[Effects of hemoglobin J-Bangkok traits on measurements of glycated hemoglobin by five methods]

OBJECTIVE

To evaluate the interference of hemoglobin variants J-Bangkok on glycated hemoglobin (HbA(1)c) detected by five measurement systems.

METHODS

Seventy cases of blood samples were collected at Zhongshan Hospital of Sun Yat-sen University from July 2012 to January 2014, the blood samples were divided into the normal control group (40 cases) and Hb J-Bangkok variant group (30 cases), and the normal control group was divided into healthy control group (20 cases) and diabetic group (20 cases). HbA(1)c measurement systems were Primus Ultra2, Variant Ⅱ, Variant Ⅱ Turbo, Modular P and Leadman. Based on the standard of the American National Glycosylated Hemoglobin Standardization Program (NGSP), Primus Ultra2 was used as comparative system, and the other 4 systems were test systems. Comparative analysis and bias evaluation were conducted on the results from five detection systems in different groups, statistical analysis were used for evaluating the differences. The estimated average glucose (eAG) was calculated by HbA(1)c values and fasting plasma glucose (FPG) of Hb J-Bangkok variant group with the different detection systems. Deming regression analysis was used to determinate whether Hb J-Bangkok produced significant clinical effect on HbA(1)c results. HbA(1)c ± 10% and relative bias at 6% and 9% HbA1c were evaluation limits.

RESULTS

The differences of the 95% confidence interval (95%CI) between the test systems and the comparative system in control group were within ±0.7% HbA(1)c, bias were less than 6%, there were no statistically significant difference (P>0.05). In Hb J-Bangkok group, the eAG calculated from HbA(1)c measured by using Primus Ultra2, Modular P and Leadman were (8.14±2.99), (8.10±3.06) and (8.23±3.00)mmol/L, which had no statistically significant difference compared with FPG ((8.21±3.12)mmol/L, t=0.996, 1.091, 1.479, all P>0.05), and the differences of 95%CI between the results measured by Modular P and the comparative system were all within ±0.7% HbA(1)c, bias were -4.3%-0.4% and -5.2%-4.9%, there were no statistically significant difference (P>0.05). At 6% and 9% HbA(1)c concentrations, the mean differences of the results from the three detection systems were less than the clinically acceptable range. These results showed that the systems of Primus Ultra2, Modular P and Leadman were not affected by Hb J-Bangkok. However, the eAG values calculated from HbA(1)c of Variant Ⅱ and Variant Ⅱ Turbo were (5.58±2.12) and(5.00±2.13)mmol/L, which showed statistically significant lower results compared with FPG level (t=12.29, 13.23 , all P<0.001). Compared with Primus Ultra2, the differences of 95%CI were outside of ± 0.7% HbA1c, bias were -31.9%--12.0% and -42.0%- -17.6% , greater than 6%, showed a negative bias.At 6% and 9% HbA(1)c concentrations, the mean differences of the results were all greater than the clinical acceptable range. These results indicated that Hb J-Bangkok had significantly clinical interference on Variant Ⅱ and Variant Ⅱ Turbo systems.

CONCLUSION

Hb J-Bangkok has different interference on different HbA(1)c measurement systems, when performs the HbA(1)c test, clinical laboratory should pay attention to identify Hb variants, and select the appropriate methods to measure the HbA(1)c values in order to prevent the occurrence of interference by Hb variants.

Maximum-biomass concentration prediction for Bifidobacteria in the pH-controlled fed-batch culture

