|HABER BOSCH PROCESS||The NH3 required to make such fertilizers is produced industrially using the Haber-Bosch process, in which an iron oxide catalyst is used to convert N2 and hydrogen gas to NH3 at high temperatures and pressures. Fritz Haber (1868Ė1934) first synthesized NH3 from N2 and H2 in 1909. Four years later, Haber and fellow German Carl Bosch of BASF modified the process for commercial production of NH3. Although early production was devoted primarily to making German explosives in World Wars I and II, the Haber-Bosch process later allowed large-scale production of nitrogen fertilizers and revolutionized modern agriculture|
|HAFTAROS||The haftarah or haftorah (in Ashkenaz pronunciation) (alt. haphtara, Hebrew: הפטרה; "parting," "taking leave", plural haftarot or haftorahs) is a series of selections from the books of Nevi'im ("Prophets") of the Hebrew Bible (Tanach) that is publicly read in synagogue as part of Jewish ...|
|HAIR PERMANENT LEAD ACETATE DYES||Another type of permanent hair dye, mostly used to darken gray hair, depends on a solution of lead acetate that gradually darkens hair by reacting with the sulfur of hair keratin. According to the Food & Drug Administration, lead acetate is safe to use as "progressive" hair color because controlled human studies show lead is not absorbed into the body from dye use|
|HAIR PERMANENT OXIDATION DYES||Oxidation is king. Depending on whom you talk to, between 60 and 90% of dyes sold are the permanent two-part systems that can last six weeks. The first part is a solution consisting of dyes and dye intermediates in an aqueous ammoniacal solution generally containing soap, detergents, and conditioning agents.
The second part is a hydrogen peroxide solution often called the developer. Users mix the two parts just before applying to their hair. This mixture swells the hair, and simultaneously bleaches the users' natural hair color and "develops" the oxidative dye in solution as it penetrates the hair shaft. Many dye kits also include conditioning as a third step
|HAIR SEMIPERMANENT DYES||OTHER TYPES of hair dyes are semipermanent, which largely depends on direct dyes and last a few washings|
|HAIR TEMPORARY DYES||which mostly depend on basic dyes and wash out after one to three washings.
|HAIRY CELL LEUKEMIA||A disease where cancer (malignant) cells are found in the blood and bone marrow. An uncommon form of leukemia that is a slowly progressing cancer of lymphocytes|
|HALITOSIS||Bad Mouth Breath|
|HAPLOTYPES||SNPs (Abbrev.) that travel in groups, & work together to cause a particular drug response|
|HAPTEN||A substance that can react selectively with antibodies of the appropriate specificity but that stimulates the prodn. of these antibodies in an animal only when it is coupled to a carrier|
|HEART ATTACK||Acute Myocardial Infarction.
caused when a blood clot obstructs a coronary artery supplying blood to the heart. This causes an inadequate flow of oxygenated and nutrient-enriched blood and results in the death of a portion of the heart muscle. Symptoms of a heart attack may include: uncomfortable pressure, fullness, squeezing or pain in the center of the chest that lasts for more than a few minutes; pain spreading to the shoulders, neck or arms; and chest discomfort with lightheadedness, fainting, sweating, nausea or shortness of breath. As many as 1.1 million Americans suffer heart attacks each year. Of these, about one-third will die, making heart attack the number one killer of men and women in the United States. About 650,000 of these cases are first attacks while 450,000 are recurrent attacks.
|HEAT DEFLECTION TEMPERATURE||Temperature at which rod made of material in
question shows prescribed deflection when subjected to certain flexural stress under three-point loading
|HECK REACTION||The reaction couples an aromatic halide or anhydride with an alkene in the presence of Pd catalyst to give an aryl alkene.
