P2 pyridine N-oxide thrombin inhibitors: a novel peptidomimetic scaffold

In this study, we have demonstrated that the critical hydrogen bonding motif of the established 3-aminopyrazinone thrombin inhibitors can be effectively mimicked by a 2-aminopyridine N-oxide. As this peptidomimetic core is more resistant toward oxidative metabolism, it also overcomes the metabolic liability associated with the pyrazinones. An optimization study of the P(1) benzylamide delivered the potent thrombin inhibitor 21 (K(i) = 3.2 nM, 2xaPTT = 360 nM), which exhibited good plasma levels and half-life after oral dosing in the dog (C(max) = 2.6 microM, t(1/2) = 4.5 h).     

A fluorescence-based high-throughput assay for antimicrotubule drugs

With the advent of combinatorial chemistry and the extensive libraries of potential drugs produced from it, there is a growing need for rapid sensitive, high-throughput screening for drug potency. Microtubules are important targets for anticancer agents, and new antimicrotubule compounds are of continued interest in drug development. The in vitro potency of antimicrotubule drugs may be evaluated by measuring the extent of tubulin assembly. The extent of polymerization is proportional to the turbidity of the solution, which usually has been measured as apparent absorption. The turbidity method has inherent problems that hinder its adaptation to a high-throughput format, such as a requirement for high protein concentrations and a high coefficient of variation. We present here a high-throughput assay for antimicrotubule activity in which fluorescence is used to monitor microtubule assembly. Both assembly-inhibiting and assembly-promoting compounds can be evaluated. The assay is rapid and easy to perform, and the data are reliable, with good accuracy and reproducibility.     

Vaccine effectiveness against SARS-CoV-2 infection or COVID-19 hospitalization with the Alpha,Delta, or Omicron SARS-CoV-2 variant: A nationwide Danish cohort study

BackgroundThe continued occurrence of more contagious Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) variants and waning immunity over time require ongoing reevaluation of the vaccine effectiveness (VE). This study aimed to estimate the effectiveness in 2 age groups (12 to 59 and 60 years or above) of 2 or 3 vaccine doses (BNT162b2 mRNA or mRNA-1273) by time since vaccination against SARS-CoV-2 infection and Coronavirus Disease 2019 (COVID-19) hospitalization in an Alpha-, Delta-, or Omicron-dominated period.Methods and findingsA Danish nationwide cohort study design was used to estimate VE against SARS-CoV-2 infection and COVID-19 hospitalization with the Alpha, Delta, or Omicron variant. Information was obtained from nationwide registries and linked using a unique personal identification number. The study included all previously uninfected residents in Denmark aged 12 years or above (18 years or above for the analysis of 3 doses) in the Alpha (February 20 to June 15, 2021), Delta (July 4 to November 20, 2021), and Omicron (December 21, 2021 to January 31, 2022) dominated periods. VE estimates including 95% confidence intervals (CIs) were calculated (1-hazard ratio∙100) using Cox proportional hazard regression models with underlying calendar time and adjustments for age, sex, comorbidity, and geographical region. Vaccination status was included as a time-varying exposure. In the oldest age group, VE against infection after 2 doses was 90.7% (95% CI: 88.2; 92.7) for the Alpha variant, 82.3% (95% CI: 75.5; 87.2) for the Delta variant, and 39.9% (95% CI: 26.3; 50.9) for the Omicron variant 14 to 30 days since vaccination. The VE waned over time and was 73.2% (Alpha, 95% CI: 57.1; 83.3), 50.0% (Delta, 95% CI: 46.7; 53.0), and 4.4% (Omicron, 95% CI: −0.1; 8.7) >120 days since vaccination. Higher estimates were observed after the third dose with VE estimates against infection of 86.1% (Delta, 95% CI: 83.3; 88.4) and 57.7% (Omicron, 95% CI: 55.9; 59.5) 14 to 30 days since vaccination. Among both age groups, VE against COVID-19 hospitalization 14 to 30 days since vaccination with 2 or 3 doses was 98.1% or above for the Alpha and Delta variants. Among both age groups, VE against COVID-19 hospitalization 14 to 30 days since vaccination with 2 or 3 doses was 95.5% or above for the Omicron variant. The main limitation of this study is the nonrandomized study design including potential differences between the unvaccinated (reference group) and vaccinated individuals.ConclusionsTwo vaccine doses provided high protection against SARS-CoV-2 infection and COVID-19 hospitalization with the Alpha and Delta variants with protection, notably against infection, waning over time. Two vaccine doses provided only limited and short-lived protection against SARS-CoV-2 infection with Omicron. However, the protection against COVID-19 hospitalization following Omicron SARS-CoV-2 infection was higher. The third vaccine dose substantially increased the level and duration of protection against infection with the Omicron variant and provided a high level of sustained protection against COVID-19 hospitalization among the +60-year-olds.

