Morphological trait-matching in plant-Hymenoptera and plant-Diptera mutualisms across an elevational gradient.

Morphological trait-matching and species abundance are thought to be the main factors affecting the frequency and strength of mutualistic interactions. However, the relative importance of trait-matching and species abundance in shaping species interactions across environmental gradients remains poorly understood, especially for plant-insect mutualisms involving generalist species. Here, we characterised variation in species and trait composition and the relative importance of trait-matching and species abundance in shaping plant-Hymenoptera and plant-Diptera mutualisms in four meadows across an elevational gradient (2,725-3,910 m) in Yulong Snow Mountain, Southwest China. We also evaluated the effects of morphological traits of flower visitors and plant composition on their foraging specialisation (d' and normalised degree). There was a high degree of dissimilarity in the composition of Hymenoptera and Diptera visitors and their visited plants between communities. This variation was mainly driven by the spatial replacement of species. Both for plant-Hymenoptera and plant-Diptera networks, trait-matching between nectar tube depth and proboscis length was a stronger predictor of the interactions between temporally co-occurring plants and flower visitors than species abundance. Fourth-corner analyses revealed statistically significant trait-matching between nectar tube depth and proboscis length in plant-Hymenoptera networks at all sites, suggesting that Hymenoptera consistently foraged on plant species with nectar tube depths matching their proboscis lengths. By contrast, significant trait-matching in plant-Diptera networks was only observed at the two lower elevation sites. The species-level specialisation d' of flower visitors increased significantly as the proboscis length and the difference in nectar tube depth between the plant community and the plants visited by flower visitors increased. Our results highlight that the importance of trait-matching in shaping pairwise interactions and niche partitioning depends on the specific features (e.g. species composition and trait availability) of the plant-pollinator system. For specialised plant-Hymenoptera systems, trait-matching is an important determinant of species interactions, whereas for generalist plant-Diptera systems, trait-matching is relatively unimportant.

Specificity and seasonal prevalence of anther smut disease Microbotryum on sympatric Himalayan Silene species.

Host sympatry provides opportunities for cross-species disease transmission and compounded disease effects on host population and community structure. Using the Silene-Microbotryum interaction (the castrating anther smut disease), eleven Himalayan Silene species were assessed in regions of high host diversity to ascertain levels of pathogen specificity. We also investigated disease prevalence, seasonal dynamics of infection and flowering patterns in five co-blooming Silene species. We identified several new Microbotryum lineages with varying degrees of specialization that is likely influenced by degrees of host divergence and ecological similarities (i.e. shared pollinator guilds). Affected species had 15%-40% of plants infected by anther smut. Flowering was seasonally overlapping among host species (except for the species pair S. asclepiadea and S. atrocastanea), but diseased flowering onset was earlier than healthy plants, leading to dramatic seasonal shifts in observed disease prevalence. Overlapping distributions and flowering provides opportunities for floral pathogen movement between host species, but host specialization may be constrained by the plant phylogenetic relatedness, adaptation to micro-habitats and difference in pollinator/vector guilds.

Floral traits influence pollen vectors' choices in higher elevation communities in the Himalaya-Hengduan Mountains.

BACKGROUND: How floral traits and community composition influence plant specialization is poorly understood and the existing evidence is restricted to regions where plant diversity is low. Here, we assessed whether plant specialization varied among four species-rich subalpine/alpine communities on the Yulong Mountain, SW China (elevation from 2725 to 3910 m). We analyzed two factors (floral traits and pollen vector community composition: richness and density) to determine the degree of plant specialization across 101 plant species in all four communities. Floral visitors were collected and pollen load analyses were conducted to identify and define pollen vectors. Plant specialization of each species was described by using both pollen vector diversity (Shannon's diversity index) and plant selectiveness (d' index), which reflected how selective a given species was relative to available pollen vectors. RESULTS: Pollen vector diversity tended to be higher in communities at lower elevations, while plant selectiveness was significantly lower in a community with the highest proportion of unspecialized flowers (open flowers and clusters of flowers in open inflorescences). In particular, we found that plant species with large and unspecialized flowers attracted a greater diversity of pollen vectors and showed higher selectiveness in their use of pollen vectors. Plant species with large floral displays and high flower abundance were more selective in their exploitation of pollen vectors. Moreover, there was a negative relationship between plant selectiveness and pollen vector density. CONCLUSIONS: These findings suggest that flower shape and flower size can increase pollen vector diversity but they also increased plant selectiveness. This indicated that those floral traits that were more attractive to insects increased the diversity of pollen vectors to plants while decreasing overlap among co-blooming plant species for the same pollen vectors. Furthermore, floral traits had a more important impact on the diversity of pollen vectors than the composition of anthophilous insect communities. Plant selectiveness of pollen vectors was strongly influenced by both floral traits and insect community composition. These findings provide a basis for a better understanding of how floral traits and community context shape interactions between flowers and their pollen vectors in species-rich communities.

