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1.
Nat Commun ; 14(1): 7427, 2023 11 16.
Article in English | MEDLINE | ID: mdl-37973991

ABSTRACT

As one of the most successful human pathogens, Mycobacterium tuberculosis (Mtb) has evolved a diverse array of determinants to subvert host immunity and alter host metabolic patterns. However, the mechanisms of pathogen interference with host metabolism remain poorly understood. Here we show that a glutamine metabolism antagonist, JHU083, inhibits Mtb proliferation in vitro and in vivo. JHU083-treated mice exhibit weight gain, improved survival, a 2.5 log lower lung bacillary burden at 35 days post-infection, and reduced lung pathology. JHU083 treatment also initiates earlier T-cell recruitment, increased proinflammatory myeloid cell infiltration, and a reduced frequency of immunosuppressive myeloid cells when compared to uninfected and rifampin-treated controls. Metabolomic analysis of lungs from JHU083-treated Mtb-infected mice reveals citrulline accumulation, suggesting elevated nitric oxide (NO) synthesis, and lowered levels of quinolinic acid which is derived from the immunosuppressive metabolite kynurenine. JHU083-treated macrophages also produce more NO potentiating their antibacterial activity. When tested in an immunocompromised mouse model of Mtb infection, JHU083 loses its therapeutic efficacy suggesting the drug's host-directed effects are likely to be predominant. Collectively, these data reveal that JHU083-mediated glutamine metabolism inhibition results in dual antibacterial and host-directed activity against tuberculosis.


Subject(s)
Mycobacterium tuberculosis , Tuberculosis , Mice , Humans , Animals , Glutamine/pharmacology , Tuberculosis/microbiology , Anti-Bacterial Agents/pharmacology
2.
bioRxiv ; 2023 Feb 23.
Article in English | MEDLINE | ID: mdl-36865287

ABSTRACT

As one of the most successful human pathogens, Mycobacterium tuberculosis (Mtb) has evolved a diverse array of determinants to subvert host immunity and alter host metabolic patterns. However, the mechanisms of pathogen interference with host metabolism remain poorly understood. Here we show that a novel glutamine metabolism antagonist, JHU083, inhibits Mtb proliferation in vitro and in vivo. JHU083-treated mice exhibit weight gain, improved survival, a 2.5 log lower lung bacillary burden at 35 days post-infection, and reduced lung pathology. JHU083 treatment also initiates earlier T-cell recruitment, increased proinflammatory myeloid cell infiltration, and a reduced frequency of immunosuppressive myeloid cells when compared to uninfected and rifampin-treated controls. Metabolomics analysis of lungs from JHU083-treated Mtb-infected mice revealed reduced glutamine levels, citrulline accumulation suggesting elevated NOS activity, and lowered levels of quinolinic acid which is derived from the immunosuppressive metabolite kynurenine. When tested in an immunocompromised mouse model of Mtb infection, JHU083 lost its therapeutic efficacy suggesting the drug's host-directed effects are likely to be predominant. Collectively, these data reveal that JHU083-mediated glutamine metabolism inhibition results in dual antibacterial and host-directed activity against tuberculosis.

3.
Acta Biomater ; 151: 134-147, 2022 10 01.
Article in English | MEDLINE | ID: mdl-35933100

ABSTRACT

Thrombogenicity poses a challenge to the clinical translation of engineered grafts. Previously, small-diameter vascular grafts (sdVG) composed of fibrin hydrogel microfiber tubes (FMT) with an external poly(ε-caprolactone) (PCL) sheath supported long-term patency in mice. Towards the development of an sdVG with off-the-shelf availability, the FMT's shelf stability, scale-up, and successful conjugation of an antithrombotic drug to the fibrin scaffold are reported here. FMTs maintain mechanical stability and high-water retention after storage for one year in a freezer, in a refrigerator, or at room temperature. Low molecular weight heparin-conjugated fibrin scaffolds enabled local and sustained delivery during two weeks of enzymatic degradation. Upscaled fabrication of sdVGs provides natural biodegradable grafts with size and mechanics suitable for human application. Implantation in a carotid artery interposition porcine model exhibited no rupture with thrombi prevented in all heparinized sdVGs (n = 4) over 4-5 weeks. Remodeling of the sdVGs is demonstrated with endothelial cells on the luminal surface and initial formation of the medial layer by 4-5 weeks. However, neointimal hyperplasia at 4-5 weeks led to the stenosis and occlusion of most of the sdVGs, which must be resolved for future long-term in vivo assessments. The off-the-shelf, biodegradable heparinized fibrin sdVG layer limits acute thrombogenicity while mediating extensive neotissue formation as the PCL sheath maintains structural integrity. STATEMENT OF SIGNIFICANCE: To achieve clinical and commercial utility of small-diameter vascular grafts as arterial conduits, these devices must have off-the-shelf availability for emergency arterial bypass applications and be scaled to a size suitable for human applications. A serious impediment to clinical translation is thrombogenicity. Treatments have focused on long-term systemic drug therapy, which increases the patient's risk of bleeding complications, or coating grafts and stents with anti-coagulants, which minimally improves patient outcomes even when combined with dual anti-platelet therapy. We systematically modified the biomaterial properties to develop anticoagulant embedded, biodegradable grafts that maintain off-the-shelf availability, provide mechanical stability, and prevent clot formation through local drug delivery.


