R

RACEMIC SWITCH The switch of racemic compd (usually in Pharma. industry) to enantiomeric compd; accompanied with improved properties such as higher therapeutic activity (requiring lesser dosages), better bioavailability, lesser toxic side effects etc.
Strategy also used to prolong Patent's Lifetime
RADIOCHEMISTRY the part of chemistry that deals with radioactive materials, including the production of radionuclides and their decay products
RADIOIMMUNOTHERAPY Biotargeted radiopharmaceuticals
RADIOISOTOPE a metalic radioisotope that enables diagnostic imaging and/or radiotherapy
RADIOMETAL a metalic radioisotope that enables diagnostic imaging and/or radiotherapy
RADIOPHARMACEUTICAL a radioactively tagged pharmaceutical
RADOMES Missile nose cones
RAF KINASE the oncogene raf encodes three serine and threonine-specific protein kinases, calledraf-1 ( c-raf), A-raf ( orraf-A ) andB-raf ( orraf-B ) that are localized in the cytoplasm.

c-raf-1 is the cellular homologue of v-raf, an oncogene found in the acute transforming replication- defective type C murine sarcoma virus 3661. Themil oncogene , a second oncogene in the avian retrovirus MH2, which contains the myc oncogene , is the avian equivalent of the murine raf oncogene . The raf-1 gene maps to human chromosome 3p25; raf-2 is a processed pseudogene on human chromosome 4pter-p15.

raf-1 is a protein of 70-75 kDa that is expressed in all organs and cell lines. raf-A and raf-B are expressed in urogenital tissues and brain, respectively.

Activated raf-1 expresses a constitutive protein kinase and functions as an intracellular activator of cell growth. A revertant cell line, generated from v-raf-transformed 3T3 fibroblasts has been found to be deficient in the induction of ERG (Early response gene ) by serum and Phorbol esters . This oncogene is important, therefore, for the regulation of some responses mediated by these stimuli.

Several cytokines have been shown to induce the synthesis of raf-1 kinase, including PDGF , M-CSF , GM-CSF , EGF , IL2 and IL3 . The activation of raf kinase, for example by the protein kinase activity of the intracellular domain of the EGF receptor eventually activates the transcription of genes, among them also cytokine genes with promoters that contain the binding site for transcription factor AP-1/PEA3 (see: jun ).

An activated raf gene has been identified in the stomach cancer of a Japanese patient and there is some evidence for a relationship of raf-1 to renal cell carcinoma. A radiation-resistant laryngeal carcinoma cell line has been shown also to contain altered raf-1 sequences. The transforming DNA in a human glioblastoma line has been found to be identical with the raf gene
RANDOM ACCESS MEMORY Pronounced ramm, acronym for random access memory, a type of computer memory that can be accessed randomly; that is, any byte of memory can be accessed without touching the preceding bytes. RAM is the most common type of memory found in computers and other devices, such as printers.

There are two different types of RAM: DRAM (Dynamic Random Access Memory) and SRAM (Static Random Access Memory). The two types differ in the technology they use to hold data, with DRAM being the more common type. In terms of speed, SRAM is faster. DRAM needs to be refreshed thousands of times per second while SRAM does not need to be refreshed, which is what makes it faster than DRAM. DRAM supports access times of about 60 nanoseconds, SRAM can give access times as low as 10 nanoseconds. Despite SRAM being faster, it's not as commonly used as DRAM because it's so much more expensive. Both types of RAM are volatile, meaning that they lose their contents when the power is turned off.

In common usage, the term RAM is synonymous with main memory, the memory available to programs. For example, a computer with 8MB RAM has approximately 8 million bytes of memory that programs can use. In contrast, ROM (read-only memory) refers to special memory used to store programs that boot the computer and perform diagnostics. Most personal computers have a small amount of ROM (a few thousand bytes). In fact, both types of memory (ROM and RAM) allow random access. To be precise, therefore, RAM should be referred to as read/write RAM and ROM as read-only RAM.

See the "DRAM Memory Guide" in the Quick Reference section of Webopedia. This Webopedia Quick Reference offers general information on the two types of RAM and provide an overview on the common modules of each type.

