Environmental and Biogeographic Drivers behind Alpine Plant Thermal Tolerance and Genetic Variation.

In alpine ecosystems, elevation broadly functions as a steep thermal gradient, with plant communities exposed to regular fluctuations in hot and cold temperatures. These conditions lead to selective filtering, potentially contributing to species-level variation in thermal tolerance and population-level genetic divergence. Few studies have explored the breadth of alpine plant thermal tolerances across a thermal gradient or the underlying genetic variation thereof. We measured photosystem heat (Tcrit-hot) and cold (Tcrit-cold) thresholds of ten Australian alpine species across elevation gradients and characterised their neutral genetic variation. To reveal the biogeographical drivers of present-day genetic signatures, we also reconstructed temporal changes in habitat suitability across potential distributional ranges. We found intraspecific variation in thermal thresholds, but this was not associated with elevation, nor underpinned by genetic differentiation on a local scale. Instead, regional population differentiation and considerable homozygosity within populations may, in part, be driven by distributional contractions, long-term persistence, and migrations following habitat suitability. Our habitat suitability models suggest that cool-climate-distributed alpine plants may be threatened by a warming climate. Yet, the observed wide thermal tolerances did not reflect this vulnerability. Conservation efforts should seek to understand variations in species-level thermal tolerance across alpine microclimates.

Extracellular vesicles and their effect on vascular haemodynamics: a systematic review.

Extracellular vesicles (EVs) are released from all cell types studied to date and act as intercellular communicators containing proteins, nucleic acids and lipid cargos. They have been shown to be involved in maintaining homoeostasis as well as playing a role in the development of pathology including hypertension and cardiovascular disease. It is estimated that there is 109-1010 circulating EVs/mL in the plasma of healthy individuals derived from various sources. While the effect of EVs on vascular haemodynamic parameters will be dependent on the details of the model studied, we systematically searched and summarized current literature to find patterns in how exogenously injected EVs affected vascular haemodynamics. Under homoeostatic conditions, evidence from wire and pressure myography data demonstrate that injecting isolated EVs derived from cell types found in blood and blood vessels resulted in the impairment of vasodilation in blood vessels ex vivo. Impaired vasodilation was also observed in rodents receiving intravenous injections of human plasma EVs from cardiovascular diseases including valvular heart disease, acute coronary syndrome, myocardial infarction and end stage renal disease. When EVs were derived from models of metabolic syndromes, such as diabetes, these EVs enhanced vasoconstriction responses in blood vessels ex vivo. There were fewer publications that assessed the effect of EVs in anaesthetised or conscious animals to confirm whether effects on the vasculature observed in ex vivo studies translated into alterations in vascular haemodynamics in vivo. In the available conscious animal studies, the in vivo data did not always align with the ex vivo data. This highlights the importance of in vivo work to determine the effects of EVs on the integrative vascular haemodynamics.

Audit on data accuracy of the Malaysian Dialysis and Transplant Registry (MDTR).

Diabetes mellitus is the main aetiology of end stage kidney disease (ESKD) in Malaysia. However, there may be concerns of over-reporting of diabetes mellitus as the cause of ESKD in the Malaysian Dialysis and Transplant Registry (MDTR). The objective of this audit is to assess the accuracy of data collected in the MDTR. There were 151 centres/source data providers (SDP) with a total of 1977 patients included in this audit. The audit showed that 80.2% of doctors' records matched the MDTR data. The results were comparable with published validation studies in other countries.

Epithelial Immune Cell Response to Initial Soft Contact Lens Wear in the Human Corneal and Conjunctival Epithelium.

