Monday, February 16, 2009
Possible Modes of Drug Distribution
Further subdivisions are shown inthe table.The volume ratio interstitial: intra-cellular water varies with age and bodyweight. On a percentage basis, intersti-tial fluid volume is large in premature ornormal neonates (up to 50 % of bodywater), and smaller in the obese and theaged.The concentration of a solutioncorresponds to the amount of sub-stance dissolved in a volume; thus, c= D/V. If the dose of drug and itsplasma concentrationare known, avolume of distributioncan be calcu-lated from V = D/c. However, this repre-sents an apparent volume of distribu-tion (Vapp), because an even distributionin the body is assumed in its calculation.Homogeneous distribution will not oc-cur if drugs are bound to cell mem-branes or to membranes of intracel-lular organelles or are stored withinthe latter. In these cases, Vapp can ex-ceed the actual size of the available fluidvolume. The significance of Vapp as apharmacokinetic parameter is dis-cussed.
Having entered the blood, drugs maybind to the protein molecules that arepresent in abundance, resulting in theformation of drug-protein complexes.Protein binding involves primarily al-bumin and, to a lesser extent, lins and acidic glycoproteins. Otherplasma proteins (e.g., transcortin, trans-ferrin, thyroxin-binding globulin) servespecialized functions in connectionwith specific substances. The degree ofbinding is governed by the concentra-tion of the reactants and the affinity of adrug for a given protein. Albumin con-centration in plasma amounts to4.6 g/100 mL or O.6 mM, and thus pro-vides a very high binding capacity (twosites per molecule). As a rule, drugs ex-hibit much lower affinity (KD approx.10–5 –10–3 M) for plasma proteins thanfor their specific binding sites (recep-tors). In the range of therapeutically rel-evant concentrations, protein binding ofmost drugs increases linearly with con-centration (exceptions: salicylate andcertain sulfonamides).The albumin molecule has differentbinding sites for anionic and cationic li-gands, but van der Waals’ forces alsocontribute. The extent of bindingcorrelates with drug hydrophobicity(repulsion of drug by water).Binding to plasma proteins is in-stantaneous and reversible, i.e., anychange in the concentration of unbounddrug is immediately followed by a cor-responding change in the concentrationof bound drug. Protein binding is ofgreat importance, because it is the con-centration of free drug that determinesthe intensity of the effect. At an identi-cal total plasma concentration (say, 100ng/mL) the effective concentration willbe 90 ng/mL for a drug 10 % bound toprotein, but 1 ng/mL for a drug 99 %bound to protein. The reduction in con-centration of free drug resulting fromprotein binding affects not only the in-tensity of the effect but also biotransfor-mation (e.g., in the liver) and elimina-tion in the kidney, because only free drug will enter hepatic sites of metab-olism or undergo glomerular filtration.When concentrations of free drug fall,drug is resupplied from binding sites onplasma proteins. Binding to plasma pro-tein is equivalent to a depot in prolong-ing the duration of the effect by retard-ing elimination, whereas the intensityof the effect is reduced. If two substanc-es have affinity for the same binding siteon the albumin molecule, they maycompete for that site. One drug may dis-place another from its binding site andthereby elevate the free (effective) con-centration of the displaced drug (a formof drug interaction). Elevation of thefree concentration of the displaced drugmeans increased effectiveness and ac-celerated elimination.A decrease in the concentration ofalbumin (liver disease, nephrotic syn-drome, poor general condition) leads toaltered pharmacokinetics of drugs thatare highly bound to albumin.Plasma protein-bound drugs thatare substrates for transport carriers canbe cleared from blood at great velocity,e.g., p-aminohippurate by the renal tu-bule and sulfobromophthalein by theliver. Clearance rates of these substanc-es can be used to determine renal or he-patic blood flow.
Thursday, January 15, 2009
Blood-Tissue Barriers
The blood-tissue barrier is devel-oped differently in the various capillarybeds. Permeability to drugs of the capil-lary wall is determined by the structuraland functional characteristics of the en-dothelial cells. In many capillary beds,e.g., those of cardiac muscle, endothe-lial cells are characterized by pro-nounced endo- and transcytotic activ-ity, as evidenced by numerous invagina-tions and vesicles (arrows in the EM mi-crograph, top right).
