In vivo determination of body fat by measuring total body carbon

Total body carbon (TBC) is measured in vivo by neutron inelastic scattering. The fast neutrons needed for the irradiation are produced by a miniature deuterium-tritium (D-T) neutron generator. Body fat and protein are the main contributors to TBC. Bone ash and carbohydrates contribute less than 3%. Fat is calculated from TBC after the subtraction of the carbon contributions from protein, bone, and glycogen. The technique was applied to 14 normal volunteers (8 females, 6 males) aged 24-94 y who underwent neutron inelastic scattering and neutron activation measurements for body carbon, nitrogen, and calcium. The initial results agree with other techniques. Unlike models that evaluate body fat by subtracting lean body mass from body weight, the TBC technique is not sensitive to assumptions on the composition of lean body; therefore, it is appropriate for studies of adults of any age and health condition.     

Inhibitory effects of benzoate on chiral inversion and clearance of N(G)-nitro-arginine in conscious rats.

N(G)-nitro-arginine (NNA) is known to exhibit stereoselective pharmacokinetics in which N(G)-nitro-d-arginine (d-NNA) has a faster clearance rate than N(G)-nitro-l-arginine (l-NNA) in anesthetized rats, and d-NNA undergoes unidirectional chiral inversion. It was postulated that chiral inversion of d-NNA was performed in a two-step pathway by d-amino acid oxidase (DAAO) followed by an unidentified transaminase. Such chiral inversion contributes (at least partially) to the pharmacokinetic stereoselectivity of NNA. This study used the selective inhibitor of DAAO, sodium benzoate, to test the above hypothesis. An i.v. bolus injection of d-NNA (32 mg/kg) and l-NNA (16 mg/kg) in conscious rats exhibited biphasic disposition with different pharmacokinetic parameters in a stereospecific manner (approximately 5-10-fold differences). Unidirectional chiral inversion of d-NNA but not l-NNA was found from these animals. In addition to its similar inhibitory effects on the d-NNA conversion and DAAO activity in kidney homogenates, sodium benzoate completely blocked chiral inversion of d-NNA and led to a smaller stereospecific difference, reflected by a nearly 50% reduction of d-NNA clearance and a 2-fold increase in t(1/2) and area under the curve of d-NNA in benzoate-pretreated rats. The results suggest that DAAO plays an essential role in chiral inversion of d-NNA and chiral inversion contributes mostly to the pharmacokinetic stereospecificity of NNA.     

Design of a bifunctional fusion protein for ovarian cancer drug delivery: single-chain anti-CA125 core-streptavidin fusion protein.

We have developed a universal ovarian cancer cell targeting vehicle that can deliver biotinylated therapeutic drugs. A single-chain antibody variable domain (scFv) that recognizes the CA125 antigen of ovarian cancer cells was fused with a core-streptavidin domain (core-streptavidin-VL-VH and VL-VH-core-streptavidin orientations) using recombinant DNA technology and then expressed in Escherichia coli using the T7 expression system. The bifunctional fusion protein (bfFp) was expressed in a shaker flask culture, extracted from the periplasmic soluble protein, and affinity purified using an IMAC column. The two distinct activities (biotin binding and anti-CA125) of the bfFp were demonstrated using ELISA, Western blot and confocal laser-scanning microscopy (CLSM). The ELISA method utilized human NIH OVCAR-3 cells along with biotinylated bovine serum albumin (B-BSA) or biotinylated liposomes, whereas, the Western blot involved probing with B-BSA. The CLSM study has shown specificity in binding to the OVCAR-3 cell-line. ELISA and Western blot studies have confirmed the bifunctional activity and specificity. In the presence of bfFp, there was enhanced binding of biotinylated antigen and liposome to OVCAR-3 cells. In contrast, the control EMT6 cells, which do not express the CA125 antigen, showed minimal binding of the bfFp. Consequently, bfFp based targeting of biotinylated therapeutic drugs, proteins, liposomes, or nanoparticles could be an alternative, convenient method to deliver effective therapy to ovarian cancer patients. Peritoneal infusion of the bfFp-therapeutic complex could also be effective in locally targeting the most common site of metastatic spread.     

