Objective: To develop a method in the determination of somatostatin level in blood for clinical medication. Methods: A method for the determination of somatostatin(Octreotide) in serum by high performance liquid chromatography with diode-array detector(DAD) was developed.After ultrafiltration,the pH values of blood samples were adjusted to 4,and samples were analyzed by Kromasil C18 column(4.6 mm? 250 mm,5 ?m i.d.) with a large pore(300) by acetonitrile/water/trifluoroacetic acid(20/80/0.01%,v/v) as mobile phase. Results:The recovery rate of Octreotide was 85%,and the calibration curve showed good linearity in the range of 0.006-0.5 mg/mL. Conclusion: The method is suitable for the detection of Octreotide content by liquid chromatography.

Objective To investigate the level of serum citrulline and its significance in the patients subject to intestinal transplantation. Methods Phenylisothiocyanate served as derivative reagent and the serum citrulline was determined by HPLC. Thirty-three healthy adults served as controls. Serum citrulline was measured in 2 cases of intestinal transplantation during different transplant periods. Results The serum citrulline level in 33 healthy adults was (16.87?5.97)?mol/L. Before operation, it was low (less than 10 ?mol/L) in the patients and after operation it reached to high levels and kept at higher levels. The maximium of serum citrulline was more than 30 ?mol/L in patient A and was over 50 ?mol/L in patient B. Following rejection, the serum citrulline level in patient A was decreased rapidly and simialr to that before operation and in patient B it was lower than that before operation. Conclusion The level of serum citrulline in intestinal transplantation patients was correlated with transplant rejection. More patients are reqiured for the further study.

Objective: Lactulose and mannitol excretion ratio in urine appears to be a marker to measure the intestinal permeability. Methods: A method has been developed for the simultaneous determination of lactulose and mannitol in urine by high performance liquid chromatography.After ultrafiltered and deionized,urine samples were analyzed with a lichrosher NH 2 column(4.6 mm?250 mm,i.d.,5 ?m),a mix of acetonitril water (72∶28,volume ratio) as mobile phase and refractive index detector. Results: The recoveries were 97.86%、 99.19% respectively and the relative standard deviation were 2.12、2.04.In 18 urine samples from healthy volunteers and patients who ingested the test solution containing 10 g lactulose and 5 g mannitol,the 6 h urinary excretion ratio of lactulose/mannitol was 0.0275?0.0113. Conclusions: It is suggested that lactulose and mannitol excretion ratio was anaccurate marker of intestinal permeability.

Objective: To compare the difference of Vitamin B in serum in healthy adults and patiens with Crohn's disease.Methods: 24 healthy adults and 20 patients were measured for Vitamin B1,B6,B12 in serum.A HPLC-DAD method was developed to determine vitamin B extracted directly from human serum.Purospher RP-18 column was used for the gradient elution with mobile phase: 0.04 mol phosphate buffer: methanol(60∶40).Results: The results proved to be linear in measurements of VB1,VB6 and VB12 and the correlation coefficients were 0.999 827,0.985 097 and 0.999 994,respectively.The contents of Vitamin B(VB1,VB6,VB12) in Cronhn's patients were significantly lower than in healthy adults.Conclusion: The measurements of Vitamin B in human serum by HPLC-DAD method are clinically helpful to diagnosis and treatment for Crohn's disease.

OBJECTIVETo analyze the influence of retinoic acid (RA) on the undifferentiated state and EB formation abilities of human embryonic stem cells.

METHODSThe biological characteristics of H9 ESCs after RA treatment were characterized by real-time PCR, MTS proliferation assay and immunofluorescence staining. The expression of three germ layers markers, osteogenic differentiation markers and adipogenic differentiation markers in H9-differentiated embryoid bodies (EBs) with RA treatment were quantified by real time PCR.

RESULTSThe proliferation of H9 ESCs in the early logarithmic growth phase was accelerated by RA treatment. In addition, RA induced differentiation of H9 ESC coupled with morphology changes, decreased expression of undifferentiated markers Oct4, Nanog, Sox2 and OCT4 mRNA binding protein Lin28 at mRNA level, and reduced expression of Oct4 at protein level. RA induced formation of cavities in EBs. Real time PCR results showed that the expressions of ectodermal markers: NeuroD1, Noggin; mesodermal markers: Brachyury, Twist and endodermal markers: AFP, GATA-4 were significantly increased (P < 0.05), especially for AFP (P < 0.01), by RA treatment in a dose-dependent manner. In addition, the expression of adipogenic differentiation marker C/EBPalpha was increased while the osteogenic differentiation marker OPN was decreased in EBs after RA treatment for 5 days.

CONCLUSIONSHigh concentrations of RA induced the loss of stemness in H9 ESCs and excessive differentiation in EBs, and damaged the balance between osteogenic and adipogenic differentiation during early EB differentiation, which may be relevant to the congenital malformations.