Mie Agermose Gram and colleagues estimate vaccine effectiveness against infection and COVID-19 hospitalization with the Alpha, Delta or Omicron variant in Denmark.     

Identification of novel Bacillus thuringiensis Cry1Ac binding proteins in Manduca sexta midgut through proteomic analysis

The crystal proteins of Bacillus thuringiensis are widely used in transgenic crops and commercially available insecticides. Manduca sexta, the tobacco hornworm, is the model insect for B. thuringiensis studies. Although brush border vesicles prepared from larval M. sexta midgut have been used in numerous mode-of-action studies of B. thuringiensis toxins, their protein components are mostly unknown. Vesicles prepared from the brush border of M. sexta midgut were analyzed using one- and two-dimensional gel electrophoresis to establish a midgut brush border proteome. Sub-proteomes were also established for B. thuringiensis Cry1Ac binding proteins and glycosylphosphatidyl inositol (GPI) anchored proteins. Peptide mass fingerprints were generated for several spots identified as Cry1Ac binding proteins and GPI-anchored proteins and these fingerprints were used for database searches. Results generally did not produce matches to M. sexta proteins, but did match proteins of other Lepidoptera. Actin and alkaline phosphatase were identified as novel proteins that bind Cry1Ac in addition to the previously reported aminopeptidase N. Aminopeptidase N was the only GPI-anchored protein identified. Actin, aminopeptidase N, and membrane alkaline phosphatase were confirmed as accurate protein identifications through western blots.     

Biogeographic Ancestry Is Associated with Higher Total Body Adiposity among African-American Females: The Boston Area Community Health Survey

Objectives

The prevalence of obesity is disproportionately higher among African-Americans and Hispanics as compared to whites. We investigated the role of biogeographic ancestry (BGA) on adiposity and changes in adiposity in the Boston Area Community Health Survey.

Methods

We evaluated associations between BGA, assessed via Ancestry Informative Markers, and adiposity (body mass index (BMI), percent body fat (PBF), and waist-to-hip ratio (WHR)) and changes in adiposity over 7 years for BMI and WHR and 2.5 years for PBF, per 10% greater proportion of BGA using multivariable linear regression. We also examined effect-modification by demographic and socio-behavioral variables.

Results

We observed positive associations between West-African ancestry and cross-sectional BMI (percent difference=0.62%; 95% CI: 0.04%, 1.20%), and PBF (β=0.35; 95% CI: 0.11, 0.58). We also observed significant effect-modification of the association between West-African ancestry and BMI by gender (p-interaction: <0.002) with a substantially greater association in women. We observed no main associations between Native-American ancestry and adiposity but observed significant effect-modification of the association with BMI by diet (p-interaction: <0.003) with inverse associations among participants with higher Healthy Eating Scores. No associations were observed between BGA and changes in adiposity over time.

Conclusion

Findings support that West-African ancestry may contribute to high prevalence of total body adiposity among African-Americans, particularly African-American women.     

