Accuracy of dexmedetomidine titration in diagnosis of restless legs syndrome / 中华麻醉学杂志

The medical records of patients of both sexes with sleep disorders treated with multimodal sleep therapy for which patient controlled sleep with dexmedetomidine was the main method, aged≥18 yr, with body mass index of 18-30 kg/m 2, from February 2019 to January 2021, were collected.Dexmedetomidine 60 ml/h (4 μg/ml) was intravenously infused until non-rapid eye movement (NREM) Ⅲ phase was reached or the consumption of dexmedetomidine reached 1 μg/kg.Whether dexmedetomidine induced restless legs syndrome (RLS) was judged according to the Chinese guidelines for the diagnosis and treatment of restless legs syndrome (2021 edition). When the titration was stopped and on the next day after emergence from anesthesia, clinical diagnosis was performed according to Chinese guidelines for the diagnosis and treatment of restless legs syndrome (2021 edition) to determine whether RLS was combined or not.Kappa consistency analysis was used to assess the consistency between dexmedetomidine titration and the Chinese guidelines for the diagnosis and treatment of restless legs syndrome (2021 Edition) in diagnosis of RLS.The sensitivity and specificity of diagnosis of RLS by dexmedetomidine titration were calculated.A total of 39 patients were included and 8 patients had RLS symptoms which were judged accroding to dexmedetomidine titration.The results of Kappa consistency test showed that there was a strong consistency between dexmedetomidine titration and Chinese guidelines for the diagnosis and treatment of restless legs syndrome (2021 edition) (Kappa value 1.0, P<0.01). The sensitivity and specificity of dexmedetomidine titration in judging RLS were 100%.In conclusion, dexmedetomidine titration can accurately judge RLS.

Structural Volume of Hippocampus and Alzheimers Disease

RESUMO Pesquisas recentes demonstram que o hipocampo apresenta uma redução de volume no final da idade adulta, mantendo uma estreita relação com o declínio cognitivo. A aquisição da imagem por diversos métodos de medição de volume nos leva a encontrar na ressonância magnética o método de destaque, pois permite quantificar o volume de determinadas estruturas cerebrais utilizando a reconstrução computadorizada tridimensional das imagens obtidas. OBJETIVOS Confirmar a existência de diferenças entre o volume hipocampal e o declínio cognitivo leve, doença de Alzheimer e cognição normal. MÉTODOS Levantamento bibliográfico de estudos que apresentassem dados referentes aos distúrbios da doença de Alzheimer, alterações macroscópicas cerebrais detectadas com softwares na ressonância magnética e segmentação. Foram adicionados estudos apenas da medição volumétrica do hipocampo, objetivando-se chegar a valores que possam estabelecer uma correlação do menor valor estrutural hipocampal e risco de desenvolvimento da doença. RESULTADOS Um total de 1.070 indivíduos foi analisado em seis estudos clínicos, demonstrando a relação da diminuição do hipocampo na neuroimagem, correlacionado com o comprometimento cognitivo leve e doença de Alzheimer. CONCLUSÕES O desenvolvimento de um valor padrão para esse fim seria bastante útil na coleta de dados, permitindo melhor compreensão de algumas alterações que podem ocorrer na cognição, determinar valores prognósticos e até, em um futuro próximo, fator de risco imagiológico para a doença.

Avaliação do teor de vitamina C de preparados sólidos para refresco comercializados em Campo Grande-MS / Evaluation of the vitamin C content of solid preparations for soft drinks marketed in Campo Grande-MS

RESUMO Os sucos naturais têm sido amplamente substituídos pelos preparados sólidos para refresco (PSR), o que pode resultar em perda nutricional de componentes importantes, como o ácido ascórbico (AA). Dessa forma, este estudo objetivou analisar o teor de AA, determinar a acidez total titulável e o pH em amostras de PSR sabor abacaxi comercializados nos mercados varejistas de Campo Grande-MS e, além disso, caracterizar o AA empregado como substância química de referência. Foram analisadas 10 amostras de PSR sabor abacaxi, por meio do método de Tillmans modificado, e todas apresentaram teor de AA acima do mínimo exigido na dose dietética recomendada, atendendo aos requisitos da RDC n° 360/2003. Entretanto, 50% das amostras apresentaram teor de AA acima do limite máximo permitido de 20% para mais ou para menos segundo o declarado no rótulo. O estudo realizado confirmou que a utilização dos PSR é uma boa opção alimentícia para alcançar a dose diária necessária de AA a baixo custo.

