Efficacy of scleral buckling for the treatment of rhegmatogenous retinal detachment using a novel foldable capsular buckle.

AIM: To evaluate the effectiveness and safety of scleral buckling for the treatment of rhegmatogenous retinal detachment (RRD) using a novel foldable capsular buckle (FCB). METHODS: This was a series of case observation studies. Eighteen patients (18 eyes) who visited our ophthalmology department between August 2020 and August 2022 and were treated for RRD with scleral buckling using FCB were included. The procedure was similar to conventional scleral buckling, while a balloon-like FCB was placed onto the retinal break with balanced salt solution filling for a broad, external indentation instead of the silicone buckle. The retinal reattachment rate, best corrected visual acuity (BCVA), intraocular pressure (IOP), refractive dioptre and astigmatism degree, and complications were evaluated and recorded. RESULTS: There were 7 males and 11 females aged 19-58y. The average time course of RRD was 12d, ranging from 7-20d. The retinal break was located in the superior quadrants in 8 eyes and in the inferior quadrants in 10 eyes, with macula-off detachments in 12 eyes. The patients were followed-up for at least 6mo. The final retinal reattachment rate was 100%. The BCVA was significantly improved compared with the baseline (P<0.05). There was no significant change in refractive dioptre or astigmatism degree at each follow-up (all P>0.05). Three patients had transiently high IOPs within one week after surgery. Mild diplopia occurred in 5 patients after surgery and then disappeared after the balloon fluid was removed. CONCLUSION: The success rate of FCB scleral buckling for RRD is satisfactory. This procedure can be expected to be applied in new, uncomplicated cases of RRD.

[Simultaneous determination of 22 antibiotics in environmental water samples by solid phase extraction-high performance liquid chromatography-tandem mass spectrometry].

The widespread and frequent use of antibiotics to treat diseases or encourage animal growth has resulted in their persistence and accumulation in water, soil, and sediments. As a typical emerging pollutant in the environment, antibiotics have become an important research focus in recent years. Antibiotics are commonly found at trace levels in water environments. Unfortunately, the determination of various types of antibiotics, all of which exhibit different physicochemical properties, remains a challenging endeavor. Thus, developing pretreatment and analytical techniques to achieve the rapid, sensitive, and accurate analysis of these emerging contaminants in various water samples is an essential undertaking.In this paper, a solid phase extraction-high performance liquid chromatography-tandem mass spectrometry (SPE-HPLC-MS/MS) method for the simultaneous determination of 22 antibiotics including 4 penicillins, 12 quinolones and 6 macrolides in environmental water samples was developed. Based on the characteristics of the screened antibiotics and sample matrix, the pretreatment method was optimized, focusing on the SPE column, pH of the water sample, and amount of ethylene diamine tetra-acetic acid disodium (Na2EDTA) added to the water sample. Prior to extraction, a 200 mL water sample was added with 0.5 g of Na2EDTA and pH-adjusted to 3 using sulfuric acid or sodium hydroxide solution. Water sample enrichment and purification were achieved using an HLB column. HPLC separation was carried out on a C18 column (100 mm×2.1 mm, 3.5 µm) via gradient elution with a mobile phase composed of acetonitrile and 0.15% (v/v) formic acid aqueous solution. Qualitative and quantitative analyses were performed on a triple quadrupole mass spectrometer in multiple reaction monitoring mode using an electrospray ionization source. The results showed correlation coefficients greater than 0.995, indicating good linear relationships. The method detection limits (MDLs) and limits of quantification (LOQs) were in the ranges of 2.3-10.7 ng/L and 9.2-42.8 ng/L, respectively. The recoveries of target compounds in surface water at three spiked levels ranged from 61.2% to 157%, with relative standard deviations (RSDs) of 1.0%-21.9%. The recoveries of target compounds in wastewater at three spiked levels were 50.1%-129%, with RSDs of 1.2%-16.9%. The method was successfully applied to the simultaneous determination of antibiotics in reservoir water, surface water, sewage treatment plant outfall, and livestock wastewater. Most of the antibiotics were detected in watershed and livestock wastewater. Lincomycin was detected in 10 surface water samples, with a detection frequency of 90%, and ofloxacin showed the highest contents (127 ng/L) in livestock wastewater. Therefore, the present method exhibits excellent performance in terms of MDLs and recoveries compared with previously reported methods. The developed method presents the advantages of small water sample volumes, wide applicability, and fast analysis times; thus, it can be considered a rapid, efficient, and sensitive analytical method with excellent potential for monitoring emergency environmental pollution. The method could also provide a reliable reference for formulating antibiotic residue standards. The results provide strong support for and an improved understanding of the environmental occurrence, treatment, and control of emerging pollutants.

