Computer visual syndrome in graduate students of a private university in Lima, Perú.

BACKGROUND: In recent decades, several studies have found a strong association between prolonged use of video display terminals and ophthalmological symptoms encompassed in the so-called computer visual syndrome (CVS). Few studies have addressed this syndrome in graduate students. METHODS: Observational, cross-sectional descriptive study. A total of 106 postgraduate students were surveyed without ophthalmological pathologies. The diagnosis of CVS was made by means of the questionnaire of Seguí et al. validated in Spanish, which evaluates the frequency and intensity of 16 ocular symptoms. RESULTS: The prevalence of CVS among graduate university students was 62.3% (95% CI: 52.3-71.5). It was found that the highest proportion of students with the syndrome was in the group of older than 40 years old (88.2%) and in the group 21-30 years old (70.0%), showing statistically significant differences (p = 0.004). According to the device and its time of use, students who used the mobile phone for 7-10 h a day showed a higher prevalence of CVS compared to those who used the device for less time (p = 0.030). The business School had the highest prevalence (75.0%). CONCLUSION: Three out of every five graduate students presented CVS with this prevalence being like reported in other populations. There is a need to investigate possible interventions that can help reduce this entity.

Computer visual syndrome in graduate students of a private university in Lima, Perú. / Síndrome visual informático en estudiantes universitarios de posgrado de una universidad privada de Lima, Perú.

BACKGROUND: In recent decades, several studies have found a strong association between prolonged use of video display terminals and ophthalmological symptoms encompassed in the so-called computer visual syndrome (CVS). Few studies have addressed this syndrome in graduate students. METHODS: Observational, cross-sectional descriptive study. A total of 106 postgraduate students were surveyed without ophthalmological pathologies. The diagnosis of CVS was made by means of the questionnaire of Seguí et al. validated in Spanish, which evaluates the frequency and intensity of 16 ocular symptoms. RESULTS: The prevalence of CVS among graduate university students was 62.3% (95% CI: 52.3-71.5). It was found that the highest proportion of students with the syndrome was in the group of older than 40 years old (88.2%) and in the group 21-30 years old (70.0%), showing statistically significant differences (p=0.004). According to the device and its time of use, students who used the mobile phone for 7 to 10hours a day showed a higher prevalence of CVS compared to those who used the device for less time (p=0.030). The business School had the highest prevalence (75.0%). CONCLUSION: Three out of every five graduate students presented CVS with this prevalence being like reported in other populations. There is a need to investigate possible interventions that can help reduce this entity.

Síndrome visual informático en estudiantes universitarios de posgrado de una universidad privada de Lima, Perú / Computer visual syndrome in graduate students of a private university in Lima, Perú

Antecedente En las últimas décadas diversos estudios han encontrado una fuerte asociación entre el uso prolongado de los videoterminales y síntomas oftalmológicos englobados en el denominado síndrome visual informático (SVI). Pocos estudios han abordado este síndrome en estudiantes de posgrado. Métodos Estudio observacional, descriptivo de corte transversal. Se encuestó a 106 estudiantes universitarios de posgrado sin patologías oftalmológicas. El diagnóstico de SVI se realizó mediante el cuestionario de Seguí et al. validado en castellano, el cual evalúa la frecuencia e intensidad de 16 síntomas oculares. Resultados La prevalencia de SVI de los estudiantes universitarios de posgrado fue del 62,3% (IC 95%: 52,3-71,5). Se encontró que la mayor proporción de estudiantes con el síndrome estuvo en el grupo mayor de 40 años (88,2%) y en el grupo de 21-30 años (70,0%), mostrando diferencias estadísticamente significativas (p=0,004). Según el dispositivo y su tiempo de uso se observó que los estudiantes que utilizaban el teléfono móvil de 7 a 10h diarias presentaron una prevalencia de SVI mayor en comparación con quienes utilizaban el dispositivo menos tiempo (p=0,030). La Facultad de Ciencias Empresariales presentó la prevalencia más elevada (75,0%). Conclusión Tres de cada cinco estudiantes universitarios de posgrado presentaron SVI, siendo esta prevalencia similar a lo reportado en otras poblaciones. Es necesario que se investiguen posibles intervenciones que puedan ayudar a reducir esta entidad (AU)