SUMMARY Natural juices have been largely replaced by solid refreshments (SR), which can result in nutrient loss of important components, such as ascorbic acid (AA). Thus, this study aimed to analyze the AA content, determine the titratable total acidity and pH in samples of pineapple-flavored SR marketed in the retail markets of Campo Grande-MS and, in addition, characterize AA used as Reference Chemical Substance. Ten samples of pineapple-flavored SR were analyzed using the modified Tillmans method, and all presented AA content above the minimum required in the recommended dietary dose, meeting the requirements of RDC 360/2003. However, 50% of the samples presented AA content above the maximum allowed limit of 20% for more or less as stated on the label. The study confirmed that the use of SR is a good dietary option to achieve the necessary daily dose of AA at a low cost.

Validación de una metodología analítica por HPLC-DAD para la cuantificación de ácido benzoico complejado, en un ensayo de permeación transdérmica in vitro empleando piel de cerdo / Validation of an analytical methodology by HPLC-DAD for the quantification of complexed benzoic acid, in an in vitro transdermal permeation assay using pig skin

RESUMEN En el presente estudio se realizó la validación de una metodología analítica por cromatografía líquida de alta eficiencia con detector de arreglo de diodos (HPLC-DAD) para la cuantificación del ácido benzoico en complejos polielectrolíticos, obtenidos con Eudragit® E100. Para ello se evaluaron las características de desempeño determinando que la metodología es selectiva; lineal en el rango de concentraciones de 2 a 10 fíg/mL; precisa con un RSD inferior a un 2%; exacta con un porcentaje de recuperación de un 98,7% y se establecieron límites de cuantificación (LOQ) de 0,72 y de 1,56 (g/mL para el sistema y método respectivamente. De acuerdo a estos resultados, la metodología analítica es adecuada para evaluar la permeación in vitro, del ácido benzoico incluido en los complejos polielectrolíticos a través de piel porcina, empleando celdas de Franz.

SUMMARY This paper presents the studies carried out about the validation of an analytical methodology by high performance liquid chromatography with diode array detector (HPLC-DAD) for the quantification of benzoic acid in polyelectrolyte complexes obtained with Eudragit® E100. Performance characteristics of the methodology were evaluated, finding that this is selective; linear in the concentration range of 2 to 10 (g / mL; accurate with a RSD of less than 2%, exact with a recovery percentage of 98.7% and quantification limits of 0.72 and 1.56 fig / mL were established for the system and method respectively. According with this results, the analytical methodology is adequate to evaluate the in vitro permeation of benzoic acid, in polyelectrolyte complexes, through porcine skin in Franz cells.

Development and validation of alternative methods by non-aqueous acid-base titration and derivative ultraviolet spectrophotometry for quantification of sildenafil in raw material and tablets

Sildenafil citrate (SILC) is a potent phosphodiesterase-5 inhibitor used for erectile dysfunction and pulmonary hypertension. This study shows two simple, fast and alternative analytical methods for SILC determination by non-aqueous titration and by derivative ultraviolet spectrophotometry (DUS) in active pharmaceutical ingredient and/or dosage forms. The quantitation method of SILC active pharmaceutical ingredient by non-aqueous acid-base titration was developed using methanol as solvent and 0.1 mol/L of perchloric acid in acetic acid as titrant. The endpoint was potentiometrically detected. The non-aqueous titration method shows satisfactory repeatability and intermediate precision (RSD 0.70-1.09%). The neutralization reaction occurred in the stoichiometric ratio 1:1 in methanol. The determination of SILC active pharmaceutical ingredient or dosage forms by DUS was developed in the linear range from 10 to 40 µg/mL, in 0.01 mol/L HCl, using the first order zero-peak method at λ 256 nm. The DUS method shows selectivity toward tablets excipients, appropriate linearity (R2 0.9996), trueness (recovery range 98.86-99.30%), repeatability and intermediate precision in three concentration levels (RSD 1.17-1.28%; 1.29-1.71%, respectively). Therefore, the methods developed are excellent alternatives to sophisticated instrumental methods and can be easily applied in any pharmaceutical laboratory routine due to simple and fast executions.

