January 2002 Blog with Durk and Sandy
by Jamie Riedeman on Jan 25, 2002
Wine from long habit has become indispensable for my health.
— Thomas Jefferson, 1815
So, we toast our readers: Best wishes for a prosperous and healthy 2002! (Remember, you can significantly increase your HDL with moderate alcohol consumption.)
Interactions Between Low-Dose Aspirin and NSAIDs Can Block Antiplatelet Effects of Aspirin
A new paper in the New England Journal of Medicine provides important use information for low-dose aspirin.1 The results showed that concomitant use of ibuprofen, but not rofecoxib, acetaminophen, or diclofenac, antagonizes the irreversible platelet inhibition induced by aspirin. For those using low-dose aspirin to protect against the risk of heart attack, therefore, these interactions are important to take into account in order to get the full benefit of the aspirin.
Aspirin acts by irreversibly acetylating a serine residue at position 529 in platelet prostaglandin G/H synthase (also called cyclooxygenase, COX), where it prevents the formation of thromboxane A2, a clot promoter. The action by aspirin at this site is irreversible, meaning that until new platelets are created to replace the ones that have been acetylated by aspirin, there can be no thromboxane A2 synthesized by the old platelets. New platelets are regenerated at a daily rate of about 10%.
NSAIDs, nonsteroidal-anti-inflammatory drugs, are widely used for treatment of pain. According to the new paper, both NSAIDs and aspirin have binding sites in COX-1 (the form of COX produced in human platelets) that lie within a narrow hydrophobic channel within the core of the enzyme. The researchers found that, when taken two hours before aspirin, ibuprofen prevented much of the antiplatelet effect of the aspirin. Those who took aspirin first, two hours before ibuprofen, had at least 98% inhibition of serum thromboxane B2 up to 24 hours after the first dosing (of aspirin). But when the subjects took ibuprofen two hours before aspirin, serum thromboxane B2 was inhibited by more than 97% two hours after taking the ibuprofen, but the levels later recovered (since ibuprofen is a reversible COX-1 inhibitor. Twenty-four hours after the administration of aspirin (before ibuprofen), the degree of inhibition of platelet aggregation was 98 ± 1 percent, but inhibition was only 2 ± 1 percent in subjects who took ibuprofen before aspirin.
Those who took more than one dose of ibuprofen a day, however, did not get antiplatelet effects from aspirin, even when the aspirin was taken first in the morning, because of the ongoing antagonism of aspirin's irreversible COX-1 effect by the multiple-dose ibuprofen regimen.
The inhibitory effects on aspirin's antiplatelet actions did not occur with the other NSAIDs tested, including diclofenac, rofecoxib (COX-2 inhibitor), or acetaminophen (a weak, reversible isoform nonspecific COX inhibitor at 1000 mg1).
- Catella-Lawson, "Cyclooxygenase inhibitors and the antiplatelet effects of aspirin," N Engl J Med 345(25):1809-17 (2001); also, in same issue, Crofford, "Rational use of analgesic and anti-inflammatory drugs."
Endogenous Cannabinoid System Controls Ras Oncogene-Dependent Tumor Growth
A new paper reports in the December 2001 FASEB Journal that two fundamental components of the endocannabinoid system, anandamide and the cannabinoid CB1 receptor, represent a potential target for the development of therapeutic agents controlling ras oncogene-dependent tumor growth.1 It had been shown previously, as reported here, that THC [(-)-delta-9-tetrahydrocannabinol, the main psychoactive ingredient in cannabis] reduces the growth of glioma tumors in mice by inducing apoptosis of glioma cancer cells. This effect was blocked by a combination of CB1 and CB2 cannabinoid-receptor antagonists, but not by either antagonist alone. In the new paper, the authors find that the cytostatic effect of anandamide on human breast and prostate cancer cells is due to activation of CB1 receptors, which is accompanied by inhibition of p21ras activity.
This is a preliminary study. Since anandamide is rapidly metabolized in vivo, the researchers used a metabolically stable analog, 2-methyl-arachidonyl-2'-fluoro-ethylamide (Met-F-AEA) to study the mechanistic effects in cancer growth regulation. Additional work is needed to determine the exact molecular mechanism by which Met-F-AEA suppresses p21ras activity. It may be, though, that cancer patients smoking marijuana for its antiemetic effects may be getting actual anticancer effects as well. Note that this study was done in Italy, not the U.S. Here, the government does not allow studies with cannabis that might show a beneficial effect.
- Bifulco et al., "Control by the endogenous cannabinoid system of ras oncogene-dependent tumor growth," FASEB J (October 29, 2001).
