NLRP11 is a pattern recognition receptor for bacterial lipopolysaccharide in the cytosol of human macrophages.

Endotoxin-bacterial lipopolysaccharide (LPS)-is a driver of lethal infection sepsis through excessive activation of innate immune responses. When delivered to the cytosol of macrophages, cytosolic LPS (cLPS) induces the assembly of an inflammasome that contains caspases-4/5 in humans or caspase-11 in mice. Whereas activation of all other inflammasomes is triggered by sensing of pathogen products by a specific host cytosolic pattern recognition receptor protein, whether pattern recognition receptors for cLPS exist has remained unclear, because caspase-4, caspase-5, and caspase-11 bind and activate LPS directly in vitro.

Reducing Avoidable Emergency Visits and Hospitalizations With Patient Risk-Based Prescriptive Analytics: A Quality Improvement Project at an Oncology Care Model Practice.

Purpose: Cancer-related emergency department (ED) visits and hospitalizations that would have been appropriately managed in the outpatient setting are avoidable and detrimental to patients and health systems. This quality improvement (QI) project aimed to leverage patient risk-based prescriptive analytics at a community oncology practice to reduce avoidable acute care use (ACU).

Methods: Using the Plan-Do-Study-Act (PDSA) methodology, we implemented the Jvion Care Optimization and Recommendation Enhancement augmented intelligence (AI) tool at an Oncology Care Model (OCM) practice, the Center for Cancer and Blood Disorders practice.

Impact of Augmented Intelligence on Utilization of Palliative Care Services in a Real-World Oncology Setting.

Purpose: For patients with advanced cancer, timely referral to palliative care (PC) services can ensure that end-of-life care aligns with their preferences and goals. Overestimation of life expectancy may result in underutilization of PC services, counterproductive treatment measures, and reduced quality of life for patients. We assessed the impact of a commercially available augmented intelligence (AI) tool to predict 30-day mortality risk on PC service utilization in a real-world setting.

Augmented intelligence to predict 30-day mortality in patients with cancer.

An augmented intelligence tool to predict short-term mortality risk among patients with cancer could help identify those in need of actionable interventions or palliative care services. An algorithm to predict 30-day mortality risk was developed using socioeconomic and clinical data from patients in a large community hematology/oncology practice. Patients were scored weekly; algorithm performance was assessed using dates of death in patients' electronic health records.

Vibrio variations on a type three theme.

Mounting evidence suggests that Type 3 Secretion Systems (T3SS) are widespread among Vibrio species, and are present in strains isolated from diverse sources such as human clinical infections, environmental reservoirs, and diseased marine life. Experiments evaluating Vibrio parahaemolyticus and Vibrio cholerae T3SS mediated virulence suggest that Vibrio T3SS pathogenicity islands have a tripartite composition. A conserved 'core' region encodes functions essential for colonization and disease in vivo, including modulation of innate immune signaling pathways and actin dynamics, whereas regions flanking core sequences are variable among strains and encode effector proteins performing a diverse array of activities.

Identification of interactions among host and bacterial proteins and evaluation of their role early during Shigella flexneri infection.

Shigella species cause diarrhoea by invading and spreading through the epithelial layer of the human colon. The infection triggers innate immune responses in the host that the bacterium combats by translocating into the host cell cytosol via a type 3 secretion system bacterial effector proteins that interfere with host processes. We previously demonstrated that interaction of the Shigella type 3 secreted effector protein IcsB with the host protein Toca-1 inhibits the innate immune response microtubule-associated protein light-chain 3 (LC3)-associated phagocytosis, and that IcsB interaction with Toca-1 is required for inhibition of this host response.

Spirochaete flagella hook proteins self-catalyse a lysinoalanine covalent crosslink for motility.

Spirochaetes are bacteria responsible for several serious diseases, including Lyme disease (Borrelia burgdorferi), syphilis (Treponema pallidum) and leptospirosis (Leptospira interrogans), and contribute to periodontal diseases (Treponema denticola)(1). These spirochaetes employ an unusual form of flagella-based motility necessary for pathogenicity; indeed, spirochaete flagella (periplasmic flagella) reside and rotate within the periplasmic space(2-11). The universal joint or hook that links the rotary motor to the filament is composed of ∼120-130 FlgE proteins, which in spirochaetes form an unusually stable, high-molecular-weight complex(9,12-17).

Characterization of V. cholerae T3SS-dependent cytotoxicity in cultured intestinal epithelial cells.

