Respiratory abnormalities and ventilatory capacity in a Papua New Guinea Island community

Several molecular forms of human glucose-6-phosphate dehydrogenase (D-glucose-6-phosphate:NADP+ 1-oxidoreductase, EC 1.1.1.49) corresponding to different stages of post-synthetic modifications have been purified from human leukocytes. The various enzyme forms were different in their specific activity, their kinetic properties and their isoelectrofusing pattern. The molecular weight of the subunits of the different forms was not modified. The changes in the electrofocusing pattern were not due to modifications of the N-terminal ends, the oxidation of thiol groups or the non-covalent fixation of an acid molecule upon the enzyme. Carboxypeptidase B cleaved a C-terminal lysine from the different enzyme forms and shifted the isoelectric point of the different enzyme active bands towards the acid pH. The different enzyme forms studied here seemed to result from the action upon 'native glucose-6-phosphate dehydrogenase' of 'modifying factors' especially abundant in some leukemic granulocytes. The modifying factors did not seem to be consumed during the 'modification' of glucose-6-phosphate dehydrogenase. Moreover, the storage for one year of unmodified enzyme resulted in changes in its electrofocusing pattern similar to those quickly induced by the 'modifying factors'. Consequently it appears that the modifying factors are catalysts of the modification of special residues of glucose-6-phosphate dehydrogenase. The hypothesis that this modification involves the deamination of asparagine or glutamine residues is put forward.     

Test of an electrical energy saving technique in an Australian abattoir

Electrical energy is used inefficiently in many abattoirs during days of no production and a technique has been proposed to save energy by operating the refrigeration plant intermittently instead of continuously. During a test in an Australian abattoir, the refrigeration plant was off for 33 h and on for 15 h between 0600 Saturday and 0600 Monday. energy savings of over half normal week-end consumption were achieved, and evaporative weight loss from chilled carcasses reduced, without risk to the hygiene quality of chilled or frozen meat.     

Internal pancreatic fistulas: pancreatic ascites and pleural effusions

Thirty-four patients seen over a 10-year period with internal pancreatic fistulas are reported. In 22 patients the fistula was into the peritoneal cavity and they presented with pancreatic ascits. In 7 patients the fistula tracked up through the mediastinum into a pleural cavity, and they presented with pancreatic pleural effusions. Five patients presented with both pancreatic ascites and pancreatic pleural effusions. Diagnosis was made by finding a markedly elevated amylase and protein content in the ascitic and pleural fluids. Serum amylase was usually, but not always, elevated. Over one half of the patients had no history of inflammatory pancreatic disease. Initial treatment was non-operative using nasogastric suction, diamox, atropine, and multiple paracenteses or thoracenteses. This was successful in 48% (12/25). If non-operative therapy failed, surgery was performed to drain or resect the internal fistula. Surgery was successful in 82% (14/17). The internal pancreatic fistula was successfully demontrated in most instances by preoperative, operative, or postmortem pancreatography, or by gross observation at the time of surgery.     

Stability of a laminar premixed supersonic free shear layer with chemical reactions

We discuss the stability of a 2-dimensional compressible supersonic flow in the wake of a flat plate. The fluid is a multi-species mixture which is undergoing finite rate chemical reactions. We consider the spatial stability of an infinitesimal disturbance in the fluid. Numerical solutions of the eigenvalue stability equations for both reactive and non-reactive supersonic flows are presented and discussed. The chemical reactions have significant influence on the stability behavior. For instance, a neutral eigenvalue is observed near the freestream Mach Number M_∞ ～- 2.375 for non-reactive case, but disappears when the reaction is turned on. For reactive flows, the eigenvalues are not very dependant on the free stream Mach number. The disturbance amplification rate is higher and the wave speed, c_r is lower for most of the reactive cases when compared with the non-reactive cases.     

Sensitivities of ocular tissues to acute pressure-induced ischemia

Intraocular pressure was artificially elevated for eight hours in eight owl monkeys. The first permanent effect (produced at a perfusion pressure of plus 15 mm Hg) was partial necrosis of iris stroma and ciliary processes, associated with microscopic lesions in the photoreceptors and retina pigment epithelium around the disc and in the retinal periphery. At a slightly higher pressure, visual nerve fibers in the retina and optic nerve and their ganglion cells were affected. Simultaneously, the outer retinal layers showed damage to the pigment epithelium, photoreceptors, and other nuclear layers. At even higher pressures, nearly all the other intraocular tissues were affected except for Müller cells, astroglia in the optic nerve head, epithelium of the pars plana, and the pigment cells of the choroid. The possibility is raised of a nonischemic pressure-induced mechanism for destruction of disc astrocytes in human chronic glaucoma.     

Three-dimensional vector graphics: a method for displaying results in a drug trial

Three-dimensional computer graphics are used to depict multidimensional outcome measures in a clinical drug trial. This graphics approach was used in a study of 116 patients with active rheumatoid arthritis, in a randomized, double-blind 21-week comparison of placebo, oral gold, and injectable gold. Three health status components, physical disability, psychological status, and pain, were generated using the Arthritis Impact Measurement Scales (AIMS). Results were presented in a three-axis perspective, one axis for each component, plotting individual patient vectors for magnitude and direction on a 10 X 10 X 10 coordinate matrix. Vectors for each patient are plotted from time 1 (start) to time 2 (finish) over the 21-week trial period. Vector symbols were added for clarity and subgroup delineation. Vector displays show trends in treatment response that clarify and strongly reinforce the statistical results. It is concluded that three-dimensional vector graphics are a useful adjunct to the statistical analysis of clinical trial results. The graphics facilitate the visual interpretation of a complex data set, and clarify the analysis of the results for both the clinician and researcher.