Review of medical imaging devices for the integration of medical technology and earmold production and grant proposal development

The first purpose of this study was to assess the feasibility of a medical device to replace the current method of earmold production. The medical device would be used to scan the external ear (i.e., external auditory canal and pinna), scan the dimensions to an imaging software system, and finally send the three-dimensional image electronically to a milling machine for the production of earmolds and hearing aid shells. Currently, audiologists use an eight step process described by Dillon (2001) which due to the invasive nature of the procedure presents potential complications to both the clinician and client, The potential complications discussed are infection control, liability risks for audiologists, and bodily harm of clients. In addition, the current method presents much variability of the earmold or hearing aid shell fit causing a high return rate from clients and potentially poor quality control. The methodology of reverse engineering implemented in abrasive computer tomography imaging was hypothesized to be the most feasible method to eliminate or reduce the risks associated with earmold impressions. An image of the external ear would be captured via an infrared camera then sent to a computer with compatible imaging software. An infrared camera with crystal clear display (CCD) and Materialise\u27 Rapid Shell Modeling (RSM) software were identified to be the necessary equipment. The second purpose of this study was to determine an appropriate request for proposal for continued audiological research of the determined medical device. The Research Competitiveness and Industrial Ties Research Subprograms of the Board of Regents Support Fund Research and Development Program was the request for proposal selected. This type of grant, if awarded, provides a greater potential for studies to be awarded at the federal level. The Research Competitiveness Subprogram Proposal awards research that is innovative and conducted within a university which is a member of the Louisiana Association of Independent Colleges and Universities. This study meets the criteria delineated by the Louisiana Board of Regents

Chitosan paste from crawfish shells as a synthetic bone graft material: Preparation, characterization and animal study

Bone loss associated with musculoskeletal trauma or metabolic diseases often requires bone grafts. Autograft or allograft bones are limited in supply. Therefore, development of synthetic bone graft materials is an active area of research. For several years the biomaterials group at LSUHSC-Shreveport has been investigating the use of chitosan purified from crawfish shells using a process patented by my research advisor, Dr. Debi Mukherjee. Chitin is a polysaccharide that exists in fungi, exoskeleton of insects and outer shell of crustaceans. It is biocompatible, osteoconductive, antimicrobial, biodegradable, non-toxic, haemostatic, fungicidal, and the second most abundant natural polysaccharide on earth. Removal of the acetyl group from chitin forms chitosan. Chitosan is more useful due to the presence of amino groups that impart a positive charge to the molecule. This positive charge interacts with cells or can act as a binding site for other functional groups thereby expanding the role of chitosan molecules. The objectives of this study are: (1) Test for the presence of bone in grafted and ungrafted defects and compare the results among the different groups. (2) Test and compare the differences in stiffnesses and fracture loads among the different groups. (3) Test, via microcomputed tomography, defect reduction in samples treated with the graft. (4) Test for the amorphous nature of crawfish chitosan. (5) Compare the purity of crawfish chitosan extracted using Dr. Debi Mukherjee\u27s procedure with commercially available chitosan. The first portion of this experiment was characterization of crawfish chitosan, extracted using a method patented by Dr. Debi Mukherjee, to determine the individual chemical fingerprint of crawfish chitosan. Tests established that crawfish chitosan contains identical functional groups as chitosan monomer and chitosan glutamate and possessing an amorphous structure. In the second portion of this study, purified chitosan was mixed with cultured osteoblasts and compounded with a calcium salt creating a bone graft paste. Eighteen male Lewis rats underwent the surgical procedure. A critical size defect was created in rat femurs following a published protocol and repaired through use of a metal plate with and without crawfish chitosan bone graft paste. Histological examination and bone graft analysis of defected areas demonstrated the presence of bone in defect areas that were filled with experimental paste material and reduced or no bone growth on control femurs. Chitosan possesses the necessary properties, when combined with plaster of Paris and osteoblasts, to create a bone graft that is osteoconductive, osteoinductive and osteogenic

Hyaluronan turnover and hypoxic brown adipocytic differentiation are co-localized with ossification in calcified human aortic valves