Subject(s)
Endothelial Cells , Fibrinolytic Agents , Animals , Anticoagulants , Biocompatible Materials/chemistry , Blood Vessel Prosthesis , Carotid Arteries/surgery , Fibrin/pharmacology , Heparin, Low-Molecular-Weight , Humans , Hydrogels , Mice , Swine , Water
4.
Ecosphere ; 13(8)2022 Aug.
Article in English | MEDLINE | ID: mdl-36590709

ABSTRACT

Living organisms are vulnerable to thermal stress which causes a diversity of physiological outcomes. Previous work has shown that the snail vectors (Biomphalaria glabrata) of an important human pathogen, Schistosoma mansoni, revert from resistant to susceptible after short exposure to a heat stress as low as 31oC; however, due to lack of replicability among labs and genetic lines of snails, it has been hypothesized that this effect is genotype dependent. We examined the effects of heat shock on resistance of two species of snail vectors including B. glabrata and B. sudanica. We used 3 different inbred laboratory snail lines in addition to the F1 generation of field collected snails from Lake Victoria, Kenya, an area with high levels of schistosomiasis transmission. Our results showed marginal effects of heat shock on prevalence of infection in B. glabrata, and that this response was genotype specific. We found no evidence of a heat shock effect on prevalence of infection in B. sudanica or on intensity of infection (number of infectious stages shed) in either snail species. Such environmentally influenced defense responses stress the importance of considering this unique interaction between snail and parasite genotypes in determining infection dynamics under climate changes.

6.
J Infect Dis ; 224(11): 1962-1972, 2021 12 01.
Article in English | MEDLINE | ID: mdl-33955457

ABSTRACT

Myeloid-derived suppressor cells (MDSCs) are present in elevated numbers in tuberculosis patients and have been found to be permissive for Mycobacterium tuberculosis proliferation. To determine whether depletion of MDSCs may improve host control of tuberculosis, we used a novel diphtheria toxin-based fusion protein DABIL-4 that targets and depletes interleukin 4 (IL-4) receptor-positive cells. We show that DABIL-4 depletes both polymorphonuclear MDSCs and monocytic MDSCs, increases interferon-γ + T cells, and reduces the lung bacillary burden in a mouse tuberculosis model. These results indicate that MDSC-depleting therapies targeting the IL-4 receptor are beneficial in tuberculosis and offer an avenue towards host-directed tuberculosis therapy.


Subject(s)
Diphtheria Toxin/therapeutic use , Immunotherapy/methods , Mycobacterium tuberculosis/immunology , Myeloid-Derived Suppressor Cells/immunology , Tuberculosis/therapy , Animals , Disease Models, Animal , Mice , Recombinant Fusion Proteins/therapeutic use , T-Lymphocytes
7.
Mol Oncol ; 15(5): 1330-1344, 2021 05.
Article in English | MEDLINE | ID: mdl-33682324

ABSTRACT

In many solid tumors including triple-negative breast cancer (TNBC), upregulation of the interleukin-4 receptor (IL-4R) has been shown to promote cancer cell proliferation, apoptotic resistance, metastatic potential, and a Th2 response in the tumor microenvironment (TME). Since immunosuppressive cells in the TME and spleen including myeloid-derived suppressor cells (MDSCs) and tumor-associated macrophages (TAMs) also express the IL-4R, we hypothesized that selective depletion of IL-4R-bearing cells in TNBC would result in the direct killing of tumor cells and the depletion of immunosuppressive cells and lead to an enhanced antitumor response. To selectively target IL-4R+ cells, we employed DABIL-4, a fusion protein toxin consisting of the catalytic and translocation domains of diphtheria toxin fused to murine IL-4. As anticipated, DABIL-4 has potent cytotoxic activity against TNBC cells both in vitro and in vivo. We demonstrate in the murine 4T1 TNBC model that DABIL-4 significantly reduces tumor growth, splenomegaly, and lung metastases. Importantly, we also show that the administration of DABIL-4 results in the selective depletion of MDSCs, TAMs, and regulatory T cells in treated mice, with a concomitant increase in IFN-γ+ CD8 effector T cells in the TME. Since the 4T1 antitumor activity of DABIL-4 was largely diminished in IL-4R knockout mice, we postulate that DABIL-4 functions primarily as an immunotherapeutic by the depletion of MDSCs, TAMs, and regulatory T cells. NanoString analysis of control and treated tumors confirmed and extended these observations by showing a marked decline of mRNA transcripts that are associated with tumorigenesis and metastasis. In conclusion, we demonstrate that DABIL-4 targeting of both tumor and immunosuppressive host cells likely represents a novel and effective treatment strategy for 4T1 TNBC and warrants further study.


