Development and validation of a HPLC method for the determination of cyclosporine a in new bioadhesive nanoparticles for oral administration.

A simple and reliable high performance liquid chromatography method was developed and validated for the rapid determination of cyclosporine A in new pharmaceutical dosage forms based on the use of poly (methylvinylether-co-maleic anhydride) nanoparticles. The chromatographic separation was achieved using Ultrabase C18 column (250×4.6 mm, 5 µm), which was kept at 75°. The gradient mobile phase consisted of acetonitrile and water with a flow rate of 1 ml/min. The effluent was monitored at 205 nm using diode array detector. The method exhibited linearity over the assayed concentration range (22-250 µg/ml) and demonstrated good intraday and interday precision and accuracy (relative standard deviations were less than 6.5% and the deviation from theoretical values is below 5.5%). The detection limit was 1.36 µg/ml. This method was also applied for quantitative analysis of cyclosporine A released from poly (methylvinylether-co-maleic anhydride) nanoparticles.

Medicación crónica durante el preoperatorio: ¿suspender o no suspender? / Chronic medications in the preoperative period: should they be stopped?

Dada la creciente implicación de diversos especialistas en la atención preoperatoria (debido por un lado a la realización de cirugías menores en el ámbito de la atención primaria y por otro lado a la necesaria coordinación de los médicos de atención primaria con los servicios quirúrgicos y de anestesiología hospitalarias para optimizar los resultados de nuestros pacientes), creemos que es necesaria una actualización sobre el manejo de las medicaciones crónicas en este periodo. A continuación intentaremos revisar la bibliografía actual sobre las recomendaciones en cuanto a la suspensión o continuación de los fármacos más frecuentes (AU)

As different specialists are becoming increasingly involved in the preoperative management of our patients (for two main reasons; Primary Care doctors have to perform minor surgical procedures, and as coordination between Primary Care and In-hospital Care is more and more necessary in order to improve their outcomes), we believe that an update is needed as regards the management of chronic medications in this period. We will try to review the current literature dealing with the recommendations about withdrawing or continuing these drugs (AU)

[Chronic medications in the preoperative period: should they be stopped?]. / Medicación crónica durante el preoperatorio: ¿suspender o no suspender?

As different specialists are becoming increasingly involved in the preoperative management of our patients (for two main reasons; Primary Care doctors have to perform minor surgical procedures, and as coordination between Primary Care and In-hospital Care is more and more necessary in order to improve their outcomes), we believe that an update is needed as regards the management of chronic medications in this period. We will try to review the current literature dealing with the recommendations about withdrawing or continuing these drugs.

Ultra high performance liquid chromatography-tandem mass spectrometry method for cyclosporine a quantification in biological samples and lipid nanosystems.

Cyclosporine A (CyA) is an immunosuppressant cyclic undecapeptide used for the prevention of organ transplant rejection and in the treatment of several autoimmune disorders. An ultra high performance liquid chromatography-tandem mass spectrometry method (UHPLC-MS/MS) to quantify CyA in lipid nanosystems and mouse biological matrices (whole blood, kidneys, lungs, spleen, liver, heart, brain, stomach and intestine) was developed and fully validated. Chromatographic separation was performed on an Acquity UPLC(®) BEH C18 column with a gradient elution consisting of methanol and 2mM ammonium acetate aqueous solution containing 0.1% formic acid at a flow rate of 0.6mL/min. Amiodarone was used as internal standard (IS). Retention times of IS and CyA were 0.69min and 1.09min, respectively. Mass spectrometer operated in electrospray ionization positive mode (ESI+) and multiple reaction monitoring (MRM) transitions were detected, m/z 1220.69→1203.7 for CyA and m/z 646→58 for IS. The extraction method from biological samples consisted of a simple protein precipitation with 10% trichloroacetic acid aqueous solution and acetonitrile and 5µL of supernatant were directly injected into the UHPLC-MS/MS system. Linearity was observed between 0.001µg/mL-2.5µg/mL (r≥0.99) in all matrices. The precision expressed in coefficient of variation (CV) was below 11.44% and accuracy in bias ranged from -12.78% to 7.99% including methanol and biological matrices. Recovery in all cases was above 70.54% and some matrix effect was observed. CyA was found to be stable in post-extraction whole blood and liver homogenate samples exposed for 6h at room temperature and 72h at 4°C. The present method was successfully applied for quality control of lipid nanocarriers as well as in vivo studies in BALB/c mice.

