Pembrolizumab-induced Stevens-Johnson syndrome/Toxic Epidermal Necrolysis in a Vietnamese patient with nonsmall-cell lung cancer.

Chemoimmunotherapy is an effective therapy for an individual with nonsmall-cell lung cancer (NSCLC) without anaplastic lymphoma kinase or epidermal growth factor receptor mutations. However, it can also be related to adverse cutaneous reactions such as Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) with high morbidities and mortality rates. We present a case of a 65-year-old male with NSCLC who underwent first-line chemotherapy with paclitaxel, carboplatin, and pembrolizumab, which was later followed by a second cycle of the same therapies. The patient developed a fever and rash 12 days after the second cycle. Pembrolizumab was strongly suspected as the culprit medication because cutaneous reactions to this drug have been frequently reported and threw other medications used as less likely candidates. This is the first case reported in Vietnam of SJS/TEN related to pembrolizumab and contributes to our knowledge of severe skin reactions associated with immune checkpoint inhibitors.

Expression and characterization of a lipase EstA from Bacillus subtilis KM-BS for application in bio-hydrolysis of waste cooking oil.

A lipase EstA from Bacillus subtilis KM-BS was expressed in Escherichia coli BL21 (DE3) cells. The recombinant enzyme achieved high activity (49.67 U/mL) with protein concentration of 1.29 mg/mL under optimal conditions at the large-scale expression of 6 h and post-induction time at 30 °C using 0.1 mM isopropyl-ß-d-thiogalactopyranoside (IPTG). The optimal temperature and pH of the purified enzyme were at 45-55 °C and pH 8.0 - 9.0, respectively. Activity of the purified enzyme was stable in the presence of 1 mM Ca2+; stimulated by 1 mM Mg2+ and Mn2+, and inhibited by Fe3+. A significant amount of fatty acids was released during the hydrolysis of waste cooking oil under the catalysis of purified lipase, indicating that this recombinant lipase showed promise as a suitable candidate in industrial fields, particularly in biodiesel and detergent sector.

Sorption of oxytetracycline to microsized colloids under concentrated salt solution: A perspective on terrestrial-to-ocean transfer of antibiotics.

The sorption of antibiotics on soil minerals and their cotransport have been widely studied for the past few years; however, these processes in concentrated salt solutions (estuary-like conditions) are not fully understood. This study aims to determine the possible sorption of oxytetracycline (OTC) on various natural and synthesized microsized minerals (including haematite, goethite, kaolinite, bentonite, lateritic, kaolinitic and illitic soil clays) under conditions mimicking pure, fresh, brackish and sea waters. The sorption of OTC was found to decrease in surface charge (herein zeta potential), hence altering the colloidal properties of the materials used. The sorption capacities of soil clays for OTC follow the inequality illitic soil clay > kaolinitic soil clay > lateritic soil clay, and the sorption capacities were found to decrease at higher salt concentrations. Seawater can intensify the release of the sorbed OTC from soil clay surfaces while favouring the coaggregation of the remaining OTC with soil clays. This implies that the long-range transport of OTC or other similar antibiotics can be governed by the mineralogical composition/properties of the suspended particles. More importantly, increasing salt concentrations in estuaries may form a chemical barrier at which limited amounts of OTC/antibiotics can pass through, while the remaining OTC/antibiotics can be favoured to aggregate simultaneously with suspended mineral particles.

Sorption of cosmetic and personal care polymer ingredients to iron oxides, clay minerals and soil clays: An environmental perspective.

