Common Mechanical Injuries

Product Hazard Categories, Common Mechanical Injuries, and Common Causes of Work Injuries... 

Pentoxifylline is stmcturaHy related to other methylxanthine derivatives such as caffeine [58-02-2] (1,3,7-trimethylxanthine), theobromine [83-67-0] (3,7-dimethylxanthine), and theophylline [58-55-9] (3,7-dihydro-1,3-dimethyl-1 H-piirine-2,6-dione or 1,3-dimethylxanthine), which also show radioprotective activity in some instances, suggesting that methylxanthines as a dmg class may radioprotect through a common mechanism (see Alkaloids). In a retrospective analysis of cervical and endometrial cancer patients receiving primary or adjuvant XRT, no association between caffeine consumption and incidence of acute radiation effects has been found. However, there was a decreased incidence of severe late radiation injury in cervical cancer patients who consumed higher levels of caffeine at the time of thek XRT (121). The observed lack of correlation between caffeine consumption and acute radiation effects is consistent with laboratory investigations using pentoxifylline. 

Synergism is appHed to a situation where the effect of two or more chemicals that have common mechanism of toxicity, given together, is significantly greater than that expected from considerations on the toxicity of each material alone. This differs from potentiation in that both materials contribute to the toxic injury, and the net effect is always greater than additive. 

In designing concrete tanks, it is common practice to carry the reinforced asphalt membrane up the walls and over the tops of the concrete, and to continue the brick lining in the same manner-over the top of the wall. Often the membrane is carried down the outside of the tank, the outside is veneered with brick as well, and the membrane and brick continued onto the surrounding floor. If such a system is properly designed and constructed, the life expectancy of the system will be a long one. This is a closed system, with no discontinuities in membrane, and except for mechanical injury there is no way corrosives can enter the building structure. 

Amacrine cells, an important class of interneurons of the inner retina, are also sensitive to ischemia and glutamate excitotoxicity. Ischemia upregulates expression of proinflammatory mediators such as COX-2 and iiNOS in amacrine cells (Ju et al., 2003). These molecules also are involved in ischemic injury to the ganglion cells, suggesting that common mechanisms of ischemic injury exist in different cells. Both of these cell types die by apoptosis (Singh et al., 2001). Amacrine cells are morphologically, functionally, and molecularly diverse, thus not all amacrine cells are equally susceptible to ischemia or excitotoxicity (Osborne and Larsen, 1996). 

Because it appears that one common mechanism of the cerebral, cardiovascular, and hepatic effects may be an acceleration of the arteriosclerotic process (see Section 2.4), individuals at risk for arteriosclerosis or those with early arteriosclerosis would probably be at increased risk for health effects following exposure to carbon disulfide (NIOSH 1978). The mechanism for carbon disulfide acceleration of arteriosclerotic plaque formation involves direct injury to the vessel endothelium and changes in lipid metabolism. 

What are the mechanisms of brain dysfunction in persistent virus infection in the brain Probably the most common mechanism of brain injury is a consequence of the immunopathology mediated by the persistent virus. While some of this immun-opathology is antiviral, it may also be in part autoimmune in nature. The inflammation causes the release of leucotrines, prostaglandins, thromboxanes and lymphokines, which interfere with normal brain activity and cause brain degeneration. Gradually, patients succumb to progressive decline in mentation and other neurological dysfunctions. 

The most common mechanism for injury is forced plantar flexion of the forefoot usually combined with a rotational force (Wiley 1981). Fracture dislocations of the tarsometatarsal joint are rare injuries in children but can often be overlooked. Missed Lisfranc injuries predispose to midfoot instability with chronic deformity and pain, making diagnosis important. Bruising in the sole at the level of the tarsometatarsal joint should raise specific concern for a Lisfranc injury. 

Nearly every common laboratory technique and operation poses safety hazards. Many of these hazards involve the likelihood of exposure to infectious agents or to mechanical injury caused by improper procedures or techniques. Learning the proper techniques to avoid the risk of exposure to infectious or hazardous agents, as well as to avoid damage to equipment, should be a fundamental goal for all those engaged in laboratory work. Part 1 (Chapters 1 to 5) covers the principles of research safety in the biomedical laboratory, discusses the hazards associated with common laboratory operations, and examines the theoretical aspects of decontamination and disinfection. 

Equipment must not be stored or used on the floor, unless of course it is large and designed to be free-standing. Unfortunately, it is common to find items, such as vacuum pumps, small ovens, roller bottle apparatus, and shakers, in the aisles between work benches. Not only do these objects present a tripping hazard, but since many involve moving parts, they present a hazard of mechanical injury as well. Locating these items in a protected space away from traffic will minimize these hazards. 

Wounds are defined as skin defects caused by chemical, mechanical, electrical, or thermal injuries, or by the presence of an underlying medical or physiological disorder. Wound dressings are materials used to cover the wounds. Many types of wounds occur in everyday life, such as mechanical injuries like abrasions, lacerations, acute bullet wounds, knife cuts, bites, and surgical wounds, and various types of bums caused by thermal, chemical, electrical, or radiational injuries. Other types of wounds such as chronic ulcerative wounds, pressure sores, and leg ulcers occur more commonly among elderly people. 

Traumatic brain injury is the most common cause of death in subjects under the age of 40, and an important risk factor for AD. Loss of hippocampal cells and depletion of ACh and of muscarinic receptors can be attenuated in injured experimental animals, improve blood perfusion in ischemic areas and increase cholinergic transmission in cortex and hippocampus the same mechanism invoked for treatment of VD. 

Muscle fatigue during this intensity range may be due to other factors besides lack of CHO substrate. The potential mechanisms include dehydration, electrolyte imbalances, and the onset of muscle injury and soreness. As these potential fatigue factors are common to the range of intensities in this section and exercise below 60% VO2 max, they will be discussed in the following section. 

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