Unravelling Different Water Management Strategies in Three Olive Cultivars: The Role of Osmoprotectants, Proteins, and Wood Properties.

Understanding the responses of olive trees to drought stress is crucial for improving cultivation and developing drought-tolerant varieties. Water transport and storage within the plant is a key factor in drought-tolerance strategies. Water management can be based on a variety of factors such as stomatal control, osmoprotectant molecules, proteins and wood properties. The aim of the study was to evaluate the water management strategy under drought stress from an anatomical and biochemical point of view in three young Italian olive cultivars (Giarraffa, Leccino and Maurino) previously distinguished for their physiological and metabolomic responses. For each cultivar, 15 individuals in pots were exposed or not to 28 days of water withholding. Every 7 days, the content of sugars (including mannitol), proline, aquaporins, osmotins, and dehydrins, in leaves and stems, as well as the chemical and anatomical characteristics of the wood of the three cultivars, were analyzed. 'Giarraffa' reduced glucose levels and increased mannitol production, while 'Leccino' accumulated more proline. Both 'Leccino' and 'Maurino' increased sucrose and aquaporin levels, possibly due to their ability to remove embolisms. 'Maurino' and 'Leccino' accumulated more dehydrins and osmotins. While neither genotype nor stress affected wood chemistry, 'Maurino' had a higher vessel-to-xylem area ratio and a larger hydraulic diameter, which allows it to maintain a high transpiration rate but may make it more susceptible to cavitation. The results emphasized the need for an integrated approach, highlighting the importance of the relative timing and sequence of each parameter analyzed, allowing, overall, to define a "strategy" rather than a "response" to drought of each cultivar.

Histidine-trytophan-ketoglutarate cardioplegia reduces inflammatory response and serum levels of myocardial enzymes in newly developed right-thoracotomy rat model.

The objective of this research was to establish a rat model for cardiopulmonary bypass (CPB) with cardiac arrest and resuscitation that is both practical and economical and simulates clinical cardiac surgery. Concurrently, the study aimed to evaluate the myocardial protective effects conferred by histidine-tryptophan-ketoglutarate (HTK) cardioplegia. Thirty rats were randomly assigned to three groups: the histidine-tryptophan-ketoglutarate (HTK), 4:1 blood cardioplegia (BC) and del Nido cardioplegia (DN) groups. The cardiopulmonary bypass (CPB) procedure was implemented and sustained for a duration of one hour. Subsequent to the cessation of CPB, the rats were subjected to monitoring and observation for an additional two hours. Following this observation period, the heart and blood samples were procured for subsequent analysis. During CPB, the average hematocrit level was significantly below the typical physiological range (P < 0.001). Histopathological scores were notably lower in the HTK group in contrast to the BC group (P < 0.001) or the DN group (P < 0.001). At 2 h after weaning off CPB, the levels of CK and CKMB in the DN and BC groups were notably elevated compared to the HTK group (P < 0.001). The levels of IL-6 and TNF-α proteins were notably increased in all three groups (P < 0.001), with the BC and DN groups showing higher increases compared to the HTK group (P < 0.001). This compact animal model of cardiopulmonary bypass (CPB) with cardiac arrest and resuscitation might allow for both the study of myocardial ischemia-reperfusion injury as well as cardioprotective strategies. HTK cardioplegia could reduce inflammatory response and serum levels of myocardial enzymes in this newly developed right thoracotomy rat model.

Metabolic engineering of Corynebacterium crenatum for enhanced L-tyrosine production from mannitol and glucose.

BACKGROUND: L-Tyrosine (L-Tyr) is a significant aromatic amino acid that is experiencing an increasing demand in the market due to its distinctive characteristics. Traditional production methods exhibit various limitations, prompting researchers to place greater emphasis on microbial synthesis as an alternative approach. RESULTS: Here, we developed a metabolic engineering-based method for efficient production of L-Tyr from Corynebacterium crenatum, including the elimination of competing pathways, the overexpression of aroB, aroD, and aroE, and the introduction of the mutated E. coli tyrAfbr gene for elevating L-Tyr generation. Moreover, the mtlR gene was knocked out, and the mtlD and pfkB genes were overexpressed, allowing C. crenatum to produce L-Tyr from mannitol. The L-Tyr production achieved 6.42 g/L at a glucose-to-mannitol ratio of 3:1 in a shake flask, which was 16.9% higher than that of glucose alone. Notably, the L-Tyr production of the fed-batch fermentation was elevated to 34.6 g/L, exhibiting the highest titers among those of C. glutamicum previously reported. CONCLUSION: The importance of this research is underscored by its pioneering application of mannitol as a carbon source for the biosynthesis of L-Tyr, as well as its examination of the influence of mannitol-associated genes in microbial metabolism. A promising platform is provided for the production of target compounds that does not compete with human food source.

