
Massachusetts Academy of Math and Science at WPI
UniversityWorcester, Massachusetts, United States
Research output, citation impact, and the most-cited recent papers from Massachusetts Academy of Math and Science at WPI (United States). Aggregated across the NobleBlocks index of 300M+ scholarly works.
Top-cited papers from Massachusetts Academy of Math and Science at WPI
BACKGROUND: Trait optimism (positive future expectations) and cynical, hostile attitudes toward others have not been studied together in relation to incident coronary heart disease (CHD) and mortality in postmenopausal women. METHODS AND RESULTS: Participants were 97 253 women (89 259 white, 7994 black) from the Women's Health Initiative who were free of cancer and cardiovascular disease at study entry. Optimism was assessed by the Life Orientation Test-Revised and cynical hostility by the cynicism subscale of the Cook Medley Questionnaire. Cox proportional hazard models produced adjusted hazard ratios (AHRs) for incident CHD (myocardial infarction, angina, percutaneous coronary angioplasty, or coronary artery bypass surgery) and total mortality (CHD, cardiovascular disease, or cancer related) over approximately 8 years. Optimists (top versus bottom quartile ["pessimists"]) had lower age-adjusted rates (per 10 000) of CHD (43 versus 60) and total mortality (46 versus 63). The most cynical, hostile women (top versus bottom quartile) had higher rates of CHD (56 versus 44) and total mortality (63 versus 46). Optimists (versus pessimists) had a lower hazard of CHD (AHR 0.91, 95% CI 0.83 to 0.99), CHD-related mortality (AHR 0.70, 95% CI 0.55 to 0.90), cancer-related mortality (blacks only; AHR 0.56, 95% CI 0.35 to 0.88), and total mortality (AHR 0.86, 95% CI 0.79 to 0.93). Most (versus least) cynical, hostile women had a higher hazard of cancer-related mortality (AHR 1.23, 95% CI 1.09 to 1.40) and total mortality (AHR 1.16, 95% CI 1.07 to 1.27; this effect was pronounced in blacks). Effects of optimism and cynical hostility were independent. CONCLUSIONS: Optimism and cynical hostility are independently associated with important health outcomes in black and white women. Future research should examine whether interventions designed to change attitudes would lead to altered risk.
Twelve rhesus monkeys were vaccinated with SIVmac316 delta nef (lacking nef sequences), and 12 were vaccinated with SIVmac239 delta3 (lacking nef, vpr, and upstream sequences in U3). SIVmac316 and SIVmac239 differ by only eight amino acids in the envelope; these changes render SIVmac316 highly competent for replication in macrophages. Seventeen of the animals developed persistent infections with the vaccine viruses. Seven of the 24 vaccinated animals, however, developed infections that were apparently transient in nature. Six of these seven yielded virus from peripheral blood when tested at weeks 2 and/or 3, three of the seven had transient antibody responses, but none of the seven had persisting antibody responses. The 24 monkeys were challenged in groups of four with 10 rhesus monkey infectious doses of wild-type, pathogenic SIVmac251 at weeks 8, 20, and 79 following receipt of vaccine. None of the seven with apparently transient infections with vaccine virus were protected upon subsequent challenge. Analysis of cell-associated viral loads, CD4+ cell counts, and viral gene sequences present in peripheral blood in the remainder of the monkeys following challenge allowed a number of conclusions. (i) There was a trend toward increased protection with length of time of vaccination. (ii) Solid vaccine protection was achieved by 79 weeks with the highly attenuated SIV239 delta3. (iii) Solid long-term protection was achieved in at least two animals in the absence of complete sterilizing immunity. (iv) Genetic backbone appeared to influence protective capacity; animals vaccinated with SIV239 delta3 were better protected than animals receiving SIV316 delta nef. This better protection correlated with increased levels of the replicating vaccine strain. (v) The titer of virus-neutralizing activity in serum on the day of challenge correlated with protection when measured against a primary stock of SIVmac251 but not when measured against a laboratory-passaged stock. The level of binding antibodies to whole virus by enzyme-linked immunosorbent assay also correlated with protection.
