RESUMEN

The most recent version of the European Society for Medical Oncology (ESMO) Clinical Practice Guidelines for the diagnosis, treatment and follow-up of prostate cancer was published in 2020. It was therefore decided, by both the ESMO and the Singapore Society of Oncology (SSO), to convene a special, virtual guidelines meeting in November 2021 to adapt the ESMO 2020 guidelines to take into account the differences associated with the treatment of prostate cancer in Asia. These guidelines represent the consensus opinions reached by experts in the treatment of patients with prostate cancer representing the oncological societies of China (CSCO), India (ISMPO), Japan (JSMO), Korea (KSMO), Malaysia (MOS), Singapore (SSO) and Taiwan (TOS). The voting was based on scientific evidence and was independent of the current treatment practices and drug access restrictions in the different Asian countries. The latter were discussed when appropriate. The aim is to provide guidance for the optimisation and harmonisation of the management of patients with prostate cancer across the different regions of Asia.

Asunto(s)

Oncología Médica , Neoplasias de la Próstata/diagnóstico , Neoplasias de la Próstata/terapia , Asia , Consenso , Europa (Continente) , Estudios de Seguimiento , Humanos , Masculino

RESUMEN

The most recent version of the European Society for Medical Oncology (ESMO) Clinical Practice Guidelines for the diagnosis, treatment and follow-up of renal cell carcinoma was published in 2019 with an update planned for 2021. It was therefore decided by both the ESMO and the Singapore Society of Oncology (SSO) to convene a special, virtual guidelines meeting in May 2021 to adapt the ESMO 2019 guidelines to take into account the ethnic differences associated with the treatment of renal cell carcinomas in Asian patients. These guidelines represent the consensus opinions reached by experts in the treatment of patients with renal cell carcinoma representing the oncological societies of China (CSCO), India (ISMPO), Japan (JSMO), Korea (KSMO), Malaysia (MOS), Singapore (SSO) and Taiwan (TOS). The voting was based on scientific evidence and was independent of the current treatment practices and drug access restrictions in the different Asian countries. The latter were discussed when appropriate.

Asunto(s)

Carcinoma de Células Renales , Neoplasias Renales , Asia , Carcinoma de Células Renales/diagnóstico , Carcinoma de Células Renales/terapia , Estudios de Seguimiento , Humanos , Neoplasias Renales/diagnóstico , Neoplasias Renales/terapia , Oncología Médica

RESUMEN

This study was commissioned to assess if there are regional differences in the acceptability of beef between consumers from Northern Ireland (NI), Republic of Ireland (ROI) and Great Britain (GB). Palatability traits were affected by socioeconomic and behavioural factors such as preferred cooking endpoint, animal welfare, value, health aspects of beef product, ease of preparation as well as consumption frequency for specific cuts. "Willingness to pay" (WTP) was influenced by income, preferred cooking endpoint, value of beef product, ease of preparation and consumption frequency for frying steak. Results showed that GB consumers scored higher for the same striploin steak compared to NI and ROI consumers. This may be due to differences in the motivation for beef choice and/or consumption habits. GB consumers were less concerned about the healthiness of beef product and beef origin. In addition, a higher consumption frequency for rump was reported in GB, which may explain the higher sensory scores observed among GB consumers for striploins.

Asunto(s)

Conducta de Elección , Comportamiento del Consumidor , Carne Roja/economía , Carne Roja/normas , Animales , Bovinos , Culinaria/métodos , Femenino , Humanos , Masculino , Irlanda del Norte , Factores Socioeconómicos , Gusto , Reino Unido

