Estudio clínico para evaluar el efecto de dos cremas humectantes con protector solar en la piel de pacientes que utilizan tretinoína0, 025% para el tratamiento del fotodaño / Clinical study to evaluate the effect of two facial moisturizer test products

Introducción: La exposición a la radiación ultravioleta (RUV) produce un deterioro en la piel denominado fotodaño, que puede mejorarse con la aplicaciónde tretinoína. Este tratamiento, sin embargo, puede causar efectos colaterales.El objetivo es comparar las diferencias en la eficacia, tolerancia y preferencias al utilizar tretinoína al 0,025%, junto con dos productos hidratantes diferentes.Materiales y métodos: Estudio abierto, prospectivo, doble ciego, randomizado. Cincuenta y siete mujeres de 35 a 55 años, con daño solar, se aplicaronen el período de pre-condicionamiento, una crema humectante en cada hemicara: una con niacinamida y otra sólo con componentes hidratantes.Luego, se agregó tretinoína tópica al 0,025%. Se evaluó fotodaño, tolerancia y preferencias.Resultados: En el período de precondicionamiento no se hallaron diferencias significativas en la tolerancia. La pérdida trans epidérmica de agua(PTEA) fue significativamente peor para el humectante B. La textura de la piel mejoró significativamente para ambos humectantes. En el período detratamiento la tolerancia disminuyó más para el humectante B en las semanas 2 y 4, mejorando al final del estudio. Los parámetros relacionados confoto daño mejoraron, más para el humectante A.La PTEA aumentó en las semanas 2 y 4, más para el humectante B; para luego disminuir.Comentario: La tretinoína tópica es bien tolerada, cuando se la utiliza en combinación con cremas humectantes. La niacinamida agrega beneficios ala acción hidratante de un producto, ya que cumple un rol en la prevención de efectos adversos y en la potenciación de los efectos beneficiosos delretinoide (AU)

Introduction: Ultraviolet radiation exposure cause a deleterious effect in the skin called photodamage. Tretinoin application can improve this damage,however it can also cause adverse effects. The objective of this paper is to compare the differences in tolerance and patient preference when usingtretinoin 0.025% along with two different moisturizers.Material and methods: It was and open, prospective, randomized, double blinded study. Fifty sevenwomen, 35 to 55 year old with photodamagedskin, applied during a preconditioning period a different moisturizer in each side of the face. One of them contained niacinamide and the other onlyhydrating components. After 15 days topical tretinoin 0,025% was added. Efficacy, tolerance and preferences were evaluated.Results: We didn’t find significative differences in tolerance during the preconditioning period. Transepidermal water loss (TEWL) was significativelyworse for moisturizer B. Skin texture improved for both used products. During the treatment period, tolerance was worse for moisturizer B in weeks 2 and 4. There was a more important improvement in photodamage related items for moisturizer A. TEWL were high for both products in weeks 2 and4, diminishing afterwards. This elevation was higher for moisturizer B.Comment: topical tretinoin is well tolerated when used in combination with moisturizer creams. Niacinamide adds benefits because it helps preventingadverse events and promote desirable anti age effects of the retinoid (AU)

Continuous-flow optical pumping NMR in a closed circuit system.

In a typical continuous-flow optical pumping setup, the chemical shift of xenon in the adsorbed phase depends on the gas flow rate due to warming of the sample surface by the gas stream. Calibration of the system using the (207)Pb resonance of solid lead nitrate is necessary to determine the actual sample temperature. Optimum pulse repetition rates are strongly affected by gas flow and spin-lattice relaxation rates. The interplay of flow and pulse repetition rate alters signal intensity ratios and may lead to the complete suppression of signals.

Cloning and characterization of a novel sequence-specific single-stranded-DNA-binding protein.

