Phospholipid fatty acids are the major constituents of the membranes of all living cells, and different groups of microorganism synthesize a variety of PLFA through various biochemical pathways. Several PLFAs can be used as "signatures" to analyze changes in microbial biomass and microbial communities structure. More and more PLFA method was used in soil microbial analysis. This article briefly reviewed the applications of PLFA methods in soil microbial analysis.

Objective To study the cause of mis-diagnosis on carcinoma of large intestine in young people. Methods We retrospectively reviewed and analyzed the diagnosis and treatment of 62 young people with carcinoma of large intestine from 1990 to 2002. Results Among 36 cases of rectal carcinomas, 7 were diagnosed as colonitis,5 as hemorrhoid,3 as dysentery and 2 as perianal abscess with anal fistula. Among 26 cases of colon carcinomas, 3 were diagnosed as periappendic abscess,2 as colonitis and 1 as iron deficiency anemia.The rate of mis-diagnosis was 37 1%. Conclusions Carcinoma of large intestine in young people was a high malignant tumor with bad prognosis and little symptom in early stage. Surgeons should pay a great attention to the characteristic of this carcinoma to diagnose and treat early

Objective To explore the operative timing and cause of death in the patients with acute cholangitis of severe type(ACST). Methods The clinical data on the treatment and the prognosis of 116 patients with ACST were analyzed retrospectively. Results 10 cases died during perioperative period.The patients who received operation within 6 hours after toxic shock all survived.Of 8 cases who received operation after 24 hours,7cases died from toxic shock and multiple organ deficiency of function (MODF) within 4 days of post-operation. Conclusion Operation should be performed before toxic shock or mental symptom occurred in the patients with ACST. The earlier the operation was performed, and the better the prognosis was. The main causes of death were delayed operative time,severe complications and senility.

Objective To assess left ventricular systolic and diastolic function in patients with hypertrophic cardiomyopathy(HCM) with the aid of pulsed Doppler tissue imaging (DTI) to measure the four sides of mitral annular. Methods Thirty subjects with HCM and Twenty five age and sex matched controls were performed 2D and Doppler echocardiography . Two groups were studied with pulsed tissue Doppler imaging of the 4 sides of the mitral annulus (septal, lateral, inferior, anterior) in 4 and 2 chamber views. The velocities of systolic wave(Sa)、early diastolic filling wave (Ea)、late filling wave (Aa) and isovolumetric relaxation time were measured by DTI. Results Compared with normal control group, HCM group shows: (1) conventional data: LV wall thickness and mass indices were significantly greater. There were no significant difference in mitral flow Velocity. (2) DTI: There were more lower velocities of systolic and early diastolic filling wave. But isovolumetric relaxation time、mitra flow velocity / mitral annual early diastolic velocity ratio(E/Ea) increased. The velocities of systolic and early diastolic of septal site were the lowest among the 4 sides of the mitral annular and were the most closely with the average velocities of systolic and early diastolic of mitral annual. In addition, DTI may detect the pseudonormalization of mitral inflow. Conclusions DTI is more sensitive than conventional echocardiogram data and may be clinically used in exactly detecting left ventricular systolic and diastolic dysfunction in patients with HCM

Objective: To modify the pulsatile bioreactor we constructed previously for simulating the high-flow, high-pressure hemodynamics of heart valve in vivo, and to experimentally cultivate the tissue-engineered heart valves (TEHV) in the modified bioreactor. Methods: T-PLS system (NewheartBio Co., Ltd Korea) was used to generate pulsatile f1ow in the modified bioreactor and we designed a new air-exchange pathway to avoid contamination. The TEHV were made by seeding human bone mesenchymal stem cells (BMSCs) on de cellularized porcine heart valve. After cultured under static condition for 4 d, the TEHVs were moved to the modified bioreactor and exposed to low-flow (0-600 ml/min) or high-flow(0-4 800 ml/min) pulsatile hydrodynamics for 7d, then the cells on TEHVs were evaluated. Results: After modification, the flow range expanded from (0-1 200) ml/min to (0-6000) ml/min and the pressure range expanded from (0 40) mmHg to (0-180) mmHg. In culture experiments, 26.3% of the seeded cells remained under low-flow environment and cells were completely lost under the high-flow dynamics. Conclusion: The modified bioreactor can basically simulate the dynamics of heart valve in vivo and can be used in TEHV cultivation research. However, the current TEHV can not tolerate the high-flow pulsatile hydrodynamics.