RESUMEN

INTRODUCTION: Modulation-based noise reduction (MBNR) is one of the common noise reduction methods used in hearing aids. Gain reduction in high frequency bands may occur for some implementations of MBNR and fricatives might be susceptible to alteration, given the high frequency components in fricative noise. The main objective of this study is to quantify the acoustic effect of MBNR on /s, z/. METHODS: Speech-and-noise signals were presented to, and recorded from, six hearing aids mounted on a head and torso simulator. Test stimuli were nonsense words mixed with pink, cafeteria, or speech-modulated noise at 0 dB SNR. Fricatives /s, z/ were extracted from the recordings for analysis. RESULTS: Analysis of the noise confirmed that MBNR in all hearing aids was activated for the recordings. More than 1.0 dB of acoustic change occurred to /s, z/ when MBNR was turned on in four out of the six hearing aids in the pink and cafeteria noise conditions. The acoustics of /s, z/ by female talkers were affected more than male talkers. Significant relationships between amount of noise reduction and acoustic change of /s, z/ were found. Amount of noise reduction accounts for 42.8% and 16.8% of the variability in acoustic change for /s/ and /z/ respectively. CONCLUSION: Some clinically-available implementations of MBNR have measurable effects on the acoustics of fricatives. Possible implications for speech perception are discussed.

Asunto(s)

Audífonos , Estimulación Acústica , Acústica , Humanos , Ruido , Fonética , Percepción del Habla

RESUMEN

There are many options in the treatment of heavily pretreated metastatic breast cancer however none of the therapeutic agents have shown promising improvement of survival with good toxicity profile. Eribulin is a novel nontaxane microtubule dynamics inhibitor. Two recent clinical trial showed that Eribulin improves progression-free and overall survival in this subset of patients. We report our experience with using Eribulin in five patients with metastatic breast cancer either in second or third-line setting, in our centre.

Asunto(s)

Antineoplásicos/uso terapéutico , Neoplasias de la Mama/tratamiento farmacológico , Furanos/uso terapéutico , Cetonas/uso terapéutico , Femenino , Humanos , Malasia , Metástasis de la Neoplasia , Resultado del Tratamiento

RESUMEN

We present a case of nasopharyngeal carcinoma complicated with hyperleucocytosis. After ruling our other causes we concluded that the hyperleucocytosis was due to paraneoplastic leukemoid reaction (PLR). The overall survival was 15 months which is rare among patients with PLR.

RESUMEN

There are few published studies on prevalence of allergic rhinitis in preschool children. The aims of this study were to verify the prevalence, clinical characteristics, and treatment of allergic rhinitis (AR) symptoms in the first year of life adding supplementary questions to the EISL instrument. A cross-sectional study used Phase III EISL written questionnaire in addition to modified allergic rhinitis ISAAC questions. One thousand and three parents of infants answered the questionnaire: 484 (48.3%) had at least one sneezing, or a runny or blocked nose episodes without cold or flu in the first year of life. A quarter of infants had recurrent wheezing (≥3 episodes) and more frequent in the presence of AR symptoms. Physician diagnosis of AR and the use of intranasal steroids and both antihistamines and intranasal steroids were more common among those infants with AR symptoms. The prevalence of AR symptoms was high and starting early in life.

Asunto(s)

Rinitis Alérgica Perenne/epidemiología , Edad de Inicio , Brasil/epidemiología , Estudios Transversales , Femenino , Humanos , Lactante , Masculino , Prevalencia , Rinitis Alérgica , Rinitis Alérgica Perenne/diagnóstico

RESUMEN

Replacing palpating fingers with an ultrasound (US) probe has resulted in an epidemic of thyroid nodules. Despite the high prevalence of thyroid nodules in the general population, thyroid malignancy is rare. Although no imaging modality can accurately predict the nature of every nodule, high-resolution US is the most sensitive, easily available and cost-effective diagnostic test available to detect thyroid nodules, measure their dimensions and identify their structure. The presence of calcifications, irregular spiculated outline, hypoechogenicity in a solid nodule, chaotic intranodular vascularity and an elongated shape are well-known US features of malignancy in thyroid nodules. Cervical lymph node metastasis and extrathyroidal extension of a thyroid nodule are highly specific for malignancy but seen infrequently. Spongiform nodules, purely or predominantly cystic nodules, nodules with well-defined hypoechoic halo and echogenic as well as isoechoic nodules are usually benign. None of the US characteristics have 100% accuracy in detecting or excluding malignancy. Fine-needle biopsy is currently the best triage test for pre-operative evaluation of a thyroid nodule. There is no significant difference in the risk for malignancy between palpable and non-palpable nodules and size is not a reliable indicator for their malignant potential. The best tool for risk stratification for malignancy in thyroid nodules is US and guided biopsy of nodules with suspicious imaging features. This is especially relevant in patients with multinodular goitre.

