[Correlation between serum uric acid and creatinine ratio and metabolic syndrome based on physical examination population in Nantong area]

To investigate the relationship between serum uric acid to creatinine ratio (SUA/Cr) and metabolic syndrome (MS) and other indexes on physical examination population in Nantong area. Using the method of cross-sectional study, 8 148 physical examiners in the physical examination center of the Affiliated Hospital of Nantong University from January 2017 to April 2020 were used as the research objects, and the clinical data and serum biochemical indicators such as smoking and alcohol addiction, physical examination and so on were collected. According to the standard diagnosis of MS of Diabetes Society of Chinese Medical Association, the patients were grouped according to the quartile of SUA/Cr and the clinical data of each group were compared. Pearson correlation analysis and logistic regression analysis were used to explore the correlation between SUA/Cr and clinical indicators and the relationship between SUA/Cr and the risk of MS. The results showed that UA and SUA/Cr were the lowest in normal metabolism group, followed by abnormal metabolism group and the highest in MS group, The difference between the two groups was statistically significant (H=919.21 and 629.34, P<0.001). According to the SUA/Cr quartile, the population was divided into four groups. After adjusting for gender, age, smoking history and drinking history, SUA/Cr in group Q₁ was positively correlated with BMI and TG (r=0.061 and 0.080, P<0.05), but negatively correlated with HDL-C (r=-0.057, P<0.05). Multivariate logistic regression results showed that after adjusting for age, sex, smoking history and drinking history, the risk of MS for BMI, SBP, DBP, FBG, TG, HDL-C and SUA/Cr [OR (95%CI)] were: 1.44 (1.41-1.47), 1.07 (1.06-1.07), 1.10 (1.10-1.11), 1.83 (1.73-1.92), 1.89 (1.79-1.99), 0.08 (0.06-0.10) and 1.54 (1.47-1.62). Compared with SUA/Cr group Q₁, the risk of MS in group Q₂, Q₃ and Q₄ increased by 75%, 162% and 346%, respectively. In conclusion, there was an independent positive correlation between SUA/Cr and MS risk in Nantong area.

[Analysis of pregnancy-related adverse outcomes in patients with severe hypothyroidism during pregnancy]

Objective: To analyze the pregnancy-related adverse outcomes in patients with severe hypothyroidism during pregnancy. Methods: Using cross-sectional study, a total of 47 pregnant women with severe hypothyroidism in the Peking University First Hospital from January 2007 to December 2020 were retrospectively collected by electronic case system. According to the occurrence of adverse pregnancy events (defined as any pregnancy complication or adverse maternal-fetal/neonatal outcomes), the patients were divided into pregnancy-related adverse outcomes group (n=33) and no pregnancy-related adverse outcomes group (n=15). The demographic data, thyroid function and thyroid autoantibody levels during pregnancy, pregnancy complications and maternal-fetal/neonatal outcomes of the two groups were recorded and analyzed. Results: The age of severe hypothyroidism women was (30.5±4.1) years. The median of gestational week at delivery was 38.6 (36.3, 39.9) weeks, the median of gestational week for diagnosis was 7.0 (6.0, 8.8) weeks, the median of the highest TSH level was 32.7(23.1,60.2)mU/L and the period of reaching the target TSH level for the first time was 6.0(4.0, 10.0)weeks. Most cases (82.5%, 33/40) had thyroid autoimmunity. All women were treated with levothyroxine (L-T₄) during pregnancy. A total of 37 cases (77.1%, 37/48) of them obtained the recommended target values. Fourty cases (83.3%, 40/48) gave birth. The birth weight of newborns was (3 041±452) g, the body length was (49.4±2.1) cm, and the head circumference was (33.6±0.7) cm. The period of reaching to target TSH level for the first time in patients without pregnancy-related adverse outcomes was shorter [5.0 (3.0, 9.0) vs 8.0 (4.5, 12.5) weeks) ] (P=0.033), and the times of thyroid function monitoring were more frequent [ (8.2±3.5) vs (6.0±3.6) times] (P=0.049) than the group with pregnancy-related adverse outcomes. Conclusions: The incidence of pregnancy complications and adverse maternal-fetal/neonatal outcomes is high in patients with severe hypothyroidism during pregnancy. Intense follow-up, treatment and restoration of euthyroidism as prompt as possible may improve pregnant outcomes.

