Effects of particle size on the pretreatment efficiency and subsequent biogas potential of polylactic acid

The fragmentation of bioplastics (BPs) before pretreatment and anaerobic digestion is conducted for higher efficiency; however, based on the literature, the size reduction varies widely. In this study, initially, various combinations of thermal-alkaline pretreatments were applied at different strengths to the polylactic acid (PLA) in three groups (<0.5, 0.5 < size < 1.0, and 1.0 < size < 2.0 mm). After pretreatment, the solubilization of PLA was increased to 11.5-40.0 % using alkaline dosage and temperature ranging from 50 to 200 g OH-/kg BP, 60-100 °C, respectively, in a 1-10 h timeframe. The results were statistically proved using a 3D response surface graph, where the pretreatment was more effective for smaller particle sizes. The reduction in particle size also increased the CH4 production, which was more pronounced at the strong pretreatment (24 % increment vs. 10-15 %). Computed results indicated 44-86 % conversion of pretreated PLA particles to CH4, supported by Fourier transform infrared spectroscopy analysis, especially focusing on the intensity of -OH bands.

Continuous production of high-concentrated ammonia broth through fermentation

Being considered as a valuable resource and energy carrier, extensive research is going on to efficiently extract ammonia (NH3) from anaerobic digestate. However, due to the well-known NH3 inhibition on methanogens, the total NH3 nitrogen (TAN) concentration is typically limited to 1-4 g N/L in digestate, making the NH3 extraction process energy-consumptive. Here, NH3 fermentation, specifically targeting augmented NH3 production through biological reaction, was performed in a continuous mode. With the increase of gelatin input (10 to 150 g COD/L), NH3 concentration and volumetric productivity gradually increased, reaching 12.0 g TAN-N/L and 36.0 g NH3-N/L/d, which were the highest values ever reported. The stepwise increase in NH3 exposure prompted a shift in microbial dominance towards Hathewaya (from 1 % to 68 %), a critical factor for having high NH3 tolerance. Finally, NH3 stripping results suggested that highly concentrated broth could reduce the specific energy consumption for NH3 extraction to 1/3.

Use of reverse osmosis concentrate for mitigating greenhouse gas emissions from pig slurry

Due to the high global warming potential (GWP) in a short time scale (GWP100 = 28 vs. GWP20 = 86), mitigating CH₄ emissions could have an early impact on reducing current global warming effects. The manure storage tank emits a significant amount of CH₄, which can diminish the environmental benefit resulting from the anaerobic digestion of manure that can generate renewable energy. In the present study, we added the reverse osmosis concentrate (ROC) rich in salt to the pig slurry (PS) storage tank to reduce CH₄ emissions. Simultaneously, pure NaCl was tested at the same concentration to compare and verify the performance of ROC addition. During 40 days of storage, 1.83 kg CH₄/ton PS was emitted, which was reduced by 7-75% by the addition of ROC at 1-9 g Na⁺/L. This decrease was found to be more intensive than that found upon adding pure sodium, which was caused by the presence of sulfate rich in ROC, resulting in synergistic inhibition. The results of the microbial community and activity test showed that sodium directly inhibited methanogenic activity rather than acidogenic activity. In the subsequent biogas production from the stored PS, more CH₄ was obtained by ROC addition due to the preservation of organic matter during storage. Overall, 51.2 kg CO₂ eq./ton PS was emitted during the storage, while 8 kg CO₂ eq./ton PS was reduced by biogas production in the case of control, resulting in a total of 43.2 kg CO₂ eq./ton PS. This amount of greenhouse gas emissions was reduced by ROC addition at 5 g Na⁺/L by 22 and 65 kg CO₂ eq./ton PS, considering GWP100 and GWP20 of CH₄, respectively, where most of the reduction was achieved during the storage process. To the best of our knowledge, this was the first report using salty waste to reduce GHG emissions in a proper place, e.g., a manure storage tank.

Upflow anaerobic sludge blanket reactor operation under high pressure for energy-rich biogas production

Autogenerative high-pressure digestion has an advantage of producing CH₄-rich biogas directly from the reactor. However, its continuous operation has rarely been reported, and has never been attempted in an upflow anaerobic sludge blanket reactor (UASB). Here, UASB was continuously operated at 10 g COD/L/d with increasing pressure from 1 to 8 bar. As the pressure increased, the CH₄ content in the biogas increased gradually, reaching 96.7 ± 0.8% at 8 bar (309 MJ/m³ biogas). The pH was dropped from 8.2 to 7.2 with pressure increase, but COD removal efficiency was maintained > 90%. The high pressure up to 8 bar did not adversely impact the physicochemical properties of granules, which was due to the increased production of extracellular polymeric substances (EPS), particularly, tightly bound EPS (34% increase). With pressure increase, there was no changes in the microbial community and ATPase gene expression, but 41% increase in carbonic anhydrase gene expression was observed.

