Principles for management of hip fracture for older adults taking direct oral anticoagulants: an international consensus statement

Hip fracture is a common serious injury among older adults, yet the management of hip fractures for patients taking direct oral anticoagulants remains inconsistent worldwide. Drawing from a synthesis of available evidence and expert opinion, best practice approaches for managing patients with a hip fracture and who are taking direct oral anticoagulants pre-operatively were considered by a working group of the Fragility Fracture Network Hip Fracture Audit Special Interest Group. The literature and related clinical guidelines were reviewed and a two-round modified Delphi study was conducted with a panel of experts from 16 countries and involved seven clinical specialities. Four consensus statements were achieved: peripheral nerve blocks can reasonably be performed on presentation for patients with hip fracture who are receiving direct oral anticoagulants; hip fracture surgery can reasonably be performed for patients taking direct oral anticoagulants < 36 h from last dose; general anaesthesia could reasonably be administered for patients with hip fracture and who are taking direct oral anticoagulants < 36 h from last dose (assuming eGFR > 60 ml.min-1.1.73 m-2); and it is generally reasonable to consider recommencing direct oral anticoagulants (considering blood loss and haemoglobin) < 48 h after hip fracture surgery. No consensus was achieved regarding timing of spinal anaesthesia. The consensus statements were developed to aid clinicians in their decision-making and to reduce practice variations in the management of patients with hip fracture and who are taking direct oral anticoagulants. Each statement will need to be considered specific to each individual patient's treatment.

Disease burden of bacteraemia with extended-spectrum beta-lactamase-producing and carbapenem-resistant Enterobacterales in Korea

BACKGROUND

Despite the significant impact of multi-drug-resistant bacteraemia, especially extended-spectrum beta-lactamase-producing Enterobacterales (ESBL-E) and carbapenem-resistant Enterobacterales (CRE), the burden of disease has not been investigated thoroughly.

AIM

To evaluate the clinical outcomes and socio-economic burden of ESBL-E and CRE bacteraemia nationwide in the Republic of Korea.

METHODS

A search was undertaken for all cases of ESBL-E and CRE bacteraemia and matched controls in 10 hospitals in the Republic of Korea over 6 months. Patients with ESBL-E or CRE bacteraemia were classified as the R group, and matched controls with antibiotic-susceptible bacteraemia and without infection were classified as the S and N groups, respectively. Patients' clinical data were collected, and the economic burden was estimated based on medical expenses, loss of productivity and total costs.

FINDINGS

In total, 795 patients were identified, including 265 patients with ESBL-E or CRE bacteraemia and their matched controls. The mean total length of stay for patients with ESBL-E and CRE in the R group was 1.53 and 1.90 times that of patients in the S group, respectively. The 90-day mortality rates for ESBL-E in the R and S groups were 12.1% and 5.6%, respectively, and the corresponding figures for CRE were 28.6% and 12.0%. There were significant differences in the total costs between the R, S and N groups for both ESBL-E and CRE (ESBL-E: $11,151 vs $8712 vs $6063, P=0.004; CRE: $40,464 vs $8748 vs $7279, P=0.024).

CONCLUSION

The clinical and economic burden imposed by ESBL-E or CRE bacteraemia was extremely high. These findings suggest that efforts to control resistant bacteraemia are necessary to reduce this burden.

Association between Hashimoto's thyroiditis and melanoma: a retrospective matched cohort study

An inflammatory microenvironment has been shown to increase risk for malignant melanoma, suggesting that melanoma may be related to a pro-inflammatory state. Though Hashimoto's thyroiditis is one of the most common autoimmune diseases, there are no investigations of its relationship with melanoma. We aim to determine if Hashimoto's increases risk of developing melanoma. A retrospective, validated cohort of patients with a diagnosis of Hashimoto's between 2005 and 2020 were identified using the Olmsted County database. Patients were age and sex matched to controls without a Hashimoto's diagnosis. The primary outcomes were development of melanoma and time to first melanoma diagnosis. 4805 patients were included in the study, with 1726 (36%) having a diagnosis of Hashimoto's. Hashimoto's patients had no significant difference in risk of melanoma (relative risk 0.96, 95% CI 0.78-1.17) or nonmelanoma skin cancer (relative risk 0.95, 95% CI 0.86-1.06) compared with matched controls. This suggests that the local proinflammatory environment present in Hashimoto's does not contribute significantly to melanoma risk. Larger studies may be needed to further characterize the relationship between these diseases.

Sub-1.4 cm3 capsule for detecting labile inflammatory biomarkers in situ

Transient molecules in the gastrointestinal tract such as nitric oxide and hydrogen sulfide are key signals and mediators of inflammation. Owing to their highly reactive nature and extremely short lifetime in the body, these molecules are difficult to detect. Here we develop a miniaturized device that integrates genetically engineered probiotic biosensors with a custom-designed photodetector and readout chip to track these molecules in the gastrointestinal tract. Leveraging the molecular specificity of living sensors1, we genetically encoded bacteria to respond to inflammation-associated molecules by producing luminescence. Low-power electronic readout circuits2 integrated into the device convert the light emitted by the encapsulated bacteria to a wireless signal. We demonstrate in vivo biosensor monitoring in the gastrointestinal tract of small and large animal models and the integration of all components into a sub-1.4 cm3 form factor that is compatible with ingestion and capable of supporting wireless communication. With this device, diseases such as inflammatory bowel disease could be diagnosed earlier than is currently possible, and disease progression could be more accurately tracked. The wireless detection of short-lived, disease-associated molecules with our device could also support timely communication between patients and caregivers, as well as remote personalized care.

Production of a 135-residue long N-truncated human keratinocyte growth factor 1 in Escherichia coli

BACKGROUND

Palifermin (trade name Kepivance®) is an amino-terminally truncated recombinant human keratinocyte growth factor 1 (KGF-1) with 140 residues that has been produced using Escherichia coli to prevent and treat oral mucositis following radiation or chemotherapy. In this study, an amino-terminally shortened KGF-1 variant with 135 residues was produced and purified in E. coli, and its cell proliferation activity was evaluated.

RESULTS

We expressed soluble KGF-1 fused to thioredoxin (TRX) in the cytoplasmic fraction of E. coli to improve its production yield. However, three N-truncated forms (KGF-1 with 140, 138, and 135 residues) were observed after the removal of the TRX protein from the fusion form by cleavage of the human enterokinase light chain C112S (hEK_L C112S). The shortest KGF-1 variant, with 135 residues, was expressed by fusion with TRX via the hEK_L cleavage site in E. coli and purified at high purity (> 99%). Circular dichroism spectroscopy shows that purified KGF-1₁₃₅ had a structure similar to that of the KGF-1₁₄₀ as a random coiled form, and MCF-7 cell proliferation assays demonstrate its biological activity.

