| differential stain | <technique> A dye used to colour one portion of a tissue or cell which remained unaffected when the other part was stained by a dye of different colour. Synonym: differential stain. (05 Mar 2000) |
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| differential thermal analysis | Technique by which phase transitions of chemical reactions can be followed by observation of the heat absorbed or liberated. (12 Dec 1998) |
| differential thermometer | <instrument, physics> An instrument for indicating changes of temperature without indicating the degree of heat by which it is affected; especially, an instrument contrived by Count Rumford which, as modified by Professor Leslie, was afterward called the differential thermometer. Origin: Thermo- + -scope. Source: Websters Dictionary (01 Mar 1998) |
| differential threshold | The smallest difference which can be discriminated between two stimuli or one which is barely above the threshold. (12 Dec 1998) |
| differential ureteral catheterization test | A study performed to determine various functional parameters of one kidney compared to the contralateral kidney; ureteral catheters are inserted at cystoscopy into the ureter or renal pelvis bilaterally, and simultaneous measurements are made of urine flow rate, insulin, or PAH (if infused), endogenous creatinine, or various urinary solutes. Synonym: differential renal function test, split renal function test. (05 Mar 2000) |
| threshold differential | The smallest difference which can be discriminated between two stimuli or one which is barely above the threshold. (12 Dec 1998) |
| light differential threshold | The smallest difference in light intensity that can be appreciated. (05 Mar 2000) |
| absolute CD4 count | The number of helper T-lymphocytes in a cubic millimeter of blood. With HIV, the absolute CD4 count declines as the infection progresses. The absolute CD4 count is frequently used to monitor the extent of immune suppression in persons with HIV. Also called a T4 count. (12 Dec 1998) |
| absolute eosinophil count | <haematology, investigation> A measurement (cells per microlitre) of the number of eosinophils in a blood specimen. This measurement is useful in the evaluation of autoimmune disease, allergies, eczema, leukaemia, asthma and hay fever. Normal absolute eosinophil counts are less than 350 cells/mcl (microlitre). (27 Sep 1997) |
| Addis count | A quantitative enumeration of the red blood count, white blood count, and casts in a 12-hr urine specimen; used to follow the progress of known renal disease. (05 Mar 2000) |
| Arneth count | The percentage distribution of polymorphonuclear neutrophils, based on the number of lobes in the nuclei (from 1 to 5). See: Arneth index. (05 Mar 2000) |
| blood count | <haematology, investigation> The determination of the proper number of red blood cells, white blood cells and platelets are present in the patients blood. Acronym: FBC (16 Dec 1997) |
| viable count | Measurement of the concentration of live cells in a microbial population. (09 Oct 1997) |
| CD4/CD8 count | The ratio of the number of helper-inducer T lymphocytes to cytotoxic-suppressor T lymphocytes, as measured by monoclonal antibodies to the CD4 surface antigen found on helper-inducer T-cells, and the CD8 surface antigen found on cytotoxic-suppressor T-cells. In healthy individuals, the H/S ratio ranges between 1.6 and 2.2.When the body mounts an immune response, as against a virus or a transplant, the ratio is almost always reduced because of a decrease in the number of circulating helper-inducer cells and an increase in suppressor cells. The CD4/CD8 count has been used to monitor for signs of organ rejection after transplants, and more recently has become a tool for assessing the relative condition of HIV patients. With the CD4 absolute count and the CD4 lymphocyte percentage, it provides a way of gauging the progression from HIV to AIDS. (05 Mar 2000) |
| CD4 count, absolute | The number of helper T-lymphocytes in a cubic millimeter of blood. With HIV, the absolute CD4 count declines as the infection progresses. The absolute CD4 count is frequently used to monitor the extent of immune suppression in persons with HIV. Also called a T4 count. (12 Dec 1998) |