Enhanced anaerobic treatment of sulfate-rich wastewater by electrical voltage application

Treatment of sulfate-rich wastewater with high methane recovery is a major concern due to sulfide inhibition. Here, an electrical voltage (EV) aims to enhance methanogenesis and sulfidogenesis to treat sulfate-rich wastewater. Two (control and EV-applied) reactors were operated with a gradual decrease in chemical oxygen demand (COD)/SO₄^2- ratios (CSR). EV-applied reactor (EVR) demonstrated an increase of ∼30 % in methane production and ∼40 % in sulfate removal, compared to the control till CSR of 2.0. At CSR 1.0, the control failed, while EVR still exhibited a stable performance of 50 % COD-methane recovery. Microbial community results showed that the relative abundance of sulfate-reducing bacteria in EVR was 1.5 times higher than the control. Furthermore, higher relative abundance of dissimilatory sulfate reductase (>50 %) and Ni/Fe hydrogenase (x15) genes demonstrated an improved tolerance against H₂S toxicity. This study highlights the importance of EV application by minimizing the byproduct inhibition in sulfate-rich wastewater.

Electrical voltage application as a novel approach for facilitating methanogenic granulation

Despite having high-rate methanogenic performance, up-flow anaerobic sludge blanket reactor still has challenges regarding long-start up period (3-8 months) for granulation. In this study, "electrical voltage (EV, 0.3 V) application" was attempted for facilitating granulation in the continuous operation with increased organic loading rates (0.5-11.0 kg COD/m³/d). Up to 11.0 kg COD/m³/d, EV-reactor exhibited the stable performance, while the control failed. After 49 days of operation (at 7 kg COD/m³/d), the granules collected from EV-reactor had larger diameter (2.3 vs 1.6 mm), higher settling velocity (2.6 vs 1.9 cm/s), and higher hydrophobicity (52.1 % vs 34.5 %), compared to the control. EV application also increased the specific methanogenic activity for propionate and hydrogen almost by two times. The relative abundance of Pseudomonas sp. (quorum sensing (QS)-related microbe) in EV-reactor was 17 % higher than that in the control. In addition, EV application increased the expression of QS genes significantly by 27 times.

Environmental Injustices of Leaks from Urban Natural Gas Distribution Systems: Patterns among and within 13 U.S. Metro Areas

Natural gas leaks in local distribution systems can develop as underground pipeline infrastructure degrades over time. These leaks lead to safety, economic, and climate change burdens on society. We develop an environmental justice analysis of natural gas leaks discovered using advanced leak detection in 13 U.S. metropolitan areas. We use Bayesian spatial regression models to study the relationship between the density of leak indications and sociodemographic indicators in census tracts. Across all metro areas combined, we found that leak densities increase with increasing percent people of color and with decreasing median household income. These patterns of infrastructure injustice also existed within most metro areas, even after accounting for housing age and the spatial structure of the data. Considering the injustices described here, we identify actions available to utilities, regulators, and advocacy groups that can be taken to improve the equity of local natural gas distribution systems.

Automatic temperature rise in the manure storage tank increases methane emissions: Worth to cool down!

A significant amount of CH₄ is emitting from livestock manure (LM) storage tank, which is being counted according to the guidelines provided by the Intergovernmental Panel on Climate Change (IPCC). Among various parameters affecting CH₄ conversion factor (MCF) of LM, temperature is known as the most influential factor. As a degree of temperature, atmospheric temperature (T_a), not the manure temperature (T_m), is used for determining the MCF. Currently, the closed-type tank is more common than open-type tank, which would cause the substantial difference between T_a and T_m, probably due to the automatic temperature rise (ATR). Here, we repeatedly observed the ATR by storing pig slurry (PS) in a pilot-scale tank (30 m³, surface/volume ratio of 1.9), and its consequent impact on the increased CH₄ emissions by comparing with the results from a lab-scale tank (1 L, surface/volume ratio of 72.2) controlled at 30 °C. As storage began, the T_m increased gradually from 16 to 23 °C to above 30 °C even in winter (-5 °C < T_a < 15 °C). During 30 d of storage, the CH₄ emissions of 1.3-2.5 kg CH₄/ton PS (MCF 26-29%) was observed in the lab-scale tank, while the emissions was increased to 2.6-4.2 kg CH₄/ton PS (MCF 40-50%) in the pilot-scale tank (Two-Tail test, |t_t|<|t_c|). For the first time, a detailed heat energy balance considering the waste heat from organic degradation, the heat requirement for warm up, and the heat loss by convection, was conducted, proving that the waste heat generated during storage was enough to reach above 30 °C. Cooling-down of LM at 20 °C was found to be effective for reducing CH₄ emissions by 90%, which sufficiently offset the greenhouse gas emissions in power consumption for cooling. Our findings strongly suggest that more CH₄ is emitting from LM storage tank than expected, and therefore, the IPCC needs to develop guidelines more accurately in determining MCF.

