Biology and Human Welfare

The surface protein gp120 conjoins the virus to the host lymphoid tissue by binding to the primary receptor CD4. It signals via several cell surface receptors.

The gag gene is encoded as a large gag-pol protein with another gene then cleaved to the precursor protein assemblin, which is then cleaved to Gag. It is involved in virion assembly and produces some of the capsid and nucleocapsid proteins. It does not encode for the lipid bilayer of the virus.

Integrins are a family of transmembrane glycoprotein receptors that mediate cell-matrix. They are involved in the anchoring of cells to an extracellular matrix. They affect tumour progression has made them an appealing target for cancer therapy.

 Angiostatin is endogenously produced in the tumor stroma. Therefore, circulating levels can control metastatic cell proliferation until a primary tumor is removed. Angiostatin inhibits angiogenesis.

ADEPT stands for antibody-directed enzyme prodrug therapy entangling the association of an enzyme to an antibody. It is the use of monoclonal antibodies (or mAb) to specifically bind to target cells or proteins.

The window period is the period between the onset of HIV infection and the appearance of detectable antibodies to the virus. The purpose of the p24 antigen portion of the test is to detect HIV before body has made antibodies, i.e., in the window period.

These cells are the vital part of the cellular immune response,destroying the cells, which bears any foreign antigen on their surface, mainly virus-infected cells.

This enzyme is involved in the production of RNA from DNA through transcription. It adds ribonucleotides to growing RNA transcripts at the 3’ end. The pol gene does not encode for NA polymerase.

For the HIV infection to occur the cell fusion is essential. This is done by the transmembrane glycoprotein gp41. HIV-1 utilises two major co-receptors along with CD4 to bind to, fuse with, and enter target cells.

Tumour suppressor genes code for proteins, which normally control progression through a cell cycle checkpoint. These genes only contribute to a cancer when both copies are mutated in a way, which produces an inactive protein product. A single mutation inactivating one gene only has no effect. They contribute to cancer because the absence of the protein product removes controls on cell division.

HAART is used to suppress HIV viral replication and the progression of HIV disease. It conjoins three or more different drugs, such as two nucleoside reverse transcriptase inhibitors (NRTIs) and a protease inhibitor. These HAART regimens have proven to reduce the amount of active virus and in many case.

An oncogene is a mutated form of a normal cellular gene (the proto-oncogene) that codes for a protein, which is either controlled abnormally, so that it is expressed in abnormally large amounts or has gained activity. It is more active than the normal protein.

Busulfan acts as an alkylating agent. It contains two sulfonyloxy groups,  which acts as  good leaving groups when the drug reacts with a nucleophile.

Epstein-Barr virus is associated with Burkitt's lymphoma and with naso-pharyngeal carcinoma.

A glioma is a type of tumor that starts in the brain or spine. It is called a glioma because it arises from glial cells. An increased incidence in gliomas has no association with HIV infection.

It is a field of research that aims to discover cancer immunotherapies to treat and retard progression of cancer.

If the original lung cancer has spread, a person may feel symptoms in other places in the body. Common places for lung cancer to spread include other parts of the lungs, lymph nodes, bones, brain, liver, and adrenal glands.

Depsipeptide is derived from a bacterial strain and is reduced to an active compound that promotes apoptosis and inhibits cell proliferation and angiogenesis.

Mutations in the APC (adenomatous polyposis coli) gene cause both classic and attenuated familial adenomatous polyposis. These mutations affect the ability of the cell to maintain normal growth and function. Cell overgrowth resulting from mutations in the APC gene leads to the development of multiple colonic polyps. These polyps are not themselves malignant but are prone to develop frank carcinoma through the accumulation of further genetic mutations.

The ras gene codes for a GTPase switch protein, which forms part of a growth factor signalling pathway. Stimulation of this protein via an occupied growth factor receptor causes it to activate by exchanging a molecule of GDP for GTP. The activated ras protein then activates downstream proteins, which ultimately activate transcription factors. Normally the ras signal is self limiting because the protein has intrinsic GTPase activity, so it hydrolyses its bound GTP to GDP, switching the signal off.

In case of HIV infection this test finds either the RNA of the HIV virus or the HIV DNA in white blood cells infected with the virus. The PCR test is very useful to find a very recent infection.

Metastasis refers to the spread of a cancer to different parts of the body and the appearance of secondary tumours.

Cancer is regarded as a genetic disease because it is caused by mutations in the genome. However, these mutations are normally in somatic cells, not the germ cells and mutations contributing to cancer are rarely inherited. To form a malignant cancer, a cell must acquire a small number of mutations (probably about six) each of which gives the cell a growth or survival advantage.