Cytological evaluation, culture and genomics to evaluate the microbiome in healthy rabbit external ear canals.

BACKGROUND: Lop-eared rabbits may be predisposed to otitis externa (OE) as a consequence of their ear conformation. Although otoscopy, otic cytological evaluation and culture are valuable tools in dogs and cats, published data on rabbits remain lacking. HYPOTHESIS/OBJECTIVES: This study aimed to assess the utility of otoscopy and cytological results in evaluating healthy rabbit external ear canals (EECs) and to characterise ear cytological and microbiological findings through culture techniques and metagenomic sequencing. ANIMALS: Sixty-three otitis-free client-owned rabbits. MATERIALS AND METHODS: All rabbits underwent otoscopy and ear cytological evaluation. In a subset of 12 rabbits, further bacterial and fungal culture, fungal DNA assessment and metagenomic sequencing were performed. RESULTS: Otic cytological results revealed yeast in 73%, cocci in 42.9% and rods in 28.6% of healthy rabbit EECs. Compared to upright-eared rabbits, lop-eared rabbits had more discharge and more bacteria per oil immersion field. Culture isolated eight different species yet metagenomic sequencing identified 36, belonging to the Bacillota (Firmicutes), Pseudomonadota and Actinomycetota phyla. Staphylococcus were the most commonly observed species with both methods. Ten of 12 rabbits were yeast-positive on cytological evaluation with only three yielding fungal growth identified as Yarrowia (Candida) lipolytica, Eurotium echinulatum and Cystofilobasidium infirmominiatum. CONCLUSIONS AND CLINICAL RELEVANCE: Healthy rabbit EECs lack inflammatory cells yet can host yeast and bacteria, emphasising the need to evaluate cytological results alongside the clinical signs. Lop-ear anatomy may predispose to bacterial overgrowth and OE. Notably, yeasts may be present despite a negative culture.

Experimental evolution of Staphylococcus aureus in macrophages: dissection of a conditional adaptive trait promoting intracellular survival.

Staphylococcus aureus is a major pathogen associated with important diseases in humans and animals. Macrophages are a key component of the innate immune response to S. aureus infection and play a major role in disease outcomes. To investigate the adaptive evolution of S. aureus in response to macrophages, we developed an experimental infection assay. S. aureus strains representing major human epidemic clones were passaged many times in a macrophage cell line, accumulating mutations in an array of genomic loci. Phenotypic analysis revealed the emergence of a lineage exhibiting increased survival in macrophages and human blood, and resistance to vancomycin. The evolved lineage exhibited a previously undescribed small colony variant (SCV) phenotype characterized by hyper-pigmentation, which resulted from a missense mutation in rsbW. Notably, the novel SCV was a conditional adaptive trait that was unstable in nutrient-replete conditions in vitro, rapidly converting from hyper-pigmented SCV to a non-pigmented large colony variant via spontaneous sigB deletion events. Importantly, we identified similar deletions in the genome sequences of a limited number of clinical S. aureus isolates from public databases, indicating that related events may occur during clinical infection. Experimental infection of zebrafish did not reveal a difference in virulence between parent and novel SCV but demonstrated an in vivo fitness cost for the compensatory sigB deletion events. Taken together, we report an experimental evolutionary approach for investigating bacterial innate immune cell interactions, revealing a conditional adaptation that promotes S. aureus survival in macrophages and resistance to vancomycin. IMPORTANCE: Staphylococcus aureus is an important human bacterial pathogen. The host response to S. aureus involves the production of innate immune cells such as macrophages which are important for fighting infection. Here we report a new model of experimental evolution for studying how S. aureus can evade killing by macrophages. We identified a novel adaptive phenotype that promotes survival in macrophages and blood and resistance to antibiotics. The phenotype is lost rapidly upon growth in nutrient-rich conditions via disruption of the alternative sigma factor sigB, revealing a conditional niche-specific fitness advantage. Genomic analysis of clinical isolates suggests similar adaptations may occur during human infections. Our model may be used broadly to identify adaptations of S. aureus to the innate immune response.

Baseline metastatic growth rate is an independent prognostic marker in patients with advanced BRAF V600 mutated melanoma receiving targeted therapy.

