Search results
Results from the WOW.Com Content Network
(right) γ-hemolysis (non-hemolytic, S. salivarius) Hemolysis is the breakdown of red blood cells. The ability of bacterial colonies to induce hemolysis when grown on blood agar is used to classify certain microorganisms. This is particularly useful in classifying streptococcal species. A substance that causes hemolysis is called a hemolysin.
A red blood cell in a hypotonic solution, causing water to move into the cell A red blood cell in a hypertonic solution, causing water to move out of the cell. Hemolysis or haemolysis (/ h iː ˈ m ɒ l ɪ s ɪ s /), [1] also known by several other names, is the rupturing of red blood cells (erythrocytes) and the release of their contents into surrounding fluid (e.g. blood plasma).
You are free: to share – to copy, distribute and transmit the work; to remix – to adapt the work; Under the following conditions: attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses ...
Thus, a positive result for blood can represent the presence of red blood cells , free hemoglobin (hemoglobinuria), or myoglobin (myoglobinuria). [51] Red blood cells can sometimes be distinguished from free hemoglobin or myoglobin as the former causes a speckled pattern on the test pad while the latter results in a uniform color change.
The most common type of cast, hyaline casts are solidified Tamm–Horsfall mucoprotein secreted from the tubular epithelial cells of individual nephrons. Low urine flow, concentrated urine, or an acidic environment can contribute to the formation of hyaline casts, and as such, they may be seen in normal individuals in dehydration or vigorous exercise.
Hematuria can be classified according to visibility, anatomical origin, and timing of blood during urination. [1] [6]In terms of visibility, hematuria can be visible to the naked eye (termed "gross hematuria") and may appear red or brown (sometimes referred to as tea-colored), or it can be microscopic (i.e. not visible but detected with a microscope or laboratory test).
Clinically, dark urine from hemoglobinuria may be observed because the hemolysis is intravascular (see Pathophysiology below). [4] Blood smear of a patient with Thrombotic Thrombocytopenic Purpura (TTP). Notice that some red blood cells are nucleated. This is a characteristic finding in such blood smears.
The normal number of red blood cells in urine should not usually exceed 3 per high power field. [13] A urine test strip showing positive for blood can also indicate hemoglobinuria, which is not detectable using a microscope due to the lysis of red blood cells in the urinary tract (particularly in alkaline or dilute urine), or intravascular ...