Our objective was to systematically study the relationship between maximum biomass concentration of different Bifidobacteria and total-acid anions accumulation, and develop a prediction equation for the maximum biomass concentration in the fed-batch culture at pH-controlled 7·0. The accumulation of acid anions and the consumption of nutrients of various strains were evaluated. In addition, minimum inhibitory concentrations (MICs) of acid anions on a range of strains were examined at pH 7·0. The inhibition of acid anions, which had the same MIC as sodium chloride, was due to the osmotic pressure under pH 7·0 conditions. Moreover, the concentration of total-acid anions completely inhibiting each strain in the fed-batch culture at pH-controlled 7·0 had no significant differences with the MIC of acid anions for the corresponding strains. The osmotic pressures under two conditions were not significantly different. Finally, the maximum biomass concentration of Bifidobacteria was found to be closely related to biomass yield per unit of acid anion produced (YX/P ) and MIC (C) which were needed for the prediction, and different strains exhibited marked correlation (P ˂ 0·01, R = 0·985). An equation for the prediction of the maximum biomass concentration was developed as follows: Xmax -X0  = (0·71 ± 0·03)·YX/P ·C.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study provides further insights into the inhibition of Bifidobacteria by dissociated acid anions (the dissociated form) at pH 7·0. The high correlation between different strains suggested that the equation established in this paper is appropriate for different strains of Bifidobacteria. The prediction equation could be used to guide practical production in the preparation of materials, the control of the end of fermentation and production plans for further products such as freeze-dried powder of Bifidobacteria or food fermentation.

Extraction and antioxidant activity of flavonoids of Morus nigra

Morus nigra has a long history of medicinal use in Chinese medicine, but the study on it is limited, the flavonoids are one of the main biological active substances. In this study, the Morus nigra flavonoids were extracted by ultrasonic and antioxidant activities both in vitro and in vivo were measured. The results showed that hydroxyl radicals clearance rate and superoxide radical anion clearance rate in vitro increased with the concentration of the total flavonoids in the range of 0-1.05 mg/mL and the maximum clearance rate was 80.33% and 87.69%, respectively. After mice were treated with flavonoids, the content of malonaldehyde (MDA) in serum and liver decreased; the activities of superoxide dismutase (SOD) in serum and liver, catalase (CAT) in liver and glutathione peroxidase (GSH-PX) in blood and liver increased; Langhans cells increased in spleen. These results revealed that the Morus nigra flavonoids possessed strong antioxidant activity.

Homology-based analysis of the GRAS gene family in tobacco

Members of the GRAS gene family are important transcriptional regulators. In this study, 21 GRAS genes were identified from tobacco, and were classified into eight subgroups according to the classification of Arabidopsis thaliana. Here, we provide a preliminary overview of this gene family in tobacco, describing the gene structure, gene expression, protein motif organization, phylogenetic analysis, and comparative analysis in tobacco, Arabidopsis, and rice. Using the sequences of 21 GRAS genes in Arabidopsis to search against the American tobacco genome database, 21 homologous GRAS genes in tobacco were identified. Sequence analysis indicates that these GRAS proteins have five conserved domains, which is consistent with their counterparts in other plants. Phylogenetic analyses divided the GRAS gene family into eight subgroups, each of which has distinct conserved domains and biological functions. Furthermore, the expression pattern of these 21 GRAS genes reveals that most are expressed in all six tissues studied; however, some have tissue specificity. Taken together, this comprehensive analysis will provide a rich resource to assist in the study of GRAS protein functions in tobacco.

Prophylactic lamivudine to improve the outcome of HBsAg-positive lymphoma patients during chemotherapy: a systematic review and meta-analysis

Hepatitis B viral (HBV) reactivation in lymphoma patients undergoing chemotherapy is associated with significant morbidity and mortality. Increasingly, lamivudine is being used to prevent hepatitis B reactivation. To assess the effects of prophylactic lamivudine on reactivation and mortality following chemotherapy in lymphoma patients who are hepatitis B surface antigen (HBsAg)-positive, we searched Medline/PubMed, Ovid MEDLINE, EMBASE, Web of Knowledge and the Cochrane Library for studies through November 2013. Statistical analysis was performed using REVMAN. Fourteen studies consisting of 636 patients were included in the analysis. The rate of HBV reactivation, incidence of hepatitis and incidence of hepatitis due to HBV reactivation in patients with lamivudine prophylaxis was significantly lower than those with no prophylaxis. Risk ratios [RRs] were 0.25 (95% confidence intervals [CI] 0.13-0.51; P=0.0001), 0.40 (95% CI 0.26-0.63; P<0.0001), and 0.21 (95% CI 0.09-0.51; P=0.0005) respectively. In addition, patients given prophylactic lamivudine had significant reductions in overall mortality and mortality attributable to HBV reactivation compared with control group. Risk ratios [RRs] were 0.45 (95% CI 0.29-0.70; P=0.0004) and 0.41 (95% CI 0.20-0.84; P=0.01) respectively. Chemotherapy disruption was not significantly different between the two groups. Risk ratios [RRs] were 0.34 (95% CI 0.09-1.26; P=0.11). Prophylactic therapy with lamivudine for HBsAg-positive lymphoma patients who are undergoing chemotherapy may reduce the risk for HBV reactivation, hepatitis due to HBV reactivation, overall mortality and mortality attributable to HBV reactivation. Additionally, patients with preventive lamivudine had a trend towards the decreased incidence of chemotherapy disruption.