The calcification process in aortic stenosis has garnered considerable interest but only limited investigation into selected signaling pathways. This study investigated mechanisms related to hypoxia, hyaluronan homeostasis, brown adipocytic differentiation, and ossification within calcified valves. Surgically explanted calcified aortic valves (nﾠ=ﾠ14) were immunostained for markers relevant to these mechanisms and evaluated in the center (NodCtr) and edge (NodEdge) of the calcified nodule (NodCtr), tissue directly surrounding nodule (NodSurr); center and tissue surrounding small ﾓprenodulesﾔ (PreNod, PreNodSurr); and normal fibrosa layer (CollFibr). Pearson correlations were determined between staining intensities of markers within regions. Ossification markers primarily localized to NodCtr and NodEdge, along with markers related to hyaluronan turnover and hypoxia. Markers of brown adipocytic differentiation were frequently co-localized with markers of hypoxia. In NodCtr and NodSurr, brown fat and ossification markers correlated with hyaluronidase-1, whereas these markers, as well as hypoxia, correlated with hyaluronan synthases in NodEdge. The protein product of tumor necrosis factor-? stimulated gene-6 strongly correlated with ossification markers and hyaluronidase in the regions surrounding the nodules (NodSurr, PreNodSurr). In conclusion, this study suggests roles for hyaluronan homeostasis and the promotion of hypoxia by cells demonstrating brown fat markers in calcific aortic valve disease

3D bioactive composite scaffolds for bone tissue engineering

Bone is the second most commonly transplanted tissue worldwide, with over four million operations using bone grafts or bone substitute materials annually to treat bone defects. However, significant limitations affect current treatment options and clinical demand for bone grafts continues to rise due to conditions such as trauma, cancer, infection and arthritis. Developing bioactive three-dimensional (3D) scaffolds to support bone regeneration has therefore become a key area of focus within bone tissue engineering (BTE). A variety of materials and manufacturing methods including 3D printing have been used to create novel alternatives to traditional bone grafts. However, individual groups of materials including polymers, ceramics and hydrogels have been unable to fully replicate the properties of bone when used alone. Favourable material properties can be combined and bioactivity improved when groups of materials are used together in composite 3D scaffolds. This review will therefore consider the ideal properties of bioactive composite 3D scaffolds and examine recent use of polymers, hydrogels, metals, ceramics and bio-glasses in BTE. Scaffold fabrication methodology, mechanical performance, biocompatibility, bioactivity, and potential clinical translations will be discussed

Effect of donor HSD17B13 genotype on patient survival after liver transplant: a retrospective cohort studyResearch in context

Summary: Background: Several genetic variants are associated with chronic liver disease. The role of these variants in outcomes after liver transplantation (LT) is uncertain. The aim of this study was to determine if donor genotype at risk-associated variants in PNPLA3 (rs738409 C>G, p.I148M) and HSD17B13 (rs72613567 T>TA; rs80182459, p.A192Lfs∗8) influences post-LT survival. Methods: In this retrospective cohort study, data on 2346 adults who underwent first-time LT between January 1, 1999 and June 30, 2020 and who had donor DNA samples available at five large Transplant Immunology Laboratories in Texas, USA, were obtained from the United Network for Organ Sharing (UNOS). Duplicates, patients with insufficient donor DNA for genotyping, those who were <18 years of age at the time of transplant, had had a previous transplant or had missing genotype data were excluded. The primary outcomes were patient and graft survival after LT. The association between donor genotype and post-LT survival was examined using Kaplan–Meier method and multivariable-adjusted Cox proportional hazards models. Findings: Median age of LT recipients was 57 [interquartile range (IQR), 50–62] years; 837 (35.7%) were women; 1362 (58.1%) White, 713 (30.4%) Hispanic, 182 (7.8%) Black/African-American. Median follow-up time was 3.95 years. Post-LT survival was not affected by donor PNPLA3 genotype but was significantly reduced among recipients of livers with two HSD17B13 loss-of-function (LoF) variants compared to those receiving livers with no HSD17B13 LoF alleles (unadjusted one-year survival: 82.6% vs 93.9%, P < 0.0001; five-year survival: 73.1% vs 82.9%, P = 0.0017; adjusted hazard ratio [HR], 2.25; 95% CI, 1.61–3.15 after adjustment for recipient age, sex, and self-reported ethnicity). Excess mortality was restricted to those receiving steroid induction immunosuppression (crude 90-day post-LT mortality, 9.3% [95% CI, 1.9%–16.1%] vs 1.9% [95% CI, 0.9%–2.9%] in recipients of livers with two vs no HSD17B13 LoF alleles, P = 0.0012; age, sex, and ethnicity-adjusted HR, 2.85; 95% CI, 1.72–4.71, P < 0.0001). No reduction was seen among patients who did not receive steroid induction (90-day mortality 3.1% [95% CI, 0%–7.3%] vs 2% [95% CI, 0.9%–3.1%], P = 0.65; adjusted HR, 1.17; 95% CI, 0.66–2.08, P = 0.60). Interpretation: Donor HSD17B13 genotype adversely affects post-LT survival in patients receiving steroid induction. Additional studies are required to confirm this association. Funding: The National Institutes of Health and American Society of Transplant Surgeons Collaborative Scientist Gran