The complex vaginal flora of West African women with bacterial vaginosis

Background

The spectrum of bacteria associated with bacterial vaginosis (BV) has recently expanded through taxonomic changes and the use of molecular methods. These methods have yet to be used in large-scale epidemiological studies in Africa where BV is highly prevalent.

Methods

An analysis of samples obtained during a clinical trial of the management of vaginal discharge in four West African countries. Samples were available from 1555 participants; 843 (54%) had BV. Nucleic acids of 13 bacterial genera or species potentially associated with BV were detected through the polymerase chain reaction.

Results

The associations between various components of the vaginal flora were complex. Excluding Lactobacillus, the other 12 micro-organisms were all associated with each other at the p≤0.001 level. The prevalence of various bacterial genera or species varied according to age, sexual activity and HIV status. In multivariate analysis, the presence of Gardnerella vaginalis, Bifidobacterium, Megasphaera elsdenii, Dialister, Mycoplasma hominis, Leptotrichia, and Prevotella were independently associated with BV as was the absence of Lactobacillus and Peptoniphilus. However, Mobiluncus, Atopobium vaginae, Anaerococcus, and Eggerthella were not independently associated with BV. Unexpectedly, after treatment with a regimen that included either metronidazole or tinidazole, the proportion of patients with a complete resolution of symptoms by day 14 increased with the number of bacterial genera or species present at enrolment.

Conclusions

Numerous bacterial genera or species were strongly associated with each other in a pattern that suggested a symbiotic relationship. BV cases with a simpler flora were less likely to respond to treatment. Overall, the vaginal flora of West African women with BV was reminiscent of that of their counterparts in industrialized countries.     

Daytime Sleep Enhances Consolidation of the Spatial but Not Motoric Representation of Motor Sequence Memory

Motor sequence learning is known to rely on more than a single process. As the skill develops with practice, two different representations of the sequence are formed: a goal representation built under spatial allocentric coordinates and a movement representation mediated through egocentric motor coordinates. This study aimed to explore the influence of daytime sleep (nap) on consolidation of these two representations. Through the manipulation of an explicit finger sequence learning task and a transfer protocol, we show that both allocentric (spatial) and egocentric (motor) representations of the sequence can be isolated after initial training. Our results also demonstrate that nap favors the emergence of offline gains in performance for the allocentric, but not the egocentric representation, even after accounting for fatigue effects. Furthermore, sleep-dependent gains in performance observed for the allocentric representation are correlated with spindle density during non-rapid eye movement (NREM) sleep of the post-training nap. In contrast, performance on the egocentric representation is only maintained, but not improved, regardless of the sleep/wake condition. These results suggest that motor sequence memory acquisition and consolidation involve distinct mechanisms that rely on sleep (and specifically, spindle) or simple passage of time, depending respectively on whether the sequence is performed under allocentric or egocentric coordinates.     

Mechanism of dopamine D2 receptor-induced Ca2 + release in PC-12 cells

Intracellular Ca^2 + levels are tightly regulated in the neuronal system. The loss of Ca^2 + homeostasis is associated with many neurological diseases and neuropsychiatric disorders such as Parkinson's, Alzheimer's, and schizophrenia. We investigated the mechanisms involved in intracellular Ca^2 + signaling in PC-12 cells. The stimulation of NGF-differentiated PC-12 cells with 3 μM ATP caused an early Ca^2 + release followed by a delayed Ca^2 + release. The delayed Ca^2 + release was dependent on prior ATP priming and on dopamine secretion by PC-12 cells. Delayed Ca^2 + release was abolished in the presence of spiperone, suggesting that it is due to the activation of D2 dopamine receptors (D2R) by dopamine secreted by PC-12 cells. This was shown to be independent of PKA activation but dependent on PLC activity. An endocytosis step was required for inducing the delayed Ca^2 + release. Given the importance of calcyon in clathrin-mediated endocytosis, we verified the role of this protein in the delayed Ca^2 + release phenomenon. siRNA targeting of calcyon blocked the delayed Ca^2 + release, decreased ATP-evoked IP₃R-mediated Ca^2 + release, and impaired subsequent Ca^2 + oscillations. Our results suggested that calcyon is involved in an unknown mechanism that causes a delayed IP₃R-mediated Ca^2 + release in PC-12 cells. In schizophrenia, Ca^2 + dysregulation may depend on the upregulation of calcyon, which maintains elevated Ca^2 + levels as well as dopamine signaling.     

