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The University of Massachusetts Medical School Child Trauma Training Center (UMMS-CTTC)

Tue, 06/18/2013 - 8:50pm

The UMMS Child Trauma Training Center mission is to improve the identification of trauma and increase trauma-sensitive care and access to evidence-based trauma-focused treatment for at-risk and underserved populations in Central and Western Massachusetts, including court-involved youth and military families, ages 6 to 18 years.

Use of antiepileptics for seizure prophylaxis after traumatic brain injury

Tue, 06/18/2013 - 1:55pm

PURPOSE: Antiepileptics used for seizure prophylaxis after traumatic brain injury (TBI) are reviewed.

SUMMARY: Of the 275,000 people who are hospitalized with TBI each year, approximately 5-7% experience a posttraumatic seizure (PTS). According to the latest guidelines issued by the Brain Trauma Foundation and the American Academy of Neurology (AAN) for the management of severe TBI, PTS prophylaxis is recommended only during the first seven days after TBI. Of the available antiepileptic drugs, phenytoin has been the most extensively studied for the prophylaxis of PTS. Phenobarbital, valproate, and carbamazepine have not been as extensively researched, and, given their adverse-effect profiles and pharmacodynamic properties, there is no advantage to using these agents over phenytoin. Levetiracetam has demonstrated comparable efficacy to phenytoin for PTS prophylaxis and is associated with fewer adverse effects and monitoring considerations; it may be a reasonable alternative to phenytoin. However, levetiracetam has been associated with an increased seizure tendency. The Brain Trauma Foundation recommends using phenytoin for early PTS prophylaxis. The guidelines also state that valproate has demonstrated similar efficacy to phenytoin but warn that its use may be associated with increased mortality.

CONCLUSION: The available literature supports the use of antiepileptics for early PTS prophylaxis during the first week after a TBI. Phenytoin has been extensively studied for this indication and is recommended by the AAN and Brain Trauma Foundation guidelines for early PTS prophylaxis. Levetiracetam has demonstrated comparable efficacy to phenytoin for early PTS prophylaxis and may be a reasonable alternative to consider in this patient population.

Cytokine markers as predictors of type of respiratory infection in patients during the influenza season

Tue, 06/18/2013 - 1:55pm

OBJECTIVE: The objective of this study is to characterize the cytokine response among patients presenting with an influenza-like illness who are infected with the influenza virus, a bacterial pneumonia, or another viral infection. We hypothesize that there are differences in proinflammatory and anti-inflammatory cytokines in relation to cytokines associated with the humoral response during viral and bacterial respiratory infections.

METHODS: We enrolled adults who presented to an urban academic emergency department during the 2008 to 2011 influenza seasons with symptoms of fever and a cough. Subjects had nasal aspirates tested by viral culture, and peripheral blood drawn to quantify cytokine concentrations. Cytokine concentrations were compared between groups using the Wilcoxon rank sum test, and receiver operating characteristic curves were calculated.

RESULTS: A total of 80 patients were enrolled: 40 with influenza infection, 14 patients with a bacterial pneumonia as determined by infiltrate on chest x-ray, and 26 patients negative for influenza infection and infiltrate. There were differences between the bacterial pneumonia group, and all other viral infections grouped together with regard to interleukin (IL) 4 (2.66 vs 16.77 pg/mL, P < .001), IL-5 (20.57 vs 57.57 pg/mL, P = .006), IL-6 (403.06 vs 52.69 pg/mL, P < .001), granulocyte macrophage colony-stimulating factor (18.26 vs 66.80 pg/mL, P < .001), and interferon gamma (0.0 vs 830.36 pg/mL, P < .001). Interleukin 10 concentrations were elevated in patients with influenza (88.69 pg/mL) compared with all other groups combined (39.19 pg/mL; P = .003).

CONCLUSION: Cytokines IL-4, IL-5, IL-6, granulocyte macrophage colony-stimulating factor, and interferon gamma may serve as distinct markers of bacterial infection in patients with an influenza-like illness, whereas IL-10 is uniquely elevated in influenza patients.

