Glycol-based Solutions Research Articles

A clinical comparison of glycol and water-based heater-cooler systems for cardiopulmonary bypass.

While newer heater-cooler technologies using ethylene glycol-based (GB) solutions during cardiothoracic surgery have become commercially available, there is a paucity of clinical data describing their effectiveness during cardiopulmonary bypass (CPB) support. This analysis aimed to compare clinical characteristics and procedural outcomes using water-based (WB) and GB heater-cooler systems. A retrospective analysis was performed on consecutive adult patients undergoing CPB from June to October 2022 comparing WB or GB groups. The primary outcome was a composite of operative death or major morbidity. Secondary endpoints included transfusion requirements on CPB, patient cooling and warming rates, and vasoactive-inotropic scores (VIS) at case completion. P-control charts were used to monitor the weekly incidence of the composite outcome. A sub-analysis was performed to evaluate the primary outcome for cardiac surgery cases indexed by the Society of Thoracic Surgeons (STS). There were 167 patients included for analysis; 87 (52.1%) underwent CPB with a WB system and 80 (47.9%) with a GB system. GB procedure subjects were younger (p = .01), experienced longer CPB times (p = .034), and were more likely to receive thoracic transplant or aortic surgery (p = 0.015). The composite outcome of operative mortality or major morbidity occurred in 29.9% and 24% of the WB and GB groups, respectively (p = .372). P-control charts indicated a weekly mean incidence of 30% during WB practice, which decreased to 24% with GB practice. Among 106 STS-indexed cardiac surgery cases, mean composite outcome incidence decreased from 19% to 6% following our GB transition. Additionally, cooling, and warming rates indexed to patient BSA and VIS at case completion were not significantly different. Our analysis demonstrated a safe transition from WB to GB heater-cooler technologies in our practice. This early analysis suggests that GB heater coolers may be safely adopted to mitigate the risks of nontuberculous mycobacterium infections for cardiac surgical patients.

Acute Kidney Injury in Patients Using Polyethylene Glycol as Bowel Cleansing Agent for Colonoscopy

Introduction: The use of polyethylene glycol-based solutions is the gold standard for bowel preparation for colonoscopy. However, polyethylene glycol use might be associated with the risk of acute kidney injury. We aim to find out acute kidney injury and risk factors associated with the development of acute kidney injury in patients using polyethylene glycol for colonoscopy.Materials and Methods: This was an observational study conducted in the Department of Nephrology and Gastroenterology, Bir hospital. Patients who underwent colonoscopy using polyethylene glycol were included in the study and assessed for acute kidney injury; its incidence, association of risk factors with acute kidney injury, and outcome (complete recovery or no recovery) of acute kidney injury by 3 months.Results: The mean age of the patients was 45.81 ± 18.60 years with the majority of the patients being male (60%). Out of 48 study participants, 4(8%) develop acute kidney injury. Multivariate regression analysis depicted that chronic kidney disease, chronic liver disease, congestive cardiac failure, and use of non-steroidal anti-inflammatory drugs, angiotensin receptor blockers, and diuretics drugs were the predictors which significantly influenced the occurrence of acute kidney injury in patients using polyethylene glycol.Conclusions: The evidence strongly suggests that in patients without preexisting renal disease, comorbidities, or use of drugs; the risk of renal impairment is low after colonoscopy using polyethylene glycol as a bowel cleansing agent. In the presence of risk factors for renal dysfunction, polyethylene glycol should be used cautiously.

Oral sulfate solution versus low-volume polyethylene glycol for bowel preparation: Meta-analysis of randomized controlled trials.

