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1.
Appl Clin Inform ; 15(3): 446-455, 2024 May.
Article in English | MEDLINE | ID: mdl-38839063

ABSTRACT

BACKGROUND: Studies have shown that documentation burden experienced by clinicians may lead to less direct patient care, increased errors, and job dissatisfaction. Implementing effective strategies within health care systems to mitigate documentation burden can result in improved clinician satisfaction and more time spent with patients. However, there is a gap in the literature regarding evidence-based interventions to reduce documentation burden. OBJECTIVES: The objective of this review was to identify and comprehensively summarize the state of the science related to documentation burden reduction efforts. METHODS: Following Joanna Briggs Institute Manual for Evidence Synthesis and Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidelines, we conducted a comprehensive search of multiple databases, including PubMed, Medline, Embase, CINAHL Complete, Scopus, and Web of Science. Additionally, we searched gray literature and used Google Scholar to ensure a thorough review. Two reviewers independently screened titles and abstracts, followed by full-text review, with a third reviewer resolving any discrepancies. Data extraction was performed and a table of evidence was created. RESULTS: A total of 34 articles were included in the review, published between 2016 and 2022, with a majority focusing on the United States. The efforts described can be categorized into medical scribes, workflow improvements, educational interventions, user-driven approaches, technology-based solutions, combination approaches, and other strategies. The outcomes of these efforts often resulted in improvements in documentation time, workflow efficiency, provider satisfaction, and patient interactions. CONCLUSION: This scoping review provides a comprehensive summary of health system documentation burden reduction efforts. The positive outcomes reported in the literature emphasize the potential effectiveness of these efforts. However, more research is needed to identify universally applicable best practices, and considerations should be given to the transfer of burden among members of the health care team, quality of education, clinician involvement, and evaluation methods.


Subject(s)
Documentation , Humans
2.
Cureus ; 15(7): e42356, 2023 Jul.
Article in English | MEDLINE | ID: mdl-37621791

ABSTRACT

Pyrrhus of Epirus, widely respected and feared by his contemporaries, was a legendary figure in the ancient world. In this paper, we investigate Plutarch's description of the king's unique dental pathology. There are several possibilities to explain the ancient king's presentation, including several different types of developmental dysplasia. However, our conclusion is that it was likely due to a significant dental calculus overgrowth, often seen in the ancient Greek diet of the time. Whatever the underlying cause, Pyrrhus' intimidating visage helped secure the king a legacy that lasts to this day.

3.
Metab Eng ; 79: 108-117, 2023 09.
Article in English | MEDLINE | ID: mdl-37473833

ABSTRACT

Chinese hamster ovary (CHO) cells are used extensively to produce protein therapeutics, such as monoclonal antibodies (mAbs), in the biopharmaceutical industry. MAbs are large proteins that are energetically demanding to synthesize and secrete; therefore, high-producing CHO cell lines that are engineered for maximum metabolic efficiency are needed to meet increasing demands for mAb production. Previous studies have identified that high-producing cell lines possess a distinct metabolic phenotype when compared to low-producing cell lines. In particular, it was found that high mAb production is correlated to lactate consumption and elevated TCA cycle flux. We hypothesized that enhancing flux through the mitochondrial TCA cycle and oxidative phosphorylation would lead to increased mAb productivities and final titers. To test this hypothesis, we overexpressed peroxisome proliferator-activated receptor γ co-activator-1⍺ (PGC-1⍺), a gene that promotes mitochondrial metabolism, in an IgG-producing parental CHO cell line. Stable cell pools overexpressing PGC-1⍺ exhibited increased oxygen consumption, indicating increased mitochondrial metabolism, as well as increased mAb specific productivity compared to the parental line. We also performed 13C metabolic flux analysis (MFA) to quantify how PGC-1⍺ overexpression alters intracellular metabolic fluxes, revealing not only increased TCA cycle flux, but global upregulation of cellular metabolic activity. This study demonstrates the potential of rationally engineering the metabolism of industrial cell lines to improve overall mAb productivity and to increase the abundance of high-producing clones in stable cell pools.