Efficacy of tension-free vaginal tape obturator and single-incision tension-free vaginal tape-Secur, hammock approach, in the treatment of stress urinary incontinence

AIM

Aim of the present study was to compare the efficacy of tension-free vaginal tape obturator and single-incision tension-free transvaginal tape Secur, hammock approach, in the treatment of stress urinary incontinence.

METHODS

Clinical data of patients who received anti-incontinence surgery between June 2008 and July 2012 were retrospectively analyzed. Efficacy and early failure rate of the tension-free vaginal tape obturator and tension-free vaginal tape-Secur hammock approach were assessed by cough test and criteria of International Consultation on Incontinence Questionnaire-Short Form. Intraoperative and postoperative complications were also computed.

RESULTS

There were 28 patients in the tension-free vaginal tape obturator group while 32 patients in the tension-free vaginal tape-Secur group. The mean operation time, intraoperative blood loss and inpatient days after surgery between the two groups showed no significant difference. The catheter retention time of the tension-free vaginal tape obturator group was longer than in the tension-free vaginal tape-Secur group. The cure rate of the tension-free vaginal tape obturator and tension-free vaginal tape-Secur groups were respectively 84% and 80%, and the recurrence rates were 14.3% and 16.7%, without significant difference. The scores of International Consultation on Incontinence Questionnaire-Short Form in two groups both decreased after surgery, but there was no difference between the two groups. There were no serious complications in the two groups.

CONCLUSION

Our study demonstrated that both tension-free vaginal tape obturator and tension-free vaginal tape-Secur can achieve a cure rate over 80% while with little complications, showing both methods are reliable to treat stress urinary incontinence.

Associations between CD36 gene polymorphisms and susceptibility to coronary artery heart disease

Associations between polymorphisms of the CD36 gene and susceptibility to coronary artery heart disease (CHD) are not clear. We assessed allele frequencies and genotype distributions of CD36 gene polymorphisms in 112 CHD patients and 129 control patients using semi-quantitative polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analysis. Additionally, we detected CD36 mRNA expression by real-time quantitative PCR, and we quantified plasma levels of oxidized low-density lipoprotein (ox-LDL) using an enzyme-linked immunosorbent assay (ELISA). There were no significant differences between the two groups (P>0.05) in allele frequencies of rs1761667 or in genotype distribution and allele frequencies of rs3173798. The genotype distribution of rs1761667 significantly differed between CHD patients and controls (P=0.034), with a significantly higher frequency of the AG genotype in the CHD group compared to the control group (P=0.011). The plasma levels of ox-LDL in patients with the AG genotype were remarkably higher than those with the GG and AA genotypes (P=0.010). In a randomized sample taken from patients in the two groups, the CD36 mRNA expression of the CHD patients was higher than that of the controls. In CHD patients, the CD36 mRNA expression in AG genotype patients was remarkably higher than in those with an AA genotype (P=0.005). After adjusted logistic regression analysis, the AG genotype of rs1761667 was associated with an increased risk of CHD (OR=2.337, 95% CI=1.336-4.087, P=0.003). In conclusion, the rs1761667 polymorphism may be closely associated with developing CHD in the Chongqing Han population of China, and an AG genotype may be a genetic susceptibility factor for CHD.

