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1.
Biochim Biophys Acta Gen Subj ; 1862(7): 1680-1692, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29679717

RESUMO

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.


Assuntos
Flavonoides/farmacocinética , Células-Tronco Mesenquimais/efeitos dos fármacos , Receptores CXCR4/fisiologia , Fator de Transcrição STAT3/fisiologia , Cálcio/análise , Adesão Celular , Diferenciação Celular , Divisão Celular , Movimento Celular , Células Cultivadas , Subunidade alfa 1 de Fator de Ligação ao Core/biossíntese , Subunidade alfa 1 de Fator de Ligação ao Core/genética , Avaliação Pré-Clínica de Medicamentos , Humanos , Células-Tronco Mesenquimais/metabolismo , Osteoblastos/citologia , Osteoporose/tratamento farmacológico , Fosforilação , Regiões Promotoras Genéticas , Processamento de Proteína Pós-Traducional , Interferência de RNA , RNA Interferente Pequeno/genética , Receptores CXCR4/biossíntese , Receptores CXCR4/genética , Fator de Transcrição STAT3/antagonistas & inibidores , Transcrição Gênica , Regulação para Cima
2.
Clin Radiol ; 70(11): 1276-80, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26350147

RESUMO

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.


Assuntos
Anti-Inflamatórios/administração & dosagem , Osteoartrite do Quadril/tratamento farmacológico , Esteroides/administração & dosagem , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Análise de Variância , Feminino , Fluoroscopia , Humanos , Injeções Intra-Articulares/métodos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Radiografia Intervencionista , Tempo para o Tratamento , Resultado do Tratamento , Adulto Jovem
3.
QJM ; 116(4): 279-283, 2023 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-34586408

RESUMO

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.


Assuntos
COVID-19 , Infarto do Miocárdio , Miocardite , Masculino , Humanos , Feminino , Miocardite/etiologia , Vacinas contra COVID-19/efeitos adversos , Estudos de Coortes , COVID-19/epidemiologia , COVID-19/prevenção & controle , Infarto do Miocárdio/etiologia , Vacinação/efeitos adversos
4.
QJM ; 115(12): 830-836, 2022 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-35866641

RESUMO

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.


Assuntos
Asiático , Equidade de Gênero , Feminino , Humanos , Masculino , Estudos Transversais
5.
Ir Med J ; 104(3): 90-1, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21667616

RESUMO

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.


Assuntos
Vírus da Influenza A Subtipo H1N1 , Influenza Humana/terapia , Insuficiência Respiratória/terapia , Progressão da Doença , Oxigenação por Membrana Extracorpórea , Humanos , Hipercapnia/etiologia , Hipóxia/etiologia , Masculino , Adulto Jovem
6.
QJM ; 114(10): 706-714, 2021 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-33533902

RESUMO

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.


Assuntos
COVID-19 , Humanos , SARS-CoV-2
7.
Int J Emerg Med ; 13(1): 6, 2020 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-32028888

RESUMO

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.

9.
J Bone Joint Surg Br ; 89(7): 948-52, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17673592

RESUMO

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.


Assuntos
Acetábulo/cirurgia , Luxação Congênita de Quadril/diagnóstico , Imageamento por Ressonância Magnética/métodos , Osteotomia/métodos , Feminino , Luxação Congênita de Quadril/fisiopatologia , Luxação Congênita de Quadril/cirurgia , Humanos , Lactente , Imageamento por Ressonância Magnética/instrumentação , Masculino , Recidiva
10.
Bone ; 105: 122-133, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28863947

RESUMO

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.


Assuntos
Flavonoides/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Osteoblastos/citologia , Osteoblastos/metabolismo , Receptores CXCR4/genética , Fator de Transcrição STAT3/metabolismo , Proliferação de Células/efeitos dos fármacos , Técnicas de Silenciamento de Genes , Humanos , Modelos Animais , Osteoblastos/efeitos dos fármacos , Ovariectomia , Fosforilação/efeitos dos fármacos , Regiões Promotoras Genéticas/genética , Ligação Proteica/efeitos dos fármacos , Receptores CXCR4/metabolismo , Regulação para Cima/efeitos dos fármacos
12.
Pharmazie ; 61(4): 318-21, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16649546

RESUMO

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).


Assuntos
Ácido Salicílico/química , Algoritmos , Etanol , Modelos Químicos , Modelos Estatísticos , Veículos Farmacêuticos , Valor Preditivo dos Testes , Propilenoglicol , Solubilidade , Solventes , Água
14.
Eye (Lond) ; 29(9): 1162-6, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26043705

RESUMO

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.