Transcytotic activ-ity entails transport of fluid or macro-molecules from the blood into the inter-stitium and vice versa. Any solutestrapped in the fluid, including drugs,may traverse the blood-tissue barrier. Inthis form of transport, the physico-chemical properties of drugs are of littleimportance.In some capillary beds (e.g., in thepancreas), endothelial cells exhibit fen-estrations. Although the cells are tight-ly connected by continuous junctions,they possess pores (arrows in EM mi-crograph, bottom right) that are closedonly by diaphragms. Both the dia-phragm and basement membrane canbe readily penetrated by substances oflow molecular weight — the majority ofdrugs — but less so by macromolecules,e.g., proteins such as insulin (G: insulinstorage granules. Penetrability of mac-romolecules is determined by molecu-lar size and electrical charge.
Fenestrat-ed endothelia are found in the capillar-ies of the gut and endocrine glands.In the central nervous system(brain and spinal cord), capillary endo-thelia lack pores and there is little trans-cytotic activity. In order to cross theblood-brain barrier, drugs must diffusetranscellularly, i.e., penetrate the lumi-nal and basal membrane of endothelialcells. Drug movement along this pathrequires specific physicochemical prop-erties (p. 26) or the presence of a trans-port mechanism (e.g., L-dopa, p. 188).Thus, the blood-brain barrier is perme-able only to certain types of drugs.Drugs exchange freely betweenblood and interstitium in the liver,where endothelial cells exhibit largefenestrations (100 nm in diameter) fac-ing Disse’s spaces (D) and where neitherdiaphragms nor basement membranesimpede drug movement.
Diffusion bar-riers are also present beyond the capil-lary wall: e.g., placental barrier of fusedsyncytiotrophoblast cells; blood: testi-cle barrier — junctions interconnectingSertoli cells; brain choroid plexus: bloodbarrier — occluding junctions betweenependymal cells.
Potential Targets of Drug Action
Theseincludeenergy-consumingpumps (e.g., Na, K-ATPase, p. 130), car-riers (e.g., for Na/glucose-cotransport, p.178), and ion channels e.g., for sodium(p. 136) or calcium (p. 122)
(1).Functional coordination betweensingle cells is a prerequisite for viabilityof the organism, hence also for the sur-vival of individual cells. Cell functionsare regulated by means of messengersubstances for the transfer of informa-tion. Included among these are “trans-mitters” released from nerves, whichthe cell is able to recognize with thehelp of specialized membrane bindingsites or receptors. Hormones secretedby endocrine glands into the blood, theninto the extracellular fluid, representanother class of chemical signals. Final-ly, signalling substances can originatefrom neighboring cells, e.g., prostaglan-dins (p. 196) and cytokines.The effect of a drug frequently re-sults from interference with cellularfunction. Receptors for the recognitionof endogenous transmitters are obvioussites of drug action (receptor agonistsand antagonists, p. 60). Altered activityof transport systems affects cell func-tion (e.g., cardiac glycosides, p. 130;loop diuretics, p. 162; calcium-antago-nists, p. 122). Drugs may also directlyinterfere with intracellular metabolicprocesses, for instance by inhibiting(phosphodiesterase inhibitors, p. 132)or activating (organic nitrates, p. 120)an enzyme.
(2).In contrast to drugs acting from theoutside on cell membrane constituents, agents acting in the cell’s interior needto penetrate the cell membrane.The cell membrane basically con-sists of a phospholipid bilayer (80Å =8 nm in thickness) in which are embed-ded proteins (integral membrane pro-teins, such as receptors and transportmolecules). Phospholipid moleculescontain two long-chain fatty acids in es-ter linkage with two of the three hy-droxyl groups of glycerol. Bound to thethird hydroxyl group is phosphoric acid,which, in turn, carries a further residue,e.g., choline, (phosphatidylcholine = lec-ithin), the amino acid serine (phosphat-idylserine) or the cyclic polyhydric alco-hol inositol (phosphatidylinositol). Interms of solubility, phospholipids areamphiphilic: the tail region containingthe apolar fatty acid chains is lipophilic,the remainder – the polar head – is hy-drophilic. By virtue of these properties,phospholipids aggregate spontaneouslyinto a bilayer in an aqueous medium,their polar heads directed outwards intothe aqueous medium, the fatty acidchains facing each other and projectinginto the inside of the membrane.
