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1.
QJM ; 116(4): 279-283, 2023 Apr 29.
Article in English | MEDLINE | ID: mdl-34586408

ABSTRACT

Emerging reports raise concerns on the potential association between the COVID-19 vaccines and cardiac manifestations. We sought to evaluate cardiac complications associated with COVID-19 vaccination in a pooled analysis from our institution's cohort study and systematic review. Consecutive patients admitted to a tertiary hospital in Singapore between 1 January 2021 and 31 March 2021, with the onset of cardiac manifestations within 14 days following COVID-19 vaccination, were studied. Furthermore, a systematic review was performed, with PubMed, Embase, Research Square, MedRxiv and LitCovid databases accessed from inception up to 29 June 2021. Relevant manuscripts reporting individual patient data on cardiac complications following COVID-19 vaccination were included. Thirty patients were included in the study cohort, with 29 diagnosed with acute myocardial infarction (AMI) and 1 with myocarditis. Five patients developed heart failure, two had cardiogenic shock, three intubated, and one had cardiovascular-related mortality. In the systematic review, 16 studies were included with 41 myocarditis and 6 AMI cases. In the pooled analysis of the study cohort and the systematic review, 35 patients had AMI and 42 had myocarditis. Majority were men, and myocarditis patients were younger than AMI patients. Myocarditis patients tended to present 72 h postvaccination, while AMI patients were older and typically presented 24 h postvaccination. Majority with AMI or myocarditis developed symptoms after the first and second vaccination dose, respectively. This pooled analysis of patients presenting with cardiac manifestations following COVID-19 vaccination highlights the differences between myocarditis and AMI presentations in temporal association with the vaccination.


Subject(s)
COVID-19 , Myocardial Infarction , Myocarditis , Male , Humans , Female , Myocarditis/etiology , COVID-19 Vaccines/adverse effects , Cohort Studies , COVID-19/epidemiology , COVID-19/prevention & control , Myocardial Infarction/etiology , Vaccination/adverse effects
3.
QJM ; 115(12): 830-836, 2022 Dec 12.
Article in English | MEDLINE | ID: mdl-35866641

ABSTRACT

BACKGROUND: While progress is evident in gender and ethnic representation in the workplace, this disparity remains prevalent in academic positions. OBJECTIVES: We examined gender and Asian ethnic representation in editorial boards of cardiology journals. METHODS: A cross-sectional analysis was conducted using publicly available data on Cardiology and Cardiovascular medicine journals in the first quartile of the 2020 Scimago Journal & Country Rank indicator. The proportions of female and Asian editorial board members, associate editors and editors-in-chief were assessed. Subgroup analyses were conducted based on the journal's geographical origin, subspecialty and demographic of the editor-in-chief. RESULTS: Seventy-six cardiology journals, involving 8915 editorial board members, were included. Only 19.6% of editorial board members were female, 20.8% Asians and 4.0% Asian females. There were less female representation amongst editors-in-chief (9.9%) compared to associate editors (22.3%). European (18.1%) and North American-based journals (21.1%) had higher female representation compared to Asian-based journals (8.7%). There was lower Asian representation in European (18.1%) and North American-based journals (19.9%) compared to Asian-based journals (72.3%). Females were underrepresented in interventional (14.5%) journals, while Asians were underrepresented in general cardiology (18.3%) and heart failure (18.3%) journals. Journals led by female editors-in-chief had significantly higher female representation compared to male-led ones, while journals with Asian editors-in-chief had greater Asian representation compared to non-Asian led ones. CONCLUSION: This study highlights the female and Asian ethnic underrepresentation in academic roles in cardiology journal editorial boards. Further analysis is needed for other ethnicities, while the community pushes towards gender-balanced and ethnic diversity across editorial boards.