Background In recent decades, several studies have found a strong association between prolonged use of video display terminals and ophthalmological symptoms encompassed in the so-called computer visual syndrome (CVS). Few studies have addressed this syndrome in graduate students. Methods Observational, cross-sectional descriptive study. A total of 106 postgraduate students were surveyed without ophthalmological pathologies. The diagnosis of CVS was made by means of the questionnaire of Seguí et al. validated in Spanish, which evaluates the frequency and intensity of 16 ocular symptoms. Results The prevalence of CVS among graduate university students was 62.3% (95% CI: 52.3-71.5). It was found that the highest proportion of students with the syndrome was in the group of older than 40 years old (88.2%) and in the group 21-30 years old (70.0%), showing statistically significant differences (p=0.004). According to the device and its time of use, students who used the mobile phone for 7 to 10hours a day showed a higher prevalence of CVS compared to those who used the device for less time (p=0.030). The business School had the highest prevalence (75.0%). Conclusion Three out of every five graduate students presented CVS with this prevalence being like reported in other populations. There is a need to investigate possible interventions that can help reduce this entity (AU)

Miastenia gravis en la infancia: una serie de tres casos / Myasthenia gravis in infancy: a series of three cases

La miastenia gravis es una enfermedad neuromuscular crónica debida a deficiencia de transmisión nerviosa en la unión neuromuscular, de origen generalmente autoinmune en el adulto, que se caracteriza por grados variables de debilidad de los músculos esqueléticos del cuerpo, que aumenta durante los períodos de actividad y disminuye después de períodos de descanso. Sin embargo en la infancia cobran especial relevancia los síndromes miasténicos congénitos, que encuentran su origen en mutaciones de genes que codifican proteínas que juegan papeles clave en el mantenimiento de la transmisión neuromuscular, teniendo edad de inicio, distribución de debilidad y respuesta a tratamiento variables. Se presentan tres casos con el objetivo de describir el comportamiento clínico de la enfermedad y la utilidad de estudios complementarios ya que es de suma importancia su precoz identificación y tratamiento. Palabras claves: Miastenia gravis, test de estimulación repetitiva, ptosis palpebral, unión neuromuscular, pares craneanos

Myasthenia gravis is a chronic neuromuscular disease due to deficiency of nerve transmission in the neuromuscular junction, usually of an autoimmune origin in the adult, which is characterized by varying degrees of weakness of the skeletal muscles of the body, which increases during periods of activity and decreases after periods of rest. In childhood, however, congenital myasthenic syndromes, which find their origin in mutations of genes that encode proteins that play key roles in maintaining neuromuscular transmission, which may have a varying age of onset, distribution of weakness and response to treatment, are particularly relevant. Three cases are presented with the aim of describing the clinical presentation and course of the disease and the usefulness of complementary studies, since its early diagnosis and treatment is of paramount importance.Keywords: Myasthenia gravis, repetitive stimulation test, palpebral ptosis, neuromuscular junction, cranial pairs.

Micosis fungoide en niños y adolescentes: descripción de una serie de 23 casos / Mycosis Fungoides in Children and Adolescents: A Series of 23 Cases

ANTECEDENTES: La micosis fungoide (MF) es el tipo más común de linfoma cutáneo de células T tanto en adultos como en niños. En algunos países se ha observado un aumento de la prevalencia de MF en niños. Hasta la fecha, no existen estudios descriptivos de MF en la población pediátrica colombiana. MÉTODOS: En una revisión ambispectiva de 128 pacientes con el diagnóstico confirmado de MF en la Sección de Dermatología y del Laboratorio de Dermatopatología de la Universidad de Antioquia entre los años 2008-2017, se describen las variantes clínicas e histopatológicas, la respuesta al tratamiento y la progresión de la enfermedad de 23 pacientes menores de 18 años de edad. RESULTADOS: Los casos de MF en niños constituyeron el 18% del total. La mediana de edad de inicio de las lesiones fue de 9 años; la mediana de edad al momento del diagnóstico fue de 11 años y la mediana del tiempo promedio entre el inicio de las lesiones y el diagnóstico fue de 2 años. Todos los pacientes se encontraban en estadios tempranos de la enfermedad. La MF hipopigmentada fue la presentación clínica más frecuente (52,2%), seguida por la MF clásica (30,4%). La MF foliculotropa se presentó en el 17,4%. Todos los pacientes recibieron terapias dirigidas a la piel con esteroides tópicos y fototerapia, uno recibió quimioterapia, aún en estadio temprano. El 59,1% obtuvieron remisión completa y el 40,9% respuesta parcial. Solo 2 casos permanecieron asintomáticos durante 5 años. CONCLUSIÓN: En nuestra experiencia, la MF hipopigmentada fue la presentación clínica más común en pacientes menores de 18 años. No se presentaron progresiones a estadios avanzados. Sin embargo, las recurrencias después de la interrupción del tratamiento fueron comunes

