Kidneys system

Wet spinning of this type of hoUow fiber is a weU-developed technology, especiaUy in the preparation of dialysis membranes for use in artificial kidneys. Systems that spin more than 100 fibers simultaneously on an around-the-clock basis are in operation. Wet-spun fibers are also used widely in ultrafiltration appUcations, in which the feed solution is forced down the bore of the fiber. Nitto, Asahi, Microgon, and Romicon aU produce this type of fiber, generaUy with diameters of 1—3 mm. 

Both liver and kidney systems are affected by a variety of secondary metabolites, and the pyrrolizidine alkaloids have been discussed earlier (Tables IV and V). The alkaloids are activated during the detoxification process, and this can lead to liver cancer. Also, many other enzyme or metabolic inhibitors (e.g., amanitine), discussed previously, are liver toxins. 

Other causes of acute nephritis are reactions to drugs, acute infection of the kidneys, systemic diseases with immune complexes such as SLE, bacterial endocarditis, and finally disease in which the antigen is unknown but possibly related to antecedent viral infections. 

Gutcho, M. "Artificial Kidney Systems" Noyes Data Corp. Park Ridge, N. J., 1970. 

Lead, originating primarily from the use of leaded gasoline in motor vehicles, may be absorbed into the body and accumulated in bone and soft tissues to the point where blood-forming, nervous and kidney systems are affected. 

Gutcho, M., "Artificial Kidney Systems," Hoyes Data Corp., Park Eidge, NJ, 1970. 

Spaeth, E.E., Washington University Case Study 9, Amtlysis ami Optimization of an Artificial Kidney System, Department of Chemical Engineering, Washington University, SL Louis, Missouri (1970). 

Babb, A. L., et al. (1967). Engineering Aspects of Artificial Kidney Systems, Chemical Engineering in Medicine and Biology (editor D. Hershey), Plenum Press, New York, 289-332. 

Fig. 8.3. IVU. Bilateral duplicated dysplastic kidney systems with megaureters and ureter dysmotility. Note dysplastic sacrum...

Recent developments in the design of artificial kidney systems have made possible repetitive hemodialysis and the sustaining of life of chronic kidney failure patients. The most important part of the artificial kidney is the semipermeable membrane itself, where commercially available regenerated cellulose and cuprophan have been used since the time of the development of the artificial kidney until the present. Because the primary action of the cellulose membrane is that of a sieve. 

M. Gutcho, "Artificial Kidney Systems", Noyes Data Corp.,... 

C7H9N402- M.p. 337 C, an alkaloid obtained from cacao seeds or prepared synthetically. Constitutionally it is similar to caffeine, and is also a weak base. It is usually administered as the sodium compound combined with either sodium ethanoate or sodium salicylate, and is employed almost entirely as a diuretic. Physiologically theobromine resembles caffeine, but its effect on the central nervous system is less, while its action on the kidneys, is more pronounced. 

Acrylonitrile is beheved to behave similarly to hydrogen cyanide (enzyme inhibition of cellular metaboHsm) (150) and is befleved to be a potential carcinogen (151). It can also affect the cardiovascular system and kidney and Hver functions (150). Eurther information on the toxicology and human exposure to acrylonitrile is available (152—154) (see Acrylonitrile). 

Effects of repeated ethylene glycol peroral overexposure in treated rats and mice can result in kidney, Hver, and nervous system damage. The most sensitive indicators of ethylene glycol toxicity are disturbances in acid—base balance and nephrotoxic (kidney) effects. Effects of repeated chronic peroral overexposure of diethylene glycol in treated rats result in kidney and Hver damage (48). 

In humans, the hypothalamic-derived protein and the hormone noncovalent complexes are packaged in neurosecretory granules, then migrate along axons at a rate of 1 4 mm/h until they reach the posterior pituitary where they are stored prior to release into the bloodstream by exocytosis (67). Considerable evidence suggests that posterior pituitary hormones function as neurotransmitters (68) vasopressin acts on the anterior pituitary to release adrenocorticotropic hormone [9002-60-2] (ACTH) (69) as well as on traditional target tissues such as kidneys. Both hormones promote other important central nervous system (CNS) effects (9,70). 

