An international laboratory comparison of dissolved organic matter composition by high resolution mass spectrometry: Are we getting the same answer?

High-resolution mass spectrometry (HRMS) has become a vital tool for dissolved organic matter (DOM) characterization. The upward trend in HRMS analysis of DOM presents challenges in data comparison and interpretation among laboratories operating instruments with differing performance and user operating conditions. It is therefore essential that the community establishes metric ranges and compositional trends for data comparison with reference samples so that data can be robustly compared among research groups. To this end, four identically prepared DOM samples were each measured by 16 laboratories, using 17 commercially purchased instruments, using positive-ion and negative-ion mode electrospray ionization (ESI) HRMS analyses. The instruments identified ~1000 common ions in both negative- and positive-ion modes over a wide range of m/z values and chemical space, as determined by van Krevelen diagrams. Calculated metrics of abundance-weighted average indices (H/C, O/C, aromaticity, and m/z) of the commonly detected ions showed that hydrogen saturation and aromaticity were consistent for each reference sample across the instruments, while average mass and oxygenation were more affected by differences in instrument type and settings. In this paper we present 32 metric values for future benchmarking. The metric values were obtained for the four different parameters from four samples in two ionization modes and can be used in future work to evaluate the performance of HRMS instruments

Acidified nitrite improves wound healing in type 2 diabetic rats: Role of oxidative stress and inflammation

Purpose: Decreased nitric oxide bioavailability in skin contributes to impaired wound healing in type 2 diabetes (T2D). This study aims at determining effects of acidified nitrite on wound closure as well as inflammatory and antioxidants markers in wound tissue of rats with T2D. Main methods: Skin wound was made on the back of rats 28 days after the induction of T2D (high-fat diet/low-dose of streptozotocin). Control and diabetic rats were subdivided into two subgroups: Untreated control (C), acidified nitrite-treated control (CN), untreated diabetes (D), and acidified nitrite-treated diabetes (DN). Acidified nitrite was applied once daily from day 3 to day 28 and the wounds were photographed for macroscopic changes. On days 3, 7, 14, 21, and 28 after wounding, wound levels of inflammatory and antioxidant markers were measured. Results: Half closure time (CT50) was significantly lower in acidified nitrite-treated diabetic rats compared to untreated ones (5.1 vs. 8.0 days, P < 0.001). Inflammatory response was delayed in diabetic rats and persistent inflammatory response was observed at day 14 after wounding. Acidified nitrite application restored the inflammatory response and antioxidant levels to control values. Conclusions: Acidified nitrite accelerated wound healing in rats with T2D by restoring delayed inflammatory response and augmentation of antioxidant defense. © 2020 Elsevier Inc

Acidified Nitrite Accelerates Wound Healing in Type 2 Diabetic Male Rats: A Histological and Stereological Evaluation

Impaired skin nitric oxide production contributes to delayed wound healing in type 2 diabetes (T2D). This study aims to determine improved wound healing mechanisms by acidified nitrite (AN) in rats with T2D. Wistar rats were assigned to four subgroups: Untreated control, AN-treated control, untreated diabetes, and AN-treated diabetes. AN was applied daily from day 3 to day 28 after wounding. On days 3, 7, 14, 21, and 28, the wound levels of vascular endothelial growth factor (VEGF) were measured, and histological and stereological evaluations were performed. AN in diabetic rats increased the numerical density of basal cells (1070 ± 15.2 vs. 936.6 ± 37.5/mm3) and epidermal thickness (58.5 ± 3.5 vs. 44.3 ± 3.4 μm) (all p < 0.05); The dermis total volume and numerical density of fibroblasts at days 14, 21, and 28 were also higher (all p < 0.05). The VEGF levels were increased in the treated diabetic wounds at days 7 and 14, as was the total volume of fibrous tissue and hydroxyproline content at days 14 and 21 (all p < 0.05). AN improved diabetic wound healing by accelerating the dermis reconstruction, neovascularization, and collagen deposition

Incidence of sex chromosome aneuploidy in Northern Italy: 27-year longitudinal study

OBJECTIVES: The availability of cell-free DNA (cfDNA) as a screening tool affords an opportunity for non-invasive identification of sex chromosome aneuploidies (SCAs). This longitudinal study from 1995 through 2021 investigates both the evolution and frequency of prenatal diagnostic testing using amniocentesis (AF) and chorionic villus sampling (CV), and the detection of SCAs through cfDNA samples from a large cohort in Northern Italy. METHODS: The results of genetic testing from CV and AF samples collected from public and private centers in Italy from 1995 to 2021 were collected. Chromosomal analysis was performed by routine Q-banding karyotype. Regression analyses and descriptive statistics were used to determine population data trends regarding the frequency of prenatal diagnostic testing and the identification of SCAs and correlated with changes in the indications for prenatal diagnostic tests and available screening options. RESULTS: In 27 years, 13,939,526 births and 231,227 invasive procedures were performed. This resulted in the prenatal diagnosis of 934 SCAs. After the commercial introduction of cfDNA use in 2015, the frequency of invasive procedures significantly decreased (P=0.03), while the frequency of prenatal SCA detection significantly increased (P=0.007). The indication for invasive procedures also shifted from advanced maternal age (AMA) to positive cfDNA results for sex chromosome trisomies (SCTs). CONCLUSIONS: Our findings suggest the inclusion of SCAs in prenatal cfDNA screening tests can increase the prenatal identification of affected individuals. As the benefits of early ascertainment are increasingly recognized, it is essential that healthcare providers are equipped with comprehensive and evidence-based information regarding the associated phenotypic differences and the availability of targeted effective interventions to improve neurodevelopmental and health outcomes for affected individuals. This article is protected by copyright. All rights reserved