Electron bifurcation reactions in dark fermentation: An overview for better understanding and improvement

Electron bifurcation (EB) is the most recently found mode of energy conservation, which involves both exergonic and endergonic electron transfer reactions to minimize energy loss. Several works have been devoted on EB reactions (EBRs) in anaerobic digestion but limited in dark fermentative hydrogen production (DF). Two main electron carriers in DF are ferredoxin (Fd) and reduced nicotinamide adenine dinucleotide (NADH), complicatedly involved in EB. Here, i) the importance of EB involvement in DF, ii) all EBRs possible to present in DF, as well as iii) the limitation of previous studies that tried incorporating any of EBRs in DF metabolic model, were highlighted. In addition, the concept of using metagenomic analysis for estimating the share of each EB reaction in the metabolic model, was proposed. This review is expected to initiate a new wave for studying EB, as a tool for explaining and predicting DF products.

Ribociclib plus fulvestrant for postmenopausal women with hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer in the phase III randomized MONALEESA-3 trial: updated overall survival

BACKGROUND

Ribociclib plus fulvestrant demonstrated significant progression-free survival (PFS) and overall survival (OS) benefits in patients with hormone receptor-positive, human epidermal growth factor receptor 2-negative (HR+/HER2-) advanced breast cancer (ABC). Here we present a new landmark in survival follow-up for a phase III cyclin-dependent kinases 4 and 6 inhibitor clinical trial in patients with ABC (median, 56.3 months).

PATIENTS AND METHODS

This phase III, randomized, double-blind, placebo-controlled trial was conducted at 174 sites (30 countries). Patients were men and postmenopausal women (age ≥18 years) with histologically/cytologically confirmed HR+/HER2- ABC. Patients could have received ≤1 line of endocrine therapy (ET) but no chemotherapy for ABC. Patients, assigned 2:1, were stratified by the presence/absence of liver/lung metastases and previous ET. Patients received intramuscular fulvestrant (500 mg, day 1 of each 28-day cycle plus day 15 of cycle 1) with oral ribociclib (600 mg/day, 3 weeks on, 1 week off) or placebo. Efficacy analyses were by intention to treat. Safety was assessed in patients receiving ≥1 dose study treatment. OS was a secondary endpoint. MONALEESA-3 is registered with ClinicalTrials.gov (NCT02422615; no longer enrolling).

RESULTS

Between 18 June 2015 and 10 June 2016, 726 patients were randomly assigned (484, ribociclib; 242, placebo). At data cut-off (30 October 2020), median OS (mOS) was 53.7 months (ribociclib) versus 41.5 months (placebo) [hazard ratio (HR), 0.73; 95% confidence interval (CI) 0.59-0.90]. Subgroup analyses were consistent with overall population. In the first-line setting, most patients in the ribociclib arm (∼60%) lived longer than median follow-up; mOS was 51.8 months in the placebo arm (HR, 0.64; 95% CI 0.46-0.88). In the second-line setting, mOS was 39.7 months (ribociclib) versus 33.7 months (placebo) (HR, 0.78; 95% CI 0.59-1.04). No apparent drug-drug interaction between ribociclib and fulvestrant or new safety signals were observed.

CONCLUSIONS

This analysis reported extended OS follow-up in MONALEESA-3. mOS was ∼12 months longer in patients with HR+/HER2- ABC treated with ribociclib plus fulvestrant compared with fulvestrant monotherapy.

