The performance of 11 fingertip pulse oximeters during hypoxemia in healthy human participants with varied, quantified skin pigment.

BACKGROUND: Fingertip pulse oximeters are widely available, inexpensive, and commonly used to make clinical decisions in many settings. Device performance is largely unregulated and poorly characterised, especially in people with dark skin pigmentation. METHODS: Eleven popular fingertip pulse oximeters were evaluated using the US Food and Drug Administration (FDA) Guidance (2013) and International Organization for Standardization Standards (ISO, 2017) in 34 healthy humans with diverse skin pigmentation utilising a controlled desaturation study with arterial oxygen saturation (SaO 2) plateaus between 70% and 100%. Skin pigmentation was assessed subjectively using a perceived Fitzpatrick Scale (pFP) and objectively using the individual typology angle (ITA) via spectrophotometry at nine anatomical sites. FINDINGS: Five of 11 devices had a root mean square error (ARMS) > 3%, falling outside the acceptable FDA performance range. Nine devices demonstrated worse performance in participants in the darkest skin pigmentation category compared with those in the lightest category. A commonly used subjective skin colour scale frequently miscategorised participants as being darkly pigmented when compared to objective quantification of skin pigment by ITA. INTERPRETATION: Fingertip pulse oximeters have variable performance, frequently not meeting regulatory requirements for clinical use, and occasionally contradicting claims made by manufacturers. Most devices showed a trend toward worse performance in participants with darker skin pigment. Regulatory standards do not adequately account for the impact of skin pigmentation on device performance. We recommend that the pFP and other non-standardised subjective skin colour scales should no longer be used for defining diversity of skin pigmentation. Reliable methods for characterising skin pigmentation to improve diversity and equitable performance of pulse oximeters are needed. FUNDING: This study was conducted as part of the Open Oximetry Project funded by the Gordon and Betty Moore Foundation, Patrick J McGovern Foundation, and Robert Wood Johnson Foundation. The UCSF Hypoxia Research Laboratory receives funding from multiple industry sponsors to test the sponsors' devices for the purposes of product development and regulatory performance testing. Data in this paper do not include sponsor's study devices. All data were collected from devices procured by the Hypoxia Research Laboratory for the purposes of independent research. No company provided any direct funding for this study, participated in study design or analysis, or was involved in analysing data or writing the manuscript. None of the authors own stock or equity interests in any pulse oximeter companies. Dr Ellis Monk's time utilised for data analysis, reviewing and editing was funded by grant number: DP2MH132941.

CD, or not CD, that is the question: a digital interobserver agreement study in coeliac disease.

OBJECTIVE: Coeliac disease (CD) diagnosis generally depends on histological examination of duodenal biopsies. We present the first study analysing the concordance in examination of duodenal biopsies using digitised whole-slide images (WSIs). We further investigate whether the inclusion of immunoglobulin A tissue transglutaminase (IgA tTG) and haemoglobin (Hb) data improves the interobserver agreement of diagnosis. DESIGN: We undertook a large study of the concordance in histological examination of duodenal biopsies using digitised WSIs in an entirely virtual reporting setting. Our study was organised in two phases: in phase 1, 13 pathologists independently classified 100 duodenal biopsies (40 normal; 40 CD; 20 indeterminate enteropathy) in the absence of any clinical or laboratory data. In phase 2, the same pathologists examined the (re-anonymised) WSIs with the inclusion of IgA tTG and Hb data. RESULTS: We found the mean probability of two observers agreeing in the absence of additional data to be 0.73 (±0.08) with a corresponding Cohen's kappa of 0.59 (±0.11). We further showed that the inclusion of additional data increased the concordance to 0.80 (±0.06) with a Cohen's kappa coefficient of 0.67 (±0.09). CONCLUSION: We showed that the addition of serological data significantly improves the quality of CD diagnosis. However, the limited interobserver agreement in CD diagnosis using digitised WSIs, even after the inclusion of IgA tTG and Hb data, indicates the importance of interpreting duodenal biopsy in the appropriate clinical context. It further highlights the unmet need for an objective means of reproducible duodenal biopsy diagnosis, such as the automated analysis of WSIs using artificial intelligence.

Identification and Structure-Guided Development of Pyrimidinone Based USP7 Inhibitors.

