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1.
RNA ; 30(9): 1246-1258, 2024 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-38942481

RESUMO

Direct methods for determining the fidelity of DNA polymerases are robust, with relatively little sample manipulation before sequencing. In contrast, methods for measuring RNA polymerase and reverse transcriptase fidelities are complicated by additional preparation steps that introduce ambiguity and error. Here, we describe a sequencing method, termed Roll-Seq, for simultaneously determining the individual fidelities of RNA polymerases and reverse transcriptases (RT) using Pacific Biosciences single molecule real-time sequencing. By using reverse transcriptases with high rolling-circle activity, Roll-Seq generates long concatemeric cDNA from a circular RNA template. To discern the origin of a mutation, errors are recorded and determined to occur within a single concatemer (reverse transcriptase error) or all concatemers (RNA polymerase error) over the cDNA strand. We used Roll-Seq to measure the fidelities of T7 RNA polymerases, a Group II intron-encoded RT (Induro), and two LINE RTs (Fasciolopsis buski R2-RT and human LINE-1). Substitution rates for Induro and R2-RT are the same for cDNA and second-strand synthesis while LINE-1 has 2.5-fold lower fidelity when performing second-strand synthesis. Deletion and insertion rates increase for all RTs during second-strand synthesis. In addition, we find that a structured RNA template impacts fidelity for both RNA polymerase and RT. The accuracy and precision of Roll-Seq enable this method to be applied as a complementary analysis to structural and mechanistic characterization of RNA polymerases and reverse transcriptases or as a screening method for RNAP and RT fidelity.


Assuntos
RNA Polimerases Dirigidas por DNA , DNA Polimerase Dirigida por RNA , DNA Polimerase Dirigida por RNA/metabolismo , DNA Polimerase Dirigida por RNA/genética , RNA Polimerases Dirigidas por DNA/metabolismo , RNA Polimerases Dirigidas por DNA/genética , Humanos , Proteínas Virais/genética , Proteínas Virais/metabolismo , Evolução Molecular , Mutação , DNA Complementar/genética
2.
Ann Hematol ; 2024 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-39249493

RESUMO

Unlike small molecule drugs and generic products, the active component of biologics and biosimilars are not identical chemical entities. Despite bioequivalence, there is limited evidence in clinical practice (i.e. Phase IV post-marketing surveillance) regarding the safety of biosimilar rituximab and even less so for "switching therapy" with respect to safety. Drug substitution by switching aims to realise cost savings by changing therapy involving a reference (biologic) product to a biosimilar. A retrospective analysis of safety outcomes including treatment-emergent adverse effects (TEAEs), rates of death and discontinuation of therapy, for all patients that received switching therapy (from reference to biosimilar rituximab, n = 33) was compared to patients who did not did not switch therapy (received biosimilar rituximab only, n = 18) at an Australian metropolitan cancer centre, over a six-month period. There was no statistical significant differences for any safety outcomes examined. Switching therapy for patients receiving rituximab does not lead to poorer safety outcomes.

3.
Palliat Support Care ; : 1-13, 2022 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-36503650

RESUMO

CONTEXT: The demand of palliative care is increasing due to the aging population and treatment hesitancy or intentional avoidance compromises symptom management. OBJECTIVES: To identify patient beliefs associated with medication hesitancy by using the theory of planned behavior (TPB) namely, attitudes, subjective norms, behavioral intention, and perceived behavioral control associated with medication hesitancy or intentional noncompliance by avoidance. METHODS: The Preferred Reporting Items for Systematic Reviews and Meta-Analysis guideline was followed to conduct a systematic literature search involving the CINAHL, Embase, MEDLINE, and PsycINFO databases from inception until March 2022. Hand-searched articles from reference lists and gray literature were included. Thematic analysis was conducted on qualitative data and triangulated with quantitative data. RESULTS: About 554 articles were retrieved from the literature search and 17 articles were included based on the eligibility criteria. Three subthemes that were identified under TPB constructs were attitude: negative attitude toward medications, passive attitude toward illness and inaccurate information about disease or medication; one subtheme was identified under subjective norms: perceived negative opinions from others; and one subtheme was identified under perceived behavioral control: perception of manageable symptoms. Quantitative data provided triangulation of qualitative findings related to fear of addiction and side effects, feelings of hopelessness, unclear direction and information, social stigma, endurable symptoms, and illness as determinants for medication avoidance. SIGNIFICANCE OF RESULTS: This systematic review highlighted some patient beliefs related to medication hesitancy or avoidance. Clinicians should take patient beliefs and concerns into consideration when creating treatment regimens for people receiving palliative care to optimize medication adherence and the quality of care.