Subject(s)
Antibodies, Monoclonal , PPAR gamma , Cricetinae , Animals , Cricetulus , CHO Cells , PPAR gamma/metabolism , Antibodies, Monoclonal/genetics , Oxidative Stress , Immunoglobulin G
4.
Biotechnol Bioeng ; 119(7): 1712-1727, 2022 07.
Article in English | MEDLINE | ID: mdl-35312045

ABSTRACT

The glutamine synthetase (GS) expression system is commonly used to ensure stable transgene integration and amplification in Chinese hamster ovary (CHO) host lines. Transfected cell populations are typically grown in the presence of the GS inhibitor, methionine sulfoximine (MSX), to further select for increased transgene copy number. However, high levels of GS activity produce excess glutamine. We hypothesized that attenuating the GS promoter while keeping the strong IgG promoter on the GS-IgG expression vector would result in a more efficient cellular metabolic phenotype. Herein, we characterized CHO cell lines expressing GS from either an attenuated promoter or an SV40 promoter and selected with/without MSX. CHO cells with the attenuated GS promoter had higher IgG specific productivity and lower glutamine production compared to cells with SV40-driven GS expression. Selection with MSX increased both specific productivity and glutamine production, regardless of GS promoter strength. 13 C metabolic flux analysis (MFA) was performed to further assess metabolic differences between these cell lines. Interestingly, central carbon metabolism was unaltered by the attenuated GS promoter while the fate of glutamate and glutamine varied depending on promoter strength and selection conditions. This study highlights the ability to optimize the GS expression system to improve IgG production and reduce wasteful glutamine overflow, without significantly altering central metabolism. Additionally, a detailed supplementary analysis of two "lactate runaway" reactors provides insight into the poorly understood phenomenon of excess lactate production by some CHO cell cultures.


Subject(s)
Glutamate-Ammonia Ligase , Glutamine , Animals , CHO Cells , Cricetinae , Cricetulus , Glutamate-Ammonia Ligase/genetics , Glutamate-Ammonia Ligase/metabolism , Glutamine/metabolism , Immunoglobulin G/genetics , Lactic Acid/metabolism , Methionine Sulfoximine/metabolism , Methionine Sulfoximine/pharmacology
5.
Comput Struct Biotechnol J ; 18: 3632-3648, 2020.
Article in English | MEDLINE | ID: mdl-33304461

ABSTRACT

Chinese Hamster Ovary (CHO) cell lines are considered to be the preferred platform for the production of biotherapeutics, but issues related to expression instability remain unresolved. In this study, we investigated potential causes for an unstable phenotype by comparing cell lines that express stably to such that undergo loss in titer across 10 passages. Factors related to transgene integrity and copy number as well as the genomic profile around the integration sites were analyzed. Horizon Discovery CHO-K1 (HD-BIOP3) derived production cell lines selected for phenotypes with low, medium or high copy number, each with stable and unstable transgene expression, were sequenced to capture changes at genomic and transcriptomic levels. The exact sites of the random integration events in each cell line were also identified, followed by profiling of the genomic, transcriptomic and epigenetic patterns around them. Based on the information deduced from these random integration events, genomic loci that potentially favor reliable and stable transgene expression were reported for use as targeted transgene integration sites. By comparing stable vs unstable phenotypes across these parameters, we could establish that expression stability may be controlled at three levels: 1) Good choice of integration site, 2) Ensuring integrity of transgene and observing concatemerization pattern after integration, and 3) Checking for potential stress related cellular processes. Genome wide favorable and unfavorable genomic loci for targeted transgene integration can be browsed at https://www.borthlabchoresources.boku.ac.at/.