(3).The hydrophobic interior of thephospholipid membrane constitutes adiffusion barrier virtually imperme-able for charged particles. Apolar parti-cles, however, penetrate the membraneeasily. This is of major importance withrespect to the absorption, distribution,and elimination of drugs.
Thursday, January 8, 2009
Drug Development
Wednesday, January 7, 2009
Drug Sources
Soaking plants parts in alcohol(ethanol) creates a tincture. In this process, pharmacologically active constituents of the plant are extracted by the alcohol. Tinctures do not contain the complete spectrum of substances that existin the plant or crude drug, only thosethat are soluble in alcohol. In the case ofopium tincture, these ingredients arealkaloids (i.e., basic substances of plantorigin) including: morphine, codeine,narcotine = noscapine, papaverine, narceine, and others.Using a natural product or extractto treat a disease thus usually entails the administration of a number of substances possibly possessing very different activities. Moreover, the dose of an individual constituent contained within agiven amount of the natural product issubject to large variations, depending upon the product‘s geographical origin (biotope), time of harvesting, or condi tions and length of storage. For the same reasons, the relative proportion of indi vidual constituents may vary considerably. Starting with the extraction of morphine from opiumin 1804 by F. W. Sertürner (1783–1841), the active principles of many other natural products were subsequently isolated in chemi cally pure form by pharmaceutical la boratories. The aims of isolating active principles are: 1. Identification of the active ingredient(s). 2. Analysis of the biological effects (pharmacodynamics) of individual in gredients and of their fate in the body (pharmacokinetics). 3. Ensuring a precise and constant dosage in the therapeutic use of chemically pure constituents. 4. The possibility of chemical synthesis, which would afford independence from limited natural supplies and create con ditions for the analysis of structureactivity relationships. Finally, derivatives of the original constituent may be synthesized in an effort to optimize pharmacological properties. Thus, derivatives of the original constituent with improved therapeutic useful ness may be developed.
History of Pharmacology
Since time immemorial, medicaments have been used for treating disease in humans and animals. The herbals of an-tiquity describe the therapeutic powers of certain plants and minerals. Belief in the curative powers of plants and certain substances rested exclusively upon traditional knowledge, that is, empirical information not subjected to critical examination.
The Idea
Claudius Galen (129–200 A.D.) first attempted to consider the theoretical background of pharmacology. Both theory and practical experience were to contribute equally to the rational use of medicines through interpretation of observed and experienced results.
“The empiricists say that all is found by experience. We, however, maintain that it is found in part by experience, in part by theory. Neither experience nor theory alone is apt to discover all.”
The Impetus
Theophrastus von Hohenheim (1493–1541 A.D.), called Paracelsus, began to quesiton doctrines handed down from antiquity, demanding knowledge of the active ingredient(s) in prescribed remedies, while rejecting the irrational concoctions and mixtures of medieval medicine. He prescribed chemically defined substances with such success that professional enemies had him prosecuted as a poisoner. Against such accusations, he defended himself with the thesis that has become an axiom of pharmacology:“If you want to explain any poison properly, what then isn‘t a poison? All things are poison, nothing is without poison; the dose alone causes a thing not to be poison.”
Early Beginnings
Johann Jakob Wepfer (1620–1695) was the first to verify by animal experimentation assertions about pharmacological or toxicological actions.“I pondered at length. Finally I resolved to clarify the matter by experiments.”
Foundation
Rudolf Buchheim (1820–1879) founded the first institute of pharmacology at the University of Dorpat(Tartu, Estonia) in 1847, ushering in pharmacology as an independent scientific discipline. In addition to a description of effects, he strove to explain the chemical properties of drugs. “The science of medicines is a theoretical, i.e., explanatory, one. It is to provide us with knowledge by which our judgement about the utility of medicines can be validated at the bedside.”