RAYNAUD'S DISEASE Blood Circulation Disorder affecting mainly the hands. Characterized by pain & tendency to color change. Disease is caused by external inflences like cold, Humidity, Vibration, Nicotin usage leading to tissue inflammation
RAYNAUD'S PHENOMEN In Raynaud's phenomenon, exposure to the cold or strong emotions trigger blood vessel spasms that result in interruption of blood flow to the fingers, toes, ears, and nose. Raynaud's phenomenon can occur without any other associated symptoms or disease
REBOXETINE 2-(I-((2-ethoxyphenoxy)benzyl)-morpholine [NARI (Abbrev.)]
RECESSIVE DYSTROPHIC EPIDERMOLYSIS BULLOSA RDEB, the most severe form of Epidermolysis Bullosa (EB), is a devastating congenital skin disorder characterized by painful ulcerations and widespread, permanent scarring resulting in deformity of the hands and feet. As a result, many RDEB patients require repeated surgeries, resulting in a need for replacement skin, to allow greater use of their extremities
RENIN A proteolytic enzyme produced by the kidney that has hormone-like properties & catalyzes the conversion og angiotensinogen to angiotensin I
RESIDUAL FUEL Fuel composed mainly of materials remaining
as unevaporated after distn. of crude oil
RESPIRATORY BURST Neutrophils serve as the body's primary cellular defense against bacterial infection. One of the mechanisms by which neutrophils destroy invading microorganisms is through the generation of various toxic oxygen metabolites via the so-called "respiratory burst" (Babior, NEJM 298: 659-668 (1978)). "Respiratory burst" is the name given the phenomenon that occurs when neutrophils undergo a large burst in respiration in which oxygen is converted to superoxide anion (O.sub.2 -), the initial product of the respiratory burst. Superoxide anion is generated by an NADPH oxidase found in neutrophils and other phagocytes (Babior, supra (1978; Clark, J. Infect. Dis. 161 : 1140-7 (1990)). This "enzyme" is actually a miniature electron transport chain consisting of multiple plasma membrane- and cytosollocalized protein components. The oxidase is apparently dormant in resting neutrophils, but acquires catalytic activity when the cells are stimulated. (See Curnutte, et al., J. Biol. Chem. 262: 6450-2 (1987).) This dramatic increase in oxidative metabolism triggered by phagocytosis or exposure to certain inflammatory mediators is also characteristic of mononuclear phagocytes and eosinophils, but it is best understood in neutrophils. (See Clark, J. Infect. Dis. 161: 1140-7 (1990).)

RESTENOSIS Vascular Artery Wall Injury occurring after Coronary Angioplasty
RESTLESS LEG SYNDROME RLS are also called (nocturnal) myoclonus, which describes frequent or involuntary muscle spasms. Restless Leg Syndrome
Restless leg syndrome was described as early as the 16th century but was not studied until the 1940s. People with RLS complain of an irresistible urge to move their legs while at rest. A person with RLS will experience a vague, uncomfortable feeling while at rest that is only relieved by moving the legs. The symptoms of RLS may be present all day long, making it difficult for an individual to sit motionless. Or they may be present only in the late evening. Late evening symptoms can lead to sleep onset insomnia, which tends to compound the effects of RLS. Pregnancy, uremia, and post-surgery conditions have also been known to increase the incidence of RLS. And, surprisingly, fever seems to decrease it.

Although one study found RLS to be most prevalent in middle-aged females, its incidence increases with age.

Restless leg syndrome is estimated to affect 5% of the population. Approximately 80% of people with RLS have PLMD, though most people with PLMD do not experience RLS.
RETARDATION FILM (LCD) The retardation film corrects birefringence, which is generated through the process of light passing through liquid crystal, to eliminate optical distortion of light. The products expand the angle of view field and brightness required for wide size television with LCD.

