14/9/2007
Tuberculosis (abbreviated as TB for tubercle bacillus or TuBerculosis) is a common and deadly infectious disease caused by mycobacteria, mainly Mycobacterium tuberculosis. Tuberculosis most commonly attacks the lungs (as pulmonary TB) but can also affect the central nervous system, the lymphatic system, the circulatory system, the genitourinary system, bones, joints and even the skin. Other mycobacteria such as Mycobacterium bovis, Mycobacterium africanum, Mycobacterium canetti, and Mycobacterium microti can also cause tuberculosis, but these species do not usually infect healthy adults.[1]
Over one-third of the world's population now carries the TB bacterium, and new infections occur at a rate of one per second.[2] Not everyone infected develops the full-blown disease, so asymptomatic, latent TB infection is most common. However, one in ten latent infections will progress to active TB disease, which, if left untreated, kills more than half of its victims.
In 2004, mortality and morbidity statistics included 14.6 million chronic active TB cases, 8.9 million new cases, and 1.6 million deaths, mostly in developing countries.[2] In addition, a rising number of people in the developed world are contracting tuberculosis because their immune systems are compromised by immunosuppressive drugs, substance abuse or HIV/AIDS.
The rise in HIV infections and the neglect of TB control programs have enabled a resurgence of tuberculosis.[3] The emergence of drug-resistant strains has also contributed to this new epidemic with, from 2000 to 2004, 20% of TB cases being resistant to standard treatments and 2% resistant to second-line drugs.[4] TB incidence varies widely, even in neighboring countries, apparently because of differences in health care systems.[5] The World Health Organization declared TB a global health emergency in 1993, and the Stop TB Partnership developed a Global Plan to Stop Tuberculosis aiming to save 14 million lives between 2006 and 2015.[6]
Other names
In the past, tuberculosis was called consumption, because it seemed to consume people from within, with a bloody cough, fever, pallor, and long relentless wasting. Other names included phthisis (Greek for consumption) and phthisis pulmonalis; scrofula (in adults), affecting the lymphatic system and resulting in swollen neck glands; tabes mesenterica, TB of the abdomen and lupus vulgaris, TB of the skin; wasting disease; white plague, because sufferers appear markedly pale; king's evil, because it was believed that a king's touch would heal scrofula; and Pott's disease, or gibbus of the spine and joints.[7][8] Miliary tuberculosis – now commonly known as disseminated TB– occurs when the infection invades the circulatory system resulting in lesions which have the appearance of millet seeds on X-ray.[7][9]
Symptoms
When the disease becomes active, 75% of the cases are pulmonary TB. Symptoms include chest pain, coughing up blood, and a productive, prolonged cough for more than three weeks. Systemic symptoms include fever, chills, night sweats, appetite loss, weight loss, pallor, and often a tendency to fatigue very easily.[2]
In the other 25% of active cases, the infection moves from the lungs, causing other kinds of TB more common in immunosuppressed persons and young children. Extrapulmonary infection sites include the pleura, the central nervous system in meningitis, the lymphatic system in scrofula of the neck, the genitourinary system in urogenital tuberculosis, and bones and joints in Pott's disease of the spine. An especially serious form is disseminated TB, more commonly known as miliary tuberculosis. Although extrapulmonary TB is not contagious, it may co-exist with pulmonary TB, which is contagious.[10]
http://en.wikipedia.org/wiki/Tuberculosis alıntıdır.
Yorum (yok)
Yorum yaz!
Kalıcı Bağlantı
14/9/2007
If you are pregnant, high blood pressure can cause problems for you and your unborn baby. You may have had high blood pressure before you got pregnant. Or you may get it once you are pregnant – a condition called gestational hypertension. Whichever you have, it can cause low birth weight or premature delivery of the baby. Serious cases may develop preeclampsia, a sudden increase in blood pressure after the 20th week of pregnancy. It can be life-threatening for both you and the unborn baby.
Treatments for high blood pressure in pregnancy may include close monitoring of the baby, lifestyle changes and certain medicines. For preeclampsia, early delivery of the baby may be necessary.
Yorum (yok)
Yorum yaz!