The increasing daily use of cosmetic and personal care ingredients (CPCIs) requires improved understanding of the fate and impacts of CPCIs in environmental systems. Effects of CPCIs on colloidal properties of various geocolloids such as iron oxides (goethite, haematite), clay minerals (kaolinite, bentonite) and soil clays (kaolinitic-, illitic- and lateritic soil clays) were studied by tracking time-resolved changes in zeta potential (ζ) and observing suspended particle density. Two polymers representing anionic CPCIs, i.e., polyacrylate crosspolymer-11 (PC11) and cationic CPCIs, i.e., polyDADMAC (PD) show contrast effects on ζ and colloidal properties of the selected materials. While PC11 tended to associate with Fe oxides, PD can be adsorbed by clay minerals and soil clays. The neutralization due to the sorption of either PC11 or PD onto opposite-charge sign surface sites can lower the net surface charge of the materials, thereby enhancing electrostatic attraction, stimulating particle size growth, and eventually intensifying co-aggregation. The observed colloidal properties of iron oxides, clay minerals and soil clays under the presence of PC11 and PD may reflect what are happening in many aquatic environments where CPCIs co-exist with various mineral colloids. Therein, CPCIs likely delay the transport of the opposite-charge sign colloids, while they increase the dispersibility and transportability of the same-charge sign colloids. This implies that intensifying presence of a given CPCI could have selective effects on colloid systems. As a whole, CPCIs can change the fate and the final destination of mineral colloids and themselves; therefore, their effects and relevant treatment techniques need to be included into the future agenda.

Multiple isolated ovarian cancer recurrences in the cervix and vagina after supracervical hysterectomy: A case report.

We present a rare case of a patient who was treated for advanced-stage ovarian cancer with optimal debulking surgery that included a supracervical hysterectomy, instead of total abdominal hysterectomy, who subsequently developed 3 isolated recurrences in the cervix and vagina. We suggest there may be a link between the type of hysterectomy and location of recurrence; we also emphasize the importance of pelvic exam and Papanicolaou smear for patients who have undergone supracervical hysterectomy as part of their ovarian cancer debulking surgery.

Pharmacological treatment in pregnant women with moderate symptoms of coronavirus disease 2019 (COVID-19) pneumonia.

OBJECTIVE: Pregnant women with moderate symptoms of COVID-19 are at risk for progressing to severe or critical illness. While there are limited data on the management of severe COVID-19 during pregnancy, information on pharmacological treatments of moderate COVID-19 is lacking. We report clinical outcomes of pregnant women hospitalized due to moderate COVID-19 illness treated with a 5-day course of remdesivir, antibiotics, and/or glucocorticoids. MATERIALS AND METHODS: Case series of pregnant women hospitalized with moderate symptoms of COVID -19 pneumonia at two INOVA Health System hospitals from April 1 to December 31, 2020. Primary outcome was clinical recovery (breathing on ambient air and/or hospital discharge) on hospital day 7 (HD7). Cox regression analysis was performed to evaluate which variables were associated with the primary outcome. RESULTS: Out of 748 pregnant women with confirmed infection by reverse transcriptase polymerase chain reaction, 35 were hospitalized due to moderate symptoms of COVID-19 pneumonia (median gestational age 29 weeks). There was no maternal death. Seventeen patients received remdesivir within 48 hours of hospitalization: 15 remained with moderate symptoms and 2 (who also received glucocorticoids) had progressed to critical COVID-19 at remdesivir initiation; all 17 women in this group achieved clinical recovery on HD7. Seven women received remdesivir >48 hours following admission after they began treatment with glucocorticoids ± antibiotics and worsened to severe or critical disease; they all required supplemental oxygen on HD7. Eleven women were treated with antibiotics ± glucocorticoids but no remdesivir; on HD7, 3/11 achieved clinical recovery. Clinical recovery was significantly different among treatment groups; p < 0.001. When analyzing only women who remained with moderate symptoms at pharmacological treatments initiation, all 15 on remdesivir and only 3 of 11 on antibiotics achieved clinical recovery on HD7; p < 0.001. Delaying remdesivir for >48 hours after admission (HR 2.32, 95% CI 1.45-4.16) and >4-day duration of symptoms prior to hospitalization (HR 1.65, 95% CI 1.27-3.50) had an inverse association with clinical recovery. Incidental oligohydramnios was seen in 3/24 (12.5%) of women within 5 days of completing remdesivir treatment. Elevated transaminases was prevalent in women treated with remdesivir (8/24, 33.3%). CONCLUSION: In our cohort, prompt initiation of remdesivir in pregnant women hospitalized with moderate symptoms of COVID-19 pneumonia within 48 hours of admission prevented worsening and allowed a fast clinical recovery by HD7. Deferring remdesivir for >48 hours after hospitalization and duration of symptoms >4 days before admission were independently associated with delayed clinical recovery and longer hospital admission. Ultrasound evaluation of the amniotic fluid in patients recovering from COVID-19 hospitalization should be considered.

