Friday, September 09, 2005

Cholesterol Function

Cholesterol is an important component of the membranes of cells, providing stability; it makes the membrane's fluidity stable over a bigger temperature interval. The hydroxyl group on cholesterol interacts with the phosphate head of the membrane, and the bulky steroid and the hydrocarbon chain is embedded in the membrane. It also reduces the permeability of the plasma memebrane to proton and sodium ions (Haines 2001). It is the major precursor for the synthesis of vitamin D, of the various steroid hormones, including cortisol, cortisone, and aldosterone in the adrenal glands, and of the sex hormones progesterone, estrogen, and testosterone. Further recent research shows that cholesterol has an important role for the brain synapses as well as in the immune system, including protecting against cancer. Recently, cholesterol has also been implicated in cell signalling processes, where it has been suggested that it forms lipid rafts in the plasma membrane.

In conditions with elevated concentrations of LDL particles, especially small LDL particles, cholesterol promotes atheroma plaque deposits in the walls of arteries, a condition known as atherosclerosis, which is a major contributor to coronary heart disease and other forms of cardiovascular disease. (In contrast, HDL particles have been the only identified mechanism by which cholesterol can be removed from atheroma. Increased concentrations of large HDL particles, not total HDL particles, correlate with lower rates of atheroma progressions, even regression.)

There is a world-wide trend to believe that lower total cholesterol levels tend to correlate with lower atherosclerosis event rates. Due to this reason, cholesterol has become a very large focus for scientific researchers trying to determine the proper amount of cholesterol needed in a healthy diet.However, the primary association of atherosclerosis with cholesterol has always been specifically with cholesterol transport patterns, not total cholesterol per se. For example, total cholesterol can be low, yet made up primarily of small LDL and small HDL particles and atheroma growth rates are high. In contrast, however, if LDL particle number is low (mostly large particles) and a large percentage of the HDL particles are large (HDL is actively reverse transporting cholesterol), then atheroma growth rates are usually low, even negative, for any given total cholesterol concentration.

Multiple human trials utilizing HMG-CoA reductase inhibitors or statins, have repeatedly confirmed that changing lipoprotein transport patterns from unhealthy to healthier patterns significantly lower cardiovascular disease event rates, even for people with cholesterol values currently considered low for adults; However, no statistically significant mortality benefit has been derived to date by lowering cholesterol using medications in asymptomatic people, i.e., no heart disease, no history of heart attack, etc.

Some of the better recent randomized human outcome trials studying patients with coronary artery disease or its risk equivalents include the Heart Protection Study (HPS), the PROVE IT trial, and the TNT trial. In addition, there are trials that have looked at the effect of lowering LDL as well as raising HDL and atheroma burden using intravascular ultrasound. Small trials have shown prevention of progression of coronary artery disease and possibly a slight reduction in atheroma burden with successful treatment of an abnormal lipid profile.

The American Heart Association provides a set of guidelines for total (fasting) blood cholesterol levels and risk for heart disease:

Level mg/dL Level mmol/L Interpretation
<200 <5.2 Desirable level corresponding to lower risk for heart disease
200-239 5.2-6.2 Borderline high risk
>240 >6.2 High risk

However, as today's testing methods determine LDL ("bad") and HDL ("good") cholesterol separately, this simplistic view has become somewhat outdated. The desirable LDL level is considered to be less than 100 mg/dl (2.6 mmol/L), although a newer target of <70 mg/dl can be considered in higher risk individuals based on some of the above-mentioned trials. A ratio of total cholesterol to HDL —another useful measure— of far less than 5:1 is thought to be healthier. Of note, typical LDL values for children before fatty streaks begin to develop is 35 mg/dl.

Patients should be aware that most testing methods for LDL do not actually measure LDL in their blood, much less particle size. For cost reasons, LDL values have long been estimated using the formula: Total-cholesterol − total-HDL − 20% of the triglyceride value = estimated LDL.