The study of autophagy is rapidly expanding, and our knowledge of the molecular mechanism and its connections to a wide range of physiological processes has increased substantially in the past decade. The vocabulary associated with autophagy has grown concomitantly. In fact, it is difficult for readers--even those who work in the field--to keep up with the ever-expanding terminology associated with the various autophagy-related processes. Accordingly, we have developed a comprehensive glossary of autophagy-related terms that is meant to provide a quick reference for researchers who need a brief reminder of the regulatory effects of transcription factors and chemical agents that induce or inhibit autophagy, the function of the autophagy-related proteins, and the roles of accessory components and structures that are associated with autophagy.
Monero is a privacy-centric cryptocurrency that allows users to obscure their transactions by including chaff coins, called “mixins,” along with the actual coins they spend. In this paper, we empirically evaluate two weaknesses in Monero’s mixin sampling strategy. First, about 62% of transaction inputs with one or more mixins are vulnerable to “chain-reaction” analysis - that is, the real input can be deduced by elimination. Second, Monero mixins are sampled in such a way that they can be easily distinguished from the real coins by their age distribution; in short, the real input is usually the “newest” input. We estimate that this heuristic can be used to guess the real input with 80% accuracy over all transactions with 1 or more mixins. Next, we turn to the Monero ecosystem and study the importance of mining pools and the former anonymous marketplace AlphaBay on the transaction volume. We find that after removing mining pool activity, there remains a large amount of potentially privacy-sensitive transactions that are affected by these weaknesses. We propose and evaluate two countermeasures that can improve the privacy of future transactions.
Despite considerable advances in the understanding of the pathogenesis of meningococcal disease, this infection remains a major cause of morbidity and mortality globally. The role of the complement system in innate immune defenses against invasive meningococcal disease is well established. Individuals deficient in components of the alternative and terminal complement pathways are highly predisposed to invasive, often recurrent meningococcal infections. Genome-wide analysis studies also point to a central role for complement in disease pathogenesis. Here we review the pathophysiologic events pertinent to the complement system that accompany meningococcal sepsis in humans. Meningococci use several often redundant mechanisms to evade killing by human complement. Capsular polysaccharide and lipooligosaccharide glycan composition play critical roles in complement evasion. Some of the newly described protein vaccine antigens interact with complement components and have sparked considerable research interest.
Autophagy is an evolutionarily conserved intracellular catabolic process that is used by all cells to degrade dysfunctional or unnecessary cytoplasmic components through delivery to the lysosome. Increasing evidence reveals that autophagic dysfunction is associated with human diseases, such as cancer. Paradoxically, although autophagy is well recognized as a cell survival process that promotes tumor development, it can also participate in a caspase-independent form of programmed cell death. Induction of autophagic cell death by some anticancer agents highlights the potential of this process as a cancer treatment modality. Here, we review our current understanding of the molecular mechanism of autophagy and the potential roles of autophagy in cell death, cancer development, and cancer treatment.
Abstract Strain and charge co-mediated magnetoelectric coupling are expected in ultra-thin ferromagnetic/ferroelectric multiferroic heterostructures, which could lead to significantly enhanced magnetoelectric coupling. It is however challenging to observe the combined strain charge mediated magnetoelectric coupling and difficult in quantitatively distinguish these two magnetoelectric coupling mechanisms. We demonstrated in this work, the quantification of the coexistence of strain and surface charge mediated magnetoelectric coupling on ultra-thin Ni 0.79 Fe 0.21 /PMN-PT interface by using a Ni 0.79 Fe 0.21 /Cu/PMN-PT heterostructure with only strain-mediated magnetoelectric coupling as a control. The NiFe/PMN-PT heterostructure exhibited a high voltage induced effective magnetic field change of 375 Oe enhanced by the surface charge at the PMN-PT interface. Without the enhancement of the charge-mediated magnetoelectric effect by inserting a Cu layer at the PMN-PT interface, the electric field modification of effective magnetic field was 202 Oe. By distinguishing the magnetoelectric coupling mechanisms, a pure surface charge modification of magnetism shows a strong correlation to polarization of PMN-PT. A non-volatile effective magnetic field change of 104 Oe was observed at zero electric field originates from the different remnant polarization state of PMN-PT. The strain and charge co-mediated magnetoelectric coupling in ultra-thin magnetic/ferroelectric heterostructures could lead to power efficient and non-volatile magnetoelectric devices with enhanced magnetoelectric coupling.
