Utilising random forests in the modelling of Eragrostis curvula presence and absence in an Australian grassland system

Eragrostis curvula is an agronomically and ecologically undesirable perennial tussock grass dispersed across Australia. The objective of this study is to investigate relationships of ecologically relevant abiotic variables with the presence of E. curvula at a landscape scale in the Snowy Monaro region, Australia. Through vegetation surveys across 21 privately owned properties and freely available ancillary data on E. curvula presence, we used seven predictor variables, including Sentinel 2 NDVI reflectance, topography, distance from roads and watercourses and climate, to predict the presence or absence of E. curvula across its invaded range using a random forest (RF) algorithm. Assessment of performance metrics resulted in a pseudo-R squared of 0.96, a kappa of 0.97 and an R squared for out-of-bag samples of 0.67. Temperature had the largest influence on the model's performance, followed by linear features such as highways and rivers. Highways' high importance in the model may indicate that the presence or absence of E. curvula is related to the density of human transit, thus as a vector of E. curvula propagule dispersal. Further, humans' tendency to reside adjacent to rivers may indicate that E. curvula's presence or absence is related to human density and E. curvula's potential to spread via water courses.

Key issues for implementation of Genomics in Healthcare: a Policy Brief

Issue/problem

Healthcare (HC) can significantly benefit from genomic information for earlier, accurate diagnosis, effective personalized treatment with less adverse events, and accurate profiling of individuals for disease prevention. However, European countries are currently at variable maturity stages regarding the implementation of genomic medicine (GM) in healthcare, hindering the equitable delivery of personalized medicine to citizens across borders.

Description of the problem

The European 1+Million Genomes Initiative (1+MG) aims to provide cross-border access to quality genomic information and related clinical data, to advance data-driven research and HC solutions to benefit citizens. This initiative is encouraging countries to develop national GM strategies, but guidance for successful implementation is needed. In this context, the Beyond 1 Million Genomes, a supporting action to the 1+MG initiative, organized three Country Exchange Visits (CEV) to discuss critical issues, share experiences and best practices, for the implementation of sustainable GM strategies in healthcare.

Results

The United Kingdom, Estonia and Finland, which have advanced GM programs, hosted CEV describing progress and lessons learnt. Representatives of 1+MG signatory countries participated in these events and were able to present country level progress. The resulting Policy Brief (PB) captures key issues discussed at the CEVs, with real-life examples, and proposes policy recommendations for the successful implementation of GM in European healthcare systems.

Lessons

Sustainable GM implementation in HC systems requires: 1) Patient and citizens trust and engagement; 2) Sustainable infrastructure and data regulation, with solid ethical and legal frameworks; 3) Capacity building of healthcare professionals; 4) A strong ecosystem involving all stakeholders, and encouraging synergies between healthcare, research and industry to promote continuous innovation.

Key messages

• The implementation of GM in healthcare will take countries further towards making personalized medicine a reality, with remarkable health and socioeconomic benefits for patients and healthcare systems.

• Promoting cooperation, capacity building and sharing of best practices is crucial to reduce asymmetries between countries, which constrains effective and equitable cross-border personalized medicine.

Abstract P1-05-08: Targeting tumor heterogeneity and breast cancer metastasis through the metastatic microenvironment mediated epigenetic reprogramming

Targeting tumor heterogeneity and breast cancer metastasis through the metastaticmicroenvironment mediated epigenetic reprogrammingLi Yang and Jae Young So, Nicolas Skrypek, Anand Merchant, George Nelson, Howard H.Yang, Maxwell P. LeeNational Cancer Institute, National Institutes of Health, Bethesda, MD 20892Current cancer treatments are largely based on the genetic characterization of primarytumors and are ineffective for metastatic disease. There is lack of mechanistic understanding ashow cancer cells are selected and evolved to establish distant metastatic colonies. In addition,tumor heterogeneity and biomarker identification remain to be some of the most difficultchallenges in cancer treatment. In the current study, we discovered an increased DNAmethyltransferase 3B (DNMT3B) in metastatic nodules and in tumor cells with epithelia tomesenchymal (EMT) phenotype. Of great interest, high levels of DNMT3B were correlated withpoor clinical outcomes in multiple human breast cancer datasets. Mechanistically, DNMT3Balters multiple pathways including STAT3, NFkappaB, PI3K/Akt, beta-catenin, Notch signalingas well as EMT, which are critical for cancer cell survival, apoptosis, proliferation, invasion, andcolonization. We further identified PGE2 and IL6 as critical inflammatory mediators inDNMT3B induction. Importantly, targeting IL6 or PGE2 production reduced DNMT3Bexpression and improved chemo treatment or PD1 immune therapy. Furthermore, perioperative(surgical removal of primary tumors) targeting DNMT3B in combination with chemotherapymarkedly suppressed tumor recurrence and metastasis in preclinical mouse models for triplenegative breast cancer. Our studies identify DNMT3B as an important mechanism fortranscription regulation in tumor heterogeneity that is critical for tumor invasion and metastasis,thus suggesting a validated target for treating metastatic disease.

Citation Format: Li Yang, Jae Young So, Nicolas Skrypek, Anand Merchant, George Nelson, Howard Yang, Maxwell Lee. Targeting tumor heterogeneity and breast cancer metastasis through the metastatic microenvironment mediated epigenetic reprogramming [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P1-05-08.