4.
J Phys Chem A ; 125(45): 9736-9756, 2021 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-34731566

RESUMO

The charge density distribution in a novel cocrystal (1) complex of 1,3-dimethylxanthine (theophylline) and propanedioic acid (malonic acid) has been determined. The molecules crystallize in the triclinic, centrosymmetric space group P1̅, with four independent molecules (Z = 4) in the asymmetric unit (two molecules each of theophylline and malonic acid). Theophylline has a notably high hygroscopic nature, and numerous cocrystals have shown a significant improvement in stability to humidity. A charge density study of the novel polymorph has identified interesting theoretical results correlating the stability enhancement of theophylline via cocrystallization. Topological analysis of the electron density highlighted key differences (up to 17.8) in Laplacian (∇2ρ) between the experimental (EXP) and single-point (SP) models, mainly around intermolecular-bonded carbonyls. Further investigation via molecular electrostatic potential maps reaffirmed that the charge redistribution enhanced intramolecular hydrogen bonding, predominantly for N(2') and N(2) (61.2 and 61.8 kJ mol-1, respectively). An overall weaker lattice energy of the triclinic form (-126.1 kJ mol-1) compared to that of the monoclinic form (-133.8 kJ mol-1) suggests a lower energy threshold to overcome to initiate dissociation. Future work via physical testing of the novel cocrystal in both dissolution and solubility will further solidify the correlation between theoretical and experimental results.


Assuntos
Teofilina , Cristalização , Ligação de Hidrogênio , Solubilidade , Molhabilidade
5.
Tob Control ; 29(5): 570-576, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-31462578

RESUMO

INTRODUCTION: American Indians and Alaska Natives face disproportionately high rates of smoking and secondhand smoke (SHS) exposure. The Cheyenne River Sioux Tribe (CRST) is among the few Tribal Nations controlling commercial tobacco exposures in public and work places. We had an opportunity to explore effects of the new commercial tobacco-free policy (implemented in 2015) in an environmental health study (2014-2016) that collected information about commercial tobacco use and SHS prevalence and examined predictor variables of serum cotinine concentrations. METHODS: Self-reported survey data were used in quantile regression statistical modelling to explore changes in cotinine levels, based on smoking status, smokeless tobacco consumption and SHS exposure. RESULTS: From enrolled 225 adults, 51% (N=114) were current smokers. Among 88 non-tobacco users, 35 (40%) reported current SHS exposure. Significant differences in cotinine median concentrations were found among participants with and without current SHS exposure. Extremely high cotinine concentrations (~100 times larger than the median) were detected in some non-tobacco users. After implementing the new smoke-free air Tribal policy, cotinine decreased in participants with intermediate (3-15 ng/mL, non-tobacco users with SHS exposure) and high (>15 ng/mL, mainly tobacco users) cotinine levels showing association with an abatement of opportunities for SHS exposure. Significant predictors of cotinine levels were sampling year, current smoking and tobacco chewing. No gender differences were observed in cotinine. CONCLUSIONS: Our results show decrease in cotinine concentrations in CRST participants since implementation of their 'Smoke-Free Clean Air Act' in 2015.


Assuntos
Indígena Americano ou Nativo do Alasca , Cotinina/sangue , Política de Saúde , Prevenção do Hábito de Fumar , Fumar/sangue , Poluição por Fumaça de Tabaco/efeitos adversos , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
6.
Nucleic Acids Res ; 46(11): 5753-5763, 2018 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-29750267

RESUMO

Ribonucleic acid (RNA) is capable of hosting a variety of chemically diverse modifications, in both naturally-occurring post-transcriptional modifications and artificial chemical modifications used to expand the functionality of RNA. However, few studies have addressed how base modifications affect RNA polymerase and reverse transcriptase activity and fidelity. Here, we describe the fidelity of RNA synthesis and reverse transcription of modified ribonucleotides using an assay based on Pacific Biosciences Single Molecule Real-Time sequencing. Several modified bases, including methylated (m6A, m5C and m5U), hydroxymethylated (hm5U) and isomeric bases (pseudouridine), were examined. By comparing each modified base to the equivalent unmodified RNA base, we can determine how the modification affected cumulative RNA polymerase and reverse transcriptase fidelity. 5-hydroxymethyluridine and N6-methyladenosine both increased the combined error rate of T7 RNA polymerase and reverse transcriptases, while pseudouridine specifically increased the error rate of RNA synthesis by T7 RNA polymerase. In addition, we examined the frequency, mutational spectrum and sequence context of reverse transcription errors on DNA templates from an analysis of second strand DNA synthesis.