The functional significance of microRNA-9 (miR-9) during evolution is evidenced by its conservation at the nucleotide level from flies to humans but not its diverse expression patterns. Recent studies in several model systems reveal that miR-9 can regulate neurogenesis through its actions in neural or non-neural cell lineages. In vertebrates, miR-9 exerts diverse cell-autonomous effects on the proliferation, migration, and differentiation of neural progenitor cells by modulating different mRNA targets. In some developmental contexts, miR-9 suppresses apoptosis and is misregulated in several types of cancer cells, influencing proliferation or metastasis formation. Moreover, downregulation of miR-9 in postmitotic neurons is also implicated in some neurodegenerative diseases. Thus, miR-9 is emerging as an important regulator in development and disease through its ability to modulate different targets in a manner dependent on the developmental stage and the cellular context.
Increasing evidence supports a connection between cancer and metabolism and emphasizes the need to understand how tumors respond to the metabolic microenvironment and how tumor cell metabolism is regulated. The insulin receptor (IR) and its close family member the insulin-like growth factor-1 receptor (IGF-1R) mediate the cellular response to insulin in normal cells and their function is tightly regulated to maintain metabolic homeostasis. These receptors are also expressed on tumor cells and their expression correlates with tumor progression and poor prognosis. Understanding how the IR/IGF-1R pathway functions in tumors is increasing in importance as the efficacy of drugs that target metabolic pathways, such as metformin, are investigated in prospective clinical trials. This review will focus on key signaling intermediates of the IR and IGF-1R, the Insulin Receptor Substrate (IRS) proteins, with an emphasis on IRS-2, and discuss how these adaptor proteins play a pivotal role at the intersection of metabolism and cancer.
HOTAIRM1 is a long intergenic non-coding RNA encoded in the human HOXA gene cluster, with gene expression highly specific for maturing myeloid cells. Knockdown of HOTAIRM1 in the NB4 acute promyelocytic leukemia cell line retarded all-trans retinoid acid (ATRA)-induced granulocytic differentiation, resulting in a significantly larger population of immature and proliferating cells that maintained cell cycle progression from G1 to S phases. Correspondingly, HOTAIRM1 knockdown resulted in retained expression of many otherwise ATRA-suppressed cell cycle and DNA replication genes, and abated ATRA induction of cell surface leukocyte activation, defense response, and other maturation-related genes. Resistance to ATRA-induced cell cycle arrest at the G1/S phase transition in knockdown cells was accompanied by retained expression of ITGA4 (CD49d) and decreased induction of ITGAX (CD11c). The coupling of cell cycle progression with temporal dynamics in the expression patterns of these integrin genes suggests a regulated switch to control the transit from the proliferative phase to granulocytic maturation. Furthermore, ITGAX was among a small number of genes showing perturbation in transcript levels upon HOTAIRM1 knockdown even without ATRA treatment, suggesting a direct pathway of regulation. These results indicate that HOTAIRM1 provides a regulatory link in myeloid maturation by modulating integrin-controlled cell cycle progression at the gene expression level.
BACKGROUND: Surgical management of ankle fractures will be an increasing part of the orthopaedic practice for aging adults. To date, there are few studies comparing outcomes after ankle fracture surgery between patients over and under 65 years. The purpose of this study was to evaluate short- and long-term outcomes after surgical treatment of isolated malleolar fractures in both the elderly and non-elderly population. MATERIALS AND METHODS: Charts and radiographs were reviewed for 25 patients over age 65 and 46 patients under age 65 who underwent operative treatment of an ankle fracture during a 2-year period. Postoperative complications and need for placement in a skilled nursing facility following discharge were noted. The SF-36 and the Olerud and Molander Ankle Score were completed. Mean duration of followup in patients greater than 65 was 27 months and 24 months for patients less than or equal to 65 years. RESULTS: Patients over 65 had a higher number of postoperative complications (40% vs. 11%, p < 0.007), and required nursing home placement more frequently than patients under 65 (p < 0.0001). At long-term followup, the data showed no significant difference in patient reported physical outcomes. CONCLUSION: Early postoperative outcomes after operative fixation of ankle fractures suggest significantly worse outcomes for patients over age 65. However, long-term function in the elderly was comparable to patients under age 65 in this sample. The elderly population had a significantly better mental composite score than the non-elderly.
