中药白花前胡有效成分Pd－Ia的提取与分离

用甲醇提取白花前胡根茎，提取液经乙醚和水萃取，将其醚提部分经硅胶柱层析，用石油醚与丙酮梯度洗脱，可分离得到有效成分Ｐｄ－Ｉａ，并经理化常数和波谱数据鉴定。     

Interaction between the insulin receptor and Grb14: a dynamic study in living cells using BRET

Grb14 is a molecular adaptor that binds to the activated insulin receptor (IR) and negatively regulates insulin signaling. We have studied the dynamics of interaction of the IR with Grb14, in real time, in living HEK cells, using bioluminescence resonance energy transfer (BRET). Insulin rapidly and dose-dependently stimulated this interaction. Removing insulin from the incubation medium only resulted in a modest decrease in BRET signal, indicating that the interaction between the IR and Grb14 can remain long after insulin stimulus has disappeared. BRET saturation experiments indicated that insulin markedly increases the affinity between IR and Grb14, resulting in recruitment of the adaptor to the activated IR. In addition, using both BRET and co-immunoprecipitation experiments, we demonstrated that insulin induced the dimerization of Grb14, most likely as a result of simultaneous binding of two Grb14 molecules on the activated IR. We also investigated the relationships between IR, Grb14 and the protein tyrosine phosphatase PTP1B. We observed that insulin-induced BRET between the IR and PTP1B was markedly reduced by Grb14, suggesting that Grb14 regulated this interaction in living cells. Using site-specific antibodies against phosphorylated tyrosines of the insulin receptor, we showed that Grb14 protected the three tyrosines of the kinase loop from dephosphorylation by PTP1B, while favouring dephosphorylation of tyrosine 972. This resulted in decreased IRS-1 binding to the IR and decreased activation of the ERK pathway. Our work suggests that Grb14 may regulate signalling through the insulin receptor by controlling its tyrosine-dephosphorylation in a site-specific manner.     

Short-term Changes in Insulin Resistance following Weight Loss Surgery for Morbid Obesity: Laparoscopic Adjustable Gastric Banding versus Laparoscopic Roux-en-Y Gastric Bypass

Background: Laparoscopic adjustable gastric banding (LAGB) and laparoscopic Roux-en-Y gastric bypass (LRYGBP) both effectively treat the insulin resistance associated with type 2 diabetes mellitus (T2DM). Restriction of caloric consumption, alterations in the entero-insular axis or weight loss may contribute to lowering insulin resistance after these procedures. The relative importance of these mechanisms, however, following LAGB and LRYGBP remain unclear. The aim of this study was to compare directly the short-term changes in insulin resistance following LAGB and LRYGBP in similar populations of patients. Methods: Patient preference determined operation type. The Homeostasis Model Assessment for Insulin Resistance (HOMA IR) was used to measure insulin resistance. Preoperative values were compared to postoperative levels obtained within 90 days of surgery. Significant differences between groups were tested by ANOVA. Results: There were no significant preoperative differences between groups. The 56 LAGB patients had a mean age of 42.5 years (25.7-63), BMI of 45.5 kg/m² (35-66) and preoperative HOMA IR of 4.1 (1.4-39.2). 75% of LAGB patients were female and 43% had T2DM. The 61 LRYGBP patients had a median age of 39.9 years (22.1-64.3), BMI of 45.0 kg/m² (36-62), and preoperative HOMA IR of 5.0 (0.6-56.5). 79% of LRYGBP patients were women and 44.3% had T2DM. Median follow-up for LAGB patients was 45 days (18-90) and for LRYGBP patients 46 days (8-88 days). LAGB patients had a median of 14.8% excess weight loss (6.9%-37.0%) and LRYGB patients 24.2% (9.8%-51.4%). Postoperative HOMA IR was significantly less after LRYGBP, 2.2 (0.7-12.2), than LAGB, 2.6 (0.8-29.6), although change in HOMA IR was not significantly different. Change in HOMA IR for both groups did not vary with length of follow-up or weight loss but correlated best with preoperative HOMA IR (LAGB r=0.8264; LRYGBP r=0.9711). Conclusions: Both LAGB and LRYGBP significantly improved insulin resistance during the first 3 months following surgery. Both operations generated similar changes in HOMA IR, although postoperative HOMA IR levels were significantly lower after LRYGBP. These findings suggest that caloric restriction plays a significant role in improving insulin resistance after both LAGB and LRYGBP.     

Burn depths evaluation based on active dynamic IR thermal imaging--a preliminary study

Proper diagnostic assessment of burn wound depth is of the highest importance in selecting the mode of burn wound treatment. Several diagnostic methods--clinical and histopathological evaluation, as well as methods employing IR imaging--static thermography and active dynamic thermography (ADT)--are compared on the basis of in vivo experiments conducted on three domestic pigs (23 burn wounds). ADT is presented here as a new, reliable and quantitative method of assessing burn wound depth on the basis of discrimination of the thermal properties of burnt tissue. In the case of ADT registration of thermal images was performed following thermal pulse excitation. A series of captured infrared images was used as the basis for calculating the thermal time constant tau for each pixel. The parameter values were compared with histopathological and clinical assessments of burn depth. The mean value of tau was found for burns, which heal within 3 weeks (tau=12.08+/-1.94s) and for burns, which did not heal during this period (tau=9.07+/-0.68s), p<0.05. The accuracy, sensitivity and specificity of all the methods tested were compared, the best results coming from ADT. The ADT method is fast, non-invasive and relatively inexpensive, although it still requires further animal experimentation as well as clinical study to confirm the results.     