Purpose: The purpose of this study was to assess the immediate ocular immune response to soft contact lens (CL) wear by examining presumed epithelial immune cell (EIC) density and morphology at the central, peripheral, limbal cornea, and conjunctiva. Methods: Fifty-four participants naïve to CL wear (mean age = 24.8 ± 9.8 years, 44% female participants), were examined using in vivo confocal microscopy at baseline and after 2 hours of CL wear (1-Day ACUVUE MOIST). Images were captured at the central, temporal far peripheral and limbal cornea, and bulbar conjunctiva. EIC density was counted manually and morphology was graded. Differences in EIC parameters pre- and post-CL wear were examined using a generalized estimating equation model with appropriate post hoc analyses. Results: After 2 hours of soft CL wear, there was a significant increase in EIC density in all regions other than the central cornea (all P < 0.001). Cell body size was significantly larger, and a higher proportion of participants exhibited EIC with long dendrites after lens wear at the central and peripheral cornea (both P < 0.001). There was a significant increase in the number of participants displaying EIC with thick dendrites at the peripheral (P = 0.04) and limbal cornea (P < 0.001) after lens wear. Conclusions: EICs were primarily recruited to the peripheral regions, whereas the central cornea shows no significant recruitment after short-term CL wear. Both central and peripheral corneas exhibited an enhanced antigen capture capacity, whereas migratory capacity was increased in the peripheral corneal regions suggesting EIC activation following a short period of CL wear.

A prospective study of incidence and outcome of acute kidney injury among hospitalised patients in Malaysia (My-AKI).

INTRODUCTION: The incidence of acute kidney injury (AKI) among hospitalised patients has not been well studied in Malaysia. MATERIALS AND METHODS: We conducted a prospective, multicentre study in seven hospitals in West Malaysia. All the adults admitted in March 2017 fulfilling Kidney Disease Improving Global Outcomes (KDIGO) criteria for AKI were included. RESULTS: Of the 34,204 patients screened, 2,457 developed AKI (7.18%), 13.1% of which occurred in intensive care unit (ICU). There were 60.2% males with a mean age of 57.8 (±17.5) years. The most common comorbidities were hypertension (55.0%), diabetes (46.6%), ischaemic heart disease (15.1%) and chronic kidney disease (12.0%). The commonest causes of AKI were sepsis (41.7%), pre-renal (24.2%) and cardiorenal syndrome (10.8%). Nephrotoxin exposure was reported in 31%. At diagnosis, the proportion of AKI stages 1, 2 and 3 were 79.1%, 9.7%, 11.2%, respectively. Referral to nephrologists was reported in 16.5%. Dialysis was required in 176 (7.2%) patients and 55.6% were performed in the ICU. Acidosis (46.2%), uraemia (31.6%) and electrolyte disturbance (11.1%) were the commonest indications. Continuous renal replacement therapy (CRRT) was required in 14%. The average length of hospital stay was 9.5 days. In-hospital mortality was 16.4%. Among survivors, full and partial renal recovery was seen in 74.7% and 16.4% respectively while 8.9% failed to recover. After a mean follow-up of 13.7 months, 593 (30.2%) of survivors died and 38 (1.9%) initiated chronic dialysis. Mortality was highest among those with malignancies (Hazard Ratio, HR 2.14), chronic liver disease (HR 2.13), neurological disease (HR 1.56) and cardiovascular disease (HR 1.17). CONCLUSION: AKI is common in hospitalised patients and is with associated high mortality during and after hospitalisation.

A turn in species conservation for hairpin banksias: demonstration of oversplitting leads to better management of diversity.

PREMISE: Understanding evolutionary history and classifying discrete units of organisms remain overwhelming tasks, and lags in this workload concomitantly impede an accurate documentation of biodiversity and conservation management. Rapid advances and improved accessibility of sensitive high-throughput sequencing tools are fortunately quickening the resolution of morphological complexes and   thereby improving the estimation of species diversity. The recently described and critically endangered Banksia vincentia is morphologically similar to the hairpin banksia complex (B. spinulosa s.l.), a group of eastern Australian flowering shrubs whose continuum of morphological diversity has been responsible for taxonomic controversy and possibly questionable conservation initiatives. METHODS: To assist conservation while testing the current taxonomy of this group, we used high-throughput sequencing to infer a population-scale evolutionary scenario for a sample set that is comprehensive in its representation of morphological diversity and a 2500-km distribution. RESULTS: Banksia spinulosa s.l. represents two clades, each with an internal genetic structure shaped through historical separation by biogeographic barriers. This structure conflicts with the existing taxonomy for the group. Corroboration between phylogeny and population statistics aligns with the hypothesis that B. collina, B. neoanglica, and B. vincentia should not be classified as species. CONCLUSIONS: The pattern here supports how morphological diversity can be indicative of a locally expressed suite of traits rather than relationship. Oversplitting in the hairpin banksias is atypical since genomic analyses often reveal that species diversity is underestimated. However, we show that erring on overestimation can yield negative consequences, such as the disproportionate prioritization of a geographically anomalous population.

