Gender interaction effect on coronary lumen volume to mass ratio after administration of sublingual GTN powder compared to tablet in coronary computed tomography angiography (CCTA)

Funding Acknowledgements

Type of funding sources: None.

Background

Nitroglycerin (GTN) results in improved CCTA image quality and diagnostic accuracy due to vasodilation and improved contrast density. Although studies have shown that sublingual (SL) GTN spray has greater vasodilation and faster onset and duration of action compared to SL tablet, it is not commonly used due to cost. The comparative efficacy of SL GTN powder in CCTA is unknown.

Purpose

The purpose of this study is to determine whether SL GTN powder can increase the coronary lumen volume (V) and the coronary lumen volume to left myocardial mass ratio (V/M) compared to SL GTN tablet.

Methods

34 patients (17 females) with 0.8 mg SL GTN powder and 34 patients (17 females) with 0.8 mg SL GTN tablet administration were included in this retrospective case-control study.  GTN was given 5 minutes pre-CCTA on a 256 slice single-heartbeat CT. Inclusion criteria: CAD-RADS 0 or 1, precontrast LM + LAD AJ-130 CAC < 100, heart rate less than 75, phase of the cardiac cycle diastole, successful motion correction, Likert score 4 or 5, right- or co-dominance. The primary outcome assessed was left main plus left anterior descending (LM + LAD) V between GTN powder vs tablet. The secondary outcomes were LM + LAD V divided by 1) length of LM + LAD (derived mean area, A), and  2) M (V/M). The outcomes were measured by blinded PI with 17 yrs CCTA experience on GE workstation, 2020 version.  Categorical variables were compared by Chi-Squared tests and continuous variables were compared between powder and tablet groups by unpaired t-tests if normally distributed, and Mann-Whitney U tests otherwise. Exploratory outcome analyses tested route of administration by sex interactions and main effects by Two-Way ANOVA’s. Further covariate-adjusted analyses were conducted using multiple linear regression models. 

Results

Baseline characteristics were similar between powder and tablet administration. No statistically significant difference in median V, LM + LAD derived A , or median V/M  was observed. A sex main effect demonstrated that females had significantly smaller V (630.6 mm3 vs 951.7 mm3, p< 0.0001) and A (4.2 mm2 vs 6.4 mm2, p< 0.0001) compared to males. These V and A sex differences were also observed when BMI or weight were included as covariates. When V and A were normalized by M, both revealed sex interactions depending on formulation. While males had higher normalized V and A in powder vs tablet (p < 0.04), females had the opposite with higher normalized V and A with tablet compared to powder (p < 0.04). 

Conclusions

SL administration of the GTN powder 5 minutes before CCTA did not result in greater vasodilatory effect compared to the GTN tablet.  However, gender interaction effects were observed, with greater V/M and A/M ratio in males with powder and greater V/M and A/M in women with tablet. These results suggest a potential differential gender effect based on the formulation of GTN.  Prospective studies are warranted to evaluate these findings.

Abstract Figure. LM + LAD Lumen Volume to LV Mass by Sex

Bacterial genome editing by coupling Cre-lox and CRISPR-Cas9 systems

The past decade has been a golden age for microbiology, marked by the discovery of an unprecedented increase in the number of novel bacterial species. Yet gaining biological knowledge of those organisms has not kept pace with sequencing efforts. To unlock this genetic potential there is an urgent need for generic (i.e. non-species specific) genetic toolboxes. Recently, we developed a method, termed chassis-independent recombinase-assisted genome engineering (CRAGE), enabling the integration and expression of large complex gene clusters directly into the chromosomes of diverse bacteria. Here we expand upon this technology by incorporating CRISPR-Cas9 allowing precise genome editing across multiple bacterial species. To do that we have developed a landing pad that carries one wild-type and two mutant lox sites to allow integration of foreign DNA at two locations through Cre-lox recombinase-mediated cassette exchange (RMCE). The first RMCE event is to integrate the Cas9 and the DNA repair protein genes RecET, and the second RMCE event enables the integration of customized sgRNA and a repair template. Following this workflow, we achieved precise genome editing in four different gammaproteobacterial species. We also show that the inserted landing pad and the entire editing machinery can be removed scarlessly after editing. We report here the construction of a single landing pad transposon and demonstrate its functionality across multiple species. The modular design of the landing pad and accessory vectors allows design and assembly of genome editing platforms for other organisms in a similar way. We believe this approach will greatly expand the list of bacteria amenable to genetic manipulation and provides the means to advance our understanding of the microbial world.

