Florentine bookbinding and restoration

Florence, Italy is a hub for art and literature. These two disciplines come together in the tradition of bookbinding, which is alive and well in Florence. A city that appreciates its own rich culture, Florence maintains many traditional practices and crafts, such as bookbinding and metalworking. The Florentines preserve more than just practices, though. The numerous museums in Florence work to physically protect and store pieces of art, artifacts, and documents. All of this preservation was challenged in 1966, with the flood of Florence’s Arno River. The flood destroyed countless manuscripts, books, and pieces of art. With this devastation, a new age of restoration was born. Though in many ways, Italian bookbinding shares a history similar to that of the rest of Western Europe, Italy has developed its own characteristics and traditions in the bookbinding trade of the past and the present. Similarly, paper restoration practices in Italy are much like that of the rest of the world, but that may not be true without Florence. The 1966 flood of the Arno River changed the practices of paper restoration from a craft to a science, which is now studied and discussed globally and not secretly passed from master to apprentice as before the flood. My goal in creating this thesis project was to explore traditional Italian bookbinding and restoration by considering the impact of the 1966 flood, including restoration techniques that emerged. I chose to do so in a traditional, hand-bound format, a process I was first exposed to in a University of South Carolina Honors College course, and a process that I continued to explore in Florence. Having spent a semester studying abroad in Florence, I wanted to include specific aspects of my time abroad in my book, including materials purchased, techniques learned, and interviews performed while still in Florence. The final products of this project are a book and a paper. The 112-page hand-bound book, with content created by hand, serves as an artistic representation of the goals of this project. While there is factual information included in the content of the book, it serves more as a physical manifestation and summary of the topics covered than as an academic text. The 25-page paper, which details the history of Italian bookbinding and restoration and describes and catalogues the process of creating the book serves as the academic aspect of this project. In completing this project, my belief that traditional techniques are alive and well in Florence was confirmed. I spoke with artisans who prove that. I also learned how one event, like a flood can change the course of history, and even of a seemingly unrelated history. While natural disasters have some obvious effects like infrastructural damage, there are less often considered effects as well, like damage to art and culture

In vivo evaluation of a neural stem cell-seeded prosthesis

Neural prosthetics capable of recording or stimulating neuronal activity may restore function for patients with motor and sensory deficits resulting from injury or degenerative disease. However, overcoming inconsistent recording quality and stability in chronic applications remains a significant challenge. A likely reason for this is the reactive tissue response to the devices following implantation into the brain, which is characterized by neuronal loss and glial encapsulation. We have developed a neural stem cell-seeded probe to facilitate integration of a synthetic prosthesis with the surrounding brain tissue. We fabricated parylene devices that include an open well seeded with neural stem cells encapsulated in an alginate hydrogel scaffold. Quantitative and qualitative data describing the distribution of neuronal, glial, and progenitor cells surrounding seeded and control devices are reported over four time points spanning 3 months. Neuronal loss and glial encapsulation associated with cell-seeded probes were mitigated during the initial week of implantation and exacerbated by 6 weeks post-insertion compared to control conditions. We hypothesize that graft cells secrete neuroprotective and neurotrophic factors that effect the desired healing response early in the study, with subsequent cell death and scaffold degradation accounting for a reversal of these results later. Applications of this biohybrid technology include future long-term neural recording and sensing studies.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65100/2/jne9_2_026005.pd

Characterizing the Activity of Antimicrobial Peptides Against the Pathogenic Bacterium Clostridium Difficile in Anaerobic Environment

Clostridium difficile is an anaerobic Gram-positive pathogen with high treatment costs and mortality and very high antibiotic tolerance. Antimicrobial host-defense peptides (HDPs) produced naturally by animal immune systems are promising candidates to develop novel therapies for bacterial infection because they cause oxidative stress that damages multiple targets in bacterial cells, so it is difficult for bacteria to evolve resistance to these attacks. Piscidins, fish-derived HDPs that can also form complexes with copper (Cu) to enhance their activities, are very active against multiple bacterial species in an aerobic environment. We examined their activity against C. difficile and other species in an anaerobic environment and found that the interaction of piscidins and copper is different in different oxygen environments. Piscidins are highly active against C. difficile and could be a good candidate for drug development.https://digitalcommons.odu.edu/sciences_achievement/1018/thumbnail.jp