CONCLUSIONS

We identified variations in N-terminus-truncated KGF-1 and selected the most stable form. Furthermore, by a simple two-step purification, highly purified KGF-1₁₃₅ was obtained that showed biological activity. These results demonstrate that KGF-1₁₃₅ may be considered an alternative protein to KGF-1.

High-level production of keratinocyte growth factor 2 in Escherichia coli

Recombinant human keratinocyte growth factor 2 (KGF-2), also known as repifermin, is used in various therapeutic applications. However, KGF-2 production has not been optimized for facilitating large-scale production. Therefore, we attempted to attain high-level production of bioactive KGF-2. KGF-2 was fused with 6HFh8 (6HFh8-KGF-2) at the tobacco etch virus protease cleavage site. The 6HFh8-KGF-2 was expressed in Escherichia coli with high expression levels of approximately 33% and 20% of soluble protein in flask culture and 5 L fermentation, respectively. 6HFh8-KGF-2 was purified via nickel affinity chromatography. To maintain a stable form of KGF-2, the conditions of the cleavage reaction were optimized based on the isoelectric point. KGF-2 was purified via ion-exchange chromatography to high purity (>99%) with an optimal purification yield (91%). Circular dichroism spectroscopy demonstrated that purified KGF-2 had a secondary structure and thermal stability similar to that of commercial KGF-2. Bioactivity assays indicated that purified KGF-2 could induce MCF-7 cell proliferation in the same manner as commercial KGF-2. These results demonstrate that bioactive KGF-2 was overexpressed in E. coli and purified to high quality. Our findings indicated that bioactive KGF-2 can be produced in large quantities in E. coli.

Polyhydroxybutyrate production from crude glycerol using a highly robust bacterial strain Halomonas sp. YLGW01

Petrochemical-based plastics are hardly biodegradable and a major cause of environmental pollution, and polyhydroxybutyrate (PHB) is attracting attention as an alternative due to its similar properties. However, the cost of PHB production is high and is considered the greatest challenge for its industrialization. Here, crude glycerol was used as a carbon source for more efficient PHB production. Among the 18 strains investigated, Halomonas taeanenisis YLGW01 was selected for PHB production due to its salt tolerance and high glycerol consumption rate. Furthermore, this strain can produce poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (P(3HB-co-3 HV)) with 17 % 3 HV mol fraction when a precursor is added. PHB production was maximized through medium optimization and activated carbon treatment of crude glycerol, resulting in 10.5 g/L of PHB with 60 % PHB content in fed-batch fermentation. Physical properties of the produced PHB were analyzed, i.e., weight average molecular weight (6.8 × 10⁵), number average molecular weight (4.4 × 10⁵), and the polydispersity index (1.53). In the universal testing machine analysis, the extracted intracellular PHB showed a decrease in Young's modulus, an increase in Elongation at break, greater flexibility than authentic film, and decreased brittleness. This study confirmed that YLGW01 is a promising strain for industrial PHB production using crude glycerol.

Enhanced production of bio-indigo in engineered Escherichia coli, reinforced by cyclopropane-fatty acid-acyl-phospholipid synthase from psychrophilic Pseudomonas sp. B14-6

Indigo dye is an organic compound with a distinctive blue color. Most of the indigo currently used in industry is produced via chemical synthesis, which generates a large amount of wastewater. Therefore, several studies have recently been conducted to find ways to produce indigo eco-friendly using microorganisms. Here, we produced indigo using recombinant Escherichia coli with both an indigo-producing plasmid and a cyclopropane fatty acid (CFA)-regulating plasmid. The CFA-regulating plasmid contains the cfa gene, and its expression increases the CFA composition of the phospholipid fatty acids of the cell membrane. Overexpression of cfa showed cytotoxicity resistance of indole, an intermediate product formed during the indigo production process. This had a positive effect on indigo production and cfa originated from Pseudomonas sp. B 14-6 was used. Optimal conditions for indigo production were determined by adjusting the expression strain, culture temperature, shaking speed, and isopropyl β-D-1-thiogalactopyranoside concentration. Treatment with Tween 80 at a particular concentration to increase the permeability of the cell membrane had a positive effect on indigo production. The strain with the CFA plasmid produced 4.1 mM of indigo after 24 h of culture and produced 1.5-fold higher indigo than the control strain without the CFA plasmid that produced 2.7 mM.

Biosynthesis of aliphatic plastic monomers with amino residues in Yarrowia lipolytica

Introduciton: The α,ω-diamines (NH₂-(CH₂)_n-NH₂) and ω -amino fatty acids (NH₂-(CH₂)_n-COOH) have been widely used as building blocks in polymerindustries. Medium- to long-chain (C₈ to C₁₈) fatty acid monomers with amino residues are almost exclusively produced via chemical processes that generate hazardous waste and induce severe environmental problems, such as global warming and pollution. Here, we present the construction platformstrains of Yarrowia lipolytica a cheese-ripening yeast, for direct biotransformation of hydrocarbons into medium- to long-chain α,ω-diamines and ωamino fatty acids using metabolic engineering of endogenous fatty acid ω- and β-oxidation pathways and introducing heterologous ω-transaminase in Y. lipolytica. Methods: We deleted six genes encoding the acyl-CoA oxidase (ACO1-6) and four fatty aldehyde dehydrogenase genes (FALDH1-4), which catalyze fatty acid β-oxidation and downstream oxidation of fatty aldehydes in Y. lipolytica, respectively. The ω-transaminase from Chromobacterium violaceum DSM30191 was introduced into the genome of the ΔPOX ΔFALDH strain under the control of Y. lipolytica-derived EXP1 promoters. Results and Discussion: The ΔPOX ΔFALDH strains with ω-CvTA successfully accumulated the corresponding C12 αω-diamines into a shaking culture medium with dodecane or dodecanol. In addition, these strains accumulated C₁₂ ω-amino fatty acids from dodecanoic acid. With the commercially available α,ω-diacid bioprocess, this yeast biosynthesis producing medium- and longchain α,ω-diamines and ω-amino fatty acids could complete the yeast platform technology generating all medium- and long-chain aliphatic polyamide monomers, α,ω-biofunctionalized with one or both carboxylic acid and amino residues.

Acute Lower Extremity Fracture Management in Chronic Spinal Cord Injury: 2022 Delphi Consensus Recommendations

Our objective was to develop a clinical practice guideline (CPG) for the treatment of acute lower extremity fractures in persons with a chronic spinal cord injury (SCI).

