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1.
Ann Biomed Eng ; 52(2): 342-354, 2024 Feb.
Article in English | MEDLINE | ID: mdl-37906375

ABSTRACT

Increased ventilator use during the COVID-19 pandemic resurrected persistent questions regarding mechanical ventilation including the difference between physiological and artificial breathing induced by ventilators (i.e., positive- versus negative-pressure ventilation, PPV vs NPV). To address this controversy, we compare murine specimens subjected to PPV and NPV in ex vivo quasi-static loading and quantify pulmonary mechanics via measures of quasi-static and dynamic compliances, transpulmonary pressure, and energetics when varying inflation frequency and volume. Each investigated mechanical parameter yields instance(s) of significant variability between ventilation modes. Most notably, inflation compliance, percent relaxation, and peak pressure are found to be consistently dependent on the ventilation mode. Maximum inflation volume and frequency note varied dependencies contingent on the ventilation mode. Contradictory to limited previous clinical investigations of oxygenation and end-inspiratory measures, the mechanics-focused comprehensive findings presented here indicate lung properties are dependent on loading mode, and importantly, these dependencies differ between smaller versus larger mammalian species despite identical custom-designed PPV/NPV ventilator usage. Results indicate that past contradictory findings regarding ventilation mode comparisons in the field may be linked to the chosen animal model. Understanding the differing fundamental mechanics between PPV and NPV may provide insights for improving ventilation strategies and design to prevent associated lung injuries.


Subject(s)
Pandemics , Respiratory Mechanics , Humans , Mice , Animals , Respiratory Mechanics/physiology , Lung , Respiration, Artificial/methods , Respiration , Mammals
2.
Curr Oncol ; 25(6): 371-377, 2018 12.
Article in English | MEDLINE | ID: mdl-30607111

ABSTRACT

Background: Communities of practice (cops) have been shown to be effective models for achieving quality outcomes in health care. Objective: Here, we describe the application of the cop model to the Canadian oncology context. Methods: We established an oncology cop at our urban community hospital and its networks. Goals were to decrease barriers to access, foster collaboration, and improve knowledge of guidelines in cancer care. We hosted 6 in-person multidisciplinary meetings, focusing on screening, diagnosis, and management of common solid tumours. Health care providers affiliated with our hospital were invited to attend and to complete post-meeting surveys. Likert scales assessed whether cop goals were realized. Results: Meetings attracted a mean of 57 attendees (range: 48-65 attendees), with a mean of 84% completing the surveys and consenting to the analysis. Attendees included family physicians (mean: 41%), specialist physicians (mean: 24%), nurses (mean: 10%), and allied health care providers (mean: 22%). Repeat attendance increased during the series, with 85% of attendees at the final meeting having attended 1 or more prior meetings. Across the series, most participants agreed or strongly agreed that the cop reduced barriers (mean: 76.0% ± 7.9%) and improved access to cancer care services (mean: 82.4% ± 8.1%) and subject matter experts (mean: 91.7% ± 4.2%); fostered teamwork (mean: 84.5% ± 6.8%) and a culture of collaboration (mean: 94.8% ± 4.2%); improved knowledge of cancer care services (mean: 93.3% ± 4.8%), standards of practice (mean: 92.3% ± 3.1%), and quality indicators (mean: 77.5% ± 6.3%); and improved cancer-related practice (mean: 88.8% ± 4.6%) and satisfaction in caring for cancer patients (mean: 82.9% ± 6.8%). Participant feedback carried a potential for bias. Conclusions: We demonstrated the feasibility of oncology cops and found that participants perceived their value in reducing barriers to access, fostering collaboration, and improving knowledge of guidelines in cancer care.


Subject(s)
Community Health Services , Medical Oncology/statistics & numerical data , Quality Improvement , Canada , Community Health Services/methods , Community Health Services/standards , Health Personnel , Humans , Patient Care Management , Patient Care Planning
3.
Curr Oncol ; 25(6): 378-383, 2018 12.
Article in English | MEDLINE | ID: mdl-30607112

ABSTRACT

Background: A community of practice (cop) is formally defined as a group of people who share a concern or a passion for something they do and who learn how to do it better as they interact regularly. Communities of practice represent a promising approach for improving cancer care outcomes. However, little research is available to guide the development of oncology cops. In 2015, our urban community hospital launched an oncology cop, with the goals of decreasing barriers to access, fostering collaboration, and improving practitioner knowledge of guidelines and services in cancer care. Here, we share insights from a qualitative analysis of feedback from participants in our cop. The objective of the project was to identify participant perspectives about preferred cop features, with a view to improving the quality of our community hospital's oncology cop. Methods: After 5 in-person meetings of our oncology cop, participants were surveyed about what the cop should start, stop, and continue doing. Qualitative methods were used to analyze the feedback. Results: The survey collected 250 comments from 117 unique cop participants, including family physicians, specialist physicians, nurses, and allied health care practitioners. Analysis identified participant perspectives about the key features of the cop and avenues for improvement across four themes: supporting knowledge exchange, identifying and addressing practice gaps, enhancing interprofessional collaboration, and fostering a culture of partnership. Conclusions: Based on the results, we identified several considerations that could be helpful in improving our cop. Our findings might help guide the development of oncology cops at other institutions.