Juvenile amyotrophic lateral sclerosis (ALS) with basophilic inclusions is a well-recognized entity. However, the molecular underpinnings of this devastating disease are poorly understood. Here, we present genetic and neuropathological characterizations in two young women with fatal rapidly progressive ALS with basophilic inclusions. In one case, a germline mutation (P525L) was detected in the fused in sarcoma/translocated in liposarcoma (FUS/TLS) gene, whereas no mutation was identified in the other case. Postmortem examination in both cases revealed severe loss of spinal motor neurons with remaining neurons showing basophilic inclusions that contain abnormal aggregates of FUS proteins and disorganized intracellular organelles, including mitochondria and endoplasmic reticulum. In both patients, the FUS-positive inclusions were also detected in neurons in layers IV-V of cerebral cortex and several brainstem nuclei. In contrast, spinal motor neurons in patients with late-onset sporadic ALS showed no evidence of abnormal accumulation of FUS protein. These results underscore the importance of FUS mutations and pathology in rapidly progressive juvenile ALS. Furthermore, our study represents the first detailed characterizations of neuropathological findings in rapidly progressive juvenile ALS patients with a mutation in the FUS/TLS gene.
In order to explain the variability noted in the fluorescein staining characteristics of the epigastric axial flap in the experimental laboratory rat, the anatomy of the blood supply of this particular flap was investigated. In 10 rats, the vascular pattern of the superficial epigastric trunk to the abdominal skin was found to be similar. A small branch of the trunk extended toward the medial abdominal skin to collateralize with a branch of the internal mammary vessel entering from the chest skin. A large extension of the superficial epigastric trunk extended laterally toward the midlateral point of the animal and cephalad to collateralize with the vessels in the lateral chest wall, presumably the lateral thoracic artery. Fluorescein staining characteristics of 10 flaps including or excluding the lateral branch were examined, and a significant difference was found in the immediate fluorescein staining characteristics. The flaps that included the lateral branch fluoresced to an average of 89.2 percent of the flap length, and those in which the lateral branch was excluded fluoresced to 68.7 percent of the flap length. The use of this flap model in experimental flap research should include a precise description of the anatomy of the particular flap used in order to ensure reproducible results.
By virtue of its ability to regulate both protein turnover and non-proteolytic signalling functions, ubiquitin protein conjugation has been implicated in the control of multiple cellular processes, including protein localization, cell cycle control, transcription regulation, DNA damage repair, and endocytosis. Ubiquitin metabolism enzymes have been identified as either oncogenes or tumor suppressors in a variety of cancers. Given that ubiquitin metabolism is governed by enzymes--E1, E2, E3, E4, deubiquitinases (DUBs), and the proteasome- the system as a whole is ripe for target and drug discovery in cancer. Of the ubiquitin/proteasome system components, the E3's and DUBs can recognize substrates with the most specificity, and are thus of key interest as drug targets in cancer. This review examines the molecular role in cancer, relevant substrates, and potential for pharmacologic development, of E3's and DUBs that have been associated thus far with human malignancies as oncogenes or tumor suppressors.
