Chorionic Gonadotropin, beta Subunit, Human ; blood ; Down Syndrome ; blood ; diagnosis ; Female ; Humans ; Pregnancy ; Pregnancy, Twin ; Prenatal Diagnosis ; alpha-Fetoproteins ; metabolism

Cofactor engineering, a vital part of metabolism engineering, changes the redox cofactor regeneration approach. Its main goal is to rebuild the components of metabolic products. The bioconversion of xylose for the production of ethanol is being studied intensively because ethanol is an alternative energy source and a potential liquid fuel. Saccharomyces cerevisiae has been traditionally used in producing ethanol from fermentable sugars but it cannot utilize xylose, only its isomer xylulose. Introduction of the xylose fermentation pathway from Pichia stipitis into S. cerevisiae enables xylose utilization in recombinant S. cerevisiae, but the ethanol yields of xylose fermentation with recombinant S. cerevisiae has been low and large amounts of the byproduct xylitol are produced. The major reason is that the catabolism of xylose with the fungal pathway leads an imbalance of redox cofactor. The process of the catabolism of xylose requires NADPH and NAD~+, both of which have to be regenerated in separated processes. More and more attention has therefore focused on the redox cofactor balance in S. cerevisia. The research progress of cofactor engineering to solve the imbalance of redox cofactor in xylose metabolism recombinant S. cerevisiae was introduced. This included expression of transhydrogenase, increasing the utilization of NADPH, and achieving the anaerobic reoxidation of NADH. Reversing the cofactor specificity of enzymes is another effective way.

Objective To compare the outcomes of off-pump versus on-pump CABG.Methods From 2002 to 2008,CABG was performed in 105 patients aged 80 years and over,including 45 without cardiopulmonary bypass (CPB) or off-pump (OP) CABG (OPCAB) and 60 with CPB (onpump CABG).The outcomes were compared between two groups.Results The mean ICU stay was (37.1±30.3) h in OPCAB group and (60.6±58.2) h in on-pump CABG group (P＜0.01).Average ventilator-assisted time was (10.8±9.7) h for OPCAB group versus (22.3±35.7) h for onpump CABG group (P＜0.01).Postoperative atrial fibrillation occurred in 31.1％ of OPCABG patients and 41.7 ％ of on-pump CABG patients (P＜0.01).The mortality rate was 5.0％ in OPCABG group versus 8.3％ in on-pump CABG group (P＜0.05).Conclusions OPCABG is a safe and efficient method of myocardial revascularization in the elderly patients with lower morbidity and complications.

Objective To evaluate the CT features and the role of CT in the diagnosis of Crohn′s disease. Methods CT manifestations of 18 patients with pathology confirmed Crohn′s disease were retrospectively analyzed. The majority of the patients were scanned with spiral CT or multidetector row CT.Results All 18 patients, segmental thickening of the bowel wall was detected. There were two different appearances in contrast-enhanced CT scans: (1) mural thickening without enhancement or mural stratification, and homogeneous attenuation in the thickened wall were observed in 7 patients; (2) mural thickening and stratification, resulting in the target or double-halo appearance, were detected in 11 patients, and the bowel wall thickening ranged from 5 to 10 mm. Nine patients had perienteric abnormalities including fibrofatty proliferation, phlegmon and mesenteric hypervascularity. According to the CT manifestations, 5 patients were initially diagnosed as other diseases including intestinal obstruction (1 case), tuberculosis (1 case), cancer (2 cases), and abscess (1 case), respectively. Conclusion CT has the unparalleled ability to depict the abnormalities in the bowel wall, mesentery, abdominal and pelvic viscera, and contrast-enhanced CT can distinguish active Crohn′s disease from quiescent Crohn′s disease. These features make CT particularly valuable in the management of Crohn′s disease.

Objective To investigate the minimal and optimal concentration of ropivacain for epidural anesthesia in patients with breast cancer.Methods 103 patients with breast cancer ASA Ⅰ-Ⅱ undergoing elective radical mastectomy were conducted with epidural anesthesia.T2-3 were selected as a puncture site.A catheter was inserted into the epidural space in a cephalic direction for 3.5-4.0 cm.The concentration of ropivacain was produced by the test of up-down sequential allocation technique.20-25 ml of 0.20 ％ ropivacaine was given after a test of 0.20 ％ 5 ml ropivacaine.If the anesthesia was effective (VAS≤3),the next concentration was down 0.01％,while the VAS was more than 5,the next concentration was up 0.01％.The anesthesia effect and segments of block were measured with acupuncture.Blood pressure (NIBP),heart rates(HR),blood oxygen saturation (SPO2),blood gas and VAS were monitored during operation.Nasal catheter oxygen inhalation was used in routine method.Results The median effective concentration (EC50) of ropivacaine was 0.10 ％ determined by the formula of dixon and massey.The 95 ％ confidence intervals was 0.1022 ％-0.1065 ％.The least and the best analgesic concentration of ropivacaine for the upper thoracic epidural block was 0.14 ％ and 0.17 ％-0.18 ％ respectively.Conclusion The minimal and the optimal analgesic concentration of ropivacaine for the upper thoracic epidural block are 0.14 ％ and 0.17 ％-0.18 ％respectively,and which provides a safe and rational use of ropivacaine for the clinic.

Objective To make a preliminary study on the results from qualitative and quantitative detection of low concentra-tion hepatitis B surface antigen(HBsAg).Methods 85 HBsAg low concentration serum samples (ELISA method test re-sults were 0.60.05)and 0.60.05).The positive detection rate showed statistically difference between ELISA (70.6%)and CMIA,TRFIA in 0.6TRFIA>ELISA.②The contents of HBsAg showed statistically difference among 0.6TRFIA>ELISA.③There was a positive correlation between the three methods of HBsAg content (t=2.939,2.928,60.915,P<0.05).The correlation between CMIA method and TRFIA method was the best (r=0.989).Con-clusion CMIA was the first choice for testing low concentration HBsAg,TRFIA was the second.For the specimens of the low concentration HBsAg detected by ELISA should be suggested to clinical and retested by CMIA or TRFIA in order to a-void missing detection.And it was not recommended to clinical that different methods of quantitative or half-quantitative re-sults were transverse compared in order to avoid misdiagnosis.