BACKGROUND: Targeted therapy (TT) of BRAF V600 mutated unresectable melanoma with inhibitors of the MAPK pathway achieves response rates of up to 76%, but most patients develop secondary resistance. Albeit TT is strikingly efficacious during the first days of treatment, even in advanced cases, long-term survival is highly unlikely, especially in patients with unfavorable baseline characteristics like elevated lactate dehydrogenase (LDH). In patients treated with anti-PD-1 immune checkpoint inhibitors, elevated baseline metastatic growth rate (MGR) was the most important prognostic factor. Here, we aimed at investigating the prognostic impact of MGR in patients with unresectable melanoma receiving TT. METHODS: Clinical records of 242 patients with at least one measurable target lesion (TL) receiving TT at seven skin cancer centers were reviewed. Baseline MGR was determined measuring the largest TL at baseline and at one earlier timepoint. RESULTS: Overall survival (OS) and progression-free survival (PFS) were significantly impaired in patients with an MGR > 3.9 mm/month (median OS: 11.4 vs. 35.5 months, P < 0.0001; median PFS: 4.8 vs. 9.2 months, P < 0.0001). Multivariable analysis of OS and PFS revealed that the prognostic impact of elevated MGR was independent of LDH, presence of brain and liver metastases, tumor burden, and line of treatment. The prognostic significance of elevated MGR was highest in patients with normal LDH. CONCLUSIONS: Baseline MGR is an important independent prognostic marker for OS and PFS in melanoma patients treated with TT. Its implementation in clinical routine is easy and could facilitate the prognostic stratification.

Prevalence of and Factors Associated with Arterial Aneurysms in Patients with Hereditary Hemorrhagic Telangiectasia: 17-Year Retrospective Series of 418 Patients.

PURPOSE: To estimate the prevalence of and identify characteristics associated with the presence of aneurysms in a cohort of patients with hereditary hemorrhagic telangiectasia (HHT). MATERIALS AND METHODS: In the study institution's HHT database, 418 patients with a definite HHT diagnosis were identified based on the clinical Curaçao criteria and/or an HHT-associated genetic mutation. Regression modeling was used to evaluate the association between arterial aneurysms and older age, male sex, smoking, alcohol consumption, hypertension, hyperlipidemia, genetic mutations, the presence of arteriovenous malformations (AVMs) unrelated to the aneurysms, and HHT-related genetic mutations. RESULTS: Forty-three (10.3%) patients had at least 1 aneurysm. Sixteen (3.8%) patients had multiple aneurysms. Of the variables analyzed, older age (odds ratio [OR] = 1.02; 95% confidence interval [CI]: 1.0-1.1), the presence of anatomically and flow-unrelated AVMs (OR = 3.2; 95% CI: 1.3-8.0), and the presence of activin A receptor type II-like 1 (ACVRL1) mutation (OR = 4.0; 95% CI: 1.5-10) were associated with the presence of at least 1 aneurysm. CONCLUSIONS: In this cohort of patients with HHT, the prevalence of intracranial and visceral arterial aneurysms was estimated to be 10.3%. Older age, the presence of unrelated AVMs, and the presence of the ACVRL1 mutation were associated with the presence of arterial aneurysms. Further study is required to assess the clinical importance and risk of rupture of aneurysms in patients with HHT.

Pretreatment metastatic growth rate determines clinical outcome of advanced melanoma patients treated with anti-PD-1 antibodies: a multicenter cohort study.

BACKGROUND: Checkpoint inhibitors revolutionized the treatment of metastatic melanoma patients. Although tumor burden and lactate dehydrogenase (LDH) are associated with overall survival (OS), the impact of tumor growth kinetics remains elusive and in part contradictory. The aims of this study were to develop a novel simple and rapid method that estimates pretreatment metastatic growth rate (MGR) and to investigate its prognostic impact in melanoma patients treated with antiprogrammed death receptor-1 (PD-1) antibodies. METHODS: MGR was assessed in three independent cohorts of a total of 337 unselected consecutive metastasized stage IIIB-IV melanoma patients (discovery cohort: n=53, confirmation cohort: n=126, independent multicenter validation cohort: n=158). MGR was computed during the pretreatment period before initiation of therapy with anti-PD-1 antibodies nivolumab or pembrolizumab by measuring the increase of the longest diameter of the largest target lesion. Tumor doubling time served as quality control. Kaplan-Meier analysis and univariable as well as multivariable Cox regression were used to examine the prognostic impact of MGR. RESULTS: Pretreatment MGR >3.9 mm/month was associated with impaired OS in the discovery cohort (HR 6.19, 95% CI 2.92 to 13.10, p<0.0001), in the confirmation cohort (HR 3.62, 95% CI 2.19 to 5.98, p<0.0001) and in the independent validation cohort (HR 2.57, 95% CI 1.56 to 4.25, p=0.00023). Prior lines of systemic treatment did not influence the significance of MGR. Importantly, the prognostic impact of MGR was independent of total tumor burden, diameter of the largest metastasis, number of prior lines of systemic treatment, LDH, as well as liver and brain metastasis (discovery and confirmation cohorts: both p<0.0001). Superiority of MGR compared with these variables was confirmed in the independent multicenter validation cohort (HR 2.92, 95% CI 1.62 to 5.26, p=0.00036). CONCLUSIONS: High pretreatment MGR is an independent strong prognostic biomarker associated with unfavorable survival of melanoma patients receiving anti-PD-1 antibodies. Further investigations are warranted to assess the predictive impact of MGR in distinct systemic therapeutic regimens.

