In situ and in vitro evaluation of two antiseptics for blood bank based on chlorhexidine gluconate/isopropyl alcohol and povidone-iodine.

BACKGROUND: Poor disinfection is the main cause of blood contamination, so its elimination is key to limiting the entry of bacteria into the collection system. With the advancement of antiseptic technology, antiseptics with sterile, disposable applicators are now available. AIM: To evaluate in situ two antiseptics (with and without applicators) for blood banks and to demonstrate in vitro antiseptic activity on bacterial biofilms of importance in transfusion medicine. METHODS: Antiseptic A (2% sterile solution of chlorhexidine gluconate/70% isopropyl alcohol provided with applicator) and bulk antiseptic B (10% povidone-iodine) were evaluated. The deferred blood donor arms were subjected to disinfection with antiseptics A and B and the contralateral arms were cultured to determine the baseline bacterial load (control). Antiseptic activity was assessed by ANOVA and logaritmic reduction values (LRV) and percentage reduction values (PRV) were calculated. Finally, the in vitro activity of antiseptic A was analyzed by confocal laser scanning microscopy (CLSM) on biofilm models. RESULTS: Prior to disinfection tests, commensal and clinically important bacteria were identified; antiseptic A showed post-disinfection bacterial growth rates of zero compared to controls (p < 0.0001). The frequency of bacterial growth with antiseptic B was 74%. A significant difference was identified between both antiseptics, where antiseptic A showed higher activity (p < 0.5468). LRV and PRV were 0.6-2.5/100% and 0.3-1.7/66.7-99.7% for antiseptics A and B, respectively. Through CLSM, disinfectant A (without applicator) showed lower in vitro antiseptic activity on the tested biofilms at the exposure times recommended by the manufacturer. CONCLUSIONS: Sterile solution of chlorhexidine gluconate/isopropyl alcohol with applicator showed advantages disinfection in deferred blood donors over povidone-iodine.

BD Chloraprep™ ("2 % chlorhexidine with 70 % isopropyl alcohol") versus povidone iodine plus alcohol, for prevention of blood culture contamination at children: An investigator-initiated, open-label, single centre, randomized controlled trial.

INTRODUCTION: One of the important problems that lower the diagnostic value of blood culture is contamination with skin organisms. The povidone-iodine, alcohol, and chlorhexidine gluconate alcohol are used for disinfection prior to blood sampling for culture. METHODS: The investigator-initiated, open label, single centre, randomised trial compared blood culture contamination rates between two groups of patients in which using a povidone iodine skin-preparation process with the contamination rate for using "2 % chlorhexidine with 70 % isopropyl alcohol" skin-disinfection. The patients who required sampling for blood cultures were included in the study and study period was from 15 March 2023 to 15 July 2023. RESULTS: A total of 400 blood cultures were obtained during the study, including 133 in the study group and 267 in the control group. In the total blood cultures, 11.75 % (n = 47) had microorganism isolation. Among them 39 (9.75 %) were contaminants and 8 (2 %) of them were true pathogens. The contaminant microorganisms were as following; 34 coagulase-negative Staphylococci, 3 Micrococcus spp, and 2 Streptococci viridans. The blood culture contamination rate in the study group was 5.3 % (n = 7) and 12.0 % (n = 32) in the control group, and significantly lower in the study group (p = 0.033). There is no significant difference regarding skin related side effects between two groups. CONCLUSIONS: This study, showed that 2 % chlorhexidine gluconate in 70 % isopropyl alcohol is more efficacious in children than 10 % povidone-iodine preparations for disinfecting the skin prior to blood specimen collection for prevention of blood culture contamination.

Isopropyl alcohol inhalation versus 5-HT3 antagonists for treatment of nausea: a meta-analysis of randomised controlled trials.

