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The analysis of prostaglandin urinary metabolites is valuable for assessing physiological processes and identifying disease biomarkers. These metabolites, derived from the breakdown of prostaglandins, offer a noninvasive means to gauge prostaglandin production and its potential impact on various biological functions. We report an efficient LC-MS method of four commonly analyzed prostaglandin urinary metabolites including tetranor-PGEM (derived from PGE 2 ), tetranor-PGDM, 11β-PGF 2α , and 2,3-dinor-11β-PGF 2α (derived from PGD 2 ). Each metabolite possesses distinct characteristics and clinical applications, collectively contributing to our understanding of prostaglandin-mediated pathways., (© 2025. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)

Bioactive lipid mediators derived from arachidonic acid constitute an attractive pool of metabolites that reflect cellular function and signaling, as well as potential biomarkers that may respond quantitatively to disease progression or pharmacological treatment. Their quantitative measurement in biological samples is complicated by the number of isomers that share common structural features, which are not easily distinguished by immunoassays or reverse phase chromatography-tandem mass spectrometry. Here, we present a method that enables the rapid analysis of a panel of over 25 biologically important eicosanoids in a 96-well format for cell culture supernatants, plasma, and organ tissues using convergence chromatography-tandem mass spectrometry to resolve these analytes of interest., (© 2025. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: Heart failure requires complex management, and increased patient knowledge has been shown to improve outcomes. This study assessed the knowledge of Chat Generative Pre-trained Transformer (ChatGPT) and its appropriateness as a supplemental resource of information for patients with heart failure., Method: A total of 107 frequently asked heart failure-related questions were included in 3 categories: "basic knowledge" (49), "management" (41) and "other" (17). Two responses per question were generated using both GPT-3.5 and GPT-4 (i.e., two responses per question per model). The accuracy and reproducibility of responses were graded by two reviewers, board-certified in cardiology, with differences resolved by a third reviewer, board-certified in cardiology and advanced heart failure. Accuracy was graded using a four-point scale: (1) comprehensive, (2) correct but inadequate, (3) some correct and some incorrect, and (4) completely incorrect., Results: GPT-4 provided 107/107 (100%) responses with correct information. Further, GPT-4 displayed a greater proportion of comprehensive knowledge for the categories of "basic knowledge" and "management" (89.8% and 82.9%, respectively). For GPT-3, there were two total responses (1.9%) graded as "some correct and incorrect" for GPT-3.5, while no "completely incorrect" responses were produced. With respect to comprehensive knowledge, GPT-3.5 performed best in the "management" category and "other" category (prognosis, procedures, and support) (78.1%, 94.1%). The models also provided highly reproducible responses, with GPT-3.5 scoring above 94% in every category and GPT-4 with 100% for all answers., Conclusions: GPT-3.5 and GPT-4 answered the majority of heart failure-related questions accurately and reliably. If validated in future studies, ChatGPT may serve as a useful tool in the future by providing accessible health-related information and education to patients living with heart failure. In its current state, ChatGPT necessitates further rigorous testing and validation to ensure patient safety and equity across all patient demographics., Competing Interests: Disclosures R.G. is a consultant for Pfizer, Alnylam, and AstraZeneca. None of the other authors have interests to disclose., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Background: Amyloidosis, a rare multisystem condition, often requires complex, multidisciplinary care. Its low prevalence underscores the importance of efforts to ensure the availability of high-quality patient education materials for better outcomes. ChatGPT (OpenAI) is a large language model powered by artificial intelligence that offers a potential avenue for disseminating accurate, reliable, and accessible educational resources for both patients and providers. Its user-friendly interface, engaging conversational responses, and the capability for users to ask follow-up questions make it a promising future tool in delivering accurate and tailored information to patients., Objective: We performed a multidisciplinary assessment of the accuracy, reproducibility, and readability of ChatGPT in answering questions related to amyloidosis., Methods: In total, 98 amyloidosis questions related to cardiology, gastroenterology, and neurology were curated from medical societies, institutions, and amyloidosis Facebook support groups and inputted into ChatGPT-3.5 and ChatGPT-4. Cardiology- and gastroenterology-related responses were independently graded by a board-certified cardiologist and gastroenterologist, respectively, who specialize in amyloidosis. These 2 reviewers (RG and DCK) also graded general questions for which disagreements were resolved with discussion. Neurology-related responses were graded by a board-certified neurologist (AAH) who specializes in amyloidosis. Reviewers used the following grading scale: (1) comprehensive, (2) correct but inadequate, (3) some correct and some incorrect, and (4) completely incorrect. Questions were stratified by categories for further analysis. Reproducibility was assessed by inputting each question twice into each model. The readability of ChatGPT-4 responses was also evaluated using the Textstat library in Python (Python Software Foundation) and the Textstat readability package in R software (R Foundation for Statistical Computing)., Results: ChatGPT-4 (n=98) provided 93 (95%) responses with accurate information, and 82 (84%) were comprehensive. ChatGPT-3.5 (n=83) provided 74 (89%) responses with accurate information, and 66 (79%) were comprehensive. When examined by question category, ChatGTP-4 and ChatGPT-3.5 provided 53 (95%) and 48 (86%) comprehensive responses, respectively, to "general questions" (n=56). When examined by subject, ChatGPT-4 and ChatGPT-3.5 performed best in response to cardiology questions (n=12) with both models producing 10 (83%) comprehensive responses. For gastroenterology (n=15), ChatGPT-4 received comprehensive grades for 9 (60%) responses, and ChatGPT-3.5 provided 8 (53%) responses. Overall, 96 of 98 (98%) responses for ChatGPT-4 and 73 of 83 (88%) for ChatGPT-3.5 were reproducible. The readability of ChatGPT-4's responses ranged from 10th to beyond graduate US grade levels with an average of 15.5 (SD 1.9)., Conclusions: Large language models are a promising tool for accurate and reliable health information for patients living with amyloidosis. However, ChatGPT's responses exceeded the American Medical Association's recommended fifth- to sixth-grade reading level. Future studies focusing on improving response accuracy and readability are warranted. Prior to widespread implementation, the technology's limitations and ethical implications must be further explored to ensure patient safety and equitable implementation., (©Ryan C King, Jamil S Samaan, Yee Hui Yeo, Yuxin Peng, David C Kunkel, Ali A Habib, Roxana Ghashghaei. Originally published in JMIR Cardio (https://cardio.jmir.org), 19.04.2024.)