Performance of Multiple Pretrained BERT Models to Automate and Accelerate Data Annotation for Large Datasets.

Purpose: To develop and evaluate domain-specific and pretrained bidirectional encoder representations from transformers (BERT) models in a transfer learning task on varying training dataset sizes to annotate a larger overall dataset. Materials and Methods: The authors retrospectively reviewed 69 095 anonymized adult chest radiograph reports (reports dated April 2020-March 2021). From the overall cohort, 1004 reports were randomly selected and labeled for the presence or absence of each of the following devices: endotracheal tube (ETT), enterogastric tube (NGT, or Dobhoff tube), central venous catheter (CVC), and Swan-Ganz catheter (SGC). Pretrained transformer models (BERT, PubMedBERT, DistilBERT, RoBERTa, and DeBERTa) were trained, validated, and tested on 60%, 20%, and 20%, respectively, of these reports through fivefold cross-validation. Additional training involved varying dataset sizes with 5%, 10%, 15%, 20%, and 40% of the 1004 reports. The best-performing epochs were used to assess area under the receiver operating characteristic curve (AUC) and determine run time on the overall dataset. Results: The highest average AUCs from fivefold cross-validation were 0.996 for ETT (RoBERTa), 0.994 for NGT (RoBERTa), 0.991 for CVC (PubMedBERT), and 0.98 for SGC (PubMedBERT). DeBERTa demonstrated the highest AUC for each support device trained on 5% of the training set. PubMedBERT showed a higher AUC with a decreasing training set size compared with BERT. Training and validation time was shortest for DistilBERT at 3 minutes 39 seconds on the annotated cohort. Conclusion: Pretrained and domain-specific transformer models required small training datasets and short training times to create a highly accurate final model that expedites autonomous annotation of large datasets.Keywords: Informatics, Named Entity Recognition, Transfer Learning Supplemental material is available for this article. ©RSNA, 2022See also the commentary by Zech in this issue.

Induction of a NOTCH3 Lehman syndrome mutation in osteocytes causes osteopenia in male C57BL/6J mice.

Lateral Meningocele or Lehman Syndrome (LMS) is associated with NOTCH3 mutations causing deletions of the PEST domain and a gain-of-NOTCH3 function. We demonstrated that Notch3em1Ecan mice harboring Notch3 mutations analogous to those found in LMS are osteopenic because of enhanced bone resorption. To determine the contribution of specific cell lineages to the phenotype, we created a conditional-by-inversion (Notch3COIN) model termed Notch3em2Ecan in which Cre recombination generates a Notch3INV allele expressing a NOTCH3 mutant lacking the PEST domain. Germ line Notch3COIN inversion caused osteopenia and phenocopied the Notch3em1Ecan mutant, validating the model. To induce the mutation in osteocytes, smooth muscle and endothelial cells, Notch3COIN mice were bred with mice expressing Cre from the Dmp1, Sm22a and Cdh5 promoters, respectively, creating experimental mice harboring Notch3INV alleles in Cre-expressing cells and control littermates harboring Notch3COIN alleles. Notch3COIN inversion in osteocytes led to femoral and vertebral cancellous bone osteopenia, whereas Notch3COIN inversion in mural Sm22a or endothelial Cdh5-expressing cells did not result in a skeletal phenotype. In conclusion, introduction of the LMS mutation in osteocytes but not in vascular cells causes osteopenia and phenocopies Notch3em1Ecan global mutant mice.

Chromosome-level de novo genome assembly of Telopea speciosissima (New South Wales waratah) using long-reads, linked-reads and Hi-C.