Subject(s)
Community Health Services , Medical Oncology , Aged , Community Health Services/methods , Community Health Services/standards , Cooperative Behavior , Health Care Surveys , Humans , Medical Oncology/methods , Middle Aged , Oncology Service, Hospital , Partnership Practice , Qualitative Research , Quality of Health Care
4.
Poult Sci ; 97(1): 279-288, 2018 Jan 01.
Article in English | MEDLINE | ID: mdl-29077916

ABSTRACT

Salmonella spp. is a foodborne pathogen that causes zoonotic disease worldwide. The aim of this study was to investigate the prevalence of antimicrobial resistance of Salmonella isolated from turkey farms in Taiwan. During the past 2 yr, 243 strains of Salmonella were isolated from 2,040 samples (11.9%) from turkey farms, including 32.5% (52/160) from the intestines of 12-day-old turkey poults, 14.2% (119/840) from feces collected from the turkey growing periods, and 6.9% (72/1,040) from finishing periods. S. Albany (35.0%, 85/243), S. Schwarzengrund (23.0%, 56/243), and S. Hadar (19.3%, 47/243) were the most common serovars on turkey farms. For these strains, a high frequency of resistance was observed against florfenicol (97.5%), oxytetracycline (89.3%), doxycycline (78.6%), colistin (77.8%), ampicillin (75.7%), amoxicillin (75.3%), trimethoprim-sulfamethoxazole (73.7%), chloramphenicol (69.1%), and nalidixic acid (67.9%). floR (63.8%), tet (A) (60.5%), blaPSE (57.6%), blaTEM (42.0%), blaCTX-M (34.2%), cmlA (34.2%), and tet (D) (29.2%) were the most common resistance genes found in this study. The int1 gene was identified in 72.4% (176/243) of Salmonella isolates in which the conserved region 3' of class 1 integrons also was amplified, whereas none had the int2 gene. This study demonstrates that imported and fattening turkeys could be a reservoir for Salmonella isolates resistant to multiple antimicrobials. These results also reinforce the need to develop strategies and implement specific control procedures to reduce the development of antimicrobial resistance.


Subject(s)
Drug Resistance, Multiple, Bacterial , Poultry Diseases/epidemiology , Salmonella Infections, Animal/epidemiology , Salmonella/drug effects , Salmonella/physiology , Animals , Anti-Bacterial Agents/pharmacology , Poultry Diseases/microbiology , Prevalence , Salmonella Infections, Animal/microbiology , Serogroup , Taiwan/epidemiology , Turkeys
5.
Am J Transplant ; 17(5): 1193-1203, 2017 May.
Article in English | MEDLINE | ID: mdl-27888551

ABSTRACT

Costimulation blockade (CoB) via belatacept is a lower-morbidity alternative to calcineurin inhibitor (CNI)-based immunosuppression. However, it has higher rates of early acute rejection. These early rejections are mediated in part by memory T cells, which have reduced dependence on the pathway targeted by belatacept and increased adhesion molecule expression. One such molecule is leukocyte function antigen (LFA)-1. LFA-1 exists in two forms: a commonly expressed, low-affinity form and a transient, high-affinity form, expressed only during activation. We have shown that antibodies reactive with LFA-1 regardless of its configuration are effective in eliminating memory T cells but at the cost of impaired protective immunity. Here we test two novel agents, leukotoxin A and AL-579, each of which targets the high-affinity form of LFA-1, to determine whether this more precise targeting prevents belatacept-resistant rejection. Despite evidence of ex vivo and in vivo ligand-specific activity, neither agent when combined with belatacept proved superior to belatacept monotherapy. Leukotoxin A approached a ceiling of toxicity before efficacy, while AL-579 failed to significantly alter the peripheral immune response. These data, and prior studies, suggest that LFA-1 blockade may not be a suitable adjuvant agent for CoB-resistant rejection.