Over-expression of RNA interference (RNAi) core machinery improves susceptibility to RNAi in silkworm larvae

RNA interference (RNAi), one of the strategies that organisms use to defend against invading viruses, is an important tool for functional genomic analysis. In insects, the efficacy of RNAi varies amongst taxa. Lepidopteran insects are, in large part, recalcitrant to RNAi. The overall goal of this study is to overcome such insensitivity in lepidopterans to RNAi. We hypothesize that over-expression of core RNAi machinery enzymes can improve RNAi efficacy in traditionally recalcitrant species. A transgenic Bombyx mori strain, Baculovirus Immediate-Early Gene, ie1, promoter driven expression of silkworm Dicer2 coding sequence (IE1-BmDicer2), which over-expresses BmDicer2, was generated by piggyBac transposon-mediated transgenesis. Two indexes, the ratio of animals that showed a silencing phenotype and the duration of silencing, were used to evaluate silencing efficiency. Significant knockdown of target gene expression was observed at 48 h postinjection at both the transcriptional and translational levels. Furthermore, we coexpressed B. mori Argonaute 2 BmAgo2）and BmDicer 2 and found that 22% of the animals (n = 18) showed an obvious silencing effect even at 72 h, suggesting that coexpression of these two RNAi core machinery enzymes further increased the susceptibility of B. mori to injected double-stranded RNAs. This study offers a new strategy for functional genomics research in RNAi-refractory insect taxa in general and for lepidopterans in particular.

Population Data Centre Profile - The Western Australian Data Linkage Branch

Established in 1995, the Western Australian Data Linkage Branch (DLB) is Australia's longest running data linkage agency. The Western Australian Data Linkage System (WADLS) employs an enduring linkage model spanning over 60 data collections supported by internally developed and supported software and IT infrastructure. DLB has delivered, and continues to deliver, a range of significant data linkage innovations, many of which have been adopted elsewhere. A current restructure within the Western Australian Department of Health (which we will refer to as the Department of Health) will provide an improved funding model geared toward addressing issues with staff retention, capacity and customer service, as well as fostering improvements to data management, governance and availability. Research using linked data provided by DLB has been used in over 800 projects resulting in over 2350 publications and outcomes for policy development, service delivery and public health. Demand continues to grow for data linkage services and with the Department of Health's bolstered commitment to resourcing, DLB looks forward to a future for data linkage in Western Australia that is sustainable, high quality, efficient, and safe.

Immune checkpoint inhibitors in mCRPC - rationales, challenges and perspectives

The advancement of immune-therapeutics in cancer treatment has proven to be promising in various malignant diseases. However, in castration resistant prostate cancer (mCRPC) major Phase III trials have been unexpectedly disappointing. To contribute to a broader understanding of the role and use of immune-therapeutics in mCRPC, we conducted a systematic review. We searched the websites ClinicalTrials.gov, PubMed and ASCO Meeting Library for clinical trials employing immune checkpoint inhibitors in mCRPC. This article not only describes the rationale of individual trials, but it also summarizes the current status of the field and sheds light on strategies for future success.

Limitations to using phloem sap to assess tree water and nutrient status

Rapid, reliable tools are needed to infer physiological and nutritional health for managing forest systems. Understanding the processes governing tree health is central to the development of these tools. Non-foliar approaches such as the collection of phloem sap reflect processes governing both the use and acquisition of plant water and nutrients at a wide range of temporal (diurnal to seasonal) and spatial (canopy) scales. Despite this, phloem sap is not commonly employed due to an incomplete understanding of transport and post-photosynthetic processes and their effects on chemical concentrations and carbon isotope discrimination. We highlight the need to characterize the influences of storage, remobilization and transport on the concentrations of metabolites to address the time and spatial decoupling of phloem contents to that of environmental stimuli. A conceptual framework is suggested to focus research on key phenomena regarding metabolite transport and highlight significant advantages, misconceptions and limitations to its application.

IL-7-induced phosphorylation of the adaptor Crk-like and other targets

IL-7 is required for T cell differentiation and mature T cell homeostasis and promotes pro-B cell proliferation and survival. Tyrosine phosphorylation plays a central role in IL-7 signaling. We identified by two-dimensional electrophoresis followed by anti-phosphotyrosine immunoblotting and mass spectrometry sixteen tyrosine phosphorylated proteins from the IL-7-dependent cell line D1. IL-7 stimulation induced the phosphorylation of the proteins STI1, ATIC and hnRNPH, involved in pathways related to survival, proliferation and gene expression, respectively, and increased the phosphorylation of CrkL, a member of a family of adaptors including the highly homologous Crk isoforms CrkII and CrkI, important in multiple signaling pathways. We observed an increased phosphorylation of CrkL in murine pro-B cells and in murine and human T cells. In addition, IL-7 increased the association of CrkL with the transcription factor Stat5, essential for IL-7 pro-survival activity. The selective tyrosine kinase inhibitor Imatinib. counteracted the IL-7 pro-survival effect in D1 cells and decreased CrkL phosphorylation. These data suggested that CrkL could play a pro-survival role in IL-7-mediated signaling. We observed that pro-B cells also expressed, in addition to CrkL, the Crk isoforms CrkII and CrkI and therefore utilized pro-B cells conditionally deficient in all three to evaluate the role of these proteins. The observation that the IL-7 pro-survival effect was reduced in Crk/CrkL conditionally-deficient pro-B cells further pointed to a pro-survival role of these adaptors. To further evaluate the role of these proteins, gene expression studies were performed in Crk/CrkL conditionally-deficient pro-B cells. IL-7 decreased the transcription of the receptor LAIR1, which inhibits B cell proliferation, in a Crk/CrkL-dependent manner, suggesting that the Crk family of proteins may promote pro-B cell proliferation. Our data contribute to the understanding of IL-7 signaling and suggest the involvement of Crk family proteins in pathways promoting survival and proliferation.

Twist1 and Slug mediate H2AX-regulated epithelial-mesenchymal transition in breast cells

The epithelial-mesenchymal transition (EMT) is thought to be essential for cancer metastasis. While chromatin remodeling is involved in EMT, which processes contribute to this remodeling remain poorly investigated. Recently, we showed that silencing or removal of the histone variant H2A.X induced mesenchymal-like characteristics, including activation of the EMT transcription factors, Slug and Zeb1 in human colon cancer cells. Here, we provide the evidence that H2A.X loss in human non-tumorigenic breast cell line MCF10A results in a robust EMT activation, as substantiated by a genome-wide expression analysis. Cells deficient for H2A.X exhibit enhanced migration and invasion, along with an activation of a set of mesenchymal genes and a concomitant repression of epithelial genes. In the breast model, the EMT-related transcription factor Twist1 cooperates with Slug to regulate EMT upon H2A.X Loss. Of interest, H2A.X expression level tightly correlates with Twist1, and to a lesser extent with Slug in the panel of human breast cancer cell lines of the NCI-60 datasets. These new findings indicate that H2A.X is involved in the EMT processes in cells of different origins but pairing with transcription factors for EMT may be tissue specific.

