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1.
Adv Med Sci ; 69(1): 51-55, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38364757

ABSTRACT

BACKGROUND: Hypocalcaemia predicts coronavirus disease 2019 (COVID-19) severity and mortality. We hypothesized an association between respiratory alkalosis secondary to hypoxia and low ionised calcium (iCa) concentration in patients with COVID-19. METHODS: Arterial blood gas samples taken from January 2019 to March 2021 were retrospectively matched with infection status. Principal components regression was undertaken to determine the correlation between pH, partial pressure arterial oxygen (PaO2), partial pressure arterial carbon dioxide (PaCO2), and iCa. RESULTS: We included 4056 patients (300 COVID-19 detected, 19 influenza detected), corresponding to 5960 arterial blood samples. The COVID-19 detected group had a statistically significantly lower iCa, PaO2 and PaCO2, and more alkalotic pH than infection-free groups. The influenza group had a lower iCa and PaCO2, higher PaO2, and a more alkalotic pH than infection-free groups, but these differences were non-significant. Principal components regression revealed that pH, PaCO2, and PaO2 explain just 2.72 % of the variance in iCa. An increase in pH by 1 unit was associated with an iCa reduction of 0.141 â€‹mmol/L (p â€‹< â€‹0.0001). CONCLUSION: Reduction in iCa concentration in patients with COVID-19 is not associated with pH derangement. Influenza infection was associated with a minor reduction in iCa in our small sample, a hitherto unreported finding, although statistical significance was not demonstrated.


Subject(s)
Blood Gas Analysis , COVID-19 , Calcium , SARS-CoV-2 , Humans , COVID-19/blood , COVID-19/complications , Hydrogen-Ion Concentration , Female , Male , Middle Aged , Retrospective Studies , Calcium/blood , Calcium/metabolism , SARS-CoV-2/isolation & purification , Aged , Oxygen/blood , Oxygen/metabolism , Hypocalcemia/blood , Carbon Dioxide/blood , Adult
2.
Basic Clin Pharmacol Toxicol ; 134(2): 231-240, 2024 Feb.
Article in English | MEDLINE | ID: mdl-37903499

ABSTRACT

The COVID-19 pandemic had a substantial impact on healthcare delivery, particularly in general practice. This study aimed to evaluate how dispensing of medications in primary care in Ireland changed following the COVID-19 pandemic's onset compared to expected trends. This interrupted time series study used data on medications prescribed in general practice 2016-2022 to patient eligible for state health cover, approximately one third of the population. Dispensing volumes for all therapeutic subgroups (ATC2 codes) and commonly dispensed medications were summarized. Pre-pandemic data were used to forecast expected trends (with 99% prediction intervals) using the Holt-Winters method, and these were compared to observed dispensing from March 2020 onwards. Many (31/77) therapeutic subgroups had dispensing significantly different from forecast in March 2020. Drugs for obstructive airway disease had the largest difference, with dispensing 26.2% (99%CI 19.5%-33.6%) higher than forecasted. Only two subgroups were significantly lower than forecasted, other gynaecologicals (17.7% lower, 99%CI 6.3%-26.6%) and dressings (11.6%, 99%CI 9.4%-41.6%). Dispensing of amoxicillin products and oral prednisolone were lower than forecasted in the months following the pandemic's onset, particularly during winter 2020/2021. There was a spike in dispensing for many long-term medications in March 2020, while pandemic restrictions likely contributed to reductions for other medications.


Subject(s)
COVID-19 , Pandemics , Humans , Ireland/epidemiology , Interrupted Time Series Analysis , COVID-19/epidemiology , Pharmaceutical Preparations
3.
Cureus ; 15(2): e34757, 2023 Feb.
Article in English | MEDLINE | ID: mdl-36909084

ABSTRACT

Acute intermittent porphyria (AIP) is a rare metabolic disorder that is challenging to diagnose and treat. Symptoms are nonspecific and severe acute attacks may be life-threatening. This is a case of a previously healthy 21-year-old woman diagnosed with an acute attack of AIP following recurrent hospitalizations with undiagnosed abdominal pain over a 12-month period with gradual onset of motor neuropathy which resulted in complete paralysis and respiratory failure. Through our case, we will highlight the challenges in AIP diagnosis and management, its potential severity, and how an early diagnosis could have prevented severe disability.