Subject(s)
Abatacept/pharmacology , Graft Rejection/drug therapy , Graft Survival/immunology , Immunologic Memory/immunology , Kidney Transplantation/adverse effects , Lymphocyte Function-Associated Antigen-1/chemistry , T-Lymphocytes/immunology , Animals , Disease Models, Animal , Glomerular Filtration Rate , Graft Rejection/etiology , Graft Rejection/pathology , Graft Survival/drug effects , Immunologic Memory/drug effects , Immunosuppressive Agents/pharmacology , Kidney Function Tests , Lymphocyte Function-Associated Antigen-1/metabolism , Macaca mulatta , Postoperative Complications , T-Lymphocytes/drug effects , T-Lymphocytes/pathology
6.
Am J Transplant ; 16(5): 1456-64, 2016 05.
Article in English | MEDLINE | ID: mdl-26602755

ABSTRACT

Costimulation blockade with the fusion protein belatacept provides a desirable side effect profile and improvement in renal function compared with calcineurin inhibition in renal transplantation. This comes at the cost of increased rates of early acute rejection. Blockade of the integrin molecule leukocyte function-associated antigen 1 (LFA-1) has been shown to be an effective adjuvant to costimulation blockade in a rigorous nonhuman primate (NHP) model of islet transplantation; therefore, we sought to test this combination in an NHP renal transplant model. Rhesus macaques received belatacept maintenance therapy with or without the addition of LFA-1 blockade, which was achieved using a murine-derived LFA-1-specific antibody TS1/22. Additional experiments were performed using chimeric rhesus IgG1 (TS1/22R1) or IgG4 (TS1/22R4) variants, each engineered to limit antibody clearance. Despite evidence of proper binding to the target molecule and impaired cellular egress from the intravascular space indicative of a therapeutic effect similar to prior islet studies, LFA-1 blockade failed to significantly prolong graft survival. Furthermore, evidence of impaired protective immunity against cytomegalovirus was observed. These data highlight the difficulties in translating treatment regimens between organ models and suggest that the primarily vascularized renal model is more robust with regard to belatacept-resistant rejection than the islet model.


Subject(s)
Abatacept/therapeutic use , Disease Models, Animal , Graft Rejection/prevention & control , Graft Survival/immunology , Kidney Failure, Chronic/immunology , Kidney Transplantation/adverse effects , Lymphocyte Function-Associated Antigen-1/immunology , Animals , Glomerular Filtration Rate , Graft Rejection/etiology , Graft Rejection/pathology , Immunologic Memory , Kidney Failure, Chronic/surgery , Kidney Function Tests , Lymphocyte Function-Associated Antigen-1/administration & dosage , Macaca mulatta , Transplantation, Homologous
7.
Science ; 350(6261): aad0313, 2015 Nov 06.
Article in English | MEDLINE | ID: mdl-26542577

ABSTRACT

Planetary auroras reveal the complex interplay between an atmosphere and the surrounding plasma environment. We report the discovery of low-altitude, diffuse auroras spanning much of Mars' northern hemisphere, coincident with a solar energetic particle outburst. The Imaging Ultraviolet Spectrograph, a remote sensing instrument on the Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft, detected auroral emission in virtually all nightside observations for ~5 days, spanning nearly all geographic longitudes. Emission extended down to ~60 kilometer (km) altitude (1 microbar), deeper than confirmed at any other planet. Solar energetic particles were observed up to 200 kilo--electron volts; these particles are capable of penetrating down to the 60 km altitude. Given minimal magnetic fields over most of the planet, Mars is likely to exhibit auroras more globally than Earth.

8.
Cell Death Differ ; 22(12): 1922-34, 2015 Dec.
Article in English | MEDLINE | ID: mdl-25952549

ABSTRACT

The Ufm1 conjugation system is a novel ubiquitin-like modification system, consisting of Ufm1, Uba5 (E1), Ufc1 (E2) and poorly characterized E3 ligase(s). RCAD/Ufl1 (also known as KIAA0776, NLBP and Maxer) was reported to function as a Ufm1 E3 ligase in ufmylation (Ufm1-mediated conjugation) of DDRGK1 and ASC1 proteins. It has also been implicated in estrogen receptor signaling, unfolded protein response (UPR) and neurodegeneration, yet its physiological function remains completely unknown. In this study, we report that RCAD/Ufl1 is essential for embryonic development, hematopoietic stem cell (HSC) survival and erythroid differentiation. Both germ-line and somatic deletion of RCAD/Ufl1 impaired hematopoietic development, resulting in severe anemia, cytopenia and ultimately animal death. Depletion of RCAD/Ufl1 caused elevated endoplasmic reticulum stress and evoked UPR in bone marrow cells. In addition, loss of RCAD/Ufl1 blocked autophagic degradation, increased mitochondrial mass and reactive oxygen species, and led to DNA damage response, p53 activation and enhanced cell death of HSCs. Collectively, our study provides the first genetic evidence for the indispensable role of RCAD/Ufl1 in murine hematopoiesis and development. The finding of RCAD/Ufl1 as a key regulator of cellular stress response sheds a light into the role of a novel protein network including RCAD/Ufl1 and its associated proteins in regulating cellular homeostasis.