Subject(s)
Adenocarcinoma/drug therapy , Myeloid-Derived Suppressor Cells/drug effects , Recombinant Fusion Proteins/therapeutic use , Triple Negative Breast Neoplasms/drug therapy , Adenocarcinoma/pathology , Animals , Antineoplastic Agents/pharmacology , Antineoplastic Agents/therapeutic use , Apoptosis/drug effects , Cell Count , Cell Line, Tumor , Female , Humans , Interleukin-4/chemistry , Interleukin-4/therapeutic use , Interleukin-4 Receptor alpha Subunit/chemistry , Interleukin-4 Receptor alpha Subunit/therapeutic use , Mice , Mice, Inbred BALB C , Mice, Knockout , Molecular Targeted Therapy , Myeloid-Derived Suppressor Cells/pathology , Recombinant Fusion Proteins/pharmacology , Triple Negative Breast Neoplasms/pathology , Xenograft Model Antitumor Assays
8.
J Biomed Sci ; 27(1): 99, 2020 Oct 30.
Article in English | MEDLINE | ID: mdl-33126859

ABSTRACT

BACKGROUND: Global ischemia is the resulting effect of a cardiopulmonary arrest (CPA). Presently there is no effective treatment to address neurological deficits in patients who survived a CPA. Granulocyte-colony stimulating factor is a growth factor (G-CSF) with a plethora of beneficial effects, including neuroprotection. Clinical application of human G-CSF (hG-CSF) is limited due to its plasma half-life of 4 h. Therefore, novel approaches need to be investigated that would (1) enable prolonged manifestation of hG-CSF and (2) demonstrate G-CSF efficacy from studying the underlying protective mechanisms of hG-CSF. In our previous work, we used the self-complementary adeno-associated virus (stereotype2: scAAV2) as a vector to transfect the hG-CSF gene into the global ischemic brain of a mouse. As an extension of that work, we now seek to elucidate the protective mechanisms of hG-CSF gene therapy against endoplasmic reticulum induced stress, mitochondrial dynamics and autophagy in global ischemia. METHOD: A single drop of either AAV-CMV-hG-CSF or AAV-CMV-GFP was dropped into the conjunctival sac of the Swiss Webster mouse's left eye, 30-60 min after bilateral common artery occlusion (BCAO). The efficacy of the expressed hG-CSF gene product was analyzed by monitoring the expression levels of endoplasmic reticulum stress (ER), mitochondrial dynamics and autophagic proteins over 4- and 7-days post-BCAO in vulnerable brain regions including the striatum, overlying cortex (frontal brain regions) and the hippocampus (middle brain regions). Statistical analysis was performed using mostly One-Way Analysis of variance (ANOVA), except for behavioral analysis, which used Repeated Measures Two-Way ANOVA, post hoc analysis was performed using the Tukey test. RESULTS: Several biomarkers that facilitated cellular death, including CHOP and GRP78 (ER stress) DRP1 (mitochondrial dynamics) and Beclin 1, p62 and LC3-ll (autophagy) were significantly downregulated by hG-CSF gene transfer. hG-CSF gene therapy also significantly upregulated antiapoptotic Bcl2 while downregulating pro-apoptotic Bax. The beneficial effects of hG-CSF gene therapy resulted in an overall improvement in functional behavior. CONCLUSION: Taken together, this study has substantiated the approach of sustaining the protein expression of hG-CSF by eye drop administration of the hG-CSF gene. In addition, the study has validated the efficacy of using hG-CSF gene therapy against endoplasmic reticulum induced stress, mitochondrial dynamics and autophagy in global ischemia.


Subject(s)
Autophagy , Carotid Stenosis/physiopathology , Endoplasmic Reticulum Stress , Genetic Therapy/methods , Granulocyte Colony-Stimulating Factor/therapeutic use , Mitochondrial Dynamics , Stroke/therapy , Animals , Disease Models, Animal , Endoplasmic Reticulum Chaperone BiP , Male , Mice
9.
J Diabetes Sci Technol ; 14(5): 837-843, 2020 09.
Article in English | MEDLINE | ID: mdl-32019329