Oral sodium sulfate (OSS) solution and low-volume polyethylene glycol-based solutions are two of the more common low-volume purgatives used as colonoscopy preparations. Data on how these different low-volume solutions compare are mixed. Our aim was to conduct a meta-analysis of randomized controlled trials (RCTs) to compare OSS with low-volume polyethylene glycol solutions (PEG) plus ascorbic acid (PEG + Asc) solution with respect to (i) satisfactory bowel preparation, (ii) excellent bowel preparation, and (iii) tolerability. Studies were identified by searching 10 medical databases for reports published from 1974 until 2019. Only fully published RCTs comparing OSS and low-volume PEG-based products with regard to overall satisfactory bowel preparation were included. Pooling was conducted by both fixed-effects and random effects models; results are presented from the random effects model when heterogeneity was significant. Seven studies (involving 2049 subjects) met the inclusion criteria. There was no difference between OSS and PEG + Asc with respect to adequate bowel preparation (risk ratio [RR] 1.02 [0.99-1.06]; P = 0.16). OSS did result in a higher chance of excellent bowel preparation (RR 1.18 [1.06-1.31]; P = 0.03). OSS was associated with a 30% increased risk of nausea (RR 1.35 [1.03-1.77]; P = 0.03) and more than double the risk of vomiting (RR 2.30 [1.63-2.23]; P < 0.05) compared with PEG + Asc. Begg's funnel plot indicated low probability of publication bias. Individuals at low risk of inadequate bowel preparation who use OSS for bowel preparation are more likely to achieve excellent bowel preparation, but are more likely to experience nausea and vomiting than are individuals using low-volume PEG-based solutions.

Electrodeposition of cobalt thin films and nanowires from ethylene glycol-based solution

Ethylene glycol-based solutions containing metal precursor chloride salts were investigated for the electrodeposition of cobalt thin films and nanowires. The electrochemical behavior of 0.5 M Co(II) chloride solution at 70 °C was studied by means of cyclic voltammetry (CV) on a Pt substrate. The reduction process was shown to be irreversible, with high faradaic efficiencies (85–90 %). A diffusion coefficient (D0) of 2.29 × 10−6 cm2 s−1 for the Co species was estimated from the electrochemical behavior at different scan rates (from 25 to 125 mV s−1). The electrodeposition process was also studied on a copper substrate at different cathodic potentials (from −0.75 V vs Pt to −0.95 V vs Pt). Field-emission scanning electron microscopy (FE-SEM) and electron dispersive spectroscopy (EDS) revealed high-purity, compact films. Template-assisted electrodeposition resulted in ~16–18 μm long cobalt nanowires with an aspect ratio L/D > 100. X-ray diffraction (XRD) analysis of Co thin films showed a preferential orientation along the HCP [100] direction, which was even more marked for the nanowires. Vibrating sample magnetometry (VSM) highlighted that the fact that Co thin films were magnetized in-plane, while in nanowires a competition between shape and magnetocrystalline anisotropy led to similar magnetic behavior for the in-plane and out-of-plane directions.

Tolerance to vitrification of rat embryos at various developmental stages

Numerous genetically engineered rat strains have been produced via genome editing. Although freezing of embryos is helpful for the production and storage of these valuable strains, the tolerance to freezing of embryos varies at each developmental stage of the embryo. This study examined the tolerance to freezing of rat embryos at various developmental stages, particularly at the pronuclear stage. Embryos that had developed to the pronuclear, 2-cell, and morula stages were frozen via vitrification using ethylene glycol- and propylene glycol-based solutions. More than 90% of the embryos at all developmental stages survived after warming. The developmental rates to offspring of thawed embryos at the pronuclear, 2-cell, and morula stages were 19%, 41%, and 52%, respectively. Pronuclear stage embryos between the early and late developmental stages were then vitrified. The developmental rates to offspring of the thawed pronuclear stage embryos collected at 24, 28, and 31 h after the induction of ovulation were 17%, 21%, and 23%, respectively. These results indicated that the tolerance to vitrification of rat embryos increased with the development of embryos. The establishment of vitrification method of rat embryos at various developmental stages is helpful for improving the production and storage of valuable rat strains used for biomedical science.

Immunological and toxicological risk assessment of e-cigarettes.

Knowledge of the long-term toxicological and immunological effects of e-cigarette (e-cig) aerosols remains elusive due to the relatively short existence of vaping. Therefore, we performed a systematic search of articles published in public databases and analysed the research evidence in order to provide critical information regarding e-cig safety. Electronic nicotine delivery systems (or e-cigs) are an alternative to traditional cigarettes for the delivery of nicotine and are typically filled with glycerol or propylene glycol-based solutions known as e-liquids. Though present in lower quantities, e-cig aerosols are known to contain many of the harmful chemicals found in tobacco smoke. However, due to the paucity of experimental data and contradictory evidence, it is difficult to draw conclusive outcomes regarding toxicological, immunological and clinical impacts of e-cig aerosols. Excessive vaping has been reported to induce inflammatory responses including mitogen-activated protein kinase, Janus tyrosine kinase/signal transducer and activator of transcription and nuclear factor-κB signalling, similar to that induced by tobacco smoke. Based on recent evidence, prolonged exposure to some constituents of e-cig aerosols might result in respiratory complications such as asthma, chronic obstructive pulmonary disease and inflammation. Future studies are warranted that focus on establishing correlations between e-cig types, generations and e-liquid flavours and immunological and toxicological profiles to broaden our understanding about the effects of vaping.