PURPOSE: Nausea is a common and unpleasant sensation for which current therapies such as serotonin (5-HT3) antagonists are often ineffective, while also conferring a risk of potential adverse events. Isopropyl alcohol (IPA) has been proposed as a treatment for nausea. We aimed to compare IPA with 5-HT3 antagonists for the treatment of nausea across all clinical settings. METHODS: MEDLINE, EMBASE, PubMed, CENTRAL and CINAHL were searched from inception to 17 July 2023 for randomised controlled trials (RCTs) comparing inhaled IPA and a 5-HT3 antagonist for treatment of nausea. Severity and duration of nausea, rescue antiemetic use, adverse events and patient satisfaction were the outcomes sought. Risk of bias (RoB) was assessed using Cochrane RoB 2. Random-effects model was used for meta-analysis. Combination of meta-analyses and narrative review was used to synthesise findings. The evidence was appraised using GRADE. RESULTS: From 1242 records, 4 RCTs were included with 382 participants. Participants receiving IPA had a significantly lower mean time to 50% reduction in nausea (MD - 20.06; 95% CI - 26.26, - 13.85). Nausea score reduction at 30 min was significantly greater in the IPA group (MD 21.47; 95% CI 15.47, 27.47). IPA led to significantly reduced requirement for rescue antiemetics (OR 0.60; 95% CI 0.37, 0.95; p = 0.03). IPA led to no significant difference in patient satisfaction when compared with a 5-HT3 antagonist. The overall GRADE assessment of evidence quality ranged from very low to low. CONCLUSION: IPA may provide rapid, effective relief of nausea when compared with 5-HT3 antagonists.

High risk and low prevalence diseases: Toxic alcohol ingestion.

INTRODUCTION: Toxic alcohol ingestion is a rare but serious condition that carries with it a high rate of morbidity and mortality. OBJECTIVE: This review highlights the pearls and pitfalls of toxic alcohol ingestion, including presentation, diagnosis, and management in the emergency department (ED) based on current evidence. DISCUSSION: Toxic alcohols include ethylene glycol, methanol, isopropyl alcohol, propylene glycol, and diethylene glycol. These substances can be found in several settings including hospitals, hardware stores, and the household, and ingestion can be accidental or intentional. Toxic alcohol ingestion presents with various degrees of inebriation, acidemia, and end-organ damage depending on the substance. Timely diagnosis is critical to prevent irreversible organ damage or death and is based primarily on clinical history and consideration of this entity. Laboratory evidence of toxic alcohol ingestion includes worsening osmolar gap or anion-gap acidemia and end organ injury. Treatment depends on the ingestion and severity of illness but includes alcohol dehydrogenase blockade with fomepizole or ethanol and special considerations for the initiation of hemodialysis. CONCLUSIONS: An understanding of toxic alcohol ingestion can assist emergency clinicians in diagnosing and managing this potentially deadly disease.

Hydrogen-rich gas production from disposable COVID-19 mask by steam gasification.

Globally, the demand for masks has increased due to the COVID-19 pandemic, resulting in 490,201 tons of waste masks disposed of per month. Since masks are used in places with a high risk of virus infection, waste masks retain the risk of virus contamination. In this study, a 1 kg/h lab-scale (diameter: 0.114 m, height: 1 m) bubbling fluidized bed gasifier was used for steam gasification (temperature: 800 °C, steam/carbon (S/C) ratio: 1.5) of waste masks. The use of a downstream reactor with activated carbon (AC) for tar cracking and the enhancement of hydrogen production was examined. Steam gasification with AC produces syngas with H2, CO, CH4, and CO2 content of 38.89, 6.40, 21.69, and 7.34 vol%, respectively. The lower heating value of the product gas was 29.66 MJ/Nm3 and the cold gas efficiency was 74.55 %. This study showed that steam gasification can be used for the utilization of waste masks and the production of hydrogen-rich gas for further applications.

Isopropyl alcohol nasal inhalation for nausea in the triage of an adult emergency department.

