An enzyme immunoassay for determining albumin in human urine samples using an ultra-microanalytical system.

Microalbuminuria is a term to describe a moderate increase in the level of albumin in urine. It is an important prognostic marker for kidney damage in diseases such as diabetes mellitus and hypertension. A simple sandwich-type ultramicroELISA assay (UMELISA) has been developed for the measurement of albumin in human urine samples. Strips coated with a high affinity monoclonal antibody directed against albumin are used as solid phase, to ensure the specificity of the assay. The albumin assay was completed in 1 hr and 30 min, with a measuring range of 1.44-200 ng/mL. The intra- and inter-assay coefficients of variation were 3.98-4.35% and 7.59-8.92%, respectively, depending on the albumin concentrations evaluated. Percentage recovery ranged from 94.26 to 98.50%. Regression analysis showed a good correlation with the commercial quantitative turbidimetric test Microalbumin-turbilatex (n = 240, r = 0.994, p < .01). The analytical performance characteristics of our UMELISA MICROALBUMINA endorse its use for the quantification of albumin in human urine samples. This test will make a cost-effective diagnostic kit accessible to low-income countries such as Latin American countries and is now available in the Cuban Public Health System.

Cocaine-induced psychotic disorders: presentation, mechanism, and management.

Cocaine, the third mostly commonly used illicit drug in the United States, has a wide range of neuropsychiatric effects, including transient psychotic symptoms. When psychotic symptoms occur within a month of cocaine intoxication or withdrawal, the diagnosis is cocaine-induced psychotic disorder (CIPD). Current evidence suggests those with CIPD are likely to be male, have longer severity and duration of cocaine use, use intravenous cocaine, and have a lower body mass index. Differentiating CIPD from a primary psychotic disorder requires a detailed history of psychotic symptoms in relation to substance use and often a longitudinal assessment. Treatment includes providing a safe environment, managing agitation and psychosis, and addressing the underlying substance use disorder. This review begins with a clinical case and summarizes the literature on CIPD, including clinical presentation, differential diagnosis, mechanism and predictors of illness, and treatment.

An enzyme immunoassay to determine human chorionic gonadotropin (HCG) in serum and urine samples using an ultra-microanalytical system.

The determination of Human Chorionic Gonadotropin (HCG) in biological fluids is of great interest in the early pregnancy diagnostics, the evaluation of pregnancy disorders, as a tumor marker, as a screening procedure for anti-doping control, and many other purposes. A simple sandwich-type UltraMicro Enzyme-Linked ImmunoSorbent Assay (UMELISA) has been developed for the measurement of HCG in serum and urine samples. Strips coated with a high affinity MAb directed against HCG are used as solid phase, to ensure the specificity of the assay. The HCG assay was completed in 1.5 h, with a measuring range of 0.76-400 mIU/mL. The intra- and inter-assay coefficients of variation were lower than 10 %, depending on the HCG concentrations evaluated. Recovery percentages were 96.43-97.16 % (serum) and 98.10-99.04 % (urine). The assay detected intact HCG, nicked HCG, HCG ß, and nicked HCG ß, and did not recognize any of the interfering molecules tested. Regression analysis showed a good correlation with Elecsys in serum (n = 1459, r = 0.952, ρc = 0.948) and urine (n = 869, r = 0.988, ρc = 0.978). A good correlation was also found with 84 RIQAS samples analyzed with the kits Elecsys (r = 0.969, ρc = 0.957), Architect (r = 0.982, ρc = 0.970), Dimension (r = 0.989, ρc = 0.977), and Bioscience (r = 0.992, ρc = 0.980), all with a p < 0.01. Comparison with transvaginal ultrasonography in early pregnancy detection showed a specificity and a sensitivity of 100 % (n = 2385, κ = 1). The analytical performance characteristics of UMELISA HCG endorse its use for the quantification of HCG in serum and urine samples. This assay will make a cost-effective diagnostic kit accessible to low-income countries and is now available in the Cuban Public Health System.

Antibacterial Properties and Mechanism of Activity of a Novel Silver-Stabilized Hydrogen Peroxide.