Clinical comparative study of oxycodone sustained-release tablet versus morphine tablet in dose titration therapy on moderate and severe chronic cancer pain / 中国医师进修杂志

Objective To observe the clinical effect and adverse reaction of oxycodone sustained-release tablet and morphine tablet in dose titration therapy on moderate and severe chronic cancer pain. Methods Sixty patients suffering from moderate and severe cancer pain, without using opioid drugs, were divided into oxycodone sustained-release tablet group and morphine tablet group by random digits table method with 30 cases each. The patients in oxycodone sustained-release tablet group were administered 10 mg oxycodone sustained-release tablet every 12 h, and the patients in morphine tablet group were administered 5 or 10 mg morphine tablet whenever needed. The total dose of opioid drugs was acquired after 24 h, and was converted into equal dose of oxycodone sustained-release tablet. The condition of pain control and adverse reaction were observed and recorded in a week. Results During the titration, the number of daily outbreak pain and daily medication in oxycodone sustained-release tablet were significantly lower than those in morphine tablet:(1.27 ± 1.53) times vs. (4.87 ± 1.98) times and (3.37 ± 1.78) times vs. (5.10 ± 2.20) times, and there were statistical differences (P0.05). At the first day after titration, the incidence of daily outbreak pain in oxycodone sustained-release tablet was significantly lower than that in morphine tablet:23.33%(7/30) vs. 53.33% (16/30), the rate of reaching steady pain control state was significantly higher than that in morphine tablet: 86.67% (26/30) vs. 63.33% (19/30), and there were statistical differences (P0.05). Conclusions The pain relief rate and side effect of oxycodone sustained-release tablet is similar to that of morphine tablet in dose titration therapy on moderate and severe chronic cancer pain, but analgesic effect is faster than morphine tablet. Oxycodone sustained-release tablet decreases the number of outbreak pain and relieves patients′ pain in the titration process. Oxycodone sustained-release tablet may have advantage of time and effect, which is worth to be widely used in clinical therapy.

Titrimetric and spectrophotometric assay of diethylcarbamazine citrate in formulations using iodate and iodide mixture as reagents

One titrimetric and two spectrophotometric methods are proposed for the determination of diethylcarbamazine citrate (DEC) in bulk drug and in formulations using potassium iodate and potassium iodide as reagent. The methods employ the well-known analytical reaction between iodate and iodide in the presence of acid. In titrimetry (method A), the drug was treated with a measured excess of thiosulfate in the presence of unmeasured excess of iodate-iodide mixture and after a standing time of 10 min, the surplus thiosulfate was determined by back titration with iodine towards starch end point. Titrimetric assay is based on a 1:3 reaction stoichiometry between DEC and iodine and the method is applicable over 2.0-10.0 mg range. The liberated iodine is measured spectrophotometrically at 370 nm (method B) or the iodine-starch complex measured at 570 nm (method C). In both methods, the absorbance is found to be linearly dependent on the concentration of iodine, which in turn is related to DEC concentration. The calibration curves are linear over 2.5-50 and 2.5-30 µg mL-1 DEC for method B and method C, respectively. The calculated molar absorptivity and Sandell sensitivity values were 6.48×103 L mol-1 cm-1 and 0.0604 µg cm-2, respectively, for method B, and their respective values for method C are 9.96×103 L mol-1 cm-1 and 0.0393 µg cm-2. The intra-day and inter-day accuracy and precision studies were carried out according to the ICH guidelines. The methods were successfully applied to the analysis of DEC formulations.

