双黄连气雾剂稳定性的研究

采用高压液相色谱法测定了双黄连气雾剂中绿原酸与黄芩甙的含量,应用恒温加速实验法探讨了双黄连气雾剂的化学动力学过程,预测其稳定性,实验结果与留样观察法相近,同时对双黄连在降解过程中pH的变化进行了考察。     

Stereotaxic Interstitial Laser Therapy of Early-Stage Breast Cancer

Abstract: Coagulation leading to fibrosis of mammo-graphically detected breast cancers by interstitial laser therapy was tested as an alternative to surgical removal. Availability of computerized stereotaxic digital imaging allows the precise placement of laser and thermal needles into the target tumor and its controlled ablation by heat. The methodology of interstitial laser therapy (ILT), evolution of the subsequently removed tumors, and their histologic appearance are outlined.
Eight patients with mammographically well-defined tumors were selected. Definitive diagnosis and receptor evaluation were made on core biopsies. Under local anesthesia, stereotaxically guided diode laser energy at 5–10 w was delivered via a 400 xm fiber in a 19-gauge needle placed into the center of the tumor until the peripheral temperature exceeded 60°C. Patients experienced transient pain and pyrexia. Subsequent to ILT, seven invasive carcinomas were excised while one case of multiple papillomas was kept under surveillance. Histologic study revealed central necrosis but some peripheral residual tumor in the first five cases. In the last two, central necrosis surrounded by concentrically arranged, recognizable but severely injured, focally "windswept" and "ghostlike" tumor and granulation tissue were noted. The multiple papillomas showed radiologic shrinkage at 5 months and extensive fibrosis on needle biopsy.
ILT is an attractive new method of treating small, well-defined breast tumors and offers a potentially significant alternative to surgical removal; further exploration is warranted.     

Damping characteristics of bone‐to‐implant interface; A clinical study with the Periotest® device.

The Periotest® device was used to evaluate the damping characteristics of different bone‐to‐implant interfaces of Brånemark implants. Implant and abutment lengths were found to have a significant influence on Periotest value (PTV). There was no statistical difference between PTVs of implants located in the anterior and posterior areas of the same jaw at abutment connection. No differences were found between PTVs of standard and self‐tapping implants. PTVs at abutment connection were highly influenced by the bone quality. The contact with two corticals, one at each extremity of the implant, was of a greater influence in the maxillary than in the mandibular jaw, indicating a firmer anchorage between the bicortical implants and the surrounding bone. A proaressive decrease of PTVs over time was observed, significant up to 5 years of loading.     

Temporal stability of lipid responses to acute psychological stress in middle-aged men

The purpose of this study was to establish the temporal stability of lipid responses to acute psychological stress. Eighteen men were tested twice an average of 16.2 months apart in identical laboratory reactivity protocols. Total cholesterol, triglycerides, high- and low-density lipoprotein-cholesterol, plasma volume, heart rate, and blood pressure were assessed during rest, serial subtraction, and speech. After correction for changes in plasma volume, significant elevations were recorded for all variables during the speech task, but fewer variables showed changes during the serial subtraction task. Strong intersession associations were found when considering levels of the variables during baseline and stress (rs≥58). Correlations for the change scores ranged from .36 to .52 for the atherogenic lipids and from .39 to .87 for the cardiovascular variables. Little evidence was found for stability of plasma volume changes. There is moderate to high temporal stability of the atherogenic lipids when considering rest and stress levels and small to moderate temporal stability when considering change scores.     

Does a tensioning device pinned to the tibia improve knee anterior–posterior load‐displacement compared to manual tensioning of the graft following anterior cruciate ligament reconstruction? A cadaveric study of two tibial fixation devices