Subject(s)
Hematopoiesis , Ubiquitin-Protein Ligases/metabolism , Anemia/etiology , Animals , Autophagy , Bone Marrow Cells/cytology , Bone Marrow Cells/metabolism , Cells, Cultured , Endoplasmic Reticulum Stress , HEK293 Cells , Hematopoietic Stem Cells/cytology , Hematopoietic Stem Cells/metabolism , Humans , Mice , Mice, Inbred C57BL , Mice, Knockout , Microtubule-Associated Proteins/genetics , Microtubule-Associated Proteins/metabolism , Mitochondria/metabolism , Mouse Embryonic Stem Cells/cytology , Mouse Embryonic Stem Cells/metabolism , RNA Interference , Reactive Oxygen Species/metabolism , Tumor Suppressor Protein p53/metabolism , Ubiquitin-Protein Ligases/deficiency , Ubiquitin-Protein Ligases/genetics , Unfolded Protein Response
9.
Am J Transplant ; 15(4): 984-92, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25703015

ABSTRACT

Costimulation blockade with the B7-CD28 pathway-specific agent belatacept is now used in clinical kidney transplantation, but its efficacy remains imperfect. Numerous alternate costimulatory pathways have been proposed as targets to synergize with belatacept, one of which being the inducible costimulator (ICOS)-ICOS ligand (ICOS-L) pathway. Combined ICOS-ICOS-L and CD28-B7 blockade has been shown to prevent rejection in mice, but has not been studied in primates. We therefore tested a novel ICOS-Ig human Fc-fusion protein in a nonhuman primate (NHP) kidney transplant model alone and in combination with belatacept. ICOS-Ig did not prolong rejection-free survival as a monotherapy or in combination with belatacept. In ICOS-Ig alone treated animals, most graft-infiltrating CD4(+) and CD8(+) T cells expressed ICOS, and ICOS(+) T cells were present in peripheral blood to a lesser degree. Adding belatacept reduced the proportion of graft-infiltrating ICOS(+) T cells and virtually eliminated their presence in peripheral blood. Graft-infiltrating T cells in belatacept-resistant rejection were primarily CD8(+) CD28(-) , but importantly, very few CD8(+) CD28(-) T cells expressed ICOS. We conclude that ICOS-Ig, alone or combined with belatacept, does not prolong renal allograft survival in NHPs. This may relate to selective loss of ICOS with CD28 loss.


Subject(s)
Inducible T-Cell Co-Stimulator Protein/metabolism , Kidney Transplantation , Abatacept/therapeutic use , Animals , Graft Rejection/prevention & control , Immunologic Memory , Immunophenotyping , Macaca mulatta , Pilot Projects , T-Lymphocytes/immunology
10.
Oncogene ; 34(13): 1688-97, 2015 Mar 26.
Article in English | MEDLINE | ID: mdl-24769896

ABSTRACT

Upregulated expression of nucleolar GTPase nucleostemin (NS) has been associated with increased cellular proliferation potential and tumor malignancy during cancer development. Recent reports attribute the growth regulatory effects of NS protein to its role in facilitating ribosome production. However, the oncogenic potential of NS remains unclear, as imbalanced levels of NS have been reported to exert growth inhibitory effect by modulating p53 tumor-suppressor activity. It also remains in questions if aberrant NS levels might have a p53-independent role in regulation of cell proliferation and growth. In this study, we performed affinity purification and mass spectrometry analysis to explore protein-protein interactions influencing NS growth regulatory properties independently of p53 tumor suppressor. We identified the alternative reading frame (ARF) protein as a key protein associating with NS and further verified the interaction through in vitro and in vivo assays. We demonstrated that NS is able to regulate cell cycle progression by regulating the stability of the ARF tumor suppressor. Furthermore, overexpression of NS suppressed ARF polyubiquitination by its E3 ligase Ubiquitin Ligase for ARF and elongated its half-life, whereas knockdown of NS led to the decrease of ARF levels. Also, we found that NS can enhance NPM stabilization of ARF. Thus, we propose that in the absence of p53, ARF can be stabilized by NS and nucleophosmin to serve as an alternative tumor-suppressor surveillance, preventing potential cellular transformation resulting from the growth-inducing effects of NS overexpression.


