Tissue , generally

Paraffins. Methane and ethane are simple asphyxiants, whereas the higher homologues are central nervous system depressants. Liquid paraffins can remove oil from exposed skin and cause dermatitis or pneumonia in lung tissue. Generally, paraffins are the least toxic class of hydrocarbons. 

Currently stem cells are the focus of a broad and burgeoning area of science aimed at marshaling their generative powers into new treatments, especially for degenerative disorders such as stroke, Parkinson s disease, and spinal-cord injury. These disorders are so destructive that the affected tissue generally cannot be repaired by the body s normal healing mechanisms. 

Cellular therapy is the replacement of lost or dysfunctional tissues with new ones. Various cell types have been evaluated and considered for therapy. In the CNS, fetal neuronal tissue has been particularly evaluated for its merit in treating neurological diseases and injuries [1]. While numerous experimental and clinical transplantation studies showed that fetal neuronal transplants improve functional deficits in models of CNS diseases [2-5], others reported less positive outcomes [6, 7]. In addition, the rate of survival of fetal neuronal cells transplanted into the adult brain is relatively low, requiring large quantities of tissue, generally from several fetuses, for therapy. Researchers are looking at other opportunities for cellular therapy, particularly in the CNS. 

Erythromycin distributes widely in the body with residue levels in tissues generally exceeding those in serum. Both hepatic and renal routes of elimination of erythromycin are significant and it undergoes enterohepatic circulation. Elimination of erythromycin in relatively high levels in the feces may follow its oral administration. As with almost all macrolides, the principal metabolic pathway of erythromycin is by A-desmethylation of the desosamine sugar (107). 

In brief, the isolation scheme is as follows. First, the lipids are all extracted from the animal tissue, generally by using chloroform-methanol or chloroform-methanol-water. An increase in the polarity of the extracting system makes it possible to extract more fully the polar glycosphingolipids, especially polysialoglycolipids, but may, however, lead to contamination... 

Changes in clinical semm and urinary parameters, as well as microscopic examination of tissues, generally indicated severe liver and kidney damage. Acute renal and/or hepatic failure was the probable cause of death. Severe hepatic, renal, and capillary damage was also indicated by light and phase-contrast microscope (Ben-Hur et al. 1972 Ben Hur and Appelbaum 1973). 

The cells from the third category, such as epithelial cells isolated from mammal glands, testes, ovaries, pituitary gland, prostate, and from ocular tissue, generally proliferate with more difficulty in a defined medium. Besides maintenance factors, these cells may also need proteins from the ECM to promote their adhesion. Those proteins can be collagen, fibronec-tin, or laminin. Non-peptide factors, such as retinol (50 ng/ml) and corticosteroids (10-100 ng/ml), may also be necessary. 

A number of important biochemical reactions occur intramitochondrially and some of these are described below. One major drawback to the study of energy metabolism in cestodes is the failure, due to technical difficulties, to produce isolated mitochondrial preparations of the purity which can be obtained from mammalian tissues. Generally, mitochondrial fractions of cestode origin are contaminated with other cellular components such as glycogen, endoplasmic reticulum and various membranes, and some of the data obtained with such mitochondria should, therefore, be treated with caution. 

Permeation studies using a number of tracers, including horseradish peroxidase and lanthanum nitrate, have confirmed that the outer third of the epithelium is the rate-limiting barrier for mucosal penetration. When applied to the outer surface of the epithelium, these tracers are seen to penetrate only through the outermost layers of cells. Thus the compacted, flattened cells of the lower superficial layer and intermediate layer present a major physical barrier to transport. The intercellular lipids also play an important role, since extraction of these lipids results in more permeable tissue. Generally, keratinized epithelium appears to be more impermeable than non-keratinized epithelium. 

Atrophic, yi e/y nodular cirrhosis, which is low in regenerative capacity and rich in connective tissue, generally develops if the underlying damage persists and its pronounced impact continues, (s. fig. 28.13)... 

Use Rapid determination of sugar in body fluids, and of animal starch in liver tissue general reagent for carbohydrates organic synthesis. 

Another important substance which blocks calcium channels is hydrogen ion (see 34). It has been known for several years that secretory tissues generally respond poorly to agonists when the pH of the medium is low. A major result of low blood pH is depression of the central nervous system (35). Secretory mechanisms in brain neurons appear to be inhibited by excessive hydrogen ions. One other naturally occurring substance which appears to block calcium channels is ammonium ion (36). Calcium channel blockade by ammonium may be important in liver disease in which tissue ammonia levels are increased and sometimes coma results... 

Because of MLCK s central role in smooth muscle contraction and various nonmuscle cell processes, many investigations have focused on the biochemical and molecular properties of purified MLCK. Purification schemes for MLCK from mammalian smooth muscle tissues generally involve modifications of the procedure originally described for avian smooth muscle MLCK (Adelstein and Klee, 1981). The kinase has been purified from many types of mammalian smooth muscles, including trachea, aorta, myometrium, and stomach (Stull et al., 1986). 

Arsenic is always present in all animals. Human body tissues generally average less than 0.3 ppm of the element. Marine organisms are noteworthy for their ability to concentrate arsenic. Cod, shrimp, oysters, and lobsters have been reported to contain up to 128 ppm of arsenic on a dry-weight basis. Values from 3 to 30 ppm are common among marine organisms. The typical human ingests between 29 and 169 mg of arsenic per day. ... 

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