Natural defenses

Bacteria require p-aminobenzoic acid to biosyn thesize folic acid a growth factor Structurally sul fanilamide resembles p-aminobenzoic acid and is mistaken for it by the bacteria Folic acid biosynthesis IS inhibited and bacterial growth is slowed suffi ciently to allow the body s natural defenses to effect a cure Because animals do not biosynthesize folic acid but obtain it in their food sulfanilamide halts the growth of bacteria without harm to the host... 

Skunks excrete 1-butanethiol and 2-methyl-1-butanethiol [1878-18-8] as a natural defense mechanism (12). Methanethiol is found in cheese, milk, coffee, and oysters (13—16). It is also found in the kuttin fmit, which is endemic to Southeast Asia. 

Viral infections continue to be significant causes of morbidity and mortality and at the same time continue to be resistant to treatment by small molecules. Avridine (6) is an antiviral compound which has shown some activity in a variety of animal tests apparently based upon its ability to stimulate a number of cells to produce the high molecular weight endogenous antiviral substance interferon. Thus, the compound is believed to operate indirectly by stimulating the body s own natural defenses against viral penetration into host cells. Avridine is synthesized by... 

Interferon (IFN) differs from bona fide antiviral diugs since it is a natural defense protein of the host organism and does not directly interfere with the viral replication steps. Interferons are small glycoproteins inducing immune modulatory and antiviral activities. They are secreted by lymphocytes, leukocytes and fibroblasts in response to foreign nucleic acids (dsRNA). 

No studies have shown yet humans can develop cancer from exposure to sweeteners. ACSH the enormous doses necessary for such experiments. .. may overwhelm the animal s natural defenses. Saccharin still available, but its use has decreased since 1983 (aspartame approval s year)... 

Metalloporphyrins, studies of, 78 591 Metalloreceptors, 76 787 Metallothermic magnesium, 75 343 Metallothermic reduction, rare-earth-metal production by, 74 643 Metallothioneins, as natural defense against silver, 22 655, 657, 681 Metal lubricant, indium and, 74 195 Metallurgical (smelter) plants, 23 792 Metallurgical additives... 

Natural antioxidants, 12 60-61 Natural attenuation, defined, 3 759t Natural boric acid, 4 133t Natural cements, 5 502 Natural colors, 12 51 Natural color system (NCS), 7 309 Natural convection, 13 245 Natural defenses, against silver, 22 655, 681... 

Silver accumulation, natural defenses against, 22 655 Silver acetate, 22 669 Silver acetylide, 22 670 Silver acetylides, 1 180 Silver alloys, 22 636... 

In Sweden, phenols did not protect introduced lodgepole pines, Pinus contorta, particularly well against debarking by the vole M. agrestis. Being an alien tree species may be an important factor (Hansson etal, 1986). The authors pointed out that, in general, any natural defense will work only at low browsing pressure by voles. 

Mycoses are most commonly due to dermatophytes, which affect the skin, hair, and nails following external infection. Candida albicans, a yeast organism normally found on body surfaces, may cause infections of mucous membranes, less frequently of the skin or internal organs when natural defenses are impaired (immunosuppression, or damage of microflora by broad-spectrum antibiotics). 

Extracts of plants have been used as insecticides by humans since before the time of the Romans. Some of these extracts have yielded compounds useful as sources (e.g., pyrethrins, rotenoids, alkaloids), others as models (e.g., pyrethrins, physostigmine) of commercial insecticides. Recent technological advances which facilitate the isolation and identification of the bioactive constituents of plants should ensure the continued usefulness of plant compounds in commercial insect control, both as sources and models of new insect control agents and also as components in host plant resistance mechanisms. The focus in this paper will be on several classes of compounds, including limonoids, chromenes, ellagitannins, and methyl ketones, which were found to be components of the natural defenses of both wild and cultivated plants and which may be useful in commercial insect control. 

Fungal infections are rarely transmitted directly from person to person. Fungi are derived from the commensal flora of the patient or from animal and innate sources in the environment, and are inoculated by (micro)trauma, ingestion or inhalation of spores. The incidence of invasive fungal infections among hospitalized patients has increased primarily due to the introduction of medical interventions that compromise the natural defenses of the patients. 

Detractors of herbal medicine use have legitimate concerns about dosage variability, possible toxicity and adulteration, herb-drug interactions, and above all, lack of FDA regulation. Far from being intrinsically harmless, many pharmacologically active plant alkaloids and other compounds are natural defensive poisons their very effectiveness may be an unanticipated consequence of their adaptive toxicity to grazing animals and... 

Local infection of a plant will stimulate the development of natural defense mechanisms often resulting in an immune reaction toward a variety of pathogens. Certain chemicals can also trigger the same biochemical reactions in plants. Among the chemicals found to induce this systemic acquired resistance (SAR) are thieno[2,3-rf [ 1,2,3]-thiadiazoles 195 <1999JPR341>. 

Some drugs situations are frankly confusing and need to be explored in greater depth. For example, tumor necrosis factor (TNF) is produced in the body as a natural defense against the many spontaneous tumors that arise in the body and has been suggested as a treatment for cancer, which may very well be effective under some conditions. However, TNF is also believed to be involved in the pain associated with rheumatoid arthritis, and monoclonal antibodies with specific activity against TNF are now on the market. The use of TNF is therefore a complex issue and needs to be evaluated with considerable care. 

The toxicity of these materials has led to the development of alternative means of insect control. Pyrethrins are natural insecticides produced by plants to ward off predators. Over the past decade or so, more of these natural defenses called allelochemicals have been investigated in the hopes of using them commercially. See the ASIDE on pyrethrins. 

The body s natural defenses against overenthusiastic oxidation include a-lipoic acid, reduced glutathione, ascorbic acid, the tocopherols, the carotenoids, and a number of enzymes such as epoxide hydrolase and the like. Very efficient DNA repair systems also operate defensively. These various means are remarkably effective, but DNA assault is continuous, cumulative, and implacable. Thus, many degenerative diseases are associated with aging because of the gradual slippage in functional fidelity of cellular machinery which occurs with age. 

Given their biological origins in the food chain, all foods are likely to contain compounds that are less beneficial to human health than others. In some cases (and notably in plant foods), these compounds may be detrimental as they form part of the organisms natural defense systems. In the case of milk products the trans-fats have a yet undiscovered role for humans, but like saturated fats their contribution to the human diet must be viewed in the context of the total diet. 

Arsenicum album 199c and Kali iodide 200c reduced fruit rot of guava and mango. Cina 1000c, applied by foliar spray, reduced root-knot disease, caused by nematode parasites, of cowpea plants. The drugs augmented the natural defense response in plants and thus reduced the parasite infection. 

Oxidizing agents (peroxides and peroxidases), antimicrobial peptides, and monoclonal antibodies also kill or inactivate sexually transmitted pathogens. However, these compounds are found naturally in the vagina and are often introduced to enhance the natural defense mechanisms, and are described below. 

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