[Two-stage Inhibition Effects of Burkholderia sp. Y4 Application on Cadmium Uptake and Transport in Wheat].

In order to evaluate the feasibility of using Burkholderia sp. Y4 as a cadmium （Cd）-reducing bacterial agent in contaminated wheat fields， the changes in the rhizosphere soil microbial community and Cd available state， as well as the content and transport characteristics of Cd in the wheat root， basal node， internode， and grain under the treatment of strain Y4 were tested using microbial high-throughput sequencing， step-by-step extraction， subcellular distribution， and occurrence analyses. The results showed that root application of strain Y4 significantly reduced the root and grain Cd content of wheat by 7.7% and 30.3%， respectively， compared with that in the control treatment. The Cd content and Cd transfer factor results in wheat vegetative organs showed that strain Y4 reduced the Cd transfer factor from basal node to internode by 79.3%， and Cd content in the wheat internode stem also decreased by 50.9%. The study of Cd occurrence morphology showed that strain Y4 treatment increased the proportion of residual Cd in roots and basal ganglia， decreased the contents of inorganic and water-soluble Cd in roots， and increased the content of residual Cd in basal ganglia. Further examination of the subcellular distribution of Cd showed that the Cd content in root cell walls and basal ganglia cell fluid increased by 21.3% and 98.2%， respectively， indicating that the Cd fixation ability of root cell walls and basal ganglia cell fluid was improved by the strain Y4 treatment. In the rhizosphere soil， it was found that the microbial community structure was changed by strain Y4 application. Under the Y4 treatment， the relative abundance of Burkholderia increased from 9.6% to 11.5%， whereas that of Acidobacteriota decreased. Additionally， the relative abundance of Gemmatimonadales， Pseudomonadales， and Chitinophagales were also increased by strain Y4 treatment. At the same time， the application of strain Y4 increased the pH value of rhizosphere soil by 8.3%. The contents of exchangeable Cd， carbonate-bound Cd， and iron-manganese oxide-bound Cd in the soil decreased by 44.4%， 21.7%， and 15.9%， respectively， whereas the proportion of residual Cd reached 53.6%. Root application of strain Y4 increased the contents of nitrate nitrogen and ammonium nitrogen in the soil by 22.0% and 21.4%， respectively， and the contents of alkaline nitrogen also increased to a certain extent. In conclusion， the root application of strain Y4 not only improved soil nitrogen availability but also inhibited Cd transport and accumulation from contaminated soil to wheat grains in a "two-stage" manner by reducing Cd availability in rhizosphere soil and improving Cd interception and fixation capacity of wheat roots and basal nodes. Therefore， Burkholderia Y4 has application potential as a Cd-reducing and growth-promoting agent in wheat.

Nomogram incorporating potent inflammatory indicators for overall survival estimation of patients with primary oral squamous cell carcinoma.

Background: Inflammation has been recognized to be a factor that substantially influences tumorigenesis and tumor prognosis. Hence, this study was aimed to investigate an inflammatory marker with the most potent prognostic ability and to evaluate the survival estimation capability of dynamic change in this marker for patients suffered from oral squamous cell carcinoma (OSCC). Methods: 469 patients' inflammatory indicators including lymphocyte-to-monocyte ratio (LMR), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR) and systemic inflammatory response index (SIRI), were calculated. Their predictive abilities for overall survival (OS) were evaluated by Kaplan-Meier curves to screen for the one with the most potent prognostic value. The predictive ability of dynamic changes in this marker was verified and a predictive nomogram incorporating inflammatory indicators was developed. Results: A high LMR was identified to be an indicator of a satisfactory survival rate. Compared with that of other inflammatory markers, area under the receiver operating characteristics (ROC) curve (AUC) of LMR for 1-year and 3-year OS was significantly larger (P<0.001). Dynamic LMR change remained an significant parameter for predicting OS (OR: 2.492, 95% CI: 1.246-4.981, p = 0.010). The nomogram incorporating LMR exhibited a superior prognostic significance than the TNM system, as suggested by the C-index (0.776 vs 0.651 in primary cohort; 0.800 vs 0.707 in validation cohort, P<0.001) and AUC. Conclusions: LMR was demonstrated to possess a more potent survival estimation capability than the other three inflammatory parameters. Dynamic changes in LMR serves as a significant parameter for overall survival estimation of primary OSCC patients. The established nomogram incorporating inflammatory markers showed more accuracy and sensitivity for survival estimation of primary OSCC patients.