AM-19226 is a pathogenic, non-O1/non-O139 serogroup strain of Vibrio cholerae that uses a Type 3 Secretion System (T3SS) mediated mechanism to colonize host tissues and disrupt homeostasis, causing cholera. Co-culturing the Caco2-BBE human intestinal epithelial cell line with AM-19226 in the presence of bile results in rapid mammalian cell death that requires a functional T3SS. We examined the role of bile, sought to identify the mechanism, and evaluated the contributions of T3SS translocated effectors in in vitro cell death.

Regulation by ToxR-Like Proteins Converges on vttRB Expression To Control Type 3 Secretion System-Dependent Caco2-BBE Cytotoxicity in Vibrio cholerae.

Unlabelled: Genes carried on the type 3 secretion system (T3SS) pathogenicity island of Vibrio cholerae non-O1/non-O139 serogroup strain AM-19226 must be precisely regulated in order for bacteria to cause disease. Previously reported results showed that both T3SS function and the presence of bile are required to cause Caco2-BBE cell cytotoxicity during coculture with strain AM-19226. We therefore investigated additional parameters affecting in vitro cell death, including bacterial load and the role of three transmembrane transcriptional regulatory proteins, VttRA, VttRB, and ToxR.

Type 3 Secretion System Island Encoded Proteins Required for Colonization by Non-O1/non-O139 Serogroup .

Vibrio cholerae is a genetically diverse species, and pathogenic strains can encode different virulence factors that mediate colonization and secretory diarrhea. Although the toxin co-regulated pilus (TCP) is the primary colonization factor in epidemic causing V. cholerae strains, other strains do not encode TCP and instead promote colonization via the activity of a type three secretion system (T3SS).

Shigella flexneri regulation of ARF6 activation during bacterial entry via an IpgD-mediated positive feedback loop.

Unlabelled: Entry into cells is critical for virulence of the human bacterial pathogens Shigella spp. Shigella spp. induce membrane ruffle formation and macropinocytic uptake, but the events instigating this process are incompletely understood.

Initial characterization of the FlgE hook high molecular weight complex of Borrelia burgdorferi.

The spirochete periplasmic flagellum has many unique attributes. One unusual characteristic is the flagellar hook. This structure serves as a universal joint coupling rotation of the membrane-bound motor to the flagellar filament.

Cryoelectron tomography reveals the sequential assembly of bacterial flagella in Borrelia burgdorferi.

Periplasmic flagella are essential for the distinctive morphology, motility, and infectious life cycle of the Lyme disease spirochete Borrelia burgdorferi. In this study, we genetically trapped intermediates in flagellar assembly and determined the 3D structures of the intermediates to 4-nm resolution by cryoelectron tomography. We provide structural evidence that secretion of rod substrates triggers remodeling of the central channel in the flagellar secretion apparatus from a closed to an open conformation.

The Vibrio cholerae trh gene is coordinately regulated in vitro with type III secretion system genes by VttR(A)/VttR(B) but does not contribute to Caco2-BBE cell cytotoxicity.

Numerous virulence factors have been associated with pathogenic non-O1/non-O139 serogroup strains of Vibrio cholerae. Among them are the thermostable direct hemolysin (TDH) and the TDH-related hemolysin (TRH), which share amino acid similarities to the TDH and TRH proteins of Vibrio parahaemolyticus, where they have been shown to contribute to pathogenesis. Although TDH and TRH homologs can be encoded on extrachromosomal elements in V.

The unique paradigm of spirochete motility and chemotaxis.

Spirochete motility is enigmatic: It differs from the motility of most other bacteria in that the entire bacterium is involved in translocation in the absence of external appendages. Using the Lyme disease spirochete Borrelia burgdorferi (Bb) as a model system, we explore the current research on spirochete motility and chemotaxis. Bb has periplasmic flagella (PFs) subterminally attached to each end of the protoplasmic cell cylinder, and surrounding the cell is an outer membrane.

Establishment and characterization of cell lines from a novel mouse model of poorly differentiated thyroid carcinoma: powerful tools for basic and preclinical research.

Background: Poorly differentiated and anaplastic thyroid carcinomas have a rather poor prognosis. The development of relevant model systems to unravel in vitro and in vivo the molecular mechanisms governing the resistance of these tumors to therapy, as well as to test novel drug combinations, is a clear priority for thyroid-focused research.

Methods: Several novel cell lines were established from tumors developed by mice engineered to simultaneously express a loss-of-function Pten allele and an oncogenic Kras allele.

Identification of Vibrio cholerae type III secretion system effector proteins.

AM-19226 is a pathogenic O39 serogroup Vibrio cholerae strain that lacks the typical virulence factors for colonization (toxin-coregulated pilus [TCP]) and toxin production (cholera toxin [CT]) and instead encodes a type III secretion system (T3SS). The mechanism of pathogenesis is unknown, and few effector proteins have been identified. We therefore undertook a survey of the open reading frames (ORFs) within the ∼49.

