In Vitro Proliferation of MG-63 Cells in Additively Manufactured Ti-6Al-4V Biomimetic Lattice Structures with Varying Strut Geometry and Porosity.

Lattice structures have demonstrated the ability to provide secondary stability in orthopedic implants by promoting internal bone growth. In response to the growing prevalence of lattices in orthopedic design, we investigated the effects of porosity and unit cell geometry in additively manufactured Ti-6Al-4V biomimetic lattice structures on the osteogenesis of human MG-63 osteoblastic cell lines in vitro. We analyzed glucose consumption, alkaline phosphatase (ALP) concentration, and end-of-culture cell count as markers for osteogenic growth.

Low-Cost, Real-Time Polymerase Chain Reaction System with Integrated RNA Extraction.

Rapid, easy-to-use, and low-cost systems for biological sample testing are important for point-of-care diagnostics and various other health applications. The recent pandemic of Coronavirus Disease 2019 (COVID-19) caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) showed an urgent need to rapidly and accurately identify the genetic material of SARS-CoV-2, an enveloped ribonucleic acid (RNA) virus, in upper respiratory specimens from people. In general, sensitive testing methods require genetic material extraction from the specimen.

Low-Cost, Real-Time Polymerase Chain Reaction System for Point-of-Care Medical Diagnosis.

Global health crises due to the prevailing Coronavirus Disease 2019 (COVID-19) pandemic have placed significant strain on health care facilities such as hospitals and clinics around the world. Further, foodborne and waterborne diseases are not only spreading faster, but also appear to be emerging more rapidly than ever before and are able to circumvent conventional control measures. The Polymerase Chain Reaction (PCR) system is a well-known diagnostic tool for many applications in medical diagnostics, environmental monitoring, and food and water quality assessment.

The Opposing Role of Propionate in Modulating Intracellular Infections.

is a Gram-positive, intracellular pathogen responsible for the highly fatal foodborne illness listeriosis. Establishing intracellular infections requires the coordinated expressions of a variety of virulence factors, such as the pore-forming toxin listeriolysin O (LLO), in response to various intra- and extracellular signals. For example, we previously reported that differentially modulated LLO production in response to exogenous propionate, a short chain fatty acid either used in salt form as a human food ingredient or produced endogenously by gut microbial fermentation.

Genetic and stochastic influences upon tumor formation and tumor types in Li-Fraumeni mouse models.

is the most frequently mutated gene in human cancers. Li-Fraumeni syndrome patients inheriting heterozygous mutations often have a much-increased risk to develop cancer(s) at early ages. Recent studies suggest that some individuals inherited mutations do not have the early onset or high frequency of cancers.

Environmental Nutrients Alter Bacterial and Fungal Gut Microbiomes in the Common Meadow Katydid, .

Insect gut microbiomes consist of bacteria, fungi, and viruses that can act as mutualists to influence the health and fitness of their hosts. While much has been done to increase understanding of the effects of environmental factors that drive insect ecology, there is less understanding of the effects of environmental factors on these gut microbial communities. For example, the effect of environmental nutrients on most insect gut microbiomes is poorly defined.

The Production of Listeriolysin O and Subsequent Intracellular Infections by Are Regulated by Exogenous Short Chain Fatty Acid Mixtures.

is a foodborne pathogen capable of secreting listeriolysin O (LLO), a pore-forming toxin encoded by the gene. While the functions of LLO have been studied extensively, how the production of LLO is modulated by the intestinal environment, devoid of oxygen and enriched in short chain fatty acids (SCFAs), is not completely understood. Using strain 10403s, we found that transcription was moderately decreased by aerobic SCFA exposures but significantly increased by anaerobic SCFA exposures.

The gut bacterial communities across six grasshopper species from a coastal tallgrass prairie.

Insect microbiomes play an important role in the health and fitness of insect hosts by contributing to nutrient absorption, immune health, and overall ecological fitness. As such, research interests in insect microbiomes have focused on agriculturally and industrially important organisms such as honey bees and termites. Orthopterans, on the other hand, have not been well explored for their resident microbial communities.

Optothermal microbubble assisted manufacturing of nanogap-rich structures for active chemical sensing.

Guiding analytes to the sensing area is an indispensable step in a sensing system. Most of the sensing systems apply a passive sensing method, which waits for the analytes to diffuse towards the sensor. However, passive sensing methods limit the detection of analytes to a picomolar range on micro/nanosensors for a practical time scale.

Optimization and Structural Stability of Gold Nanoparticle-Antibody Bioconjugates.

Gold nanoparticles (AuNPs) bound with biomolecules have emerged as suitable biosensors exploiting unique surface chemistries and optical properties. Many efforts have focused on antibody bioconjugation to AuNPs resulting in a sensitive bioconjugate to detect specific types of bacteria. Unfortunately, bacteria thrive under various harsh environments, and an understanding of bioconjugate stability is needed.

Stimulating Respiratory Activity Primes Anaerobically Grown for Subsequent Intracellular Infections.

is a Gram-positive, enteric pathogen and the causative agent of listeriosis. During transition through the gastrointestinal tract, routinely encounters suboxic conditions. However, how the exposure to the low oxygen environment affects subsequent pathogenesis is not completely understood.

Response to Propionate Is Differentially Modulated by Anaerobicity.

Propionate is a common food preservative and one of the major fermentation acids in the intestines. Therefore, exposure to propionate is frequent for foodborne pathogens and likely takes place under suboxic conditions. However, it is not clear whether the absence of oxygen affects how pathogens respond to propionate.

An Examination of the Application of the Kidney Donor Risk Index in British Columbia.

