Thursday, March 28, 2013

Allergies and Cancer


Allergies

Sometimes the immune system overreacts to a particular substance called an allergen, producing an allergy. This may result from eating certain foods, inhaling particles or exposure of the skin to chemicals. Common allergies include asthma, hay fever, urticaria, farmer’s lung, food allergies and contact dermatitis. Treatments include avoiding allergens and antihistamine drugs. In some cases anaphylactic shock the body reacts so violently to an allergen, such as a wasp sting, that without treatment the patient may die.

Cancer

The body’s tissue cells constantly divide and replace themselves. Some times “rouge” cells divide out of control to produce an abnormal tissue growth or malignant tumor. Diseases involving these tumors are called cancers. If untreated, cancer cells spread from the tumour via the blood stream to other parts of the body where they produce secondary tumours. Eventually, cancer cells overwhelm the body and the patient dies. The risk of developing a cancer may be inherited, or it may be increased by smoking, drinking alcohol or exposure to chemicals. Cancer affects around 25 percent of people in the western world at some point in their lives and is the second most common cause of death after heart disease. Different types of cancers do not occur with the same frequency worldwide. This uneven distribution points to the involvement of environmental factors- such as food intake, smoking or exposure to ultra violet light- as causes of cancer. For example, stomach cancer in Japan and Chile is believed to be related to diets high in salted and pickled food.

Monday, March 18, 2013

Infectious And Non Infectious Diseases

 
Infectious Diseases

 Infections arise when disease causing micro organisms penetrate the body’s physical defenses such as the skin and entire bloodstream and tissues near their route of entry can be by infection of infected droplets, ingestion of contaminated food or water, entry through broken skin, skin to skin contact, injection by needle or other sharp object, sexual contact, insect bites, or by transmission from mother to fetus. In most of the case the body immune system acts to destroy the invading micro organism before it can do harm. Most disease signs and symptoms such as spots in measles- are indicators of the battle between the micro organism and the body’s immune system. In rare cases, the infection may be so virulent that kills the patient before the immune system has time to fight back. Before the 20th century infectious diseases were a major cause of deaths in the world. In developed countries today, deaths from infectious disease have been dramatically reduced, and non infectious diseases such as cancers and heart disease have taken over as major killers. This reduction has been achieved by better public health and sanitation; the use of antibiotics and other antimicrobial drugs; and the use of vaccines.

However there is no room for complacency since old diseases such as TB, malaria are again on the increase, some bacteria are now resistant to drugs; many viral conditions are untreatable and new diseases such as AIDS are appearing. Disease causing organisms include viruses, with are non living infectious agents; single celled organisms including bacteria, chlamydiae, rickettsiae, fungi and protists, and multicellular organisms such as parasitic worms. Viruses consist of genetic material surrounded by a protein coat, and cause diseases such as measles, mumps and rabies. Viruses have to invade host cells to reproduce. They lose their outer protein coat and use the host cell’s DNA to replicate their genetic materials. A protein coat is constructed around the rebuilt genetic material and newly formed viruses burst out of the host cell or exit in an envelope and invade other host cells to multiply further.

Non Infectious Diseases 

Non infectious diseases are now the major cause of death in the developed world. The reason for this is that many infectious diseases are now treatable with drugs. Also the incidence of non infectious diseases increases with age, and averaged life expectancy is increasing. Non infectious diseases include circulatory diseases including heart attacks and strokes, in which the blood vessels to the heart or brain becomes blocked; cancers diabetes mellitus, which is the body’s inability to control blood sugar levels; nervous system diseases such as motor neuron disease; respiratory system diseases digestive system diseases ; kidney diseases and allergies. On average, infectious diseases are responsible for just five deaths per 100000 of the population per year in the developed world, as compared with nearly 1000 deaths per 100000 caused by major non infectious diseases.

Tuesday, February 26, 2013

Immunization


While immunity is being acquired a person develops symptoms of the disease. But some infections can be prevented by allowing the body to acquire active immunity artificially. This is achieved by the introduction into the body of a vaccine made from dead or weakened microorganisms that are no longer capable of causing the disease itself. When injected into the skin or bloodstream (or as in the case of polio vaccine, swallowed) they stimulate B lymphocytes to produce antibodies but no significant disease symptoms. And if, or when, the body encounters the real disease causing microorganisms, it is already protected against infection because the memory cells immediately produce antibodies.

Booster shots may be needed at later dates to ensure that active immunity is still effective. Vaccines are available against many formerly dangerous diseases including polio, measles an d diphtheria. Immunization programmes for children have virtually eliminated most common childhood diseases, and confer immunity into adult life. But vaccination is advisable for travelers to countries where they may contract potentially fatal diseases not previously encountered. Sometimes antibodies themselves from external sources are injected into the body to provide protection without stimulating the immune system. This is called artificial passive immunity and is useful in providing instant protection where a disease might kill the person before their active immune system has time to come into operation. Examples include gamma globulin, given against hepatitis A infection; anti toxin to treat tetanus; and anti rabies injections.

Wednesday, February 20, 2013

Diets and Dieting!


The word diet is commonly used these days to describe an eating regime followed by someone in order for him or her to lose weight, even though in its correct usage the word simply describes what we eat each day. A diet designed for weight loss is better described as a slimming diet, and there are many of these to choose from. As the percentage over weight and obese children and adults in the western world steadily increases as a result of increased in activity and increased consumption of junk food – so new slimming diets, and books on slimming, become available in order to commercially exploit fatness. However, most of these diets are not effective because they fail to promote long term weight loss and in fact may well cause the slimmer to end up fatter and heavier than when they started the diet. Being overweight will of course affect an individual’s health and reducing body weight will help to reduce those health risks. But to be healthy, a diet designed to reduce body weight needs to be in tune with the body’s physiology.