The role of Fc glycans on clearance of IgG molecule has been examined by various groups in experiments where specific glycans have been enriched or the entire spectrum of glycans was studied after administration in pre-clinical or clinical pharmacokinetic (PK) studies. The overall conclusions from these studies are inconsistent, which may result from differences in antibody structure or experimental design. In the present study a well-characterized recombinant monoclonal IgG1 molecule (mAb-1) was analyzed from serum samples obtained from a human PK study. mAb-1 was recovered from serum using its ligand cross-linked to Sepharose beads. The overall purity and recovery of all isoforms were carefully evaluated using a variety of methods. Glycans were then enzymatically cleaved, labeled using 2-aminobenzamide and analyzed by normal phase high performance liquid chromatography. The assays for recovering mAb-1 from serum and subsequent glycan analysis were rigorously qualified at a lower limit of quantitation of 15 μg/mL, thus permitting analysis to day 14 of the clinical PK study. Eight glycans were monitored and classified into two groups: (1) the oligomannose type structures (M5, M6 and M7) and (2) fucosylated biantennary oligosaccharides (FBO) structures (NGA2F, NA1F, NA2F, NA1F-GlcNAc and NGA2F-GlcNAc). We observed that the oligomannose species were cleared at a much faster rate (40%) than FBOs and conclude that high mannose species should be carefully monitored and controlled as they may affect PK of the therapeutic; they should thus be considered an important quality attribute. These observations were only possible through the application of rigorous analytical methods that we believe will need to be employed when comparing innovator and biosimilar molecules.
BACKGROUND AND PURPOSE: Despite a paucity of evidence supporting a true association of ischemic stroke and the inherited thrombophilias, it is common practice for many neurologists to order these tests as part of the work-up of ischemic stroke, especially in young patients. Treatment with oral anticoagulation is often used in patients with positive results for the inherited thrombophilias. METHODS: We reviewed the literature focusing on case-control studies of the 5 most commonly inherited disorders of coagulation: protein C deficiency, protein S deficiency, antithrombin deficiency, and the factor V Leiden and prothrombin gene mutations in patients with stroke. We also analyzed the available data on stroke patients with inherited thrombophilia and patent foramen ovale. RESULTS: Multiple case-control studies have not convincingly shown an association of the inherited thrombophilias with ischemic stroke, even in young patients and patients with patent foramen ovale. CONCLUSIONS: If there is an association between the inherited thrombophilias and arterial stroke, then it is a weak one, likely enhanced by other prothrombotic risk factors. The consequences of ordering these tests and attributing causality to an arterial event can result in significant costs to the health care system and pose a potential risk to patients, because this may lead to inappropriate use of long-term oral anticoagulants, exposing patients to harm without a clearly defined benefit.
Abstract In a series of 12 newborn kittens, horseradish peroxidase (HRP) was used to trace retrograde axoplasmic flow in the motor neurons to laryngeal muscles. The animals were sacrificed 24 hours after injection of HRP into a specific laryngeal muscle, and the brain stems were stained for peroxidase. This clear‐cut colorimetric method permitted the localization of the motor neurons in two nuclei of the ipsilateral brain stem. These are the nucleus ambiguus and the retrofacial nucleus. The primary source of laryngeal motor supply is the nucleus ambiguus. All the laryngeal muscles were represented here in two divisions. Adductor neurons were located in the dorsal division and were more loosely arranged in the lateral reticular formation. The abductor neurons of the posterior cricoarytenoid muscle formed the compact ventral division of the nucleus ambiguus and were fewer in number than adductor neurons by a factor of four to one. Since the expiratory and inspiratory centers are also located dorsally and ventrally in the brain stem reticular formation, the motor cells of the nucleus ambiguus are conveniently arranged to receive their afferent input. This arrangement is probably the result of phylogenetic development of abductor laryngeal function and pulmonary function in lower forms. A second source of laryngeal innervation is the retrofacial nucleus. This small nucleus is situated rostral to the nucleus ambiguus and is made up of small and medium‐sized neurons of at least two types. Only the cricothyroid (CT) and posterior cricoarytenoid (PCA) muscles were shown to have significant innervation from this nucleus. The CT neurons were located peripherally while the PCA cells occupied the central portion of the nucleus. The functional significance of this nucleus is unknown, but it is suggested that it may have something to do with the various types of muscle units that have been demonstrated physiologically in the CT and PCA muscles.