4.
Article in English | MEDLINE | ID: mdl-34344766

ABSTRACT

OBJECTIVES: The COVID-19 pandemic has had an unprecedented impact across primary care. Primary care services have seen an upheaval, and more and more patients are engaging in telephone consultations in order to maintain social distancing. In the present study, we seek to quantify the effect of the pandemic on primary care prescribing. DESIGN: We conducted a retrospective analysis of the English Prescribing Dataset from January 2014 to November 2020, totalling 7 542 293 921 prescriptions. Data were separated into prepandemic and pandemic sets. A Holt-Winters predictive model was used to forecast individual drug prescribing based on historic trends. Observed data were compared with the forecast quantitatively and qualitatively. SETTING: All prescriptions signed in England and dispensed during the years 2014-2020. PARTICIPANTS: All residents of England who received a prescription from primary care facilities during 2014-2020. RESULTS: Prescribing of numerous health-critical medications was above predicted in March 2020, including salbutamol (53.0% (99% CI (41.2% to 66.9%))), insulin aspart (26.9% (99% CI (18.5% to 36.6%))) and tacrolimus (18.6% (99% CI (8.3% to 31.1%))). Medications for end-of-life symptom control increased in April, including levomepromazine hydrochloride (94.7% (99% CI (54.6% to 163.0%))). Medications requiring face-to-face visits decreased, including the local anaesthetic bupivacaine hydrochloride (86.6% (99% CI (89.3% to 82.0%))). There was no observed change in medications relating to type 2 diabetes, hypertension or mental health conditions. CONCLUSIONS: Significantly increased prescribing of several medications was observed, especially among those critical for health. A dramatic spike in end-of-life prescribing highlights the adversity faced by community practitioners during 2020. Medications involving face-to-face consultations declined, as did contraceptives, travel-related vaccines and drugs used in dementia and Parkinson's disease. Drugs relating to type 2 diabetes, hypertension and mental health were unchanged.


Subject(s)
COVID-19 Drug Treatment , Drug Prescriptions , Practice Patterns, Physicians' , Primary Health Care , England , Forecasting , Humans , Pandemics , Retrospective Studies , SARS-CoV-2
5.
Bioorg Med Chem Lett ; 38: 127872, 2021 04 15.
Article in English | MEDLINE | ID: mdl-33636307

ABSTRACT

A series of novel (R)-6,6a,7,8,9,10-hexahydro-5H-pyrazino[1,2-a][1,n]naphthyridines were identified as potent and selective agonists of the 5-HT2C receptor. Optimizations performed on a previously reported series of racemic tetrahydroquinoline-based tricyclic amines, delivered an advanced drug lead, (R)-4-(3,3,3-trifluoropropyl)-6,6a,7,8,9,10-hexahydro-5H-pyrazino[1,2-a][1,8]naphthyridine, which displayed excellent in vitro and in vivo pharmacological profiles.


Subject(s)
Receptor, Serotonin, 5-HT2C/metabolism , Serotonin 5-HT2 Receptor Agonists/pharmacology , Animals , Dose-Response Relationship, Drug , Humans , Microsomes, Liver/chemistry , Microsomes, Liver/metabolism , Molecular Structure , Rats , Serotonin 5-HT2 Receptor Agonists/chemical synthesis , Serotonin 5-HT2 Receptor Agonists/chemistry , Structure-Activity Relationship
6.
Lancet Child Adolesc Health ; 4(10): 750-760, 2020 10.
Article in English | MEDLINE | ID: mdl-32735783

