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Bacterial behavior is often controlled by structural and composition elements of their cell wall. Using genetic mutant strains that change specific aspects of their surface structure, we modified bacterial behavior in response to semiconductor surfaces. We monitored the adhesion, membrane potential, and catalase activity of the Gram-negative bacterium Escherichia coli (E. coli) that were mutant for genes encoding components of their surface architecture, specifically flagella, fimbriae, curli, and components of the lipopolysaccharide membrane, while on gallium nitride (GaN) surfaces with different surface potentials. The bacteria and the semiconductor surface properties were recorded prior to the biofilm studies. The data from the materials and bioassays characterization supports the notion that alteration of the surface structure of the E. coli bacterium resulted in changes to bacterium behavior on the GaN medium. Loss of specific surface structure on the E. coli bacterium reduced its sensitivity to the semiconductor interfaces, while other mutations increase bacterial adhesion when compared to the wild-type control E. coli bacteria. These results demonstrate that bacterial behavior and responses to GaN semiconductor materials can be controlled genetically and can be utilized to tune the fate of living bacteria on GaN surfaces.

Bacterial behavior is often controlled by structural and composition elements of their cell wall. Using genetic mutant strains that change specific aspects of their surface structure, we modified b...

Current in vitro prostate cancer (PCa) research tools do not incorporate the complexities of the tumor microenvironment including perfusion, multiple cell types, extracellular matrix (ECM) and 3D-orientation. Additionally, these models lack racial/ethnic (R/E) diversity, failing to address the cancer health disparity (CHD) observed in Black men with PCa who experience double the incidence and mortality rates as compared to White men. Population-based in vitro PCa models that support crosstalk between different cell types will improve our understanding of the underlying mechanisms contributing to this CHD and improve the prediction of drug response in specific populations. Here, we used the high-throughput, perfusion-based microfluidic platform called the MIMETAS OrganoPlate® to culture up to 96 individual, multicellular PCa-on-a-chip cultures in parallel. PCa PDX cells of various R/E were embedded together with E2Crimson-labeled stromal fibroblasts in a migration-permissive hyaluronic acid hydrogel in the gel compartment, alongside an endothelium-lined perfusion channel containing a targeted immune cell population. Using high content imaging, we confirmed the stability and viability of the cultures over 7 days. The cultures maintained a 3D structure with PCa cells and fibroblasts evenly dispersed throughout the height of the gel compartment and a blood vessel-like structure within the perfusion channel. Closer evaluation of the gel compartment revealed a close association between PCa cells and stromal fibroblasts in a core-shell structure with PCa clusters surrounded by fibroblasts. Further, all cells maintained expected expression of phenotypic markers (PCa: epCAM, PSMA; fibroblast: vimentin, endothelium: CD31). For the immune component, medium and cell tracker dye conditions were optimized to support immune cell viability. Over 72 hours, immune cells were monitored, revealing migration of PBMCs through the gel compartment. Finally, the value of the complex, population-based multicellular in vitro model of PCa will be evaluated in a drug screen comparing the system with simple, PCa PDX monocultures. This R/E diverse 3D prostate tumor model will enable the full incorporation of all cell types and ECM into a single model which will better recapitulate population specific PCa and drug response. Citation Format: Divya Iyer, Andrei Bonteanu, Peter Shepherd, Rick Kittles, Nora Navone, Daniel Harrington, Kristin Bircsak. A 3D multicellular in vitro prostate cancer model featuring racially/ethnically diverse PDXs [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 284.

Introduction: Sickle cell disease is an inherited disorder, with multiorgan dysfunction resulting from vaso-occlusion and chronic haemolysis. Avascular necrosis of long bones is a known complication. Anaesthetists are frequently involved throughout perioperative period, which involves preoperative assessment, management of acute pain and prevention of postoperative complications. Case presentation: We report a case of a 56 year old female patient with sickle cell disease who underwent total hip replacement for avascular necrosis of femoral head under spinal anaesthesia combined with general anaesthesia. Conclusion: Meticulous perioperative care which includes careful planning, ensuring adequate oxygenation, hydration, tissue perfusion and pain control is vital in successful management of these patients.