Chronic Interferon-gamma expression triggers a female bias in the development of primary biliary cholangitis

An important issue in autoimmunity research has been the ability to identify the mechanisms that link genetic susceptibility to environmental influences. In most autoimmune diseases, including primary biliary cholangitis (PBC), the serologic hallmarks of disease precede clinical pathology by years, thus making early diagnosis and potential treatment difficult if not unlikely. Thus identifying animal models that present early events becomes essential to understanding disease initiation and progression. Although murine models of PBC have been identified, there are none that fully recapitulate the human disease. Herein we have utilized a novel mouse model exhibiting dysregulation of interferon-gamma (IFNg) expression, characterized by prolonged and chronic expression of IFNg as a result of the replacement of the IFNg 3′ UTR AU-rich element with random nucleotides (designated ARE-Del−/−). These C57 BL/6 ARE-Del−/− mice develop autoimmune cholangitis with a female predominance characterized by upregulation of total serum bile acids, portal duct inflammation, spontaneous production of AMA and increased skin pigmentation. RNA seq data has revealed that female ARE-Del−/− mice have >1000 genes deferentially expressed in hepatocytes compared to control mice, including genes that represent early responses in disease progression. Furthermore, the data indicates that the Type 1 IFN pathway is also involved, implying that Type II interferon interplays with Type I IFNs in the initiation of PBC. Thus persistent IFNg expression, along with Type I and Type II IFN pathway interactions, is critical for the pathogenesis of PBC and recapitulates the sex bias observed in patients.

The histone variant H2A.X is a regulator of the epithelial-mesenchymal transition

The epithelial–mesenchymal transition (EMT), considered essential for metastatic cancer, has been a focus of much research, but important questions remain. Here, we show that silencing or removing H2A.X, a histone H2A variant involved in cellular DNA repair and robust growth, induces mesenchymal-like characteristics including activation of EMT transcription factors, Slug and ZEB1, in HCT116 human colon cancer cells. Ectopic H2A.X re-expression partially reverses these changes, as does silencing Slug and ZEB1. In an experimental metastasis model, the HCT116 parental and H2A.X-null cells exhibit a similar metastatic behaviour, but the cells with re-expressed H2A.X are substantially more metastatic. We surmise that H2A.X re-expression leads to partial EMT reversal and increases robustness in the HCT116 cells, permitting them to both form tumours and to metastasize. In a human adenocarcinoma panel, H2A.X levels correlate inversely with Slug and ZEB1 levels. Together, these results point to H2A.X as a regulator of EMT.

The histone H2A variants are involved in DNA repair, gene regulation and cancer development. In this study, the authors unravel an additional role for H2A.X in the regulation of mesenchymal-like traits and activation of the EMT transcription factors, Slug and ZEB1, in colon cancer cells.

Abstract 4094: Neutralizing anti-TGF-β antibodies elicit heterogeneous therapeutic responses in a panel of murine metastatic breast cancer models

Overexpression of transforming growth factor-βs (TGF-βs) correlates with metastasis and poor prognosis in many advanced cancers, and TGF-βs have pro-oncogenic effects on nearly every cell type in the ecosystem of advanced tumors. Based on these observations and encouraging results in preclinical models, strategies to block TGF-β signaling are in early phase clinical oncology trials. To date however, preclinical studies supporting the development of anti-TGF-β therapeutics in cancer have focused around a few well-characterized mouse models which do not capture the heterogeneity of the human disease. To assess the generalizability of these findings within a given tumor type, we have assembled a panel of transplantable mouse models of metastatic breast cancer. Using this panel of models, we tested the efficacy of a pan-TGF-β neutralizing antibody (1D11), against the metastatic endpoint using fully immunocompetent mouse hosts to capture the contribution of anti-tumor immune responses. We observed therapeutic efficacy or trend to efficacy in 5 models (InhibMet), no effect in 2 models (NoEff) and an undesirable stimulation or trend to stimulation of metastasis in 4 models (StimMet). This heterogeneity in therapeutic responses suggests that it will be critical to develop good predictive biomarkers for patient selection in clinical trials using TGF-β antagonists. Plausible candidate biomarkers suggested by the existing literature, such as p53 mutation status, claudin-low status, or TGF-β protein expression, did not correlate with therapeutic response, so we applied integrated genomic discovery approaches to the panel. We find significant differences in patterns of gene expression, gene polymorphism/mutation and copy number variation between the StimMet and InhibMet models. Notably, transcriptomic analyses of the untreated primary tumors show that these segregate by response to therapy in principal component analysis, after removal of mouse strain and tumor origin (spontaneous vs genetically-engineered) as factors. Analysis of differentially-expressed genes suggests that InhibMet models are characterized by higher TGF-β pathway activation, higher angiogenesis, poor immune cell infiltration/activation, and other markers of tumor aggressiveness such as higher tumor cell proliferation and survival. The data point to fundamental differences in tumor biology between the two classes of model and suggest that it will be possible to generate biomarkers that predict therapeutic response to TGF-β pathway antagonists.

Citation Format: Yu-an Yang, Kathleen C. Flanders, Binwu Tang, Miriam R. Anver, Anand Merchant, Howard Yang, Maxwell Lee, Scott Lonning, John M. McPherson, Lalage M. Wakefield. Neutralizing anti-TGF-β antibodies elicit heterogeneous therapeutic responses in a panel of murine metastatic breast cancer models. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4094. doi:10.1158/1538-7445.AM2015-4094

Genome-wide redistribution of BRD4 binding sites in transformation resistant cells

Hutchinson-Gilford progeria syndrome (HGPS) patients do not develop cancer despite a significant accumulation of DNA damage in their cells. We have recently reported that HGPS cells are refractory to experimental oncogenic transformation and we identified the bromodomain-containing 4 protein (BRD4) as a mediator of the transformation resistance. ChIP-sequencing experiments revealed distinct genome-wide binding patterns for BRD4 in HGPS cells when compared to control wild type cells. Here we provide a detailed description of the ChIP-seq dataset (NCBI GEO accession number GSE61325), the specific and common BRD4 binding sites between HGPS and control cells, and the data analysis procedure associated with the publication by Fernandez et al., 2014 in Cell Reports 9, 248-260 [1].