Astragaloside IV ameliorates metabolic disorder in db/db obese mice as a PPARγ antagonist.

Metabolic disorder is highly related to obesity, insulin resistance, hypertension, and hyperlipidemia. The present study found that astragaloside IV (ASI) attenuated metabolic disorder related symptoms and modulated hepatic lipid metabolism associated gene mRNA expression in db/db mice. ASI inhibited rosiglitazone-induced adipocyte differentiation of 3T3-L1 cells, and lipid accumulation in palmitic acid (PA)-induced HepG2 cells with down-regulated mRNA expression of lipogenesis-related genes. In addition, it was predicted to bind to the ligand binding domain (LBD) of PPARγ and inhibit its transactivity. Collectively, our study suggested that ASI improves lipid metabolism in obese mice probably through suppressing PPARγ activity.

[Cumulative effects of K-function in the research of point patterns]. / ç‚¹æ ¼å±€ç ”ç©¶è¿‡ç¨‹ä¸­K-函数的累积效应.

The spatial pattern of plant population is one of primary issues in ecological research. Point pattern analy-sis is considered as an important method to study the spatial pattern of plant population. Ripley's K function has been commonly used for point pattern analysis. However, the cumulative effect of Ripley's K function may lead to specific spatial pattern charcteristics. To explore how the cumulative effect of Ripley's K function affects population pattern, the data of clumped distribution, random distribution and regular distribution of Stipa grandis were simulated by R software. All data generated by R software were analyzed by Ripley's K function and the non-cumulative pairwise correlation function g(r). The results showed that for clumped distribution (or regular distribution), the cumulative effect of Ripley's K function was manifested in two aspects. On the one hand, the scale of clumped distribution (or regular distribution) was increased due to Ripley's K function. On the other hand, Ripley's K function could detect the difference of the distribution of cluster (or negative interaction range) in the sampling space, exhibiting different pattern characteristics. For random distribution, Ripley's K function had no cumulative effect. In conclusion, the combination of Ripley's K function and pairwise correlation function by collecting replicate samples could better reveal the essential characteristics of the pattern in the study of population pattern.

Effectiveness and Safety of Anlotinib with or without PD-1 Blockades in the Treatment of Patients with Advanced Primary Hepatocellular Carcinoma: A Retrospective, Real-World Study in China.

Purpose: Anlotinib, a novel multi-target tyrosine kinase inhibitor, has shown encouraging antitumor effects in advanced hepatocellular carcinoma (HCC). This study evaluated the effectiveness and safety of anlotinib with or without programmed death-1 (PD-1) blockades for patients with advanced primary HCC in a real-world setting in China. Patients and Methods: Between July 2019 and May 2021, 27 patients with advanced primary HCC who received at least 2 cycles of anlotinib were included in this retrospective study. Primary endpoint was objective response rate (ORR). Secondary endpoints were disease control rate (DCR), progression-free survival (PFS), overall survival (OS), and safety. Results: Of the 27 patients, ORR and DCR were 25.93% and 74.07%, respectively. The median follow-up time was 6.27 months (range: 1.30-17.40) with a median PFS and OS of 3.29 months (95% CI: 1.31-15.47) and 6.21 months (95% CI: 2.23-15.87), respectively. A total of 14 patients received anlotinib and PD-1 blockade combination therapy, and 13 received anlotinib monotherapy. No significant differences were observed in ORR (28.57 vs 23.08%), DCR (71.43 vs 76.92%), PFS (3.38 [95% CI: 2.66-13.14] vs 11.86 months [95% CI: 4.27-15.93]) and OS (4.90 [95% CI: 2.56-13.60] vs 11.04 months [95% CI: 1.31-17.18]) between the two groups (all p>0.05). Treatment-related AEs were reported in 88.89% of patients. Grade 3 AE was bleeding, which occurred in 3 patients (11.11%). Conclusion: Anlotinib yielded a promising efficacy and manageable safety in patients with advanced primary HCC irrespective of whether patients received PD-1 blockades, indicating that anlotinib might be a promising treatment option for this patient population.