[Analysis of experience in diagnosis and treatment of fetal goiter in patients with Graves' disease complicated with pregnancy]

This article reported the clinical diagnosis and treatment experience of two cases of fetal goiter in Graves' disease (GD) complicated with pregnancy. Two GD patients took antithyroid drugs regularly during pregnancy and their thyroid functions were well controlled, but the levels of thyrotropin receptor antibody (TRAb) of the two cases were still above the upper limit in the second and third trimester. Two fetuses had fetal goiter in the middle and late stages of pregnancy. After continuously controlling maternal thyroid function and closely monitoring fetal ultrasound, there was no aggravation of the fetal goiter, and the delivery went smoothly. One case had neonatal hyperthyroidism. It is suggested that although the thyroid function was well controlled during pregnancy in patients with GD, the high level of serum TRAb still needs to be alert to the occurrence of fetal goiter, and fetal ultrasound is the most direct non-invasive monitoring method.

Identification of Tiletamine, Zolazepam and Their Metabolites in Drug Facilitated Sexual Assault by GC-QTOF-MS

Objective To identify tiletamine, zolazepam and their metabolites in samples from drug facilitated sexual assault by gas chromatography-quadrupole time of flight mass spectrometry （GC-QTOF-MS）. Methods Urine samples of victims were collected, and detected by GC-QTOF-MS after liquid-liquid extraction and concentration. The molecular formula of fragments ions was identified by determination of accurate mass numbers, to detect related substances. Results Tiletamine, zolazepam, three metabolites of tiletamine and two metabolites of zolazepam were identified in urine samples from actual cases. Conclusion GC-QTOF-MS provides abundant and accurate information of fragment ions mass numbers, which can be used for qualitative identification of tiletamine, zolazepam and their metabolites in drug facilitated sexual assault.

MMS observations of electron scale magnetic cavity embedded in proton scale magnetic cavity

Magnetic cavities (sometimes referred to as magnetic holes) at electron kinetic scale are thought to be one of the extremely small intermittent structures formed in magnetized turbulent plasmas, where the turbulence energy cascaded down to electron scale may finally be dissipated and consequently energize the electrons. However, the geometry and formation of these structures remain not definitively resolved. Here we discuss an electron scale magnetic cavity embedded in a proton scale magnetic cavity observed by the MMS spacecraft in the magnetosheath. By applying an innovative particle sounding technique, we directly depict the boundary of the electron scale magnetic cavity and uncover the geometry. We find that this structure is nearly circular with a radius of 10.0 km and its formation is due to the diamagnetic current. Investigation of the electron scale structure is only recently made possible by the high spatial and temporal resolution provided by MMS observations.

[Application of pegylated recombinant human granulocyte colony-stimulating factor to prevent chemotherapy-induced neutropenia in patients with lymphoma: a prospective, multicenter, open-label clinical trial]

目的

评价聚乙二醇化重组人粒细胞刺激因子（PEG-rhG-CSF）预防淋巴瘤患者化疗后发生中性粒细胞减少症的有效性和安全性。

方法

本研究为多中心、开放、单臂、Ⅳ期临床试验。纳入410例淋巴瘤患者接受多周期化疗并预防性使用PEG-rhG-CSF。主要观察患者各化疗周期Ⅲ/Ⅳ度中性粒细胞减少症和发热性中性粒细胞减少（FN）的发生率，同时观察患者整个化疗期间抗生素的使用率。

结果

①410例患者中，违背入选标准8例（1.95%），失访35例（8.54%），发生不良事件19例（4.63%），出现符合终止研究标准者12例（2.93%），疾病进展或复发15例（3.66%），故最终321例（78.29%）进入符合方案集。②在第1~4个治疗周期，初级预防给予PEG-rhG-CSF后，Ⅳ度中性粒细胞减少症的发生率分别为19.14%（49/256）、12.50%（32/256）、12.18%（24/197）、13.61%（20/147），FN的发生率分别为3.52%（9/256）、0.39%（1/256）、2.54%（5/197）、2.04%（3/147）；次级预防给药后，Ⅳ度中性粒细胞减少症的发生率从61.54%（40/65）降至16.92%（11/65）、18.46%（12/65）、20.75%（11/53），FN的发生率从16.92%（11/65）降至1.54%（1/65）、4.62%（3/65）、3.77%（2/53）。③整个化疗期间接受抗生素治疗的受试者比例为34.39%（141/410）。④与PEG-rhG-CSF相关的不良事件发生率为4.63%（19/410），最常见的不良反应为骨痛[3.90%（16/410）]、乏力（0.49%）和发热（0.24%）。