Background: Mitral valve stenosis can be a highly symptomatic condition with significant complications if left untreated. In such cases, mitral valve replacement with a bioprosthetic or mechanical valve may be a viable solution to prevent progressive disease. Current guidelines do not recommend continued anticoagulation beyond 6 months for patients who have undergone bioprosthetic valve replacement without a separate indication for anticoagulation. With this case discussion we aim to 1) Review the current indications for anticoagulation for bioprosthetic mitral valves in patients without atrial fibrillation and 2) Discuss the constellation of comorbidities that may affect the decision to begin anticoagulation therapy., Case Presentation: We present a case describing a 55-year-old male with end-stage renal disease, coronary artery disease with coronary artery bypass graft surgery, and bioprosthetic mitral valve replacement 2 years prior with rapid degeneration of the replaced valve and on warfarin without a clear indication for anticoagulation. The patient was admitted for symptomatic, severe mitral stenosis and consideration of transcatheter mitral valve-in-valve replacement. During hospital admission, warfarin was discontinued and replaced with prophylactic anticoagulation. However, 8 days after warfarin cessation an intraoperative transesophageal echocardiography revealed a newly developed large left atrial thrombus leading to cancellation of the planned operation., Conclusions: This patient developed a left atrial thrombus after discontinuing warfarin in the setting of rapidly deteriorating bioprosthetic valve stenosis and vascular comorbidities. The decision to discontinue warfarin was made in concordance with current guidelines, which do not indicate systemic anticoagulation post 3-6 months after bioprosthetic valve replacement without separate indication for anticoagulation. This case identifies the need to investigate rebound hypercoagulability and further risk stratify comorbidities which may independently increase the risk of clot formation in the setting of severe mitral valve stenosis., (© 2023. The Author(s).)

