Polar metabolomics using trichloroacetic acid extraction and porous graphitic carbon stationary phase.

INTRODUCTION: Accurately identifying and quantifying polar metabolites using untargeted metabolomics has proven challenging in comparison to mid to non-polar metabolites. Hydrophilic interaction chromatography and gas chromatography-mass spectrometry are predominantly used to target polar metabolites. OBJECTIVES: This study aims to demonstrate a simple one-step extraction combined with liquid chromatography-mass spectrometry (LC-MS) that reliably retains polar metabolites. METHODS: The method involves a MilliQ + 10% trichloroacetic acid extraction from 6 healthy individuals serum, combined with porous graphitic carbon liquid chromatography-mass spectrometry (LC-MS). The coefficient of variation (CV) assessed retention reliability of polar metabolites with logP as low as - 9. QreSS (Quantification, Retention, and System Suitability) internal standards determined the method's consistency and recovery efficiency. RESULTS: The method demonstrated reliable retention (CV < 0.30) of polar metabolites within a logP range of - 9.1 to 5.6. QreSS internal standards confirmed consistent performance (CV < 0.16) and effective recovery (70-130%) of polar to mid-polar metabolites. Quality control dilution series demonstrated that ~ 80% of annotated metabolites could be accurately quantified (Pearson's correlation coefficient > 0.80) within their concentration range. Repeatability was demonstrated through clustering of repeated extractions from a single sample. CONCLUSION: This LC-MS method is better suited to covering the polar segment of the metabolome than current methods, offering a reliable and efficient approach for accurate quantification of polar metabolites in untargeted metabolomics.

Exposures to drinking water disinfection byproducts and kidney function in Chinese women.

BACKGROUND: Disinfection byproducts (DBPs), the ubiquitous contaminants in drinking water, have been shown to impair renal function in experimental studies. However, epidemiological evidence is sparse. OBJECTIVE: To investigate exposures to DBPs in associations with renal function among women. METHODS: A total of 920 women from December 2018 to January 2020 were abstracted from the Tongji Reproductive and Environmental (TREE) Study, an ongoing cohort study in Wuhan, China. Urine samples were gathered at baseline recruitment and analyzed for dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA) as biomarkers of DBP exposures. Serum uric acid (UA), creatinine, and estimated glomerular filtration rate (eGFR) were measured as indicators of renal function. Multivariate linear regression and restricted cubic spline (RCS) models were conducted to assess urinary DCAA and TCAA concentrations in associations with renal function indicators. Stratified analyses by age and body mass index (BMI) were also performed. RESULTS: We found null evidence of urinary TCAA in associations with renal function indicators. However, elevated urinary DCAA tertiles were related to decreased eGFR (ß = -1.78%, 95% CI: 3.21%, -0.36%, comparing the upper vs. lower tertile; P for trend = 0.01). This inverse association still existed when urinary DCAA concentration was treated as a continuous variable, and the dose-response relationship was linear based on the RCS model (P for overall association = 0.002 and P for non-linear associations = 0.44). In the stratified analyses, we found an association of urinary DCAA concentration with decreased UA level among women <30 years but an association with increased UA level among women ≥30 years (P for interaction = 0.04). CONCLUSION: Urinary DCAA but not TCAA was associated with impaired renal function among women undergoing assisted reproductive technology.

Degradation of trichloroacetic acid by Fe/Ni bimetallic reactive PMS with hierarchical layered structure.

Overuse of chlorinated disinfectants leads to a significant accumulation of disinfection by-products. Trichloroacetic acid (TCA) is a typical carcinogenic disinfection by-product. The efficacy of the conventional degradation process is reduced by the complex nature of its structure, causing a yearly increase in its prevalence within the ecological environment and consequent infliction of significant harm. In this paper, TCA was chosen as the research subject, Fe/Ni bimetallic nanoparticles were employed as the reducing catalyst, ZIF-8@HMON as the catalytic carrier combined with Fe/Ni nanoparticles, and peroxymonosulfate (PMS) was introduced to construct the reducing-advanced oxidation synergistic system and investigated the effect of this system on the degradation performance and degradation pathway of TCA. Various characterization techniques, including TEM, SEM, XRD, FT-IR, XPS, BET, were employed to investigate the morphology, element composition and structure of composite materials analysis. Moreover, the conditions for TCA degradation can be optimized by changing the experimental environment. The results showed that 25 mg of composite catalyst (mole ratio Fe: Ni = 1:1) and 10 mg of PMS effectively degraded TCA within 20-80 mg/L range at pH = 3 and 55 °C, achieving maximum degradation within 20 min. Finally, the potential pathways of TCA degradation were analyzed using EPR and LC-MS, and the corresponding reaction mechanisms were proposed.