Telopea speciosissima, the New South Wales waratah, is an Australian endemic woody shrub in the family Proteaceae. Waratahs have great potential as a model clade to better understand processes of speciation, introgression and adaptation, and are significant from a horticultural perspective. Here, we report the first chromosome-level genome for T. speciosissima. Combining Oxford Nanopore long-reads, 10x Genomics Chromium linked-reads and Hi-C data, the assembly spans 823 Mb (scaffold N50 of 69.0 Mb) with 97.8% of Embryophyta BUSCOs "Complete". We present a new method in Diploidocus (https://github.com/slimsuite/diploidocus) for classifying, curating and QC-filtering scaffolds, which combines read depths, k-mer frequencies and BUSCO predictions. We also present a new tool, DepthSizer (https://github.com/slimsuite/depthsizer), for genome size estimation from the read depth of single-copy orthologues and estimate the genome size to be approximately 900 Mb. The largest 11 scaffolds contained 94.1% of the assembly, conforming to the expected number of chromosomes (2n = 22). Genome annotation predicted 40,158 protein-coding genes, 351 rRNAs and 728 tRNAs. We investigated CYCLOIDEA (CYC) genes, which have a role in determination of floral symmetry, and confirm the presence of two copies in the genome. Read depth analysis of 180 "Duplicated" BUSCO genes using a new tool, DepthKopy (https://github.com/slimsuite/depthkopy), suggests almost all are real duplications, increasing confidence in the annotation and highlighting a possible need to revise the BUSCO set for this lineage. The chromosome-level T. speciosissima reference genome (Tspe_v1) provides an important new genomic resource of Proteaceae to support the conservation of flora in Australia and further afield.

Conserving the genetic diversity of condemned populations: Optimizing collections and translocation.

We consider approaches for conserving genetic diversity from plant populations whose destruction is imminent. We do this using SNP genotype data from two endangered species, Pimelea spicata and Eucalyptus sp. Cattai. For both species, we genotyped plants from a 'condemned' population and designed ex situ collections, characterizing how the size and composition of the collection affected the genetic diversity preserved. Consistent with previous observations, populations where genetic diversity was optimized captured more alleles than populations of equal size chosen at random. This benefit of optimization was larger when the propagation population was small. That is, small numbers of individuals (e.g. 20) needed to be selected carefully to capture a comparable proportion of alleles to optimized populations, but larger random populations (e.g. >48) captured almost as many alleles as optimized populations. We then examined strategies for generating translocation populations based on the horticultural constraints presented by each species. In P. spicata, which is readily grown from cuttings, we designed translocation populations of different sizes, using different numbers of ramets from each member of propagation populations. We then performed simulations to predict the loss of alleles from these populations over 10 generations. Large translocation populations were predicted to maintain a greater proportion of source population alleles than smaller translocation populations, but this effect was saturated beyond 200 individuals. In E. sp. Cattai, we examined strategies to promote the diversity of progeny from a conservation planting scenario with 36 individuals. This included the optimization of the spatial arrangement of the planting and supplementing the diversity of the condemned population with individuals from additional sites. In sum, we studied approaches for designing genetically diverse translocations of condemned populations for two species that require contrasting methods of propagation, illustrating the application of approaches that were useful in different circumstances.

Pathogens associated with pleuritic pig lungs at an abattoir in Queensland Australia.

OBJECTIVE: Pleurisy in pigs has economic impacts in the production stage and at slaughter. This study sought to establish if some micro-organisms can be found in high numbers in lungs with pleurisy by assessing batches of pigs at an abattoir in Queensland Australia. DESIGN: Samples of lung (including trachea/bronchus and lymph nodes) from a maximum of 5 pleurisy affected pigs were collected from 46 batches of pigs representing 46 Queensland farms. PROCEDURE: Pleurisy-affected lung areas were cultured by traditional bacteriological methods and bacteria quantified by plate scores. Additionally, tracheal or bronchial swabs and apical lobe fluid were tested for Mycoplasma hyopneumoniae DNA and the superior tracheobronchial lymph nodes were tested for porcine circovirus type 2 DNA by polymerase chain reaction (PCR). All apparently significant bacteria were identified via PCR or sequencing. Typing was undertaken on some of the bacterial isolates. RESULTS: The most prevalent pathogens were M. hyopneumoniae, Streptococcus suis and Porcine Circovirus type 2, being found in 34, 38 and 31 batches, respectively. Other bacteria found were Actinobacillus species (29 batches), Pasteurella multocida (24 batches), Mycoplasma flocculare (9 batches), Actinobacillus pleuropneumoniae (7 batches), Mycoplasma hyorhinis (4 batches), Bisgaard Taxon 10 (1 batch), Glaesserella parasuis (1 batch), Streptococcus minor (1 batch) and Streptococcus porcinus (1 batch). Most batches had more than one bacterial species. CONCLUSION: The high percentage of batches infected with S. suis (83%), M. hyopneumoniae (74%) and PCV2 (70%) and clustering by a batch of these pathogens, as well as the presence of many secondary pathogens, suggests synergy between these organisms may have resulted in pleurisy.