6.
Mol Cell ; 72(2): 222-238.e11, 2018 10 18.
Article in English | MEDLINE | ID: mdl-30293786

ABSTRACT

DNA polymerase stalling activates the ATR checkpoint kinase, which in turn suppresses fork collapse and breakage. Herein, we describe use of ATR inhibition (ATRi) as a means to identify genomic sites of problematic DNA replication in murine and human cells. Over 500 high-resolution ATR-dependent sites were ascertained using two distinct methods: replication protein A (RPA)-chromatin immunoprecipitation (ChIP) and breaks identified by TdT labeling (BrITL). The genomic feature most strongly associated with ATR dependence was repetitive DNA that exhibited high structure-forming potential. Repeats most reliant on ATR for stability included structure-forming microsatellites, inverted retroelement repeats, and quasi-palindromic AT-rich repeats. Notably, these distinct categories of repeats differed in the structures they formed and their ability to stimulate RPA accumulation and breakage, implying that the causes and character of replication fork collapse under ATR inhibition can vary in a DNA-structure-specific manner. Collectively, these studies identify key sources of endogenous replication stress that rely on ATR for stability.


Subject(s)
Ataxia Telangiectasia Mutated Proteins/antagonists & inhibitors , Ataxia Telangiectasia Mutated Proteins/genetics , DNA Replication/genetics , Microsatellite Repeats/genetics , Animals , Cell Cycle Proteins/genetics , Chromatin/genetics , Chromatin Immunoprecipitation/methods , DNA Breaks, Double-Stranded , DNA Damage/genetics , Female , Genomic Instability/genetics , Humans , Mice , Replication Protein A/genetics
7.
Metab Eng ; 43(Pt B): 218-225, 2017 09.
Article in English | MEDLINE | ID: mdl-28122259

ABSTRACT

Industrial bioprocesses place high demands on the energy metabolism of host cells to meet biosynthetic requirements for maximal protein expression. Identifying metabolic phenotypes that promote high expression is therefore a major goal of the biotech industry. We conducted a series of 13C flux analysis studies to examine the metabolic response to IgG expression during early stationary phase of CHO cell cultures grown in 3L fed-batch bioreactors. We examined eight clones expressing four different IgGs and compared with three non-expressing host-cell controls. Some clones were genetically manipulated to be apoptosis-resistant by expressing Bcl-2Δ, which correlated with increased IgG production and elevated glucose metabolism. The metabolic phenotypes of the non-expressing, IgG-expressing, and Bcl-2Δ/IgG-expressing clones were fully segregated by hierarchical clustering analysis. Lactate consumption and citric acid cycle fluxes were most strongly associated with specific IgG productivity. These studies indicate that enhanced oxidative metabolism is a characteristic of high-producing CHO cell lines.


Subject(s)
Antibodies, Monoclonal/biosynthesis , Carbon Isotopes/chemistry , Citric Acid Cycle , Gene Expression , Immunoglobulin G/biosynthesis , Isotope Labeling , Animals , Antibodies, Monoclonal/genetics , CHO Cells , Cricetulus , Immunoglobulin G/genetics , Recombinant Proteins/biosynthesis , Recombinant Proteins/genetics
8.
J Hand Microsurg ; 8(1): 49-51, 2016 Apr.
Article in English | MEDLINE | ID: mdl-27616828

ABSTRACT

Anomalous flexor digitorum superficialis muscles in the hand are an uncommon phenomenon, and therefore present challenges in diagnosis and management. We report a case of a 16-year-old girl presenting with a painful, slowly enlarging palmar swelling. The swelling was investigated with ultrasound and magnetic resonance imaging, and was found to be an anomalous muscle belly of the flexor digitorum superficialis muscle. After careful consideration, multidisciplinary discussion, and thorough imaging, the patient was treated successfully without surgical exploration or excision, in comparison to previously reported cases. The patient was pain free and had no concerns at 8-month follow-up, demonstrating the value of conservative management in these cases.

