|
Home >> Dictionary of Bioinformatics, Biochemistry, Biotechnology >> Hyperosmolal Non Ketotic Coma - Hyperviscosity Syndrome
|
|
Hyperlysinaemias
Rare disorders of lysine metabolism resulting from impaired conversion of lysine to saccharopine. Two types have been recognised: periodic hyperlysinaemia, and persistent hyperlysinaemia without hyperammonaemia inherited as an autosomal recessive trait.
Hypermutable phenotype
Bacterial strains that lack the ability to remove uracil residues that aberrantly arise in place of cytosine in cellular DNA. This leads to high rates of mutation in these strains.
|
Hyperornithinaemia
A disorder characterised by a deficiency of ornithine d aminotransferase associated with gyrate atrophy of the choroid and retina. There is a 5- 20 fold elevation in the plasma levels of ornithine accompanied by excessive urinary excretion. Due to the common renal transport system, cystine, lysine and arginine are also excreted together with ornithine.
Hyperosmolal non ketotic
coma an acute metabolic complication of type 2 diabetes mellitus. There is adequate insulin to prevent excessive lipolysis and generation of ketone bodies. However, the concentration of insulin is sufficiently low to cause hyperglycaemia. Plasma glucose levels are generally >500 mmol/L (900 mg/dL). There is sustained osmotic diuresis with severe dehydration and a very high plasma to cerebral cellular dehydration. The condition is common in elderly diabetics in whom water intake is inadequate.
|
It can also be precipitated by dialysis, high intake of carbohydrates and proteins, and administration of osmotic agents such as mannitol and urea. The osmotic diuresis causes a decrease in GFR with retention of urea and creatinine and elevation of protein concentration. Plasma bicarbonate is slightly above normal because of decreased excretion of hydrogen ions. Plasma sodium is increased due to loss of water in excess of sodium. Management involves rehydration and administration of insulin by intravenous infusion together with hypotonic saline. Heparin is given to prevent hyperviscosity and thrombosis. After treatment of acute illness, patients can be managed with diet alone or with diet and oral hypoglycaemic agents.
Hyperparathyroidism
Excess secretion of parathyroid hormone by the parathyroid glands. This results in the disturbance of calcium homeostasis leading to Hypercalcaemia, hypophosphataemia, loss of calcium from bone, and kidney stone formation.
|
|
Hyperprolinaemia
Increased excretion of proline in urine. There are two types of hyperprolinaemia characterised by increased excretion of proline, Hydroxyproline and glycine because of a common renal transport system. The enzyme defect in type I is proline dehydrogenase, whereas in type II, there is deficiency of pyroline 5 carboxylate oxidase. Hyperprolinaemia type II I more severe that type I with impaired catabolism of both proline and Hydroxyproline. In type I, hyperprolinaemia is not associated with impaired catabolism of Hydroxyproline.
Hyperpyrexia
Extremely high body temperature.
|
|
|
Hypersensitive sites
Regions in the DNA that are highly susceptible to digestion by endonucleases
Hypersensitivity
A state of reactivity to antigen that is greater than normal for the antigenic challenge. It is similar to allergy and denotes a deleterious outcome.
Hypertension
High arterial blood pressure
|
Hypertext
Describing a document in HTML.
Hypertext transfer protocol (HTTP)
The communication protocol used by the web server.
Hyperlipidaemia
Elevated concentration of plasma lipids
Hyperlipoproteinaemia
An increase in the concentration of lipoproteins in the blood.
Hyperphenylalaninaemia
An excess of phenylalanine in the blood.
Hyperplasia
An increase in the number of cells in a tissue or organ
Hyperploid
A genetic condition I which a chromosome or a segment of a chromosome is over represented in the genotype.
Hyperproliferation
a state in which cell division occurs at a very high rate.
Hyperthyroidism
hyperfunction of th thyroid gland characterised by an increased rate of metabolism with enlargement of the thyroid (goiter). The two major causes of hyperthyroidism are those due to Graves disease and toxic nodular goiter. The characteristic clinical features of hyperthyroidism include: toxic diffuse or multinodular goiter with or without exophthalmos, increased BMR with increase in body temperature, increase sweating and sensitivity to heat, tachycardia, weight loss, diarrhoea, weakness, warm and moist skin, and metabolic abnormalities such as hypocholesterolaemia, decreased glucose tolerance, hyperglycaemia and glycosuria.
Hypertonic
A solution with an osmotic potential greater than that of living cells. Cells placed in a hypertonic solution show water loss and shrinkage.
Hypertriglyceridaemia
Elevated level of triglycerides in the blood
Hypertrophy
An increase in size of cells in a tissue or organ
Hypervalinaemia
A disorder characterised by a defect in the transamination of valine to α ketoisovalerate. As a consequence, increase concentration of valine is chain amino acids leucine and isoleucine is however, not affected.
Hypervariable regions (HVR)
1. A region in a genome containing variable number of repeated sequences. Thus is characteristic for each individual. 2. The regions both the heavy and light chains of an antibody molecules that allow binding to a specific site on an antigen.
Hypervariable segment
A region of a protein that exhibits considerable variations between strains or individuals.
Hyperviscosity syndrome
A syndrome most common in macroglobulinaemia and sometimes in multiple myeloma. It is characterised by an increase in plasma viscosity that can impede blood low leading to retinal vein thrombosis with impairment of vision, cerebral thrombosis and peripheral gangrene.
Hypervitaminosis
Toxicity due to excess consumption of fat soluble vitamins
Hypervolaemia
An abnormal rise in plasma volume.
Hypha A long, branching filament of connected cells seen in fungi. The hyphae may be segmented, i.e. the individual nuclei are separated by a cell wall or non segmented, in which many nucleic share a common cytoplasm.
Hyphenated repeats
Repetitive DNA sequences that are separated by small gaps.
Hypoalbuminaemia
A decrease in albumin levels in blood. Hypoproteinaemia is almost always due to a decrease in plasma albumin levels in blood. Hypoproteinaemia is increase in globulin levels. Hypoalbuminaemia can result from expanded vascular pool, decreased synthesis, increased catabolism or increased loss from the body. In many cases, a combination of these factors is involved. Low plasma albumin can lead to oedema, because albumin is responsible for about 80 per cent of plasma colloid oncotic pressure. Hypoalbuminaemia also causes decreased binding sites for drugs resulting in increased concentrations of free drugs and the risk of drug toxicity, and increased concentrations of free drugs and the risk of drug toxicity, and increased susceptibility of neonates to Hyperbilirubinaemia leading to kernicterus.
|
|
