柴胡皂甙q及其甙元的结构鉴定

从小叶黑柴胡(Bupleurum smithii Wolffvar;parvifolium ShanetY.Li)的根中得到3个化合物,柴胡皂甙元A和Q及柴胡皂甙q。柴胡皂甙元Q和柴胡皂甙q为新化合物,根据理化性质和波谱分析,确定其结构分别为齐墩果烷-11,13(18)-二烯-3β,16β,23,28,30-五醇和3β,16β,23,28,3O-五羟基齐墩果烷-11,13(18)-二烯-3-O-β-D-吡喃葡萄糖基(1→6)-[α-L-吡喃鼠李糖基(1→4)]-β-D-吡喃葡萄糖甙。     

The economics of primary prevention of cardiovascular disease – a systematic review of economic evaluations

Background

Global resource needs estimation is a critical part of addressing the HIV/AIDS epidemic. To generate these estimates knowledge of costs and cost structures is required. The evidence base for costs of HIV prevention programmes is limited. Even less is known about the existence of economies scale and whether, as economic theory suggests, average costs form a 'u'-shaped curve as scale increases. Using an econometric analysis, this paper addresses this question by estimating marginal costs and economies of scale for HIV prevention programmes for vulnerable groups in Southern India with different levels of coverage.

Methods

Two hybrid translog-cost functions were estimated. First, expenditure data from 78 state-funded HIV prevention projects in Andhra Pradesh were used to explore the impact of scale, institutional history and price on costs; second, economic cost data from 16 commercial sex worker projects across Tamil Nadu and Andhra Pradesh were analysed to additionally assess the impact of the value of inputs not reported in expenditure data and location. Coefficient estimates were used to calculate marginal costs and economies of scale.

Results

The econometric model yielded a good fit (R² = 0.46, p < 0.001 and R² = 0.79, p < 0.001, for the expenditure and economic cost datasets, respectively). The economies of scale index was greater than 1 for both datasets and fell as coverage increased. Analysis of the expenditure data found economies of scale were not exhausted, with a 0.002% change in total cost for each extra person reached and an 11% difference in total cost between target group categories. Estimation using the economic cost data suggests a point of minimum efficient scale at around 1750–2000 people reached, a 0.03% change in total cost for each extra person reached, and 28% lower costs in Tamil Nadu than Andhra Pradesh.

Conclusion

Econometric analysis of these standardized datasets provides insights into how costs change with coverage, the impact of project location and nature of the project target group. The results demonstrate the importance of understanding the nature of the cost function when designing, budgeting and estimating resource requirements for scaling up coverage of HIV prevention projects.     

Pediatric peripheral blood progenitor cell collection: haemonetics MCS 3P versus COBE Spectra versus Fresenius AS104

BACKGROUND: An increasing number of apheresis machines are becoming available for peripheral blood progenitor cell (PBPC) collection in children. STUDY DESIGN AND METHODS: At the Children's Hospital of Florence (Italy), three apheresis machines were evaluated: MCS 3P (Haemonetics) (10 procedures in 4 patients, aged 10–12 years, weight 23.5-64 kg), Spectra, (COBE) (8 procedures in 3 patients, aged 4–17 years, weight 19–59 kg), and AS104 (Fresenius) (24 procedures in 9 patients, aged 2–16 years, weight 13.6-60 kg). For PBPC quantitative analysis, CD34 cytofluorimetry was employed. Relevant variables analyzed included efficiency of CD34+ cell extraction and enrichment, mononuclear cell purity and red cell contamination of the apheresis components, and platelet count decreases after leukapheresis. RESULTS: No significant differences in CD34+ cell-extraction abilities were found. However, the AS104 provided consistently purer leukapheresis components in terms of mononuclear cell and CD34+ cell enrichment (441 +/− 59%, vs. 240 +/− 35% and 290 +/− 42% for MCS 3P and Spectra, respectively). Postapheresis platelet counts dropped the least with the AS104. The smallest patient who underwent apheresis with MCS 3P (the only machine working on discontinuous flow and hence with greater volume shifts) weighed 23.5 kg and tolerated the procedure well, with no signs of hemodynamic instability. No significant complications were observed. CONCLUSION: All machines seem to have comparable PBPC extraction efficiency, but the AS104 seems to give the component with the greatest PBPC enrichment. This feature might be relevant for further ex vivo cell processing (CD34+ cell selection, expansion, and so on).     