Rapid and cost-effective virus-derived transient expression systems for plants are invaluable in elucidating gene function and are particularly useful in plant species for which transformation-based methods are unavailable or are too time and labor demanding, such as wheat ( Triticum aestivum ) and maize ( Zea mays ). The virus-mediated overexpression (VOX) vectors based on Barley stripe mosaic virus and Wheat streak mosaic virus described previously for these species are incapable of expressing free recombinant proteins of more than 150 to 250 amino acids, are not suited for high-throughput screens, and have other limitations. In this study, we report the development of a VOX vector based on a monopartite single-stranded positive sense RNA virus, Foxtail mosaic virus (genus Potexvirus ). In this vector, PV101, the gene of interest was inserted downstream of the duplicated subgenomic promoter of the viral coat protein gene, and the corresponding protein was expressed in its free form. The vector allowed the expression of a 239-amino acid-long GFP in both virus-inoculated and upper uninoculated (systemic) leaves of wheat and maize and directed the systemic expression of a larger approximately 600-amino acid protein, GUSPlus, in maize. Moreover, we demonstrated that PV101 can be used for in planta expression and functional analysis of apoplastic pathogen effector proteins such as the host-specific toxin ToxA of Parastagonospora nodorum Therefore, this VOX vector opens possibilities for functional genomics studies in two important cereal crops., (© 2018 The authors(s). All rights reserved.)

Technological advances in sensors and communications have enabled discrete integration into everyday objects, both in the home and about the person. Information gathered by monitoring physiological, behavioural, and social aspects of our lives, can be used to achieve a positive impact on quality of life, health, and well-being. Wearable sensors are at the cusp of becoming truly pervasive, and could be woven into the clothes and accessories that we wear such that they become ubiquitous and transparent. To interpret the complex multidimensional information provided by these sensors, data fusion techniques are employed to provide a meaningful representation of the sensor outputs. This paper is intended to provide a short overview of data fusion techniques and algorithms that can be used to interpret wearable sensor data in the context of health monitoring applications. The application of these techniques are then described in the context of healthcare including activity and ambulatory monitoring, gait analysis, fall detection, and biometric monitoring. A snap-shot of current commercially available sensors is also provided, focusing on their sensing capability, and a commentary on the gaps that need to be bridged to bring research to market., (Copyright © 2017. Published by Elsevier Ltd.)

A recombinant in-bred line population derived from a cross between Solanum lycopersicum var. cerasiforme (E9) and S. pimpinellifolium (L5) has been used extensively to discover quantitative trait loci (QTL), including those that act via rootstock genotype, however, high-resolution single-nucleotide polymorphism genotyping data for this population are not yet publically available. Next-generation resequencing of parental lines allows the vast majority of polymorphisms to be characterized and used to progress from QTL to causative gene. We sequenced E9 and L5 genomes to 40- and 44-fold depth, respectively, and reads were mapped to the reference Heinz 1706 genome. In L5 there were three clear regions on chromosome 1, chromosome 4, and chromosome 8 with increased rates of polymorphism. Two other regions were highly polymorphic when we compared Heinz 1706 with both E9 and L5 on chromosome 1 and chromosome 10, suggesting that the reference sequence contains a divergent introgression in these locations. We also identified a region on chromosome 4 consistent with an introgression from S. pimpinellifolium into Heinz 1706. A large dataset of polymorphisms for the use in fine-mapping QTL in a specific tomato recombinant in-bred line population was created, including a high density of InDels validated as simple size-based polymerase chain reaction markers. By careful filtering and interpreting the SnpEff prediction tool, we have created a list of genes that are predicted to have highly perturbed protein functions in the E9 and L5 parental lines., (Copyright © 2015 Kevei et al.)