In vitro and in vivo anti-cancer activity of formononetin on human cervical cancer cell line HeLa.

Worldwide, cervical cancer (CC) is the third most common malignancy in women, and it remains a leading cause of cancer-related death of women. Genomic studies indicate that phosphoinositide 3-kinase (PI3K)/AKT signaling is one of the most frequently deregulated pathways in several human cancers, including CC. This signaling pathway has an important role in cancer cell proliferation, survival, motility, and metabolism, and therefore could be an attractive therapeutic target. In a previous study, we used a sensitive and high-speed homogeneous assay for the detection of kinase activity and for screening of PI3K/AKT signaling inhibitors in a high-throughput screening (HTS) format and then obtain formononetin, as an O-methylated isoflavone existed in a number of plants and herbs like Astragalus membranaceus. We showed that formononetin inhibited the phosphorylation of AKT and induced the apoptosis of CC cell line HeLa in a dose-dependent manner. Furthermore, formononetin suppressed xenograft tumor growth in nude mice. Our results indicated that formononetin may be used as an anti-cancer drug for cervical cancer in the future.

Cisplatin targets the stromal cell-derived factor-1-CXC chemokine receptor type 4 axis to suppress metastasis and invasion of ovarian cancer-initiating cells.

In ovarian cancer, CD44+/CD117+ stem cells, also known as cancer-initiating cells (CICs), are highly proliferative and invasive. Therefore, the CD44+/CD117+ subpopulation is thought to be an important target for novel therapeutic strategies. In this study, we investigated the effects of cisplatin (CDDP) on metastasis and invasion suppression of ovarian CICs by targeting the CXC chemokine receptor-4 (CXCR4) signaling pathway in vitro and in vivo. CD44+/CD117+ ovarian CICs were enriched from human primary ovarian tumor tissues and confirmed by flow cytometry sorting. A 3-(4,5-dimethylthiazol-2-yl)-2.5-dipheny-tetrazolium bromide (MTT) assay revealed significant inhibition of proliferation of ovarian CICs with increasing CDDP drug concentrations. Moreover, colony formation and transwell migration assays indicated that CDDP significantly suppressed the invasive capacity of ovarian CICs in vitro. The expression levels of stromal cell-derived factor (SDF)-1, CXCR4, matrix metalloproteinase (MMP) 2, and MMP9 mRNA and protein levels were significantly reduced in CDDP-treated cells compared to untreated ovarian CICs. Furthermore, xenograft experiments confirmed that CDDP suppressed the growth of xenograft tumors formed by ovarian CICs in vivo. In addition, CXCR4 agonist (diprotin A) treatment of ovarian CICs weakened the effects of CDDP and enhanced SDF-1-CXCR4 axis expression in ovarian CICs. Thus, the SDF-1-CXCR4 axis is an important mediator of proliferation and invasion in CXCR4-overexpressing ovarian cancer-initiating cells (OCICs). Furthermore, CDDP inhibits invasion and metastasis of OCICs by targeting SDF-1-CXCR4 axis expression.

The adaptation of bumblebees to extremely high elevation associated with their gut microbiota.