Subject(s)
Carrier Proteins/antagonists & inhibitors , GTP-Binding Proteins/physiology , Nuclear Proteins/physiology , Tumor Suppressor Protein p14ARF/physiology , Ubiquitin-Protein Ligases/antagonists & inhibitors , Cell Line, Tumor , G1 Phase Cell Cycle Checkpoints , GTP-Binding Proteins/chemistry , Humans , Nuclear Proteins/chemistry , Protein Stability , Protein Structure, Tertiary , Proto-Oncogene Proteins c-mdm2/physiology , Tumor Suppressor Protein p14ARF/chemistry , Tumor Suppressor Protein p53/physiology
11.
Am J Transplant ; 14(11): 2460-6, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25323029

ABSTRACT

CD28 is a primary costimulation molecule for T cell activation. However, during the course of activation some T cells lose this molecule and assume a CD28-independent existence. These CD28- T cells are generally antigen-experienced and highly differentiated. CD28- T cells are functionally heterogeneous. Their characteristics vary largely on the context in which they are found and range from having enhanced cytotoxic abilities to promoting immune regulation. Thus, CD28 loss appears to be more of a marker for advanced differentiation regardless of the cytotoxic or regulatory function being conducted by the T cell. CD28- T cells are now being recognized as playing significant roles in several human diseases. Various functional CD28- populations have been characterized in inflammatory conditions, infections and cancers. Of note, the recent introduction of costimulation blockade-based therapies, particularly those that inhibit CD28-B7 interactions, has made CD28 loss particularly relevant for solid organ transplantation. Certain CD28- T cell populations seem to promote allograft tolerance whereas others contribute to alloreactivity and costimulation blockade resistant rejection. Elucidating the interplay between these populations and characterizing the determinants of their ultimate function may have relevance for clinical risk stratification and personal determination of optimal posttransplant immune management.


Subject(s)
CD28 Antigens/immunology , T-Lymphocytes/immunology , Humans
12.
Vet Rec ; 175(8): 203, 2014 Aug 30.
Article in English | MEDLINE | ID: mdl-24958553

ABSTRACT

Edwardsiellosis is one of the most important bacterial diseases in eels. Edwardsiella tarda (E. tarda) isolates (n=94) from diseased eels were screened against the eight most commonly used antimicrobial agents in aquaculture in Taiwan. These isolates were highly susceptible to ampicillin, amoxicillin, florfenicol, oxolinic acid and flumequine. In total, 20 of the 94 (21.3 per cent) isolates tested were resistant to oxytetracycline (OTC). Among the 20 tetracycline-resistant E. tarda isolates, tet(A) was the predominant resistance determinant and was detected in 100 per cent of the isolates, whereas 90 per cent of these isolates carried the tet(M) determinant. The efflux pump inhibitor omeprazole reduced the minimum inhibitory concentrations (MICs) of OTC for these isolates by twofold to eightfold, suggesting that an intact efflux pump, presumably encoded by tet(A), is required for high-level tetracycline resistance. Real-time PCR experiments showed that increased expression levels of tet(A) and tet(R) could contribute to OTC resistance. Southern blot hybridisation also confirmed that the 20 OTC-resistant E. tarda isolates all carried the TetA determinant on a plasmid that is approximately 50 or 70 kb in size, and restriction fragment length polymorphisms (RFLP) showed that the tet(A) gene was located on an 8-10 kb EcoRI fragment in all of these plasmids. The same plasmid type and RFLP patterns were detected across different farms in the same region, but differences in their pulsed-field gel electrophoresis (PFGE) patterns were observed. This suggests a possible role for horizontal spreading and local transmission of the plasmid in the OTC-resistant E. tarda population of eels from two different geographic origins.


Subject(s)
Edwardsiella tarda/drug effects , Edwardsiella tarda/isolation & purification , Eels , Enterobacteriaceae Infections/veterinary , Fish Diseases/microbiology , Oxytetracycline/pharmacology , Tetracycline Resistance/genetics , Animals , Enterobacteriaceae Infections/microbiology , Taiwan
13.
J Anim Physiol Anim Nutr (Berl) ; 98(4): 739-46, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24164218

ABSTRACT

Succinate dehydrogenase (SDH), Ca(2+) ATPase, Lactate dehydrogenase (LDH), are involved in energy metabolism. These enzymes can be used as indicators of the energy capacity of aerobic cells. The study investigated the effects of L-carnitine supplementation on M. pectoralis superficialis, M. pectoralis profundus, M. extensor carpi radialis muscle and M. flexor carpi ulnaris. Twenty-eight racing pigeons hatched at the same time were divided randomly into three groups. Eight pigeons, which were used as the control group, were sacrificed at 92-day old. The remaining twenty pigeons continued training until they reached 157-day old, with half the pigeons getting 25 mg/head/day of L-carnitine, while the other half given the same amount of water. The pigeons were assessed by histochemical methods and reverse transcription polymerase chain reaction (RT-PCR). To assess influence of L-carnitine on muscle fibre composition and the performance of three genes' mRNA, this study applied SDH localization, SDH, Ca(2+) ATPase and LDH mRNA expression to examine the results after oral administration of L-carnitine in vivo in racing pigeons. The results showed that L-carnitine significantly elevated the amount of white muscle fibre type IIa (p < 0.05). The mRNA expression quantities of SDH and LDH gene was higher via RT-PCR method. However, the expression of Ca(2+) ATPase remains similar. In conclusion, appropriate oral administration of L-carnitine of 25 mg/pigeon/day will result in an improvement of muscles related to flying.