Production of high-calorific biogas from food waste by integrating two approaches: Autogenerative high-pressure and hydrogen injection

Auto-generative high pressure digestion (AHPD) and hydrogen-injecting digestion (HID) have been introduced to directly produce high CH₄-content biogas from anaerobic digester. However, each approach has its own technical difficulties (pH changes), and practical issues (high cost of H₂) to obtain > 90% CH₄ containing biogas, particularly, from the high-strength waste like food waste (FW). To overcome this problem, in this study, AHPD and HID were integrated, which can offset each drawback but maximize its benefit. Substrate concentration of FW tested here was 200 g COD/L, the highest ever applied in AHPD and HID studies. At first, the reactor was operated by elevating the autogenerative pressure from 1 to 3, 5, and 7 bar without H₂ injection. With the pressure increase, the CH₄ content in the biogas gradually increased from 52.4% at 1 bar to 77.4% at 7 bar. However, a drop of CH₄ production yield (MPY) was observed at 7 bar, due to the pH drop down to 6.7 by excess CO₂ dissolution. At further operation, H₂ injection began at 5 bar, with increasing its amount. The injection was effective to increase the CH₄ content to 82.8%, 87.2%, and 90.6% at 0.09, 0.13, and 0.18 L H₂/g COD_FW.fed of H₂ injection amount, respectively. At 0.25 L H₂/g COD_FW.fed, there was a further increase of CH₄ content to 92.1%, but the MPY was dropped with pH increase to 8.7 with residual H₂ being detected (4% in the biogas). Microbial community analysis showed the increased abundance of piezo-tolerant microbe with pressure increase, and direct interspecies electron transfer contributors after H₂ injection. In conclusion, the integration of two approaches enabled to directly produce high calorific biogas (90% > CH₄, 180 MJ/m³ biogas) from high-strength FW at the lowest requirement of H₂ (0.18 L H₂/g COD_FW.fed) ever reported.

Use of citric acid for reducing CH4 and H2S emissions during storage of pig slurry and increasing biogas production: Lab- and pilot-scale test, and assessment

The use of sulfuric acid (SA) for reducing greenhouse gases (GHGs, mainly CH₄) emissions in manure management encounters with problems related with safety issue and increased H₂S emissions. In the present study, citric acid (CA) as an alternative to SA was assessed in the lab-scale experiment at various dosages (pH 5.0-7.0), and then confirmed in the pilot-scale tank (effective volume of 30 ton). During 35 d of pig slurry (PS) storage at 30 °C, it was found that the CA addition to initial pH down to 6.5 could lead negligible reduction, while 85-99% and 48-72% reduction of CH₄ and H₂S emissions were achieved at pH ≤ 6.0, respectively. The similar reduction performance was confirmed (control vs. pH 6.0) in the pilot-scale test, but, interestingly, two times higher CH₄ emissions of 123.7 kg CO₂ eq./ton PS was detected caused by the automatic temperature increase (≥35 °C). The pH of acidified PS did not exceed 6.5 during the whole storage period, while it was maintained 7.3-7.7 in the control. A continuous AD reactor fed with acidified PS exhibited a higher CH₄ yield of 10.0 m³ CH₄/ton PS, compared to the control (5.7 m³ CH₄/ton PS), due to the preservation of organic matters and added CA. In overall, about 8.5 [(4.4, storage) + (4.1, biogas)] kg of CH₄/ton PS was generated from raw PS and it was reduced to 7.8 [(0.7, storage) + (7.1, biogas)] kg of CH₄/ton PS by CA-acidification. Despite the carbon footprint for manufacturing CA, it was calculated that GHG reduction of 107 kg CO₂ eq./ton PS could be attained by CA-acidification. In terms of economic profit, it was estimated that 6.3 USD/ton PS can be gained by CA-acidification, while it was 2.4 USD/ton PS in case of control.

Combination of H2SO4-acidification and temperature-decrease for eco-friendly storage of pig slurry