Ubiquitin specific protease 7 (USP7, HAUSP) has become an attractive target in drug discovery due to the role it plays in modulating Mdm2 levels and consequently p53. Increasing interest in USP7 is emerging due to its potential involvement in oncogenic pathways as well as possible roles in both metabolic and immune disorders in addition to viral infections. Potent, novel, and selective inhibitors of USP7 have been developed using both rational and structure-guided design enabled by high-resolution cocrystallography. Initial hits were identified via fragment-based screening, scaffold-hopping, and hybridization exercises. Two distinct subseries are described along with associated structure-activity relationship trends, as are initial efforts aimed at developing compounds suitable for in vivo experiments. Overall, these discoveries will enable further research into the wider biological role of USP7.

Discovery and characterization of highly potent and selective allosteric USP7 inhibitors.

Given the importance of ubiquitin-specific protease 7 (USP7) in oncogenic pathways, identification of USP7 inhibitors has attracted considerable interest. Despite substantial efforts, however, the development of validated deubiquitinase (DUB) inhibitors that exhibit drug-like properties and a well-defined mechanism of action has proven particularly challenging. In this article, we describe the identification, optimization and detailed characterization of highly potent (IC50 < 10 nM), selective USP7 inhibitors together with their less active, enantiomeric counterparts. We also disclose, for the first time, co-crystal structures of a human DUB enzyme complexed with small-molecule inhibitors, which reveal a previously undisclosed allosteric binding site. Finally, we report the identification of cancer cell lines hypersensitive to USP7 inhibition (EC50 < 30 nM) and demonstrate equal or superior activity in these cell models compared to clinically relevant MDM2 antagonists. Overall, these findings demonstrate the tractability and druggability of DUBs, and provide important tools for additional target validation studies.

Extracellular cathepsin S and intracellular caspase 1 activation are surrogate biomarkers of particulate-induced lysosomal disruption in macrophages.

BACKGROUND: Particulate matter has been shown to stimulate the innate immune system and induce acute inflammation. Therefore, while nanotechnology has the potential to provide therapeutic formulations with improved efficacy, there are concerns such pharmaceutical preparations could induce unwanted inflammatory side effects. Accordingly, we aim to examine the utility of using the proteolytic activity signatures of cysteine proteases, caspase 1 and cathepsin S (CTSS), as biomarkers to assess particulate-induced inflammation. METHODS: Primary peritoneal macrophages and bone marrow-derived macrophages from C57BL/6 mice and ctss(-/-) mice were exposed to micro- and nanoparticulates and also the lysosomotropic agent, L-leucyl-L-leucine methyl ester (LLOME). ELISA and immunoblot analyses were used to measure the IL-1ß response in cells, generated by lysosomal rupture. Affinity-binding probes (ABPs), which irreversibly bind to the active site thiol of cysteine proteases, were then used to detect active caspase 1 and CTSS following lysosomal rupture. Reporter substrates were also used to quantify the proteolytic activity of these enzymes, as measured by substrate turnover. RESULTS: We demonstrate that exposure to silica, alum and polystyrene particulates induces IL-1ß release from macrophages, through lysosomal destabilization. IL-1ß secretion positively correlated with an increase in the proteolytic activity signatures of intracellular caspase 1 and extracellular CTSS, which were detected using ABPs and reporter substrates. Interestingly IL-1ß release was significantly reduced in primary macrophages from ctss(-/-) mice. CONCLUSIONS: This study supports the emerging significance of CTSS as a regulator of the innate immune response, highlighting its role in regulating IL-1ß release. Crucially, the results demonstrate the utility of intracellular caspase 1 and extracellular CTSS proteolytic activities as surrogate biomarkers of lysosomal rupture and acute inflammation. In the future, activity-based detection of these enzymes may prove useful for the real-time assessment of particle-induced inflammation and toxicity assessment during the development of nanotherapeutics.

The application of a novel, cell permeable activity-based probe for the detection of cysteine cathepsins.