ABSTRACT

Background Increasing numbers of neonates are undergoing painful procedures in low-income and middle-income countries, with adequate analgesia seldom used. In collaboration with a multi-disciplinary team in Kenya, we aimed to establish the first evidence-based guidelines for the management of routine procedure-related neonatal pain that consider low-resource hospital settings. METHODS: We did a systematic review by searching MEDLINE, Embase, CINAHL, and CENTRAL databases for studies published from Jan 1, 1953, to March 31, 2019. We included data from randomised controlled trials using heart rate, oxygen saturation (SpO2), premature infant pain profile (PIPP) score, neonatal infant pain scale (NIPS) score, neonatal facial coding system score, and douleur aiguë du nouveau-né scale score as pain outcome measures. We excluded studies in which neonates were undergoing circumcision or were intubated, studies from which data were unextractable, or when pain was scored by non-trained individuals. We did a narrative synthesis of all studies, and meta-analysis when data were available from multiple studies comparing the same analgesics and controls and using the same outcome measures. 17 Kenyan health-care professionals formed our clinical guideline development panel, and we used the Grading of Recommendations, Assessment, Development and Evaluation framework and the panel's knowledge of the local health-care context to guide the guideline development process. This study is registered with PROSPERO, CRD42019126620. FINDINGS: Of 2782 studies assessed for eligibility, data from 149 (5%) were analysed, with 80 (3%) of these further contributing to our meta-analysis. We found a high level of certainty for the superiority of breastfeeding over placebo or no intervention (standardised mean differences [SMDs] were -1·40 [95% CI -1·96 to -0·84] in PIPP score and -2·20 [-2·91 to -1·48] in NIPS score), and the superiority of oral sugar solutions over placebo or no intervention (SMDs were -0·38 [-0·61 to -0·16] in heart rate and 0·23 [0·04 to 0·42] in SpO2). We found a moderate level of certainty for the superiority for expressed breastmilk over placebo or no intervention (SMDs were -0·46 [95% CI -0·87 to -0·05] in heart rate and 0·48 [0·20 to 0·75] in SpO2). Therefore, the panel recommended that breastfeeding should be given as first-line analgesic treatment, initiated at least 2 min pre-procedure. Given contextual factors, for neonates who are unable to breastfeed, 1-2 mL of expressed breastmilk should be given as first-line analgesic, or 1-2 mL of oral sugar (≥10% concentration) as second-line analgesic. The panel also recommended parental presence during procedures with adjunctive provision of skin-to-skin care, or non-nutritive sucking when possible. INTERPRETATION: We have generated Kenya's first neonatal analgesic guidelines for routine procedures, which have been adopted by the Kenyan Ministry of Health, and have shown a framework for clinical guideline development that is applicable to other low-income and middle-income health-care settings. FUNDING: Wellcome Trust Research Programme, and the Africa-Oxford Initiative.


Subject(s)
Infant Care/methods , Kangaroo-Mother Care Method/methods , Pain Management/methods , Pain/prevention & control , Analgesics/therapeutic use , Female , Humans , Infant , Infant, Newborn , Kenya , Male , Pain/drug therapy , Phlebotomy/adverse effects , Practice Guidelines as Topic , Punctures/adverse effects
7.
Article in English | MEDLINE | ID: mdl-32565488

ABSTRACT

OBJECTIVE: In the present study, we sought to explore the relationship between socioeconomic status and prescribing magnitude and cost in primary care throughout Northern Ireland. DESIGN: We performed a retrospective data analysis of general practitioner (GP) prescribing using open-source databases with data collected from May to October 2019 to determine the number of prescriptions and cost of drugs and drug classes by area, ranking these by deprivation index. We used Kendall's tau to quantify the relationship between prescribing and deprivation. SETTING: We analysed open-source data collected from 325 GP practices in Northern Ireland during the period from May to October 2019. PARTICIPANTS: We analysed a total of 2 764 303 prescriptions signed during our study period. RESULTS: Our study indicates a clear trend of increased overall spending per patient (r=-0.1232, p=0.02) and number of prescriptions per patient (r=-0.3440, p<0.001) in areas of higher deprivation. The mean cost per item was higher in less deprived areas (r=0.3809, p<0.001). Overall, £13.79 more was spent and 3.5 more items were prescribed per patient in the most compared with the least deprived decile, although more expensive items tended to be prescribed in areas with lower socioeconomic deprivation (£11.27 per item vs £9.20 per item). We found a statistically significant correlation of prescribing of key drug classes, such as bronchodilators, antidepressants and drugs used to treat diabetes, among others, with greater deprivation. Prescribing of vaccines and drugs used in the treatment of glaucoma was correlated with lower deprivation. CONCLUSION: We provide an exploration of the correlation of prescribing with deprivation by analysing all prescriptions signed within a 6-month period in Northern Ireland. Our study broadly agrees with published literature, although a few notable exceptions are highlighted. We provide evidence of discrepancies in medication cost between areas of differing deprivation and suggest possible explanations for these trends. This information will be valuable for future investigation of disease prevalence, as well as targeting of patient education and future funding.