Asunto(s)

Biopsia con Aguja Fina/métodos , Nódulo Tiroideo/diagnóstico por imagen , Nódulo Tiroideo/patología , Ultrasonografía Intervencional , Diagnóstico Diferencial , Humanos , Medición de Riesgo/métodos

RESUMEN

PURPOSE: We assessed the effects of TAK-491 (a newly designed potent and selective ARB) alone and in combination with pioglitazone (PIO) on myocardial infarct size (IS). METHODS: Rats received TAK-491 (0.3, 1, 3, or 10 mgkg(-1)d(-1)), PIO (1.0 or 2.5 mgkg(-1)d(-1)), or PIO 2.5 mgkg(-1)d(-1) with TAK-491 (1 or 3 mgkg(-1)d(-1)) for 4 days. On day 5 rats underwent 30-minute coronary artery occlusion and 4-hour reperfusion. Area at risk (AR) was assessed by blue dye and IS by TTC. Left ventricular (LV) dimensions and function was assessed by echocardiography 35 days after infarction. RESULTS: TAK (1.0-10 mgkg(-1)d(-1)), PIO (1.0 to 2.5 mgkg(-1)d(-1)), PIO2.5+TAK1.0, and PIO2.5+TAK3.0 significantly reduced IS. IS was the smallest in the TAK 10.0, followed by PIO+TAK 3.0. The protective effects of TAK and PIO were additive, as IS was smaller in the PIO2.5+TAK1.0 than in PIO 2.5 alone (p = 0.008) or TAK1.0 alone (p = 0.002); and in PIO2.5+TAK3.0 than in PIO alone (p < 0.001) or TAK3.0 alone (p < 0.001). TAK, PIO and their combination tended to attenuate LV remodeling and improved LV function 35 days after infarction; however, the differences among individual groups were not statistically significant. Both TAK-491 and PIO increased calcium-dependent nitric oxide synthase activity, whereas only PIO increased COX2 expression and activity. Both PIO and TAK-491 increased Akt, ERK 1/2 and eNOS phosphorylation and inhibited BAX activation. CONCLUSIONS: TAK-491 and PIO independently limited myocardial IS in a dose-dependent fashion; and the effects were additive. The mechanism of protection and the role of TAK-491 in this clinical setting should be further investigated.

Asunto(s)

Bloqueadores del Receptor Tipo 1 de Angiotensina II/uso terapéutico , Infarto del Miocardio/prevención & control , Tiazolidinedionas/uso terapéutico , Bloqueadores del Receptor Tipo 1 de Angiotensina II/farmacología , Animales , Apoptosis/efectos de los fármacos , Presión Sanguínea/fisiología , Ciclooxigenasa 1/metabolismo , Ciclooxigenasa 2/metabolismo , Quimioterapia Combinada , Frecuencia Cardíaca/fisiología , Ventrículos Cardíacos/efectos de los fármacos , Ventrículos Cardíacos/metabolismo , Ventrículos Cardíacos/patología , Hipoglucemiantes/farmacología , Hipoglucemiantes/uso terapéutico , Masculino , Proteínas de la Membrana/metabolismo , Proteína Quinasa 1 Activada por Mitógenos/metabolismo , Proteína Quinasa 3 Activada por Mitógenos/metabolismo , Infarto del Miocardio/metabolismo , Infarto del Miocardio/patología , Infarto del Miocardio/fisiopatología , Daño por Reperfusión Miocárdica/metabolismo , Daño por Reperfusión Miocárdica/patología , Daño por Reperfusión Miocárdica/fisiopatología , Daño por Reperfusión Miocárdica/prevención & control , Óxido Nítrico Sintasa de Tipo I/metabolismo , Óxido Nítrico Sintasa de Tipo II/metabolismo , Óxido Nítrico Sintasa de Tipo III/metabolismo , Fosforilación/efectos de los fármacos , Pioglitazona , Proteínas Proto-Oncogénicas c-akt/metabolismo , Ratas , Ratas Sprague-Dawley , Tiazolidinedionas/farmacología , Función Ventricular Izquierda/fisiología , Proteína X Asociada a bcl-2/metabolismo , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo

