Evaluación del músculo ciliar y del grosor escleral anterior en miopes altos mediante tomografía de coherencia óptica / Assessment of the ciliary muscle and scleral anterior thickness in high myopia by optical coherence tomography

Propósito: Evaluar las dimensiones del músculo ciliar (MC) y del grosor escleral anterior (AST) in vivo en miopes altos mediante tomografía de coherencia óptica de fuente de barrido (SS-OCT) y comparar con sujetos emétropes e hipermétropes.MétodosEstudio transversal en el que se incluyeron 34 miopes altos (≥−6dioptrías [D]), 90 emétropes (−1 a +1D) y 38 hipermétropes (≥+3,5D). Se midieron el grosor del MC (CMT) y el AST en los cuadrantes temporal y nasal a 1, 2 y 3mm del espolón escleral utilizando la SS-OCT. Además, se evaluó la longitud del MC (CML).ResultadosLas dimensiones tanto del CML como del CMT en cualquiera de sus puntos de medida fueron mayores en miopes altos y en emétropes que en hipermétropes, tanto en el cuadrante nasal como en el temporal (p<0,001). Sin embargo, no existieron diferencias entre miopes magnos y emétropes para ninguno de los parámetros (p≥0,076), salvo para el CMT a 3mm en temporal (p<0,001). No existieron diferencias en el AST entre miopes altos, emétropes e hipermétropes, en ninguno de los puntos de medida ni cuadrantes estudiados (p>0,05).ConclusionesLa SS-OCT permite medir el MC in vivo, no observándose diferencias en sus dimensiones entre miopes altos y emétropes, pero sí que fueron menores en hipermétropes. En la medida de la esclera anterior no se observaron diferencias entre los tres grupos analizados según la refracción. (AU)

Purpose: To assess ciliary muscle (CM) and anterior scleral thickness (AST) dimensions in vivo in high myopia using swept-source optical coherence tomography (SS-OCT) and to compare with emmetropic and hyperopic subjects.MethodsCross-sectional study that included 34 high myopic patients (≥−6 diopters [D]), 90 emmetropes (−1 to +1D) and 38 hyperopic patients (≥+3.5D). CM thickness (CMT) and AST were measured in the temporal and nasal quadrants at 1, 2, and 3mm from the scleral spur using SS-OCT. In addition, the length of the CM (CML) was evaluated.ResultsThe dimensions of the CML and the CMT at any of their measurement points were greater in high myopes and emmetropes than in hyperopes, both in the nasal and temporal quadrants (P<.001). However, there were no differences between high myopes and emmetropes for any of the parameters (P≥.076) except for the CMT at 3mm in the temporal quadrant (P<.001). There were no differences in the AST between high myopes, emmetropes and hyperopes, in any of the measurement points or quadrants studied (P>.05).ConclusionsThe SS-OCT allows to measure the CM in vivo, not observing differences in its dimensions between high myopes and emmetropes, but they were smaller in hyperopes. In the measurement of the anterior sclera, no differences were observed between the three groups analyzed according to refraction. (AU)

Assessment of the ciliary muscle and scleral anterior thickness in high myopia by optical coherence tomography.

PURPOSE: To assess ciliary muscle (CM) and anterior scleral thickness (AST) dimensions in vivo in high myopia using swept-source optical coherence tomography (SS-OCT) and to compare with emmetropic and hyperopic subjects. METHODS: Cross-sectional study that included 34 high myopic patients (≥ -6 diopters [D]), 90 emmetropes (-1 to +1 D) and 38 hyperopic patients (≥ +3.5 D). CM thickness (CMT) and AST were measured in the temporal and nasal quadrants at 1, 2, and 3 mm from the scleral spur using SS-OCT. In addition, the length of the CM (CML) was evaluated. RESULTS: The dimensions of the CML and the CMT at any of their measurement points were greater in high myopes and emmetropes than in hyperopes, both in the nasal and temporal quadrants (P < .001). However, there were no differences between high myopes and emmetropes for any of the parameters (P ≥ .076) except for the CMT at 3 mm in the temporal quadrant (P < .001). There were no differences in the AST between high myopes, emmetropes and hyperopes, in any of the measurement points or quadrants studied (P > .05). CONCLUSIONS: The SS-OCT allows to measure the CM in vivo, not observing differences in its dimensions between high myopes and emmetropes, but they were smaller in hyperopes. In the measurement of the anterior sclera, no differences were observed between the three groups analyzed according to refraction.

