Risk Factors for Ebola Exposure in Health Care Workers in Boende, Tshuapa Province, Democratic Republic of the Congo.

BACKGROUND: Health care workers (HCW) are more likely to be exposed to Ebola virus (EBOV) during an outbreak compared to people in the general population due to close physical contact with patients and potential exposure to infectious fluids. However, not all will fall ill. Despite evidence of subclinical and paucisymptomatic Ebola virus disease (EVD), prevalence and associated risk factors remain unknown. METHODS: We conducted a serosurvey among HCW in Boende, Tshuapa Province, Democratic Republic of Congo. Human anti-EBOV glycoprotein IgG titers were measured using a commercially available ELISA kit. We assessed associations between anti-EBOV IgG seroreactivity, defined as ≥2.5 units/mL, and risk factors using univariable and multivariable logistic regression. Sensitivity analyses explored a more conservative cutoff, >5 units/mL. RESULTS: Overall, 22.5% of HCWs were seroreactive for EBOV. In multivariable analyses, using any form of personal protective equipment when interacting with a confirmed, probable, or suspect EVD case was negatively associated with seroreactivity (adjusted odds ratio, 0.23; 95% confidence interval, .07-.73). DISCUSSION: Our results suggest high exposure to EBOV among HCWs and provide additional evidence for asymptomatic or minimally symptomatic EVD. Further studies should be conducted to determine the probability of onward transmission and if seroreactivity is associated with immunity.

Optimized plant compound with potent anti-biofilm activity across gram-negative species.

Many human diseases, including cystic fibrosis lung infections, are caused or exacerbated by bacterial biofilms. Specialized modes of motility, including swarming and twitching, allow gram-negative bacteria to spread across surfaces and form biofilms. Compounds that inhibit these motilities could slow the spread of biofilms, thereby allowing antibiotics to work better. We previously demonstrated that a set of plant-derived triterpenes, including oleanolic acid and ursolic acid, inhibit formation of Escherichia coli and Pseudomonas aeruginosa biofilms, and alter expression of genes involved in chemotaxis and motility. In the present study, we have prepared a series of analogs of oleanolic acid. The analogs were evaluated against clinical isolates of E. coli and P. aeruginosa in biofilm formation assays and swarming assays. From these analogs, compound 9 was selected as a lead compound for further development. Compound 9 inhibits E. coli biofilm formation at 4 µg/mL; it also inhibits swarming at ≤1 µg/mL across multiple clinical isolates of P. aeruginosa, E. coli, Burkholderia cepacia, and Salmonella enterica, and at <0.5 µg/mL against multiple agricultural strains. Compound 9 also potentiates the activity of the antibiotics tobramycin and colistin against swarming P. aeruginosa; this is notable, as tobramycin and colistin are inhaled antibiotics commonly used to treat P. aeruginosa lung infections in people with cystic fibrosis. qPCR experiments suggested that 9 alters expression of genes involved in regulating Type IV pili; western blots confirmed that expression of Type IV pili components PilA and PilY1 decreases in P. aeruginosa in the presence of 9.

Are there relevant animal models to set research priorities in LUTD? ICI-RS 2019.

AIM: To discuss animal models of lower urinary tract disorders (LUTD) and their translational impact. METHODS: Report of discussions based on presented literature-search based reviews relevant for the purpose. RESULTS: Animal models can be used to investigate fundamental biological mechanisms, but also as tools to elucidate aspects of the pathogenesis of disease and to provide early evidence of any safety risk. Several different models may be required to obtain information that can have a translational impact. The term "translational research" covers not only the process of directly transferring knowledge from basic sciences to human trials to produce new drugs, devices, and treatment options for patients (T1 type translation) but also the implementation of early clinical research findings (phases I-III) into practice to improve care for patients (T2 type). Direct transfer of animal data to T2 is rarely possible, and the process often does not continue after the first trials in humans (phase I). It should be emphasized that many preclinical observations do not have (and do not need to have) immediate translational impact. CONCLUSIONS: No single animal model can mimic the complexity of the human disease. Still, animal models can be useful for gaining information on LUT function in humans, for elucidating pathophysiological mechanisms, and for the definition of targets for future drugs to treat LUT disorders.