Abstract 2843: Tumor macrophages utilize ATF3 to promote breast cancer metastasis

Objective: Cancer progression is facilitated by a complex network of interactions between cancer cells and host-derived components, such as stromal cells and extracellular matrix in the tumor microenvironment. We sought to identify the factors that mediate these dynamic cancer-host interplays. Specifically, we asked how the host responds to signals from the cancer cells. To this end, we investigated the role of ATF3, an adaptive-response gene in the cellular stress response network. Overwhelming evidence indicates that ATF3 is induced by a broad spectrum of extra- and intra-cellular signals in a variety of cell types. As such, it is as an excellent candidate for mediating host responses to cancer cells.

Methods: We injected breast cancer cells (MMTV-PyMT cells) into syngeneic wild type (WT) or ATF3 knockout (KO) mice, performed survival surgery to remove the primary tumors, and examined metastasis two months after tumor removal.

Results: We found that ATF3 deficiency in the host did not affect primary tumor formation; excitingly, though, it dramatically decreased lung metastasis. Analyses of the circulating tumor cells and lung colonization indicated that both early and late steps in the metastatic cascade were defective in the KO host. Since soluble factors are an integral part of the mechanisms by which the host transmits systemic responses, we analyzed the plasma of normal and tumor-bearing mice by an antibody array. Intriguingly, plasma from tumor-bearing KO mice demonstrated a marked impairment in the abundance of various molecules that are known to play important roles in metastasis, suggesting that ATF3 in the host promotes a systemic environment that enhances cancer metastasis. Since the KO mice are whole body KO, the results above do not indicate the cell type(s) in which ATF3 is playing this critical role. We will present evidence that ATF3 plays an important role, at least in part, in the tumor associated macrophages (TAMs), where it up-regulates MMP9 as a functionally important target gene. Two lines of evidence indicated that our findings on ATF3 have clinical relevance. First, analyses of human tumor microarrays by immunohistochemistry revealed that ATF3 expression in monocytic cells correlated with poor outcome. Second, analyses of the mouse TAMs from the WT and KO host identified ∼400 ATF3-regulated genes. Among these genes, a 60-gene signature was identified that could distinguish the human breast tumor stroma from the normal breast stroma (McGill Breast Stroma dataset). Significantly, this signature predicted outcome in two independent patient cohorts.

Conclusion and Significance: We uncovered a previously unknown role for ATF3: it is induced in the host during cancer development and its expression in the host cells, specifically the TAMs, promotes metastasis. This finding is significant because it not only links host stress response to cancer metastasis, it also identified a new gene signature that predicts outcome.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2843. doi:10.1158/1538-7445.AM2011-2843

An ets2-driven transcriptional program in tumor-associated macrophages promotes tumor metastasis

Tumor-associated macrophages (TAM) are implicated in breast cancer metastasis, but relatively little is known about the underlying genes and pathways that are involved. The transcription factor Ets2 is a direct target of signaling pathways involved in regulating macrophage functions during inflammation. We conditionally deleted Ets in TAMs to determine its function at this level on mouse mammary tumor growth and metastasis. Ets2 deletion in TAMs decreased the frequency and size of lung metastases in three different mouse models of breast cancer metastasis. Expression profiling and chromatin immunoprecipitation assays in isolated TAMs established that Ets2 repressed a gene program that included several well-characterized inhibitors of angiogenesis. Consistent with these results, Ets2 ablation in TAMs led to decreased angiogenesis and decreased growth of tumors. An Ets2-TAM expression signature consisting of 133 genes was identified within human breast cancer expression data which could retrospectively predict overall survival of patients with breast cancer in two independent data sets. In summary, we identified Ets2 as a central driver of a transcriptional program in TAMs that acts to promote lung metastasis of breast tumors.

Pten in stromal fibroblasts suppresses mammary epithelial tumours

The tumour stroma is believed to contribute to some of the most malignant characteristics of epithelial tumours. However, signalling between stromal and tumour cells is complex and remains poorly understood. Here we show that the genetic inactivation of Pten in stromal fibroblasts of mouse mammary glands accelerated the initiation, progression and malignant transformation of mammary epithelial tumours. This was associated with the massive remodelling of the extracellular matrix (ECM), innate immune cell infiltration and increased angiogenesis. Loss of Pten in stromal fibroblasts led to increased expression, phosphorylation (T72) and recruitment of Ets2 to target promoters known to be involved in these processes. Remarkably, Ets2 inactivation in Pten stroma-deleted tumours ameliorated disruption of the tumour microenvironment and was sufficient to decrease tumour growth and progression. Global gene expression profiling of mammary stromal cells identified a Pten-specific signature that was highly represented in the tumour stroma of patients with breast cancer. These findings identify the Pten-Ets2 axis as a critical stroma-specific signalling pathway that suppresses mammary epithelial tumours.