The reaction couples OrgX with H-Olefin to provide Org-Olefin; Org = aryl, heteroaryl, vinyl, acetylenyl, alkyl, allyl, benzyl, acyl, or benzoyl, or mono- or poly-substituted aryl, heteroaryl, vinyl, acetylenyl, alkyl, allyl, or benzoyl
|HEEL||Industry jargon for the layer of filter cake that is not pushed out of the filtration vessel. In industrial filtration, a stirring bar stirs the slurry while the liquid passes through the filter. After the last of the liquid is gone, the stirring bar pushes the solid out of the vessel. But there is always a layer at the bottom that the stirring bar doesn't reach, & that is the heel|
|HEEL EFFECT (Imaging Diag.)||Phenomen caused by equipment that makes difficult the visualization of small anatomic structures in images|
|HELICASE||An enzyme that binds ahead of the replicating fork in the discontinuous repli
cation of DNA & that catalyzes the energy-
depending unwinding of the duplex. The enzy
me has ATPase activity & hydrolyzes 2 mole
cules of ATP per DNA base pair broken
|HELMINTHOLOGY||The Science of Worms|
|HELPER T LYMPHOCITES (HTL)||The class of T cells that help B cells to proliferate, differentiate, and to synthesize antibodies. They also help stimulate CTL proliferation in a similar fashion|
|HEMATOCRIT||The relative vol. of blood occupied by the erythrocytes & expressedin cubic cm per 100 cc of blood|
|HEMOCHROMATOSIS||Fe Metabolism Disorder, in which the organism absorbs excessively Fe & could lead to death|
|HEMOGLOBINOPATHY||Reduced Affinity of patient's Hemoglobin for Oxygen.|
|HEMOGLOBINOPATHY||Pathological condition characterized by decreased affinity of hemoglobin for Oxygen|
|HEMOLYSIS||Lysis of erythrocytes|
|HEMOPHILIA B||Absence or deficiency of Factor IX & is about one-fifth as common rel. to hemophilia A|
|HEMORRHAGIC STROKE DUE TO CAA||Deposition of amyloid fibrils in the cerebral vasculature can lead to the development of hemorrhagic stroke. Hemorrhagic stroke remains a largely untreatable disease often undiagnosed until autopsy. It ranges in severity from asymptomatic amyloid deposition in otherwise normal cerebral vessels to situations where progressive invasion of the vascular wall by amyloid fibril leads to lobar hemorrhaging. Hemorrhagic stroke due to CAA represents approximately 7 % of all strokes and the incidence will increase as the population ages. Incidentally, some patients who have Alzheimer's Disease may also develop hemorrhagic stroke due to cerebral amyloid angiopathy. This disease is considered the only major type of stroke without either preventive or acute treatment. The only known intervention for hemorrhagic stoke due to cerebral amyloid angiopahty is avoidance of anticoagulants and anti-platelets agents.
Seventy to 80 % of lobar hemorrhages are not fatal in their first occurrence, providing the opportunity for therapeutic intervention. However, recurrent lobar hemorrhages are frequent (10 % per year) and carry high morbidity and mortality rates.
|HEMOSTATIC DEVICES||are used to control bleeding during surgeries to ensure effective closure of surgical wounds and to avoid serious or life-threatening complications which include; blood loss, tissue damage, infection and excessive scarring|
|HEPARIN||Heparin was one of the first biopolymeric drugs and is one of only a few commercial carbohydrate drugs. It is an endogenous polysaccharide, expressed mostly in mast cells (noncirculating white blood cells). Pharmaceutical heparin is isolated from mast cells obtained from pig mucosa.
Heparin is a polydisperse mixture having an average molecular weight corresponding to about 80 saccharide units. Heparin and other HLGAGs are highly variable structurally, in terms of both their sequence and their length.
|HEPAROSANS||Large heparan sulfate precursors. Heparosans are nonsulfated polysaccharides that are less highly charged than heparin or heparan sulfate, making them easier to analyze|
|HEPATORENAL SYNDROME||combined liver and kidney failure; usually caused by serious injury to the liver associated with hemorrhage, chock, and acute renal insufficiency|
|HEREDITARY ANGIOEDEMA||Hereditary angioedema (HAE) is a rare genetic disorder (autosomal dominant) that leads to acute attacks of localized swelling and inflammation. The prevalence of hereditary angioedema is believed to be between 1/10,000 and 1/50,000 people worldwide.
HAE is caused by the deficiency of C1 esterase inhibitor (C1-INH), a molecule that inhibits kallikrein and other serine proteases in the blood. HAE is characterized by acute episodic attacks of edema (swelling) in body parts, most notably the hands, feet, face, and abdomen. In the case of an attack that effects the airway passages, HAE can be life-threatening. Abdominal attacks are often associated with bouts of severe pain, nausea, and vomiting caused by swelling in the intestinal wall.
|HEREDITARY TYROSINEMIA TYPE 1||This disease makes it difficult for the body to break down the amino acid tyrosine, resulting in the formation and accumulation of harmful substances in the body. The disease is usually diagnosed at a young age and in most cases results in the death of the child unless treatment is begun at an early stage.|
|HERNIA||occurs from weakening of the muscular walls (usually of the abdomen/groin area) resulting in the underlying organs protruding through this weakness.|
|HIGH PRODUCTION VOLUME CHEMICALS||Substances made in amount exceeding 1 million lb/year|
|HIGH THROUGHPUT EXPERIMENTATION||"the accelerated completion of two or more experimental stages in a concerted and integrated fashion." High-throughput experimentation incorporates a variety of different technologies, of which combinatorial chemistry is sometimes one.