Incidence and risks of excessive distension absorption in hysteroscopic surgery using 5% mannitol solution: a retrospective descriptive study.

OBJECTIVE: To clarify the incidence of excessive distension absorption in hysteroscopic surgery using 5% mannitol solution, evaluate the associated risks, and help to establish a safe fluid deficit threshold for such complication. DESIGN: Retrospective descriptive study. SETTING: Academic medical center. PATIENTS: Ten thousand six hundred ninety-three patients underwent inpatient hysteroscopic surgery with 5% mannitol perfusion using a monopolar electrosurgical instrument from Jan. 2015 to Sep. 2020. INTERVENTION(S): None. This study has been approved by the Ethics Committee of Sun Yat-sen Memorial Hospital. MEASUREMENTS AND MAIN RESULTS: A fluid deficit of more than 1000 mL was defined as the diagnostic criteria for excessive distension absorption. The overall incidence of excessive distension absorption in this study was 0.46% (49/10693). The incidence was 2.57% (16/623) for transcervical resection of fibroid (TCRF), 2.36% (9/381) for retained products of conception (RPOC) removal, 1.20% (6/501) for hysteroscopic uterine septum resection (HSR), 0.48% (4/828) for transcervical resection of the endometrium (TCRE), and 0.53% (14/2621) for transcervical resections of adhesion (TCRA). Excessive distension absorption could occur within seven minutes in HSR. Among the patients diagnosed with excessive distension absorption, 30.77% (12/39) exhibited signs or symptoms related to circulation overload with a fluid deficit under 2500 mL, and 10.26% (4/39) developed pulmonary edema. CONCLUSION: Excessive distension absorption could happen in all kinds hysteroscopic surgical treatment including RPOC removal and TCRA which were rarely reported. The overall incidence of excessive distension absorption could be low. But it would be five times higher in certain procedures such as TCRF, RPOC removal and TCRA. Resection using a needle electrode in HSR and TCRA may contribute to the short time development of excessive distension absorption. 30.77% of the patients could not tolerate the fluid deficit of less than 2500 mL which was set as a threshold for isotonic distending media and presented with circulation overload related signs or symptoms.

Role of Preservation Solution in Human Aneurysmatic Aorta Harvest and Transport: A Comparative Analysis of Different Solutions for Tissue Injury Protection.

INTRODUCTION: Human aortic tissues in vitro are tools to clarify the pathophysiological mechanisms of the cardiovascular system, cell culture, and transplants. Therefore, this study aims to analyze and compare the preservation of human aneurysmatic aortic tissues in three different solutions. METHODS: Six human abdominal aortic aneurysms were obtained from patients after surgical ablation. The aorta samples were incubated in different solutions - 0.9% normal physiological saline solution, Ringer's lactate solution, and histidine-tryptophan-ketoglutarate solution (Custodiol®). Segments were collected at 0, 6, 24, and 48 hours. Creatine kinase and nitrate/nitrite were quantified for each incubation time. The tissue's alpha-smooth muscle actin was analyzed by immunofluorescence. RESULTS: There was a significant increase in creatine kinase formation in the normal saline group at 0 and 48 hours and in the Ringer's lactate group at 0 and 48 hours (P=0.018 and P=0.028). The lower levels of creatine kinase and nitrate/nitrite and the aortic tissues' morphological integrity show that histidine-tryptophan-ketoglutarate has better tissue protection. These data suggest that histidine-tryptophan-ketoglutarate induces a protective effect on smooth muscle cells, with less tissue depletion in the aortic aneurysm. CONCLUSION: This study compared three preservation solutions with the potential for human abdominal aortic aneurysm tissue preservation. The histidine-tryptophan-ketoglutarate solution reduced tissue injury and improved tissue preservation in human abdominal aortic aneurysm tissue samples.

UROPOT: study protocol for a randomized, double-blind phase I/II trial for metabolism-based potentiation of antimicrobial prophylaxis in the urological tract.