Resequencing and annotation of the Nostoc punctiforme ATTC 29133 genome: facilitating biofuel and high-value chemical production

Cyanobacteria have the potential to produce bulk and fine chemicals and members belonging to Nostoc sp. have received particular attention due to their relatively fast growth rate and the relative ease with which they can be harvested. Nostoc punctiforme is an aerobic, motile, Gram-negative, filamentous cyanobacterium that has been studied intensively to enhance our understanding of microbial carbon and nitrogen fixation. The genome of the type strain N. punctiforme ATCC 29133 was sequenced in 2001 and the scientific community has used these genome data extensively since then. Advances in bioinformatics tools for sequence annotation and the importance of this organism prompted us to resequence and reanalyze its genome and to make both, the initial and improved annotation, available to the scientific community. The new draft genome has a total size of 9.1 Mbp and consists of 65 contiguous pieces of DNA with a GC content of 41.38% and 7664 protein-coding genes. Furthermore, the resequenced genome is slightly (5152 bp) larger and contains 987 more genes with functional prediction when compared to the previously published version. We deposited the annotation of both genomes in the Department of Energy's IMG database to facilitate easy genome exploration by the scientific community without the need of in-depth bioinformatics skills. We expect that an facilitated access and ability to search the N. punctiforme ATCC 29133 for genes of interest will significantly facilitate metabolic engineering and genome prospecting efforts and ultimately the synthesis of biofuels and natural products from this keystone organism and closely related cyanobacteria.

The effectiveness of using in-game cards as reward

The research team has developed a web-based multiplayer trading card game to allow teachers choosing cards as rewards for students who actively participate in discussions and classroom activities as well as perform well in terms of doing assignments and writing exams or quizzes. In order to verify the effectiveness of the use of in-game cards as rewards, the research team integrated the trading card game into a web-based English vocabulary learning system. Students can receive cards as rewards every time after they use the learning system. A 6-week experiment had been conducted at an elementary school with 172 fifth-grade students. The results showed that boys have higher intention of getting the in-game cards as rewards. The research also showed that the use of the in-game cards as educational rewards not only motivates students to use the vocabulary learning system but also improves their learning outcome. The research result supported the recommended process for teachers to adopt the trading card game in their courses.

Recurrent epistaxis: predicting risk of 30-day readmission, derivation and validation of RHINO-ooze score

BACKGROUND

To derive and validate a predictive scoring tool (RHINO-ooze score) with good sensitivity and specificity in identifying patients with epistaxis at high risk of 30 day readmission and to enable risk stratification for possible definitive intervention.

METHODS

Using medical databases, we searched for factors influencing recurrent epistaxis. The information ascertained together with our analysis of retrospective data on patients admitted with epistaxis between October 2013 and September 2014, was used as the derivation cohort to develop the predictive scoring model (RHINO-ooze score). The tool was validated by performing statistical analysis on the validation cohort of patients admitted with epistaxis between October 2014 and October 2015. Multiple linear regressions with backwards elimination was used to derive the predictive model. The area under the curve (AUC), sensitivity and specificity were calculated.