Enriched Environment Decreases Self-Administration of Amphetamine by Rats1
Female and male rats were raised from age 21 days in one of three environments: an enriched condition (novel objects along with social partners, EC), an environment containing only social partners (SC), or an isolated condition without objects or social partners, IC. At 51 days, the rats were tested for operant response to a sucrose reinforcer. Then the rats were implanted with chronic indwelling catheters whereby they could self-administer amphetamine.
At first, EC rats showed an increase in sucrose-reinforced responding relative to IC rats, with the difference greater in females than males. In both sexes, however, this additional sucrose-reinforced responding dissipated completely over repeated sessions. Both EC and SC rats "earned" fewer infusions of amphetamine than the IC rats at the low dose (0.03 mg/kg per infusion), but not at the higher dose (0.1 mg/kg per infusion). The effects of environmental enrichment on amphetamine self-administration were similar for both males and females.
The authors suggest that environmental enrichment might serve as a protective factor for reducing amphetamine self-administration. The rats that had the least environmental stimulation (being in a bare cage with nothing to do) were more likely to seek stimulation via amphetamines. It seems plausible that an enriched environment would be a protective factor from stimulant drug self-administration (e.g., use of cocaine or amphetamines) in people too. We do know that people who actively use their brains seem to be protected from the "normal" decline with age in many cognitive functions and are even less likely to get Alzheimer's disease.
- Bardo et al., "Environmental enrichment decreases intravenous self-administration of amphetamine in female and male rats,"
- Psychopharmacology 155(3):278-84 (2001), as reported in CA Selects: Psychobiochemistry, Issue 24, 2001.
A Start in Dealing with a Dysfunctional Patent System
Like other government services, the U.S. Patent Office (USPO) has delivered a poor product at a high cost. The patent system is supposed to allow for the establishment of intellectual property rights for inventors in order to encourage investment and development of new products and technologies, yet, to prevent a bottleneck in progress, restricting the period of exclusive ownership of the intellectual property rights to a limited time. The USPO is blowing it, imposing huge costs largely by patenting things that should never have been patented. As a result, we routinely see billion-dollar battles over badly considered patents.
In order to be patented, a thing must be novel (new and nonobvious), useful, and described in the patent so that the thing can be duplicated by someone skilled in the art. The problem begins with the fact that the USPO is a monopoly and doesn't have to be good. Individuals evaluating patents at the USPO are lawyers, not scientists or engineers. Because they are lawyers, they grant patents for things that may not be obvious to lawyers but are obvious to scientists and engineers skilled in the art. Moreover, the patent lawyers merely search prior patents, not the public literature or products that are already on the market, so there are many patents being granted for products that are not new. A part of the problem is that the USPO lawyers are hired at a starting salary of about $25,000 a year plus fringe benefits. Hence, you are getting the bottom of the barrel of available lawyers. But even if the USPO lawyers were paid $250,000 a year, the USPO would still be a monopoly, which is the major problem, and hence the agency would still have no incentive to do a good job.
An example of a patent that should have never happened is Amazon.com's patent on a business practice that is nothing more than a running tabulation for more than one purchase by a known customer. Every bartender has been doing this for thousands of years! Yet this patent that should never have been granted is costing huge amounts of money because companies are being sued and having to pay for patent litigation when they use this obvious and not new method.
Another example occurs in the dietary supplement industry, where large numbers of products that are slight variations on other products (and hence obvious) are receiving patents. Some university patent departments are particularly predatory in this respect, by patenting the obvious applications of work by scientists (who are not even necessarily at their institution!) and then shaking down large numbers of the small dietary supplement companies to pay royalties on their patents. It is often less expensive to pay or to discontinue offering these patented products when you face the deep pockets of university-funded legal attacks.
What can be done about this? There are some interesting possibilities. A private organization has a Web site where they offer bounties for evidence of prior art that was not cited in a patent. A patent can be invalidated (at great expense in time, money, and uncertainty) if it can be shown that the basis for the patent (the prior art) was in the public domain a year or more before the patent was filed.
Another suggestion was made in the December 2001 Nature Biotechnology, where the authors note that
The best solution would be competition in patenting services. But how can you have competitors in light of the fact that the government is likely to enforce only its own patents? As we see it, monopolies maintained with government guns are inherently dysfunctional.
