5 results on '"Timmons CL"'
Search Results
2. Particulate Generation Mechanisms during Bulk Filling and Mitigation via New Glass Vial.
- Author
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Timmons CL, Liu CY, and Merkle S
- Subjects
- Chemistry, Pharmaceutical methods, Glass, Humans, Injections, Particulate Matter, Drug Contamination prevention & control, Drug Packaging, Pharmaceutical Preparations standards
- Abstract
Contamination with foreign particulate matter continues to be a leading cause of parenteral drug recalls, despite extensive control and inspection during manufacturing. Glass is a significant source of particulate matter contamination; however, the mechanism, source, and quantification have not been extensively analyzed. Quantification of particulate matter generation with lab simulations suggests that glass-to-glass contact on the filling line produces large quantities of glass particles of various sizes. A new strengthened glass vial with a low coefficient of friction surface is proposed to address this root cause of glass particle generation. Lab simulations and two line trials using this new vial demonstrated a substantial reduction of glass particulate generation, of resulting product contamination, as well as of the frequency of required filling line interventions. These results suggest that substantial reductions in particulate matter contamination of all types, glass and non-glass, can be achieved through the use of a new glass vial designed to effectively eliminate a root cause of glass particle generation. LAY ABSTRACT: Contamination with foreign particulate contamination continues to be a leading cause of injectable drug recalls, despite extensive control and inspection during manufacturing. Glass particles are one of the most common types of particulate identified; however, the generation mechanism has not been extensively studied. Lab simulations suggest that routine glass-to-glass contact of vials during the filling process results in large quantities of glass particulate. A new, strengthened glass vial with a low coefficient of friction surface is proposed to address this mechanism. Lab simulations and multiple filling line trials demonstrated a substantial reduction of glass particulate matter generation and product contamination with use of the new vial. These results suggest that this new vial reduces contamination risk by eliminating a root cause of glass particulate generation., (© PDA, Inc. 2017.)
- Published
- 2017
- Full Text
- View/download PDF
3. GB virus type C E2 protein inhibits human immunodeficiency virus type 1 Gag assembly by downregulating human ADP-ribosylation factor 1.
- Author
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Wang C, Timmons CL, Shao Q, Kinlock BL, Turner TM, Iwamoto A, Zhang H, Liu H, and Liu B
- Subjects
- Blotting, Western, Coinfection virology, Down-Regulation, Fluorescent Antibody Technique, HEK293 Cells, HeLa Cells, Humans, Microscopy, Confocal, Real-Time Polymerase Chain Reaction, Transfection, Virus Assembly physiology, Virus Release physiology, ADP-Ribosylation Factor 1 metabolism, HIV-1 metabolism, Viral Envelope Proteins metabolism, gag Gene Products, Human Immunodeficiency Virus metabolism
- Abstract
GB virus type C (GBV-C) glycoprotein E2 protein disrupts HIV-1 assembly and release by inhibiting Gag plasma membrane targeting, however the mechanism by which the GBV-C E2 inhibits Gag trafficking remains unclear. In the present study, we identified ADP-ribosylation factor 1 (ARF1) contributed to the inhibitory effect of GBV-C E2 on HIV-1 Gag membrane targeting. Expression of GBV-C E2 decreased ARF1 expression in a proteasomal degradation-dependent manner. The restoration of ARF1 expression rescued the HIV-1 Gag processing and membrane targeting defect imposed by GBV-C E2. In addition, GBV-C E2 expression also altered Golgi morphology and suppressed protein traffic through the secretory pathway, which are all consistent with a phenotype of disrupting the function of ARF1 protein. Thus, our results indicate that GBV-C E2 inhibits HIV-1 assembly and release by decreasing ARF1, and may provide insights regarding GBV-C E2's potential for a new therapeutic approach for treating HIV-1.
- Published
- 2015
- Full Text
- View/download PDF
4. PTEN loss increases PD-L1 protein expression and affects the correlation between PD-L1 expression and clinical parameters in colorectal cancer.