Effects of Supplementation of β-Mannanase in Corn-soybean Meal Diets on Performance and Nutrient Digestibility in Growing Pigs

A total of 288 crossbred (Duroc×Landrace×Yorkshire) growing pigs were used in two experiments to investigate the effects of adding β-mannanase to corn-soybean meal-based diets on pig performance and apparent total tract digestibility (ATTD). Both experiments lasted 28 d and were split into two phases namely 1 to 14 days (phase 1) and 15 to 28 days (phase 2). In Exp. 1,144 pigs weighing 23.60±1.59 kg BW were assigned to one of four corn-soybean meal-based diets containing 0, 200, 400 or 600 U/kg β-mannanase. Increasing the level of β-mannanase increased weight gain (quadratic effect; p<0.01) and feed efficiency (linear and quadratic effect; p<0.01) during the second phase and the overall experiment. However, performance was unaffected (p>0.05) by treatment during phase 1. Increasing the amount of β-mannanase in the diet improved (linear and quadratic effect; p<0.05) the ATTD of CP, NDF, ADF, calcium, and phosphorus during both phases. Based on the results of Exp. 1, the optimal supplementation level was determined to be 400 U/kg and this was the level that was applied in Exp. 2. In Exp. 2, 144 pigs weighing 23.50±1.86 kg BW were fed diets containing 0 or 400 U/kg of β-mannanase and 3,250 or 3,400 kcal/kg digestible energy (DE) in a 2×2 factorial design. β-Mannanase supplementation increased (p<0.01) weight gain and feed efficiency while the higher energy content increased (p<0.01) feed intake and feed efficiency during both phases and overall. Increased energy content and β-mannanase supplementation both increased (p<0.05) the ATTD of DM, CP, NDF, ADF, phosphorus, and GE during both phases. There were no significant interactions between energy level and β-mannanase for any performance or digestibility parameter. In conclusion, the β-mannanase used in the present experiment improved the performance of growing pigs fed diets based on corn and soybean. The mechanism through which the improvements were obtained appears to be related to improvements in ATTD.

Synthesis of conjugated linoleic acid by the linoleate isomerase complex in food-derived lactobacilli

AIMS

To assess strains of lactobacilli for their capacity to produce functional fatty acid-conjugated linoleic acid. To assess the linoleate isomerase for CLA production in the most efficient CLA producer.

METHODS AND RESULTS

In this study, strains of food-derived lactobacilli were cultured in media with linoleic acid and CLA production was assessed. Most of the selected strains produced CLA at different levels, with Lactobacillus plantarum ZS2058 being the most efficient CLA producer converting over 50% of linoleic acid to c9, t11-CLA and t9, t11-CLA. Some intermediates 10-hydroxy-cis-12-octadecenoic acid, 10-oxo-cis-12-octadecenoic acid and 10-oxo-trans-11-octadecenoic acid were determined via GC-MS. The genes coding the multicomponent linoleate isomerase containing myosin-cross-reactive antigen, short-chain dehydrogenase/oxidoreductase and acetoacetate decarboxylase for CLA production in Lact. plantarum ZS2058 were cloned and expressed in Escherichia coli. With the mixture of recombinant E. coli, c9, t11-CLA and three kinds of intermediates were produced from linoleic acid, which were in line with those in the lactobacilli.

CONCLUSIONS

The ability for CLA production by lactobacilli exhibited variation. Lactobacillus plantarum and Lact. bulgaricus were the most efficient producers in the selected strains. Lact. plantarum ZS2058 converted linoleic acid to CLAs with 10-hydroxy-cis-12-octadecenoic acid, 10-oxo-cis-12-octadecenoic acid and 10-oxo-trans-11-octadecenoic acid as intermediates. The multiple-step reactions for CLA production catalysed by multicomponent linoleate isomerase in Lact. plantarum ZS2058 were confirmed successfully.

SIGNIFICANCE AND IMPACT OF THE STUDY

Multicomponent linoleate isomerase provides important results for the illustration of the mechanism for CLA production in lactic acid bacteria. Food-derived lactobacilli with CLA production ability offers novel opportunities for functional foods development.