METHODS

Information from a previous systematic review that addressed lower extremity fracture care in persons with an SCI as well as information from interviews of physical and occupational therapists, searches of the literature, and expert opinion were used to develop this CPG. The Grading of Recommendations, Assessment, Development and Evaluations (GRADE) system was used to determine the quality of evidence and the strength of the recommendations. An overall GRADE quality rating was applied to the evidence.

CONCLUSIONS

Individuals with a chronic SCI who sustain an acute lower extremity fracture should be provided with education regarding the risks and benefits of operative and nonoperative management, and shared decision-making for acute fracture management should be used. Nonoperative management historically has been the default preference; however, with the advent of greater patient independence, improved surgical techniques, and advanced therapeutics and rehabilitation, increased use of surgical management should be considered. Physical therapists, kinesiotherapists, and/or occupational therapists should assess equipment needs, skills training, and caregiver assistance due to changes in mobility resulting from a lower extremity fracture. Therapists should be involved in fracture management as soon as possible following fracture identification. Pressure injuries, compartment syndrome, heterotopic ossification, nonunion, malunion, thromboembolism, pain, and autonomic dysreflexia are fracture-related complications that clinicians caring for patients who have an SCI and a lower extremity fracture may encounter. Strategies for their treatment are discussed. The underlying goal is to return the patient as closely as possible to their pre-fracture functional level with operative or nonoperative management.

External validation of the biomarker based ABCD score in atrial fibrillation patients with a non gender CHA2DS2 VASc score 0 to 1, A Korean multicenter retrospective cohort

Background

Patients with low to intermediate risk atrial fibrillation (AF), defined as non-gender CHA2DS2-VASc score of 0–1, are still at risk of stroke. This study verified the usefulness of ABCD score (Age [≥60 years], B-type natriuretic peptide [BNP] or N-terminal pro-BNP [≥300 pg/ml], Creatinine clearance [&lt;50 ml/min/1.73 m2], and Dimension of the left atrium [≥45 mm]) for stroke risk stratification in non-gender CHA2DS2-VASc score 0–1.

Methods

This multi-center cohort study retrospectively analyzed AF patients with non-gender CHA2DS2-VASc score 0–1. The primary endpoint was the incidence of stroke with or without anti-thrombotic treatment (ATT). An ABCD score was also validated.

Results

Overall, 2694 patients (56.3±9.5 years; female, 726 [26.9%]) were followed-up for 4.0±2.8 years. The overall stroke rate was 0.84/100 person-years (P-Y), stratified as follows: 0.46/100P-Y for an ABCD score 0; 1.02/100P-Y for an ABCD score≥1. The ABCD score was superior to the non-gender CHA2DS2-VASc score in stroke risk stratification (C-index=0.618, P=0.015; net reclassification improvement=0.576, P=0.040; integrated differential improvement=0.033, P=0.066). ATT was prescribed in 2353 patients (86.5%), and the stroke rate was significantly lower in patients receiving non-vitamin K antagonist oral anticoagulant (NOAC) therapy and an ABCD score≥1 than in those without ATT (0.44/100P-Y versus 1.55/100 P-Y; hazard ratio=0.26, 95% confidence interval 0.11–0.63, P=0.003).

Conclusion

The biomarker-based ABCD score demonstrated improved stroke risk stratification in AF patients with non-gender CHA2DS2-VASc score 0–1. Furthermore, NOAC with an ABCD score≥1 was associated with significantly lower stroke rate in AF patients with a non-gender CHA2DS2-VASc score 0–1.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Korean Disease Control and Prevention Agency

Clinical and radiological outcome of the locked plate osteosynthesis in distal metadiaphyseal tibial fracture according to the severity of comminution: Varus reduction would not be preferable with lower clinical outcomes

BACKGROUND

The optimal treatment for distal tibial fractures remains a matter of debate. Nonetheless, plate osteosynthesis produces favorable results to intramedullary stabilization in aspects of alignment restoration.

AIM

The aim of the study was to compare the radiologic and clinical outcomes of distal metadiaphyseal tibial fracture between a simple/wedge fracture (SWF) and a comminuted fracture (CF) using minimally invasive plate osteosynthesis (MIPO).

PATIENTS AND METHODS

This retrospective study analyzed patients with SWF or CF of the distal tibial metadiaphysis that was surgically treated with a locking compression plate. Postoperative radiographic assessments and the time to radiologic union were noted. Clinical assessments were evaluated using both the American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot score and the foot function index (FFI). Postoperative complications were documented.

RESULTS

Seventy-one cases were analyzed over a mean follow-up period of 20.9 months. Thirty-six patients had SWF and 35 patients presented with CF. The mean time to radiologic union, amounts of postoperative coronal angulation, and incidence of malunion showed no statistical differences. Fibular fixation was more applied in the CF group (P < 0.001). Moreover, the clinical scores revealed no differences. Nonetheless, in the valgus union group, the AOFAS ankle-hindfoot score was 90.9 compared to 84.1 in the varus union group (P = 0.042) and the FFI was 9.2% compared to 20.2% in the varus union group (P = 0.017).

CONCLUSION

Plate osteosynthesis for SWF or CF of the distal tibial metadiaphysis led to high union rates and good clinical outcomes. There was no significant difference in the radiologic and clinical results according to the presence of fracture comminution. Nonetheless, the valgus union group showed better clinical outcomes than the varus union group. Clinically, it would be preferred to avoid intraoperative varus reduction.

Controlling catabolite repression for isobutanol production using glucose and xylose by overexpressing the xylose regulator

Using lignocellulosic biomass is immensely beneficial for the economical production of biochemicals. However, utilizing mixed sugars from lignocellulosic biomass is challenging because of bacterial preference for specific sugar such as glucose. Although previous studies have attempted to overcome this challenge, no studies have been reported on isobutanol production from mixed sugars in the Escherichia coli strain. To overcome catabolite repression of xylose and produce isobutanol using mixed sugars, we applied the combination of three strategies: (1) deletion of the gene for the glucose-specific transporter of the phosphotransferase system (ptsG); (2) overexpression of glucose kinase (glk) and glucose facilitator protein (glf); and (3) overexpression of the xylose regulator (xylR). xylR gene overexpression resulted in 100% of glucose and 82.5% of xylose consumption in the glucose-xylose mixture (1:1). Moreover, isobutanol production increased by 192% in the 1:1 medium, equivalent to the amount of isobutanol produced using only glucose. These results indicate the effectiveness of xylR overexpression in isobutanol production. Our findings demonstrated various strategies to overcome catabolite repression for a specific product, isobutanol. The present study suggests that the selected strategy in E. coli could overcome the major challenge using lignocellulosic biomass to produce isobutanol.

Postoperative Pneumonia and Aspiration Pneumonia Following Elderly Hip Fractures

OBJECTIVES

The present study aimed to investigate the incidence of and risk factors for postoperative pneumonia and aspiration pneumonia after hip fracture surgery.