BACKGROUND: Mycosis fungoides (MF) is the most common type of cutaneous T-cell lymphoma in adults and children. The prevalence has increased in some countries, but no descriptive studies of MF in the pediatric population have been done in Colombia to date. METHODS: A combined prospective-retrospective study of 128 patients with a diagnosis of MF confirmed by the dermatology department and dermatopathology laboratory of Universidad de Antioquia between 2008 and 2017. We describe the clinical and histopathologic variants, response to treatment, and progression of the disease in 23 patients under 18 years of age. RESULTS: The pediatric cases of MF accounted for 18% of all the cases on record. The median age of onset of lesions was 9 years, the median age at diagnosis was 11 years, and the median time between onset of lesions and diagnosis was 2 years. All patients were in early stages of the disease. Hypopigmented MF was the most common clinical presentation (in 52.2%), followed by classical MF (in 30.4%). Folliculotropic MF was identified in 17.4%. All patients were treated with topical corticosteroids and phototherapy. One patient received chemotherapy while still in the early stage of disease.complete remission was achieved in 59.1% and a partial response in 40.9%. Only 2 patients remained asymptomatic for 5 years. CONCLUSIÓN: We found hypopigmented MF to be the most common clinical presentation in patients under 18 years of age. The disease did not progress to advanced stages in any of the patients, although recurrence after treatment interruption was common

Mycosis Fungoides in Children and Adolescents: A Series of 23 Cases. / Micosis fungoide en niños y adolescentes: descripción de una serie de 23 casos.

BACKGROUND: Mycosis fungoides (MF) is the most common type of cutaneous T-cell lymphoma in adults and children. The prevalence has increased in some countries, but no descriptive studies of MF in the pediatric population have been done in Colombia to date. METHODS: A combined prospective-retrospective study of 128 patients with a diagnosis of MF confirmed by the dermatology department and dermatopathology laboratory of Universidad de Antioquia between 2008 and 2017. We describe the clinical and histopathologic variants, response to treatment, and progression of the disease in 23 patients under 18 years of age. RESULTS: The pediatric cases of MF accounted for 18% of all the cases on record. The median age of onset of lesions was 9 years, the median age at diagnosis was 11 years, and the median time between onset of lesions and diagnosis was 2 years. All patients were in early stages of the disease. Hypopigmented MF was the most common clinical presentation (in 52.2%), followed by classical MF (in 30.4%). Folliculotropic MF was identified in 17.4%. All patients were treated with topical corticosteroids and phototherapy. One patient received chemotherapy while still in the early stage of disease. Complete remission was achieved in 59.1% and a partial response in 40.9%. Only 2 patients remained asymptomatic for 5 years. CONCLUSION: We found hypopigmented MF to be the most common clinical presentation in patients under 18 years of age. The disease did not progress to advanced stages in any of the patients, although recurrence after treatment interruption was common.

Evolución de artralgias posterior a cirugía bariátrica / Evolution of arthralgia subsequent to bariatric surgery