ABSTRACT

BACKGROUND: Closed loop (CL) automated insulin delivery systems are demonstrated to be safe and effective in regulating glucose levels and reducing cognitive burden in people with type 1 diabetes (T1D). However, given the limited market options and the do-it-yourself nature of most systems, it can be difficult for potential users to shape their expectations fitting them into daily lives and management routines. As such, we examined the potential feasibility of a virtual reality (VR) intervention. METHODS: A four-part VR intervention was created to expose adults with T1D to expected CL system barriers: body image, perceived hassles of using CL, deskilling fears, and unwanted social attention. Goals of the pilot were to assess feasibility and expose patients to CL. Surveys were conducted pre- and postparticipating in the VR experience. RESULTS: A total of 20 adults with T1D completed the pilot. Average time to complete the experience was 14.1 minutes (8.8-39.9). Reported VR sickness was low. Willingness to use VR was maintained in 90% (n = 18) and did not change expectations of CL in 95% (n = 19). Virtual reality changed perceived hassles of CL in 25% (n = 5) with four concerned over alarms and one connectivity issues: positive diabetes technology attitudes, confidence in managing hypoglycemia, overall perceptions of appearance, and positive affect maintained after the VR intervention. Negative affect significantly decreased after exposure and perceptions of being overweight trended toward significance. CONCLUSION: This pilot VR intervention demonstrated high potential in addressing expected barriers to uptake and usage of CL systems without decreasing enthusiasm or changing expectations of CL.


Subject(s)
Diabetes Mellitus, Type 1/drug therapy , Glycemic Control , Hypoglycemic Agents/administration & dosage , Insulin Infusion Systems , Insulin/administration & dosage , Virtual Reality , Adolescent , Adult , Attitude to Computers , Biomarkers/blood , Blood Glucose/drug effects , Blood Glucose/metabolism , Diabetes Mellitus, Type 1/blood , Diabetes Mellitus, Type 1/diagnosis , Diabetes Mellitus, Type 1/psychology , Feasibility Studies , Female , Glycemic Control/adverse effects , Health Knowledge, Attitudes, Practice , Humans , Hypoglycemic Agents/adverse effects , Insulin/adverse effects , Insulin Infusion Systems/adverse effects , Male , Middle Aged , Patient Acceptance of Health Care , Patient Satisfaction , Pilot Projects , Young Adult
10.
Proc Natl Acad Sci U S A ; 116(42): 21054-21060, 2019 10 15.
Article in English | MEDLINE | ID: mdl-31570588

ABSTRACT

Development of multicellular organs requires the coordination of cell differentiation and patterning. Critical for sound detection, the mammalian organ of Corti contains functional units arranged tonotopically along the cochlear turns. Each unit consists of sensory hair cells intercalated by nonsensory supporting cells, both specified and radially patterned with exquisite precision during embryonic development. However, how cell identity and radial patterning are jointly controlled is poorly understood. Here we show that ß-catenin is required for specification of hair cell and supporting cell subtypes and radial patterning of the cochlea in vivo. In 2 mouse models of conditional ß-catenin deletion, early specification of Myosin7-expressing hair cells and Prox1-positive supporting cells was preserved. While ß-catenin-deficient cochleae expressed FGF8 and FGFR3, both of which are essential for pillar cell specification, the radial patterning of organ of Corti was disrupted, revealed by aberrant expression of cadherins and the pillar cell markers P75 and Lgr6. Moreover, ß-catenin ablation caused duplication of FGF8-positive inner hair cells and reduction of outer hair cells without affecting the overall hair cell density. In contrast, in another transgenic model with suppressed transcriptional activity of ß-catenin but preserved cell adhesion function, both specification and radial patterning of the organ of Corti were intact. Our study reveals specific functions of ß-catenin in governing cell identity and patterning mediated through cell adhesion in the developing cochlea.


Subject(s)
Cochlea/metabolism , Cochlea/physiology , beta Catenin/metabolism , Animals , Biomarkers/metabolism , Cell Adhesion/physiology , Cell Differentiation/physiology , Gene Expression Regulation, Developmental/physiology , Hair Cells, Auditory/metabolism , Hair Cells, Auditory/physiology , Hair Cells, Auditory, Inner/metabolism , Hair Cells, Auditory, Inner/physiology , Mice , Organ of Corti/metabolism , Organogenesis/physiology
11.
PLoS One ; 11(9): e0162652, 2016.
Article in English | MEDLINE | ID: mdl-27669006