Subject(s)
Carnitine/pharmacology , Columbidae/physiology , Muscle Fibers, Skeletal/drug effects , Aging/physiology , Animals , Gene Expression Regulation/drug effects , Gene Expression Regulation/physiology , Muscle Fibers, Skeletal/physiology , Muscle Proteins/genetics , Muscle Proteins/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolism
14.
Am J Transplant ; 13(12): 3085-93, 2013 Dec.
Article in English | MEDLINE | ID: mdl-24119188

ABSTRACT

The integrin αvß6 activates latent transforming growth factor-ß (TGF-ß) within the kidney and may be a target for the prevention of chronic allograft fibrosis after kidney transplantation. However, TGF-ß also has known immunosuppressive properties that are exploited by calcineurin inhibitors (CNIs); thus, the net benefit of αvß6 inhibition remains undetermined. To assess the acute impact of interference with αvß6 on acute rejection, we tested a humanized αvß6-specific monoclonal antibody (STX-100) in a randomized, double-blinded, placebo-controlled nonhuman primate renal transplantation study to evaluate whether αvß6 blockade alters the risk of acute rejection during CNI-based immunosuppression. Rhesus monkeys underwent renal allotransplantation under standard CNI-based maintenance immunosuppression; 10 biopsy-confirmed rejection-free animals were randomized to receive weekly STX-100 or placebo. Animals treated with STX-100 experienced significantly decreased rejection-free survival compared to placebo animals (p = 0.049). Immunohistochemical analysis confirmed αvß6 ligand presence, and αvß6 staining intensity was lower in STX-100-treated animals (p = 0.055), indicating an apparent blockade effect of STX-100. LAP, LTBP-1 and TGF-ß were all decreased in animals that rejected on STX-100 compared to those that rejected on standard immunosuppression alone, suggesting a relevant effect of αvß6 blockade on local TGF-ß. These data caution against the use of αvß6 blockade to achieve TGF-ß inhibition in kidney transplantation.


Subject(s)
Antibodies, Monoclonal/adverse effects , Immunosuppressive Agents/adverse effects , Integrins/antagonists & inhibitors , Kidney Transplantation/methods , Allografts , Animals , Antibodies, Monoclonal/chemistry , Antigens, Neoplasm , Biopsy , Graft Rejection , Immunosuppression Therapy , Macaca mulatta , Pilot Projects , Random Allocation , Transforming Growth Factor beta1/blood
15.
Biotechnol Bioeng ; 110(10): 2742-8, 2013 Oct.
Article in English | MEDLINE | ID: mdl-23613195

ABSTRACT

Recently, Rajapaksa et al. (2010) showed that the rate of uptake of potential vaccine delivery nanoparticles in the mucosal layer is a function of the electrostatic properties of the corresponding solvent. This fundamentally implies that the dominant driving forces that may be capitalized on for mucosal vaccine strategies are electrostatic in nature. We hypothesize that the driving force normal to the cell (in the direction from apical to basolateral across the cell) is of particular importance. In addition, it has been theoretically shown that the electrostatic properties of mucosal cells are directly related to their development of brush border. Here we correlate the development of brush border on a human mucosal epithelial model (Caco-2) cultured in DMEM on 3.0 µm pore sized polycarbonate membranes to their corresponding electrostatic properties characterized by measuring their normal zeta potential. Properties of normal streaming potential, hydraulic permeability, and brush border development (as determined by size and number) were monitored for 2, 6, and 16 days (after cells were confluent). Human endothelial cells (HECs), which lack brush border, were used as the control. Our results demonstrate that normal zeta potential of Caco-2 cells significantly changed from -5.7 ± 0.11 mV to -3.4 ± 0.11 mV for a period between 2 and 16 days, respectively. The zeta potential of the control cell line, HECs, stayed constant (statistically not different, P > 0.05) for the duration of the experiments. Our results show that the calculated increase in surface area of the Caco-2 cells with microvilli from 6 to 16 days was directly proportional to the corresponding measured zeta potential difference. These results imply that microvilli alter the electrostatic local environment around Caco-2 cells and, hence, enhance the normal electrostatic selective transport of solute across the mucosal barrier.


