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Showing posts from January, 2009

Adrenal Cortex's Aldosterone

No, aldosterone is not a new dietary supplement to pump you up the size of Arnold. It’s a hormone made up by your adrenal glands to help you hold onto sodium and rid off potassium whenever needed (1). How is aldosterone released? Particularly it begins with the electrolyte-fluctuation-sensitive kidneys (1). They stimulate aldosterone production by secreting renin, a proteolytic enzyme (1). The secretion happens whenever there is decreased perfusion pressure that’s sensed by receptors in the kidneys’ juxtaglomerular apparatuses (“kidney brains” that tell the kidneys’ functional units, its nephrons, what to do) (1). The renin hydrolyzes angiosteninogen, a free-wheeling protein coming from the liver, to angiotensin I (1). Another enzyme, appropriately named angiotensin-converging enzyme (ACE), converts angiotensin I to angiotensin II. Angiotensin II interacts with adrenal cortical cell receptors and voila! aldosterone is released (1). Decreased atrial natriuretic peptide will stimulate re

Exercise lowers inflammation associated with heart disease

A study published in 2005 evaluated levels of C-reactive protein in sedentary men and women when placed on an exercise training program for five months. The patients significantly reduced the C-reactive proteins in the blood.  High levels of C-reactive protein in the blood indicates inflammation associated with heart disease, stroke and hypertension.  The patients who exercised also produced marked changes in body weight, glucose, LDL cholesterol, HDL cholesterol, triglycerides, and blood pressure.  What does this mean? That despite all my efforts to avoid exercise by living an otherwise healthy lifestyle, I gotta head to the gym. Or else.   Reference Lakka TA, Lakka HM, Rankinen T, Leon AS, Rao DC, Skinner JS, Wilmore JH, Bouchard C. Effect of exercise training on plasma levels of C-reactive protein healthy adults: the HERITAGE Family Study. European Heart Journal, 26, 2018–2025, 2005 doi:10.1093/eurheartj/ehi394

What? Another possible risk factor for heart disease?

More research is needed to determine if hyperhomocysteinemia may be a risk factor to heart disease, but if it is, then that's just another reason to eat less meat (1). Eating meat increases levels of homocysteine in the blood (1). Leafy greens and a variety of fruits in the diet supplies folic acid and B vitamins, which help break homocysteine down (1). Vitamin B12 (almost exclusive to meat) helps as well so choosing to give up meat entirely is not advisable (1). Reference Web MD. Homocysteine: Heart disease risk. Available at: http://www.webmd.com/heart-disease/guide/homocysteine-risk

Fats and Heart Disease

Just because fats don't have a direct affect on heart disease, it doesn't mean they shouldn't be worried about. Saturated fats and trans fats increase LDL cholesterol in the blood (1) creating a greater situation of LDL oxidation, which contributes to inflammation that is the cause of heart disease. A diet with a high ratio of omega-6 to omega-3 oils creates a proinflammatory state (2), which also enhances risk.  Through knowledge of fats and how they affect the body in different ratios, it is possible change course of health. Additional omega-3 fatty acids and lesser amounts of saturated fats, trans fats, and omega-6 fatty acids could largely benefit through reduction of LDL cholesterol in the blood, reduction of triglycerides and less inflammation. References 1. http://www.mayoclinic.com/health/fat/NU00262 2. http://www.medscape.com/viewarticle/555736

Cause of Heart Disease: Inflammation? Yes, but don't forget cholesterol's role

The medical establishment in the U.S. has been professing benefits of controlling cholesterol since 1985, because of research linking cholesterol to atherosclerosis and coronary artery disease (1). Short sighted, however, is the regard to these diseases as based completely on excess cholesterol as often assumed (2-3).  New research has proved that an assay of C-reactive proteins in the blood can predict coronary artery events (2). The higher C-reactive proteins are in the blood, the higher risk of an event and less likelihood of survival from the event (2). The C-reactive proteins, which increase during inflammation, suggest heart disease itself is an inflammatory condition (2).  If inflammation is the cause of heart disease, then inflammation should be the target of therapy, but it's important to not forget the link between cholesterol and heart disease. The atherogenic nature of LDL cholesterol in the arteries (now considered an independent factor to heart disease) leads to oxida