Precision Measurement of the Lamb Shift in Muonium.

We report a new measurement of the n=2 Lamb shift in Muonium. Our result of 1047.2(2.3)_{stat}(1.1)_{syst} MHz comprises an order of magnitude improvement upon the previous best measurement. This value matches the theoretical calculation within 1 standard deviation allowing us to set limits on Lorentz and CPT violation in the muonic sector, as well as on new physics coupled to muons and electrons which could provide an explanation of the muon g-2 anomaly.

Intense beam of metastable Muonium.

Precision spectroscopy of the Muonium Lamb shift and fine structure requires a robust source of 2S Muonium. To date, the beam-foil technique is the only demonstrated method for creating such a beam in vacuum. Previous experiments using this technique were statistics limited, and new measurements would benefit tremendously from the efficient 2S production at a low energy muon ( < 20  keV) facility. Such a source of abundant low energy µ + has only become available in recent years, e.g. at the Low-Energy Muon beamline at the Paul Scherrer Institute. Using this source, we report on the successful creation of an intense, directed beam of metastable Muonium. We find that even though the theoretical Muonium fraction is maximal in the low energy range of 2-5 keV, scattering by the foil and transport characteristics of the beamline favor slightly higher µ + energies of 7-10 keV. We estimate that an event detection rate of a few events per second for a future Lamb shift measurement is feasible, enabling an increase in precision by two orders of magnitude over previous determinations.

New Bounds from Positronium Decays on Massless Mirror Dark Photons.

We present the results of a search for a hidden mirror sector in positronium decays with a sensitivity comparable with the bounds set by the prediction of the primordial He^{4} abundance from big bang nucleosynthesis. No excess of events compatible with decays into the dark sector is observed, resulting in an upper limit for the branching ratio of this process of 3.0×10^{-5} (90% C.L.). This is an order of magnitude more stringent than the current existing laboratory bounds and it constrains the mixing strength of ordinary photons to dark mirror photons at a level of ϵ<5.0×10^{-8}.

Agreement between Fourier-domain and swept-source optical coherence tomography used for optic nerve head measurements.

PURPOSE: To assess the correlation between optic nerve head measurements generated by Fourier-domain (FD) and swept-source (SS) optical coherence tomography (OCT) both in healthy Caucasian subjects and patients with primary open angle glaucoma (POAG). MATERIALS AND METHODS: This was a cross-sectional study of the right eyes of 118 subjects. In each participant, the measurements of disc area, cup to disc ratio (CDR), vertical cup to disc ratio (VCDR), rim area and rim volume were performed consecutively by FD-OCT and then SS-OCT. Participant age, gender and spherical equivalent were also recorded. Agreement between the two devices was assessed through intraclass correlation coefficients (ICC) and Bland-Altman plots. RESULTS: The study sample consisted of 95 healthy eyes and 23 eyes with glaucoma. Mean participant age was 48.6±20.0 years, 54.2% were female, and mean spherical equivalent was -1.6±3.0 diopters. FD-OCT and SS-OCT measurements were respectively: mean disc area 1.79±0.3 vs 1.83±0.3 mm2 (ICC=0.71), mean CDR 0.38±0.2 vs 0.33±0.2 (ICC=0.91), mean VCDR 0.58±0.2 vs 0.52±0.2 (ICC=0.92), mean rim area 1.05±0.4mm2 vs 1.03±0.5mm2 (ICC=0.29), and mean rim volume 0.14±0.11 vs 0.21±0.17mm3 (ICC=0.53). Good agreement between the devices was noted for rim area and rim volume in glaucoma subjects (ICC=0.76 and 0.68 respectively), while weak agreement was observed for these variables in healthy subjects (ICC≤0.50). CONCLUSIONS: The CDR and VCDR measurements provided by FD and SS OCT showed excellent agreement for the overall sample. When the devices were used for rim measurements, agreement was excellent only in the POAG patients.