Serologic Markers for Ebolavirus Among Healthcare Workers in the Democratic Republic of the Congo.

Healthcare settings have played a major role in propagation of Ebola virus (EBOV) outbreaks. Healthcare workers (HCWs) have elevated risk of contact with EBOV-infected patients, particularly if safety precautions are not rigorously practiced. We conducted a serosurvey to determine seroprevalence against multiple EBOV antigens among HCWs of Boende Health Zone, Democratic Republic of the Congo, the site of a 2014 EBOV outbreak. Interviews and specimens were collected from 565 consenting HCWs. Overall, 234 (41.4%) of enrolled HCWs were reactive to at least 1 EBOV protein: 159 (28.1%) were seroreactive for anti-glycoprotein immunoglobulin G (IgG), 89 (15.8%) were seroreactive for anti-nucleoprotein IgG, and 54 (9.5%) were VP40 positive. Additionally, sera from 16 (2.8%) HCWs demonstrated neutralization capacity. These data demonstrate that a significant proportion of HCWs have the ability to neutralize virus, despite never having developed Ebola virus disease symptoms, highlighting an important and poorly documented aspect of EBOV infection and progression.

Frailty and Aging: How the Danish Experience Might Inform Canada.

Scandinavian countries are widely acknowledged as leaders in innovative models of care for their aging populations. To learn what might be potentially applicable to the health system in Canada, the Canadian Frailty Network (CFN) led a contingent of government, administrative, research and patient representatives to Denmark to directly observe Danish approaches for providing healthcare for older adults living with frailty. In this paper and based on what we learned from these observations, we discuss healthcare challenges faced by Canada's aging population for which Danish strategies provide clues as to where and how to improve care and system efficiencies, thereby maximizing the value of Canadian healthcare.

Flow Rates at Thirty Days after Construction of Radiocephalic Arteriovenous Fistula Predict Hemodialysis Function.

BACKGROUND: Construction of radiocephalic arteriovenous fistula (RC-AVF) results in successful hemodialysis (HD) in approximately 40% of end-stage renal disease patients. We investigated whether RC-AVF flow measured by ultrasound 30 days postoperative predicted successful HD. METHODS: In this prospective study, color Doppler ultrasound was used to measure cephalic vein outflow volume at 3 forearm sites at 1 and 3 months postoperatively. RESULTS: Of 45 consecutive patients screened for feasibility of RC-AVF by physical examination and US arterial and vein mapping, 41 were considered suitable for construction of RC-AVF. Mean age was 70 (60-78) years. Of the 41 patients who had a forearm RC-AVF, 25 (61%) proceeded to successful AVF dialysis, 4 (10%) had HD via central venous catheter, and 12 (29%) ceased function within the first 30 days postoperatively. The mean flow at 30 days for patent fistulas was 629 ± 305 ml/min and by the third month had increased to 663 ± 367 mL/min. At 1 month, 8/29 (27.6%) patients had a flow rate <400 mL/min. Two (25%) of these clotted, 2 of 3 with closed revisions went on to HD, and 1 died. Of the 21 patients with a flow rate ≥400 mL/min, 19 (90%) functioned for HD, and 2 (10%) AVF occluded before 1 year, resulting in 17 functioning at 1 year (81% 1-year patency). Sixty-two percent of the low-flow fistulas had successful patency within 1 year. CONCLUSIONS: An RC-AVF flow rate of ≥400 mL/min in the first month predicted more successful HD than low flow (<400 mL/min) (81% vs. 62%). Without intervention, low flow rates do not improve significantly and maturation is unlikely. We recommend imaging for all patients at 30 days to identify and promptly correct stenosis in those with low flow rates.

The natural history of type 2 endoleaks after endovascular aneurysm repair justifies conservative management.