Cysteine cathepsins, such as cathepsin S (CTSS), are implicated in the pathology of a wide range of diseases and are of potential utility as diagnostic and prognostic biomarkers. In previous work, we demonstrated the potency and efficiency of a biotinylated diazomethylketone (DMK)-based activity-based probe (ABP), biotin-PEG-LVG-DMK, for disclosure of recombinant CTSS and CTSS in cell lysates. However, the limited cell permeability of both the biotin and spacer groups restricted detection of CTSS to cell lysates. The synthesis and characterisation of a cell permeable ABP to report on intracellular CTSS activity is reported. The ABP, Z-PraVG-DMK, a modified peptidyl diazomethylketone, was based on the N-terminus of human cystatin motif (Leu-Val-Gly). The leucine residue was substituted for the alkyne-bearing proparcylglycine to facilitate conjugation of an azide-tagged reporter group using click chemistry, following irreversible inhibition of CTSS. When incubated with viable Human Embryonic Kidney 293 cells, Z-PraVG-DMK permitted disclosure of CTSS activity following cell lysis and rhodamine azide conjugation, by employing standard click chemistry protocols. Furthermore, the fluorescent tag facilitated direct detection of CTSS using in-gel fluorescent scanning, obviating the necessity for downstream biotin-streptavidin conjugation and detection procedures.

Strategies for detection and quantification of cysteine cathepsins-evolution from bench to bedside.

The cysteine cathepsins are a family of closely related thiol proteases, normally found in the endosomal and lysosomal compartments of cells. A growing body of evidence has clearly linked the dysregulated activity of these proteases with many diseases and pathological conditions, offering therapeutic, prognostic and diagnostic potential. However, these proteases are synthesised as inactive precursors and once activated, are controlled by factors such as pH and presence of endogenous inhibitors, meaning that overall protein and activity levels do not necessarily correlate. In order to fully appreciate the role and potential of these proteases, tools are required that can detect and quantify overall cathepsin activity. Two main strategies have evolved; synthetic substrates and protease-labelling with affinity-binding probes (or activity-based probes). This review examines recent innovations in these approaches as the field moves towards developing tools that could ultimately be used in patients for diagnostic or prognostic applications.

Impact of counselling on quality of life and sleep in cancer patients.

It has been acknowledged that poor quality of sleep significantly correlates with poor quality of life; evidence suggests that counselling has a positive impact not only on the cancer patient's quality of life, but also on family members and friends. The aim of this service evaluation was to determine if there was an improvement in clients' quality of life and sleep patterns following counselling as offered by a local cancer charity. A total of 60 matched pre- and post-counselling questionnaires were completed and subjected to statistical analysis. When considering quality of life, in the domains of Role Emotional, Mental Health and Mental Component Summary Score, it can be concluded that counselling has a positive effect on emotional health and mental wellbeing. The mean total number of hours sleep per night significantly increased from 6 hours sleep per night at baseline to 6.8 hours sleep per night at the completion of counselling (p=0.005) showing clients gained an extra 48 minutes sleep per night. The improved emotional and mental wellbeing alongside the extra 48 minutes sleep per night provides evidence that there is a positive outcome for those patients and families who use counselling services. Nurses and other members of the multidisciplinary team should be encouraged to discuss supportive therapies with patients and those affected by cancer at all stages of the cancer trajectory, regardless of social status, gender or cancer type.

Factors influencing participation in breast cancer screening.

Despite the efficacy of mammography and the widespread promotion of screening programmes, a significant number of eligible women still do not attend for regular breast screening. An integrative review methodology was considered the most appropriate means to critically analyse the available literature pertaining to factors which influence participation in breast cancer screening. From the extensive literature search, 12 selected core research papers met the inclusion criteria and were incorporated in the literature review. Four themes emerged from the literature which impact on participation in mammography screening: psychological and practical issues, ethnicity issues, influence of socioeconomic status and issues related to screening programmes. The recent Independent Review Panel on Breast Cancer Screening endorsed the importance of access to information which clearly communicates the harms and benefits of breast screening to enable women to make informed decisions about their health. The recommendations from the panel and others have been included in this review.

Gastric neuroendocrine cell hyperplasia and type 1 tumours occurring within gastric hyperplastic polyps.

We wish to highlight the unusual occurrence of gastric neuroendocrine cell hyperplasia and type I neuroendocrine tumours within three hyperplastic polyps. In all cases, the neuroendocrine component was present within and between the hyperplastic foveolar glands of the polyps and overall formed the minor part of the polyps. Two of the patients presented with epigastric pain and the other with fatigue from anaemia, and on endoscopy, all three were found to have superficially ulcerated gastric polyps in the body (cases 1 and 2) and fundus (case 3). Two of the cases had serologically proven autoimmune atrophic gastritis, while the third case had histological evidence of an atrophic gastritis, most likely also autoimmune in aetiology. Cases 1 and 3 had single hyperplastic polyps, while case 2 had three polyps. All polyps showed linear neuroendocrine cell hyperplasia within hyperplastic foveolar epithelium both at the surface and within deeper-situated glands. Neuroendocrine immunohistochemistry highlighted the neuroendocrine cell hyperplasia. The bulk of the neuroendocrine component was restricted to hyperplastic mucosa forming the polyps. Non-hyperplastic adjacent mucosa showed less prominent neuroendocrine cell hyperplasia. It is unclear whether the two pathologies occurred simultaneously or independently. The common feature and causal link is atrophic gastritis, which predisposed the gastric mucosa to the development of both neuroendocrine cell hyperplasia and tumours, and hyperplastic polyps.