Chiral inversion of 2-arylpropionoic acid (2-APA) enantiomers during simulated biological wastewater treatment.

This study examined the removal and enantio­specific fate of a suite of eleven chiral 2-arylpropionic acids (2-APAs) during biological wastewater treatment simulated in a laboratory-scale membrane bioreactor (MBR). Using pure (R)- and (S)- enantiomers in the MBR influent, chiral inversion was determined through the increase in the concentration of the non-dominant enantiomer and changes in the enantiomeric fraction (EF) between the two enantiomers during the treatment process. Effective (>90%) and similar removal rates between (R)- and (S)- enantiomers were confirmed for eight 2-APAs. In this study, 2-APAs exhibited diverse and distinctive chiral inversion behaviours: two 2-APAs showed (R→S) unidirectional inversion, three 2-APAs showed (S→R) unidirectional inversion, and six 2-APAs showed bidirectional inversion. This is the first study to report chiral inversion behaviours of a comprehensive suite of 2-APAs with a variety of functional groups substituted onto the aryl ring. A decrease in effluent EF over time was observed for two 2-APAs. This study shows that chiral inversion of 2-APAs varies significantly from compound to compound, despite the high similarity in their chemical structures.

Monitoring antibiotic resistance genes in wastewater treatment: Current strategies and future challenges.

Antimicrobial resistance (AMR) is a growing threat to human and animal health. Progress in molecular biology has revealed new and significant challenges for AMR mitigation given the immense diversity of antibiotic resistance genes (ARGs), the complexity of ARG transfer, and the broad range of omnipresent factors contributing to AMR. Municipal, hospital and abattoir wastewater are collected and treated in wastewater treatment plants (WWTPs), where the presence of diverse selection pressures together with a highly concentrated consortium of pathogenic/commensal microbes create favourable conditions for the transfer of ARGs and proliferation of antibiotic resistant bacteria (ARB). The rapid emergence of antibiotic resistant pathogens of clinical and veterinary significance over the past 80 years has re-defined the role of WWTPs as a focal point in the fight against AMR. By reviewing the occurrence of ARGs in wastewater and sludge and the current technologies used to quantify ARGs and identify ARB, this paper provides a research roadmap to address existing challenges in AMR control via wastewater treatment. Wastewater treatment is a double-edged sword that can act as either a pathway for AMR spread or as a barrier to reduce the environmental release of anthropogenic AMR. State of the art ARB identification technologies, such as metagenomic sequencing and fluorescence-activated cell sorting, have enriched ARG/ARB databases, unveiled keystone species in AMR networks, and improved the resolution of AMR dissemination models. Data and information provided in this review highlight significant knowledge gaps. These include inconsistencies in ARG reporting units, lack of ARG/ARB monitoring surrogates, lack of a standardised protocol for determining ARG removal via wastewater treatments, and the inability to support appropriate risk assessment. This is due to a lack of standard monitoring targets and agreed threshold values, and paucity of information on the ARG-pathogen host relationship and risk management. These research gaps need to be addressed and research findings need to be transformed into practical guidance for WWTP operators to enable effective progress towards mitigating the evolution and spread of AMR.

Impact of ABO-Incompatible Living Donor Kidney Transplantation on Patient Survival.