Subject(s)
Drug Prescriptions , General Practitioners , Practice Patterns, Physicians' , Social Class , Databases, Factual , Drug Prescriptions/economics , Humans , Northern Ireland , Poverty Areas , Qualitative Research , Retrospective Studies
8.
J Med Eng Technol ; 44(4): 169-176, 2020 May.
Article in English | MEDLINE | ID: mdl-32401550

ABSTRACT

The ongoing COVID-19 pandemic is unprecedented in the modern age both due to its scale and its disruption to daily life throughout the world. Widespread social isolation and restrictions in the age of modern communicative technology, coupled with some early successes for makers, have united the open-source community towards a common goal in a way not previously seen. Local hospitals and care facilities are turning to makers to print essential consumable parts, such as simple visors, while in the hardest hit areas, critical pieces of medical technology are being fabricated. While important and effective innovations are appearing almost daily, there are also some worrying trends towards hobbyists attempting manufacture of complex medical devices with little understanding of the clinical or scientific rationale behind their design. The nature of the open-source community, an area of intensive innovation, fluidity, and experimentation, jars with the exacting standards of medical device regulation. Here, we review the involvement of rapid prototyping and the open-source community in the key areas of personal protective equipment (PPE), diagnostics, critical care technology, and information acquisition and sharing, highlighting where makers and hackers have clashed with medical device regulations, and areas where the system has worked well to facilitate change.


Subject(s)
Coronavirus Infections/prevention & control , Pandemics/prevention & control , Pneumonia, Viral/prevention & control , COVID-19 , Coronavirus Infections/diagnosis , Critical Care/methods , Humans , Personal Protective Equipment , Pneumonia, Viral/diagnosis , Printing, Three-Dimensional
9.
Bioorg Med Chem Lett ; 30(5): 126929, 2020 03 01.
Article in English | MEDLINE | ID: mdl-31952960

ABSTRACT

A series of potential new 5-HT2 receptor scaffolds based on a simplification of the clinically studied, 5-HT2CR agonist vabicaserin, were designed. An in vivo feeding assay early in our screening process played an instrumental part in the lead identification process, leading us to focus on a 6,5,7-tricyclic scaffold. A subsequent early SAR investigation provided potent agonists of the 5-HT2C receptor that were highly selective in both functional and binding assays, had good rat PK properties and that significantly reduced acute food intake in the rat.


Subject(s)
Benzodiazepines/pharmacology , Heterocyclic Compounds, 3-Ring/pharmacology , Receptor, Serotonin, 5-HT2C/metabolism , Serotonin 5-HT2 Receptor Agonists/pharmacology , Animals , Benzodiazepines/chemical synthesis , Benzodiazepines/metabolism , Benzodiazepines/pharmacokinetics , Dogs , Drug Discovery , Drug Stability , Heterocyclic Compounds, 3-Ring/chemical synthesis , Heterocyclic Compounds, 3-Ring/metabolism , Heterocyclic Compounds, 3-Ring/pharmacokinetics , Humans , Macaca fascicularis , Male , Mice , Microsomes/metabolism , Molecular Structure , Rats, Sprague-Dawley , Serotonin 5-HT2 Receptor Agonists/chemical synthesis , Serotonin 5-HT2 Receptor Agonists/metabolism , Serotonin 5-HT2 Receptor Agonists/pharmacokinetics , Structure-Activity Relationship
10.
Trends Anaesth Crit Care ; 34: 4-13, 2020 Oct.
Article in English | MEDLINE | ID: mdl-38620391

