The Latex Serologic Test for Syphilis—A New Screening Procedure

A new macroscopic screening test for syphilis, the Latex-sts test, is extraordinarily simple. After inactivation of the patient''s serum for 30 minutes at 56°C the test is performed by mixing the patient''s serum with latex particles coated with cardiolipin and a protein fraction obtained from the non-pathogenic Reiter strain of Treponema pallidum. Two to three minutes after mixing, the result of the test is observed on a ringed serologic plate. The sensitivity, specificity and reproducibility of the new test are equivalent to those of the qualitative Venereal Disease Research Laboratory tube test. The advantages of the Latex-sts are that it can be done in a short time, it is simple and it requires a minimum of laboratory equipment. The coated latex particles are stable for 12 months.     

Overall Informativity,OI, in DNA Polymorphisms Revealed by inter-AluPCR: Detection of Genomic Rearrangements

We studied two systems of multilocus markers revealed by PCR using primers directing amplification betweenAlurepeats in a tail-to-tail orientation. Genomic polymorphisms were detected as the presence or absence of the electrophoretic bands representing DNA fragments of a given length. A total of 104 such fragments segregating as Mendelian markers in a panel of eight CEPH families were analyzed by two-point linkage analysis. Fifty-one of these fragments were localized with respect to CEPH markers; they represented 33 loci, 7 of which were multiallelic. Locus-specific oligonucleotides were developed and used as hybridization probes to identify the mapped loci within a complex pattern of inter-AluPCR products. A great proportion of inter-AluPCR polymorphisms represented length variants within amplified DNA segments, while others were presumably due to mutations within the priming sites. To describe the expected number of informative loci per typing experiment we introduced a parameter called overall informativity (OI), which provides a single measure of the multiplex ratio and the informativity of markers contributing to a multilocus system (OIof a single locus is equivalent to its heterozygosity and cannot exceed 0.5 for a biallelic codominant marker). HighOIvalues (5.8 and 11.5) of the two presented systems of inter-AluPCR markers of random chromosomal distribution render them suitable for mapping genomic rearrangements such as genomic deletions in tumoral tissues. This was illustrated by the detection of loss of heterozygosity in the 9q22–qter region in sporadic colon cancer.     

Systemic effects of chronically administered methyl prednisolonate and methyl 17-deoxyprednisolonate

The systemic activities of methyl prednisolonate and methyl 17-deoxyprednisolonate (1) were studied in rats. Methyl 17-deoxyprednisolonate produced significant changes in the amount of sodium ion (decreased) and potassium ion (increased) in urine; however, methyl prednisolonate had no effect on electrolyte balance. Both methyl prednisolonate and methyl 17-deoxyprednisolonate had no effect on liver glycogen content, plasma corticosterone level and relative adrenal weight. In contrast, the parent compound prednisolone caused a significant decrease in liver glycogen content, plasma corticosterone level and relative adrenal weight.     

Side chain and backbone assignments in isotopically labeled proteins from two heteronuclear triple resonance experiments.

Two multi-dimensional heteronuclear NMR experiments are described for assigning the resonances in uniformly 15N- and 13C-labeled proteins. In one experiment (HCNH-TOCSY), the amide nitrogen and proton are correlated to the side-chain protons and carbons of the same and preceding residue. In a second triple resonance experiment (HC(CO)NH-TOCSY), the amide nitrogen and proton of one residue is correlated exclusively with the side-chain proton and carbon resonances of the preceding residue by transferring magnetization through the intervening carbonyl. The utility of these two experiments for making sequential resonance assignments in proteins is illustrated for [U-15N,13C]FKBP (107 residues) complexed to the immunosuppressant, ascomycin.     

Stereospecific assignments and chi 1 rotamers for FKBP when bound to ascomycin from 3JH alpha,H beta and 3HN,H beta coupling constants.

3JH alpha,H beta and 3JN,H beta coupling constants were measured for isotopically labeled FKBP when bound to the immunosuppressant, ascomycin, using a 1H-coupled 3D HCCH-TOCSY and 15N-coupled 3D HSQC-TOCSY experiment, respectively. From an analysis of these two sets of coupling constants, stereospecific beta-proton assignments and chi 1 rotamers for FKBP have been obtained. All of the chi 1 rotamers were consistent with the chi 1 angles measured in the X-ray crystal structure of the FKBP/FK506 complex, suggesting that the structures of the two complexes are similar.     

Fibrous Aggregates of Short Peptides Containing Two Distinct Aromatic Amino Acid Residues

The aim of the study was the assessment of the ability of short peptides to form aggregates under physiological conditions. The dipeptides studied were derived from different aromatic amino acids (heteroaromatic peptides). Tripeptides were obtained from two distinct aromatic amino acids and cysteine or methionine residue in the C‐terminal, N‐terminal, or central position. The ability of the peptides to form fibrous aggregates under physiological conditions was evaluated using three independent methods: the Congo Red assay, the Thioflavin T assay, and microscopic examinations using normal and polarized light. Materials potentially useful for regenerative medicine were selected based on their cytotoxicity to the endothelial cell line EA.hy 926 and physicochemical properties of films formed by peptides. The required parameters of biocompatibility were fulfilled by H?PheCysTrp?OH, H?PheCysTyr?OH, H?PheTyrMet?OH, and H?TrpTyr?OH.     

Anisotropic 2H-nuclear magnetic resonance spin-lattice relaxation in cerebroside- and phospholipid-cholesterol bilayer membranes.

The axially symmetric powder pattern 2H-nuclear magnetic resonance (NMR) lineshapes observed in the liquid crystalline phase of pure lipid or lipid/cholesterol bilayers are essentially invariant to temperature, or, equivalently, to variations in the correlation times characterizing C-2H bond reorientations. In either of these melted phases, where correlation times for C-2H bond motions are shorter than 10(-7) s, information on the molecular dynamics of the saturated hydrocarbon chain would be difficult to obtain using lineshape analyses alone, and one must resort to other methods, such as the measurement of 2H spin-lattice relaxation rates, in order to obtain dynamic information. In pure lipid bilayers, the full power of the spin-lattice relaxation technique has yet to be realized, since an important piece of information, namely the orientation dependence of the 2H spin-lattice relaxation rates is usually lost due to orientational averaging of T1 by rapid lateral diffusion. Under more favorable circumstances, such as those encountered in the lipid/cholesterol mixtures of this study, the effects of orientational averaging by lateral diffusion are nullified, due to either a marked reduction (by at least an order of magnitude) in the diffusion rate, or a marked increase in the radii of curvature of the liposomes. In either case, the angular dependence of 2H spin-lattice relaxation is accessible to experimental study, and can be used to test models of molecular dynamics in these systems. Simulations of the partially recovered lineshapes indicate that the observed T1 anisotropies are consistent with large amplitude molecular reorientation of the C-2H bond among a finite number of sites.(ABSTRACT TRUNCATED AT 250 WORDS)