Subject(s)
Asian , Gender Equity , Female , Humans , Male , Cross-Sectional Studies
6.
QJM ; 114(10): 706-714, 2021 Dec 20.
Article in English | MEDLINE | ID: mdl-33533902

ABSTRACT

BACKGROUND/INTRODUCTION: There are little data on outcomes of COVID-19 patients with the presence of fever compared to the presence of symptoms. AIM: We examined the associations between symptomology, presence of fever and outcomes of a COVID-19 cohort. DESIGN AND METHODS: Between 23 January and 30 April 2020, 554 COVID-19 patients were admitted to a tertiary hospital in Singapore. They were allocated into four groups based on symptomology and fever-Group 1: asymptomatic and afebrile, Group 2: symptomatic but afebrile, Group 3: febrile but asymptomatic and Group 4: symptomatic and febrile. The primary outcomes were intensive care unit (ICU) admissions and mortality. The composite end-point included ICU admissions, mortality or any COVID-19 related end-organ involvement. RESULTS: There were differences in ferritin (P=0.003), C-reactive protein (CRP) levels (P<0.001) and lymphopenia (P=0.033) across all groups, with the most favourable biochemical profile in Group 1, and the least in Group 4. Symptomatic groups (Groups 2 and 4) had higher ICU admissions (1.9% and 6.0%, respectively, P=0.003) than asymptomatic groups (Groups 1 and 3). Composite end-point was highest in Group 4 (24.0%), followed by Group 3 (8.6%), Group 2 (4.8%) and Group 1 (2.4%) (P<0.001). The presence of fever (OR 4.096, 95% CI 1.737-9.656, P=0.001) was associated with the composite end-point after adjusting for age, pulse rate, comorbidities, lymphocyte, ferritin and CRP. Presence of symptoms was not associated with the composite end-point. DISCUSSION/CONCLUSION: In this COVID-19 cohort, presence of fever was a predictor of adverse outcomes. This has implications on the management of febrile but asymptomatic COVID-19 patients.


Subject(s)
COVID-19 , Humans , SARS-CoV-2
7.
Int J Emerg Med ; 13(1): 6, 2020 Feb 07.
Article in English | MEDLINE | ID: mdl-32028888

ABSTRACT

INTRODUCTION: Methanol poisoning usually occurs in a cluster and initial diagnosis can be challenging. Mortality is high without immediate interventions. This paper describes a methanol poisoning outbreak and difficulties in managing a large number of patients with limited resources. METHODOLOGY: A retrospective analysis of a methanol poisoning outbreak in September 2018 was performed, describing patients who presented to a major tertiary referral centre. RESULT: A total of 31 patients were received over the period of 9 days. Thirty of them were males with a mean age of 32 years old. They were mostly foreigners. From the 31 patients, 19.3% were dead on arrival, 3.2% died in the emergency department and 38.7% survived and discharged. The overall mortality rate was 61.3%. Out of the 12 patients who survived, two patients had toxic optic neuropathy, and one patient had uveitis. The rest of the survivors did not have any long-term complications. Osmolar gap and lactate had strong correlations with patient's mortality. Serum pH, bicarbonate, lactate, potassium, anion gap, osmolar gap and measured serum osmolarity between the alive and dead patients were significant. Post-mortem findings of the brain were unremarkable. CONCLUSION: The mortality rate was higher, and the morbidity includes permanent visual impairment and severe neurological sequelae. Language barrier, severity of illness, late presentation, unavailability of intravenous ethanol and fomipezole and delayed dialysis may have been the contributing factors. Patient was managed based on clinical presentation. Laboratory parameters showed difference in median between group that survived and succumbed for pH, serum bicarbonate, lactate, potassium and osmolar and anion gap. Management of methanol toxicity outbreak in resource-limited area will benefit from a well-designed guideline that is adaptable to the locality.