Evaluación de los signos de la pseudoexfoliación en el segmento anterior mediante tomografía de coherencia óptica y cámara de Scheimpflug / Pseudoexfoliation signs in the anterior segment assessed by optical coherence tomography and Scheimpflug device

Objetivo: Evaluar diferentes parámetros del segmento anterior en ojos con pseudoexfoliación (PSX), ojos contralaterales y controles mediante tomografía de coherencia óptica (OCT) y cámara Scheimpflug. Métodos: Se estudiaron 3 grupos: 44 ojos de 44 pacientes con PSX, 30 ojos contralaterales no afectos y 148 ojos de 148 controles sanos. Mediante la cámara de Scheimpflug (Pentacam, Oculus Inc.; Wetzlar, Alemania) se midieron la profundidad y volumen de la cámara anterior, volumen corneal y paquimetría, diámetro pupilar y densitometría corneal. Mediante OCT RTVue 100 (Optovue, Fremont, CA, EE. UU.) se midieron la abertura angular, la longitud y el área de la malla trabecular, el grosor del iris, y se valoró la visualización de depósitos PSX. Resultados. No se observaron diferencias en cuanto a la profundidad ni volumen de la cámara anterior, ni en el volumen corneal o paquimetría (p≥0,228 en todos los parámetros) entre grupos. Sin embargo, la densitometría corneal fue mayor en PSX y en los ojos contralaterales que en el grupo control (p < 0,001). En cuanto a los parámetros de OCT no existieron diferencias en la abertura angular ni en el tamaño de la malla entre los 3 grupos, siendo el grosor del iris menor en controles (p = 0,005); identificándose en todos los pacientes el depósito PSX mediante OCT. Conclusiones: No se detectaron diferencias entre las medidas biométricas del segmento anterior entre los pacientes con PSX y controles, salvo en el caso de la densitometría corneal central y el grosor del iris que fueron mayores en el grupo con PSX y en los ojos contralaterales (AU)

Objective: To evaluate different anterior segment parameters in eyes with pseudoexfoliation (PSX), fellow eyes, and controls using optical coherence tomography and a Scheimpflug imaging system. Methods: Three groups were studied: 44 eyes of 44 patients with PSX, 30 clinically unaffected fellow eyes, and 148 eyes of 148 healthy controls. The anterior chamber depth and volume, corneal volume and thickness, pupil diameter and corneal densitometry were measured using a Scheimpflug imaging system (Pentacam, Oculus Inc.; Wetzlar, Germany). The angle width, the length and area of the trabecular meshwork, and the iris thickness were measured using an optical coherence tomography RTVue 100 device (Optovue, Fremont, CA, USA). The presence of PSX deposits was also assessed by OCT. Results: There were no differences in the anterior chamber volume or depth in the corneal volume or central thickness (P ≥ .228). The corneal densitometry was similar between PSX and fellow eyes; however it was greater than in the control group (P < .001). As regards the parameters measured by OCT, there were no differences in the angle width or in the trabecular meshwork size between the 3 groups; however, the iris was thinner in controls (P = .005). In all patients the PSX deposits were correctly visualised by OCT after the identification by biomicroscopy. Conclusions: There were no differences in the anterior segment biometric measurements between patients with PSX and controls, although the corneal densitometry and iris thickness were greater in the PSX and fellow eyes groups (AU)

Agreement between Pentacam and optical coherence tomography in the assessment of iridocorneal angle width in a large healthy population.

PURPOSE: To analyze the agreement between Pentacam and optical coherence tomography (OCT) in the assessment of trabecular-iris angle (TIA) width in a large population of normal subjects. METHODS: A cross-sectional study was performed in 989 right eyes of 989 healthy subjects. The trabecular-iris angle (TIA) was measured in the temporal and nasal quadrants using the Pentacam (Oculus, Wetzlar, Germany), a device based on Scheimpflug technology and RTVue 100 OCT (Optovue, Fremont, CA, USA). Intraclass correlation coefficients (ICC) and Bland-Altman plots were used to evaluate agreement between these devices. RESULTS: Mean age was 49.1±15.2 years (18-84); 61% were women and spherical error range was -14 to 8.25. TIA could be measured by OCT in 94.9% and 94.1% in the temporal and nasal quadrants, with a mean value of 35.8±13.2 degrees (2.5-78.7) and 35.7±12.9 degrees (2.2-76.8) respectively. TIA was able to be measured by Pentacam in 95.2% and 95% in the temporal and nasal quadrants and means were 35.7±7.3 degrees (11-74.2) and 36.4±8.2 degrees (14.5-64) respectively. An ICC of 0.378 (95% confidence interval [CI], 0.322-0.431) and 0.589 (95% CI 0.546-0.629) for the temporal and nasal quadrants was obtained, showing moderate agreement between the devices. Bland-Altman plots revealed that, compared with OCT, Pentacam tends to overestimate measurements in narrow angles and underestimate these in open angles. CONCLUSIONS: Agreement between OCT and Pentacam was mediocre, indicating the two devices are not interchangeable when used to measure angle width.