OBJECTIVES: Nausea and vomiting (N&V) are among the most common complaints in the emergency department (ED). However, low acuity is assigned to most of these patients at the triage, and waiting for long hours without medication decreases patient safety and satisfaction. We aimed to compare the inhalation of isopropyl alcohol (IPA) with placebo (P) to treat nausea at the triage area of an ED. METHODS: In this prospective, randomized and placebo-controlled trial, we used a convenience sample of consecutive adult (ages 18-65) patients presented to the triage area of the ED with the complaint of N&V, and we randomized them to inhale IPA or P embedded gauzes. We used an 11-point (0-10) numeric rating scale (NRS) to evaluate the degree of N&V before the inhalation, at the baseline, and at 2, 4 and 10 min after the inhalation. RESULTS: We randomized 118 patients (IPA, n = 62; P, n = 56, intent-to-treat), three patients left the ED without being seen, and 115 patients completed the study. IPA and P groups were similar according to age, sex, comorbidities, and vital signs. We found that patients in the IPA group had significantly lower mean NRS starting with the 2nd minute (robust two-way mixed ANOVA between-subjects, p = 0.008). We also observed a significant within-subjects effect in the IPA group. The mean NRS value was decreased at each consecutive time point in the IPA group (all pairwise comparisons, p < 0.001). CONCLUSION: In this study, IPA was significantly more effective than P for N&V at the triage. Moreover, patients in the IPA group had less need for rescue treatment.

Toxic transdermal absorption of isopropyl alcohol with falsely elevated creatinine.

Transdermal absorption of isopropyl alcohol (IPA) can cause toxicity at high doses, but case reports of this phenomenon are limited. This is a single patient encounter and chart review describing a 33-year-old previously healthy female who presented obtunded, wrapped in IPA soaked round cotton pads with overlying shrink wrap, her family's home remedy for a mild persistent rash. This case highlights several interesting aspects of IPA toxicity, including evidence that toxic doses of IPA are possible through transdermal absorption and creatinine may be falsely elevated due to acetone's interference with the measurement of creatinine on some assays.

Contact sensitizations to disinfectants containing alcohols or quaternary ammonium compounds are rarely of clinical relevance.

BACKGROUND: The use of disinfectants is part of the everyday life of people, especially in the medical profession. During the coronavirus disease 2019 (COVID-19) pandemic, the use of disinfectants continues to increase and is of fundamental importance in infection control. OBJECTIVES: To determine the frequency of sensitization and the value of patch testing to didecyldimethylammonium chloride (DDAC) and the alcohols ethanol, 1-propanol, and isopropanol. METHODS: Clinical patch test data of 145 patients with suspected contact allergy to disinfectants were retrospective analysed. RESULTS: Among the 145 patients patch tested with the different alcohols, only one nurse was detected with a possible allergy to 1-propanol. Additional patch testing in 84 patients with DDAC 0.05% resulted in five patients with weakly positive reactions only, without clinical relevance. Patch testing with DDAC 0.03% showed no positive reactions at all on day 3 readings. CONCLUSIONS: DDAC and alcohols are rarely responsible for allergic contact dermatitis. The accused products of the patients should be checked for other allergens and further additives with skin-irritating properties. Individual susceptibility and mishandling of the disinfectants should be considered.

Comparison of the quality of the microwave cell-block method with the conventional cell-block method in processing body fluid samples.

INTRODUCTION: Conventional cell blocks (CCB) prepared from cytological specimens are very useful but the method is relatively time-consuming. Suitable modifications in cell-block techniques are beneficial for improving the turnaround time. We share our experience of a rapid microwave cell-block (MCB) technique. AIM AND OBJECTIVES: To study the quality of routine and immunohistochemical (IHC) staining of cell-block sections from serous body fluids prepared by the MCB technique compared with the CCB technique. METHOD: A total of 177 serous body fluid samples were processed by routine centrifugation technique, and the sediments were used for cell-block preparations by both conventional and rapid microwave methods. Cell-block sections were stained with haematoxylin and eosin stain. Haematoxylin and eosin staining quality was analysed using three parameters (cellularity, morphology and staining intensity). IHC for epithelial membrane antigen and calretinin were also performed, and the quality of staining was evaluated on 62/177 samples. Results were analysed using appropriate statistical tests. RESULTS: The time taken for processing cell blocks by the MCB method was 1 hour and 18 minutes compared to 13 hours and 45 minutes by CCB. The quality of sections by both methods showed good agreement for cellularity and intensity of staining, and moderate agreement for morphology. A 100% concordance was noted for distinguishing benign and malignant samples on morphology as well as with IHC stain results. CONCLUSION: Although the techniques are comparable in terms of quality of routine and IHC staining, we recommend using the MCB technique due to its short turnaround time.

