Influence of hepatic fibrosis and inflammation: Correlation between histopathological changes and Gd-EOB-DTPA-enhanced MR imaging

Objective To evaluate the influence of an active inflammatory process in the liver on Gd-EOB-DTPA-enhanced MR imaging in patients with different degrees of fibrosis/cirrhosis. Material and methods Overall, a number of 91 patients (61 men and 30 women; mean age 58 years) were included in this retrospective study. The inclusion criteria for this study were Gd-EOB-DTPA-enhanced MRI of the liver and histopathological evaluation of fibrotic and inflammatory changes. T1-weighted VIBE sequences of the liver with fat suppression were evaluated to determine the relative signal change (RE) between native and hepatobiliary phase (20 min). In simple and multiple linear regression analyses, the influence of liver fibrosis/cirrhosis (Ishak score) and the histopathological degree of hepatitis (Modified Hepatic Activity Index, mHAI) on RE were evaluated. Results RE decreased significantly with increasing liver fibrosis/cirrhosis (p < 0.001) and inflammation (mHAI, p = 0.004). In particular, a correlation between RE and periportal or periseptal boundary zone hepatitis (moth feeding necrosis, mHAI A, p = 0.001) and portal inflammation (mHAI D, p < 0.001) was observed. In multiple linear regression analysis, both the degree of inflammation and the degree of fibrosis were significant predictors for RE (p < 0.01). Conclusion The results of this study suggest that the MR-based hepatic enhancement index RE is not only influenced by the degree of fibrosis, but also by the degree of inflammation

Ancient and recent differences in the intrinsic susceptibility of Mycobacterium tuberculosis complex to pretomanid

Objectives To develop a robust phenotypic antimicrobial susceptibility testing (AST) method with a correctly set breakpoint for pretomanid (Pa), the most recently approved anti-tuberculosis drug. Methods The Becton Dickinson Mycobacterial Growth Indicator Tube™ (MGIT) system was used at six laboratories to determine the MICs of a phylogenetically diverse collection of 356 Mycobacterium tuberculosis complex (MTBC) strains to establish the epidemiological cut-off value for pretomanid. MICs were correlated with WGS data to study the genetic basis of differences in the susceptibility to pretomanid. Results We observed ancient differences in the susceptibility to pretomanid among various members of MTBC. Most notably, lineage 1 of M. tuberculosis, which is estimated to account for 28% of tuberculosis cases globally, was less susceptible than lineages 2, 3, 4 and 7 of M. tuberculosis, resulting in a 99th percentile of 2 mg/L for lineage 1 compared with 0.5 mg/L for the remaining M. tuberculosis lineages. Moreover, we observed that higher MICs (≥8 mg/L), which probably confer resistance, had recently evolved independently in six different M. tuberculosis strains. Unlike the aforementioned ancient differences in susceptibility, these recent differences were likely caused by mutations in the known pretomanid resistance genes. Conclusions In light of these findings, the provisional critical concentration of 1 mg/L for MGIT set by EMA must be re-evaluated. More broadly, these findings underline the importance of considering the global diversity of MTBC during clinical development of drugs and when defining breakpoints for AST

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Hyponatriämie bei einer 58-jährigen Patientin mit einem EGFR-positiven pulmonalen Adenokarzinom

The case of a 58-year old female patient with epidermal growth factor-positive pulmonary adenocarcinoma treated with the tyrosine kinase inhibitor afatinib is reported. After several months of first-line therapy the patient developed severe hyponatremia and tumor reassessment revealed a progressive course of the lung cancer. Rebiopsy showed transformation of the tumor into small-cell lung cancer. Therapy with afatinib was stopped immediately and platin-based chemotherapy was started. This case shows that tumor transformation under tyrosine kinase inhibitor therapy from non-small-cell into small-cell lung cancer can occur in rare cases

