Mechanoresponsive Protein Crystals for NADH Recycling in Multicycle Enzyme Reactions.

NAD(H)-dependent enzymes play a crucial role in the biosynthesis of pharmaceuticals and fine chemicals, but the limited recyclability of the NAD(H) cofactor hinders its more general application. Here, we report the generation of mechano-responsive PEI-modified Cry3Aa protein crystals and their use for NADH recycling over multiple reaction cycles. For demonstration of its practical utility, a complementary Cry3Aa protein particle containing genetically encoded and co-immobilized formate dehydrogenase for NADH regeneration and leucine dehydrogenase for catalyzing the NADH-dependent l-tert-leucine (l-tert-Leu) biosynthesis has been produced. When combined with the PEI-modified Cry3Aa crystal, the resultant reaction system could be used for the efficient biosynthesis of l-tert-Leu for up to 21 days with a 10.5-fold improvement in the NADH turnover number.

Cellular and molecular mechanisms involved in the analgesic effects of botulinum neurotoxin: A literature review.

Botulinum neurotoxins (BoNTs), derived from Clostridium botulinum, have been employed to treat a range of central and peripheral neurological disease. Some studies indicate that BoNT may be beneficial for pain conditions as well. It has been hypothesized that BoNTs may exert their analgesic effects by preventing the release of pain-related neurotransmitters and neuroinflammatory agents from sensory nerve endings, suppressing glial activation, and inhibiting the transmission of pain-related receptors to the neuronal cell membrane. In addition, there is evidence to suggest that the central analgesic effects of BoNTs are mediated through their retrograde axonal transport. The purpose of this review is to summarize the experimental evidence of the analgesic functions of BoNTs and discuss the cellular and molecular mechanisms by which they can act on pain conditions. Most of the studies reviewed in this article were conducted using BoNT/A. The PubMed database was searched from 1995 to December 2022 to identify relevant literature.

The effect of smoking on response to methotrexate in rheumatoid arthritis patients: A systematic review and meta-analysis.

OBJECTIVES: In the current study, we aimed to investigate the effect of smoking on inadequate response to methotrexate (MTX-IR) in rheumatoid arthritis (RA) patients. METHODS: We searched PubMed, Embase, and Web of Science until 6 June 2022. Observational or interventional studies investigating MTX-IR in RA patients based on smoking status were included. Two independent reviewers assessed the risk of bias and the certainty of the evidence using the Risk of Bias in Nonrandomized Studies-of Interventions and Grades of Recommendation, Assessment, Development, and Evaluation tools, respectively. RESULTS: We included 23 studies in the systematic review and 13 in the meta-analysis. Of the 13 included studies, 6 had a moderate risk, 3 had a serious risk, and 4 had a critical risk of bias. The overall random-effect meta-analysis suggested that smokers were 58% more likely to be MTX-IR when compared with nonsmokers [odds ratio (OR) 1.58, 95% confidence interval 1.21-2.06; P = .001; I2 = 69.3%]. The common-effect meta-analysis of the adjusted ORs demonstrated an overall OR of 2.69 (1.88-3.83; P < .001; I2 = 27.1%). CONCLUSIONS: The current study showed that smoking is a significant predictor of MTX-IR, especially in disease-modifying antirheumatic drug-naïve early RA patients, as most of the included studies in the meta-analysis consisted of this population.

Food products as potential carriers of SARS-CoV-2.

At present, humanity is confronting with a novel life-threatening challenge from the COVID-19 pandemic infectious disease caused by the novel coronavirus SARS-CoV-2. To date, the various transmission modes of SARS-CoV-2 have not been completely determined. Food products might be carriers for SARS-CoV-2. The COVID-19 pandemic not only can spread through the respiratory tract like SARS and MERS but also the presence of the SARS-CoV-2 RNA in feces of several patients, shows the possibility of their fecal-oral route spread. Besides, people with gastric problems, including gastric intestinal metaplasia and atrophic gastritis, may be susceptible to this kind of COVID-19 infection. Accordingly, food may act as a potential vehicle of SARS-CoV-2 due to whether carry-through or carry-over contaminations. Considering carry-over, SARS-CoV-2 spread from personnel to food products or food surfaces is feasible. Beyond that, some shreds of evidence showed that pigs and rabbits can be infected by SARS-CoV-2. Thus, viral transmission through meat products may be conceivable, indicating carry-through contamination. As the spread rate of SARS-CoV-2 is high and its stability in different environments, especially food processing surfaces, is also remarkable, it may enter foods in whether industrialized processing or the traditional one. Therefore, established precautious acts is suggested to be applied in food processing units. The present review elucidates the risk of various staple food products, including meat and meat products, dairy products, bread, fruits, vegetables, and ready-to-eat foods as potential carriers for transmission of SARS-CoV-2.