8.
Biochim Biophys Acta Gen Subj ; 1862(7): 1680-1692, 2018 Jul.
Article in English | MEDLINE | ID: mdl-29679717

ABSTRACT

Mesenchymal stem cell (MSC) dysfunction has been implicated in the pathogenesis of osteoporosis. MSCs derived from osteoporotic subjects demonstrate significant impairment in proliferation, adhesion and chemotaxis, and osteogenic differentiation, leading to reduced functional bone-forming osteoblasts and ultimately nett bone loss and osteoporosis. Epimedium herbs and its active compound Icaritin (ICT) have been used in Chinese ethnopharmacology for the treatment of metabolic bone diseases. Using an in-vitro cell culture model, we investigated the benefits of ICT treatment in enhancing MSC proliferation, migration and osteogenic differentiation, and provide novel data to describe its mechanism of action. ICT enhances MSC proliferation, chemotaxis to stromal cell-derived factor-1 (SDF-1) and osteogenic differentiation through the activation of signal transduction activator transcription factor 3 (STAT-3), with a consequential up-regulation in the expression and activity of cysteine (C)-X-C motif chemokine receptor 4 (CXCR4). These findings provide a strong basis for future clinical studies to confirm the therapeutic potential of ICT for the prevention and treatment of osteoporosis and fragility fractures.


Subject(s)
Flavonoids/pharmacokinetics , Mesenchymal Stem Cells/drug effects , Receptors, CXCR4/physiology , STAT3 Transcription Factor/physiology , Calcium/analysis , Cell Adhesion , Cell Differentiation , Cell Division , Cell Movement , Cells, Cultured , Core Binding Factor Alpha 1 Subunit/biosynthesis , Core Binding Factor Alpha 1 Subunit/genetics , Drug Evaluation, Preclinical , Humans , Mesenchymal Stem Cells/metabolism , Osteoblasts/cytology , Osteoporosis/drug therapy , Phosphorylation , Promoter Regions, Genetic , Protein Processing, Post-Translational , RNA Interference , RNA, Small Interfering/genetics , Receptors, CXCR4/biosynthesis , Receptors, CXCR4/genetics , STAT3 Transcription Factor/antagonists & inhibitors , Transcription, Genetic , Up-Regulation
9.
Bone ; 105: 122-133, 2017 Dec.
Article in English | MEDLINE | ID: mdl-28863947

ABSTRACT

In this study, we examined the effects of a natural prenylflavonoid Icaritin (ICT), on human osteoblast proliferation and osteogenic function. We observed that ICT dose-dependently enhanced osteoblast proliferation by ~15% over a 7day period. This increase in cell proliferation was associated with corresponding increases in osteoblast functions as measured by ALP secretion, intracellular calcium ions influx and calcium deposition. These anabolic effects were associated with a 4-fold increase in CXCR4 mRNA and protein expression. Silencing of CXCR4 protein expression using small interfering RNA reversed ICT-induced increase in cell proliferation, ALP activity and calcium deposition. Interestingly, we observed that ICT dose-dependently increased STAT-3 phosphorylation; and this resulted in increased binding of phosphorylated STAT-3 to the promoter region of the CXCR4 gene, to increase CXCR4 protein expression. Furthermore, we found that inhibition of STAT-3 phosphorylation resulted in a decrease in CXCR4 protein expression; whilst increasing phosphorylation of STAT-3 using a constitutive active STAT-3 vector significantly increased CXCR4 levels. Moreover, the chemical inhibition of STAT-3 phosphorylation annulled our previously observed ICT-induced increases of osteoblast proliferation and function. Finally, in a rat model of estrogen-deficient osteoporosis, ICT restored both osteoblasts numbers and CXCR4 expression. Taken together, both cellular and animal models support the novel findings that ICT; through the phosphorylation of STAT-3, up-regulated CXCR4, to increase osteoblast proliferation and function.