Background: The patient's perception and satisfaction are increasingly considered as a useful factor in the assessment of competency of health care providers and quality of care. However, these patient focused assessments are largely ignored when assessing health care outcomes., Objective: The study assessed the perception and satisfaction of patients receiving antiretroviral therapy (ART) with pharmaceutical services received in outpatient HIV treatment settings., Setting: Seventeen HIV treatment centres in Nigeria., Methods: This cross-sectional survey included 2,700 patients randomly selected from 26,319 HIV patients on ART, who received pharmaceutical services in the study setting. A study-specific Likert-type instrument was administered to the participants at point of exit from the pharmacy. Midpoint of the 5-point scale was computed and scores above it were regarded as positive while below as negative. Chi-square was used for inferential statistics. All reported p values were 2-sided at 95 % confidence interval (CI)., Main Outcome Measure: Patient satisfaction with pharmaceutical services., Results: Of 2,700 patients sampled, data from 1,617 (59.9 %) were valid for analysis; 62.3 % were aged 26-40 years and 65.4 % were females. The participants had received pharmaceutical services for a mean duration of 25.2 (95 % CI 24.3-26.1) months. Perception of participants regarding the appearance of pharmacy was positive while that regarding the pharmacists' efforts to solve patients' medication related problems was negative. The participants' rating of satisfaction with the waiting time to access pharmaceutical services was negative; the satisfaction decreases with increasing waiting time. However, the satisfaction with the overall quality of pharmaceutical services received was rated as positive; 90.0 % reported that they got the kind of pharmaceutical services they wanted; 98.2 % would come back to the pharmacy if they were to seek help again and would recommend services to others. The level of satisfaction was found to be associated with educational status of the participants (p = 0.006) unlike age, sex, marital and employment status., Conclusion: The satisfaction with overall quality of pharmaceutical services received by participants was positive. Longer waiting times resulted in lower patient satisfaction. High patient load may be the cause of the long waiting time and the inadequate duration of interaction between pharmacist and the patient.

Purpose: This study assessed the incidence and types of medication errors, interventions and outcomes in patients on antiretroviral therapy (ART) in selected HIV treatment centres in Nigeria., Methods: Of 69 health facilities that had program for active screening of medication errors, 14 were randomly selected for prospective cohort assessment. All patients who filled/refilled their antiretroviral medications between February 2009 and March 2011 were screened for medication errors using study-specific pharmaceutical care daily worksheet (PCDW). All potential or actual medication errors identified, interventions provided and the outcomes were documented in the PCDW. Interventions included pharmaceutical care in HIV training for pharmacists amongst others. Chi-square was used for inferential statistics and P<0.05 indicated statistical significance., Results: Of 6,882 participants, 67.0% were female and 93.5% were aged ≥ 15 years old. The participants had 110,070 medications filling/refilling visits, average (± SD) of 16.0 (± 0.3) visits per patient over the observation period. Patients were followed up for 9172.5 person-years. The number of drug items dispensed to participants was 305,584, average of 2.8 (± 0.1) drug items per patient. The incidence rate of medication errors was 40.5 per 100 person-years. The occurrence of medication errors was not associated with participants' sex and age (P>0.05). The major medications errors identified were 26.4% incorrect ART regimens prescribed; 19.8% potential drug-drug interaction or contraindication present; and 16.6% duration and/or frequency of medication inappropriate. Interventions provided included 67.1% cases of prescriber contacted to clarify/resolve errors and 14.7% cases of patient counselling and education; 97.4% of potential/actual medication error(s) were resolved., Conclusion: The incidence rate of medication errors was somewhat high; and majority of identified errors were related to prescription of incorrect ART regimens and potential drug-drug interactions; the prescriber was contacted and the errors were resolved in majority of cases. Active screening for medication errors is feasible in resource-limited settings following a capacity building intervention.