ABSTRACT

While the COVID-19 pandemic sweeps the world, much evidence is being gathered regarding its novel pathological mechanisms. It is the authors' clinical experience that patients in the intensive care unit suffering from COVID-19 are extremely pro-coagulable, with venous and arterial thromboembolism frequently observed, and losses of vascular access lines and filtration circuits to thrombosis now commonplace. Here, we explore the evidence for hypercoagulability in this group, presenting evidence of both a localised pulmonary hypercoagulability, and a systemic hypercoagulability resulting in thrombosis distant to the pulmonary vasculature. Furthermore, we discuss the possible risk factors exacerbated by, or selected for in COVID-19. We review the available evidence for use of plasma D-dimer as a prognostic marker, exploring the possibility that it acts as a marker of a COVID-19-associated hypercoagulability. We review the evidence for a pro-coagulant subtype of disseminated intravascular coagulation, discussing its clinical significance. Finally, we discuss the current evidence surrounding treatment of COVID-19 hypercoagulability, including prophylactic and treatment-dose heparin, thrombolytic agents, antiplatelet agents, and direct thrombin inhibitors, among others. We suggest areas in which further investigation is urgently needed to reduce the startling incidence of thrombosis in this group, a complication no doubt contributing to morbidity and mortality.

11.
Intern Emerg Med ; 14(6): 885-898, 2019 09.
Article in English | MEDLINE | ID: mdl-31049783

ABSTRACT

Tobacco heating products (THPs) are a potentially safer alternative to combustible cigarette smoking. Through continued use, THPs may reduce smoking-related disease risk, whilst maintaining the sensorial experience and nicotine delivery sought by smokers. While literature evidence of the biological effects of THP aerosol exposure is increasing, there remains a knowledge gap with respect to substantiation of THP reduced risk potential in longer term real-life use. This randomized, multi-centre, controlled clinical study will test the hypotheses that following a switch from combustible cigarettes to a THP for 1 year, participants will experience a sustained reduction in exposure to tobacco-related toxicants that will lead to favourable changes in health effect indicators associated with smoking-related disease development. Changes in such indicators will be contextualized against smoking cessation and never-smoker cohorts. Up to 280 participants who do not intend to quit smoking will be randomized to continued combustible smoking (arm A, up to n = 80) or a commercially available THP (arm B n = 200). Furthermore, up to 190 participants with a high intent to quit smoking will undergo smoking cessation (arm D), and 40 never smokers will serve as a control group (arm E). Recruitment numbers were determined to be sufficient to achieve n = 50 in arms A, B and D, at study end. Enrolment started in March 2018 and the trial is scheduled to be completed in March 2020. Data from this study will be a valuable addition to the growing body of evidence in the field of understanding the individual and public health impact of THPs.Clinical Trial Registration: https://www.isrctn.com/ISRCTN81075760.


Subject(s)
Cigarette Smoking/blood , Healthy Volunteers/statistics & numerical data , Nicotine/analysis , Adult , Biomarkers/analysis , Biomarkers/blood , Cigarette Smoking/metabolism , Female , Humans , Male , Middle Aged , Nicotine/blood , Tobacco Products/analysis
13.
Cell Signal ; 50: 9-24, 2018 Oct.
Article in English | MEDLINE | ID: mdl-29928987

ABSTRACT

Angiotensin (1-7) has been reported to be a ligand for the GPCR MAS1. Small molecule MAS1 modulators have also been recently characterized. Aside from convincing evidence for MAS1 activation of Gq signaling, little is known about MAS1 mediated signaling pathways initiated by these ligands, especially Ang (1-7). We performed a comprehensive characterization of recombinant MAS1 signaling induced by Ang (1-7) and small molecule ligands through numerous G protein-dependent and independent pathways, and in a signaling pathway agnostic approach. We find that small molecule ligands modulate numerous G protein-dependent and independent pathways through MAS1, including Gq and Gi pathways, GTPγS binding, ß-arrestin recruitment, Erk1/2 and Akt phosphorylation, arachidonic acid release, and receptor internalization. Moreover, in dynamic mass redistribution (DMR) assays that provide a pathway-agnostic readout of cellular responses, small molecule agonists produced robust responses. In contrast, Ang (1-7) failed to induce or block signaling in any of these assay platforms. We detected specific binding of radiolabeled Ang (1-7) to rat aortic endothelial cell (RAEC) membranes, but not to recombinant MAS1. Biphasic, concentration-dependent biased signaling responses to Ang II were detected in RAEC. These phases were associated with vastly different DMR characteristics and this likely provides a molecular basis for previously observed concentration-dependent divergent physiological actions of Ang II. Both phases of Ang II signaling in RAECs were potently inhibited by Ang (1-7), providing a plausible molecular mechanism for Ang (1-7) as counter regulator of the Ang II- AT1 axis, responsible at least in part for Ang (1-7) physiological activities.