Objective Management of type 2 endoleaks after endovascular aneurysm repair has been controversial. Some advocate for conservative management, while others believe that intervention is indicated. This study investigated the natural history of type 2 endoleaks in order to derive direction in management. Methods Patients who had endovascular aneurysm repair at the Veterans Affairs Long Beach were retrospectively identified and computerized tomographic angiography was independently reviewed by a radiologist and a vascular surgeon. Type 2 endoleaks were analyzed for the following outcomes: rupture, duration of endoleak, spontaneous resolution, changes in the size of the aneurysm sac, and reintervention rates. Results Of the 160 patients who had completed required follow-up to date (mean 3 years) after endovascular aneurysm repair, 39 (24.4%) patients were identified as having a type 2 endoleak on computerized tomographic angiography imaging. 6 (15.4%) of these 39 patients required repair due to aneurysm sac growth >1 cm. 2 (5.13%) were repaired with an open procedure and 4 (10.3%) with an endovascular approach. Of these 6 aneurysm leaks requiring repair, 4 (66.7%) had a simultaneous endoleak (types 1 or 3) in addition to the identified type 2 endoleak. Spontaneous resolution of type 2 endoleaks occurred in 16 (41.0%) patients. 4 patients (10.3%) had delayed type 2 endoleaks that presented 4, 9, 12, and 23 months after their 30 day post op computed tomography was normal. None of the 4 patients with delayed type 2 endoleaks required reintervention and none had aneurysm sac growth greater than 5 mm. Conclusions Overall, we found that 85% of patients who had type 2 endoleaks did not require intervention after a mean follow-up time of 3 years. The association of a type 1 or 3 endoleak with a type 2 endoleak was more likely to require correction due to aneurysm expansion >1 cm, thus type 2 endoleaks associated with another type of endoleak require more aggressive management.

Protease-activated Receptor-2 (PAR-2)-mediated Nf-κB Activation Suppresses Inflammation-associated Tumor Suppressor MicroRNAs in Oral Squamous Cell Carcinoma.

Oral cancer is the sixth most common cause of death from cancer with an estimated 400,000 deaths worldwide and a low (50%) 5-year survival rate. The most common form of oral cancer is oral squamous cell carcinoma (OSCC). OSCC is highly inflammatory and invasive, and the degree of inflammation correlates with tumor aggressiveness. The G protein-coupled receptor protease-activated receptor-2 (PAR-2) plays a key role in inflammation. PAR-2 is activated via proteolytic cleavage by trypsin-like serine proteases, including kallikrein-5 (KLK5), or by treatment with activating peptides. PAR-2 activation induces G protein-α-mediated signaling, mobilizing intracellular calcium and Nf-κB signaling, leading to the increased expression of pro-inflammatory mRNAs. Little is known, however, about PAR-2 regulation of inflammation-related microRNAs. Here, we assess PAR-2 expression and function in OSCC cell lines and tissues. Stimulation of PAR-2 activates Nf-κB signaling, resulting in RelA nuclear translocation and enhanced expression of pro-inflammatory mRNAs. Concomitantly, suppression of the anti-inflammatory tumor suppressor microRNAs let-7d, miR-23b, and miR-200c was observed following PAR-2 stimulation. Analysis of orthotopic oral tumors generated by cells with reduced KLK5 expression showed smaller, less aggressive lesions with reduced inflammatory infiltrate relative to tumors generated by KLK5-expressing control cells. Together, these data support a model wherein KLK5-mediated PAR-2 activation regulates the expression of inflammation-associated mRNAs and microRNAs, thereby modulating progression of oral tumors.

A Total Synthesis of Bifidenone.

The first total synthesis of bifidenone, a novel natural tubulin polymerization inhibitor, has been achieved in 12 steps starting from commercially available 1,4-dioxaspiro[4.5]decan-8-one. The synthesis includes a newly developed method to generate the dihydrobenzodioxolone core by palladium-catalyzed aerobic dehydrogenation. The three stereocenters were installed with an AD-mix-ß dihydroxylation step followed by a late-stage palladium-catalyzed decarboxylation-allylation procedure. The absolute stereochemistry of 3 was determined via 13a by single-crystal X-ray analysis.

Isolation and Identification of the Novel Tubulin Polymerization Inhibitor Bifidenone.

The pursuit of structurally novel compounds has led to the isolation of a series of neolignans (2-6), for which the structures have been determined from microgram quantities using microcryoprobe NMR technology. Compounds 2-6 provided some unexpectedly clear structure-activity relationship data, with compound 2 demonstrating significantly more potency in the in vitro cytotoxicity assay than the other analogues. Further screening found that compound 2 induces apoptosis with activation of caspase 3/7. The NCI Compare algorithm suggested that compound 2 acts through the inhibition of tubulin/microtubule dynamics. Compound 2 was confirmed to be a tubulin polymerization inhibitor that binds directly to tubulin.