ABSTRACT

BACKGROUND: The pathogenesis of albuminuria in SCD remains incompletely understood. We evaluated the association of albuminuria with measures of endothelial function, and explored associations of both albuminuria and measures of endothelial function with selected biological variables (vascular endothelial growth factor [VEGF], endothelin-1 [ET-1], soluble fms-like tyrosine kinase-1 [sFLT-1], soluble vascular cell adhesion molecule-1 [soluble VCAM-1] and plasma hemoglobin). METHODS: Spot urine measurements for albumin-creatinine ratio (UACR) and 24-hour urine protein were obtained. Endothelial function was assessed using brachial artery ultrasound with measurements of flow-mediated dilation (FMD), nitroglycerin-mediated dilation (NTMD) and hyperemic velocity. RESULTS: Twenty three subjects with varying degrees of albuminuria were evaluated. UACR was significantly correlated with FMD (ρ = -0.45, p = 0.031). In univariate analysis, UACR was correlated with VEGF (ρ = -0.49; 95% CI: -0.75 --0.1, p = 0.015), plasma hemoglobin (ρ = 0.50; 95% CI: 0.11-0.75, p = 0.013) and ET-1 (ρ = 0.40; 95% CI: -0.03-0.69, p = 0.06). Multivariable analysis showed significant associations of ET-1 (estimate: 455.1 [SE: 198.3], p = 0.02), VEGF (estimate: -1.1 [SE: 0.53], p = 0.04) and sFLT-1 (estimate: -1.14 [SE: 0.49], p = 0.02) with UACR. Only ET-1 (estimate: -8.03 [SE: 3.87], p = 0.04) was significantly associated with FMD in multivariable analyses. Finally, UACR was correlated with both 24-hour urine protein (ρ = 0.90, p < 0.0001) and urine aliquots for albumin-creatinine ratio obtained from the 24-hour urine collection (ρ = 0.97, p < 0.0001). CONCLUSION: This study provides more definitive evidence for the association of albuminuria with endothelial dysfunction in SCD. Elevated circulating levels of ET-1 may contribute to SCD-related glomerulopathy by mediating endothelial dysfunction.

12.
HPB (Oxford) ; 18(3): 221-8, 2016 Mar.
Article in English | MEDLINE | ID: mdl-27017161

ABSTRACT

BACKGROUND: This multicentre, randomized clinical trial assessed the safety and effectiveness of the EVARREST™ Fibrin Sealant Patch (FP) in treating parenchymal bleeding following anatomic and non-anatomic liver resections. METHODS: One hundred and two patients were stratified according to the type of hepatic resection (anatomic/non-anatomic), and randomized (1:1) after identification of an appropriate bleeding site, to FP vs Standard of Care (SoC, manual compression ± topical haemostat). The primary endpoint was haemostasis at 4 min from bleeding site identification with no re-bleeding requiring re-treatment. RESULTS: The FP was superior in achieving haemostasis at 4 min (96%, 48/50) to SoC (46%, 24/52; p < 0.001). Stratification for resection type showed treatment differences for primary endpoint for anatomic (24/25 FP vs 13/23 SoC; p = 0.001) and non-anatomic liver resections (24/25FP vs 11/29 SoC; p < 0.001). Adverse events related to the study procedure were reported in 40/50 patients (80%) in the FP group and 43/52 patients (83%) in the SoC group. One (2%) adverse event (infected intra-abdominal fluid collection) was possibly related to study treatment. CONCLUSION: This clinical trial confirms that the FP is safe and highly effective in controlling parenchymal bleeding following hepatectomy regardless of the type of resection. ClinicalTrials.gov NCT01993888.


Subject(s)
Fibrin Tissue Adhesive/therapeutic use , Hemostatic Techniques , Hemostatics/therapeutic use , Hepatectomy/adverse effects , Postoperative Hemorrhage/prevention & control , Tissue Adhesives/therapeutic use , Adult , Aged , Aged, 80 and over , Australia , Blood Transfusion , Elective Surgical Procedures , Female , Fibrin Tissue Adhesive/adverse effects , Hemostatic Techniques/adverse effects , Hemostatics/adverse effects , Humans , Male , Middle Aged , New Zealand , Postoperative Hemorrhage/etiology , Prospective Studies , Time Factors , Tissue Adhesives/adverse effects , Treatment Outcome , United Kingdom , United States , Young Adult
14.
World J Surg ; 39(11): 2663-9, 2015 Nov.
Article in English | MEDLINE | ID: mdl-26041587

ABSTRACT

BACKGROUND: In surgery, rapid hemostasis can be required in various settings and bleeding intensities to minimize complications related to blood loss. While effective hemostats are available for mild-to-moderate surgical bleeding, few are effective against challenging severe hemorrhage. We report the effectiveness and safety of the fibrin pad (FP), a novel combination hemostat (device/human biologic), in controlling severe soft-tissue bleeding as compared to the standard of care (SoC). METHODS: This randomized, controlled, superiority study enrolled subjects ≥18 years, requiring elective abdominal, retroperitoneal, pelvic, or thoracic (non-cardiac) surgery. A severe target bleeding site (TBS) was identified intra-operatively following which, subjects were randomized to the FP or the SoC group. Hemostatic status was observed at 4 min (primary endpoint) and 10 min post-randomization. Safety variables included TBS-related bleeding and thrombotic events. RESULTS: At 4 min post-randomization, 50/59 (84.7 %) subjects in the FP group and 10/32 (31.3%) [Corrected] subjects in the SoC group achieved hemostasis without needing re-treatment (P < 0.0001). Compared to the SoC group, the FP group showed better hemostasis at 10 min post-randomization [58/59 (98.3 %) vs. 28/32 (87.5 %); P = 0.01], lower mean time to hemostasis (6.1 ± 13.5 vs. 17.8 ± 32.0 min), and a less frequent need for re-treatment (5.1 vs. 53.1 %). The triangular test for binary response demonstrated the FP to be superior to SoC (95 % CI 1.474-3.290; P < 0.0001). Safety profiles in both groups were similar to those typically observed after long-duration surgery. CONCLUSION: The FP is safe and superior to SoC for controlling challenging severe soft-tissue bleeding encountered during intra-abdominal and thoracic surgical procedures.