Assuntos
Doenças Orbitárias/patologia , Adulto , Idoso , Biópsia/métodos , Diplopia/etiologia , Inglaterra , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doenças Orbitárias/fisiopatologia , Complicações Pós-Operatórias/etiologia , Estudos Retrospectivos , Acuidade Visual/fisiologia , Adulto Jovem
15.
Endocrinology ; 96(5): 1270-9, 1975 May.
Artigo em Inglês | MEDLINE | ID: mdl-1122885

RESUMO

Delta5,3beta-Hydroxysteroid dehydrogenase (3beta-HSD) activity has been measured in homogenates of ovary and trophoblast from 9th to 21st day pregnant rats under conditions where there was little or no further metabolism of the progesterone formed from pregnenolone. Trophoblast 3beta-HSD activity is first detectable on the 11th day of gestation; the specific activity peaks on the 13th day, and falls thereafter. The ovary enzyme activity rises gradually to the 19th day and falls on the 21st day. Decidua homogenates contain very low levels of 3beta-HSD activity, while embryo and yolk sac homogenates do not posses significant amounts. Total 3beta-HSD activities were also determined on a per conceptus basis. At no time during pregnancy does the total trophoblast 3beta-HSD activity exceed 40% the activity of the ovary. This may explain why the progesterone-producing capacity of trophoblast in the rat is inadequate to support normal pregnancy following ovariectomy. The temporal patterns of trophoblast and ovary 3beta-HSD activity suggest that the enzymes are not coordinately controlled in the two tissues.


Assuntos
Hidroxiesteroide Desidrogenases/metabolismo , Ovário/enzimologia , Prenhez , Trofoblastos/enzimologia , Animais , Decídua/enzimologia , Decídua/metabolismo , Embrião de Mamíferos/enzimologia , Feminino , Ovário/metabolismo , Gravidez , Progesterona/metabolismo , Proteínas/metabolismo , Ratos , Fatores de Tempo , Trofoblastos/metabolismo
16.
Neurology ; 57(3): 529-31, 2001 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-11502928

RESUMO

In a hospital series of 70 patients on follow-up after radiotherapy for nasopharyngeal carcinoma, 14 patients (20%) developed delayed post-irradiation bulbar palsy 1 to 18 years after radiotherapy (mean 5.5 years). Functional disability was moderate to severe. Three patients had aspiration pneumonia with one mortality. Post-irradiation bulbar palsy was a common complication and probably resulted from direct neuronal damage.


Assuntos
Paralisia Bulbar Progressiva/etiologia , Irradiação Craniana/efeitos adversos , Neoplasias Nasofaríngeas/radioterapia , Adulto , Paralisia Bulbar Progressiva/fisiopatologia , Eletromiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Nasofaríngeas/fisiopatologia , Fatores de Tempo
17.
Int J Pharm ; 200(1): 87-92, 2000 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-10845689

RESUMO

The effect of the spacers (Fisonair, Breath-A-Tech, Volumatic and Nebuhaler) on the in vitro aerosol characteristics of two propellant-driven metered dose inhalers (MDIs), Tilade (nedocromil sodium) and Intal (disodium cromoglycate), was studied. The measurement was carried out on a Marple-Miller impactor operating at 30 l/min. Five actuations were collected for the drug assay. The results showed that Tilade (label claim 2 mg active per actuation) and Intal (label claim 5 mg active per actuation) generated aerosols with a fine particle mass (FPM, i.e. mass of particles 5 microm in the aerosol) of 0.34 mg (S.D. 0.01, n = 4) and 0.02 mg (S.D. 0.01, n = 4) per actuation, respectively. For both inhalers, large volume spacers increased (Fisonair > Nebuhaler > Volumatic) while small volume spacer (Breath-A-Tech) decreased the FPM. The FPM (per actuation) for Tilade with Fisonair, Nebuhaler, Volumatic and Breath-A-Tech was 0.52 (0.03), 0.45 (0.03), 0.41 (0.04) and 0.09 (0.04) mg, respectively, while for Intal the corresponding values were 0.41 (0.02), 0.32 (0.04), 0.28 (0.03) and 0.08 (0.01) mg. Thus, the fine particle mass can be either increased or decreased, depending on the spacer selected. In addition, all spacers significantly reduced the coarse particle (> or = 10 microm) mass, with Fisonair, Breath-A-Tech, Nebuhaler and Volumatic producing only 7.6, 0.4, 5.2 and 2.6, respectively of that from Tilade alone and 15.6, 0.7, 5.4 and 4.1%, respectively of that from Intal alone. The general trends for Tilade and Intal were similar but not quantitatively identical. The proper choice of spacers is therefore important for the optimal delivery of Tilade and Intal.