Comparative Analysis of Efficacy of Lactic Acid 30% with Ferulic Peel 12% (Combination Peel) Versus TCA 10% with Ferulic Peel 12% (Combination Peel) for Photoageing Skin.

OBJECTIVES: Chemical peels are used to treat photoageing, pigmentation, improve complexion and dull skin, fine lines and scars. The objective of this study is to do comparative analysis of Lactic Acid 30% with Ferulic peel 12% (combination peel) versus TCA 10% with Ferulic peel 12% (combination peel) for Photoageing Skin. MATERIALS AND METHODS: This is a retrospective study from September 2021 to 2022 with total 50 female patients aged between 25 and 40 years were treated. Randomisation of patients was done (simple randomisation using lottery method) for both groups with 25 patients enrolled in each group. The first group (Group A-25 patients) were treated with lactic acid 30% with Ferulic peel 12% (combination peel). The second group (Group B-25 patients) were treated with TCA 10% with Ferulic peel 12% (combination peel). Inclusion and exclusion criteria have been defined for the study. Two scales have been used for assessing the results: Allergan Skin Roughness Scale (ASRS) and Allergan Fine Line Scale (AFLS). ASRS and AFLS scores were assessed at pre-treatment (pre) and post treatment (post-1 month after last peel session). Data were summarised in Mean ± SD (standard deviation). Pre and post groups were compared by paired t test. The pre to post change in outcome measures between two independent groups were compared by independent Student's t test. Discrete (categorical) groups were compared by Chi-square (χ2) test. A two-tailed (α=2) P < 0.05 was considered statistically significant. Analyses were performed on SPSS software (Windows version 22.0). Patients were followed up for 6 months post treatment. RESULTS: In Group A, comparing the pre and post ASRS score, paired t test showed significant (P < 0.001) decrease or improvement of 56.1%. In Group B, comparing the pre and post ASRS score, paired t test showed significant (P < 0.001) decrease or improvement of 52.8%. Comparing the pre to post mean decrease or improvement in ASRS score of two groups, Student's t test showed similar (P > 0.05) improvement between the two groups though it was 2.5% higher in Group B as compared to Group A. In Group A, comparing the pre and post AFLS score, paired t test showed significant (P < 0.001) decrease or improvement of 63.2% at post as compared to pre. In Group B, comparing the pre and post AFLS score, paired t test showed significant (P < 0.001) decrease or improvement of 58.8% at post as compared to pre. Further, comparing the pre to post mean decrease or improvement in AFLS score of two groups, Student's t test showed similar (P > 0.05) improvement between the two groups though it was 16.7% higher in Group A as compared to Group B. CONCLUSION: Study found both the treatments equally effective in the management of ageing skin after 6 months of treatment. However, study needs further validation on larger sample size, varied age groups and male gender. LEVEL OF EVIDENCE V: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Reliable purity assay of highly hygroscopic trichloroacetic acid for the development of high-purity reference material of NMIJ CRM 4074-a.

Trichloroacetic acid is known as one of the harmful disinfection byproducts with chlorine of tap water and is regulated according to legally binding standards in Japanese Drinking Water Quality Standards. We developed a high-purity trichloroacetic acid reference material, NMIJ CRM 4074-a, with certified purity as a traceability source of standard solution supplied under the Japan Calibration Service System (JCSS). As trichloroacetic acid is hygroscopic, water could be the main impurity. Although all impurities in the sample can be possibly detected by the freezing point depression method (FPD), it was unclear for trichloroacetic acid whether water was detected by FPD owing to evaporation of water from the sample during fusion. Therefore, we confirmed that water in trichloroacetic acid was detected as an impurity by FPD. The procedure was validated from an increment of purity by FPD due to reduction of water content and an agreement of purity by FPD with those by neutralization titrimetry (NT) and mass balance approach (MBA), both methods were based on different measurement principles from FPD. The certified value was determined to be (0.999 ± 0.003) kg kg-1 from the purity assay by FPD and NT, and uncertainties due to the homogeneity and stability of the CRM were included in the expanded uncertainty. The reliability of the certified value was verified by the agreement of purities by FPD, NT, and MBA.