Goods and Bads of Antipyretic Therapy

Should antipyretic therapy be used at all? A fever is a natural response to infections, toxins, immunologic diseases or injury in many a warm-blooded animal (1p58). It can help enhance immune system function and filtering out of infection through phagocytosis (1p58). The elevated temperature also can interfere with bacteria's ability to grow and reproduce (1p58).  "Goods" of Antipyretic Therapies  A fever should max out at 105 degrees Fahrenheit, but if it reaches 106 degrees then a potential malfunctioning hypothalamus means it's time to go to the emergency medical care (1p58). The fever is to the point that cranial pressure is posing a risk to the brain, the heat may interfere with cardiac function in compromised patients, and the elevated core temperature could hurt a fetus if pregnant (1p58).  It's time to intervene with antipyretic therapy. Wet cloths, cool blankets, ice baths and cold IVs all help to offset the elevated temperature (1p59). Drugs like aspirin

Don't mix Tylenol and Motrin

I've got a fever right now that's driving my head crazy. After reading my Pathophys chapters I've got a wet cloth on my forehead. But still it's making it very difficult to take the dive into my exam.  Pain stinks. I'm strongly considering that Tylenol/Motrin combination. But, no...  While multimodual analgesic combinations such as Tylenol and Motrin do provide significantly more pain relief, the safety of this kind of use has not been completely determined, at least since 2001 (1). But, pending further, research, combinations could be useful such as before surgery (2-3).  Reference 1. http://www.americantherapeutics.com/pt/re/ajt/abstract.00045391-200111000-00008.htm;jsessionid=J8LWFGlcf03xsySCLsR15pGrc1w1yVLGzL6F7jjh4n2l1rqdQPcc!-1854079795!181195628!8091!-1 2. http://linkinghub.elsevier.com/retrieve/pii/S1366007104000749 3. http://www.anesthesia-analgesia.org/cgi/content/abstract/105/1/228

Don't take Tylenol without protecting your liver

Acetaminophen like Tylenol depletes glutathione and damages the liver (1), but chances are people won't be getting away from using them anytime soon. What can be done is help protect the liver from damage induced through supplementation.  Silymarin (from milk thistle) may serve as a support while taking acetaminophen. In a rat study, acetaminophen decreased glutathione and glycogen quickly (1). Unlike the control, rats taking silymarin showed no significant increase in lipid peroxidation or disruption of enzyme activities (1). Thus, while the silymarin didn't prevent glutathione depletion in rats, it did protect the liver possibly through antioxidant properties and helped with restoring glycogen (1).  Human studies have not yet been conducted, but many doctors already recommend silymarin supplements based on its recent research (2).  Reference 1. Muriel, P; Garciapina, T; Perez Alvarez, V; Mourelle, M. Silymarin protects against paracetamol-induced lipid peroxidation and liver

What's the most important part of the cell?

The earliest cell is thought to have emerged at least 3.8 billion years ago at a time when the environment was anaerobic in nature (1-2). It is suggested that simple organic molecules formed and gave rise to a self-replicating RNA that found itself within a phospholipid membrane (2).    The evolution of metabolism began with glycolysis (2), the sequence of reactions would produce life's universal energy source: ATP (1-3). Photosynthesis and oxidative phosphorylation would come later (2).  While cells may not need certain parts to remain living, all still depend on glycolysis to generate energy (2). The pathway is contained within the cytoplasmic matrix (1-2). Thus, I propose the cytoplasmic matrix is the most important part of the cell.  References 1. Dennison KJ, Topping J, Caret RL. General, Organic, and Biochemistry. New York: McGraw-Hill, 2007. 2. Cooper, G.M. "The Origin and Evolution of Cells." The Cell: A Molecular Approach. Available at: http://www.ncbi.nlm.nih.go

Trust a biochemist

At the molecular level of life matters may be small and energy gains and losses seemingly insignificant, but a broad understanding of biochemistry leads to profound, larger conclusions of cell biology and the energy of which is ultimately the existence of life. Just as the smallest ingredient such as a dash of salt can change the flavor of a recipe, the cell can be affected by the slightest difference that ultimately means life or death. Biochemical knowledge, in short, is fundamental for comprehending cells. And because cell biology is fundamental to all biological sciences, lack of biochemistry training severely limits the would-be biologist, medical practitioner, and health practitioner.  So be sure to ask your doctor, nutritionist and nutrition science writer, "How's your biochemistry?" If they can adequately explain the difference between activation energy and change in free energy (see last post), then they pass the test. If they roll their eyes at you, be cautiou

The reason why hemolytic anemia probably exists

Hemolytic anemia Within the cytoplasmic matrix of a red blood cell occurs an anaerobic pathway of glucose catabolism known as glycolysis consisting of 10 reactions (1). The enzyme that catalyzes the last reaction is pyruvate kinase (1). The reaction is one of two that produces ATP and also pyruvate, the molecule generally converted to acetyl CoA for entry into aerobic respiration (1). A deficiency of pyruvate kinase results in low ATP levels (2). It is one of the most common defects of a blood cell (2). A young red blood cell, or reticulocyte, starts out with organelles and then loses them. While retaining their mitochondria they require a lot more oxygen and if it goes through the spleen while in this stage it could mean its failure, since the spleen is deficient in oxygen and glucose (2). Lack of sufficient energy causes failure of ion pumps leading to a disrupted intracellular electrolyte concentration (2). The performance of the pentose phosphate pathway is diminished (2). The path

How does stuff happen anyway?