RESULTS

834 admissions were encountered within the study period. Using the derivative cohort (n= 302) the RHINO-ooze score with a maximum score of 8 from five variables (Recent admission, Haemorrhage point unidentified, Increasing age over 70, posterior Nasal packing, Oral anticoagulant) was developed. The RHINO-ooze score had a chi-square value of 99.72 with a significance level of smaller than 0.0001 and hence an overall good model fit. Comparison between the derivative and validation groups revealed similar rates of 30-day readmission between the cohorts. The sensitivity and specificity of predicting 30-day readmission in high risk patients with recurrent epistaxis (RHINO-ooze score equal/larger than 6) was 81% and 84%, respectively.

CONCLUSIONS

The RHINO-ooze scoring tool demonstrates good specificity and sensitivity in predicting the risk of 30 day readmission in patients with epistaxis and can be used as an adjunct to clinical decision making with regards to timing of operative intervention in order to reduce readmission rates.

Commercial chicken breeds exhibit highly divergent patterns of linkage disequilibrium

The analysis of linkage disequilibrium (LD) underpins the development of effective genotyping technologies, trait mapping and understanding of biological mechanisms such as those driving recombination and the impact of selection. We apply the Malécot-Morton model of LD to create additive LD maps that describe the high-resolution LD landscape of commercial chickens. We investigated LD in chickens (Gallus gallus) at the highest resolution to date for broiler, white egg and brown egg layer commercial lines. There is minimal concordance between breeds of fine-scale LD patterns (correlation coefficient <0.21), and even between discrete broiler lines. Regions of LD breakdown, which may align with recombination hot spots, are enriched near CpG islands and transcription start sites (P<2.2 × 10^-16), consistent with recent evidence described in finches, but concordance in hot spot locations between commercial breeds is only marginally greater than random. As in other birds, functional elements in the chicken genome are associated with recombination but, unlike evidence from other bird species, the LD landscape is not stable in the populations studied. The development of optimal genotyping panels for genome-led selection programmes will depend on careful analysis of the LD structure of each line of interest. Further study is required to fully elucidate the mechanisms underlying highly divergent LD patterns found in commercial chickens.

The genomic architecture of resistance to Campylobacter jejuni intestinal colonisation in chickens

BACKGROUND

Campylobacter is the leading cause of foodborne diarrhoeal illness in humans and is mostly acquired from consumption or handling of contaminated poultry meat. In the absence of effective licensed vaccines and inhibitors, selection for chickens with increased resistance to Campylobacter could potentially reduce its subsequent entry into the food chain. Campylobacter intestinal colonisation levels are influenced by the host genetics of the chicken. In the present study, two chicken populations were used to investigate the genetic architecture of avian resistance to colonisation: (i) a back-cross of two White Leghorn derived inbred lines [(61 x N) x N] known to differ in resistance to Campylobacter colonisation and (ii) a 9(th) generation advanced intercross (61 x N) line.

RESULTS

The level of colonisation with Campylobacter jejuni following experimental infection was found to be a quantitative trait. A back-cross experiment using 1,243 fully informative single nucleotide polymorphism (SNP) markers revealed quantitative trait loci (QTL) on chromosomes 7, 11 and 14. In the advanced intercross line study, the location of the QTL on chromosome 14 was confirmed and refined and two new QTLs were identified located on chromosomes 4 and 16. Pathway and re-sequencing data analysis of the genes located in the QTL candidate regions identified potential pathways, networks and candidate resistance genes. Finally, gene expression analyses were performed for some of the candidate resistance genes to support the results.

CONCLUSION

Campylobacter resistance in chickens is a complex trait, possibly involving the Major Histocompatibility Complex, innate and adaptive immune responses, cadherins and other factors. Two of the QTLs for Campylobacter resistance are co-located with Salmonella resistance loci, indicating that it may be possible to breed simultaneously for enhanced resistance to both zoonoses.