9.
Metab Eng ; 25: 92-102, 2014 Sep.
Article in English | MEDLINE | ID: mdl-25014175

ABSTRACT

Anti-apoptosis engineering is an established technique to prolong the viability of mammalian cell cultures used for industrial production of recombinant proteins. However, the effect of overexpressing anti-apoptotic proteins on central carbon metabolism has not been systematically studied. We transfected CHO-S cells to express Bcl-2∆, an engineered anti-apoptotic gene, and selected clones that differed in their Bcl-2∆ expression and caspase activity. (13)C metabolic flux analysis (MFA) was then applied to elucidate the metabolic alterations induced by Bcl-2∆. Expression of Bcl-2Δ reduced lactate accumulation by redirecting the fate of intracellular pyruvate toward mitochondrial oxidation during the lactate-producing phase, and it significantly increased lactate re-uptake during the lactate-consuming phase. This flux redistribution was associated with significant increases in biomass yield, peak viable cell density (VCD), and integrated VCD. Additionally, Bcl-2∆ expression was associated with significant increases in isocitrate dehydrogenase and NADH oxidase activities, both rate-controlling mitochondrial enzymes. This is the first comprehensive (13)C MFA study to demonstrate that expression of anti-apoptotic genes has a significant impact on intracellular metabolic fluxes, especially in controlling the fate of pyruvate carbon, which has important biotechnology applications for reducing lactate accumulation and enhancing productivity in mammalian cell cultures.


Subject(s)
Apoptosis Regulatory Proteins/metabolism , Lactic Acid/metabolism , Metabolic Flux Analysis/methods , Mitochondrial Proteins/metabolism , Proto-Oncogene Proteins c-bcl-2/metabolism , Pyruvic Acid/metabolism , Signal Transduction/physiology , Animals , Apoptosis Regulatory Proteins/genetics , CHO Cells , Cricetinae , Cricetulus , Mitochondrial Proteins/genetics , Proto-Oncogene Proteins c-bcl-2/genetics
10.
Biomed Res Int ; 2013: 108902, 2013.
Article in English | MEDLINE | ID: mdl-23936770

ABSTRACT

Methadone remains the most common form of pharmacological therapy for opioid dependence; however, there is a lack of explanation for the reports of its relatively low success rate in achieving complete abstinence. One hypothesis is that in vivo binding of methadone to the plasma glycoprotein alpha-1-acid glycoprotein (AGP), to a degree dependent on the molecular structure, may render the drug inactive. This study sought to determine whether alterations present in the glycosylation pattern of AGP in patients undergoing various stages of methadone therapy (titration < two weeks, harm reduction < one year, long-term > one and a half years) could affect the affinity of the glycoprotein to bind methadone. The composition of AGP glycosylation was determined using high pH anion exchange chromatography (HPAEC) and intrinsic fluorescence analysed to determine the extent of binding to methadone. The monosaccharides galactose and N-acetyl-glucosamine were elevated in all methadone treatment groups indicating alterations in AGP glycosylation. AGP from all patients receiving methadone therapy exhibited a greater degree of binding than the normal population. This suggests that analysing the glycosylation of AGP in patients receiving methadone may aid in determining whether the therapy is likely to be effective.


Subject(s)
Analgesics, Opioid/adverse effects , Glycoproteins/blood , Methadone/administration & dosage , Substance-Related Disorders/drug therapy , Acetylglucosamine/blood , Adolescent , Adult , Chromatography, Ion Exchange , Female , Galactose/blood , Glycosylation/drug effects , Humans , Male , Protein Binding , Substance-Related Disorders/blood , Substance-Related Disorders/metabolism , Treatment Outcome
11.
Biomed Chromatogr ; 25(1-2): 39-46, 2011 Jan.
Article in English | MEDLINE | ID: mdl-20821735

ABSTRACT

An appreciation of the structures of the oligosaccharide chains which become attached to biomolecules (the process known as glycosylation), and their relevance to the biological function of the molecule concerned, has progressed rapidly in recent years with developments in site-selective protein glycosylation, oligosaccharide synthesis and in vivo targeting of oligosaccharides. These developments have necessitated the parallel development of effective analytical tools for the determination of the structures of glycosylation. The conclusion of studies in the 1980s and 1990s was that high pH anion exchange chromatography (HPAEC) was the most effective HPLC mode for the analysis of glycosylation. It allowed the fractionation of complex mixtures of monosaccharides or oligosaccharides, the latter in terms of charge, size, composition, anomerity and intra-chain linkages. This review reinvestigates whether HPAEC still appears to offer the most effective means of analysing glycosylation.


