Nardostachys jatamansi， A Medicinal Plant from Qinghai-Tibet Plateau： A Review / 中国实验方剂学杂志

Nardostachyos Radix et Rhizoma is the dry root and rhizome of Nardostachys jatamansi （Valerianaceae） with a long medical history and a broad range of application， which is effective in regulating Qi， relieving pain， resolving depression， and enlivening spleen， as well as dispelling dampness and relieving swelling by external application. It can be used for the treatment of abdominal distension， loss of appetite， and vomiting. Besides， it can also relieve toothache and treat dermatophytosis and pyogenic infection by external use. Moreover， it serves as a common medicinal material in ancient Ayurveda and Unani medical systems in India and also as an ingredient in spices， foods， and cosmetics. Modern pharmacological studies have shown that Nardostachyos Radix et Rhizoma possesses multiple pharmacological activities， such as sedation， anti-epilepsy， anti-convulsion， anti-depression， anti-arrhythmia， anti-malaria， anti-inflammation， anti-bacteria， anti-oxidation， and blood sugar metabolism improvement due to its multiple compounds contained， including terpenes， flavonoids， coumarins， and lignans. The main active components are sesquiterpenoids represented by nardosinone. The pharmacological activities， chemical compositions， and clinical applications of Nardostachyos Radix et Rhizoma have been investigated， but the research on resources， distribution， quality control， cultivation status， and applications are rarely reported. As an important genuine medicinal material from the Qinghai-Tibet plateau， Nardostachyos Radix et Rhizoma is obtained mainly from wild N. jatamansi. Accordingly， the conservation and sustainable utilization of N. jatamansi have attracted much attention all around the world. Based on the resource survey， cultivation research， and relevant literature available， the present study reviewed resources， geographical distribution， chemical compositions， pharmacological activities， quality control， cultivation， and applications of N. jatamansi， aiming to provide references for the conservation and development of N. jatamansi.

Prevalence and Years Lived with Disability for Dental Caries among Children Aged 0-14 Years in China, 1990-2016.

The estimate of dental caries among Chinese children at the microscale level using standard methodology remains unclear. In this study, we assessed and analyzed the disease burden of childhood dental caries in China by extracting data from the Global Burden of Disease, Injuries, and Risk Factors Study 2016 (GBD 2016). In 2016, the number of cases, prevalence, years lived with disability (YLD), and age-standardized YLD rate of dental caries was 93.0 million, 43.0%, 32,200 person years, and 14.8 per 100,000, respectively. Across 33 provincial units, the disease burden was highest in Hubei (YLD rate 28.6 per 100,000), lowest in Macao (9.1 per 100,000), while geographical clustering was not observed. Compared with 1990, the prevalence in 2016 decreased from 46.8% to 43.0%, and the YLD rate decreased from 16.5 per 100,000 to 14.8 per 100,000. Given the slight decrease in dental caries burden, the prevalence and disease burden remained high among Chinese children. Strategies for addressing the spatial inequity of childhood dental caries require geographical targeting.

Live birth rates and safety profile using dydrogesterone for luteal phase support in assisted reproductive techniques