RESUMEN

Tungsten-loaded TiO(2) photocatalyst has been successfully prepared and characterized. TEM analysis showed that the photocatalysts were nanosize with the tungsten species forming layers of coverage on the surface of TiO(2), but not in clustered form. This was confirmed by XRD and FT-Raman analyses where tungsten species were well dispersed at lower loading (<6.5 mol%), but were in crystalline WO(3) at higher loadings (>12 mol%). In addition, loading with tungsten could stabilize the anatase phase from transforming into inactive rutile phase and did not shift the optical absorption to the visible region as shown by DRUV-vis analysis. PZC value of TiO(2) was found at 6.4, but the presence of tungsten at 6.5 mol% WO(3), decreased the PZC value to 3. Tungsten-loaded TiO(2) was superior to unmodified TiO(2) with 2-fold increase in degradation rate of methylene blue, and equally effective for the degradation of different class of dyes such as methyl violet and methyl orange at 1 mol% WO(3) loading.

Asunto(s)

Colorantes/química , Procesos Fotoquímicos , Titanio/química , Tungsteno/química , Compuestos Azo/química , Catálisis , Violeta de Genciana/química , Cinética , Azul de Metileno/química , Microscopía Electrónica de Transmisión , Nanopartículas , Análisis Espectral , Eliminación de Residuos Líquidos , Contaminantes Químicos del Agua/química

RESUMEN

Cyclosporine A (CsA), a calcineurin inhibitor produced by the fungi Trichoderma polysporum and Cylindrocarpon lucidum, is an immunosuppressant prescribed in organ transplants to prevent rejection. Its adverse effect on renal dysfunction has limited its use in a clinical setting. Apigenin (4',5',7'-Trihydroxyflavone), a herbal extract, with anti-inflammatory and anti-tumour properties, has been investigated for properties to reverse this adverse effect. This research was conducted to establish a standard protocol for immunohistochemical estimation of Transforming Growth Factor beta (TGF-beta) expression, as an indicator of Cyclosporine A induced damage, and to observe whether apoptotic index and TGF-beta expression can be used to assess effects of Apigenin on CsA induced renal dysfunction. Six groups of 5 male Sprague-Dawley albino rats each were dosed once daily for 21 days, as follows: (1) negative control--oral corn oil, (2) positive control--Cyclosporine A (25 mg/kg), (3) Group 3--Apigenin (20 mg/kg), (4) Group 4--Cyclosporine A (25 mg/kg) +Apigenin (10 mg/kg), (5) Group 5--Cyclosporine A (25 mg/kg) +Apigenin (15 mg/kg) and (6) Group 6--Cyclosporine A (25 mg/kg) +Apigenin (20 mg/kg). Cyclosporine A was administered intra-peritoneally while Apigenin was given orally. The rat kidneys were harvested and examined microscopically to assess the apoptotic index, and stained by immunohistochemistry for multifunctioning polypeptide TGF-beta expression. A high apoptotic index and TGF-beta intensity was observed in the Cyclosporine A group. Apigenin significantly reduced the both apoptotic index and TGF-beta intensity. The apoptotic index correlated with TGF-beta intensity, especially in glomeruli. This study indicates that Cyclosporine A can enhance the TGF-beta expression in rat kidney, signifying accelerated apoptosis. TGF-beta and apoptotic index may be used to assess Apigenin and its effect on Cyclosporine A induced renal damage.

