• Symptoms of HIV infection include fever, lethargy, pharyngitis, nausea, headache, rashes, etc.
• For prevention, one should avoid sharing needles, syringes and should have safe sex.
• Although there is no cure for AIDS, use of certain drugs can prolong the life of AIDS patient.
Use of contaminated needles and
syringes to inject drugs or vaccines.Use of contaminated
needles for boring
pinnae.From infected mother to
child through placenta.Artificial insemination.Transmission of
AIDS virus
Organ transplantation.Transfusion of
infected blood.Use of contaminated
razors.Sexual intercourse with an
infected partner without a
condom.Cancer
• Cancer is an abnormal and uncontrolled proliferation of cells without any differentiation.
• Due to uncontrolled divisions, an abnormal growth called tumor occurs.
• Tumor or neoplasm is any abnormal swelling, lump or mass in the body. Tumor is of two types : Benign and malignant. Benign
tumor remains confined to the site of origin and does not spread to other body parts. Malignant tumors spread to distant sites
through body fluids to develop secondary tumor, by the process called metastasis.
Carcinomas
• Mainly derived from epithelial cells.
• E.g., cervical (cervix is part of uterus) cancer, breast cancer, skin
cancer, lung cancer, stomach cancer, etc.Leukemias
• Commonly called as blood cancers.
• Result from excessive formation of WBCs in the bone marrow and
lymphatic nodes.Melanoma
• Cancer of the pigment producing cells especially in the skin
(melanocytes).Germ cell tumor
• Tumor derived from totipotent cells, found in adults, most often in
the testes and ovaries.Blastic tumor
• Tumor resembles an immature or embryonic tissue. Many of
these tumors are most common in children.Myeloma
• Cancer of plasma cells (B-lymphocytes) which are immune system
cells in bone marrow that produce antibodies.Sarcomas
• Derived from mesodermal cells, these cancers are located in
connective and muscular tissues.
• Include the cancers of bones, cartilages, tendons, adipose tissue,
lymphoid tissue and muscles.Types of CancerCauses of cancer
• Chemical and physical agents that can cause cancer are called carcinogens. Carcinogens fall into three basic categories:
(i) Oncogenic transformations: They are
carcinogens which bring about changes
in genetic material, e.g., adiations r (X-rays,
cosmic rays, UV rays etc.) and chemicals.
(ii) Tumor promoters: They promote
proliferation of cells which have undergone
oncogenic transformation, e.g., some
growth factors, hormones etc.Table : Carcinogens and organs affected
Carcinogens Organs affected
(i) Soot Skin, lungs
(ii) Coal tar (3, 4-benzopyrene) Skin, lungs
(iii) Cigarette smoke (N-nitrosodimethylene) Lungs
(iv) Cadmium oxide Prostate gland