Prostate cancer (PCa) incidence and mortality is nearly twice that in Black men than any other race (Non-Hispanic White, Asian/Pacific Islander, American Indian/Alaska Native, Hispanic (any race)). Characterization of the underlying biological factors that contribute to this cancer health disparity (CHD) is required to close the gap and improve patient outcome for Black men. In vitro PCa research tools which reflect the racial/ethnic diversity of this patient population are urgently needed, as most PCa cell lines are of Non-Hispanic White-origin. PCa patient-derived xenografts (PDXs) retain many of the characteristics of patient tumors and can be isolated from specific racial/ethnic groups to address this concern. Rodent PDX models provide a valuable resource for studying human cancer, however recent trends in reducing animal usage have instituted a search for alternative methods for studying PDXs that also maintain their complexity. While 2D in vitro culture of PCa PDXs has been largely unsuccessful, recent evidence suggests 3D in vitro culture of PCa PDXs may enable better long-term culture of the tumor cells. Here, we present a racially/ethnically diverse PCa PDX library of specimens (Black, Non-Hispanic White, Hispanic) developed at MD Anderson Cancer Center (the MDA PCa PDX series) compatible with 3D in vitro culture. In order to confirm self-reported race/ethnicity, each PCa PDX was characterized by whole-exome sequencing and compared to reference populations for a genetic ancestry estimation. For 3D in vitro culture, we utilized a high throughput microfluidic culture platform with 96 chips, the MIMETAS OrganoPlate® 2-lane. This platform suits both 3D tissue/cell model development and throughput needs required for drug discovery. MDA-PCa PDX cell clusters were suspended in hyaluronic acid-based hydrogel solutions, seeded into the OrganoPlate, and cultured under continuous perfusion. Genetic ancestry estimation studies revealed that patient-reported race/ethnicity often aligned with the same racial/ethnic population genetic signatures. For example, two self-reported Black PDXs were primarily of West African origin (74.6-84.6%). When cultured in 3D, PCa PDX cultures were stable and viable for at least 7 days, as determined by high content fluorescence imagining coupled with cell viability dyes. By immunofluorescent staining, PCa PDX cultures exhibited appropriate expression of phenotypic prostate-specific antigen (PSA) and androgen receptor (AR) which was maintained over the life of the culture. Studies are ongoing to screen a panel of chemotherapy drugs and determine the predictivity of the platform. This well characterized racially/ethnically diverse PCa PDX library, together with the 3D in vitro platform and methods is a valuable resource for evaluating population-based tumor response. Citation Format: Peter Shepherd, Andrei Bonteanu, Stanley Hooker, Kristin Bircsak, Divya Iyer, Dwayne Dexter, Daniel A. Harrington, Rick Kittles, Nora M. Navone. 3D in vitro prostate cancer PDX resource for studying cancer health disparities [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2625.