<p><b>INTRODUCTION</b>Assisted reproductive techniques (ARTs) result in a deficient luteal phase, requiring the administration of intramuscular, intravaginal or oral exogenous progesterone. Dydrogesterone, an oral retroprogesterone with good bioavailability, has been used in assisted reproductive cycles with outcomes that are comparable to those of vaginal or intramuscular progesterone. However, there are limited reviews on its use for luteal phase support in ARTs, in terms of pregnancy outcomes and associated fetal anomalies. This study aimed to review the live birth rates and associated fetal anomalies of women who were given dydrogesterone for luteal phase support in assisted reproductive cycles at a tertiary hospital in Singapore.</p><p><b>METHODS</b>This retrospective descriptive study included 1,050 women who underwent in vitro fertilisation/intracytoplasmic sperm injection at the Centre for Assisted Reproduction of Singapore General Hospital between 2000 and 2011. The women were given dydrogesterone for luteal phase support. The main outcome measures were rates of pregnancy, live birth, miscarriage and fetal anomalies.</p><p><b>RESULTS</b>The pregnancy and live birth rates were 34.7% and 27.7%, respectively. Among those who achieved pregnancy, 17.0% miscarried, 0.8% had ectopic pregnancies and 0.3% had molar pregnancies. Fetal anomalies were detected in 1.9% of pregnancies, all of which were terminated by choice.</p><p><b>CONCLUSION</b>Since the outcomes of dydrogesterone are comparable to those of intramuscular and vaginal progesterone, it is a reasonable option to provide luteal phase support for women who are uncomfortable with injections or vaginal insertions. Randomised controlled studies are needed to determine the optimal dosage of dydrogesterone for luteal phase support in ARTs.</p>

Use of In Vitro Fertilisation Prediction Model in an Asian Population-Experience in Singapore

<p><b>INTRODUCTION</b>This retrospective study was conducted to perform an external validation of the in vitro fertilisation (IVF) predict model developed by Scott Nelson et al in an Asian population.</p><p><b>MATERIALS AND METHODS</b>All IVF cycles registered in the study centre from January 2005 to December 2010 were included. Observed and predicted values of at least 1 live birth per cycle were compared by discrimination, calibration. Hosmer-Lemeshow test was used to assess the goodness-of-fit of the model calibration and Brier score was used to assess overall model performance.</p><p><b>RESULTS</b>Among 634 IVF cycles, rate of at least 1 live birth was 30.6%. Causes of infertility were unexplained in 35.5% cases. Fifty-seven percent of women came for their first IVF treatment. First IVF cycle showed significantly higher success in comparison to subsequent cycles. The odds ratio of successful live birth was worse in women with endometriosis. Observed outcome was found to be more than the prediction of the model. The area under the curve (AUC) in this study was found to be 0.65 that was close to that of Nelson model (0.6335) done in internal validation. Brier score (average prediction error) of model was 0.2. Chi square goodness-of-fit test indicated that there was difference between the predicted and observed value (x² =18.28, df = 8, P = 0.019). Overall statistical findings indicated that the accuracy of the prediction model fitted poorly with the study population.</p><p><b>CONCLUSION</b>Ovarian reserve, treatment centre and racial effect on predictability cannot be excluded. So it is important to make a good prediction model by considering the additional factors before using the model widely.</p>

Academy of Medicine-Ministry of Health Clinical Practice Guidelines: assessment and management of infertility at primary healthcare level

The Academy of Medicine (AMS) and Ministry of Health (MOH) have developed the clinical practice guidelines on Assessment and Management of Infertility at Primary Healthcare Level to provide doctors and patients in Singapore with evidence-based treatment for infertility. This article reproduces the introduction and executive summary (with recommendations from the guidelines) from the AMS-MOH clinical practice guidelines on Assessment and Management of Infertility at Primary Healthcare Level, for the information of SMJ readers. Chapters and page numbers mentioned in the reproduced extract refer to the full text of the guidelines, which are available from the Ministry of Health website: http://www.moh.gov.sg/content/moh_web/healthprofessionalsportal/doctors/guidelines/cpg_medical/2013/cpgmed_infertility.html. The recommendations should be used with reference to the full text of the guidelines. Following this article are multiple choice questions based on the full text of the guidelines.

pH responsive PEGylation through metal affinity for gene delivery mediated by histidine-grafted polyethylenimine.

