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糖皮质激素是临床上皮肤科医生处方最多的外用药物之一,自20世纪50年代问世以来,糖皮质激素极大改善了皮肤病的治疗效果,被誉为皮肤科药物治疗学的"里程碑"。但随着新型外用糖皮质激素不断问世和广泛应用,其在治疗疾病的同时不可避免带来了更多副反应。与抗生素一样,外用糖皮质激素是目前临床上滥用最为严重的药物之一。由于儿童生理和皮肤组织结构特点,外用糖皮     

Egg size and yolk steroids vary across the laying order in cockatiel clutches: A strategy for reinforcing brood hierarchies?

When a female bird begins incubation before clutch completion, the nestlings hatch sequentially, and a size hierarchy forms within the brood. This size hierarchy may be minimized or exacerbated through differential allocation of resources to eggs across the laying order. In this study, we characterize intra-clutch variation in cockatiel clutches by measuring egg mass, yolk mass, and concentrations of yolk testosterone, androstenedione, and corticosterone. Cockatiels are a long-lived member of the Psittaciformes. Because asynchronous hatching may reduce sibling competition and allow for extended development periods in long-lived birds, we predicted that female cockatiels would allocate maternal resources in a way that would reinforce the brood size hierarchy. Significant within-clutch differences in egg size and steroid concentrations were observed. Eggs at the end of the laying sequence were smaller and had significantly smaller yolks than eggs early in the laying order. Fifth-laid eggs, as well as first-laid eggs, contained significantly lower concentrations of testosterone than eggs in other positions of the laying sequence. No differences in yolk androstenedione concentration were observed. Yolk corticosterone concentrations increased linearly with laying order. Together, these patterns might reinforce the brood size hierarchy created by asynchronous hatching.     

Is a picture worth a thousand (forgotten) words?: neuroimaging evidence for the cognitive deficits in ‘chemo‐fog’/’chemo‐brain’

The diminution in cognitive function reported to occur in patients treated with adjuvant cancer chemotherapy (a phenomenon known as 'chemo-fog, 'chemo-brain' or similar designation) is supported with varying degrees of evidence by prospective and retrospective clinical studies. However, the cognitive deficits are often subtle and the methodologies used to measure them not consistent. Additionally, patients might be able to compensate for the deficits, thereby leading to underestimates of the problem by this type of assessment. For these reasons, direct neuroimaging techniques might provide additional insight. The relatively few such studies, and fewer electrophysiological studies, offer an alternative way to evaluate changes that might be related to cognitive deficits in patients treated with cancer chemotherapeutic regimens.     

The gastrointestinal effects that may follow the administration of theophylline reflect the pharmacodynamic profiles of both the parent drug and its metabolites

This study investigates the effect of theophylline along the rabbit gastrointestinal tract in comparison with the pharmacodynamic effect produced by the combined application of its three major metabolites. At concentrations up to 10^?3 m , theophylline relaxed, in a declining order from the lower oesophageal sphincter (LOS) to pylorus, all regions of the upper gastrointestinal tract, but only the ascending colon from the intestinal regions studied. At concentrations higher than 10^?3 m , instead of relaxing, theophylline strongly contracted the antrum and pylorus. In all three small intestinal regions, at concentrations up to 10^?3 m , theophylline produced a weak contraction, which at higher concentrations became very strong, and at 10^?2 m was comparable to that produced by a supramaximal dose of acetylcholine. The additive relaxing effect resulting from the combined application of the theophylline’s metabolites was, from oesophagus to pylorus, weaker than that produced by theophylline, while on the ascending colon it was comparable to that of the parent drug. In contrast, the additive contractile effect of the metabolites on the three small intestinal regions was four to five times higher the one produced by theophylline. In conclusion, this study shows that the additive effect of the combined application of theophylline’s major metabolites on the rabbit gastrointestinal tract plays a major role in the final response of the intestine, and a minor one in the final responses of the gastric regions, while both the parent drug and the metabolites contribute to the final responses of the oesophagus and LOS.     

Miglitol,a new α-glucosidase inhibitor

Miglitol (Bay m 1099, Bayer) is a second generation α-glucosidase inhibitor. It is a derivative of 1-desoxynojirimycin, and binds reversibly to the brushborder α-glucosidase enzymes. In contrast to its parent drug (acarbose, Bay g 5421, Bayer), miglitol is almost completely absorbed in the small intestine. It has to be taken with each main meal, and through its effect on carbohydrate digestion it blunts the postprandial blood glucose increase. Miglitol has no or a very small effect on fasting blood glucose levels. The blood-glucose lowering effects of miglitol in patients with Type 2 diabetes are lower than those of the frequently-used sulphonylurea compounds. Long-term studies show that a moderate average reduction of HbA1c of 0.3 - 0.7% point from baseline can be achieved. An advantage over sulphonylurea is the effect on serum insulin levels: miglitol therapy leads to slightly lower postprandial levels of serum insulin, whereas chronic sulphonylurea treatment usually increases serum insulin levels. This insulin-sparing effect may, in theory, lead to a lesser weight gain or even no weight gain and reduced risk of hypoglycaemia during chronic treatment. Long-term experience in Type 1 diabetic patients is limited. Similarly, miglitol may lead to reduced postprandial glucose excursions, slightly reduced insulin requirements and perhaps, as a consequence, a lower risk of hypoglycaemia. More long-term data are needed to fully assess to the clinical use of miglitol in these patients.     

Alternative Medicine Techniques Have Non-Linear Effects on Radiation Response and Can Alter the Expression of Radiation Induced Bystander Effects

Many so-called “alternative medicine” techniques such as Reiki and acupuncture produce very good outcomes for intractable pain and other chronic illnesses but the efficacy is often dismissed as being psychosomatic. However a plausible mechanism does exist i.e. that the treatments alter the electromagnetic fields in living organisms and thereby prevent or reduce activity of neurons which lead to the pain. Low doses of ionising radiation have similar effects on electromagnetic fields and are known to induce signaling cascades in tissues due to ion gradients. To test this hypothesis cell cultures were exposed to Reiki – like and to acupuncture – like treatments, both performed by qualified practitioners. The cells were exposed either before or after the treatment to x-rays and were monitored for production of direct damage or bystander signals. The data suggest that the alternative techniques altered the response of cells to direct irradiation and altered bystander signal mechanisms. We conclude that alternative medicine techniques involving electromagnetic perturbations may modify the response of cells to ionizing radiation. In addition to the obvious implications for mechanistic studies of low dose effects, this could provide a novel target to exploit in radiation protection and in optimizing therapeutic gain during radiotherapy.     

Cercarial Dermatitis

Cercarial dermatitis or “swimmers’ itch” is a maculopapular skin eruption associated with the penetration of the skin by cercaria of certain species of nonhuman schistosomes. It is globally distributed and affects those who work or play in fresh and salt water.

The etiology and epidemiology of the disease are similar to that of human schistosomiasis (bilharziasis). The trematode parasite passes through a life cycle that involves both warm-blooded and molluscan hosts.

The clinical manifestations of “swimmers’ itch” are principally associated with an intensely pruritic dermatitis that lasts five to ten days and becomes more severe with subsequent exposure. Prevention is directed toward control of the molluscan hosts and their supporting environment. Treatment is symptomatic.