Owing to the economic benefit and efficiency, H₂SO₄-acidification is often applied for reducing CH₄ emissions during storage of pig slurry (PS). However, it encounters with several problems related with safety and the concomitant H₂S emissions. To reduce the required amount of H₂SO₄, in this study, the storage at low temperature (20-35 °C) was applied to the mild-acidified PS (pH 6.5 and 7.0). 55.1 kg CO₂ eq./ton PS of CH₄ was emitted from the control (non-acidified at 35 °C), which was reduced to 14.4-40.2 kg CO₂ eq./ton PS at 20-30 °C. Temperature-decrease led to the increase of the abundance of methanogens (Methanobrevibacter and Methanolobus) that can grow at low temperature and the drop of specific methanogenic activity value. To achieve 70 % CH₄ reduction, 1.6 kg H₂SO₄/ton PS was needed in PS acidification, which was decreased to 0.5 kg H₂SO₄/ton PS by decreasing temperature from 35 °C to 25 °C. CH₄ production potential of the PS stored at 35 °C-pH 6.5 and 25 °C-pH 7.0 was increased by 21-33 % compared to the control. The GHG reduction of 33.6-41.9 kg CO₂ eq./ton PS and the profit of 6.6 USD/ton PS could be attained by applying acidification or combined storage, indicating that the temperature-decrease can be effectively combined with H₂SO₄-acidification.

Role of bilateral corticobulbar tracts in dysphagia after middle cerebral artery stroke

BACKGROUND AND PURPOSE

The corticobulbar tract is a potential neural pathway involved in swallowing. The frontal operculum, insular cortex, corona radiata and internal capsule, which are frequently involved in middle cerebral artery (MCA) strokes, are locations in which lesions cause dysphagia. However, it is unclear whether the locations are linked to the corticobulbar tract or whether corticobulbar tract integrity is associated with dysphagia severity. This study aimed to assess the association between corticobulbar tract integrity and dysphagia severity after MCA stroke.

METHODS

Thirty dysphagic patients after MCA stroke and 27 healthy controls were examined. Diffusion tensor imaging (DTI)-derived parameters of the corticobulbar tract were compared between patient and control groups. Next, patients were divided into mild and moderate-to-severe dysphagia groups, and DTI-derived parameters of the corticobulbar tract were compared between the subgroups. Logistic regression analysis was used to determine the association between corticobulbar tract integrity and dysphagia severity.

RESULTS

The tract volume (TV) of the affected corticobulbar tract was lower in dysphagic patients than in healthy controls (P < 0.001). According to dysphagia severity, TV of the unaffected corticobulbar tract was higher in the mild dysphagia group than in the moderate-to-severe dysphagia group (P = 0.012). TV of the unaffected corticobulbar tract was independently associated with dysphagia severity according to the logistic regression model (adjusted odds ratio 0.817, 95% confidence interval 0.683-0.976).

CONCLUSIONS

The corticobulbar tract was affected after MCA stroke and may be associated with dysphagia. A higher corticobulbar TV in the unaffected hemisphere was indicative of better swallowing function in dysphagic patients after MCA stroke.

Enhanced Anaerobic Digestion of Long Chain Fatty Acid by Adding Magnetite and Carbon Nanotubes

This study investigated the impact of stimulating direct interspecies electron transfer (DIET), by supplementing nano-sized magnetite (nFe3O4, 0.5 g Fe/g VSS) and carbon nanotubes (CNT, 1 g/L), in anaerobic digestion of oleic acid (OA) at various concentrations (0.10 - 4.00 g chemical oxygen demand(COD)/L). Both supplementations could enhance CH4 production, and its beneficial impact increased with increased OA concentration. The biggest improvements of 114% and 165% compared to the control were achieved by nFe3O4 and CNT, respectively, at OA of 4 g COD/L. The enhancement can be attributed to the increased sludge conductivity: 7.1 ± 0.5 (control), 12.5 ± 0.8 (nFe3O4-added), and 15.7 ± 1.1 µS/cm (CNT-supplemented). Dissolved iron concentration, released from nFe3O4, seemed to have a negligible role in improving CH4 production. The excretion of electron shuttles, i.e., humic-like substances and protein-like substances, were found to be stimulated by supplementing nFe3O4 and CNT. Microbial diversity was found to be simplified under DIET-stimulating conditions, whereby five genera accounted for 88% of the total sequences in the control, while more than 82% were represented by only two genera (Methanotrix concilli and Methanosarcina flavescens) by supplementing nFe3O4 and CNT. In addition, the abudance of electro-active bacteria such as Syntrophomonas zehnderi was significantly increased from 17% to around 45%.

