RESUMEN
Adapalene and tretinoin are molecules used in the topical treatment of acne vulgaris. Commercial formulations (adapalene 0.1% gel and tretinoin 0.025% gel) were mixed with equal volumes of commercially available benzoyl peroxide formulation (10% lotion) and subsequently exposed to light over 24 h. With and without exposition to light, adapalene exhibits a remarkable stability whereas tretinoin is very sensitive to light and oxidation. The combination of benzoyl peroxide and light results in more than 50% degradation of tretinoin in about 2 h and 95% in 24 h.
Asunto(s)
Antiinflamatorios no Esteroideos/efectos de la radiación , Peróxido de Benzoílo/efectos de la radiación , Queratolíticos/efectos de la radiación , Luz , Naftalenos/efectos de la radiación , Tretinoina/efectos de la radiación , Rayos Ultravioleta , Adapaleno , Antiinflamatorios no Esteroideos/química , Peróxido de Benzoílo/química , Cromatografía Líquida de Alta Presión , Combinación de Medicamentos , Estabilidad de Medicamentos , Geles , Queratolíticos/química , Naftalenos/química , Tretinoina/químicaRESUMEN
A high through-put method to assay for binding of retinoids to their cytosolic binding protein is described. The protein-bound retinoid is quantified following its complete separation from the free ligand by a single gel filtration chromatography step on Sephadex G-25 columns. The method allows a single person to process up to 100 samples per day. A new, substituted benzo[b]thiophene carboxylic acid derivative (tritiated) is proposed as an alternative ligand for cytosolic retinoic acid binding protein. This new analog (CD270), which contains no olefinic double bonds, is characterized by its chemical stability to light and atmospheric oxidation. This molecule shows binding characteristics similar to those of retinoic acid, both in terms of binding affinity and binding specificity (Kd of about 2 nM), and offers the additional advantage that the unbound molecule is absorbed on Sephadex G-25, while the protein-bound ligand is unaffected by the carbohydrate gel matrix. When the affinities of retinoic acid and several analogs were determined by competition binding experiments, similar results were obtained when either tritiated retinoic acid or tritiated CD270 were used as the labeled ligand. The tritiated, heterocyclic retinoic acid analog, CD270, is thus proposed as an alternative ligand for cytosolic retinoic acid binding protein.
Asunto(s)
Proteínas Portadoras/análisis , Citosol/análisis , Ligandos , Animales , Sitios de Unión , Unión Competitiva , Cromatografía en Gel , Masculino , Ratas , Receptores de Ácido Retinoico , Testículo/análisisRESUMEN
The social sciences have made few direct empirical contributions to the understanding of 'non-specific' benefits of treatment and generally the symbolic healing of indigenous non-Western medicine has received most attention in this field. This paper reports some results of a wider study of neurological clinics in England in which it is shown that a sample attending for headaches experienced considerable improvement in symptoms when followed up 1 year after attendance. Most of this improvement appeared not to be due to any intended treatments received at the clinics but could be attributed to the quality of patients' immediate responses to clinic attendance as assessed from reach interviews conducted after their consultations. This relationship between immediate 'satisfied' response and subsequent symptomatic improvement is interpreted in terms of the general levels of expectancy and sense of potential control achieved by obtaining referral to a specialist which directly enhanced recovery in those patients who felt the doctor's actions to be directly relevant to their personal concerns. Disappointment with the doctor reduced the 'non-specific' therapeutic benefits of the hospital referral. The intimate connections of patient satisfaction, treatment received and subsequent outcomes need more careful consideration in social studies of Western medicine.
Asunto(s)
Cefalea/terapia , Comportamiento del Consumidor , Estudios de Seguimiento , Cefalea/psicología , Investigación sobre Servicios de Salud , Humanos , Estudios Longitudinales , Relaciones Médico-PacienteRESUMEN
A representative sample of 130 people was interviewed shortly following self-poisoning or self-injury. The interview method is described. Events in the week prior to the attempt, and the incidence of various kinds of chronic problems are reported. Events involving key relationships were much more common than other kinds. The most important event was a quarrel, particularly in the 48 hours prior to the attempts and more common with female than with male attempters. The possible relevance of quarrels to understanding overdose behaviour is discussed. Nearly a third were receiving non-psychiatric treatment at the time of the 'attempt'. Approximately one quarter were currently receiving psychiatric treatment and a half had received it at some time. A substantial proportion had been admitted to either psychiatric or non-psychiatric hospitals within the past year. The proportions indicating the need for various kinds of help are reported. Most people said they needed 'someone to talk to'. More than half had been in contact with some form of helping agency during the week prior to the attempt. The possible significance of these findings is discussed. An attempt was made to look for 'syndromes' or groupings of problems. The resulting analysis, whilst of interest, did not lead to a satisfactory method for classifying individuals. It was concluded that a more satisfactory typology of 'attempters' is likely if types of relationship problems are investigated in more detail.