Assuntos
RNA Polimerases Dirigidas por DNA/metabolismo , DNA Polimerase Dirigida por RNA/metabolismo , RNA/química , Proteínas Virais/metabolismo , Sequência de Bases , DNA Complementar/biossíntese , DNA Complementar/química , RNA/biossíntese , Transcrição Reversa , Ribonucleotídeos/química , Ribonucleotídeos/metabolismo , Transcrição Gênica
7.
Nucleic Acids Res ; 46(13): e79, 2018 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-29741723

RESUMO

DNA ligases are key enzymes in molecular and synthetic biology that catalyze the joining of breaks in duplex DNA and the end-joining of DNA fragments. Ligation fidelity (discrimination against the ligation of substrates containing mismatched base pairs) and bias (preferential ligation of particular sequences over others) have been well-studied in the context of nick ligation. However, almost no data exist for fidelity and bias in end-joining ligation contexts. In this study, we applied Pacific Biosciences Single-Molecule Real-Time sequencing technology to directly sequence the products of a highly multiplexed ligation reaction. This method has been used to profile the ligation of all three-base 5'-overhangs by T4 DNA ligase under typical ligation conditions in a single experiment. We report the relative frequency of all ligation products with or without mismatches, the position-dependent frequency of each mismatch, and the surprising observation that 5'-TNA overhangs ligate extremely inefficiently compared to all other Watson-Crick pairings. The method can easily be extended to profile other ligases, end-types (e.g. blunt ends and overhangs of different lengths), and the effect of adjacent sequence on the ligation results. Further, the method has the potential to provide new insights into the thermodynamics of annealing and the kinetics of end-joining reactions.


Assuntos
DNA Ligases , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Análise de Sequência de DNA/métodos , Pareamento Incorreto de Bases , Reparo do DNA por Junção de Extremidades
8.
Org Biomol Chem ; 15(3): 576-580, 2017 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-27991628

RESUMO

Preparation of N-(indol-2-yl)amides and N-(indol-3-yl)amides are scarce in the scientific literature due to unstable intermediates impeding current reported syntheses. We have employed cheap and readily available substrates in the Curtius rearrangement of indole-3-carboxazide to afford N-(indol-3-yl)amides. The reaction is observed for alkyl and aryl carboxylic acids and both N-substituted or 1H-indole derivatives are tolerated. This approach was extended to the preparation of N-(indol-2-yl)amides from the corresponding indole-2-carboxazides.

9.
Bioorg Med Chem ; 23(24): 7676-84, 2015 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-26616289

RESUMO

The three peroxisome proliferator-activated receptor (PPAR) isoforms; PPARα, PPARγ and PPARδ, play central roles in lipid metabolism and glucose homeostasis. Dual PPARα/γ agonists, which stimulate both PPARα and PPARγ isoforms to similar extents, are gaining popularity as it is believed that they are able to ameliorate the unwanted side effects of selective PPARα and PPARγ agonists; and may also be used to treat dyslipidemia and type 2 diabetes mellitus simultaneously. In this study, virtual screening of natural product libraries, using both structure-based and ligand-based drug discovery approaches, identified ten potential dual PPARα/γ agonist lead compounds (9-13 and 16-20). In vitro assays confirmed these compounds to show no statistically significant toxicity to cells, with the exception of compound 12 which inhibited cell growth to 74.5%±3.5 and 54.1%±3.7 at 50µM and 100µM, respectively. In support of their potential as dual PPARα/γ agonists, all ten compounds upregulated the expression of cholesterol transporters ABCA1 and ABCG1 in THP-1 macrophages, with indoline derivative 16 producing the greatest elevation (2.3-fold; 3.3-fold, respectively). Furthermore, comparable to the activity of established PPARα and PPARγ agonists, compound 16 stimulated triacylglycerol accumulation during 3T3-L1 adipocyte differentiation as well as fatty acid ß-oxidation in HuH7 hepatocytes.