Subject(s)
Flavonoids/pharmacology , Gene Expression Regulation/drug effects , Osteoblasts/cytology , Osteoblasts/metabolism , Receptors, CXCR4/genetics , STAT3 Transcription Factor/metabolism , Cell Proliferation/drug effects , Gene Knockdown Techniques , Humans , Models, Animal , Osteoblasts/drug effects , Ovariectomy , Phosphorylation/drug effects , Promoter Regions, Genetic/genetics , Protein Binding/drug effects , Receptors, CXCR4/metabolism , Up-Regulation/drug effects
10.
Clin Radiol ; 70(11): 1276-80, 2015 Nov.
Article in English | MEDLINE | ID: mdl-26350147

ABSTRACT

AIM: To demonstrate the benefits of fluoroscopy-guided intra-articular steroid injection in the hip with varying degrees of disease severity, and to investigate the financial aspects of the procedure and impact on waiting time. MATERIALS AND METHODS: A prospective study was undertaken of patients who underwent fluoroscopic intra-articular steroid injection over the 9-month study period. Comparative analysis of the Oxford hip pain score pre- and 6-8 weeks post-intra-articular injection was performed. Hip radiographs of all patients were categorised as normal, mild, moderate, or severe disease (four categories) based on the modified Kellgren-Lawrence severity scale, and improvement on the Oxford hip pain score on each of these four severity categories were assessed. RESULTS: Within the study cohort of 100 patients, the mean increase in post-procedure hip score of 7.32 points confirms statistically significant benefits of the therapy (p<0.001, 95% confidence interval: 5.55-9.09). There was no significant difference in pre-injection hip score or change in score between the four severity categories (p=0.51). Significant improvement in hip score (p<0.05) was demonstrated in each of the four severity categories 6-8 weeks post-injection. No associated complications were observed. CONCLUSION: The present study confirms that fluoroscopy-guided intra-articular steroid injection is a highly effective therapeutic measure for hip osteoarthritis across all grades of disease severity with significant cost savings and the potential to reduce waiting times.


Subject(s)
Anti-Inflammatory Agents/administration & dosage , Osteoarthritis, Hip/drug therapy , Steroids/administration & dosage , Adolescent , Adult , Aged , Aged, 80 and over , Analysis of Variance , Female , Fluoroscopy , Humans , Injections, Intra-Articular/methods , Male , Middle Aged , Prospective Studies , Radiography, Interventional , Time-to-Treatment , Treatment Outcome , Young Adult
11.
Eye (Lond) ; 29(9): 1162-6, 2015 Sep.
Article in English | MEDLINE | ID: mdl-26043705

ABSTRACT

PURPOSE: To review the histopathological diagnoses, visual outcome, and complication rate of orbital biopsy in a UK tertiary referral centre. METHODS: This was a retrospective, clinical-pathological, interventional, consecutive case series. All orbital biopsies performed between July 2004 and June 2014 in Newcastle Eye Centre (Newcastle upon Tyne, UK) were included in this study. All relevant data collected from the local electronic database and medical records were analysed. RESULTS: A total of 166 orbital biopsies were identified during the study period: 86 patients (53.1%) were female and the mean age was 53.7 ± 19.7 years. Of all the cases, orbital biopsies were performed unilaterally in 158 (97.5%) patients and bilaterally in 4 (2.5%) patients. The mean follow-up period was 2.2 ± 2.3 years. The two most common histopathological diagnoses were non-specific inflammatory disease (62, 38.3%) and lymphoproliferative disease (40, 24.7%). None of the patients experienced ≥ 2-Snellen line visual loss. There were 7 (4.2%) postoperative complications noted: 1 (0.6%) orbital haemorrhage with no loss of vision, 4 (2.4%) diplopia, 1 (0.6%) short-term symblepharon, and 1 (0.6%) conjunctival granuloma. Postoperative diplopia was associated with lateral orbitotomy (P = 0.044) and excisional biopsy (P = 0.015). CONCLUSIONS: Orbital biopsy serves as a safe diagnostic tool in managing orbital diseases. Patient should be made aware of the risk of postoperative diplopia. Our data provides useful guidance to clinicians when counselling patients for orbital biopsy.