Home-based tele-rehabilitation presents comparable positive impact on self-reported functional outcomes as usual care: The Singapore Tele-technology Aided Rehabilitation in Stroke (STARS) randomised controlled trial.

INTRODUCTION: The aim of this research was to evaluate the impact of a novel tele-rehabilitation system on self-reported functional outcomes compared to usual care during the first three months after stroke. METHODS: A parallel, two-arm, evaluator-blinded, randomised controlled trial was conducted. Adults aged ≥40 years who had suffered a stroke within four weeks of the start of the study were recruited from the general community. The intervention group received access to a novel tele-rehabilitation system and programme for three months. The primary outcome measures utilised were the frequency and limitation total scores of the Late-Life Function and Disability Instrument (LLFDI) at three months. RESULTS: A total of 124 individuals were recruited. The mean differences in the LLDFI frequency and limitation total scores at three months comparing the intervention and control groups were -3.30 (95% confidence interval (CI) -7.81 to 1.21) and -6.90 (95% CI -15.02 to 1.22), respectively. Adjusting for the respective baseline covariates and baseline Barthel Index also showed no significant difference between interventions in the LLFDI outcomes. DISCUSSION: The intervention and control groups self-reported similar improvements in functional outcomes. Tele-rehabilitation may be a viable option to provide post-stroke rehabilitation services in Singapore while reducing barriers to continue rehabilitation conventionally after discharge from hospital and encouraging more participation.

The effect of neuromuscular blocking agents uses in acute respiratory distress syndrome: a systematic review and meta-analysis of randomized controlled trials.

INTRODUCTION: With the latest addition from Re-evaluation of Systemic Early Neuromuscular Blockade (ROSE) Trial result, the question of mortality benefit from neuromuscular blocking agents (NMBAs) in different studies, remained unanswered. We hypothesize that NMBAs use in moderate to severe acute respiratory distress syndrome (ARDS) does not influence intensive care unit (ICU) mortality. EVIDENCE ACQUISITION: Pubmed, Embase and the Cochrane Library were searched for randomized controlled trials (RCTs) related to NMBAs infusion in patients with ARDS. The primary outcome was ICU mortality. Secondary outcomes were mortality at day 28 and day 90, oxygenation response to NMBA, ICU length of stay (LOS), ICU Acquired weakness (ICU-AW) and ventilator-free days (VFDs). Meta-analysis was conducted to re-evaluate the effect of NMBAs on patients with ARDS with all randomized controlled trials available. EVIDENCE SYNTHESIS: NMBAs infusion was associated with reduced ICU mortality (relative ratio [RR]: 0.69; 95% confidence-interval [CI]: 0.55-0.88; I2=0%), but not 28 days mortality (RR: 0.76; 95% CI: 0.57-1.0; I2=49%) and 90-day mortality (RR: 0.87; 95% CI: 0.70-1.08; I2=46%). NMBA use was not associated with increased risk of ICU-AW (RR: 1.21; 95% CI, 0.84 to 1.76; I2=34%). CONCLUSIONS: Early 48-hour NMBAs infusion in patients with moderate to severe ARDS was associated with reduced ICU mortality without improvement in oxygenation, VFDs, 28-day and 90-day mortality. It did not contribute significantly to ICU-AW. Based on these results, NMBAs infusion is recommended for moderate to severe ARDS for its short-term benefit in early phase of disease. Prolonged use of NMBAs beyond 48 hours requires further study.