Subject(s)
Angiotensin I/metabolism , Peptide Fragments/metabolism , Proto-Oncogene Proteins/metabolism , Receptor, Angiotensin, Type 1/metabolism , Receptors, G-Protein-Coupled/metabolism , Signal Transduction/physiology , Angiotensin II/metabolism , Animals , Arrestins/metabolism , CHO Cells , Cell Line , Cricetulus , Endothelial Cells/metabolism , GTP-Binding Proteins/metabolism , HEK293 Cells , Humans , Mitogen-Activated Protein Kinases/metabolism , Phosphorylation/physiology , Proto-Oncogene Mas , Rats , beta-Arrestins/metabolism
14.
Br J Haematol ; 167(3): 394-401, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25066629

ABSTRACT

Children and adolescents with Burkitt Lymphoma (BL) and combined central nervous system (CNS) and bone marrow involvement still have a poor prognosis with chemotherapy alone. We therefore investigated in children and adolescents with bone marrow (≥25% blasts) and/or CNS-positive Burkitt lymphoma the chemoimmunotherapy combination of rituximab (375 mg/m(2) ) and the standard chemotherapy arm of our previously reported French-American-British (FAB) Lymphome Malins de Burkitt (LMB) 96 trial. Central pathological and cytogenetic characterization was also performed. There were 40 evaluable patients with Burkitt histology (25 with leukaemia and 15 with CNS disease ± leukaemia). The chemoimmunotherapy regimen was well tolerated. The incidence of grade III/IV mucositis during induction cycles with combined chemotherapy and rituximab was 31% and 26%, respectively. The 3-year event-free survival (EFS)/overall survival (OS) was 90% (95% confidence interval [CI], 76-96%) in the entire cohort and 93% (95% CI, 61-99%) in patients with CNS disease. Based on the results of this trial, an international randomized study of FAB/LMB 96 chemotherapy ± rituximab for high-risk patients is currently under investigation.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Burkitt Lymphoma/drug therapy , Central Nervous System Neoplasms/drug therapy , Lymphoma, B-Cell/drug therapy , Adolescent , Antibodies, Monoclonal, Murine-Derived/administration & dosage , Antibodies, Monoclonal, Murine-Derived/adverse effects , Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Bone Marrow/pathology , Burkitt Lymphoma/genetics , Child , Consolidation Chemotherapy , Cyclophosphamide/administration & dosage , Cyclophosphamide/adverse effects , Cytarabine/administration & dosage , Cytarabine/adverse effects , Disease-Free Survival , Doxorubicin/administration & dosage , Doxorubicin/adverse effects , Drug Administration Schedule , Etoposide/administration & dosage , Etoposide/adverse effects , Female , Genes, myc , Humans , Immunotherapy , Infusions, Intravenous , Kaplan-Meier Estimate , Lymphoma, B-Cell/genetics , Maintenance Chemotherapy , Male , Methotrexate/administration & dosage , Methotrexate/adverse effects , Prednisone/administration & dosage , Prednisone/adverse effects , Remission Induction , Rituximab , Typhlitis/chemically induced , Vincristine/administration & dosage , Vincristine/adverse effects
15.
J Pharmacol Exp Ther ; 347(3): 645-59, 2013 Dec.
Article in English | MEDLINE | ID: mdl-24049061