Screening vs staging magnetic resonance imaging-guided core needle breast biopsies: Does MRI indication impact upgrade rate?

Adjunct magnetic resonance imaging (MRI) for both screening high-risk patients and staging for patients with newly diagnosed breast cancer leads to an increased number of biopsies and increased detection of atypical lesions. We assessed whether the malignancy upgrade frequency for high-risk atypia identified via MRI-guided biopsies varied based on indication: high-risk screening vs staging for malignancy. Among 399 MRI-guided biopsies, 46 (11.5%) high-risk lesions (ADH, ALH, and LCIS) were identified. Surgical excision was performed on 37% of 46%, and 24.3% were upgraded to invasive malignancy or DCIS. Of lesions identified by staging MRI, a slightly higher percentage, 28.5%, were upgraded (P = .36). Our data suggest that surgeons should carefully consider excisional biopsy for atypia identified on MRI regardless of indication.

Papillary and sclerosing lesions of the breast detected and biopsied by MRI: Clinical management, upgrade rate, and association with apocrine metaplasia.

Benign papillary and sclerosing lesions of the breast (intraductal papillomas, complex sclerosing lesions, radial scars) are considered high-risk lesions due to the potential for upgrade to carcinoma on subsequent surgical excision. Optimal clinical management of such lesions remains unclear due to variable reported upgrade rates. Apocrine metaplasia is a common finding in breast tissue and its role in MRI enhancing lesions is increasingly being recognized. The purpose of this study was to investigate the MRI features of papillary and sclerosing lesions of the breast, evaluate the clinical management and upgrade rate of such lesions, and examine the contribution of apocrine metaplasia to the imaging findings. A 13-year retrospective review of MRI-guided biopsies identified 70 MRI-detected and -biopsied papillary and sclerosing lesions. Sixteen lesions without atypia underwent surgical excision; only one case (6%) was upgraded to pleomorphic lobular carcinoma in situ. The majority (64%) of biopsies contained apocrine metaplasia either within or adjacent to the targeted lesion. We found that half of MRI-detected lesions had T2 hyperintense foci (2-5 mm) or masses (>5 mm) adjacent to the lesion. Histologic correlation showed apocrine cysts were likely responsible for this imaging finding in 56% of these cases.

Changes in Primary Care Health Care Utilization after Inclusion of Epidemiologic Data in Lumbar Spine MR Imaging Reports for Uncomplicated Low Back Pain.

Purpose To determine whether inclusion of an epidemiologic statement in radiology reports of lumbar magnetic resonance (MR) imaging influences downstream health care utilization in the primary care population. Materials and Methods Beginning July 1, 2013, a validated epidemiologic statement regarding prevalence of common findings in asymptomatic patients was included in all lumbar MR imaging reports at a tertiary academic medical center. Data were collected from July 1, 2012, through June 30, 2014, and retrospective analysis was completed in September 2016. The electronic medical record was reviewed to capture health care utilization rates in patients for 1 year after index MR imaging. Of 4527 eligible adult patients with low back pain referred for lumbar spine MR imaging during the study period, 375 patients had their studies ordered by in-network primary care providers, did not have findings other than degenerative disease, and had at least one follow-up encounter within the system within 1 year of index MR imaging. In the before-and-after study design, a pre-statement-implementation cohort was compared with a post-statement-implementation cohort by using univariate and multivariate statistical models to evaluate treatment utilization rates in these groups. Results Patients in the statement group were 12% less likely to be referred to a spine specialist (137 of 187 [73%] vs 159 of 188 [85%]; P = .007) and were 7% less likely to undergo repeat imaging (seven of 187 [4%] vs 20 of 188 [11%]; P = .01) compared with patients in the nonstatement group. The intervention was not associated with any change in narcotic prescription (53 of 188 [28%] vs 54 of 187 [29%]; P = .88) or with the rate of low back surgery (24 of 188 [13%] vs 16 of 187 [9%]; P = .19). Conclusion In this study, inclusion of a simple epidemiologic statement in lumbar MR imaging reports was associated with decreased utilization in high-cost domains of low back pain management. © RSNA, 2018.