DESIGN

Retrospective cohort study from 2005 to 2021.

SETTING

Asan Medical Center in Seoul, Republic of Korea.

PARTICIPANTS

A total 1,208 patients aged ≥ 65 years who underwent hip fracture surgery.

MEASUREMENTS

Postoperative pneumonia was defined as cases with new infiltration on chest x-ray or chest computed tomography (CT) after surgery or confirmed by a pulmonologist's consultation and diagnosis. Aspiration pneumonia was defined as: 1) radiologic findings of hospital-acquired pneumonia on chest radiographs or CT, medical record of aspiration pneumonia confirmed by a pulmonologist's consultation, and history of vomiting or aspiration, or 2) gravity-dependent opacity on chest CT when the history of vomiting or aspiration is ambiguous. Patient demographics, past medical history, pre-injury Koval score, Charlson Comorbidity Index (CCI), blood test results, length of hospital stay, and in-hospital mortality were evaluated. A comparison analysis and binary logistic regression were performed to identify the incidence and risk factors for postoperative pneumonia and aspiration pneumonia.

RESULTS

Postoperative pneumonia was diagnosed in 47 patients (3.9%), including 20 with aspiration pneumonia (1.7%). In the multivariate analysis, postoperative delirium (odds ratio [OR], 3.42; P < 0.001), American Society of Anesthesiologists (ASA) scores ≥ 3 (OR, 2.11; P = 0.021), and CCI (OR, 1.21; P = 0.013) were significant risk factors for postoperative pneumonia. Male sex (OR, 3.01; P = 0.017), postoperative delirium (OR, 3.16; P = 0.014), and preoperative serum albumin levels < 3.5 g/dL (OR, 7.00; P = 0.010) were significant risk factors for aspiration pneumonia.

CONCLUSION

ASA classification ≥ 3, higher CCI, and postoperative delirium were the risk factors for postoperative pneumonia. Male sex, postoperative delirium, and lower preoperative serum albumin level were the risk factors for aspiration pneumonia. Thus, physicians should pay attention to patients with the risk factors.

Enhanced mating-type switching and sexual hybridization in heterothallic yeast Yarrowia lipolytica

Yarrowia lipolytica is a non-conventional, heterothallic, oleaginous yeast with wide range of industrial applications. Increasing ploidy can improve advantageous traits for industrial applications including genetic stability, stress resistance, and productivity, but the construction of knockout mutant strains from polyploid cells requires significant effort due to the increased copy numbers of target genes. The goal of this study was to evaluate the effectiveness of a mating-type switching strategy by single-step transformation without a genetic manipulation vestige, and to optimize the conventional method for increasing ploidy (mating) in Y. lipolytica. In this study, mating-type genes in haploid Y. lipolytica cells were scarlessly converted into the opposite type genes by site-specific homologous recombination, and the resulting MATB-type cells were mated at low temperature (22°C) with addition of sodium citrate with each MATA-type haploid cell to yield a MATA/MATB-type diploid strain with genetic information from both parental strains. The results of this study can be used to increase ploidy and for whole genome engineering of a yeast strain with unparalleled versatility for industrial application.

Expression and purification of soluble and active human enterokinase light chain in Escherichia coli

•

Recombinant production of soluble, active enterokinase (EK) is challenging.

•

Maltose binding protein-fusion improves EK solubility but reduces activity.

•

GroEL/ES and Erv2/PDI induces correct refolding and improves EK activity.

•

Replacing free cysteine with serine dramatically improves EK activity.

Human enterokinase light chain (hEK_L) specifically cleaves the sequence (Asp)₄-Lys↓X (D₄K), making this a frequently used enzyme for site-specific cleavage of recombinant fusion proteins. However, hEK_L production from Escherichia coli is limited due to intramolecular disulphide bonds. Here, we present strategies to obtain soluble and active hEK_L from E. coli by expressing the hEK_L variant C112S fused with maltose-binding protein (MBP) through D₄K and molecular chaperons including GroEL/ES. The fusion protein self-cleaved in vivo, thereby removing the MBP in the E. coli cells. Thus, the self-cleaved hEK_L variant was released into the culture medium. One-step purification using HisTrap™ chromatography purified the hEK_L variant exhibiting an enzymatic activity of 3.1 × 10³ U/mL (9.934 × 10⁵ U/mg). The approaches presented here greatly simplify the purification of hEK_L from E. coli without requiring refolding processes.

Insights into collateral susceptibility and collateral resistance in Acinetobacter baumannii during antimicrobial adaptation

The susceptibility of Acinetobacter baumannii exposed to primary antibiotic can be either increased or decreased when exposed to secondary antibiotic. This study was designed to assess the relative fitness, collateral susceptibility and collateral resistance of polymyxin B- (PMB-) adapted A. baumannii to ciprofloxacin (CIP), meropenem (MER), PMB, tetracycline (TET) and tobramycin (TOB). Strains of wild-type A. baumannii KACC 12454 (AB^KACC ), wild-type A. baumannii CCARM 12088 (AB^CCARM ), PMB-adapted AB^KACC , PMB-adapted AB^CCARM , stabilized AB^KACC and stabilized AB^CCARM were used in this study. Compared to the wild-type AB^KACC , the MICs of PMB were increased from 2 to 128 μg ml^-1 against PMB-adapted AB^KACC , while MICs of CIP, MER, TET and TOB were decreased from 2 to 1 μg ml^-1 , 16 to 1 μg ml^-1 , 16 to 2 μg ml^-1 and 64 to 16 μg ml^-1 , respectively. The PMB-adapted AB^CCARM was resistant to CIP (32 μg ml^-1 ) and PMB (64 μg ml^-1 ) compared to the wild-type AB^CCARM . The resistance of stabilized AB^KACC and AB^CCARM to all antibiotics was lost after antibiotic-free culture in the exception of CIP and TET. The susceptibilities of wild-type, PMB-adapted and stabilized AB^KACC and AB^CCARM to CIP, MER, PMB, TET and TOB were increased in the presence of β-lactamase and efflux pump inhibitors. The high levels of relative fitness were observed for stabilized AB^KACC , PMB-adapted AB^CCARM and stabilized AB^CCARM . The stabilized AB^KACC and PMB-adapted AB^CCARM were highly heteroresistance to PMB and TET, respectively. The PMB-adapted AB^KACC and AB^CCARM showed various antibiotic patterns, known as collateral susceptibility and collateral resistance. The results provide useful information for designing effective antibiotic regimens that can enhance the antibiotic activity against A. baumannii infections.

Medical Care Disruptions During the First Six-Months of the COVID19 Pandemic: The Experience of Older Breast Cancer Survivors

Purpose.