Subject(s)
Orbital Diseases/pathology , Adult , Aged , Biopsy/methods , Diplopia/etiology , England , Female , Humans , Male , Middle Aged , Orbital Diseases/physiopathology , Postoperative Complications/etiology , Retrospective Studies , Visual Acuity/physiology , Young Adult
12.
J Hand Surg Eur Vol ; 38(2): 129-32, 2013 Feb.
Article in English | MEDLINE | ID: mdl-22733699

ABSTRACT

A previous ultrasound study showed inflammation around the extensor pollicis longus tendon and surrounding structures at 6 weeks after manipulation, with or without pin fixation, and immobilization for distal radius fracture. Ultrasound examination after plating of distal radius fracture followed by early active mobilization of the wrist showed a short-lived inflammatory response, evident at 2 weeks but not at 6 weeks, around the extensor pollicis longus tendon (26 wrists examined) and flexor pollicis longus tendon (18 wrists examined). Early active mobilization of the wrist appears to limit the duration of inflammation around these tendons.


Subject(s)
Fracture Fixation, Internal/methods , Intra-Articular Fractures/diagnostic imaging , Intra-Articular Fractures/surgery , Radius Fractures/diagnostic imaging , Radius Fractures/surgery , Tendon Injuries/diagnostic imaging , Tendon Injuries/physiopathology , Tendons/diagnostic imaging , Adult , Aged , Bone Plates , Bone Wires , Female , Humans , Inflammation/diagnostic imaging , Inflammation/physiopathology , Intra-Articular Fractures/physiopathology , Male , Middle Aged , Radius Fractures/physiopathology , Statistics, Nonparametric , Time Factors , Ultrasonography
13.
JBR-BTR ; 96(5): 301-3, 2013.
Article in English | MEDLINE | ID: mdl-24479293

ABSTRACT

Deep extra-abdominal fibromatoses (desmoids) are rare benign fibrous mesenchymal tumours occurring in adults, which may mimic primary malignancy on imaging. We present a case of a 64-year-old man with a hard painless lump in his left calf. The solid and partially hypervascular appearance on ultrasound, the infiltrative appearance, lesion heterogeneity and heterogeneous enhancement pattern on Magnetic Resonance Imaging (MRI) were suspicious for a soft tissue sarcoma. Moreover, PET-CT demonstrated FDG-avidity. Despite these aggressive imaging features, histopathology revealed a benign but locally aggressive desmoid tumour. The radiologist should be aware that PET-CT is not always helpful as an additional tool for differentiation between malignant and benign soft tissue lesions. Intralesional bandlike areas of low signal intensity on all pulse MR sequences and intimate relationship with the muscle fascia are more useful clues to the diagnosis of this soft tissue lesion.


Subject(s)
Fibromatosis, Aggressive/diagnosis , Positron-Emission Tomography/methods , Tomography, X-Ray Computed/methods , Diagnosis, Differential , Fibromatosis, Aggressive/surgery , Humans , Leg/diagnostic imaging , Leg/pathology , Magnetic Resonance Imaging/methods , Male , Middle Aged , Ultrasonography
14.
Ir Med J ; 104(3): 90-1, 2011 Mar.
Article in English | MEDLINE | ID: mdl-21667616

ABSTRACT

Rapidly progressive acute respiratory failure attributed to 2009 H1N1 influenza A infection has been reported worldwide-3. Refractory hypoxaemia despite conventional mechanical ventilation and lung protective strategies has resulted in the use a combination of rescue therapies, such as conservative fluid management, prone positioning, inhaled nitric oxide, high frequency oscillatory ventilation and extracorporeal membrane oxygenation (ECMO)4. ECMO allows for pulmonary or cardiopulmonary support as an adjunct to respiratory and cardiac failure, minimising ventilator-associated lung injury (VALI). This permits treatment of the underlying disease process, while concurrently allowing for recovery of the acute lung injury. This case documents a previously healthy twenty-two year old Asian male patient with confirmed pandemic (H 1N1) 2009 influenza A who was successfully managed with ECMO in the setting of severe refractory hypoxaemia and progressive hypercapnia.