Stability of severe acute respiratory syndrome coronavirus 2 in dairy products.

The present investigation was performed to determine the stability of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) under several industrial processing situations in dairies, including pasteurization, freezing, and storage in acidic conditions. Ten treatments were selected, including high-temperature short-time (HTST)-pasteurized low-fat milk, low-temperature long-time-pasteurized low-fat milk, extended shelf life (ESL)-pasteurized low-fat milk, HTST-pasteurized full-fat milk, LTLT-pasteurized full-fat milk, ESL-pasteurized full-fat milk, pasteurized cream, ice cream frozen and stored at -20 or -80°C, and Doogh (as a fermented milk drink with initial pH < 3.5) refrigerated for 28 days. The viral particles were quantified by RT-PCR methodology. Besides, the virus infectivity was assessed through fifty-percent tissue culture infective dose (TCID50) assay. These products were seeded with a viral load of 5.65 log TCID50/mL as a simulated cross-contamination condition. Pasteurization techniques were sufficient for complete inactivation of the SARS-CoV-2 in the most dairy products, and 1.85 log TCID50/mL virus reduction in full-fat milk (fat content = 3.22%). Freezing (either -20°C or -80°C) did not result in a virally safe product within 60 days of storage. Storage at high acidic conditions (initial pH < 3.5) completely hampered the viral load at the end of 28 days of refrigerated storage. This research represents an important practical achievement that the routine HTST pasteurization in dairies was inadequate to completely inactivate the viral load in full-fat milk, probably due to the protective effect of fat content. Furthermore, freezing retain the virus infectivity in food products, and therefore, relevant contaminated foods may act as carriers for SARS-CoV-2.

Hyaluronic acid-decorated liposomal nanoparticles for targeted delivery of 5-fluorouracil into HT-29 colorectal cancer cells.

The use of liposomes as drug carriers improves the therapeutic efficacy of anticancer drugs, while at the same time reducing side effects. Hyaluronic acid (HA) is recognized by the CD44 receptor, which is overexpressed in many cancer cells. In this study, we developed HA-modified liposomes encapsulating 5-fluorouracil (5-FU) and tested them against a CD44 expressing colorectal cell line (HT29) and a non-CD44 expressing hepatoma cell line. The average size of 5-FU-lipo and 5-FU-lipo-HA nanoparticles were 112 ± 28 and 144 ± 77 nm, respectively. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT) assay showed selective cancer cell death depending on the CD44 expression in a time-dependent manner. Apoptosis assays and cell-cycle analysis indicated that G0/G1 arrest occurred. The colony formation study revealed that cells treated with 5-FU-lipo and 5-FU-lipo-HA had reduced colony formation. Quantitative reverse-transcription polymerase chain reaction study showed that the oncogenic messenger RNA and microRNA levels were significantly reduced in the 5-FU-lipo-HA-treated group, while tumor suppressors were increased in that group. We suggest that optimal targeted delivery and release of 5-FU into colorectal cancer cells, renders them susceptible to apoptosis, cell-cycle arrest, and decreased colony formation.

Exploring the interactions of a Tb(III)-quercetin complex with serum albumins (HSA and BSA): spectroscopic and molecular docking studies.