Propõem-se titulação e dois métodos espectrofotométricos para a determinação de citrato de dietilcarbamazina (DEC) a granel e em suas formulações, usando iodato de potássio e iodeto de potássio como reagente. Os métodos utilizam a reação analítica conhecida entre iodato e iodeto, na presença de ácido. Na titulometria (Método A), o fármaco foi tratado com excesso medido de tiossulfato, na presença de excesso não medido de mistura iodato-iodeto e, depois de um tempo de repouso de 10 min, o excesso de tiossulfato foi determinado por titulação de retorno com iodo até o ponto final com amido. A titulação é baseada em reação com estequiometria 1:3 entre DEC e iodo e o método é aplicável na faixa de 2.0-10.0 mg. O iodo liberado é medido espectrofotometricamente a 370 nm (método B) ou o complexo de iodo-amido medido a 570 nm (método C). Em ambos os métodos, a absorvância é considerada linearmente dependente da concentração de iodo, a qual, por sua vez, está relacionada à concentração de DEC. As curvas de calibração são lineares para concentrações de DEC de 2.5-50 e 2.5-30 mg mL- 1 para o método B e para o método C, respectivamente. A absortividade molar calculada e os valores de sensibilidade Sandel foram 6.48×103 L mol-1 cm- 1 e 0.0604 ug cm-2, respectivamente, para o método B, e os seus respectivos valores para o método C são 9.96×103 L mol-1 cm-1 e 0.0393 mg cm-2. Os estudos de exatidão e precisão intra-dia e inter-dia foram realizados de acordo com as diretrizes da ICH. Os métodos foram aplicados com sucesso na análise de formulações de DEC.

Development of a new ferulic acid certified reference material for use in clinical chemistry and pharmaceutical analysis

This study compares the results of three certified methods, namely differential scanning calorimetry (DSC), the mass balance (MB) method and coulometric titrimetry (CT), in the purity assessment of ferulic acid certified reference material (CRM). Purity and expanded uncertainty as determined by the three methods were respectively 99.81%, 0.16%; 99.79%, 0.16%; and 99.81%, 0.26% with, in all cases, a coverage factor (k) of 2 (P=95%). The purity results are consistent indicating that the combination of DSC, the MB method and CT provides a confident assessment of the purity of suitable CRMs like ferulic acid.

Therapeutic effect of increasing dose of metoprolol by rapid titration method on acute myocardial in-farction / 心血管康复医学杂志

Objective:To observe and compare the therapeutic effect of metoprolol by routine increasing dose method and rapid titration method on acute myocardial infarction (AMI).Methods:A total of 60 inpatients,who were di-agnosed with AMI within 24h and without contraindications for metoprolol,were randomly divided into two groups:routine therapy group (received metoprolol using routine methods,the dose was added in seven days)and rapid ti-tration group (metoprolol was added in three days using titration).The dosage maintained with 190 mg/d after both groups reaching the target dose of 190mg/d;then therapeutic effects were observed in both groups.Results: ①There were no re-myocardial infarction,rehospitalization caused by heart failure and sudden death etc.in both groups;② Patients received echocardiography in outpatients after three months.Compared with routine increasing dose group,there was significant reduction in left ventricular end-diastolic diameter [LVEDd,(55.00±7.56)mm vs.(50.00± 5.81)mm]and significant rise in left ventricular ejection fraction [LVEF,(49.13 ± 10.18)% vs. (57.84±10.34)%]in rapid titration group,P <0.01 both.Conclusion:Rapid titration method could make the pa-tients rapidly reach the targeted dose of metoprolol and inhibit renin release earlier,block the renin-angiotensin sys-tem,and improve myocardial remodeling and cardiac function.

Quantitative determination of Asenapine in both bulk and formulations using neutralization titrations.

Asenapine is used in the treatment of schizophrenia disease.Asenapine mainly control the psychotic symptoms’ mainly antagonist to various receptors like, serotonin (5-HT1A, 5- HT1B,5-HT2A,5-HT2B,),histamine, and dopamine(D1,D2,D3,D4) receptors. It is also lower affinity towards muscaranic and acetylcholine receptors. In the present study, simple titrimetric method was developed. Respective quantities of Asenapine were taken in aqueous methanol titrated against 0.1N sodium hydroxide acid and 0.1N potassium hydroxide acid using phenolphthalein as an indicators for neutralization titration. This method were found to be sensitive and inexpensive, do not require any sample processing steps and can be utilized for estimation of asenapine in bulk and formulations.