RATIONALE & OBJECTIVE: Compared with recipients of blood group ABO-compatible (ABOc) living donor kidney transplants (LDKTs), recipients of ABO-incompatible (ABOi) LDKTs have higher risk for graft loss, particularly in the first few weeks after transplantation. However, the decision to proceed with ABOi LDKT should be based on a comparison of the alternative: waiting for future ABOc LDKTs (eg, through kidney paired exchange) or for a deceased donor kidney transplant (DDKT). We sought to evaluate the patient survival difference between ABOi LDKTs and waiting for an ABOc LDKT or an ABOc DDKT. STUDY DESIGN: Retrospective cohort study of adults in the Scientific Registry of Transplant Recipients. SETTING & PARTICIPANTS: 808 ABOi LDKT recipients and 2,423 matched controls from among 245,158 adult first-time kidney-only waitlist registrants who did not receive an ABOi LDKT and who remained on the waitlist or received either an ABOc LDKT or an ABOc DDKT, 2002 to 2017. EXPOSURE: Receipt of ABOi LDKT. OUTCOME: Death. ANALYTICAL APPROACH: We compared mortality among ABOi LDKT recipients versus a weighted matched comparison population using Cox proportional hazards regression and Cox models that accommodated for changing hazard ratios over time. RESULTS: Compared with matched controls, ABOi LDKT was associated with greater mortality risk in the first 30 days posttransplantation (cumulative survival of 99.0% vs 99.6%) but lower mortality risk beyond 180 days posttransplantation. Patients who received an ABOi LDKT had higher cumulative survival at 5 and 10 years (90.0% and 75.4%, respectively) than similar patients who remained on the waitlist or received an ABOc LDKT or ABOc DDKT (81.9% and 68.4%, respectively). LIMITATIONS: No measurement of ABO antibody titers in recipients; eligibility of participants for kidney paired donation is unknown. CONCLUSIONS: Transplant candidates who receive an ABOi LDKT and survive more than 180 days posttransplantation experience a long-term survival benefit compared to remaining on the waitlist to potentially receive an ABOc kidney transplant.

Derivation of volatile fatty acid from crop residues digestion using a rumen membrane bioreactor: A feasibility study.

This study evaluates the feasibility of a novel rumen membrane bioreactor (rumen MBR) to produce volatile fatty acids (VFA) from crop residues (i.e. lignocellulosic biomass). Rumen MBR can provide a sustainable route for VFA production by mimicking the digestive system of ruminant animals. Rumen fluid was inoculated in a reactor coupled with ultrafiltration (UF) membrane and fed with maize silage and concentrate feed at 60:40% (w/w). Continuous VFA production was achieved at an average daily yield of 438 mg VFA/g substrate. The most abundant VFA were acetic (40-80%) and propionic (10-40%) acids. The majority (73 ± 15%) of produced VFA was transferred through the UF membrane. Shifts in dominant rumen microbes were observed upon the transition from in vivo to in vitro environment and during reactor operation, however, stable VFA yield was maintained for 35 days, providing the first proof-of-concept of a viable rumen MBR.

Long-term renal function in living kidney donors with simple renal cysts: A retrospective cohort study.

Simple (Bosniak I) renal cysts are considered acceptable in living kidney donor selection in terms of cancer risk. However, they tend to increase in number and size over time and might compromise renal function in donors. To clarify their implications for long-term renal function, we characterized the prevalence of renal cysts in 454 individuals who donated at our center from 2000 to 2007. We estimated the association between the presence of cysts in the kidney remaining after nephrectomy (ie, retained cysts) and postdonation eGFR trajectory using mixed-effects linear regression. Donors with retained cysts (N = 86) were older (P < .001) and had slightly lower predonation eGFR (median 94 vs 98 mL/min/1.73 m2 , P < .01) than those without cysts. Over a median 7.8 years, donors with retained cysts had lower baseline eGFR (-8.7 -5.6 -2.3  mL/min/1.73 m2 , P < .01) but similar yearly change in eGFR (-0.4 0.02 0.4  mL/min/1.73 m2 , P = .2) compared to those without retained cysts. Adjusting for predonation characteristics, there was no difference in baseline eGFR (P = .6) or yearly change in eGFR (P > .9). There continued to be no evidence of an association when we considered retained cyst(s) ≥10 mm or multiple retained cysts (all P > .05). These findings reaffirm current practices of accepting candidates with simple renal cysts for donor nephrectomy.