BACKGROUND: Urinary tract catheters, including Double-J or ureteral stents, are prone to bacterial colonization forming biofilms and leading to asymptomatic bacteriuria. In the context of asymptomatic bacteriuria, endourological procedures causing mucosa-inducing lesions can lead to severe infections. Antibiotic prophylaxis is warranted, yet its efficacy is limited by biofilm formation on stents. Biofilms promote antibiotic tolerance, the capacity of genetically susceptible bacteria to survive a normally lethal dose of antimicrobial therapy. The UROPOT study evaluates the effectiveness of a first-in-type metabolism-based aminoglycoside potentiation for (i) preventing infectious complications of asymptomatic bacteriuria during mucosa lesion-inducing endourological procedures and (ii) assessing its anti-tolerance efficacy. METHODS: The UROPOT trial is a phase I/II single-center (Lausanne University Hospital (CHUV), Switzerland) randomized double-blinded trial. Over 2 years, patients with asymptomatic Escherichia coli and/or Klebsiella pneumoniae bacteriuria, undergoing endourological procedures, will be randomly allocated to one of three treatment arms (1:1:1 randomization ratio, 30 patients per group) to evaluate the efficacy of mannitol-potentiated low-dose amikacin compared to established standard treatments (ceftriaxone or amikacin standard dose). Patients will be recruited at the CHUV Urology Outpatient Clinic. The primary outcome is the comparative incidence of postoperative urinary tract infections (assessed at 48 h) between the investigational amikacin/mannitol therapy and standard (ceftriaxone or amikacin) antibiotic prophylaxis, defined by specific systemic symptoms and/or positive blood and/or urine culture. Secondary outcomes include assessing microbiological eradication through anti-biofilm activity, sustained microbiological eradication, and mannitol and antibiotics pharmacokinetics in blood and urine. Safety outcomes will evaluate the incidence of adverse events following amikacin/mannitol therapy and postoperative surgical complications at postoperative day 14. DISCUSSION: UROPOT tests a novel antimicrobial strategy based on "metabolic potentiation" for prophylaxis enabling aminoglycoside dose reduction and targeting biofilm activity. The anti-biofilm effect may prove beneficial, particularly in patients who have a permanent stent in situ needing recurrent endourological manipulations strategies in preventing infections and achieving sustained microbiological eradication in pre-stented patients. TRIAL REGISTRATION: The protocol is approved by the local ethics committee (CER-VD, 2023-01369, protocole 2.0) and the Swiss Agency for Therapeutic Products (Swissmedic, 701,676) and is registered on the NIH's ClinicalTrials.gov (trial registration number: NCT05761405). Registered on March 07, 2023.

How carbon sources drive cellulose synthesis in two Komagataeibacter xylinus strains.

Bacterial cellulose synthesis from defined media and waste products has attracted increasing interest in the circular economy context for sustainable productions. In this study, a glucose dehydrogenase-deficient Δgdh K2G30 strain of Komagataeibacter xylinus was obtained from the parental wild type through homologous recombination. Both strains were grown in defined substrates and cheese whey as an agri-food waste to assess the effect of gene silencing on bacterial cellulose synthesis and carbon source metabolism. Wild type K2G30 boasted higher bacterial cellulose yields when grown in ethanol-based medium and cheese whey, although showing an overall higher D-gluconic acid synthesis. Conversely, the mutant Δgdh strain preferred D-fructose, D-mannitol, and glycerol to boost bacterial cellulose production, while displaying higher substrate consumption rates and a lower D-gluconic acid synthesis. This study provides an in-depth investigation of two K. xylinus strains, unravelling their suitability for scale-up BC production.

Mitigating Cold Ischemic Injury: HTK, UW and IGL-2 Solution's Role in Enhancing Antioxidant Defence and Reducing Inflammation in Steatotic Livers.