Consolidation – General Recognition
reputation of pharmacology. Fundamental concepts such as structure-activity relationship, drug receptor, and selective toxicity emerged from the work of, respectively, T. Frazer (1841–1921) in Scotland, J. Langley (1852–1925) in England, and P. Ehrlich (1854–1915) in Germany. Alexander J. Clark (1885–1941) in England first formalized receptor theory in the early 1920s by applying the Law of Mass Action to drug-receptor interactions. Together with the internist, Bernhard Naunyn (1839–1925), Schmiedeberg founded the first journal of pharmacology, which has since been published without interruption. The “Father of American Pharmacology”, John J. Abel(1857–1938) was among the first Americans to train in Schmiedeberg‘s laboratory and was founder of the Journal of Pharmacology and Experimental Therapeutics (published from 1909 until the present).
Status Quo
After 1920, pharmacological laboratories sprang up in the pharmaceutical industry, outside established university institutes. After 1960, departments of clinical pharmacology were set up at many universities and in industry.
Sunday, November 9, 2008
MEBO burned video report by CNN in 1992
During the academic exchanges, Xu Rongxiang, professor even declared that deep burn wounds can be extended to the site of the trauma of the new skin to heal without skin grafting, and that can be verified in a laboratory. Barbara, from the Hackensack Medical Center's burn expert, a professor in the United States, NJ, are invited to repeat the experiment in oncology NIN ins credit institutions under Help in Baltimore, and the results of Professor Xu has been done to verify the Conclusions.
In May 1990, the United States of Newsweek published an article entitled "a single article of the way to save lives," the report will change the way t he world for the treatment of burn injuries, Dr. Xu's new wet was exposed burn therapy (MEBT).
They visited China in the hospital and interviewed patients with burns were treated by the therapy after, CNN has also led to a special program.
The MeBo Burn this on the record, the CNN video. You may see the benefits of this patients with MeBo / MEBT agreement. (Not a bandage, not a typical antibiotics, non-sterile isolation)
Wednesday, October 22, 2008
Interpretation of hair to see the health of password
Heat and cooling.
The cooling function easily be overlooked, but Chinese medicine, hair and body as a whole is considered to be the most positive part of the foot yang, and so they need to heat hair.
Hair diseases:
Bald:
Chinese medicine practitioners say bald Shenqi belonging to the divergence over.
Dandruff:
Yinshengyangshuai. Shoubu Zhu Shen Jing virtual fire, fire on the virtual drift, for a long time, the blood to reduce the fine, not nourishing the scalp, they have dandruff.
Hair oil and more:
Spleen, lung disease. Temper too cloth lose, not on the lung function decline, oil up the human body float, with the result that the first oil.
Body hair and what he:
Chinese medicine practitioners believe that the human hair and blood and qi that are most relevant, so that made for the best of the kidney, blood apart. Hair is a kidney flowers, is the appearance of the kidney, the kidney is mainly black, so black hair and black is not good or bad kidneys are closely related. If people Shenqi strong convergence, nourishing hair, hair loss is not easy, and vice versa.
Related Links: thin yellow hair is Angelica and the patient can make up date
Traditional medicine of the motherland, "dry-run inspections of its coat color, you can now organs of the disease." In response, China Academy of Traditional Chinese Medicine Hospital Wangjing HUO Yan-ming, director of internal medicine Chinese medicine point out that the hair changes can really understand the body's physiological conditions, access to the existence of the disease in the body and its development and changes. However, this applies mainly young and middle-aged, because the two types of human blood was strong, more easily released from the show abnormalities.
"Made for blood, blood is made Run-sheng, blood loss was fat dry" and "liver blood," "China in the kidney fat," said HUO Yan, from the hair on the record is not hard to see in the hair of Growth, shedding, moisturizing, haggard, with more than two: First, the lack of adequate liver and kidney, and the other is whether or weak blood. Of these, the most important thing is qi.
Sparse hair on the young and middle-aged people, mostly Shenqi weak performance is the most common male hair loss over the forehead or hair loss. Were relatively more vulnerable to this type of fatigue, forgetfulness, and some are not functional.
Child hair chlorosis, and with "no later than five" phenomenon (that is, sit, stand, line, say, dental growth retardation), also a congenital lack of qi, but not so good digestion.
Brown hair, easily broken, that lack of blood, hair, lack of nutrition. Such people are usually not easy, poor sleep, people often say that belong to the "virtual body."