Development and optimization of an indirect enzyme-linked immunosorbent assay for the determination of Hexoestrol

An indirect enzyme-linked immunosorbent assay (ELISA) for the detection of hexoestrol (HES) was developed, optimized and validated for the analysis of HES in pork. Many parameters, such as the volume ratio of solution A and solution B, colour developing time, pH value, incubation time, the volume ratio of the standard solution and diluted antiserum, blocking solution, blocking condition, coating solution and coating condition were studied and optimized in the paper. The regression equation of the final inhibition curve is y = - 0.3345x + 1.4955, R²=0.9913. The linear range is 0.1-8.1 ng/ml, and the IC₅₀ is 0.671 ng/ml. The specificity of the assay was evaluated by the cross-reactivity rates of six compounds, of which two structurally related compounds had a relatively higher cross-reactivity rate of 25% and 6%. HES was added into a pork sample at 5 ng/g level and then the sample was extracted. The recovery is between 49.6% and 79.2%, and the variation coefficient is 0.164.     

给药系统

近年来，伴随着药物治疗的快速发展．以药理活性非常强的药物为代表，开发出许多用药时必须给予足够关注的药物，“用药最适化”这一概念逐渐成为人们非常关注的问题。这主要是为了实现用药时的最佳形式。尽可能地根据选择或者需要控制药物的浓度．时间模式。输送到药物的作用表达部位。实现治疗用药的安全性。但是，历来的方法却很难实现这一点，通过利用新的技术和方法调控药物在体内的动态变化，以获得最好治疗效果为中心的药物使用方法和药剂正在开发之中。这就是给药系统，使用可以表达自身概念的语言来命名。虽然都是以各种药物在体内的动态过程作为调控对象，但是还分为①controlled release（调控释放给药）；②开发新的给药途径、克服药物吸收障碍；③靶向给药（targeting）等三个途径。     

Study on hemostatic mechanism of fully soluble hemostatic fiber.

Fully soluble hemostatic fiber (FHF) is made from cotton yarn through a series of chemical reactions with NaOH and chloroacetic acid. The major component of FHF is carboxymethylcellulose. FHF is a kind of biodegradation macromolecule material that can disassociate into a low-molecular-weight compound or a simple substance by hydrolytic and enzymatic courses. The purpose of the present study is to investigate the hemostatic mechanism of FHF. The study indicated that FHF can stop bleeding by physical, chemical and physiological routes. In the physical route, expansion of carboxymethylcellulose in FHF stops bleeding by forming a mechanical clog after contacting with the blood. In the chemical route, the platelets can quickly aggregate around FHF and stimulate releasing and disaggregating reactions, after contacting with the rough surface of FHF, producing thrombus and hemostasis. In the physiological route, gluey particles with negative charges can activate intrinsic coagulation systems by activating the blood coagulation factor XII after FHF dissolution.     

中、晚期肝癌并发脾功能亢进的介入治疗

目的 探讨肝癌介入治疗与部分脾动脉栓塞同时进行的疗效。方法 对18倒不能手术切除且经B超或CT确诊，脾肿大并有WBC、PLT明显低于正常的肝癌患者行PSE TACE或经导管肝动脉化疗(TAI)介入治疗，记录治疗前后WBC、PLT、甲胎蛋白(AFP)数值进行分析。结果 栓塞后3天、7天、60天WBC、PLT值明显升高，AFP值明显下降，临床症状明显改善。结论 PSE TAI或TACE治疗肝癌并脾功亢进是一种行之有效的办法。     

Roles of mast cells and PMN leukocytes in cardiotoxin-induced rat paw edema

Cardiotoxin, isolated from the venom of Naja naja atra, was found to cause rat hind-paw edema in a dose-dependent manner. This edematous response was significantly suppressed by pretreatment with diphenhydramine, methysergide or compound 48/80, which reduced the tissue histamine content. Polymorphonuclear (PMN) leukocyte infiltration appeared within 1 h and had accumulated markedly in the rat paw 3-6 h after subplantar injection of cardiotoxin. Methotrexate pretreatment significantly reduced not only the peripheral leukocyte count but also cardiotoxin-induced paw edema. Captopril, a kininase inhibitor, potentiated the edematous response caused by a low dose of cardiotoxin. The initial phase, occurring within 3 h, of paw edema induced by cardiotoxin was suppressed by trasylol, [Thi5,8,D-Phe7]bradykinin, or by cellulose sulfate pretreatment which greatly reduced plasma kininogen levels. Both mast cells and PMN leukocytes possess kinin-forming activities, but with different properties. The kinin-forming activity of mast cells but not of PMN leukocytes was inhibited by trasylol. In isolated mast cells, cardiotoxin caused a dose-dependent release of histamine, beta-glucuronidase, lactate dehydrogenase and kinin-forming activity. These observations suggest that mast cells and PMN leukocytes are involved in cardiotoxin-induced paw edema, and that inflammatory mediators such as histamine, serotonin and kinins were supplied directly or indirectly by mast cells, at least in the initial phase.