Activation Energy A sling shot metaphor can be used to help understand  activation energy . In endothermic reactions—like the force used pull the rubber strip of a sling shot— a ctivation energy  is the energy invested to raise reactant molecules to an "elevated" intermediate state. In exothermic reactions—like the force of letting go of the rubber— activation energy  is also the energy required to release the reactant molecules in exothermic reactions. Enzyme catalysis can reduce the amount of  activation energy  needed.   Change in Free Energy Change in free energy  is the amount of energy that occurs at a standard condition in which there is a precise temperature, pressure and concentration of reactants and their products. It is calculated as the difference between free energy of the reactants and the content of the products in that standard condition. Reference Gropper SS, Smith JL, Groff JL. Advanced Nutrition and Human Metabolism, 5th ed. Belmont, CA: Thomson Wadsworth,

Don't drink and eat french fries

A high-fat diet and alcohol may lead to a harmful combination. A proposal in Am J Clin Nutr in 2006 proposed that cells containing extra fat made them more susceptible to lipid peroxidation. The hypothesis is because of a tie between elevated levels of the detox enzyme GGT and obesity. Elevated levels of GGT may be a compensatory factor. According to the study, obesity in animals and humans can accentuate alcohol-induced liver damage and cell injury. Reference http://www.ajcn.org/cgi/reprint/83/6/1351.pdf

Fish oil for joint pain

An effective natural treatment for joint inflammation such as that occurs with rheumatoid arthritis may be high-dose fish oil, according to a study published in 1995 in Arthritis Rheumatology. The study had patients on NSAIDs take up dietary supplementation of fish oil. The patients taking the fish oil showed improvement including a reduction innumber of tender joints after eight weeks. Some patients were able to discontinue NSAIDs without any further flare-ups. Note: The study used dosages of 130mg of DHA/EPA omega-3 fatty acids from fish oil per kg daily. Reference Kremer JM, Lawrence DA, Petrillo GF, Litts LL, Mullaly PM, Rynes RI, Stocker RP, Parhami N, Greenstein NS, Fuchs BR, et al. Effects of high-dose fish oil on rheumatoid arthritis after stopping nonsteroidal antiinflammatory drugs. Clinical and immune correlates. Arthritis Rheum. 1995 Aug;38(8):1107-14.

Lupus summary

One in 700 women aged 20 to 65 and 1 in 245 American black women will be affected by systemic lupus erythematosus (lupus), a chronic inflammatory disorder that occurs when the body's own immune system attacks organs and tissues (1-2). Lupus means "wolflike", so named because symptoms of the autoimmune disease include an appearance of a rash over cheeks and the nose (1). Symptoms can also include mouth sores, joint pain, swelling around the lungs and heart, and kidney disease (2).  Diagnosis and Treatment  An antinuclear antibody (ANA) test makes it easy to diagnose lupus because almost every lupus patient tests positive (1). Other ways to diagnose are with complete blood count since lupus can commonly cause anemia, erythrocyte sedimintation due to inflammation, kidney and liver assesment, urinalysis that checks for protein and red blood cells in urine, chest X-ray to see inflammation, electrocariogram to identify irregular rhythms or damage in the heart, and a syphilis te

A possible cause for IBS

The cause of IBS/IBD is considered unknown, but the inflammation is suggested to be due to small intestine bacterial overgrowth (SIBO), according to research published in JAMA in 2004 (1). Normally bacteria reside in the large intestine, but little if any is found in the small intestine (1). A few years earlier in 2000, California researchers found that in IBS patients SIBO could be discovered using a simple breath test (2). When given treatment of antibiotics almost half of patients showed IBS symptoms were eliminated (2). Other studies did not show the same results (3) so more research is necessary. Based on this research, nutritionists and doctors have often used antibiotics to treat IBS and then followed up with using probiotics and prebiotics to replenish healthy gut flora. References 1. University Of Southern California (2004, September 3). Bacteria May Be The Cause Of Irritable Bowel Syndrome. ScienceDaily. Available at: http://www.sciencedaily.com/releases/2004/09/040903093237.

