Characterization of microsatellite loci for the Argentine ant,Linepithema humile,and their potential for analysis of colony structure in invading Hawaiian populations

We developed primers for five polymorphic microsatellite loci to analyse the genetic structure of colonies in an invading Argentine ant population located in Haleakala National Park on the island of Maui, Hawaii. Microsatellite loci were isolated using both a polymerase chain reaction‐based and a cloning‐based method. With a range of 3–18 alleles and expected levels of heterozygosity of 0.46–0.77, these loci provide useful markers for the detection of colony and population structure in new or expanding populations of this species.     

Functional insights from proteome-wide structural modeling of <Emphasis Type="Italic">Treponema pallidum</Emphasis> subspecies <Emphasis Type="Italic">pallidum</Emphasis>, the causative agent of syphilis

Background

Syphilis continues to be a major global health threat with 11 million new infections each year, and a global burden of 36 million cases. The causative agent of syphilis, Treponema pallidum subspecies pallidum, is a highly virulent bacterium, however the molecular mechanisms underlying T. pallidum pathogenesis remain to be definitively identified. This is due to the fact that T. pallidum is currently uncultivatable, inherently fragile and thus difficult to work with, and phylogenetically distinct with no conventional virulence factor homologs found in other pathogens. In fact, approximately 30% of its predicted protein-coding genes have no known orthologs or assigned functions. Here we employed a structural bioinformatics approach using Phyre2-based tertiary structure modeling to improve our understanding of T. pallidum protein function on a proteome-wide scale.

Results

Phyre2-based tertiary structure modeling generated high-confidence predictions for 80% of the T. pallidum proteome (780/978 predicted proteins). Tertiary structure modeling also inferred the same function as primary structure-based annotations from genome sequencing pipelines for 525/605 proteins (87%), which represents 54% (525/978) of all T. pallidum proteins. Of the 175 T. pallidum proteins modeled with high confidence that were not assigned functions in the previously annotated published proteome, 167 (95%) were able to be assigned predicted functions. Twenty-one of the 175 hypothetical proteins modeled with high confidence were also predicted to exhibit significant structural similarity with proteins experimentally confirmed to be required for virulence in other pathogens.

Conclusions

Phyre2-based structural modeling is a powerful bioinformatics tool that has provided insight into the potential structure and function of the majority of T. pallidum proteins and helped validate the primary structure-based annotation of more than 50% of all T. pallidum proteins with high confidence. This work represents the first T. pallidum proteome-wide structural modeling study and is one of few studies to apply this approach for the functional annotation of a whole proteome.

     

Dose effects of modified alternate-day fasting regimens on in vivo cell proliferation and plasma insulin-like growth factor-1 in mice.

Reduced cell proliferation is associated with lower cancer risk. Alternate-day fasting (ADF), defined as alternating 24-h periods of ad libitum feeding and fasting, decreases cell proliferation. The effect of modified regimens of ADF on cell proliferation, however, has not been examined. This study measured the effects of modified ADF regimens on prostate and splenic T-cell proliferation and circulating insulin-like growth factor-1 (IGF-1) levels in mice. In a 4-wk study, 24 male C57BL/6J mice were randomized to one of four interventions: 1) ADF-25% [25% calorie restriction (CR) on fast day], 2) ADF-50% (50% CR on fast day), 3) ADF-100% (100% CR on fast day), and 4) control. Body weight of the ADF-100% group was less (P < 0.005) than that of the ADF-25% and ADF-50% groups posttreatment. On the feast day, the ADF-100% and ADF-50% groups ate 85% and 45% more food, respectively, than controls, indicating a hyperphagic response to fasting. Proliferation rates of T-cells were 6% and 30% lower (P < 0.05) in the ADF-50% and ADF-100% groups, respectively, relative to controls. Prostate cell proliferation was reduced (P < 0.05) by 49% in the ADF-100% group, relative to controls, but did not change in the other groups. IGF-1 levels were reduced (P < 0.05) by 40%, relative to controls, in the ADF-100% group. These findings confirm the beneficial effects of ADF-100% on cancer risk by decreasing cell proliferation and IGF-1 levels and suggest that modified ADF regimens comprising 25-50% CR on the fast day do not replicate these effects.     

On the presence and localization of glycogen accumulations inside coronet cells of the saccus vasculosus of the dogfish (Scylliorhinus caniculus)

Summary In several coronet cells of the saccus vasculosus of Scylliorhinus large quantities of glycogen occur, as shown by light and electron microscopy. The significance of glycogen as an energy storage necessary for a transcellular ion transport process taking place in the coronet cells is discussed.The authors thank Dr. F.C.G. van de Veerdonk, W. F. Jansen and W. F. G. Flight for reading the manuscipt and for their critical remarks. They are also indebted to Mr. H. van Kooten and his staff for their valuable photographic assistance.     

Insulin Stimulates S100B Secretion and These Proteins Antagonistically Modulate Brain Glucose Metabolism

Neurochemical Research - Brain metabolism is highly dependent on glucose, which is derived from the blood circulation and metabolized by the astrocytes and other neural cells via several pathways....     