|HIPPOCAMPAL LTP (See Abbrev.)||Measure of learning & memory function|
|HIRSUTISM||Excessive growth of facial or body hair in women|
|HISTOLOGY||The branch of anatomy that deals with the structure & the properties of tissues, as examined by staining & microscopy|
|HLGAG (Abbrev.)||HLGAGs are made up of disaccharide repeat units containing one glucosamine and one uronic acid. The disaccharide units can be modified at four positions. Two carbon atoms on each glucosamine ring and one carbon on each uronic acid ring can potentially be oxysulfated, and one glucosamine carbon can be either N-acetylated or N-sulfated. Together, these possible modifications lead to the 32 possible disaccharide units found in HLGAGs--making their "information density" considerably higher than that of proteins or DNA|
|HODGKIN'S DISEASE||A malignant disorder characterized by painless, progressive enlargement of lymphoid tissue|
|HOMEOSTASIS||1. The constancy of the internal environment
of an organism; the steady state with res
pect to functions, tissues & fluids of
2. The processes involved in the regulation &
maintenance of the internal environment of
|HORMONE||A regulatory substance that is synthesized by specialized cells of an orga
nisn, that is active at low concn., & that exerts its effect either on all of the cells of the organism or only on certain cells in specific organs. Hormones act by binding to macromolecular receptors that are located either on the cell mem
brane or inside responsive cells. Hormones have three major functions:
(a) A integrative function that deals with the interrelations between different
hormones & with the interrelations between hormones & the nervous sys
tem, the blood flow, the blood pressure & other factors.
(b) A morphogenetic function that deals with the control of the type & rate of
growth of various tissues &
(c) A regulatory function that deals with the maintenance of a constant inter
nal environment with respect to the intra- & extracellular fluids.
An animal hormone is a substance such as protein, peptide or steroid that is secreted principally ny an endocrine gland & that is transported by way of the circulation to target organs or tissues; there the hormone exerts its effect either directly or indirectly & helps to regulate such overall physiological pro
cesses as metabolism, growth, & reproduction.
A plant hormone is an organic compd. that controls growth or some other function at a site removed from its place of prodn. in the plant.
Five major types of plant hormones have been identified:
- Auxin, Cytokinin, Gibberellin, Abscisic acid & Ethylene.
All of the plant hormones are pleiotropic; that is, they have multiple effects
|HPDE (See Abbrevn.)||C6F5-CO-C6H4-O-C6H4-OH|
|HTML DOCUMENT||Document Written in HyperText Markup Language|
|HUMORAL IMMUNITY||Immunity that is due to circulating antibodies in the blood & antibodies secre
ted onto mucous surfaces in contrast to cellular immunity; it involves extrace
llular phases of infection & is associated with B lymphocytes
|HUNTINGTON'S DISEASE||It is a neurological hereditary disease. The neurons of certain brain areas dye, which causes unvoluntary body movements & progressive dementia. Children of father & mother with the disease have a 50% chance of getting the disease.
Generally, the disease manifests itself at 35-40 years age. But in every generation, the disease appears earlier.
At initial stage, the unvoluntary body movements are almost unperceptible. With time, they become more evident. In some cases, they affect all the body; making simple activities like seating & eating difficult.
The mental changes are gradual, starting with irritability & lack of interest in routine activities. Immediately, the patient losses control of his impulses. At the advanced stage, there is total loss of memory.
The genetic mutation responsible for disease was identified in 80's decade. The mutant gene is in chromosome 4
|HYALINE MEMBRANE DISEASE||Respiratory Distress Syndrome in PreMature Infants|
|HYBRIDIZATION||A technique for assessing the extent of sequence homology between single strands of nucleic acids. The technique is based on allowing the polynucleotide strands to form double-helical segments through hydrogen-bonding between complementary base pairs. The greater the extent of complementarity between the strands, the greater is the extent of formation of double-helical segments. The polynucleotide strands may be those of single-stranded nucleic acids or they may be derived from denatured double stranded nucleic acids. The hybrids formed can be of the DNA/DNA, RNA/RNA or DNA/RNA type|
|HYDANTOINASE||Enzyme that converts hydantoins to carbamoyl
|HYDROCARBON SWEETENING||Sulfur Compd Removal Process|
|HYDROCARBYL||Organic Monovalent Group contg. only H & C|
|HYDROCODONE||Narcotic analgesic related to codeine, but more potent and more addicting by weight. It is used also as cough suppressant.