Pseudoexfoliation signs in the anterior segment assessed by optical coherence tomography and Scheimpflug device. / Evaluación de los signos de la pseudoexfoliación en el segmento anterior mediante tomografía de coherencia óptica y cámara de Scheimpflug.

OBJECTIVE: To evaluate different anterior segment parameters in eyes with pseudoexfoliation (PSX), fellow eyes, and controls using optical coherence tomography and a Scheimpflug imaging system. METHODS: Three groups were studied: 44 eyes of 44 patients with PSX, 30 clinically unaffected fellow eyes, and 148 eyes of 148 healthy controls. The anterior chamber depth and volume, corneal volume and thickness, pupil diameter and corneal densitometry were measured using a Scheimpflug imaging system (Pentacam, Oculus Inc.; Wetzlar, Germany). The angle width, the length and area of the trabecular meshwork, and the iris thickness were measured using an optical coherence tomography RTVue 100 device (Optovue, Fremont, CA, USA). The presence of PSX deposits was also assessed by OCT. RESULTS: There were no differences in the anterior chamber volume or depth in the corneal volume or central thickness (P≥.228). The corneal densitometry was similar between PSX and fellow eyes; however it was greater than in the control group (P<.001). As regards the parameters measured by OCT, there were no differences in the angle width or in the trabecular meshwork size between the 3 groups; however, the iris was thinner in controls (P=.005). In all patients the PSX deposits were correctly visualised by OCT after the identification by biomicroscopy. CONCLUSIONS: There were no differences in the anterior segment biometric measurements between patients with PSX and controls, although the corneal densitometry and iris thickness were greater in the PSX and fellow eyes groups.

Identificación de estructuras del ángulo iridocorneal mediante tomografía de coherencia óptica de dominio Fourier / Identification of iridocorneal angle structures assessed by Fourier domain optical coherence tomography

OBJETIVO: Estudiar las estructuras que conforman el ángulo iridocorneal mediante tomografía de coherencia óptica (OCT) de segmento anterior, definiendo sus características tomográficas y cuantificando su frecuencia de identificación. MATERIAL Y MÉTODOS: Estudio transversal realizado en 267 ojos derechos de 267 pacientes consecutivos sanos. Se empleó una OCT de dominio Fourier RTVue (Optovue Inc, CA, EE. UU.) para explorar el ángulo iridocorneal en los sectores nasal y temporal. Las estructuras evaluadas fueron: el limbo externo, transición corneoescleral, línea de Schwalbe, malla trabecular, canal de Schlemm, espolón escleral y receso angular. Se calculó la concordancia intra- e interobservador para la identificación de las estructuras mediante el coeficiente kappa. RESULTADOS: La edad media fue 41,3 ± 14,3 años (rango 20-80); el 57% eran mujeres. El limbo externo, la transición córneo-escleral y la línea de Schwalbe se identificaron en un 98,7; 97 y 93,4%, respectivamente de las imágenes. La malla trabecular y el canal de Schlemm se identificaron en el 91% de los casos. El espolón escleral pudo ser identificado en un 85,4% y el receso angular en un 74,5%. No existió diferencia en la identificación entre el sector temporal y nasal. La concordancia intra- e interobservador fue de k = 0,92 y k = 0,88 respectivamente, en la identificación de las estructuras para el total de las imágenes estudiadas. CONCLUSIONES: La OCT de dominio Fourier es una técnica eficaz para la identificación de las estructuras que conforman el ángulo iridocorneal, entre las que destacan la malla trabecular, el canal de Schlemm, el espolón escleral y la línea de Schwalbe