ABSTRACT

The kinetics of drug-receptor interactions can profoundly influence in vivo and in vitro pharmacology. In vitro, the potencies of slowly associating agonists may be underestimated in assays capturing transient signaling events. When divergent receptor-mediated signaling pathways are evaluated using combinations of equilibrium and transient assays, potency differences driven by kinetics may be erroneously interpreted as biased signaling. In vivo, drugs with slow dissociation rates may display prolonged physiologic effects inconsistent with their pharmacokinetic profiles. We evaluated a panel of 5-hydroxytryptamine2B (5-HT2B) receptor agonists in kinetic radioligand binding assays and in transient, calcium flux assays, and inositol phosphate accumulation assays; two functional readouts emanating from Gαq-mediated activation of phospholipase C. In binding studies, ergot derivatives demonstrated slow receptor association and dissociation rates, resulting in significantly reduced potency in calcium assays relative to inositol phosphate accumulation assays. Ergot potencies for activation of extracellular signal-regulated kinases 1 and 2 were also highly time-dependent. A number of ergots produced wash-resistant 5-HT2B signaling that persisted for many hours without appreciable loss of potency, which was not explained simply by slow receptor-dissociation kinetics. Mechanistic studies indicated that persistent signaling originated from internalized or sequestered receptors. This study provides a mechanistic basis for the long durations of action in vivo and wash-resistant effects in ex vivo tissue models often observed for ergots. The 5-HT2B agonist activity of a number of ergot-derived therapeutics has been implicated in development of cardiac valvulopathy in man. The novel, sustained nature of ergot signaling reported here may represent an additional mechanism contributing to the valvulopathic potential of these compounds.


Subject(s)
Receptor, Serotonin, 5-HT2B/drug effects , Serotonin Receptor Agonists/pharmacology , Signal Transduction/drug effects , Adrenergic alpha-Antagonists/pharmacology , Amphetamines/pharmacokinetics , Arrestins/metabolism , Calcium/metabolism , Dose-Response Relationship, Drug , Ergot Alkaloids/pharmacology , Extracellular Signal-Regulated MAP Kinases/metabolism , HEK293 Cells , Humans , Phenoxybenzamine/pharmacology , Phosphorylation , Radioligand Assay , beta-Arrestins
17.
Bioorg Med Chem Lett ; 22(1): 71-5, 2012 Jan 01.
Article in English | MEDLINE | ID: mdl-22172695

ABSTRACT

The design of a new clinical candidate histamine-H(3) receptor antagonist for the potential treatment of excessive daytime sleepiness (EDS) is described. Phenethyl-R-2-methylpyrrolidine containing biphenylsulfonamide compounds were modified by replacement of the sulfonamide linkage with a sulfone. One compound from this series, 2j (APD916) increased wakefulness in rodents as measured by polysomnography with a duration of effect consistent with its pharmacokinetic properties. The identification of a suitable salt form of 2j allowed it to be selected for further development.


Subject(s)
Biphenyl Compounds/chemistry , Biphenyl Compounds/pharmacology , Histamine Antagonists/chemistry , Pyrrolidines/chemistry , Pyrrolidines/pharmacology , Receptors, Histamine H3/chemistry , Sulfones/chemistry , Animals , Area Under Curve , Brain/metabolism , Central Nervous System/drug effects , Chemistry, Pharmaceutical/methods , Drug Design , ERG1 Potassium Channel , Ether-A-Go-Go Potassium Channels/chemistry , Histamine Antagonists/pharmacokinetics , Humans , Inhibitory Concentration 50 , Mice , Models, Chemical , Pyrrolidines/antagonists & inhibitors , Rats , Sleep/drug effects , Temperature , Wakefulness/drug effects
18.
J Pediatr Hematol Oncol ; 33(2): 158-60, 2011 Mar.
Article in English | MEDLINE | ID: mdl-20829716

ABSTRACT

Translocations are key oncogenic events, and many rearrangements are characteristic for a specific malignancy. We present here a case of phenotypic precursor-B acute lymphoblastic leukemia (ALL), subsequently found to have both MYC and MLL translocations. Owing to the potential prognostic impact of these translocations, a novel treatment strategy was applied which merged precursor-B ALL, Burkitt-ALL, and "MLL-adapted" rationales. With the advent of expanding diagnostic panels and molecular therapeutic options, use of such adapted therapies for individualized treatment will undoubtedly continue to increase as we move toward pharmacogenomic-based approaches.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Myeloid-Lymphoid Leukemia Protein/genetics , Precursor B-Cell Lymphoblastic Leukemia-Lymphoma/drug therapy , Precursor B-Cell Lymphoblastic Leukemia-Lymphoma/genetics , Proto-Oncogene Proteins c-myc/genetics , Translocation, Genetic , Child, Preschool , Cyclophosphamide/administration & dosage , Cytarabine/administration & dosage , Doxorubicin/administration & dosage , Flow Cytometry , Histone-Lysine N-Methyltransferase , Humans , Male , Methotrexate/administration & dosage , Prednisone/administration & dosage , Vincristine/administration & dosage
19.
J Med Chem ; 53(15): 5696-706, 2010 Aug 12.
Article in English | MEDLINE | ID: mdl-20684606