Homology-based cloning and expression analysis of Rf genes encoding PPR-containing proteins in tobacco

As a model plant, mechanisms of the cytoplasmic male sterility/restoration of fertility (CMS/Rf) system in tobacco are seldom studied. Using Rf gene sequences from other Solanaceae plants and the draft genome of Nicotiana benthamiana, degenerate primers were designed to amplify the cDNA pool of N. tomentosiformis. In total, six possible Rf sequences were identified, two of which contained base-deletion mutations. The other four were intact open reading frames, of which NtomPPR5 harbored a 3-pentatricopeptide repeat (PPR) motif deletion. Structure analysis revealed that they all encoded a PPR-containing protein with putative mitochondrial targeting signals at their N-terminus, and they all belong to the P subfamily. Phylogenetic analysis showed that all of the Rf-coding PPRs clustered together, and recent duplication events might have occurred in tobacco after the divergence of the species. Quantitative reverse transcription polymerase chain reaction analysis demonstrated that the NtomRfs were expressed in all tissues of N. tomentosiformis and (CMS) K326, although the expression levels varied with gene, organ, and developmental stage. Furthermore, the expression levels of Rf sequences in K326 were lower than those in CMS K326. The molecular basis of the CMS/Rf system in tobacco requires further investigation.

A general catalyst for Suzuki–Miyaura and Sonogashira reactions of aryl and heteroaryl chlorides in water

An air-stable sulfonated indenyl phosphine/Pd-catalyst system was used in Suzuki–Miyaura and Sonogashira coupling reactions in water.

Identification of the forensically important beetles Nicrophorus japonicus, Ptomascopus plagiatus and Silpha carinata (Coleoptera: Silphidae) based on 16S rRNA gene in China

Sarcophagous beetles play an important role in estimating postmortem interval time (PMI) in the later stages decomposition of carcasses. However, the morphological similarity of beetles usually poses a challenge for forensic scientists within their routine work. As a supplementary to traditional morphological method, molecular genetics identification is simple and time-saving. A molecular identification method involving a 288-bp segment of the 16S ribosomal RNA (16S rRNA) gene from 15 beetles of Silphidae (Coleoptera), collected from 5 locations in 4 Chinese provinces, was evaluated. Phenogram analysis of the sequenced segments by the unweighted pairgroup method analysis (UPGMA) method showed that all specimens were properly assigned into four species with strong similarity, which indicated the possibility of separation congeneric species with the short 16S rRNA fragment. These results will be instrumental for implementation of the Chinese database of forensically relevant beetles.

Flagellin-PAc fusion protein is a high-efficacy anti-caries mucosal vaccine

We previously demonstrated that an anti-caries DNA vaccine intranasally administered with recombinant flagellin protein as a mucosal adjuvant enhanced salivary IgA response and conferred better protection against caries. However, the relatively weak immunogenicity of DNA vaccines and the necessity for a large quantity of antigens remain significant challenges. Here, we fused the flagellin derived from E. coli (KF) and target antigen PAc containing the A-P fragment of PAc from S. mutans (rPAc) to produce a single recombinant protein (KF-rPAc). The abilities of KF-rPAc to induce rPAc-specific mucosal and systemic responses and protective efficiency against caries following intranasal immunization were compared with those of rPAc alone or a mixture of rPAc and KF (KF + rPAc) in rats. Results showed that KF-rPAc promoted significantly higher rPAc-specific antibodies in serum as well as in saliva than did an equivalent dose of rPAc alone or a mixture of KF + rPAc. Intranasal immunization of 8.5 µg KF-rPAc could achieve 64.2% reduction of dental caries in rats. In conclusion, our study demonstrated that flagellin and PAc fusion strategy is promising for anti-caries vaccine development, and KF-rPAc could be used as an anti-caries mucosal vaccine.