Suicide and non-suicide mortality and associated risk factors among suicide attempters: A 10-year follow-up of a large cohort in rural China.

Previous suicide attempt is a strong risk factor for subsequent suicide and other causes of mortality, but evidence from China is sparse. In this study, follow up face-to-face interviews were conducted with suicide attempters or a key informant, and any subsequent deaths were examined through local cause-of-death censoring databases to ascertain details surrounding the death. Competitive risk models and Cox proportional hazard regression models were used to ascertain significant risk factors of suicide, non-suicide and overall deaths following suicide attempt. Predictive nomograms were also constructed to predict the probability of suicide, non-suicide, and overall deaths. A total of 1103 suicide attempters were successfully interviewed with an average follow-up time of 7.48 (7.38-7.57) years. The cumulative rates of suicide at 1, 2, 3, 5 and 10 years were 0.27%, 0.63%, 0.91%, 1.56%, and 1.83%, respectively. Factors significantly associated with subsequent suicide were advancing age, history of suicide attempt, and mental disorders. Significant risk factors for non-suicide death included males, advancing age, and physical illness. Overall deaths during the follow-up period were associated with males, advancing age, physical illness, and mental disorders. Predictive models showed good ability with satisfactory C-indexes (between 0.77 and 0.86) and excellent calibration performance in predicting the varying causes of subsequent death among suicide attempters in rural China.

Depressive symptoms as a mediator between perceived social support and suicidal ideation among Chinese adolescents.

OBJECTIVE: Little is known about the association between perceived social support (PSS) and suicidal ideation in Chinese adolescents. This study was to examine the association of perceived social support and suicidal ideation (SI) and the mediating role of depressive symptoms in a large sample of adolescents in China. METHOD: A total of 11,831 adolescents who participated in the baseline Shandong Adolescent Behavior & Health Cohort were included for analysis. Perceived social support, depressive symptoms, and other variables were assessed by a self-administrated questionnaire. Path analysis was used to estimate the association between PSS, depressive symptoms, and suicidal ideation. RESULTS: The prevalence rate of SI in the past year was 12.5%. Suicidal ideation and depressive symptoms were significantly associated with low PSS from family, friends, and significant others. Path analysis revealed that depressive symptoms partially mediated the relationship between PSS from family, friends, and significant others and suicidal ideation. After controlling for covariates, the mediation effect proportion of depressive symptoms on the associations between perceived social support from family, friends, and significant others and SI ranged from 19.20% to 62.12%. LIMITATIONS: As this is a cross-sectional study, no causal relationship could be made. CONCLUSIONS: Depressive symptoms partially mediated the association between perceived social support and suicidal ideation. Longitudinal research is needed to better understand the association between social support and suicidal ideation in adolescents.

Prediction of recurrent suicidal behavior among suicide attempters with Cox regression and machine learning: a 10-year prospective cohort study.

BACKGROUND: Research on predictors and risk of recurrence after suicide attempt from China is lacking. This study aims to identify risk factors and develop prediction models for recurrent suicidal behavior among suicide attempters using Cox proportional hazard (CPH) and machine learning methods. METHODS: The prospective cohort study included 1103 suicide attempters with a maximum follow-up of 10 years from rural China. Baseline characteristics, collected by face-to-face interviews at least 1 month later after index suicide attempt, were used to predict recurrent suicidal behavior. CPH and 3 machine learning algorithms, namely, the least absolute shrinkage and selection operator, random survival forest, and gradient boosting decision tree, were used to construct prediction models. Model performance was accessed by concordance index (C-index) and the time-dependent area under the receiver operating characteristic curve (AUC) value for discrimination, and time-dependent calibration curve along with Brier score for calibration. RESULTS: The median follow-up time was 7.79 years, and 49 suicide attempters had recurrent suicidal behavior during the study period. Four models achieved comparably good discrimination and calibration performance, with all C-indexes larger than 0.70, AUC values larger than 0.65, and Brier scores smaller than 0.06. Mental disorder emerged as the most important predictor across all four models. Suicide attempters with mental disorders had a 3 times higher risk of recurrence than those without. History of suicide attempt (HR = 2.84, 95% CI: 1.34-6.02), unstable marital status (HR = 2.81, 95% CI: 1.38-5.71), and older age (HR = 1.51, 95% CI: 1.14-2.01) were also identified as independent predictors of recurrent suicidal behavior by CPH model. CONCLUSIONS: We developed four models to predict recurrent suicidal behavior with comparable good prediction performance. Our findings potentially provided benefits in screening vulnerable individuals on a more precise scale.

