Clearance of mercury (HG-197, HG-203) vapor inhaled by human subjects

Five human subjects inhaled a mixture of stable and radioactive mercury vapor for periods of 14 to 24 minutes. The subjects retained an average of 74% of that inhaled. Evidence is submitted to show that the retention occurred almost entirely in the alveoli. For 3 days after exposure, the exhaled breath was passed at intervals through activated charcoal traps for sampling periods of 10 to 35 minutes. The data indicated that an average of 7% of the retained mercury was lost in the expired breath, with a half time of 18 hours. Examination of the subjects in a whole body counter yielded average half times for mercury clearance from different parts of the body as follows: lung, 1.7 days; head, 21 days; kidney region, 64 days; chest, 43 days; and whole body, 58 days.     

The resolution of membrane proteins based upon size, charge, and hydrophobicity

Currently available systems for resolving membrane proteins are based only on size and charge differences. Recently, it has been shown that Triton-urea-acetic acid gels which separate proteins on the basis of charge, size and hydrophobicity are capable of resolving proteins differing only by the substitution of a single neutral amino acid. We have applied this new method to the resolution of bacterial envelope proteins. Conditions for optimal resolution of different bacterial envelope proteins were determined by electrophoresis through transverse urea and Triton X-100 gradient gels. We have also correlated the components resolved in this system with those resolved by classical sodium dodecyl sulfate-gel electrophoresis by using two-dimensional slab gels combining the two systems. Furthermore, envelope protein fractions from different species and strains of bacteria were compared to identify specific proteins. This system appears to be a promising method for investigating envelope proteins which are due to missense mutations.     

Relationship between mouth occlusion pressure and electrical activity of the diaphragm: effects of flow-resistive loading

We determined the relationship between mouth occlusion pressure and diaphragmatic electromyography during CO2 rebreathing with and without inspiratory flow resistance. Diaphragmatic electromyography was measured as a moving time average; occlusion pressures were measured 150 msec after onset of an inspiratory effort against a closed airway (P.15). P.15 versus diaphragmatic electromyographic plots during CO2 rebreathing with and without inspiratory flow resistance were linear. In 3 subjects the slope of P.15 versus diaphragmatic electromyography was unchanged with inspiratory flow resistance whereas in 3 others the slope increased, indicating greater inspiratory force for a given degree of diaphragmatic activity. We concluded that under unloaded conditions P.15 is a reliable index of respiratory neural output but may no longer reflect only inspiratory motoneuron drive during mechanical loading.     

Formation of individual somatotype parameters and features of constitutional organization in 7-12-year-old boys (longitudinal)

Individual somatotype parameters and peculiarities of constitution in 7-12 years boys were evaluated in the present investigation. The age range studied was shown to be divided on 3 stages. Regular growth processes with the prevalence of "infantal" proportions occur at the age of 7-9. Signs of definite constitutional type are expressed yet insufficiently. The age of 10-11 is transitional which shows in delay of muscle growth. At the age of 11-12 prepubescent sets in, during which features of constitution types and appropriate somatotype parameters are distinctly manifested.