Effects of storage temperature on CH4 emissions from cattle manure and subsequent biogas production potential

CH₄ is one of the main greenhouse gases (GHGs) generated from agricultural sector, and a significant amount of it is emitted during the storage of livestock manure. To mitigate the CH₄ emissions, strong acid addition to the manure was attempted, which is only applicable to slurry-type manure. On the other hand, lowering the storage temperature could be an effective method to reduce the CH₄ emissions, particularly applicable to solid-type manure. In this study, cattle manure (CM) with a high-solid content (TS > 30%) was stored at different temperatures (15-35 °C) for 80 d. The highest CH₄ emissions of 375.1 kg CO₂ eq./ton VS was observed at 35 °C, and this was reduced to less than half at ≤20 °C. Like the difference in CH₄ emissions, the degradation of organic matter showed a similar trend. The maximum VS reduction of 29% was observed at 35 °C, while only 8% reduction was observed at 15 °C. Results from microbial community analyses and specific methanogenic activity tests indicated that hydrogenotrophic methanogens were the dominant indigenous CH₄-producers, and the abundance of psychrophilic methanogens increased with decreasing temperature. The conservation of organic matter at low temperature led to an increase in biogas production potential from 25 to 43 L CH₄/kg CM. It was calculated that the GHGs emissions from electricity consumption for cooling CM below 25 °C can be offset by mitigating CH₄ emissions during storage but increasing in subsequent biogas production potential of CM. Compared at 35 °C, 91.6 kg CO₂ eq./ton CM of GHGs reduction can be attained at 15 °C.

Effects of pig slurry acidification on methane emissions during storage and subsequent biogas production

In addition to undesirable odorous gases, substantial amounts of greenhouse gases (GHG), particularly methane (CH₄), are generated during the storage of livestock manure. To reduce the CH₄ emissions, first, pig slurry (PS) was stored for 40 d at 30 °C after adjusting the pH at 5.0-7.0 using H₂SO₄ solution. In the control (non-acidified PS), 3.7 kg CO₂ eq./ton PS of CH₄ emissions was detected, which was reduced to 1.8, 0.9, 0.4, 0.2, and 0.1 kg CO₂ eq./ton PS at pH 7.0, 6.5, 6.0, 5.5, and 5.0, respectively. Methanosarcina was found to be the dominant genus (67% of the total archaeal sequence) in the control, whose dominance was reduced as storage pH decreased. The results of ribonucleic acid analysis and specific methanogenic activity test further confirmed the inhibition of indigenous methanogens by acidification. Later, the biochemical CH₄ potential of stored PS was tested. Compared to the control (10.6 L CH₄/L PS), the acidified PS showed higher CH₄ yields of 12.7-14.6 L CH₄/L PS, presumably by keeping degradable organic matters in PS under acidic condition. Among different acidification pHs tested, the maximum amount of GHG reduction was achieved at pH 6.0 by reducing CH₄ emission to +0.4 kg CO₂ eq./ton PS during storage while increasing biogas production potential equivalent to 48.3 kWh/ton PS (-22.5 kg CO₂ eq./ton PS), resulting in a further reduction of (-)9.6 kg CO₂ eq./ton PS compared to the control.

Reliability and main findings of the flexible endoscopic evaluation of swallowing-Tensilon test in patients with myasthenia gravis and dysphagia

BACKGROUND AND PURPOSE

Diagnosis of pharyngeal dysphagia caused by myasthenia gravis (MG) based on clinical examination alone is often challenging. Flexible endoscopic evaluation of swallowing (FEES) combined with Tensilon (edrophonium) application, referred to as the FEES-Tensilon test, was developed to improve diagnostic accuracy and to detect the main symptoms of pharyngeal dysphagia in MG. Here we investigated inter- and intra-rater reliability of the FEES-Tensilon test and analyzed the main endoscopic findings.

METHODS

Four experienced raters reviewed a total of 20 FEES-Tensilon test videos in randomized order. Residue severity was graded at four different pharyngeal spaces before and after Tensilon administration. All interpretations were performed twice per rater, 4 weeks apart (a total of 160 scorings). Intra-rater test-retest reliability and inter-rater reliability levels were calculated.

RESULTS

The most frequent FEES findings in patients with MG before Tensilon application were prominent residues of semi-solids spread all over the hypopharynx in varying locations. The reliability level of the interpretation of the FEES-Tensilon test was excellent regardless of the rater's profession or years of experience with FEES. All four raters showed high inter- and intra-reliability levels in interpreting the FEES-Tensilon test based on residue clearance (kappa = 0.922, 0.981). The degree of residue normalization in the vallecular space after Tensilon application showed the highest inter- and intra-rater reliability level (kappa = 0.863, 0.957) followed by the epiglottis (kappa = 0.813, 0.946) and pyriform sinuses (kappa = 0.836, 0.929).

CONCLUSION

Interpretation of the FEES-Tensilon test based on residue severity and degree of Tensilon clearance, especially in the vallecular space, is consistent and reliable.