Equilibrium vitrification of mouse embryos at various developmental stages

Previously, we developed a new method by which 2-cell mouse embryos can be vitrified in liquid nitrogen in a near-equilibrium state, and then kept at -80°C for several days. In the present study, we examined whether or not the method was effective for mouse embryos at other developmental stages. Eight-cell embryos, morulae, and expanded blastocysts of ICR mice were vitrified with ethylene glycol-based solutions, named EFSc because of their composition of ethylene glycol (30-40%, v/v) and FSc solution. The FSc solution was PB1 medium containing 30% (w/v) Ficoll PM-70 plus 1.5 M sucrose. The extent of equilibrium was assessed by examining how well vitrified embryos survived after being kept at -80°C. When 8-cell embryos and morulae were vitrified with EFS35c or EFS40c and then kept at -80°C, the survival rate was high even after 4 days in storage and remained high after re-cooling in liquid nitrogen. On the other hand, the survival of vitrified-expanded blastocysts kept at -80°C was low. Therefore, 8-cell embryos and morulae can be vitrified in a near-equilibrium state using the same method as for 2-cell embryos. A high proportion of C57BL/6J embryos at the 2-cell, 8-cell, and morula stages vitrified with EFS35c developed to term after transportation on dry ice, re-cooling in liquid nitrogen, and transfer to recipients. In conclusion, the near-equilibrium vitrification method, which is effective for 2-cell mouse embryos, is also effective for embryos at the 8-cell and morula stages. The method would enable handy transportation of vitrified embryos using dry ice.

Effect of polyethylene glycol-based preservation solutions on graft injury in experimental kidney transplantation (Br J Surg 2010; 98: 368–378)

Effect of polyethylene glycol-based preservation solutions on graft injury in experimental kidney transplantation (<i>Br J Surg</i> 2010; 98: 368–378)

Vitrification of Two-Cell Rat Embryos Derived from Immature HypothyroidrdwRats byin VitroFertilization in Ethylene Glycol-Based Solutions

Two-cell embryos derived from immaturerdwrats byin vitrofertilization (IVF) were vitrified in ethylene glycol-based solutions. Embryos exposed to EFS20 before being vitrified in EFS40 exhibited improved viabilityin vitro.All embryos exposed to EFS20 for 1–3 min before vitrification in EFS40 were morphologically normal. However, 2–3 min of exposure to EFS20 increased the number of embryos that developed beyond the four-cell stage. More embryos exposed to EFS20 for 2–3 min developed to morulae (63–64%) and blastocysts (34–38%) than those exposed for 1 min (35 and 10%, respectively). After transfer, 33% of embryos exposed to EFS20 for 3 min and vitrified in EFS40 developed to term compared to 29% of fresh embryos. Fifteen (47%) of live young were homozygousrdwand all of the others were heterozygous rats. The present study demonstrated that vitrification in EFS solution can be routinely used to cryopreserve rat two-cell IVF-embryos with no loss of viability.

Sugars Exert a Major Influence on the Vitrification Properties of Ethylene Glycol-Based Solutions and Have Low Toxicity to Embryos and Oocytes