OBJECTIVE: To study the structures of the iridocorneal angle using anterior segment optical coherence tomography (OCT) defining their tomographic characteristics and quantifying their identification frequency. MATERIAL AND METHODS: A cross-sectional study was performed on 267 right eyes of 267 consecutive healthy patients. Fourier domain OCT RTVue (Optovue Inc, CA, EE. UU.) was used to examine the iridocorneal angle in the nasal and temporal sectors. The structures evaluated were: Sclerocorneal limbus, sclerocorneal transition, Schwalbe's line, trabecular meshwork, Schlemm's canal, scleral spur, and angular recess. Within and between agreements to identify structures were calculated using Cohen's kappa coefficient. RESULTS: The mean age was 41.3 ± 14.3 years (range 20-80), with 57% being women. The sclerocorneal limbus, sclerocorneal transition, and Schwalbe's line were identified by 98.7, 97 and 93.4% of the images, respectively, with the trabecular meshwork and Schlemm's canal being identified in 91% of cases. The scleral spur could be identified in 85.4%, and the angular recess in 74.5%. There was no difference in the identification between the temporal and nasal sectors. Within and between agreement was k = 0.92 and k = 0.88, respectively, in the identification of the structures of the total images studied. CONCLUSIONS: Fourier domain OCT is a reliable technique for the identification of the structures of the iridocorneal angle, among which can be highlighted are, the trabe

Identification of iridocorneal angle structures assessed by Fourier domain optical coherence tomography.

OBJECTIVE: To study the structures of the iridocorneal angle using anterior segment optical coherence tomography (OCT) defining their tomographic characteristics and quantifying their identification frequency. MATERIAL AND METHODS: A cross-sectional study was performed on 267 right eyes of 267 consecutive healthy patients. Fourier domain OCT RTVue (Optovue Inc, CA, EE. UU.) was used to examine the iridocorneal angle in the nasal and temporal sectors. The structures evaluated were: Sclerocorneal limbus, sclerocorneal transition, Schwalbe's line, trabecular meshwork, Schlemm's canal, scleral spur, and angular recess. Within and between agreements to identify structures were calculated using Cohen's kappa coefficient. RESULTS: The mean age was 41.3 ± 14.3 years (range 20-80), with 57% being women. The sclerocorneal limbus, sclerocorneal transition, and Schwalbe's line were identified by 98.7, 97 and 93.4% of the images, respectively, with the trabecular meshwork and Schlemm's canal being identified in 91% of cases. The scleral spur could be identified in 85.4%, and the angular recess in 74.5%. There was no difference in the identification between the temporal and nasal sectors. Within and between agreement was k=0.92 and k=0.88, respectively, in the identification of the structures of the total images studied. CONCLUSIONS: Fourier domain OCT is a reliable technique for the identification of the structures of the iridocorneal angle, among which can be highlighted are, the trabecular meshwork, Schlemm's canal, scleral spur, and Schwalbe's line.

Aggregation and coalescence of oil droplets in water via electrohydrodynamic flows.

Electrohydrodynamic (EHD) flows are known to cause rigid colloids to aggregate near electrodes. Here we report that EHD flows also induce immiscible oil droplets to aggregate and, for sufficiently strong field strengths, to coalesce. We measure the aggregation and coalescence rates of micrometer-scale oil droplets in water, and we find that the most effective way to induce coalescence is by suddenly decreasing the applied frequency. We interpret the results in terms of a balance between EHD flow and colloidal forces, and we discuss the implications for using EHD flows to separate trace oils from solution.

Synergism of CAY-1 with amphotericin B and itraconazole.

BACKGROUND: CAY-1 is a fungicidal saponin from cayenne pepper whose mode of action differs from amphotericin B (AB) and itraconazole (IT). This work determined CAY-1 synergism with AB or IT. METHODS: CAY-1 was purified and used in checkerboard microdilution studies where CAY-1 and AB or IT were mixed with nongerminated (NG) and germinating (G) conidia of three Aspergillus species and Candida albicans. Inhibition was visually determined at 24 and 48 h. RESULTS: CAY-1 had predominantly additive-synergistic interaction with AB or IT against the Aspergillus NG and G conidia. Excellent synergy between CAY-1 and AB occurred at 24 and 48 h against C. albicans. Results suggest CAY-1 enhances AB and IT efficacy.

Further evaluation of microswitch clusters to enhance hand response and head control in persons with multiple disabilities.