The chloroperoxidase immobilized on porous carbon nanobowls for the detection of trichloroacetic acid by electroenzymatic synergistic catalysis.

Trichloroacetic acid (TCA), as a by-product of chlorination disinfection, is a highly carcinogenic chemical. Due to the widespread use of chlorination disinfection, it is critical to detect TCA in drinking water to decrease the incidence of disease. In this work, we developed an efficient TCA biosensor via electroenzymatic synergistic catalysis. The porous carbon nanobowls (PCNB) are prepared and wrapped by an amyloid like proteins formed by phase-transitioned lysozyme (PTL-PCNB), then, chloroperoxidase (CPO) is abounding to PTL-PCNB owing to its strong adhesion. The ionic liquid of 1-ethyl-3-methylimidazolium bromide (ILEMB) is co-immobilized on PTL-PCNB to from CPO-ILEMB@PTL-PCNB nanocomposite to assist the direct electron transfer (DET) of CPO. The PCNB plays two roles here. In addition, to increasing the conductivity, it serves as an ideal support for holding CPO; The CPO-ILEMB@PTL-PCNB nanocomposite modified electrode presents high efficiency for sensing TCA. Through electroenzymatic synergistic catalysis, a wide detection range of 33 µmol L-1 to 98 mmol L-1 can be achieved with a low detection limit of 5.9 µmol L-1, and high stability, selectivity as well as reproducibility, which ensures its potential practical applicability. This work provides a new platform for the electro-enzyme synergistic catalysis in one pot.

MALDI Mass Spectrometry Imaging and Semi-Quantification of Topically Delivered Lactic Acid.

BACKGROUND: Lactic acid is a common active ingredient in many topical skincare products; however, measuring its delivery into the skin is challenging due to the presence of a large level of endogenous lactic acid. In this study, matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) was used to quantitatively and qualitatively measure the delivery of lactic acid into the skin from a range of topical skincare products. MATERIALS AND METHODS: Porcine skin samples were treated with various skincare products containing lactic acid. After 24 h, skin samples were sectioned and treated via H&E staining or prepared for MALDI-MSI using chemical derivatization. Samples were then analyzed by MALDI-MSI imaging to obtain lactic acid distribution in the entire skin section. RESULTS: Due to the high level of endogenous lactic acid in the skin, a "triple isotope" of lactic acid (L-Lactic acid-13 C3 ), was needed to provide full resolution from the skin's background signal with MALDI-MSI. With this approach, the topically delivered lactic acid could be quantitatively and qualitatively analyzed from a variety of skincare products. CONCLUSIONS: The combination of L-Lactic acid-13 C3 and MALDI-MSI was successfully used to quantitatively and qualitatively measure the topical delivery of lactic acid from a variety of skincare products. This approach could be used in future work to better understand the mode of action of lactic acid as an active ingredient in skincare products.

Towards Formulation of Highly Acidic Active Ingredients: Development of Clinically Effective Concentrated Trichloroacetic Acid Gel for Wart Management.

Common warts are benign skin lesions caused by the human papillomavirus. Although they are usually not harmful, they can cause pain, depending on their location. While many modalities are available for treatment of warts, none is a gold standard, and many are not affordable and/or have suboptimal outcomes. Trichloroacetic acid (TCA) is a chemical tissue-destroying agent used as a highly concentrated solution for wart management. While available and efficient, it is difficult to handle as the solution spreads to tissue surrounding the wart causing pain and burning. Hence, we developed a new polymer-based gel of high TCA content (100% w/v). Gels were formed successfully as hydroxyethyl cellulose (HEC) and chitosan were used to impart viscosity and bioadhesion. Formulae of different concentrations were tested for their physical properties, and the optimal formulation was selected for clinical evaluation. A combination of 3% HEC and 2% chitosan provided optimal viscosity and limited water content and have acceptable stability. The efficacy and safety of the biweekly application of TCA gel were evaluated in 30 patients. The clinical study revealed gel's efficacy and tolerability; half of the patients showed a complete cure, and 90% showed improvement within 6 weeks. Only 10-12% of the patients reported side effects. In summary, transforming TCA solution into a gel enabled its application and handling in a practical manner by physicians and patients alike, while maintaining its efficacy as a tissue-destroying agent. Moreover, it is economic and easy to apply, rendering it a promising formulation for similar conditions requiring controlled tissue ablation.