Lineage-specific chromatin signatures reveal a regulator of lipid metabolism in microalgae

Alga-derived lipids represent an attractive potential source of biofuels. However, lipid accumulation in algae is a stress response tightly coupled to growth arrest, thereby imposing a major limitation on productivity. To identify transcriptional regulators of lipid accumulation, we performed an integrative chromatin signature and transcriptomic analysis to decipher the regulation of lipid biosynthesis in the alga Chlamydomonas reinhardtii. Genome-wide histone modification profiling revealed remarkable differences in functional chromatin states between the algae and higher eukaryotes and uncovered regulatory components at the core of lipid accumulation pathways. We identified the transcription factor, PSR1, as a pivotal switch that triggers cytosolic lipid accumulation. Dissection of the PSR1-induced lipid profiles corroborates its role in coordinating multiple lipid-inducing stress responses. The comprehensive maps of functional chromatin signatures in a major clade of eukaryotic life and the discovery of a transcriptional regulator of algal lipid metabolism will facilitate targeted engineering strategies to mediate high lipid production in microalgae.

Lentivirus delivery of IL-10 to promote and sustain macrophage polarization towards an anti-inflammatory phenotype

Gene delivery from biomaterials can create an environment that promotes and guides tissue formation. However, the immune response induced upon biomaterial implantation can be detrimental to tissue regeneration. Macrophages play a central role in mediating early phases of this response, and functional "polarization" of macrophages towards M1 (inflammatory) or M2 (anti-inflammatory) phenotypes may bias the local immune state at the implant site. Since gene delivery from biomaterial scaffolds can confer transgene expression in macrophages in vivo, we investigated whether transduction of macrophages with an IL-10 encoding lentivirus can (1) induce macrophage polarization toward an M2 phenotype even in an pro-inflammatory environment, and (2) prevent a shift in polarization from M2 to M1 following exposure to pro-inflammatory stimuli. IL-10 lentivirus delivery to pre-polarized M1 macrophages reduced TNF-α production 1.5-fold when compared to cells treated with either a control virus or a bolus delivery of recombinant IL-10 protein. IL-10 lentivirus delivery to naïve macrophages reduced the amount of TNF-α produced following an inflammatory challenge by 2.5-fold compared to cells treated with both the control virus and recombinant IL-10. At a mechanistic level, IL-10 lentivirus delivery mediated sustained reduction in NF-κB activation and, accordingly, reduced transcription of TNF-α. In sum, lentiviral delivery of IL-10 to macrophages represents a promising strategy for directing and sustaining macrophage polarization towards an M2 phenotype in order to promote local immune responses that facilitate tissue engineering.

Leiomyosarcoma in the nasopharynx: MR imaging findings

The MR imaging findings of a leiomyosarcoma arising from the nasopharynx are presented. To our knowledge, this is the first MR imaging description of this entity.

Secured medical imaging over the Internet

The Internet has established itself as an affordable, extremely viable and ubiquitous communications network that can be easily accessed from virtually any point in the world. This makes it ideally suited for medical image communications. Issues regarding security and confidentiality of information on the Internet, however, need to be addressed for both occasional, individual users and consistent enterprise-wide users. In addition, the limited bandwidth of most Internet connections must be factored into the development of a realistic usermodel and resulting protocol. Open architecture issues must also be considered so that images can be communicated to recipients who do not have similar programs. Further, application-specific software is required to integrate image acquisition, encryption and transmission into a single, streamlined process. Using Photomailer software provided by PhysiTel Inc., the authors investigated the use of sending secured still images over the Internet. The scope of their investigation covered the use of the Internet for communicating images for consultation, referral, mentoring and education. Photomailer software was used at several local and remote sites. The program was used for both sending and receiving images. It was also used for sending images to recipients who did not have Photomailer, but instead relied on conventional email programs. The results of the investigation demonstrated that using products such as Photomailer, images could be quickly and easily communicated from one location to another via the Internet. In addition, the investigators were able to retrieve images off of their existing email accounts, thereby providing greater flexibility and convenience than other systems which require scheduled transmission of information on dedicated systems. We conclude that Photomailer and similar products may provide a significant benefit and improve communications among colleagues, providing an inexpensive means of sending secured images on the Internet.