结论

在淋巴瘤患者化疗过程中，预防性使用PEG-rhG-CSF能够有效降低化疗过程中Ⅲ/Ⅳ度中性粒细胞减少症和FN的发生率，确保淋巴瘤患者接受标准剂量化疗，提高治愈率。

[A single center large cohort study on perioperative complications of carotid endarterectomy of 547 cases]

Objective: To analyze the risk factors of perioperative complications within 30 days of carotid endarterectomy(CEA) in the treatment of carotid atherosclerosis stenosis(CAS) during 2011-2017, and to discuss the techniques for reducing the perioperative complication rates. Methods: From August 2011 to August 2017, 486 patients with CAS were retrospective included, and 61 of them underwent bilateral CEA, with a total of 547 cases of CEA included. Perioperative complications were collected within 30 days after operation, and the risk factors related to perioperative complications were analyzed by statistical analysis. Results: In total 547 cases, 12 cases had a postoperative stroke, while 1 case died. A total of 7 cases underwent cranial nerve injury, and 5 cases had an incision related complications. In chi-square test analysis, data suggested that there was a significant difference in the incidence of complications in patients with heart disease, preoperative neurological score difference, contralateral carotid serious stenosis or occlusion and intraoperative shunt in CCA/ICA technique application (P<0.05). In the multivariate Logistic regression, it suggested that poor preoperative neurological score and contralateral carotid serious stenosis or occlusion were independent risk factors for perioperative stroke and death. Conclusion: Our results showed that CEA is effective to prevent stroke and treat patients with CAS. Patients with poor preoperative neurological score and contralateral carotid serious stenosis or occlusion may increase the risk of postoperative stroke rates.

[Current epidemiology and pathogenesis of non-alcoholic fatty liver disease-associated liver cancer]

Liver cancer is a common malignant tumor. Although the overall incidence and mortality rates of liver cancer has been decreasing in recent years, the incidence of nonalcoholic fatty liver disease (NAFLD)-associated liver cancer tends to increase. The health and social issues brought by NAFLD-associated liver cancer have attracted more and more attention, and its epidemiology, pathogenesis, and diagnosis and treatment await further research. This article summarizes the current epidemiology and pathogenesis of NAFLD-associated liver cancer.

Expression of prion protein in the cerebrospinal fluid of patients with Parkinson's disease complicated with rapid eye movement sleep behavior disorder

Parkinson's disease (PD) is one of the most common neurodegenerative diseases and mainly manifests with decreasing numbers of dopaminergic neurons. Rapid eye movement (REM) sleep behavior disorder (RBD) has an incidence of 15-47% in all PD patients. Prion proteins (PrPs), which are expressed in both neurons and glial cells of the brain, are believed to be correlated with abnormal neurological functions, although their role in PD-related sleeping disorders remains unclear. We therefore investigated the expressional profiles of PrP in PD patients with RBD. Quantitative real-time polymerase chain reaction and western blotting were used to detect the mRNA and protein levels of PrP, respectively, in the cerebrospinal fluid (CSF) of PD patients with RBD, PD patients without sleeping disorder, and healthy people (N = 23 each). We investigated the correlation between the CSF PrP level and sleeping behavior in PD patients. Patients with PD complicated with RBD had significantly elevated CSF PrP expression levels (both mRNA and protein) compared with either PD patients without sleeping disorder or healthy individuals (P < 0.05 in both cases). There is elevated expression of PrP in the CSF of PD patients with RBD. This may benefit the diagnosis of PD-related RBD.

Study on the synthesis and tribological properties of anti-corrosion benzotriazole ionic liquid

Anti-corrosion benzotriazole ionic liquid (IL, BTAP₄₄₄₄) was synthesized by neutralizing 1H-benzotriazole (BTAH) with terabutylphosphonium hydroxide (P₄₄₄₄OH).