Recombinant human interleukin-3 stimulation of hematopoiesis in humans: loss of responsiveness with differentiation in the neutrophilic myeloid series

Recombinant human (rh) interleukin-3 (IL-3) stimulated the proliferation and differentiation of erythroid, granulocyte, macrophage, eosinophil (Eo), and mixed colonies as well as megakaryocytes from human bone marrow cells. rh IL-3 was a weaker stimulus than rh granulocyte-macrophage colony-stimulating factor (GM- CSF) for day 14 myeloid cell colonies. At day 7 of incubation, rh IL-3 stimulated a few G, M, and Eo clusters but no colonies. This loss of responsiveness of myeloid cells to rh IL-3 was accentuated with further differentiation of the cells. rh IL-3 stimulated very few or no clones after five-day incubation with enriched promyelocytes and myelocytes, whereas rh GM-CSF was an efficient stimulus. Responsiveness to rh IL-3 was completely lost in postmitotic mature neutrophils. Incubation of these cells with rh IL-3 did not result in enhanced antibody-dependent cell-mediated cytotoxicity (ADCC) of tumor cells or superoxide anion production after stimulation with formyl-methyl-leucyl-phenylalanine (FMLP), although they could be stimulated by rh GM-CSF. In addition, preincubation of neutrophils with different concentrations of rh IL-3 failed to increase or decrease their response to rh GM-CSF. In contrast to neutrophils, mature Eos could be stimulated by rh IL-3 to kill antibody-coated tumor cells. These results show that cells of the neutrophilic myeloid series lose their responsiveness to h IL-3 as they differentiate and suggest that although h IL-3 may be an important therapeutic agent to use for hematopoietic regeneration in vivo, the lack of stimulation of mature neutrophil function makes it an unlikely sole candidate as adjunct therapy for treatment of infectious diseases.     

Endothelial cell seeding of polytetrafluoroethylene vascular prostheses coated with a fibroblastic matrix

One of the most serious problems with endothelial cell (EC) seeding of prosthetic materials is the poor adhesion and stability of the cells. Although several substrates that improve the initial adhesion have been assayed, the EC are lost within a limited period of time. In this study we attempted to modify the hydrophobic conditions of expanded polytetrafluoroethylene (ePTFE) by treating it with ethanol prior to seeding. In addition, we created a fibroblastic matrix that was also fixed by ethanol to the prosthetic material. In vitro studies were carried out at intervals of 24 hours and 15 days after seeding. EC from umbilical cord vein and fibroblasts from skin were seeded onto disks of PTFE with a porosity of 30 µm. The results obtained show that treatment of ePTFE with ethanol prior to EC seeding modifies its permeability, preventing cellular adhesion. The seeding of fibroblasts onto ePTFE allows a coating to form at 24 hours. The EC seeded onto this matrix adhere to it, forming a monolayer that persisted throughout the entire study period. The fibroblastic matrix allows the long-term survival of the EC on ePTFE.Supported by a grant from the CICYT SAF 92-0875.     

Digital subtraction angiography of the thoracic aorta

Forty-three patients with acquired and congenital abnormalities of the thoracic aorta were studied using digital subtraction angiography (DSA) after an intravenous bolus injection of 40 ml of contrast material. Abnormalities studied included coarctation, pseudocoarctation, Marfan syndrome, cervical aorta, double aortic arch, aneurysm, dissection, and tumor. Twenty-four patients also had conventional angiography. DSA was accurate in 95% of cases; in the other 5%, involving patients with acute type I dissection, the coronary arteries could not be seen. The authors concluded that in 92% of their patients, DSA could have replaced the standard aortogram.     

Psychosocial health risk factors and resources of medical students and physicians: a cross-sectional study

Background  

Epidemiological data indicate elevated psychosocial health risks for physicians, e. g., burnout, depression, marital disturbances, alcohol and substance abuse, and suicide. The purpose of this study was to identify psychosocial health resources and risk factors in profession-related behaviour and experience patterns of medical students and physicians that may serve as a basis for appropriate health promoting interventions.     

Catheter ablation of accessory pathways, atrioventricular nodal reentrant tachycardia, and the atrioventricular junction: final results of a prospective, multicenter clinical trial. The Atakr Multicenter Investigators Group

BACKGROUND: The purpose of this study was to evaluate the safety and efficacy of a temperature-controlled radiofrequency catheter ablation system. METHODS AND RESULTS: The patient population included 1050 patients who had undergone ablation of atrioventricular nodal reentrant tachycardia (AVNRT), an accessory pathway (AP), or the atrioventricular junction (AVJ). Ablation was successful in 996 patients. The probability of success was highest among patients who had undergone ablation of the AVJ, lowest in patients who had undergone ablation of an AP, and in between for patients who had undergone ablation of AVNRT. A major complication occurred in 32 patients. Four variables predicted ablation success (AVJ, AVNRT, or left free wall AP ablation and an experienced center). Four factors predicted arrhythmia recurrence (right free wall, posteroseptal, septal, and multiple APs). Two variables predicted development of a complication (structural heart disease and the presence of multiple targets), and 3 variables predicted an increased risk of death (heart disease, lower ejection fraction, and AVJ ablation). CONCLUSIONS: These findings may serve as a guide to clinicians considering therapeutic options in patients who are candidates for ablation.