Statins and Antioxidants May Not Mix
We were sorry to see the results of a clinical study of a statin plus niacin, the statin plus niacin in combination with antioxidants, and antioxidants alone, in the treatment of low HDL in seriously ill heart disease patients. Taking antioxidants along with the statin plus niacin reduced the effects of treatment with the latter combination, resulting in a lower increase in HDL. After a year, the statin plus niacin had decreased LDL by 34% and increased HDL by 25%. Those receiving placebos got worse, and those receiving antioxidants alone had little improvement. The statin plus niacin and antioxidants group had only an 18% increase in HDL, with about the same decrease in LDL. Moreover, the HDL2 - the fraction of HDL most predictive of heart disease risk - increased by 42% in those getting statin plus niacin but didn't show an increase in those who also got antioxidants.1 On the basis of this study, some are saying that patients taking a statin shouldn’t also take antioxidants.
Maybe. This is a small study that had 153 patients who were already seriously ill, divided into four groups. Other studies of antioxidants have shown cardiovascular benefits, such as improvement in endothelial function (vasodilation) with vitamin C.2 It may be, however, that there is interference by antioxidants with the main mechanism by which statins work, the inhibition of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMG-CoA reductase), the rate-limiting enzyme in the synthesis of cholesterol.
A different study3 looked at the mechanism by which green tea from Camellia sinensislowers plasma cholesterol in animal models of hypercholesterolemia. Cultured human HepG2 liver cells were used. An ethyl acetate extract of green tea, containing 70% by weight of catechins (green tea antioxidants) increased the LDL-receptor binding activity, protein, and mRNA. (The LDL receptor is the major mechanism by which cholesterol is removed from the circulation.) By upregulating the LDL receptor, the amount of cholesterol in the cells was decreased by 30%, and the conversion of the sterol-regulated element binding protein (SREBP-1) from the inactive precursor form to the active transcription-factor form was increased. The authors report that, consistent with this, the mRNA of HMG-CoA reductase was increased by green tea, presumably as a response to the decrease in intracellular cholesterol concentration.
Note that the green tea catechins (which are antioxidants, though they undoubtedly have other effects) reduced cholesterol by increasing LDL receptor expression, but they also increased the mRNA of HMG-CoA reductase, unlike the statins, which inhibit the enzyme. We do not know whether this is related to the reported interference by antioxidants in the study described above on the effects of a statin (or statin plus niacin), but it is curious nevertheless. A separate study4 has reported on what the authors consider to be a promising new class of hypolipidemic drugs, which also increase the expression in the liver of both LDL receptor and HMG-CoA reductase. Would this class of drugs also interfere with the effects of statins if combined with them? We don't know, but it certainly seems plausible.
- Brown et al., Atherosclerosis, Thrombosis, and Vascular Biology (August 2001), as reported in Science News, August 11, 2001.
- See, e.g., Carr and Frei, "Vitamin C and Cardiovascular Diseases," in Cadenas and Packer, Eds., Handbook of Antioxidants, 2nd ed., p. 154, Marcel Dekker, New York, 2002.
- Bursill et al., "Green tea upregulates the low-density lipoprotein receptor through the sterol-regulated element binding protein in HepG2 liver cells," J Agric Food Chem 49:5639-45 (2001).
- Grand-Perret et al., "SCAP ligands are potent new lipid-lowering drugs," Nature Medicine 7(12):1332-8 (2001).
Government Takeover of Health Care in the Name of Public Health
If you read our special supplement newsletter for November 2001, then you know about the Centers for Disease Control's suggested model state "Emergency Health Powers Act," which, in the name of public health, advocates that (under "emergency" conditions) government could treat, vaccinate, and quarantine individuals on a compulsory basis, as well as having broad powers to confiscate property, from subways to health-care facilities to drug companies (supposedly eventually compensating for these seizures). They could even force unwilling doctors to test unwilling patients. See the supplement for other features of this CDC plan.
In public health, it is the health of the collective that is the unit of analysis, not the health of the individual. Therefore, you should consider how any public health plan will affect you, because public health officials surely will not be doing so.
An interesting analysis published in the Dec. 5, 2001 JAMA discusses possible bioterrorism disease-control measures,1 including large-scale quarantines, and concludes that such quarantines "should not be considered a primary public health strategy in most imaginable circumstances. In the majority of contexts, other less extreme public health actions are likely to be more effective and create fewer unintended adverse consequences than quarantine." The paper notes that a review of the medical literature found no large-scale human quarantine implemented within U.S. borders during the past 80 years. Nevertheless, the statutory authority for quarantines has existed since 1797, when Massachusetts established state quarantine powers in the first comprehensive state public health statute.