Site fidelity and homing in tropical coral reef cardinalfish: are they using olfactory cues?

A number of tropical coral reef fish hold station and display restricted home ranges. If artificially displaced, they will return to their home site. We questioned if marine fish are using the same mechanisms for home site detection as many freshwater fish, that is, by olfactory sensing of chemical signals deposited on the substrate by conspecific fish. Behavioral experiments were conducted on Lizard Island Research Station, Queensland, Australia, in 2001 and 2002. Five-lined cardinalfish (Cheilodipterus quinquelineatus) were tested in groups with split-branded cardinalfish (Apogon compressus) as a reference species and individually against Apogon leptacanthus as well as conspecifics of another reef site. The group tests showed that both species preferred artificial reef sites that had previously been occupied by conspecifics. Individual C. quinquelineatus preferred scent of conspecifics from their own reef site to that from another site. They also preferred the scent released by artificial reefs previously occupied by conspecifics of their reef site to that of similar reefs previously occupied by conspecifics of another reef site. No discrimination between species from the same reef site was obtained in experiments with individual fish. Our data suggest that cardinalfish are keeping station and are homing by use of conspecific olfactory signals.     

Determinants of the interaction of the spinal muscular atrophy disease protein SMN with the dimethylarginine-modified box H/ACA small nucleolar ribonucleoprotein GAR1

Deletion or mutation of the SMN1 (survival of motor neurons) gene causes the common, fatal neuromuscular disease spinal muscular atrophy. The SMN protein is important in small nuclear ribonucleoprotein (snRNP) assembly and interacts with snRNP proteins via arginine/glycine-rich domains. Recently, SMN was also found to interact with core protein components of the two major families of small nucleolar RNPs, fibrillarin and GAR1, suggesting that SMN may also function in the assembly of small nucleolar RNPs. Here we present results that indicate that the interaction of SMN with GAR1 is mediated by the Tudor domain of SMN. Single point mutations within the Tudor domain, including a spinal muscular atrophy patient mutation, impair the interaction of SMN with GAR1. Furthermore, we find that either of the two arginine/glycine-rich domains of GAR1 can provide for interaction with SMN, but removal of both results in loss of the interaction. Finally, we have found that unlike the interaction of SMN with the Sm snRNP proteins, interaction with GAR1 and fibrillarin is not enhanced by arginine dimethylation. Our results argue against post-translational arginine dimethylation as a general requirement for SMN recognition of proteins bearing arginine/glycine-rich domains.     

Rain use efficiency as affected by climate warming and biofuel harvest: results from a 12‐year field experiment

The efficiency of a terrestrial ecosystem to use rainfall in production is critical in regulating the ecological functions of the earth system under global change. However, it remains unclear how rain use efficiency (RUE) will be altered by changes in climate and human activities such as biofuel harvest. In this study, we used RUE data from a long‐term experiment in a tallgrass prairie to analyze the effects of warming and biofuel harvest (clipping). From 2000 to 2011, experimental warming enhanced RUE in most years, with larger positive effects in normal and wet than dry hydrological years. Clipping decreased RUE in dry and normal hydrological years, but had no impact on RUE in wet years. The observed RUE responses resulted from treatment‐induced changes in both biologically ineffective (i.e., runoff and soil evaporation) and effective (i.e., transpiration) parts of precipitation. For example, litter cover was increased in warming plots, but reduced by clipping, leading to negative and positive effects on runoff and soil evaporation, respectively. The dominance of C₄ species, which usually have higher water use efficiency than C₃ species, was enhanced by warming, but reduced by clipping. Moreover, RUE was positively correlated with ratios of rainfall in the late growing season (June–August), when the growth of C₄ plants was most active, relative to that in the other seasons. Our results indicate that RUE is positively influenced by climate warming, but negatively affected by biofuel harvest in tallgrass prairie of the Great Plains. These findings highlight the important roles of plant community structure and temporal distribution of precipitation in regulating ecosystem RUE.