RETENTATE IN ALL FOUR TYPES of membrane filtration, the liquid that passes through the membrane is known as the permeate, and the material that does not pass through is called the retentate. The membranes are made of a variety of materials, including polymers, ceramics, and metals. They are usually manufactured as flat sheets mounted on supports or as spiral-wound or tubular modules
RETROSYNTHETIC ANALYSIS the logical deconstruction of molecules to be synthesized into simpler and simpler precursors until simple or commercially available compounds are obtained. Developed in the 1960s, the method systematized the way chemists designed syntheses. At the time, when syntheses were planned on the basis of trial and error, assumed starting points, or inexplicable insights, the concept was radical
RETT SYNDROME Is a progressive neurodevelopmental disorder that occurs almost exclusively in girls. The disease is named for ANDREAS RETT, an Austrian physician who first described the condition in 1966. It became known world
wide 2 decades later following publication of a report describing 35 affected girls from Sweden, Portugal & France.
Infants & children with Rett syndrome develop normally until they are 6-18 months old. Then these children hit a wall. They stop learning new skills & gradually or suddenly lose the ability to do things that they had already learned to do - such as controlling their hands, speaking, & walking. Purposeful hand use is gradually replaced by repetitive, uncontrolled hand movements including clapping or "washing & wringing" motions. Children may also develop autistic symptoms like decreased eye contact & inattentive behavior, impaired walking & trunk movement, severe motor apraxia (the inability to plan movement), as well as breathing trouble, seizures, swallowing difficulties, & a cognitive decline. Severe scoliosis & muscle wasting often land the firls in wheelchairs.
These symptoms tend to worsen, but when the child is older, say 2-10 years old, the regression stops & the symptoms become rel. stable. Some improvement in communication skills may also be achieved & continue into adulthood. But many of those with Rett syndrome remain in this stage of stabilization. It is a devastating diagnosis.
The disorder is seen in every ethnic & geographic population worldwide. Although it remains underrecognized, Rett syndrome is thought to be a leading cause of progressive neurodevelopmental impairment in females. The frequency of the disorder appears to vary among different populations & geographic regions, ranging from an estimated 1 in 10,000-20,000 female births. There is evidence that males with the genetic mutation die before birth.
More than 99% of those affected have no history of Rett syndrome in their family.
There is no cure. Therapies to improve the quality of life of girls with Rett remain elusive.
Update: 12.00
REVERSE TRANSCRIPTASE An RNA-dependent DNA polymerase that catalyzes the synthesis of DNA from deoxyribonucleoside-5'-triphosphates, using RNA as a template. The enzyme has been found in retroviruses & in some other viruses. The reaction catalyzed by the enzyme is in contradiction to the flow of genetic information described by the original central dogma of molecular biology: DNA to RNA to Protein.
The enzyme actually has three enzymatic activities:
(1) It copies a single-stranded RNA mole. to yield a double-stranded
DNA-RNA hybrid
(2) It copies a single-stranded DNA mole. to yield a double-stranded DNA
mole.
(3) It degrades the RNA in DNA-RNA hybrid (this is called its ribonuclease
H, RNAase H, activity)
REVERSE CHEMICAL GENETICS Geneticists have recently developed a new strategy, often called "reverse genetics", involving gene knockouts. Mutations are used on a specific, previously identified gene to create & study a biological system in which that gene is no longer expressed.
In a paralell manner, the strategy of reverse chemical genetics involves finding small molecules that will bind to and/or disrupt the function of pure proteins in vitro. The small molecules are then used to study the effects of deleting the function of that specific protein in a cell or organism.
To use the lock-and-key metaphor, reverse chemical genetics involves starting with a specific lock & door you have already identified (i.e., you already have your target protein). Then you try a very wide range of keys in order to find one that fits. Once you have found one that fits, you open the door & see what you can discover
REVERSE ENGG. is the process of taking 3D scan data from a physical object to create a robust CAD format consequently giving the capability to re-engineer (modify or update) the part.
REVERSE LIPID TRANSPORT The RLT pathway is a four-step process responsible for removing excess cholesterol and other lipids from the walls of arteries and other tissues, and transporting them to the liver for elimination from the body. The first step is the removal of cholesterol from the walls of arteries by HDL in a process called "cholesterol removal". In the second step, cholesterol is converted to a new form that is more tightly associated with HDL as it is carried in the blood; this process is called "cholesterol conversion". The third step is the transport and delivery of that converted cholesterol to the liver in a process called "cholesterol transport". The final step is the transformation and discarding of cholesterol by the liver in a process known as "cholesterol elimination". We believe our product candidates have the potential to enhance the effectiveness of these four steps in the RLT pathway in humans.

In a healthy human body, there is a balance between the delivery and removal of cholesterol. Over time, however, an imbalance can occur in our bodies in which there is too much cholesterol delivery by LDL and too little removal by HDL. When people have a high level of LDL-cholesterol, or LDL-C, and a low level of HDL-C, the imbalance results in more cholesterol being deposited in arterial walls than being removed. This imbalance can also be exaggerated by, among other factors, age, gender, high blood pressure, smoking, diabetes, obesity, genetic factors, physical inactivity and consumption of a high fat diet. The excess cholesterol carried in the blood in LDL particles can be deposited throughout the body, but can frequently end up in the arterial walls, especially those found in the heart. As a consequence, repeated deposits of cholesterol called plaque can form and possibly narrow the arteries, which may lead to acute chest pain (i.e. angina) or a heart attack. These are known as the "acute coronary syndromes".