Resumen Objetivo: En este estudio, se propuso establecer la relación entre la pérdida de peso y la evolución de las artropatías en un grupo de pacientes obesos sometidos a cirugía bariátrica. Materiales y Método: Investigación correlacional y de corte longitudinal, retrospectivo, donde se revisaron 33 historias de pacientes obesos mórbidos con artralgia en cualquier articulación, sometidos a cirugía bariátrica. Se realizó el análisis descriptivo de las variables numéricas según la distribución de los datos. Como prueba de relación se utilizó la Prueba T de Student para comparación de proporciones, asumiendo un valor p < 0,05. Resultados: 63,3% fueron femeninas, siendo la rodilla la principal articulación afectada (51,5%), con reducción considerable de su índice de masa corporal poscirugía. Al compararse los promedios del IMC inicial, a los 3, 6 y 12 meses, se encontraron diferencias estadísticamente significativas (p < 0,01). La desaparición de la artralgia en la mayoría de los pacientes ocurrió durante los primeros 3 meses, principalmente pacientes con obesidad grado I y II, en contraste con aquellos pacientes con obesidad grado III y IV, quienes requirieron un mayor lapso, para lograr la desaparición total de la artralgia. Conclusiones: La disminución gradual del dolor articular estuvo en relación directa a la reducción de las cifras de peso del paciente ya operado, mejorando la calidad de vida de los pacientes de la muestra.

Aim: In this study it was proposed to establish the relationship between weight loss and the evolution of the joint diseases in a group of obese patients undergoing bariatric surgery. Materials and Method: Cutting longitudinal, retrospective, and correlational research where studied 33 morbidly obese patients histories and arthralgia, in any joint they was undergoing bariatric surgery. It was the descriptive analysis of the numerical variables according to the distribution of the data. As proof of relationship the Student T test was used for comparison of proportions, assuming a P-value < 0.05. Results: 63.3% were female, being the main affected joint (51.5%), with significant reduction in their rate of body mass post surgery knee. To compare the averages of initial IMC, 3, 6 and 12 months statistically significant differences were found (p < 0.01). The disappearance of arthralgia in patients most occurred during the first 3 months, mainly patients with obesity grade I and II, in contrast to those patients with obesity grade III and IV, who required a greater period, to achieve the total disappearance of arthralgia. Conclusion: The gradual decrease in the pain joint was in direct relation to the reduction of the numbers of weight of the patient already operated, improving the quality of life of the patients of the indicated.

Characterization of polycaprolactone/rGO nanocomposite scaffolds obtained by electrospinning.

The incorporation of nanoparticles inside polymeric matrices has led to the development of multifunctional composites necessary to repair human tissues. The addition of nanoparticles may improve the properties of the composite materials such as surface area, mechanical properties, flexibility, hydrophilicity, electrical conductivity, etc. These properties can help in cellular growth, proliferation and/or differentiation. In this work, scaffolds of polycaprolactone (PCL) and reduced graphite oxide (rGO) were built by electrospinning technique. The ratios of rGO/PCL employed were 0.25, 0.5, 0.75 and 1 wt%. Two different voltage setup (10 and 15 kV) and distance of 10 cm were used for electrospinning. Thermal, mechanical, morphological, electrical, porosity and absorption water tests were made to the scaffolds. Samples electrospun at 10 kV with rGO showed improvement in mechanical properties with an increase of 190% of Young's Modulus in comparison with sample without rGO. Furthermore, samples electrospun at 15 kV showed an important deterioration with the addition of rGO but had an increase in the electrical conductivity and porosity. Overall, the addition of 0.75 and 1 wt% of rGO led to a detriment on properties due to formation of aggregates. The voltage on the electrospinning process plays a very important role in the final properties of the nanocomposites scaffolds of PCL-rGO.

A systematic review and meta-analysis of the relative efficacy and safety of treatment regimens for HIV-associated cerebral toxoplasmosis: is trimethoprim-sulfamethoxazole a real option?

