Del nido cardioplegia in adults: a retrospective observational study in comparison to modified St. Thomas cardioplegia in cardiac surgery

BACKGROUND

St. Thomas cardioplegia is commonly administered to adults, yet repeated dosing at brief intervals is required. Del Nido's cardioplegic solution provides a prolonged duration of safe myocardial arrest, yet it was primarily intended for pediatric cardiac surgery. Recently, there has been an increasing interest in using Del Nido's in adults; this might be due to its ease of administration and extended re-dosing intervals. This study contrasted Del Nido's to modified St. Thomas cardioplegia in adults.

METHODS

This study was conducted on 200 patients. Troponin-T was the primary outcome within the first 24 and 48 h post-surgery. Cardiopulmonary bypass time, cross-clamp time, intraoperative use of inotropic support, defibrillator and/or intra-aortic balloon were the secondary outcomes of the study.

RESULTS

There was a significant reduction in post-operative Troponin-T levels in the first 24 and 48 h within Del Nido's group compared to the modified St. Thomas group. The cross-clamp and cardiopulmonary bypass times were also found to be lower within Del Nido's group.

CONCLUSION

This study has demonstrated a significant reduction in early postoperative Troponin-T levels as well as operative times favoring Del Nido's in adults.

Cord-Blood Derived Chemistry Reference Values in Preterm Infants for Sodium, Chloride, Potassium, Glucose, and Creatinine

OBJECTIVE

 International guidelines recommend that preterm infants should be supported to maintain their serum electrolytes within "normal" ranges. In term babies, cord blood values differed in pathological pregnancies from healthy ones.

STUDY DESIGN

 We examined cord blood sodium, chloride, potassium, glucose, and creatinine to derive maturity-related reference intervals. We examined associations with gestational age, delivery mode, singleton versus multiple, and prenatal maternal adverse conditions. We compared preterm cord values to term, and to adult reference ranges.

RESULTS

 There were 591 infants, 537 preterm and 54 term. Preterm cord glucose levels were steady (3.7 ± 1.1 mmol/L), while sodium, chloride, and creatinine increased over GA by 0.17, 0.14 mmol/L/week, and 1.07 µmol/L/week, respectively (p < 0.003). Average preterm cord potassium and chloride were higher than the term (p < 0.05). Compared with adult reference intervals, cord preterm reference intervals were higher for chloride (100-111 vs. 98-106 mmol/L), lower for creatinine (29-84 vs. 62-115 µmol/L), and more variable for potassium (2.7-7.9 vs. 3.5-5.0 mmol/L) and sodium (130-141 vs. 136-145 mmol/L). Cesarean section was associated with higher potassium and lower glucose, multiple births with higher chloride and creatinine and lower glucose, and SGA with lower glucose.

CONCLUSION

 Cord blood values varied across the GA range with increases in sodium, chloride, and creatinine, while glucose remained steady. Average preterm reference values were higher than term values for potassium and chloride. Preterm reference values differed from published adults' reference values. The changes across GA and by delivery mode, SGA, and being a multiple, which may have direct implications for neonatal care and fluid management.

KEY POINTS

· Cord blood electrolyte, creatinine, and glucose values vary across neonatal gestational age.. · Average preterm cord values of potassium and chloride were higher than term values.. · Cord reference values differ by delivery mode, growth, and multiple impacting neonatal care decisions..

A propensity score matched analysis of liver transplantation outcomes in the setting of preservation solution shortage

The recent shortage of the University of Wisconsin (UW) solution prompted increased utilization of histidine-tryptophan-ketoglutarate (HTK) solution for liver graft preservation. This contemporary study analyzed deceased donor liver transplant outcomes following preservation with HTK vs UW. Patients receiving deceased donor liver transplantations between January 1, 2019, and June 30, 2022, were retrospectively identified utilizing the Organ Procurement and Transplant Network database, stratified by preservation with HTK vs UW, and a propensity score matching analysis was performed. Outcomes assessed included rates of primary nonfunction, graft survival, and patient survival. There were 4447 patients in each cohort. Primary nonfunction occurred in 60 (1.35%) patients in the HTK group vs 25 (0.54%) in the UW group (P < .001). HTK was associated with lower 90-day graft survival (94.39% vs 96.09%; P < .001) and 90-day patient survival (95.97% vs 97.38%; P = .001). Unmatched donation after cardiac death-specific analysis of HTK vs UW demonstrated respective rates of primary nonfunction of 1.63% vs 0.82% (P = .20), 90-day graft survival of 92.50% vs 95.29% (P = .069), and 90-day patient survival of 93.90% vs 96.35% (P = .077). These results suggest that HTK may not be an equivalent preservation solution for deceased donor liver transplantation.

Comparing a range of potassium-enriched low sodium salt substitutes to common salt: Results of taste and visual tests in South African adults

BACKGROUND AND AIMS

Potassium-enriched low sodium salt substitutes (LSSS), which replace a proportion of sodium chloride (NaCl) with potassium chloride (KCl), have been shown to reduce blood pressure and offer a potential solution to address the high burden of hypertension in South Africa. However, it is unknown which proportions of KCl in LSSS are acceptable. We compared the taste and visual acceptability of various LSSS in South African adults.

METHODS AND RESULTS

Fifty-six adults underwent double-blind taste and visual tests of four LSSS (35%KCl/65%NaCl; 50%KCl/50%NaCl; 66%KCl/34%NaCl; 100%KCl) in comparison to 100%NaCl (common salt). Participants scored each product by taste ranking, taste perception and likeliness to use. Participants then visually inspected the five products and attempted to identify which was which. Almost half (45 %) of participants ranked the taste of 50%KCl/50 %NaCl as fantastic or really good. Furthermore, 62 % of participants liked and would be happy to use the 50 %KCl/50 %NaCl or felt this tasted like common salt. Only 12 % rated the 100%KCl highly for taste, and over half reported being unlikely to use this. Most participants (57.3 % and 36.4 %) were able to visually identify 100%NaCl and 100%KCl, while identification of other blends was generally poor. Responses were similar for 35%KCl/65%NaCl and 66%KCl/34%NaCl throughout.

CONCLUSION

Our findings suggest that the taste of the 50%KCl salt substitute would be well tolerated by South African adults, most of which could not visually differentiate between this salt substitute and common salt.

Potassium-Enriched Salt Substitutes: A Review of Recommendations in Clinical Management Guidelines

Excess dietary sodium intake and insufficient dietary potassium intake are both well-established risk factors for hypertension. Despite some successful initiatives, efforts to control hypertension by improving dietary intake have largely failed because the changes required are mostly too hard to implement. Consistent recent data from randomized controlled trials show that potassium-enriched, sodium-reduced salt substitutes are an effective option for improving consumption levels and reducing blood pressure and the rates of cardiovascular events and deaths. Yet, salt substitutes are inconsistently recommended and rarely used. We sought to define the extent to which evidence about the likely benefits and harms of potassium-enriched salt substitutes has been incorporated into clinical management by systematically searching guidelines for the management of hypertension or chronic kidney disease. We found incomplete and inconsistent recommendations about the use of potassium-enriched salt substitutes in the 32 hypertension and 14 kidney guidelines that we reviewed. Discussion among the authors identified the possibility of updating clinical guidelines to provide consistent advice about the use of potassium-enriched salt for hypertension control. Draft wording was chosen to commence debate and progress consensus building: strong recommendation for patients with hypertension-potassium-enriched salt with a composition of 75% sodium chloride and 25% potassium chloride should be recommended to all patients with hypertension, unless they have advanced kidney disease, are using a potassium supplement, are using a potassium-sparing diuretic, or have another contraindication. We strongly encourage clinical guideline bodies to review their recommendations about the use of potassium-enriched salt substitutes at the earliest opportunity.

Anesthesia and humane euthanasia methods for king worm larvae (Zophobas morio)

A growing spotlight on insect welfare as research subjects, fodder for vertebrate animals, and patients for veterinarians highlights the need to establish humane euthanasia methods for these species. An insect of increasing commercial importance is the king worm (Zophobas morio), a type of darkling beetle larvae. The initial objective of this study was to determine if prolonged exposure to isoflurane would lengthen anesthetic recovery and lead to euthanasia. Larvae were exposed to isoflurane for 10 min, 40 min, 70 min, 190 min, 13 h, and 24 h (n = 10 for each treatment duration group), and time to recovery was subsequently monitored in room air. The second objective was to determine effectiveness of secondary euthanasia methods: injectable potassium chloride at 1 mg/g body weight (n = 5) and 3 mg/g body weight (n = 5) doses; immersion in 200 proof ethanol (n = 10), 10% buffered formalin (n = 10), and water (n = 10); and freezing at -18°C (n = 10). Prolonged exposure to isoflurane led to extended recovery times, but 100% mortality was not achieved. Submersion in ethanol and injection of potassium chloride at a 3 mg/g body weight dose resulted in 100% mortality. If these larvae are to be used as future food sources, a humane euthanasia method that preserves the ability to be consumed is required.