Prognostic value of miR-141 downregulation in gastric cancer

Previous research has shown that microRNA-141 (miR-141) expression levels are associated with survival in several types of cancer. In the present study, we investigated the clinical significance and prognostic value of miR-141 in gastric cancer. Paired tissue specimens (tumor and adjacent normal mucosa) from 95 patients with gastric cancer were obtained at the Department of General Surgery, Xiangya Hospital, Central South University from March 2009 to February 2014. The levels of miR-141 in cancerous and corresponding non-cancerous tissues were detected by quantitative reverse transcription-polymerase chain reaction. Associations between clinicopathological parameters and miR-141 expression were evaluated using chi-square tests. Overall survival was calculated and survival curves were plotted using the Kaplan-Meier method; differences between groups were compared using log-rank tests. Compared to the matched normal gastric mucosa, gastric cancer tissues had significantly lower miR-141 expression levels (P < 0.001). This decreased miR-141 expression was significantly associated with tumor differentiation (P = 0.044), positive lymph node metastasis (P = 0.010), distant metastasis (P < 0.001), and advanced tumor-node-metastasis (TNM) stage (P < 0.001). Furthermore, a significant relationship was found between miR-141 expression and overall survival (P = 0.012, log-rank test). Cox regression analysis revealed that lymph node metastasis (P = 0.003), distant metastasis (P = 0.001), TNM stage (P < 0.001), and miR- 141 expression (P = 0.007) were independent prognostic factors in patients with gastric cancer. Our data provide evidence that the downregulation of miR-141 may contribute to the aggressive progression and poor prognosis of human gastric cancer.

Realization of a fast-response flexible ultraviolet photodetector employing a metal–semiconductor–metal structure InGaZnO photodiode

A flexible UV photodetector (PD) has been fabricated based on the amorphous InGaZnO film. It shows good photoresponse characteristics before and after bending, and fast response speed compared with the most reported flexible UV PDs.

Reduced STMN1 expression induced by RNA interference inhibits the bioactivity of pancreatic cancer cell line Panc-1

Increased expression of STMN1 has been observed in many tumor forms, but its expression and potential biological role in pancreatic cancer is still unknown. In this study, we demonstrated that STMN1 was expressed to a large extent in pancreatic cancer tissues and cell lines as compared to normal pancreatic tissues. Suppression of STMN1 expression via transfection with STMN1-specific siRNA could not only significantly inhibit the proliferation, migration and invasion ability of Panc-1 cells, but also enhance the apoptosis of Panc-1 cells. In addition, downregulation of STMN1 obviously enhanced the acetylation level of α-tubulin. All these results indicated that STMN1 plays an important role in pancreatic cancer development, and might serve as a potential therapeutic target for pancreatic cancer.

CIAPIN1 gene silencing enhances chemosensitivity in a drug-resistant animal model in vivo

Overexpression of cytokine-induced apoptosis inhibitor 1 (CIAPIN1) contributes to multidrug resistance (MDR) in breast cancer. This study aimed to evaluate the potential of CIAPIN1 gene silencing by RNA interference (RNAi) as a treatment for drug-resistant breast cancer and to investigate the effect of CIAPIN1 on the drug resistance of breast cancer in vivo. We used lentivirus-vector-based RNAi to knock down CIAPIN1 in nude mice bearing MDR breast cancer tumors and found that lentivirus-vector-mediated silencing of CIAPIN1 could efficiently and significantly inhibit tumor growth when combined with chemotherapy in vivo. Furthermore, Western blot analysis showed that both CIAPIN1 and P-glycoprotein expression were efficiently downregulated, and P53 was upregulated, after RNAi. Therefore, we concluded that lentivirus-vector-mediated RNAi targeting of CIAPIN1 is a potential approach to reverse MDR of breast cancer. In addition, CIAPIN1 may participate in MDR of breast cancer by regulating P-glycoprotein and P53 expression.

Investigation of the shape change of bio-flocs and its influence on mass transport using particle image velocimetry

In this laboratory study, an advanced flow visualization technique - particle image velocimetry (PIV) - was employed to investigate the change of shape of activated sludge flocs in water and its influence on the material transport characteristics of the flocs. The continuous shape change of the bio-flocs that occurred within a very short period of time could be captured by the PIV system. The results demonstrate that the fluid turbulence caused the shift of parts of a floc from one side to the other in less than 200 ms. During the continuous shape change, the liquid within the floc was forced out of the floc, which was then refilled with the liquid from the surrounding flow. For the bio-flocs saturated with a tracer dye, it was shown that the dye could be released from the flocs at a faster rate when the flocs were swayed around in water. The experimental results indicate that frequent shape change of bio-flocs facilitates the exchange of fluid and materials between the floc interior and the surrounding water. This mass transfer mechanism can be more important than molecular diffusion and internal permeation to the function and behavior of particle aggregates, including bio-flocs, in natural waters and treatment systems.