Asunto(s)

Apigenina/farmacología , Apoptosis/efectos de los fármacos , Ciclosporina/toxicidad , Inmunosupresores/toxicidad , Enfermedades Renales/prevención & control , Factor de Crecimiento Transformador beta/metabolismo , Administración Oral , Animales , Recuento de Células , Antagonismo de Drogas , Inmunohistoquímica , Inyecciones Intraperitoneales , Riñón/efectos de los fármacos , Riñón/metabolismo , Riñón/patología , Enfermedades Renales/inducido químicamente , Enfermedades Renales/patología , Glomérulos Renales/efectos de los fármacos , Glomérulos Renales/metabolismo , Glomérulos Renales/patología , Túbulos Renales/efectos de los fármacos , Túbulos Renales/metabolismo , Túbulos Renales/patología , Masculino , Tamaño de los Órganos/efectos de los fármacos , Ratas , Ratas Sprague-Dawley

RESUMEN

INTRODUCTION: Soft tissue infections are common, but erysipelas, especially its blistering feature, is an under-recognised entity. There have been few reports of blistering erysipelas. We aim to describe the clinical characteristics, management and the risk factors for erysipelas in 20 patients admitted in a tertiary hospital in Singapore. METHODS: A chart review of all cases of erysipelas, diagnosed by experienced dermatologists and admitted to the Singapore General Hospital during the period January 2006 to August 2006, was conducted. RESULTS: There were 20 patients (11 male, nine female) with an average age of 62.2 (range 31-86) years. The most commonly-involved site was the leg (75 percent), followed by the arm (15 percent) and face (ten percent). The clinical characteristics were well dermarcated (50 percent), erythema (100 percent) and oedema (85 percent), and bullae and vesicles formation (80 percent). Most presented with no pain (40 percent) and minimal signs of systemic toxicity. There was no positive blood culture, but the swab on the blistering erysipelas yielded positive cultures in 67 percent. The most common predisposing factor was disruption in the skin barrier (65 percent), followed by venous insufficiency (20 percent) and lymphoedema (25 percent). All patients received empirical antibiotics, most commonly penicillin and cloxacillin (65 percent), for an average duration of 20.65 (10-41) days, and with local care, there was complete resolution. CONCLUSION: In our experience, erysipelas is a clinically distinct entity and commonly presents with bullae or vesicles. It has favourable prognosis, and rarely develops any complication with timely and appropriate therapy.

Asunto(s)

Erisipela/microbiología , Erisipela/terapia , Adulto , Anciano , Anciano de 80 o más Años , Vesícula , Erisipela/complicaciones , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Factores de Riesgo , Singapur , Piel/microbiología , Piel/fisiopatología , Enfermedades Cutáneas Bacterianas/diagnóstico , Enfermedades Cutáneas Bacterianas/terapia , Resultado del Tratamiento

Asunto(s)

Tos/etiología , Conducta Alimentaria/etnología , Análisis de Componente Principal , Esputo , Humanos

RESUMEN

An adaptive signal enhancer based on third-order statistics with a genetic-type, variable step-size prefilter is introduced to recover evoked potentials (EPs). EPs are usually embedded in the ongoing electroencephalogram with a very low signal-to-noise ratio (SNR). As a higher-order statistics technique has a natural tolerance to Gaussian noise, it is applicable for filtering EPs. An adaptive signal enhancer based on third-order statistics was used as the major filter in this study. However, the efficiency of the adaptive signal enhancer was reduced when the total power of uncorrelated noises was large. To improve the performance for EPs under poor SNR, a low-noise signal is required. Therefore a prefilter with a genetic-type, variable step-size algorithm was employed to enhance the SNR of the signal in this study. The fundamental idea of a genetic-type, variable step-size algorithm is that its step-sizes are regularly readjusted to optimum. Therefore this algorithm can be used as a prefilter with different noise levels. Experimental results showed that, for filtering EPs, the proposed scheme is superior to the adaptive signal enhancer with a normalised least mean square algorithm.