The paper also notes that issues of federalism would be sure to make it unclear which authorities - federal, state, or local - have authority over any particular quarantine during an epidemic. As the authors note: "Perhaps the most important understanding that can be extracted from these [legal] reviews is that though legal powers exist to quarantine in many contexts, the imposition of quarantine would likely be challenged in the courts using modern interpretations of civil liberties provided by the U.S. Constitution."
The issue of mistrust in government and what happens if the public simply defies a quarantine is also extensively discussed. The paper notes that, during an outbreak of smallpox in Muncie, Indiana, in 1893, public health officials attempted to quarantine entire neighborhoods by having armed guards patrol them. Violators were incarcerated, and mandatory vaccination was instituted. However, violence broke out as some civilians resisted official public health commands, and several public health officials were shot. It was ultimately determined that the attempt at maintaining quarantine was "an utter failure" because of public defiance. When we consider the extensive mistrust of government today, particularly when it comes to compulsory health treatment or incarceration when you have not committed a crime, we have to agree that attempting quarantine as a public health measure would surely fail.
The report suggests the possibility of such measures as rapid vaccination or treatment programs, widespread use of disposable masks, short-term voluntary home curfew, restrictions on assembly of groups (such as schools and entertainment sites), or closure of mass public transportation. The authors note that such disease control measures should not be termed "quarantine" or "quarantine actions."
- Barbera et al., "Large-scale quarantine following biological terrorism in the United States," JAMA 286(21):2711-7 (2001).
Immunity and the Brain Inflammatory Matters
A very interesting paper appeared in the July 2001 FASEB Journal that describes the involvement of the neurotransmitter acetylcholine in the regulation of pro- and anti-inflammatory cytokines.1
As the authors note, while expression of proinflammatory cytokines is an integral part of the immune response to invading pathogens, anti-inflammatory mechanisms keep them in check. The unchecked systemic overexpression of the proinflammatory cytokines and other mediators can result in cytokine cascades with potentially fatal results, for example, toxic shock following bacterial infection. This scenario has been likened to "friendly fire" injury induced by the immune system.
In their fascinating discussion, the authors explain that cytokines, endotoxin, and other products of inflammation stimulate afferent neural signals in the vagus nerve that increases the acute-phase responses, induce fever, and upregulate the expression of the proinflammatory cytokine IL-1beta in the brain. The afferent vagus neural signals rapidly reach the hypothalamic-pituitary axis, where they result in the release of adrenocorticotropic hormone (ACTH). Glucocorticoids released in response to the ACTH then inhibit the release of proinflammatory cytokines by the innate immune system. The CNS also releases melanocyte-stimulating hormone (MSH), which is another anti-inflammatory protein that inhibits cytokine synthesis. Thus, the CNS directly regulates the immune response to bacterial challenge.
The authors discovered that efferent activity in the vagus nerve attenuates systemic inflammation. They found that direct electrical stimulation of the vagus nerve during endotoxemia (toxic shock syndrome) attenuated the deleterious effects of the proinflammatory cytokine tumor necrosis factor (TNF) by attenuating TNF synthesis in tissue macrophages, reducing serum TNF levels, and preventing lethal hypotension resulting from overexpression of the inducible form of nitric oxide synthase. (Nitric oxide has powerful antibacterial effects and hence may be released in large quantities in response to microbial invasion.)
The neurotransmitter acetylcholine is the basis for the communication between the vagus nerve and the immune system. Macrophages express cholinergic receptor activity. Acetylcholine significantly inhibits the TNF released in response to the presence of bacterial LPS. Acetylcholine also inhibits the release of other proinflammatory cytokines, including IL-1beta, IL-6, and IL-18. This mechanism has been termed, the authors state, the "cholinergic anti-inflammatory pathway."
It is interesting to speculate that supplementation with choline and vitamin B5, precursor and essential cofactor for making acetylcholine, might be useful in the amelioration of some types of inflammation, such as (perhaps) rheumatoid arthritis or septic shock. We wonder, too, what (if any) effects regular choline and vitamin B5 supplementation might have on the chronic inflammation associated with the development of serious conditions such as atherosclerosis and Alzheimer's disease.
- Tracey, Czura, Ivanova, "Mind over immunity," FASEB J 15:1575-6 (2001).
Adhesion molecules in artery walls cause leukocytes from the bloodstream to adhere, an important initiating step in atherogenesis. Adhesion molecules are induced by proinflammatory cytokines such as tumor necrosis factor alpha (TNF-alpha), which in turn depends upon the activation of the gene transcription factor nuclear factor kappa B (NF-kappa B). Agents that block NF-kappa B signaling also block adhesion-molecule expression and hence can prevent or reduce inflammation. Since oxidative stress is one of the known activators of NF-kappa B, it has been thought that antioxidants may be useful in opposing inflammatory processes. Some antioxidants have shown anti-inflammatory effects in some cell types, such as N-acetyl-L-cysteine, a precursor to glutathione.