50-Hz magnetic field induces EGF-receptor clustering and activates RAS

PURPOSE

In a previous study, we found that exposure to a 50 Hz magnetic field (MF) could activate stress-activated protein kinase (SAPK) and P38 mitogen-activated protein (MAP) kinase (P38 MAPK) in Chinese hamster lung (CHL) fibroblast cells, and simultaneous exposure to a 'noise' MF of the same intensity inhibited these effects. In order to explore the possible target sites and upstream signal transduction molecules of SAPK and P38 MAPK, and further validate the interference effects of 'noise' MF on 50 Hz MF, the effects of MF exposure on clustering of epidermal growth factor (EGF) receptors and Ras protein activation were investigated.

MATERIALS AND METHODS

CHL cells were exposed to a 50 Hz sinusoidal MF at 0.4 mT for different durations, and clustering of EGF receptors on cellular membrane and Ras protein activation were analyzed using immunofluorescence confocal microscopy and co-precipitation technology. EGF treatment served as the positive control.

RESULTS

The results showed that, compared with sham-exposed cells, exposure to a 50 Hz MF at 0.4 mT for 5 min slightly induced EGF receptor clustering, whereas exposure for 15 min enhanced receptor clustering significantly. Corresponding to receptor clustering, Ras protein was also activated after exposure to the 50 Hz MF. Exposure to a 'noise' MF (with frequency ranges from 30 - 90 Hz) at the same intensity and durations, did not significantly affect EGF receptor clustering and Ras protein. However, by superimposing the 'noise' MF, receptor clustering and Ras activation induced by 50 Hz MF were inhibited.

CONCLUSION

The results suggested that membrane receptors could be one of the most important targets where extremely low frequency (ELF) MF interacts with cells, and Ras may participate in the signal transduction process of 50 Hz MF. Furthermore, a 'noise' MF could inhibit these effects caused by ELF-MF.

Simple direct extraction of unknown phase shift and wavefront reconstruction in generalized phase-shifting interferometry: algorithm and experiments

An algorithm to extract the arbitrary unknown phase shift and then reconstruct the complex object wave in generalized phase-shifting interferometry (GPSI) without the iteration process and measurement of object wave intensity is proposed. This method can be used for GPSI of any frame number >or=2. Both computer simulations with smooth and diffusing object surfaces and optical experiments have verified the effectiveness of this method over a wide range of phase shifts with very satisfactory results.

Effects of silencing of mutant p53 gene in human lung adenocarcinoma cell line Anip973

The mutational spectrum of p53 gene and the biological effects of mutant p53 protein vary greatly from one type of tumor to another. To investigate the biological effects of mutant p53 gene in human lung adenocarcinoma, mutant p53 was silenced by RNA interference (RNAi) in cell line Anip973. Then, the effects of mutant p53 silencing on cell cycle distribution and regulators, and on the TGFbeta/BMP signaling pathway were then investigated by flow cytometry, RT-PCR, and cDNA array screening. This study showed that mutant p53 silencing in Anip973 resulted in G1 arrest and G2/M arrest, for which the increased expression of p27 gene might be an important contribution factor. It was also found that the absence of mutant p53 affected the signal transduction of TGFbeta/BMP pathway mainly by up-regulating the expression of BMP superfamily cytokine growth differentiation factor 9 (GDF9), activin superfamily cytokine inhibin beta B (INHBB), smads target genes insulin-like growth factor binding protein 3 (IGFBP3) and involucrin (IVL). These results indicated the basic mechanism and the significant effects of mutant p53 on specific biological processes such as cell cycle and signal transduction in lung adenocarcinoma. These activities of mutant p53 may contribute to its 'gain of function' effects, which accelerate the oncogenesis and promotion of the tumor.