Hydraziae is toxic and readily absorbed by oral, dermal, or inhalation routes of exposure. Contact with hydraziae irritates the skin, eyes, and respiratory tract. Liquid splashed iato the eyes may cause permanent damage to the cornea. At high doses it can cause convulsions, but even low doses may result ia ceatral aervous system depressioa. Death from acute exposure results from coavulsioas, respiratory arrest, and cardiovascular coUapse. Repeated exposure may affect the lungs, Hver, and kidneys. Of the hydraziae derivatives studied, 1,1-dimethylhydrazine (UDMH) appears to be the least hepatotoxic monomethyl-hydrazine (MMH) seems to be more toxic to the kidneys. Evidence is limited as to the effect of hydraziae oa reproductioa and/or development however, animal studies demonstrate that only doses that produce toxicity ia pregaant rats result ia embryotoxicity (164). 

Exposure to excessive amounts of lead over a long period of time (chronic exposure) increases the risk of developing certain diseases. The parts of the body which may be affected include the blood, nervous system, digestive system, reproductive system, and kidneys. These effects include anemia, muscular weakness, kidney damage, and reproductive effects, such as reduced fertiHty in both men and women, and damage to the fetus of exposed pregnant women. 

Lead is toxic to the kidney, cardiovascular system, developiag red blood cells, and the nervous system. The toxicity of lead to the kidney is manifested by chronic nephropathy and appears to result from long-term, relatively high dose exposure to lead. It appears that the toxicity of lead to the kidney results from effects on the cells lining the proximal tubules. Lead inhibits the metaboHc activation of vitamin D in these cells, and induces the formation of dense lead—protein complexes, causing a progressive destmction of the proximal tubules (13). Lead has been impHcated in causing hypertension as a result of a direct action on vascular smooth muscle as well as the toxic effects on the kidneys (12,13). 

Spira.1- Wound Modules. Spiral-wound modules were used originally for artificial kidneys, but were fuUy developed for reverse osmosis systems. This work, carried out by UOP under sponsorship of the Office of Saline Water (later the Office of Water Research and Technology) resulted in a number of spiral-wound designs (63—65). The design shown in Figure 21 is the simplest and most common, and consists of a membrane envelope wound around a perforated central coUection tube. The wound module is placed inside a tubular pressure vessel, and feed gas is circulated axiaUy down the module across the membrane envelope. A portion of the feed permeates into the membrane envelope, where it spirals toward the center and exits through the coUection tube. 

Phenol. Phenol monomer is highly toxic and absorption by the skin can cause severe blistering. Large quantities can cause paralysis of the central nervous system and death. Ingestion of minor amounts may damage kidneys, Hver, and pancreas. Inhalation can cause headaches, dizziness, vomiting, and heart failure. The threshold limit value (TLV) for phenol is 5 ppm. The health and environmental risks of phenol and alkylated phenols, such as cresols and butylphenols, have been reviewed (66). 

One unique appHcation area for PSF is in membrane separation uses. Asymmetric PSF membranes are used in ultrafiltration, reverse osmosis, and ambulatory hemodialysis (artificial kidney) units. Gas-separation membrane technology was developed in the 1970s based on a polysulfone coating appHed to a hoUow-fiber support. The PRISM (Monsanto) gas-separation system based on this concept has been a significant breakthrough in gas-separation... 

Thorotrast (colloidal Th02) was once used as a radiopaque agent in medicine (see Radiopaques). Its injection in a dose of 2.0—15.0 g caused rises in body temperature, nausea, and injury to tissues at the injection site, followed by anemia, leukopenia, and impairment of the reticuloendothehal system. After intravenous adrninistration, thorotrast particles are taken up by reticuloendothehal cells of the fiver and spleen. Thorotrast is virtually not eliminated from the body (91). Between 1947 and 1961, 33 cases of cancer of the fiver, larynx, and bronchi and sarcoma of the kidneys, developing from 6 to 24 years after thorotrast administering, have been described in the literature (92). 

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