This study was a further evaluation of microswitch clusters (combinations of two microswitches) to improve adaptive responding together with correct head position in two persons with multiple disabilities. The two participants were 19.7 and 6.6 yr. old and had profound intellectual disabilities, spastic tetraparesis, and visual impairment. They were initially taught an adaptive hand response that activated a pressure microswitch and produced favorite stimulation. Thereafter, their performance of the hand response produced favorite stimulation only when it was combined with a correct head position (detected through a mercury microswitch). Analysis showed that both participants increased the frequency of the hand response and, subsequently, the percentage of times they emitted this response in combination with correct (upright) head position. In essence, they were able to coordinate constructive occupation with exercise of appropriate posture. Performance was maintained at a 2-mo. postintervention check.

Microswitch clusters to enhance adaptive responses and head control: a programme extension for three children with multiple disabilities.

PURPOSE: We assessed the possibility of extending adaptive responding and head control in three children with multiple disabilities through the use of microswitch clusters. METHOD: The children had previously learned to perform an adaptive hand response and to control head position during that response. They were now taught one or two new adaptive responses (foot lifting, leg touching, or vocalization) and to combine such responses with appropriate head position. Microswitch clusters served to ensure that an adaptive response was followed by positive stimulation only if it was combined with appropriate head position. RESULTS: The results were positive with the children learning the new adaptive responses and combining them with appropriate head position. This performance was maintained during two- or three-month post-intervention checks. During these checks, the children were also successful in using the old adaptive hand response with appropriate head position. CONCLUSIONS: The use of microswitch clusters was effective to extend the level of adaptive responding and enhance appropriate head position during this responding. This outcome, which indicates a successful technical replication and procedural extension of previous work in the area, has positive practical implications for educational and occupational programmes for children with multiple disabilities.

Role of oral rapamycin to prevent restenosis in patients with de novo lesions undergoing coronary stenting: results of the Argentina single centre study (ORAR trial).

OBJECTIVE: To assess the role of oral rapamycin in the prevention of coronary restenosis in patients undergoing coronary stenting. METHODS: From December 2001 through February 2003, 76 patients with 103 de novo lesions treated percutaneously with bare stents received a loading dose of oral rapamycin 6 mg followed by a daily dose of 2 mg during 28 days in phase I (49 arteries in 34 patients) and 2 mg/day plus 180 mg/day of diltiazem in phase II (54 arteries in 42 patients). Rapamycin blood concentrations were measured in all patients. A six month follow up angiogram was performed in 82.5% (85 of 103 arteries). Follow up angiographic binary restenosis (> 50%), target vessel revascularisation, late loss, treatment compliance, and major adverse cardiovascular events were analysed and correlated with rapamycin concentrations. RESULTS: Rapamycin was well tolerated and only three patients discontinued the treatment for mild side effects. Angiographic restenosis was found in 15% of the arteries with angiographic restudy (13 of 85). The target vessel had been revascularised at follow up in 13.6% of the 103 vessels initially treated (14 of 103) and in 18.4% of the 76 patients (14 of 76). In-stent restenosis in phase I was 19% compared with 6.2% in phase II (p = 0.06). Angiographic in-stent restenosis in lesions of patients with rapamycin blood concentrations > or = 8 ng/ml was 6.2% and with rapamycin concentrations < 8 ng/ml was 22% (p = 0.041). Late loss was also significantly lower when rapamycin concentrations were > or = 8 ng/ml (0.6 mm v 1.1 mm, p = 0.031). A Pearson test showed a linear correlation between follow up late loss and rapamycin blood concentration (r = -0.826, p = 0.008). CONCLUSION: Oral rapamycin administered for one month after percutaneous coronary intervention was safe and with few minor side effects. High rapamycin blood concentrations were associated with significantly lower late loss and angiographic in-stent restenosis.

Microswitch clusters to support responding and appropriate posture of students with multiple disabilities: three case evaluations.

PURPOSE: This study extended the evaluation of microswitch clusters to support responding and appropriate posture with three students with multiple disabilities. METHOD: Initially, a baseline level was established for the target response selected for each student. Then, Intervention I was implemented to increase the frequency of that response through the presentation of favourite stimuli. During Intervention II, the response was followed by favourite stimuli only if the microswitch cluster detected it in combination with appropriate posture. Post-intervention checks were carried out within 2 or 3 months from the end of Intervention II. RESULTS AND CONCLUSIONS: All students showed an increase in the frequency of the target response during Intervention I and in the percentage of times the response occurred in combination with appropriate posture during Intervention II. These changes lasted over time. The importance of microswitch clusters to enhance the performance of students with multiple disabilities was underlined.