Pregnancy outcome in gestational diabetes

OBJECTIVE

To assess maternal and neonatal outcomes of gestational diabetes mellitus (GDM) following glycemic screening and diabetic management, with special focus on concurrent GDM and pre-eclampsia.

METHODS

A retrospective chart review of 782 women diagnosed with and treated for GDM at a Chinese university teaching hospital. Data on maternal and neonatal outcome, glycemic control, concurrent pre-eclampsia, and diabetic management were collected and analyzed.

RESULTS

The incidence of GDM was 3.8%. Of the affected women, 62.9% were managed with diet only and the remainder received insulin treatment. Overall, 80.7% had good glycemic control. Poor glycemic control and concurrent pre-eclampsia correlated with maternal and neonatal complications.

CONCLUSION

Aggressive management for tight glycemic control improves maternal and neonatal outcomes in women with GDM.

Cerebrospinal fluid tau, Aβ1–42 and inflammatory cytokines in patients with Alzheimer's disease and vascular dementia

In this study we aimed to evaluate the possibility of using cerebrospinal fluid (CSF) tau, Abeta(1-42) and inflammatory cytokines for diagnosis of Alzheimer's disease (AD) and vascular dementia (VD). We measured levels of total tau (T-tau), phospho-tau (P-tau), Abeta(1-42), IL-6, and TNFalpha in CSF in groups of AD, VD, and controls using enzyme-linked immunosorbent assay (ELISA). T-tau level was found significantly higher in groups of AD (t = 3.015, P < 0.01) and VD (t = 2.872, P < 0.01) than in controls. IL-6 level as also higher in AD (t = 2.883, P < 0.01) and VD (t = 3.032, P < 0.01) than in controls. Both T-tau and IL-6 were not significantly different between AD and VD (P > 0.05). The group of AD had remarkably higher P-tau (t = 4.261 and 3.883, respectively, P < 0.01) and lower Abeta(1-42) (t = 3.883 and 4.129, respectively, P < 0.01), as compared with those in VD and controls. TNFalpha level in AD was significantly higher than that in controls (t = 2.745, P < 0.01), but lower than in VD (t = 3.032, P < 0.01). Our data suggested that increment of T-tau and IL-6 levels in CSF was useful for screening AD and VD in certain population, while descending Abeta(1-42) and ascending TNFalpha in CSF are preferable to diagnose AD. In addition, a higher level of CSF P-tau might support AD diagnosis.

Intrasplenic transplantation of IL-18 gene-modified hepatocytes: an effective approach to reverse hepatic fibrosis in schistosomiasis through induction of dominant Th1 response

Hepatic fibrosis is a common outcome of chronic liver diseases. In schistosomiasis, chronic parasite egg-induced granuloma formation can lead to fibrosis, which is immunologically characterized by the dominant Th2 response. Recently, it has been shown that gene therapy is an attractive approach for the treatment of hepatic fibrosis. To investigate the antifibrotic effects of IL-18 gene transfer, a normal murine liver cell line BNL.CL2 was transfected with recombinant adenovirus encoding mouse IL-18, and then intrasplenically transplanted into mice infected with Schistosoma japonicum (S. japonicum). Our data show that IL-18 gene-modified hepatocytes intrasplenically transplanted into mice can effectively express IL-18 in the liver and in peripheral blood. Intrasplenic transplantation of IL-18 gene-modified hepatocytes into S. japonicum-infected mice could result in a significantly increased IFN-gamma and IL-2 but decreased IL-4 and IL-10 concentration both in the liver and in the serum, suggesting that the dominant Th2 response in mice with schistosomiasis could be reversed by this intervention. Consistent with the changes in Th1 and Th2 cytokine production, mice intrasplenically transplanted with IL-18 gene-modified hepatocytes developed much less hepatic fibrosis at 20 weeks after infection, which was evaluated by liver content of hydroxyproline, collagens, and hepatic mRNA expression of procollagens. These data indicate that intrasplenic transplantation of IL-18 gene-modified hepatocytes can be a candidate for therapeutic intervention in hepatic fibrosis through induction of a dominant Th1 response.