Assuntos
Metabolismo dos Lipídeos/efeitos dos fármacos , PPAR alfa/agonistas , PPAR gama/agonistas , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/farmacologia , Células 3T3-L1 , Animais , Linhagem Celular , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/metabolismo , Desenho de Fármacos , Células HEK293 , Humanos , Ligantes , Camundongos , Simulação de Acoplamento Molecular , PPAR alfa/metabolismo , PPAR gama/metabolismo
10.
Clin Exp Pharmacol Physiol ; 41(9): 623-7, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25115309

RESUMO

GABAB autoreceptors inhibit release of GABA from GABAergic nerve terminals. Agonists of these receptors (e.g. baclofen) inhibit, whereas antagonists (e.g. (+)-(S)-5,5-dimethylmorpholinyl-2-acetic acid; Sch 50911) enhance release of the transmitter. The actions of thymol (2-isopropyl-5-methylphenol) and the structurally related compound 2-tert-butyl-4-methylphenol, (4MP) on the release of [(3) H]-GABA were examined in rat neocortical slices where the GABAergic nerves had been preloaded with [(3) H]-GABA and subsequently stimulated electrically on two occasions (S1 and S2 ). Test agents, baclofen and Sch 50911 were added to the superfusion medium prior to the second period of stimulation (S2 ). Stimulation-induced overflow (SIO) of [(3) H]-GABA as a consequence of these stimulations (SIO1 and SIO2 ) were calculated and the effects of agents determined by comparing the SIO2 /SIO1 ratio in the presence of each agent with that in control tissue. Thymol potentiated the release of [(3) H]-GABA (EC50 170 µmol/L), an action reversed by baclofen (2 µmol/L). Baclofen alone had little effect on GABA release. Release of [(3) H]-GABA was inhibited by 4MP (IC50 3 µmol/L) and this effect was blocked by Sch 50911 (10 µmol/L). Alone, Sch 50911 markedly potentiated the release of GABA. These results imply that 4MP is an agonist of GABAB autoreceptors; however, further studies are needed to confirm that thymol is indeed a GABAB autoreceptor antagonist. Of interest are structural differences in these agents. Thymol has a propyl group in the ortho position relative to the phenolic hydroxyl, whereas in 4MP this is a butyl group and the methyl group moves from position 5 to 4. Whether one or both of these changes was responsible for the above actions is unknown.


Assuntos
Autorreceptores/agonistas , Autorreceptores/antagonistas & inibidores , Antagonistas de Receptores de GABA-B/farmacologia , Receptores de GABA-B/metabolismo , Timol/farmacologia , Ácido gama-Aminobutírico/metabolismo , Animais , Baclofeno/farmacologia , Hidroxitolueno Butilado/análogos & derivados , Hidroxitolueno Butilado/química , Hidroxitolueno Butilado/farmacologia , Relação Dose-Resposta a Droga , Agonistas GABAérgicos/farmacologia , Antagonistas de Receptores de GABA-B/química , Masculino , Morfolinas/farmacologia , Neocórtex/efeitos dos fármacos , Neocórtex/metabolismo , Fenóis/farmacologia , Ratos , Timol/química
11.
BMC Anesthesiol ; 14: 33, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24914400

RESUMO

BACKGROUND: Tramadol is an atypical centrally acting analgesic agent available as both oral and parenteral preparations. For patients who are unable to take tramadol orally, the subcutaneous route of administration offers an easy alternative to intravenous or intramuscular routes. This study aimed to characterise the absorption pharmacokinetics of a single subcutaneous dose of tramadol in severely ill patients and in healthy subjects. METHODS/DESIGN: Blood samples (5 ml) taken at intervals from 2 minutes to 24 hours after a subcutaneous dose of tramadol (50 mg) in 15 patients (13 male, two female) and eight healthy male subjects were assayed using high performance liquid chromatography. Pharmacokinetic parameters were derived using a non-compartmental approach. RESULTS: There were no statistically significant differences between the two groups in the following parameters (mean ± SD): maximum venous concentration 0.44 ± 0.18 (patients) vs. 0.47 ± 0.13 (healthy volunteers) mcg/ml (p = 0.67); area under the plasma concentration-time curve 177 ± 109 (patients) vs. 175 ± 75 (healthy volunteers) mcg/ml*min (p = 0.96); time to maximum venous concentration 23.3 ± 2 (patients) vs. 20.6 ± 18.8 (healthy volunteers) minutes (p = 0.73) and mean residence time 463 ± 233 (patients) vs. 466 ± 224 (healthy volunteers) minutes (p = 0.97). CONCLUSIONS: The similar time to maximum venous concentration and mean residence time suggest similar absorption rates between the two groups. These results indicate that the same dosing regimens for subcutaneous tramadol administration may therefore be used in both healthy subjects and severely ill patients. TRIAL REGISTRATION: ACTRN12611001018909.