Osteosarcoma in Paget's disease of bone

Paget's disease of bone (PDB) is a focal disorder of bone metabolism first described by Sir James Paget in 1876. It is presumed benign in nature and mediated by abnormal osteoclast function. The incidence of osteosarcomas complicating PDB is estimated at <1%. These cancers occur mostly in persons with long-standing, polyostotic disease and affect patients in their seventh decade or when osteosarcoma is remarkably rare in the general population. Epidemiological studies suggest that this late peak of osteosarcomas is absent in regions where Paget's is infrequently reported. Whereas PDB has a predilection for the axial skeleton, skull, femurs, and tibias, pagetic osteosarcoma tend to spare the spine, and are reported more commonly in the pelvis, femur, humerus, and skull. A molecular basis for the association of osteosarcoma with Paget's disease is unclear. These osteosarcomas are osteogenic in origin, consistently arise in sites of pagetic bone, and may present as metachronous, multifocal lesions. On histopathology, the lesions are usually osteoblastic, and the tumor phenotype is sometimes characterized as an exaggerated, chaotic form of the accelerated bone remodeling that characterizes PDB. New insights from the biology of adolescent osteosarcomas, VCP and SQSTM1 mutations now defined in patients with Paget's disease, and emerging evidence that stromal lesions are present in patients with Paget's disease are changing the way we think about the pathogenesis of PDB and the rare complication of pagetic osteosarcomas.

A cardiologist's guide to waist management

Clinical management of obesity remains a challenge.

Ischemic preconditioning in deceased donor liver transplantation: a prospective randomized clinical trial of safety and efficacy

Ischemic preconditioning (IPC) has the potential to decrease graft injury and morbidity after liver transplantation. We prospectively investigated the safety and efficacy of 5 minutes of IPC induced by hilar clamping in local deceased donor livers randomized 1:1 to standard (STD) recovery (N = 28) or IPC (N = 34). Safety was assessed by measurement of heart rate, blood pressure, and visual inspection of abdominal organs during recovery, and efficacy by recipient aminotransferases (aspartate aminotransferase [AST] and alanine aminotransferase [ALT], both measured in U/L), total bilirubin, and international normalized ratio of prothrombin time (INR) after transplantation. IPC performed soon after laparotomy did not cause hemodynamic instability or visceral congestion. Recipient median AST, median ALT, and mean INR, in STD vs. IPC were as follows: day 1 AST 696 vs. 841 U/L; day 3 AST 183 vs. 183 U/L; day 1 ALT 444 vs. 764 U/L; day 3 ALT 421 vs. 463 U/L; day 1 INR 1.7 +/- .4 vs. 2.0 +/- .8; and day 3 INR 1.3 +/- .2 vs. 1.4 +/- .3; all P > .05. No instances of nonfunction occurred. The 6-month graft and patient survival STD vs. IPC were 82 vs. 91% and median hospital stay was 10 vs. 8 days; both P > .05. In conclusion, deceased donor livers tolerated 5 minutes of hilar clamping well, but IPC did not decrease graft injury. Further trials with longer periods of preconditioning such as 10 minutes are needed.

Effect of sirolimus on infection incidence in liver transplant recipients

Sirolimus is a new immunosuppressive agent that lacks the nephrotoxicity and neurotoxicity associated with calcineurin inhibitors. The addition of sirolimus to immunosuppressive protocols may thus allow sparing of calcineurin inhibitors and reduction or elimination of associated toxicities. Between January 2000 and July 2001, sirolimus was administered to 55 of 116 consecutive liver recipients. The remaining 61 patients served as the comparison group in the retrospective analysis. In the sirolimus group, perioperative steroids were reduced, and calcineurin inhibitor initiation was delayed. All infectious episodes that occurred within 60 days of liver transplantation were evaluated but were limited to 1 per patient for statistical analysis of sepsis. Demographic variables were comparable between groups. Patients receiving sirolimus experienced more infection (47.2% vs. 18.03%, P<0.001), and this effect persisted across high and low dosage ranges and sirolimus levels. A trend toward increased length of stay was noted (P=0.07). No difference between groups was found in acute rejection rates (17.5% vs. 22.5%), 1-year graft (81% vs. 89%), patient survival (86% vs. 89%), or hepatic artery thrombosis. In conclusion, despite reduction of other immunosuppressants, patients receiving even low doses of sirolimus experienced increased sepsis rates. This agent may have greater usefulness for patients with threatened renal function or patients with chronic rejection after wound healing has occurred.

Donors with cardiac arrest: improved organ recovery but no preconditioning benefit in liver allografts

BACKGROUND

Historically, organ recovery rates in donors with cardiac arrest (CA) have been low, presumably from hemodynamic instability. We hypothesized that donor resuscitation has improved hemodynamic stability and organ recovery in CA donors, and that CA triggers ischemic preconditioning (IP) in liver grafts.

METHODS

A total of 131 donor pairs with and without CA were matched in age, gender, and year of recovery. Hemodynamic stability was determined by vasopressor use. Abdominal and thoracic organs recovered and livers transplanted were compared between the groups. Liver graft function, injury, and IP benefit were examined by comparing liver chemistries after transplantation and postperfusion biopsies between recipients of grafts from both groups (n=40 each).

RESULTS

Hemodynamic stability was similar in both groups, but recovery of thoracic organs was significantly lower in CA versus non-CA donors (35 vs. 53%, P<0.01). On the other hand, recovery rates of three or more abdominal organs from CA donors approached those of non-CA donors (77 vs. 87%, not significant). Although significantly fewer livers were transplanted from CA donors (69 vs. 85%, P<0.01), posttransplantation graft function and injury parameters were similar between the two groups, and CA did not appear to trigger IP.

CONCLUSION

Compared with historical data, cardiovascular stability and abdominal organ recovery rates have improved considerably in CA donors. Liver grafts from CA donors function similarly to grafts from non-CA donors with no IP from CA. Our data support the increased use of livers and other organs from donors with CA.

Effect of Fas and Fas ligand deficiency in resistance of C57BL/6 mice to HSV-1 keratitis and chorioretinitis

PURPOSE

To investigate the effect of Fas and Fas ligand (FasL) deficiency on the development of herpes stromal keratitis and on the von Szily model of herpes retinitis in C57BL/6 mice, which are ordinarily resistant to development of both of these herpetic diseases.

METHODS

Anterior chamber inoculation of the right eye of each mouse with various titers of HSV-1 (KOS strain) was performed. Both eyes of each mouse were enucleated on postinoculation day 15 and processed for histopathologic examination. HSV-1 was inoculated into one cornea of other mice, and the severity of stromal keratitis was scored.