Effects of vitamin D-related gene polymorphisms on attempted suicide.

OBJECTIVE: Emerging evidence suggests that vitamin D might protect from attempted suicide. The study aimed to investigate the associations between single-nucleotide polymorphisms (SNPs) related to vitamin D levels identified in a large genome-wide association study and attempted suicide in rural China. METHODS: This 1:1 matched case-control study included altogether 510 suicide attempters and 510 community controls. Genotypes of four target SNPs (DHCR7-rs12785878, CYP2R1-rs10741657, GC-rs2282679, and CYP24A1-rs6013897) were determined, and a genetic risk score (GRS) was constructed to evaluate the combined effect of them. Demographic and psychological information was acquired through face-to-face interviews. RESULTS: The A allele of CYP24A1-rs6013897 was significantly associated with attempted suicide (OR = 1.27, 95% CI, 1.03-1.58, P = 0.029), even after adjusting for demographic and psychological confounders (adjusted OR = 1.53, 95% CI, 1.01-2.30, P = 0.043). The GRS analyses revealed a significantly higher risk of attempted suicide with a greater number of low vitamin D alleles (adjusted OR = 1.33, 95% CI, 1.13-1.58, P < 0.001). Subgroup analyses stratified by sex indicated that the genetic associations were only significant among males with adjusted ORs of 3.77 (95% CI, 1.56-9.10) for the A allele of rs6013897 and 2.04 (95% CI, 1.32-3.17) for GRS. CONCLUSIONS: Our findings identity CYP24A1-rs6013897 as a potential biomarker for attempted suicide and indicate that a genetic predisposition to lower vitamin D levels may contribute to attempted suicide. It suggests the possibility that vitamin D may have the preventive potential for attempted suicide.

Psychometric properties of the psychological strain scales (PSS) in suicide attempters and community controls of rural China.

BACKGROUND: Psychological Strain Scales (PSS) were developed to measure four types of strain comprising value strain, deprivation strain, aspiration strain, and coping strain. This study aimed to evaluate the psychometric properties of the Chinese version of 40-item PSS in suicide attempters and community controls of rural China. METHODS: Data of this study came from the investigation of 132 suicide attempters and their paired community controls matched with the same sex, age (±3 years) and residence in five counties in rural Shandong, China. The Chinese version of PSS, the Center for Epidemiologic Studies Depression Scale (CES-D), the Trait Anxiety Inventory (TAI) and the Self-esteem Scale (SES) were administered and reliability test and validity test of the PSS were conducted. RESULTS: Cronbach's α and Guttman Spilt-Half coefficient of PSS was 0.942 and 0.842 for suicide attempters, and 0.950 and 0.874 for community controls. For both suicide attempters and community controls, the Exploratory Factor Analysis indicated a one-factor structure of each strain scale, which accorded with the original factor structure proposed by the authors. The scores of the total PSS and four subscales were positively correlated with the scores of CES-D and TAI; and negatively correlated with the score of SES, which indicated a good performance in convergent validity. LIMITATIONS: This study was limited to its generalizability to the Chinese urban population. CONCLUSIONS: The Chinese version of the 40-item PSS has satisfactory psychometric properties in terms of reliability and validity in Chinese rural suicide attempters and community controls.

Depressive symptoms are associated with short and long sleep duration: A longitudinal study of Chinese adolescents.