Bumblebees are among the most abundant and important pollinators for sub-alpine and alpine flowering plant species in the Northern Hemisphere, but little is known about their adaptations to high elevations. In this article, we focused on two bumblebee species, Bombus friseanus and Bombus prshewalskyi, and their respective gut microbiota. The two species, distributed through the Hengduan Mountains of southwestern China, show species replacement at different elevations. We performed genome sequencing based on 20 worker bee samples of each species. Applying evolutionary population genetics and metagenomic approaches, we detected genes under selection and analyzed functional pathways between bumblebees and their gut microbes. We found clear genetic differentiation between the two host species and significant differences in their microbiota. Species replacement occurred in both hosts and their bacteria (Snodgrassella) with an increase in elevation. These extremely high-elevation bumblebees show evidence of positive selection related to diverse biological processes. Positively selected genes involved in host immune systems probably contributed to gut microbiota changes, while the butyrate generated by gut microbiota may influence both host energy metabolism and immune systems. This suggests a close association between the genomes of the host species and their microbiomes based on some degree of natural selection.IMPORTANCETwo closely related and dominant bumblebee species, distributed at different elevations through the Hengduan Mountains of southwestern China, showed a clear genomic signature of adaptation to elevation at the molecular level and significant differences in their respective microbiota. Species replacement occurred in both hosts and their bacteria (Snodgrassella) with an increase in elevation. Bumblebees' adaptations to higher elevations are closely associated with their gut microbiota through two biological processes: energy metabolism and immune response. Information allowing us to understand the adaptive mechanisms of species to extreme conditions is implicit if we are to conserve them as their environments change.

[A random control study of indomethacin-containing MYCu intrauterine contraceptive device for 60 months].

OBJECTIVE: To explore the clinical efficacy and safety of MYCu intrauterine contraceptive device (IUD) containing indomethacin. METHODS: From October 1 to December 31, 2004, women of child-bearing age requiring IUD for contraception were chosen from the Outpatient Departments of China-Japan Friendship Hospital of Jilin University, Peking University First Hospital, Peking University Third Hospital, Jilin University Second Hospital and Affiliated Shengjing Hospital of China Medical University. They were randomly inserted with MYCuIUD and control TCu380A IUD each for 1000 cases and followed up at 1, 3, 6, 12, 24, 36, 48 and 60 months post-insertion. RESULTS: When MYCu IUD group and TCu380A group 60 months post-insertion were compared, the cumulative pregnancy rates with IUD in situ were 2.38/100 women per year and 2.84/100 women per year respectively. And the difference had no statistical significance (P > 0.05); the cumulative expulsion rates, mostly of partial expulsion and downward movement, were 0.87/100 women per year and 2.94/100 women per year respectively. And the difference had statistical significance (P < 0.05); the cumulative termination rates due to bleeding/pain were 3.57/100 women per year and 4.83/100 women per year respectively. And the difference had no statistical significance (P > 0.05); Side effects in MYCu group were less pronounced than those in TCu group. And the inter-group differences had statistical significance (P < 0.05). CONCLUSION: As a comparatively ideal medicated medical device, MYCu IUD has an excellent contraceptive efficacy, a low rate of expulsion and side effects and good reversibility. Particularly a low occurrence rate of bleeding and pain during early insertion is recommended. Its life expectancy is 15 years. And its contraceptive effectiveness and safety after 5 years should be examined during further follow-ups.

Determination of 123 polycyclic aromatic hydrocarbons and their derivatives in atmospheric samples.

Polycyclic aromatic hydrocarbons (PAHs) are a class of toxic organic pollutants. Until now, they have been detected in many regions and various environmental matrix. However, not all PAHs are usually detected by researchers, and no methods is established to analyze systematically hundreds of PAHs. In this study, 123 PAHs were identified and quantified using gas chromatography-tandem triple-quadrupole mass spectrometry (GC-MS/MS), which were divided into 3 groups: 32 regular PAHs (R-PAHs), 50 methyl-PAHs (Me-PAHs), 30 Nitro-PAHs (N-PAHs) and 11 hydroxyl-PAHs (OH-PAHs). The developed method was applied to detect the target PAHs in 6 marine gaseous samples and 6 particulate samples collected on board the research vessel Snow Dragon. Limits of detection (LOD) and limits of quantification (LOQ) were determined from 0.009 to 2.50 and 0.03-8.33 pg/m3, respectively. Recoveries of the internal standards in atmosphere were from 88% to 112%, 70%-104%, and 72%-102% for R-PAHs、Me-PAHs、N-PAHs and OH-PAHs, respectively, which showed the reliability of the experimental method. The total concentrations of 123 PAHs in marine air and particle samples were from 1532 to 7877 and 206-1022 pg/m3, respectively.