Background: The use of medicines is an essential component of many public health programs (PHPs). Medicines are important not only for their capacity to treat and prevent diseases. The public confidence in healthcare system is inevitably linked to their confidence in the availability of safe and effective medicines and the measures for ensuring their rational use. However, pharmacy services component receives little or no attention in most public health programs in developing countries. This article describes the strategies, lessons learnt, and some accomplishments of Howard University Pharmacists and Continuing Education (HU-PACE) Centre towards improving hospital pharmacy practice through PHP in Nigeria., Method: In a cross-sectional survey, 60 hospital pharmacies were randomly selected from 184 GHAIN-supported health facilities. The assessment was conducted at baseline and repeated after at least 12 months post-intervention using a study-specific instrument. Interventions included engagement of stakeholders; provision of standards for infrastructural upgrade; development of curricula and modules for training of pharmacy personnel; provision of job aids and tools amongst others. A follow-up hands-on skill enhancement based on identified gaps was conducted. Chi-square was used for inferential statistics. All reported p-values were 2-tailed at 95% confidence interval., Results: The mean duration of service provision at post-intervention assessment was 24.39 (95% CI, 21.70-27.08) months. About 16.7% of pharmacies reported been trained in HIV care at pre-intervention compared to 83.3% at post-intervention. The proportion of pharmacies with audio-visual privacy for patient counseling increased significantly from 30.9% at pre-intervention to 81.4% at post-intervention. Filled prescriptions were cross-checked by pharmacist (61.9%) and pharmacy technician (23.8%) before dispensing at pre-intervention compared to pharmacist (93.1%) and pharmacy technician (6.9%) at post intervention. 40.0% of pharmacies reported tracking consumption of drugs at pre-intervention compared to 98.3% at post-intervention; while 81.7% of pharmacies reported performing periodic stock reconciliation at pre-intervention compared to 100.0% at post-intervention. 36.5% of pharmacies were observed providing individual counseling on medication use to patients at pre-intervention compared to 73.2% at post-intervention; and 11.7% of pharmacies had evidence of monitoring and reporting of suspected adverse drug reaction at pre-intervention compared to 73.3% at post-intervention. The institution of access to patients' clinical information by pharmacists in all pharmacies at post-intervention was a paradigm shift., Conclusion: Through public health program, HU-PACE created an enabling environment and improved capacity of pharmacy personnel for quality HIV/AIDS and TB services. This has contributed in diverse ways to better monitoring of patients on pharmacotherapy by pharmacists through access of pharmacists to patients' clinical information.

Riluzole (1) is an approved therapeutic for the treatment of ALS and has also demonstrated anti-melanoma activity in metabotropic glutamate GRM1 positive cell lines, a mouse xenograft assay and human clinical trials. Highly variable drug exposure following oral administration among patients, likely due to variable first pass effects from heterogeneous CYP1A2 expression, hinders its clinical use. In an effort to mitigate effects of this clearance pathway and uniformly administer riluzole at efficacious exposure levels, several classes of prodrugs of riluzole were designed, synthesized, and evaluated in multiple in vitro stability assays to predict in vivo drug levels. The optimal prodrug would possess the following profile: stability while transiting the digestive system, stability towards first pass metabolism, and metabolic lability in the plasma releasing riluzole. (S)-O-Benzyl serine derivative 9 was identified as the most promising therapeutically acceptable prodrug., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Hypoxia in solid tumours is associated with the promotion of various metabolic mechanisms and induces resistance to radio- and chemotherapy. Non-invasive positron emission tomography (PET) or single photon emission computed tomography by use of selective biomarkers has emerged as valuable tools for the detection of hypoxic areas within tumours so treatment can be modified accordingly. The aim of this investigation was to evaluate [(18)F]3-NTR, a 3-nitro-1,2,4-triazole analogue (N(1) substituted) of [(18)F]FMISO as a potential hypoxia selective tracer. 3-NTR and its (18)F-radiolabelled isotopic isomer were synthesised and compared with FMISO in vitro and in vivo. Their physicochemical properties were measured, the enzymatic reduction was evaluated, and the reactivity of their metabolites was investigated. Biodistribution and PET scans were performed on CBA mice bearing hypoxic CaNT tumour cells, using (18)F-labelled versions of the tracers. [(18)F]3-NTR uptake within hypoxic cells was lower than [(18)F]FMISO and [(18)F]3-NTR did not exhibit any better selectivity than FMISO as a PET tracer in vivo. Both (18)F-radiolabelled compounds are relatively evenly distributed within the whole body and the radioactive uptake within hypoxic tumours reaches a maximum at 30 min post injection and decreases thereafter. Xanthine oxidase exhibited a nitroreductase activity toward 3-NTR under anaerobic conditions, but reduced metabolites did not bind covalently. It is confirmed that 3-NTR is an electron acceptor. It is postulated that radiolabelled metabolites and fragments of [(18)F]3-NTR are freely diffusing due to their poor binding capacities. Thus [(18)F]3-NTR cannot be used as a hypoxia selective tracer for PET. The investigation provides insights into the importance of the propensity to form covalent adducts for such biomarkers., (Crown Copyright 2010. Published by Elsevier Inc. All rights reserved.)