Older cancer survivors required medical care during the COVID-19 pandemic despite infection risks, but there are limited data on medical care in this age group.

Methods.

We evaluated care disruptions in a longitudinal cohort of non-metastatic breast cancer survivors ages 60–98 from five US regions (n=321). Survivors completed a web-based or telephone survey from May 27, 2020 to September 11, 2020. Care disruptions included self-reported interruptions in ability to see doctors, receive treatment or supportive therapies, or fill prescriptions. Logistic regression models evaluated bivariate and multivariate associations between care disruptions and education, medical, psychosocial and COVID-19-related factors. Multivariate models included age, county COVID-19 rates, comorbidity and post-diagnosis time.

Results.

There was a high response rate (n=262, 81.6%). Survivors were 32.2 months post-diagnosis (SD 17.5, range 4–73). Nearly half (48%) reported a medical disruption. The unadjusted odds of care disruptions were significantly higher with more education (OR 1.23 per one-year increase, 95% CI 1.09–1.39, p =0.001) and greater depression (OR 1.04 per one-point increase in CES-D score, CI 1.003–1.08, p=0.033); tangible support decreased the odds of disruptions (OR 0.99, 95% CI 0.97–0.99 per one-point increase, p=0.012). There was a trend for associations between disruptions and comorbidity (unadjusted OR 1.13 per 1 added comorbidity, 95% CI 0.99–1.29, p=0.07). Adjusting for covariates, only higher education (p=0.001) and tangible social support (p=0.006) remained significantly associated with having care disruptions.

Conclusions.

Older breast cancer survivors reported high rates of medical care disruptions during the COVID-19 pandemic and psychosocial factors were associated with care disruptions.

Bioprospecting of exopolysaccharide from marine Sphingobium yanoikuyae BBL01: Production, characterization, and metal chelation activity

In the present study, an exopolysaccharide (EPS)-producing bacterial strain was isolated from the Eastern Sea (Sokcho Beach) of South Korea and identified as Sphingobium yanoikuyae BBL01. Media optimization was performed using response surface design, and a yield of 2.63 ± 0.02 g/L EPS was achieved. Purified EPS produced using lactose as the main carbon source was analyzed by GC-MS and found to be composed of α-D-xylopyranose (28.6 ± 2.0%), β-D-glucopyranose (21.0 ± 1.6%), α-D-mannopyranose (18.5 ± 1.2%), β-d-mannopyranose (13.1 ± 1.4%), β-D-xylopyranose (10.2 ± 2.1%), α-d-talopyranose (5.9 ± 1.1%), and β-d-galacturonic acid (2.43 ± 0.8%). Interestingly, different carbon sources (glucose, galactose, glycerol, lactose, sucrose, and xylose) showed no effect on EPS monomer composition, with a slight change in the mass percentage of various monosaccharides. Purified EPS was stable up to 233 °C, indicating its possible suitability as a thickening and gelling agent for food-related applications. EPS also showed considerable emulsifying, flocculating, free-radical scavenging, and metal-complexion activity, suggesting various biotechnological applications.

Impact of a specialised palliative care intervention in patients with advanced soft tissue sarcoma - a single-centre retrospective analysis

BACKGROUND

Soft tissue sarcomas (STS) account for less than 1% of all malignancies. Approximately 50% of the patients develop metastases with limited survival in the course of their disease. For those patients, palliative treatment aiming at symptom relief and improvement of quality of life is most important. However, data on symptom burden and palliative intervention are limited in STS patients.

AIM

Our study evaluates the effectiveness of a palliative care intervention on symptom relief and quality of life in STS patients.

DESIGN/SETTING

We retrospectively analysed 53 inpatient visits of 34 patients with advanced STS, admitted to our palliative care unit between 2012 and 2018. Symptom burden was measured with a standardised base assessment questionnaire at admission and discharge.

RESULTS

Median disease duration before admission was 24 months, 85% of patients had metastases. The predominant indication for admission was pain, weakness and fatigue. Palliative care intervention led to a significant reduction of pain: median NRS for acute pain was reduced from 3 to 1 (p < 0.001), pain within the last 24 h from 5 to 2 (p < 0.001) and of the median MIDOS symptom score: 18 to 13 (p < 0.001). Also, the median stress level, according to the distress thermometer, was reduced significantly: 7.5 to 5 (p = 0.027).

CONCLUSIONS

Our data underline that specialised palliative care intervention leads to significant symptom relief in patients with advanced STS. Further efforts should aim for an early integration of palliative care in these patients focusing primarily on the identification of subjects at high risk for severe symptomatic disease.

Effective production of human growth factors in Escherichia coli by fusing with small protein 6HFh8

Background

Growth factors (GFs) are signaling proteins that affect cellular processes such as growth, proliferation, and differentiation. GFs are used as cosmeceuticals, exerting anti-wrinkle, anti-aging, and whitening effects, and also as pharmaceuticals to treat wounds, growth failure, and oral mucositis. However, in mammalian and bacterial cells, low productivity and expression in inclusion bodies, respectively, of GFs does not satisfy the consumer demand. Here, we aimed to develop a bacterial expression system that produces high yields of soluble GFs that can be purified in their native forms.

Results

We present Fh8, an 8-kDa peptide from Fasciola hepatica with an N-terminal hexa-histidine (6HFh8), as a fusion partner for enhanced human GF production in recombinant Escherichia coli. The fusion partner harboring a tobacco etch virus (TEV) protease cleavage site was fused to the N-terminus of 10 human GFs: acidic and basic fibroblast growth factors (aFGF and bFGF, respectively), epidermal growth factor (EGF), human growth hormone (hGH), insulin-like growth factor 1 (IGF-1), vascular endothelial growth factor 165 (VEGF165), keratinocyte growth factor 1 (KGF-1), placental growth factor (PGF), stem cell factor (SCF), and tissue inhibitor of metalloproteinase 1 (TIMP-1). The fusion proteins were expressed in E. coli under the control of T7 promoter at three temperatures (25 °C, 30 °C, and 37 °C). All individual fusion proteins, except for SCF and TIMP-1, were successfully overexpressed in cytoplasmic soluble form at more than one temperature. Further, the original aFGF, IGF-1, EGF, and VEGF165 proteins were cleaved from the fusion partner by TEV protease. Five-liter fed-batch fermentation approaches for the 6HFh8-aFGF (lacking disulfide bonds) and 6HFh8-VEGF165 (a cysteine-rich protein) were devised to obtain the target protein at concentrations of 9.7 g/l and 3.4 g/l, respectively. The two GFs were successfully highly purified (> 99% purity). Furthermore, they exerted similar cell proliferative effects as those of their commercial equivalents.

