Point-of-Need Additive Manufacturing in Austere Arctic Environments: An Evaluation of Medical Logistics Requirements and Capabilities Demonstration.

Medical response to military conflicts, natural disasters, and humanitarian crises are challenged by operational logistics with unreliable supply chains, delayed medical evacuation, and compatibility of the disparate medical equipment and consumables. In these environments, stocks of supplies will become more quickly depleted and the need for equipment parts increases secondary to their higher likelihood for failure from overuse. Additive Manufacturing (AM), or 3D printing, at or closer to the point-of-need provides potential solutions to mitigate these logistics challenges.

A review on fabricating tissue scaffolds using vat photopolymerization.

Unlabelled: Vat Photopolymerization (stereolithography, SLA), an Additive Manufacturing (AM) or 3D printing technology, holds particular promise for the fabrication of tissue scaffolds for use in regenerative medicine. Unlike traditional tissue scaffold fabrication techniques, SLA is capable of fabricating designed scaffolds through the selective photopolymerization of a photopolymer resin on the micron scale. SLA offers unprecedented control over scaffold porosity and permeability, as well as pore size, shape, and interconnectivity.

3D Printing All-Aromatic Polyimides using Mask-Projection Stereolithography: Processing the Nonprocessable.

High-performance, all-aromatic, insoluble, engineering thermoplastic polyimides, such as pyromellitic dianhydride and 4,4'-oxydianiline (PMDA-ODA) (Kapton), exhibit exceptional thermal stability (up to ≈600 °C) and mechanical properties (Young's modulus exceeding 2 GPa). However, their thermal resistance, which is a consequence of the all-aromatic molecular structure, prohibits processing using conventional techniques. Previous reports describe an energy-intensive sintering technique as an alternative technique for processing polyimides with limited resolution and part fidelity.

3D Printing Phosphonium Ionic Liquid Networks with Mask Projection Microstereolithography.

Photopolymerization coupled with mask projection microstereolithography successfully generated various 3D printed phosphonium polymerized ionic liquids (PILs) with low UV light intensity requirements and high digital resolution. Varying phosphonium monomer concentration, diacrylate cross-linking comonomer, and display images enabled precise 3D design and polymeric properties. The resulting cross-linked phosphonium PIL objects exhibited a synergy of high thermal stability, tunable glass transition temperature, optical clarity, and ion conductivity, which are collectively well-suited for emerging electro-active membrane technologies.

Chemical genetics define the roles of p38alpha and p38beta in acute and chronic inflammation.

The p38 MAP kinase signal transduction pathway is an important regulator of proinflammatory cytokine production and inflammation. Defining the roles of the various p38 family members, specifically p38alpha and p38beta, in these processes has been difficult. Here we use a chemical genetics approach using knock-in mice in which either p38alpha or p38beta kinase has been rendered resistant to the effects of specific inhibitors along with p38beta knock-out mice to dissect the biological function of these specific kinase isoforms.

Essential role for p38alpha mitogen-activated protein kinase in placental angiogenesis.

The p38 family of mitogen-activated protein kinases (MAPKs) mediates signaling in response to environmental stresses and inflammatory cytokines, but the requirements for the p38 MAPK pathway in normal mammalian development have not been elucidated. Here, we show that targeted disruption of the p38alpha MAPK gene results in homozygous embryonic lethality because of severe defects in placental development. Although chorioallantoic placentation is initiated appropriately in p38alpha null homozygotes, placental defects are manifest at 10.

Susceptibility of stromelysin 1-deficient mice to collagen-induced arthritis and cartilage destruction.

Objective: It has long been proposed that stromelysin is one of the major degradative matrix metalloproteinases responsible for the loss of cartilage in rheumatoid arthritis (RA) and osteoarthritis (OA). This hypothesis was tested by examining the arthritic paws of stromelysin 1 (SLN1)-deficient mice for loss of cartilage and for generation of neoepitopes that would be indicative of aggrecan cleavage.

Methods: The SLN1 gene was inactivated in murine embryonic stem cells, and knockout mice deficient in SLN1 activity were bred onto the B10.

Altered responses to bacterial infection and endotoxic shock in mice lacking inducible nitric oxide synthase.