Fibrosis-Associated Single-Nucleotide Polymorphisms in TGFB1 and CAV1 Are Not Associated With the Development of Nephrogenic Systemic Fibrosis

Tue, 06/18/2013 - 1:55pm

OBJECTIVE:: To test the hypothesis that the subset of patients with impaired renal function who are exposed to gadolinium-containing contrast agents (GCCAs) and develop nephrogenic systemic fibrosis (NSF) have a genetic predisposition for disease.

METHODS:: We examined whether an intronic single-nucleotide polymorphism (SNP) in caveolin-1 (CAV1 rs4730751) and 2 coding SNPs in transforming growth factor-beta 1 (TGFB1 rs1800471, codon 25; and rs1800470, codon 10) were associated with the NSF phenotype.

RESULTS:: Forty-one patients with a history of chronic kidney disease and GCCA administration were studied, including NSF cases (n = 17) and control subjects (n = 24) without clinical or histological evidence of NSF. No significant differences in the genotype frequencies at these SNPs in TGFB1 and CAV1 were found between patients with NSF and subjects without NSF.

CONCLUSIONS:: We conclude that polymorphisms in the genes encoding TGFB1 and CAV1 previously associated with the development and progression of fibrosis in several organ systems are not associated with development of NSF in this cohort of patients with renal impairment after GCCA exposure.

Pilomatrix carcinoma: a case report and review of the literature

Tue, 06/18/2013 - 1:55pm

Pilomatrixoma is a common benign neoplasm of children and young adults with a female predilection. In contrast, its malignant counterpart, pilomatrix carcinoma is a rare neoplasm of older adults with a male preponderance. Pilomatrix carcinomas are locally aggressive with a tendency to recur. We report a case of a 44-year-old male who presented with an enlarging soft tissue tumor on the right upper back. Histology revealed an asymmetric, poorly circumscribed, lobulated neoplasm located deeply in the dermis with infiltration into the underlying subcutaneous tissue. The tumor was comprised of basaloid cells containing vesicular nuclei, prominent nucleoli, scant cytoplasm, and brisk mitotic activity. A focus of basaloid cells transitioning to shadow cells with central keratinized material and tumor necrosis was also present. The diagnosis of a pilomatrix carcinoma was rendered. Considering the infiltrative nature of this neoplasm with perineural and intramuscular invasion, the patient underwent 3 surgical excisions before it was completely removed.

Improved detection rate of cytogenetic abnormalities in chronic lymphocytic leukemia and other mature B-cell neoplasms with use of CpG-oligonucleotide DSP30 and interleukin 2 stimulation

Tue, 06/18/2013 - 1:55pm

Detection of cytogenetic abnormalities requires successful culture of the clonal population to obtain metaphase chromosomes for study, and as such, has been hampered by low mitotic indices of mature B cells in culture. Our study presents data on the improved abnormality detection rate with the use of a CpG-oligonucleotide/interleukin 2 (OL/IL-2) culture protocol for mature B-cell neoplasms, including chronic lymphocytic leukemia (CLL) and non-CLL specimens. The increased detection rate of abnormalities, compared with unstimulated culture and traditional pokeweed mitogen culture, was statistically significant for both CLL and non-CLL neoplasms. For CLL specimens, our data also showed that for cytogenetically visible aberrations, OL/IL-2 was as, if not more, sensitive than detection with interphase fluorescence in situ hybridization (iFISH). Use of OL/IL-2 allowed a number of abnormalities to be detected, which were not covered by specific iFISH panels, especially balanced translocations. Therefore, OL/IL-2 stimulation improves diagnostic sensitivity and increases discovery rate of novel prognostic findings.

Evaluating the Role of Macrocycles in the Susceptibility of Hepatitis C Virus NS3/4A Protease Inhibitors to Drug Resistance

