Extracting flavonoids from Smilax glabra by microwave-assisted method]

OBJECTIVE: To optimize the process of extracting flavonoids from Smilax glabra. METHODS: Flavonoids were extracted from Smilax glabra by microwave-assisted method, and the extracting time, microwave power, ethanol concentration, solid-solvent ratio and extracting temperature were optimized through single factor experiment and orthogonal test. RESULTS: The optimun process parameters of extracting flavonoids were as follows: the extracting time, microwave power, ethanol concentration, solid-liquid ratio and extracting temperature were 5 minutes, 600 W, 60%, 1:30 and 80 degrees C, respectively. CONCLUSION: The proposed method has been applied stably and reliably to the extraction of flavonoids from Smilax glabra which has the advantages of high recovery and short extraction time. The recovery, the yield and the content of falvonoids are 93.2%, 2.66% and 32.6%, respectively.     

Systolic cessation of the flow in the mid stent segment of the previously stented ostial vein graft with normal flow during diastole. A case report and brief review.

We present a case of intermittent cessation of blood flow through stent struts during systole, with normal flow during diastole in the previously stented ostial vein graft. After reviewing the initial procedure, we discovered that the operator had difficulty in positioning the stent. After stent deployment, the ostial stent was malpositioned and was protruding more than 50% into the aorta. During systole, the contrast in the stent struts, which are situated in the aorta, was being washed off by systolic blood flow, while in the diastole, the flow of contrast was normal. This is the first case report of this observation with a brief review.     

Resolution of homonymous visual field loss documented with functional magnetic resonance and diffusion tensor imaging.

A 68-year-old man developed right homonymous hemianopic paracentral scotomas from acute infarction of the left extrastriate area. He was studied over the ensuing 12 months with visual fields, conventional MRI, functional MRI (fMRI), and diffusion tensor imaging (DTI). As the visual field defect became smaller, fMRI demonstrated progressively larger areas of cortical activation. DTI initially showed that the lesioned posterior optic radiations were completely interrupted. This interruption lessened in time and had disappeared by one year after onset. fMRI and DTI are innovative measures to follow functional and structural recovery in the central nervous system. This is the first reported application of these imaging techniques to acute cerebral visual field disorders.     

新的高强度高选择性阿片μ受体激动剂[11C]-羟甲芬太尼的合成

羟甲芬太尼(I)是一个新的高强度高选择性阿片μ受体激动剂。本文用cis-A-N-[1-(2-羟基-2-苯乙基)-3-甲基-4-哌啶基]-苯胺(II)或cis-N-[1-(苯甲酰甲基)-3-甲基-4-哌啶基]-苯胺(III)作为前体合成了[¹¹C]-羟甲芬太尼,以便用正电子发射断层扫描(PET)来观察μ受体。通过水解cis-A-羟甲芬太尼(I)和cis-N-[1-(苯甲酰甲基)-3-甲基-4-哌啶]-N-苯基丙酰胺(cis-IV)的4-N-丙酰基分别获得II和III。溴乙烷的格氏试剂与回旋加速器产生的[¹¹C]-二氧化碳反应后继而直接加入邻苯二甲酸二酰氯和2,6-二叔丁基吡啶生成同位素标记中间体[¹¹C]-丙酰氯。[¹¹C]-丙酰氯与OH-前体(II)反应后再经HPLC分离纯化直接得[¹¹C]-羟甲芬太尼;[¹¹C]-丙酰氯与酮-前体(III)反应后,再用硼氢化钠甲醇溶液处理,然后进行HPLC分离纯化得[¹¹C]-羟甲芬太尼。两种方法均可获得ll.1～14.8GBq/μmol的特异性放射化学纯[¹¹C]-羟甲芬太尼。总共耗时为40～50min(EOB)。     

Comparison of dynamic and step-and-shoot intensity-modulated radiation therapy planning and delivery.

Intensity-modulated radiation therapy (IMRT) is commonly delivered using the dynamic or segmental mode of multileaf collimators (DMLC or SMLC). Both methods are designed to deliver intensity-modulated beams as determined by inverse planning software. In this study, we have used the Helios IMRT planning system to generate ideal treatment plans for 10 cases of 2 common treatment sites (prostate and head and neck) and have investigated the actual treatment fluence distributions generated for each of the MLC leaf motion choices. The 2 dose delivery techniques were dosimetrically compared to each other and to the treatment plans. For each technique, point doses were measured in a water phantom using ionization chambers. Also for each technique, 2-dimensional dose distributions at a selected depth in a plastic phantom were obtained, using extended range film. The total delivery time and the number of monitor units (MU) delivered by each method were also compared. Our results indicate that the 2 delivery methods produce comparable results dosimetrically. For the cases reviewed, the delivery time was an average of 15% longer for SMLC deliveries, while the number of MUs (beam-on time) required by SMLC was an average of 15% fewer, than that for the DMLC. In the interest of simplicity, lower beam-on time, and potentially fewer mechanically-related problems, we think that the SMLC delivery technique may be the better choice when Helios is used for planning and Varian linear accelerators are used for delivery.     