The promoter region of the chicken alpha2(I) collagen gene contains a pyrimidine-rich element that is well conserved in different mammalian species. This sequence can also form an unusual DNA structure as shown by its sensitivity to SI nuclease in vitro and it lies in a region that is DNase I-hypersensitive only when this promoter is active. We have recently reported that fibroblast nuclear proteins, including chicken Y-box-binding protein 1, bind to this single-stranded pyrimidine-rich sequence. Here we report the isolation, from a chick embryo fibroblast cDNA expression library, of a partial cDNA clone encoding a previously unknown protein, designated SSDP (sequence-specific single-stranded DNA-binding protein), that binds this single-stranded sequence. This clone contains 1199 bp of chicken sequence and has a single long open reading frame that encodes 284 amino acid residues. The affinity-purified recombinant protein encoded by this cDNA binds sequence-specifically to the single-stranded pyrimidine sequence. This cDNA sequence lacks significant similarity to any known gene in the data banks, but it is highly conserved in expressed sequence tags derived from both mouse and human. The corresponding amino acid sequence is remarkably conserved, having 97% identity with mouse and human expressed sequences. The corresponding mRNA is approx. 1800 nt in length and is expressed in both fibroblasts and chondrocytes. The high affinity of this protein for this conserved pyrimidine-rich region suggests that it might be involved in the transcriptional regulation of the alpha2(I) collagen gene.

Effects of ketoconazole on the iodide uptake by FRTL-5 cells.

Ketoconazole is an imidazole derivative used as an antimycotic agent with reported effects on the endocrine system, but very little is known about its possible actions on thyroid function. Our purpose was to study the influence of this substance on the basal and TSH-stimulated iodide uptake in the rat thyroid cell strain FRTL-5. Ketoconazole (1-50 mumol/l) was shown to slightly increase the basal iodide uptake but, at higher concentrations (75-100 mumol/l), it sharply decreased iodide uptake below the basal levels. When the cells were cultured under bTSH stimulation (30 UI/l), the inhibitory effect of ketoconazole was exerted at concentrations as low as 25 mumol/l. This inhibition was observed even if it was added to the culture medium immediately before the Na125I addition. Forskolin, a stimulator of adenylate cyclase activity, was unable to prevent the iodide uptake inhibition. Low doses of ketoconazole increased cAMP concentrations. In the presence of TSH this effect was more evident in an inverse dose-dependent way. Because of its dual action, it can be assumed that ketoconazole could influence the iodide uptake in the FRTL-5 cells through more than one mechanism.

Graves' disease: evolution and prognosis after eight months of treatment with methimazole

We studied 26 patients with Graves' disease, from a population with sufficient iodine supply, treated with high doses of methyl mercaptoimidazole (MMI) during eight moths. We evaluated: a) their evolution after treatment withdrawal; b) the correlation between evolution and TSH-receptor antibodies (TRAb), thyroid hormone levels, microsomal antibodies (MAb), T3/T4 index and clinical data; c) their prognosis. The patients were followed during 12-60 months, and blood samples were collected before treatment withdrawal. Out of 26 patients, 20 relapsed, with T3/T4 index and TRAb significantly higher than those under remission. The T3/T4 index correlated with TRAb. All the TRAb-positive patients, and only 57.1% of the negatives, relapsed. The relapses were significantly more frequent prior to the 6th month in the TRAb-positive patients than afterwards. The TRAb-negatives who relapsed during that period, showed TRAb and age means significantly higher than those under remission. The TRAb test, as a prognostic marker of evolution, showed a sensitivity of 60% and a specificity of 100%. No significant differences were found between evolution to relapse or to remission and the other parameters. It can be concluded that TRAb and T3/T4 index were different in the group that relapsed from that which remitted, and that a TRAb positive value, at the moment of treatment withdrawal, is a useful marker of relapse

Graves disease: evolution and prognosis after eight months of treatment with methimazole