Subject(s)
Influenza A Virus, H1N1 Subtype , Influenza, Human/therapy , Respiratory Insufficiency/therapy , Disease Progression , Extracorporeal Membrane Oxygenation , Humans , Hypercapnia/etiology , Hypoxia/etiology , Male , Young Adult
15.
Br J Radiol ; 81(971): e259-62, 2008 Nov.
Article in English | MEDLINE | ID: mdl-18941037

ABSTRACT

Intra-orbital extension of giant pituitary adenomas is an extremely uncommon event. We describe the imaging appearances of a giant prolactinoma presenting with proptosis owing to an unusual pattern of intraorbital extension and extensive skull base involvement. The CT and MRI findings of a middle-aged man presenting with proptosis are described. The orbital component of the tumour closely resembled a dilated superior ophthalmic vein on CT, which was subsequently clarified on MRI. The patient was treated with cabergoline, with good clinical and radiological recovery. In conclusion, radiologists should be wary of such an unusual pattern of intraorbital extension of giant pituitary adenomas, which may mimic an enlarged superior ophthalmic vein on axial CT imaging. MRI is the best tool for evaluating skull base and orbital invasion.


Subject(s)
Orbital Neoplasms/diagnosis , Pituitary Neoplasms/diagnosis , Prolactinoma/diagnosis , Adult , Exophthalmos/etiology , Humans , Magnetic Resonance Imaging , Male , Neoplasm Invasiveness , Orbital Neoplasms/complications , Pituitary Neoplasms/complications , Prolactin/blood , Prolactinoma/complications , Retinal Vein/diagnostic imaging , Tomography, X-Ray Computed
17.
Br J Radiol ; 81(964): e123-6, 2008 Apr.
Article in English | MEDLINE | ID: mdl-18344271

ABSTRACT

Here, we describe neuroimaging findings of an unusual case of severe vertebrobasilar dolichoectasia producing obstructive hydrocephalus. CT and MRI performed in a 71-year-old woman presenting with clinical features of raised intracranial pressure revealed severely ectatic and tortuous vertebral and basilar arteries. The ectatic basilar artery was causing compression and flattening of the midbrain. This had resulted in aqueductal compression and consequent obstructive hydrocephalus. The patient underwent emergency ventricular drainage, with resulting decompression of the ventricles and resolution of symptoms. Vertebrobasilar dolichoectasia refers to a markedly dilated and tortuous vertebrobasilar arterial system, occasionally presenting with thomboembolic episodes or symptoms related to local compressive effects, such as cranial nerve palsies. Direct midbrain compression with obstructive hydrocephalus is a rare complication that mandates emergency ventricular decompression.


Subject(s)
Hydrocephalus/diagnosis , Vertebrobasilar Insufficiency/diagnosis , Aged , Basilar Artery , Cerebral Aqueduct , Decompression, Surgical/methods , Female , Humans , Hydrocephalus/etiology , Magnetic Resonance Angiography/methods , Magnetic Resonance Imaging , Tomography, X-Ray Computed , Treatment Outcome , Ventriculoperitoneal Shunt , Vertebrobasilar Insufficiency/complications
18.
J Bone Joint Surg Br ; 89(7): 948-52, 2007 Jul.
Article in English | MEDLINE | ID: mdl-17673592

ABSTRACT

Our aim was to determine whether abnormalities noted on MRI immediately after reduction for developmental dysplasia of the hip could predict the persistance of dysplasia and aid surgical planning. Scans of 13 hips in which acetabular dysplasia had resolved by the age of four years were compared with those of five which had required pelvic osteotomy for persisting dysplasia. The scans were analysed by two consultant musculoskeletal radiologists who were blinded to the outcome in each child. The postreduction scans highlighted a number of anatomical abnormalities secondary to developmental dysplasia of the hip, but statistical analysis showed that none were predictive of persisting acetabular dysplasia in the older child, suggesting that the factors which determine the long-term outcome were not visible on these images.