RESULTS

Contralateral destructive chorioretinitis developed in susceptible Balb/cByj mice (19/23); ipsilateral chorioretinitis did not occur (0/23). Stromal keratitis developed in susceptible C.AL-20 mice (15/16). None of the C57BL/6 (0/10 for keratitis or 0/20 for retinitis) developed inflammation. Neither did B6.SMN.C3H.gld (FasL deficient; 0/12 or 0/28) or B6.MRL.lpr (Fas deficient; 0/11 or 0/34) mice (keratitis or contralateral chorioretinitis). Minimal scattering of inflammatory cells in the contralateral retina but not destructive chorioretinitis was observed in two C57BL/6, three B6.SMN.C3H.gld, and five B6.MRL.lpr mice. Few inflammatory cells were also found in the ipsilateral vitreous and vitreoretinal interface (but not destructive chorioretinitis) of all C57BL/6, two gld, and three lpr mice.

CONCLUSIONS

Immune dysregulation secondary to deficiency in Fas or FasL system does not influence the resistance of the C57BL/6 mice to develop herpes simplex keratitis or destructive herpes simplex chorioretinitis.

Candidal endophthalmitis after keratoplasty

PURPOSE

To report a case of explosive fungal endophthalmitis after penetrating keratoplasty and to review additional published and unpublished cases to consider possible strategies for prevention.

METHODS

Records of this patient with postkeratoplasty candidal endophthalmitis and previously reported cases of postkeratoplasty candidal endophthalmitis were reviewed. Additional information of 26 unpublished cases was obtained from the Eye Bank Association of America.

RESULTS

After standard keratoplasty, the patient developed precipitous endophthalmitis on the second postoperative day. Abundant contamination with Candida was found in the residual donor corneoscleral rim, and Candida albicans was isolated from the aqueous humor of the recipient. Despite therapy with local antimicrobial agents, intraocular amphotericin B, and systemic fluconazole, the patient had a poor outcome with hand-motion visual acuity. Of the 44 collected cases of postkeratoplasty candidal endophthalmitis, 40 (91%) had the same organism cultured from the donor rim or medium. Forty-three donor corneas had been preserved in cold storage medium at 4 degrees C. Of 15 cases in which the outcome was available, 9 (60%) resulted in visual acuity of 20/200 or worse.

CONCLUSION

Case reports confirm the occurrence of donor-to-host transmission of postkeratoplasty candidal endophthalmitis. Despite the low reported incidence, the poor prognosis of the affected eye in the ajority of these cases suggests the need for antifungal supplementation of cold preservation media and other preventative strategies.

Paan without tobacco: an independent risk factor for oral cancer

Oral cancer is the second most common cancer in women and the third most common in men in Pakistan. Tobacco is smoked and chewed extensively in Pakistan. Paan is a quid of piper betel leaf that contains areca nut, lime, condiment, sweeteners, and sometimes tobacco, which is also used extensively. We did this study to clarify the independent association of paan and oral cancer. Between July 1996 and March 1998, we recruited biopsy-proven, primary cases of oral squamous-cell carcinoma, from 3 tertiary teaching centers in Karachi, Pakistan, and controls pair-matched for age, gender, hospital and time of occurrence, excluding persons with a past or present history of any malignancy. There were 79 cases and 149 controls. Approximately 68% of the cases were men, 49 years old on average, the youngest being 22 years old and the eldest 80. People with oral submucous fibrosis were 19.1 times more likely to develop oral cancer than those without it, after adjusting for other risk factors. People using paan without tobacco were 9.9 times, those using paan with tobacco 8.4 times, more likely to develop oral cancer as compared with non-users, after adjustment for other covariates. This study identifies an independent effect of paan without tobacco in the causation of oral cancer. Its findings may be of significance in South Asian communities where paan is used, and among health-care providers who treat persons from South Asia.

Leukocyte adhesion molecule expression in scleritis

OBJECTIVE

To analyze the expression and cellular distribution of intercellular adhesion molecule 1, E-selectin (endothelial leukocyte adhesion molecule), vascular cell adhesion molecule 1, very late antigen 4, and lymphocyte function associated antigen 1 (LFA-1) in diseased and normal human sclera.

METHODS

Monoclonal antibodies to vascular cell adhesion molecule 1, very late antigen 4, intercellular adhesion molecule 1, LFA-1, and E-selectin were used to perform immunohistochemical staining on frozen sections of 16 cryopreserved human sclera specimens and 5 conjunctival specimens.

RESULTS

The normal human sclera did not express any of the adhesion molecules. The expression of LFA-1 was dramatic in all the scleral and conjunctival specimens on the inflammatory cells. Intercellular adhesion molecule 1, the ligand for LFA-1, was expressed in 7 of 12 scleral specimens. Furthermore, the expression of LFA-1 and intercellular adhesion molecule 1 were focally present in areas of inflammatory infiltrate. E-selectin expression was detected on the vascular endothelial cells in 8 of 12 patients. There was variable expression of vascular cell adhesion molecule 1 and very late antigen 4 in the inflamed sclera and conjunctiva.

CONCLUSIONS

Our results demonstrate the presence of LFA-1 in the sclera and in the conjunctiva of patients with scleritis. Variable expression of other leukocyte adhesion molecules was noted in the sclera and the conjunctiva of these patients.

Chronic keratoconjunctivitis associated with congenital dyskeratosis and erythrokeratodermia variablis. Two rare genodermatoses

OBJECTIVE

The purpose of the study was to report the ocular manifestations and immunohistopathologic description of two rare forms of genodermatosis: congenital dyskeratosis (CD) and erythrokeratodermia variabilis (EKV).

DESIGN

Case reports.

PARTICIPANTS

Two patients with CD and EKV presenting with chronic keratoconjunctivitis were studied.

INTERVENTION

Clinical photography to show ocular manifestations and dermatologic findings was performed. Conjunctival biopsy was performed to determine the histopathology and immunohistopathology.