AIMS: Sleep loss and irregular sleep patterns in adolescents are major public health concerns in the modern society. This study aimed to explore the associations between short and long sleep duration and depressive symptoms among Chinese adolescents. METHODS: A total of 7311 adolescents who participated in the baseline survey and were followed up 1 year or 2 years later were included in the analyses. Participants completed a self-administered questionnaire at baseline and follow-up surveys. The Center for Epidemiologic Studies Depression (CES-D) scale was used to assess depressive symptoms. Generalized estimating equation (GEE) and restrictive cubic spline models were used to estimate the association between sleep duration and depressive symptoms. RESULTS: After adjusting for adolescent and family covariates, sleep duration <8 h and >=9 h on weekdays and sleep duration <8 h and >=12 h on weekends were significantly associated with depressive symptoms compared with sleep 8 h. Weekend-weekday sleep difference >=3 h or <-1 h (ie. sleeping >1 h on weekdays than weekends) was also associated with depressive symptoms. There were U-shaped relationships between sleep duration on weekdays, weekends, or weekday-weekend sleep difference and depressive symptoms. LIMITATIONS: Sleep duration and depression were measured by self-report. CONCLUSIONS: Our findings highlight the risk of short and long sleep duration, and weekday-weekend sleep imbalance for depression in adolescents.

Stressful life events, insomnia and suicidality in a large sample of Chinese adolescents.

AIMS: This study aimed to examine the associations between stressful life events, insomnia, and suicidality including suicidal ideation (SI), suicide plan (SP) and suicide attempt (SA) in a large sample of Chinese adolescents. METHODS: A total of 11,831 adolescents who participated in the baseline survey of Shandong Adolescent Behavior and Health Cohort were included for the analysis. Participants were sampled from 8 middle/high schools in 3 counties of Shandong, China. Participants completed a structured behavior and health questionnaire, including suicidality, demographics, depression/anxiety, stressful life events (SLEs), and insomnia in November-December 2015. A series of logistic regression models and mediation analyses were performed to examine the associations between SLEs, insomnia and suicidality. RESULTS: The prevalence rates of overall suicidality, SI, SP and SA in the last year were 13.1%, 12.5%, 3.3%, and 1.5%, respectively. SLEs were significantly associated with overall suicidality, SI, and SP. Insomnia was an independent risk factor of suicidality and a mediator of the association between SLEs and suicidality. The total effect of SLEs on overall suicidality was 0.597 (95%CI: 0.534-0.661), including 0.457 (95%CI: 0.391-0.523) for direct effect and 0.158 (95%CI: 0.138-0.178) for indirect effect. Insomnia also mediated the associations of SLEs with SI, SP and SA, respectively. LIMITATIONS: Causal relationship could not be concluded because this study is cross-sectional. CONCLUSIONS: Stressful life events and insomnia are directly associated with suicidality in adolescents. The association between SLEs and suicidality is partially mediated by insomnia.

Functional and dysfunctional impulsivity and attempted suicide in rural China: A paired case-control study.

This study aimed to clarify the relationship between functional and dysfunctional impulsivity and attempted suicide in rural China. Data of this study came from the investigation of 407 suicide attempters and their paired non-suicide attempters matched with the same gender, age (±3 years) and residence area in six counties in rural Shandong, China. Suicide attempters accounted for a lower proportion on high functional impulsivity, but a higher proportion on high dysfunctional impulsivity than non-suicide attempters. Dysfunctional impulsivity in the male denoted a significant risk factor for attempted suicide, even after adjustment for psychiatric disorder and demographic factors. Suicide attempters with high dysfunctional impulsivity had a higher percent of family suicide history than those with low dysfunctional impulsivity. High functional impulsivity was a significant protective factor for attempted suicide in the group aged 35-59 years, but a significant risk factor in the group aged 15-34 years. Suicide attempters with low functional impulsivity had poorer economic status and older age than those with high functional impulsivity. Our findings support the key roles of functional and dysfunctional impulsivity in attempted suicide among rural residents of China.

GABA and GABA receptors alterations in the primary visual cortex of concave lens-induced myopic model.

Until recently most researches on myopia mechanisms have mainly been focused on the eye ball and few investigations were explored on the upper visual pathway, such as the visual cortex. The roles of gamma-aminobutyric acid (GABA) in the retinal and in the upper visual pathway are inter-correlated. As the retinal glutamate decarboxylase (GAD), GABA, and the mRNA levels of GABA receptors increased during the concave lens induced myopia formation, however, whether GABA alterations also occurred in the visual cortex during the concave lens induction is still unknown. In the present study, using HPLC, Enzyme-Linked Immunosorbent Assay (ELISA) and Real-Time Quantitative-PCR (RT-PCR) methods, we observed the changing trends of GABA, glutamate decarboxylase (GAD), and GABA receptors in the visual cortex of concave lens-induced myopic guinea pigs. Similar to the changing patterns of retinal GABA, the concentrations of GAD, GABA and the mRNA levels of GABA receptors in the visual cortex also increased. These results indicate that the exploration on myopia mechanisms should possibly be investigated on the whole visual pathway and the detailed significance of cortical GABA alterations needs further investigation.