Increasing clinical evidence has strongly supported the greater predictive value of more-sophisticated testing that directly measures both LDL and HDL particle concentrations and size, as opposed to the more usual estimates/measures of the total cholesterol carried within LDL particles or the total HDL concentration. There are three commercial labs in the United States that offer more-sophisticated analysis using different methodologies. As outlined above, the real key is cholesterol transport, which is determined by both the proteins that form the lipoprotein particles and the proteins on cell surfaces with which they interact.
Based on Wikipedia

Thursday, September 08, 2005

Osteoporosis Treatment

There is a new experimental non-drug treatment for osteoporosis. The method involves standing on the special little oscillating bathroom scale for ten minutes per day which is sending an appropriate signal to the regions like your hip bone, or the spine which are at risk of fracture for osteoporosis.

"The vibrations are very slight," notes Stefan Judex, assistant professor of biomedical engineering at the State University of New York at Stony Brook, who worked on the research. The plate vibrates at 90 Hz (1 Hz = 1 cycle per second), with each brief oscillation imparting an acceleration equivalent to one-third of Earth's gravity. "If you touch the plate with your finger, you can feel a very slight vibration," he added. "If you watch the plate, you cannot see any vibration at all."

Although the vibrations are subtle they have had a profound effect on bone loss in laboratory animals such as turkeys, sheep, and rats. The results show that the vibration treatment maintained normal bone formation rates.

Wednesday, September 07, 2005

Calcium channel blockers

Calcium channel blockers are a class of drugs effectting the muscle of the heart and the muscles of the rest of the body. The main action of calcium channel blockers is to lower the blood pressure. Most calcium channel blockers decrease the force of contraction of the myocardium. This is known as the negative inotropic effect of calcium channel blockers. They are avoided in patients with cardiomyopathy because of the negative inotropic effects.

Many calcium channel blockers also slow down the conduction of electrical activity within the heart, by blocking the calcium channel during the plateau phase of the action potential of the heart. This causes a lowering of the heart rate and may cause heart blocks. This is known as the negative chronotropic effect of calcium channel blockers. The negative chronotropic effects of calcium channel blockers make them a commonly used class of agents in individuals with atrial fibrillation or flutter in whom control of the heart rate is an issue.

Calcium channel blockers work by blocking voltage-sensitive calcium channels in the heart and in the blood vessels. This prevents calcium levels from increasing as much in the cells when stimulated, leading to less contraction.

This decreases total peripheral resistance by dilating the blood vessels, and decreases cardiac output by lowering the force of contraction. Because resistance and output drop, so does blood pressure.

Unlike with beta-blockers, the heart is still responsive to sympathetic nervous system stimulation, so blood pressure can be maintained more effectively.

Sunday, September 04, 2005

Anxiety and Nutrition

Anxiety is a psychosomatic symptom which is the combination of the feeling of fear, apprehension and worry often accompanied by physical sensations such as palpitations, chest pain and/or shortness of breath. It may exist as a primary brain disorder or may be associated with other medical problems including other psychiatric disorders.

A chronically recurring case of anxiety that has a serious effect on your life may be clinically diagnosed as an anxiety disorder. The most common are Generalized anxiety disorder, Panic disorder, Social anxiety disorder, phobias, Obsessive-compulsive disorder, and posttraumatic stress disorder (PTSD).

There are several natural medications which are used for their anti-anxiety properties. Kava Kava is a popular herbal treatment, small doses can be taken regularly through the day, or when early symptoms are noticed. Valerian Root is also reputed to have anti-anxiety and sedative properties, as is Passion Fruit, Hops, and Chamomile.

Anxiety can be caused by intake of certain foods - Chinese Food Syndrome or lack of some aminoacids see Lysine Deficiency.

Saturday, September 03, 2005

Tocotrienol as Antioxidant

Tocotrienol belongs to the group of Vitamin E, however is far more potent than the common forms of Tocopherol. Vitamin E is a generic term for both Tocopherols and Tocotrienols derivatives and consists of eight different compounds.