Huwa-San peroxide (hydrogen peroxide; HSP) is a NSF Standard 60 (maximum 8 mg/L(-1)) new generation peroxide stabilized with ionic silver suitable for continuous disinfection of potable water. Experiments were undertaken to examine the mechanism of HSP against planktonic and biofilm cultures of indicator bacterial strains. Contact/kill time (CT) relationships that achieve effective control were explored to determine the potential utility in primary disinfection. Inhibitory assays were conducted using both nutrient rich media and a medium based on synthetic wastewater. Assays were compared for exposures to three disinfectants (HSP, laboratory grade hydrogen peroxide (HP) and sodium hypochlorite) at concentrations of 20 ppm (therefore at 2.5 and 5 times the NSF limit for HP and sodium hypochlorite, respectively) and at pH 7.0 and 8.5 in dechlorinated tap water. HSP was found to be more or equally effective as hypochlorite or HP. Results from CT assays comparing HSP and HP at different bacterial concentrations with neutralization of residual peroxide with catalase suggested that at a high bacterial concentration HSP, but not HP, was protected from catalase degradation possibly through sequestration by bacterial cells. Consistent with this hypothesis, at a low bacterial cell density residual HSP was more effectively neutralized as less HSP was associated with bacteria and therefore accessible to catalase. Silver in HSP may facilitate this association through electrostatic interactions at the cell surface. This was supported by experiments where the addition of mono (K(+)) and divalent (Ca(+2)) cations (0.005-0.05M) reduced the killing efficacy of HSP but not HP. Experiments designed to distinguish any inhibitory effect of silver from that of peroxide in HSP were carried out by monitoring the metabolic activity of established P. aeruginosa PAO1 biofilms. Concentrations of 70-500 ppm HSP had a pronounced effect on metabolic activity while the equivalent concentrations of ionic silver (50- 375 ppb) had a negligible effect, demonstrating that the microbiocidal activity of HSP was due to peroxide rather than silver. Overall, it was found that the antimicrobial activity of HSP is enhanced over that of hydrogen peroxide; the presence of the ionic silver enhances interactions of HSP with the bacterial cell surface rather than acting directly as a biocide at the tested concentrations.

Crystal structure of a novel prokaryotic Ser/Thr kinase and its implication in the Cpx stress response pathway.

The Cpx signalling system of Escherichia coli and Salmonella enterica senses extracytoplasmic stress and controls expression of factors that allow the bacterium to adapt to these stressors and thereby enhance survival. Many of the Cpx-responsive genes products are of unknown function. We determined the crystal structure of one of these gene products, called YihE in E. coli, which exhibits a eukaryotic kinase fold. Functional assays established that both YihE and the S. enterica YihE homologue, RdoA, undergo autophosphorylation and phosphorylate protein substrates at Ser/Thr residues in vitro, demonstrating that YihE/RdoA is a novel Ser/Thr protein kinase in prokaryotic cells. Phenotypic analysis of yihE/rdoA null strains indicates that this kinase is most abundant in stationary phase, and is important for long-term cell survival and for expression of surface appendages in both a Cpx-independent and -dependent manner. YihE/RdoA is therefore a previously unknown kinase component of a new type of bacterial phosphorelay mechanism, adding kinase activity as another response to the Cpx sensing system that functions to maintain cellular homeostasis.

The genome and proteome of coliphage T1.

The genome of enterobacterial phage T1 has been sequenced, revealing that its 50.7-kb terminally redundant, circularly permuted sequence contains 48,836 bp of nonredundant nucleotides. Seventy-seven open reading frames (ORFs) were identified, with a high percentage of small genes located at the termini of the genomes displaying no homology to existing phage or prophage proteins. Of the genes showing homologs (47%), we identified those involved in host DNA degradation (three endonucleases) and T1 replication (DNA helicase, primase, and single-stranded DNA-binding proteins) and recombination (RecE and Erf homologs). While the tail genes showed homology to those from temperate coliphage N15, the capsid biosynthetic genes were unique. Phage proteins were resolved by 2D gel electrophoresis, and mass spectrometry was used to identify several of the spots including the major head, portal, and tail proteins, thus verifying the annotation.