Pharmaceutical care, meant to complement a proper drug supply system, is a key component of a robust health care system and is the direct, responsible provision of medication-related care designed to achieve definite outcomes that improve a patient's quality of life. Beyond simply dispensing medicine, pharmaceutical care promotes adherence to therapeutic regimens and addresses problems such as overdosage, sub-therapeutic dosage, adverse drug reactions, medication errors, and untreated indications. The dearth of health care workers trained in pharmaceutical care coupled with inadequate access to medications creates multiple disease management challenges in Sub-Saharan Africa (SSA), which has 25% of the world's disease burden but only 1.3% of the world's health workforce. To prevent and treat HIV/AIDS, TB, malaria, and other maladies, the need is urgent to train and integrate the contributions of current workers who handle medications for major and minor health problems, especially those in licensed pharmacies and drug shops. On the aggregate in SSA, pharmaceutical care is in a nascent stage in most countries but needs to grow as a discipline as well as be tailored to specific country needs. The SSA solution lies in establishing health care system components where cadres of workers engage in pharmaceutical care practices, as well as store and distribute medications. Curriculum changes in pre-service education, more continuing education for the health workforce in place, and training pharmacists to supervise a lower cadre of assistants and others are among the elements in a pharmaceutical care paradigm shift which is the focus of this article., (Copyright (c) 2009 John Wiley & Sons, Ltd.)

Laparoscopic surgery is a challenging task in minimally invasive surgery, which involves complex instrument control, extensive manual dexterity, and hand-eye coordination. This requires a greater attention to training and skills evaluation. In order to provide a more objective skills assessment method, this paper presents a wireless sensor platform for the capture of laparoscopic hand gesture data and a hidden-Markov-model-based analysis framework for optimal sensor selection and placement. Detailed experimental validation is provided to illustrate how the proposed method can be used to assess surgical performance improvement over repeated training.

A simple and automated spot sampling operation mode for a liquid microjunction surface sampling probe/electrospray ionization mass spectrometry (LMJ-SSP/ESI-MS) system is reported. Prior manual and automated spot sampling methods with this probe relied on a careful, relatively slow alignment of the probe and surface distance (<20 microm spacing) to form the probe-to-surface liquid microjunction critical to successful surface sampling. Moreover, sampling multiple spots required retraction of the surface from the probe and a repeat of this careful probe-to-surface distance alignment at the next sampling position. With the method described here, the probe was not positioned as close to the surface, the exact probe-to-surface positioning was found to be less critical (spanning distances from about 100-300 microm), and this distance was not altered during the sampling of an entire array of sample spots. With the probe positioned within the appropriate distance from the surface, the liquid microjunction was formed by letting the liquid from the sampling end of the probe extend out from the probe to the surface. This was accomplished by reducing the self-aspiration liquid flow rate of the probe to a value less than the volume flow rate pumped into the probe. When the self-aspiration rate of the probe was subsequently increased, analytes on the surface that dissolved at the liquid microjunction were aspirated back into the probe with the liquid that created the liquid microjunction and electrosprayed. Presented here are the basics of this new sampling mode, as well as data that illustrate the potential analytical capabilities of the device to conduct high-throughput quantitative analysis.

