By X. Zarkos. Pennsylvania State University, Worthington Scranton.
One method by which mucus protects the nasal epithelium is by acting as a physical barrier and respiratory mucus has been reported to retard the diffusion of water and a range of β-lactam antibiotics used to treat respiratory infections florinef 0.1mg with visa gastritis hiv. However generic florinef 0.1mg line gastritis eating before bed, other studies have shown that antibodies (150–970 kDa) are able to diffuse through cervical mucus relatively unimpeded; these latter studies tend to suggest that the diffusion barrier presented by mucus in the nasal cavity would be insignificant. Positively charged drug molecules can bind to mucus glycoproteins via electrostatic interactions with the large number of negatively charged sialic acid and sulfate ester residues. Such residues have low pKa values and are thus ionized under most physiological conditions. Hydrogen-bonding is also possible, between drugs and the hydroxyl groups on the sugars and other O- and N-containing groups on the protein backbone. Hydrophobic interactions between drugs and a globular protein region of the glycoprotein molecule can also occur. Tetracycline has been shown to bind to gastrointestinal mucus by hydrogen-bonding and via electrostatic and hydrophobic interactions. It has been suggested that cephaloridine and gentamicin bind intestinal mucin via ionic interactions. As has been stressed for all the transepithelial routes in this book, it is important to remember that although a drug molecule may be predominantly absorbed via one particular route/mechanism, it is also likely that sub-optimal transport will occur via alternative routes and mechanisms. Passive diffusion between the cells is driven by a concentration gradient, with the rate of absorption governed by Fick’s first law of diffusion (see Section 1. Again, movement occurs down a concentration gradient, according to Fick’s first law of diffusion (see Section 1. The degree of ionization of a drug species is an important property for absorption via passive transcellular diffusion (see Section 1. Carrier-mediated processes Active transport mechanisms for di- and tri-peptides, as well as L-amino acids, have been demonstrated in the nasal epithelium. Endocytic processes Most compounds of interest for nasal delivery have a molecular weight in excess of 1,000 Da and until recently were thought to cross the cells endocytically. These factors influence the mechanism and rate of drug absorption through the nasal epithelium. For nasal drug delivery, it has been suggested that two mechanisms of absorption exist, based on the physicochemical properties of the drug: • a fast rate, which is dependent on the lipophilicity of the drug; • a slower rate, which is dependent on molecular weight. Thus, lipophilic drugs such as propanolol, progesterone, 17β-œstradiol, naloxone and testosterone are absorbed rapidly and completely from the nasal cavity. In contrast, their oral bioavailabilities range from 25% for propranolol to less than 1% for progesterone. As such, the rate of absorption will be affected by the concentration of drug in solution at the absorbing membrane. The higher the drug concentration, the steeper the concentration gradient driving the absorption process and the faster the drug will be absorbed. Therefore if the drug is formulated as a solution, the highest concentration possible should be chosen that is compatible with an accurate and reproducible dosing volume. However, care must be taken, as high local drug concentrations over extended periods of time may also cause severe local irritation or adverse tissue reactions. For absorption of aerosol formulations, deposition of the aerosol must occur followed by dissolution of solid particles if applicable. The extent and site of deposition of an aerosol from a nasal spray will depend upon: • the aerodynamic diameter of the particle (which is also a function of droplet size, shape and density); • the particle charge (which might also depend on the drug, formulation excipients and method of aerosolization); • the velocity at which the particle is moving (which depends on respiratory patterns). In general, particles or droplets in the size range 5–10 μm tend to deposit in the nasal passages.