Assuntos
Antiasmáticos/administração & dosagem , Antiasmáticos/química , Cromolina Sódica/administração & dosagem , Cromolina Sódica/química , Nedocromil/administração & dosagem , Nedocromil/química , Propelentes de Aerossol , Aerossóis , Excipientes , Nebulizadores e Vaporizadores , Tamanho da Partícula
18.
Int J Pharm ; 206(1-2): 75-83, 2000 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-11058812

RESUMO

Recently, the dispersion of mannitol powders has demonstrated the importance of particle size, air flow and inhaler device (Chew and Chan, 1999). The aim of the present study is to extend our investigation to a different compound, disodium cromoglycate (DSCG) powders. Solid state characteristics of the powders were assessed by particle sizing, scanning electron microscopy, X-ray powder diffraction, moisture content, particle density determination and freeze fracture. The aerosol behaviour of the powders was studied by dispersion using Rotahaler(R) and Dinkihaler(R), connected to a four-stage liquid impinger operating at 30-120 l/min. Three amorphous powders with a mass median diameter (MMD) of 2.3, 3.7, 5.2 microm and a similar polydispersity were prepared. The particles were nearly spherical with a particle density of 1.6 g/cm(3) and moisture content of 6.6 wt.%. Using Rotahaler(R), the maximum fine particle fraction (FPF(max)) for all three powders was only 15 wt.%, attained at the highest flow of 120 l/min. Using Dinkihaler(R), the FPF(max) was two to four times higher, being 36 and 29 wt.% for the 2.3 and 3.7 microm powder, respectively, at 60 l/min; and 18 wt.% for the 5.2 microm powder at 120 l/min. Hence, the study shows that the FPF in the DSCG powder aerosols was determined by the interaction of the particle size, air flow and inhaler design. The attribution of the amorphous nature and the different physico-chemical properties of the powder may explain the incomplete and low dispersibility of DSCG.


Assuntos
Antiasmáticos/química , Cromolina Sódica/química , Nebulizadores e Vaporizadores , Aerossóis , Tamanho da Partícula , Pós
19.
J Investig Allergol Clin Immunol ; 10(4): 215-22, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11039838

RESUMO

Six Hevea brasiliensis latex protein allergens, Hevb 1, Hev b 2, Hev b 3, Hev b 4, and two variants of Hev b 7 (7b and 7c), were purified from Hevea latex, while a seventh protein, Hev b 5, was prepared in recombinant form. The presence of these proteins in glove extracts was indicated by their respective antibodies in the serum of rabbits immunized against the extracts. The relative propensities of IgE binding to the individual latex allergens were compared using sera from latex-allergic patients. IgE recognition of Hev b 4, Hev b 7b, Hev b 5 and Hev b 2 was most frequently encountered, with 75, 61, 31 and 28%, respectively, of the patient sera reacting. Sensitivity to multiple latex proteins was common, and out of the 31 seropositive patients, 23 (74%/ ) had IgE against at least two latex allergens, while 12 (39%) had IgE specific for at least three allergens. Statistical analysis of the data suggested that many patients might have acquired sensitivity to Hev b 2, Hev b 4 and Hev b 7b from a common source. (e.g., from latex products). On the other hand, sensitivity to Hev b 5 and to Hev b 7c were interrelated. It is plausible that sensitivity to these two proteins might have been acquired from sources other than latex products (e.g., from certain foods).


Assuntos
Alérgenos/efeitos adversos , Hipersensibilidade ao Látex/diagnóstico , Hipersensibilidade ao Látex/etiologia , Látex/efeitos adversos , Proteínas de Plantas/efeitos adversos , Alérgenos/imunologia , Animais , Luvas Protetoras , Humanos , Imunoglobulina E/sangue , Imunoglobulina E/metabolismo , Látex/química , Látex/imunologia , Proteínas de Plantas/genética , Proteínas de Plantas/imunologia , Coelhos
20.
Respir Care ; 45(6): 764-8, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10894466

RESUMO

By understanding the way the regulatory concepts of safety and effectiveness are interpreted by CDER, especially by the Division of Pulmonary Drug Products, value can be added to the data developed. Keeping regulatory requirements in mind during early product development aids rapid evaluation of aerosol drug candidates and can lead to more efficient decisions about further development. Health care practitioners, the medical research community, and patient advocates can and do have a voice in the development of new regulations.


Assuntos
Aerossóis , Legislação de Medicamentos , Administração por Inalação , Propelentes de Aerossol , Aerossóis/normas , Clorofluorcarbonetos , Ensaios Clínicos como Assunto , Humanos , Ozônio , Nações Unidas , Estados Unidos , United States Food and Drug Administration
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