Cyclic diguanylate signaling in Gram-positive bacteria

The nucleotide second messenger 3′-5′ cyclic diguanylate monophosphate (c-di-GMP) is a central regulator of the transition between motile and non-motile lifestyles in bacteria, favoring sessility. Most research investigating the functions of c-di-GMP has focused on Gram-negative species, especially pathogens. Recent work in Gram-positive species has revealed that c-di-GMP plays similar roles in Gram-positives, though the precise targets and mechanisms of regulation may differ. The majority of bacterial life exists in a surface-associated state, with motility allowing bacteria to disseminate and colonize new environments. c-di-GMP signaling regulates flagellum biosynthesis and production of adherence factors and appears to be a primary mechanism by which bacteria sense and respond to surfaces. Ultimately, c-di-GMP influences the ability of a bacterium to alter its transcriptional program, physiology and behavior upon surface contact. This review discusses how bacteria are able to sense a surface via flagella and type IV pili, and the role of c-di-GMP in regulating the response to surfaces, with emphasis on studies of Gram-positive bacteria

\u3ci\u3eClostridioides difficile\u3c/i\u3e Spore Production in Response to Antibiotic and Immune Stress

Clostridioides (Clostridium) difficile, an anaerobic, spore-forming Gram-positive pathogenic bacterium, is a major cause of hospital-acquired infections and can persist as surface-attached biofilms for protection from antibiotic and immune stress. C. difficile can form biofilms as a single species or with other anaerobic intestinal bacteria. The environmental signals that cause individual cells to secrete toxins, form biofilms, or develop into spores that can spread the infection to new patients are unknown. In these studies, we investigate bacterial responses to different stress. Antimicrobial host-defense peptides (HDPs) produced by animal immune systems are promising candidates to develop novel therapies for bacterial infection because they cause oxidative stress that damages multiple targets in bacterial cells, so it is difficult for bacteria to evolve resistance to these attacks. We investigate antibiotic treatments, metal ions and sugars, and antimicrobial peptide treatments to determine how. C. difficile reacts to multiple environmental stresses like those from antibiotic treatment or the human immune system. In our investigation of C. difficile and HDPs in an anaerobic environment, we found that the interaction of piscidin and copper is different in different oxygen environments. Antibiotics and oxidative stresses from other sources cause the cells to form spores and/or biofilms to protect themselves, but piscidin kill vegetative C. difficile cells without triggering these protective responses. Piscidins are highly active against C. difficile and could be a good candidate for drug development.https://digitalcommons.odu.edu/gradposters2022_sciences/1016/thumbnail.jp

Expanding Our Grasp of Two-Component Signaling in \u3ci\u3eClostridioides difficile\u3c/i\u3e

The intestinal pathogen Clostridioides difficile encodes roughly 50 TCS, but very few have been characterized in terms of their activating signals or their regulatory roles. A. G. Pannullo, B. R. Zbylicki, and C. D. Ellermeier (J Bacteriol 205:e00164-23, 2023, https://doi.org/10.1128/jb.00164-23) have identified both for the novel C. difficile TCD DraRS. DraRS responds to antibiotics that target lipid-II molecules in the bacterial cell envelope, and regulates the production of a novel glycolipid necessary for bacitracin and daptomycin resistance in C. difficile

A Purification and \u3ci\u3eIn Vitro\u3c/i\u3e Activity Assay for a (p)ppGpp Synthetase from \u3ci\u3eClostridium difficile\u3c/i\u3e

Kinase and pyrophosphokinase enzymes transfer the gamma phosphate or the beta-gamma pyrophosphate moiety from nucleotide triphosphate precursors to substrates to create phosphorylated products. The use of γ-32-P labeled NTP precursors allows simultaneous monitoring of substrate utilization and product formation by radiography. Thin layer chromatography (TLC) on cellulose plates allows rapid separation and sensitive quantification of substrate and product. We present a method for utilizing the thin-layer chromatography to assay the pyrophosphokinase activity of a purified (p)ppGpp synthetase. This method has previously been used to characterize the activity of cyclic nucleotide and dinucleotide synthetases and is broadly suitable for characterizing the activity of any enzyme that hydrolyzes a nucleotide triphosphate bond or transfers a terminal phosphate from a phosphate donor to another molecule