A Rayleigh-Brillouin scattering spectrometer for ultraviolet wavelengths.

A spectrometer for the measurement of spontaneous Rayleigh-Brillouin (RB) scattering line profiles at ultraviolet wavelengths from gas phase molecules has been developed, employing a high-power frequency-stabilized UV-laser with narrow bandwidth (2 MHz). The UV-light from a frequency-doubled titanium:sapphire laser is further amplified in an enhancement cavity, delivering a 5 W UV-beam propagating through the interaction region inside a scattering cell. The design of the RB-scattering cell allows for measurements at gas pressures in the range 0-4 bars and at stably controlled temperatures from -30 °C to 70 °C. A scannable Fabry-Perot analyzer with instrument resolution of 232 MHz probes the RB profiles. Measurements on N(2) and SF(6) gases demonstrate that the high signal-to-noise ratio is achievable with the instrument at the 1% level at the peak amplitude of the scattering profile.

Spectroscopic observation and characterization of H(+)H(-) heavy Rydberg states.

A series of discrete resonances was observed in the spectrum of H2, which can be unambiguously assigned to bound quantum states in the 1/R Coulombic potential of the H+H- ion-pair system. Two-step laser excitation was performed, using tunable extreme ultraviolet radiation at lambda = 94-96 nm in the first step, and tunable ultraviolet radiation in the range lambda = 310-350 nm in the second step. The resonances, detected via H+ and H2+ ions produced in the decay process, follow a sequence of principal quantum numbers (n = 140-230) associated with a Rydberg formula in which the Rydberg constant is mass scaled. The series converges upon the ionic H+H- dissociation threshold. This limit can be calculated without further assumptions from known ionization and dissociation energies in the hydrogen system and the electronegativity of the hydrogen atom. A possible excitation mechanism is discussed in terms of a complex resonance. Detailed measurements are performed to unravel and quantify the decay of the heavy Rydberg states into molecular H2+ ions, as well as into atomic fragments, both H(n = 2) and H(n = 3). Lifetimes are found to scale as n3.

Observation of a Rydberg series in H+H-: a heavy Bohr atom.

We report on the realization of a heavy "Bohr atom," through the spectroscopic observation of a Rydberg series of bound quantum states at principal quantum numbers n=140 to 230. The system is made heavy by replacing an electron inside a hydrogen atom by a composite H- particle, thus forming a H+H- Coulombically bound system obeying the physical laws of a generalized atom with appropriate mass scaling.

Cytokine IL-1 beta but not IL-1 alpha promoter polymorphism is associated with Alzheimer disease in a population from the Canary Islands, Spain.

AIMS: Previous studies have reported the presence of low-grade inflammation in Alzheimer disease (AD). Based on these data, our work attempts to investigate the effects of some promoter polymorphisms of pro-inflammatory cytokines [interleukin (IL)-1 alpha and IL-1 beta] on AD. PATIENTS AND METHODS: A PCR-RFLP technique was used to analyze the promoter polymorphisms of both IL-1 alpha (-889 C/T) and IL-1 beta (-511 C/T) and the APOE genotype from the DNA samples of 282 patients (according to NINCDS-ADRDA criteria) and 312 control subjects. RESULTS: (i) The risk of developing AD in our population was associated with the IL-1 beta (-511 C/T) promoter polymorphism; (ii) such risk was independent of the risk factor allele in the APOE gene (APOE4); and (iii) the IL-1 alpha promoter polymorphism (-889 C/T) was not associated with the disease. CONCLUSION: In our population, IL-1 beta promoter polymorphism (-511 C/T) is an independent risk factor for AD.

Interactions of the 3ppi u c1Pi u(v=2) Rydberg-complex member in isotopic N2.

The 3ppi u c1Pi u-X 1Sigmag+(2,0) Rydberg and b' 1Sigmau+-X 1Sigmag+(7,0) valence transitions of 14N2, 14N15N, and 15N2 are studied using laser-based 1 extreme ultraviolet (XUV)+1' UV two-photon-ionization spectroscopy, supplemented by synchrotron-based hotoabsorption measurements in the case of 14N2. For each isotopomer, effective rotational interactions between the c(v=2) and b'(v=7) levels are found to cause strong Lambda-doubling in c(v=2) and dramatic P/R-branch intensity anomalies in the b'-X(7,0) band due to the effects of quantum interference. Local perturbations in energy and predissociation line width for the c(v=2) Rydberg level are observed and attributed to a spin-orbit interaction with the crossing, short-lived C 3Pi u(v=17) valence level.