A systematic approach was taken to assess the vitrification properties of ethylene glycol-based solutions supplemented with carbohydrates. Solutions were prepared by weight (gravimetrically) using ethylene glycol as the cryoprotectant, 0.9% NaCl in water, and six different sugars:d-glucose,d(−)-fructose,d-sorbitol, sucrose,d(+)-trehalose, and raffinose. Sugars were added on a molal basis (0.1, 0.5, and 1m). Characteristics of the solutions were measured during warming by differential scanning calorimetry using a cooling rate of 100°C/min and a warming rate of 10°C/min. In the absence of carbohydrates a 59 wt% EG-saline solution formed a stable glass. When EG was replaced by an equimolal concentration of glucose, fructose, or sorbitol (monosaccharides) at 0.1, 0.5, or 1.0mthere was no change in the total solute concentration at which vitrification occurred, but the glass transition (Tg) occurred at a higher temperature than in EG-saline alone. When EG was replaced by an equimolal concentration of sucrose or trehalose (disaccharides) both the Tg and the lowest total solute concentration required for vitrification became progressively higher as the molecular weight, or the ratio of sugar to EG in the solutions, increased. At the highest tested disaccharide concentration (1m) vitrification was achieved at a total solute concentration of 65 wt% (sucrose) and 67 wt% (trehalose). The polysaccharide raffinose significantly modified the vitrification properties of ethylene glycol solutions. When 0.5 or 0.1mraffinose replaced EG on an equimolal basis the glass transition point was raised more than with either the monosaccharides or the disaccharides. Raffinose allowed vitrification at a total solute concentration of 67 wt% (0.5m) and 63 wt% (0.1m). The maturation of immature mouse oocytes, and the development of embryos in media containing 5–7 mM of any sugar was comparable to controls, indicating that they are not toxic. Exposure of freshly collected GV or MII oocytes to sugar concentrations between 0.5 and 1.0 M, for up to 10 min had no significant effect on the proportion which subsequently formed two cells. We conclude that added sugars do contribute to a solutions overall vitrification properties, and their properties should be taken into consideration when vitrification solutions are being designed or modified.

Mechanical Bowel Preparation for Elective Colorectal Surgery: A Prospective, Randomized, Surgeon-Blinded Trial Comparing Sodium Phosphate and Polyethylene Glycol-Based Oral Lavage Solutions

AIM: The aim of this study was to compare the cleansing ability, patient compliance, and safety of two oral solutions for elective colorectal surgery. METHODS: All eligible patients were prospectively randomized to receive either 4 1 of standard polyethylene glycol (PEG) solution or 90 ml of sodium phosphate (NaP) as mechanical bowel preparation for colorectal surgery. A detailed questionnaire was used to assess patient compliance. In addition, the surgeons, blinded to the preparation, intraoperatively evaluated its quality. Postoperative septic complications were also assessed. The calcium serum level was monitored before and after bowel preparation. Statistical analysis was performed using the Wilcoxon's rank-sum test and Fisher's exact test. RESULTS: Two hundred patients, well matched for age, gender, and diagnosis, were prospectively randomized to receive either PEG or NaP solutions for elective colorectal surgery. All patients completed all phases of the trial. There was a significant decrease in serum calcium levels after administration of both NaP (mean, 9.3-8.8 mg/dl) and PEG (9.2-8.9 mg/dl), respectively (P < 0.0001), with no clinical sequelae. However, patient tolerance to NaP was superior to PEG: less trouble drinking the preparation (17 vs. 32 percent; P < 0.0002), less abdominal pain (12 vs. 22 percent; P = 0.004), less bloating (7 vs. 28 percent), and less fatigue (8 vs. 17 percent), respectively. Additionally, 65 percent of patients who received the NaP preparation stated they would repeat this preparation again compared with only 25 percent for the PEG group (P < 0.0001). Ninety-five percent of patients who received the NaP solution tolerated 100 percent of the solution compared with only 37 percent of the PEG group (P < 0.0001). For quality of cleansing, surgeons scored NaP as excellent or good in 87 compared with 76 percent after PEG (P = not significant). Rates of septic and anastomotic complications were 1 percent and 1 percent for NaP and 4 percent and 1 percent for PEG, respectively (P = not significant). CONCLUSION: Both oral solutions proved to be equally effective and safe. However, patient tolerance of the small volume of NaP demonstrated a clear advantage over the traditional PEG solution.

Vitrification of human embryos based on the assessment of suitable conditions for 8-cell mouse embryos.