Radiologic characteristics and management of screen-detected metastatic carcinoid tumor of the breast: a case report.

Carcinoid tumors are known to metastasize to the breast, but their appearance can mimic a primary breast carcinoma, making biopsy essential in order to give the correct preoperative diagnosis. It has been suggested that core biopsy might precipitate a carcinoid crisis and should be avoided. We describe a case of screen-detected carcinoid tumor metastasis in the breast safely diagnosed by core biopsy and present the imaging findings, including magnetic resonance imaging and elastography. This case illustrates the importance of preoperative histologic diagnosis in enabling the appropriate surgical or medical management of these patients. Review of the literature also supports the policy that biopsy of nonhormonally active tumors may be safely performed.

Low-level TOP2A amplification in prostate cancer is associated with HER2 duplication, androgen resistance, and decreased survival.

HER2 and TOP2A genes, located on 17q, can be coamplified in cancer. Overexpression of both genes has been reported in high-grade, androgen-resistant prostate cancer. Both genes have not been compared in a single prostate cancer study and the frequency of TOP2A amplifications in prostate cancer is unknown. Using tissue microarrays, we did immunohistochemistry and fluorescence in situ hybridization for HER2 and TOP2A in 100 prostate cancers (41 localized and 59 advanced) and 42 cases of benign prostatic hyperplasia (BPH). Amplification was defined as a target/centromere signal ratio of > or =1.5. HER2 immunohistochemistry was scored from 0 to 3+. Percentage nuclei staining for topoisomerase IIalpha (topoIIalpha) was recorded; overexpression was defined as > or =5% cells staining. Eighteen (31%) advanced prostate cancers showed topoIIalpha overexpression; 12 (26%) showed TOP2A low-level amplification; 9 (16%) expressed HER2; and 6 (13%) showed HER2 low-level amplification. No high-level amplification of either gene (target/centromere signal ratio of > or =3.0) was detected. TOP2A coexpression and coamplification were seen in 75% and 66% of HER2-positive cases, respectively. Localized prostate cancer or BPH showed no gene amplification or topoIIalpha overexpression. Gene amplification or overexpression correlated with high stage and Gleason score. The presence of TOP2A amplification in advanced cancer was associated with androgen resistance and decreased survival by multivariate analysis. This is the first study to document low-level TOP2A amplification in prostate cancer and an association with reduced survival. TOP2A amplification may occur with or without HER2 duplication and is often associated with topoIIalpha expression. Therapies directed against topoIIalpha (and HER2) in such patients may improve survival.

Parvovirus infects cardiac myocytes in hydrops fetalis.

Parvovirus infection during pregnancy is an important cause of hydrops fetalis. It is attributed to anemia caused by viral-induced destruction of red blood cells. Infection of other organs has been reported including the heart, liver, and lungs. Few of these reports, however, convincingly demonstrate virions within the functional parenchyma of the tissue. This is of particular concern regarding myocardium in the context of hydrops fetalis which is, in part, due to cardiac failure. The problem in routine pathology practice is that most fetuses with the infection are macerated. This, in part, probably explains the paucity of published information on cardiac involvement. This study examined five cases of fatal hydrops fetalis with variable maceration with serologically proven parvovirus B19 infection. Transmission electron microscopy of cardiac tissue demonstrated intranuclear virions in both erythroid precursor cells and in cardiac myocytes in three of these cases. In each of these, immuno-gold electron microscopy provided confirmatory evidence of parvovirus infection. Virions were not identifiable where maceration had caused disintegration of nuclei in the myocytes. In addition, virions were absent in the three negative control cases where retroplacental hemorrhage was confirmed as the cause of death. This study suggests that parvovirus infection of cardiac myocytes may play a more important role in causing hydrops fetalis than previously realized. It also demonstrates that maceration should not discourage the use of electron microscopy.