Asunto(s)

Electroencefalografía/métodos , Potenciales Evocados , Procesamiento de Señales Asistido por Computador , Algoritmos , Humanos

RESUMEN

Breast cancer is one of the commonest cancers among women in Malaysia. The relation between lifestyle practices and the risk of breast cancer in Chinese women aged 21-55 years were assessed using data collected from June to October 2001, via a face-to face interview in a case control study in the Breast Clinics of Kuala Lumpur Hospital and University Malaya Medical Centre. A total of 89 cases with breast cancer were compared with 85 controls without the disease. Our study showed that breastfeeding had an odds ratio of 4.43 after adjustment for confounders. The results add to the evidence of a protective association between breast feeding practices and breast cancer particularly among Chinese women receiving treatment at two government hospitals in the Klang Valley.

Asunto(s)

Lactancia Materna , Neoplasias de la Mama/epidemiología , Neoplasias de la Mama/etiología , Estilo de Vida , Adulto , Neoplasias de la Mama/etnología , Estudios de Casos y Controles , Distribución de Chi-Cuadrado , China/etnología , Estudios Transversales , Femenino , Humanos , Modelos Logísticos , Malasia/epidemiología , Persona de Mediana Edad , Factores de Riesgo , Población Rural

RESUMEN

Community methicillin-resistant Staphylococcus aureus (CMRSA) strains are being isolated with increasing frequency around the world. In Western Australia CMRSA are endemic in geographically remote communities and have been found to belong to five different contour-clamped homogeneous electric field (CHEF) electrophoretic patterns. Representatives of each of these CHEF patterns have been compared to CMRSA representative of CHEF patterns from other Australian states and New Zealand. With one exception, all of the isolates were nonmultiresistant and were not resistant to many antimicrobial agents other than the beta-lactams. With one exception, which is not believed to be a CMRSA, all of the isolates harbored a beta-lactamase plasmid. Erythromycin resistance was associated with a 2-kb plasmid. One of the beta-lactamase plasmids was found to be able to acquire additional resistance determinants to become a multiple resistance plasmid. There were 10 multilocus sequence types belonging to eight distantly related clonal complexes of S. aureus. One new sequence type was found. Although most of the CMRSA harbored the type IVa SCCmec, a type IV structural variant was found and two new SCCmec types were identified. Protein A gene (spa) typing revealed two new spa types and, with two exceptions, corresponded to multilocus sequence typing. In contrast to other reports on CMRSA, most of the CMRSA strains studied here did not contain the Panton-Valentine leukocidin genes. The results also demonstrate that nonmultiresistant hospital strains such as UK EMRSA-15 may be able to circulate in the community and could be mistaken for CMRSA based on their resistance profiles.

Asunto(s)

Resistencia a la Meticilina , Staphylococcus aureus/clasificación , Técnicas de Tipificación Bacteriana , Farmacorresistencia Bacteriana Múltiple , Pruebas de Sensibilidad Microbiana , Plásmidos , Polimorfismo de Longitud del Fragmento de Restricción , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/genética

RESUMEN

OBJECTIVE: Salbutamol is commonly delivered as a racemic mixture of pharmacologically active (R)-salbutamol and inactive (S)-salbutamol. This study investigated inactive (S)- and active (R)-salbutamol plasma levels and their relationship to dose in patients with severe asthma. METHODS: Basic demographics, racemic-salbutamol dose in the preceding 24 h, lung function tests at baseline and 1 h, and a 10 mL plasma sample were obtained from subjects presenting to the Department of Emergency Medicine with acute asthma. Plasma determinations were carried out using an LC-MS assay with solid phase extraction. RESULTS: All patients (n = 5) had detectable levels of drug in plasma with range of 0.9-7.7 and 4.7-27.4 ng/mL for (R)-salbutamol and (S)-salbutamol respectively. These were correlated to total racemic salbutamol dose. The range of the (S) : (R) ratio was 2.0-5.2, with (R)-salbutamol representing 16-33% of the total plasma concentration, which did not correlate with total salbutamol dose. CONCLUSION: Only a small fraction of total plasma salbutamol concentration was found to consist of active enantiomer in patients with an acute severe exacerbation of asthma actively undergoing treatment with racemic-salbutamol. As a result of the possible contribution of (S)-salbutamol to poor asthma control further enantioselective investigations are warranted in severe asthma.

