Distinct lung cell signatures define the temporal evolution of diffuse alveolar damage in fatal COVID-19

Background Lung damage in severe COVID-19 is highly heterogeneous however studies with dedicated spatial distinction of discrete temporal phases of diffuse alveolar damage (DAD) and alternate lung injury patterns are lacking. Existing studies have also not accounted for progressive airspace obliteration in cellularity estimates. We used an imaging mass cytometry (IMC) analysis with an airspace correction step to more accurately identify the cellular immune response that underpins the heterogeneity of severe COVID-19 lung disease. Methods Lung tissue was obtained at post-mortem from severe COVID-19 deaths. Pathologist-selected regions of interest (ROIs) were chosen by light microscopy representing the patho-evolutionary spectrum of DAD and alternate disease phenotypes were selected for comparison. Architecturally normal SARS-CoV-2-positive lung tissue and tissue from SARS-CoV-2-negative donors served as controls. ROIs were stained for 40 cellular protein markers and ablated using IMC before segmented cells were classified. Cell populations corrected by ROI airspace and their spatial relationships were compared across lung injury patterns. Findings Forty patients (32M:8F, age: 22–98), 345 ROIs and >900k single cells were analysed. DAD progression was marked by airspace obliteration and significant increases in mononuclear phagocytes (MnPs), T and B lymphocytes and significant decreases in alveolar epithelial and endothelial cells. Neutrophil populations proved stable overall although several interferon-responding subsets demonstrated expansion. Spatial analysis revealed immune cell interactions occur prior to microscopically appreciable tissue injury. Interpretation The immunopathogenesis of severe DAD in COVID-19 lung disease is characterised by sustained increases in MnPs and lymphocytes with key interactions occurring even prior to lung injury is established

A review of current treatment options in the treatment of ocular and/or periocular squamous cell carcinoma in horses: is there a definitive "best" practice?

This review examines the most commonly reported treatment options for ocular squamous cell carcinoma (OSCC) and periocular squamous cell carcinoma (POSCC) in horses and proposes to conclude on the most viable method based on available published studies in terms of treatment outcome, known side effects, advantages, disadvantages, and reliability of available evidence. After a literature search for peer-reviewed published articles, seven most commonly reported on treatments for OSCC and/or POSCC were identified: surgery, photodynamic therapy, carbon dioxide (CO2) laser ablation, radiofrequency hyperthermia, cryotherapy, chemotherapy, and radiation therapy. Combination therapies were supported as a most successful recommendation; however, when considering site-specific outcomes, the following conclusions may be drawn: limbal squamous cell carcinoma (SCC) was most effectively treated with surgery and adjunctive therapy including CO2 laser ablation, mitomycin C, and brachytherapy; third eyelid SCC reported good outcomes when treated with surgery alone (clear margins) and in combination with brachytherapy for unclear margins; eyelid SCC, surgical resection was usually limited and most reports supported the use of adjunctive brachytherapy, although photodynamic therapy appeared to be a promising new treatment. It was deemed unreasonable to conclude on the best treatment for cornea, conjunctivae (palpebral and bulbar), and medial canthi in isolation because of lack of evidence. A consistently favored treatment for OSCC and/or POSCC in horses does not currently exist. The presentation of data in the literature and its lack of consistency make it impossible to statistically analyze and make comparative conclusions on treatment outcomes. This review provides a basis for further research to establish a best-practice protocol

The trajectory of COVID-19 cardiopulmonary disease: insights from an autopsy study of community-based, pre-hospital deaths

Background Post mortem examination of lung and heart tissue has been vital to developing an understanding of COVID-19 pathophysiology; however studies to date have almost uniformly used tissue obtained from hospital-based deaths where individuals have been exposed to major medical and pharmacological interventions. Methods In this study we investigated patterns of lung and heart injury from 46 community-based, pre-hospital COVID-19-attributable deaths who underwent autopsy. Results The cohort comprised 22 females and 24 males, median age 64 years (range 19–91) at time of death with illness duration range 0–23 days. Comorbidities associated with poor outcomes in COVID-19 included obesity (body mass index >30 kg·m−2) in 19 out of 46 cases (41.3%). Diffuse alveolar damage in its early exudative phase was the most common pattern of lung injury; however significant heterogeneity was identified with bronchopneumonia, pulmonary oedema consistent with acute cardiac failure, pulmonary thromboembolism and microthrombosis also identified and often in overlapping patterns. Review of clinical records and next of kin accounts suggested a combination of unexpectedly low symptom burden, rapidly progressive disease and psychosocial factors may have contributed to a failure of hospital presentation prior to death. Conclusions Identifying such advanced acute lung injury in community-based deaths is extremely unusual and raises the question why some with severe COVID-19 pneumonitis were not hospitalised. Multiple factors including low symptom burden, rapidly progressive disease trajectories and psychosocial factors provide possible explanations

HPV status of oropharyngeal cancer by combination HPV DNA/p16 testing: biological relevance of discordant results

Background and Purpose. Human papillomavirus (HPV) causes up to 70 % of oropharyngeal cancers (OSCC). HPV positive OSCC has a more favorable outcome, thus HPV status is being used to guide treatment and predict outcome. Combination HPV DNA/p16(ink4) (p16) testing is commonly used for HPV status, but there are no standardized methods, scoring or interpretative criteria. The significance of discordant (HPV DNA positive/p16 negative and HPV DNA negative/p16 positive) cancers is controversial. In this study, 647 OSCCs from 10 Australian centers were tested for HPV DNA/p16 expression. Our aims are to determine p16 distribution by HPV DNA status to inform decisions on p16 scoring and to assess clinical significance of discordant cancers.Methods. HPV DNA was identified using a multiplex tandem HPV E6 polymerase chain reaction (PCR) assay and p16 expression by semiquantitative immunohistochemistry.Results. p16 distribution was essentially bimodal (42 % of cancers had >= 70 % positive staining, 52

New evidence for geographic variation in the role of human papillomavirus in tonsillar carcinogenesis

Aims: Our previous studies of tonsillar cancers from New South Wales, Australia, and Jilin Province in the north-east of China, provided evidence that the proportion of these cancers attributable to human papillomavirus (HPV) varies geographically. This study provides the first data on HPV in tonsillar cancers from Hong Kong. Methods: A total of 49 Hong Kong tonsillar cancers were analysed for HPV DNA by PCR/sequencing and for p16INK4A, retinoblastoma (pRb) protein, cyclin D1 and p53 expression by semiquantitative immunohistochemistry as evidence of virus causality. Results were compared with those from New South Wales and Jilin Province. Results: Of the 31 Hong Kong cancers with amplifiable DNA, nine (29%) were HPV positive by PCR compared with 46% from New South Wales and 0% from Jilin Province. HPV positivity correlated with female gender, young age, over-expression of p16INK4A and loss of pRb and cyclin D1. Five year disease-specific survival for patients with HPV positive and HPV negative cancers was 82 and 42%, respectively. Relationships between HPV status and cell protein expression in Hong Kong cancers were consistent with those from New South Wales and Jilin Province. The proportion of HPV associated cancers reflected the relative incidence of oropharyngeal cancer in these regions. Conclusions: HPV is responsible for a small proportion of tonsillar cancers in Hong Kong patients. Differences in the proportions of tumours attributable to HPV in Hong Kong, New South Wales and Jilin Province may be due to environmental, cultural or genetic factors in the different populations