- Author
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Song M, Chen D, Lu B, Wang C, Zhang J, Huang L, Wang X, Timmons CL, Hu J, Liu B, Wu X, Wang L, Wang J, and Liu H
- Subjects
- Aged, Aged, 80 and over, B7-H1 Antigen metabolism, Cell Line, Tumor, Colorectal Neoplasms metabolism, Colorectal Neoplasms mortality, Colorectal Neoplasms pathology, Enzyme Activation drug effects, Female, Follow-Up Studies, Gene Expression Regulation, Neoplastic drug effects, Gene Knockdown Techniques, Humans, Interferon-gamma pharmacology, Male, Middle Aged, Neoplasm Metastasis, Neoplasm Staging, PTEN Phosphohydrolase metabolism, Prognosis, Proto-Oncogene Proteins c-akt metabolism, B7-H1 Antigen genetics, Colorectal Neoplasms genetics, PTEN Phosphohydrolase genetics
- Abstract
Background: Programmed death ligand-1 (PD-L1) has been identified as a factor associated with poor prognosis in a range of cancers, and was reported to be mainly induced by PTEN loss in gliomas. However, the clinical effect of PD-L1 and its regulation by PTEN has not yet been determined in colorectal cancer (CRC). In the present study, we verified the regulation of PTEN on PD-L1 and further determined the effect of PTEN on the correlation between PD-L1 expression and clinical parameters in CRC., Methods/results: RNA interference approach was used to down-regulate PTEN expression in SW480, SW620 and HCT116 cells. It was showed that PD-L1 protein, but not mRNA, was significantly increased in cells transfected with siRNA PTEN compared with the negative control. Moreover, the capacity of PTEN to regulate PD-L1 expression was not obviously affected by IFN-γ, the main inducer of PD-L1. Tissue microarray immunohistochemistry was used to detect PD-L1 and PTEN in 404 CRC patient samples. Overexpression of PD-L1 was significantly correlated with distant metastasis (P<0.001), TNM stage (P<0.01), metastatic progression (P<0.01) and PTEN expression (P<0.001). Univariate analysis revealed that patients with high PD-L1 expression had a poor overall survival (P<0.001). However, multivariate analysis did not support PD-L1 as an independent prognostic factor (P = 0.548). Univariate (P<0.001) and multivariate survival (P<0.001) analysis of 310 located CRC patients revealed that high level of PD-L1 expression was associated with increased risks of metastatic progression. Furthermore, the clinical effect of PD-L1 on CRC was not statistically significant in a subset of 39 patients with no PTEN expression (distant metastasis: P = 0.102; TNM stage: P = 0.634, overall survival: P = 0.482)., Conclusions: PD-L1 can be used to identify CRC patients with high risk of metastasis and poor prognosis. This clinical manifestation may be partly associated with PTEN expression.
- Published
- 2013
- Full Text
- View/download PDF
5. GB virus type C E2 protein inhibits human immunodeficiency virus type 1 assembly through interference with HIV-1 gag plasma membrane targeting.
- Author
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Timmons CL, Shao Q, Wang C, Liu L, Liu H, Dong X, and Liu B
- Subjects
- CD4 Lymphocyte Count, Cell Membrane virology, Coinfection virology, GB virus C genetics, Glycosylation, HEK293 Cells, HIV Infections metabolism, HIV Infections virology, HIV-1 genetics, HIV-1 pathogenicity, HeLa Cells, Humans, Plasmids genetics, Plasmids metabolism, Protein Structure, Tertiary, Protein Transport, Transfection, Viral Envelope Proteins genetics, Viral Load, Virus Release, gag Gene Products, Human Immunodeficiency Virus genetics, Cell Membrane metabolism, GB virus C metabolism, HIV-1 metabolism, Viral Envelope Proteins metabolism, Virus Assembly, gag Gene Products, Human Immunodeficiency Virus metabolism
- Abstract
GB virus type C (GBV-C) is a single-stranded positive-sense RNA virus classified in the Flaviviridae family. Persistent coinfection with GBV-C is associated with lower human immunodeficiency virus type 1 (HIV-1) load, higher CD4(+) T-cell count, and prolonged survival in HIV-1 coinfected patients. The GBV-C envelope glycoprotein E2 has been reported to interfere with HIV-1 entry. In this study, we showed that the expression of GBV-C E2 inhibited HIV-1 Gag assembly and release. Expression of glycosylated GBV-C E2 inhibited HIV-1 Gag precursor processing, resulting in lower production of CAp24 and MAp17, while the overall expression level of the Gag precursor Pr55 remained unchanged. Membrane floatation gradient and indirect immunofluorescence confocal microscopy analysis showed that glycosylated E2 disrupted HIV-1 Gag trafficking to the plasma membrane, resulting in Gag accumulation in subcellular compartments. This interference in HIV-1 Gag trafficking led to diminished HIV-1 particle production, which is a critical step for HIV-1 to infect new host cells. These findings shed light on a novel mechanism used by GBV-C E2 to inhibit HIV-1 replication and may provide insight into new approaches for suppressing HIV-1 replication.
- Published
- 2013
- Full Text
- View/download PDF
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