Aspiration and dysphagia screening in acute stroke - the Gugging Swallowing Screen revisited

BACKGROUND AND PURPOSE

The Gugging Swallowing Screen (GUSS) is a tool to screen aspiration risk in acute stroke. We aimed to replicate its validity in a larger second cohort of patients with acute stroke, including the more severe with a National Institutes of Health Stroke Scale (NIHSS) ≥ 15.

METHODS

In a prospective, double-blind design, the GUSS was validated with the Fiberoptic Endoscopic Evaluation of Swallowing scale. Patients were categorized into different stroke severities as assessed by the NIHSS, and the diagnostic properties were calculated separately for each subgroup.

RESULTS

A total of 100 patients with acute stroke were evaluated consecutively at a mean 1.7 ± 2.2 days after stroke. With the GUSS cut-off value of 14 points, the GUSS screened aspiration risk with a 96.5% sensitivity and 55.8% specificity (area under the curve, 0.76; 95% CI, 0.67-0.84), which corresponded well with the original publication. In the NIHSS < 5 group, the sensitivity and specificity levels were 71.4% and 88.8%, respectively. In the NIHSS ≥ 15 group, these levels changed to 100% and 20%, respectively. The high failure rate in completing the first part of the GUSS in the latter group was related to the low specificity. Diet recommendations following the GUSS were more conservative than those after Fiberoptic Endoscopic Evaluation of Swallowing. In particular, the GUSS overestimated the need for nasogastric tube feeding.

CONCLUSIONS

This is the first time that a swallowing screening tool for patients with acute stroke has been revalidated in a larger population from another stroke center. The validity of a swallow screening test may vary according to different stroke severities.

Adolescent alcohol exposure alters the rat adult hypothalamic-pituitary-adrenal axis responsiveness in a sex-specific manner

Exposure to alcohol during adolescence exerts long-term effects on the adult brain stress circuits, causing many changes that persist into adulthood. Here we examined the consequences of adolescent intermittent ethanol (AIE, administered from postnatal day (PND) 28-42) on the hypothalamic-pituitary-adrenal (HPA) axis-related brain circuitry of rats challenged with intragastric (ig) administration of alcohol in adulthood (PND 70-71). Both male and female adolescent rats were exposed to alcohol vapors, while controls did not receive the drug, to assess whether AIE alters adult alcohol response in a sex-specific manner. We demonstrated that AIE increased paraventricular nucleus (PVN) Avp mRNA levels during late (PND 42) but not middle (PND 36) adolescence in males. While an alcohol challenge administered to 70-71-day-old rats increased Crf mRNA levels in males and Avp mRNA levels in females, AIE blunted both effects. These results suggest that AIE produced long-lasting changes in the responsiveness of the HPA axis to a subsequent alcohol challenge in a sex-specific manner. Furthermore, AIE altered adrenergic brain stem nuclei involved in stress responses in adulthood, resulting in increased numbers of phenylethanolamine N-methyltransferase (PNMT) neurons in male C2 and female C1 regions. This tended to enhance activation of the male C2 nucleus upon alcohol challenge. Collectively, these results suggest that AIE exerts long-term effects on the ability of the PVN to respond to an alcohol challenge in adulthood, possibly mediated by catecholaminergic input from the brain stem to the PVN.

TGF-β suppresses the expression of genes related to mitochondrial function in lung A549 cells

TGF-β is a mediator of lung fibrosis and regulates the alveolar epithelial type II cell phenotype. TGF-β can induce epithelial mesenchymal transition of idiopathic pulmonary disease and cancer metastasis. Peroxisome proliferator-activated receptor gamma co-activator 1-alpha (PGC-1 α) is a key metabolic regulator that stimulates mitochondrial biogenesis and promotes remodeling of muscle tissue to oxidative fiber-type composition. Here, we report that the induction of TGF-β decreased mRNA expression of PGC-1α, and PGC-1 target genes, such as the transcription factors NRF-2, ERR-α, and PPAR-γ in lung epithelial A549 cells. In addition, TGF-β led to the reduction of super oxide dismutase 2 (anti-oxidant enzyme), cytochrome C (electron transport chain in mitochondria), and MCAD (a mitochondrial β-oxidant enzyme) in A549 cells. Together, our results suggest that TGF-β may suppress the transcriptional activity of the genes related to mitochondrial biogenesis or function. This mechanism may provide a novel insight into the understanding of fibrosis disease.