Polyethylene glycol (PEG) has been used to enhance the stability of a gene delivery system. The most commonly used approach is to add the PEG molecule by way of chemical conjugation. In this study, we prepared PEG-bearing nitrilotriacetic acid (ntaPEG) followed by chelation with either nickel or zinc ions. Polyethylenimine was grafted with histidine (hisPEI) and used as a primary gene carrier to form complexes with DNA. PEGylation was performed by incubating the complexes with chelated ntaPEG. It was noted that the coating of the chelated ntaPEG could provide a shielding effect against aggregation induced by bovine serum albumin and DNA release induced by heparin displacement, respectively. The coating was also found to improve cellular viability and maintain the transfection efficiency at a moderate level. The coated ntaPEG could dissociate from the complexes in an acidic condition of pH 4, suggesting that dePEGylation might occur in some acidic intracellular organelles, such as endosomes. This simple and effective PEGylation approach could be extended to other delivery systems to enhance the stability and to facilitate the dePEGylation process.

Is semen polymorphonuclear leucocytes count a good predictor of male genital tract infection?

<p><b>INTRODUCTION</b>This study aims to evaluate whether an increased polymorphonuclear leucocyte (PMN) count in semen is a good predictor of male genital tract infection, which is detected by semen culture.</p><p><b>METHODS</b>A retrospective cross-sectional study examining the semen of 388 men was conducted at the in vitro fertilisation centre of a tertiary hospital. We compared the culture results of 109 men with increased semen PMN count against those of 279 men with normal semen PMN count.</p><p><b>RESULTS</b>There was no significant difference in the percentage of positive cultures between men with increased PMN count in their semen and those without PMN count elevation (original sensitivity 20.8%, specificity 70.3%; p = 0.1289). The overall percentage of positive semen cultures among all 388 patients was 18.6%.</p><p><b>CONCLUSION</b>Based on the positive cultures of significant organisms in the semen of our cohort, an increased semen PMN count is not a good predictor of genital tract infection in men.</p>

Using trehalose delivered by the intramuscular injection of plasmid DNA as an adjuvant for transgene expression.

BACKGROUND: Intramuscular injection is a popular and effective approach to administer naked plasmid for transgene expression. The use of an adjuvant can provide a straightforward approach for enhancing transgene expression. METHODS: Expression plasmid was formulated with various concentrations of trehalose for injection into the skeletal muscles of C57BL/6 mice. The effects of trehalose on gene dosage and the duration of transgene expression were assessed. The levels of transgene expression were indicated by levels of luciferase expression of the homogenized whole skeletal muscle or by histological X-gal staining of beta-galactosidase expression. Trehalose was also added to serum to examine the ability of protecting the DNA from degradation. RESULTS: It was found that an optimal trehalose concentration of 10 mM will achieve a level of transgene expression that is seven-fold higher than in the absence of trehalose. When compared with other disaccharides, only the incorporation of trehalose can effectively enhance transgene expression. Trehalose is able to improve transgene expression by intramuscular injection at a low gene dosage as well as prolong the duration of transgene expression. CONCLUSIONS: Trehalose is an effective adjuvant for intramuscular administration of naked plasmid with respect to both enhanced levels and prolonged duration of transgene expression, most likely due to retarding plasmid degradation.

Trehalose enhances transgene expression mediated by DNA-PEI complexes.

Using enhancers to improve the transfection efficiency of polyethylenimine (PEI) can circumvent the needs of chemical modifications as well as subsequent purification and characterization of the modified PEI. In this study, we found that incorporating trehalose into the transfection reagent could improve the transgene expression mediated by DNA-PEI complexes. Such enhancements were not observed when trehalose was replaced by other disaccharides. In an effort to explore the mechanisms, we examined how the timing of trehalose treatments and the durations of trehalose affected the percentages of cells expressing green fluorescent protein and the levels of intracellular ethidium monoazide labeled plasmid. Treatments with trehalose for 5-120 min prior to transfection could cause drops in transfection efficiency by 30-50%; such treatments, however, hardly affected the amounts of intracellular plasmid, indicating that the preexistence of intracellular trehalose could reduce transfection efficiency without lowering the endocytic activity. The transfection efficiency remained almost unchanged when the transfected cells were treated with trehalose after the removal of transfection reagents, indicating that trehalose had minimal effects on the machinery of protein synthesis. Despite the enhanced transgene expression, the presence of trehalose during transfection showed inhibitory effects on the internalization of DNA-PEI complexes. Additionally, the extent of enhancement in transgene expression strongly depended on the duration of trehalose. As the above observations suggested, only during the transfection process when complexes and trehalose coexisted, trehalose became an effective enhancer of transgene expression mediated by DNA-PEI complexes possibly by affecting the mechanisms of intracellular trafficking.