Subject(s)
Fibrin Tissue Adhesive/adverse effects , Hemostasis, Surgical/adverse effects , Abdomen/surgery , Adult , Aged, 80 and over , Female , Humans , Male , Middle Aged , Patient Safety , Pelvis/surgery , Retroperitoneal Space/surgery , Thoracic Surgical Procedures , Treatment Outcome
15.
Rev Urol ; 17(1): 25-30, 2015.
Article in English | MEDLINE | ID: mdl-26028998

ABSTRACT

In the United States, fibrin sealants have been used to achieve hemostasis for nearly two decades. Although their clinical utility was first demonstrated in cardiac surgery, their effectiveness and safety have since been demonstrated to extend to a wide array of procedures. Fibrin sealants typically contain two components-fibrinogen and thrombin-that are combined and delivered simultaneously to a target bleeding site in order to achieve hemostasis. However, many commercial formulations contain other additional components, such as antifibrinolytic agents, that have been associated with adverse outcomes. This subanalysis compares the safety and effectiveness of a fibrin sealant versus an absorbable hemostat for achieving hemostasis during urologic procedures with mild to moderate bleeding.

16.
PLoS One ; 9(11): e112239, 2014.
Article in English | MEDLINE | ID: mdl-25379771

ABSTRACT

PAKs are serine/threonine kinases that regulate cytoskeletal dynamics and cell migration. PAK1 is activated by binding to the small EF hand protein, CIB1, or to the Rho GTPases Rac1 or Cdc42. The role of PAK1 in angiogenesis was established based only on in vitro studies and its role in angiogenesis in vivo has never been examined. Here we tested the hypothesis that PAK1 is an essential regulator of ischemic neovascularization (arteriogenesis and angiogenesis) and wound healing using a global PAK1 knockout mouse. Neovascularization was assessed using unilateral hindlimb ischemia. We found that plantar perfusion, limb use and appearance were not significantly different between 6-8 week old PAK1-/- and PAK1+/+ mice throughout the 21-day period following hindlimb ischemia; however a slightly delayed healing was observed in 16 week old PAK1-/- mice. In addition, the wound healing rate, as assessed with an ear punch assay, was unchanged in PAK1-/- mice. Surprisingly, however, we observed a notable increase in PAK2 expression and phosphorylation in ischemic gastrocnemius tissue from PAK1-/- but not PAK1+/+ mice. Furthermore, we observed higher levels of activated ERK2, but not AKT, in ischemic and non-ischemic muscle of PAK1-/- mice upon hindlimb ischemic injury. A group I PAK inhibitor, IPA3, significantly inhibited endothelial cell sprouting from aortic rings in both PAK1-/- and PAK1+/+ mice, implying that PAK2 is a potential contributor to this process. Taken together, our data indicate that while PAK1 has the potential to contribute to neovascularization and wound healing, PAK2 may functionally compensate when PAK1 is deficient.


Subject(s)
Hindlimb/blood supply , Ischemia/metabolism , Wound Healing , p21-Activated Kinases/metabolism , Animals , Cell Movement , Female , Gene Deletion , Hindlimb/metabolism , Hindlimb/pathology , Ischemia/genetics , Ischemia/pathology , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Mitogen-Activated Protein Kinase 1/metabolism , Mitogen-Activated Protein Kinase 3/metabolism , Neovascularization, Physiologic , p21-Activated Kinases/genetics
17.
J Am Coll Surg ; 217(3): 385-93, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23969113

ABSTRACT

BACKGROUND: This study evaluated the hemostatic effectiveness and safety of Fibrin Pad (Omrix Biopharmaceuticals Ltd.) vs absorbable hemostat in patients undergoing nonemergent surgery. Fibrin Pad is a topical absorbable hemostat designed to be effective in a variety of soft tissues and across multiple bleeding intensities. STUDY DESIGN: Patients 18 years and older, requiring abdominal, retroperitoneal, pelvic, or thoracic (noncardiac) surgery and with an appropriate soft-tissue target bleeding site (TBS), were randomized to receive Fibrin Pad or absorbable hemostat (NCT00658723). Patients were stratified by bleeding severity at the TBS. Assessments included percentage of patients achieving hemostasis at 4 minutes after randomization with no rebleeding requiring treatment during the subsequent 6 minutes (primary endpoint), proportion of patients achieving hemostasis at 10 minutes, and incidence of treatment failure. RESULTS: On the primary endpoint, 98.3% of patients with Fibrin Pad and 53.3% with absorbable hemostat achieved hemostasis at 4 minutes (p < 0.0001). The treatment differential was magnified (efficacy was maintained with Fibrin Pad but decreased with absorbable hemostat) with increasing bleeding intensity: in patients with mild bleeding, 100.0% vs 80.0% achieved hemostasis with Fibrin Pad and absorbable hemostat (p = 0.03), respectively; rates were 96.6% vs 26.7%, respectively (p < 0.0001) with moderate bleeding. Percentages of patients who achieved hemostasis at 10 minutes were: Fibrin Pad, 98.3% and absorbable hemostat, 73.3% (p < 0.0001). Incidences of adverse events were comparable between groups. CONCLUSIONS: Fibrin Pad is superior to absorbable hemostat (SURGICEL Original Absorbable Hemostat [Ethicon]) in soft-tissue bleeding control and is safe and effective as an adjunct for rapidly and reliably achieving hemostasis for soft-tissue bleeding during surgery.