Suicide attempters with high and low suicide intent: Different populations in rural China.

This paired case-control study aimed to compare characteristics between suicide attempters with high and low suicide intent in rural China. We evaluated 409 suicide attempters and their paired controls who were matched with the same gender, age (a difference of no more than 3 years), and similar residence. Compared to paired control, suicide attempt with high and low suicide intent shared the 3 common risk factors of negative life event, high depression score, and low social support score. In addition, mental disorder was an independent risk factor of suicide attempt with high intent. Having a low education level and occupation as a farmer were risk factors of suicide attempt with low intent. Mental disorder and depression were associated with a significantly increased risk of suicide attempt with high intent compared to low intent. Depression was found to be related to suicide attempt with high intent compared to low intent in the subgroups of male or female aged 35-54 or 55-70 years. Distinct characteristics were found in the suicide attempters with different intent. These findings are important and the aim is to transform them into concrete ideas for the prevention of suicide attempt in rural China.

Menarche, menstrual problems and suicidal behavior in Chinese adolescents.

BACKGROUND: Menarche is the first menstrual cycle. Menstrual problems, such as dysmenorrheal menorrhagia, oligomenorrhea, and irregular cycle are common in female adolescents. This research aims to examine the associations between age at menarche and menstrual problems and suicidal behavior among Chinese female adolescents. METHODS: An epidemiological survey of 5831 female adolescents from eight high schools of three counties of Shandong province, China, was conducted. A self-administered paper-and-pencil questionnaire was used to collect information. Logistic regression analyses were used to examine the association between menstruation and suicidality. RESULTS: The mean age of the sample was 15.02 (SD=1.44) years. Of the sample, 5,231 (90.0%) had experienced their first menstrual cycle, and 23.2%, 10.4%, and 4.5% of the sample reported having had suicidal ideation, plan and attempt, respectively. In multivariate models, menarche at ≤11 years was associated with increased risk of suicidal ideation (OR=1.41, 95%CI: 1.10-1.81) and menarche at 12 years was associated with suicide plan (OR=1.23, 95%CI: 1.00-1.51). Irregular menstrual cycle was significantly associated with increased risk of suicidal ideation (OR=1.40, 95%CI: 1.05-1.86) and menstrual period less than or equal to 4 days was significantly associated with increased risk of suicide plan (OR=1.32, 95%CI: 1.06-1.66). LIMITATIONS: This cross-sectional study cannot establish the causal directions between menstrual problems and suicidality in adolescents. CONCLUSIONS: Our study suggests that earlier menarche, irregular menstrual cycle and short menstrual period are associated with suicidal behavior in female adolescents. Further research is warranted to examine the causal relationship between menstrual problems and suicidal behavior in adolescents.

Association of Brain-Derived Neurotrophic Factor G196A and Attempted Suicide: A Case-Control Study in Rural China.

BACKGROUND: Suicide is an important public problem, the mechanism of which has not been clarified. Many studies have focused on the molecular, biological and genetic mechanisms of suicide. Brain-derived neurotrophic factor (BDNF) G196A is one of the most leading loci in recent studies, but the results are inconsistent. METHODS: We conducted a 1:1 age- and sex-matched case-control study in rural areas of Shandong Province, China. A total of 365 pairs of cases and controls were finally recruited into our study. The adjusted odds ratios (AORs) of BDNF 196G/G and their 95% confidence intervals (CIs) were calculated by multivariate conditional logistic regression models. RESULTS: No association between BDNF polymorphisms and attempted suicide was found in the overall population. However, the BDNF 196G/G genotype was significantly related to attempted suicide in the elderly population (AOR = 7.85, 95% CI: 1.12-54.90, p = 0.038), while the associations were not significant in young and middle-aged groups. CONCLUSION: Our study suggests that the BDNF 196G/G genotype increases the risk of attempted suicide in elderly people.

[Cleistogenes squarrosa population at different restorative succession stages in Inner Mongolia of China: a point pattern analysis].

