Acne Vulgaris: an Understanding
Acne is chronic inflammatory disease of pilosebaceous glands. It is mainly characterized by seborrhea, formation of comedones, papules and pustules. Less commonly symptom like nodules, deep pustules and in some cases scarring is seen.
Four factors are involved in pathogenesis (1) Seborrhea (increase sebum production) (2) Hyper cornification of pilosebaseous duct (3) Colonization of pilosebaseous duct by P. acne (propionobacterium acne) and (4) Inflammation.
Categories: Acne Tags: Atopic dermatitis, Cornification, Seborrhea
The Global Magnitude of the Problem of Cancer
Cancer afflict all the communities throughout the world. At present more than 11 million people are diagnosed with cancer and more than 7 million people die due to cancer every year, throughout the world. More than 30 million people are living with cancer at present. In term of incidence, the most common cancers are Lung cancer (12.3% of all cancer), breast cancer (10.4%) and colorectal cancer (9.4%). In terms of death from cancer the most common cancers is Lung cancer (17.8% of all deaths due to cancer).
For a disease, the relationship of incidence to mortality rate is an indication of prognosis. Similar incidence and mortality rate is indication of essentially fatal condition. That is why lung cancer accounts for most deaths from cancer (1.1 million) in the world annually, because its incidence and mortality rate is similar and it is invariably associated with poor prognosis. On the other hand for breast cancer appropriate management can be effective in avoiding fatal out come. That is why although it is second in term of incidence but in terms of mortality it is ranked 5th .
Categories: Cancer Tags: Helicobacter pylori, Lung cancer, Surveillance Epidemiology and End Results (SEER)
Cancer control (Secondary prevention)
Secondary prevention comprises the following measures:
(1) Cancer registration:
Cancer registration is a sine qua non for any cancer control programme. It provides a base for planning the necessary services and for assessment of the magnitude of the problem of cancer. Cancer registries are of two types: hospital-based and population based registries.
(a) Hospital-based registries: The hospital-based registry includes all patients treated by a particular institution, both inpatients and out patients. Registries collect data as recommended by WHO in the “WHO Handbook for Standardized Cancer Registers”. If follow-up is long-term, hospital-based registries can be of considerable value in the evaluation of diagnostic and treatment programmes and also for research. Since hospital population will always be a selected population, the use of hospital-based registries for epidemiological purposes is limited.
(b) Population-based registries: The best thing to do is to set up a “hospital-based cancer registry” and extend it to a “population-based cancer registry”. 2-7 million is the optimum size of base population for population based registry. The aim is to cover the complete cancer situation in a given geographic area. The data from such registries alone can provide the incidence rate of cancer and serve as a useful tool for initiating epidemiological enquiries into causes of cancer, surveillance of time trends and planning and evaluation of operational activities in all main areas of cancer control.
(2) Early detection of cases:
Cancer screening is the main weapon for early detection of cancer at a pre-invasive (in situ) or pre malignant (cancerous) stage. Effective screening programmes have been developed for cervical cancer (Papanicolaou smear, known as pap smear), breast cancer (mammography) and oral cancer. Like primary prevention, early diagnosis has to be conducted on a large scale. But it is possible to increase the efficiency of screening programmes by focusing on high-risk groups. but there is no point in detecting cancer at an early stage unless facilities for treatment and after care are available. Early detection programmes will require mobilization of all available resources and development of a cancer infrastructure starting at the level of primary health care, ending with complex cancer centers or institutions at state or national levels (tertiary health care).
(3) Treatment:
Treatment facilities should be available to all cancer patients. Some of the cancers are amenable to surgical removal, while some others respond favorably to radiation or chemotherapy or combination of both. Since most of the known methods of treatment have only complementary effect on the ultimate outcome of the patient, multi-modality approach to cancer control has become a standard practice in cancer centers. In the developed countries cancer treatment is geared to high technology. For those who are beyond the curable stage, the goal must be to provide pain relief. A largely neglected problem in cancer care is the management of pain. The WHO has developed guidelines on relief of cancer pain “Freedom from cancer pain” is now considered a right for cancer patients.