Endoscopic full-thickness resection (EFTR) in the lower gastrointestinal tract

Background Endoscopic full-thickness resection (EFTR) significantly expands the spectrum of endoscopic colorectal resection methods for lesions that show no lifting sign, submucosal lesions and mucosal carcinomas. The aim of our study was to evaluate the efficacy and safety of EFTR using a commercially available full thickness resection device (FTRD) by assessing the completeness of the full-thickness resection, the technical success, as well as complications in a cohort of patients from three referral centers in Germany. Another aim was to determine which patient subpopulations benefit most in clinical practice. Methods This retrospective multicenter study was conducted on consecutive patients who were admitted to three referral centers in Germany between November 2014 and December 2017. The EFTR was conducted according to the standard indications using the FTRD System (OVESCO, Tubingen, Germany). Data were obtained from prospectively maintained institutional databases. Results There were 70 patients, 42 males and 25 females with a mean age of 79.5 years (range 25-89 years) who had colonoscopy for EFTR. In three patients EFTR was not feasible because the lesions were too large. Of the remaining 67 patients, 52 had recurrent adenomas, 10 had high-grade intraepithelial neoplasia or mucosal carcinoma and five had a subepithelial lesion. Resection was technically successful in 65 patients (97.0%). Histologically complete resection (R0) was achieved in 59/65 patients (90.8%). The R0 resection rate was lower for lesions > 20 mm (86.5%) versus lesions <= 20 mm (92.9%). The total complication rate was 14.9%: there was one major complication (perforation of sigmoid colon), while all other complications were minor. Conclusions EFTR yields excellent resection rates for benign recurrent adenomas with non-lifting sign, advanced histopathological findings or submucosal lesions when the procedure is performed in experienced hands and for the correct indication. Thus, surgery can be avoided in many cases. For all lesions the risk of R1 resection goes up with the size of the lesion and careful patient selection is mandatory

Diagnostic performance of ultrasound strain elastography for differentiation of malignant breast lesions

OBJECTIVE: Objective of the study was to assess the performance of ultrasound strain elastography combined with conventional B-mode ultrasound to diagnose suspicious breast lesions (BI-RADS 4 and 5). METHODS: Between January 2015 and December 2017, a total of 86 patients (55 +/- 17.9 years) with solid or unclear, non-cystic breast lesions were enrolled in the study. The breast lesions were evaluated by B-mode ultrasound and subsequent ultrasound strain elastography. Ultrasound features including echo pattern, lesion shape, marginal characteristics, calcifications, orientation and posterior features are useful for differentiating benign breast lesions from malignant ones. Malignant ultrasound features are irregular shape, hypoechoic pattern, spiculated margin, nonparallel orientation and posterior shadowing. Lesions with benign features such a circumscribed margin were classified as low conspicuous. In patients with highly conspicuous malignant masses ultrasound-guided core needle biopsy or surgical excision was performed. RESULTS: Among the 86 patients, 60 masses were histologically proven and 36 of these were malignant. Of the malignant lesions 26 invasive carcinomas were of no special type (NST), 1 invasive lobular carcinoma, 3 ductal carcinomas in situ and 6 metastases. 20 of these patients had breast density classified as ACR 3 or 4. The mean size of the masses was 1.2 cm (range: 0.5-5 cm). Based on ultrasound B-mode imaging, the lesions were classified as BI-RADS category 4 (n= 20; three 4a, nine 4b and eight 4c) and BI-RADS category 5 (n= 16). One patient had to be reclassified after strain elastographxy to BI-RADS 3. The sensitivity of ultrasound with strain elastography and additional B-Mode ultrasound for the characterization of solid breast lesions was 97%, for conventional B-mode alone 92%; the respective specificities were 82% and 73%, respectively. CONCLUSION: Ultrasound elastography can be a supplementary approach to conventional ultrasound to improve the diagnostic accuracy of malignant breast lesions

Genome-Wide RNA Sequencing Analysis of Quorum Sensing-Controlled Regulons in the Plant-Associated Burkholderia glumae PG1 Strain

Burkholderia glumae PG1 is a soil-associated motile plant-pathogenic bacterium possessing a cell density-dependent regulation system called quorum sensing (QS). Its genome contains three genes, here designated bgaI1 to bgaI3, encoding distinct autoinducer-1 (AI-1) synthases, which are capable of synthesizing QS signaling molecules. Here, we report on the construction of B. glumae PG1 ΔbgaI1, ΔbgaI2, and ΔbgaI3 mutants, their phenotypic characterization, and genome-wide transcriptome analysis using RNA sequencing (RNA-seq) technology. Knockout of each of these bgaI genes resulted in strongly decreased motility, reduced extracellular lipase activity, a reduced ability to cause plant tissue maceration, and decreased pathogenicity. RNA-seq analysis of all three B. glumae PG1 AI-1 synthase mutants performed in the transition from exponential to stationary growth phase revealed differential expression of a significant number of predicted genes. In comparison with the levels of gene expression by wild-type strain B. glumae PG1, 481 genes were differentially expressed in the ΔbgaI1 mutant, 213 were differentially expressed in the ΔbgaI2 mutant, and 367 were differentially expressed in the ΔbgaI3 mutant. Interestingly, only a minor set of 78 genes was coregulated in all three mutants. The majority of the QS-regulated genes were linked to metabolic activities, and the most pronounced regulation was observed for genes involved in rhamnolipid and Flp pilus biosynthesis and the type VI secretion system and genes linked to a clustered regularly interspaced short palindromic repeat (CRISPR)-cas gene cluster