Prostate cancer (PCa) is the most common occurring cancer in men and the second-most leading cause of cancer-related deaths in the United States. To improve patient outcome, research tools which mimic the prostate tumor microenvironment (TME) and accurately predict drug response are urgently needed. However, current in vitro PCa models do not recapitulate the complexities of the prostate TME including three-dimensional (3D) orientation, perfusion, extracellular matrix (ECM), and the presence of multiple cell types such as tumor cells, fibroblasts, and endothelium. Further, many complex in vitro model systems fail to maintain the throughput required for robust drug screening. To address this need, here, we highlight the stepwise development of a 3D in vitro PCa model by optimizing the individual culture conditions for each cell type (PCa cells, fibroblasts (FB), endothelial cells (EC)) within MIMETAS' high throughput perfusable 3D cell culture platform, the OrganoPlate® 2-lane 96. All monocultures (PCa, fibroblast, endothelial cell) were viable and expressed respective phenotypic markers (PCa: AR and PSA; FB: vimentin; EC: CD-31, VE-cadherin) as detected by immunofluorescent staining and high-content imaging. To demonstrate the statistical retention of heterogeneity within PCa populations, PCa cells (MDA-PCa-2b) were pre-labeled with 4 different tracking dyes and clustered into multicellular aggregates using a multiwell, ultra-low attachment plate. After 3D encapsulation within a migration permissive hyaluronic acid (MP-HA) hydrogel, PCa clusters retained uniform size clusters and even distribution of the pre-labeled populations within each cluster. Additionally, use of this pre-clustering reduced cell debris in the encapsulated 3D cultures. 3D FB cultures, mimicking normal or reactive stroma, were established with bone stroma cell lines and primary human mesenchymal stem cells. The cells' phenotypic stretched morphology and migration through the ECM were tuned by tailoring the hydrogel crosslinking assessed further by measuring the permeability of 2,000 kDa FITC-dextran. EC (primary human lung microvascular endothelium) were seeded against MP-HA to form a tubule structure within the perfusion channel. Culture conditions were optimized to reduce the permeability of smaller molecules (4.4, 150 KDa Dextran) through EC barriers and further imaging revealed the formation of a 3D blood vessel-like structure within the perfusion channel. Studies are ongoing to combine all three cell types into a single model. This stepwise approach, for building a complex, 3D prostate tumor model, will enable the full incorporation of all cell types and ECM into a single model which will have the potential to better recapitulate the in vivo prostate TME and improve the predictivity of PCa in vitro models. Citation Format: Divya Iyer, Andrei Bonteanu, Jedidiah Z. Zhu, Peter Shepherd, Rick Kittles, Nora M. Navone, Daniel A. Harrington, Dwayne Dexter, Kristin M. Bircsak. Development of a 3D in vitro model of the prostate tumor microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2641.

Introduction: Asian American subgroups (Asian Indian, Chinese, Filipino, Korean, Japanese, and Vietnamese) display significant differences in mortality due to cardiovascular disease. It has previously been proposed that cancer is the leading cause of death for all Asian Americans. However, recent analysis of each individual subgroup reveals that heart disease is actually the leading cause of death for Asian Indian, Filipino and Japanese populations. Additionally, certain Asian American subgroups have an increased burden of risk factors and disease mortality at younger ages when compared to Non-Hispanic Whites. Years of potential life lost (YPLL) provides a measure of premature mortality due to cardiovascular disease by taking into account race-specific life expectancy and the younger age at death that is specific to Asian American populations. Hypothesis: We assessed the hypothesis that certain subgroups, such as Asian Indian and Filipino populations, lost more years of life due to cardiovascular disease when compared to other Asian American subgroups and Non-Hispanic Whites. Methods: We used National Center for Health Statistics Multiple Causes of Death mortality files from 2003-2012. Sample size for Asian Americans was 354,256 and for Non-Hispanic Whites was 19,722,445. We calculated life expectancy, mean YPLL, and YPLL per 100,000 population for each Asian subgroup. We further characterized race-specific life expectancy using linear interpolation, and YPLL per 100,000 was standardized and age-adjusted using age categories. Results: Asian American subgroups display heterogeneity in cardiovascular disease burden. Asian Indians had a high burden of ischemic heart disease (IHD); Asian Indian men lost a mean of 17 years of life to IHD while Japanese and Non-Hispanic White men lost 14 years of life. Regarding cerebrovascular disease, Vietnamese populations lost a mean of 17 years of life, and Filipino populations lost a mean of 16 years. All Asian subgroups had higher years of life lost to cerebrovascular disease compared to Non-Hispanic Whites. Conclusion: Cardiovascular disease burden varies among Asian subgroups, and contributes to significant premature mortality in certain populations. Asian Indian and Filipino populations have the highest years of life lost due to ischemic heart disease. Filipino and Vietnamese have the highest years of life lost due to cerebrovascular disease. Mean YPLL due to cardiovascular disease was higher for Asian Indians, Korean, Vietnamese, and Filipino subgroups than mean YPLL for Non-Hispanic Whites. To address these health disparities, an analysis of risk factors is required and subgroup-specific interventions must be developed.