Liver transplantation remains the only definitive treatment for end-stage liver diseases. However, the increasing prevalence of fatty liver disease among potential donors exacerbates the shortage of suitable organs. This study evaluates the efficacy of the preservation solution Institut Georges Lopez-2 (IGL-2) compared to Histidine-Tryptophan-Ketoglutarate (HTK) and University of Wisconsin (UW) preservation solutions in mitigating ischemia-reperfusion injury (IRI) in steatotic livers. Using Zucker Obese rat livers, we assessed the impact of 24-h static cold storage (SCS) with each solution on transaminase release, glutathione redox balance, antioxidant enzyme activity, lipoperoxidation, and inflammation markers. IGL-2 and UW solutions demonstrated reduced transaminase and lactate levels compared to HTK, indicating better preservation of liver integrity. IGL-2 maintained a higher reduced glutathione/oxidized glutathione (GSH/GSSG) ratio, suggesting more effective management of oxidative stress. Antioxidant enzyme activities catalase, superoxide dismutase, and glutathione peroxidase (CAT, SOD, GPX) were higher in IGL-2 preserved livers, contributing to decreased oxidative damage. Lipid peroxidation markers and inflammatory markers were lower in IGL-2 than in HTK, indicating reduced oxidative stress and inflammation. Additionally, improved mitochondrial function was observed in the IGL-2 group, correlating with reduced reactive oxygen species (ROS) production and lipid peroxidation. These findings suggest that IGL-2 offers superior preservation of liver viability, reduces oxidative stress, and minimizes inflammation compared to HTK and UW solutions. By maintaining a higher ratio of reduced glutathione and antioxidant enzyme activity, IGL-2 effectively mitigates the harmful effects of ischemia-reperfusion injury. The reduced lipid peroxidation and inflammation in the IGL-2 group further underscore its potential in improving liver transplant outcomes. These results highlight the importance of optimizing preservation solutions to enhance the viability and functionality of donor organs, potentially expanding the donor pool and improving the success rates of liver transplantation. Future research should focus on refining preservation techniques and exploring additional protective agents to further improve organ preservation and transplant outcomes.

Comparison of routine del Nido cardioplegia vs two types of modified del Nido cardioplegias for myocardial protection among patients undergoing coronary artery bypass grafting (CABG) surgeries: A randomized double-blind clinical trial.

BACKGROUND: The del Nido cardioplegia solution is a widely used method for myocardial protection in various settings. However, there is limited evidence of its effectiveness in adult cardiac surgery, and the baseline solution, Plasma Lyte A, is not readily available, leading to the use of alternative baseline solutions. This study aims to investigate the effectiveness of routine del Nido cardioplegia in adult cardiac surgery and the impact of different baseline solutions on myocardial protection and other perioperative outcomes. METHODS: This study was a prospective, double-blind randomized parallel group clinical trial conducted at a single tertiary care hospital in Iran. A total of 187 adult patients were evaluated for eligibility, of which 120 met the inclusion criteria for elective isolated CABG surgery. The patients were randomly assigned to three groups, with each group consisting of 40 patients. The control group received a normal saline-based routine del Nido cardioplegia, Intervention Group A received Ringer lactate-based del Nido cardioplegia, and Intervention Group B received plain Ringer-based del Nido cardioplegia. The levels of Creatine Kinase-MB (CK-MB), Troponin T, Troponin I, and lactate were primarily assessed at four different times: after anesthesia induction (Baseline), 2 h, 12 h, and 24 h. RESULTS: Preoperative demographic and clinical characteristics were the same among groups with insignificant differences (p > 0.05). There was no significant difference among groups based on CK-MB, Troponin T, Troponin I, and lactate levels (p = 0.078, 0.143, 0.311, and 0.129 respectively). However, there was a significant difference in the time effect of Troponin T and Lactate (p = 0.034, p = <0.001). CONCLUSION: Normal saline, Ringer lactate, and plain Ringer provide comparable myocardial protection in adult-isolated CABG surgery with modified del Nido cardioplegia. Larger studies are needed to identify the best alternative to Plasma Lyte A while maintaining del Nido cardioplegia as the control.

Development of a Short-Term Embolic Agent Based on Cilastatin for Articular Microvessels.