Identification of a human papillomavirus-associated oncogenic miRNA panel in human oropharyngeal squamous cell carcinoma validated by bioinformatics analysis of the Cancer Genome Atlas.

High-risk human papillomavirus (HPV) is a causative agent for an increasing subset of oropharyngeal squamous cell carcinomas (OPSCCs), and current evidence supports these tumors as having identifiable risk factors and improved response to therapy. However, the biochemical and molecular alterations underlying the pathobiology of HPV-associated OPSCC (designated HPV(+) OPSCC) remain unclear. Herein, we profile miRNA expression patterns in HPV(+) OPSCC to provide a more detailed understanding of pathologic molecular events and to identify biomarkers that may have applicability for early diagnosis, improved staging, and prognostic stratification. Differentially expressed miRNAs were identified in RNA isolated from an initial clinical cohort of HPV(+/-) OPSCC tumors by quantitative PCR-based miRNA profiling. This oncogenic miRNA panel was validated using miRNA sequencing and clinical data from The Cancer Genome Atlas and miRNA in situ hybridization. The HPV-associated oncogenic miRNA panel has potential utility in diagnosis and disease stratification and in mechanistic elucidation of molecular factors that contribute to OPSCC development, progression, and differential response to therapy.

Postintervention Patency: A Comparison of Stenting versus Patch Angioplasty for Dysfunctional Hemodialysis Access Sites.

BACKGROUND: Arteriovenous access dysfunction is commonly caused by venous outflow stenosis, leading to thrombosis of the conduit. Given that there are limited lifetime hemodialysis access sites, the preservation of existing sites through novel means is of high priority. This study compares the efficacy of balloon angioplasty and stent placement to surgical patch angioplasty for upper arm (brachium) thrombosed or dysfunctional hemodialysis access sites in a group of patients at a single institution. METHODS: Using the operating room log and electronic medical record system, we retrospectively examined the outcomes of 52 consecutive patients (3 were lost to follow-up), who had either stent placement (34 patients) or patch angioplasty (15 patients) for hemodialysis access salvage to calculate postintervention patency. RESULTS: Initial postinterventional patency (PIP1) for patch angioplasty compared with stent placement was not statistically significant at any time during a mean 6-month follow-up (60% vs. 67.65% at 1 month, 33.33% vs. 41.18% at 3 months, and 13.33% vs. 17.65% at 6 months, respectively; P = 0.75). Patency after secondary reintervention (PIP2) was longer for patients who had stent placement as the initial intervention (n = 15) than patients who had patch angioplasty (n = 5; 100% vs. 80% at 1 month, 66.68% vs. 80% at 3 months, and 46.67% vs. 40% at 6 months, respectively), but again there was no statistically significant difference between the 2 groups (P = 0.84). At last, the initial PIP1 of arteriovenous fistula (AVF) and arteriovenous graft (AVG) salvaged before occlusion was significantly different from that of occluded access sites (40% vs. 10% at 6 months, P = 0.024). CONCLUSIONS: Our data suggest that AVF had a longer postinterventional primary patency than AVG though the difference did not reach statistical significance. Stents extended PIP1 for the thrombosed or failing arteriovenous access longer than patch angioplasty, but the difference was not statistically significant. Patency is longer if intervention is made before graft thrombosis. Our data also indicate better prolongation of patency with a second reintervention (PIP2) if the first intervention was a stent placement. Patch angioplasty appears to be a less attractive alternative for correction of venous outflow stenosis given the more invasive and occasionally technically difficult procedure.

Evolution of Efficient Modular Polyketide Synthases by Homologous Recombination.