Categories: Cancer Tags: Cancer registries, Cancer screening
Cancer control (Primary Prevention)
Cancer control consists of a series of measures based on present medical knowledge in the fields of prevention, early detection through screening and population education, diagnosis, treatment, after care and rehabilitation, aimed at reducing the number of new cases, increasing the number of “cures” and reducing the invalidism due to cancer.
The basic approach to the control of cancer is through primary prevention and secondary prevention. It is estimated that at least one third of all cancers are preventable. If we analyze the causes of cancer it is seen that environmental factors are the most important in causation of cancer which are modifiable. Genetic factors which are not modifiable are responsible in small number of cases of cancer.
Categories: Cancer Tags: Danger signals, Energy balance, Personal hygiene, Screening for Cancer
Causes of cancer
Cancer is a chronic disease. As with any other chronic diseases, cancer has a multifactorial etiology (cause). Carcinogens are the substances which can cause cancer to humans.
1. Environmental factors: Environmental factors are responsible for at least 90 per cent of all human cancers. The major environmental factors identified include the following:
a. Tobacco: Tobacco in various forms of usage (e.g. smoking, chewing, sniffing) is the major environmental cause of cancers of lungs, larynx, mouth, pharynx, esophagus, bladder, pancreas and also kidney. It has been estimated that cigarette smoking is responsible for more than one million premature deaths every year throughout the world in the form of cancer, respiratory problems and also in many other way. There is hardly any organ system which is not affected adversely due to cigarette smoking.
Categories: Cancer Tags: Burkitt’s lymphoma, Carcinogens, Cytomegalovirus, Epstein-Barr virus, Hodgkin’s disease, Human papilloma virus, Kangri cancer, Leukaemia, Retinoblastoma
Cancer: a General understanding
Cancer can be regarded as a group of most serious diseases which are characterized by (1) abnormal growth of cells without control. (2) ability to invade nearby tissues and even to distant organs, by local invasion, through lymphatic system and blood. (3) the eventual death of patient it the tumor (cancer) has progressed beyond the stage when it can be successfully removed by surgery . Cancer can occur at any site of the body and it can involve any type of cells.
If cancer occurs in a tissue, the cells of the tissue starts growing abnormally fast. But the cells can not mature and because cells are not mature they cannot perform the function for which they are present in the body. For example if there is cancer of liver (hepatocellular carcinoma) the cancerous liver cells cannot perform functions of liver, but they consume the nutrition and due to large number and fast growing they consume large number of calories. This is the reason of weight loss in cancer. These immature cells keeps growing in number without any function and may spread to nearby tissues or to a distant site through blood. One cancerous cell is enough for spread to distant organ which keep growing very fast.
Cancer can be categorized into the following major categories:
- Caremomas :They arise from epithelial cells which is the cell lining the surface of various organs like mouth, uterus, intestines, stomach, inner side of nose etc, This type may arise from skin also from skin epithelium .
- Sarcomas :They arise from various cells which constitute connective tissues like bone, fat, fibrous tissues, bran tissue etc.
- Lymphomas, myelomas and leukemias (blood cancer) arise from the cells of immune system as well as from bone marrow. Blood cancer or leukemia arise from bone marrow, because blood cells are formed in bone marrow.
In blood cancer (leukemia) white blood cells, whose main function is to fight with the invading microorganisms (bacteria, virus, fungus etc), starts growing abnormally rapidly in bone marrow but they are not mature. Because of immaturity they can not perform their primary function, which is to fight with invading microorganisms. And patient eventually die due to infection.
