Relevance of the College of American Pathologists guideline for validating whole slide imaging for diagnostic purposes to cytopathology

Whole slide imaging (WSI) allows pathologists to view virtual versions of slides on computer monitors. With increasing adoption of digital pathology, laboratories have begun to validate their WSI systems for diagnostic purposes according to reference guidelines. Among these the College of American Pathologists (CAP) guideline includes three strong recommendations (SRs) and nine good practice statements (GPSs). To date, the application of WSI to cytopathology has been beyond the scope of the CAP guideline due to limited evidence. Herein we systematically reviewed the published literature on WSI validation studies in cytology. A systematic search was carried out in PubMed-MEDLINE and Embase databases up to November 2021 to identify all publications regarding validation of WSI in cytology. Each article was reviewed to determine if SRs and/or GPSs recommended by the CAP guideline were adequately satisfied. Of 3963 retrieved articles, 25 were included. Only 4/25 studies (16%) satisfied all three SRs, with only one publication (1/25, 4%) fulfilling all three SRs and nine GPSs. Lack of a suitable validation dataset was the main missing SR (16/25, 64%) and less than a third of the studies reported intra-observer variability data (7/25, 28%). Whilst the CAP guideline for WSI validation in clinical practice helped the widespread adoption of digital pathology, more evidence is required to routinely employ WSI for diagnostic purposes in cytopathology practice. More dedicated validation studies satisfying all SRs and/or GPSs recommended by the CAP are needed to help expedite the use of WSI for primary diagnosis in cytopathology.     

A NEW TRAVERSODONTID CYNODONT (THERAPSIDA, EUCYNODONTIA) FROM THE MIDDLE TRIASSIC SANTA MARIA FORMATION OF RIO GRANDE DO SUL, BRAZIL

Abstract:  Remains of a peculiar traversodontid cynodont, Protuberum cabralensis gen. et sp. nov., are described herein. The material was collected from two outcrops representing the Therapsid Cenozone (Middle Triassic) of the Santa Maria Formation, and consists of a cranium with most of its dentition preserved and an associated postcranial skeleton. The upper postcanines have two sharp cusps that are connected by a medial crest on unworn postcanines. The specimens possess several autapomorphies, including: (1) presence of thickened bone on the dorsal surface of the skull; (2) thick dorsal ribs, with remarkable processes situated on their dorsal borders that decrease in size distally; and (3) an iliac blade with a series of rugosities along its dorsal border. The lumbar ribs bear overlapping costal plates and have distally projecting rib shafts that differ from the pattern observed in Thrinaxodon , Pascualgnathus and Cynognathus .     

Local DNA dynamics shape mutational patterns of mononucleotide repeats in human genomes

Single base substitutions (SBSs) and insertions/deletions are critical for generating population diversity and can lead both to inherited disease and cancer. Whereas on a genome-wide scale SBSs are influenced by cellular factors, on a fine scale SBSs are influenced by the local DNA sequence-context, although the role of flanking sequence is often unclear. Herein, we used bioinformatics, molecular dynamics and hybrid quantum mechanics/molecular mechanics to analyze sequence context-dependent mutagenesis at mononucleotide repeats (A-tracts and G-tracts) in human population variation and in cancer genomes. SBSs and insertions/deletions occur predominantly at the first and last base-pairs of A-tracts, whereas they are concentrated at the second and third base-pairs in G-tracts. These positions correspond to the most flexible sites along A-tracts, and to sites where a ‘hole’, generated by the loss of an electron through oxidation, is most likely to be localized in G-tracts. For A-tracts, most SBSs occur in the direction of the base-pair flanking the tracts. We conclude that intrinsic features of local DNA structure, i.e. base-pair flexibility and charge transfer, render specific nucleotides along mononucleotide runs susceptible to base modification, which then yields mutations. Thus, local DNA dynamics contributes to phenotypic variation and disease in the human population.     

High-performance liquid chromatography with UV detection and diode-array UV confirmation of isonicotinic acid hydrazide in cattle milk

A method for the determination of isonicotinic acid hydrazide (isoniazid) in milk was developed. Milk was deproteinized with trichloroacetic acid. Isoniazid was condensed with cinnamaldehyde and assayed on a reversed-phase HPLC system, with good sensitivity and accuracy (10 μg/l) with UV detection at 330 nm. Use of solid-phase extraction with a C₁₈ cartridge allows the detection limit to be lowered to 0.1 μg/l with UV detection and confirmation of isoniazid hydrazone from the diode-array UV spectrum.     

Tolerance of Landoltia punctata to arsenate: an evaluation of the potential use in phytoremediation programs

Abstract

Plants used in phytoremediation should accumulate and tolerate a specific pollutant. Here, we aimed at evaluating a possible arsenic (As) accumulation and mechanisms of tolerance against As-induced damage in Landoltia punctata to explore this species for phytoremediation. Plants were subjected to increasing As levels. As absorption was higher with increasing As levels. The activity of superoxide dismutase and glutathione reductase as well as anthocyanin levels increased with As levels. Catalase and peroxidase activities increased in plants subjected to As levels up to 1.0?mg L^?1 and decreased at higher levels. Due to the antioxidant system, higher levels of reactive oxygen species were restrained in plants under low levels of As. However, the levels of superoxide anion, hydrogen peroxide, and lipid peroxidation increased in response to the impaired antioxidant system induced by the highest As levels. Biomass decreased in plants exposed to As and scanning electron microscopy revealed root structural damage in the root cap of plants under 3.0?mg L^?1?As. This work highlights that L. punctata can be considered a hyperaccumulator species and has potential for As phytoremediation when levels are lower than 1.0?mg L^?1—a concentration 100-fold higher than that recommended for drinking water.

Novelty Statement: Landoltia punctata can be considered a hyperaccumulator species and has the potential for arsenic phytoremediation when levels are lower than 1.0?mg L^?1.