Because of the non-covalent interaction between glucose and Con A best florinef 0.1mg gastritis atrophic symptoms, the formed cross-links are reversible (Figure 16 order 0.1mg florinef gastritis questionnaire. Individual free glucose molecules can compete with the polymer- attached glucose molecules. Thus, the maintenance of the cross-links depends on the relative concentration of free glucose in the environment. The gel is formed by mixing glucose-containing polymers with Con A in the absence of external glucose. In the presence of elevated glucose levels in solution, however, the gel becomes a sol (i. As the environmental glucose level decreases again, the competition of free glucose against the polymer-bound glucose decreases and thus the gel is formed again. It has been shown that diffusion of insulin is much slower in the gel state than in the sol state, and insulin release can be controlled as a function of the glucose concentration in the environment. Glucose-sensitive phase-reversible hydrogels can also be prepared without using Con A. Glucose, having pendant hydroxyl groups, competes with polyol polymers for the borate groups. Thus, as the glucose concentration increases, the cross-linking density of the gel decreases and the gel swells to release more insulin. The glucose exchange reaction is reversible, and borate-polyol cross-linking is re-formed at a lower glucose concentration. Instead of long chain polyol polymers, shorter molecules, such as diglucosylhexanediamine, can be used as a cross-linking agent. Since the phenylboronic acid gel is sensitive to glucose only at alkaline conditions (pH ≥ 9), various copolymers containing phenylboronic acid were synthesized to provide glucose sensitivity at physiological pH. All the components of the system in the sol state are essentially in the dissolved state, and thus they can be released to the environment in the absence of protecting membranes. During the process of gel to sol transition by the addition of glucose, the incorporated insulin can be released as a function of glucose concentration. There are of course other polymeric systems which can be used in glucose-sensitive erodible insulin delivery. Small closed and open circles represent a polymer-attached glucose and a free glucose, respectively. Diffusion of insulin through the solution (sol) can be an order of magnitude faster than that through the hydrogel (gel) As discussed in Section 16. The uniqueness of poly (N,N′- dimethylaminoethyl methacrylate and ethylacrylamide) is that the critical transition temperature increases as the polymer becomes ionized (i. Thus, the insoluble polymer matrix at a certain temperature becomes water-soluble as the pH of the environment becomes lower. This unique property has been used for glucose-controlled insulin release as illustrated in Figure 16. In the presence of glucose, gluconic acid generated by glucose oxidase protonates dimethylamino groups of the polymer. This induces shift of the critical transition temperature to a higher temperature for the polymers at the surface of the insulin-loaded polymer matrix. This leads to the dissolution of the polymer from the surface and thus the release of insulin. An erodible matrix system based on the shift of the critical transition temperature can also be made using polymers containing phenylboronic acid groups. Poly(N,N-dimethylacrylamide-co-3- (acrylamido)phenylboronic acid) shifts its critical transition temperature in response to changes in glucose concentration.
It is used as a bulk substance in foods and laxatives and as an adhesive or emulsifier Methylphenidate hydrochloride - a drug that is chemically related to amphetamine order florinef 0.1mg visa chronic gastritis juice. It is used in treating narcolepsy and attention deficit disorder Microorganisms – a living organism too small to be perceived with the naked eye buy 0.1 mg florinef mastercard gastritis what not to eat, especially a virus, bacterium, fungus, protozoan, or intracellular, parasite, and some helminths Micturition – the voiding of urine Miosis – abnormal contraction of the pupil, period of distinguishing symptoms in a disease, method of cell division which allows each daughter nucleus to receive half the number of chromosomes present in the somatic cell Mitochondrial – cell organelles or rod or oval shape. Nonselective versions of these medications produced hypertensive crisis and other severe side effects when they were taken with tyramine-containing foods (some cheeses) and several other drugs. Newer members of this class of drugs do not have these effects, but should be used with caution, especially in persons who take selective reuptake inhibitors Mononucleosis – presence of an abnormally high number of mononuclear leukocytes in the blood. An acute infectious disease caused by the Epstein Barr virus, a member of the herpes virus group. The virus is transmitted through the saliva with an incubation period of 30 to 45 days. Symptoms include a gradual onset of 7 to 14 days of flu like symptoms including a severe sore throat, fatigue, headache, chest pain, and