RESULTS

In the patient with EKV, the eyelid skin was dry, erythematous, and thickened. The lid margins showed plugging of some of the Meibomian glands, madarosis, and occasional trichiasis. The epibulbar conjunctiva was injected and had a moderate papillary reaction. Both corneas had pronounced vascularization and stromal scarring. Conjunctival biopsy results disclosed a striking number of degranulating mast cells and moderate numbers of plasma cells. Immunohistopathology showed pronounced immunoglobulin G (IgG)-positive cells in the stroma and immunoglobulin A (IgA) positivity in the epithelium. There was scattered immunoglobulin M (IgM) and moderate C3 and C4 positivity in the stroma. In CD, the patient had keratinized lid margins, entropion formation, trichiasis, cicatrizing conjunctivitis, and symblephra formation. The corneal surface was keratinized, with deep and superficial vascularization. Conjunctival biopsy specimens showed pronounced epithelial keratinization and squamous metaplasia. Degranulating mast cells and eosinophils were prominent in the stroma. Immunohistopathology showed C4 and immunoglobulin D positivity on the keratinized epithelial surface with rare foci of immunoglobulin E-positive cells. Basal epithelial cells were positive for IgA and IgG, and a large number of IgA and IgG plasma cells were present in the substantia propria.

CONCLUSION

To the authors' knowledge, these case reports represent the first clinical description of the ocular manifestation of EKV and the first immunohistopathologic description of the affected conjunctiva in EKV and CD, both of which should be considered in the differential diagnosis of genodermatosis associated with chronic keratoconjunctivitis.

Pharmacomanipulation of HSV-1 induced chorioretinitis in mice

In the von Szily mouse model, intracameral inoculation of herpes simplex virus type-1 (HSV-1) results in inflammation of the ipsilateral anterior segment with relative chorioretinal sparing and destructive contralateral chorioretinitis. We studied the effect of the systemic antiviral agent acyclovir (ACV) and anti-HSV-1 antibody therapy in this model. Contralateral chorioretinitis developed in none of the 18 mice receiving ACV from post-inoculation day (pid) 1 (p < 0.0001), in 6 of 10 (60%) mice when treatment was delayed until pid 7 (p = 0.40) and in 14 of 18 (77%) controls. Contralateral disease developed in 8 of 16 (50%) mice that received anti-HSV-1 antibody from pid 1 (p = 0.02), in 13 of 16 (81%) treated from pid 5 (p = 0.64), in 7 of 8 (87.5%) treated from pid 7 (p = 1.0) and in 17 of 20 (85%) controls. We conclude that early treatment with ACV or anti-HSV-1 antibody reduces the incidence of contralateral chorioretinitis in mice.

Ocular rosacea: patient characteristics and follow-up

PURPOSE

The purpose of this report is to review the presenting symptoms and signs, treatment regimens used, complications encountered, and outcome in a cohort of patients with ocular rosacea.

METHODS

The medical records of 131 patients with a diagnosis of ocular rosacea were reviewed retrospectively. Data were entered in a tabulated form, and a descriptive analysis was performed.

RESULTS

The age range at presentation was between 23 and 85 years (mean, 56 years). Cutaneous manifestations of rosacea were present in 112 of the patients at their first visit. The most common presenting symptoms were foreign body sensation and burning, and the most common signs were telangiectasia and irregularity of lid margins, and meibomian gland dysfunction. Thirteen patients had decreased visual acuity at the time of presentation due to corneal complications. Six of these patients required penetrating keratoplasty during the course of their disease. Seven patients had severe cicatrizing conjunctivitis at the time of referral. One hundred thirteen patients were treated with oral tetracycline derivatives. Seven patients were left with visual acuity less than 20/400, and one patient underwent enucleation for corneal perforation and endophthalmitis.

CONCLUSIONS

Ocular rosacea is a common disease involving the skin and the eyes. It is widely underdiagnosed by many ophthalmologists despite the blinding potential. Successful therapy requires a multidisciplinary approach.

Herpes simplex virus type 2 induced retinal necrosis in BALB/c mice

We injected herpes simplex virus type 2 of MS- or G-strain into the anterior chamber of BALB/c mice. In the contralateral eye inflammatory cell infiltration began in the ciliary body; focal retinitis, detected by day 8, led to total destruction of the retina by day 10. Contralateral disease was observed in 75% of mice inoculated with 8 x 10(3) pfu herpes simplex virus type 2, but in only 20% of mice receiving 80 pfu herpes simplex virus type 2. Still this low concentration, however, produced a suppressed delayed-type hypersensitivity response. Anti-herpes simplex virus type 2 antibody, first detected on day 8, reached high titers on day 10; by then, most of the mice had died of encephalitis. The G-strain of herpes simplex virus type 2 was more neurotoxic than the MS-strain, but produced the same incidence of contralateral retinitis. Herpes simplex virus type 2 products contralateral necrotizing retinitis comparable to that produced by herpes simplex virus type 1. These findings, like those of other authors, suggest a role for herpes simplex virus type 2 in some cases of acute retinal necrosis in humans.

Molecular skins: a new concept for quantitative shape matching of a protein with its small molecule mimics

A novel analytical method for comparing molecular shapes by optimizing the intersection of molecular "SKINS" has been developed. This method provides a quantitative measure of the shape similarity by maximizing the intersection volume of molecular surfaces with a finite thickness; a molecular skin. We report shape matching of a small tripeptide inhibitor (DFKi) of elastase class proteins with the 56 residue turkey ovomucoid inhibitor (TOMI). To match a large elastase inhibitor such as TOMI with a small inhibitor or drug, we found that it is necessary to use a skin match rather than molecular volume. Skin based comparisons of TOMI protein with DFKi successfully found the alignment expected from comparison of their respective crystallographic complexes with elastase (i.e. HLE/TOMI complex and PPE/tripeptide complex). In the skin comparison of the tripeptide with the TOMI protein, blind searching for skin matches involved optimization of the skin intersection from 172 starting positions randomly selected from a set of 500 points on the TOMI van der Waals surface [within 9.5 A of the Leu-18 on the TOMI binding loop (1 point/A2)]. The tripeptide center of mass was placed at these points and its orientation was randomized before optimization was initiated. The best skin intersection, 86.4 A3, was found three times and corresponds to the experimental alignment. The next best skin intersection was 78.1 A3 giving a discrimination factor in this case of 10%. Searches over the entire surface of the TOMI protein did not identify any new matches with skin intersection greater than 78.1 A3. Matching the DFKi with a TOMI structure relaxed from its crystal conformation by molecular dynamics gives similar results.