Influências da variação sazonal e tipos de secagem nas características da droga vegetal - raízes de Pfaffia glomerata (Spreng.) Pedersen (Amaranthaceae) / Influence of seasonal variation and drying on root’s characteristics derived from Pfaffia glomerata (Spreng.) Pedersen (Amaranthaceae)

Analisou-se a variação sazonal e a influência de diferentes tipos de secagem (sol, sombra e estufa) no teor de saponinas e nas características físico-químicas da droga vegetal - raízes de Pfaffia glomerata (Spreng.) Pedersen (Amaranthaceae). A avaliação sazonal apontou a ocorrência de diferenças significativas nos teores de extrativos (maior no inverno: 61,1 por cento±1,9), saponinas totais (maior no inverno: 17,1±0,2 por cento), e entre cinzas totais (maiores no inverno e primavera: 6,5±0,4 e 6,5±1,0 por cento, respectivamente) e cinzas insolúveis em ácido(maiores no verão e outono: 0,57±0,11 e 0,44±0,18 por cento, repectivamente). Quanto à variação sazonal do teor de saponinas, o valor do lote colhido no inverno foi maior do que nas outras estações, confirmando o conceito geral de maior ocorrência de ativos em órgãos subterrâneos no inverno. Quanto à influência dos métodos de secagem, o lote seco ao sol forneceu maior teor de extrativos (61,2±2,3 por cento) do que os lotes secos na sombra e em estufa, contradizendo a regra geral de que a radiação solar degrada os ativos vegetais. Esse mesmo perfil de dados ocorreu com relação ao teor de saponinas, pois o lote seco ao sol mostrou maior valor(15,4 por cento) do que daqueles secos na sombra ou em estufa (14,4 e 11,6 por cento, respectivamente). Desta forma, verificou-se que, de fato, ocorre variação sazonal nas raízes de P. glomerata, particularmente, no que diz respeito aos teoes de extrativos, cinzas e saponinas totais, sendo que essas variações indicam maior concentração de ativos nos períodos de inverno e primavera. Dentre os métodos de secagem testados, o emprego do sol parece favorecer os teores de saponinas e de extrativos, embora tal conclusão mereça ser melhor investigada.

The seasonal variation and the influence of drying (sun, shadow and hot-house greenhouse) were analysed in relation to the total saponin content and physicochemical characteristics. The seasonal evaluation detected significant differences in the parameters of extractable matter (larger in winter: 61.1 percent±1.9), total saponin content (larger in winter; 17.1±0.2 percent) and between total ash (larger in winter and spring; 6.5±0.4 and 6.5±1.0 percent, respectively) and acid-insoluble ash (larger in summer and autumn; 0.57±0.11 and 0.44±0.18 percent, respectively). In relation to the seasonal variation of total saponin content, the value of the sample collected in winter was larger than in other seasons, confirming the general rule that the largest content of substances in underground organs occurred in winter. In relation to the influence of drying methods, the sample dried at the sun presented a larger value of extractable matter (61.2±2.3 percent) than those dried on shadow and in hot-house greenhouse, contradicting the general rule that the sun radiation would degrade natural substances. The same profile was found in relation to the total saponin content, because the sample dried at the sun showed a larger value (15.4 percent) than those dried on shadow or in hot-house (14.4 and 11.6 percent, respectively). However, these conclusions have to be more investigated.

CAY-1, a novel antifungal compound from cayenne pepper.

CAY-1, a novel saponin from Capsicum frutescens (commercially known as cayenne pepper) was investigated to determine its in vitro antifungal activity, mechanism of action and mammalian cell cytotoxicity. CAY-1 was active against 16 different fungal strains, including Candida spp. and Aspergillus fumigatus [minimum inhibitory concentrations (MIC) ranging from 4 to 16 microg ml(-1)], and was especially active against Cryptococcus neoformans (90% inhibition at 1 microg ml(-1)). Synergistic activity was also observed between CAY-1 and amphotericin B against Candida albicans and A. fumigatus. No significant cytotoxicity was demonstrated when CAY-1 was tested against 55 mammalian cell lines at up to 100 microg ml(-1). Importantly, CAY-1 appears to act by disrupting the membrane integrity of fungal cells.