Conclusions

We demonstrated that 6HFh8-GF fusion proteins could be overexpressed on a g/l scale in the cytoplasm of E. coli, with the GFs subsequently highly purified and maintaining their biological activity. Hence, the small protein 6HFh8 can be used for efficient mass-production of various GFs.

Engineering Yarrowia lipolytica for de novo production of tetraacetyl phytosphingosine

AIMS

To genetically engineer the oleaginous yeast Yarrowia lipolytica for de novo production of tetraacetylphytosphingosine (TAPS), a precursor of phytosphingosine, and optimization of fermentation conditions for high yield.

METHODS AND RESULTS

We successfully constructed a TAPS-producing Y. lipolytica CE3 strain by co-expression of Wickerhamomyces ciferrii-derived acetyl transferases, Sli1p and Atf2p. Next, we optimized several environmental factors including temperature, initial pH and C/N ratio for TAPS production in a shake culture. Deletion of LCB4 in CE3 strain increased the volumetric TAPS titre and cell-specific yield to 142·1 ± 10·7 mg_TAPS  l^-1 and 3·08 ± 0·11 mg_TAPS  g_DCW ^-1 , respectively, in a shake flask culture incubated for 120 h at 28°C with glycerol as the carbon source. Finally, we developed a 5-l fed-batch process with NaOH-mediated pH control and olive oil as a carbon source, exhibiting 650 ± 24 mg_TAPS  l^-1 of TAPS production within 56 h of the fermentation.

CONCLUSIONS

The introduction of codon-optimized Sli1p and Atf2p, deletion of LCB4 gene and sexual hybridization, accompanied by specific fermentation conditions, enhanced TAPS yield in Y. lipolytica.

SIGNIFICANCE AND IMPACT OF THE STUDY

Our results highlight Y. lipolytica as a promising candidate for the industrial production of TAPS, an important component of cosmetic formulations.

The brief window of time comprising a wheelchair transfer confers a significant fracture risk on elderly Americans

OBJECTIVES

Wheelchairs grant increased mobility to their users but can result in injuries of varying severities, including fractures which are often associated with wheelchair transfers. However, this fracture burden remains poorly characterized in elderly Americans. The purpose of this study was to report demographic and environmental risk factors for these injuries.

STUDY DESIGN

We used data from the National Electronic Injury Surveillance System (NEISS) for the years 2007-2017 to perform a retrospective, cross-sectional analysis of wheelchair transfer fractures in patients aged 65 years and older.

METHODS

Each yearly sample in the NEISS database was queried between 2007 and 2017 for fractures associated with wheelchair transfers in patients aged 65 years or older. The narrative sections of the database were individually read and reviewed to identify cases in which a patient explicitly transferred into or out of a wheelchair while sustaining said fracture.

RESULTS

Between 2007 and 2017, the average number of patients aged 65 years and older presenting to US emergency departments was 3924 (95% confidence interval [CI] = 2792-5055). A significantly higher percentage of fractures (61.8%; 95% CI = 56.7%-66.8%) is associated with transferring out of wheelchairs. Moreover, such fractures were often associated with transferring to and from beds (29.9%; 95% CI = 25.4%-34.3%), with the hip (37.5%; 95% CI = 33.3%-41.6%) being the most commonly fractured anatomical region overall. A majority of patients required admission to the hospital (60.2%; 95%CI = 52.4%-68.0%) and most wheelchair transfer fractures occurred at home (44.1%; 95% CI = 36.7%-51.5%), with women (71.9%; 95% CI = 68.3%-75.6%) comprising the majority of these patients.

CONCLUSIONS

Our findings show that wheelchair transfers are associated with significant risk of severe fracture in elderly Americans. As such, wheelchair transfer events merit extra attention from healthcare providers because they comprise a brief window of time relative to the number of occupancy hours in full-time wheelchair users yet can result in significant morbidity and mortality. Preventative measures and patient education should be encouraged to preserve patient mobility and reduce injury.

P966 Impact of systolic dysfunction and elevated left ventricular end diastolic pressure on three years clinical outcome in patients with atrial fibrillation

Background

Systolic and diastolic dysfunction is related with adverse clinical outcomes in the patients with sinus rhythm. Purpose: The aim of this study is to clarify the prognostic significance of both systolic and diastolic dysfunction in the patients with chronic persistent atrial fibrillation (AF). Methods: A total of 114 consecutive patients who have chronic persistent AF. Whole patients were divided into 2 groups according to left ventricular ejection fraction (LVEF): those with an LVEF &lt; 50 (n = 24) (REF) and those with an LVEF ≥ 50 (n = 90) (PEF). And PEF group was also divided into two groups according to left ventricular end diastolic filling pressure (LVEDP): patients with LVEDP ≥ 15 mmHg (n = 38) and those with &lt; 15 mmHg (n = 52). Results: 3-year clinical outcomes were compared between each groups (PEF groups vs. REF groups and LVEDP ≥ 15 mmHg vs LVEDP &lt; 15 mmHg). The incidence of death, hospitalization, stroke, bleeding, AF with rapid ventricular rhythm (RVR) and heart failure (HF) hospitalization were similar PEF and REF group. However, during 3-year follow up period, the incidence of HF hospitalization (29.2% vs 8.9%, p &lt; 0.02) and AF with RVR (20.8% vs 3.3%, p &lt; 0.01) were frequent in REF group compared with PEF group. In multivariate analysis, REF is an only predictor of HF hospitalization (Table 1). Conclusion: During 3-year follow up period, systolic dysfunction is an important predictor of HF hospitalization in AF patients. However, elevated LVEDP is not related with 3-year adverse clinical outcomes in AF patients without systolic dysfunction.

Table 1 variable Odd Ratio (HR) 95% Confidence Interval (CI) P Age .973 .925-1.023 .286 Diabetes mellitus .487 .138-1.721 .264 BNP 1.000 1.000-1.000 .908 Hypertension 1.061 .330-3.413 .921 LVEDP &gt; 15 mmHg 1.302 .396-4.285 .664 EF &lt; 50 4.712 1.478-15.016 .009 Predictors of 3-year follow-up clinical outcomes of all participants

3334Updated meta-analysis of biodegradable polymer drug-eluting stent versus second-generation durable polymer drug-eluting stent implantations

Background

Data regarding clinical outcomes of biodegradable polymer drug-eluting stent (BP-DES) versus second-generation durable polymer drug-eluting stent (DP-DES) in patients undergoing percutaneous coronary intervention (PCI) are inconclusive.

Purpose

We aimed to perform a meta-analysis to investigate the clinical outcomes of BP-DES compared with second-generation DP-DES in patients who have undergone PCI.

