Defense, immobile

Sherwood RL, McCormick DL, Zheng S, et al. Influence of steric stabilization of liposome-encapsulated hemoglobin on Listeria monocytogenes host defense. Artif Cells Blood Substit Immobil Biotechnol 1995 23 665. 

Animal toxins are roughly divided into venoms and poisons. Venoms are offensive, used in the quest for food. Snakes produce toxins that can immobilize or kill prey for food. The venom of spiders paralyzes insects to allow the spider to feed on the victim s body fluids. While the venoms may also be used defensively, their primary purpose is in the quest for food. Most venom is delivered from the mouth, as in snakes and spiders, but there are exceptions like the scorpion that uses its tail. 

Snakes occupy a unique place in our collective imagination. The primary function of snake venom is to immobilize or kill prey for food. A secondary function of the venom is defensive or protective, but clearly snakes are not capable of eating large animals, such as humans. Often venomous snakes will strike but not release venom, which conserves a valuable resource. Approximately 400 of the more than 3500 species of snake are sufficiently venomous to be a threat to humans and other large animals. 

Diethylcarbamazine immobilizes microfilariae and alters their surface structure, displacing them from tissues and making them more susceptible to destruction by host defense mechanisms. The mode of action against adult worms is unknown. 

The majority of biomonitoring studies involves analyzing the bulk contaminant concentration in the whole body or selected tissues of organisms. However, many marine organisms (both vertebrate and invertebrate) possess defense mechanisms to cope with contamination, through immobilization and accumulation in specific organs, cells, or proteins 106 accumulated contaminants can then be stored, metabolized, or excreted. In view of this, the validity of bulk chemical analyses as a measure of contaminant impact and toxicity must be questioned. 

One pattern that appears to be consistent with RAM is that immobile phlorotannins are often present at much higher concentrations (typically 0 to 18% dry mass) than immobile defenses (0 to 2% dry mass).111 Recent evidence suggests that turnover of phlorotannins is relatively slow, and that less than 1% of photosynthate from three brown seaweeds is allocated to maintain polyphenolic concentrations of 3 to 5%.69 Those authors calculated that the phenolic pool would turnover in 120 to 260 days, depending on the species, which is considerably more than the 32 to 110 days calculated in other studies.69 No comparable data are available for mobile secondary metabolites from seaweeds. 

This model says nothing about what type of compounds a species should use to defend itself, such as high concentrations of polyphenolics or low concentrations of terpenes. The authors suggest that since there is little indication that quantitative/immobile and qualitative/mobile defenses differ in cost, effectiveness, or mode of action, there is little need for the model to predict classes of secondary metabolites. This model could be equally applied to invertebrates by replacing the words seaweed and herbivore with invertebrate and predator. 

Another approach to function ascribes anti-feedant effects to vanadium65. Aside from weather, adult tunicates, which are sessile (stationary) animals, are primarily vulnerable to two types of ecological threats. They may succumb to predatory crustaceans and fish, or they may be fouled i.e., covered over by growths of smaller organisms such as smaller tunicates, or algae. How do immobile tunicates survive these pressures Is it possible that they use a chemical defense to thwart their enemies If so, is vanadium their main line of defense ... 

J. Wright, L. Peurrung, T. Moody, J. Conca, X. Chen, P. Didzerekis, and E. Wyse, In situ immobilization of heavy metals in apatite mineral formation. Tech. Report to the Strategic Environmental Research and Development Program, Department of Defense, Pacific Northwest Laboratory, Richland, WA, 1995. 

Capsaicinoids cause dermatitis as well as nasal, ocular, pulmonary, and gastrointestinal effects in humans. OC gained popularity in the 1990s as a defensive weapon for civilians and law enforcement agencies because they produce an immediate, temporary immobilization and incapacitation when sprayed directly into the face or eyes. It is important to note that hand-held pepper spray formulations can contain OC by themselves or a mixture of OC and CS. 

Of the 25 animal phyla, almost half are worms. Thus, it is not at all surprising that some worms contain toxins. The nemertines are a phylum of over 800 known species which resemble flatworms but are active predators on crustaceans and other worms. This phylum is exceptionally toxic among the various worm phyla. The Heteronemertine side possesses peptide toxins which appear to be only defensive, as these animals have no means of injecting a venom. The peptides include neurotoxins, which enhance excitability of nerve membranes, and cytolysins, which permeabilize and destroy cell membranes. Members of the Hoplonemertine class inject a venom into their prey using a mineralized stylet located in their proboscis, which is also used to immobilize the prey. Their toxins are alkaloids similar to nicotine which in minute amounts paralyze crustaceans and annelid worms and primarily activate nicotinic acetylcholine receptors. Another well-known worm toxin is nereistoxin, a disulfide-containing alkaloid which also binds to nicotinic... 

All in all, there are at least forty-one elements in most human bodies, of which only twenty-one are known to be essential. We cannot assume that just because an element is found in the human body, it must serve some purpose. Our natural defenses, such as the white blood cells, antibodies, antioxidants, and macrophages, don t attack or immobilize toxic or nonessential chemical elements and remove them from the body as they do with harmful bacteria or viruses.We pick up some of these unneeded or unwanted elements from our food, water, and air, and they simply settle in the body, usually in the fatty tissue, liver, or bones. There are ways of getting them out, which I will mention later. 

The U.S. Army Medical Research Institute of Chemical Defense has developed an enzyme-immobilized polyurethane sponge that can absorb chemical threat agents that can then be destroyed by enzymatic activity. These polyurethane sponges have been found to have excellent adsorption properties related to organophosphorous vapors (Lukey et al. 2004). 

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