Rapid titrimetric and spectrophotometric determination of ofloxacin in pharmaceuticals using N-bromosuccinimide / Determinação titulométrico e espectrofotométrico rápido de ofloxacina em produtos farmacêuticos usando N -bromosuccinimida

One titrimetric and two spectrophotometric methods have been described for the determination of ofloxacin (OFX) in bulk drug and in tablets, employing N-Bromosuccinimide as an analytical reagent. The proposed methods involve the addition of a known excess of NBS to OFX in acid medium, followed by determination of unreacted NBS. In titrimetry, the unreacted NBS is determined iodometrically, and in spectrophotometry, unreacted NBS is determined by reacting with a fixed amount of either indigo carmine (Method A) or metanil yellow (Method B). In all the methods, the amount of NBS reacted corresponds to the amount of OFX. Titrimetry allows the determination of 1-8 mg of OFX and the calculations are based on a 1:5 (OFX:NBS) reaction stoichiometry. In spectrophotometry, Beer's law is obeyed in the concentration ranges 0.5-5.0 µg/mL for method A and 0.3-3.0 µg/mL for method B. The molar absorptivities are calculated to be 5.53x10(4) and 9.24x10(4) L/mol/cm for method A and method B, respectively. The methods developed were applied to the assay of OFX in tablets, and results compared statistically with those of a reference method. The accuracy and reliability of the methods were further ascertained by performing recovery tests via the standard-addition method.

Descrevem-se métodos, um titulométrico e dois espectrofotométricos, para a determinação de ofloxacino (OFX) na matéria-prima e em comprimidos, empregando a N-bromossuccinimida (NBS) como reagente analítico. Os métodos propostos envolvem a adição de excesso conhecido de NBS ao OFX, em meio ácido, seguida de determinação do NBS que não reagiu. Na titulometria, o NBS que não reagiu é determinado iodometricamente e na espectrofotometria, o NBS que não reagiu é determinado pela reação com quantidade fixa de índigo carmim (Método A) ou amarelo de metanila (Método B). Em todos os métodos, a quantidade de NBS que reagiu corresponde à quantidade de OFX. A titulometria permite a determinação de 1-8 mg de OFX e os cálculos se baseiam na estequiometria de reação de 1:5 (OFX:NBS). Na espectrofotometria, a Lei de Beer é obedecida nas faixas de concentração de 0,5-5,0 µg/mL, para o método A, e de 0,3-3,0 µg/mL, para o método B, respectivamente. Os métodos desenvolvidos foram aplicados para o teste de OFX em comprimidos e os resultados foram comparados estatisticamente com aqueles do método de referência. A precisão e a confiabilidade dos métodos foram, posteriormente, verificadas por meio dos testes de recuperação via método de adição de padrão.

Avaliação de kits comerciais para análise de cloro ativo utilizado em soluções de hipoclorito de sódio / Evaluation of testing kits to measurement of active chlorine in sodium hypochlorite solutions

O objetivo deste estudo foi verificar a confiabilidade de um kit comercial para análise de cloro ativo, comparando-os ao processo de titulometria. O pH de 15 amostras de hipoclorito de sódio 0,5% de diferentes marcas foi medido, e assim submetidos ao processo de titulometria. Na sequência as amostras foram analisadas novamente utilizando o kit de medição de teor de cloro ativo, e os dados tabulados. Os valores encontrados foram submetidos ao teste de Mann-Whitney, com nível de significância de 5%. Os resultados apresentaram diferença significante entre os métodos (p<0,0001). Pode-se concluir que kit testado para medição de cloro ativo em soluções de hipoclorito de sódio não é eficaz para uso em Odontologia.

The aim of this study was verify the reliability of an active chlorine testing kit, comparing it to process of titration. The pH of 15 samples of sodium hypochlorite 0,5% was measured, and it done the titration process. The samples were analyzed again by active chlorine testing kit. Data were tabulated, and Mann-Whitney test was performed at 5% level of significance. The results showed significant difference between methods (p<0,0001). It can be concluded that tested kit to measurement of active chlorine in sodium hypochlorite solutions is not effective for use in dentistry.