Mice deficient in inducible nitric oxide synthase (iNOS) were generated to test the idea that iNOS defends the host against infectious agents and tumor cells at the risk of contributing to tissue damage and shock. iNOS-/-mice failed to restrain the replication of Listeria monocytogenes in vivo or lymphoma cells in vitro. Bacterial endotoxic lipopolysaccharide (LPS) caused shock and death in anesthetized wild-type mice, but in iNOS-/-mice, the fall in central arterial blood pressure was markedly attenuated and early death averted.

Molecular cloning, structure, and chromosomal localization of the human inducible nitric oxide synthase gene.

Nitric oxide, a multifunctional effector molecule synthesized by nitric oxide synthase (NOS) from L-arginine, conveys signals for vasorelaxation, neurotransmission, and cytotoxicity. Three different NOS isoforms have been identified which fall into two distinct types, constitutive and inducible. The inducible NOS (iNOS) isoform is expressed in a variety of cell types and tissues in response to inflammatory agents and cytokines.

Probing the role of interleukin-1 beta convertase in interleukin-1 beta secretion.

Interleukin-1 beta must be processed from its precursor form of 31.5 kDa to its mature form of 17 kDa in order to elaborate its wide array of bioactivities. The recent identification of a monocyte-specific endoprotease, termed interleukin-1 beta-converting enzyme (ICE), capable of generating authentic, bioactive 17 kDa IL-1 beta suggests that this protease may serve a specific role in the processing and subsequent secretion of IL-1 beta.

Discoordinate expression of stromelysin, collagenase, and tissue inhibitor of metalloproteinases-1 in rheumatoid human synovial fibroblasts. Synergistic effects of interleukin-1 and tumor necrosis factor-alpha on stromelysin expression.

Primary and passaged human synovial fibroblasts isolated from rheumatoid pannus were treated with recombinant interleukin-1 (IL-1) alpha or beta, tumor necrosis factor-alpha (TNF), or phorbol myristate acetate (PMA) to determine the effects of these stimuli on the relative expression of stromelysin, collagenase, and tissue inhibitor of metalloproteinases (TIMP). The steady-state mRNA levels for these genes and glyceraldehyde-3-phosphate dehydrogenase were determined on Northern blots. Immunoblot analyses of the conditioned media using monoclonal antibodies generated against recombinant human stromelysin, collagenase, or TIMP showed that protein levels reflected the corresponding steady-state mRNA levels.

Protoplast fusion in microtiter plates for expression cloning in mammalian cells: demonstration of feasibility using membrane-bound alkaline phosphatase as a reporter enzyme.

Protoplast fusion is a method for directly transferring cloned DNA from bacteria to mammalian cells at high efficiency. Here, we have used membrane-bound alkaline phosphatase as a reporter enzyme in a miniprotoplast fusion assay. This work demonstrates the principle that large numbers of protoplast fusions can be done simultaneously and successfully, to assay for an activity encoded by an expression vector.

Identification of a monocyte specific pre-interleukin 1 beta convertase activity.

Interleukin 1 (IL-1) is a lymphokine secreted by monocytes in response to a variety of inflammatory stimuli. IL-1 beta, the predominant form of IL-1 produced by human monocytes, is synthesized as an inactive precursor of 31 kDa and is cleaved at Asp116-Ala117 to yield a 17.5-kDa extracellular form.

Rhizobium japonicum USDA 191 has two nodD genes that differ in primary structure and function.

Several Rhizobium genes (designated nod genes) are involved in early steps in nodule formation. Here we present the results of DNA sequence and functional analysis of two nodD genes from the symbiotic plasmid of USDA 191, a fast-growing strain that forms nitrogen-fixing nodules on soybeans. Both genes encoded full-length nodD-related polypeptides, which were 69% homologous to each other.

Expression of symbiotic genes of Rhizobium japonicum USDA 191 in other rhizobia.

A 200-megadalton plasmid was mobilized from Rhizobium japonicum USDA 191 to other Rhizobium strains either that cannot nodulate soybeans or that form Fix- nodules on certain cultivars. The symbiotic properties of the transconjugants indicate that both soybean specificity for nodulation and cultivar specificity for nitrogen fixation are plasmid encoded.