We studied 26 patients with Graves disease, from a population with sufficient iodine supply, treated with high doses of methyl mercaptoimidazole (MMI) during eight moths. We evaluated: a) their evolution after treatment withdrawal; b) the correlation between evolution and TSH-receptor antibodies (TRAb), thyroid hormone levels, microsomal antibodies (MAb), T3/T4 index and clinical data; c) their prognosis. The patients were followed during 12-60 months, and blood samples were collected before treatment withdrawal. Out of 26 patients, 20 relapsed, with T3/T4 index and TRAb significantly higher than those under remission. The T3/T4 index correlated with TRAb. All the TRAb-positive patients, and only 57.1% of the negatives, relapsed. The relapses were significantly more frequent prior to the 6th month in the TRAb-positive patients than afterwards. The TRAb-negatives who relapsed during that period, showed TRAb and age means significantly higher than those under remission. The TRAb test, as a prognostic marker of evolution, showed a sensitivity of 60% and a specificity of 100%. No significant differences were found between evolution to relapse or to remission and the other parameters. It can be concluded that TRAb and T3/T4 index were different in the group that relapsed from that which remitted, and that a TRAb positive value, at the moment of treatment withdrawal, is a useful marker of relapse (Au)

Graves' disease: evolution and prognosis after eight months of treatment with methimazole.

We studied 26 patients with Graves' disease, from a population with sufficient iodine supply, treated with high doses of methyl mercaptoimidazole (MMI) during eight moths. We evaluated: a) their evolution after treatment withdrawal; b) the correlation between evolution and TSH-receptor antibodies (TRAb), thyroid hormone levels, microsomal antibodies (MAb), T3/T4 index and clinical data; c) their prognosis. The patients were followed during 12-60 months, and blood samples were collected before treatment withdrawal. Out of 26 patients, 20 relapsed, with T3/T4 index and TRAb significantly higher than those under remission. The T3/T4 index correlated with TRAb. All the TRAb-positive patients, and only 57.1% of the negatives, relapsed. The relapses were significantly more frequent prior to the 6th month in the TRAb-positive patients than afterwards. The TRAb-negatives who relapsed during that period, showed TRAb and age means significantly higher than those under remission. The TRAb test, as a prognostic marker of evolution, showed a sensitivity of 60% and a specificity of 100%. No significant differences were found between evolution to relapse or to remission and the other parameters. It can be concluded that TRAb and T3/T4 index were different in the group that relapsed from that which remitted, and that a TRAb positive value, at the moment of treatment withdrawal, is a useful marker of relapse.

Graves disease: evolution and prognosis after eight months of treatment with methimazole.

We studied 26 patients with Graves disease, from a population with sufficient iodine supply, treated with high doses of methyl mercaptoimidazole (MMI) during eight moths. We evaluated: a) their evolution after treatment withdrawal; b) the correlation between evolution and TSH-receptor antibodies (TRAb), thyroid hormone levels, microsomal antibodies (MAb), T3/T4 index and clinical data; c) their prognosis. The patients were followed during 12-60 months, and blood samples were collected before treatment withdrawal. Out of 26 patients, 20 relapsed, with T3/T4 index and TRAb significantly higher than those under remission. The T3/T4 index correlated with TRAb. All the TRAb-positive patients, and only 57.1

of the negatives, relapsed. The relapses were significantly more frequent prior to the 6th month in the TRAb-positive patients than afterwards. The TRAb-negatives who relapsed during that period, showed TRAb and age means significantly higher than those under remission. The TRAb test, as a prognostic marker of evolution, showed a sensitivity of 60

and a specificity of 100

. No significant differences were found between evolution to relapse or to remission and the other parameters. It can be concluded that TRAb and T3/T4 index were different in the group that relapsed from that which remitted, and that a TRAb positive value, at the moment of treatment withdrawal, is a useful marker of relapse.

Graves disease: evolution and prognosis after eight months of treatment with methimazole.