Subject(s)
Chromatography, Ion Exchange/methods , Monosaccharides/chemistry , N-Acetylneuraminic Acid/chemistry , Oligosaccharides/chemistry , Anions/chemistry , Biomarkers/chemistry , Carbohydrate Conformation , Glycosylation , Humans , Hydrogen-Ion Concentration , Monosaccharides/metabolism , Oligosaccharides/metabolism
12.
Cancer Res ; 70(23): 9693-702, 2010 Dec 01.
Article in English | MEDLINE | ID: mdl-21098704

ABSTRACT

Previous studies indicate that oncogenic stress activates the ATR-Chk1 pathway. Here, we show that ATR-Chk1 pathway engagement is essential for limiting genomic instability following oncogenic Ras transformation. ATR pathway inhibition in combination with oncogenic Ras expression synergistically increased genomic instability, as quantified by chromatid breaks, sister chromatid exchanges, and H2AX phosphorylation. This level of instability was significantly greater than that observed following ATR suppression in untransformed control cells. In addition, consistent with a deficiency in long-term genome maintenance, hypomorphic ATR pathway reduction to 16% of normal levels was synthetic lethal with oncogenic Ras expression in cultured cells. Notably, elevated genomic instability and synthetic lethality following suppression of ATR were not due to accelerated cycling rates in Ras-transformed cells, indicating that these synergistic effects were generated on a per-cell-cycle basis. In contrast to the synthetic lethal effects of hypomorphic ATR suppression, subtle reduction of ATR expression (haploinsufficiency) in combination with endogenous levels of K-ras(G12D) expression elevated the incidence of lung adenocarcinoma, spindle cell sarcoma, and thymic lymphoma in p53 heterozygous mice. K-ras(G12D)-induced tumorigenesis in ATR(+/-)p53(+/-) mice was associated with intrachromosomal deletions and loss of wild-type p53. These findings indicate that synergistic increases in genomic instability following ATR reduction in oncogenic Ras-transformed cells can produce 2 distinct biological outcomes: synthetic lethality upon significant suppression of ATR expression and tumor promotion in the context of ATR haploinsufficiency. These results highlight the importance of the ATR pathway both as a barrier to malignant progression and as a potential target for cancer treatment.


Subject(s)
Cell Cycle Proteins/genetics , Genes, ras/genetics , Genomic Instability , Neoplasms, Experimental/genetics , Protein Serine-Threonine Kinases/genetics , Animals , Antineoplastic Agents, Hormonal/pharmacology , Ataxia Telangiectasia Mutated Proteins , Blotting, Western , Cell Cycle Proteins/metabolism , Cell Transformation, Neoplastic/genetics , Cells, Cultured , Checkpoint Kinase 1 , Dose-Response Relationship, Drug , Female , Gene Expression Regulation, Neoplastic , Male , Mice , Mice, 129 Strain , Mice, Inbred C57BL , Mice, Knockout , NIH 3T3 Cells , Neoplasms, Experimental/metabolism , Neoplasms, Experimental/pathology , Protein Kinases/genetics , Protein Kinases/metabolism , Protein Serine-Threonine Kinases/metabolism , RNA Interference , Recombination, Genetic/drug effects , Reverse Transcriptase Polymerase Chain Reaction , Signal Transduction , Tamoxifen/pharmacology , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolism
13.
J Cell Biol ; 187(1): 15-23, 2009 Oct 05.
Article in English | MEDLINE | ID: mdl-19805627