Microbial conversion of indene to indandiol: a key intermediate in the synthesis of CRIXIVAN

Indene is oxidized to mixtures of cis- and trans-indandiols and related metabolites by Pseudomonas putida and Rhodococcus sp. isolates. Indene metabolism is consistent with monooxygenase and dioxygenase activity. P. putida resolves enantiomeric mixtures of cis-1,2-indandiol by further selective oxidation of the 1R, 2S-enantiomer yielding high enantiomeric purity of cis-(1S, 2R)-indandiol, a potential intermediate in the synthesis of indinavir sulfate (CRIXIVAN), a protease inhibitor used in the treatment of AIDS. Molecular cloning of P. putida toluene dioxygenase in Escherichia coli confirmed the requirement for the dihydrodiol dehydrogenase in resolving racemic mixtures of cis-indandiol. Rhodococcus sp. isolates convert indene to cis-(1S, 2R)-indandiol at high initial enantiomeric excess and one isolate also produces trans-(1R, 2R)-indandiol, suggesting the presence of monooxygenase activity. Scale up and optimization of the bioconversions to these key synthons for chiral synthesis of potential intermediates for commercial manufacture of indinavir sulfate are described.

Process optimization for large-scale production of TGF-alpha-PE40 in recombinant Escherichia coli: effect of medium composition and induction timing on protein expression

The effects of medium composition and induction timing on expression of a chimeric fusion protein TGF-alpha-PE40 (TP-40) in Escherichia coli strain RR1 were examined using a complex medium at several fermentor scales. Two distinctive phases in E. coli catabolism were identified during fermentation based on preferential utilization between protein hydrolysate and glycerol. Maximum specific and volumetric productivities were achieved by inducing the culture when the cells were switching substrate utilization from protein hydrolysate to glycerol. By increasing the yeast extract concentration in the production medium, initiation of the catabolic switch was delayed until high cell mass was achieved. The final titer of TP-40 at the 15-L fermentation scale was doubled from 400 mg L-1 to 850 mg L-1 by increasing the yeast extract concentration from 1% to 4% (w/v) and delaying the time of induction. This fermentation process was rapidly scaled up in 180-L and 800-L fermentors, achieving TP-40 titers of 740 and 950 mg L-1, respectively.

Structure of gel phase saturated lecithin bilayers: temperature and chain length dependence

Systematic low-angle and wide-angle x-ray scattering studies have been performed on fully hydrated unoriented multilamamellar vesicles of saturated lecithins with even chain lengths N = 16, 18, 20, 22, and 24 as a function of temperature T in the normal gel (L beta') phase. For all N, the area per chain Ac increases linearly with T with an average slope dAc/dT = 0.027 A2/degree C, and the lamellar D-spacings also increase linearly with an average slope dD/dT = 0.040 A/degree C. At the same T, longer chain length lecithins have more densely packed chains, i.e., smaller Ac's, than shorter chain lengths. The chain packing of longer chain lengths is found to be more distorted from hexagonal packing than that of smaller N, and the distortion epsilon of all N approaches the same value at the respective transition temperatures. The thermal volume expansion of these lipids is accounted for by the expansion in the hydrocarbon chain region. Electron density profiles are constructed using four orders of low-angle lamellar peaks. These show that most of the increase in D with increasing T is due to thickening of the bilayers that is consistent with a decrease in tilt angle theta and with little change in water spacing with either T or N. Because of the opposing effects of temperature on area per chain Ac and tilt angle 0, the area expansivity alpha A is quite small. A qualitative theoretical model based on competing head and chain interactions accounts for our results.

Structure of the ripple phase in lecithin bilayers

The phases of the x-ray form factors are derived for the ripple (Pbeta') thermodynamic phase in the lecithin bilayer system. By combining these phases with experimental intensity data, the electron density map of the ripple phase of dimyristoyl-phosphatidylcholine is constructed. The phases are derived by fitting the intensity data to two-dimensional electron density models, which are created by convolving an asymmetric triangular ripple profile with a transbilayer electron density profile. The robustness of the model method is indicated by the result that many different models of the transbilayer profile yield essentially the same phases, except for the weaker, purely ripple (0,k) peaks. Even with this residual ambiguity, the ripple profile is well determined, resulting in 19 angstroms for the ripple amplitude and 10 degrees and 26 degrees for the slopes of the major and the minor sides, respectively. Estimates for the bilayer head-head spacings show that the major side of the ripple is consistent with gel-like structure, and the minor side appears to be thinner with lower electron density.