Pharmacological action: analgesics, opioid, antitussive agents, narcotics.
Chemical name: Morphinan-6-one, 4,5-epoxy-3-methoxy-17-methyl
|HYDRODESULFURIZATION (HDS)||Conversion of sulfur-contg molecules (present in heavy crude oil, petroleum) to volatile hydrogen sulfide|
|HYDROGENASE||an enzyme that makes molecular hydrogen from two electrons and two protons|
|HYDROMORPHONE||Synonyms:4,5a-Epoxy-3-hydroxy-17-methylmorphinan-6-one, dihydromorphinone, Dimorphone, Hydromorphone, Morphinan-6-one, 4,5-epoxy-3-hydroxy-17-methyl-, (5.alpha.)-, Novolaudon|
|HYPERALGESIA||An increased response to a stimulus that is normally painful. Please note two considerations. One is the absence of the word noxious in the definition, because of difficulties in its use. The second is the inclusion of some features of allodynia in the definition. Many cases of hyperalgesia have features of allodynia. The term allodynia pertains when there is not an increased response to a stimulus that normally provokes pain. However, when there is also a response of increased pain to a stimulus that normally is painful, hyperalgesia is the appropriate word. With allodynia the stimulus and the response are in different modes, whereas with hyperalgesia they are in the same mode|
|HYPERCALCEMIA||An excess of calcium in the blood; can be caused by cancerous destruction of bone tissue.|
|HYPERCHOLESTEROLEMIA||Genetically inherited metabolic defect in humans that is characterized by elevated levels of plasma cholesterol & by accelerated atherosclerosis; it is caused by a deficiency of functional LDL receptors on cells & surfaces. Due to this deficiency, the entry of cholesterol into cells is impaired, intracellular feedback on cholesterol biosynthesis is lacking, & cholesterol synthesis in the liver & other tissues is excessive. The genetic defects are of 3 types:
(a) Lack of receptors for LDL & hence no binding of LDL
(b) Decreased binding of LDL to the receptors
(c) Normal binding of LDL to the receptors but no internalization of LDL
|HYPEREOSINOPHILIC SYNDROME||The precise cause or trigger for HES in patients who donít have the FIP1L1/PDGFRA gene mutation is often unknown. Some patients, however, have been shown to have an increased number of abnormal T-lymphocytes, a type of immune blood cell, which produce high levels of interleukin-5.
While there is no cure and the clinical effects of HES can vary greatly from patient to patient, the disease is often managed long term with a combination of drugs frequently including corticosteroids, such as prednisone.
|HYPERINSULINEMIA||See COMPENSATORY HYPERINSULINEMIA|
|HYPERPHENYLALANINEMIA||Disorders of phenylalanine (Phe) metabolism can lead to abnormal elevations of blood Phe levels, also called hyperphenylalaninemia (HPA). Two inborn errors of metabolism, phenylketonuria (PKU) and tetrahydrobiopterin (BH4) deficiency, account for the majority of cases of HPA|
|HYPERPHOSPHATEMIA||The presence of excessive amounts of phosphate in blood|
|HYPERURICEMIA||Hyperuricemia (abnormal elevation of serum uric acid levels) is the single most common abnormality seen in patients with TLS who develop severe metabolic abnormalities which may lead to acute renal failure. Ultimately, if left untreated, hyperuricemia and TLS can lead to acute kidney failure7,11.
Destroyed tumor cells release their intracellular contents, inducing electrolytes, nucleic acids, proteins, and their metabolites into the circulation at a more rapid rate than the kidneys are able to remove them, leading to metabolic abnormalities that can cause renal failure2. The purines released undergo accelerated catabolism, resulting in increased uric acid,8 which is soluble at physiologic pH (7.4). At acidic pH, uric acid crystals can form and deposit in the kidneys, joints, and other soft tissues. When uric acid crystals form in the renal tubules and collecting ducts, where the normal urine pH is around 5.0, obstruction, inflammation, and/or damage to the kidney tissues may occur.10 When uric acid crystals deposit in the joints, they can cause joint pain and inflammation.10
|HYPOCHOLESTEROLEMIA||A deficiency of cholesterol in the blood|
|HYPONATREMIA||decreased concentration of sodium in the blood|
|HYPOTHALAMUS||Basal part of the brain|
|HYPOXIA||Low Oxygen Concn.|