There are significant differences in their chemical structures which make them act very differently in humans. Besides free radical scavenging effect, the antioxidant function of tocotrienols is also associated with lowering tumor formation, DNA damage and cell damage. Tocotrienols have been shown to be a powerful antioxidant with anti-cancer and cholesterol lowering properties. Experimental work and clinical studies have confirmed that Tocotrienol activity as an antioxidant, anti-cancer and cholesterol reducing substance to be much stronger than Tocopherols.

The market of Tocotrienols is limited by supply and its antioxidant power has been proven to be much stronger than Tocopherol. Tocotrienols are obtained from natural sources. Commercially available Tocotrienols are mainly derived from palm or rice bran oil.

Much attention has been given by pharmaceutical companies to develop new cholesterol lowering agents. Recent research programs provided insight and significance to Tocotrienols. Especially δ- and γ-Tocotrienols were shown to be effective nutritional agents to treat high cholesterol. In particular, γ-Tocotrienol appear to act on a specific enzyme called 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMG-CoA) involved in cholesterol production in the liver. Tocotrienols suppress the production of this enzyme, which may result in less cholesterol being manufactured by liver cells.

Friday, September 02, 2005

Lysine Deficiency

The insufficient intake of lysine in the diet can lead to a poor appetite and anaemia. It may also cause anxiety, headaches, dizziness, and nausea. Lysine deficiency in the body has also been associated with reduced ability to concentrate, pneumonia, nephrosis, and acidosis, as well as with rickets in children.

The main sources of lysine are leafy vegetables, pulses and legumes, meat, poultry, milk and milk products, and ripe fruits. Lysine inhibits the growth of viruses. Along with vitamin C, zinc, and vitamin A, it helps in eliminating some of the viral infections. Vitamin C protects lysine in the body, so the combination of lysine and vitamin C has a much stronger anti-virus effect than if either is used separately.

Lysine is considered to be a natural remedy for cold sores, shingles, and genital herpes.

Lysine is generally available in 500 mg capsules or tablets. The usual dose is 1-2 daily, just before mealtimes. In case that you have herpes, lysine supplements (L-lysine) in doses of 3-6 grams daily - plus lysine rich foods - are strongly recommended. For cold sores or fever blisters prevention take 500 to 1000 mg L-lysine daily, between meals.

Thursday, September 01, 2005

Chinese Food Syndrome

Chinese Food Syndrome was first described in 1968 in people who had eaten Chinese food with added MSG (monosodium glutamate). The syndrome occurs in small number of people. Their symptoms may include headache, throbbing of the head, dizziness, lightheadedness, a feeling of facial pressure, tightness of the jaw, burning or tingling sensations over parts of the body, chest pain, and back pain. Large amounts of MSG may cause arterial dilatation (widening of arteries). Many Chinese do not believe in the existence of the Chinese restaurant syndrome. In some people it may be a hypersensitive (allergic) reaction. It should be also noted that foods with added MSG do not necessarily contain more glutamate than what is found naturally in some other foods.

MSG is a sodium salt of the amino acid glutamic acid that enhances the flavor of certain foods. Originally isolated from seaweed, MSG is now made by fermenting corn, potatoes and rice. It does not enhance the four basic tastes (bitter, salty, sour, sweet) but it does enhance the complex flavors of meat, poultry, seafood, and vegetables. MSG is an important ingredient in the cuisines of China and Japan and is used commercially worldwide in many types of foods. It is naturally present at high levels in tomatoes and Parmesan cheese. In China, MSG is also known as wei jing, which means flavor essence.


PharmaBlogging Conference is hosted by Pharmaceutical Education Associates, the conference will take place November 14-15, 2005 at the Sheraton University City Hotel in Philadelphia, Pennsylvania.

PharmaBlogging is the first national event to provide healthcare communications professionals with a means to identify key strategies to promote their brand and company image through blogs. The conference will provide insight into why blogs are important for the pharmaceutical and healthcare industries and outline the steps of building a success blog. In addition, the seminar will highlight the negative effects of blogs, including unapproved blogs about your brand/company and risk management techniques.