Unravelling a trichloroacetic acid-catalyzed cascade access to benzo[f]chromeno[2,3-h]quinoxalinoporphyrins.

A facile one-pot four-component synthetic methodology is evolved to construct novel copper(II) benzo[f]chromeno[2,3-h]quinoxalinoporphyrins in good yields via a sequential reaction of copper(II) 2,3-diamino-5,10,15,20-tetraarylporphyrins, 2-hydroxynaphthalene-1,4-dione, aromatic aldehydes, and dimedone in the presence of a catalytic amount of trichloroacetic acid in chloroform at 65 °C. Further, the newly prepared copper(II) porphyrins were transformed to the corresponding free base and zinc(II) benzo[f]chromeno[2,3-h]quinoxalinoporphyrins under standard demetallation and zinc insertion conditions. The absorption and emission properties of the obtained porphyrins were investigated by using UV-visible and fluorescence spectroscopy. The preliminary photophysical results revealed a significant red-shift in their absorption and emission spectra as compared to the meso-tetrakis(4-methylphenyl)porphyrins due to the extended π-conjugation.

Associations of Urinary Trichloroacetic Acid Concentrations with Spermatozoa Apoptosis and DNA Damage in a Chinese Population.

Exposure to trichloroacetic acid (TCAA) has been associated with impaired semen quality; however, its association with spermatozoa apoptosis and DNA damage remains unclear. We, therefore, collected single semen and repeated urine samples from male partners of couples attending a reproductive center, which were measured for spermatozoa apoptosis and DNA damage parameters and TCAA concentrations, respectively. Multivariable linear regression models were used to explore the associations between urinary TCAA concentrations and spermatozoa apoptosis (n = 462) and DNA damage parameters (n = 512). After adjusting for potential confounders, positive dose-response relationships were found between urinary TCAA concentrations and percentage of tail DNA (tail%) and tail-distributed moment (TDM) (both p for trend <0.10). Compared with men in the lowest tertile of urinary TCAA concentrations, men in the highest tertile had a greater tail% and TDM of 6.2% (95% CI: 0.7, 12.2%) and 8.9% (95% CI: -1.9, 20.5%), respectively. Urinary TCAA concentrations were unrelated to spermatozoa apoptosis parameters in a dose-response manner. However, urinary TCAA concentrations were positively associated with the percentage of Annexin V+/PI- spermatozoa (apoptotic cells), when urinary TCAA concentrations were modeled as continuous variables. Our results suggest that exposure to TCAA at concentrations in real-world scenarios may be associated with spermatozoa apoptosis and DNA damage.

Efficacy and safety of topical timolol 0.5% plus saline 0.9% versus each one alone in acne scar trichloroacetic acid-CROSS therapy: A blinded randomized controlled trial.

Trichloroacetic acid-CROSS (TCA-CROSS) or chemical reconstruction of scars is an approved method in the treatment of ICE-PICK scars. Timolol is a blocker of beta-adrenergic receptors that speeds up the healing of skin wounds. In this study, for the first time, the TCA-CROSS technique was combined with the use of saline injection and topical timolol to increase the effectiveness of treatment, and reduce the number of treatment sessions and complications, and thus improve the aesthetic result. In this parallel-group split-face randomized controlled assessor and analyst-blinded study, 45 patients with atrophic acne scars were randomly divided into 3 equal groups. TCA-CROSS treatment was performed on all facial scars of patients. In group 1, before TCA-CROSS, saline was injected under the scars on one side of the face, in group 2, after TCA-CROSS, 0.5% timolol eye drops were applied on the scars on one side, and in group 3, saline was injected before TCA-CROSS. After that, timolol eye drops were applied on the scars of the same side. In all groups, the choice of control side was random. The number of scars and patient and physician satisfaction were the main variables evaluating the effectiveness of the treatment. TCA-CROSS improved scars in both control and treatment sides of all 3 groups. Although the number of scars decreased on the treatment side of groups 2 and 3, the decrease was not statistically significant. In the saline + TCA group, the number of scars on the treatment side was slightly more than on the control side. In the group of patients who used timolol, the severity and duration of scar hyperpigmentation were significantly lower (group 2 p = 0.016, group 3 p = 0.002). No permanent complication was observed in the patients. Patients' satisfaction in groups 2 and 3 was higher in the treatment side than the control side. The combination of saline injection followed by TCA-CROSS is not recommended. Application of 0.5% timolol after TCA-CROSS caused a slight decrease in scar severity and a significant reduction of post-inflammatory hyperpigmentation (PIH) duration. So, the topical timolol makes a better result of TCA-CROSS for acne scar treatment.