Brief Report: Willingness to Accept HIV-Infected and Increased Infectious Risk Donor Organs Among Transplant Candidates Living With HIV.

BACKGROUND: HIV-infected (HIV+) donor to HIV+ recipient (HIV D+/R+) transplantation might improve access to transplantation for people living with HIV. However, it remains unknown whether transplant candidates living with HIV will accept the currently unknown risks of HIV D+/R+ transplantation. METHODS: We surveyed transplant candidates living with HIV from 9 US transplant centers regarding willingness to accept HIV+ donor organs. RESULTS: Among 116 participants, the median age was 55 years, 68% were men, and 78% were African American. Most were willing to accept HIV+ living donor organs (87%), HIV+ deceased donor organs (84%), and increased infectious risk donor organs (70%). Some (30%) were concerned about HIV superinfection; even among these respondents, 71% were willing to accept an HIV D+ organ. Respondents from centers that had already performed a transplant under an HIV D+/R+ transplantation research protocol were more willing to accept HIV+ deceased donor organs (89% vs. 71%, P = 0.04). Respondents who chose not to enroll in an HIV D+/R+ transplantation research protocol were less likely to believe that HIV D+/R+ transplantation was safe (45% vs. 77%, P = 0.02), and that HIV D+ organs would work similar to HIV D- organs (55% vs. 77%, P = 0.04), but more likely to believe they would receive an infection other than HIV from an HIV D+ organ (64% vs. 13%, P < 0.01). CONCLUSIONS: Willingness to accept HIV D+ organs among transplant candidates living with HIV does not seem to be a major barrier to HIV D+/R+ transplantation and may increase with growing HIV D+/R+ transplantation experience.

Application of rumen and anaerobic sludge microbes for bio harvesting from lignocellulosic biomass.

This study investigated the production of biogas, volatile fatty acids (VFAs), and other soluble organic from lignocellulosic biomass by two microbial communities (i.e. rumen fluid and anaerobic sludge). Four types of abundant lignocellulosic biomass (i.e. wheat straw, oaten hay, lurence hay and corn silage) found in Australia were used. The results show that rumen microbes produced four-time higher VFAs level than that of anaerobic sludge reactors, indicating the possible application of rumen microorganism for VFAs generation from lignocellulosic biomass. VFA production in the rumen fluid reactors was probably due to the presence of specific hydrolytic and acidogenic bacteria (e.g. Fibrobacter and Prevotella). VFA production corroborated from the observation of pH drop in the rumen fluid reactors indicated hydrolytic and acidogenic inhibition, suggesting the continuous extraction of VFAs from the reactor. Anaerobic sludge reactors on the other hand, produced more biogas than that of rumen fluid reactors. This observation was consistent with the abundance of methanogens in anaerobic sludge inoculum (3.98% of total microbes) compared to rumen fluid (0.11%). VFA production from lignocellulosic biomass is the building block chemical for bioplastic, biohydrogen and biofuel. The results from this study provide important foundation for the development of engineered systems to generate VFAs from lignocellulosic biomass.

Cervical Cancer Screening for Women With Disabilities: Time for a New Approach?

