雷公藤叶中二萜化合物的研究

从雷公藤(Tripterygium wilfordii)叶中分离出九个二萜化合物,经物理常数测定、化学反应、以及波谱数据分析,分别鉴定为雷公藤内酯酮(triptonide,1)、雷公藤内酯醇(triptolide,2)、雷公藤内酯二醇(tripdiolide,3);雷醇内酯(triptolidenol,4)、16-羟基雷公藤内酯醇(16-hydroxytriptolide,5)、雷公藤氯内酯醇(tripehlorolide,6)、雷藤内酯三醇(triptriolide,7),以及新化合物雷公藤内酯二醇酮(tripdiotolnide,8)和13,14-环氧9,11,12-三羟雷公藤内酯(13,14-epoxide 9,11,12-trihydroxytriptolide,9)。新化合物的生物活性正在研究。     

Phantom pain: A sensitivity analysis

Purpose: To analyse how decisions to dichotomise the frequency and impediment of phantom pain into absent and present influence the outcome of studies by performing a sensitivity analysis on an existing database.

Method: Five hundred and thirty-six subjects were recruited from the database of an orthopaedic workshop and filled out a questionnaire in which the following items were assessed: demographics, side, date, level and reason of amputation, presence and frequency of phantom sensations, phantom pain and stump pain, and impediment due to phantom pain.

Results: The prevalence of phantom pain ranged from 7 - 72% when different cut off points for the frequency of phantom pain were applied. The significance of the various risk factors for the prevalence of phantom pain changed when different cut off points were applied. Only stump pain and phantom sensations were significant risk factors for all cut off points. Risk factors for the impediment of phantom pain changed when different cut off points were applied and these risk factors were different from those for the prevalence of phantom pain.

Conclusion: The choice of cut off points influences the outcome of phantom pain studies considerably. This study provides some insight into the differences in prevalence and risk factors found in literature.     

The Significance of Endoscopically Placed Prostheses in the Management of Biliary Obstruction Due to Carcinoma of the Pancreas: Results of Nonoperative Decompression in 277 Patients

Nonoperative methods for decompressing the biliary tree obstructed by tumor offer viable alternatives to the use of surgery alone to palliate jaundice, pruritus, and impending cholangitis. Published data indicate that biliary drainage through endoscopic means may be superior to the percutaneous route, both being superior to surgical palliation in patients with unresectable pancreatic adenocarcinoma. We have inserted endoprostheses in 277 patients with carcinoma of the pancreas with a success rate of 89%. Eighteen percent of the patients were deceased in 30 days, however, there was no procedure related surgery or death. These results were achieved with a complication rate of only 21% (major = 4%). The occlusion rate was found to be 30% in 3 months. Patients were hospitalized for a mean of 3.5 days with a mean survival of 129 days. The advantages of endoscopic biliary drainage are as follows: low procedure related mortality, low incidence of major complications, and short hospital stay. In conclusion, given the short mean survival of patients with unresectable malignant biliary obstruction, nonsurgical decompression should be considered as primary treatment.     

Massive Bleeding from the Ileum: a Late Complication of Pelvic Radiotherapy

Recurrent massive hemorrhage from the ileum as a late complication of radiotherapy has not previously been documented. We describe two patients with a history of pelvic radiotherapy 18 months and 11 yr before, in whom the source of melena was localized to the small bowel preoperatively. Characteristic serosal appearances of ileal radiation injury were present at laparotomy and resection of the terminal ileum controlled the hemorrhage. Pathological study revealed no ulceration but multiple telangiectatic vessels in the tips of mucosal villi. This cause should be considered in patients with obscure gastrointestinal bleeding previously exposed to pelvic radiotherapy.     

Hippocampus development and function: role of epigenetic factors and implications for cognitive disease

Lagali PS, Corcoran CP, Picketts DJ. Hippocampus development and function: role of epigenetic factors and implications for cognitive disease. The hippocampus is a primary region of the brain controlling the formation of memories and learned behaviours. The ability to learn or form a memory requires a neuron to translate a transient signal into gene expression changes that have a long‐lasting effect on synapse activity and connectivity. Numerous studies over the past decade have detailed changes in epigenetic modifications under various learning paradigms to support a role for chromatin remodelling in these processes. Moreover, the identification of mutations in epigenetic regulators as the cause of mental retardation or intellectual disability (MR/ID) disorders further strengthens their importance to learning and memory. Animal models for many of these disorders are emerging and advancing our understanding of the molecular mechanisms linking epigenetic regulation and cognitive function. Here, we review how chromatin remodelling proteins implicated in MR/ID contribute to the development of the hippocampus and memory formation.     

Causes and Mechanisms of Nondipping Hypertension

Growing evidence indicates that nondippers have worsened cardiovascular outcomes than dippers. Ambulatory blood pressure monitoring with a lack of nocturnal BP fall (nondipping) have also been shown to be more closely associated with target organ damage and worsened cardiovascular outcome than in patients with essential hypertension with dipping pattern. The underlying pathogenetic mechanisms potentially linking nondipping with cardiovascular disease are not fully understood. There are multiple possible underlying pathophysiologic mechanisms in the impaired BP decline during the night. Extrinsic and intrinsic factors including abnormal neurohormonal regulation, lack of physical activity, nutritional factors such as increased dietary sodium intake, and smoking of tobacco have been implicated for blunted circadian rhythm of BP. Certain diseases such as diabetes and chronic renal diseases also affect the circadian BP rhythm. Currently, the clinical importance of nondipping is known well; however, the relationship between certain disease states and nondipping has not been fully explained yet. This paper will attempt to address to clarify the underlying basis for nondipping and the specific associations with various disease states.