Cell Differentiation ; drug effects ; Cell Proliferation ; drug effects ; Cells, Cultured ; Embryonic Stem Cells ; cytology ; drug effects ; Humans ; Tretinoin ; pharmacology

Objectives:This study was designed to observe the effect of S adenosyl L methionine (SAMet) on total parenteral nutrition (TPN) induced cholestasis in infected rats and to analyse the change of the bile acids in the bile. Methods:18 Sprague Dawley rats were divided randomly into 3 groups,control group,infection plus TPN group,and infection plus TPN and SAMet group.Each contained 6 rats.Caecum was ligated to induce intra abdominal infection.Nutritional support was maintained for 5 days.Bile was collected by cannulating catheter.The bile flow was determined.The blood samples were gathered to measure the levels of serum total bile acid(STBA),gammaglutamyltranspeptidase (GGT),alanine aminotransferase (ALT)and alkaline phosphatase (AKP).The pathological change in the liver was observed under light microscope and electron microscope.The billiary bile acid contents were determined by high performance liquid chromatographic (HPLC) method. Results:The infection plus TPN group showed that the bile flow was reduced,levels of STBA,GGT and AKP were elevated,and fat infiltration,bile capillary dilatation and bile embolism were obvious in the liver.However,the infection plus TPN and SAMet group showed that the bile flow was increased,levels of STBA,GGT,ALT and AKP were decreased,and the liver was kept normal. Conclusions:The use of SAMet is helpful to could prevent TPN induced cholestasis in infected rats.

Objectives:To observe the metabolism of glutamine in the rat Kupffer cells and the effect of endotoxin. Methods:The changes of glutamine concentrations were measured before and 24 h after the in vitro cultures of the rat Kupffer cells with or without the stimulations of lipopoly saccharide. Results:Consumption and utilization rate of Gln in Kupffer cells with no LPS were (225?24)?mol/L and (9 33?0 99)% repectively.When the concention of LPS was 10.00 mg/L,consumptoin and utilization of Gln were (4 937?289)?mol/L and (73.29? 4.72 )%. Conclusions:Glutamine is an important substrate of Kupffer cell metabolism in the rest and LPS activated conditions.

Objectives:To establish a confident and sensible method of measuring lactulose(L) and mannitol(M) in human urine, and to research lactulose and mannitol excretion ratio of urine in normal Chinese volunteers in 6 hours after taking lactulose and mannitol. Methods:20 healthy volunteers took 10g of lactulose and 5g of mannitol, and 6 hours of urine was collected. The L and M concentration was analyzed by HPLC RI. The excretion of L and M and the L/M ratio was calculated. Results:The excretion of L and M in the urine was 5.74%?0.58% (0.65 %~11.47%) and 0.132%?0.012%( 0.005 %~0.206%),while the L/M ratio was 0.028? 0.010 (0.013~0.051). Conclusions: HPLC is a kind of confident and sensible method to analyze L and M concentration. The L/M ratio can reflect the intestinal mucosal permeability and can be used to monitor intestinal barrier function in clinical practice.

Objective: To investigate the metabolic effects of two different formula of amino acids on postoperative patients . Methods: According to prospective ,randomized , single blind and controlled rule, 120 patients after abdominal operation were randomized to receive parenteral nutrition with either amino acid enriched BCAA or balanced amino acid (18 F).From the second day after operation, total parenteral nutrition was infused to the patients with equal calorie and equal nitrogen by central or peripheral vein for 6 days. Meanwhile, every day nitrogen balance was monitored by collecting urine in 24 hours .The indices were investigated such as amino acids patterns, and serum levels of total protein, albumin, prealbumin, thansferrin and fibronectin. Results: Nitrogen balance of patients in study group on day5 was higher than those of control group. The decreased serum levels of albumin in study group were lower than the control group. Concentrations of valine increased more significantly in study group than that of the control group. Conclusions: The formula of amino acid enriched BCAA may be more suitable and effective for the postoperative traumatic patients on protein metabolism.

Objectives:To determine 3-methylhistidine(3-MH) and tyrosine(Tyr) in standard solution and preparations by high performance liquid chromatography(HPLC) with phenylisothicyanate(PITC) pre-column derivation. Methods:PITC was used as pre-column derivative of HPLC and stored in refrigerator after drying.Two phases gradient elution was performed with acetic sodium and cyanide for 50 minites. Results:The linearity of the measurement was very good for 3-MH and Tyr(r= 0.999 1 and 0.999 2).The recovery rate was 82.6% and 87.6%,respectively. Conclusions:The method of HPLC with PITC pre-column derivation for determination of 3-MH and Tyr is stable,efficient,and sensitive.PITC is an ideal derivative.