More white hair is due to enter in old age, lack of blood, qi virtual failure caused by normal physical development of the law, but too severe, it may be for a long time liver and kidney damage, blood caused by Dakui. It is worth mentioning that, "Shao Baitou" with the three main factors: first, innate lack of Shen Jing; Second, mental or emotional, hot blood Piansheng; Third, depression, Ganqiyuzhi, hair root dystrophy, Will lead to white boy.
For liver and kidney deficiency or blood loss, it is necessary to add more than Angelica, Polygonum multiflorum, date and so on. White hair as early as the prescription can try this: the two Polygonum multiflorum 3, 7, the two walnut meat, sesame seeds and 2 jin, along with fried dried, ground into powder, each of the two and a half, brown sugar with water to serve.
The hair growth rate associated with the blood, liver and the main hair. If the lack of blood, hair will be white and dry, causing hair loss.
Hair maintenance and repair:
To the life of decompression. Also known as hair worry, therefore, made hair care support, we must first eliminate the trouble.
Do head massage. More hair. About hair, not too many of the comb, preferably with Mushu, can not comb their hands. Hair in accordance with the rules, not arbitrary, should start again after the forehead. Such as a finger, a little hard in the head massage, hair is very good for conservation.
Wet hair does not go to bed. Hair is dry to sleep easily lead to diseases such as headaches, hair loss, can lead to serious diseases such as deafness. At the same time, the best dry naturally, do not commonly used hair dryer, dry hair Yi Zhi.
Reminder: Although the hair often means that the abnormal changes in certain diseases, but a clear diagnosis of the disease is a need for multi-evidence. As a result, abnormal hair appeared to change after the deal is still in the doldrums, especially accompanied by exophthalmos, loss of appetite hyperthyroidism, suffering from weight loss, emotional expression, such as abnormal, it should go to hospital for treatment.
Thursday, October 16, 2008
ABUSE Of MEDICINES Use
Friends, The study below done a few years ago should scare the socksoff us all. We can do much better in this country.
We all know that drugs has done much to save lives in this country,but I would bet that only ONE out of TEN knows the other side of thestory concerning AMA aproved drugs USE and Abuse. Well I'll tell youin a minute.
A while back I was talking to an elderly lady explaining about theefficacy of LIMU MOUI liquid. About all the studies (over 500) Theclinical trials, and the numerous testimonials that I collect frompeople that suffer from various Illnesses. Pains, chronic diseases,stroke, allergies, cancer, depression etc.
I told her about the study that I have shared with you all, howFucoidan the main ingredient LIMU MOUI , causes cancer cells to selfdistruct within 72 hours in vitro.
I told her how AMA has decided that Americans need to supplementtheir diet. How limu moui has been called the perfect food by no lessthan the president of the American Nutraceutical Association Dr.Derrick DeSilva (Of Ask the Doctor fame). Considered one of America'sbest doctors. It has everything the body needs plus thousands ofvitamin like substances that scientists are just beginning tounderstand.
This elderly lady told me that she had never had to take anything inher life. I told her LIMU was a FOOD. All natural, No harful effects.We have people that take it with all kinds of meds. Didn't matter toher. Naturally , she was a mother of a friend and I care about her.
Now , she had been on 5 different kinds of medication for years. Shedidn't count DRUGS to be "BEING ON SOMETHING."
Reccently she has been in the hospital to remove a cyst the size of agrapefruit. I haven't spoken to her since then.
I tell you this story because we have a lot of people that feel thesame way. Little do they know that the harmful effects of variousaspects of drug use makes 911 seem like a small blip in our lives,when you know the truth.
The study below Noted by JAMA the journal of the American MedicalAssociation. Shows exactly what I am saying.
300 Americans die each day from some effect from drug use.6000 Americans, each day, suffer from very serious ADVERSE REACTIONSfrom drugs.Remember all these are FDA aproved drugs. From Aspirin that isestimated to kill 46 people a day to the more exotic drugs likeStatins.
Is this an epidemic? What would happen if this was caused bysupplements?
Anyway, below is the study summary. As always I let the ones doingthe study speak for themselves. If you have trouble understanding it,SKIP to the CONCLUSION or ask your Doctor.