ABSTRACT

The Tim (Timeless)-Tipin complex has been proposed to maintain genome stability by facilitating ATR-mediated Chk1 activation. However, as a replisome component, Tim-Tipin has also been suggested to couple DNA unwinding to synthesis, an activity expected to suppress single-stranded DNA (ssDNA) accumulation and limit ATR-Chk1 pathway engagement. We now demonstrate that Tim-Tipin depletion is sufficient to increase ssDNA accumulation at replication forks and stimulate ATR activity during otherwise unperturbed DNA replication. Notably, suppression of the ATR-Chk1 pathway in Tim-Tipin-deficient cells completely abrogates nucleotide incorporation in S phase, indicating that the ATR-dependent response to Tim-Tipin depletion is indispensible for continued DNA synthesis. Replication failure in ATR/Tim-deficient cells is strongly associated with synergistic increases in H2AX phosphorylation and DNA double-strand breaks, suggesting that ATR pathway activation preserves fork stability in instances of Tim-Tipin dysfunction. Together, these experiments indicate that the Tim-Tipin complex stabilizes replication forks both by preventing the accumulation of ssDNA upstream of ATR-Chk1 function and by facilitating phosphorylation of Chk1 by ATR.


Subject(s)
Carrier Proteins/metabolism , Cell Cycle Proteins/metabolism , DNA, Single-Stranded/biosynthesis , Intracellular Signaling Peptides and Proteins/metabolism , Nuclear Proteins/metabolism , Protein Kinases/metabolism , Protein Serine-Threonine Kinases/metabolism , Animals , Ataxia Telangiectasia Mutated Proteins , Carrier Proteins/chemistry , Carrier Proteins/physiology , Cell Cycle Proteins/genetics , Cell Cycle Proteins/physiology , Cell Line , Checkpoint Kinase 1 , DNA Replication , DNA, Single-Stranded/genetics , DNA-Binding Proteins , Enzyme Activation , Genetic Vectors , Immunohistochemistry , Intracellular Signaling Peptides and Proteins/deficiency , Intracellular Signaling Peptides and Proteins/genetics , Intracellular Signaling Peptides and Proteins/physiology , Lentivirus/genetics , Mice , Models, Genetic , NIH 3T3 Cells , Nuclear Proteins/chemistry , Nuclear Proteins/deficiency , Nuclear Proteins/physiology , Phosphorylation , Protein Kinases/genetics , Protein Kinases/physiology , Protein Serine-Threonine Kinases/genetics , Protein Serine-Threonine Kinases/physiology , RNA, Small Interfering/metabolism
14.
J Urol ; 181(4): 1742-6, 2009 Apr.
Article in English | MEDLINE | ID: mdl-19233424

ABSTRACT

PURPOSE: We describe our experience with laparoscopic ureteral reimplantation in 45 adults, and report success rates and complications at intermediate term followup. MATERIALS AND METHODS: We performed a retrospective chart review of 45 patients who underwent laparoscopic ureteral reimplantation between 1997 and 2007. Demographics, clinicopathological parameters, perioperative course, complications and followup studies were analyzed. RESULTS: Elective laparoscopic ureteral reimplantation was performed in 35 female and 10 male patients with a mean followup of 24.1 months (range 1 to 76). All patients presented with distal ureteral stricture with a mean stricture length of 3 cm and a mean +/- SD preoperative serum creatinine of 0.91 +/- 0.04 mg/dl. Mean patient age was 47.8 +/- 2.2 years (range 17 to 87). Mean American Society of Anesthesiologists score was 2 (range 1 to 3). Median estimated blood loss was 150 ml. The overall success rate, defined as radiographic evidence of no residual obstruction, symptoms, renal deterioration or need for subsequent procedures, was 96%. Two patients had recurrent strictures and 1 underwent nephrectomy for flank pain and preexisting chronic pyelonephritis. CONCLUSIONS: According to intermediate followup data laparoscopic ureteral reimplantation can be performed with an excellent success rate and low morbidity. Our data substantiate this technique as an effective method for managing distal ureteral stricture.


