Local kinetics of morphogen gradients

Some aspects of pattern formation in developing embryos can be described by nonlinear reaction-diffusion equations. An important class of these models accounts for diffusion and degradation of a locally produced single chemical species. At long times, solutions of such models approach a steady state in which the concentration decays with distance from the source of production. We present analytical results that characterize the dynamics of this process and are in quantitative agreement with numerical solutions of the underlying nonlinear equations. The derived results provide an explicit connection between the parameters of the problem and the time needed to reach a steady state value at a given position. Our approach can be used for the quantitative analysis of tissue patterning by morphogen gradients, a subject of active research in biophysics and developmental biology.     

Facile transfer of [2Fe-2S] clusters from the diabetes drug target mitoNEET to an apo-acceptor protein

MitoNEET (mNT) is an outer mitochondrial membrane target of the thiazolidinedione diabetes drugs with a unique fold and a labile [2Fe-2S] cluster. The rare 1-His and 3-Cys coordination of mNT's [2Fe-2S] leads to cluster lability that is strongly dependent on the presence of the single histidine ligand (His87). These properties of mNT are similar to known [2Fe-2S] shuttle proteins. Here we investigated whether mNT is capable of cluster transfer to acceptor protein(s). Facile [2Fe-2S] cluster transfer is observed between oxidized mNT and apo-ferredoxin (a-Fd) using UV-VIS spectroscopy and native-PAGE, as well as with a mitochondrial iron detection assay in cells. The transfer is unidirectional, proceeds to completion, and occurs with a second-order-reaction rate that is comparable to known iron-sulfur transfer proteins. Mutagenesis of His87 with Cys (H87C) inhibits transfer of the [2Fe-2S] clusters to a-Fd. This inhibition is beyond that expected from increased cluster kinetic stability, as the equivalently stable Lys55 to Glu (K55E) mutation did not inhibit transfer. The H87C mutant also failed to transfer its iron to mitochondria in HEK293 cells. The diabetes drug pioglitazone inhibits iron transfer from WT mNT to mitochondria, indicating that pioglitazone affects a specific property, [2Fe-2S] cluster transfer, in the cellular environment. This finding is interesting in light of the role of iron overload in diabetes. Our findings suggest a likely role for mNT in [2Fe-2S] and/or iron transfer to acceptor proteins and support the idea that pioglitazone's antidiabetic mode of action may, in part, be to inhibit transfer of mNT's [2Fe-2S] cluster.     

Serodiagnosis of influenza by indirect haemagglutination test.

Results of studies on serodiagnosis of influenza A and B by the indirect haemagglutination test (IHA) with lyophilized erythrocyte diagnostic preparations, highly stable upon storage, are presented. The diagnostic value of the IHA test was in good agreement with, that of virus neutralization tests.     

Myocardial infarct in motor transport drivers and the results of long-term observations]

As many as 283 drivers with a history of acute myocardial infarction were examined. In the long-term postinfarction period, the number of the able-bodied accounted for 22.8%, the number of persons with restricted work fitness was 43.3%, that of the disabled amounted to 33.9%. It should be noted that about 60% of the able-bodied and those with restricted work fitness returned to the driving-related work. However, in some cases, the type of the trucking was either changed of the work scope was to be minimized. Criteria forming the basis for predicting the recovery of work fitness of the drivers were as follows: non-transmural character of myocardial infarction for the most part, the effective staged rehabilitation program, positive dynamics and smoothing of the ECG signs of myocardial infarction, the lack of areas of regional hypo- and akinesia of the myocardium, normalization of the ejection fraction, high and mean indicators of physical work fitness, exercise tolerance, coronary reserves, functional class I and II angina pectoris of effort, either the lack or initial clinical signs of circulatory failure, psychological readaptation, high occupational class, and labour orientation.     

Indirect hemadsorption reaction

Summary A new method has been suggested for the study of the synthesis of antibodies by isolated cells of immunized animals — indirect hemadsorption reaction. The reaction essentially consists of the fact that erythrocytes sensitized by bacterial haptens become capable of specific attachment to the surface of cells synthesizing antibodies. For sensitivity this test is not inferior to the bacterial attachment reaction and is superior to the latter with regard to specificity, particularly when the object of study is the formation of antibodies to antigens of immotile bacteria.(Presented by Active Member of the Academy of Medical Sciences of the USSR L. A. Zil'ber) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 61, No. 5, pp. 121–123, May, 1966Basic principles of the work were reported in July 1964 at the meeting of the immunology section of the 14 Congress of Epidemiologists, Microbiologists, and Specialists in Infectious Diseases.