Tue, 06/18/2013 - 1:55pm

The hepatitis C virus (HCV) infects an estimated 150 million people worldwide and is the major cause of viral hepatitis, cirrhosis, and liver cancer. The available antiviral therapies, which include PEGylated interferon, ribavirin, and one of the HCV NS3/4A protease inhibitors telaprevir or boceprevir, are ineffective for some patients and cause severe side effects. More potent NS3/4A protease inhibitors are in clinical development, but the long-term effectiveness of these drugs is challenged by the development of drug resistance. Here, we investigated the role of macrocycles in the susceptibility of NS3/4A protease inhibitors to drug resistance in asunaprevir, danoprevir, vaniprevir, and MK-5172, with similar core structures but varied P2 moieties and macrocyclizations. Linear and macrocyclic analogues of these drugs were designed, synthesized, and tested against wild-type and drug-resistant variants R155K, V36M/R155K, A156T, and D168A in enzymatic and antiviral assays. Macrocyclic inhibitors were generally more potent, but the location of the macrocycle was critical for retaining activity against drug-resistant variants: the P1-P3 macrocyclic inhibitors were less susceptible to drug resistance than the linear and P2-P4 macrocyclic analogues. In addition, the heterocyclic moiety at P2 largely determined the inhibitor resistance profile, susceptibility to drug resistance, and the extent of modulation by the helicase domain. Our findings suggest that to design robust inhibitors that retain potency to drug-resistant NS3/4A protease variants, inhibitors should combine P1-P3 macrocycles with flexible P2 moieties that optimally contact with the invariable catalytic triad of this enzyme.

HOX antisense lincRNA HOXA-AS2 is an apoptosis repressor in all trans retinoic acid treated NB4 promyelocytic leukemia cells

Tue, 06/18/2013 - 1:55pm

HOXA cluster antisense RNA 2 (HOXA-AS2) is a long non-coding RNA located between the HOXA3 and HOXA4 genes in the HOXA cluster. Its transcript is expressed in NB4 promyelocytic leukemia cells and human peripheral blood neutrophils, and expression is increased in NB4 cells treated with all trans retinoic acid (ATRA). Knockdown of HOXA-AS2 expression by transduced shRNA decreases the number of viable cells and increases the proportion of apoptotic cells, measured by annexin V binding and by activity and cleavage of caspases-3, -8, and -9. The increase in death of HOXA-AS2 knockdown cells was accompanied by an elevated TNF-related apoptosis-inducing ligand (TRAIL) levels, but ATRA-induced NB4 cells treated with TRAIL did show an increase in HOXA-AS2 expression. These results demonstrate that ATRA induction of HOXA-AS2 suppresses ATRA-induced apoptosis, possibly through a TRAIL-mediated pathway. HOXA-AS2-mediated negative regulation thus contributes to the fine-tuning of apoptosis during ATRA-induced myeloid differentiation in NB4 cells. J. Cell. Biochem. (c) 2013 Wiley Periodicals, Inc.

IMP3 Protein Promotes Chemoresistance in Breast Cancer Cells by Regulating Breast Cancer Resistance Protein (ABCG2) Expression

Tue, 06/18/2013 - 1:55pm

IMP3, a member of a family of insulin-like growth factor II (IGF-II) mRNA-binding proteins (IMPs), is expressed preferentially in triple-negative breast cancers, which are resistant to many chemotherapeutics. However, the mechanisms by which it impacts breast cancer have not been elucidated. We hypothesized a role for IMP3 in chemoresistance based on these observations. Depletion of IMP3 expression in triple-negative breast cancer cells increased their sensitivity to doxorubicin and mitoxantrone significantly but not to taxol. Given that doxorubicin and mitoxantrone are effluxed by breast cancer resistance protein (BCRP), we assessed whether IMP3 regulates BCRP. The data obtained demonstrate that IMP3 binds to BCRP mRNA and regulates BCRP expression. These findings are significant because they provide insight into the mechanism by which IMP3 contributes to aggressive cancers, and they highlight the potential for targeting this mRNA-binding protein for the clinical management of cancer.

MEN1 is a Melanoma Tumor Suppressor that Preserves Genomic Integrity by Stimulating Transcription of Genes that Promote Homologous Recombination-Directed DNA Repair