Assuntos
Analgésicos Opioides/farmacocinética , Cromatografia Líquida de Alta Pressão/métodos , Tramadol/farmacocinética , Adulto , Analgésicos Opioides/administração & dosagem , Área Sob a Curva , Estudos de Casos e Controles , Estado Terminal , Feminino , Humanos , Injeções Subcutâneas , Masculino , Pessoa de Meia-Idade , Tramadol/administração & dosagem , Adulto Jovem
12.
Am J Pharm Educ ; : 101288, 2024 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-39304009

RESUMO

OBJECTIVE: This study explored the impact of Mental Health First Aid (MHFA) training and simulated psychosis care role-plays on pharmacy students' stigma, confidence and behaviors when supporting people experiencing mental health symptoms or crises. METHODS: MHFA training was delivered to final year pharmacy students. Post-MHFA training, students were invited to participate in simulated psychosis care role-plays (co-designed and content validated with mental health stakeholders) with trained actors. Role-plays were observed by peers, tutors and mental health consumer educators (MHCEs). Students immediately engaged in self-assessment, feedback and debrief discussions with peers, tutors and MHCEs. Quantitative analyses (ANOVA and chi-square tests) were conducted on scores awarded by each rater (self, tutor, MHCE) and for each scenario (n=3). Students completed a 15-item survey exploring mental health stigma and mental health confidence, at three timepoints (pre-MHFA training, post-MHFA training, post-role-plays). Survey scores were analyzed using paired t-tests. RESULTS: Of 209 MHFA-trained students, 86 participated in role-play. Self-assessment mean score was lowest and MHCEs' mean score highest. Post-MHFA training, 14 survey item scores significantly improved, implying reduced stigma and increased confidence in providing psychosis care. Post-role-play scores suggested improvements in 12 survey items. CONCLUSION: Psychosis care role-plays are associated with short-term improvements in pharmacy students' stigma and mental health confidence post-MHFA training; students' self-assessment scores are lower than tutors and MHCEs. It is recommended that future studies further integrate observed behaviors with self-reported data and use simulated patients in clinical practice to evaluate MHFA outcomes longitudinally.

13.
Int J Pharm Pract ; 31(2): 218-224, 2023 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-36541698

RESUMO

OBJECTIVES: To examine the self-perceived knowledge, confidence and preparedness of undergraduate pharmacy students to provide palliative care. METHODS: A descriptive exploratory analysis was conducted in 2021 at an Australian university involving final-year pharmacy students (n = 200) who were provided with the opportunity to complete a survey on self-perceived knowledge, confidence and preparedness overall and with respect to a range of graduate capabilities which are essential to provide care in palliative care settings. Key capability areas include: communication, showing empathy, making clinical judgements and self-reflection. This was measured using the Palliative Care Curriculum for Undergraduates Questionnaire which was distributed electronically. Descriptive statistics were undertaken and Mann-Whitney U tests were used to explore any differences in outcomes with respect to factors related to demographics, personal experience and education. Thematic analysis was utilised for qualitative data. KEY FINDINGS: Forty-five percent of the student cohort (n = 89) responded, 70% of whom were female, and the median age for students was 22 years. Median scores (interquartile range) were modest for overall self-perceived knowledge: 5.0 (3.0-5.0), confidence: 4.0 (3.0-5.0) and preparedness: 4.0 (2.5-5.0). Students who had participated in learning about palliative care through clinical placements (n = 25, 28%), self-directed learning activities (n = 18, 20%) or case-/problem-based learning (n = 14, 16%) demonstrated a statistically significant increase in overall preparedness (P = 0.017), confidence with specific capabilities including evidence-based practice (P = 0.013), responding to medication queries (P < 0.05) and managing symptoms other than pain (P = 0.018). CONCLUSIONS: Findings suggest students were confident to manage symptoms and medication-related issues but less confident to address distress or discuss sensitive matters with patients and their families. There may be a need for greater exposure and practical experience in palliative care settings.


Assuntos
Cuidados Paliativos , Farmácia , Humanos , Feminino , Adulto Jovem , Adulto , Masculino , Cuidados Paliativos/métodos , Austrália , Estudantes , Currículo
14.
Artigo em Inglês | MEDLINE | ID: mdl-36429656

RESUMO

Many tribal populations are characterized by health disparities, including higher rates of infection, metabolic syndrome, and cancer-all of which are mediated by the immune system. Members of the Navajo Nation have suffered chronic low-level exposure to metal mixtures from uranium mine wastes for decades. We suspect that such metal and metalloid exposures lead to adverse health effects via their modulation of immune system function. We examined the relationships between nine key metal and metalloid exposures (in blood and urine) with 11 circulating biomarkers (cytokines and CRP in serum) in 231 pregnant Navajo women participating in the Navajo Birth Cohort Study. Biomonitored levels of uranium and arsenic species were considerably higher in participants than NHANES averages. Each biomarker was associated with a unique set of exposures, and arsenic species were generally immunosuppressive (decreased cellular and humoral stimulating cytokines). Overall, our results suggest that environmental metal and metalloid exposures modulate immune status in pregnant Navajo women, which may impact long-term health outcomes in mothers and their children.