HD as a probe for detecting mass variation on a cosmological time scale.

The strong electronic absorption systems of the B1 Sigma u+-X1 Sigma g+ Lyman and the C1Pi u-X1 Sigma g+ Werner bands can be used to probe possible mass-variation effects on a cosmological time scale from spectra observed at high redshift, not only in H2 but also in the second most abundant hydrogen isotopomer HD. High resolution laboratory determination of the most prominent HD lines at extreme ultraviolet wavelengths is performed at an accuracy of delta lambda/lambda approximately 5 x 10(-8), forming a database for comparison with astrophysical data. Sensitivity coefficients Ki = d ln lambda i/d ln mu are determined for HD from quantum ab initio calculations as a function of the proton-electron mass ratio mu. Strategies to deduce possible effects beyond first-order baryon/lepton mass ratio deviations are discussed.

[Autoimmune diseases and multiple sclerosis]. / Enfermedades autoinmunes y esclerosis múltiple.

INTRODUCTION: Multiple sclerosis (MS) is a demyelinating disease affecting the central nervous system with an unknown origin, although the immunological system plays a crucial role in its pathogenesis. It has been observed that the relatives of MS patients very often have other autoimmune diseases (ADs) and it has been suggested that there may be susceptibility genes that are common to this group of diseases. AIMS: Our aim was to estimate the prevalence of ADs in first and second degree relatives of patients with MS and to determine the coexistence of other ADs in MS patients. PATIENTS AND METHODS: We selected 251 patients with MS defined by the Poser criteria and face-to-face interviews with the patients and/or their relatives were conducted to investigate the following ADs: MS, rheumatoid arthritis, systemic lupus erythematosus, polyarteritis nodosa, autoimmune thyroid disease (ATD), inflammatory bowel disease, myasthenia gravis, type I diabetes mellitus (DMI) and psoriasis. RESULTS. 29.9% of the patients with MS had a first and/or second degree relative with an AD. Prevalence of ADs in first degree relatives was 15.5%, 30% in familial MS and 40% if the patient had both MS and another AD. The most frequent ADs were: MS 27%, psoriasis 18%, ATD 16% and DMI 15%. 15 patients had MS and another AD: six ATD, three DMI, four psoriasis, one inflammatory bowel disease and one myasthenia gravis. CONCLUSIONS: These findings lend support to the existence of susceptibility genes that are common to the different ADs and would act as risk factors.

Prevalence and incidence of multiple sclerosis in Las Palmas, Canary Islands, Spain.

OBJECTIVES: To determine the prevalence and incidence of multiple sclerosis (MS) in the city of Las Palmas (Canary Islands, Spain), geographically belonging to north-western Africa, but with European ancestry. METHODS: This population-based survey was conducted for a period of 5 years (1998-2002) in a Sanitary District of Las Palmas city (28 degrees 20' N), with a population of 82,623 inhabitants. Multiple sources were periodically investigated for case ascertainment. Patients with definite and probable MS were included. RESULTS: Sixty-four patients with MS were identified on prevalence day, December 31, 2002. According to Poser's criteria the crude prevalence rate was 77.5 per 100,000 (95% CI: 59.7-98.9). This rate decreased to 73.8 (95% CI: 56.5-94.8) according to McDonald's criteria. Age-adjusted rates for the world and European standard populations were 61.6 (95% CI: 47.1-78.9) and 70.6 (95% CI: 55-89), respectively. Prevalence was higher for women aged 25-44 years. In 17 patients onset of MS occurred within the study period. Average annual incidence was 4.1 per 100,000 (95% CI: 2.4-6.6). CONCLUSIONS: The prevalence and incidence rates in Las Palmas city are close to those reported from Continental Spain and other countries of southern Europe with similar social and ethnic background. These results highlight the role of racial-ethnic factors in the genesis of MS.

[Gender has a strong modulating effect on the risk of Alzheimer's disease conferred by the apolipoprotein E gene in the population of the Canary Islands, Spain]. / Fuerte modulacion de genero sobre el riesgo conferido por el gen de la apolipoproteina E para la enfermedad de Alzheimer en la poblacion de las Islas Canarias, España.