Methods

We searched PubMed, MEDLINE, EMBASE, and Cochrane databases through January 2019 for randomized controlled trials comparing BP-DES with second-generation DP-DES in patients treated with PCI. All-cause death, cardiac death, myocardial infarction (MI), target vessel revascularization (TVR), target lesion revascularization (TLR), definite/probable stent thrombosis (ST) were compared between the groups. Additionally, a landmark analysis with the landmark set at 1 year and a subgroup analysis according to stent characteristics were performed.

Results

Data from 23 trials including 28802 randomized patients were analyzed. At a median follow up of 3.1 years, no significant differences were found in terms of all-cause death (odds ratio [OR] 1.05, 95% confidence interval [CI] 0.95–1.16), cardiac death (OR 1.01, 95% CI 0.87–1.17), MI (OR 0.92, 95% CI 0.82–1.03), TVR (OR 0.97, 95% CI 0.86–1.11), TLR (OR 0.97, 95% CI 0.85–1.11), and definite/probable ST (OR 0.86, 95% CI 0.70–1.07) between the groups. Landmark analysis showed that there were similar risks in all-cause death (OR 1.04, 95% CI 0.93–1.17), cardiac death (OR 1.11, 95% CI 0.92–1.36), MI (OR 0.94, 95% CI 0.79–1.13), TVR (OR 0.95, 95% CI 0.73–1.23), TLR (OR 1.00, 95% CI 0.80–1.24), and definite/probable ST (OR 0.92, 95% CI 0.67–1.28) between the groups. The similar tendency of any study endpoints between the groups was consistent in the subgroup, including stent platform (stainless steel vs. alloy), the drug coating distribution (abluminal vs. circumferential), the polymer degradation period (<6 months vs. >6 months), or the drug release duration (<6 months vs. >6 months) of BP-DES, or the DAPT duration (≥6 months vs. ≥12 months). However, the uses of BP-DES with sirolimus-eluting (OR 0.84, 95% CI 0.72–0.98) or ultrathin strut (defined as <70μm; OR 0.81, 95% CI 0.68–0.97) were predictive for lower risk of MI.

Clinical outcomes

Conclusions

In our updated meta-analysis, BP-DES implantation was associated with comparable clinical outcomes compared with second-generation DP-DES implantation. However, PCI with ultrathin biodegradable polymer sirolimus-eluting stent could reduce the risk of MI.

P1026Risk factors for the occurrence of stroke after atrial fibrillation ablation

Background

Risk factors for the occurrence of embolic stroke (ES) after atrial fibrillation (AF) ablation have not been fully elucidated. Our aim was to assess incidence of ES during long-term follow-up following AF ablation and to identify predicting factors associated with post-ablation ES.

Methods

We enrolled patients who experienced ES after AF ablation and body mass index-matched controls from AF ablation registries. Epicardial adipose tissue (EAT) was assessed using multislice computed tomography prior to ablation.

Results

A total of 3,464 patients who underwent AF ablation were recruited. During a mean follow-up of 47.2 months, ES occurred in 47 patients (1.36%) with a mean CHA2DS2-VAS score of 2.15 and overall incidence of ES was 0.34 per 100 patients/year. Compared with control group (n=190), ES group had more higher prior thromboembolic event and AF recurrence rates, larger LA size, lower creatinine clearance rate (CCr), and greater total and periatrial EAT volumes although no differences in AF type, CHA2DS2-VASc score, ablation extent, and anti-thrombotics use were found. On multivariate regression analysis, a prior history of thromboembolism, CCr, and periatrial EAT volume were independently associated with ES occurrence after AF ablation.

Cox regression analysis Risk factor Univariate Multivariate HR (95% CI) p value HR (95% CI) p value Age 1.017 (0.984–1.051) 0.31 Prior thromboembolism 2.488 (1.134–5.460) 0.023 2.916 (1.178–7.219) 0.021 CHA2DS2-VASc score 1.139 (0.899–1.445) 0.282 CCr 0.984 (0.970–0.999) 0.038 0.982 (0.996–0.998) 0.029 LA diameter (mm) 1.070 (1.012–1.130) 0.017 1.072 (0.999–1.150) 0.054 EAT_total (ml) 1.020 (1.010–1.029) <0.001 1.008 (0.993–1.023) 0.297 EAT_periatrial (ml) 1.085 (1.045–1.126) <0.001 1.065 (1.005–1.128) 0.032 PVI + additional ablation 0.846 (0.460–1.557) 0.592 No anticoagulant use 0.651 (0.346–1.226) 0.184 Recurrence 2.011 (1.007–4.013) 0.048 1.240 (0.551–2.793) 0.603 CCr, creatinine clearance rate; EAT, epicardial adipose tissue; LA, left atrium; PVI, pulmonary vein isolation.

K-M curve for stroke-free survival

Conclusions

Incidence of ES after AF ablation was lower than expected rate based on CHA2DS2-VASc score even though anticoagulants use was limited. Periatrial EAT volume, a prior thromboembolism event, and CCr were independent factors in predicting ES irrespective of AF recurrence and CHA2DS2-VASc score in patients who underwent AF ablation.

P2799Long-term outcomes after percutaneous coronary intervention with biodegradable polymer drug-eluting stent versus second-generation durable polymer drug-eluting stent: evidence from a meta-analysis

Background

The true benefit of biodegradable polymer drug-eluting stent (BP-DES) over second-generation durable polymer drug-eluting stent (DP-DES) expected to be represented during late period of follow-up after percutaneous coronary intervention (PCI), but prior meta-analysis only evaluated short-term outcomes.

Purpose

We aimed to compare the long-term clinical outcomes after PCI with BP-DES versus second-generation DP-DES by a meta-analysis of randomized controlled trials.

Methods

Randomized controlled trials comparing BP-DES with second-generation DP-DES implantations were searched through PubMed, MEDLINE, EMBASE, and Cochrane databases. All-cause death, cardiac death, myocardial infarction (MI), target vessel revascularization (TVR), target lesion revascularization (TLR), and definite/probable stent thrombosis (ST) were compared between the groups. In addition, a landmark analysis with the landmark set at 1-year and a subgroup analysis based on stent characteristics were performed.