Serum albumins (human serum albumin (HSA) and bovine serum albumin (BSA), two main circulatory proteins), are globular and monomeric macromolecules in plasma that transport many drugs and compounds. In the present study, we investigated the interactions of the Tb(III)-quercetin (Tb-QUE) complex with HSA and BSA using common spectroscopic techniques and a molecular docking study. Fluorescence data revealed that the inherent fluorescence emission of HSA and BSA was markedly quenched by the Tb-QUE complex through a static quenching mechanism, confirming stable complex formation (a ground-state association) between albumins and Tb-QUE. Binding and thermodynamic parameters were obtained from the fluorescence spectra and the related equations at different temperatures under biological conditions. The binding constants (Kb ) were calculated to be 0.8547 × 103 M-1 for HSA and 0.1363 × 103 M-1 for BSA at 298 K. Also, the number of binding sites (n) of the HSA/BSA-Tb-QUE systems was obtained to be approximately 1. Thermodynamic data calculations along with molecular docking results indicated that electrostatic interactions have a main role in the binding process of the Tb-QUE complex with HSA/BSA. Furthermore, molecular docking outputs revealed that the Tb-QUE complex has high affinity to bind to subdomain IIA of HSA and BSA. Binding distances (r) between HSA-Tb-QUE and BSA-Tb-QUE systems were also calculated using the Forster (fluorescence resonance energy transfer) method. It is expected that this study will provide a pathway for designing new compounds with multiple beneficial effects on human health from the phenolic compounds family such as the Tb-QUE complex.

The impact of water molecules on binding affinity of the anti-diabetic thiazolidinediones for catalase: Kinetic and mechanistic approaches.

Water molecules play a vital role in efficient drug binding to its target. Thiazolidinediones (TZDs), a class of anti-diabetic drugs, are widely used for treatment of type 2 diabetes mellitus. In the present study, the possible contribution of water molecules to the binding of TZDs to catalase, a potential target in the liver, was investigated by different experimental and theoretical methods. These studies indicated that TZDs could significantly improve the catalase catalytic function with a significant contribution from water molecules. As a probe for the differential number of released water molecules during the catalase transition from E to E* states, the activity of TZDs-catalase complexes was demonstrated to be mainly dependent on water activity. However, free catalase decomposed the substrate more independently. In addition, the spectrofluorimetry studies showed that the binding of TZDs to catalase needed the release of water molecules from the enzyme's binding pocket. The thermodynamic studies indicated that the binding enthalpy and entropy of TZDs for catalase were decreased with lower water activity. The favorable process contributes to release of water molecules from the binding pocket through the formation of hydrophobic interactions between catalase and TZDs in an enthalpic manner. Molecular docking simulations confirmed that the depletion of water molecules from the binding cavity is essential for effective interactions between TZDs and catalase.

Activation of catalase by pioglitazone: Multiple spectroscopic methods combined with molecular docking studies.

Pioglitazone is an important prescription antidiabetic drug with positive roles in controlling high blood sugar in patients with type 2 diabetes. In the present study, we investigated the effects of pioglitazone on the structure and function of bovine liver catalase (BLC) using different spectroscopic and theoretical methods. UV-Vis absorption, fluorescence spectroscopy, synchronous fluorescence, and circular dichroism studies revealed conformational changes in the BLC structure and heme group in the presence of different concentrations of pioglitazone. Kinetic studies indicated that pioglitazone can increase BLC activity by approximately threefold compared with free enzyme. The fluorescence quenching data showed one binding site for pioglitazone, and the binding constants at 298, 304, and 310 K were calculated as 5.01 × 107  M-1 , 5.8 × 107  M-1 , and 6.6 × 107  M-1 , respectively. The static type of quenching mechanism was mainly involved in the quenching of intrinsic emission of the enzyme. Thermodynamic data suggested that hydrophobic interactions played a major role in the binding reaction of pioglitazone with BLC. The molecular docking studies indicated that pioglitazone interacts with the cavity in the middle of the ß-barrel and wrapping domain of BLC. Thus, pioglitazone can increase catalase activity by changing the BLC structure.

Probing binding mode between sodium acid pyrophosphate and albumin: multi-spectroscopic and molecular docking analysis.

Sodium acid pyrophosphate (SAPP) food additive is widely used as a preservative, bulking agent, chelating agent, emulsifier and pH regulator. It is also used as an improver of color and water retention capacity in the processing of various types of seafood, canned food, cooked meat and flour products. For the first time, we evaluated the SAPP interaction with bovine serum albumin (BSA) using spectroscopic methods including UV-Vis absorption, fluorescence spectroscopy, and surface plasmon resonance, and docking analysis to understand the mechanisms of complex formation and binding. The fluorescence intensity of BSA reduces when titrated with various concentrations of SAPP by forming a complex with BSA via a static quenching mechanism. The binding constant between BSA and SAPP decreased from 123,300 to 15,800 (M-1) with rising temperature, which indicates a decrement in complex formation owing to the interaction of SAPP with BSA. A negative ΔG° value means that SAPP binds spontaneously to BSA at all temperatures, and both ΔH° and ΔS° negative values indicate that hydrogen bonds (H-bonding) and van der Waals forces are the primary forces involved in the binding processes. The UV-Vis spectrum of BSA reduced upon increasing SAPP concentrations due to forming a new ground state complex between SAPP and BSA. Molecular docking study shows that residues Arg256, Ser259, Ser286, Ile 289 and Ala 290 play an important role in SAPP binding process to site I (subdomain IIA) of BSA through H-bonding and van der Waals forces, which is supported by the thermodynamic study.Communicated by Ramaswamy H. Sarma.