Background Asian‐American subgroups (Asian‐Indian, Chinese, Filipino, Korean, Japanese, and Vietnamese) display varied cardiovascular disease mortality patterns, especially at younger ages. This study aims to examine the years of potential life lost because of ischemic heart disease and cerebrovascular disease among the 6 largest Asian‐American subgroups compared with non‐Hispanic whites. Methods and Results We used National Center for Health Statistics Multiple Causes of Death mortality files from 2003 to 2012 to calculate race‐specific life expectancy, mean years of potential life lost, and years of potential life lost per 100 000 population for each Asian subgroup and non‐Hispanic whites. Asian‐American subgroups display heterogeneity in cardiovascular disease burden. Asian‐Indians had a high burden of ischemic heart disease; Asian‐Indian men lost 724 years per 100 000 population in 2012 and a mean of 17 years to ischemic heart disease. Respectively, Vietnamese and Filipino men and women lost a mean of 17 and 16 years of life to cerebrovascular disease; Filipino men lost 352 years per 100 000 population in 2012. All Asian subgroups for both sexes had higher years of life lost to cerebrovascular disease compared with non‐Hispanic whites. Conclusions Cardiovascular disease burden varies among Asian subgroups, and contributes to greater premature mortality in certain subgroups. Asian‐Indian and Filipino populations have the highest years of life lost because of ischemic heart disease and Filipino and Vietnamese have the highest years of life lost because of cerebrovascular disease. Analysis of risk factors and development of subgroup‐specific interventions are required to address these health disparities.

Overweight and obesity are at the root of many serious health problems such as type 2 diabetes, coronary heart diseases, high blood pressure, stroke, some types of cancer, osteoarthritis, sleep apnea, and infertility. This chapter focuses on type 2 diabetes, cardiovascular disease, and other weight related conditions. Early detection, treatment and self-management reduce the risk of developing complications, improve quality of life and health outcomes. However, there are many barriers that prevent patients and providers from preventing and appropriately treating type 2 diabetes and/or cardiovascular disease in South Asian Americans. Having a high percentage of foreign-born immigrants, lack of health insurance, and lack of access to culturally and linguistically appropriate resources and care, and lack of race/ethnic specific cut points for obesity perpetuate this health disparity. Systemic and policy changes are necessary to raise awareness, address quality of care and access to service, and prevent future cases of diabetes and cardiovascular disease in South Asian Americans.

We present a computational study, using density functional theory, of the role of internal and external donors in supported heterogeneous Ziegler−Natta polymerization catalyst systems. The focus of the investigation is the ability of the donors to stabilize the MgCl2 support through the zip mode of coordination. Phthalates and alkoxy benzoates have been considered as representative internal and external donors, respectively. Models for the α (ccp) and the β (hcp) phases of the (110) MgCl2 lateral cut have been considered. Studies were first done with a “Fully Fixed Model”, where the atoms in the MgCl2 lateral cuts were kept fixed. The studies indicated that the phthalate donors would preferentially stabilize the α phase of MgCl2, while the alkoxy benzoate donors would stabilize the β phase more, corroborating experimental results. A comparison of the zip coordination mode with other modes of coordination (mono, chelate, and bridge) indicates that it would be preferred over the mono and chelate coordinatio...

Prevotella intermedia binds and invades a variety of host cells. This binding is most probably mediated through cell surface proteins termed adhesins. To identify proteins binding to the host extracellular matrix (ECM) component, fibronectin, and study the molecular mechanism underlying bacterial colonization, we applied proteomic approaches to perform a global investigation of P. intermedia strain 17 outer membrane proteins. 2-DE followed by Far Western Blot analysis using fibronectin as a probe revealed a 29-kDa fibronectin-binding protein, designated here AdpB. The molecular identity of the protein was determined using PMF followed by a search of the P. intermedia 17 protein database. Database searches revealed the similarity of AdpB to multiple bacterial outer membrane proteins including the fibronectin-binding protein from Campylobacter jejuni. A recombinant AdpB protein bound fibronectin as well as other host ECM components, including fibrinogen and laminin, in a saturable, dose-dependent manner. Binding of AdpB to immobilized fibronectin was also inhibited by soluble fibronectin, laminin, and fibrinogen, indicating the binding was specific. Finally, immunoelectron microscopy with anti-AdpB demonstrated the cell surface location of the protein. This is the first cell surface protein with a broad-spectrum ECM-binding abilities identified and characterized in P. intermedia 17.