myalgia. Findings include enlarged lymph nodes, exudative tonsillitis, and an enlarged spleen. It is caused by antibodies to the acetylcholine receptor in the neuromuscular junction and a decrease in receptor sites for acetylcholine. Because the smallest concentration of acetylcholine receptors in the body is in the cranial nerves, weakness and fatigue of the eye muscles, muscles of mastication, and pharyngeal muscles are the most prominently affected in most patients. The disease is rare, affecting about 60 persons out of one million Mydriasis – abnormal dilatation of the pupil like fright, sudden emotion, anemia, anesthesia, drugs, coma, hysteria, botulism irritation of cervical sympathetic nerve Myelosuppressive – inhibition of bone marrow function Myelotoxicity – destroying bone marrow; pertaining to or arising from diseased bone marrow Myocardial – pertaining to the heart muscle Myocarditis – inflammation of heart muscle, usually as a consequence of infections Myoclonus – twitching or clonic spasm of a muscle or group of muscles, condition marked by persistent and continuous muscular spasms Myopia – defect in vision so that objects can only be seen distinctly when very close to the eyes, nearsightedness Myxedema – infiltration of the skin by mucopolysaccharides, giving it a waxy or coarsened appearance. The clinical 424 and metabolic manifestations of hypothyroidism in adults, adolescents and children are complaints of sluggishness, cold intolerance, apathy, fatigue and constipation. Findings may include infiltration of the subcutaneous layers of the skin by mucopolysaccharides, which coarsen the features and create nonpitting edema. If the syndrome is left untreated, hypothermia, coma, and death may result N Narcolepsy – a disorder marked by recurrent, uncontrollable attacks of daytime sleepiness, often associated with temporary muscular paralysis (cataplexy) that may occur after powerful emotional experiences. Typically, narcoleptic patients arouse from sleep relatively easily Narcotic – producing stupor or sleep, a drug which in moderate doses depress the central nervous system thus relieving pain and producing sleep, but which in excessive doses produces unconsciousness, stupor, coma, and possibly death Nasopharyngitis – inflammation of the nasopharynx (throat/part of the pharynx situated above the soft palate) Necrolysis – necrosis and dissolution of tissue – death of cells, tissues or organs Necrosis – deaths of areas of tissue surrounded by healthy parts, a gradual degeneration caused by blood supply to the area, physical agents such as trauma, radiant energy or products (toxins) of bacteria Neonates – a newborn infant up to 1 month of age Nephrolithiasis – a disorder characterized by the presence of calculi (stones) in the kidney Nephrotoxic – a specific toxin (poison), which destroys renal (kidney) cells Nerve terminal – a small nerve originating in the cerebral hemisphere in the region st of the olfactory trigone, the 1 cranial nerve. The terminal nerve courses anteriorly (in front of) along the olfactory tract and passes through the ethmoid bone. Most filaments of the nerve form a single strand, which passes to the membrane near the anterior superior border of the nasal septum and communicates in the nasal cavity with the ophthalmic division of the trigeminal nerve. The central communications of the terminal nerve end in the septal nuclei, the olfactory lobe, and the posterior commissural and supraoptic regions of the brain Neuralgia – severe pain along the course of a nerve due to pressure on nerve trunks, faulty nerve nutrition, toxins, neuritis, usually no changes can be detected 425 Neuroleptic – a condition of the nervous system, exhaustion of a nerve or nerves from prolonged stimulation, stretching of a nerve to relieve tension, loosening of adhesions surrounding a nerve, disintegration of nerve tissue Neuromuscular – concerning the nerves and muscles Neuroma – former term for any type of tumor composed of nerve cells. Classification is now made with respect to the specific portion of the nerve involved Neuron – a nerve cell, the structural and functional unit of the nervous system, consisting of a cell body and its processes, an axon and one or more dendrites, neurons function in the initiation and conduction of impulses Neurosis – also called psychoneurosis, a disorder of the thought processes not due to demonstrable disease of the structure of the central nervous system, probably due to unresolved internal conflicts which make for an uneasy adjustment in life, contact with reality is maintained which is not the case in psychosis, the neuroses are classified as fatigue, simple nervousness (anxiety), phobic, obsessive compulsive, hysteria, hypochondrial, reactive depression, the disease rarely occurs in one of these pure forms, thus most neurotic persons would be classes as having mixed psychoneuroses Neurosyphillis – an infection of the central nervous system by syphilis organisms, which may invade the meninges and cerebrovascular system. If the brain tissue is affected by the disease, general paresis may