Release kinetic modeling of Satureja Khuzestanica Jamzad essential oil from fish gelatin/succinic anhydride starch nanocomposite films: The effects of temperature and nanocellulose concentration.

Fish gelatin (FG) and octenyl succinic anhydride starch (OSAS) composite films loaded with 1, 2, 3 and 4 wt% bacterial nanocellulose (BNC) and Satureja Khuzestanica Jamzad essential oil (SKEO) were achieved successfully and their physicochemical and release properties were investigated. The results revealed that incorporation of BNC improved the tensile strength which was associated with FE-SEM, FTIR and XRD. Moreover, this study focused on the release modeling of SKEO in 4, 25 and 37 °C from nanocomposite films using different release kinetic and Arrhenius models. Also, analysis of variance-simultaneous component analysis (ASCA) and exploratory data visualization by principal component analysis (PCA) were carried out to investigate the effects of two controlled factors. Consequently, the Peleg model showed the best fitting of experimental data. The activation energies decreased by increasing the BNC concentration. This research demonstrated the nanocomposite film containing SKEO would be a suitable candidate for active food packaging.

Effect of using biodegradable film constituting red grape anthocyanins as a novel packaging on the qualitative attributes of emergency food bars during storage.

This study presents a novel packaging film based on whey protein isolate/κ-carrageenan (WC) with red grape pomace anthocyanins (RGA) to investigate its impact on some qualitative attributes of emergency food bars (EFBs) for 6 months at 38°C. Increasing the RGA dose in WC films from 5% (WCA5) to 10% (WCA10) reduced hydrogen bonding between polymers and polymer homogeneity in the matrix according to FTIR and SEM. Tensile strength slightly declined in WCA5 from 7.47 ± 0.26 to 6.97 ± 0.12, while elongation increased from 27.74 ± 1.36 to 32.36 ± 1.25% compared to WC film. The maximum weight loss temperature (TM) increased by incorporating 5 wt% RGA from 182.95°C to 244.36°C, whereas TM declined to 187.19°C in WCA10 film. WVP and OTR slightly changed in WCA5 (from 7.83 ± 0.07 and 2.57 ± 0.18 to 8.41 ± 0.03 g H2O.m/m2.Pa.s × 10-9 and 1.79 ± 0.32 cm3 O2/m2.d.bar, respectively), but significantly impaired in WCA10 compared to WC film. WCA5 and WCA10 films had high AA%, 68.77%, and 79.21%, respectively. WCA10 film presented great antimetrical properties against Staphylococcus aureus with an inhibition zone of 6.00 mm. The light transmission of RGA-contained films in the UV spectrum was below 10%. The WCA5 film effectively restrained moisture loss and hardness increment until the end of the storage period, which were 14.33% and 28.76%, respectively, compared to day 0. Antioxidant films provided acceptable resistance against oxidation to EBF treatment. Sensory panels scored WCA5 and WCA10 higher in overall acceptance with 5.64 and 5.40 values, respectively, while complaining about the hardness of OPP treatment. The results of this investigation demonstrated that incorporating RGA, preferably 5 wt%, into WC-based film effectively improved the qualitative properties of EFB during the 6-month shelf life. This film might be a promising alternative for packaging light and oxygen-sensitive food products.

The influence of ionic polysaccharides on the physicochemical and techno-functional properties of soy proteins; a comprehensive review.