Exposure to disinfection by-products and reproductive hormones among women: Results from the Tongji Reproductive and Environmental (TREE) study.

BACKGROUND: Disinfection by-products (DBPs) have been shown to impair female reproductive function. However, epidemiological evidence on reproductive hormones is scarce. OBJECTIVE: To investigate the associations between DBP exposures and reproductive hormones among women undergoing assisted reproductive technology. METHODS: We included 725 women from the Tongji Reproductive and Environmental (TREE) Study, an ongoing cohort conducted in Wuhan, China during December 2018 and January 2020. Urine samples collected at recruitment were quantified for dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA) as biomarkers of DBP exposures. At day 2-5 of menstruation, serum reproductive hormones including luteinizing hormone (LH), estradiol (E2), total testosterone (T), progesterone (PRGE), and prolactin (PRL) were determined. Multivariate linear regression models were performed to assess the associations of urinary DCAA and TCAA concentrations with reproductive hormone levels. Dose-response relationships were investigated using natural cubic spline (NCS) and restricted cubic spline (RCS) models. RESULTS: After adjusting for relevant confounders, we observed that higher urinary DCAA levels were associated with increased serum PRGE (9.2%; 95% CI: -0.55%, 19.8% for the highest vs. lowest tertile; P for trend = 0.06). Based on NCS models, we observed U-shaped associations of urinary DCAA with serum PRGE and PRL; each ln-unit increment in urinary DCAA concentrations above 3.61 µg/L and 6.30 µg/L was associated with 18.9% (95% CI: 4.8%, 34.7%) and 23.3% (95% CI: -0.92%, 53.5%) increase in serum PRGE and PRL, respectively. The U-shaped associations were further confirmed in RCS models (P for overall association ≤0.01 and P for non-linear associations ≤0.04). We did not observe evidence of associations between urinary TCAA and reproductive hormones. CONCLUSION: Urinary DCAA but not TCAA was associated with altered serum PRGE and PRL levels among women undergoing assisted reproductive technology.

A novel electrochemical sensor based on autotropic and heterotrophic nitrifying biofilm for trichloroacetic acid toxicity monitoring.

Trichloroacetic acid (TCA), a toxic substance produced in the disinfection process of wastewater treatment plants, will accumulate in the receiving water. The detection of TCA in the water can achieve the purpose of early warning. However, currently there are few reports on microbial sensors used for TCA detection, and the characteristics of their microbial communities are still unclear. In this work, a toxicity monitoring microbial system (TMMS) with nitrifying biofilm as a sensing element and cathode oxygen reduction as a current signal was successfully constructed for TCA detection. The current and nitrification rate showed a linear relationship with low TCA concentration from 0 to 50 µg/L (R2current = 0.9892, R2nitrification = 0.9860), and high concentration range from 50 to 5000 µg/L (R2current = 0.9883, R2nitrification = 0.9721). High-throughput sequencing revealed that the TMMS was composed of autotrophic/heterotrophic nitrifying and denitrifying microorganisms. Further analysis via symbiotic relationship network demonstrated that Arenimonas and Hyphomicrobium were the core nodes for maintaining interaction between autotropic and heterotrophic nitrifying bacteria. Kyoto Encyclopedia of Genes and Genomes analysis showed that after adding TCA to TMMS, the carbon metabolism and the abundance of the tricarboxylic acid cycle pathway were reduced, and the activity of microorganisms was inhibited. TCA stress caused a low abundance of nitrifying and denitrifying functional enzymes, resulting in low oxygen consumption in the nitrification process, but more oxygen supply for cathode oxygen reduction. This work explored a novel sensor combined with electrochemistry and autotrophic/heterotrophic nitrification, which provided a new insight into the development of microbial monitoring of toxic substances.

Preparation and Application of Electrochemical Horseradish Peroxidase Sensor Based on a Black Phosphorene and Single-Walled Carbon Nanotubes Nanocomposite.