Considerações sobre a determinação quantitativa de alendronato de sódio: titulometria x cromatografia / Observations on the quantitative determination of alendronate sodium: titrimetry vs. chromatography

O alendronato de sódio é um composto aminodifosfonado capaz de se fixar à matriz óssea e inibir a reabsorção mediada por osteoclastos. A escassez de metodologias oficiais para a determinação quantitativa deste fármaco levou ao desenvolvimento de diversos métodos, os quais empregam, em sua maioria, a cromatografia líquida de alta eficiência (CLAE), com a derivatização do fármaco para poder empregar detectores de ultravioleta. Também há relatos sobre metodologias mais simples para a análise do alendronato, utilizando titulometria ou análise espectrofotométrica. Neste trabalho foi avaliado o emprego da titulometria de neutralização na determinação quantitativa do alendronato de sódio em três lotes de matéria-prima, utilizando NaOH 0,1 M como titulante. Os resultados obtidos na titulometria foram comparados aos encontrados em método cromatográfico de referência (CLAE com derivatização por 9-fluorenilmetilcloroformato ou FMOC), descrito na Farmacopéia Americana (United States Pharmacopeia), os quais apresentaram valores estatisticamente diferentes. Ensaios para a caracterização das amostras também foram realizados e foi observado comportamento distinto das 3 matérias-primas em relação à substância de referência (padrão secundário). O método titulométrico apresentou adequada precisão, mas não mostrou especificidade para a determinação das matérias-primas, embora possa ser validado para determinação do fármaco em produto acabado.

Alendronate sodium is an aminobisphosphonate compound that can bind to the bone matrix and inhibit its osteoclast-mediated resorption. The lack of official monographs on the quantitative analysis of this drug has led to the proposal of a number of different methods for its determination, most of which employ high performance liquid chromatography (HPLC), performed after derivatization of the drug to enable ultraviolet detection. Simpler methodologies based on titrimetry and spectrophotometry have also been described. In this paper, the results obtained by acid-base titration of three batches of bulk alendronate, with 0.1 M sodium hydroxide as titrant, were compared with those achieved by a chromatographic reference method (HPLC of an FMOC derivative of the drug) published in the United States Pharmacopeia. The two methods gave statistically different results for the analysis of the three samples. Also, physical and chemical characterization of these samples showed differences between them and the reference substance (brand-name drug). The acid-base titrimetry was precise but not specific for determination of the bulk drug. However, it may be employed in the quality control of alendronate sodium dosage forms, since the excipients do not interfere with the analysis.

Sensitive and rapid titrimetric and spectrophotometric methods for the determination of stavudine in pharmaceuticals using bromate-bromide and three dyes

Four sensitive and rapid methods for the determination of stavudine (STV) in bulk drug and in dosage forms were developed and optimized. In titrimetry, aqueous solution of STV was treated with a known excess of bromate-bromide in HCl medium followed by estimation of unreacted bromine by iodometric back titration. Spectrophotometric methods involve the addition of a measured excess of bromate-bromide in HCl medium and subsequent estimation of the residual bromine by reacting with a fixed amount of methyl orange, indigocarmine or thymol blue followed by measurement of absorbance at 520 nm (method A), 610 nm (method B) or 550 nm (method C). In all the methods, the amount of bromate reacted corresponds to the amount of STV. Calculations in titrimetry were based on a 1:0.666 (STV:KBrO3) stoichiometry and the method was found to be applicable over 3.5-10 mg range. A linear increase in absorbance with concentration of STV was observed in the spectrophotometric methods, and the Beer's law was obeyed over the concentration ranges 0.125-1.75, 1-10 and 1-9.0 µg mL-1 STV for method A, method B and method C, respectively. The methods when applied to the determination of STV in tablets and capsules were found to give satisfactory results.

Este trabalho descreve quatro métodos rápidos e sensíveispara a determinação de estavudina (STV) na matéria-prima ou em produtos formulados. Soluções aquosas de STV podem ser tituladas tratando-as com excesso de bromato-brometo em meio ácido clorídrico, seguido da determinação iodimétrica de bromo em excesso. Métodos espectrofotométricos tambémenvolvem a adição de excesso de bromato-brometo à amostra, seguida da determinação de bromo residual por adição de uma quantidade fixa de alaranjado de metila, índigo-carmim ou azul de timol, e de medidas de absorbância nos comprimentos de onda apropriados: 520, 610 ou 550 nm. Em todos os métodos, a quantidade de bromato consumida corresponde à quantidade de STV e os resultados da sua aplicação à determinação de STV em comprimidos e cápsulas são satisfatórios.