Since the world's population has surged in recent decades, the need for sustainable as well as environmentally friendly protein sources is growing. However, there are daunting challenges in utilizing these protein sources in the food industry due to their poor techno-functional properties compared with animal proteins. Numerous procedures have been introduced to improve plant protein functionalities with related pros and cons. Among them, complexation with polysaccharides is considered a safe and effective process for modulating plant proteins' technological and industrial applications. Notwithstanding the nutritional value of soy protein (SP) as a "complete protein," it is a crucial protein commercially because of its rank as the highest-traded plant-based protein worldwide. The current review deals with SP complexation with ionic polysaccharides, including chitosan, alginate, carrageenan, and xanthan gum, and their effects on the physicochemical and techno-functional properties of SP. Accordingly, the structure of SP and the abovementioned polysaccharides have been considered for a better understanding of the possible interactions. Then, the changes in the physicochemical and functional properties of SP and their potential applications in the formulation of plant-based food products have been discussed. Overall, ionic polysaccharides at optimum conditions would improve the functional properties of SP by altering its secondary structure, making it suitable for a wide range of applications in the food industry.

Glomerulonephritis associated with systemic sclerosis: a case report.

BACKGROUND: Systemic sclerosis is a multiorgan autoimmune disease that can overlap with other rheumatologic disorders; however, co-occurrence with antineutrophil cytoplasmic antibody-associated vasculitis is rare. CASE PRESENTATION: A 39-year-old Persian female patient with systemic sclerosis according to American College of Rheumatology/European League Against Rheumatism 2013 criteria with a disease duration of 6 years was admitted to the hospital due to a rise in creatinine level in July 2021. She had complaints of nasal speech and feeling of nasal perforation. The first symptoms of antineutrophil cytoplasmic antibody-associated vasculitis had started 5 years earlier with palpable purpura in the lower limbs, hemoptysis, and positive perinuclear (p)-antibody-associated vasculitis level (> 300 AU/mL). Still, the diagnosis was not achieved due to the patient's reluctance to undergo a biopsy. She was treated with azathioprine (150 mg/day) and prednisolone (10 mg/day) during the 5-year follow-up. Her renal biopsy results showed cortical renal tissue with a cellular crescent in more than 50% of the specimen, rupture of the Bowman capsule and the glomerular basement membrane, peri-glomerular inflammation, and mild tubular atrophy in microscopic examinations. The immunofluorescence study resulted in a granular pattern of immune deposits along the glomerular basement membrane, mesangial tissue, and tubular basement membranes. CONCLUSION: We reported a rare case of comorbid systemic sclerosis and antineutrophil cytoplasmic antibody-associated vasculitis with nasal perforation. Her renal biopsy showed immune deposits along the glomerular basement membrane, mesangial tissue, and tubular basement membranes. Overlapping with other collagen vascular diseases can occur in rheumatology patients with uncommon manifestations. In systemic sclerosis, renal involvement in the form of glomerulonephritis is infrequent, and comorbid systemic lupus erythematosus or antineutrophil cytoplasmic antibody-associated vasculitis should be considered.

Translation and validation of the Persian version of the scleroderma health assessment questionnaire (SHAQ).

The present study aimed to translate and validate the Scleroderma Health Assessment Questionnaire (SHAQ) for Persian-speaking patients (SHAQ-P), using a cross-sectional study. This cross-sectional study included SSc patients with 2013 ACR/EULAR criteria. The SHAQ was translated using a "forward-backward" method. HAQ-DI and SSc-HAQ scores were calculated from the patient-answered questionnaires. Rheumatology experts assessed the face and content validities of the SHAQ-P. Psychometric properties of the SHAQ-P were then assessed: Structural validity was analyzed using principal component factor analysis. Discriminant and convergent validities were measured on subgroups of the initial patient population. Test-retest reliability was measured on patients who filled the SHAQ-P again after 1 month. The Scale-CVI-average (S-CVI/Ave) score for content validity was 88.7%. Face validity was measured to be 68.17% using the QQ10 questionnaire. Factor analysis revealed a two-factor structure with 20 out of 26 questions loading on the first factor (N = 285). One-way ANOVA showed that patients with a higher number of involved organs had higher average HAQ-DI and SSc-HAQ-scores (N = 60, P = 0.019 and 0.023, respectively). HAQ-DI and SSc-HAQ-scores were significantly correlated with the physical component score of SF36 (N = 31, correlation coefficient = - 0.65 and - 0.72, respectively). Reliability testing after one month demonstrated that HAQ-DI and SSc-HAQ-scores were significantly correlated with their initial (N = 40, correlation coefficient = 0.86 and 0.84, respectively), proving that the Persian SHAQ was a valid and reliable questionnaire to evaluate scleroderma patients' quality of life.