<p>Full-Core Biopsy Systems Take Larger Liver Tissue Samples with Lower Fragmentation Rates Than Conventional Side-Notch Systems: A Randomized Trial</p>

Background: The aim of this study was to compare the histopathological quality and physical features of the specimen of a full-core end-cut biopsy system with that of the standard side-notch system for liver biopsies. Methods: A full-core end-cut 16G biopsy device and a standard side-notch 16G needle were used to take biopsies of unclear liver lesions. Patients were randomized in two groups of 16 patients each. The primary endpoint of this prospective study was the core length measured using a dedicated microscope imaging software. Secondary endpoints were the quality of the specimen rated by an independent pathologist unaware of the device (scale from 1 to 5; with 1 as best and 5 as worst), the core diameter (determined by the microscopic imaging software) and presence of fragmentation (evaluated by the pathologist). Results: For the full-core (FC) and side-notch (SN) groups, the mean core length was similar with 13,599 mu m and 11,570 mu m (p=0.131), respectively. The quality of the specimen was significantly better in the FC-group with an average rating of 1.68 vs 2.50 (p=0.009). The fragmentation rate in the FC-group was statistically significantly lower at 2/27 (7%) than in the SN-group at 13/33 (39%) (p=0.021). The diameter in the FC-group was 1042 mu m vs 930 mu m in SN-group (p=0.018)

Complexity of PEComas

Perivascular epithelioid cell neoplasms (PEComas) are a family of mesenchymal neoplasms with features of both melanotic and smooth muscle differentiation. PEComa morphology is highly variable and encompasses epithelioid to spindle cells often with clear cytoplasm and prominent nucleoli. Molecularly, most PEComas are defined by a loss of function of the TSC1/TSC2 complex. Additionally, a distinct small subset of PEComas harboring rearrangements of theTFE3(Xp11) gene locus has been identified. By presenting a series of three case reports with distinct features, we demonstrate diagnostic pitfalls as well as the importance of molecular work-up of PEComas because of important therapeutic consequences

Simulated Microgravity Influences VEGF, MAPK, and PAM Signaling in Prostate Cancer Cells

Prostate cancer is one of the leading causes of cancer mortality in men worldwide. An unusual but unique environment for studying tumor cell processes is provided by microgravity, either in space or simulated by ground-based devices like a random positioning machine (RPM). In this study, prostate adenocarcinoma-derived PC-3 cells were cultivated on an RPM for time periods of 3 and 5 days. We investigated the genes associated with the cytoskeleton, focal adhesions, extracellular matrix, growth, survival, angiogenesis, and metastasis. The gene expression of signaling factors of the vascular endothelial growth factor (VEGF), mitogen-activated protein kinase (MAPK), and PI3K/AKT/mTOR (PAM) pathways was investigated using qPCR. We performed immunofluorescence to study the cytoskeleton, histological staining to examine the morphology, and a time-resolved immunofluorometric assay to analyze the cell culture supernatants. When PC-3 cells were exposed to simulated microgravity (s-mu g), some cells remained growing as adherent cells (AD), while most cells detached from the cell culture flask bottom and formed multicellular spheroids (MCS). After 3-day RPM exposure, PC-3 cells revealed significant downregulation of the VEGF, SRC1, AKT, MTOR, and COL1A1 gene expression in MCS, whereas FLT1, RAF1, MEK1, ERK1, FAK1, RICTOR, ACTB, TUBB, and TLN1 mRNAs were not significantly changed. ERK2 and TLN1 were elevated in AD, and FLK1, LAMA3, COL4A5, FN1, VCL, CDH1, and NGAL mRNAs were significantly upregulated in AD and MCS after 3 days. After a 5-day culture in s-mu g, the PC-3 cells showed significant downregulations of VEGF mRNA in AD and MCS, and FN1, CDH1, and LAMA3 in AD and SCR1 in MCS. In addition, we measured significant upregulations in FLT1, AKT, ERK1, ERK2, LCN2, COL1A1, TUBB, and VCL mRNAs in AD and MCS, and increases in FLK1, FN1, and COL4A5 in MCS as well as LAMB2, CDH1, RAF1, MEK1, SRC1, and MTOR mRNAs in AD. FAK1 and RICTOR were not altered by s-mu g. In parallel, the secretion rate of VEGFA and NGAL proteins decreased. Cytoskeletal alterations (F-actin) were visible, as well as a deposition of collagen in the MCS. In conclusion, RPM-exposure of PC-3 cells induced changes in their morphology, cytoskeleton, and extracellular matrix protein synthesis, as well as in their focal adhesion complex and growth behavior. The significant upregulation of genes belonging to the PAM pathway indicated their involvement in the cellular changes occurring in microgravity