The term primary (cancer) tumor means cancer in the organ of origin, but secondary (cancer) tumor means the cancer which has spread to distant organ or to regional lymph nodes. When cancer cells multiply and reach a critical size cancer can be clinically evident as mass or ulcer in the particular area. Some time primary tumor can not be detected or found, but the secondary tumor became the main cancer. In this type of cases the primary tumor shrinks due some reason and become undetectable.
Categories: Cancer Tags: Caremoma, Connective tissue, Epithelial cell, Leukemia, Lymphomas, Myeloma, Sarcoma
Effects of Heat on Humans
Effects of Heat: There are 14 documented disorders which can be due to excess exposure to heat. Some of the common and important disorders are discussed below:
- Heat stroke: Also known as sunstroke. This is due to failure of heat regulating mechanism of human body . The main feature of heat stroke is very high body temperature of about 110 degree Fahrenheit(430 Centigrade). High temperature is accompanied by convulsion, delirium and partial or complete loss of consciousness. Skin is usually dry and hot. Sweating is absent or very scanty. Death rate is high (about 40%) even it quick medical attention is provided. Treatment of heat stroke consists of rapidly cooling the body in ice water till rectal temperature falls blow 102 degree Fahrenheit. Rectal temperature should be continuously monitored. It indicate the progress of treatment as well as guard against hypothermia, that may occur if cooling is continued for very long . Further treatment of heat stroke is supportive & symptomatic. The patient should be hospitalized for several days, till temperature control & regulatory mechanism become stable.
Categories: Environment & Health Tags: Heat cramps, Heat exhaustion, Heat Hyperpyrexia, Heat stroke, Heat syncope, Sunstroke
Effects of Radiation on Humans
The biological effects of radiation on human can be divided into two groups, somatic effects and genetic effects.
(1) Somatic effects: A dose of 600 to 700 roentgen is invariably fatal in humans and a dose of 400 to 500 roentgen can kill up to 50% of people. Those who are not killed, also suffer from severe damage and radiation sickness. If a person is exposed to 25 to 50 roentgen of radiation it effects white blood cells (corpuscles) and produce lassitude and softening of the muscles. Somatic effects of radiation can be immediate and delayed. Immediate effects are radiation sickness and acute radiation syndrome. Delayed effects take time to develop and can take from few weeks to few years to develop. Delayed effects of radiation are mainly leukemia (blood cancer), malignant tumors ( cancer) shortening of life and fetal developmental abnormalities.
(2) Genetic effects: Somatic effects are seen during ones lifetime of the person exposed to ionizing radiation genetic effects generally manifest in the life of off-spring . Genetic effects of radiation are mainly due to point mutation and chromosomal mutation. Chromosomal mutation generally is involved with sterility and point mutation effects the genes .
Protection from Radiation: The amount of radiation received from outer space is about 0.1rad per year and at present it is not considered a hazard. The additional permissible dose from man made sources is about 5rad per year. Out of all the man made sources x-ray constitute the greatest hazard. In routine fluoroscopy a dose of 4rad is delivered to a part in one minute, which means unnecessary x-ray examination should be avoided, mainly in pregnant woman an children.
There is requirement of adequate control & surveillance of x-ray installations, protection of workers, improvement of techniques to reduce dose of radiation.
Effective protective measures include use of lead shields, and lead rubber aprons by radiographers .Lead aprons of 0.5mm thickness of lead reduces the intensity of scattered x-rays up to 90% and all workers should use them who are associated with x-rays. Worker also should wear a dosimeter or a film badge that shows accumulated exposure to radiation. Besides all the above periodic medical cheek up, regular working hours & recreation should be provided to the health workers who are exposed to x-rays.
Radiation hygiene is one of the latest branch of hygiene. International agencies like WHO(World Health Organization), IAEA(International Atomic Energy Agency) and International Commission on Radiological Protection (ICRP) are active in the field of radiation hygiene. The ICRP has recommended that the genetic dose to the whole population from man made sources (other than natural sources) should not exceed 5rems per year over period of 30 years. Many countries in the world have adopted the ICRP recommendation . The main concern is to promote peaceful use of atomic energy with out any problem on heath.