Background and Objectives: This study aimed to develop an embolic agent with short-term embolic effects using cilastatin as the basic material. Materials and Methods: The particle size distribution of 25 mg cilastatin-based short-term embolic agents was evaluated microscopically under three different mixing conditions. A total of thirty-six healthy male Sprague Dawley rats were divided into four groups. Each group of six rats was injected once into the tail artery with 0.4 mL each of (A) Cilastatin + D-Mannitol Mixture, (B) Iohexol, (C) Prepenem, and (D) embolization promoter (EGgel). Results: A visual inspection of the tail appearance of rats in each group was performed at 0, 3, 7, 15, and 21 days. At weeks 1 and 3, three rats per group were euthanized, and histopathological analyses were performed on the specimens obtained from each group. No significant differences were observed on day 7, but mild inflammation was observed in Group (D) on day 15. Histopathological inflammation scoring of tail central artery embolization was performed using a six-point scale (from 0 = absent to 5 = marked inflammation). Three groups were formed consisting of six male New Zealand white rabbits each: control, positive control, and test groups. The control group received an Iohexol injection (rabbits: 0.8 mL). The positive control and experimental groups were injected with prepenem and cilastatin/D-mannitol compound, respectively (0.8 mL), and vascular angiography was performed. The order of occlusion progression after embolization was as follows: test group, positive control group, and control group. Conclusions: We developed a cilastatin/D-mannitol compound that exhibits characteristics of short-term embolization by utilizing the pharmacokinetic properties of cilastatin and the crystalline material D-mannitol. We evaluated its particle size distribution microscopically, conducted histopathological evaluation including inflammation via animal experiments, and assessed the embolization effect.

Effectiveness of Mannitol Use on Clinical Outcomes of Severe Traumatic Brain Injury Patients.

Background: Head injuries are considered as a silent epidemic due to the high incidence rate throughout the world. The main cause of morbidity and mortality in patients with head injury is cerebral edema which is defined as abnormal fluid accumulation in the brain parenchyma. Mannitol is a hyperosmolar solution given to reduce fluid volume in the brain. Increased high intracranial pressure can affect prognosis and can be evaluated by assessing clinical outcomes in patients with severe traumatic brain injury using the Glasgow Outcome Discharge Scale (GODS) instrument. Methods: Observational analytical study with a cross sectional design on 50 patients with severe traumatic brain injury at dr. Zainoel Abidin General Hospital Banda Aceh to determine the effect of mannitol use on the clinical outcomes of severe traumatic brain injury patients which used t test analysis. Results: The mean value of the group that received mannitol had a higher GODS score than the group that did not receive mannitol. The results of the T test between groups obtained a p value of 0.000 which is smaller than 0.05, so it can be concluded that the use of mannitol has an effect on the GODS score in Severe traumatic brain injury patients. The results showed that the mean GODS value in patients who received mannitol was higher than those who did not receive mannitol. Conclusion: This concludes that the administration of mannitol is effective in improving the clinical outcomes of patients with severe traumatic brain injury at dr. Zainoel Abidin General Hospital Banda Aceh.

Formulation of protein-loaded nanoparticles via freeze-drying.

Several nanotechnology-based formulation strategies have been reported for the oral administration of biological drugs. However, a prerequisite often overlooked in developing these formulations is their adaptation to a solid dosage form. This study aimed to incorporate a freeze-drying step, using either mannitol or sucrose laurate (SLAE), into the formulation of new insulin-zinc nanocomplexes to render them resistant to intestinal fluids while maintaining a high protein loading. The resulting freeze-dried insulin-zinc nanocomplexes exhibited physicochemical properties consistent with the target product profile, including a particle size of ∼ 100 nm, a zeta potential close to neutrality (∼ -15 mV) and a high association efficiency (> 90%). Importantly, integrating the freeze-drying step in the formulation significantly improved the colloidal stability of the system and preserved the stability of the insulin molecules. Results from in vitro and in vivo studies indicated that the insulin activity remained fully retained throughout the entire formulation and freeze-drying processes. In brief, we present a novel protein formulation strategy that incorporates a critical freeze-drying step, resulting in a dry powder enabling efficient protein complexation with zinc and optimized for oral administration.

Assessment of Mannitol-Induced Chronic Blood-Brain Barrier Dysfunction In Vivo Using Magnetic Resonance.

