Immunoglobulin mimicry by Hepatitis C Virus envelope protein E2

Hepatitis C virus (HCV) establishes persistent infection in the majority of infected individuals. The currently accepted hypothesis of immune evasion by antigenic variation in hypervariable region 1 (HVR1) of glycoprotein E2 does not however, explain the lack of subsequent immune recognition. Here, we show that the N-terminal region of E2 is antigenically and structurally similar to human immunoglobulin (Ig) variable domains. E2 is recognized by anti-human IgG antibodies and also possesses common amino acid (aa) sequence features of the conserved v-gene framework regions of human Ig light chains in particular but also heavy chains and T cell receptors. Using a position specific scoring system, the degree of similarity of HVR1 to Ig types correlated with immune escape and persistence in humans and experimentally infected chimpanzees. We propose a unique role for threshold levels of Ig molecular mimicry in HCV biology that not only advances our concept of viral immune escape and persistent infection but also provides insight into host-dependent disease patterns.     

Oncogenic BRAF and KRAS mutations in endosalpingiosis

Endosalpingiosis, a microscopic lesion composed of ectopic Fallopian tube epithelium, frequently involves the peritoneum and lymph nodes in patients with ovarian serous borderline tumour or low-grade serous carcinoma, but its pathogenic significance remains unclear. Using laser-capture microdissection and droplet digital PCR, we investigated whether endosalpingiosis harbours the driver mutations in BRAF and KRAS that characterise ovarian low-grade serous neoplasms. Somatic mutations were detected in 14 (33%) of 43 endosalpingiotic lesions analysed. Of 21 women with endosalpingiosis associated with a synchronous or metachronous ovarian low-grade serous tumour, mutations were identified in endosalpingiotic lesions from 11 (52%) women, with most cases (10/11, 91%) demonstrating identical mutations in both tumour and endosalpingiosis. In contrast, of 13 cases of endosalpingiosis not associated with an ovarian tumour, only one harboured a KRAS mutation. The proliferative activity as assessed by Ki-67 immunohistochemistry was lower in endosalpingiosis than in low-grade serous tumours, and endosalpingiosis with either a BRAF or KRAS mutation had a significantly lower Ki-67 index than those without. Ectopic expression of KRAS^G12V in Fallopian tube epithelial cells led to ERK phosphorylation, p21 induction, growth arrest and cellular senescence. In conclusion, we demonstrate that endosalpingiosis represents an interesting example of cancer driver mutations in deceptively normal-appearing cells, which may be prone to neoplastic transformation upon bypass of endogenous oncosuppressive mechanisms. © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Segmentation and reconstruction of hepatic veins and intrahepatic portal vein based on the coronal sectional anatomic dataset

Three-dimensional (3D) reconstruction of intrahepatic vessels is very useful in visualizing the complex anatomy of hepatic veins and intrahepatic portal vein. It also provides a 3D anatomic basis for diagnostic imaging and surgical operation on the liver. In the present study, we built a 3D digitized model of hepatic veins and intrahepatic portal vein based on the coronal sectional anatomic dataset of the liver. The dataset was obtained using the digital freezing milling technique. The pre-reconstructed structures were identified and extracted, and then were segmented by the method of manual intervention. The digitized model of hepatic veins and intrahepatic portal vein was established using 3D medical visualization software. This model facilitated a continuous and dynamic displaying of the hepatic veins and intrahepatic portal vein at different orientations, which demonstrated the complicated relationship of adjacent hepatic veins and intrahepatic portal vein realistically in the 3D space. This study indicated that high-quality 2D images, precise data segmentation, and suitable 3D reconstruction methods ensured the reality and accuracy of the digital visualized model of hepatic veins and intrahepatic portal vein.     