Disodium calcium dinickel(II) bis-[diphosphate(V)] deca-hydrate.

In the title compound, Na(2)CaNi(2)(P(2)O(7))(2)(H(2)O)(10), there are two distinct P-atom sites, each tetra-hedrally coordinated by four O atoms. The resulting phosphate tetra-hedra link through a common O atom, forming a [P(2)O(7)](4-) diphosphate unit. The Ni-O coordination is square pyramidal with four O atoms from two diphosphate groups in equatorial positions and the vertex occupied by a water O atom. The (P(2)O(7))(H(2)O) units link the Ni atoms, forming a chain of pyramids and tetra-hedra. As a result of the d-glide and twofold-axis symmetry of space group Fdd2, the chains propagate along [101] and [10], and chains in adjacent layers are mutually orthogonal. The Ca cation, located on a rotation axis, and the Na cation are each octa-hedrally coordinated by four O atoms and two waters. The Ni-chain arrangement is stabilized by Ca and Na coordination and a network of O-H⋯O hydrogen bonds.

Bimodal activity of diurnal flower visitation at high elevation.

Successful pollination in animal-pollinated plants depends on the temporal overlap between flower presentation and pollinator foraging activity. Variation in the temporal dimension of plant-pollinator networks has been investigated intensely across flowering seasons. However, over the course of a day, the dynamics of plant-pollinator interactions may vary strongly due environmental fluctuations. It is usually assumed there is a unimodal, diurnal, activity pattern, while alternative multimodal types of activity patterns are often neglected and deserve greater investigation. Here, we quantified the daily activity pattern of flower visitors in two different habitats contrasting high elevation meadows versus forests in Southwest China to investigate the role of abiotic conditions in the temporal dynamics of plant-pollinator interactions. We examined diurnal activity patterns for the entire pollinator community. Pollinator groups may differ in their ability to adapt to habitats and abiotic conditions, which might be displayed in their patterns of activity. We hypothesized that (a) pollinator communities show multimodal activity patterns, (b) patterns differ between pollinator groups and habitat types, and (c) abiotic conditions explain observed activity patterns. In total, we collected 4,988 flower visitors belonging to six functional groups. There was a bimodal activity pattern when looking at the entire pollinator community and in five out of six flower visitor groups (exempting solitary bees) regardless of habitat types. Bumblebees, honeybees, dipterans, lepidopterans, and other insects showed activity peaks in the morning and afternoon, whereas solitary bees were most active at midday. Activity of all six pollinator groups increased as solar radiation increased and then decreased after reaching a certain threshold. Our findings suggest that in habitats at higher elevations, a bimodal activity pattern of flower visitation is commonly employed across most pollinator groups that are diurnal foragers. This pattern may be caused by insects avoiding overheating due to elevated temperatures when exposed to high solar radiation at midday.

Effect of ciRS-7 expression on clear cell renal cell carcinoma progression.

BACKGROUND: Circular RNA ciRS-7 has been reported to be involved in the progression of various cancers. However, ciRS-7 expression and its role in clear cell renal cell carcinoma (ccRCC) progression remains unclear. This study aimed to investigate the effect of ciRS-7 expression on ccRCC and the related signaling pathway. METHODS: ciRS-7 expression was analyzed using quantitative reverse transcription polymerase chain reaction in 87 pairs of ccRCC and matched adjacent normal tissues. The role of ciRS-7 in ccRCC cell proliferation and invasion was determined using the cell counting kit-8 and invasion assays, respectively. Potential mechanisms underlying the role of ciRS-7 in promoting ccRCC progression were explored by Western blotting. The relationship between the expression of ciRS-7 and features of ccRCC was analyzed by the Chi-square test and progression-free survival was determined using a Kaplan-Meier plot. RESULTS: ciRS-7 was overexpressed in ccRCC tissues compared with that in matched adjacent normal tissues. In addition, ciRS-7 up-regulation was closely associated with tumor diameter (P = 0.050), clinical stage (P = 0.009), and distant metastasis (P = 0.007). ciRS-7 knockdown in 786O and 769P cells markedly inhibited their proliferative and invasive abilities. In addition, ciRS-7 inhibition reduced phosphorylated epidermal growth factor receptor (p-EGFR) and phosphorylated serine/threonine kinase (p-Akt) levels. CONCLUSIONS: ciRS-7 up-regulation could promote ccRCC cell proliferation and invasion, which may be related with the EGFR/Akt signaling pathway. ciRS-7 might be a potential ccRCC therapeutic target.