ABSTRACT

Recent developments in sleep research suggest that antagonism of the serotonin 5-HT(2A) receptor may improve sleep maintenance insomnia. We herein report the discovery of a series of potent and selective serotonin 5-HT(2A) receptor antagonists based on a phenethylpiperazine amide core structure. When tested in a rat sleep pharmacology model, these compounds increased both sleep consolidation and deep sleep. Within this series of compounds, an improvement in the metabolic stability of early leads was achieved by introducing a carbonyl group into the phenethylpiperazine linker. Of note, compounds 14 and 27 exhibited potent 5-HT(2A) receptor binding affinity, high selectivity over the 5-HT(2C) receptor, favorable CNS partitioning, and good pharmacokinetic and early safety profiles. In vivo, these two compounds showed dose-dependent, statistically significant improvements on deep sleep (delta power) and sleep consolidation at doses as low as 0.1 mg/kg.


Subject(s)
Amides/chemical synthesis , Piperazines/chemical synthesis , Pyrazoles/chemical synthesis , Serotonin 5-HT2 Receptor Antagonists , Sleep Initiation and Maintenance Disorders/drug therapy , Sleep/drug effects , Administration, Oral , Amides/pharmacokinetics , Amides/pharmacology , Animals , Biological Availability , Blood Proteins/metabolism , Brain/metabolism , Dogs , Drug Inverse Agonism , Haplorhini , Humans , Male , Microsomes, Liver/metabolism , Piperazines/pharmacokinetics , Piperazines/pharmacology , Protein Binding , Pyrazoles/pharmacokinetics , Pyrazoles/pharmacology , Rats , Rats, Sprague-Dawley , Structure-Activity Relationship
20.
J Med Chem ; 53(11): 4412-21, 2010 Jun 10.
Article in English | MEDLINE | ID: mdl-20455563

ABSTRACT

Serotonin, which is stored in platelets and is released during thrombosis, activates platelets via the 5-HT(2A) receptor. 5-HT(2A) receptor inverse agonists thus represent a potential new class of antithrombotic agents. Our medicinal program began with known compounds that displayed binding affinity for the recombinant 5-HT(2A) receptor, but which had poor activity when tested in human plasma platelet inhibition assays. We herein describe a series of phenyl pyrazole inverse agonists optimized for selectivity, aqueous solubility, antiplatelet activity, low hERG activity, and good pharmacokinetic properties, resulting in the discovery of 10k (APD791). 10k inhibited serotonin-amplified human platelet aggregation with an IC(50) = 8.7 nM and had negligible binding affinity for the closely related 5-HT(2B) and 5-HT(2C) receptors. 10k was orally bioavailable in rats, dogs, and monkeys and had an acceptable safety profile. As a result, 10k was selected further evaluation and advanced into clinical development as a potential treatment for arterial thrombosis.


Subject(s)
Arteries/drug effects , Benzamides/chemistry , Benzamides/pharmacology , Drug Discovery/methods , Drug Inverse Agonism , Morpholines/chemistry , Morpholines/pharmacology , Pyrazoles/chemistry , Pyrazoles/pharmacology , Serotonin 5-HT2 Receptor Agonists , Thrombosis/drug therapy , Animals , Benzamides/metabolism , Benzamides/pharmacokinetics , Dogs , Female , Humans , Inhibitory Concentration 50 , Male , Morpholines/metabolism , Morpholines/pharmacokinetics , Platelet Aggregation/drug effects , Pyrazoles/metabolism , Pyrazoles/pharmacokinetics , Rats , Receptor, Serotonin, 5-HT2A/metabolism , Structure-Activity Relationship , Substrate Specificity , Thrombosis/metabolism
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