Results

Fifteen trials that included a total of 21311 randomized patients with at least 2 years follow-up were analyzed. At a median follow-up of 4.2 years, no significant differences in the risks of all-cause death (odds ratio [OR] 1.03, 95% confidence interval [CI] 0.94–1.14), cardiac death (OR 1.03, 95% CI 0.88–1.20), MI (OR 0.90, 95% CI 0.79–1.01), TVR (OR 0.96, 95% CI 0.82–1.12), TLR (OR 0.97, 95% CI 0.85–1.11), and definite/probable ST (OR 0.84, 95% CI 0.67–1.05) were found between the groups. In the 1-year landmark analysis, the rates of all-cause death (OR 1.04, 95% CI 0.93–1.17), cardiac death (OR 1.11, 95% CI 0.92–1.36), MI (OR 0.94, 95% CI 0.79–1.13), TVR (OR 0.95, 95% CI 0.73–1.23), TLR (OR 1.00, 95% CI 0.80–1.24), and definite/probable ST (OR 0.94, 95% CI 0.67–1.31) were similar between the groups. There were comparable rates of any study endpoints between the groups regardless of stent platform (stainless steel vs. alloy), the polymer degradation period (<6 months vs. >6 months) or the drug release duration (<6 months vs. >6 months) of BP-DES, or the DAPT duration (≥6 months vs. ≥12 months). However, the use of BP-DES with sirolimus eluting (OR 0.82, 95% CI 0.70–0.97), circumferential drug distribution (OR 0.79, 95% CI 0.65–0.96), thin strut (defined as <100μm; OR 0.83, 95% CI 0.70–0.97), or ultrathin strut (defined as <70μm; OR 0.78, 95% CI 0.64–0.94) were associated with lower rates of MI than did second-generation DP-DES. Moreover, BP-DES with circumferential drug distribution (OR 0.82, 95% CI 0.69–0.98) was predictive for reduced rates of TVR.

Clinical outcomes

Conclusions

In this meta-analysis, long-term clinical outcomes were equivalent between BP-DES and second-generation DP-DES implantations. However, among BP-DESs, the improved risks of MI in those with sirolimus eluting, circumferential drug distribution, thin strut, or ultrathin strut and decreased rates of TVR in those with circumferential drug distribution were noted.

Factors affecting willingness to get assessed and treated for osteoporosis

Individuals with poor knowledge of osteoporosis and lower socioeconomic status, including being single and having a lower level of annual income, are less likely to be assessed or treated for osteoporosis. Individuals with particular osteoporosis risk factors such as smokers and heavy drinkers are overlooked for diagnosis. Further study is needed to identify and address the existing barriers and to promote osteoporosis management for women with these risk factors.

INTRODUCTION

Despite the negative health consequences of osteoporosis and the availability of effective treatment, a pervasive and persistent prevention care gap for osteoporosis remains present throughout the world. We attempted to identify the factors affecting the willingness of patients to either undergo or avoid assessment and treatment for osteoporosis.

METHODS

A nationwide online survey was conducted in 926 Korean women over age 50. The survey included questions addressing three domains: (1) clinical and socio-demographic characteristics, (2) questions concerning the reasons for undergoing or avoiding osteoporosis assessment or treatment, and (3) knowledge of osteoporosis as measured using the modified Korean version of Facts on Osteoporosis Quiz. The assessed and non-assessed participants were compared in terms of their clinical and socioeconomic statuses, reasons for undergoing or avoiding osteoporosis management, and levels of knowledge of osteoporosis.

RESULTS

The highest-ranked reason for undergoing osteoporosis assessment was fear of osteoporotic fracture, while the highest-ranked reason for avoiding osteoporosis assessment was not feeling a need to get tested for osteoporosis. Participants who sought assessment for osteoporosis were older and more likely to be married, and had greater knowledge of osteoporosis than those who did not seek assessment. The two groups were found to be similar in terms of tobacco use and daily alcohol use. Patients who had been diagnosed with osteoporosis but either did not initiate or discontinued osteoporosis treatment within 1 year were younger and had lower levels of annual income than those who began and continued treatment.

CONCLUSION

Individuals with poor knowledge of osteoporosis and those of lower socioeconomic status, including those who were single and had a lower level of annual income, were less likely to be assessed and treated for osteoporosis. Individuals with particular osteoporosis risk factors such as smokers and heavy drinkers are overlooked for diagnosis. Further study is needed to identify and address the existing barriers and to promote osteoporosis management for women with these risk factors.

Comparative identification, nutritional, and physiological regulation of chicken liver-enriched genes

The liver performs a number of vital functions in the chicken. In order to identify unique gene expression patterns and link them to potential functions in the chicken liver, genes enriched in the liver of chickens needed to be investigated in a comparative manner. In this study, 41 liver-enriched genes were identified through chicken microarray, and many of them were validated through comparative analysis of mice and humans. Thirteen of them were unique in chickens, and their liver enhancement was confirmed by reverse transcription PCR. Furthermore, the expression of those 13 chicken liver-enriched genes was investigated, in response to nutritional and physiological challenges. Real-time PCR revealed that expression of PIT54 (P < 0.01), phosphoribosyl pyrophosphate synthetase 2 (PRPS2) (P < 0.05), sulfotransferase (SULT) (P < 0.05), and cytochrome P450 family 2 subfamily C, polypeptide 18 (CYP2C18) (P < 0.05) were significantly decreased in the liver during fasting compared to ad libitum control. During the post-laying stage, expression of GAL8 was significantly increased (P < 0.01), but CYP2C18 expression was significantly reduced (P < 0.05). Liver-enriched genes that were identified in this study and their expression patterns under fasting and the post-laying stage will serve as future targets to gain a better understanding of liver physiology, function and development in poultry.

Unexpected Stretching of Entangled Ring Macromolecules

In the melt state at equilibrium, entangled nonconcatenated ring macromolecules adapt more compact conformations compared to their linear analogs and do not form an entanglement network. We show here that, when subjected to uniaxial stretching, they exhibit a unique response, which sets them apart from any other polymer. Remarkably, whereas both linear and ring polymers strain-harden, the viscosity of the rings increases dramatically (the melt thickens) at very low stretch rates due to the unraveling of their conformations along the stretching direction. At high rates, stretching leads to viscosity thinning similar to that of entangled linear polymers, albeit with subtle differences.

L-Glycine Alleviates Furfural-Induced Growth Inhibition during Isobutanol Production in Escherichia coli

Lignocellulose is now a promising raw material for biofuel production. However, the lignin complex and crystalline cellulose require pretreatment steps for breakdown of the crystalline structure of cellulose for the generation of fermentable sugars. Moreover, several fermentation inhibitors are generated with sugar compounds, majorly furfural. The mitigation of these inhibitors is required for the further fermentation steps to proceed. Amino acids were investigated on furfural-induced growth inhibition in E. coli producing isobutanol. Glycine and serine were the most effective compounds against furfural. In minimal media, glycine conferred tolerance against furfural. From the IC₅₀ value for inhibitors in the production media, only glycine could alleviate growth arrest for furfural, where 6 mM glycine addition led to a slight increase in growth rate and isobutanol production from 2.6 to 2.8 g/l under furfural stress. Overexpression of glycine pathway genes did not lead to alleviation. However, addition of glycine to engineered strains blocked the growth arrest and increased the isobutanol production about 2.3-fold.