Association of anti-Ro52 autoantibody with interstitial lung disease in autoimmune diseases: a systematic review and meta-analysis.

OBJECTIVES: Interstitial lung disease (ILD) is an important manifestation of autoimmune diseases that can lead to morbidity and mortality. Although several autoantibodies have been linked with ILD presentation and adverse outcomes, the association of anti-Ro52 antibody with ILD is less studied. Hence, we investigated this association in various autoimmune diseases in the current study. DESIGN: We designed a systematic review and meta-analysis and did a comprehensive search from inception until 2 January 2023. DATA SOURCES: A systematic search was conducted in four electronic databases: PubMed, Web of Science, Scopus and Embase. ELIGIBILITY CRITERIA: Observational studies that reported ILD diagnosis (outcome) and anti-Ro antibody (exposure) status in any autoimmune conditions (population) were included. The association between rapidly progressive ILD (RP-ILD) and anti-Ro52 was studied in idiopathic inflammatory myopathies (IIM). DATA EXTRACTION AND SYNTHESIS: Collected data included study characteristics and ORs with 95% CIs. Quality assessment was performed using a modified version of the Newcastle-Ottawa Scale for cross-sectional studies. Random effects meta-analysis was used to pool the effect estimates. RESULTS: A total of 2353 studies were identified, from which 59 articles met the eligibility criteria. Anti-Ro52/SSA positivity was associated with ILD in all autoimmune disease subgroups: IIM (OR=3.08; 95% CI: 2.18 to 4.35; p value<0.001; I2=49%), systemic lupus (OR=2.43; 95% CI: 1.02 to 5.79; p=0.046; I2=71%), Sjogren (OR=1.77; 95% CI: 1.09 to 2.87; p=0.021; I2=73%), systemic sclerosis (OR=1.71; 95% CI: 1.04 to 2.83; p=0.036; I2=43%), mixed connective tissue disease (OR=3.34; 95% CI: 1.82 to 6.13; p<0.001; I2=0%). Additionally, anti-Ro52-positive myopathy patients were more likely to have simultaneous RP-ILD (OR=2.69; 95% CI:1.50 to 4.83; p<0.001; I2=71%). CONCLUSION: Anti-Ro52/SSA positivity is associated with a higher frequency of ILD diagnosis in various autoimmune diseases. Anti-Ro52/SSA is also linked with a more severe lung involvement (RP-ILD). Future studies can investigate the benefits of screening for anti-Ro52 and its association with ILD development. PROSPERO REGISTRATION NUMBER: CRD42022381447.

The role of non-enzymatic glycation on Tau-DNA interactions: Kinetic and mechanistic approaches.

Despite the regulatory role of Tau protein in the stabilization and assembly of microtubules, this protein has an important function in the protection and stabilizing of DNA molecules in the cell nucleus. In the present study, it has been indicated that glycation of lysine residues (Lys-267, Lys-274, and Lys-280) in the microtubule-binding domain (MBD) can considerably decrease its binding affinity to DNA molecules. The structural analysis also confirmed that the decreased glycated tau-DNA complex's stability was due to structural modification of this protein after the glycation process. The study of hippocampal cells under hyperglycemic conditions showed that near to 70% of Tau proteins glycated in these cells, although the expression of Tau remained unaffected. The assessment of H3K9me2, as a marker for binding of Tau to pericentromeric heterochromatin (PCH), indicated that localization of Tau protein on PCH was remarkably decreased at high glucose conditions relative to the controls. It is suggested that increasing the structural stability of Tau protein limits the ability of this protein for DNA binding, while the molecular and physical barrier of glycated Lys residues should not be neglected.

The protective effect of natural phenolic compound on the functional and structural responses of inhibited catalase by a common azo food dye.