Asunto(s)

Albuterol/sangre , Asma/tratamiento farmacológico , Broncodilatadores/sangre , Estado Asmático/sangre , Administración por Inhalación , Adulto , Albuterol/química , Albuterol/uso terapéutico , Asma/sangre , Broncodilatadores/química , Broncodilatadores/uso terapéutico , Relación Dosis-Respuesta a Droga , Femenino , Humanos , Modelos Lineales , Masculino , Proyectos Piloto , Estereoisomerismo

RESUMEN

A sensitive enantioselective liquid chromatography-mass spectrometry (LC-MS) assay using a manual solid-phase extraction (SPE) procedure, a non-deuterated internal standard and an ion trap LC-MS was developed to measure (R)- and (S)-albuterol in plasma. Sample extraction from plasma was achieved by a manual SPE extraction procedure with methoxyphenamine added as the internal standard. Chiral separation was achieved using a teicoplanin-based stationary phase and a mobile phase consisting of methanol, acetic acid and 28% (w/v) ammonia (1000:5:1, v/v/v). Samples were analyzed by selected reaction monitoring of product ions from the protonated molecular ions. The detection limit of the assay was 0.1 ng/ml with a conservative lower limit of quantification of 0.25 ng/ml for each enantiomer. Recovery of albuterol enantiomers from plasma spiked at 10 ng/ml of racemate was determined to be 89+/-5.8% (mean+/-S.D.). Reproducibility at 10 ng/ml of racemate assessed by the coefficient of variation was found to be 6.5% (n=5). Instrument precision (measured as coefficient of variation) was 1.4% (n=5). The correlation coefficient r(2) determined from the calibration curve over the range 0.5-50.0 ng/ml racemate in plasma was 0.998. This assay allows adequate sensitivity, recovery and reproducibility for the application to studies of inhaled albuterol.

Asunto(s)

Albuterol/sangre , Albuterol/normas , Albuterol/química , Cromatografía de Gases y Espectrometría de Masas/métodos , Humanos , Estereoisomerismo

RESUMEN

The peripheral arterial vessel often appears as an elliptic shape under the constraints of the surrounding tissues. In this study, the gradient-based Hough transform was used to detect the central location of the ellipse and the lumen area of the arterial vessel non-invasively using power Doppler imaging. Sequential ultrasound images were used to construct arterial distension waveforms in both the major- and minor-axis directions for a few cardiac cycles. The common carotid arteries (CCAs) for nine healthy male volunteers (mean age 24 years), in the sitting position, were investigated in vivo. The CCAs (n = 9) had a mean diameter of 5.83mm, and the pulsatile diameter distension was 13.7+/-1.9%. The brachial artery and dorsalis pedis artery for five healthy male volunteers (mean age 26 years), in the supine position, had mean diameters of 4.03mm and 2.83mm and distensions of 16.7+/-4.6% and 15.5+/-5.4%, respectively. The movement of the arterial centre location during the cardiac cycle reflected the asymmetry of the reaction forces produced by the surrounding soft tissues. The present method can obtain the response of vessel distension to pulse pressure, as well as the constrained conditions of the arteries.

Asunto(s)

Arterias/diagnóstico por imagen , Flujo Pulsátil , Ultrasonografía Doppler/métodos , Adulto , Arterias/fisiología , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Masculino