We studied 26 patients with Graves disease, from a population with sufficient iodine supply, treated with high doses of methyl mercaptoimidazole (MMI) during eight moths. We evaluated: a) their evolution after treatment withdrawal; b) the correlation between evolution and TSH-receptor antibodies (TRAb), thyroid hormone levels, microsomal antibodies (MAb), T3/T4 index and clinical data; c) their prognosis. The patients were followed during 12-60 months, and blood samples were collected before treatment withdrawal. Out of 26 patients, 20 relapsed, with T3/T4 index and TRAb significantly higher than those under remission. The T3/T4 index correlated with TRAb. All the TRAb-positive patients, and only 57.1

of the negatives, relapsed. The relapses were significantly more frequent prior to the 6th month in the TRAb-positive patients than afterwards. The TRAb-negatives who relapsed during that period, showed TRAb and age means significantly higher than those under remission. The TRAb test, as a prognostic marker of evolution, showed a sensitivity of 60

and a specificity of 100

. No significant differences were found between evolution to relapse or to remission and the other parameters. It can be concluded that TRAb and T3/T4 index were different in the group that relapsed from that which remitted, and that a TRAb positive value, at the moment of treatment withdrawal, is a useful marker of relapse.

An in vitro method for estimating ocular irritation.

Three variations of an in vitro assay system called EYTEX were evaluated by comparing maximum in vivo Draize scores for 70 experimental consumer product formulations. The EYTEX in vitro assay (EIA) was chosen for in-house evaluation because it is an economical, objective system that is easy to learn. In the present study, double-blind samples were tested at National Testing Corporation (Lab 1) and an in-house laboratory (Lab 2). All products were tested in the standard, membrane, and rapid membrane (RMA) EIA. Most samples qualified for the membrane and RMA EIA, whereas approximately half qualified for the standard EIA. Results from both Labs 1 and 2 were highly correlated. The RMA assay gave the best overall performance of the three assays. The RMA EIA demonstrated the best correlation with in vivo data and qualified the highest percentage of formulations. RMA showed a 7.5% false positive identification of irritants. False negatives or irritants not identified were 6.1%. The predictive value for identifying irritants was 89%. Specificity or the ratio of non-irritants giving negative results to the total was 84%. The ratio of positive irritants to the total or sensitivity was 93%. Based on these results, EIA has demonstrated value as a screening tool for a broad variety of consumer products. Advantages of EIA include the opportunity to test undiluted products, reduce animal use, and lower costs.

A correlative study between glucocorticoid receptor levels in human mononuclear leukocytes and biochemical data in Cushing's disease.

UNLABELLED: We determined glucocorticoid receptors in human mononuclear leukocytes in 9 patients with Cushing's disease, in order to correlate them with laboratory data. Receptors were measured by a whole-cell assay method, after incubation with [3H]-dexamethasone in the presence or absence of excess unlabelled hormone. In Cushing's disease, there were 4425 +/- 364 sites/cell (N = 9), similar to in the controls: 4473 +/- 476 (N = 10); average Kd was 2.42 +/- 0.52 nmol/l (N = 3) similar to in the controls: 2.0 +/- 0.20 nmol/l (N = 3). In Cushing's patients we found significant negative correlations between basal glucocorticoid receptors and: 1) morning blood cortisol (r = -0.67, P less than 0.05), and 2) 17-ketogenic steroids after 2 mg of dexamethasone (r = -0.85, P less than 0.01). No correlations were observed with afternoon blood cortisol, free urinary cortisol, basal and post-8-mg dexamethasone 17-ketogenic steroids, TRH-TSH area, urinary calcium, plasma glucose, or systolic blood pressure. CONCLUSIONS: In Cushing's disease, a subtle receptor down-regulation may exist, as suggested by the inverse relationship between glucocorticoid receptors and morning blood cortisol. Secondly, the relationship between basal receptors and 17-ketogenic steroids after 2 mg of dexamethasone suggests that glucocorticoid receptors in human mononuclear leukocytes could reflect the sensitivity of the nervous system-pituitary-adrenal axis to dexamethasone inhibition.