Th3 cells in peripheral tolerance. II. TGF-beta-transgenic Th3 cells rescue IL-2-deficient mice from autoimmunity

We developed a transgenic (Tg) mouse that expresses TGF-beta under control of the IL-2 promoter to investigate Th3 cell differentiation both in vitro and in vivo. We previously found that repetitive in vitro Ag stimulation results in constant expression of Foxp3 in TGF-beta-Tg Th3 cells that acquire regulatory function independent of surface expression of CD25. To examine the differentiation and function of Th3 cells in vivo and to compare them with thymic-derived CD4(+)CD25(+) regulatory T cells (Treg), we introduced the TGF-beta transgene into T cells of IL-2-deficient (IL-2(-/-)) mice. We found that the induction, differentiation, and function of TGF-beta-derived Foxp3(+) Th3 cells were independent of IL-2, which differs from thymic Tregs. In an environment that lacks functional CD25(+) thymic-derived Tregs, expression of the TGF-beta transgene in IL-2(-/-) mice led to the induction of distinct CD25(-) regulatory cells in the periphery. These cells expressed Foxp3 and efficiently controlled hyperproliferation of T cells and rescued the IL-2(-/-) mouse from lethal autoimmunity. Unlike IL-2(-/-) animals, TGF-beta/IL-2(-/-) mice had normal numbers of T cells, B cells, macrophages, and dendritic cells and did not have splenomegaly, lymphadenopathy, or inflammation in multiple organs. Accumulation of Foxp3(+) cells over time, however, was dependent on IL-2. Our results suggest that TGF-beta-derived Foxp3(+)CD25(+/-) Th3 regulatory cells represent a different cell lineage from thymic-derived CD25(+) Tregs in the periphery but may play an important role in maintaining thymic Tregs in the peripheral immune compartment by secretion of TGF-beta.     

Identification and quantification of glycoside flavonoids in the energy crop Albizia julibrissin

Oxygen radical absorbance capacity (ORAC) values showed that methanolic extracts of Albizia julibrissin foliage displayed antioxidant activity. High performance liquid chromatography (HPLC) and mass spectrometry (MS) techniques were utilized in the identification of the compounds. The analysis confirmed the presence of three compounds in A. julibrissin foliage methanolic extract: an unknown quercetin derivative with mass of 610 Da, hyperoside (quercetin-3-O-galactoside), and quercitrin (quercetin-3-O-rhamnoside). Fast performance liquid chromatography (FPLC) was employed to fractionate the crude A. julibrissin foliage methanolic extract into its individual flavonoid components. The flavonoids were quantified in terms of mass and their respective contribution to the overall ORAC value. Quercetin glycosides accounted for 2.0% of total foliage.     

Diel patterning in the bacterial community associated with the sea anemone Nematostella vectensis

Microbes can play an important role in the physiology of animals by providing essential nutrients, inducing immune pathways, and influencing the specific species that compose the microbiome through competitive or facilitatory interactions. The community of microbes associated with animals can be dynamic depending on the local environment, and factors that influence the composition of the microbiome are essential to our understanding of how microbes may influence the biology of their animal hosts. Regularly repeated changes in the environment, such as diel lighting, can result in two different organismal responses: a direct response to the presence and absence of exogenous light and endogenous rhythms resulting from a molecular circadian clock, both of which can influence the associated microbiota. Here, we report how diel lighting and a potential circadian clock impacts the diversity and relative abundance of bacteria in the model cnidarian Nematostella vectensis using an amplicon‐based sequencing approach. Comparisons of bacterial communities associated with anemones cultured in constant darkness and in light:dark conditions revealed that individuals entrained in the dark had a more diverse microbiota. Overall community composition showed little variation over a 24‐hr period in either treatment; however, abundances of individual bacterial OTUs showed significant cycling in each treatment. A comparative analysis of genes involved in the innate immune system of cnidarians showed differential expression between lighting conditions in N. vectensis, with significant up‐regulation during long‐term darkness for a subset of genes. Together, our studies support a hypothesis that the bacterial community associated with this species is relatively stable under diel light conditions when compared with static conditions and that particular bacterial members may have time‐dependent abundance that coincides with the diel photoperiod in an otherwise stable community.     

Reduced Slow-Wave Rebound during Daytime Recovery Sleep in Middle-Aged Subjects

Cortical synchronization during NREM sleep, characterized by electroencephalographic slow waves (SW <4Hz and >75 μV), is strongly related to the number of hours of wakefulness prior to sleep and to the quality of the waking experience. Whether a similar increase in wakefulness length leads to a comparable enhancement in NREM sleep cortical synchronization in young and older subjects is still a matter of debate in the literature. Here we evaluated the impact of 25-hours of wakefulness on SW during a daytime recovery sleep episode in 29 young (27y ±5), and 34 middle-aged (51y ±5) subjects. We also assessed whether age-related changes in NREM sleep cortical synchronization predicts the ability to maintain sleep during daytime recovery sleep. Compared to baseline sleep, sleep efficiency was lower during daytime recovery sleep in both age-groups but the effect was more prominent in the middle-aged than in the young subjects. In both age groups, SW density, amplitude, and slope increased whereas SW positive and negative phase duration decreased during daytime recovery sleep compared to baseline sleep, particularly in anterior brain areas. Importantly, compared to young subjects, middle-aged participants showed lower SW density rebound and SW positive phase duration enhancement after sleep deprivation during daytime recovery sleep. Furthermore, middle-aged subjects showed lower SW amplitude and slope enhancements after sleep deprivation than young subjects in frontal and prefrontal derivations only. None of the SW characteristics at baseline were associated with daytime recovery sleep efficiency. Our results support the notion that anterior brain areas elicit and may necessitate more intense recovery and that aging reduces enhancement of cortical synchronization after sleep loss, particularly in these areas. Age-related changes in the quality of wake experience may underlie age-related reduction in markers of cortical synchronization enhancement after sustained wakefulness.