Assuntos
Arsênio , Indígenas Norte-Americanos , Urânio , Gravidez , Criança , Humanos , Feminino , Estudos de Coortes , Urânio/análise , Arsênio/efeitos adversos , Citocinas , Inquéritos Nutricionais , Coorte de Nascimento , Biomarcadores
15.
Curr Protoc ; 2(11): e595, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36374013

RESUMO

The formation and persistence of DNA damage can impact biological processes such as DNA replication and transcription. To maintain genome stability and integrity, organisms rely on robust DNA damage repair pathways. Techniques to detect and locate DNA damage sites across a genome enable an understanding of the consequences of DNA damage as well as how damage is repaired, which can have key diagnostic and therapeutic implications. Importantly, advancements in technology have enabled the development of high-throughput sequencing-based DNA damage detection methods. These methods require DNA enrichment or amplification steps that limit the ability to quantitate the DNA damage sites. Further, each of these methods is typically tailored to detect only a specific type of damage. RAre DAmage and Repair (RADAR) sequencing is a DNA sequencing workflow that overcomes these limitations and enables detection and quantitation of DNA damage sites in any organism on a genome-wide scale. RADAR-seq works by replacing DNA damage sites with a patch of modified bases that can be directly detected by Pacific Biosciences Single-Molecule Real Time sequencing. Here, we present three protocols that enable detection of thymine dimers and ribonucleotides in bacterial and archaeal genomes. Basic Protocol 1 enables construction of a reference genome required for RADAR-seq analyses. Basic Protocol 2 describes how to locate, quantitate, and compare thymine dimer levels in Escherichia coli exposed to varying amounts of UV light. Basic Protocol 3 describes how to locate, quantitate, and compare ribonucleotide levels in wild-type and ΔRNaseH2 Thermococcus kodakarensis. Importantly, all three protocols provide in-depth steps for data analysis. Together they serve as proof-of-principle experiments that will allow users to adapt the protocols to locate and quantitate a wide variety of DNA damage sites in any organism. © 2022 New England Biolabs. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Constructing a reference genome utilizing SMRT sequencing Basic Protocol 2: Mapping and quantitating genomic thymine dimer formation in untreated versus UV-irradiated E. coli using RADAR-seq Basic Protocol 3: Mapping and quantitating genomic ribonucleotide incorporation in wildtype versus ΔRNaseH2 T. kodakarensis using RADAR-seq.


Assuntos
Reparo do DNA , Dímeros de Pirimidina , Dímeros de Pirimidina/genética , Reparo do DNA/genética , Escherichia coli/genética , Dano ao DNA/genética , Ribonucleotídeos , Genoma Arqueal
16.
Sci Rep ; 12(1): 13017, 2022 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-35906281

RESUMO

In vitro transcribed synthetic messenger RNAs (mRNAs) represent a novel therapeutic modality. To overcome the inherent immunogenicity, as well as to increase the therapeutic efficacy of the molecules, uridine analogs-such as pseudouridine (Ψ) and N1-methyl-pseudouridine (m1Ψ), are incorporated in the synthetic mRNA. To decipher the fidelity with which these modifications are incorporated during the in vitro transcription (IVT) process, we compared the incorporation fidelity of uridine analogs with different RNA polymerases. We demonstrate that m1Ψ is incorporated with higher fidelity than Ψ. The fidelity of nucleotide incorporation differs between RNA polymerases; however, the spectrum of mutations observed between the RNAPs is similar. We also show that the array of nucleotide misincorporation is not dependent on the template DNA sequence context and that the distribution of these misincorporated nucleotides is not localized to any specific region along the length of the RNA. Based on our findings, we introduce a novel method to improve uridine analog incorporation fidelity during IVT. Our proof-of-concept experiments for higher-fidelity incorporation of uridine analogs during IVT provide guidelines when choosing RNAPs for the generation of modified uridine-containing mRNAs in vitro.