Anomalous phase behavior of long chain saturated lecithin bilayers

X-ray scattering has been performed on fully hydrated unoriented multilamellar vesicles of lecithins with even chain lengths n from 16 to 24 as a function of temperature in chain ordered phases. The longer chain lengths, n > or = 20, show anomalous behavior compared to the shorter chain lengths, n < 20. This report concentrates on n = 24. Although the history and time dependence shows that equilibrium was not always achieved, it appears that there is a second gel-like phase G2 below 40 degrees C. The G2 phase has a small tilt angle and opposite hexagonal symmetry breaking from the usual G1 gel phase. Also, as T is raised above 45 degrees C, the wide-angle data suggest the appearance of a phase with hexagonal chain packing and small chain tilt angle.

Kinetics of subgel formation in DPPC: X-ray diffraction proves nucleation-growth hypothesis

Wide-angle and low-angle X-ray diffraction data were obtained during the time course of the gel to subgel phase transformation in fully hydrated DPPC. When the system was kept close to equilibrium by following a T-jump protocol, the X-ray data unequivocally demonstrate the coexistence of growing subgel and shrinking gel domains. When the system was supercooled and held further from equilibrium as in previous studies, the kinetic behavior was more complicated. These data prove that the basic mechanism for the gel to subgel phase transformation is one of nucleation of subgel domains followed by growth of the domains.

Measurement of chain tilt angle in fully hydrated bilayers of gel phase lecithins

The tilt angle theta tilt of the hydrocarbon chains has been determined for fully hydrated gel phase of a series of saturated lecithins. Oriented samples were prepared on glass substrates and hydrated with supersaturated water vapor. Evidence for full hydration was the same intensity pattern of the low angle lamellar peaks and the same lamellar repeat D as unoriented multilamellar vesicles. Tilting the sample permitted observation of all the wide angle arcs necessary to verify the theoretical diffraction pattern corresponding to tilting of the chains towards nearest neighbors. The length of the scattering unit corresponds to two hydrocarbon chains, requiring each bilayer to scatter coherently rather than each monolayer. For DPPC, theta tilt was determined to be 32.0 +/- 0.5 degrees at 19 degrees C, slightly larger than previous direct determinations and considerably smaller than the value required by recent gravimetric measurements. This new value allows more accurate determinations of a variety of structural parameters, such as area per lipid molecule, A = 47.2 +/- 0.5 A2, and number of water molecules of hydration, nw = 11.8 +/- 0.7. As the chain length n of the lipids was increased from 16 to 20 carbons, the parameters A and nw remained constant, suggesting that the headgroup packing is at its excluded volume limit for this range. However, theta tilt increased by 3 degrees and the chain area Ac decreased by 0.5 A2. This behavior is explained in terms of a competition between a bulk free energy term and a finite or end effect term.

[TLC-densitometric determination of sarsasapogenin in Anemarrhena asphodeloides Bge]

The sarsasapogenin content in Anemarrhena asphodeloides and its preparations was assayed by TLC-densitometric method. The developing solvent used was benzene-acetone (9:1). The chromatographic plate was sprayed with a mixture of 8% vanillin in alcoholic solution-70% H2SO4 solution (0.5:5). This plate was scanned using 445 nm as wavelength lambda s and 600 nm as wavelength lambda s.

[The effect of ginseng stem, leaf and rhizoma saponins on the formation of lipid peroxides in rats of various ages]

The effect of saponins isolated from the stem, leaf and rhizoma of panax ginseng on the formation of lipid peroxides in aged (30, 24 and 20 months) and middle-aged (14 months) wistar rats was studied with both in vivo and in vitro methods. The results showed: The formation of lipid peroxides increased with age in rats and mice: the two saponins of ginseng stem, leaf and rhizoma can obviously inhibit the lipid peroxidation in the serum (plasma) and liver homogenate of aged and middle-aged rats (p less than 0.05 and less than 0.001). The same effect was also shown in the aged LACA mouse (18 months) experiment.

[Studies on the chemical constituents of Aconitum szechenyianum Gay]

Five constituents were isolated from Aconitum szechenyianum Gay. The structures of these compounds were identified as beta-sitosterol (I), aconitine (II), 3-acetylaconitine (III), songorine (IV) and a new compound whose structure was elucidated to be szechenyine (V) on the basis of UV, IR, 1HNMR, 13CNMR and Mass spectra.