Subject(s)
Acetabulum/surgery , Hip Dislocation, Congenital/diagnosis , Magnetic Resonance Imaging/methods , Osteotomy/methods , Female , Hip Dislocation, Congenital/physiopathology , Hip Dislocation, Congenital/surgery , Humans , Infant , Magnetic Resonance Imaging/instrumentation , Male , Recurrence
19.
Eur Respir J ; 27(5): 944-50, 2006 May.
Article in English | MEDLINE | ID: mdl-16707393

ABSTRACT

Mannitol inhalation increases urinary excretion of 9alpha,11beta-prostaglandin F2 (a metabolite of prostaglandin D2 and marker of mast cell activation) and leukotriene E4. The present study tested the hypothesis that beta2-adrenoreceptor agonists and disodium cromoglycate (SCG) protect against mannitol-induced bronchoconstriction by inhibition of mast cell mediator release. Fourteen asthmatic subjects inhaled mannitol (mean dose 252+/-213 mg) in order to induce a fall in forced expiratory volume in one second (FEV1) of > or = 25%. The same dose was given 15 min after inhalation of formoterol fumarate (24 microg), SCG (40 mg) or placebo. Pre- and post-challenge urine samples were analysed by enzyme immunoassay for 9alpha,11beta-prostaglandin F2 and leukotriene E4. The maximum fall in FEV1 of 32+/-10% on placebo was reduced by 95% following formoterol and 63% following SCG. Following placebo, there was an increase in median urinary 9alpha,11beta-prostaglandin F2 concentration from 61 to 92 ng.mmol creatinine(-1), but no significant increase in 9alpha,11beta-prostaglandin F2 concentration in the presence of either formoterol (69 versus 67 ng.mmol creatinine(-1)) or SCG (66 versus 60 ng.mmol creatinine(-1)). The increase in urinary leukotriene E4 following placebo (from 19 to 31 ng.mmol creatinine(-1)) was unaffected by the drugs. These results support the hypothesis that the drug effect on airway response to mannitol is due to inhibition of mast cell prostaglandin D2 release.


Subject(s)
Adrenergic beta-Agonists/pharmacology , Asthma/metabolism , Asthma/physiopathology , Bronchoconstriction/drug effects , Cromolyn Sodium/pharmacology , Ethanolamines/pharmacology , Mannitol/pharmacology , Mast Cells/drug effects , Mast Cells/metabolism , Prostaglandin D2/antagonists & inhibitors , Prostaglandin D2/metabolism , Adolescent , Adult , Cross-Over Studies , Double-Blind Method , Female , Formoterol Fumarate , Humans , Male , Prostaglandin D2/urine
20.
Pharmazie ; 61(4): 318-21, 2006 Apr.
Article in English | MEDLINE | ID: mdl-16649546

ABSTRACT

To show the applicability of a solution model, i.e. the Jouyban-Acree model, for predicting the solubility of a solute in ternary solvent systems based on model constants computed using solubility data of the solute in binary solvent systems, the solubility of salicylic acid in water-ethanol, water-propylene glycol, ethanol-propylene glycol mixtures was determined. A minimum number of three data points from each binary system was used to calculate the binary interaction parameters of the model. Then the solubility in other binary solvent compositions and also in a number of ternary solvents was predicted, and the mean percentage deviation (MPD) was calculated as an accuracy criterion. The overall MPD (+/-SD) was 7.3 (+/-7.3)% and those of a similar predictive model was 15.7 (+/-11.5)%. The mean difference between the proposed and a previous model was statistically significant (paired t-test, p < 0.004).


Subject(s)
Salicylic Acid/chemistry , Algorithms , Ethanol , Models, Chemical , Models, Statistical , Pharmaceutical Vehicles , Predictive Value of Tests , Propylene Glycol , Solubility , Solvents , Water
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