Spontaneous rupture of an unscarred uterus with an intact amniotic sac extrusion and fetal leg entrapment at 28 gestational weeks: a case report.

The spontaneous rupture of an unscarred uterus at 28 gestational weeks is an extremely rare event, particularly when associated with an intact amniotic sac extrusion and fetal leg entrapment, which has not been previously reported. A 27-year-old primigravid woman was referred to our department, due to perpetual abdominal pain, at 28 weeks and 5 days of gestation. The patient, G3p0, had previously undergone two induced abortions. At the time of admission, abdominal ultrasonography suggested a defect in the left uterine horn. An emergency laparotomy was subsequently performed and revealed an intact amniotic sac extrusion and fetal leg entrapment. Considering the risk of placental abruption, and the possibility of a secondary rupture if the gestation was not terminated, an emergency Cesarean section was recommended. Uterine rupture may be suspected whenever a patient complains of durative abdominal pain at 28 weeks and 5 days of gestation, even in the absence of an intra-abdominal hemorrhage or vaginal bleeding.

[Genetic analysis of genitourinary malformations].

OBJECTIVE: To analyze the expression of genes from chromosomal region 22q11.2 and assess the association between mutation(s) of particular gene(s) from this region and malformations of the urinary system. METHODS: Expression of rat homologs of 33 genes from above region was determined in kidney tissues derived from rats of different fetal development ages (E13, E15, E19) and adulthood with reverse transcriptase-PCR. Potential mutation(s) in candidate gene SNAP29, whose expression pattern appeared to be unique, was screened in 44 patients and 220 normal controls with PCR-single strand conformation polymorphism (SSCP). Suspected positive regions were sequenced to verify the mutations. RESULTS: Nine genes showed no expression throughout the whole development process; 18 genes with various expression levels showed continuous expression from the beginning of development; 6 genes only expressed for a short time, among which SNAP29 was selected for mutation screening. Upon sequencing, three mutations were identified from the 44 patients, including a G to A transition (GAG to AAG) in exon 2, and two A to G transitions (AGC to GGC) in exon 3. CONCLUSION: Through systematic analysis of the expression of genes from chromosomal region 22q11.2, the SNAP29 gene was found to have a potential role in the development of genitourinary system. Two missense mutations were identified in three patients. These included one in exon 2 (featuring cryptorchidism), and the other in exon 3 (featuring cryptorchidism and hypospadia). Neither of the mutations was found in the normal controls. The results suggested that mutation(s) of gene(s) from chromosomal region 22q11.2 may play an important role in the genesis of genitourinary malformations.

First trimester Doppler velocimetry of the uterine artery ipsilateral to the placenta improves ability to predict early-onset preeclampsia.

This study sought to investigate the effects of placental laterality on the measurements of uterine artery (UtA) Doppler velocimetry and their application in predicting early-onset preeclampsia (PE).We conducted a prospective cohort study on all women with singleton, uncomplicated pregnancies scheduled for first-trimester nuchal translucency at our institution. Pulsatility index (PI) for both UtAs was measured by Doppler velocimetry, and placental laterality was determined. Additionally, pregnancy outcome data were abstracted from the medical records. Receiver operating characteristic curves (ROCs) were plotted.Of the 304 patients enrolled, 247 met the inclusion criteria. Among these patients, 240 had uncomplicated delivery, while 7 had early delivery at <34 weeks due to PE. For the uncomplicated pregnancies, PI measurements of the UtA ipsilateral to the placenta were similar (left versus right UtA: 1.06 ±â€Š0.38 vs. 1.04 ±â€Š0.40; P = .745). However, PI measurements of the UtA contralateral to the placenta differed significantly (left versus right UtA: 1.45 ±â€Š0.51 vs. 1.3 ±â€Š0.47; P = .027). In predicting early-onset PE, the ideal cut-off value for the placental side PI was 1.91, with sensitivity 100% and specificity 96.3%. For nonplacental side PI, the ideal cut-off value for PI was 1.975, with sensitivity 57.1% and specificity 79.2%. Using the mean of the left and right UtA PI, the ideal cut-off value was 1.63, with sensitivity 100% and specificity 74.2%.ROC analysis confirmed that PI measurements of the UtA on the placental side were significantly lower than those on the contralateral side, PI measurements of the UtA ipsilateral to the placenta were similar.