Alpha-lipoic acid (LA) was studied for its effects on TNF-alpha-induced NF-kappa B activation and adhesion-molecule expression in human aortic endothelial cells.1 The paper notes that LA has been used safely for more than 30 years in Germany to treat diabetic complications and polyneuropathies. (High glucose levels cause increased oxidative stress in cells.) The study reported that LA inhibits TNF-alpha-induced activation of NF-kappa B and degradation of I-kappa B (which allows the NF-kappa B to enter the nucleus, where it binds to DNA). However, LA didn't inhibit NF-kappa B by increasing cellular glutathione levels or because of its antioxidant action in the human aortic endothelial cells. The researchers propose that the LA effects were due to its being an effective chelator of iron and copper. Quercetin is also a very effective iron and copper chelator; we wonder if, because of this effect, it also inhibits the activity of NF-kappa B.
- Zhang and Frei, "Alpha-lipoic acid inhibits TNF-alpha-induced NF-kappa B activation and adhesion-molecule expression in human aortic endothelial cells," FASEB J 15:2423-32 (2001).
Gamma-tocopherol is a less well known form of vitamin E that, however, has a number of interesting properties not shared by alpha-tocopherol. It (and its major metabolite, gamma-CEHC), but not alpha-tocopherol, have anti-inflammatory properties because they inhibit cyclooxygenase (COX) activity.1 The authors recently found that both gamma-tocopherol and gamma-CEHC inhibit prostaglandin E2 synthesis in lipopolysaccharide (a bacterial product)-stimulated macrophages and in IL-lbeta-activated epithelial cells, another anti-inflammatory effect. Alpha-tocopherol has no effect at the same concentrations (4-10 micromol gamma-tocopherol/L and about 30 micromol gamma-CEHC/L, respectively). Recently, another study found that gamma-tocopherol was superior to alpha-tocopherol in inhibiting the neoplastic transformation of a certain line of colon cells; the authors of the Reference 1 paper suggest that the anti-inflammatory properties of gamma-tocopherol could partially explain this difference.
Gamma-tocopherol is found in fairly large amounts in vegetable oils such as corn, soybean, and sesame, and nuts such as walnuts, pecans, and peanuts. In fact, because of the widespread consumption of these foods, about 70% of the vitamin E obtained in a typical American diet is gamma-tocopherol. It has been reported1 that gamma-tocopherol constitutes as much as 30-50% of the total vitamin E in human skin, muscle, vein, and adipose tissue.
Interestingly, gamma-tocopherol consumption alone leads to a marked increase in the concentrations of both alpha- and gamma-tocopherol, whereas supplementation with alpha-tocopherol alone increases the concentration of alpha-tocopherol but decreases that of gamma-tocopherol.
Although gamma-tocopherol is a somewhat less potent antioxidant than alpha-tocopherol, the unsubstituted C-5 position of gamma-tocopherol appears to make it better able to trap lipophilic (fat-loving) electrophiles (electron-grabbing molecular species) such as reactive nitrogen oxide species (RNOS). Excess generation of RNOS is associated with diseases that feature chronic inflammation, such as cancer, cardiovascular disease, and neurodegenerative disorders. RNOS formed during inflammation include peroxynitrite (resulting from the chemical reaction of nitric oxide and superoxide radicals), nitrogen dioxide, and nitrogen dioxide-like species generated from myeloperoxidase or superoxide dismutase.
Curcumin is a component of the spice turmeric and is also the source of the yellow color in the combination of spices called curry. It has well documented anti-inflammatory properties, which are largely mediated through suppression of NF-kappa B activation. With activation of NF-kappa B, expression of a large number of genes is induced, including various inflammatory cytokines and adhesion molecules, all of which are said to be suppressed by curcumin.1
- Aggarwal et al., "Spices as Potent Antioxidants with Therapeutic Potential," in Cadenas and Packer, Eds., Handbook of Antioxidants, 2nd ed., p. 445, Marcel Dekker, New York, 2002.
Vitamin E and the Regulation of Heart-Rate Variability
Reduced heart-rate variability is a good predictor of increased risk of sudden death by heart attack. A new study1 shows that vitamin E (600 IU/day) in patients with type 2 diabetes and cardiac autonomic regulatory neuropathy greatly improves heart-rate variability.
The paper begins by explaining that