Women with disabilities are underscreened for cervical cancer compared with the general population, likely because, in part, of both emotional and physical challenges associated with Pap testing. Women with certain disabilities often require an examination under anesthesia to undergo a speculum examination. However, anesthesia is not without risks and the perioperative experience can be burdensome to patients and caregivers. Either self-collected or provider-collected samples for human papillomavirus (HPV) testing might be better tolerated by patients, and recent evidence suggests that it is a suitable primary screening strategy. The Society of Gynecologic Oncology and the American Society for Colposcopy and Cervical Pathology published an Interim Guidance Report outlining using primary HPV testing as an option for women 25 years and older. More recently, the US Preventive Services Task Force released a recommendation statement that included the option to use oncogenic HPV testing alone for women aged 30 to 65 years. We encourage clinical researchers and professional organizations to evaluate primary HPV screening among women with disabilities to advise providers about how to best perform cervical cancer screening without the need for a speculum examination. We cannot ignore the screening disparity experienced by this population, and advocating for screening approaches that reduce patient and caregiver burden would be a step in the right direction.

Willingness to Donate Organs Among People Living With HIV.

BACKGROUND: With passage of the HIV Organ Policy Equity (HOPE) Act, people living with HIV (PLWH) can donate organs to PLWH awaiting transplant. Understanding knowledge and attitudes regarding organ donation among PLWH in the United States is critical to implementing the HOPE Act. METHODS: PLWH were surveyed regarding their knowledge, attitudes, and beliefs about organ donation and transplantation at an urban academic HIV clinic in Baltimore, MD, between August 2016 and October 2016. Responses were compared using Fisher exact and χ tests. RESULTS: Among 114 survey respondents, median age was 55 years, 47.8% were female, and 91.2% were African American. Most were willing to be deceased donors (79.8%) or living donors (62.3%). Most (80.7%) were aware of the US organ shortage; however, only 24.6% knew about the HOPE Act, and only 21.1% were registered donors. Respondents who trusted the medical system or thought their organs would function adequately in recipients were more likely to be willing to be deceased donors (P < 0.001). Respondents who were concerned about surgery, worse health postdonation, or need for changes in HIV treatment because of donation were less likely to be willing to be living donors (P < 0.05 for all). Most believed that PLWH should be permitted to donate (90.4%) and that using HIV+ donor organs for transplant would reduce discrimination against PLWH (72.8%). CONCLUSIONS: Many of the PLWH surveyed expressed willingness to be organ donors. However, knowledge about the HOPE Act and donor registration was low, highlighting a need to increase outreach.

Cellular Tight Junctions Prevent Effective Campylobacter jejuni Invasion and Inflammatory Barrier Disruption Promoting Bacterial Invasion from Lateral Membrane in Polarized Intestinal Epithelial Cells.

Campylobacter jejuni invasion is closely related to C. jejuni pathogenicity. The intestinal epithelium contains polarized epithelial cells that form tight junctions (TJs) to provide a physical barrier against bacterial invasion. Previous studies indicated that C. jejuni invasion of non-polarized cells involves several cellular features, including lipid rafts. However, the dynamics of C. jejuni invasion of polarized epithelial cells are not fully understood. Here we investigated the interaction between C. jejuni invasion and TJ formation to characterize the mechanism of C. jejuni invasion in polarized epithelial cells. In contrast to non-polarized epithelial cells, C. jejuni invasion was not affected by depletion of lipid rafts in polarized epithelial cells. However, depletion of lipid rafts significantly decreased C. jejuni invasion in TJ disrupted cells or basolateral infection and repair of cellular TJs suppressed lipid raft-mediated C. jejuni invasion in polarized epithelial cells. In addition, pro-inflammatory cytokine, TNF-α treatment that induce TJ disruption promote C. jejuni invasion and lipid rafts depletion significantly reduced C. jejuni invasion in TNF-α treated cells. These data demonstrated that TJs prevent C. jejuni invasion from the lateral side of epithelial cells, where they play a main part in bacterial invasion and suggest that C. jejuni invasion could be increased in inflammatory condition. Therefore, maintenance of TJs integrity should be considered important in the development of novel therapies for C. jejuni infection.

Quantifying Postdonation Risk of ESRD in Living Kidney Donors.