Soluble Expression and Efficient Purification of Recombinant Class I Hydrophobin DewA.

Hydrophobins are small proteins (<20 kDa) with an amphipathic tertiary structure that are secreted by various filamentous fungi. Their amphipathic properties provide surfactant-like activity, leading to the formation of robust amphipathic layers at hydrophilic-hydrophobic interfaces, which make them useful for a wide variety of industrial fields spanning protein immobilization to surface functionalization. However, the industrial use of recombinant hydrophobins has been hampered due to low yield from inclusion bodies owing to the complicated process, including an auxiliary refolding step. Herein, we report the soluble expression of a recombinant class I hydrophobin DewA originating from Aspergillus nidulans, and its efficient purification from recombinant Escherichia coli. Soluble expression of the recombinant hydrophobin DewA was achieved by a tagging strategy using a systematically designed expression tag (ramp tag) that was fused to the N-terminus of DewA lacking the innate signal sequence. Highly expressed recombinant hydrophobin DewA in a soluble form was efficiently purified by a modified aqueous two-phase separation technique using isopropyl alcohol. Our approach for expression and purification of the recombinant hydrophobin DewA in E. coli shed light on the industrial production of hydrophobins from prokaryotic hosts.

Microbial properties of the granular sludge in a psychrophilic UASB reactor fed with electronics industry wastewater containing organic chemicals.

In this study, a lab-scale upflow anaerobic sludge blanket (UASB) reactor was applied to the treatment of artificial electronics industry wastewater containing tetramethylammonium-hydroxide (TMAH), monoethanolamine (MEA), and isopropyl-alcohol (IPA) in order to evaluate process performance and degradation properties. During 800 days of operation, 96% efficiency of chemical oxygen demand (COD) removal was stably achieved at an organic loading rate of 8.5 kgCOD/m3/day at 18-19 °C. MEA degradation, carried out by acid-forming eubacteria, was confirmed within a week. The physical properties of the retained granular sludge were degraded by feeding with TMAH wastewater, but maintained by feeding with MEA wastewater due to an accumulation of species from the genus Methanosaeta and family Geobacteraceae. Analysis of the microbial community structure via SEM and 16S rRNA genes showed a proliferation of Methanomethylovorans-like cells and Methanosaeta-like cells at the surface and in the core of the granular sludge with TMAH, MEA and IPA acclimation. Furthermore, a batch degradation experiment confirmed that process inhibition due to increasing chemical concentration was relatively stronger for TMAH than for MEA or IPA. Thus, controlling the TMAH concentration of the influent to below 1 gCOD/L will be important for the stable treatment of electronics industry wastewater by UASB technology.

Air filters for indoor environments: Interlaboratory evaluation of the new international filter testing standard ISO 16890.

Electret filters are widely used in HVAC systems to decrease particulate matter in indoor environments. The previous standard in Europe for testing air filters for general ventilation was EN 779. In July 2018, it was replaced by the new international standard ISO 16890. One major change is the discharging process: It is now performed by treating the filters with saturated isopropyl alcohol (IPA) vapor. The process is intended to simulate a worst-case scenario of the filtration efficiency due to the reduction of the electret effect. These minimal efficiencies are a principal part of the filter classification. Therefore, two round robin tests with different filter classes (F9 and F7 according to EN 779) and up to eleven participants were carried out to evaluate the new test method by comparing the filtration efficiencies and pressure drops before and after the IPA treatment. Pressure drop measurements showed no mechanical altering of the material due to the discharging process. The calculated filter classes had a maximum deviation of 5%. Even with different equipment, the results indicate that the new ISO 16890 seems to be a viable test standard and a decent replacement for previous national standards.

Treatment of Basal Cell Carcinoma Via Binary Ethosomes of Vismodegib: In Vitro and In Vivo Studies.