Progress in the Development of Subunit Vaccines against Malaria.

Malaria is a life-threatening disease and one of the main causes of morbidity and mortality in the human population. The disease also results in a major socio-economic burden. The rapid spread of malaria epidemics in developing countries is exacerbated by the rise in drug-resistant parasites and insecticide-resistant mosquitoes. At present, malaria research is focused mainly on the development of drugs with increased therapeutic effects against Plasmodium parasites. However, a vaccine against the disease is preferable over treatment to achieve long-term control. Trials to develop a safe and effective immunization protocol for the control of malaria have been occurring for decades, and continue on today; still, no effective vaccines are available on the market. Recently, peptide-based vaccines have become an attractive alternative approach. These vaccines utilize short protein fragments to induce immune responses against malaria parasites. Peptide-based vaccines are safer than traditional vaccines, relatively inexpensive to produce, and can be composed of multiple T- and B-cell epitopes integrated into one antigenic formulation. Various combinations, based on antigen choice, peptide epitope modification and delivery mechanism, have resulted in numerous potential malaria vaccines candidates; these are presently being studied in both preclinical and clinical trials. This review describes the current landscape of peptide-based vaccines, and addresses obstacles and opportunities in the production of malaria vaccines.

Sexual function, self-esteem, and general well-being in Chinese adult survivors of childhood cancers: a cross-sectional survey.

INTRODUCTION: This study was conducted to evaluate sexual function in adult survivors of childhood cancers and investigate possible relationships between sexual function and quality of life, as measured by general well-being, self-esteem, body image, and depressive symptoms. METHODS: This cross-sectional survey was performed in our centre from 14 August 2015 to 8 September 2017. Adult patients who had a history of childhood cancers, and who were disease-free for >3 years, were approached for the study during clinical follow-up. Clinical information was collected from medical records. Self-administered questionnaires regarding quality of life and sexual functioning were given to the patients and resulting data were analysed. RESULTS: Two hundred patients agreed to participate in the study. The overall response rate was 64.8%. Ninety-one (45.5%) patients were women, and the mean age was 25.4 ± 5.57 years. The overall sexual functioning score was 28.3 ± 20.09. Forty-eight (24.0%) patients reported at least one sexual problem. Among patients who reported no sexual problems, more had haematological cancers (P=0.009), fewer underwent surgery (P=0.004), fewer underwent surgery with external effects (P=0.032), and fewer were regular social drinkers (P=0.013); additionally, they had a higher mean Rosenberg self-esteem scale score (P=0.010), lower mean body image scale score (P=0.008), and lower mean Patient Health Questionnaire score (P=0.001). CONCLUSION: Aspects of life beyond disease condition and physical function should be considered in adult survivors of childhood cancers. Appropriate referral and intervention should be initiated for these patients when necessary.

Binding partner- and force-promoted changes in αE-catenin conformation probed by native cysteine labeling.

Adherens Junctions (AJs) are cell-cell adhesion complexes that sense and propagate mechanical forces by coupling cadherins to the actin cytoskeleton via ß-catenin and the F-actin binding protein αE-catenin. When subjected to mechanical force, the cadherin•catenin complex can tightly link to F-actin through αE-catenin, and also recruits the F-actin-binding protein vinculin. In this study, labeling of native cysteines combined with mass spectrometry revealed conformational changes in αE-catenin upon binding to the E-cadherin•ß-catenin complex, vinculin and F-actin. A method to apply physiologically meaningful forces in solution revealed force-induced conformational changes in αE-catenin when bound to F-actin. Comparisons of wild-type αE-catenin and a mutant with enhanced vinculin affinity using cysteine labeling and isothermal titration calorimetry provide evidence for allosteric coupling of the N-terminal ß-catenin-binding and the middle (M) vinculin-binding domain of αE-catenin. Cysteine labeling also revealed possible crosstalk between the actin-binding domain and the rest of the protein. The data provide insight into how binding partners and mechanical stress can regulate the conformation of full-length αE-catenin, and identify the M domain as a key transmitter of conformational changes.

Diverse strains of Actinobacillus lignieresii isolated from clinically affected cattle in a geographically restricted area.

