Lymphocytosis Health Dictionary

The ?uid within the ventricles of the brain and bathing its surface and that of the spinal cord. Normally a clear, colourless ?uid, its pressure when an individual is lying on one side is 50 to 150 mm water. A LUMBAR PUNCTURE should not be done if the intracranial pressure is raised (see HYDROCEPHALUS).

The cerebrospinal ?uid (CSF) provides useful information in various conditions and is invaluable in the diagnosis of acute and chronic in?ammatory diseases of the nervous system. Bacterial MENINGITIS results in a large increase in the number of polymorphonuclear LEUCOCYTES, while a marked lymphocytosis is seen in viral meningitis and ENCEPHALITIS, tuberculous meningitis and neurosyphilis. The total protein content is raised in many neurological diseases, being particularly high with neuro?bromatosis (see VON RECKLINGHAUSEN’S DISEASE) and Guillan-Barré syndrome, while the immunoglobulin G fraction is raised in MULTIPLE SCLEROSIS (MS), neurosyphilis, and connective-tissue disorders. The glucose content is raised in diabetes (see DIABETES MELLITUS), but may be very low in bacterial meningitis, when appropriately stained smears or cultures often de?ne the infecting organism. The CSF can also be used to measure immune proteins produced in response to infection, helping diagnosis in cases where the organism is not grown in the laboratory culture.... cerebrospinal fluid

A variety of white blood cell produced in the LYMPHOID TISSUE and lymphatic glands (see LYMPHATICS; GLAND) of the body. It contains a simple, rounded nucleus surrounded by protoplasm generally described as non-granular. Two varieties of lymphocyte are described, small and large, and together they form over 20 per cent of the white cells of the blood. They play an important part in the production of ANTIBODIES, and in the rejection of transplanted organs such as the heart (see TRANSPLANTATION). This they do in two di?erent ways: what are known as B-lymphocytes produce antibodies, while T-lymphocytes attack and destroy antigens (see ANTIGEN) directly. The latter are known as T-lymphocytes because they are produced by the THYMUS GLAND. Their numbers are increased in TUBERCULOSIS and certain other diseases. Such an increase is known as LYMPHOCYTOSIS.... lymphocyte

n. an increase in the number of white blood cells (leucocytes) in the blood. see basophilia; eosinophilia; lymphocytosis; monocytosis.... leucocytosis