OBJECTIVES: Apolipoprotein E (ApoE) gen has been found to confer risk for Alzheimer disease in every population studied. We are interested in analyzed the exonic variants and the promoter polymorphisms in our Canary population. SUBJECTS AND METHODS: By means of PCR RFLP analysis of DNA from patients (NINCS ADRDA criteria) and controls (cognitive state CAMCOG test measured) we analyzed the known exonic and promoter polymorphism of ApoE gen. RESULTS: We have found an association of Alzheimer disease risk based on exonic variants of ApoE gen, with a clear cut dose effect on susceptibility and no risk conferred by the promoter polymorphisms. Age at onset are not affected by variants of ApoE gen, and patients gender strongly modulate the disease susceptibility. CONCLUSION: We have found in our Canary population an association between Alzheimer disease with exonic variants of ApoE gen with a strong modulation by the patients gender.

Rapid and simple determination of doxycycline in serum by high-performance liquid chromatography. Application to particulate drug delivery systems.

A simple, rapid and sensitive reversed-phase high-performance liquid chromatographic (HPLC) method for the measurement of doxycycline concentrations in both drug delivery systems (DDS) and serum extracted from mice after intraperitoneal (free drug) and intravenous (doxycycline administered in DDS) administration, has been developed. For the analysis of doxycycline in DDS, a known amount of particles was dissolved in chloroform and, after precipitating the polymer with methanol, the drug was assessed in the supernatant. For doxycycline quantification in microsamples of serum, proteins were precipitated with acetonitrile before chromatographic analysis. After centrifugation, the supernatant was mixed with a mixture of methanol and acetic acid (1:1) for analysis. The samples were chromatographed on a narrow-bore C18 column (Alltech Alltima 150 mm x 2.1 mm) using a mobile phase with 55% acetic acid (5%), 25% acetonitrile and 20% methanol. Doxycycline was detected 347 nm and the run time was 10 min. Linearity was confirmed in the concentration range 0.4-80 microg/ml for doxycycline quantification in serum and from 1 to 800 microg/ml for doxycycline extracted from DDS samples.

Eosinofilia: ¿principal parámetro para la detección de toxocarosis? / Eosinophilia: major parameter for toxocarosis detection?

La toxocarosis es una parasitosis causada por la ingesta accidental de huevos de Toxacara canis/cati (el primero especialmente), sobre todo en niños de corta edad. Se manifiesta de dos maneras distintas: larva migrans visceral (VLM) y larva migrans ocular(OLM). Los signos y síntomas de la VLM van desde un cuadro totalmente asintomático con leve eosinofilia, a uno severo con distintas manifestaciones clínicas. Los pacientes con OLM varían ampliamente en su presentación; pueden ser sintomáticos o no. Uno de los signos marcadores es la presencia de eosinofilia (valores mayores de 700 elementos/mm al cubo). El objeto de éste estudio es analizar la relación entre eosinofilia y toxocarosis. Para ello se estudiaron 33 niños con eosinofilia. Se les realizó un parasitológico seriado de material fecal y un test serológico para detectar anticuerpos anti Toxacara canis/cati, mediante el método de ELISA. Se consideró la prueba positiva con valores de lectura mayores de 0,7. Se encontraron 19 pacientes (58 por ciento) con toxocarosis (lecturas mayores de 0,7), 7 (21 por ciento) con resultados dudosos (lecturas entre 0,3 y 0,7) y 7 (21 por ciento) negativos (lecturas menores de 0,3). Esta situación lleva a tener presente la importancia de realizar un exámen de rutina; y ante la presencia de eosinofilia, solicitar un test de ELISA para Toxocara, que ayudará a descartar (o no) otras patologías. Por otro lado, en caso de un examen positivo, se estaría contribuyendo a cortar la cadena de transmisión de ésta parasitosis no muy conocida y sin embargo tan común en niños de corta edad

Eosinofilia: ¿principal parámetro para la detección de toxocarosis? / Eosinophilia: major parameter for toxocarosis detection?