This paper describes an automated workflow for the determination of selected reaction monitoring (SRM) transitions and optimum mass spectrometric (MS) instrument parameters. The approach uses a Nanomate from Advion Biosciences for automated infusion of small amounts of sample in combination with Automaton optimization software from Sciex. The results are stored in the Analyst software Compound Database for automated acquisition method building. Comparisons are presented between the more traditional optimization methods of manual flow injection optimization, Autotune infusion optimization, Automaton flow injection optimization and the Nanomate-Automaton optimization approach. Data is also presented to show that acquisition methods developed on the Sciex model API3000 instrument can be effectively transferred to the Sceix API4000 and API5000 model instruments., (Copyright (c) 2009 John Wiley & Sons, Ltd.)

Unlabelled: A water-soluble glucose conjugate of the hypoxia tracer 64Cu-diacetyl-bis(N4-methylthiosemicarbazone) (64Cu-ATSM) was synthesized and radiolabeled (64Cu-ATSE/A-G). Here we report our initial biological experiments with 64Cu-ATSE/A-G and compare the results with those obtained for 64Cu-ATSM and 18F-FDG., Methods: The uptake of 64Cu-ATSE/A-G and 64Cu-ATSM into HeLa cells in vitro was investigated at a range of dissolved oxygen concentrations representing normoxia, hypoxia, and anoxia. Small-animal PET with 64Cu-ATSE/A-G was performed in male BDIX rats implanted with P22 syngeneic carcinosarcomas. Images of 64Cu-ATSM and 18F-FDG were obtained in the same model for comparison., Results: 64CuATSE/A-G showed oxygen concentration-dependent uptake in vitro and, under anoxic conditions, showed slightly lower levels of cellular uptake than 64Cu-ATSM; uptake levels under hypoxic conditions were also lower. Whereas the normoxic uptake of 64Cu-ATSM increased linearly over time, 64Cu-ATSE/A-G uptake remained at low levels over the entire time course. In the PET study, 64CuATSE/A-G showed good tumor uptake and a biodistribution pattern substantially different from that of each of the controls. In marked contrast to the findings for 64Cu-ATSM, renal clearance and accumulation in the bladder were observed. 64Cu-ATSE/A-G did not display the characteristic brain and heart uptake of 18F-FDG., Conclusion: The in vitro cell uptake studies demonstrated that 64Cu-ATSE/A-G retained hypoxia selectivity and had improved characteristics when compared with 64Cu-ATSM. The in vivo PET results indicated a difference in the excretion pathways, with a shift from primarily hepatointestinal for 64Cu-ATSM to partially renal with 64Cu-ATSE/A-G. This finding is consistent with the hydrophilic nature of the glucose conjugate. A comparison with 18F-FDG PET results revealed that 64Cu-ATSE/A-G was not a surrogate for glucose metabolism. We have demonstrated that our method for the modification of Cu-bis(thiosemicarbazonato) complexes allows their biodistribution to be modified without negating their hypoxia selectivity or tumor uptake properties.