Sound the (Smaller) Alarm: The Triphosphate Magic Spot Nucleotide pGpp

It has recently become evident that the bacterial stringent response is regulated by a triphosphate alarmone (pGpp) as well as the canonical tetra- and pentaphosphate alarmones ppGpp and pppGpp [together, (p)ppGpp]. Often dismissed in the past as an artifact or degradation product, pGpp has been confirmed as a deliberate endpoint of multiple synthetic pathways utilizing GMP, (p)ppGpp, or GDP/GTP as precursors. Some early studies concluded that pGpp functionally mimics (p)ppGpp and that its biological role is to make alarmone metabolism less dependent on the guanine energy charge of the cell by allowing GMP-dependent synthesis to continue when GDP/GTP has been depleted. However, recent reports that pGpp binds unique potential protein receptors and is the only alarmone synthesized by the intestinal pathogen Clostridioides difficile indicate that pGpp is more than a stand-in for the longer alarmones and plays a distinct biological role beyond its functional overlap (p)ppGpp

In vivo stability and biocompatibility of implanted calcium alginate disks

Alginate is a commonly used biomedical hydrogel whose in vivo degradation behavior is only beginning to be understood. The use of alginate in the central nervous system is gaining popularity as an electrode coating, cell encapsulation matrix, and for duraplasty. However, it is necessary to understand how the hydrogel will behave in vivo to aid in the development of alginate for use as a neural interface material. The goal of the current study was to compare the rheological behavior of explanted alginate disks and the inflammatory response to subcutaneously implanted alginate hydrogels over a 3-month period. Specifically, the effects due to (1) in situ gelling, (2) diffusion gelling, and (3) use of a poly- l -lysine (PLL) coating were investigated. While all samples' complex moduli decreased 80% in the first day, in situ gelled alginate was more stable for the first week of implantation. The PLL coating offered some stability increases for diffusion gelled alginate, but the stability in both conditions remained significantly lower than that in in situ gelled alginate. There were no differences in biocompatibility that clearly suggested one gelation method over another. These results indicate that in situ gelation is the preferred method in neural interface applications where stability is the primary concern. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 2007Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/57402/1/31275_ftp.pd

Cell Scaffold- and Drug-based Strategies for Improving the Integration of Neural Prostheses into Brain Tissue.

Neuroprosthetic devices record extracellular cortical signals which may be used to place exterior devices under a patient’s direct control. Therefore, these systems may restore function to individuals immobilized by paralysis or neurodegenerative disease. For neuroprosthetics to be useful in clinical and research settings, long-term, stable recordings must be achieved. However, these devices are plagued by recording instability, and the reactive tissue response that occurs after insertion into the brain is a likely cause. Specifically, neuronal density is reduced surrounding devices, and encapsulation (composed of microglia and astrocytes) isolates neuroprostheses from their neuronal signal sources. The research presented describes the development and evaluation of two strategies to improve the tissue response to neuroprostheses: (1) a neural stem cell (NSC)-seeded scaffold and (2) a cell cycle-inhibiting drug. NSCs were hypothesized to secrete factors, such as neurotrophins, which would improve device-tissue integration. The cells were encapsulated in an alginate hydrogel and seeded into a well on the devices. In the first study, in vitro testing identified the optimal alginate composition for NSC encapsulation. The second study characterized the relationship between alginate composition, degradation, and biocompatibility in vivo. The third study evaluated the effects of the NSC scaffold on the tissue response to implanted probes in vivo. The scaffold mitigated the early tissue response, but exacerbated it by six weeks post-implantation. Based on research showing a link between central nervous system injury and cell-cycle re-entry, the final study of the dissertation investigated the role of this phenomenon in the tissue response to neural prostheses. Specifically, the effects of a cell cycle-inhibiting drug (flavopiridol) on electrophysiology and tissue response metrics were explored. Flavopiridol reduced expression of a cell cycle protein in microglia surrounding probes three days after implantation and decreased impedance over the 28 day study period. Additionally, the data revealed novel, significant correlations between recording quality, impedance, and endpoint histology measurements. In conclusion, the studies demonstrate significant effects of two intervention strategies on tissue response and electrophysiology measurements, characterize alginate stability and its use as a NSC scaffold, and add insight into the relationship between the tissue-device interface and recording quality.Ph.D.Biomedical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/61573/1/erinfred_1.pd