Vismodegib (VMD) is a hedgehog inhibitor which indicated for basal cell skin cancer (BCC). This work focuses on investigating the influence of isopropyl alcohol additive for topical delivering and targeting of VMD-loaded binary ethosomes for BCC treatment. Different binary ethosome formulae were prepared based on Box-Behnken design using different concentrations of phospholipid (A), cholesterol (B) and isopropyl alcohol/total alcohol ratio (C). The prepared formulae were characterized for %entrapment efficiency (R1), vesicle size (R2), %release (R3) and steady-state flux (R4). Increasing A, B and C resulted in significant increase of R1 and R2 and significant decrease of R3 and R4. The optimization was achieved and the optimum formula was selected to investigate its anti-tumour efficacy in vivo. The optimum formula showed a localized VMD and consequently a significant anti-tumour activity compared with oral VMD. Briefly, VMD-loaded binary ethosome gel could be an effective treatment of BCC with lower side effects. Graphical abstract.

Environmental sustainability in endodontics. A life cycle assessment (LCA) of a root canal treatment procedure.

BACKGROUND: To analyse via life cycle analysis (LCA) the global resource use and environmental output of the endodontic procedure. METHODOLOGY: An LCA was conducted to measure the life cycle of a standard/routine two-visit RCT. The LCA was conducted according to the International Organization of Standardization guidelines; ISO 14040:2006. All clinical elements of an endodontic treatment (RCT) were input into OpenLCA software using process and flows from the ecoinvent database. Travel to and from the dental clinic was not included. Environmental outputs included abiotic depletion, acidification, freshwater ecotoxicity/eutrophication, human toxicity, cancer/non cancer effects, ionizing radiation, global warming, marine eutrophication, ozone depletion, photochemical ozone formation and terrestrial eutrophication. RESULTS: An RCT procedure contributes 4.9 kg of carbon dioxide equivalent (CO2 eq) emissions. This is the equivalent of a 30 km drive in a small car. The main 5 contributors were dental clothing followed by surface disinfection (isopropanol), disposable bib (paper and plastic), single-use stainless steel instruments and electricity use. Although this LCA has illustrated the effect endodontic treatment has on the environment, there are a number of limitations that may influence the validity of the results. CONCLUSIONS: The endodontic team need to consider how they can reduce the environmental burden of endodontic care. One immediate area of focus might be to consider alternatives to isopropyl alcohol, and look at paper, single use instrument and electricity use. Longer term, research into environmentally-friendly medicaments should continue to investigate the replacement of current cytotoxic gold standards with possible natural alternatives. Minimally invasive regenerative endodontics techniques designed to stimulate repair or regeneration of damaged pulp tissue may also be one way of improving the environmental impact of an RCT.

Development of a method for the detection of polystyrene microplastics in paraffin-embedded histological sections.

The concerns about the presence of microplastics (MPs) in marine ecosystems have widely increased in the past years. This is reflected in a growing number of studies addressing the effects of exposure to these materials in indigenous, farmed and even laboratory marine animals subjected to toxicity-oriented bioassays. There have been, however, many constraints in the detection of MPs in biological tissues, as routine histological techniques tend to degrade these materials, which are especially sensitive to organic solvents. This issue hinders the application of standard histopathological procedures based on convenient paraffin wax-embedding protocols, with consequences for biomonitoring and bioassay procedures. The method described here was developed and validated for the detection of polystyrene microplastics in biological tissue processed for paraffin-based histology. The strategy was developed and tested from whole-soft body sections of marine mussels that internalised the MPs following dedicated bioassays. The protocol is based on the replacement of xylenes with isopropanol for the purpose of intermediate infiltration and deparaffinization. Special modifications for staining, mounting and archiving are needed and are detailed as well. The protocol is shown to be a highly cost- and time-effective procedure compatible with formalin-based fixatives plus standard sectioning and staining, yielding complete preservation of MPs and optimal tissue conditioning. The method also produced excellent results with pre-stained MPs, with fluorochromes included, altogether providing excellent localisation of polystyrene MPs in paraffin-processed biological tissue.

Features of Terra Firma-Forme Dermatosis.