Hydrazinonicotinamide (HYNIC) is an established bifunctional complexing agent for technetium-99m ((99m)Tc) but the structure of the technetium coordination sphere remains uncertain. To gain further insight into this, we have prepared conjugates of HYNIC and hydrazinobenzoic acid (HYBA) with a model peptide, and radiolabelled them with (99m)Tc using three well-established co-ligand systems: EDDA, tricine and tricine-nicotinic acid. The labelled peptides were studied by LC-MS and by subjecting them to serum stability and protein binding assays. For each co-ligand system, HYNIC conjugates formed fewer and more stable labelled species than the corresponding HYBA conjugates. LC-MS analysis showed that all conjugates contained one hydrazine moiety bound to Tc, that binding of Tc to HYNIC-peptide and co-ligand occurs with displacement of 5H(+) indicating a Tc formal oxidation state of +5, and that the Tc has no oxo- or halide ligands. LC-MS also shows that complexes formed with the HYNIC conjugate contain fewer coordinating co-ligand molecules than the HYBA conjugate indicating that HYNIC is able to more effectively satisfy the coordination requirement of technetium, perhaps by binding in chelating mode.

A hybrid linear ion trap/triple quadrupole mass spectrometer was used to demonstrate the value of collecting full scan qualitative data during quantitative analysis of target compounds. We present examples of the additional information that can be obtained from plasma samples analyzed primarily for target compound concentrations. This information includes detection of circulating metabolites, dosing vehicle, interfering matrix components, and potential interfering drug conjugates. Additionally, the quantitative results from selected reaction monitoring (SRM) analysis and from combined full scan and SRM analysis (SRM/EMS) were compared. The quantitative data in both scan modes are acceptable in terms of sensitivity, accuracy and precision. One can conclude from this work that the hybrid linear ion trap/triple quadrupole mass analyzer can provide in a single analysis both useful qualitative data, and accurate and precise quantitative data from the samples routinely prepared and analyzed for target drug concentrations., (Copyright 2003 John Wiley & Sons, Ltd.)

A combinatorial library of 300HIV protease inhibitors has been synthesized. The library was screened against recombinant wild-type and mutant HIV-1 protease enzymes. The pharmacokinetics of the library was evaluated by dosing in dogs. Compounds that are notably more potent than indinavir and have favorable pharmacokinetic properties were identified.

The past years have seen only the beginning of our understanding of metabolic processes and the importance of these processes to the development of safe and effective medicines. The trend to bring more detailed information into earlier stages of drug discovery will continue to drive improvements in technology and in experimental and analytical procedures for the study of biotransformation of drugs. The challenges are significant, but so is the promise of the contributions that can be made by biotransformation studies.

The Aria LX4 staggered parallel high performance liquid chromatography (HPLC) system is evaluated for application to good laboratory practice (GLP) level quantitative analysis by liquid chromatography/tandem mass spectrometry (LC/MS/MS). This system consists of four fully independent binary HPLC pumps, a modified autosampler, and a series of switching and selector valves all controlled by a single computer program. The system improves sample throughput without sacrificing chromatographic separation or data quality. Validation results for four different compounds, each analyzed on a separate channel of the Aria system, show precision and accuracy equivalent to that required of a single-channel system. The results show that sample throughput can be increased nearly four-fold without requiring significant changes in current analytical procedures. The flexibility and ease of use of the Aria system suggest that it should be possible to quickly implement it in any analytical LC/MS/MS environment., (Copyright 2001 John Wiley & Sons, Ltd.)

Purpose: Insertion of a composite graft and reimplantation of the coronary arteries through an intermediate Dacron tube (Cabrol composite graft procedure) has been used to treat ascending aortic aneurysms and dissections. The CT findings after the Cabrol composite graft procedure have not been previously described., Method: Retrospective review of 12 postoperative CT and CT angiography (CTA) studies both in the immediate postoperative period as well as during long-term follow-up was conducted., Results: The Cabrol composite graft procedure produces typical CT findings consisting of a coronary conduit separate from the aortic graft. The presence of perigraft flow can be normal or abnormal depending on the time point of its occurrence and the extent of its hemodynamic consequences., Conclusion: Knowledge of the typical CT and CTA findings following a Cabrol composite graft procedure is essential for the correct interpretation of these studies.