Capturing single cell genomes of active polysaccharide degraders: an unexpected contribution of Verrucomicrobia

Microbial hydrolysis of polysaccharides is critical to ecosystem functioning and is of great interest in diverse biotechnological applications, such as biofuel production and bioremediation. Here we demonstrate the use of a new, efficient approach to recover genomes of active polysaccharide degraders from natural, complex microbial assemblages, using a combination of fluorescently labeled substrates, fluorescence-activated cell sorting, and single cell genomics. We employed this approach to analyze freshwater and coastal bacterioplankton for degraders of laminarin and xylan, two of the most abundant storage and structural polysaccharides in nature. Our results suggest that a few phylotypes of Verrucomicrobia make a considerable contribution to polysaccharide degradation, although they constituted only a minor fraction of the total microbial community. Genomic sequencing of five cells, representing the most predominant, polysaccharide-active Verrucomicrobia phylotype, revealed significant enrichment in genes encoding a wide spectrum of glycoside hydrolases, sulfatases, peptidases, carbohydrate lyases and esterases, confirming that these organisms were well equipped for the hydrolysis of diverse polysaccharides. Remarkably, this enrichment was on average higher than in the sequenced representatives of Bacteroidetes, which are frequently regarded as highly efficient biopolymer degraders. These findings shed light on the ecological roles of uncultured Verrucomicrobia and suggest specific taxa as promising bioprospecting targets. The employed method offers a powerful tool to rapidly identify and recover discrete genomes of active players in polysaccharide degradation, without the need for cultivation.     

Conjugation of oligosaccharides by reductive amination to amine modified chondroitin oligomer and γ-cyclodextrin

Carbohydrates present on cell surfaces participate in numerous biological recognition phenomena including cell–cell interactions, cancer metastasis and pathogen invasion. Therefore, synthetic carbohydrates have a potential to act as pharmaceutical substances for treatment of various pathological phenomena by inhibiting specifically the interaction between cell surface carbohydrates and their protein receptors (lectins). However, the inherently low affinity of carbohydrate-protein interactions has often been an obstacle for successful generation of carbohydrate based pharmaceuticals. Multivalent glycoconjugates, i.e. structures carrying several copies of the active carbohydrate sequence in a carrier molecule, have been constructed to overcome this problem. Here we present two novel types of multivalent carbohydrate conjugates based on chondroitin oligomer and cyclodextrin carriers. These carriers were modified to express primary amino groups, and oligosaccharides were then bound to carrier molecules by reductive amination. Multivalent conjugates were produced using the human milk type oligosaccharides LNDFH I (Lewis-b hexasaccharide), LNnT, and GlcNAcβ1-3Galβ1-4GlcNAcβ1-3Galβ1-4Glc.     

Text Messaging to Improve Attendance at Post-Operative Clinic Visits after Adult Male Circumcision for HIV Prevention: A Randomized Controlled Trial

Background

Following male circumcision for HIV prevention, a high proportion of men fail to return for their scheduled seven-day post-operative visit. We evaluated the effect of short message service (SMS) text messages on attendance at this important visit.

Methodology

We enrolled 1200 participants >18 years old in a two-arm, parallel, randomized controlled trial at 12 sites in Nyanza province, Kenya. Participants received daily SMS text messages for seven days (n = 600) or usual care (n = 600). The primary outcome was attendance at the scheduled seven-day post-operative visit. The primary analysis was by intention-to-treat.

Principal Findings

Of participants receiving SMS, 387/592 (65.4%) returned, compared to 356/596 (59.7%) in the control group (relative risk [RR] = 1.09, 95% confidence interval [CI] 1.00–1.20; p = 0.04). Men who paid more than US$1.25 to travel to clinic were at higher risk for failure to return compared to those who spent ≤US$1.25 (adjusted relative risk [aRR] 1.35, 95% CI 1.15–1.58; p<0.001). Men with secondary or higher education had a lower risk of failure to return compared to those with primary or less education (aRR 0.87, 95% CI 0.74–1.01; p = 0.07).

Conclusions

Text messaging resulted in a modest improvement in attendance at the 7-day post-operative clinic visit following adult male circumcision. Factors associated with failure to return were mainly structural, and included transportation costs and low educational level.

Trial Registration

ClinicalTrials.gov NCT01186575     

Monoclonal antibody disulfide reduction during manufacturing

Manufacturing-induced disulfide reduction has recently been reported for monoclonal human immunoglobulin gamma (IgG) antibodies, a widely used modality in the biopharmaceutical industry. This effect has been tied to components of the intracellular thioredoxin reduction system that are released upon cell breakage. Here, we describe the effect of process parameters and intrinsic molecule properties on the extent of reduction. Material taken from cell cultures at the end of production displayed large variations in the extent of antibody reduction between different products, including no reduction, when subjected to the same reduction-promoting harvest conditions. Additionally, in a reconstituted model in which process variables could be isolated from product properties, we found that antibody reduction was dependent on the cell line (clone) and cell culture process. A bench-scale model using a thioredoxin/thioredoxin reductase regeneration system revealed that reduction susceptibility depended on not only antibody class but also light chain type; the model further demonstrates that the trend in reducibility was identical to DTT reduction sensitivity following the order IgG1λ > IgG1κ > IgG2λ > IgG2κ. Thus, both product attributes and process parameters contribute to the extent of antibody reduction during production.