Assuntos
Nucleotídeos , Pseudouridina , Sequência de Bases , Pseudouridina/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Uridina/metabolismo
17.
Clin Exp Pharmacol Physiol ; 38(4): 203-7, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21255061

RESUMO

1. GABA(B) autoreceptors are a subclass of GABA(B) receptors that inhibit the release of [(3) H]GABA from GABAergic nerve terminals. Baclofen is an agonist that reduces [(3)H]GABA, whilst the antagonist (+)-(S)-5,5-dimethylmorpholinyl-2-acetic acid (Sch 50911) enhances [(3)H]GABA release in electrically-stimulated rat neocortical brain slices preloaded with [(3)H]GABA. Here, the pharmacological actions of a series of compounds derived from the positive allosteric modulator, 2,6-di-tert-butyl-4-(3-hydroxy-2,2-dimethyl-propyl)-phenol (CGP7930), were examined on GABA(B) autoreceptors. 2. The compound, 3-(3,5-ditbutyl-4-hydroxyphenyl)-2,2-dimethyl-1-oximinopropane (compound 2), at 10 µmol/L had little effect on the stimulation-induced overflow of [(3)H]GABA when superfused alone, but when superfused in the presence of baclofen (2 µmol/L) inhibited the overflow of [(3)H]GABA. These effects were reversed by Sch 50911 (10 µmol/L). Although compounds 1-(4-chlorophenyl)-3-(4-hydroxy-3,5-diisopropylphenyl)-2-methyl-1-oximinopropane (compound 1), 1-[(3,5-ditbutyl-4-hydroxyphenyl)methyl]-1-oximinomethylcyclohexane (compound 3), 3-(3,5-ditbutyl-4-hydroxyphenyl)-1,2-diphenyl-1-oximinopropane (compound 4) and 4-(3,5-ditbutyl-4-hydroxyphenyl)-3-methyl-2-oximinobutane (compound 5) (each at 10 µmol/L) tended to reduce the stimulation-induced overflow in the presence of baclofen, an effect reversed by Sch 50911, their status as modulators is not confirmed in the present study. 3. Another derivative, 3-(3,5-ditbutyl-4-hydroxyphenyl)-1-(4-chlorophenyl)-2-methyl-1-oximinopropane (compound 6) (10 µmol/L), acted as an agonist as it inhibited the release of [(3)H]GABA by 32% (EC(50) of 3.3 µmol/L), an effect reversed by Sch 50911 (10 µmol/L). The other compounds, 1-[(3,5-ditbutyl-4-hydroxyphenyl)methyl]-1-methyl-2-oximinocyclohexane (compound 7), 4-(3,5-ditbutyl-4-hydroxyphenyl)-3,3-dimethyl-2-oximinobutane (compound 8) and 4-(4-hydroxy-3,5-diisopropylphenyl)-3,3-dimethyl-2-oximinobutane (compound 9) (each at 10 µmol/L), were inactive. 4. These findings indicate that this series of compounds show different modes of activity at GABA(B) autoreceptors.


Assuntos
Autorreceptores/metabolismo , Oximas/farmacologia , Propofol/análogos & derivados , Propofol/farmacologia , Receptores de GABA-B/metabolismo , Animais , Baclofeno/farmacologia , Estimulação Elétrica , Agonistas dos Receptores de GABA-B/farmacologia , Antagonistas de Receptores de GABA-B/farmacologia , Masculino , Morfolinas/farmacologia , Neocórtex/diagnóstico por imagem , Neocórtex/efeitos dos fármacos , Neocórtex/metabolismo , Fenóis/farmacologia , Cintilografia , Ratos , Ratos Sprague-Dawley , Trítio/análise , Ácido gama-Aminobutírico/metabolismo
18.
Sci Rep ; 11(1): 160, 2021 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-33420304

RESUMO

The BLL lectin from the edible Japanese "Kurokawa" mushroom (Boletopsis leucomelaena) was previously reported to bind to N-glycans harboring terminal N-acetylglucosamine (GlcNAc) and to induce apoptosis in a leukemia cell line. However, its gene has not been reported. In this study, we used a transcriptomics-based workflow to identify a full-length transcript of a BLL functional ortholog (termed BGL) from Boletopsis grisea, a close North American relative of B. leucomelaena. The deduced amino acid sequence of BGL was an obvious member of fungal fruit body lectin family (Pfam PF07367), a highly conserved group of mushroom lectins with a preference for binding O-glycans harboring the Thomsen-Friedenreich antigen (TF-antigen; Galß1,3GalNAc-α-) and having two ligand binding sites. Functional characterization of recombinant BGL using glycan microarray analysis and surface plasmon resonance confirmed its ability to bind both the TF-antigen and ß-GlcNAc-terminated N-glycans. Structure-guided mutagenesis of BGL's two ligand binding clefts showed that one site is responsible for binding TF-antigen structures associated with O-glycans, whereas the second site specifically recognizes N-glycans with terminal ß-GlcNAc. Additionally, the two sites show no evidence of allosteric communication. Finally, mutant BGL proteins having single functional bindings site were used to enrich GlcNAc-capped N-glycans or mucin type O-glycopeptides from complex samples in glycomics and glycoproteomics analytical workflows.


