates. Thorough cooking of an infected crustacean kills all stages of the parasite. Crab meat should not be eaten raw if pickled, because the pickling solution fails to kill all the parasites. Utensils and cutlery boards should be cleaned before and after food preparation
A pulmonary alveolus is a hollow cavity found in the lung parenchyma, is the basic unit of ventilation. Lung alveoli are the ends of the respiratory tree, branching from either alveolar sacs or alveolar ducts, which like alveoli are both sites of gas exchange with the blood as well. Alveoli are particular to mammalian lungs. Different structures are involved in gas exchange in other vertebrates; the alveolar membrane is the gas exchange surface. Carbon dioxide rich blood is pumped from the rest of the body into the capillaries that surround the alveoli where, through diffusion, carbon dioxide is released and oxygen is absorbed; the alveoli are located in the respiratory zone of the lungs, at the ends of the alveolar ducts and alveolar sac, representing the smallest units in the respiratory tract. They provide total surface area of about 75m2. A typical pair of human lungs contain about 480 million alveoli; each alveolus is wrapped in a fine mesh of capillaries covering about 70% of its area. An adult alveolus has an average diameter of 200 µm, with an increase in diameter during inhalation.
The alveoli consist of an epithelial layer and an extracellular matrix surrounded by small blood vessels called capillaries. In some alveolar walls there are pores between alveoli called Pores of Kohn; the alveoli contain elastic fibers. The elastic fibres allow the alveoli to stretch, they spring back during exhalation in order to expel the carbon dioxide-rich air. There are three major types of cell in the alveolar wall: two types of alveolar cell and a large phagocyte known as an alveolar macrophage. Type I cells form the structure of the alveoli. Type I alveolar cells are squamous and cover 90–95% of the alveolar surface. Type I cells are involved in the process of gas exchange between blood; these cells are thin – the electron microscope was needed to prove that all alveoli are covered with an epithelial lining. These cells need to be so thin to be permeable for enabling an easy gas exchange between the alveoli and the blood. Organelles of type I alveolar cells such as the endoplasmic reticulum, Golgi apparatus and mitochondria are clustered around the nucleus.
The nuclei occupy large areas of free cytoplasm. This reduces the thickness of the cell; the cytoplasm in the thin portion contains pinocytotic vesicles which may play a role in the removal of small particulate contaminants from the outer surface. In addition to desmosomes, all type I alveolar cells have occluding junctions that prevent the leakage of tissue fluid into the alveolar air space. Type I pneumocytes are susceptible to toxic insults. In the event of damage, type II cells can proliferate and differentiate into type I cells to compensate. Type II cells secrete pulmonary surfactant to lower the surface tension of water and allows the membrane to separate, therefore increasing its capability to exchange gases; the surfactant is continuously released by exocytosis. It forms an underlying aqueous protein-containing hypophase and an overlying phospholipid film composed of dipalmitoyl phosphatidylcholine. Type II alveolar cells cover a small fraction of the alveolar surface area. Type II cells are capable of cellular division, giving rise to more type I and II alveolar cells when the lung tissue is damaged.
These cells are granular and cuboidal. Type II alveolar cells are found at the blood-air barrier. Although they only make up <5% of the alveolar surface, they are numerous. The alveolar macrophages called dust cells, destroy foreign materials and microbes such as bacteria. Type I cells are flat cells lining the alveolar walls; each alveolus is surrounded by numerous capillaries, is the site of gas exchange, which occurs by diffusion. The low solubility of oxygen necessitates the large internal surface area and thin walls of the alveoli. Weaving between the capillaries and helping to support them is an extracellular matrix, a meshlike fabric of elastic and collagenous fibres; the collagen fibres, being more rigid, give the wall firmness, while the elastic fibres permit expansion and contraction of the walls during breathing. Type II cells in the alveolar wall contain secretory granular organelles known as lamellar bodies that fuse with the cell membranes and secrete pulmonary surfactant; this surfactant is a film of fatty substances, a group of phospholipids that reduce alveolar surface tension.
The phospholipid are stored in the lamellar bodies. Without this coating, the alveoli would collapse and large forces would be required to re-expand them. Type II cells start to develop at about 26 weeks of gestation, secreting small amounts of surfactant. However, adequate amounts of surfactant are not secreted until about 35 weeks of gestation - this is the main reason for increased rates of infant respiratory distress syndrome, which drastically reduces at ages above 35 weeks gestation. Type II pneumocytes will replicate to replace damaged type I cells. MUC1, a human gene associated with type II pneumocytes, has been identified as a marker in lung cancer. Another type of cell, known as an alveolar macrophage, resides on the internal surfaces of the air cavities of the alveoli, the alveolar ducts, the bronchioles, they are mobile scavengers that serve to engulf