Variaciones de la función tiroidea expresadas por el cálculo del área bajo la curva de TRn-TSH / Variations of thyroid function expressed by the calculation of the area under the TRH-TSH curve

En este trabajo, tomando un método descripto por Ridgway y col. se analizaron pruebas de TRH-TSH con el objeto de: a) expresar este examen funcional mediante un valor numérico; b) establecer sus valores en sujetos normales; c) comparar la capacidad discriminativa de esta prueba en relación con otros parámetros de función y diagnóstico clínico, y d) estudiar la validez de una prueba corta estableciendo los tiempos más adecuados para la misma. El área bajo la curva de TRS-TSH discriminó perfectamente al grupo testigo (877 ñ 57 micronUI/ml1/min) de los tirotóxicos (145 ñ 25) y de los hipotiroideos (8846 ñ 1092). El análisis de las tiroideopatías eutiroideas mostró la presencia de dos grupos que se ubicaron funcionalmente uno entre los tirotóxicos y los testigos (266 ñ 17 micronUI/ml1/min) y otro entre los hipotiroideos y los testigos (2610 ñ 195). Estos eran dos grupos estadísticamente diferentes a los clásicamente conocidos, que no se podían diferenciar por los niveles séricos de T3 y T4, ya que estaban dentro de parámetros normales y a los que definimos como hipertiroideos subclínicos e hipotiroideos subclínicos, respectivamente. El análisis global de todas las curvas estudiadas mostró que de los cuatro parámetros de función analizados, T4, T3, TSH basal y área de TRH-TSH, el que mostró mayor poder discriminativo fue el último, pudiéndose establecer nueve estadios funcionales diferentes que abarcan toda una gama que va desde la tirotoxicosis franca hasta el hipotiroidismo manifiesto. Se buscó la correlación entre el área total y una área corta de 20 y 30min, siendo la misma altamente significaticva (r + 0,975; p <0,000001). El delta de TSH se produjo en el 77% de los casos entre los 20 y 30min en el 12,8% a los 40min. Se puede concluir que el cálculo del área bajo la curva de TRH-TSH es el método más válido para valorar función tiroidea

Variaciones de la función tiroidea expresadas por el cálculo del área bajo la curva de TRn-TSH / Variations of thyroid function expressed by the calculation of the area under the TRH-TSH curve

En este trabajo, tomando un método descripto por Ridgway y col. se analizaron pruebas de TRH-TSH con el objeto de: a) expresar este examen funcional mediante un valor numérico; b) establecer sus valores en sujetos normales; c) comparar la capacidad discriminativa de esta prueba en relación con otros parámetros de función y diagnóstico clínico, y d) estudiar la validez de una prueba corta estableciendo los tiempos más adecuados para la misma. El área bajo la curva de TRS-TSH discriminó perfectamente al grupo testigo (877 ñ 57 micronUI/ml1/min) de los tirotóxicos (145 ñ 25) y de los hipotiroideos (8846 ñ 1092). El análisis de las tiroideopatías eutiroideas mostró la presencia de dos grupos que se ubicaron funcionalmente uno entre los tirotóxicos y los testigos (266 ñ 17 micronUI/ml1/min) y otro entre los hipotiroideos y los testigos (2610 ñ 195). Estos eran dos grupos estadísticamente diferentes a los clásicamente conocidos, que no se podían diferenciar por los niveles séricos de T3 y T4, ya que estaban dentro de parámetros normales y a los que definimos como hipertiroideos subclínicos e hipotiroideos subclínicos, respectivamente. El análisis global de todas las curvas estudiadas mostró que de los cuatro parámetros de función analizados, T4, T3, TSH basal y área de TRH-TSH, el que mostró mayor poder discriminativo fue el último, pudiéndose establecer nueve estadios funcionales diferentes que abarcan toda una gama que va desde la tirotoxicosis franca hasta el hipotiroidismo manifiesto. Se buscó la correlación entre el área total y una área corta de 20 y 30min, siendo la misma altamente significaticva (r + 0,975; p <0,000001). El delta de TSH se produjo en el 77% de los casos entre los 20 y 30min en el 12,8% a los 40min. Se puede concluir que el cálculo del área bajo la curva de TRH-TSH es el método más válido para valorar función tiroidea (AU)