Experiments were conducted to find a suitable cryoprotectant and suitable procedure for vitrification of 8-cell mouse embryos. The method was then applied clinically to the cryopreservation of human embryos in our assisted reproduction programme. Mouse embryos were vitrified with 30 or 40% 1,2-propanediol (PROH), dimethylsulphoxide (DMSO), ethylene glycol, glycerol, or acetamide, each diluted with a solution containing 30% Ficoll plus 0.5 M sucrose. Embryos were exposed to the solutions for 0.5 or 2 min at 20 or 25 degrees C, cooled in liquid nitrogen and warmed rapidly. Embryo survival was assessed by in-vitro development. In PROH-, DMSO- and acetamide-based solutions, higher survival rates (29-82%) were obtained with less permeating conditions, suggesting that these cryoprotectants are considerably toxic. In glycerol- and ethylene glycol-based solutions, however, higher survival rates (74 and 92% respectively) were obtained with more permeating conditions, suggesting that these cryoprotectants are less toxic. Human embryos on days 2-3 were vitrified in an ethylene glycol-based solution (EFS40). Survival, assessed by the morphology, was higher in 4-cell embryos on day 2 and 8-cell embryos on day 3 than in 2-3-cell embryos on day 2 or 2-7-cell embryos on day 3. From 18 transfers, one ended with the delivery of healthy twin babies.

Optimization of the Procedures for the Vitrification of Expanded Mouse Blastocysts in Glycerol-Based Solutions.

Experiments were conducted to find optimal conditions for obtaining high survival of expanded mouse blastocysts after vitrification in glycerol-based solutions. The solutions were GFS20, GFS30, GFS40 and GFS50, which contained 20%, 30%, 40% and 50% glycerol, respectively, diluted in PB1 medium containing 30% Ficoll + 0.5 M sucrose. The toxicity tests of the solutions and glycerol showed that longer exposure to a higher concentration of glycerol is more injurious to the embryos. For vitrification, expanded blastocysts were exposed to the GFS solution at 20 or 25 C for various periods; they were then vitrified in liquid nitrogen, and were warmed rapidly. When the embryos were directly exposed to GFS40 for 2 min at 25 C, 68% of them re-expanded during 48 h of post-warming culture. The re-expansion rates decreased, when exposure time was shortened or extended, when the exposure temperature was lowered (20 C), or when embryos were vitrified in GFS20, GFS30, and GFS50. When embryos had been pretreated in a dilute (10-20%) ethylene glycol solution for 5 min, followed by short exposure (0.5 min) to GFS40 at 25 C, the post-vitrifica-tion survival rate increased to 82-87%; furthermore, the rate reached 92% when GFS40 was re-placed by GFS50. Expanded blastocysts cryopreserved in GFS50 had the ability to develop into live young. The findings showed that glycerol-based solutions are as effective as ethylene glycol-based solutions, although the optimal solution needs a higher concentration of glycerol, probably because glycerol permeates the embryos more slowly than ethylene glycol.

Cryopreservation of expanded mouse blastocysts by vitrification in ethylene glycol-based solutions.

Experiments were conducted to find optimal conditions for obtaining high survival of expanded mouse blastocysts after vitrification. The vitrification solutions used were designated EFS20, EFS30 and EFS40, and contained 20%, 30% and 40% ethylene glycol, respectively, diluted in PB1 medium containing 30% Ficoll plus 0.5 mol sucrose l-1. In the toxicity test of the solutions and each cryoprotectant, ethylene glycol was found to be toxic to embryos. For vitrification, expanded blastocysts were exposed to the vitrification solutions at 10, 20 or 25 degrees C for various periods; they were then cooled rapidly in liquid nitrogen, after which they were warmed rapidly. When the embryos were directly exposed to EFS40 at 20 degrees C for 2 min before vitrification, 66% of them re-expanded during 48 h of post-warming culture. The re-expansion rates decreased when exposure time was shortened (0.5 min), when exposure temperature was lowered (10 degrees C), or when embryos were vitrified in EFS20 and EFS30, although these conditions should be less toxic. When embryos had been pretreated in a dilute (10-20%) ethylene glycol solution for 5 min, followed by short exposure (0.5 min) to EFS40 at 20 degrees C, post-vitrification survival rate increased to 83-84%; furthermore, the rate reached 94% when the temperature was increased to 25 degrees C. Expanded blastocysts cryopreserved by this two-step method developed into live young as well as control embryos after transfer.(ABSTRACT TRUNCATED AT 250 WORDS)

Anodic oxidation of indium phosphide in glycol-based solutions

An anodic native oxide has been grown onto indium phosphide using glycol-based solutions. The variation of the anodic current behaviour with various circuit parameters has been measured, together with the thickness of the oxide as a function of voltage. MOS capacitor structures have been fabricated using this native oxide as the insulator and the I/ V and C/ V characteristics of these structures have been measured and analysed.