Terra-firma-forme dermatosis (TFFD) is a little known hyperpigmented skin disease that is more common than expected. We examined retrospectively the medical records of 79 patients: 88.6% were children, the mean age was 10.4 years (SD = 7.5 years), and 64.6% were female. The dermatoses were found on the trunk in 27.8%, extremities in 26.6%, fold zones in 8.9%, and head in 2.5% of the patients. The lesions appeared in more than 1 location in 34.2% of the patients and were symmetrically located 77.2% of the time. Swabbing with alcohol is sufficient for diagnosis and treatment. TFFD, mostly seen in children and female patients, should be kept in mind to avoid unnecessary diagnostic testing and treatment.

Influence of tetramethylammonium hydroxide (TMAH) on the microbial properties of anaerobic granular sludge acclimated to isoplophyl alcohol (IPA) wastewater under psychrophilic conditions.

In this study, a continuous flow experiment was conducted in which a lab-scale upflow anaerobic sludge blanket (UASB) reactor at psychrophilic conditions (18-19°C) was fed with artificial wastewater, containing tetramethylammonium hydroxide (TMAH) and isoplophyl alcohol (IPA), from the electronics industry. This was done to evaluate process performance and microbial properties of the granular sludge that was retained in the reactor. The inoculated granular sludge was precultured with IPA containing wastewater but not TMAH; as a result, no degradation was observed in 30 days of operation. To enhance degradation, the reactor was seeded with 2% weight of the TMAH-enriched sludge, after which TMAH was enhanced. Consequently, the total COD removal efficiency reached 90% at an organic loading rate of 7.5 kg COD/m3/day. The TMAH inflow decreased the diameter of the retained granular sludge, but the sludge retained its settleability. The proliferation of the Methanometylovorans microorganisms present in the enrichment culture was confirmed by analysis of the 16 S rRNA gene in the retained sludge. In addition, TMAH degradation was inhibited by addition chloroform, a methanogen inhibitor. These results suggested species in the genus Methanometylovorans in the granular sludge contributed significantly to methanogenic TMAH degradation.

Chlorhexidine-Induced Chemical Burns in Very Low Birth Weight Infants.

Skin disinfection with chlorhexidine gluconate has not been standardized in preterm infants. We present 5 cases of chemical burns that occurred within the first 2 days of life in very low birth weight neonates after skin disinfection with aqueous and alcohol-based chlorhexidine solutions.

Metabolic engineering of isopropyl alcohol-producing Escherichia coli strains with 13 C-metabolic flux analysis.

Metabolic engineering of isopropyl alcohol (IPA)-producing Escherichia coli strains was conducted along with 13 C-metabolic flux analysis (MFA). A metabolically engineered E. coli strain expressing the adc gene derived from Clostridium acetobutylicum and the IPADH gene from C. beijerinckii did not produce IPA during its exponential growth phase in the aerobic batch culture. 13 C-MFA was carried out, and revealed a deficiency in NADPH regeneration for IPA production in growth phase. Based on these findings, we used nitrogen-starved culture conditions to reduce NADPH consumption for biomass synthesis. As a result, IPA yield was increased to 20% mol/mol glucose. 13 C-MFA revealed that the relative flux levels through the oxidative pentose phosphate (PP) pathway and the TCA cycle were elevated in nitrogen-starved condition relative to glucose uptake rate. To prevent CO2 release in the 6-phosphogluconate dehydrogenase (6PGDH) reaction, metabolism of this E. coli strain was further engineered to redirect glycolytic flux to the glucose 6-phosphate dehydrogenase (G6PDH) and Entner-Doudoroff (ED) pathway. IPA yield of 55% mol/mol glucose was achieved by combining the nitrogen-starved culture condition with the metabolic redirection. The 13 C-MFA data and intracellular NADPH levels obtained under these IPA production conditions revealed linear correlations between the specific IPA production rate and NADPH concentration, as well as between IPA yield and the pyruvate dehydrogenase (PDH) flux. Our results showed that 13 C-MFA is a helpful tool for metabolic engineering studies, and that further improvement in IPA production by E. coli may be achieved by fine-tuning the cofactor ratio and concentrations, as well as optimizing the metabolic pathways and culture conditions.