In this research retrieval effects of natural yellow (NY) on the performance of carmoisine (CAR) inhibited bovine liver catalase (BLC) was studied using multispectral and theoretical methods. Kinetic studies showed that CAR inhibited BLC through competitive inhibition (IC50 value of 2.24 × 10-6 M) while the addition of NY recover the activity of CAR-BLC up to 82% in comparison with the control enzyme. Circular dichroism data revealed that NY can repair the structural changes of BLC, affected by CAR. Furthermore, an equilibrium dialysis study indicated that NY could reduce the stability of the CAR-catalase complex. The surface plasmon resonance (SPR) data analysis indicated a high affinity of NY to BLC compared to CAR and the binding of NY led to a decrease in the affinity of the enzyme to the inhibitor. On the other hand, fluorescence and molecular docking studies showed that the quenching mechanism of BLC by CAR occurs through a static quenching process, and van der Waals forces and hydrogen bonding play a crucial role in the binding of CAR to BLC. MLSD data demonstrated that NY could increase the binding energy of CAR-BLC complex from -7.72 kJ mol-1 to -5.9 kJ mol-1, leading to complex instability and catalase activity salvage.

Cardiopulmonary predictors of mortality in patients with COVID-19: What are the findings?

BACKGROUND: Since 2019, coronavirus disease 2019 (COVID-19) has been the leading cause of mortality worldwide. AIMS: To determine independent predictors of mortality in COVID-19, and identify any associations between pulmonary disease severity and cardiac involvement. METHODS: Clinical, laboratory, electrocardiography and computed tomography (CT) imaging data were collected from 389 consecutive patients with COVID-19. Patients were divided into alive and deceased groups. Independent predictors of mortality were identified. Kaplan-Meier analysis was performed, based on patients having a troponin concentration>99th percentile (cardiac injury) and a CT severity score ≥18. RESULTS: The mortality rate was 29.3%. Cardiac injury (odds ratio [OR] 2.19, 95% confidence interval [CI] 1.14-4.18; P=0.018), CT score ≥18 (OR 2.24, 95% CI 1.15-4.34; P=0.017), localized ST depression (OR 3.77, 95% CI 1.33-10.67; P=0.012), hemiblocks (OR 3.09, 95% CI 1.47-6.48; P=0.003) and history of leukaemia/lymphoma (OR 3.76, 95% CI 1.37-10.29; P=0.010) were identified as independent predictors of mortality. Additionally, patients with cardiac injury and CT score ≥ 18 were identified to have a significantly shorter survival time (mean 14.21 days, 95% CI 10.45-17.98 days) than all other subgroups. There were no associations between CT severity score and electrocardiogram or cardiac injury in our results. CONCLUSIONS: Our findings suggest that using CT imaging and electrocardiogram characteristics together can provide a better means of predicting mortality in patients with COVID-19. We identified cardiac injury, CT score ≥18, presence of left or right hemiblocks on initial electrocardiogram, localized ST depression and history of haematological malignancies as independent predictors of mortality in patients with COVID-19.

Effects of using different O2 scavengers on the qualitative attributes of bifidus yogurt during refrigerated storage.

Among the factors that adversely influence the viability of probiotics, the oxygen content of the product and the permeation of oxygen molecules through the packaging system have a noticeable role in the viability loss during the manufacture and storage of fermented milk products. The objective of this study was to examine the qualitative attributes of probiotic yogurt containing different O2 scavengers, including the commercial O2 absorber and cysteine-ascorbic acid. Bifidobacterium lactis BIA-7 and B. longum BIA-8 were used as probiotic strains for the production of bio-yogurts. The biochemical parameters, including the changes in pH, titratable acidity, redox potential and incubation time, were determined throughout the fermentation period at 30-min intervals. Also, the changes in viable count, pH, redox potential, titratable acidity, and dissolved oxygen were evaluated at 7-day intervals during the 28 days of refrigerated storage. In addition, the evaluation of rheological and sensory properties measured in the freshly made samples was carried out. The results showed that the utilization of different oxygen scavengers has an effective impact on the decrement of oxygen content and improvement of probiotic viability. As such, the population of B. lactis in the treatments containing various oxygen scavengers was maintained above 7 log CFU/mL throughout the refrigerated storage. Notwithstanding the effective function of cysteine-ascorbic acid in the enhancement of viability, the containing treatments had not only weaker gel structure probably due to short incubation time (360 min) and fast acidification [22.20-22.35 (˚D/min) × 10-2], but also lower sensory acceptance. Overall, the yogurt treatment containing commercial O2 scavenger and B. lactis indicated a great potential for the industrial applications. To the best of our knowledge, there is no study on the efficiency of commercial O2 absorber as a potential factor to maintain the viability of probiotics in yogurt.