Identification of Fluorescent-Antibody Labeled Group A Streptococci by Fluorometry

A quantitative system, amenable to automation, for determining the presence of group A streptococci in broth culture is described. After separation from the broth, the cells' protein coats are removed by digestion with 0.1% trypsin, and they are then stained with anti-A fluorescent antibody (FA). Excess FA is removed, and bound FA is put into solution by dissociation with demineralized distilled water. The amount of FA bound to the cells is quantitated by fluorometry of the solution. The level of nonspecific staining is measured by staining the cells with fluorescein-conjugated normal rabbit globulin absorbed with group A cells, dissociating, and quantifying, as above. The two quantities are subtracted to measure specific binding of FA to group A cells. A clinical trial showed 92% agreement with microscopists.     

Experimental models of maternal–fetal interface and their potential use for nanotechnology applications

During pregnancy, the placenta regulates the transfer of oxygen, nutrients, and residual products between the maternal and fetal bloodstreams and is a key determinant of fetal exposure to xenobiotics from the mother. To study the disposition of substances through the placenta, various experimental models are used, especially the perfused placenta, placental villi explants, and cell lineage models. In this context, nanotechnology, an area of study that is on the rise, enables the creation of particles on nanometric scales capable of releasing drugs aimed at specific tissues. An important reason for furthering the studies on transplacental transfer is to explore the potential of nanoparticles (NPs), in new delivery strategies for drugs that are specifically aimed at the mother, the placenta, or the fetus and that involve less toxicity. Due to the fact that the placental barrier is essential for the interaction between the maternal and fetal organisms as well as the possibility of NPs being used in the treatment of various pathologies, the aim of this review is to present the main experimental models used in studying the maternal–fetal interaction and the action of NPs in the placental environment.     

Validation of a Dehydroepiandrosterone-Sulfate Assay in Three Platyrrhine Primates (Alouatta caraya,Aotus azarae infulatus,and Sapajus apella)

International Journal of Primatology - The hormone dehydroepiandrosterone (DHEA) and its sulfate ester (DHEAS) are the most abundant circulating steroids in human and some nonhuman primates, and...     

Heme induces significant neutrophil adhesion in vitro via an NFκB and reactive oxygen species-dependent pathway

Molecular and Cellular Biochemistry - Intravascular hemolysis, a major manifestation of sickle cell disease (SCD) and other diseases, incurs the release of hemoglobin and heme from red blood cells,...     

Antitumor activity via apoptotic cell death pathway of water soluble copper(II) complexes: effect of the diamino unit on selectivity against lung cancer NCI-H460 cell line

BioMetals - The cytotoxicity against five human tumor cell lines (THP-1, U937, Molt-4, Colo-205 and NCI-H460) of three water soluble copper(II) coordination compounds containing the ligands...     

The Ozone-Iodine-Chlorate Clock Reaction

This work presents a new clock reaction based on ozone, iodine, and chlorate that differs from the known chlorate-iodine clock reaction because it does not require UV light. The induction period for this new clock reaction depends inversely on the initial concentrations of ozone, chlorate, and perchloric acid but is independent of the initial iodine concentration. The proposed mechanism considers the reaction of ozone and iodide to form HOI, which is a key species for producing non-linear autocatalytic behavior. The novelty of this system lies in the presence of ozone, whose participation has never been observed in complex systems such as clock or oscillating reactions. Thus, the autocatalysis demonstrated in this new clock reaction should open the possibility for a new family of oscillating reactions.     

Prevalence of HIV,STIs, and Risk Behaviors in a Cross-Sectional Community- and Clinic-Based Sample of Men Who Have Sex with Men (MSM) in Lima,Peru

Background

Further research is necessary to understand the factors contributing to the high prevalence of HIV/STIs among men who have sex with men (MSM) in Peru. We compared HIV/STI prevalence and risk factors between two non-probability samples of MSM, one passively enrolled from an STI clinic and the other actively enrolled from community venues surrounding the clinic in Lima, Peru.

Methods

A total of 560 self-identified MSM were enrolled between May-December, 2007. 438 subjects enrolled from a municipal STI clinic and 122 subjects enrolled during community outreach visits. All participants underwent screening for HIV, syphilis, HSV-2, gonorrhoea, and chlamydia and completed a survey assessing their history of HIV/STIs, prior HIV testing, and sexual behavior.

Results

HIV prevalence was significantly higher among MSM enrolled from the clinic, with previously undiagnosed HIV identified in 9.1% compared with 2.6% of community participants. 15.4 % of all MSM screened were infected with ≥1 curable STI, 7.4% with early syphilis (RPR≥1∶16) and 5.5% with urethral gonorrhoea and/or chlamydia. No significant differences between populations were reported in prevalence of STIs, number of male sex partners, history of unprotected anal intercourse, or alcohol and/or drug use prior to sex. Exchange of sex for money or goods was reported by 33.5% of MSM enrolled from the clinic and 21.2% of MSM from the community (p = 0.01).

Conclusions

Our data demonstrate that the prevalence of HIV and STIs, including syphilis, gonorrhoea, and chlamydia are extremely high among MSM enrolled from both clinic and community venues in urban Peru. New strategies are needed to address differences in HIV/STI epidemiology between clinic- and community-enrolled samples of MSM.