Background: The Kidney Donor Risk Index (KDRI) is a continuous measure of deceased donor kidney transplant failure risk that was derived in US patients based on 10 donor characteristics. In the United States, the KDRI is utilized to guide organ allocation and to inform clinical decisions regarding organ acceptance.

Objective: To examine the application of the US-derived KDRI in a large Canadian province.

Metabolic determinants in Listeria monocytogenes anaerobic listeriolysin O production.

Listeria monocytogenes is a human pathogen and a facultative anaerobe. To better understand how anaerobic growth affects L. monocytogenes pathogenesis, we first showed that anaerobic growth led to decreased growth and changes in surface morphology.

The evolution of thymic lymphomas in p53 knockout mice.

Germline deletion of the p53 gene in mice gives rise to spontaneous thymic (T-cell) lymphomas. In this study, the p53 knockout mouse was employed as a model to study the mutational evolution of tumorigenesis. The clonality of the T-cell repertoire from p53 knockout and wild-type thymic cells was analyzed at various ages employing TCRβ sequencing.

Selected drugs that inhibit DNA methylation can preferentially kill p53 deficient cells.

The p53 protein ensures cellular fidelity by suppressing or killing cells under stresses that enhance the mutation rate. Evidence suggests that the p53 protein may also ensure the fidelity of the epigenome. In this study a group of drugs that alter the deoxycytosine methylation patterns in cellular DNA are shown to preferentially kill human and mouse cells that contain p53 mutations or deficiencies.

Regulation of bacterial pathogenesis by intestinal short-chain Fatty acids.

The human gut microbiota is inextricably linked to health and disease. One important function of the commensal organisms living in the intestine is to provide colonization resistance against invading enteric pathogens. Because of the complex nature of the interaction between the microbiota and its host, multiple mechanisms likely contribute to resistance.

Multiple roles of p53-related pathways in somatic cell reprogramming and stem cell differentiation.

The inactivation of p53 functions enhances the efficiency and decreases the latency of producing induced pluripotent stem cells (iPSC) in culture. The formation of iPSCs in culture starts with a rapid set of cell divisions followed by an epigenetic reprogramming of the DNA and chromatin. The mechanisms by which the p53 protein inhibits the formation of iPSCs are largely unknown.

Fatty acids regulate stress resistance and virulence factor production for Listeria monocytogenes.

Fatty acids (FAs) are the major structural component of cellular membranes, which provide a physical and chemical barrier that insulates intracellular reactions from environmental fluctuations. The native composition of membrane FAs establishes the topological and chemical parameters for membrane-associated functions and is therefore modulated diligently by microorganisms especially in response to environmental stresses. However, the consequences of altered FA composition during host-pathogen interactions are poorly understood.

Regulation of female reproduction by p53 and its family members.

Tumor suppressor p53 is crucial for embryonic implantation through transcriptional up-regulation of uterine leukemia inhibitory factor (LIF). This article reports that p53 and estrogen receptor α were activated in endometrial tissues during implantation to coordinately regulate LIF production. By using human p53 knockin (Hupki) mice carrying a single nucleotide polymorphism (SNP) at codon 72 (arginine/proline), the arginine allele was demonstrated to produce higher uterine LIF levels during implantation than the proline allele.

Branched-chain fatty acids promote Listeria monocytogenes intracellular infection and virulence.

Anteiso-branched-chain fatty acids (BCFA) represent the dominant group of membrane fatty acids and have been established as crucial determinants in resistance against environmental stresses in Listeria monocytogenes, a facultative intracellular pathogen. Here, we investigate the role of anteiso-BCFA in L. monocytogenes virulence by using mutants deficient in branched-chain alpha-keto acid dehydrogenase (BKD), an enzyme complex involved in the synthesis of BCFA.

Negative regulation of tumor suppressor p53 by microRNA miR-504.

Tumor suppressor p53 plays a central role in tumor prevention. p53 protein levels and activity are under a tight and complex regulation in cells to maintain the proper function of p53. MicroRNAs play a key role in the regulation of gene expression.

Glutaminase 2, a novel p53 target gene regulating energy metabolism and antioxidant function.

Whereas cell cycle arrest, apoptosis, and senescence are traditionally thought of as the major functions of the tumor suppressor p53, recent studies revealed two unique functions for this protein: p53 regulates cellular energy metabolism and antioxidant defense mechanisms. Here, we identify glutaminase 2 (GLS2) as a previously uncharacterized p53 target gene to mediate these two functions of the p53 protein. GLS2 encodes a mitochondrial glutaminase catalyzing the hydrolysis of glutamine to glutamate.

A polymorphic variant in human MDM4 associates with accelerated age of onset of estrogen receptor negative breast cancer.

Murine double minute 4 (MDM4) shares significant structural homology with murine double minute 2 (MDM2) and interacts and regulates transcriptional activity of the tumor suppressor p53. In tumors with wild-type p53, there is often overexpression of MDM2 or MDM4 leading to functional inactivation of p53. A single-nucleotide polymorphism (SNP) in the promoter of human MDM2 (SNP309) was shown to associate with increased MDM2 expression and increased risk of cancer.

Behavioral response of dissimilatory perchlorate-reducing bacteria to different electron acceptors.

The response behavior of three dissimilatory perchlorate-reducing bacteria to different electron acceptors (nitrate, chlorate, and perchlorate) was investigated with two different assays. The observed response was species-specific, dependent on the prior growth conditions, and was inhibited by oxygen. We observed attraction toward nitrate when Dechloromonas aromatica strain RCB and Azospira suillum strain PS were grown with nitrate.