Physical and Chemical Compatibility of Medications Commonly Used in Critically Ill Patients With Balanced Crystalloids: A Systematic Review

OBJECTIVE

Evaluate available evidence of physical and/or chemical compatibility of commonly used medications in critically ill patients with balanced crystalloids.

DATA SOURCES

Ovid MEDLINE, Embase, Cochrane Central Register of Controlled Trials, and Cochrane Database of Systematic Reviews were queried from inception to September 2022.

STUDY SELECTION AND DATA EXTRACTION

This review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. English-language studies reporting physical and/or chemical compatibility data between 50 selected medications and balanced crystalloids were included. A previously designed tool to assess risk of bias was adapted for use.

DATA SYNTHESIS

Twenty-nine studies encompassing 39 (78%) medications and 188 unique combinations with balanced crystalloids were included. Combinations included 35 (70%) medications with lactated Ringer's, 26 (52%) medications with Plasma-Lyte, 10 (20%) medications with Normosol, and one (2%) medication with Isolyte. Studies commonly evaluated physical and chemical compatibility (55.2%). More medications were evaluated via Y-site than admixture. Incompatibilities were identified in 18% of combinations comprising 13 individual drugs.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

This systematic review evaluates the compatibility of select critical care medications with balanced crystalloid solutions. Results may be used as a tool to guide clinicians on balanced crystalloid compatibility, potentially increasing ubiquitous use and reducing patient exposure to normal saline.

CONCLUSION AND RELEVANCE

Data are limited regarding chemical/physical compatibility of commonly used medications in critically ill patients with balanced crystalloids. Additional compatibility studies are warranted, particularly methodologically rigorous studies assessing Plasma-Lyte, Normosol, and Isolyte. Of the evaluated medications, there was a low frequency of incompatibilities with balanced crystalloids.

[Inability of hospital computerised physician order entry systems to secure the use of concentrated potassium intravenous solutions]

OBJECTIVES

To determine whether hospital computerised physician order entry (CPOE) systems contribute to securing intravenous potassium chloride (KCl) prescriptions with reference to the recommendations issued by French healthcare agencies.

METHODS

We sent a questionnaire to the members of the Association pour le Digital et l'Information en Pharmacie.

RESULTS

More than three quarters of the 84 responses received involving 23 CPOE systems indicate that it is possible to: prescribe an ampoule of concentrated potassium chloride 10% 10mL intravenously without any diluents (80%); prescribe 4g of KCl in a bag of 500mL of NaCl 0,9% (98%); prescribe a solution that contains 6 grams of KCl per liter (94%); prescribe the administration of an injectable ampoule orally by means of a free text comment (83%). Nearly half of the responses indicate that it is possible to prescribe: concentrated KCl ampoules as administration solvent (50%); an injectable vial to be administered by oral route (52%).

CONCLUSION

At least 23 hospital CPOE systems are unable to secure the prescriptions of injectable KCl. This finding lifts the veil on an unthought, namely the role of CPOE systems in securing high-risk medications. In order to solve this problem, it should be mandatory that health information technology vendors pay particular attention to these drugs. With regard to injectable KCl, the utilisation of a dilution vehicle, maximum concentration and maximum infusion flow rate are the first four constraints to be satisfied.

Effect of 5% albumin on endothelial glycocalyx degradation during off-pump coronary artery bypass

PURPOSE

The integrity of the endothelial glycocalyx (EG), a critical player in vascular homeostasis, reportedly influences the outcomes of critically ill patients. We investigated the effect of 5% albumin, which preserved EG integrity in preclinical studies, vs balanced crystalloid solution on EG degradation in patients undergoing off-pump coronary surgery.

METHODS

Patients were randomized to receive either 5% albumin (N = 51) or balanced crystalloid solution (Plasma-Lyte [Baxter Incorporated, Seoul, Republic of Korea]; N = 53) for intravenous volume replacement during surgery (double-blinded). The primary outcome was plasma syndecan-1 concentration, a marker of EG degradation, measured after anesthetic induction (baseline), completion of grafting, and sternal closure. Secondary outcomes were atrial natriuretic peptide (ANP), tumour necrosis factor (TNF)-α, soluble thrombomodulin, and perioperative fluid balance.

RESULTS

The mean (standard deviation) fluid requirements were 833 (270) mL and 1,323 (492) mL in the albumin and Plasma-Lyte group, respectively (mean difference, -489 mL; 95% confidence interval [CI], -643 to -335; P < 0.001). Plasma syndecan-1 concentration increased after completion of grafting (median difference, 116 ng·mL-1; 95% CI, 67 to 184; P < 0.001) and sternal closure (median difference, 57 ng·mL-1; 95% CI, 36 to 80; P < 0.001) compared with those at baseline, without any intergroup differences. Atrial natriuretic peptide, TNF-α, and soluble thrombomodulin concentrations were similar between the two groups. The amount of chest tube drainage was greater in the albumin group than that in the Plasma-Lyte group (median difference, 190 mL; 95% CI, 18 to 276; P = 0.03).

CONCLUSION

Off-pump coronary surgery was associated with significant EG degradation. Yet, intraoperative fluid therapy with 5% albumin could not ameliorate EG degradation when compared with balanced crystalloid solution.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT03699462); first posted 9 October 2018.

A pragmatic, open-label, randomized controlled trial of Plasma-Lyte-148 versus standard intravenous fluids in children receiving kidney transplants (PLUTO)

Acute electrolyte and acid-base imbalance is experienced by many children following kidney transplant. This is partly because doctors give very large volumes of artificial fluids to keep the new kidney working. When severe, fluid imbalance can lead to seizures, cerebral edema and death. In this pragmatic, open-label, randomized controlled trial, we randomly assigned (1:1) pediatric kidney transplant recipients to Plasma-Lyte-148 or standard of care perioperative intravenous fluids (predominantly 0.45% sodium chloride and 0.9% sodium chloride solutions). We then compared clinically significant electrolyte and acid-base abnormalities in the first 72 hours post-transplant. The primary outcome, acute hyponatremia, was experienced by 53% of 68 participants in the Plasma-Lyte-148 group and 58% of 69 participants in the standard fluids group (odds ratio 0·77 (0·34 - 1·75)). Five of 16 secondary outcomes differed with Plasma-Lyte-148: hypernatremia was significantly more frequent (odds ratio 3·5 (1·1 - 10·8)), significantly fewer changes to fluid prescriptions were made (rate ratio 0·52 (0·40-0·67)), and significantly fewer participants experienced hyperchloremia (odds ratio 0·17 (0·07 - 0·40)), acidosis (odds ratio 0·09 (0·04 - 0·22)) and hypomagnesemia (odds ratio 0·21 (0·08 - 0·50)). No other secondary outcomes differed between groups. Serious adverse events were reported in 9% of participants randomized to Plasma-Lyte-148 and 7% of participants randomized to standard fluids. Thus, perioperative Plasma-Lyte-148 did not change the proportion of children who experienced acute hyponatremia compared to standard fluids. However fewer fluid prescription changes were made with Plasma-Lyte-148, while hyperchloremia and acidosis were less common.

Cyclosporine A-enhanced cardioplegia preserves mitochondrial basal respiration after ischemic arrest

BACKGROUND

Mitochondrial permeability transition pore (mPTP) opening plays a crucial role in cell death during ischemia-reperfusion injury (IRI). Cyclosporine A (CsA) inhibits mPTP opening. This study aimed to investigate the effects of CsA treatment during cardioplegia on the mitochondrial function and cardiac IRI.