Objective To explore the protective effect of co-treatment with antioxidants 4-hydroxy-2,2,6,6-tetra-methylpiperidine 1-oxyl (TEMPOL) and reduced glutathione (GSH) in pancreatic injury induced by intermittent hypoxia (IH) in mice. Methods Fifty male C57BL/6J mice were randomly divided into control group(CON), IH group (IH), IH+TEM-POL group (IH+TEMPOL), IH+GSH group (IH+GSH) and IH+TEMPOL+GSH group (IH+TEMPOL+GSH). After successful-ly prepared animal model, the insulin resistance (IR) level, pancreatic malondialdehyde (MDA) level,superoxide dismutase (SOD) activity,glutathione reductase (GR) concentration and pancreatic β-cell apoptosis were detected in five groups. Re-sults The blood glucose level was significantly increased in IH group than that in CON group (P<0.01), but which was sig-nificantly decreased in IH+TEMPOL+GSH group than that of IH group (P<0.01). The MDA content was significantly higher in the IH group than that in CON group (4.48±0.25 vs 1.94±0.21, P<0.01), but SOD activity and GR content were signifi-cantly lower in IH group than those of CON group (61.52±3.33 vs 100.05± 7.26,107.81±7.54 vs 170.54±4.90,P<0.01). The level of MDA was significantly lower in IH+TEMPOL+GSH group (2.07±0.35) than that in IH group. The levels of SOD and GR were significantly higher in IH+TEMPOL+GSH group (96.68±5.85 and 166.87±5.75) than those of IH group (P<0.01). The apoptotic rate of pancreaticβcells was significantly increased in IH group than that in CON group (2.43±0.07 vs 0.54± 0.06, P<0.01), but it was significantly lower in IH+TEMPOL+GSH group (0.56 ± 0.06) than that in IH group (P<0.01). There were no significantly differences in all above indexes between IH group, IH+TEMPOL group and IH+GSH group ( P>0.05). Conclusion The co-treatment with the antioxidant TEMPOL and GSH can obviously protect IH-induced pancreatic injury in mice. However, there was no significant protective effect of TEMPOL or GSH alone on pancreatic injury.

The specific ScFv gene against botulinum neurotoxin A (BoNTa)was cloned into pPIC9k. Positive integrators were screened by increasing the dose of G418 in culture and expressed in Pichia pastoris GS115. As a result, engineered recombinant clone were obtained. 26 kD product of interest was seen easily in SDS-PAGE. Expression of human ScFv got the highest level 15% of total secreted proteins during 72～84 h after 1% methanol inducing. Purification of ScFv was finished by two steps: gel filter and ion exchange. Competing ELISA showed that recombinant ScFv could compete with antiserum to specific bind BoNTa.

The carotene content of 63 kinds of plant materials including vegetables, grasses, wild plants and tree leaves were determined by the column chromatography method. Alfalfa, shepherd purse and carrot had the highest carotene content among the tested plants.Four methods were tried for the preparation of carotene concentrates. It was found that percolation with ethyl ether after grinding in ethanol showed the highest yield at low cost.The carotene content of the above mentioned concentrates was almost completely destroyed after 4 months when stored at room temperature and exposed to light. There was appreciable loss of the vitamin after 5 months' storage in the dark at low temperature (below 6℃), however, the loss was much smaller than that stored at room temperature. The loss of carotene was greatly reduced when the carotene concentrates were stored under nitrogen either at low temperature or at room temperature compared with those stored in the air. The addition of heated soy-bean meal to the carotene concentrate also considerably reduced the carotene loss during storage at room temperature.

Objective To investigate the feasibility and accuracy of velocity vector imaging(VVI)to assess strain and strain rate of right ventrieule(RV)during varying myocardial functional states.Methods VVI of the longitudinal RV were recorded in 7 closed-chest anesthetized mongrel dogs from the apical 4-chamber view during 3 different inotropic states.Peak dp/dt from the RV contraction during the right cardiac catheterization,which was used as the gold standard of RV contractility,was obtained simultaneously in each inotropic state.Peak systolic velocities(V), peak systolic strain rates(SR),peak systolic strains(S)at the basal, middle and apical segments of RV free wall and septal from the longitudinal axis were quantitatively measured by using VVI software system respectively.Results The peak systolic strain and strain rate of the longitudinal RV free wall and septal were increased with the infusion of dobutamine and decreased with the infusion of metoprolol.A significant correlation was found between peak RV dp/dt and RV mean strain and mean strain rate(r=0.79, 0.75;P <0.01).Among all RV segments, the peak systolic S,SR of RV basal free wall had the most significant correlation to peak dp/dt (r=0.83,0.78;P<0.01).Conclusions Strain rate imaging drived from VVI could quantitatively and sensitively detect the longitudinal RV contractile function.Peak systolic S and SR determined at the longitudinal RV basal free wall were the strong noninvasive indices of RV contractility.

Objective To characterize the systolic torsion in dilated cardiomyopathy (DCM) by velocity vector imaging(VVI).Methods Eighty-seven subjects were studied using VVI:27 patients with DCM and 60 healthy control subjects.Left ventricular short-axis acoustic images were acquired at base and apex levels.The rotation angle and rotation velocity of endocardium and epicardium were measured.Results LVEF of DCM group was significantly lower than that of control group ( P＜0.01).The basal and apical rotation angle, rotation velocity were significantly lower in DCM group.The endocardial and epicardial rotation angle, rotation velocity were also significantly lower in DCM group than those in control group (P＜0.01).Conclusions VVI is a rapid and noninvasive tool to quantitatively assess cardiac torsional deformation in DCM patients,which providing another useful modality for evaluating cardiac function.