The structural scaffolds of many complex natural products are produced by multifunctional type I polyketide synthase (PKS) enzymes that operate as biosynthetic assembly lines. The modular nature of these mega-enzymes presents an opportunity to construct custom biocatalysts built in a lego-like fashion by inserting, deleting, or exchanging native or foreign domains to produce targeted variants of natural polyketides. However, previously engineered PKS enzymes are often impaired resulting in limited production compared to native systems. Here, we show a versatile method for generating and identifying functional chimeric PKS enzymes for synthesizing custom macrolactones and macrolides. PKS genes from the pikromycin and erythromycin pathways were hybridized in Saccharomyces cerevisiae to generate hybrid libraries. We used a 96-well plate format for plasmid purification, transformations, sequencing, protein expression, in vitro reactions and analysis of metabolite formation. Active chimeric enzymes were identified with new functionality. Streptomyces venezuelae strains that expressed these PKS chimeras were capable of producing engineered macrolactones. Furthermore, a macrolactone generated from selected PKS chimeras was fully functionalized into a novel macrolide analogue. This method permits the engineering of PKS pathways as modular building blocks for the production of new antibiotic-like molecules.

Dereplication of natural products using minimal NMR data inputs.

A strategy for the dereplication of a complete or a partial structure using (1)H NMR, (1)H-(13)C HSQC and (1)H-(1)H COSY spectral data, a molecular formula composition range and structural fragments against a massive database of about 22 million compounds is considered. As the increasing availability of public online databases containing natural products continues to grow the potential of utilizing these resources for dereplication purposes increases. This work examines approaches for NMR dereplication of natural products and includes a comparison with approaches for molecular formula and mass-based dereplication. The strategy is an application of computer-assisted structure elucidation using ACD/Structure Elucidator and data obtained from the ChemSpider database hosted by the Royal Society of Chemistry.

Digging Deep for New Compounds from the Compass Plant, Silphium laciniatum.

The compass plant, Silphium laciniatum, is an iconic perennial plant of the North American tallgrass prairie. The plants of the tallgrass prairie historically have been subjected to a number of biological and environmental stresses. Among the adaptations developed by S. laciniatum is a large deep taproot. An investigation of the secondary metabolites found in the root of a S. laciniatum specimen has led to the identification of 15 new terpenoids (3-8, 10-17, and 22), which were screened for cytotoxic activity in the NCI-H460 human large-cell lung carcinoma cell line.

Diterpenes from the endangered goldenrod Solidago shortii.

Species extinction is tantamount to loss of chemical diversity, and so it is important to seize all opportunities to study species on the brink of extinction. Such studies are often hampered by the limited material available, but that obstacle is surmountable through collaboration with botanical gardens and advances in instrumentation. The goldenrod Solidago shortii is one example of an endangered species native to the United States. From S. shortii, one known diterpene (1), two new diterpenes (2 and 3), and three new hydrolysis products (4-6) are described. This work was made possible through collaboration with the Missouri Botanical Garden and with the use of highly sensitive microcryoprobe NMR technology for structure elucidation and VCD spectroscopy for the determination of absolute configuration.

Surveillance computed tomographic arteriogram does not change management before 3 years in patients who have a normal post-EVAR study.

BACKGROUND: Standard surveillance after endovascular abdominal aortic aneurysm repair (EVAR) consists of periodic computed tomographic arteriographies (CTAs) usually performed at postoperative months 1, 6, and 12, and then annually. This imaging regimen is expensive and exposes patients to the hazards of radiation and intravenous contrast. We hypothesized that a normal 1-month CTA after EVAR with no endoleak or other significant abnormality predicts a low rate of future complications, which would justify a reduction in frequency of subsequent CTAs. METHODS: We identified 106 consecutive patients who underwent EVAR at a single hospital from 2003 to 2010 and reviewed all their CTAs. Fifteen patients for whom we could not review a postoperative CTA were excluded. Of the remaining 91 patients, 70 (76.9%) had no abnormality on their CTA at 1 month after EVAR. The medical records of these 70 patients were analyzed for subsequent complications and interventions related to EVAR. RESULTS: The mean patient follow-up was 3.4 ± 2.1 years. Five of the 70 (7.1%) patients with a normal post-EVAR CTA developed late complications consisting of 1 type I endoleak, 3 type II endoleaks, and 1 case of endotension. Only the type I endoleak and one of the type II endoleaks met criteria for intervention, and in both cases, the endoleaks were discovered >3 years after EVAR. Log-rank test showed a statistically significant increased freedom from aneurysm sac expansion in patients with a normal compared with an abnormal 1-month CTA (P < 0.001). CONCLUSIONS: For patients who have a normal CTA with no endoleak 1 month after EVAR, it is reasonable to consider less-frequent CTA surveillance because no significant complications requiring intervention occurred before 3 years. This would decrease unnecessary CTAs and health care expenditures as well as minimize patient exposure to radiation and intravenous contrast.