METHODS

Landrace pigs (52.9 ± 3.7 kg) were subjected to midline sternotomy, cardiopulmonary bypass at 34°C and 90 minutes of cardiac arrest. They received either a single shot of standard 4°C cold histidine-tryptophan-α-ketoglutarate (HTK)-Bretschneider solution (n = 11) or HTK-Bretschneider plus 1.2 mg/L CsA (histidine-tryptophan-α-ketoglutarate plus cyclosporine A (HTK/CsA); n = 11). During reperfusion global left-ventricular function was assessed and myocardial biopsies were harvested at baseline, during ischemia and 45 minutes following reperfusion. High-resolution respirometry and hydrogen peroxide production were measured. Immunohistochemical stainings for apoptosis-inducing factor and hypoxia-inducible factor-1α as well as a flow cytometry-based JC-1 mitochondrial membrane potential assay were performed.

RESULTS

Hemodynamic parameters were comparable between both groups. The cytochrome C release (HTK: 930.3 ± 804.4 pg/mg, HTK/CsA: 699.7 ± 394.0 pg/mg, p = 0.457) as well as PGC1α content (HTK: 66.7%, HTK/CsA: 33.3%, p = 0.284) was lower in the HTK/CsA group. Respiratory measurements revealed that the oxygen flux under basal respiration was higher in the HTK/CsA group (8.2 ± 1.3 pmol·O2·s-1·mg-1·ww) than in the HTK group (3.8 ± 1.4 pmol·O2·s-1·mg-1·ww, p = 0.045). There were no significant differences regarding histological surrogates of apoptosis and necrosis.

CONCLUSIONS

Supplementing cardioplegic solutions with CsA enhances the basal mitochondrial respiration thereby exerting a cardioprotective effect and diminishing IRI-induced damage. CsA seems to preserve mitochondrial function via non-ROS related pathways.

Compatibility of Omadacycline With Select Parenteral Products in Simulated Y-site Administration

PURPOSE

Omadacycline is a broad-spectrum intravenous and oral tetracycline antibiotic approved for the treatment of community-acquired bacterial pneumonia and acute bacterial skin and skin structure infections. Available information on the compatibility of intravenous omadacycline is limited to sterile water, 0.9% sodium chloride, and 5% dextrose via a dedicated line. The objective of this work was to determine the intravenous compatibility of omadacycline with commonly used intravenous fluids and medications using simulated Y-site administration.

METHODS

Omadacycline was prepared at concentrations consistent with a maintenance dose (1 mg/mL) and a loading dose (2 mg/mL) with 0.9% sodium chloride according to the prescribing information. Compatibility via simulated Y-site administration was assessed with selected crystalloids (lactated Ringer's solution, magnesium sulfate, and normal saline with potassium chloride) and intravenous medications (bumetanide, furosemide, heparin, and insulin). Y-site administration was simulated by mixing 5 mL of omadacycline with 5 mL of each parenteral product prepared at standard concentrations for infusion. Compatibility was assessed by using visual, Tyndall beam, microscopy, and spectrophotometry methods at 0, 30, and 60 minutes.

FINDINGS

Omadacycline appeared physically compatible with lactated Ringer's solution, magnesium sulfate, normal saline with potassium chloride, bumetanide, heparin, and insulin at standard infusion concentrations. However, although the lower concentrations of omadacycline 1 mg/mL and furosemide 2 mg/mL showed compatibility, higher concentrations of either agent in combination resulted in incompatibility.

IMPLICATIONS

Omadacycline appeared physically compatible with all products tested and incompatible with furosemide. Simultaneous administration of omadacycline with tested intravenous medications, except furosemide, is suggested to be safe.

Deceased Donor Flush Volume Similar for Histidine-Tryptophan-Ketoglutarate and University of Wisconsin at a Single US Organ Procurement Organization: Adult and Pediatric Data

BACKGROUND

Histidine-tryptophan-ketoglutarate (HTK) and University of Wisconsin (UW) solutions are the two primary solid-organ preservation solutions used in the United States (>95%), but flush volumes vary markedly by region and center. This study analyzes data from a single organ procurement organization (OPO) to determine the actual clinical flush volumes used for HTK and UW for liver and pancreas grafts.

METHODS

All procurements at Indiana Donor Network were analyzed (2016-2020), and data were extracted from the on-site records. Variables included procuring center, solution, volumes, and vessels flushed. Brand and generic versions were considered equivalent. No clinical transplant outcomes were available.

RESULTS

Data were analyzed from 875 liver and 192 pancreas procurements by over 70 U.S. centers representing 10 of 11 UNOS regions. The large majority of liver grafts were preserved with HTK (n=810, 93%; UW n=93, 7%). All liver donors received an aortic flush (100%), while portal vein flush was 14% in-situ and 88% back table. For liver grafts, the median volume of infused solution was less for HTK when compared to UW (4225mL vs 5500mL, p=0.04). For pancreas procurement, 100% received aortic flush of the graft, with median HTK and UW volumes being equivalent (3000mL; p=0.85). Pediatric organs were flushed with markedly higher weight-based volumes.

CONCLUSIONS

Flush volumes for HTK and UW are similar at one midwestern OPO, with data comprised of procurements performed by centers from across the U.S. These data demonstrate that low-volume HTK flush is commonly used, and this practice may be considered as a cost-saving measure.

Sodium bicarbonate and salbutamol facilitate recovery from hyperkalemia-induced electrocardiogram abnormalities in bullfrog hearts

Hyperkalemia is a common electrolyte abnormality frequently complicated with chronic kidney disease. By injecting potassium chloride (KCl) solutions intravenously into bullfrogs, we reproduced typical electrocardiogram (ECG) abnormalities of hyperkalemia in the frog hearts, such as the peaked T waves and the widening of QRS complexes. Simultaneous recordings of cardiac action potentials showed morphological changes that synchronized with those of ECG. After 100 mM KCl injection, the widened QRS complexes continued for a while and gradually restored to their baseline widths. However, pre-treatment with sodium bicarbonate or salbutamol, which directly or indirectly stimulates Na+/K+-ATPase activity, significantly facilitated the recovery from the widened QRS duration, indicating the transcellular movement of potassium ions from the extracellular fluid into the intracellular stores.

Kaliuresis and Intracellular Uptake of Potassium with Potassium Citrate and Potassium Chloride Supplements: A Randomized Controlled Trial

BACKGROUND

A potassium replete diet is associated with lower cardiovascular risk but may increase the risk of hyperkalemia, particularly in people using renin-angiotensin-aldosterone system inhibitors. We investigated whether intracellular uptake and potassium excretion after an acute oral potassium load depend on the accompanying anion and/or aldosterone and whether this results in altered plasma potassium change.

METHODS

In this placebo-controlled interventional cross-over trial including 18 healthy individuals, we studied the acute effects of one oral load of potassium citrate (40 mmol), potassium chloride (40 mmol), and placebo in random order after overnight fasting. Supplements were administered after a 6-week period with and without lisinopril pretreatment. Linear mixed effect models were used to compare blood and urine values before and after supplementation and between the interventions. Univariable linear regression was used to determine the association between baseline variables and change in blood and urine values after supplementation.

RESULTS

During the 4-hour follow-up, the rise in plasma potassium was similar for all interventions. After potassium citrate, both red blood cell potassium-as measure of the intracellular potassium-and transtubular potassium gradient (TTKG)-reflecting potassium secretory capacity-were higher than after potassium chloride or potassium citrate with lisinopril pretreatment. Baseline aldosterone was significantly associated with TTKG after potassium citrate, but not after potassium chloride or potassium citrate with lisinopril pretreatment. The observed TTKG change after potassium citrate was significantly associated with urine pH change during this intervention ( R =0.60, P < 0.001).

CONCLUSIONS

With similar plasma potassium increase, red blood cell potassium uptake and kaliuresis were higher after an acute load of potassium citrate as compared with potassium chloride alone or pretreatment with lisinopril.

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER

Potassium supplementation in patients with chronic kidney disease and healthy subjects: effects on potassium and sodium balance, NL7618.

Nutrient Composition of Donor Human Milk and Comparisons to Preterm Human Milk

BACKGROUND

Human milk is the preferred diet for very low birth weight (VLBW, <1500 g) infants. When mother's own milk is unable to meet the needs of VLBW infants, donor human milk (DHM) is the preferred alternative. Unfortunately, the composition of DHM remains elusive and no comparative studies between preterm human milk and DHM have been performed previously.

OBJECTIVES

We aimed to analyze the nutrient content of commercial pooled DHM and compare nutrient content in DHM with that of early and mature preterm human milk.