Subject(s)
Laparoscopy , Ureter/surgery , Ureteral Diseases/surgery , Adolescent , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Retrospective Studies , Treatment Outcome , Urologic Surgical Procedures/methods , Young Adult
15.
J Biol Chem ; 284(13): 8777-85, 2009 Mar 27.
Article in English | MEDLINE | ID: mdl-19112184

ABSTRACT

Genome integrity is maintained during DNA replication by coordination of various replisome-regulated processes. Although it is known that Timeless (Tim) is a replisome component that participates in replication checkpoint responses to genotoxic stress, its importance for genome maintenance during normal DNA synthesis has not been reported. Here we demonstrate that Tim reduction leads to genomic instability during unperturbed DNA replication, culminating in increased chromatid breaks and translocations (triradials, quadriradials, and fusions). Tim deficiency led to increased H2AX phosphorylation and Rad51 and Rad52 foci formation selectively during DNA synthesis and caused a 3-4-fold increase in sister chromatid exchange. The sister chromatid exchange events stimulated by Tim reduction were largely mediated via a Brca2/Rad51-dependent mechanism and were additively increased by deletion of the Blm helicase. Therefore, Tim deficiency leads to an increased reliance on homologous recombination for proper continuation of DNA synthesis. Together, these results indicate a pivotal role for Tim in maintaining genome stability throughout normal DNA replication.


Subject(s)
Cell Cycle Proteins/metabolism , DNA Damage/physiology , DNA Replication/physiology , Genomic Instability/physiology , Intracellular Signaling Peptides and Proteins/metabolism , Sister Chromatid Exchange/physiology , Animals , BRCA2 Protein/genetics , BRCA2 Protein/metabolism , Cell Cycle Proteins/genetics , Cells, Cultured , Histones/genetics , Histones/metabolism , Intracellular Signaling Peptides and Proteins/genetics , Mice , Mice, Knockout , Phosphorylation/physiology , Rad51 Recombinase/genetics , Rad51 Recombinase/metabolism , Rad52 DNA Repair and Recombination Protein/genetics , Rad52 DNA Repair and Recombination Protein/metabolism , RecQ Helicases/genetics , RecQ Helicases/metabolism
16.
Vet Clin Pathol ; 36(2): 209-11, 2007 Jun.
Article in English | MEDLINE | ID: mdl-17523099

ABSTRACT

A 1-year-old, 5- to 6-week pregnant cat was presented with a history of aborting 3 kittens the previous night. During the examination, the cat began to seizure and died. At necropsy, formalin-fixed tissues and blood smears prepared from an EDTA blood sample collected via cardiac puncture were submitted to a diagnostic laboratory. Examination of the blood smears revealed numerous large (15-75 microm) clumped macrophages containing dark blue intracytoplasmic organisms consistent with Cytauxzoon merozoites. Scattered erythrophagocytic macrophages were also observed. Within several erythrocytes, 1-2 small, round, ring-like piroplasms consistent with Cytauxzoon were observed. Histologic examination revealed numerous large, schizont-laden macrophages filling the blood vessels of multiple organs. The cytologic and histologic findings were diagnostic for Cytaxuzoon felis infection. This case was of particular interest because of the unusually large number of organism-laden macrophages in the cardiac blood sample, an uncommon finding in peripheral blood. Although the cat was presented for complications of abortion, it remains uncertain whether C felis organisms crossed the placenta and infected the fetuses or lead to the abortions.


Subject(s)
Abortion, Veterinary/blood , Babesiosis/veterinary , Cat Diseases/blood , Cat Diseases/diagnosis , Pregnancy Complications, Parasitic/veterinary , Abortion, Veterinary/etiology , Abortion, Veterinary/parasitology , Animals , Babesiosis/diagnosis , Babesiosis/parasitology , Cats , Fatal Outcome , Female , Piroplasmida/isolation & purification , Pregnancy , Pregnancy Complications, Parasitic/blood
17.
Biomed Chromatogr ; 20(6-7): 551-60, 2006.
Article in English | MEDLINE | ID: mdl-16779786