Studies have estimated the average risk of postdonation ESRD for living kidney donors in the United States, but personalized estimation on the basis of donor characteristics remains unavailable. We studied 133,824 living kidney donors from 1987 to 2015, as reported to the Organ Procurement and Transplantation Network, with ESRD ascertainment via Centers for Medicare and Medicaid Services linkage, using Cox regression with late entries. Black race (hazard ratio [HR], 2.96; 95% confidence interval [95% CI], 2.25 to 3.89; P<0.001) and male sex (HR, 1.88; 95% CI, 1.50 to 2.35; P<0.001) was associated with higher risk of ESRD in donors. Among nonblack donors, older age was associated with greater risk (HR per 10 years, 1.40; 95% CI, 1.23 to 1.59; P<0.001). Among black donors, older age was not significantly associated with risk (HR, 0.88; 95% CI, 0.72 to 1.09; P=0.3). Greater body mass index was associated with higher risk (HR per 5 kg/m2, 1.61; 95% CI, 1.29 to 2.00; P<0.001). Donors who had a first-degree biological relationship to the recipient had increased risk (HR, 1.70; 95% CI, 1.24 to 2.34; P<0.01). C-statistic of the model was 0.71. Predicted 20-year risk of ESRD for the median donor was only 34 cases per 10,000 donors, but 1% of donors had predicted risk exceeding 256 cases per 10,000 donors. Risk estimation is critical for appropriate informed consent and varies substantially across living kidney donors. Greater permissiveness may be warranted in older black candidate donors; young black candidates should be evaluated carefully.

Featured Article: Pyruvate preserves antiglycation defenses in porcine brain after cardiac arrest.

Cardiac arrest (CA) and cardiocerebral resuscitation (CCR)-induced ischemia-reperfusion imposes oxidative and carbonyl stress that injures the brain. The ischemic shift to anaerobic glycolysis, combined with oxyradical inactivation of glyceraldehyde 3-phosphate dehydrogenase (GAPDH), provokes excessive formation of the powerful glycating agent, methylglyoxal. The glyoxalase (GLO) system, comprising the enzymes glyoxalase 1 (GLO1) and GLO2, utilizes reduced glutathione (GSH) supplied by glutathione reductase (GR) to detoxify methylglyoxal resulting in reduced protein glycation. Pyruvate, a natural antioxidant that augments GSH redox status, could sustain the GLO system in the face of ischemia-reperfusion. This study assessed the impact of CA-CCR on the cerebral GLO system and pyruvate's ability to preserve this neuroprotective system following CA. Domestic swine were subjected to 10 min CA, 4 min closed-chest CCR, defibrillation and 4 h recovery, or to a non-CA sham protocol. Sodium pyruvate or NaCl control was infused (0.1 mmol/kg/min, intravenous) throughout CCR and the first 60 min recovery. Protein glycation, GLO1 content, and activities of GLO1, GR, and GAPDH were analyzed in frontal cortex biopsied at 4 h recovery. CA-CCR produced marked protein glycation which was attenuated by pyruvate treatment. GLO1, GR, and GAPDH activities fell by 86, 55, and 30%, respectively, after CA-CCR with NaCl infusion. Pyruvate prevented inactivation of all three enzymes. CA-CCR sharply lowered GLO1 monomer content with commensurate formation of higher molecular weight immunoreactivity; pyruvate preserved GLO1 monomers. Thus, ischemia-reperfusion imposed by CA-CCR disabled the brain's antiglycation defenses. Pyruvate preserved these enzyme systems that protect the brain from glycation stress. Impact statement Recent studies have demonstrated a pivotal role of protein glycation in brain injury. Methylglyoxal, a by-product of glycolysis and a powerful glycating agent in brain, is detoxified by the glutathione-catalyzed glyoxalase (GLO) system, but the impact of cardiac arrest (CA) and cardiocerebral resuscitation (CCR) on the brain's antiglycation defenses is unknown. This study in a swine model of CA and CCR demonstrated for the first time that the intense cerebral ischemia-reperfusion imposed by CA-resuscitation disabled glyoxalase-1 and glutathione reductase (GR), the source of glutathione for methylglyoxal detoxification. Moreover, intravenous administration of pyruvate, a redox-active intermediary metabolite and antioxidant in brain, prevented inactivation of glyoxalase-1 and GR and blunted protein glycation in cerebral cortex. These findings in a large mammal are first evidence of GLO inactivation and the resultant cerebral protein glycation after CA-resuscitation, and identify novel actions of pyruvate to minimize protein glycation in postischemic brain.