Using disaccharides to enhance in vitro and in vivo transgene expression mediated by a lipid-based gene delivery system.

BACKGROUND: Lipid-based vectors have been widely applied to in vivo and in vitro gene delivery. Disaccharides can effectively stabilize lipid membranes. This study examined whether disaccharides could enhance the transgene expression mediated by lipid-based vectors. METHODS: Different disaccharides were incorporated into the vectors prepared with DOTAP/protamine/DNA (LPD) or with DNA/cationic liposomes containing DOTAP, DOTAP/Chol, DOTAP/DOPE, or DC-Chol/DOPE. The levels of transgene expression and internalized plasmid of CHO cells were represented by the percentages of GFP-positive cells and the fluorescence intensity of ethidium-monoazide covalently labeled plasmid, respectively. The vectors containing either cellobiose or trehalose were also intravenously injected into mouse tail vein to investigate the potentials of in vivo applications. RESULTS: For enhancing the transgene expression, cellobiose was found to be effective for all the vectors whereas maltose decreased the effectiveness of DOTAP/Chol liposomes and LPD. For the internalization of plasmid, most disaccharides were able to increase the cellular delivery of DOTAP, DOTAP/Chol, and DOTAP/DOPE liposomes, but caused decreases in the cellular entry of DC-Chol/DOPE liposomes. An approximately linear correlation between the internalized plasmid and the transgene expression was observed for all the treatments in this study. When the vectors were administered to mouse by intravenous injection, 10-fold and 3-fold increases in the luciferase expression of lung were observed for DOTAP liposomes containing 330 mM cellobiose and trehalose, respectively. CONCLUSIONS: This study showed that using trehalose and cellobiose with a lipid-based delivery system provides a straightforward approach to effectively enhance both in vitro and in vivo transgene expression.

Dependence of transgene expression and the relative buffering capacity of dextran-grafted polyethylenimine.

Branched polyethylenimine (PEI) is a cationic polymer capable of forming self-assembly complexes with DNA to become a highly efficient agent used in gene delivery. Conjugation through the primary amines of PEI is a most commonly used approach further to enable the targeting delivery or to improve the stability of the DNA-polymer complexes. An understanding of how the conjugation affects the transfection mechanisms can help in the design of efficient polycationic vectors. In order to investigate the effects of conjugation, folate and the dextrans of molecular weight 1500 (dex-1500) and 10 000 (dex-10000) were used to prepare three different types of PEI conjugates: dextran-PEI, folate-PEI, and folate-dextran-PEI, which were subsequently employed to form complexes with DNA. These conjugates were found to cause less cytotoxicity than the unmodified PEI as revealed by the MTT method, and to be able to deliver an approximate amount of ethidium monoazide labeled plasmid into the cells. The efficiencies of green fluorescent protein (GFP) expression mediated by these conjugates, however, were less efficient than those mediated by the unmodified PEI. A titration experiment suggested that conjugation through the primary amines of PEI resulted in the loss of relative buffering capacity, a major factor aiding the release of plasmid from the endosomes, presumably because the conjugated molecules hindered the protonation of the PEI conjugates. When a quantitative relationship between relative buffering capacity and transfection efficiency was examined, a threshold of relative buffering capacity, around 50% of the unmodified PEI, was noted to be required for minimal detection of GFP positive cells. In addition, the cytotoxicity could be also related to the relative buffering capacity in an approximately linear trend. It is thus concluded that the severe loss of relative buffering capacity by conjugation might be attributed to the inefficiency of transgene expression mediated by the dextran-PEI conjugates.