ABSTRACT

One of the most ubiquitous plasma proteins, alpha-1-acid glycoprotein (AGP), has a high affinity, low capacity binding for basic drugs positively charged at physiological pH. Moreover, as an acute phase protein its level is increased in various disease states in a manner that is likely to influence the free plasma level of a drug, the ability to attain minimum effective concentration and overall in vivo effectiveness. AGP is a glycoprotein known to display disease specific changes in glycosylation and although this secondary modification is not directly involved in drug binding, it may influence the conformation of the binding site. Binding studies reveal that alpha-1-acid glycoprotein bind mainly to the tuberculosis drugs: rifampicin; isoniazid; pyrazinamide; p-aminosalicylic acid; capreomycin; ethionamide; levofloxacin and ofloxacin out with the therapeutic plasma range tested. These results are however still considered significant as not only are alpha-1-acid glycoprotein levels increased during the acute phase response but specific alpha-1-acid glycoprotein from tuberculosis samples are subject to glycosylation changes which can increase the binding affinity and cause binding to occur at the therapeutic concentration.


Subject(s)
Antitubercular Agents/metabolism , Antitubercular Agents/therapeutic use , Orosomucoid/metabolism , Glycosylation , Humans , Hydrogen-Ion Concentration , Spectrometry, Fluorescence
19.
Biomed Chromatogr ; 17(6): 361-4, 2003 Sep.
Article in English | MEDLINE | ID: mdl-13680845

ABSTRACT

The concentration and glycosylation of alpha(1)-acid glycoprotein (AGP) alter significantly during inflammation. A definitive physiological role for AGP remains elusive and is the subject of extensive investigation. This study investigated the influence of AGP on the activity of collagenase-3, an important mediator of cartilage destruction in rheumatoid arthritis. AGP was isolated from normal and rheumatoid plasma. Fucosylation was determined by high pH anion-exchange chromatography; sialylation was assessed following enzymatic digest. Rheumatoid AGP displayed elevated fucosylation and sialylation compared with normal. The influence of each sample on collagenase-3 activity was measured fluorometrically. AGP influenced collagenase-3 catalysis and collagen binding, with catalytic activity correlating with fucosylation. Rheumatoid AGP exhibited less efficient inhibition than normal plasma AGP. It is hypothesized that AGP within rheumatoid synovial fluid may be inadequate to prevent excessive cartilage destruction and hence may exacerbate the disease process.


Subject(s)
Arthritis, Rheumatoid/enzymology , Collagenases/metabolism , Orosomucoid/metabolism , Arthritis, Rheumatoid/metabolism , Chromatography, Ion Exchange , Humans , Hydrogen-Ion Concentration , Matrix Metalloproteinase 13 , Recombinant Proteins/metabolism
20.
Biomed Chromatogr ; 17(2-3): 143-8, 2003.
Article in English | MEDLINE | ID: mdl-12717803

ABSTRACT

Tamoxifen is administered for the treatment of breast cancer; however resistance to therapy is commonplace. Postulated mechanisms of resistance to tamoxifen include altered pharmacology of the drug, changes in the structure and function of the oestrogen receptor and expression of genes that function to support the growth of cells resistant to tamoxifen. However, binding of drugs to proteins found in the plasma is known to affect the efficacy of drugs and alter their distribution. It is already known that tamoxifen is bound 99% to albumin. We investigated the interaction between the plasma protein, alpha-1-acid glycoprotein (AGP), and tamoxifen, since if binding did occur then the free plasma concentration of the drug would be reduced, resulting in the minimum effective concentration of tamoxifen not being attained. Using a recently described intrinsic fluorescence technique for the study of drug-protein interactions, the extent of binding between tamoxifen citrate and AGP was determined. Furthermore, analysis of binding of the known active metabolites of tamoxifen (4-hydroxytamoxifen, N-desmethyltamoxifen, N-desdimethyltamoxifen, cis-alpha-hydroxytamoxifen and trans-alpha-hydroxytamoxifen) to AGP was conducted. Tamoxifen citrate and metabolites were shown to bind AGP, however the level of interaction was low and negligible at the concentration of the drug found in the plasma.


Subject(s)
Orosomucoid/metabolism , Tamoxifen/metabolism , Humans , Protein Binding
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