Subject(s)
Abdomen/surgery , Blood Loss, Surgical/prevention & control , Cellulose, Oxidized/therapeutic use , Fibrin/therapeutic use , Hemostasis, Surgical/methods , Hemostatics/therapeutic use , Pelvis/surgery , Retroperitoneal Space/surgery , Thoracic Surgery , Female , Humans , Male , Middle Aged , Prospective Studies , Treatment Outcome , United States
18.
HPB (Oxford) ; 15(1): 61-70, 2013 Jan.
Article in English | MEDLINE | ID: mdl-23216780

ABSTRACT

INTRODUCTION: Haemostasis after liver resection may be difficult to achieve as a result of the presence of challenging bleeding, the anatomic landscape of the liver and the quality of tissue making up the hepatic parenchyma. The fibrin pad (FP) is a topical absorbable haemostat designed to be effective in a variety of tissues and across multiple bleeding intensities. This is the first clinical trial to evaluate the hemostat's safety and effectiveness in controlling bleeding during elective hepatic resection. METHODS: This prospective, randomized, controlled superiority trial enrolled 104 subjects undergoing elective hepatectomy in 5 countries. After parenchymal transection, subjects with an appropriately defined target bleeding site (TBS) were stratified according to the type of hepatic parenchyma and immediately randomized 1:1: FP versus Standard of Care (SoC). SoC comprised manual compression with the use of an approved topical absorbable haemostat. The primary endpoint was haemostasis at 4 min from identification of the TBS, with no re-bleeding requiring re-treatment prior to abdominal closure. Results were stratified for both normal and abnormal (steatosis or cirrhosis) hepatic parenchyma. All subjects were followed for 60 days post-operatively. RESULTS: The intent-to-treat (ITT) analysis showed an overall treatment difference of 53.0% (P < 0.001), 82.5% (33/40 FP) versus 29.5% (13/44 SoC) in achieving haemostasis at 4 min with no re-bleeding requiring treatment up to wound closure. The per protocol analysis showed an overall treatment difference of 65.7% (P < 0.001), with 33/35 successes (94.3%) in the FP group and 12/42 in the SoC group (28.6%). The stratification results showed treatment differences between the normal parenchyma group, 63.6% (95.8% FP versus 32.3% SoC P < 0.001) and a larger difference of 72.7% in the abnormal parenchyma group (90.9% FP versus 18.2% SoC P = 0.0003). Post-operative intra-abdominal fluid collections were less frequent in the FP group (3.4% FP versus 13.3% SoC P = 0.059). There was no difference in the safety profile between the FP or SoC groups. CONCLUSIONS: The FP is safe and effective when used as an adjunct to achieve haemostasis during hepatic surgery. The success rate of achieving haemostasis with a FP remained high compared with the SOC group, especially in steatotic or cirrhotic liver tissue where the control success rates diminish. In addition, FP treatment of hepatic parenchymal surfaces may reduce the risk of post-operative biliary and fluid collections.


Subject(s)
Blood Loss, Surgical/prevention & control , Fibrin/therapeutic use , Hemostatic Techniques , Hemostatics/therapeutic use , Hepatectomy/adverse effects , Adolescent , Adult , Aged , Australia , Blood Transfusion , Elective Surgical Procedures , Europe , Female , Fibrin/adverse effects , Hemostatic Techniques/adverse effects , Hemostatics/adverse effects , Humans , Male , Middle Aged , New Zealand , Postoperative Complications/etiology , Pressure , Prospective Studies , Time Factors , Treatment Outcome , Young Adult
19.
BMC Nephrol ; 13: 147, 2012 Nov 08.
Article in English | MEDLINE | ID: mdl-23137020