In this paper, the spatial pattern of Cleistogenes squarrosa population in different restorative succession communities of the typical steppe dominated by Stipa grandis and Leymus chinensis in Inner Mongolia was measured by photography orientation, and analyzed by complete spatial randomness model, Poisson cluster process, and nested double-cluster process. In severely degraded community, C. squarrosa population fitted well nested double-cluster process for all scales, i. e., high density small clusters existed at the centers of large clusters; whereas in 5-, 8-, and 21-year-old restored communities, C. squarrosa population fitted well Poisson cluster process for all scales, i. e. , high density small clusters did not exist at the centers of the clusters. It was suggested that facilitation was the dominant interaction in severely degraded community, while competition dominated in restored communities. The differences in the spatial pattern of C. squarrosa population during the restorative succession could be induced by the shift from facilitation to competition along the gradient of grazing stress.

Increased glucagon-like peptide-1 secretion may be involved in antidiabetic effects of ginsenosides.

Panax ginseng is one of the most popular herbal remedies. Ginsenosides, major bioactive constituents in P. ginseng, have shown good antidiabetic action, but the precise mechanism was not fully understood. Glucagon-like peptide-1 (GLP1) is considered to be an important incretin that can regulate glucose homeostasis in the gastrointestinal tract after meals. The aim of this study was to investigate whether ginseng total saponins (GTS) exerts its antidiabetic effects via modulating GLP1 release. Ginsenoside Rb1 (Rb1), the most abundant constituent in GTS, was selected to further explore the underlying mechanisms in cultured NCI-H716 cells. Diabetic rats were developed by a combination of high-fat diet and low-dose streptozotocin injection. The diabetic rats orally received GTS (150 or 300 mg/kg) daily for 4 weeks. It was found that GTS treatment significantly ameliorated hyperglycemia and dyslipidemia, accompanied by a significant increase in glucose-induced GLP1 secretion and upregulation of proglucagon gene expression. Data from NCI-H716 cells showed that both GTS and Rb1 promoted GLP1 secretion. It was observed that Rb1 increased the ratio of intracellular ATP to ADP concentration and intracellular Ca2+ concentration. The metabolic inhibitor azide (3 mM), the KATP channel opener diazoxide (340 µM), and the Ca2+ channel blocker nifedipine (20 µM) significantly reversed Rb1-mediated GLP1 secretion. All these results drew a conclusion that ginsenosides stimulated GLP1 secretion both in vivo and in vitro. The antidiabetic effects of ginsenosides may be a result of enhanced GLP1 secretion.

P-glycoprotein and multidrug resistance-associated protein 2 are oppositely altered in brain of rats with thioacetamide-induced acute liver failure.

BACKGROUND: P-glycoprotein (P-GP) and multidrug resistance-associated protein 2 (MRP2) are involved in transport of many drugs across blood-brain barrier (BBB). The function and expression of P-GP and MRP2 may be modulated by different pathologies. Acute liver failure (ALF) was reported to impair BBB function, resulting in the increased BBB permeability. AIMS: We investigated whether ALF altered function and expression of P-GP and MRP2 in brain of thioacetamide-induced ALF rats. METHODS: ALF was induced by intraperitoneal injection of thioacetamide (300 mg/kg) for 2 days with a 24-h interval. The rats were used for experiments at 6, 12 and 24 h after the second administration. P-GP and MRP2 function in brain were determined using the brain-to-plasma ratios of corresponding substrates (rhodamine 123 and vincristine for P-GP; sulfobromophthalein and dinitrophenyl-S-glutathione for MRP2). Evans blue was used for examining the BBB integrity. Western blot was accomplished to determine P-GP and MRP2 protein expression. RESULTS: The brain-to-plasma ratios of rhodamine 123 and vincristine were significantly increased in ALF-6 h rats and almost returned to normal levels in ALF-24 h rats, whereas those of sulfobromophthalein and dinitrophenyl-S-glutathione were decreased in all ALF rats. Western blot results showed that ALF decreased brain P-GP levels at 6 and 12 h, whereas increased MRP2 levels at 6, 12 and 24 h. No significant difference of Evans blue concentrations in brain was found among the four groups. CONCLUSIONS: Function and expression of P-GP and MRP2 in brain of thioacetamide-induced ALF rats were oppositely altered.