Comparation of the predictive value between ultrasonography and urodynamics for the efficacy of transurethral resection of prostate in benign prostatic hyperplasia patients

BACKGROUND

Transurethral resection of prostate (TURP) has been widely used as a golden standard therapy of benign prostatic hyperplasia for over 40 years. However, not all patients achieved favorable outcome postoperatively. Since the level of bladder outlet obstruction and the dysfunction of detrusor (overactive and underactive) were both found to affect surgical efficacy, urodynamics was recommended as routine preoperative examination in selecting proper surgical candidates by International Continence Society in spite of its invasiveness and high cost. The aim of this research was to compare the predictive value between ultrasonography and urodynamics for TURP efficacy and determine if preoperative urodynamic test could be replaced by ultrasonography.

METHODS

Two hundred and seventy-one patients took part in the retrospective analysis. All the subjects had preoperative evaluation of symptoms, life quality, and combined examination of ultrasonography and urodynamics. Surgical efficacy was measured according to the recovery of international prostate symptom score, quality of life score, and maximal flow rate 6 months after TURP. Fisher's linear discriminant analysis was applied to establish the predictive models of surgical efficacy by choosing parameters from ultrasonography or urodynamics as independent factors. Receiver's operating characteristic curve was then plotted to compare the values between the models.

RESULTS

Sensitivity, specificity, positive and negative predictive value of models consisting of parameters from both ultrasonography and urodynamics were favorable. Corresponding models of ultrasonography and urodynamics were found to have non-significant difference in area under curve (P > 0.05).

CONCLUSIONS

Preoperative ultrasonography has as strong value as urodynamics does in predicting surgical outcome of patients undergone TURP and might take the place of urodynamics in selecting surgical candidates. Further prospective analysis with larger popularity and longer period of follow up should be launched to verify the result of this research.

The utility of mitochondrial DNA fragments for genetic identification of forensically important sarcophagid flies (Diptera: Sarcophagidae) in China

Species-diagnostic anatomical characters of fleshflies are not known for most immature stages or even adults, and an existing key may be incomplete or difûcult for nonspecialists to use. The use of sarcophagids for PMI estimations has been greatly hampered by their highly similar morphological characters. DNA-based method can be used as a supplemental means of morphological method in identification of forensically important sarcophagid flies. However, relying solely on single DNA fragment for delimiting species is considered to be unreliable, especially when the fragment was small. Sequence data of selected regions of the cytochrome oxidase subunit two (COII) and 16S ribosomal RNA (16S rRNA) genes of the most important Chinese fleshfly taxa associated with cadavers are presented, which can be instrumental for implementation of the Chinese Sarcophagidae database. Phylogenetic analysis of the sequenced segments showed that all sarcophagid specimens were properly assigned into five species, which indicated the possibility of separation congeneric species with the short fragments.

Mitochondrial DNA and STR analyses for human DNA from maggots crop contents: a forensic entomology case from central-southern China

Insect larvae and adult insects found on human corpses can provide important forensic evidence however it is useful to be able to prove evidence of association. Without this, it could be claimed that the insect evidence was a contaminant or had been planted on the body. This paper describes how mitochondrial DNA (mtDNA) and STR analysis of the crop contents of larvae of the blowfly Aldrichina grahami collected from separated body parts was used to provide evidence of association.

The fabrication of vanadium-doped ZnO piezoelectric nanofiber by electrospinning

Zn(1-x)V(x)O (x = 0.015, 0.02, 0.025, 0.03, V-ZnO) nanofibers were synthesized by electrospinning, and a butterfly-shaped piezoelectric response was measured by scanning force microscopy. The diameters of V-ZnO nanofibers with hexagonal wurtzite phase are in the range of 50-300 nm. The large piezoelectric coefficient d(33) of 121 pm V(-1) was obtained and the high piezoelectric property may be attributed to the switchable spontaneous polarization induced by V dopants and the easier rotation of V-O bonds under an electric field. The result shows that the V-ZnO nanofiber is a promising candidate for nanoscale piezoelectric devices.