Subject(s)
Microvilli/physiology , Static Electricity , Transcytosis/physiology , Caco-2 Cells , Cell Culture Techniques , Humans , Membranes, Artificial , Microscopy, Electron, Transmission , Tight Junctions/physiology
16.
Am J Transplant ; 13(2): 320-8, 2013 Feb.
Article in English | MEDLINE | ID: mdl-23311611

ABSTRACT

Belatacept is an inhibitor of CD28/B7 costimulation that is clinically indicated as a calcineurin inhibitor (CNI) alternative in combination with mycophenolate mofetil and steroids after renal transplantation. We sought to develop a clinically translatable, nonlymphocyte depleting, belatacept-based regimen that could obviate the need for both CNIs and steroids. Thus, based on murine data showing synergy between costimulation blockade and mTOR inhibition, we studied rhesus monkeys undergoing MHC-mismatched renal allotransplants treated with belatacept and the mTOR inhibitor, sirolimus. To extend prior work on costimulation blockade-resistant rejection, some animals also received CD2 blockade with alefacept (LFA3-Ig). Belatacept and sirolimus therapy successfully prevented rejection in all animals. Tolerance was not induced, as animals rejected after withdrawal of therapy. The regimen did not deplete T cells. Alefecept did not add a survival benefit to the optimized belatacept and sirolimus regimen, despite causing an intended depletion of memory T cells, and caused a marked reduction in regulatory T cells. Furthermore, alefacept-treated animals had a significantly increased incidence of CMV reactivation, suggesting that this combination overly compromised protective immunity. These data support belatacept and sirolimus as a clinically translatable, nondepleting, CNI-free, steroid-sparing immunomodulatory regimen that promotes sustained rejection-free allograft survival after renal transplantation.


Subject(s)
Immunoconjugates/administration & dosage , Immunosuppressive Agents/therapeutic use , Kidney Transplantation/methods , Sirolimus/administration & dosage , T-Lymphocytes/immunology , Abatacept , Animals , CD2 Antigens/metabolism , CD3 Complex/metabolism , Disease Progression , Disease-Free Survival , Graft Rejection , Graft Survival , Immunologic Memory , Macaca mulatta , Phenotype , T-Lymphocytes, Regulatory/immunology , Transplantation, Homologous , Treatment Outcome
17.
Rev Sci Instrum ; 83(7): 074302, 2012 Jul.
Article in English | MEDLINE | ID: mdl-22852705

ABSTRACT

The characteristics of transport across confluent cell monolayers may often be attributed to its electrostatic properties. While tangential streaming potential is often used to quantify these electrostatic properties, this method is not effective for transport normal to the apical cell surface where the charge properties along the basolateral sides may be important (i.e., confluent cells with leaky tight junctions). In addition, even when cells have a uniform charge distribution, the shear stress generated by the conventional tangential flow device may dislodge cells from their confluent state. Here we introduce a novel streaming potential measurement device to characterize the normal electrostatic properties of confluent cells. The streaming potential device encompasses a 24 mm cell-seeded Transwell(®) with two AgCl electrodes on either side of the cell-seeded Transwell. Phosphate buffered saline is pressurized transversal to the Transwell and the resultant pressure gradient induces a potential difference. Confluent monolayers of HEK and EA926 cells are used as examples. The corresponding zeta potential of the cell-membrane configuration is calculated using the Helmholtz-Smoluchowski equation and the zeta potential of the confluent cell layer is deconvolved from the overall measurements. For these test models, the zeta potential is consistent with that determined using a commercial dispersed-cell device. This novel streaming potential device provides a simple, easy, and cost-effective methodology to determine the normal zeta potential of confluent cells cultured on Transwell systems while keeping the cells intact. Furthermore, its versatility allows periodic measurements of properties of the same cell culture during transient studies.


Subject(s)
Cell Culture Techniques/instrumentation , Cell Membrane/physiology , Conductometry/instrumentation , Flow Cytometry/instrumentation , Membrane Potentials/physiology , Specimen Handling/instrumentation , Equipment Design , Equipment Failure Analysis , HEK293 Cells , Humans , Static Electricity
18.
AJNR Am J Neuroradiol ; 33(1): 57-60, 2012 Jan.
Article in English | MEDLINE | ID: mdl-21998103

ABSTRACT

BACKGROUND AND PURPOSE: Many authors have reported the increase in vertebral body height after vertebroplasty. However, McKiernan et al demonstrated dynamic mobility in patients who underwent vertebroplasty and concluded that any article that claims vertebral height restoration must control for the dynamic mobility of fractured vertebrae. The purpose of this study was to compare prevertebroplasty (supine cross-table with a bolster beneath) with postvertebroplasty vertebral body height to find out whether vertebroplasty itself really increases the vertebral height. MATERIALS AND METHODS: From July 2005 to July 2010, 102 consecutive patients with 132 VCFs underwent vertebroplasty at our institution. The indications for vertebroplasty were severe pain that was not responsive to medical treatment, and MR imaging-confirmed edematous lesions. Prevertebroplasty (supine cross-table with bolster beneath) lateral radiographs were compared with postvertebroplasty radiographs to evaluate the height change in vertebroplasty. Kyphotic angle and anterior vertebral body height were measured. RESULTS: The patients ranged in age from 62 to 90 years. There were 16 men and 86 women. The difference in the kyphotic angle between supine cross-table with bolster and postvertebroplasty was -0.49 ± 3.59° (range, -9°-16°), which was not statistically significant (P = 0.124). The difference in the anterior vertebral body height between supine cross-table with bolster and postvertebroplasty was 0.84 ± 3.01 mm (range, -7.91-8.81 mm), which was statistically significant (P = .002). CONCLUSIONS: The restoration of vertebral body height in vertebroplasty seems to be mostly due to the dynamic mobility of fractured vertebrae; vertebroplasty itself does not contribute much to the restoration of vertebral height.