Emergence and scattering of multiple neurofibromatosis (NF1)-related sequences during hominoid evolution suggest a process of pericentromeric interchromosomal transposition

Type 1 neurofibromatosis (NF1) gene encodes for a member of the GTPase activating protein family and is considered to be a tumor suppressor gene. Its very high rate of de novo mutation in humans led us to study a specific feature of this gene: the presence of numerous NF1-related sequences. According to our results, the human genome contains at least 11 NF1-related sequences, nine of which are scattered near centromeric sequences of seven different chromosomes. These NF1-related sequences, whose extent is quite varied according to loci, are unprocessed copies of the NF1 gene, and bear numerous mutations. A phylogenetic analysis of the six largest sequences indicates that they are all derived from a common ancestor, which would have appeared 22-33 million years ago, and was subsequently duplicated several times during hominoid evolution. The most recent duplication and interchromosomal transposition occurred in the last million years suggesting that the process could still be ongoing. Intriguing similarities between the evolution of alpha- satellite DNA and NF1-related sequences suggest the involvement of a common genetic mechanism for the generation and pericentric spreading of these NF1 partial copies.      

Slipped capital femoral epiphysis: rationale for the technique of percutaneous in situ fixation

In pinning a slipped capital femoral epiphysis (SCFE), the position of the pin within the center of the femoral head is important for two reasons. The pin may disrupt the lateral epiphyseal artery and cause avascular necrosis (AVN), or pin penetration in certain locations may go unrecognized on radiographs. To place the pin accurately, the surgeon must be aware of where the femoral head lies in relation to the femoral neck and the shaft. Radiographs of models and of patients in various positions support the view that the femoral head in most cases of chronic SCFE rotates around the axis of the femoral neck and does not slip inferiorly. Therefore, the starting point for an in situ fixation device is the anterior femoral neck, the exact location depending on the amount of slipping.     

Characterization of adhesive interactions between human endothelial cells and megakaryocytes.

Cell-cell adhesion is essential for many immunological functions and is believed to be important in the regulation of hematopoiesis. Adhesive interactions between human endothelial cells and megakaryocytes were characterized in vitro using the CMK megakaryocytic cell line as well as marrow megakaryocytes. Although there was no adhesion between unactivated human umbilical vein endothelial cells (HUVEC) and megakaryocytes, treatment of HUVEC with inflammatory cytokines such as IL-1 beta, tumor necrosis factor alpha, INF-gamma, or the phorbol ester phorbol myristate acetate (PMA) resulted in a time- and dose-dependent increase in adhesion. Stimulation of marrow megakaryocytes or CMK cells with the cytokines IL-1 beta, GM-CSF, IL-6, IL-3, or PMA augmented their adhesion to endothelium. Monoclonal antibodies against the LFA-1 subunit of the leukocyte adherence complex CD18 inhibited the binding of marrow megakaryocytes or CMK cells to HUVEC. Adhesion blocking experiments also demonstrated that the VLA-4/VCAM-1 pathway was important for megakaryocyte attachment to HUVEC. Adhesion promoted maturation of megakaryocytic cells as measured by increased expression of glycoproteins GpIb and GpIIb/IIIa and by increased DNA content. These observations suggest that alterations in megakaryocyte adhesion may occur during inflammatory conditions, mediated by certain cytokines, resulting in augmented megakaryocyte maturation.     

正常人口腔粘膜不同部位表面感觉的测试

目的 建立正常人口腔粘膜不同部位表面感觉的正常参考值，并测试各年龄组感觉值是否存在差异。方法 利用动静两点辨别觉试验，测试90例健康人口腔粘膜不同部位的表面感觉。结果 舌尖感觉功能最好，其次为舌背、舌腹、颊粘膜、口底和硬腭。健康人的口腔粘膜不同部位的表面感觉随着年龄增长有显著性变化。结论 口腔粘膜不同部位感觉辨别力存在差异，健康人口底、舌腹、舌背、颊和硬腭粘膜感觉功能有增龄性变化。