Tue, 06/18/2013 - 1:55pm

Multiple endocrine neoplasia type 1 is a familial cancer syndrome resulting from loss-of-function mutations in the MEN1 gene. We previously identified the tumor suppressor MEN1 as a gene required for oncogene-induced senescence in melanocytes, raising the possibility that MEN1 is a melanoma tumor suppressor. Here we show that MEN1 expression is lost in a high percentage of human melanomas and melanoma cell lines. We find that melanocytes depleted of MEN1 are deficient in homologous recombination (HR)-directed DNA repair, which is accompanied by increased non-homologous end joining activity. Following DNA damage, MEN1 levels increase resulting from phosphorylation by the DNA damage kinase ATM/ATR. Most importantly, we show that MEN1 functions by directly stimulating transcription of several genes, including BRCA1, RAD51 and RAD51AP1, that encode proteins involved in HR. MEN1 and its coactivator, the histone methyltransferase MLL, are recruited to the BRCA1, RAD51 and RAD51AP1 promoters by estrogen receptor 1, resulting in increased histone H3-lysine 4 trimethylation and transcription. Collectively, our results indicate that MEN1 is a melanoma tumor suppressor that functions by stimulating transcription of genes involved in HR-directed DNA repair.

Metabolite sensing in eukaryotic mRNA biology

Tue, 06/18/2013 - 1:55pm

All living creatures change their gene expression program in response to nutrient availability and metabolic demands. Nutrients and metabolites can directly control transcription and activate second-messenger systems. More recent studies reveal that metabolites also affect post-transcriptional regulatory mechanisms. Here, we review the increasing number of connections between metabolism and post-transcriptional regulation in eukaryotic organisms. First, we present evidence that riboswitches, a common mechanism of metabolite sensing in bacteria, also function in eukaryotes. Next, we review an example of a double stranded RNA modifying enzyme that directly interacts with a metabolite, suggesting a link between RNA editing and metabolic state. Finally, we discuss work that shows some metabolic enzymes bind directly to RNA to affect mRNA stability or translation efficiency. These examples were discovered through gene-specific genetic, biochemical, and structural studies. A directed systems level approach will be necessary to determine whether they are anomalies of evolution or pioneer discoveries in what may be a broadly connected network of metabolism and post-transcriptional regulation. WIREs RNA 2013. doi: 10.1002/wrna.1167 For further resources related to this article, please visit the WIREs website.

Gender differences of mental health consumers accessing integrated primary and behavioral care

Tue, 06/18/2013 - 1:55pm

Persons with severe mental illness and addiction are at higher risk for early morbidity and mortality than the general population, and are less likely to receive primary care and preventive health services. Primary and behavioral integrated care programs aim to reduce these health disparities by providing comprehensive health and wellness services. Gender in particular may play a significant role in individuals' engagement and outcomes in such programs. Hence, this study examines the salient characteristics of behavioral health consumers accessing an integrated care program at a large community mental health center. Baseline gender differences in consumer demographics, substance use, psychological distress and functioning, physical health indicators, and risk factors for serious medical conditions are examined. Our results demonstrate that key gender differences exist and may warrant distinct treatment needs for men and women receiving integrated care.

IFN-gamma production by human natural killer cells in response to HCV-infected hepatoma cells is dependent on accessory cells

Tue, 06/18/2013 - 1:55pm

BACKGROUND and AIMS: Interferon-gamma (IFN-gamma), a cytokine produced by activated natural killer cell (NK) and T lymphocytes, is an important regulator of innate and adaptive immunity during hepatitis C virus (HCV) infection. However, the cellular sources and mechanisms of IFN-gamma induction in HCV-infection are not fully understood.

METHODS: We cultured normal human peripheral blood mononuclear cells (PBMCs) with different populations of immune cells and JFH-1 HCV-infected Huh7.5 (JFH-1/Huh7.5) cells.

RESULTS: We found that PBMCs produced large amounts of IFN-gamma after co-culture with JFH-1/Huh7.5 cells. Using intracellular cytokine staining we confirmed that NK cells and NKT cells (to a lesser extent) were the major IFN-gamma producers within PBMCs. Purified NK/NKT cells did not produce IFN-gamma in response to JFH-1/Huh7.5 cells and depletion of accessory (HLA-DR+) cells prevented IFN-gamma induction in PBMCs. Through selective cell depletion of dendritic cells or monocytes from PBMCs, we determined that plasmacytoid dendritic cells (pDCs) were indispensable for NK-IFN-gamma induction and the presence of monocytes was needed for maximal NK-IFN-gamma induction. We further revealed that NK-IFN-gamma induction depended on pDC-derived IFN-alpha while other IFN-gamma inducing cytokines, IL-12 and IL-18, played minimal roles. Close contact between JFH-1/Huh7.5 cells and NK cells was required for IFN-gamma production and monocyte-derived IL-15, significantly augmented IFN-gamma induction.