La toxocarosis es una parasitosis causada por la ingesta accidental de huevos de Toxacara canis/cati (el primero especialmente), sobre todo en niños de corta edad. Se manifiesta de dos maneras distintas: larva migrans visceral (VLM) y larva migrans ocular(OLM). Los signos y síntomas de la VLM van desde un cuadro totalmente asintomático con leve eosinofilia, a uno severo con distintas manifestaciones clínicas. Los pacientes con OLM varían ampliamente en su presentación; pueden ser sintomáticos o no. Uno de los signos marcadores es la presencia de eosinofilia (valores mayores de 700 elementos/mm al cubo). El objeto de éste estudio es analizar la relación entre eosinofilia y toxocarosis. Para ello se estudiaron 33 niños con eosinofilia. Se les realizó un parasitológico seriado de material fecal y un test serológico para detectar anticuerpos anti Toxacara canis/cati, mediante el método de ELISA. Se consideró la prueba positiva con valores de lectura mayores de 0,7. Se encontraron 19 pacientes (58 por ciento) con toxocarosis (lecturas mayores de 0,7), 7 (21 por ciento) con resultados dudosos (lecturas entre 0,3 y 0,7) y 7 (21 por ciento) negativos (lecturas menores de 0,3). Esta situación lleva a tener presente la importancia de realizar un exámen de rutina; y ante la presencia de eosinofilia, solicitar un test de ELISA para Toxocara, que ayudará a descartar (o no) otras patologías. Por otro lado, en caso de un examen positivo, se estaría contribuyendo a cortar la cadena de transmisión de ésta parasitosis no muy conocida y sin embargo tan común en niños de corta edad (AU)

[Myasthenia gravis associated with carcinoma of the thymus. A report of three cases]. / Miastenia gravis asociada a carcinoma tímico. Presentación de tres casos.

INTRODUCTION: Although the association between benign neoplasias of the thymus and myasthenia gravis is well known, with greater predominance of squamous thymomas over other histological types, carcinoma of the thymus is only exceptionally associated with auto immune disorders. CASE REPORTS: We present three patients with myasthenia gravis associated with carcinoma of the thymus. They were three men aged between 38 and 73 years. Clinical features of myasthenia were generalized in two cases and ocular only in the third. Antireceptor antibodies to acetylcholine and anti striped muscle antibodies were present in all three patients. Repetitive stimulation was abnormal in two of the three cases. On CAT of the thorax there was a tumour of the thymus with the radiological characteristics of a benign thymoma in two of the patients and data suggesting an invasive thymoma in the third. In all three cases the diagnosis of carcinoma of the thymus was made on the post operative histological findings. CONCLUSIONS: The association of carcinoma of the thymus with myasthenia gravis in our series of cases was probably due to chance. We consider that this association is exceptional since the histological characteristics of carcinoma of the thymus do not favour the development of auto immunity.

Comparative pharmacokinetics, tissue distributions, and effects on renal function of novel polymeric formulations of amphotericin B and amphotericin B-deoxycholate in rats.

The pharmacokinetic profiles of a traditional formulation of amphotericin B (Fungizone) and novel nanosphere and mixed micelle delivery systems developed for amphotericin B were compared and described. Six groups of male Wistar rats received intravenous injections of the different formulations. Plasma and tissue samples were obtained at 11 different times after dosing, with three animals used each time. The amphotericin B concentrations in plasma and tissues were analyzed by high-performance liquid chromatography. The plasma drug concentration-time profiles were best described by a two-compartment model. Models that described the observed single or double peak disposition kinetics in kidney, liver, and spleen were also developed. Parameter estimates from those models show that components of the formulation such as poloxamer 188, which is present in all new formulations, seem to play an important role in the rate of drug uptake by the tissues; in general, the levels of amphotericin B in tissues were increased after the administration of the new formulations compared with those after the administration of Fungizone. The increment in the baseline plasma creatinine level was used as an index of renal function. All formulations increased this baseline value, but the novel formulations exhibited fewer renal effects than Fungizone did. However, a direct relationship between drug exposure in the kidneys and development of renal damage could not be found.

High-performance liquid chromatographic determination of amphotericin B in plasma and tissue. Application to pharmacokinetic and tissue distribution studies in rats.

A sensitive HPLC method with piroxicam as internal standard was developed for assaying amphotericin B in plasma and tissue. An Ultrabase-C18 column and a simple mobile phase consisting of an acetonitrile-acetic acid (10%)-water (41:43:16) mixture were used. The flow-rate was 1 ml/min and the effluent was monitored at 405 nm. The linearity of the assay method was up to 1000 ng/ml and 100 micrograms/g for plasma and tissue, respectively. Intra-day and inter-day RSDs were below 10% for all the sample types. This HPLC assay has been applied to determine amphotericin B in plasma and tissue samples taken during pharmacokinetic and tissue distribution studies in rats.