 An effective diet should promote the loss of fatty or adipose tissue from the body so that its overall fat content is reduced. To do this successfully, the dieter should eat a well balanced high carbohydrate, high fiber low fat diet with energy content of between 1200 and 1500 calories per day, combining this with regular exercise. This should cause a weight loss of 0.45 to 0.95 KG per week, that weight loss being mainly in the form of fat. At the same time, exercise will build up muscle tissue which pound for pound consumes far more energy than fat does as well as increasing metabolic rate, the rate at which the body burns carbohydrates and fat to release energy. Once the desired weight has been reached – and the body fat content has been reduced to within safe limits- then the dieter can gradually increase his or her calorie consumption while maintain the same balance of foods in order to keep at the weight for life.

Other sliming diets put the body in a defensive stance. Because its calorie intake has been severely reduced the body reduces its metabolic rate to conserve its fat energy reserves and actually burns lean muscle tissues in order to provide energy. When the diet stops the body diverts as much spare food energy as possible to build up its fat reserves in case another calorie famine happens and in consequence the diet regains lost weight and ends with more fat than before

Thursday, December 20, 2012

Bulimia nervosa and Food Poisoning

Bulimia nervosa

 Like anorexia, bulimia is an eating disorder found most commonly among younger women, often those who have had anorexia. Bulimics crave food but fear becoming fat. They indulge in binge eating by consuming vast amounts of food and then induce vomiting and use laxatives. This constant bingeing and vomiting can cause severe medical problems. Sufferers from bulimia require the same medical care as anorexics.

 Food poisoning


This refers to illnesses caused by eating food contaminated by certain micro organisms or the toxins, they produce. Worldwide, the incidence of food poisoning is on the increase. This is probably due to the growing use of convenience foods, such as cook chill meals, and the consumption of fast foods, which are easily subject to contamination by the people who make and serve them. Spores in raw rice, chicken beef, water or milk contaminated faeces are caused by Bacillus cerus and Campylobacter fetus. Botulism and Clostridium Perfinges are through food contaminated with bacterial toxin. Meat or vegetables contaminated by faeces. Amoebic dysentery can caused by food or water contaminated by faeces. Norwalk virus can infect through contaminated shell fishes and the rotavirus can introduced to our system by contaminated water or food. Undercooked poultry or egg can cause Salmonella. Food that contaminated by contact with wounds are the reason for the Staphylococcus.

Monday, December 10, 2012

Obesity and Anorexia Nervosa


Obesity:

 The condition in which the body has so much fat is called obesity. Someone is considered to be obese if their weight is 20 percent over their ideal maximum or if their BMI is greater than 30. Around 30 percent of people in western countries are overweight and around five percent of them are obese. Long term obesity is a serious threat to health. It increases significantly the chances of developing high blood pressure, coronary artery disease, stroke, adult onset diabetes mellitus, certain cancers, osteoarthritis, back pain and varicose veins. Obese patients are advised under medical supervision, to lose weight using a calorie reduced diets and increased aerobic exercise.

Anorexia Nervosa:

 Popularly, but incorrectly, known as the “slimmers’ disease”, anorexia nervosa is an eating disorder found mainly among teenage girls and young women, and only rarely increases. In fact, one in hundred of the women suffer from the condition and increasing to one in twenty in those categories of women, such as dancers actors especially concerned with their bodies. Anorexia may be a phobia about being fat or a symptom of mental illness. Whatever its cause, however anorexia is a serious illness in which the individual starves herself and may die. She not only loses her appetite but, more seriously, fails to have a normal perception of the size and shape of her body- she thinks she is fat even when she is way below her normal weight. The main features of anorexia are as follows; excessive weight loss, over activity, secretive and defensive behavior, being choosy about food, obsessive exercising, tiredness always feeling cold , induced vomiting, use of laxatives, thinning of hair on heat, appearance of Languo (Baby hair) on the body, dry skin and cessation of periods (amenorrhea). Anorexics require medical treatment and counseling.

Sunday, December 9, 2012

Diet and Diseases



Fats in foods are divided into saturated fats found mainly in meat and dairy products and unsaturated fats- found in fish and vegetable oils. Research has established a link between the high level of consumption of saturated fats in northern Europe and USA and the incidence of coronary heart disease, leading to death from heart attacks. Coronary artery disease is caused by the buildup of obstructions called atheromas that contain cholesterol.

Studies have indicated a strong link between diet and the chances of developing certain cancers. Cancers of the colon, rectum and stomach may be up to 90 percent diet dependent and diet may be responsible for up to 35 percent of cancers in western countries. For example, there appears to be a close correlation between levels of fat consumption and incidence of breast cancer. In Japan fat provides 22 percent of energy requirements in the diet and the death rate from breast cancer is four per 100,000 people, in USA, fat provides 40 percent of energy requirements and the death rate is 24 per 100,000. Dietary components linked to cancers include:

Excessive alcohol- cancers of the bowel, liver, mouth, oesophagus, stomach and throat, especially in smokers;

 Fatty and low fiber foods – breast and bowel cancers;

 Pickled foods- stomach cancer;

Salt- cured meat and fish, nitrate- cured meat- throat and stomach cancers.

 Dietary recommendations to reduce cancer risk:

 Eat foods rich in fiber daily.

 Eat fresh vegetables only.

 Eat less fat.

 Consume alcohol in moderation.

 Eat fewer smoked and salted foods.

 Keep weight at recommended level.