Respiratory efficiency

Rosenberg C, Tuomi T. 1984. Airborne isocyanates in polyurethane spray painting Determination and respiratory efficiency. Am Ind Hyg Assoc J 45(2) 117-121. 

Normally, epithelial cells that line the inner surface of the lungs secrete a substance that traps and kills bacteria, and the cilia on the epithelial cells constantly sweep away the resulting debris. When CFTR is defective or missing, this process is less efficient, and frequent infections by bacteria such as S. aureus and P. aeruginosa progressively damage the lungs and reduce respiratory efficiency. 

The effects of the prolonged action of acetylcholine on skeletal muscle may also reduce the respiratory efficiency of the diaphragm and chest wall muscles, which would limit ventilation of Jim s lungs. 

Incorporation of applied, radioactive leucine into the mitochondrial proteins of pea cotyledons has been observed within 6 h of the start of imbibition, and it may continue for at least another 18 h [95]. Inhibition of protein synthesis on cytoplasmic ribosomes prevents this synthesis of mitochondrial proteins, whereas inhibition of mitochondrial ribosomes does not. Therefore these new mitochondrial proteins are synthesized in the cytoplasm and not in the mitochondria themselves. But even in the absence of synthesis of new mitochondrial proteins, cytochrome oxidase and malate dehydrogenase levels rise and the mitochondria increase in their respiratory efficiency [74, 95]. Therefore protein... 

As the cotyledonary reserves are consumed the mitochondria become disorganized and gradually lose their respiratory efficiency, enzyme complement and activity. In cotyledons of dark-grown Alaska peas this is marked by a decline in respiratory control (Fig. 5.7A), a loss of efficiency of oxidative phosphorylation (shown by the fall in ADP/0 ratio) (Fig. 5.7 B) and in cytochrome oxidase activity (Fig. 5.7 C). Another mitochondrial enzyme, malate dehydrogenase does not decline however. The gradual loss of mitochondrial activity is accompanied by the disruption of cell structure (see Chap. 6). 

Particles are present in outdoor air and are also generated indoors from a large number of sources including tobacco smoking and other combustion processes. Particle size, generally expressed in microns (10-6 m) is important because it influences the location where particles deposit in the respiratory system (U.S. Environmental Protection Agency 1995), the efficiency of particle removal by air filters, and the rate of particle removal from indoor air by deposition on surfaces. 

Dusts and fumes have been a part of industrial life for many years and the hazards associated with them are well known. The diseases and respiratory disorders found in foundries, potteries and cotton works are examples that are familiar to many. These need not occur with a better understanding of control measures and more efficient equipment. 

Studies (see, e.g., (101)) indicate that photosynthesis originated after the development of respiratory electron transfer pathways (99, 143). The photosynthetic reaction center, in this scenario, would have been created in order to enhance the efficiency of the already existing electron transport chains, that is, by adding a light-driven cycle around the cytochrome be complex. The Rieske protein as the key subunit in cytochrome be complexes would in this picture have contributed the first iron-sulfur center involved in photosynthetic mechanisms (since on the basis of the present data, it seems likely to us that the first photosynthetic RC resembled RCII, i.e., was devoid of iron—sulfur clusters). 

Some nickel compounds may be irritant to skin and eyes and dermal contact with nickel can result in allergic contact dermatitis. Nickel carbonyl is extremely toxic by inhalation and should be handled in totally enclosed systems or with extremely efficient ventilation. Air monitors linked to alarms may be required to detect leaks. Respiratory equipment must be available for dealing with leaks. Biological checks (e.g. nickel in urine) should be considered for routine operations involving nickel catalysts. 

Akron Research Commercialization Corp. has recently disclosed a drug candidate based on Ag-NHC complexes (Silvamist ). These NHC complexes were proven efficient for the treatment of respiratory diseases, and the company is currently applying for Investigational New Drug (IND) status with the FDA (US Food and Drug Administration)... 

Figure 18.2 Summary of respiratory energy flows. Foods ate converted into the reduced form of nicotinamide adenine dinucleotide (NADH), a strong reductant, which is the most reducing of the respiratory electron carriers (donors). Respiration can he based on a variety of terminal oxidants, such as O2, nitrate, or fumarate. Of those, O2 is the strongest, so that aerobic respiration extracts the largest amount of free energy from a given amount of food. In aerobic respiration, NADH is not oxidized directly by O2 rather, the reaction proceeds through intermediate electron carriers, such as the quinone/quinol couple and cytochrome c. The most efficient respiratory pathway is based on oxidation of ferrocytochrome c (Fe ) with O2 catalyzed by cytochrome c oxidase (CcO). Of the 550 mV difference between the standard potentials of c)Tochrome c and O2, CcO converts 450 mV into proton-motive force (see the text for further details).

In terminal areas, the air volumes are much greater, and typical HVAC filtration systems do not remove aerosol particles from the air as efficiently as do aircraft Environmental Control Systems (see Chapter 2). Thus, the costs and benefits of various enhanced filtration and air-cleaning strategies would have to be carefully assessed. An ancillary benefit to be considered would be the reduction of the transmission of common ills such as cold and flu viruses (or more serious viruses, such as the severe acute respiratory syndrome [SARS] virus) among airport patrons. 

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