Subject(s)
Artifacts , Movement , Vertebroplasty , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Reproducibility of Results , Sensitivity and Specificity , Treatment Outcome
19.
AJNR Am J Neuroradiol ; 32(1): 121-4, 2011 Jan.
Article in English | MEDLINE | ID: mdl-20930002

ABSTRACT

BACKGROUND AND PURPOSE: Many authors have reported the increase in vertebral body height after vertebroplasty; if the fractured vertebrae are mobile, we should be able to demonstrate their mobility in radiographs. The purpose of this study was to discover the diagnostic value of dynamic radiographs and the percentage of mobile vertebrae in painful VCFs. MATERIALS AND METHODS: From September 2005 to September 2008, 105 patients underwent surgery to treat 144 painful osteoporotic VCFs. The indications for surgery were severe pain and MR imaging-confirmed active edematous lesions. Preoperative sitting lateral radiographs of the fractured vertebrae were compared with supine cross-table (with a bolster beneath) lateral radiographs to determine the presence or absence of dynamic mobility. Kyphotic angle and anterior vertebral body height were measured. RESULTS: The patients' ages ranged from 62 to 90 years. There were 19 men and 86 women. The total number of mobile VCFs was 126 (87.5%). One hundred four (99%) patients had at least 1 mobile VCF. The average anterior vertebral height in sitting lateral radiographs was 13.53 ± 6.80 mm and increased to 22.01 ± 6.13 mm in supine cross-table with bolster lateral radiographs. The average vertebral body height increase was 8.48 ± 5.36 mm. CONCLUSIONS: Dynamic (sitting and supine with bolster) radiographs can be valuable in diagnosing painful vertebrae in VCFs. The sensitivity was 0.88 in this study.


Subject(s)
Fractures, Compression/complications , Fractures, Compression/diagnostic imaging , Osteoporotic Fractures/complications , Osteoporotic Fractures/diagnostic imaging , Pain/etiology , Spinal Fractures/complications , Spinal Fractures/diagnostic imaging , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Pain/diagnosis , Radiography , Reproducibility of Results , Sensitivity and Specificity
20.
Am J Transplant ; 11(1): 22-33, 2011 Jan.
Article in English | MEDLINE | ID: mdl-21070604

ABSTRACT

Costimulation blockade (CoB), specifically CD28/B7 inhibition with belatacept, is an emerging clinical replacement for calcineurin inhibitor-based immunosuppression in allotransplantation. However, there is accumulating evidence that belatacept incompletely controls alloreactive T cells that lose CD28 expression during terminal differentiation. We have recently shown that the CD2-specific fusion protein alefacept controls costimulation blockade-resistant allograft rejection in nonhuman primates. Here, we have investigated the relationship between human alloreactive T cells, costimulation blockade sensitivity and CD2 expression to determine whether these findings warrant potential clinical translation. Using polychromatic flow cytometry, we found that CD8(+) effector memory T cells are distinctly high CD2 and low CD28 expressors. Alloresponsive CD8(+) CD2(hi) CD28(-) T cells contained the highest proportion of cells with polyfunctional cytokine (IFNγ, TNF and IL-2) and cytotoxic effector molecule (CD107a and granzyme B) expression capability. Treatment with belatacept in vitro incompletely attenuated allospecific proliferation, but alefacept inhibited belatacept-resistant proliferation. These results suggest that highly alloreactive effector T cells exert their late stage functions without reliance on ongoing CD28/B7 costimulation. Their high CD2 expression increases their susceptibility to alefacept. These studies combined with in vivo nonhuman primate data provide a rationale for translation of an immunosuppression regimen pairing alefacept and belatacept to human renal transplantation.


Subject(s)
Immunoconjugates/pharmacology , Abatacept , Alefacept , CD2 Antigens/biosynthesis , CD28 Antigens/immunology , CD8-Positive T-Lymphocytes/immunology , Cytokines , Humans , Immunologic Memory/immunology , Immunosuppression Therapy/methods , Kidney Transplantation/methods , Leukocytes, Mononuclear/immunology , Recombinant Fusion Proteins/pharmacology , T-Lymphocytes/immunology
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