The blood-brain barrier (BBB) is essential for protection and plays a crucial role in chronic neurological disorders like small-vessel disease and Alzheimer's disease. Its complexity poses significant challenges for effective diagnostics and treatments, highlighting the need for novel animal models and comprehensive BBB dysfunction studies. This study investigates chronic BBB dysfunction induction using osmotic disruption via mannitol in healthy adult male Sprague Dawley rats over 12 weeks. Group 1 received 1 bolus/week (2.0 g/kg), Group 2 received 3 boluses/week (1.5 g/kg), and Group 3 received 3 boluses/week (2.5 g/kg). BBB dysfunction was assessed using gadolinium (Gd) infusion and MRI to evaluate location, severity, evolution, and persistence. MR spectroscopy (MRS) examined the brain metabolism changes due to intravenous mannitol, with T2-weighted MRI assessing brain lesions. Biomarkers of neuroinflammation were analyzed in the highest mannitol dose group. Our data show chronic BBB dysfunction primarily in the cortex, hippocampus, and striatum, but not in the corpus callosum of rats under periodic mannitol dosing in groups 1 and 2. MRS identified a distinctive metabolite signature, including changes in alanine, choline, and N-acetyl aspartate in the striatum of Group 1. No significant differences were found in the serum levels of all pro- and anti-inflammatory cytokines analyzed in the high-dose Group 3. This study underscores the feasibility and implications of using osmotic disruption to model chronic BBB dysfunction, offering insights for future neuroprotection and therapeutic strategies research.

Recent advances in Del Nido cardioplegia: A comprehensive analysis of randomized clinical trials in adult cardiac surgery.

BACKGROUND: Del Nido cardioplegia (DNC) has extensively been used for pediatric population undergoing cardiac surgery. However, its use in adult cardiac surgeries have been limited thus, its benefits are not yet fully known. This analysis was performed to evaluate the impact of DNC versus any other type of cardioplegia in adult patients who are undergoing cardiac surgery. METHODS: We systematically searched PubMed, Cochrane Library, and Scopus from database inception till March 2023, and moderate to high-quality randomized controlled trials were included which compared DNC to other cardioplegia. The primary outcome was postoperative stroke and/or transient ischemic attack (TIA). Secondary outcomes included spontaneous rhythm return, postoperative myocardial infarction, all-cause mortality, postoperative atrial fibrillation, defibrillation after coronary reperfusion, postoperative intra-aortic balloon pump, postoperative kidney injury, postoperative low cardiac output syndrome, inotropic support, cardiopulmonary bypass time, cross-clamp time, blood transfusion, cardioplegia volume, hospital stay, intensive care unit stay, mechanical ventilation stay, postoperative left ventricular ejection fraction, and cardiac markers. RESULTS: In this meta-analysis, 13 studies were included with a patient population of 2207. Stroke and/or TIA studies (risk ratio [RR]: 0.54, 95% CI [0.29, 1.00]) and all-cause mortality studies (RR: 1.30, 95% CI [0.66, 2.56]) were insignificant. From the secondary outcomes, spontaneous rhythm return (RR: 1.58, 95% CI [1.02, 2.45]), defibrillation after coronary reperfusion (RR: 0.49, 95% CI [0.30, 0.79]), inotropic support (RR: 0.70, 95% CI [0.57, 0.85]), composite risk of stroke and/or TIA and/or acute kidney injury and mortality (RR: 0.72, 95% CI [0.53, 0.99]), cross-clamp time (mean difference [MD]: -6.01, 95% CI [-11.14, -0.89]), blood transfusion (RR: 0.73, 95% CI [0.60, 0.90]), cardioplegia volume (MD: -537.17, 95% CI [-758.89, -315.45]), troponin T (MD: -1.71, 95% CI [-2.11, -1.32]), creatine phosphokinase-MB (MD: -2.96, 95% CI [-5.84, -0.07]) were significant. Whereas all other secondary outcomes were found to be insignificant. CONCLUSION: No significant difference was observed between patients undergoing Del Nido administration in comparison to other cardioplegia solutions for the primary outcome, stroke or/and TIA.

Effect of processing and formulation factors on Catalase activity in tablets.

The manufacturing of tablets containing biologics exposes the biologics to thermal and shear stresses, which are likely to induce structural changes (e.g., aggregation and denaturation), leading to the loss of their activity. Saccharides often act as stabilizers of proteins in formulations, yet their stabilizing ability throughout solid oral dosage processing, such as tableting, has been barely studied. This work aimed to investigate the effects of formulation and process (tableting and spray-drying) variables on catalase tablets containing dextran, mannitol, and trehalose as potential stabilizers. Non-spray-dried and spray-dried formulations were prepared and tableted (100, 200, and 400 MPa). The enzymatic activity, number of aggregates, reflecting protein aggregation and structure modifications were studied. A principal component analysis was performed to reveal underlying correlations. It was found that tableting and spray-drying had a notable negative effect on the activity and number of aggregates formed in catalase formulations. Overall, dextran and mannitol failed to preserve the catalase activity in any unit operation studied. On the other hand, trehalose was found to preserve the activity during spray-drying but not necessarily during tableting. The study demonstrated that formulation and process variables must be considered and optimized together to preserve the characteristics of catalase throughout processing.