Prevalence and factors affecting REM and slow wave sleep rebound on CPAP titration styudy in patients with obstructive sleep apnea / Prevalencia de los factores que afectan el sueño REM y el brote de ondas lentas en los estudios con CPAP en apnea obstructiva del sueño

Background: In patients with obstructive sleep apnea syndrome (OSAS) treatment with CPAP results in an increase of REM sleep and slow wave sleep, but there is limited information about the prevalence of REM rebound in patients with OSAS and possible factors related to the rebound. Objective. REM rebound (RR) and slow wave sleep rebound (SWSR) has been described as a frequent phenomenon that occurs during CPAP titration, but the quantity that qualify for RR has not been mentioned in literature. The objective of our study was to determine the prevalence of REM rebound and slow wave sleep rebound in our sleep disorders center, to attempt to define RR and look for factors that may affect RR and SWSR on the first night of CPAP titration. Materials and methods. We included patients who had both baseline polysomnogram (bPSG) and CPAP polysomnogram (cPSG) studies done in the same laboratory. We included 179 patients>18 years with Apnea hypopnea index (AHI)>10/hr on the baseline study, with an adequate CPAP titration study. We compared the percentages of REM sleep and slow wave sleep during bPSG and cPSG. We analyzed the frequency of presentation and looked for the factors affecting RR and SWSR. Results. 179 patients were enrolled (M/F:118/61), with a mean age of 48.6±4 for men, and 51.6±12.9 for women. The mean interval between the bPSG and cPSG was 45 days. The mean REM percentage during the bPSG was 15.55 percent and during cPSG study it was 21.57 percent. We took 6 percent as our differential point as the results became statistically significant at this point (p:0001). We therefore present our data by dividing our patients population with RR<6 percent and RR>6 percent. The mean SWS percentage during the bPSG was 8.11±9.68 and during the cPSG was 13.17±10, with a p:0.35 which is not statistically significant...

Antecedentes: En pacientes con síndrome de apnea obstructiva del sueño (SAOS) el tratamiento con CPAPproduce un incremento en el sueño REM y el sueño profundo, pero no hay suficiente información acerca de laprevalencia del rebote de sueño REM en pacientes con SAOS y los posibles factores relacionados con este fenómeno. Objetivo. El rebote de sueño REM (RR) y del sueño deondas lentas (RSOL) ha sido descrito como un fenómeno de frecuente presentación que ocurre durante la titulación de la presión del CPAP, pero la cantidad en el incrementodel estado de sueño que lo califique como rebote no ha sido mencionado en la literatura. El objetivo del estudiofue determinar la prevalencia de RR y RSOL en nuestro centro de sueño e intentar definir RR y buscar los factoresque puedan afectar el RR y el RSOL en la primera noche de titulación de CPAP.Material y métodos. Se incluyeron pacientes que tenían polisomnograma de base (bPSG) y PSG con CPAP (cPAG)realizados en un laboratorio del sueño. Se incluyeron 179 pacientes mayores de 18 años con índice de apneashipopneas (IAH) mayor de 10/hora en el estudio de base,con titulación de CPAP adecuada. Se comparó los porcentajes de sueño REM y sueño profundo durante el bPSSG y cPSG. Se analizó la frecuencia de presentación y los factores que afectan el RR y el RSOL. Resultados. Se incluyeron 179 pacientes (M/F 118/61), con edad promedio de 48.6 años ±12.9 para hombres y...

Use of chloramine-T and two dyes in the sensitive determination of stavudine in pharmaceuticals