CONCLUSIONS: We discovered a novel mechanism where NK cells interact with pDCs and monocytes, efficiently producing IFN-gamma in response to HCV-infected cells. This indicates that co-operation between NK cells and accessory cells is critical for IFN-gamma production and regulators of immunity during HCV infection.

The CD225 Domain of IFITM3 is Required for both IFITM Protein Association and Inhibition of Influenza A Virus and Dengue Virus Replication

Tue, 06/18/2013 - 1:55pm

IFITM3 is an interferon stimulated gene which inhibits the replication of multiple pathogenic viruses in vitro and in vivo. IFITM3 is a member of a large protein super family, whose members share a functionally-undefined area of high amino acid conservation, the CD225 domain. We performed mutational analyses of IFITM3 and identified multiple residues within the CD225 domain, consisting of the first intramembrane domain (IM1) and a conserved intracellular loop (CIL), that are required for restriction of both influenza A virus (IAV) and dengue virus (DENV) infection in vitro. Two phenylalanines within IM1 (F75 and F78) also mediate a physical association between IFITM proteins, and the loss of this interaction decreases IFITM3-mediated restriction. By extension, similar IM1-mediated associations may contribute to the functions of additional members of the CD225 domain family. IFITM3's distal N-terminal domain is also needed for full anti-viral activity, including a tyrosine (Y20), whose alteration results in mislocalization of a portion of IFITM3 to the cell periphery and surface. Comparative analyses demonstrate that similar molecular determinants are needed for IFITM3's restriction of both IAV and DENV. However, a portion of the CIL including Y99 and R87 is preferentially needed for inhibition of the orthomyxovirus. Several IFITM3 proteins engineered with rare single nucleotide polymorphisms demonstrated reduced expression or mislocalization, and these events were associated with enhanced viral replication in vitro, suggesting that possessing such alleles may impact an individual's risk for viral infection. Based on this and other data, we propose a model for IFITM3-mediated restriction.

Dynamic Nucleosome Organization at hox Promoters during Zebrafish Embryogenesis

Tue, 06/18/2013 - 1:55pm

Nucleosome organization at promoter regions plays an important role in regulating gene activity. Genome-wide studies in yeast, flies, worms, mammalian embryonic stem cells and transformed cell lines have found well-positioned nucleosomes flanking a nucleosome depleted region (NDR) at transcription start sites. This nucleosome arrangement depends on DNA sequence (cis-elements) as well as DNA binding factors and ATP-dependent chromatin modifiers (trans-factors). However, little is understood about how the nascent embryonic genome positions nucleosomes during development. This is particularly intriguing since the embryonic genome must undergo a broad reprogramming event upon fusion of sperm and oocyte. Using four stages of early embryonic zebrafish development, we map nucleosome positions at the promoter region of 37 zebrafish hox genes. We find that nucleosome arrangement at the hox promoters is a progressive process that takes place over several stages. At stages immediately after fertilization, nucleosomes appear to be largely disordered at hox promoter regions. At stages after activation of the embryonic genome, nucleosomes are detectable at hox promoters, with positions becoming more uniform and more highly occupied. Since the genomic sequence is invariant during embryogenesis, this progressive change in nucleosome arrangement suggests that trans-factors play an important role in organizing nucleosomes during embryogenesis. Separating hox genes into expressed and non-expressed groups shows that expressed promoters have better positioned and occupied nucleosomes, as well as distinct NDRs, than non-expressed promoters. Finally, by blocking the retinoic acid-signaling pathway, we disrupt early hox gene transcription, but observe no effect on nucleosome positions, suggesting that active hox transcription is not a driving force behind the arrangement of nucleosomes at the promoters of hox genes during early development.

Chemical exchange saturation transfer effect in blood

Tue, 06/18/2013 - 1:55pm

PURPOSE: In this report, the feasibility of using blood as an agent for Chemical Exchange Saturation Transfer (CEST) effect is investigated.

METHODS: The CEST effect of porcine blood samples was investigated on a 3.0 T MRI scanner using various power levels and on a 14.1 T NMR spectrometer. As a proof-of-concept that CEST can be used to image blood in vivo, the technique was applied in two locations of healthy human volunteers, namely, the femoral artery and the M1-segment of the middle cerebral artery.