To design a new electrochemical horseradish peroxidase (HRP) biosensor with excellent analytical performance, black phosphorene (BP) nanosheets and single-walled carbon nanotubes (SWCNTs) nanocomposites were used as the modifier, with a carbon ionic liquid electrode (CILE) as the substrate electrode. The SWCNTs-BP nanocomposite was synthesized by a simple in situ mixing procedure and modified on the CILE surface by the direct casting method. Then HRP was immobilized on the modified electrode with Nafion film. The electrocatalysis of this electrochemical HRP biosensor to various targets was further explored. Experimental results indicated that the direct electrochemistry of HRP was realized with a pair of symmetric and quasi-reversible redox peaks appeared, which was due to the presence of SWCNTs-BP on the surface of CILE, exhibiting synergistic effects with high electrical conductivity and good biocompatibility. Excellent electrocatalytic activity to trichloroacetic acid (TCA), sodium nitrite (NaNO2), and hydrogen peroxide (H2O2) were realized, with a wide linear range and a low detection limit. Different real samples, such as a medical facial peel solution, the soak water of pickled vegetables, and a 3% H2O2 disinfectant, were further analyzed, with satisfactory results, further proving the potential practical applications for the electrochemical biosensor.

Time-concentration-dependent profile of histone modifications on human hepatocytes treated by trichloroacetic acid.

Trichloroacetic acid (TCA) is a common non-volatile by-product of chlorination disinfection for drinking water. It is necessary to know the epigenetic toxicity and mechanisms for establishing safe exposure limit for environmental TCA exposure. This study explored the histone modification variations of TCA-treated human hepatocytes L-02 at different time and concentrations. TCA (0.1 mM, 0.3 mM and 0.9 mM) had an inhibitory effect on the growth of L-02 cells, with no significant changes in morphology. Treated with TCA for 24 h and 48 h, L-02 cells showed decreased mRNA and protein level of histone deacetylases (HDACs), but increased after 72 h. The downregulation of HDACs in early stage of TCA exposure might be one of the important reasons for the increase of H3K9ac level. These changes of histone modification may serve as early epigenetic biomarkers for TCA exposure and the related diseases, offering the safe environmental exposure concentration reference.

Origanum majorana essential oil improves the rat's sexual behavior and testicular oxidative damage induced by imidacloprid via modulating the steroidogenesis pathways.

The neonicotinoid insecticide imidacloprid has been linked to significant reproductive damage in mammals. Origanum majorana essential oil (OME) is a natural herbal product used in the management of many diseases due to its strong antioxidant effects. The oil was hydrodistilled from O. Majorana and analyzed using GC/MS then its possible protective mechanisms against IMI-induced reprotoxicity in male rats were investigated. 28-adult male Wistar rats were divided into 4 groups as follows: group (1) control group, group (2) OME, group (3) IMI, and group (4) IMI + OME. The treatments were applied daily via oral gavage for 60 days. Remarkable abnormalities in both territorial aggressive and sexual behaviors were observed in IMI-treated rats with a significant elevation of serum FSH and LH as well as altered testicular redox status. Along with inhibition of the testicular expression of StAR and aromatase genes and serum total testosterone in addition to abnormal sperm count, viability, motility, and morphology. Histopathological examination showed severe degeneration and necrosis in both germ cells and Leydig cells with atrophy in most of the seminiferous tubules. Co-administration of OME with IMI notably improved all the above-mentioned studied parameters, and restored rats' spermatogenesis, sexual behavior, and favorably modulates the levels of both testosterone and gonadotropic hormones via its potent antioxidant effect. These findings support the use of OME as a fertility enhancer and suggest that it could be used to manage pesticide-induced male infertility.

Most worthwhile superficial chemical peel for melasma of skin of color: Authors' experience of glycolic, trichloroacetic acid, and lactic peel.

Glycolic acid (GA), lactic acid (LA) and trichloroacetic acid (TCA) peels have been used in various combinations for treating melasma patients, but none of the studies have compared their therapeutic efficacy and improvement in quality of life (QOL) index with these three peeling agents in melasma. Our study aims to compare the clinical efficacy, safety, tolerability and improvement in QOL index between 30% GA, 92% LA, and 15% TCA peeling in epidermal melasma. Ninety patients were divided into three groups with 30 in each. First group was treated with 30% GA peel, second with 92% LA peel, and third with 15% TCA peel at every 2 weeks interval for 12 weeks. Melasma area severity index (MASI) and QOL index (Melasma quality of life and Health related quality of life index) were used for clinical evaluation. Patients were observed for side effects and tolerability. The mean MASI score after therapy was significantly lower in patients treated with GA and TCA peels as compared with the group receiving LA peel. However, there was no significant difference in the mean MASI scoring at 12 weeks between GA peel and TCA peel groups. The improvement in QOL index was higher among patients undergoing GA peel followed by TCA and LA peel. Adverse effects were noted mostly with TCA peels followed by GA and LA peel. Thus, GA and TCA peels were equally efficacious and more effective than LA peels. LA peel had minimum side effects and better tolerability than GA and TCA peels.