REVERSE OSMOSIS And reverse osmosis, which employs membranes with the smallest pore sizes, is a high-pressure water-removing process that is widely used to purify wastewater and desalinate seawater
REVERSE TRANSCRIPTASE INHIBITORS Interfere with conversion of viral RNA to DNA
REVERSE TRANSCRIPTION The reaction catalyzed by the enzyme reverse transcriptase
REVERSE TRANSFECTION Technology platform extends upon a routine laboratory technique called transfection. Transfection involves the introduction of foreign nucleic acids (e.g. siRNA or DNA) into a cell to study their effect on cellular networks and pathways. In conventional transfection, scientists add a solution containing siRNA or DNA and a transfection reagent onto cells growing in a petri dish or small vessel known as a microwell, and the foreign nucleic acids are subsequently taken up by the cell. Reverse transfection technology uses a microwell surface coated with foreign siRNA or DNA and adds cells to the coated surface rather than vice versa. This reduces the time, labor and amount of expensive reagents required for experiments and greatly increases the number of targets that can be examined.
RIBONOMICS has been used to describe the subset of mRNAs that bind with proteins
RIBOPROTEOMICS The study of RNA-protein interactions
RIBOSOMAL SUBUNIT One of the two ribonucleoprotein particles that make up the complete ribosome; the 30S or the 50S particle in bacteria, the 40S or the 60S particle in plant & animal cells
RIBOZYME A catalytic RNA segment that has the ability to break & form covalent bonds
RING CLOSING METATHESIS (CH2=CH)2-(CH2)n = CycloOlefin (n+2 C)+Ethy
lene
RING OPENING METATHESIS CycloOlefin (n CH2)+CH2=CHR = CH2=CH-(CH2)n-
CH=CH-R
RING OPENING METATHESIS POLYMN. n CycloOlefin (m CH2) = [=CH-(CH2)m=]n
RINGER'S SOLUTION isotonic saline solution comprising 0.86 gm of NaCl, 0.03 gm of KCl, and 0.033 gm of CaCl.sub.2 in 100 ml of purified water.

RLT PATHWAY The cardiovascular system is comprised of the heart and blood vessels and delivers oxygen and other nutrients to the tissues and organs of the body, such as the brain, kidneys and lungs; in addition, it is able to remove waste products. The heart propels blood through a network of arteries and veins. The kidneys regulate blood volume, and the lungs put oxygen in the blood and remove carbon dioxide. To accomplish these tasks, the cardiovascular system must maintain adequate blood flow, which can be dramatically reduced by the excessive deposit of a fat, or lipid, called "cholesterol" within the artery walls. Cholesterol is essential for normal cell function. Our bodies obtain cholesterol both through the foods we eat and by manufacturing cholesterol inside some of our cells and organs. Cholesterol either remains within the cell or is transported by the blood to various organs. The major carriers for cholesterol in the blood are known as lipoproteins, which are particles composed of fat and protein, including low-density lipoprotein, or LDL, and high-density lipoprotein, or HDL. LDL delivers cholesterol to organs where it can be used to produce hormones, maintain healthy cells or be transformed into natural products that assist in the digestion of other lipids. HDL removes excess cholesterol from arteries and tissues to transport it back to the liver for elimination.



The RLT pathway is a four-step process responsible for removing excess cholesterol and other lipids from the walls of arteries and other tissues, and transporting them to the liver for elimination from the body. The first step is the removal of cholesterol from the walls of arteries by HDL in a process called "cholesterol removal". In the second step, cholesterol is converted to a new form that is more tightly associated with HDL as it is carried in the blood; this process is called "cholesterol conversion". The third step is the transport and delivery of that converted cholesterol to the liver in a process called "cholesterol transport". The final step is the transformation and discarding of cholesterol by the liver in a process known as "cholesterol elimination". We believe our product candidates have the potential to enhance the effectiveness of these four steps in the RLT pathway in humans.



In a healthy human body, there is a balance between the delivery and removal of cholesterol. Over time, however, an imbalance can occur in our bodies in which there is too much cholesterol delivery by LDL and too little removal by HDL. When people have a high level of LDL-cholesterol, or LDL-C, and a low level of HDL-C, the imbalance results in more cholesterol being deposited in arterial walls than being removed. This imbalance can also be exaggerated by, among other factors, age, gender, high blood pressure, smoking, diabetes, obesity, genetic factors, physical inactivity and consumption of a high fat diet. The excess cholesterol carried in the blood in LDL particles can be deposited throughout the body, but can frequently end up in the arterial walls, especially those found in the heart. As a consequence, repeated deposits of cholesterol called plaque can form and possibly narrow the arteries, which may lead to acute chest pain (i.e. angina) or a heart attack. These are known as the "acute coronary syndromes".


RNA APTAMER protein-binding oligonucleotide
RNA INTERFERENCE In this process, short pieces of double-stranded RNA are incorporated into a protein complex known as the RNA-induced silencing complex (RISC), which catalyzes the cleavage of messenger RNA and thus suppresses gene expression.
ROCHOW REACTION Alkyl or Aryl Halide + Si = OrganoHaloSilane
ROMP (Abbrev.) GELS (CombiChem) soluble or insoluble oligomeric or polymeric reagents and scavengers that can be used in combinatorial synthesis.
RSS EDITOR is a software application for writing and editing RSS feeds offline (i.e. on the local computer)
RUMEN Is the section of the bovine stomach where the first round of digestion takes place