The CtBP transcriptional corepressors promote cancer cell survival and migration/invasion. CtBP senses cellular metabolism via a regulatory dehydrogenase domain, and is antagonized by p14/p19(ARF) tumor suppressors. The CtBP dehydrogenase substrate 4-methylthio-2-oxobutyric acid (MTOB) can act as a CtBP inhibitor at high concentrations, and is cytotoxic to cancer cells. MTOB induced apoptosis was p53-independent, correlated with the derepression of the proapoptotic CtBP repression target Bik, and was rescued by CtBP overexpression or Bik silencing. MTOB did not induce apoptosis in mouse embryonic fibroblasts (MEFs), but was increasingly cytotoxic to immortalized and transformed MEFs, suggesting that CtBP inhibition may provide a suitable therapeutic index for cancer therapy. In human colon cancer cell peritoneal xenografts, MTOB treatment decreased tumor burden and induced tumor cell apoptosis. To verify the potential utility of CtBP as a therapeutic target in human cancer, the expression of CtBP and its negative regulator ARF was studied in a series of resected human colon adenocarcinomas. CtBP and ARF levels were inversely-correlated, with elevated CtBP levels (compared with adjacent normal tissue) observed in greater than 60% of specimens, with ARF absent in nearly all specimens exhibiting elevated CtBP levels. Targeting CtBP may represent a useful therapeutic strategy in human malignancies.
Sarcoidosis is an idiopathic inflammatory disease characterized by granulomatous infiltration of multiple organs including the brain. The natural history is highly variable and neurologic involvement has been associated with greater resistance to treatment and increased overall morbidity and mortality.1,2⇓ Corticosteroids are the mainstay of treatment but adjuvant approaches with antimalarials, cyclosporine, cytotoxic agents, and the anti–tumor necrosis factor-alpha (TNFα) agents thalidomide and pentoxifylline have been associated with some degree of disease response.3 Increasing evidence suggests that TNFα plays a pivotal role in the inflammatory cascade of this disease4,5⇓ and recent observations suggest a beneficial response of refractory systemic sarcoidosis to infliximab, a chimeric monoclonal human-murine antibody directed against TNFα.6,7⇓ We describe a case of refractory neurosarcoidosis in which the patient responded dramatically to infliximab therapy. ### Case presentation. A 46-year-old man developed biopsy-proven sarcoidosis 16 years previously initially involving the skin (lupus pernio) and subsequently the liver (granulomatous hepatitis), knees (synovitis), lungs (hilar lymphadenopathy), and brain (left temporal lobe lesion with associated focal …
We describe a simple, effective approach to the creation of autologous tissue-engineered cartilage in the shape of a human nipple by injecting a reverse thermosensitive polymer seeded with autologous chondrocytes in an immunocompetent porcine animal model. A biodegradable, biocompatible copolymer of polyethylene oxide and polypropylene oxide (Pluronic F-127), which exists as a liquid below 4 degrees C and polymerizes to a thick gel when it is exposed to physiologic temperatures (body temperatures), was used as a vehicle for chondrocyte delivery and as a scaffold to guide growth. Autologous chondrocytes isolated from porcine auricular elastic cartilage and suspended in 30% (weight/volume) Pluronic F-127 were injected on the ventral surface of the pigs from which the cells had been isolated. A circumferential subdermal suture was used to support the contour of the implant and assist in its projection in the form of a human nipple. After 3 weeks, the skin over and surrounding the implant was tattooed to create the appearance of a human nipple-areolar complex. As controls, an equal number of injections were made using either cells alone (not suspended in hydrogel), or hydrogel alone. After 10 weeks, all specimens were excised and examined both grossly and histologically. Before harvesting, visual inspection of the tattooed chondrocyte-Pluronic F-127 hydrogel implant sites revealed that they closely resembled a human female nipple-areolar complex. Nodules were similar in size, shape, and texture to a human nipple at each injection site. Glistening opalescent tissue was surgically isolated from each implant site. Hematoxylin and eosin, safranine o, trichrome blue, and Verhoeff's stains of the experimental implants showed nodules with the characteristic histologic signs of elastic cartilage. Control injections of copolymer hydrogel alone exhibited no evidence of cartilage formation. Control injections of chondrocytes alone showed evidence of dissociated microscopic nodules of elastic cartilage.