Testing for Detox Enzymes

When a high level of a toxin like alcohol or poison is in the body, the cells respond quickly with detoxification enzymes (1p23). One such enzyme is glutamyl transferase (GGT) (1p23) that is largely present in hepatocytes. The enzyme plays a role in transferring amino acids across the cell membrane and the biosynthesis of the antioxidant glutathione (2). A simple blood test called a gamma-glutamyl transpeptidase (GGTP) can indicate if levels of GGT are greater than normal (2). The test is performed by drawing blood from the elbow orback of the hand (2). An increase in GGT levels could be caused by alcohol intake, heart failure, cholestatis, cirrhosis, hepatitis, liver ischemia, liver necrosis, liver tumor or a drug/poison toxic to the liver (2). A decrease in levels could be caused by clofibrte or birth control pills (2). Because it is unclear what elevated GGT levels may indicate, physicians will often also include other tests such as one for the enzyme ALP (3). If only GGT is elevate

Neurotoxic pesticides and how to avoid them

To find out just how much we are exposed to chemicals, look up the research from National Human Adipose Tissue Survey performed by U.S. Environmental Protection Agency and others (1-3).  Unfortunately, according to their research, most of us have organophosphate and carbamate pesticides accumulated in our fat tissue. Included in these are neurotoxins that can affect cognition, mood, and associated with chronic neurological illnesses like Alzheimer's disease (3).  The organophosphates, first synthesized for nerve gas research, actually destroys acetylcholinesterase and its effects are irreversible (3). Without it you get an excess of acetylcholine causing problems and the effects worsen if exposure continues (3). More of the enzyme needs to be produced to restore health of the synapses (3).  Carbamates bind to acetylcholinesterase and its effects don't last because the bond is reversible via hydrolysis (3).  References 1. Phillips LJ, Birchard GF. Regional variations in human to

Your brain on wine, tea and chocolate

Who would've thought? Before my next game of chess, I'll drink a glass of cabernet, a cup of green tea and a bite into a piece of chocolate. All three foods contain antioxidant flavonoids that support brain health and, according to a study of Oxford and Norwegian researchers, elderly subjects had better test scores in cognitive performance when they consumed these foods. Those that consume all three foods in moderation generated the best test scores. You don't need much of each. The study revealed that a maximum effect of cognition at an intake of 10g of chocolate, 75-100ml of wine and the same for wine. Too much of either of these three foods are known to have ill effects. Reference Nurk E, Refsum H, Drevon CA, Tell GS, Nygaard HA, Engedal K, Smith AD. Intake of flavonoid-rich wine, tea, and chocolate by elderly men and women is associated with better cognitive test performance. J Nutr. 2009 Jan;139(1):120-7. Epub 2008 Dec 3. Available at: http://www.ncbi.nlm.nih.gov/pubme

Expanding my tea horizons

You fill up my senses with a hint of orange peel that drives me to sing John Denver songs and your light bitterness warms my complex taste buds like no other tea. Oh, Taragui "Sabor Naranja" maté! Could I ever fall in love with any other tea?  Doubtful. So it's a good thing I have enough bags to last me six months because you never know when there might be an disaster. That trek to Argentina is a long one.   But I am interested in mixing up my tea-drinking habit. We've all heard about—what seems like weekly—the studies that come out about green tea's preventive effects on cancer and heart disease. And while maté does have the same antioxidant epicatechins that tea has there are studies that suggest its tannins can cause possible cancers such as esophageal and bladder cancer [1-6]. While I believe more research is necessary to prove these effects and because some of the studies may have been related to other factors like how hot a maté is, I gotta drink it only in

New Year's Health Resolutions

If I was a rational human I wouldn't wait until New Year's Day to make a health resolution. But like most humans I know, I'm not very rational. I'm really emotional. My habits largely depend on how I feel. Every morning before work I hug my pillow for as long as possible because it feels good and procrastinate getting ready for the day. My resolution last year to get up early and jog daily lasted less than a month. My resolution to make healthy lunches and take them with me to work died much sooner than that. Why go through the trouble when I could easily settle for a cheap, big greasy burrito at mid-day. After work? Forget exercise. I'm taking kids to dance, cheer and jiu jitsu. No time to make a balanced meal for dinner either. I've got homework. Kids, we're having pasta again.  The obvious is that what I need is discipline. Easier said. The idea of punishment and reward feels like jail. And no matter how rational it is, rationalization can always take ove