METHODS

We analyzed nutrient content in 15 DHM samples provided from 7 commercial milk banks including calories, carbohydrate, fat, protein, sodium, chloride, potassium, zinc, calcium, phosphorus, magnesium, and vitamin D and compared each nutrient to early (7 d of life) and mature (28 d of life) preterm human milk samples (n = 28-36 per nutrient, gestational age = 28 ± 3 wk). Protein-to-energy ratio and carbohydrate-to-nonprotein energy ratio were calculated for each sample and compared.

RESULTS

Mean values for all macro- and micronutrients in DHM are reported. In comparison to early or mature preterm human milk, DHM had significantly lower protein, sodium, chloride, potassium, and zinc content. Calorie, carbohydrate, calcium, phosphorus, magnesium, and vitamin D content did not differ statistically between DHM and early or mature preterm human milk. Fat content was modestly lower in early but not mature human milk when compared with DHM.

CONCLUSIONS

We provide mean values for several macro- and micronutrients for DHM and identify key differences between DHM and preterm human milk, which may be considered when designing human milk-based feeding plans. This study was registered at clinicaltrials.gov as NCT05742815.

Investigation of Potassium Chloride for Euthanasia of Anesthetized African Clawed Frogs (Xenopus laevis)

Euthanasia is frequently performed in amphibians, but techniques are currently limited in number and variable in effectiveness. The current study examined the use of potassium chloride (KCl) for euthanasia of anesthetized African clawed frogs (Xenopus laevis). Twenty adult, female African clawed frogs were anesthetized by immersion in buffered tricaine methanesulfonate (MS-222) for 5 min beyond loss of righting reflex. Frogs were then randomly assigned to receive one of 4 treatments: KCl via intracardiac injection (10 mEq/kg; IC, n = 5), intracoelomic injection (100 mEq/kg; ICe, n = 5), immersion (4,500 mEq/L; IMS, n = 5), or no treatment (C, n = 5). After treatment, serial heart rate was measured via Doppler device until either the loss of Doppler sounds, a 60-min endpoint (IC, ICe, IMS), or recovery (C). Times to loss of righting reflex, loss of Doppler sounds, and/or recovery were recorded. Plasma potassium concentrations were measured immediately after Doppler sound cessation in frogs in IC (n = 1), ICe (n = 2), and IMS (n = 5). Injection failure occurred in 1 IC frog, and 1 Ice frog regained spontaneous movement 4 min after treatment administration. Data from these 2 frogs were not included in statistical analysis. Doppler sound cessation occurred in 4 of 4, 4 of 4, 0 of 5, and 0 of 5 frogs in IC, ICe, IMS, and C, respectively. Median (range) times to Doppler sound cessation in IC and ICe were 6 (0 to 16) s and 18 (10 to 25) min, respectively. Plasma potassium concentration was greater than 9.0 mmol/L in sampled frogs. Intracardiac KCl at 10 mEq/kg and intracoelomic KCl at 100 mEq/kg were effective for euthanasia of anesthetized African clawed frogs. Return to MS-222 solution after KCl administration may be warranted to prevent unintended, premature anesthetic recovery prior to death.

Potassium Chloride-Induced Phlebitis via a Malpositioned Central Venous Catheter

We present a case of potassium chloride-induced phlebitis with severe, burning, left-sided chest pain when infused via a malpositioned central venous catheter. Using a malpositioned central venous catheter requires careful consideration, but this novel case prompts the need for additional review before its use for the infusion of potentially irritating medications.

Nonquantal transmission at the vestibular hair cell-calyx synapse: KLV currents modulate fast electrical and slow K+ potentials

Vestibular hair cells transmit information about head position and motion across synapses to primary afferent neurons. At some of these synapses, the afferent neuron envelopes the hair cell, forming an enlarged synaptic terminal called a calyx. The vestibular hair cell-calyx synapse supports a mysterious form of electrical transmission that does not involve gap junctions, termed nonquantal transmission (NQT). The NQT mechanism is thought to involve the flow of ions from the presynaptic hair cell to the postsynaptic calyx through low-voltage-activated channels driven by changes in cleft [K⁺] as K⁺ exits the hair cell. However, this hypothesis has not been tested with a quantitative model and the possible role of an electrical potential in the cleft has remained speculative. Here, we present a computational model that captures experimental observations of NQT and identifies features that support the existence of an electrical potential (ϕ) in the synaptic cleft. We show that changes in cleft ϕ reduce transmission latency and illustrate the relative contributions of both cleft [K⁺] and ϕ to the gain and phase of NQT. We further demonstrate that the magnitude and speed of NQT depend on calyx morphology and that increasing calyx height reduces action potential latency in the calyx afferent. These predictions are consistent with the idea that the calyx evolved to enhance NQT and speed up vestibular signals that drive neural circuits controlling gaze, balance, and orientation.

Treatment of textile industry wastewater by using high-performance forward osmosis membrane tailored with alpha-manganese dioxide nanoparticles for fertigation

Forward osmosis (FO) technology has been acknowledged as an energy-efficient cutting-edge water treatment innovation; however, the inefficient performance of polymer-based membranes remains a tailback in the practical utilization of FO. A significant issue in FO is membrane fouling, which negatively influences the flux efficiency, working expenses and membrane life expectancy. Membranes having high water flux and minimum reverse solute flux at low operating pressures are the ideal membranes for this process. This study reports a thin-film nanocomposite (TFNC) membrane for the treatment of textile industry wastewater utilizing fertilizer as draw solution fabricated via the phase inversion process. The chemical structure and morphology of the synthesized manganese oxide (MnO₂) incorporated membrane were studied by various characterization techniques like X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy-energy-dispersive X-ray spectroscopy, contact angle and gravimetry. The outcomes demonstrated that the nanoparticles were bonded to cellulose acetate polymer via covalent bonds and showed very hydrophilic membrane surface, along with an increased osmotic water flux of 52.5 L.m².h^-1 and reverse salt flux of 10.9 g.m².h^-1, when deionized wastewater and potassium chloride were used as the feed solution and the draw solution, respectively. In this manner, incorporating manganese oxide into the FO membrane may introduce its extraordinary possible application for the production of diluted fertilizer solution with balanced nutrients.

Reduction of sodium chloride: a review

Sodium chloride (NaCl) is an enjoyable condiment. However, evidence is accumulating to indicate that an excessive intake of Na⁺ in food may lead to an increased risk of cardiovascular and cerebrovascular diseases. Previous systematic reviews have focused on replacing NaCl with other metal salts (e.g. KCl). However, new salty flavor enhancers (yeast extract, taste peptides, and odor compounds) have yet to be reviewed. This systematic review evaluates the methods for, and feasibility, of NaCl reduction. It defines NaCl reduction and considers the methods used for this purpose, especially the use of flavor enhancers (yeast extract, taste peptides, and odor compounds). © 2022 Society of Chemical Industry.

Effects of different metal ions on the physicochemical properties and microstructure of egg white gel

BACKGROUND

To ameliorate egg white gel's salinity and undesirable texture characteristics during curing, different metal ions (K⁺ , Mg²⁺ , Ca²⁺ , Zn²⁺ ) were used to replace sodium chloride (NaCl) to simulate salted eggs partially. The effects of these ions on the physicochemical properties, microstructure, and gel characteristics of egg white protein were studied.

RESULTS

Low field nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) analysis showed that adding K⁺ , Mg²⁺ , Ca²⁺ , and Zn²⁺ could decrease immobile water content and increase free water content in egg white gel. Circular dichroism/fluorescence spectrophotometry (CD/FL) analysis showed that substitutive addition of K⁺ , Mg²⁺ , Ca^2+, and Zn²⁺ changed the conformational structure of the protein, which was not conducive to the formation of the three-dimensional mesh gel structure. Differential scanning calorimetry (DSC) results show that the addition of four metal ions could reduce the thermal denaturation temperature of egg white gel. Scanning electron microscopy (SEM) showed that the gel structure of egg white in the zinc chloride (ZnCl₂ ) group was rougher and more chaotic, the crosslinking degree was worse, so it was not suitable for low sodium salted egg preparations. The gel strength of the calcium chloride (CaCl₂ ) group was significantly higher than other groups (P < 0.05), while the gel strength of the potassium chloride (KCl) group was similar to the NaCl group (P > 0.05).

CONCLUSION

CaCl₂ and KCl could be used as partial NaCl substitutes to study the addition level and ratio further and improve salted egg white quality. © 2021 Society of Chemical Industry.