ABSTRACT

BACKGROUND: Bleeding severity, anatomic location, tissue characteristics, and visibility are common challenges encountered while managing intraoperative bleeding, and conventional hemostatic measures (suture, ligature, and cautery) may sometimes be ineffective or impractical. While topical absorbable hemostats (TAH) are useful hemostatic adjuvants, each TAH has associated disadvantages. METHODS: We evaluated the safety and hemostatic efficacy of a new advanced biologic combination product-fibrin pad-to potentially address some gaps associated with TAHs. Fibrin pad was assessed as adjunctive hemostat in open partial nephrectomy in single-center, open-label, Phase I study (N = 10), and as primary hemostat in multicenter, single-blind, randomized, standard-of-care (SOC)-controlled Phase I/II study (N = 7) in Israel. It was used to control mild-to-moderate bleeding in Phase I and also spurting arterial bleeding in Phase I/II study. Phase I study assessed safety and Phase I/II study, proportion of successes at 10 min following randomization, analyzed by Fisher exact tests at 5% significance level. RESULTS: Phase I (N = 10): All patients completed the study. Hemostasis was achieved within 3-4 min (average = 3.1 min) of a single application in all patients. Fibrin pad was found to be safe for human use, with no product-related adverse events reported. Phase I/II (N = 7): Hemostatic success at 10 min (primary endpoint) was achieved in 3/4 patients treated with fibrin pad versus 0/3 patients treated with SOC. No clinically significant change in laboratory or coagulation parameters was recorded, except a case of post-procedural hemorrhage with fibrin pad, which was considered serious and related to the fibrin pad treatment, and required re-operation. Although Data Safety Monitoring Board authorized trial continuation, the sponsor decided against proceeding toward an indication for primary treatment of severe arterial hemorrhage as a replacement for sutures. The study was suspended after 7/30 planned subjects were enrolled. CONCLUSIONS: The first-in-man trial of fibrin pad demonstrated its safety and efficacy as an adjunctive hemostatic technique for mild-to-moderate bleeding in partial nephrectomy. The study also suggested that the product should not replace sutures or meticulous surgical techniques for the treatment of severe arterial hemorrhage. TRIAL REGISTRATION: Phase I/II trial, NCT00598130.


Subject(s)
Fibrin Tissue Adhesive/administration & dosage , Hemostatics/administration & dosage , Nephrectomy/standards , Standard of Care/standards , Adolescent , Adult , Aged , Cohort Studies , Female , Fibrin Tissue Adhesive/adverse effects , Follow-Up Studies , Hemostatics/adverse effects , Humans , Male , Middle Aged , Nephrectomy/adverse effects , Prospective Studies , Single-Blind Method , Treatment Outcome , Young Adult
20.
Int Forum Allergy Rhinol ; 2(1): 75-9, 2012.
Article in English | MEDLINE | ID: mdl-22311845

ABSTRACT

BACKGROUND: Chronic rhinosinusitis is a multifactorial disease characterized by a local inflammatory response and impaired mucociliary clearance. Our prior work suggests that nonpolypoid inflammation can blunt ciliary dynamics. Thus, we set out to determine whether exogenously applied recombinant keratinocyte chemoattractant (KC), mouse homologue of interleukin-8 (IL-8), modulates ciliary function. METHODS: Murine primary sinonasal cultures were established in an air-liquid interface. Exogenous KC was administered to apical and basal surfaces at 500 pg/mL (n = 6) or 5 ng/mL (n = 3). Basal and stimulated cilia beat frequency (CBF) was recorded at 6, 12, 24, and 48 hours after exposure. Control groups were treated with buffered saline solution (n = 6). Cilia were mechanically stimulated with bursts of pressurized air (55 mmHg). CBF after prolonged KC exposure (96 hours) was also measured. RESULTS: KC-treated cultures had significantly increased basal CBF at 24 hours and 48 hours. KC (500 pg/mL) yielded a 41.6% ± 9.5 increase in basal CBF (p < 0.001) at 24 hours, which persisted at 48 hours, 35.8% ± 10.2 (p < 0.05), while high-concentration KC (5 ng/mL) yielded a 50.2% ± 6.6 (p < 0.01) increase in basal CBF at 24 hours, which declined to 15.2% ± 5.2 (p < 0.01) at 48 hours. After 48 hours, the KC group demonstrated decreased response to mechanical stimulus vs control (500 pg/mL: p < 0.01, 5 ng/mL: p ≤ 0.04). With prolonged KC exposure (500 pg/mL) CBF declined: -25.5% ± 6.9 (p < .001) at 72 hours, and -19.6% ± 5.4 (p < 0.01) at 96 hours. CONCLUSION: Our results demonstrate modulation of cilia function of murine sinonasal epithelial cells by the inflammatory cytokine KC, which acutely increases basal CBF while decreasing the response of cilia to mechanical stimulation. Prolonged KC exposure decreases basal CBF.


Subject(s)
Cilia/drug effects , Epithelial Cells/drug effects , Interleukin-8/pharmacology , Nasal Mucosa/drug effects , Animals , Cells, Cultured , Dose-Response Relationship, Drug , Mice , Nasal Mucosa/cytology
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