Comparison of LightCycler-based PCR,COBAS amplicor CMV monitor,and pp65 antigenemia assays for quantitative measurement of cytomegalovirus viral load in peripheral blood specimens from patients after solid organ transplantation

In order to evaluate the LightCycler-based PCR (LC-PCR) as a diagnostic assay technique, a classical pp65 antigenemia assay and the commercially available COBAS Amplicor CMV Monitor (CACM) assay were compared to the LC-PCR assay for the detection and quantitation of cytomegalovirus (CMV) load in 404 parallel specimens of peripheral blood from 66 patients after solid organ transplantation. A good correlation existed among these three assays (r congruent with 0.6, P < 0.0001). The LC-PCR assay was the most sensitive (54% of specimens positive) compared to the CACM (48.6%) and the pp65 antigenemia (26%) assays. The LC-PCR assay detected all samples found positive by using both the CMV pp65 antigenemia assay and the CACM assay. The LC-PCR also had the widest dynamic range (from 250 to 10(7) DNA copies/ml of plasma). No cross-reactions were found among CMV and Epstein-Barr virus, varicella-zoster virus, or herpes simplex virus in the LC-PCR by using amplification with specifically designed primer pairs. Precision, expressed as the coefficient of variation, was <3% with standard DNA from cell cultures and between 6.55 and 14.1% with clinical specimens in repeat LC-PCR runs. One run of the LC-PCR took half of the time required for the semiautomated CACM procedure. Because of its sensitivity, specificity, cost-effectiveness, and simplicity, the LC-PCR assay could replace the pp65 antigenemia and the CACM assays as the preferred technique for the surveillance, diagnosis, and monitoring of response of CMV diseases in high-risk populations.     

alpha4-Integrin(+) endothelium derived from primate embryonic stem cells generates primitive and definitive hematopoietic cells

The mechanism of commencement of hematopoiesis in blood islands of the yolk sac and the aorta-gonad-mesonephros (AGM) region during primate embryogenesis remains elusive. In this study, we demonstrated that VE-cadherin(+)CD45(-) endothelial cells derived from nonhuman primate embryonic stem cells are able to generate primitive and definitive hematopoietic cells sequentially, as revealed by immunostaining of floating erythrocytes and colony-forming assay in cultures. Single bipotential progenitors for hematopoietic and endothelial lineages are included in this endothelial cell population. Furthermore, hemogenic activity of these endothelial cells is observed exclusively in the alpha4-integrin(+) subpopulation; bipotential progenitors are 4-fold enriched in this subpopulation. The kinetics of this hemogenic subpopulation is similar to that of hemogenic endothelial cells previously reported in the yolk sac and the AGM region in vivo in that they emerge for only a limited time. We suggest that VE-cadherin(+)CD45(-)alpha4-integrin(+) endothelial cells are involved in primitive and definitive hematopoiesis during primate embryogenesis, though VE-cadherin(-)CD45(-)alpha4-integrin(+) cells are the primary sources for primitive hematopoiesis.     

Reduced-order parameter optimization for simplifying prostate IMRT planning

Intensity-modulated radiotherapy (IMRT) has become an effective tool for cancer treatment with radiation. However, even expert radiation planners still need to spend a substantial amount of time manually adjusting IMRT optimization parameters such as dose limits and costlet weights in order to obtain a clinically acceptable plan. In this paper, we describe two main advances that simplify the parameter adjustment process for five-field prostate IMRT planning. First, we report the results of a sensitivity analysis that quantifies the effect of each hand-tunable parameter of the IMRT cost function on each clinical objective and the overall quality of the resulting plan. Second, we show that a recursive random search over the six most sensitive parameters as an outer loop in IMRT planning can quickly and automatically determine parameters for the cost function that lead to a plan meeting the clinical requirements. Our experiments on a ten-patient dataset show that for 70% of the cases, we can automatically determine a plan in 10 min (on the average) that is either clinically acceptable or requires only minor adjustment by the planner. The outer-loop optimization can be easily integrated into a traditional IMRT planning system.     