OBJECTIVES: The objective of this study was to perform a systematic review and meta-analysis of the literature to evaluate the efficacy and safety of therapies for cerebral toxoplasmosis in HIV-infected adults. The pyrimethamine plus sulfadiazine (P-S) combination is considered the mainstay therapy for cerebral toxoplasmosis and pyrimethamine plus clindamycin (P-C) is the most common alternative treatment. Although trimethoprim-sulfamethoxazole (TMP-SMX) has potential advantages, its use is infrequent. METHODS: We searched PubMed and four other databases to identify randomized controlled trials (RCTs) and cohort studies. Two independent reviewers searched the databases, identified studies and extracted data. Risk ratios (RRs) were pooled across studies using random-effects models. RESULTS: Nine studies were included (five RCTs, three retrospective cohort studies and one prospective cohort study). In comparison to P-S, treatment with P-C or TMP-SMX was associated with similar rates of partial or complete clinical response [P-C: RR 0.87; 95% confidence interval (CI) 0.70-1.08; TMP-SMX: RR 0.97; 95% CI 0.78-1.21], radiological response (P-C: RR 0.92; 95% CI 0.82-1.03), skin rash (P-C: RR 0.81; 95% CI 0.56-1.17; TMP-SMX: RR 0.17; 95% CI 0.02-1.29), gastrointestinal impairment (P-C: RR 5.16; 95% CI 0.66-40.11), and drug discontinuation because of adverse events (P-C: RR 0.32; 95% CI 0.07-1.47). Liver impairment was more frequent with P-S than P-C (P-C vs. P-S: RR 0.48; 95% CI 0.24-0.97) CONCLUSIONS: The current evidence fails to identify a superior regimen in terms of relative efficacy or safety for the treatment of HIV-associated cerebral toxoplasmosis. Use of TMP-SMX as preferred treatment may be consistent with the available evidence and other real-world considerations. Larger comparative studies are needed

Obesity-related insulin resistance in adolescents: a systematic review and meta-analysis of observational studies.

Insulin resistance is common among obese adolescents; however, the extent of this problem is not clear. We conducted a systematic review of PubMed-Medline, CINAHL, The Web of Science, EMBASE and Scopus for observational studies evaluating components defining insulin resistance (insulin, C-peptide and homeostatic model assessment-insulin resistance [HOMA-IR]) in obese adolescents (12-18 years) versus non-obese adolescents. Our systematic review and meta-analysis followed the PRISMA guidelines. Data were combined using a random-effects model and summary statistics were calculated using the mean differences (MDs). 31 studies were included (n = 8655). In 26 studies, fasting insulin levels were higher in obese adolescents when compared to non-obese adolescents (MD = 64.11 pmol/L, 95%CI 49.48-78.75, p < 0.00001). In three studies, fasting C-peptide levels were higher in obese adolescents when compared to non-obese adolescents (MD = 0.29 nmol/L, 95%CI 0.22-0.36, p < 0.00001). In 24 studies, HOMA-IR values were higher in obese adolescents when compared to non-obese adolescents (MD = 2.22, 95%CI 1.78-2.67, p < 0.00001). Heterogeneity of effects among studies was moderate to high. Subgroup analyses showed similar results to the main analyses. Circulating insulin and C-peptide levels and HOMA-IR values were significantly higher in obese adolescents compared to those non-obese.

A systematic review and meta-analysis of the relative efficacy and safety of treatment regimens for HIV-associated cerebral toxoplasmosis: is trimethoprim-sulfamethoxazole a real option?

OBJECTIVES: The objective of this study was to perform a systematic review and meta-analysis of the literature to evaluate the efficacy and safety of therapies for cerebral toxoplasmosis in HIV-infected adults. The pyrimethamine plus sulfadiazine (P-S) combination is considered the mainstay therapy for cerebral toxoplasmosis and pyrimethamine plus clindamycin (P-C) is the most common alternative treatment. Although trimethoprim-sulfamethoxazole (TMP-SMX) has potential advantages, its use is infrequent. METHODS: We searched PubMed and four other databases to identify randomized controlled trials (RCTs) and cohort studies. Two independent reviewers searched the databases, identified studies and extracted data. Risk ratios (RRs) were pooled across studies using random-effects models. RESULTS: Nine studies were included (five RCTs, three retrospective cohort studies and one prospective cohort study). In comparison to P-S, treatment with P-C or TMP-SMX was associated with similar rates of partial or complete clinical response [P-C: RR 0.87; 95% confidence interval (CI) 0.70-1.08; TMP-SMX: RR 0.97; 95% CI 0.78-1.21], radiological response (P-C: RR 0.92; 95% CI 0.82-1.03), skin rash (P-C: RR 0.81; 95% CI 0.56-1.17; TMP-SMX: RR 0.17; 95% CI 0.02-1.29), gastrointestinal impairment (P-C: RR 5.16; 95% CI 0.66-40.11), and drug discontinuation because of adverse events (P-C: RR 0.32; 95% CI 0.07-1.47). Liver impairment was more frequent with P-S than P-C (P-C vs. P-S: RR 0.48; 95% CI 0.24-0.97). CONCLUSIONS: The current evidence fails to identify a superior regimen in terms of relative efficacy or safety for the treatment of HIV-associated cerebral toxoplasmosis. Use of TMP-SMX as preferred treatment may be consistent with the available evidence and other real-world considerations. Larger comparative studies are needed.