Impact of the Cardioplegia Interval on Myocardial Protection Using the Modified St. Thomas Solution in Minimally Invasive Mitral Valve Surgery: A Double-Center Study

It has been reported that a single-dose cardioplegia interval is useful, but the safe interval doses are not clear. We aimed to investigate the impact of the cardioplegia interval on myocardial protection using the modified St. Thomas solution. We included consecutive isolated minimally invasive mitral valvuloplasty procedures (n = 229) performed at a hospital and medical center from January 2014 to December 2020. We compared postoperative peak creatine kinase MB and creatine kinase levels and other indicators between the short (Group S, n = 135; maximum myocardial protection interval <60 minutes) and long (Group L, n = 94; maximum myocardial protection interval ≥60 minutes) interval groups. Propensity score matching was used to adjust for confounders between the two groups. After propensity score matching, Groups S and L contained 47 patients each. Groups S and L did not differ significantly in peak creatine kinase MB (45.8 ± 26.3 IU/L and 41.5 ± 27.9 IU/L, respectively; p = .441) and creatine kinase levels (1,133 ± 567 IU/L and 1,100 ± 916 IU/L, respectively; p = .837) after admission to the intensive care unit on the day of surgery based on propensity score matching. In multivariate analysis, a cardioplegia dosing interval ≥60 minutes was not significantly associated with the maximum creatine kinase MB level after admission to the intensive care unit on the day of surgery (p = .354; 95% confidence interval: -1.67 to 4.65). Using the antegrade modified St. Thomas solution, the long interval dose method is useful and safe in minimally invasive mitral valvuloplasty.

Improving hemocompatibility of decellularized liver scaffold using Custodiol solution

Organ decellularization is one of the most promising approaches of tissue engineering to overcome the shortage of organs available for transplantation. However, there are key hurdles that still hinder its clinical application, and the lack of hemocompatibility of decellularized materials is a central one. In this work, we demonstrate that Custodiol (HTK solution), a common solution used in organ transplantation, increased the hemocompatibility of acellular scaffolds obtained from rat livers. We showed that Custodiol inhibited ex vivo, in vitro, and in vivo blood coagulation to such extent that allowed successful transplantation of whole-liver scaffolds into recipient animals. Scaffolds previously perfused with Custodiol showed no signs of platelet aggregation and maintained in vitro and in vivo cellular compatibility. Proteomic analysis revealed that proteins related to platelet aggregation were reduced in Custodiol samples while control samples were enriched with thrombogenicity-related proteins. We also identified distinct components that could potentially be involved with this anti-thrombogenic effect and thus require further investigation. Therefore, Custodiol perfusion emerge as a promising strategy to reduce the thrombogenicity of decellularized biomaterials and could benefit several applications of whole-organ tissue engineering.

Double-stranded flanking ends affect the folding kinetics and conformational equilibrium of G-quadruplexes forming sequences within the promoter of KIT oncogene

G-quadruplexes embedded within promoters play a crucial role in regulating the gene expression. KIT is a widely studied oncogene, whose promoter contains three G-quadruplex forming sequences, c-kit1, c-kit2 and c-kit*. For these sequences available studies cover ensemble and single-molecule analyses, although for kit* the latter were limited to a study on a promoter domain comprising all of them. Recently, c-kit2 has been reported to fold according to a multi-step process involving folding intermediates. Here, by exploiting fluorescence resonance energy transfer, both in ensemble and at the single molecule level, we investigated the folding of expressly designed constructs in which, alike in the physiological context, either c-kit2 or c-kit* are flanked by double stranded DNA segments. To assess whether the presence of flanking ends at the borders of the G-quadruplex affects the folding, we studied under the same protocols oligonucleotides corresponding to the minimal G-quadruplex forming sequences. Data suggest that addition of flanking ends results in biasing both the final equilibrium state and the folding kinetics. A previously unconsidered aspect is thereby unravelled, which ought to be taken into account to achieve a deeper insight of the complex relationships underlying the fine tuning of the gene-regulatory properties of these fascinating DNA structures.

Use of potassium chloride for low-residue euthanasia of anesthetized California sea lions (Zalophus californianus) and northern elephant seals (Mirounga angustirostris) with life-threatening injury or disease

OBJECTIVE

To demonstrate the efficacy of potassium chloride (KCl) for low-residue euthanasia of anesthetized pinnipeds in field settings for which carcass retrieval for disposal is not feasible.

ANIMALS

Stranded, free-ranging California sea lions (CSLs; Zalophus californianus; n = 17) and northern elephant seals (NESs; Mirounga angustirostris; 6) with life-threatening injury or disease between May and August 2020.

PROCEDURES

Each animal was anesthetized and then received a lethal dose of KCl solution administered by IV or intracardiac injection. The effective KCl dose; durations to cardiac arrest, respiratory arrest, and pupil dilation; and presence or absence of agonal breaths, muscle fasciculations, or skeletal movements were recorded.

RESULTS

Mean effective dose of KCl was 207.4 mg/kg (94.3 mg/lb) for the 17 CSLs and 209.1 mg/kg (95.0 mg/lb) for 5 of 6 NESs (1 outlier NES was excluded). The range in duration from the beginning of KCl injection to cardiac arrest was 0 to 6 minutes, to pupil dilation was 0 to 5 minutes, and to respiratory arrest was 0 to 5 minutes. Muscle fasciculations, skeletal movements, and agonal breaths were observed in both species during and after KCl administration.

CONCLUSIONS AND CLINICAL RELEVANCE

The use of KCl provides an effective, low-residue method of euthanasia in anesthetized CSLs and NESs. Our recommended dose for these species is 250 mg KCl/kg (113.6 mg KCl/lb) delivered by intracardiac injection. Compared with euthanasia by barbiturate overdose, the use of KCl reduces the potential for secondary intoxication of scavengers and is appropriate in field scenarios in which the carcass cannot be retrieved for disposal.

Funic potassium chloride injection during intact dilation and evacuation

OBJECTIVE

To describe effectiveness of funic potassium chloride (KCl) injection for fetal demise during intact dilation and evacuation (D&E).

STUDY DESIGN

We abstracted medical records of patients who underwent standard or intact D&E to identify those who had intact D&E from 20 weeks 0 days through 23 weeks 6 days from February 2016 to August 2017 at one academic center. We extracted data on time to asystole following KCl injection, as well as incidents including hemorrhage, infection, uterine perforation, and unplanned admissions for up to 6 months following each procedure.

RESULTS

Of 57 procedures, 32 (56%) were intact. Median time from KCl injection to fetal asystole was 48 seconds (interquartile range [IQR] 34-100). Median time to asystole at weeks 20 and 21 (46 seconds [IQR 34-60 seconds]) did not differ significantly from weeks 22 and 23 (85 seconds [IQR 34-200 seconds]), p = 0.15. Asystole occurred in less than four minutes in all cases but one. No adverse events occurred with either the funic KCl injections or the intact D&E procedures.

CONCLUSION

Funic KCl injection for intact D&E usually causes fetal asystole in less than 4 minutes.

IMPLICATIONS

Funic KCl injection under direct visualization is a feasible method to induce fetal asystole at the time of intact dilation and evacuation.

Successful management of three cases of interstitial pregnancies with local instillation of potassium chloride: avoiding a potential cornuostomy

Here, we present three cases of women with interstitial pregnancy who were managed with local instillation of potassium chloride. These women were in their 20s-30s and presented in stable condition. Of them, two had a history of previous ectopic pregnancy. Interstitial pregnancy was diagnosed by transvaginal sonography which showed an empty uterine cavity with a gestational sac 1 cm away from the lateral edge of the uterine cavity, with <5 mm myometrium surrounding it in all planes. Two of the three cases failed to respond to methotrexate injection. Due to the presence of high-end ultrasound machine and technical expertise, local instillation of potassium chloride was offered as an alternative to surgical treatment, which is definitive, and all three patients had a successful outcome. One patient returned with pain in the abdomen, which required inpatient monitoring and was later diagnosed with urinary tract infection and was given appropriate antibiotics.