There is growing concern throughout the world in recent times for codes of practice for the safe operation of nuclear power plants and safe disposals of nuclear waste which is generated from nuclear power plants.
Categories: Environment & Health Tags: Genetic effect, IAEA(International Atomic Energy Agency), Protection from Radiation, Radiation hygiene, Radiation sickness, Somatic effect
Types of radiation
Ionizing radiation is the radiation which can penetrate tissues and deposit its energy within them. They are of three types of electromagnetic radiation: alpha particles, beta particles (electron) and protons.
Alpha particles are 10 times more harmful than X-rays, beta particles or gamma rays but they have very little penetrating force. But they are dangerous it enters the body by inhalation or wound. X-rays & gamma rays are of short wave length and can penetrate deep.
Alpha particles can penetrate 4cm in air, 0.05mm in tissue and no penetration in lead. Beta particles can penetrate 6 to 300cm in air, 0.06-4mm in tissue and 0.005 to0.3 mm in lead. Gamma rays can penetrate 400 meters in air, 50cm in tissue and 40mm in lead. X-rays can penetrate 120-240 meters in air 15 to 30cm in tissue and 0.3 mm in lead.
Categories: Environment & Health Tags: Alpha particles, Becquerel(Bq), Beta particles, Coulomb per kilogram(c/kg), Dose equivalent(H), Electromagnetic radiation, Gamma rays, Gray(GY), Ionizing radiation, Non ionizing radiation, Rad, Rem, Roentgen
Radiation: a Discussion
Radiation is a part of man’s environment. Man is exposed from two sources of radiation natural and man made.
Natural sources of radiation are cosmic rays internal rays like carbon-14 and Potassium-40, atmospheric and terrestrial. Man made sources of radiation are medical & dental X-rays, radioisotopes for treatment of killer disease like cancer, radioactive fall out from nuclear explosions. Miscellaneous man made radioactive sources are television sets, radioactive dial matches, luminous markers, isotope tagged products. They are too small a source of radiation to be significant at present.
Natural sources:
Man is exposed to radiation throughout life continuously. Cosmic rays originate in outer space and become weak as they pass through atmosphere. Generally a person is exposed to about 35mrad of radiation a year. At higher attitude of about 20 km cosmic radiation becomes important. A commercial jet pilot receives about 300mrad of radiation a year compare to normal 35mrad.
Terrestrial radiation: Radioactive elements like thorium, uranium, radium and radioactive isotopes are present in man’s environment e.g. soil, rocks, buildings. Man derives about 50mrad of radiation from terrestrial sources. Some areas like Kerala in India, rock formations contain uranium, where radiation exposure may be as high as 2000mrad per year. Radiation from radioactive gases like radon contribute about 2mrad of radiation per year.
Internal radiation: Man is exposed to internal radiation from radioactive materials stored in body tissues. These include minute quantities of uranium, thorium, radioactive isotopes of carbon(C14), Potassium(K40), strontium(Sr90). From these sources radiation is about 25mrad per year but it may be as high as 70 to 80. it is estimated that a person is exposed to about 0.1rad of radiation per year from natural sources.
Man made sources:
Man is exposed to man made sources of radiation in addition to natural sources.
X-ray: this is the largest source of man made radiation. Two groups of people are exposed to X-ray radiation, patients and radiologists & radio technicians and radiotherapists. When optimum radiographic techniques are used a single X-ray film can give more than 0.02rad.
Radioactive fallout:
Nuclear explosions release tremendous amount of energy in the form of heat, light, radiation and also it releases many radioactive substances like carbon (C14), iodine (I 131), cesium (Cs 137) and strontium (Sr 90). Cesium and strontium are very important because they are released in large quantities and their half lives are 30 years and 28 years respectively. They float for few years and due to air current the particles are distributed throughout the world. Miscellaneous sources contribute too small am out of radiation to be important.