Evaluación de impacto del proyecto Treatnet en Colombia: la experiencia en la ESE CARISMA. 2007 / Impact assessment of Treatnet project in Colombia: the CARISMA experience in 2007

Desde el año 2005 la Empresa Social del Estado E.S.E. CARISMA ("Centro de Atención y Rehabilitación Integral en Salud Mental de Antioquia") en Medellín, Colombia, hasido punto de referencia en Latinoamérica para la implementación del proyecto TREATNET (Red internacional de centros de tratamiento y rehabilitación de drogodependientes). Esta estrategia, que recoge veinte centros de atención a la población farmacodependiente en el mundo, busca fomentar el diálogo y el intercambio de experiencias entre sus miembros y con sus asociados, intentando diversificar y volver eficaces, y de calidad, los servicios de tratamiento y rehabilitación, abarcando 4 áreas de atención en el problema de la adicción a las drogas: 1) El tratamiento institucional, 2) El manejo de la adicción a las drogas en prisiones, 3) La intervención en pacientes drogodependientes con VIH/SIDA y 4) Los programas para mejorar la rehabilitación. Con el fin de revisar la evaluación de impacto del proyecto, y a partir de los protocolos establecidos por la Oficina de las Naciones Unidas contra las Drogas y el Delito (ONUDD), la Universidad CES (Medellín, Colombia) realizó un proceso de evaluación con todos los integrantes de la institución durante los meses de junio a septiembre de 2007. Se evidencian elementos de alta coherencia en los resultados acorde a las poblaciones encuestadas, en la percepción del servicio y en las fortalezas y debilidades de la E.S.E. CARISMA, y un fuerte compromiso con la temática objeto de intervención en esta institución.

Since 2005, CARISMA (Medellín, Colombia) has been a center of reference in Latin America for implementation the TREATNET project (International Network of Drug Treatment and Rehabilitation Resource Centers). This project, that gathers twenty centers for the treatment of drug addiction in the world, seeks to promote the dialogue and the exchange of experiences amongst it's members, in order to diversify and improve the effectiveness and quality of the treatment centers. They include 4 knowledge areas: 1) Community- based treatment, 2) Drug addiction treatment in prisons, 3) Drug addiction treatment in patients with HIV/AIDS and 4) Sustainable livelihoods for rehabilitation/reintegration. With the purpose of reviewing the impact of the project according to the protocols established by the United Nations Office on Drugs and Crime (UNODC), the CES University (Medellín, Colombia) assessed all the members of the CARISMA institute. There were elements of high coherence in the protocols of attention, perception of the service and the strengths and weaknesses of CARISMA, and a strong commitment with the thematic object of intervention of this institution.

Study of cadmium, zinc and lead biosorption by orange wastes using the subsequent addition method.

The biosorption of several metals (Cd2+, Zn2+ and Pb2+) by orange wastes has been investigated in binary systems. Multicomponent sorption isotherms were obtained using an original procedure, similar to that proposed by Pagnanelli et al. [Pagnanelli, F., Petrangeli, M.P., Toro, L., Trifoni, M., Veglio, F., 2001a. Biosorption of metal ions on Arthrobacter sp.: biomass characterization and biosorption modelling. Environ. Sci. Technol. 34, 2773-2778] for monoelement systems, known as subsequent addition method (SAM). Experimental sorption data were analysed using an extended multicomponent Langmuir equation. The maximum sorption uptake was approximately 0.25mmol/g for the three binary systems studied. The reliability of the proposed procedure for obtaining the equilibrium data in binary systems was verified by means of a statistical F-test.

Removal of cadmium from aqueous solutions by adsorption onto orange waste.