Genital tract infections among HIV-infected pregnant women in Malawi, Tanzania and Zambia

SUMMARY

The aim of this study was to compare the prevalence and factors associated with genital tract infections among HIV-infected pregnant women from African sites. Participants were recruited from Blantyre and Lilongwe, Malawi; Dar es Salaam, Tanzania; and Lusaka, Zambia. Genital tract infections were assessed at baseline. Of 2627 eligible women enrolled, 2292 were HIV-infected. Of these, 47.8% had bacterial vaginosis (BV), 22.4% had vaginal candidiasis, 18.8% had trichomoniasis, 8.5% had genital warts, 2.6% had chlamydia infection, 2.2% had genital ulcers and 1.7% had gonorrhoea. The main factors associated with genital tract infections included genital warts (adjusted odds ratio [AOR] 1.8, 95% CI 1.2-2.7), genital ulcers (AOR 2.4, 95% CI 1.2-5.1) and abnormal vaginal discharge (AOR 2.5, 95% CI 1.9-3.3) for trichomoniasis. BV was the most common genital tract infection followed by candidiasis and trichomoniasis. Differences in burdens and risk factors call for enhanced interventions for identification of genital tract infections among HIV-infected women.

Uptake and distribution of N, P and heavy metals in three dominant salt marsh macrophytes from Yangtze River estuary, China

We examined the variation in aboveground biomass accumulation and tissue concentrations of nitrogen (N), phosphorus (P), copper (Cu), zinc (Zn) and lead (Pb) in Phragmites australis (common reed), Spartina alterniflora (salt cordgrass), and Scirpus mariqueter throughout the growing season (April-October 2005), in order to determine the differences in net element accumulation and distribution between the three salt marsh macrophytes in the Yangtze River estuary, China. The aboveground biomass was significantly greater in the plots of S. alterniflora than in the plots of P. australis and S. mariqueter throughout the growing season (P<0.05). In August, the peak aboveground biomass was 1246+/-89 gDW/m(2), 2759+/-250 gDW/m(2) and 548+/-54 gDW/m(2) for P. australis, S. alterniflora and S. mariqueter, respectively. The concentrations of nutrients and heavy metals in plant tissues showed similar seasonal patterns. There was a steady decline in element concentrations of the aboveground tissues from April to October. Relative element concentrations in aboveground tissues were at a peak during the spring sampling intervals with minimum levels during the fall. But the concentrations of total nitrogen and total phosphorus in the belowground tissues were relatively constant throughout growing season. Generally, trace metal concentrations in the aboveground tissues of S. mariqueter was the highest throughout the growing season, and the metal concentrations of S. alterniflora tissues (aboveground and belowground) were greater than those of P. australis. Furthermore, the aboveground pools of nutrients and metals were consistently greater for S. alterniflora than for P. australis and S. mariqueter, which suggested that the rapid replacement of native P. australis and S. mariqueter with invasive S. alterniflora would significantly improve the magnitude of nutrient cycling and bioavailability of trace metals in the salt marsh and maybe transport more toxic metals into the water column and the detrital food web in the estuary.

Intron 2 (T/C) CYP46 polymorphism is associated with Alzheimer's disease in Chinese patients

BACKGROUND

Cholesterol metabolism has been implicated in the pathophysiology of Alzheimer's disease (AD), and cholesterol-related genes are plausible candidate genes for AD. Genetic association of CYP46A1 polymorphisms with AD had been under extensive investigations; however, observations on intron 2 T-->C (rs754203) generated inconclusive results.

OBJECTIVE

To analyse an independent data set in a Chinese population to see whether the polymorphic site rs754203 of the CYP46A1 gene is associated with AD.

METHODS

We analysed 130 sporadic AD patients and 110 healthy controls of the Southern Chinese origin.

RESULTS

An association between the genotype frequency and AD was suggested in the general population (p = 0.047, odds ratio, OR = 1. 61, 95% confidence interval, CI = 0.96-2.70), while the association was most significant in the apolipoprotein E (ApoE) epsilon4-negative group (p = 0.004, OR = 2.54, 95% CI =1.31-4.95). Linkage disequilibrium block prediction results also favoured this association. Consistent with previous reports, intron 3 C-->T (rs4900442) polymorphism did not show any evidence of association; in our data set ApoEepsilon4 was confirmed to be a genetic risk factor for AD (p = 0.0016, OR = 2.76, 95% CI = 1.50-5.11).