The oral bacterium Prevotella intermedia attaches to and invades gingival epithelial cells, fibroblasts, and endothelial cells. Several genes encoding proteins that mediate both the adhesion and invasion processes are carried on the genome of this bacterium. Here, we characterized one such protein, AdpC, belonging to the leucine-rich repeat (LRR) protein family. Bioinformatics analysis revealed that this protein shares similarity with the Treponema pallidum LRR (LRR TP ) family of proteins and contains six LRRs. Despite the absence of a signal peptide, this protein is localized on the bacterial outer membrane, indicating that it is transported through an atypical secretion mechanism. The recombinant form of this protein (rAdpC) was shown to bind fibrinogen. In addition, the heterologous host strain Escherichia coli BL21 expressing rAdpC (V2846) invaded fibroblast NIH 3T3 cells at a 40-fold-higher frequency than control E. coli BL21 cells expressing a sham P. intermedia 17 protein. Although similar results were obtained by using human umbilical vein endothelial cells (HUVECs), only a 3-fold-increased invasion of V2846 into oral epithelial HN4 cells was observed. Thus, AdpC-mediated invasion is cell specific. This work demonstrated that AdpC is an important invasin protein of P. intermedia 17.

Porphyromonas gingivalis,previously classified as a strict anaerobe, can grow in the presence of low concentrations of oxygen. Microarray analysis revealed alteration in gene expression in the presence of 6 % oxygen. During the exponential growth phase, 96 genes were upregulated and 79 genes were downregulated 1.4-fold. Genes encoding proteins that play a role in oxidative stress protection were upregulated, including alkyl hydroperoxide reductase (ahpCF), superoxide dismutase (sod) and thiol peroxidase (tpx). Significant changes in gene expression of proteins that mediate oxidative metabolism, such as cytochromedubiquinol oxidase-encoding genes,cydAandcydB, were detected. The expression of genes encoding formate uptake transporter (PG0209) and formate tetrahydrofolate ligase (fhs) was drastically elevated, which indicates that formate metabolism plays a major role under aerobic conditions. The concomitant reduction of expression of a gene encoding the lactate transporter PG1340 suggests decreased utilization of this nutrient. The concentrations of both formate and lactate were assessed in culture supernatants and cells, and they were in agreement with the results obtained at the transcriptional level. Also, genes encoding gingipain protease secretion/maturation regulator (porR) and protease transporter (porT) had reduced expression in the presence of oxygen, which also correlated with reduced protease activities under aerobic conditions. In addition, metal transport was affected, and while iron-uptake genes such as the genes encoding the haemin uptake locus (hmu) were downregulated, expression of manganese transporter genes, such asfeoB2, was elevated in the presence of oxygen. Finally, genes encoding putative regulatory proteins such as extracellular function (ECF) sigma factors as well as small proteins had elevated expression levels in the presence of oxygen. AsP. gingivalisis distantly related to the well-studied model organismEscherichia coli, results from our work may provide further understanding of oxygen metabolism and protection in other related bacteria belonging to the phylumBacteroidetes.

In the present study, early stage apoptosis is explored with high temporal resolution. In addition to monitoring early apoptosis induction in single cells by ultrasensitive confocal fluorescence microscopy (UCFM), the mitochondrial proteins release kinetics was explored. The current study shows development and optimization of a novel, rapid apoptosis assay to explore the earliest changes in cells by the intrinsic apoptosis pathway. We show that early apoptotic changes in the mitochondria begin nearly simultaneously with the addition of an apoptosis-inducing drug, such as staurosporine. With a temporal resolution of five minutes, this non-invasive analytical technique can elucidate the earliest apoptotic events in living cells. Moreover, our results show that the mitochondrial inter-membrane proteins are not involved in the extrinsic pathway of Ramos cells mediated by an anti-CD95 antibody. Additional techniques such as light microscopy and flow cytometry were employed to confirm the results obtained by ultrasensitive confocal fluorescence microscopy. The results of this study help to understand the earliest mechanisms of apoptosis induction in cells, enabling new methods of drug testing and dose-response analyses.