Embryonic mouse blood flow and oxygen correlate with early pancreatic differentiation.

The mammalian embryo represents a fundamental paradox in biology. Its location within the uterus, especially early during development when embryonic cardiovascular development and placental blood flow are not well-established, leads to an obligate hypoxic environment. Despite this hypoxia, the embryonic cells are able to undergo remarkable growth, morphogenesis, and differentiation.

Sledding injuries: a rationale for helmet usage.

Background: Sledding is a popular and seeming innocuous winter sport, but we hypothesize that sled injuries are much like bicycle injuries. Current literature supports helmet usage in other winter sports, but little information can be found to clarify the use of helmets in sledding. The objectives of the study are to assess the injury patterns of sled riders and clarify the need for helmet usage and to locate specific geographic catchments in which resources can be better focused.

Extracellular secretion of overexpressed glycosylphosphatidylinositol-linked cell wall protein Utr2/Crh2p as a novel protein quality control mechanism in Saccharomyces cerevisiae.

Eukaryotic cells employ a variety of mechanisms to maintain protein quality control and homeostasis. Here we provide evidence that one such mechanism in Saccharomyces cerevisiae involves the regulated release of excess or misfolded proteins to the extracellular space. The overexpression of an epitope-tagged allele of the glycosylphosphatidylinositol (GPI)-linked cell wall protein Utr2/Crh2p (Utr2/Crh2-green fluorescent protein [GFP] or -hemagglutinin [HA]) causes endoplasmic reticulum (ER) stress and the secretion of Crh2-GFP/HA into the extracellular space.

Controlling plasma protein binding: structural correlates of interactions of hydrophobic polyamine endotoxin sequestrants with human serum albumin.

Hydrophobically substituted polyamine compounds, particularly N-acyl or N-alkyl derivatives of homospermine, are potent endotoxin (lipopolysaccharide) sequestrants. Despite their polycationic nature, the aqueous solubilites are limited owing to the considerable overall hydrophobicity contributed by the long-chain aliphatic substituent, but solubilization is readily achieved in the presence of human serum albumin (HSA). We desired first to delineate the structural basis of lipopolyamine-albumin interactions and, second, to explore possible structure-activity correlates in a well-defined, congeneric series of N-alkyl and -acyl homospermine lead compounds.

Oncogenic Kras requires simultaneous PI3K signaling to induce ERK activation and transform thyroid epithelial cells in vivo.

Thyroid tumors arising from the follicular cells often harbor mutations leading to the constitutive activation of the PI3K and Ras signaling cascades. However, it is still unclear what their respective contribution to the neoplastic process is, as well as to what extent they interact. We have used mice harboring a Kras oncogenic mutation and a Pten deletion targeted to the thyroid epithelium to address in vivo these questions.

Protection from endotoxic shock by EVK-203, a novel alkylpolyamine sequestrant of lipopolysaccharide.

Lipopolysaccharides (LPS) play a key role in the pathogenesis of septic shock, a major cause of mortality in the critically ill patient. The only therapeutic option aimed at limiting downstream systemic inflammatory processes by targeting lipopolysaccharide is Toraymyxin, an extracorporeal hemoperfusion device using solid phase-immobilized polymyxin B (PMB). While PMB is known to effectively sequester LPS, its severe systemic toxicity proscribes its parenteral use, and hemoperfusion may not be feasible in patients in shock.

Bound to shock: protection from lethal endotoxemic shock by a novel, nontoxic, alkylpolyamine lipopolysaccharide sequestrant.

Lipopolysaccharide (LPS), or endotoxin, a structural component of gram-negative bacterial outer membranes, plays a key role in the pathogenesis of septic shock, a syndrome of severe systemic inflammation which leads to multiple-system organ failure. Despite advances in antimicrobial chemotherapy, sepsis continues to be the commonest cause of death in the critically ill patient. This is attributable to the lack of therapeutic options that aim at limiting the exposure to the toxin and the prevention of subsequent downstream inflammatory processes.

Structural correlates of antibacterial and membrane-permeabilizing activities in acylpolyamines.

A homologous series of mono- and bis-acyl polyamines with varying acyl chain lengths originally synthesized for the purpose of sequestering lipopolysaccharide were evaluated for antimicrobial activity to test the hypothesis that these bis-cationic amphipathic compounds may also bind to and permeabilize intact gram-negative bacterial membranes. Some compounds were found to possess significant antimicrobial activity, mediated via permeabilization of bacterial membranes. Structure-activity relationship studies revealed a strong dependence of the acyl chain length on antimicrobial potency and permeabilization activity.