COVID-19: Topical agents and therapeutic prevention of nasal viral acquisition.

Since the spread of SARS-CoV-2 became a pandemic, the number of cases has been continuously growing worldwide. Numerous recommendations and suggestions have been published to prevent the acquisition and spread of the SARS-CoV-2, especially to protect health workers and front-line caregivers. SARS-CoV-2 is transmitted by aerosol, rendering air defense with suitable ventilation and adequate mask use pivotal. Recently, locally applied antiseptic, antiviral, or structure competitive receptor blockers were suggested to attack the virus at its main point of invasion, the nasal mucosa and nasopharynx. We discuss the most plausible and safe ideas to reduce viral load at the point of entry, and subsequently the spread of SARS-CoV-2 to the lower respiratory tract, lungs, and other organs. In addition, we analyze the value and recommend clinical trials employing topical trichloroacetic acid (TCA), a substance well known from dermatologic and cosmetic procedures. It has been proven to successfully block the nasal entry for airborne allergens, preventing the development of allergic rhinitis and asthma, and to be curative for early stages of viral infections entering through the oral mucosa. For SARS-CoV-2, TCA in a single, short-time application is expected to remodel the nasal and nasopharyngeal epithelia, eliminating both the receptors and cells responsible for viral entry and subsequent viral spread to the lower respiratory tract. Moreover, this may have therapeutic benefits for those recently infected by reducing local viral replication. Such procedures are cheap, safe, and can be conducted in almost every setting, especially in regions with inadequate financial and logistic resources.

Comparison of 40% trichloroacetic acid and cryotherapy for the treatment of plantar warts: A single-blind, randomized clinical trial.

Plantar warts can cause pain near the toes and the sole of the foot and may result in referral for treatment. This study was aimed at comparing 40% trichloroacetic acid (TCA) and cryotherapy (Cryo) for the treatment of plantar warts. This single-blind, randomized clinical trial was performed on 60 subjects presenting with plantar wart in Sabzevar, Iran in 2018. The first intervention group was treated with 40% TCA in four sessions within 4 weeks. The second intervention group was treated with Cryo using liquid nitrogen in four sessions within 8 weeks. The mean (SD) age of subjects was 20.16 ± 5.96 years and 68.33% (n = 41) were male. Although the resolution rate of warts in the TCA 40% group was greater than the Cryo group, there was no statistical association found between the two groups by adjusting age, sex, and basal time (P = .648). Findings suggest that although 40% TCA was almost as effective as Cryo in the treatment of plantar warts, considering the lower adverse effects of TCA 40% group as compared to the Cryo group, it could be a proper alternative.

Cryopeeling versus trichloroacetic acid peeling in the treatment of solar lentigines: Effect on epidermal Langerhans cells.

Trichloroacetic acid (TCA) peeling may be effective in solar lentigines, but with concerns regarding potential tumorigenesis. Cryopeeling would be better with improving the whole sun-damaged skin. We aimed to compare the efficacy and safety of cryopeeling and TCA 35% peeling for treatment of solar lentigines and assess their influence on the number of epidermal Langerhans cells (LC). Twenty-five patients were treated with TCA 35% and cryopeeling on the right and left hands, respectively. Two sessions were done 3 weeks apart. Evaluations were scheduled at weeks 0, 3, and 6. Skin biopsies, taken before and after treatment, were evaluated histologically and immunohistochemically for the number of CD1a + epidermal LCs. Lentigines decreased after cryopeeling from the first session (p < .001), but after the second session with TCA peeling (p = .004). Cryopeeling produced significant lightening, compared with TCA (p = .015). Blistering, hyper/hypopigmentation were reported with cryopeeling, whereas only hyperpigmentation was noted after TCA peeling. The LCs remained at about the pretreatment number after cryopeeling (p = .058), though they decreased after TCA (p = .002). Cryopeeling provided faster and superior improvement of lentigines compared with TCA peeling. Furthermore, TCA seems to suppress LCs raising the concern for carcinogenic potential.