Effect of mannitol on postoperative delirium in patients undergoing coronary artery bypass graft: a randomised controlled trial.

OBJECTIVE: Postoperative delirium (POD), especially after cardiac surgery with cardiopulmonary bypass (CPB), is a relatively common and severe complication increasing side effects, length of hospital stay, mortality and healthcare resource costs. This study aimed to determine the impact of using mannitol serum in the prime of CPB for preventing the occurrence of delirium in patients undergoing coronary artery bypass surgery. METHODS: This study is a single-centre, double-blinded, randomised, controlled trial that was conducted from December 2022 to May 2023. Patients in the age range of 18-70 who underwent elective coronary artery bypass surgery were included in the study. In the control group (n=45), the prime solution included Ringer's lactate serum. In the intervention group (n=45), the prime solution consisted of 200 mL mannitol serum and Ringer's lactate serum. The primary outcome of the study was the incidence of POD. Secondary outcomes included the duration of mechanical ventilation, length of stay in the intensive care unit (ICU) and 30-day in-hospital mortality. RESULTS: There were no statistically significant differences in demographic characteristics and risk factors between the control and intervention groups (p<0.05). However, the incidence of POD was significantly lower in the intervention group compared with the control group (22.25% vs 42.2%, p=0.035). There were no significant differences between the two groups regarding CPB time, aortic cross-clamp time, duration of mechanical ventilation and length of stay in ICU (p<0.05). Additionally, mortality rates and rates of return to the operating room did not differ significantly between the two groups (p<0.05). CONCLUSIONS: This study concluded that adding mannitol to the prime of CPB pump can help reduce the incidence of delirium after cardiac surgery. TRIAL REGISTRATION NUMBER: IRCT20221129056660N1.

Prolongation of the Time Window From Traumatic Limb Amputation to Replantation From 6 to 33 Hours Using Ex Vivo Limb Perfusion.

INTRODUCTION: Continuous extracorporeal perfusion (ECP), or machine perfusion, holds promise for prolonged skeletal muscle preservation in limb ischemia-reperfusion injury. This study aimed to extend the amputation-to-replantation time window from currently 6 hours to 33 hours using a 24-hour ECP approach. MATERIALS AND METHODS: Six large white pigs underwent surgical forelimb amputation under general anesthesia. After amputation, limbs were kept for 9 hours at room temperature and then perfused by 24-hour ECP with a modified histidine-tryptophan-ketoglutarate (HTK) solution. After ECP, limbs were orthotopically replanted and perfused in vivo for 12 hours. Clinical data, blood, and tissue samples were collected and analyzed. RESULTS: All 6 forelimbs could be successfully replanted and in vivo reperfused for 12 hours after 9 hours of room temperature ischemia followed by 24 hours ECP. Adequate limb perfusion was observed after replantation as shown by thermography and laser Doppler imaging. All pigs survived without severe organ failure, and no significant increase in inflammatory cytokines was found. Macroscopy and histology showed marked interstitial muscular edema of the limbs, whereas myofiber necrosis was not evident, implying the preservation of muscular integrity. CONCLUSIONS: The use of a 24-hour ECP has successfully extended limb preservation to 33 hours. The modified histidine-tryptophan-ketoglutarate perfusate demonstrated its ability for muscle protection. This innovative approach not only facilitates limb replantation after combat injuries, surmounting geographical barriers, but also broadens the prospects for well-matched limb allotransplants across countries and continents.

[Recent advances in the bioproduction of mannitol].