Smooth muscle cell-specific TMEM16A deletion does not alter Ca2+ signaling, uterine contraction, gestation length, or litter size in mice†

Ion channels in myometrial cells play critical roles in spontaneous and agonist-induced uterine contraction during the menstrual cycle, pregnancy maintenance, and parturition; thus, identifying the genes of ion channels in these cells and determining their roles are essential to understanding the biology of reproduction. Previous studies with in vitro functional and pharmacological approaches have produced controversial results regarding the presence and role of TMEM16A Ca2+-activated Cl- channels in myometrial cells. To unambiguously determine the function of this channel in these cells, we employed a genetic approach by using smooth muscle cell-specific TMEM16A deletion (i.e. TMEM16ASMKO) mice. We found that myometrial cells from TMEM16ASMKO mice generated the same pattern and magnitude in Ca2+ signals upon stimulation with KCl, oxytocin, and PGF2α compared to the isogenic control myometrial cells. At the uterine tissue level, TMEM16A deletion also did not cause detectable changes in either spontaneous or agonist (i.e. KCl, oxytocin, and PGF2α)-induced contractions. Moreover, in vivo the TMEM16ASMKO mice gave birth at full term with the same litter size as genetically identical control mice. Finally, TMEM16A immunostaining in both control and TMEM16ASMKO mice revealed that this protein was highly expressed in the endometrial stroma, but did not co-localize with a smooth muscle specific marker MYH11. Collectively, these results unequivocally demonstrate that TMEM16A does not serve as a pacemaking channel for spontaneous uterine contraction, neither does it function as a depolarizing channel for agonist-evoked uterine contraction. Yet these two functions could underlie the normal gestation length and litter size in the TMEM16ASMKO mice.

Recombinant Penicillium oxalicum 16 β-Glucosidase 1 Displays Comprehensive Inhibitory Resistance to Several Lignocellulose Pretreatment Products, Ethanol, and Salt

β-Glucosidase (BGL) is a rate-limiting enzyme of lignocellulose hydrolysis for second-generation bioethanol production, but its inhibition by lignocellulose pretreatment products, ethanol, and salt is apparent. Here, the recombinant Penicillium oxalicum 16 BGL 1 (rPO16BGL1) from Pichia pastoris GS115 kept complete activity at 0.2-1.4 mg/mL furan derivatives and phenolic compounds, 50 mg/mL sodium chloride (potassium chloride), or 100 mg/mL ethanol at 40 °C. rPO16BGL1 retained above 50% residual activity at 30 mg/mL organic acid sodium, and 60% residual activity at 40 °C with 300 mg/mL ethanol. Sodium chloride and potassium chloride had a complicated effect on rPO16BGL1, which resulted in activation or inhibition. The inhibition kinetics of the enzyme reaction demonstrated that organic acids and organic acid sodium were non-competitive inhibitors and that ethanol was a competitive inhibitor at < 1.5 mg/mL salicin. Moreover, substrate inhibition of the enzyme was found at > 2 mg/mL salicin, and the Km/KI and Km/KSI average values revealed that the inhibitory strength was ranked as salicin-organic acids > organic acids > salicin-organic acid sodium salt > organic acid sodium salt > salicin > salicin-KCl > salicin-NaCl > salicin-ethanol > ethanol.

Pimpinella anisum extract attenuates spontaneous and agonist-induced uterine contraction in term-pregnant rats

ETHNOPHARMACOLOGY RELEVANCE

Pimpinella anisum is a well-known traditional medicinal herb which has been used in folk medicine as an antiulcer, anticancer, antibacterial and as a muscle relaxant.

AIM OF THE STUDY

This study was performed to explore the modulatory effects of Pimpinella anisum on term-pregnant rat uterine contractility and to investigate its possible underlying mechanisms.

MATERIAL AND METHODS

Intact uterine strips without endometrial layer were isolated from female term-pregnant Wistar rats (22 days of gestation) and mounted in a tissue bath apparatus for in vitro isometric force recording. The effects of different concentrations of Pimpinella anisum extract (PAE) (1, 3, 5, and 7 mg/mL) were examined on uterine contractions generated spontaneously or induced with oxytocin (5 nmol/L), Bay K8644 (1 μmol/L), and carbachol (10 μmol/L). In some experiments, PAE was applied on depolarized myometrium in the presence of high-KCl solution (60 mmol/L). The effect on Ca²⁺ release was also examined.

RESULTS

Application of PAE significantly reduced uterine contractions generated spontaneously or induced with oxytocin, Bay K8644, and carbachol in a concentration-dependent manner (n = 7; P < 0.01). In depolarized myometrium, PAE significantly reduced the tonic force induced by high-KCl solution (n = 7; P < 0.01). PAE prevented oxytocin-induced transient contraction in the entire absence of external calcium (n = 7; P < 0.01).

CONCLUSION

The present findings demonstrate the potentials of PAE to relax pregnant uterine contractions possibly by blocking Ca²⁺ entry via L-type calcium channels and inhibiting Ca²⁺ release from the internal store. The tocolytic effects of PAE may be a potential adjuvant against strong premature uterine contractions which threaten early pregnancy although clinical studies are required.

Estimated population wide benefits and risks in China of lowering sodium through potassium enriched salt substitution: modelling study

OBJECTIVES

To estimate the effects of nationwide replacement of discretionary salt (used at table or during cooking) with potassium enriched salt substitute on morbidity and death from cardiovascular disease in China.

DESIGN

Modelling study.

SETTING

China.

POPULATION

Adult population in China, and specifically individuals with chronic kidney disease (about 17 million people).

INTERVENTIONS

Comparative risk assessment models were used to estimate the effects of a nationwide intervention to replace discretionary dietary salt with potassium enriched salt substitutes (20-30% potassium chloride). The models incorporated existing data and corresponding uncertainties from randomised trials, the China National Survey of Chronic Kidney Disease, the Global Burden of Disease Study, and the Chronic Kidney Disease Prognosis Consortium.

MAIN OUTCOME MEASURES

Averted deaths from cardiovascular disease, non-fatal events, and disability adjusted life years from a reduction in blood pressure were estimated after implementation of potassium enriched salt substitution. In individuals with chronic kidney disease, additional deaths from cardiovascular disease related to hyperkalaemia from increased intake of potassium were calculated. The net effects on deaths from cardiovascular disease were estimated as the difference and ratio of averted and additional deaths from cardiovascular disease.

RESULTS

Nationwide implementation of potassium enriched salt substitution could prevent about 461 000 (95% uncertainty interval 196 339 to 704 438) deaths annually from cardiovascular disease, corresponding to 11.0% (4.7% to 16.8%) of annual deaths from cardiovascular disease in China; 743 000 (305 803 to 1 273 098) non-fatal cardiovascular events annually; and 7.9 (3.3 to 12.9) million disability adjusted life years related to cardiovascular disease annually. The intervention could potentially produce an estimated 11 000 (6422 to 16 562) additional deaths related to hyperkalaemia in individuals with chronic kidney disease. The net effect would be about 450 000 (183 699 to 697 084) fewer deaths annually from cardiovascular disease in the overall population and 21 000 (1928 to 42 926) fewer deaths in individuals with chronic kidney disease. In deterministic sensitivity analyses, with changes to key model inputs and assumptions, net benefits were consistent in the total population and in individuals with chronic kidney disease, with averted deaths outweighing additional deaths.

CONCLUSIONS

Nationwide potassium enriched salt substitution in China was estimated to result in a substantial net benefit, preventing around one in nine deaths from cardiovascular disease overall. Taking account of the risks of hyperkalaemia, a substantial net benefit was also estimated for individuals with chronic kidney disease.

Two-step numerical procedure on the removal process of gaseous potassium chloride generated from waste incineration via the injection of sulfate-based additives

Gaseous potassium chloride (KCl) that constitutes a relatively large portion of the combustion gas of municipal solid waste can condense on the surface of boiler heat exchanger tubes, causing severe corrosion attacks. To reduce the chlorine-induced high-temperature corrosion, sulfate-based additives have been used. In this study, a two-step numerical procedure is proposed to quickly predict the effect of the injection of sulfate-based additives on the removal of gaseous KCl. A computational fluid dynamics (CFD) simulation is first carried out to obtain the temperature distribution. Then, the thermal decomposition of sulfate additives, sulfation of gaseous KCl, and condensation of K₂SO₄ are calculated to predict the species concentration profiles at the temperature conditions given by the CFD simulation. After validation with a laboratory-scale experiment using [Formula: see text] , the procedure is applied to a pilot-scale boiler to examine the effects of [Formula: see text] , [Formula: see text] , and [Formula: see text] . The calculation results show that each additive has an optimal injection temperature range: approximately 800 °C for [Formula: see text] and 1000 °C for both [Formula: see text] and [Formula: see text] , which are consistent with the values reported in the literature. The expressions for the stoichiometric KCl removal efficiency of each additive are derived and compared with the calculated efficiencies.