Kalıcı Bağlantı
28/8/2007
Cancer is a class of diseases or disorders characterized by uncontrolled division of cells and the ability of these to spread, either by direct growth into adjacent tissue through invasion, or by implantation into distant sites by metastasis (where cancer cells are transported through the bloodstream or lymphatic system). Cancer may affect people at all ages, but risk tends to increase with age. It is one of the principal causes of death in developed countries.There are many types of cancer. Severity of symptoms depends on the site and character of the malignancy and whether there is metastasis. A definitive diagnosis usually requires the histologic examination of tissue by a pathologist. This tissue is obtained by biopsy or surgery. Most cancers can be treated and some cured, depending on the specific type, location, and stage. Once diagnosed, cancer is usually treated with a combination of surgery, chemotherapy and radiotherapy. As research develops, treatments are becoming more specific for the type of cancer pathology. Drugs that target specific cancers already exist for several types of cancer. If untreated, cancers may eventually cause illness and death, though this is not always the case.The unregulated growth that characterizes cancer is caused by damage to DNA, resulting in mutations to genes that encode for proteins controlling cell division. Many mutation events may be required to transform a normal cell into a malignant cell. These mutations can be caused by radiation, chemicals or physical agents that cause cancer, which are called carcinogens, or by certain viruses that can insert their DNA into the human genome. Mutations occur spontaneously, and may be passed down from one cell generation to the next as a result of mutations within germ lines. However, some carcinogens also appear to work through non-mutagenic pathways that affect the level of tran******ion of certain genes without causing genetic mutation.Many forms of cancer are associated with exposure to environmental factors such as tobacco smoke, radiation, alcohol, and certain viruses. Some risk factors can be avoided or reduced.Today, the Greek term carcinoma is the medical term for a malignant tumor derived from epithelial cells. It is Celsus who translated carcinos into the Latin cancer, also meaning crab. Galen used "oncos" to describe all tumours, the root for the modern word oncology.[1]Breast cancer in a mastectomy specimen (top). The cancerous tumour (pale yellow) resembles the figure of a crab, giving the disease its name.Hippocrates described several kinds of cancers. He called benign tumours oncos, Greek for swelling, and malignant tumours carcinos, Greek for crab or crayfish. This name probably comes from the appearance of the cut surface of a solid malignant tumour, with a roundish hard center surrounded by pointy projections, vaguely resembling the shape of a crab (see photo). He later added the suffix -oma, Greek for swelling, giving the name carcinoma. Since it was against Greek tradition to open the body, Hippocrates only described and made drawings of outwardly visible tumors on the skin, nose, and breasts. Treatment was based on the humor theory of four bodily fluids (black and yellow bile, blood, and phlegm). According to the patient's humor, treatment consisted of diet, blood-letting, and/or laxatives. Through the centuries it was discovered that cancer could occur anywhere in the body, but humor-theory based treatment remained popular until the 19th century with the discovery of cells.Though treatment remained the same, in the 16th and 17th centuries it became more acceptable for doctors to dissect bodies to discover the cause of death. The German professor Wilhelm Fabry believed that breast cancer was caused by a milk clot in a mammary duct. The Dutch professor Francois de la Boe Sylvius, a follower of Descartes, believed that all disease was the outcome of chemical processes, and that acidic lymph fluid was the cause of cancer. His contemporary Nicolaes Tulp believed that cancer was a poison that slowly spreads, and concluded that it was contagious.[2]With the widespread use of the microscope in the 18th century, it was discovered that the 'cancer poison' spread from the primary tumor through the lymph nodes to other sites ("metastasis"). This view of the disease was first formulated by the English surgeon Campbell De Morgan between 1871 and 1874 [3]. The use of surgery to treat cancer had poor results due to problems with hygiene. The renowned Scottish surgeon Alexander Monro saw only 2 breast tumor patients out of 60 surviving surgery for two years. In the 19th century, asepsis improved surgical hygiene and as the survival statistics went up, surgical removal of the tumor became the primary treatment for cancer. With the exception of William Coley who in the late 1800s felt that the rate of cure after surgery had been higher before asepsis (and who injected bacteria into tumors with mixed results), cancer treatment became dependent on the individual art of the surgeon at removing a tumor. During the same period, the idea that the body was made up of various tissues, that in turn were made up of millions of cells, laid rest the humor-theories about chemical imbalances in the body. The age of cellular pathology was born.When Marie Curie and Pierre Curie discovered radiation at the end of the 19th century, they stumbled upon the first effective non-surgical cancer treatment. With radiation came also the first signs of multi-disciplinary approaches to cancer treatment. The surgeon was no longer operating in isolation, but worked together with hospital radiologists to help patients. The complications in communication this brought, along with the necessity of the patient's treatment in a hospital facility rather than at home, also created a parallel process of compiling patient data into hospital files, which in turn led to the first statistical patient studies.Cancer patient treatment and studies were restricted to individual physicians' practices until World War II, when medical research centers discovered that there were large international differences in disease incidence. This insight drove national public health bodies to make it possible to compile health data across practises and hospitals, a process that many countries do today. The Japanese medical community observed that the bone marrow of bomb victims in Hiroshima and Nagasaki was completely destroyed. They concluded that diseased bone marrow could also be destroyed with radiation, and this led to the discovery of bone marrow transplants for leukemia. Since WWII, trends in cancer treatment are to improve on a micro-level the existing treatment methods, standardize them, and globalize them as a way to find cures through epidemiology and international partnerships.
Yorum (yok)
Yorum yaz!
Kalıcı Bağlantı
28/8/2007
Bilgisayar güvenliği uzmanları, bir internet arama motorundan bulunan siteye tıklandığında yüzde 4 casus yazılım veya bilgisayar virüsü bulaşma ihtimali bulunduğu uyarısı yaptılar.
Anti virüs yazılım şirketi McAfee tarafından yapılan bir araştırmada, sadece ABD’deki kullanıcıların kendilerini online güvenlik sitelerine götürmesi amacıyla ayda 276 milyon civarında arama yaptıkları ortaya çıktı.
Virüsle mücadele şirketinin, internetin beş büyük arama motoru, webdeki aramaların yüzde 93’ünü oluşturan Google, Yahoo, MSN, AOL ve Ask’da yaptığı araştırmada, American On Line (AOL) şirketi en güvenli, Yahoo ise en riskli çıktı. AOL’de yapılan aramalarda sitelerin yüzde 2,9’u, Yahoo’da ise yüzde 5,4’ünün riskli olduğu belirlendi.
McAfee şirketinin araştırmasında, webde yapılacak en tehlikeli aramaların da dijital müzik paylaşımının olduğu P2P siteleri olduğu ortaya çıktı.
"Bearshare" P2P sitesi yüzde 45,9 ile en riskli sonucu verirken, bunu yüzde 37,1 "Limewire", yüzde 34,9 ile "Kazaa" ve yüzde 32 ile "Winmix" izledi.
Diğer riskli arama kelimelerinin de yüzde 42 ile "screensavers" (ekran koruyucu) ve yüzde 31,1 ile "wallpapers" (duvar kağıdı) olduğu belirlendi.
http://www.milliyet.com.tr/2007/06/05/son/sonyas12.asp
Yorum (yok)
Yorum yaz!
Kalıcı Bağlantı