RESULTS: The blood sample experiments showed that maximum CEST Magnetization Transfer Ratio asymmetry (MTRasym ) values of approximately 12% were achieved, with likely contributions from multiple blood components. These findings were confirmed during the in vivo experiments where CEST signal of blood was clearly greater than surrounding muscular (2%) and brain tissue (3%).

CONCLUSION: Ex vivo and in vivo results show that blood is a suitable CEST agent that generates sufficient CEST contrast relative to surrounding tissue.

CD4+ T Cells Provide Intermolecular Help To Generate Robust Antibody Responses in Vaccinia Virus-Vaccinated Humans

Tue, 06/18/2013 - 1:55pm

Immunization with vaccinia virus elicits a protective Ab response that is almost completely CD4+ T cell dependent. A recent study in a rodent model observed a deterministic linkage between Ab and CD4+ T cell responses to particular vaccinia virus proteins suggesting that CD4+ T cell help is preferentially provided to B cells with the same protein specificity (Sette et al. 2008. Immunity 28: 847-858). However, a causal linkage between Ab and CD4+ T cell responses to vaccinia or any other large pathogen in humans has yet to be done. In this study, we measured the Ab and CD4+ T cell responses against four vaccinia viral proteins (A27L, A33R, B5R, and L1R) known to be strongly targeted by humoral and cellular responses induced by vaccinia virus vaccination in 90 recently vaccinated and 7 long-term vaccinia-immunized human donors. Our data indicate that there is no direct linkage between Ab and CD4+ T cell responses against each individual protein in both short-term and long-term immunized donors. Together with the observation that the presence of immune responses to these four proteins is linked together within donors, our data suggest that in vaccinia-immunized humans, individual viral proteins are not the primary recognition unit of CD4+ T cell help for B cells. Therefore, we have for the first time, to our knowledge, shown evidence that CD4+ T cells provide intermolecular (also known as noncognate or heterotypic) help to generate robust Ab responses against four vaccinia viral proteins in humans.

Crystal Structure of the DNA Cytosine Deaminase APOBEC3F: The Catalytically Active and HIV-1 Vif-Binding Domain

Tue, 06/18/2013 - 1:55pm

Human APOBEC3F is an antiretroviral single-strand DNA cytosine deaminase, susceptible to degradation by the HIV-1 protein Vif. In this study the crystal structure of the HIV Vif binding, catalytically active, C-terminal domain of APOBEC3F (A3F-CTD) was determined. The A3F-CTD shares structural motifs with portions of APOBEC3G-CTD, APOBEC3C, and APOBEC2. Residues identified to be critical for Vif-dependent degradation of APOBEC3F all fit within a predominantly negatively charged contiguous region on the surface of A3F-CTD. Specific sequence motifs, previously shown to play a role in Vif susceptibility and virion encapsidation, are conserved across APOBEC3s and between APOBEC3s and HIV-1 Vif. In this structure these motifs pack against each other at intermolecular interfaces, providing potential insights both into APOBEC3 oligomerization and Vif interactions.

Gene silencing in adipose tissue macrophages regulates whole-body metabolism in obese mice

Tue, 06/18/2013 - 1:55pm

Adipose tissue (AT) inflammation and infiltration by macrophages is associated with insulin resistance and type 2 diabetes in obese humans, offering a potential target for therapeutics. However, whether AT macrophages (ATMs) directly contribute to systemic glucose intolerance has not been determined. The reason is the lack of methods to ablate inflammatory genes expressed in macrophages specifically localized within AT depots, leaving macrophages in other tissues unaffected. Here we report that i.p. administration of siRNA encapsulated by glucan shells in obese mice selectively silences genes in epididymal ATMs, whereas macrophages within lung, spleen, kidney, heart, skeletal muscle, subcutaneous (SubQ) adipose, and liver are not targeted. Such administration of GeRPs to silence the inflammatory cytokines TNF-alpha or osteopontin in epididymal ATMs of obese mice caused significant improvement in glucose tolerance. These data are consistent with the hypothesis that cytokines produced by ATMs can exacerbate whole-body glucose intolerance.