A hemagglutination test capable of demonstrating antibodies in sera of ragweed-sensitive individuals has been described in detail. This test involves coupling of the antigen to rabbit erythrocytes via stable azo bonds. The antigen-coated cells are then suspended in the serum which is suspected to contain the homologous antibodies. The test has been shown to be specific and highly sensitive. Pre...

Many gram-negative bacteria are susceptible to the bactericidal action of complement in the presence of specific antibody. As a general rule, rough strains are readily killed, whereas smooth strains are relatively resistant. The results of this study show that the serum sensitivity of smooth gram-negative organisms can be controlled by the environmental conditions imposed by the test system. Sm...

The descriptive phase of glycosphingolipid biochemistry has blossomed over the past decade with the application of exquisitely sensitive analytical methods of mass spectrometry, NMR, and monoclonal antibody technology. Consequently, appreciation of the interrelation among the complex carbohydrate structures that are expressed on the cell surface has focused attention on the regulation of the gl...

The actions of divalent cations on voltage-gated ion channels suggest that these cations bind to specific sites and directly influence gating kinetics. We have examined some chemical properties of the external divalent cation binding sites on neuronal potassium channels. Patch clamp techniques were used to measure the electrophysiological properties of these channels and Zn ions were used to pr...

Salmonella PhoQ is a histidine kinase with a periplasmic sensor domain (PD) that promotes virulence by detecting the macrophage phagosome. PhoQ activity is repressed by divalent cations and induced in environments of acidic pH, limited divalent cations, and cationic antimicrobial peptides (CAMP). Previously, it was unclear which signals are sensed by salmonellae to promote PhoQ-mediated virulen...

The effects of Mg++, Mn++, and KCl addition, individually and in combination, on the rate of DNA- and RNA-primed DNA synthesis by avian myeloblastosis virus DNA polymerase (reverse transcriptase) using a variety of natural and synthetic template-primer combinations were examined. Optimal divalent cation concentrations were found to vary by as much as 10-fold depending upon the template-primer u...

RESOLFT super-resolution microscopy allows subdiffraction resolution imaging of living cells using low intensities of light. It relies on the light-driven switching of reversible switchable fluorescent proteins (RSFPs). So far, RESOLFT imaging was restricted to living cells, because chemical fixation typically affects the switching characteristics of RSFPs. In this study we created a fusion con...

A 36 kDa extracellular metalloprotease (designated to as vEP-MO6) was purified and characterized from Vibrio vulnificus sp. strain MO6 24/0. vEP-MO6 cleaved azocasein and a few other proteins such as prothrombin, plasminogen, fibrinogen and Factor Xa, which are associated with the blood coagulation pathway. The enzyme activity of vEP-MO6 was inhibited by EDTA, which was reversed by the addition...

Mevalonate pyrophosphate decarboxylase (MPD) in mouse liver was purified by affinity chromatography. The purified enzyme was a homodimer of 46-kDa subunits and had an isoelectric point of 5.0. Kinetic analysis revealed an apparent Km value of 10 microm for mevalonate pyrophosphate. The enzyme required ATP as a phosphate acceptor and Mg as a divalent cation, which could be substituted with Mn or...

background: celiac disease is one of the malabsorption syndromes leads to growth and development retardation in children. there is no test lonely can definitely diagnose celiac; however, the collection of clinical findings, serologic tests, intestinal biopsy, and response to treatment may diagnose it. although diagnostic value is variable in different studies, they are used a non-invasive and a...