Devices that are pinned to the tibia to tension an anterior cruciate ligament (ACL) graft produce joint reaction loads that in turn can affect the maintenance of graft initial tension after tibial fixation and hence knee anterior-posterior (AP) load-displacement. However, the effect of these devices on AP load-displacement is unknown. Our objectives were to determine whether tensioning by device versus tensioning by hand causes differences in AP load-displacement and intraarticular graft tension for two commonly used tibial fixation devices: a bioresorbable interference screw and a WasherLoc. AP load-displacement and intraarticular graft tension were measured in 20 cadaveric knees using a custom arthrometer. An initial tension of 110 N was applied to a double-looped tendon graft with the knee at extension using a tensioning device pinned to the tibia and a simulated method of tensioning by hand. After inserting the tibial fixation device, the 134 N anterior limit (i.e., anterior position of the tibia with respect to the femur with a 134 N anterior force applied to the tibia) and 0 N posterior limit (i.e., AP position of the tibia relative to the femur with a 0 N force applied to the tibia) were measured with the knee in 25 degrees flexion. Intraarticular graft tension was measured at extension. These limits and intraarticular graft tension were also measured after cyclically loading the knee 300 times. Compared to a simulated method of tensioning by hand, tensioning with a device pinned to the tibia did not decrease the 134 N anterior limit and did not cause posterior tibial translation. However, intraarticular graft tension was maintained better with a tensioning device pinned to the tibia for the Washerloc, but not the interference screw. For two commonly used tibial fixation devices, a tensioning device pinned to the tibia does not improve AP load-displacement at 25 degrees flexion over tensioning by hand when the graft is tensioned at full extension, but does improve the maintenance of intraarticular graft tension for the Washerloc.     

头孢哌酮钠在醋酸钠平衡液中的稳定性

考察了头孢哌酮钠在醋酸钠平衡液中的稳定性。二药配伍后，置室温（２５℃）及３７℃水浴中，６ｈ内溶液无颜色改变，亦无沉淀、气体产生，头孢哌酮钠均在初始浓度的９５％以上。     

大肠杆菌表达耐热DNA聚合酶的纯化和鉴定

目的探讨工程菌表达的耐热ＤＮＡ聚合酶的纯化方法。②方法收集ＩＰＴＧ诱导带有耐热ＤＮＡ聚合酶（ＴＤ聚合酶）基因表达质粒的工程菌株ＤＨ－ＴＤ４，用溶菌酶裂解，６０℃处理后，上清液用硫酸铵沉淀，根据溶解度差异进行粗分级，然后进行离子交换层析细分级，并经聚合酶链式反应（ＰＣＲ扩增）鉴定其活性。③结果纯化的ＴＤ聚合酶具有良好的聚合活性。④结论溶解度差异与离子交换层析是工程菌表达的耐热ＤＮＡ聚合酶纯化的主要步骤。基因工程制备的ＤＮＡ聚合酶可用于ＰＣＲ检测     

A protease inhibitor attenuates gastric erosions and microcirculatory disturbance in the early period after thermal injury in rats

The effects of camostat mesilate, a synthetic serine protease inhibitor on gastric microcirculation and active oxygen species generated by leucocytes from the gastric and jugular veins in the early period after thermal injury were assessed. Male Wistar rats were anaesthetized and a 30% full skin-thickness dorsal burn was inflicted. Camostat mesilate (100 mg/kg) was dissolved in distilled water and administered orally to rats 40 min before thermal injury (the camostat group). The control animals (the vehicle group) were administered distilled water orally. Rolling leucocytes as well as Monastral blue B deposits in venules were observed using in vivo microscopy. Active oxygen species were measured by chemiluminescence. Camostat mesilate decreased the total length of gastric erosion, venular deposits of Monastral blue B, and rolling of leucocytes in venules, and relatively increased luminol-dependent chemiluminescence activity generated by zymosan-stimulated leucocytes 15 min after thermal injury. These results suggest that serine proteases are involved in the formation of gastric erosions and gastric microcirculatory disturbance in the early period after thermal injury.     

Oral Controlled Release Technology for Peptides: Status and Future Prospects

In spite of significant efforts in academic and commercial laboratories, major breakthroughs in oral peptide and protein formulation have not been achieved. The major barriers to developing oral formulations for peptides and proteins include poor intrinsic permeability, lumenal and cellular enzymatic degradation, rapid clearance, and chemical and conformational stability. Pharmaceutical approaches to address these barriers, which have been successful with traditional, small, organic drug molecules, have not readily translated into effective peptide and protein formulations. The success achieved by Sandoz with cyclosporin formulations remains one clear example of what can be achieved, although it is likely that effective oral formulations for peptides and proteins will remain highly compound specific. Although the challenges are significant, the potential therapeutic benefit remains high, particularly with the increasing identification of potential peptide and protein drug candidates emerging from the biotechnology arena. Successful formulations will most likely require a systematic and careful merger of formulation and design delivery systems which maximize the potential for absorption across the epithelial cell layer.