The active transport of phosphate into the yeast cell

Phosphate can distribute in the cell wall space, but is not bound to an appreciable extent at the cell surface in non-metabolizing yeast. During metabolism of sugars, phosphate is actively transported into the yeast cell by a mechanism specifically involving glycolysis reactions. The movement of phosphate is in the inward direction only (no appreciable efflux), and it can proceed against a concentration gradient of 100 to 1. It is dependent on external phosphate concentrations in an asymptotic relationship, but is independent of the cellular orthophosphate concentration. The pH optimum for the phosphate uptake of 6.5 is shifted to the acid side by potassium. At certain values of pH a stimulation of 700 per cent by potassium can be observed. The nature of the effects of K⁺ and H⁺ are discussed.     

Rapid separation of the alpha, beta, G gamma and A gamma globin chains by reversed-phase high pressure liquid chromatography.

The main human globin chains present in cord blood hemoglobins, α,β,^Gγ and ^Aγ, can be separated in 45 minutes by reversedphase high pressure liquid chromatography. The chains were identified by carboxymethyl cellulose chromatography and partial amino acid analysis of the cyanogen bromide fragments of the two γ chains. The purification of cyanogen bromide fragments and the separation and quantitation of their dansylated amino acids were accomplished using a similar system to that used for the separation of the globin chains. These results show the potential of this type of chromatography for the analytical and semi-preparative analysis of globin chains and the large advantages over conventional chromatographic techniques.     

The role of the lymphoid system in the regulation of the blood glucose level.

Recent findings have led to a new hypothesis in which it is proposed that the immune system plays a role in regulating the increase in blood glucose levels after a meal. The relevant findings are: (1) the primary lymphoid tissue, the lymph nodes are mostly present within adipose tissue depots throughout the body (there are at least 12 such depots and about 10 (12) lymphocytes, 99% of which are present in lymph nodes); (2) lymphocytes and other immune cells utilize glucose at a high rate but almost all of it is converted to lactate which accumulates in the cells prior to release; (3) glutamine, some of which is synthesized in muscle from glucose, is utilized at a high rate by immune cells, the end-product of which is mainly aspartate, which also accumulates in the cells prior to release; and (4) finally, there is a common blood supply to the lymph node and the adipose tissue depot and the blood flow through the depot and hence the node is increased after a meal. It is proposed that, after a meal, some of the absorbed glucose is taken up from the blood by the lymphocytes and converted to lactate and glutamine is converted to aspartate. These are released slowly into the blood from where they are removed and converted to glycogen by the liver. Hence the immune cells provide a temporary buffer for glucose in the form of lactate and aspartate and, in this way, restrict the rise in blood glucose during and after a meal.     

Short communications. separation of p-nitrophenylphosphate, ATP and inorganic phosphate by anion exchange thin layer chromatography.

Aqueous solutions of the heteropoly acids, phosphotungstic and phosphomolybdic, are excellent precipitin brighteners for analytical immunological reactions such as radial immunodiffusion and electroimmunodiffusion in agarose gel media. These substances not only enhance the immunoprecipitate, enabling distinct differentiation from background residual protein, but also enable subsequent removal of residual nonimmunoprecipitated protein by saline solution prior to staining.     

The multifactor method of EEG separation into the cortical and deep components

A new method of separation of multichannel brain electrical activity into cortical and subcortical components with the help of multifactor analysis is proposed. The method provides a means for isolation and, consequently, more reliable localization of sources of electrical activity not only in deep brain structures (on the basis of the dipole model) but also on the cortical surface. The proposed method does not depend on the rotation and interpretation of factors, and no data losses occur. The mufasel algorithm is based on integration of all selected factors (within a particular EEG or EP time segment) in two groups using a statistical criterion, which defines general and specific factors. It is assumed that general factors loaded with highly correlated derivations predominantly describe the electrical activity of deep brain structures, whereas specific factors loaded by the dynamics of electrical activity in individual derivations, reflect the integrated activity of cortical brain structures.