Assuntos
Basidiomycota/metabolismo , Proteínas Fúngicas/metabolismo , Lectinas/metabolismo , Agaricales/química , Agaricales/genética , Agaricales/metabolismo , Sequência de Aminoácidos , Basidiomycota/química , Basidiomycota/genética , Sítios de Ligação , Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Humanos , Lectinas/química , Lectinas/genética , Polissacarídeos/química , Polissacarídeos/metabolismo , Ligação Proteica , Alinhamento de Sequência
19.
Eur J Anaesthesiol ; 27(3): 241-6, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19918182

RESUMO

BACKGROUND AND OBJECTIVE: Pain relief using intermittent subcutaneous injections of an opioid (e.g. morphine) avoids the need for venous access and does not require complex or expensive pumps and devices. Although data on the pharmacokinetics of subcutaneous morphine exist, there are no comparable data for fentanyl in healthy volunteers. Therefore, the aim of this study was to characterize the pharmacokinetics of 200 microg fentanyl administered as a single bolus dose via the subcutaneous route in healthy opioid-naive volunteers. METHODS: Nine healthy male volunteers were given 200 microg of subcutaneous fentanyl for more than 30 s. Opioid effects were blocked by administration of naltrexone. Venous blood samples taken at intervals from 5 min to 10 h after the dose were assayed using a liquid chromatography-mass spectrometry method. Pharmacokinetic data were analysed using a noncompartmental analysis approach. RESULTS: After subcutaneous bolus dose administration, the median maximum concentration of fentanyl was 0.55 ng ml(-1) (range 0.28-0.87 ng ml(-1)), reached at a median time of 15 min (range 10-30 min). The terminal half-life was 10.00 h (range 5.48-16.37 h). CONCLUSION: Absorption of subcutaneous fentanyl was relatively rapid and similar to the rate of absorption previously reported for subcutaneous morphine; the terminal half-life for fentanyl was substantially longer (10 h) than that of morphine (2.1 h), and blood concentrations were no more variable than that after administration by other nonintravenous routes.


Assuntos
Fentanila/administração & dosagem , Fentanila/farmacocinética , Adulto , Fentanila/sangue , Humanos , Injeções Subcutâneas , Masculino , Adulto Jovem
20.
J Pain Palliat Care Pharmacother ; 34(4): 225-236, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32730108

RESUMO

Evidence to support the use of antipsychotic medications for the management of delirium symptoms remains limited. The primary objective of this study was to compare the effect of antipsychotic and non-antipsychotic treatments for delirium symptoms among palliative care inpatients. Secondary outcomes were use of midazolam and overall survival. This involved retrospective analysis of medical records (November 2018 to April 2019) for adult palliative care patients diagnosed with delirium at an Australian tertiary hospital. NuDESC was used to assess symptoms daily from baseline to Day 3. All 65 patients (mean age 73.5 ± 13.7 years, 48% female, 59% with cancer) included received standard care which included management of underlying causes of delirium symptoms, of which 17 received additional treatment using antipsychotic medications. Forty-eight did not receive any antipsychotic medication. An absolute reduction in NuDESC score was observed in the group that did not receive additional treatment using antipsychotics (by 1.37 units, 95% CI 0.79-1.95, p < 0.0001). A significantly higher proportion of midazolam use (n = 9, 53% versus n = 2, 4%, p < 0.001) and shorter median survival (13 days versus 26 days, p = 0.03) was observed in the group of patients that received antipsychotics. The use of antipsychotic medications in addition to standard treatments targeting underlying precipitants did not lead to a significant improvement in delirium symptoms and was associated with a greater midazolam use and lower median duration of survival. Individualized treatment of underlying causes still appears to be essential in the management of delirium in patients receiving palliative care.


Assuntos
Antipsicóticos , Delírio , Adulto , Idoso , Idoso de 80 Anos ou mais , Antipsicóticos/uso terapêutico , Austrália , Delírio/tratamento farmacológico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Cuidados Paliativos , Estudos Retrospectivos
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