Chronic stimulation induces adaptive potassium channel activity that restores calcium oscillations in pancreatic islets in vitro

Insulin pulsatility is important to hepatic response in regulating blood glucose. Growing evidence suggests that insulin-secreting pancreatic β-cells can adapt to chronic disruptions of pulsatility to rescue this physiologically important behavior. We determined the time scale for adaptation and examined potential ion channels underlying it. We induced the adaptation both by chronic application of the ATP-sensitive K⁺ [K(ATP)] channel blocker tolbutamide and by application of the depolarizing agent potassium chloride (KCl). Acute application of tolbutamide without pretreatment results in elevated Ca²⁺ as measured by fura-2AM and the loss of endogenous pulsatility. We show that after chronic exposure to tolbutamide (12-24 h), Ca²⁺ oscillations occur with subsequent acute tolbutamide application. The same experiment was conducted with potassium chloride (KCl) to directly depolarize the β-cells. Once again, following chronic exposure to the cell stimulator, the islets produced Ca²⁺ oscillations when subsequently exposed to tolbutamide. These experiments suggest that it is the chronic stimulation, and not tolbutamide desensitization, that is responsible for the adaptation that rescues oscillatory β-cell activity. This compensatory response also causes islet glucose sensitivity to shift rightward following chronic tolbutamide treatment. Mathematical modeling shows that a small increase in the number of K(ATP) channels in the membrane is one adaptation mechanism that is compatible with the data. To examine other compensatory mechanisms, pharmacological studies provide support that Kir2.1 and TEA-sensitive channels play some role. Overall, this investigation demonstrates β-cell adaptability to overstimulation, which is likely an important mechanism for maintaining glucose homeostasis in the face of chronic stimulation.

Amplification of Salt-Induced Protein Diffusiophoresis by Varying Salt from Potassium to Sodium to Magnesium Chloride in Water

Salt-induced diffusiophoresis is the migration of a macromolecule or a colloidal particle induced by a concentration gradient of salt in water. Here, the effect of salt type on salt-induced diffusiophoresis of the protein lysozyme at pH 4.5 and 25 °C was examined as a function of salt concentration for three chloride salts: NaCl, KCl, and MgCl₂. Diffusiophoresis coefficients were calculated from experimental ternary diffusion coefficients on lysozyme-salt-water mixtures. In all cases, diffusiophoresis of this positively charged protein occurs from high to low salt concentration. An appropriate mass transfer process was theoretically examined to show that concentration gradients of MgCl₂ produce significant lysozyme diffusiophoresis. This is attributed to the relatively low mobility of Mg²⁺ ions compared to that of Cl^- ions at low salt concentration and a strong thermodynamic nonideality of this salt at high salt concentration. These findings indicate that MgCl₂ concentration gradients could be exploited for protein manipulation in solution (e.g., using microfluidic technologies) with applications to protein adsorption and purification. The dependence of lysozyme diffusiophoresis on salt type was theoretically examined and linked to protein charge. The effect of salts on hydrogen-ion titration curves was experimentally characterized to understand the role of salt type on protein charge. Our results indicate that binding of Mg²⁺ ions to lysozyme further enhances protein diffusiophoresis.

Effect of Balanced Crystalloid, Gelatin and Hydroxyethyl Starch on Coagulation Detected by Rotational Thromboelastometry In Vitro

BACKGROUND

Fluid resuscitation with crystalloid and colloid solutions is a common treatment in perioperative medicine. However, a variety of unbalanced or balanced solutions are used in clinical practice and there is still vivid debate going on regarding selection of optimal fluid with minimal negative effect on coagulation to minimize bleeding and blood transfusion requirements. The aim of the study was to investigate adverse effects of balanced crystalloids and colloids on coagulation measured by thromboelastometry in vitro.

METHODS

Blood samples were obtained from healthy volunteers undergoing knee arthroscopy. Adverse effects of balanced crystalloid, hydroxyethyl starch, and gelatin were evaluated by thromboelastometry after 20% dilution of blood with the solution in vitro. Parameters of EXTEM and FIBTEM test were evaluated.

RESULTS

Clotting time of EXTEM was not significantly influenced by any of the investigated solutions (p > 0.05). However, significant impairment of clot formation time of EXTEM was detected in hydroxyethyl starch and gelatin groups in comparison with controls (p < 0.05), while crystalloid did not affect this parameter significantly (p > 0.05). Similar results were found in α angle although significant coagulopathy effect was found only in hydroxyethyl starch samples (p < 0.05). Maximum clot firmness of EXTEM and FIBTEM tests was significantly affected by both hydroxyethyl starch and gelatin (p < 0.05) but not by crystalloid.

CONCLUSIONS

Balanced crystalloid solution does not seem to have a negative influence on the coagulation process as measured by thromboelastometry. On the other hand, balanced colloids may impair propagation phase of coagulation, strength of coagulum, and level of functional fibrinogen. Hydroxyethyl starch seems to have a stronger anticoagulant effect compared to gelatin.

Polymorphism of G4 associates: from stacks to wires via interlocks

We examined the assembly of DNA G-quadruplexes (G4s) into higher-order structures using atomic force microscopy, optical and electrophoretic methods, NMR spectroscopy and molecular modeling. Our results suggest that parallel blunt-ended G4s with single-nucleotide or modified loops may form different types of multimers, ranging from stacks of intramolecular structures and/or interlocked dimers and trimers to wires. Decreasing the annealing rate and increasing salt or oligonucleotide concentrations shifted the equilibrium from intramolecular G4s to higher-order structures. Control antiparallel and hybrid G4s demonstrated no polymorphism or aggregation in our experiments. The modification that mimics abasic sites (1',2'-dideoxyribose residues) in loops enhanced the oligomerization/multimerization of both the 2-tetrad and 3-tetrad G4 motifs. Our results shed light on the rules that govern G4 rearrangements. Gaining control over G4 folding enables the harnessing of the full potential of such structures for guided assembly of supramolecular DNA structures for nanotechnology.

Cytoprotective Mechanisms in Fatty Liver Preservation against Cold Ischemia Injury: A Comparison between IGL-1 and HTK

Institute Goeorges Lopez 1 (IGL-1) and Histidine-Tryptophan-Ketoglutarate (HTK) preservation solutions are regularly used in clinical for liver transplantation besides University of Wisconsin (UW) solution and Celsior. Several clinical trials and experimental works have been carried out comparing all the solutions, however the comparative IGL-1 and HTK appraisals are poor; especially when they deal with the underlying protection mechanisms of the fatty liver graft during cold storage. Fatty livers from male obese Zücker rats were conserved for 24 h at 4 °C in IGL-1 or HTK preservation solutions. After organ recovery and rinsing of fatty liver grafts with Ringer Lactate solution, we measured the changes in mechanistic target of rapamycin (mTOR) signaling activation, liver autophagy markers (Beclin-1, Beclin-2, LC3B and ATG7) and apoptotic markers (caspase 3, caspase 9 and TUNEL). These determinations were correlated with the prevention of liver injury (aspartate and alanine aminostransferase (AST/ALT), histology) and mitochondrial damage (glutamate dehydrogenase (GLDH) and confocal microscopy findings). Liver grafts preserved in IGL-1 solution showed a marked reduction on p-TOR/mTOR ratio when compared to HTK. This was concomitant with significant increased cyto-protective autophagy and prevention of liver apoptosis, including inflammatory cytokines such as HMGB1. Together, our results revealed that IGL-1 preservation solution better protected fatty liver grafts against cold ischemia damage than HTK solution. IGL-1 protection was associated with a reduced liver damage, higher induced autophagy and decreased apoptosis. All these effects would contribute to limit the subsequent extension of reperfusion injury after graft revascularization in liver transplantation procedures.

Ischemic Type Biliary Lesions in Histidine-Tryptophan-Ketoglutarate (HTK) Preserved Liver Grafts

Ischemic type biliary lesions lead to considerable morbidity following orthotopic liver transplantation. The exact pathogenesis is unknown. One major hypothesis is that insufficient perfusion of the arterial vessels of the biliary tree, especially under perfusion with the high viscous University of Wisconsin solution, might be responsible for ischemic type biliary lesions. Due to low viscosity, HTK solution is reported to have a lower incidence of biliary complications. However, there is no data concerning ischemic type biliary lesions in HTK preserved livers. In this paper we report our results after orthotopic liver transplantation with special regard to ischemic type biliary lesions in liver grafts preserved with HTK solution. Between 09/1997 and 01/2005 300 liver transplantations were performed in our center. Thirty-two (10.7%) liver grafts were preserved with HTK solution, 268 (89.3%) were preserved with UW solution. Six and 43 grafts showed ischemic type biliary lesions after orthotopic liver transplantation in HTK- (18.8%) and UW- (16.0%) groups, respectively (p=0.696). There was no statistical significant difference between the two groups. Donor related factors, recipient age, indication for transplantation, transplantation technique, immunosuppression and ischemia time were comparable in both groups.