Novel Shear-horizontal Surface Acoustic Wave Based Immunosensors Using SiO<inf>2</inf>Waveguiding Layers And Flow Injection Analysis

Surface acoustic wave (SAW) devices based on shear-horizontal (SH) waves can be used as mass-sensitive immunosensors. This paper presents a novel SH-SAW sensor to detect anti-immunoglobulin (IgG) molecules by means of the antibody-antigen binding mechanism. The sensor system comprising dual delay lines was fabricated on 36&#176; Y-X LiTaO<inf>3</inf>substrate. A SiO<inf>2</inf>layer was used as love mode waveguiding layers, well as insulating and chemically resistant protective layer. Moreover, flow injection analysis (FIA) method was used for continuous detection the protein molecules. The protein A was immobilized on the optional surface of the gold layer, then coupled with IgG to adsorb the antigens to be measured in the protein solution. The operational frequency of the system changed due to the interaction of antibody-antigen binding. The experimental result demonstrates the sensor has stable frequency response to the mass loading effect of the various anti-IgG concentrations with the sensitivity up to 3.3ng/ml/Hz.

Capacitive monitoring of the antigen-antibody reactions enhanced by nanogold

An immunosensor for measuring antigen-antibody binding by nanogold particles enhancement was present here. A gold plate electrode was modified by a SAM (self-assembled monolayer) of 11-Mercaptoundecanioc Acid. Then sheep anti-rabbit IgG was immobilized onto the end of the 11-Mercaptoundecanioc Acid. With that the gold electrode was exposed to the mixed solution of rabbit IgG and nanogold labeled sheep anti-rabbit IgG. The differential capacitance of the electrical double layer was monitored to detect the antigen-antibody reaction. The result showed the capacity of the electrical double layer by nanogold enhancement was largely increased compared to that in traditional capacitive immunosensor. The detection sensitivity is up to 10nF / &#956;g/ml.

Congener-specific polychlorinated biphenyl-induced cell death in human kidney cells in vitro: potential role of caspase

Polychlorinated biphenyls (PCBs) are among the most widespread and persistent pollutants in the global environment. Coplanar and noncoplanar PCBs have been shown to cause congener-specific apoptosis mediated neurotoxicity in rats. Very few, if any, such studies have been reported on human renal cell toxicity. The authors report here caspase-dependent or caspase-independent renal toxicity, as measured by apoptotic death induced by PCBs, depending on the planarity of congeners PCB-77 (coplanar) and PCB-153 (noncoplanar) in human kidney cells (HK2) in vitro. The authors have combined morphological and biological techniques to discover the relevance of apoptosis in renal proximal tubule cell death induced by these two PCB congeners. Treatment with both PCB congeners caused accelerated apoptosis in a time- and concentration-dependent manner. Based on our findings using human kidney (HK2) cells, there was more apoptosis-mediated loss of cell viability by non-ortho-substituted PCB-77 when compared to PCB-153. A significant increase of caspase-3 expression through immunoblot studies showed the involvement of apoptosis by PCB-77 compared to none by PCB-153. The broad-spectrum caspase inhibitor z-VAD-fmk showed increased cell death when treated by PCB-153, but not by PCB-77, confirming that caspase inhibitor induced a switch in the mode of cell death. It is reasonable to assume that apoptotic cell death in the renal proximal tubule cells treated by PCBs may have both caspase-dependent and caspase-independent pathways.

Semiparametric estimation of proportional mean residual life model in presence of censoring

A mean residual life function is the average remaining life of a surviving subject, as it varies with time. The proportional mean residual life model was proposed by Oakes and Dasu (1990, Biometrika77, 409-410) in regression analysis to study its association with related covariates in absence of censoring. In this article, we develop some semiparametric estimation procedures to take censoring into account. The proposed methodology is evaluated via simulation studies, and further applied to a clinical trial of chemotherapy in postoperative radiotherapy of lung cancer patients.