Disease model discovery from 3,328 gene knockouts by The International Mouse Phenotyping Consortium.

Although next-generation sequencing has revolutionized the ability to associate variants with human diseases, diagnostic rates and development of new therapies are still limited by a lack of knowledge of the functions and pathobiological mechanisms of most genes. To address this challenge, the International Mouse Phenotyping Consortium is creating a genome- and phenome-wide catalog of gene function by characterizing new knockout-mouse strains across diverse biological systems through a broad set of standardized phenotyping tests. All mice will be readily available to the biomedical community. Analyzing the first 3,328 genes identified models for 360 diseases, including the first models, to our knowledge, for type C Bernard-Soulier, Bardet-Biedl-5 and Gordon Holmes syndromes. 90% of our phenotype annotations were novel, providing functional evidence for 1,092 genes and candidates in genetically uncharacterized diseases including arrhythmogenic right ventricular dysplasia 3. Finally, we describe our role in variant functional validation with The 100,000 Genomes Project and others.

[Diagnostic Imaging in Cases of Acute Scrotum]. / Bildgebende Diagnostik beim akuten Skrotum.

Acute scrotum is one of the most common urologic emergencies in children and adolescents. This condition involves acute testicular pain, which is often accompanied by scrotal swelling and erythema. It is most important to distinguish between cases that require immediate surgery and those that can be treated conservatively. As patient history and physical findings may not always be unequivocal, ultrasound with Colour-Coded Doppler Sonography is the imaging modality of choice for further evaluation. Testicular torsion and other differential diagnoses such as epididymitis, appendiceal torsion, intratesticular haematoma after trauma, or complicated inguinal hernia have to be considered. Other imaging modalities such as MRI, scintigraphy and contrast-enhanced ultrasound are only necessary if the diagnosis remains unclear or if complications occur during the course of disease.

Symptomatic Lumbar Facet Synovial Cysts: Clinical Outcomes Following Percutaneous CT-Guided Cyst Rupture with Intra-articular Steroid Injection.

PURPOSE: To evaluate clinical outcomes following percutaneous rupture of symptomatic lumbar facet synovial cysts (LFSCs) with intra-articular steroid injection. MATERIALS AND METHODS: In this retrospective review, 44 consecutive patients with symptomatic LFSCs received primary treatment with CT-guided synovial cyst rupture with intra-articular steroid injection. Outcomes questionnaires were obtained before and 1, 4, 26, and 52 weeks after LFSC rupture. Assessment included pain medication use and numeric rating scale (NRS), Oswestry Disability Index (ODI), and 12-item short form health survey (SF-12) physical and mental composite scores (PCS and MCS). Clinical endpoint was 52-week survey response or surgery. RESULTS: LFSC rupture was technically successful in 84% (37/44) of cases. Clinical endpoint was reached in 68% (30/44) of patients with 82% overall 1-year follow-up. Lumbar spine surgery was performed in 25% (11/44) of patients within 1 year after procedure. Mean NRS, ODI, and SF-12 PCS demonstrated significant improvement at all follow-up time points (P < .001). At 52-week follow-up, NRS decreased from 8.1 to 3.7 (P < .001), ODI improved from 35 to 24 (P = .006), and SF-12 PCS improved from 31 to 42 (P < .001). Daily pain medication decreased from 71% (31/44) of patients before procedure to 29% (9/26) at 52-week follow-up (P = .012). History of prior lumbar intervention was associated with poorer LFSC rupture success (P = .025) and ODI (P = .047). CONCLUSIONS: NRS, ODI, and SF-12 PCS indices improved and pain medication use decreased significantly at all time points over 1-year follow-up after percutaneous rupture of symptomatic LFSCs with intra-articular steroid injection.