Molecular shape comparison of angiotensin II receptor antagonists

A new and powerful analytical method for comparing molecular shapes by optimizing the overlap of molecular volumes has been developed. This shape comparison method provides both a quantitative measure of the shape similarity of molecules and a means to align molecules such that shape similarity if maximized. Our MSC method has been enhanced with an option to allow discrimination between groups with different chemical properties. Atoms or groups of atoms may be assigned to different classes based on specific properties such as electrostatic potential, hydrogen bonding ability, or hydrophobicity. This enables matches based on criteria such as alignment of hydrophobic groups or hydrogen bond acceptor groups. In this study, we report shape comparisons of angiotensin II (AII) receptor antagonists from two structural classes, 4-(biphenyl-4-ylmethoxy)-quinoline derivatives such as ICI D8731 and N-(biphenyl-4-ylmethyl)imidazole derivatives, such as DuP753. Starting with a list of low-energy conformations for the two molecules, each conformation of the first molecule is paired with each of the conformations of the second molecule. For each of these conformational pairs, an MSC comparison, which generates multiple MSC maxima, is initiated. Eight high scoring conformational pairings were found with shape matching based on the intersection of the total molecular volume, while nine high-scoring pairs were identified with matching by atom type. MSC identifies conformational pairs with high shape similarity, as measured by the intersection volume, and thus generates and prioritizes several alternative models for the AII antagonist pharmacophore.

Systemic (serum) soluble interleukin-2 receptor levels in corneal transplant recipients

Elevated soluble interleukin-2 receptor levels (sIL-2R), a measure of T cell activation, have been used as a serum marker for early rejection in solid organ transplant patients. In this preliminary study, we measured sequential sIL-2R levels of 53 otherwise immunologically normal corneal transplant recipients. Eleven of these transplants rejected; sIL-2R was significantly elevated during the acute rejection episode, compared to pre-rejection and post-rejection levels (p = 0.01). Five patients' sIL-2R rose one to nine months prior to rejection. These data indicate that sIL-2R levels may correlate with corneal graft rejection and may be predictive of impending rejection. A larger prospective study with many immunologically normal patients and careful monitoring of sIL-2R levels prior to and during the acute rejection episode will be necessary to determine the value of sIL-2R monitoring as a predictive tool for corneal graft rejection.

Topical cyclosporine A and corneal wound healing

The effect of 2% topical cyclosporine A (CsA) ointment on corneal epithelial and stromal wound healing was evaluated in a masked, placebo-controlled study in rabbits. The difference in epithelial would healing rate in the treatment and placebo group was not statistically significant. There was also no difference in the values of bursting strength of 2-mm central penetrating wounds and in the measurement of hydroxyproline content in the central corneal buttons from the wounded area in both the groups. Clinical evaluation of the quality of regenerating epithelium, stromal edema, haze, and iritis did not reveal a difference between the two groups. There was a significantly higher incidence of conjunctival injection in the CsA-treated group. We conclude that topical cyclosporine A 2% does not significantly inhibit epithelial or stromal corneal wound healing.

The epidemiology of psychiatrist-ascertained depression and DSM-III depressive disorders. Results from the Eastern Baltimore Mental Health Survey Clinical Reappraisal

Psychiatrists used a semi-structured Standardized Psychiatric Examination method to examine 810 adults drawn from a probability sample of eastern Baltimore residents in 1981. Of the population, 5.9% was found to be significantly depressed. DSM-III major depression (MD) had a prevalence of 1.1% and 'non-major depression' (nMD), our collective term for the other depressive disorder categories in DSM-III, had a prevalence of 3.4%. The two types of depression differed by sex ratio, age-specific prevalence, symptom severity, symptom profiles, and family history of suicide. Analyses using a multiple logistic regression model discerned that both types of depression were influenced by adverse life events, and that nMD was influenced strongly by gender, marital status, and lack of employment outside the home. Neither type of depression was influenced by income, education, or race. This study validates the concept of major depression as a clinical entity. Future studies of the aetiology, mechanism, and treatment of depression should distinguish between these two types of depression.

DSM-III compulsive personality disorder: an epidemiological survey

A two-stage probability sample of community subjects was developed with a full psychiatric examination employing DSM-III criteria in conjunction with the Epidemiological Catchment Area (ECA) survey conducted in Baltimore, MD. This report details the observation on those subjects diagnosed with compulsive personality disorder and compulsive personality traits. The results indicate that this condition has a prevalence of 1.7% in a general population. Male, white, married and employed individuals receive this diagnosis most often. Our data suggest a dimensional rather than categorical character for this disorder. The disorder imparts a vulnerability for the development of anxiety disorders.

Thymosin alpha 1 enhancement of human lymphocyte proliferation is not mediated by prostaglandin E2

Prostaglandins of the E series have been implicated as possible mediators of thymosin alpha 1 (TA-1) effect on mitogen stimulated lymphoproliferation. In the present study human peripheral blood mononuclear cells were stimulated with concanavalin A in the presence of TA-1, prostaglandin E2 and indomethacin individually, or in combination. Both TA-1 and indomethacin significantly enhanced the proliferative response over that seen with mitogen alone (less than 0.001). The magnitude of enhancement observed with indomethacin (20 microM) was considerably less than that of TA-1 and it was abolished with prostaglandin E2. The combination of indomethacin and TA-1 did not alter TA-1 effect and prostaglandin E2 (up to 250 ng/ml) did not abolish thymosin effect. These results suggest that TA-1 and prostaglandin E2 have opposite effects and that thymosin enhancement of mitogen induced proliferation is not mediated by prostaglandin E2.