Mediator mechanisms of cathinone effects on animal behaviour

The effect of cathinone on the visual differentiation of cats was investigated by the method of defense conditioned reflexes. It was found that cathinone decreases the differentiation of both the short-term and prolonged visual stimuli. These effects of cathinone increase when the serotoninergic system is activated and decrease under dopaminergic system activation.     

测定极化聚合物膜的二阶非线性光学系数的新方法──偏振红外光谱法

本文报道在一维刚性取向气体模型基础上用偏振红外光谱测出的极化膜的取向度估算其二阶非线性光学系数α值的方法。方法表明,在目前采用的各种极化方法所能达到的极化效率范围内,取向因子可表示为     

5－羟色胺能神经在扬子鳄食管的配布

用ＡＢＣ法显示扬子鳄食管壁的５－羟色胺（５－ＨＴ）能神经。在肌内丛和粘膜下丛内见有５－ＨＴ能神经细胞。粗、细不等的膨体纤维在肌内交织成网，粘膜下层内散在的５－ＨＴ能神经细胞和膨体纤维围绕血管和伸向上皮之间。粘膜下层、固有层内还见有５－ＨＴ阳性反应的内分泌细胞和肥大细胞。实验结果对神经比较解剖学的研究、神经内分泌和神经免疫调节机制的研究提供了形态学依据。     

Regulation of lipid raft proteins by glimepiride- and insulin-induced glycosylphosphatidylinositol-specific phospholipase C in rat adipocytes

The insulin receptor-independent insulin-mimetic signalling provoked by the antidiabetic sulfonylurea drug, glimepiride, is accompanied by the redistribution and concomitant activation of lipid raft-associated signalling components, such as the acylated tyrosine kinase, pp59(Lyn), and some glycosylphosphatidylinositol-anchored proteins (GPI-proteins). We now found that impairment of glimepiride-induced lipolytic cleavage of GPI-proteins in rat adipocytes by the novel inhibitor of glycosylphosphatidylinositol-specific phospholipase C (GPI-PLC), GPI-2350, caused almost complete blockade of (i) dissociation from caveolin-1 of pp59(Lyn) and GPI-proteins, (ii) their redistribution from high cholesterol- (hcDIGs) to low cholesterol-containing (lcDIGs) lipid rafts, (iii) tyrosine phosphorylation of pp59(Lyn) and insulin receptor substrate-1 protein (IRS-1) and (iv) stimulation of glucose transport as well as (v) inhibition of isoproterenol-induced lipolysis in response to glimepiride. In contrast, blockade of the moderate insulin activation of the GPI-PLC and of lipid raft protein redistribution by GPI-2350 slightly reduced insulin signalling and metabolic action, only. Importantly, in response to both insulin and glimepiride, lipolytically cleaved hydrophilic GPI-proteins remain associated with hcDIGs rather than redistribute to lcDIGs as do their uncleaved amphiphilic versions. In conclusion, GPI-PLC controls the localization within lipid rafts and thereby the activity of certain GPI-anchored and acylated signalling proteins. Its stimulation is required and may even be sufficient for insulin-mimetic cross-talking to IRS-1 in response to glimepiride via redistributed and activated pp59(Lyn).     

Prediction of incident hypertension and arterial stiffness using the non–insulin‐based metabolic score for insulin resistance (METS‐IR) index

Hypertension is associated with insulin resistance (IR), metabolic syndrome (MS), and arterial stiffness. Non–insulin‐based IR indexes were developed as tools for metabolic screening. Here, we aimed to evaluate the novel non–insulin‐based Metabolic Score for IR (METS‐IR) index for the prediction of incident hypertension and arterial stiffness evaluated using pulse wave velocity (PWV) analysis, compared with other non–insulin‐based IR indexes. We evaluated two populations, a cross‐sectional evaluation of high‐risk individuals (n = 305) with a wide range of metabolic comorbidities and dyslipidemia in whom PWV measurement was performed and a 3‐year prospective cohort of normotensive individuals (N = 6850). We observed a positive correlation between METS‐IR and PWV in the cross‐sectional cohort, which was higher compared with other non–insulin‐based fasting IR indexes; furthermore, PWV values >75th percentile were associated with the upper tercile of METS‐IR values. In the prospective cohort, we observed an increased risk for incident hypertension for the upper METS‐IR tercile (METS‐IR ≥ 46.42; HR: 1.81, 95% CI: 1.41‐2.34), adjusted for known cardiovascular risk factors, and observed that METS‐IR had greater increases in the predictive capacity for hypertension along with SBP and the Framingham Hypertension Risk Prediction Model compared with other non–insulin‐based IR indexes. Therefore, METS‐IR is a novel non–insulin‐based IR index which correlates with arterial stiffness and is a predictor of incident hypertension, complementary to previously validated risk prediction models.     

Characterizing the Three‐Dimensional Orientation in Polymers using FT‐IR Spectroscopy with Linear Polarized Light

The quantity of absorbance of linear polarized light depends for a given wavelength on the angle between an absorbing transition moment vector and the electric vector of the polarized light. Fraser used this relationship to interpret the infrared dichroism in axially oriented polymers. This model can be extended to calculate the orientation in three dimensions by transforming the Fraser's equation into a P₂‐Legendre polynomial. As a result the orientation in three directions—f_x, f_y, and f_z—can be calculated directly from the individual absorbances measured with an electric vector along the axes of interest, the structural absorbance A₀ of the sample, and the angle of the transition moment vector in reference to the chain axis. Applying the f values into ‘Hermans’ Orientation function', it becomes possible to calculate the average angle of the chain axis with reference to the axes of interest.