result; if the spinal cord is infected, tabes dorsalis (an abnormal condition characterized by the slow degeneration of all or part of the body and the progressive loss of peripherial reflexes) may result Neutropenia – the presence of an abnormally small number of neutrophils (a white blood cell) in the blood. Severely low levels predispose patients to infection Neurotoxicity – having the capability to be poisonous or harmful to the nerve cells Neutropenia – abnormally small number neutrophil (white blood cell) cells in the blood Neutrotransmitter – a substance (norepinephrine, acetylcholine, dopamine) that is released when the axon terminals of a presynaptic neuron is excited and acts by inhibiting or exciting a target cell. Many patients experience side effects of these medications, including upper gastrointestinal inflammation or bleeding. These side effects occur most often in elderly people, tobacco users, and people who drink alcohol. Other potential complications include acute and chronic renal failure, liver function abnormalities, and aseptic meningitis Norepinephrine – a hormone produced by the adrenal gland similar in chemical and pharmalogical, properties to epinephrine but is chiefly a vasoconstrictor and has little effect on cardiac output Nucleic acid – any one of a group of high-molecular weight chemicals that carry the genetic information crucial to the replication of cells and the manufacturing of cellular proteins. They have a complex structure formed of sugars, phorphoric acid, and nitrogen bases. The hallmarks of the disease are thickening, scaling, and discoloration of the nailbed.
These ques- from a common database buy generic florinef 0.1mg gastritis eating plan, and therefore there is some tions are all different than those in the book buy florinef 0.1 mg lowest price gastritis diet journal printable, and will overlap between the questions used. The examination is give you exposure to many more based on interpreting constructed so that the number of questions in each photomicrographs. Set aside an allotted time period certification examinations is normalized in order to min- of at least 1 hour each day when you are alert and can stay imize the variance between examinations. Introduction xv Assemble all of your study materials before you begin special activity that you may have planned as a reward for your review. At this point, you tendency to “give up” looking for needed materials, if you have successfully completed a rigorous course of classroom do not have them readily available. Therefore, you may and clinical training and the examination represents neglect or not study a major content area. Choose a quiet, comfort- that you have adequately practiced and prepared for the able area for your study. Re- During the Exam gardless of your study plan, you should take some portion Read all directions. Make sure you understand how to of the review process, for example, the mock examination, take the examination. Accept the question as you first read it; should be timed, uninterrupted, and designed to observe do not read your own thoughts into the question and do realistic testing practices. You may wish to mentally place a T for A few days before the exam, be sure to again read true or an F for false beside each alternative, or to reject through the instructions sent to you by the certification outright obviously wrong choices. Answer all of the ques- grammable calculators) may be prohibited and you should tions. There is no penalty for guessing on certification know what you can and cannot bring with you. Always answer to the best of your ability your travel arrangements and familiarize yourself with the first time. Choose Eat properly and, if possible, engage in some light physical one of the longest answers. Dress comfortably with layered clothing that you may re- Do not overlook words such as not, never, always, most, move, if the examination room is too warm. Statements that contain unquali- you bring two forms of signed identification including fied absolutes (always, never) are usually incorrect. Do not panic if you do them must match the name on your letter of admission not know an answer. Continue the test and do not allow to the exam that you should also have with you. Do Work steadily and do not spend too much time on not take notes or books with you. Try pared prior to the examination day, you will not succeed to pace yourself so that sufficient time remains after com- by trying to cram last-minute facts. Do not ious before or during the exam, close your eyes and change your original answer unless you are certain that you breathe deeply for a few seconds. All of these options, depending on the patient volume of packed cells, will increase. A A mature erythrocyte is approximately 7–8 μm in procedures/Microscopic morphology/Diﬀerential/2 diameter. Variation in red cell size observed on the indicates increased central pallor in erythrocytes, and peripheral smear is described as: poikilocytosis denotes variation in red cell shape.
9 of 10 - Review by X. Zarkos
Votes: 338 votes
Total customer reviews: 338