[Correlation between killer cell immunoglobulin-like receptors genes and pre-eclampsia].

OBJECTIVE: To analyze the killer cell immunoglobulin-like receptors (KIR) gene polymorphism of pre-eclampsia patients and approach the correlation between KIR genes and pre-eclampsia. METHODS: The KIR gene polymorphisms of 71 pre-eclampsia patients and 100 healthy pregnant women were detected by PCR-SSP. The KIR2DL4 mRNA level in placentas from pre-eclampsia and gestational normal pregnancies were quantified by real time RT-PCR. Forty pre-eclampsia patients and 38 healthy pregnant women were detected for single nucleotide polymorphisms (SNP) in the gene coding and joint areas between introns and extrons by directly sequencing techniques of KIR2DL4 genomic DNA. Finally, all alleles and genotypes of KIR2DL4 gene were case-control studied. RESULT: Distributions of some relatively activating KIR genotypes shewed a significant association with pre-eclampsia. Real-time RT-PCR showed that KIR2DL4 mRNA can be measured both in placenta of women with pre-eclampsia being of pre-eclampsia was significantly lower than that of normal pregnancy, only as much as 0.276 times that of controls. We identified 18 polymorphisms, of which, 7 were first reported. But no significant differences in genotype distributions or allele frequencies were observed in these SNPs between cases and controls. CONCLUSION: The distributions of some relatively activating KIR genotypes showed a significant association with pre-eclampsia, which indicates that the polymorphism of KIR genes may be associated with the genetic predisposition to pre-eclampsia. And because the expression of KIR2DL4 mRNA in the placentas of cases was significantly lower than control group, it is speculated that the decrease of KIR2DL4 expression in placenta may participate in the pathogenesis of pre-eclampsia.

Does reproductive isolation reflect the segregation of color forms in Spiranthes sinensis (Pers.) Ames complex (Orchidaceae) in the Chinese Himalayas?

Isolation between species, or taxa sharing a common lineage, depends primarily on the relative strengths of various reproductive barriers. Previous studies on reproductive isolation between orchids emphasized mechanical and ethological barriers in flowers of species showing food and/or sexual mimicry. In this study, we investigated and quantified a series of prepollination and postpollination barriers between pink and white forms of Spiranthes sinensis sl, a nectar-secreting complex. We generated ML trees based on trnS-G and matK to explore phylogenetic relationships in this species complex. Spiranthes sinensis sl segregated from some other congeners, but the white form constituted a distinct clade in relation to the pink form. The white form secreted 2-Phenylethanol as it is a single-scent compound and was pollinated almost exclusively by native, large-bodied Apis cerana and Bombus species (Apidae). Apis cerana showed a high floral constancy to this form. The scentless, pink form was pollinated primarily by smaller bees in the genera Ceratina (Apidae), and members of the family Halictidae, with infrequent visits by A. cerana and Bombus species. Fruit set and the production of large embryos following interform pollination treatments were significantly lower compared to intraform pollination results for the white form. Our results suggested that pollinator isolation, based on color and scent cues, may result in greater floral constancy in white populations when both forms are sympatric as two different, guilds of pollinators forage selectively preventing or reducing prospective gene flow. Postpollination barriers appear weaker than prepollination barriers but they also play a role in interform isolation, especially in the white form. Our findings suggest that floral color forms in S. sinensis do not represent an unbalanced polymorphism. Interpretations of the evolutionary status of these forms are discussed.

[Another grey zone for clinical genetics: chromosomal microduplication 22q11.2].