Three new methods are described for the assay of stavudine (STV) in bulk drug and in dosage forms using chloramine-T (CAT) and two dyes, methyl orange and indigocarmine, as reagents. Titrimetry involves treating STV with a measured excess of CAT in hydrochloric acid medium, and after the oxidation of STV is judged to be complete, the unreacted oxidant is determined iodometrically. Spectrophotometric methods entail the addition of a known excess of CAT to STV in hydrochloric acid medium followed by determination of residual oxidant by reacting with a fixed amount of either methyl orange and measuring the absorbance at 520 nm (Method A) or indigo carmine and measuring the absorbance at 610 nm (Method B). In all the methods, the amount of CAT reacted corresponds to the amount of STV. In titrimetric method, the reaction follows 1:1 stoichiometry (STV: CAT), and is applicable over the range 1.5-10 mg of STV. In spectrophotometric methods, the absorbance is found to increase linearly with concentration of STV. The systems obey Beer's law for 0.2-2.0 and 1.0-10.0 mg/mL for method A and method B, respectively. The apparent molar absorptivities are calculated to be 5.7x10(4) and 1.5x10(4) L/mol/cm for method A and method B, respectively, and the corresponding Sandell sensitivity values are 0.004 and 0.015 µg/cm². The limits of detection and quantification are reported for both methods. Intra-day and inter-day precision and accuracy of the developed methods were evaluated as per the current ICH guidelines. The methods were successfully applied to the assay of STV in tablet and capsule formulations and the results were compared with those of a reference method by applying Student's t-test and F-test. No interference was observed from common tablet adjuvants. The accuracy and reliability of the methods were further ascertained by performing recovery experiments via standard-addition method.

Descrevem-se três novos métodos para o ensaio de estavudina (STV) na matéria-prima e nas formulações utilizando-se clroamina-T (CAT) e dois corantes, alaranjado de metila e índigo carmim como reagentes. A titulação envolve o tratamento de STV com excesso medido de CAT em meio de ácido clorídrico, e, quando a oxidação se completar, o oxidante que não reagiu é determinado iodometricamente. Os métodos espectrofotométricos compreendem a adição de excesso conhecido de CAT ao STV em ácido clorídrico, seguida da determinação do oxidante residual por meio da reação com quantidade fixada de alaranjado de metila, medindo-se a absorvância a 520 nm (Método A) ou índigo carmim, medindo-se a absorvância a 610 nm (Método B). Em todos os métodos, a quantidade de CAT que reagiu corresponde à quantidade de STV. No método titulométrico, a reação segue a estequiometria 1:1 (STV:CAT) e é aplicável na faixa de 1,5 a 10 mg de STV. Nos métodos espectrofotométricos, a absorvância aumenta linearmente com a concentração de STV. Os sistemas obedecem a lei de Beer nos intervalos de 0,2 a 2,0 mg/mL e 1,0 a 10,00 mg/mL para os métodos A e B, respectivamente, e os valores de sensibilidade de Sandell correspondentes são 0,004 e 0,015 µg/cm². Os limites de detecção e de quantificação são apresentados para ambos os métodos. A precisão e a exatidão intra-dia e inter-dia dos métodos desenvolvidos são avaliadas de acordo com as normas ICH. Os métodos foram aplicados com êxito aos ensaios de STV em comprimidos e em cápsulas e os resultados foram comparáveis com aqueles obtidos com o método de referência, utilizando-se o teste t de Student e o teste F. Não se observou interferência dos adjuvantes comuns em comprimidos. A exatidão e a confiabilidade dos métodos foram ajustadas por meio de experimentos de recuperação via método de adição de padrão.

Relationship of CPAP pressure titration methods and CPAP compliance / 中国耳鼻咽喉头颈外科

OBJECTIVE To study the relationship between the methods of CPAP pressure titration (under whole night PSG or by auto-set) and CPAP compliance. METHODS Forty-five patients with serious OSAHS who had been diagnosed in our sleep lab between 2001 and 2004 and were willing to try CPAP treatment were enrolled. They were divided into A and B group according to their wills: pressure titration under whole night PSG in lab (group A) or by auto-set in their families (group B). After pressure titration, patients and their families were educated for the knowledge of CPAP treatment in OSAHS patients. Questionnaires about QOL before CPAP treatment and half year later were carried out on the phone. The decreased score was used to evaluate the effect of CPAP treatment. The hours of per day using machine were used to evaluate the compliance of CPAP. RESULTS Group A and group B got the similar decreased score (14 VS 14.3) , compliance (4.91h VS 4.97h) and adherence (85.7 % VS 88 %) . CONCLUSION OSAHS patients under go pressure titration either in lab with PSG or in their home with auto-set have the same effect and same compliance of CPAP treatment. That means the simple auto-titration can substitute the traditional titration under whole night in lab.