D-mannitol is a six-carbon sugar alcohol and one of the most abundant polyols in the nature. With antioxidant and osmotic pressure-regulating effects and non-metabolism by the human body, D-mannitol has been widely used in functional food and pharmaceutical industries. At present, a major way for industrial production of D-mannitol is chemical hydrogenation. In addition, D-Mannitol can be produced by microbial metabolism or catalysis. Compared with the chemical hydrogenation, the microbial methods for synthesizing mannitol do not produce sorbitol as a by-product and have the advantages of mild reaction conditions, strong specificity, and high conversion rate. Microbial fermentation is praised for easy access of strains and raw materials and simple separation of the product. Microbial catalysis usually adopts a multi-enzyme coupling strategy, which uses enzymes produced by engineered bacteria for whole-cell catalysis, and the cofactor recycling pathway is introduced to replenish expensive cofactor. This method can achieve high yields with cheap substrates under mild conditions without the formation of by-products. However, the application of microbial methods in the industrial production of D-mannitol is limited by the high costs of fermentation media and substrates and the long reaction time. This article reviews the reported microbial methods for producing D-mannitol, including the use of high-yielding strains and their fermentation processes, the utilization of low-cost substrates, whole-cell catalytic strategies, and the process control for high productivity. The biosynthesis of mannitol is not only of great significance for promoting industrial upgrading and realizing green manufacturing, but also provides strong support for the development of new bio-based products to meet the growing market demand. With the continuous improvement of technological innovation and industrial chain, it is expected to become one of the main ways of mannitol production in the future.

Mannitol as a Growth Substrate for Facultative Methylotroph Methylobrevis pamukkalensis PK2.

Biochemistry of carbon assimilation in aerobic methylotrophs growing on reduced C1 compounds has been intensively studied due to the vital role of these microorganisms in nature. The biochemical pathways of carbon assimilation in methylotrophs growing on multi-carbon substrates are insufficiently explored. Here we elucidated the metabolic route of mannitol assimilation in the alphaproteobacterial facultative methylotroph Methylobrevis pamukkalensis PK2. Two key enzymes of mannitol metabolism, mannitol-2-dehydrogenase (MTD) and fructokinase (FruK), were obtained as His-tagged proteins by cloning and expression of mtd and fruK genes in Escherichia coli and characterized. Genomic analysis revealed that further transformation of fructose-6-phosphate proceeds via the Entner-Doudoroff pathway. During growth on mannitol + methanol mixture, the strain PK2 consumed both substrates simultaneously demonstrating independence of C1 and C6 metabolic pathways. Genome screening showed that genes for mannitol utilization enzymes are present in other alphaproteobacterial methylotrophs predominantly capable of living in association with plants. The capability to utilize a variety of carbohydrates (sorbitol, glucose, fructose, arabinose and xylose) suggests a broad adaptability of the strain PK2 to live in environments where availability of carbon substrate dynamically changes.

Urinary excretion of gluten immunoreactive peptides as an indicator of gastrointestinal function after fasting and dietary provocation in healthy volunteers.

Introduction: Understanding intestinal permeability is paramount for elucidating gastrointestinal health and pathology. The size and nature of the molecule traversing the intestinal barrier offer crucial insights into various acute and chronic diseases, as well as the evolution of some conditions. This study aims to assess the urinary excretion kinetics of gluten immunogenic peptides (u-GIP), a unique class of dietary peptides detectable in urine, in volunteers under controlled dietary conditions. This evaluation should be compared to established probes like lactulose, a non-digestible disaccharide indicative of paracellular permeability, and mannitol, reflecting transcellular permeability. Methods: Fifteen participants underwent simultaneous ingestion of standardized doses of gluten (10 g), lactulose (10 g), and mannitol (1 g) under fasting conditions for at least 8 hours pre-ingestion and during 6 hours post-ingestion period. Urine samples were collected over specified time intervals. Excretion patterns were analyzed, and correlations between the lactulose-to-mannitol ratio (LMR) and u-GIP parameters were assessed. Results: The majority of u-GIP were detected within the first 12 hours post-ingestion. Analysis of the variability in cumulative excretion across two sample collection ranges demonstrated that lactulose and u-GIP exhibited similar onset and excretion dynamics, although GIP reached its maximum peak earlier than either lactulose or mannitol. Additionally, a moderate correlation was observed between the LMR and u-GIP parameters within the longest urine collection interval, indicating potential shared characteristics among permeability pathways. These findings suggest that extending urine collection beyond 6 hours may enhance data reliability. Discussion: This study sheds light on the temporal dynamics of u-GIP in comparison to lactulose and mannitol, established probes for assessing intestinal permeability. The resemblance between u-GIP and lactulose excretion patterns aligns with the anticipated paracellular permeability pathway. The capacity to detect antigenic food protein fragments in urine opens novel avenues for studying protein metabolism and monitoring pathologies related to the digestive and intestinal systems.