Epigenetic therapy potentiates transposable element transcription to create tumor-enriched antigens in glioblastoma cells.

Inhibiting epigenetic modulators can transcriptionally reactivate transposable elements (TEs). These TE transcripts often generate unique peptides that can serve as immunogenic antigens for immunotherapy. Here, we ask whether TEs activated by epigenetic therapy could appreciably increase the antigen repertoire in glioblastoma, an aggressive brain cancer with low mutation and neoantigen burden. We treated patient-derived primary glioblastoma stem cell lines, an astrocyte cell line and primary fibroblast cell lines with epigenetic drugs, and identified treatment-induced, TE-derived transcripts that are preferentially expressed in cancer cells. We verified that these transcripts could produce human leukocyte antigen class I-presented antigens using liquid chromatography with tandem mass spectrometry pulldown experiments. Importantly, many TEs were also transcribed, even in proliferating nontumor cell lines, after epigenetic therapy, which suggests that targeted strategies like CRISPR-mediated activation could minimize potential side effects of activating unwanted genomic regions. The results highlight both the need for caution and the promise of future translational efforts in harnessing treatment-induced TE-derived antigens for targeted immunotherapy.

Acetylated dammarane-type bisdesmosides from Combretum inflatum.

The first study of the chemical constituents of Combretum inflatum has resulted in the isolation of seven new acetylated dammarane-type bisdesmosides (1-7). Their structures were determined from microgram quantities on hand using Bruker BioSpin TCI 1.7 mm MicroCryoProbe technology, ESIMS, and comparison to data found in the literature. Compounds 1-7 were screened for inhibition of an Escherichia coli strain UTI89 biofilm, MRSA inhibition, and cytotoxicity in NCI-H460 human lung cancer cells. Compounds 3-7 reduced the growth of MRSA at 16 µg/mL by 71-45%, and compound 7 had an IC50 value of 3.9 µM in NCI-H460.

Noncompressible arteries correlate with increased cardiovascular mortality at 2 years.

BACKGROUND: The ankle-brachial index (ABI) is a useful screening tool for the detection of peripheral vascular disease (PVD). Using ABI measurements, patients can be stratified into different severities of arterial occlusive disease. METHODS: Four hundred forty-four Veterans Health Administration Medical Center patients were referred for PVD between 2004 and 2005. Of those, 231 patients had an ABI ≤0.90 or >1.2 with known treatment and follow-up obtained from electronic medical records. These individuals had bilateral ABI measurements and were observed for a median of 23 months (range, 4.0-60.0 months). Patients were divided into 4 ABI categories: severe (ABI ≤0.30; n = 62), moderate (ABI 0.30-≤0.60; n = 138), mild (ABI 0.60-≤0.90; n = 89), normal (ABI 0.90-≤1.2; n = 86), and noncompressible (ABI >1.2; n = 69). RESULTS: Mortality from cardiovascular disease in the severe, moderate, mild, normal, and noncompressible groups was 4.8%, 8.0%, 10.1%, 0%, and 21.7%, respectively, at the mean follow-up of 2 years. For all-cause mortality, the overall percent for each group respectively was 32.3%, 31.9%, 31.5%, 14%, and 42% (P = 0.003). To our surprise, ABIs <0.9 did not show a linear correlation with 2-year survival. However, an ABI >1.2, indicating noncompressible arteries, correlated significantly with higher rates of mortality at a mean follow-up of 2 years (33.3%). Cardiovascular disease and amputation were also significantly higher in those with noncompressible arteries than in the other groups. CONCLUSIONS: ABI is a noninvasive, inexpensive test that provides valuable information on a patient's risk of death. We recommend that patients with noncompressible vessels undergo systemic cardiovascular work-up, including coronary and carotid artery evaluation.