Ischemic type biliary lesions occurred with the same frequency in HTK preserved livers compared to UW preserved organs. We suggest that low viscosity of the preservation fluid by itself does not guarantee reliable perfusion of the small arteries of a liver graft and a pressure perfusion might be beneficial even in HTK solution.

Circulatory Failure During Noninhaled Forms of Cyanide Intoxication

Our objective was to determine how circulatory failure develops following systemic administration of potassium cyanide (KCN). We used a noninhaled modality of intoxication, wherein the change in breathing pattern would not influence the diffusion of CN into the blood, akin to the effects of ingesting toxic levels of CN. In a group of 300 to 400 g rats, CN-induced coma (CN i.p., 7 mg/kg) produced a central apnea within 2 to 3 min along with a potent and prolonged gasping pattern leading to autoresuscitation in 38% of the animals. Motor deficits and neuronal necrosis were nevertheless observed in the surviving animals. To clarify the mechanisms leading to potential autoresuscitation versus asystole, 12 urethane-anesthetized rats were then exposed to the lowest possible levels of CN exposure that would lead to breathing depression within 7 to 8 min; this dose averaged 0.375 mg/kg/min i.v. At this level of intoxication, a cardiac depression developed several minutes only after the onset of the apnea, leading to cardiac asystole as PaO2 reached value approximately 15 Torr, unless breathing was maintained by mechanical ventilation or through spontaneous gasping. Higher levels of KCN exposure in 10 animals provoked a primary cardiac depression, which led to a rapid cardiac arrest by pulseless electrical activity (PEA) despite the maintenance of PaO2 by mechanical ventilation. These effects were totally unrelated to the potassium contained in KCN. It is concluded that circulatory failure can develop as a direct consequence of CN-induced apnea but in a narrow range of exposure. In this "low" range, maintaining pulmonary gas exchange after exposure, through mechanical ventilation (or spontaneous gasping), can reverse cardiac depression and restore spontaneous breathing. At higher level of intoxication, cardiac depression is to be treated as a specific and spontaneously irreversible consequence of CN exposure, leading to a PEA.

Quercetin relaxes guinea pig gallbladder strips

Quercetin, a phytoestrogen and flavonoid, relaxes intestinal and vascular smooth muscle. The purpose of this study was to determine if quercetin had an effect on gallbladder smooth muscle. An in vitro technique was used to determine the effects of quercetin on gallbladder strips and which system(s) mediated the relaxation. Paired t tests were used; differences between means of P < .05 were considered significant. Adding quercetin before cholecystokinin or KCl produced a significant (P < .001) decrease in the amount of tension (0.80 ± 0.04 vs 0.48 ± 0.04 g cholecystokinin octapeptide and 0.8 ± 0.06 vs 0.54 ± 0.05 g KCl, respectively). When the protein kinase C (PKC) inhibitors bisindolymaleimide IV and chelerythrine Cl^- were simultaneously, a significant (P < .001) reduction in the quercetin-induced relaxation (45.7% ± 4.3% vs 27.6% ± 3.4%) was observed. To determine if protein kinase A (PKA) mediated the quercetin-induced relaxation, PKA inhibitor 14-22 amide myristolated was used. It significantly (P < .05) decreased the amount (40.4% ± 3.7% vs 34.5% ± 3.3%) of quercetin-induced relaxation. The use of 2-APB also significantly (P < .001) reduced the amount of quercetin-induced relaxation (51.2% ± 3.5% vs 14.8% ± 3.6%). l-N^G-methyl-l-arginine acetate salt, a nitric oxide synthase inhibitor, significantly (P < 001) decreased the quercetin-induced relaxation (45.7% ± 4.2% vs 35.2% ± 3.6%). KT5823, a PKC inhibitor, had no effect on the quercetin-induced relaxation. Quercetin blocked extracellular Ca²⁺ entry which affected downstream events such as activation of PKC, PKA, intracellular Ca²⁺ release, and activation of nitric oxide synthase. Quercetin relaxed cholecystokinin octapeptide and KCl-induced tension in a concentration dependent manner. Thus quercetin-induced relaxation was mediated by multiple signaling pathways.

Effect of saline 0.9% or Plasma-Lyte 148 therapy on feeding intolerance in patients receiving nasogastric enteral nutrition

OBJECTIVE

To compare the effect of Plasma-Lyte (PL)-148 and saline 0.9% (saline) on gastrointestinal (GI) feeding intolerance in mechanically ventilated patients receiving nasogastric (NG) feeding in an intensive care unit.

DESIGN AND SETTING

A single-centre pilot study, nested within a multicentre, double-blind, cluster-randomised, double-crossover trial, performed in a mixed medical and surgical ICU.

PARTICIPANTS

All adult patients who required crystalloid fluid therapy as part of the 0.9% Saline versus Plasma-Lyte 148 for Intensive Care Unit Fluid Therapy (SPLIT) trial, were expected to need mechanical ventilation for more than 48 hours and were receiving enteral nutrition exclusively by NG tube were eligible. We enrolled 69 patients and assigned 35 to PL-148 and 34 to saline.

INTERVENTIONS

We randomly allocated saline or PL-148 for four alternating 7-week blocks, with staff blinded to the solution.

MAIN OUTCOME MEASURES

The primary outcome was the proportion of patients with GI feeding intolerance, defined as high gastric residual volume (GRV), diarrhoea or vomiting while receiving NG feeding in the ICU. The proportions of patients with each of high GRV, diarrhoea and vomiting were secondary outcomes.

RESULTS

In the PL-148 group, 21 of 35 patients (60.0%) developed GI feeding intolerance, compared with 22 of 34 patients (64.7%) in the saline group (odds ratio [OR], 0.82; 95% CI, 0.31-2.17; P = 0.69). A high GRV was seen in four of 35 patients (11.4%) in the PL-148 group, and in 11 of 34 patients (32.4%) in the saline group (OR, 0.27; 95% CI, 0.08-0.96; P = 0.04).

CONCLUSION

Among mechanically ventilated patients receiving NG feeding, the use of PL-148, compared with saline, did not reduce the proportion of patients developing GI feeding intolerance, but was associated with a decreased incidence of high GRV.

Versatile Miniature Tunable Liquid Lenses Using Transparent Graphene Electrodes

This paper presents, for the first time, versatile and low-cost miniature liquid lenses with graphene as electrodes. Tunable focal length is achieved by changing the droplet curvature using electrowetting on dielectric (EWOD). Ionic liquid and KCl solution are utilized as lens liquid on the top of a flexible Teflon-coated PDMS/parylene membrane. Transparent and flexible, graphene allows transmission of visible light as well as large deformation of the polymer membrane to achieve requirements for different lens designs and to increase the field of view without damaging of electrodes. The tunable range for the focal length is between 3 and 7 mm for a droplet with a volume of 3 μL. The visualization of bone marrow dendritic cells is demonstrated by the liquid lens system with a high resolution (456 lp/mm).

Impact of Different Salts in Soaking Water on the Cooking Time, Texture and Physical Parameters of Cowpeas

The characteristics of modern life has led consumers to seek convenience and speed in food preparation, but storage, which is often prolonged, can result in grain hardening, leading to higher energy consumption during preparation, grain with increased hardness is often discarded. Due to the increasing global demand for grain, the use of alternative techniques aimed at reducing grain waste is necessary. Therefore, we studied a method that meets consumer demand and results in better use of harvested grain. The beans studied were cowpea beans (Vigna unguiculata) of the BRS Guariba cultivar after 1 and 12 months of storage. Sodium chloride (NaCl), potassium chloride (KCl) and sodium bicarbonate (NaHCO3) were added to soaking water at different concentrations as a way to reduce cooking time. These beans were placed in soaking water for 12 h at 3 concentrations (0, 1.0 and 2.5%). The cowpeas soaked in water containing NaHCO3 presented the highest hydration coefficient, which increased with the salt concentration; these beans also had decreased hardness, chewiness and cooking time.