Theoretically, microduplication of chromosomal region 22q11.2, which is rich in segmental duplications, should be as frequent as microdeletions of the same region. Preliminary analysis on the rarity of reports for 22q11.2 microduplication in the literature has suggested that, for the discovery of 22q11.2 microduplication, there has been a lack of sensitivity for routine diagnostic techniques such as karyotyping, PCR and FISH. On the other hand, the diverse anomalies and extremely variable phenotypes of carriers also implied great difficulties one has to face upon clinical consultation. Genetics as well as clinical problems in connection with 22q11.2 microduplication has vividly illustrated the great challenge for the interpretation of genotype-phenotype correlation, and thereby posed yet another gray zone for clinical genetics research.

[Palindromic sequence-mediated de novo chromosome translocation in sperm samples derived from normal and oligospermic males].

OBJECTIVE: To systematically explore the occurrence of a novel type of chromosome translocation in human sperm samples. METHODS: Specific translocation junction fragments were quantified using nested and/or multi-nested PCR in sperm DNA derived from 28 oligospermic patients and 32 normal controls. RESULTS: t(11;22) was detected in 49 samples. At least 4 samples were found to have t(1;22) (p21.2;q11.2), t(17;22) (q11;q11) or t(X;22) (q27;q11). The mutation rate seemed to be associated not with age or semen volume, but with sperm concentration (r = -0.389, P < 0.05) and motility (r = -0.397, P < 0.05). Correlation was not found between homology of palindromic sequences and mutation rate. CONCLUSION: Palindromic sequence mediated chromosome translocation is common in human sperm, and associated with sperm concentration and motility. Measurement of such mutations may provide a molecular-level reference for assessing sperm quality.

[Relationship between dopamine-beta-hydroxylase gene polymorphism and hypertensive disorder complicating pregnancy].

OBJECTIVE: To investigate the association between the single nucleotide polymorphism (SNP) at locus 589 of dopamine-beta-hydroxylase (DbetaH) gene and hypertensive disorder complicating pregnancy (HDCP). METHODS: One hundred and seven pregnant women with hypertensive disorder complicating pregnancy (HDCP group) and 95 normal pregnant women (control group) matched for age and gestation were selected. Genotypes of the SNP at locus 589 were typed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). RESULTS: (1) The frequencies of DbetaH GG, GA and AA genotypes of the SNP at locus 589 were 75.7%, 21.5% and 2.8% in HDCP group, respectively. They were 72.6%, 24.2% and 3.2% in normal control group, respectively (P > 0.05). The frequencies of the two alleles G and A were 86.4% and 13.6% in HDCP group, and 84.7% and 15.3% in normal control group, respectively (P > 0.05). (2) No evident differences existed in distribution of genotypes of the SNP at locus 589 between mild preeclampsia, severe preeclampsia and eclampsia groups (P > 0.05). CONCLUSION: The SNP at locus 589 of DbetaH gene is not associated with hypertensive disorder complicating pregnancy, nor is it associated with the severity of hypertensive disorder complicating pregnancy.

[Performance of Electricity Generation and Feasibility of Discontinuous Power Supply of MFC by Using Pretreated Excess Sludge as Fuel].

The feasibility of treating pretreated excess sludge and capacity of supplying continuous power of microbial fuel cells (MFCs) were investigated. Two-chamber microbial fuel cells were started up and operated by using thermal pretreated excess sludge as the substrate. Potential fluctuations were achieved by changing the cathode electron acceptor. During the changes of electron acceptor, the operational stability of MFCs was assessed. The results indicated that the MFCs started successfully with oxygen as the cathode electron acceptor and reached 0.24 V after 148 hours. When the cathode electron acceptor was replaced by potassium ferricyanide, MFCs could obtain the maximum output voltage and maximum power density of 0.66 V and 4.21 W · m⁻³, respectively. When the cathode electron acceptor was changed from oxygen to potassium ferricyanide or the MFCs were closed circuit, the output power of MFCs recovered rapidly. In addition, changes of electron acceptor showed no effect on the removal of COD and ammonia nitrogen. Their removal efficiencies approached to 70% and 80%, respectively. This study concluded that MFC could treat the pretreated excess sludge and produce electricity simultaneously with a high power density. The MFC could also achieve discontinuous electricity supply during operation.