OBJECTIVE: To investigate whether an outbreak of Actinobacillus lignieresii was caused by one or multiple strains. METHODS: Nine isolates of A. lignieresii were obtained from the lymph nodes of 15 affected cattle from two farms to determine whether a single strain was involved. An enterobacterial repetitive insertion consensus sequence (ERIC) PCR was used for genotyping, and the repeats-in-toxin genes were analysed by PCR and sequencing. RESULTS: Isolates from the two farms belonged to two and three genotypes, with a total of four genotypes detected. Genes of the apxICABD operons of some strains had deletions in the apxIA (~697 bp) and in the apxID (~187 bp) genes. The toxin gene deletions and the ERIC PCR patterns suggested the involvement of different A. lignieresii genotypes. CONCLUSION: There was no evidence that a unique genotype was associated with actinobacillosis on the two farms, confirming that this disease was associated with other contributing factors.

Peptide-based targeted polymeric nanoparticles for siRNA delivery.

The development of polymer-based nanoparticulate delivery systems for siRNA is important for the clinical success of gene therapy. However, there are some major drawbacks that need to be overcome. Short interfering RNA (siRNA) has been investigated as a potential therapeutic drug to silence disease-associated genes, but its usage is limited due to the lack of effective and safe nanocarriers. In this study, DOPE-PEI, a nanoparticle consisting of the fusogenic lipid 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) conjugated with low-molecular-weight, 600 Da, branched polyethylenimine (PEI) was produced and optimized for siRNA delivery. This delivery system was modified with other components such as 1,2-dioleoyl-sn-glycerol-3-phosphoethanolamine-N-[methoxy(polyethyleneglycol)2000] (DOPE-PEG2K), DOPE-PEG3.4K-bombesin and 1,2-dioleoyl-sn-glycerol-3-phosphoethanolamine/1,2-dioleoyl-3-trimethylammonium-propane (DOPE/DOTAP) and tested on PC-3 cells. The conjugation of DOPE to PEI polymer (DOPE-PEI) improved the efficiency of PEI to deliver siRNA into the cytosol and knockdown genes, but demonstrated high toxicity. The addition of DOPE-PEG2K reduced cellular toxicity by masking the surface positive charge of the DOPE-PEI/siRNA complex, with the incorporation of a gastrin-releasing peptide receptor (GRPR) targeting peptide and DOPE/DOTAP components improving the cellular uptake of siRNA into targeted cells and the siRNA knockdown efficiency.

Flood protection ecosystem services in the coast of Puerto Rico: Associations between extreme weather, flood hazard mitigation and gastrointestinal illness.

Floods are becoming increasingly influential in coastal cities due to the intensification of extreme weather events. The impacts of flooding go beyond damages to infrastructure, it also affects human health. During floods, discharge of sewage into streets increases exposure to pathogens causing gastrointestinal (GI) illnesses. A potential strategy for coastal protection during weather hazards is the use of flood protection ecosystem services, but their effectiveness at ameliorating the impact of floods on GI illnesses remain understudied. Here we explore the relationship between extreme rainfall, flood protection ecosystem services, and the occurrence of Medicare claims for gastrointestinal (GI) illnesses in Puerto Rico. We first conducted model averaging to detect variables explaining flood impact for the years (1999-2014), and then used these variables as predictors in a spatio-temporal analysis of GI illness in the same period (1999-2013). Our results show that flood impact varies proportionally with extreme rainfall, and inversely with flood protection ecosystem services, particularly due to the presence of karst soils. The protective effect of karst soils is lost when there is a high percentage of people living in flood prone areas, as suggested by a significant interaction effect between these two variables. In support of our hypotheses, cases of GI illness also spike after extreme rainfall events and are affected by the interaction effect of karst soils and people living in flood prone areas. Our results support the linkage between extreme weather events, flood damages and GI illnesses, and suggests a buffering role of ecosystem services that promote rainfall infiltration. The relevance of these ecosystem services, however, is affected by planning decisions such as residential development in flood prone areas. Our results help inform planning strategies for future weather hazards, accounting for the role of natural and built infrastructure on minimizing flood impacts and human health effects.