The use of orange wastes, generated in the orange juice industry, for removing cadmium from aqueous solutions has been investigated. The material was characterized by Fourier transform infrared spectroscopy and batch experiments were conducted to determine the adsorption capacity of the biomass. A strong dependence of the adsorption capacity on pH was observed, the capacity increasing as pH value rose. Kinetics and adsorption equilibrium were studied at different pH values (4-6). The adsorption process was quick and the equilibrium was attained within 3h. The maximum adsorption capacity of orange waste was found to be 0.40, 0.41 and 0.43 mmol/g at pH 4-6, respectively. The kinetic data were analysed using various kinetic models - pseudo-first order equation, pseudo-second order equation, Elovich equation and intraparticle diffusion equation - and the equilibrium data were tested using four isotherm models - Langmuir, Freundlich, Sips and Redlich-Peterson. The data were fitted by non-linear regression and five error analysis methods were used to evaluate the goodness of the fit. The Elovich equation provides the greatest accuracy for the kinetic data and the Sips model the closest fit for the equilibrium data.

An initial investigation of spinal mechanisms underlying pain enhancement induced by fractalkine, a neuronally released chemokine.

Fractalkine is a chemokine that is tethered to the extracellular surface of neurons. Fractalkine can be released, forming a diffusible signal. Spinal fractalkine (CX3CL1) is expressed by sensory afferents and intrinsic neurons, whereas its receptor (CX3CR1) is predominantly expressed by microglia. Pain enhancement occurs in response both to intrathecally administered fractalkine and to spinal fractalkine endogenously released by peripheral neuropathy. The present experiments examine whether fractalkine-induced pain enhancement is altered by a microglial inhibitor (minocycline) and/or by antagonists/inhibitors of three putative glial products implicated in pain enhancement: interleukin-1 (IL1), interleukin-6 (IL6) and nitric oxide (NO). In addition, it extends a prior study that demonstrated that intrathecal fractalkine-induced mechanical allodynia is blocked by a neutralizing antibody to the rat fractalkine receptor, CX3CR1. Here, intrathecal anti-CX3CR1 also blocked fractalkine-induced thermal hyperalgesia. Furthermore, blockade of microglial activation with minocycline prevented both fractalkine-induced mechanical allodynia (von Frey test) and thermal hyperalgesia (Hargreaves test). Microglial activation appears to lead to the release of IL1, given that pretreatment with IL1 receptor antagonist blocked both fractalkine-induced mechanical allodynia and thermal hyperalgesia. IL1 is not the only proinflammatory cytokine implicated, as a neutralizing antibody to rat IL6 also blocked fractalkine-induced pain facilitation. Lastly, NO appears to be importantly involved, as l-NAME, a broad-spectrum NO synthase inhibitor, also blocked fractalkine-induced effects. Taken together, these data support that neuronally released fractalkine enhances pain via activation of spinal cord glia. Thus, fractalkine may be a neuron-to-glia signal triggering pain facilitation.

Evidence that exogenous and endogenous fractalkine can induce spinal nociceptive facilitation in rats.

Recent evidence suggests that spinal cord glia can contribute to enhanced nociceptive responses. However, the signals that cause glial activation are unknown. Fractalkine (CX3C ligand-1; CX3CL1) is a unique chemokine expressed on the extracellular surface of spinal neurons and spinal sensory afferents. In the dorsal spinal cord, fractalkine receptors are primarily expressed by microglia. As fractalkine can be released from neurons upon strong activation, it has previously been suggested to be a neuron-to-glial signal that induces glial activation. The present series of experiments provide an initial investigation of the spinal pain modulatory effects of fractalkine. Intrathecal fractalkine produced dose-dependent mechanical allodynia and thermal hyperalgesia. In addition, a single injection of fractalkine receptor antagonist (neutralizing antibody against rat CX3C receptor-1; CX3CR1) delayed the development of mechanical allodynia and/or thermal hyperalgesia in two neuropathic pain models: chronic constriction injury (CCI) and sciatic inflammatory neuropathy. Intriguingly, anti-CX3CR1 reduced nociceptive responses when administered 5-7 days after CCI, suggesting that prolonged release of fractalkine may contribute to the maintenance of neuropathic pain. Taken together, these initial investigations of spinal fractalkine effects suggest that exogenous and endogenous fractalkine are involved in spinal sensitization, including that induced by peripheral neuropathy.