Outcomes of continuously infused 5-fluorouracil, doxorubicin, and mitomycin-C (iFAM) as salvage regimen in patients with biliary tract cancer

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Background: In advanced biliary tract cancer, after failure of first-line chemotherapy, salvage chemotherapy has not yet been established and the prognostic factors in salvage setting have not been widely known. The purpose of this study was to evaluate the efficacy and safety of iFAM as salvage chemotherapy in biliary tract cancer and to reveal the prognostic factors.

Methods: Eligibility included: 1) age 18-75, 2) histologically confirmed biliary tract cancer, 3) previously treated with palliative first-line chemotherapy, 4) ECOG PS 0-2, 5) adequate organ function. iFAM consisted of 5-FU 800 mg/m2 over 12 hour on days 1-5, doxorubicin 30 mg/m2 on day 1, and mitomycin-C 8 mg/m2 on day 1, every 4 weeks.

Results: Between February 2003 and August 2009, 50 patients (pts) were enrolled. The median age was 57.3 yrs (range: 26.0-71.5 yrs), and there were 33 men (66%). 32 pts (64%) had ECOG PS 0-1 and 18 pts (36%) had PS 2. Biliary tract cancers were extrahepatic cholangiocarcinoma (30%), intrahepatic cholangiocarcinoma (30%) and gallbladder cancer (40%). Previous chemotherapy mainly consisted of gemcitabine-based and 5-FU-based regimens. Median cycles of iFAM were 2 (range: 1-6). Best responses to iFAM were PR in 2 (4%) pts and SD in 9 (18%), that is response rate was 4% and disease control rate was 22% (95% CI: 7.35-28.65). The median PFS and OS were 2.2 (95% CI: 2.0–2.4) months and 5.0 (95% CI: 3.3–6.7) months, respectively. Grade 3/4 hematologic toxicities were neutropenia (10%), anemia (2%), and thrombocytopenia (8%). Frequent nonhematologic toxicities were alopecia (34%), stomatitis (28%), vomiting (24%), and diarrhea (12%), which were grade 1/2. ECOG PS (0-1 vs 2) was significant prognostic factor for both PFS (p=0.029) and OS (p=0.025). Poor response to previous chemotherapy (p=0.031) were poor prognostic factors for OS.

Conclusions: iFAM is an effective and safe treatment option in refractory biliary tract cancer and can be considered as salvage regimen, especially for patients with good PS and good response to previous chemotherapy.

No significant financial relationships to disclose.

AVANT: Results from a randomized, three-arm multinational phase III study to investigate bevacizumab with either XELOX or FOLFOX4 versus FOLFOX4 alone as adjuvant treatment for colon cancer

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Background: Bevacizumab (BEV), a humanized anti-VEGF monoclonal antibody, has demonstrated clinical efficacy in combination with 5-FU-based regimens in patients with metastatic colorectal cancer. The therapeutic impact of concurrent BEV with either FOLFOX4 or XELOX chemotherapy in the adjuvant setting was evaluated in this international, controlled phase III trial.

Methods: Eligible patients had high-risk stage II or stage III colon cancer and had undergone surgical resection. Patients were randomly assigned to one of three treatment groups and stratified by geographic region and tumor stage: Arm A: FOLFOX4 on weeks 1–24; Arm B: FOLFOX4 + BEV on weeks 1–24, then BEV alone on weeks 25–48; Arm C: XELOX + BEV on weeks 1–24, then BEV alone on weeks 25–48. The primary endpoint was disease-free survival (DFS) for patients with stage III colon cancer; secondary endpoints included overall survival (OS), and safety. DFS/OS follow-up assessments were performed every 6 months after randomization for 4 years, then annually until recurrence or death.

Results: 3,451 (2,867 stage III) patients were enrolled between December 2004 and June 2007; median age was 58–59 years. Median duration of follow-up was 48 months (range 0–66 months). BEV did not prolong DFS or OS when added to either FOLFOX4 or XELOX in patients with stage III colon cancer based on the final efficacy analysis conducted in September 2010. Efficacy results favored the chemotherapy-alone control arm. Numerically more relapses and deaths occurred in both the BEV arms compared to control. The observed adverse events were consistent with those previously reported in pivotal trials of BEV across tumor types for approved indications.

Conclusions: The primary endpoint of the AVANT study was not met. BEV does not prolong DFS when added to either FOLFOX4 or XELOX in patients with stage III colon cancer. The safety profile of BEV was consistent with prior study results.

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