Improved fermentative production of gamma-aminobutyric acid via the putrescine route: Systems metabolic engineering for production from glucose, amino sugars, and xylose.

Gamma-aminobutyric acid (GABA) is a non-protein amino acid widespread in Nature. Among the various uses of GABA, its lactam form 2-pyrrolidone can be chemically converted to the biodegradable plastic polyamide-4. In metabolism, GABA can be synthesized either by decarboxylation of l-glutamate or by a pathway that starts with the transamination of putrescine. Fermentative production of GABA from glucose by recombinant Corynebacterium glutamicum has been described via both routes. Putrescine-based GABA production was characterized by accumulation of by-products such as N-acetyl-putrescine. Their formation was abolished by deletion of the spermi(di)ne N-acetyl-transferase gene snaA. To improve provision of l-glutamate as precursor 2-oxoglutarate dehydrogenase activity was reduced by changing the translational start codon of the chromosomal gene for 2-oxoglutarate dehydrogenase subunit E1o to the less preferred TTG and by maintaining the inhibitory protein OdhI in its inhibitory form by changing amino acid residue 15 from threonine to alanine. Putrescine-based GABA production by the strains described here led to GABA titers up to 63.2 g L-1 in fed-batch cultivation at maximum volumetric productivities up to 1.34 g L-1 h-1 , the highest volumetric productivity for fermentative GABA production reported to date. Moreover, GABA production from the carbon sources xylose, glucosamine, and N-acetyl-glucosamine that do not have competing uses in the food or feed industries was established. Biotechnol. Bioeng. 2017;114: 862-873. © 2016 Wiley Periodicals, Inc.

Pyruvate stabilizes electrocardiographic and hemodynamic function in pigs recovering from cardiac arrest.

Cardiac electromechanical dysfunction may compromise recovery of patients who are initially resuscitated from cardiac arrest, and effective treatments remain elusive. Pyruvate, a natural intermediary metabolite, energy substrate, and antioxidant, has been found to protect the heart from ischemia-reperfusion injury. This study tested the hypothesis that pyruvate-enriched resuscitation restores hemodynamic, metabolic, and electrolyte homeostasis following cardiac arrest. Forty-two Yorkshire swine underwent pacing-induced ventricular fibrillation and, after 6 min pre-intervention arrest, 4 min precordial compressions followed by transthoracic countershocks. After defibrillation and recovery of spontaneous circulation, the pigs were monitored for another 4 h. Sodium pyruvate or NaCl were infused i.v. (0.1 mmol·kg(-1)·min(-1)) throughout precordial compressions and the first 60 min recovery. In 8 of the 24 NaCl-infused swine, the first countershock converted ventricular fibrillation to pulseless electrical activity unresponsive to subsequent countershocks, but only 1 of 18 pyruvate-treated swine developed pulseless electrical activity (relative risk 0.17; 95% confidence interval 0.13-0.22). Pyruvate treatment also lowered the dosage of vasoconstrictor phenylephrine required to maintain systemic arterial pressure at 15-60 min recovery, hastened clearance of excess glucose, elevated arterial bicarbonate, and raised arterial pH; these statistically significant effects persisted up to 3 h after sodium pyruvate infusion, while infusion-induced hypernatremia subsided. These results demonstrate that pyruvate-enriched resuscitation achieves electrocardiographic and hemodynamic stability in swine during the initial recovery from cardiac arrest. Such metabolically based treatment may offer an effective strategy to support cardiac electromechanical recovery immediately after cardiac arrest.