Spatiotemporal tracking of cells in tissue‐engineered cardiac organoids

Cardiac tissue engineering aims to create myocardial patches for repair of defective or damaged native heart muscle. The inclusion of non‐myocytes in engineered cardiac tissues has been shown to improve the properties of cardiac tissue compared to tissues engineered from enriched populations of myocytes alone. While attempts have been made to mix non‐myocytes (fibroblasts, endothelial cells) with cardiomyocytes, very little is understood about how the tissue properties are affected by varying the respective ratios of the three cell types and how these cells assemble into functional tissues with time. The goal of this study was to investigate the effects of modulating the ratios of the three cell types and to spatially and temporally track cardiac tri‐cultures of cells. Primary neonatal cardiac fibroblasts and D4T endothelial cells were incubated in 5 µM CellTracker^? green dye and CellTracker^? red dye, respectively, while neonatal cardiomyocytes were labelled with 20 µg/mL DAPI. The non‐myocytes were seeded either sequentially (pre‐culture) or simultaneously (tri‐culture) in Matrigel‐coated microchannels and allowed to form organoids, as in our previous studies. We also varied the seeding percentage of cardiomyocytes while keeping the total cell number constant in an attempt to improve the functional properties of the organoids. Organoids were imaged on days 1 and 4. Endothelial cells were seen to aggregate into clusters when simultaneously tri‐cultured with myocytes and fibroblasts, while pre‐cultures contained elongated cells. Functional properties of organoids were improved by increasing the seeding percentage of enriched cardiomyocytes from 40% to 80%. Copyright © 2009 John Wiley & Sons, Ltd.     

Factors associated with lower quality of life among patients receiving palliative care

Title.  Factors associated with lower quality of life among patients receiving palliative care.
Aim.  This paper is a report of a study conducted to (1) assess the quality of life (QoL) and physical functioning status of patients diagnosed with advanced cancer and receiving palliative care; (2) determine if there was a statistically significant relationship between their physical functioning and QoL and (3) identify the demographic and disease-related variables related to their QoL.
Background.  Achieving the best possible QoL is a major goal in palliative care. However, research findings about the relationship between QoL and demographic variables have been inconsistent.
Method.  Three hundred patients with advanced cancer were recruited from four district hospitals in Hong Kong between February 2005 and July 2006. Their QoL and physical functioning status were assessed by face-to-face interview, using the McGill Quality of Life Questionnaire (Hong Kong version) and the Palliative Performance Scale respectively.
Results.  Participants reported reduced ambulation, inability to perform hobbies or housework, and the need for occasional assistance in self-care (mean: 64·6 out of 100, sd : 19·3, range: 20–100). QoL was fair (mean: 6·2 out of 10, sd : 1·5, range: 0·9–10). There was a weak positive association between physical functioning and QoL scores. Multiple regression analysis showed that patients who were older, female, had ever been married, or had higher physical functioning tended to have better QoL.
Conclusion.  More could be done in symptom and psychosocial management to improve patients' QoL, in particular for those who are younger, male or single, or who have lower physical functioning.     

Antioxidant vitamins reduce acute meal-induced memory deficits in adults with type 2 diabetes

Memory impairment is observed in adults with type 2 diabetes mellitus (T2DM), with further acute deficits after meal ingestion. This study explored whether postprandial oxidative stress was a contributor to these meal-induced memory deficits. Sixteen adults with T2DM (mean age, 63.5 ± 2.1 years) who were not regularly taking high-dose antioxidant supplements were fed a high-fat meal, the same test meal with vitamins C (1000 mg) and E (800 IU) tablets, or water on 3 separate occasions. After meal ingestion, a battery of cognitive tests were administered, which included measures of delayed verbal memory, assessed at 60 and 105 minutes after meal ingestion. Relative to water consumption, the high-fat meal resulted in poorer performance at 105 minutes postingestion on measures of delayed verbal recall (word list and paragraph recall) and working memory (Digit-Span Forward). Coconsumption of antioxidant vitamins and high-fat meal prevented this meal-induced deficit such that performance on these tasks was indistinguishable from that after water intake. At the same time point, a small but significant improvement on the word-naming and color-naming components of Stroop was observed after meal ingestion, relative to water, irrespective of whether antioxidants were consumed, demonstrating the specificity of meal-induced impairments to memory function. Executive function, assessed by Trails Parts A and B, was not influenced by meal or antioxidant ingestion. In adults with T2DM, coconsumption of antioxidant vitamins minimizes meal-induced memory impairment, implicating oxidative stress as a potential contributor to these decrements.