[Effects of Burkholderia sp. Y4 on Cadmium Damage and Uptake in Rice Seedlings].

In order to investigate the effects of Burkholderia sp. Y4 on rice seedlings under cadmium (Cd) stress, seed germination and vermiculite culture experiments were conducted using low Cd-accumulation xiangzaoxian 24 (X24) and high Cd-accumulation Tyou 705 (T705) varieties. The effects of Burkholderia sp. Y4 on rice growth, oxidative damage caused by Cd, and Cd accumulation were studied. Additionally, the Cd2+ flux rates in the elongation zone of rice roots under Burkholderia sp. Y4 application were detected using non-invasive micro-test technology. Burkholderia sp. Y4 alleviated the inhibition effect of Cd on rice seed germination by 13.8%. After inoculation with Burkholderia sp. Y4 for 7 d, the length of rice roots and buds increased by 83.3% and 12.2%, and their dry weight increased by 56.8% and 12.5%, respectively; those in the 10 d Y4 inoculation group increased by 28.6% and 20.0% in length and by 113.2% and 46.0% in dry weight, respectively. Burkholderia sp. Y4 inoculation also alleviated rice oxidative stress damage caused by Cd. The application of strain Y4 significantly reduced the content of the oxidative damage product malondialdehyde (MDA) in the shoots and roots of rice seedlings by 21.5% and 16.9%, respectively. Under Burkholderia sp. Y4 inoculation, the significant changes in antioxidant enzyme SOD and CAT activities caused by Cd stress disappeared in rice roots; those in shoots also decreased from 176.9% and 74.8% to 53.3% and 21.5%, respectively. Conversely, Burkholderia sp. Y4 inhibited Cd uptake by rice seedlings with different genotypes, including the low Cd-accumulation variety X24 and high Cd-accumulation variety T705. The root application of strain Y4 significantly reduced Cd accumulation in the shoots and roots of rice seedlings by 79.2% and 62.7% in T705 and by 57.3% and 24.1% in X24, respectively. The Cd2+ flux rate of high Cd-accumulation variety T705 was significantly higher than that of low Cd-accumulation variety X24. Under Burkholderia sp. Y4 inoculation, the yellow membrane was formed on the root surface of rice seedlings, and the Cd2+ flux rate in the elongation zone of T705 and X24 roots decreased by 36.0% and 35.0% in 3-day-old seedlings, as well as by 44.6% and 24.9% in 10-day-old seedlings, respectively. In conclusion, Burkholderia sp. Y4 inoculation inhibited the toxic effects of Cd on rice seedling growth through alleviating oxidative stress and damage caused by Cd. Furthermore, the root application of Burkholderia sp. Y4 effectively decreased the Cd2+ flux rate in the elongation zone of roots to inhibit the Cd uptake and accumulation in roots and shoots of rice seedlings. This study provides theoretical basis and data support for the application of Burkholderia sp. Y4 as a Cd-reducing and growth-promoting agent for rice in contaminated farmland.

External penetrating laryngeal trauma caused by a metal fragment: A Case Report.

BACKGROUND: Although external penetrating laryngeal trauma is rare in the clinic, such cases often result in a high mortality rate. The early recognition of injury, protection of the airway, one-stage laryngeal reconstruction with miniplates and interdisciplinary cooperation are important in the treatment of such patients. CASE SUMMARY: A 58-year-old male worker sustained a penetrating injury in the left neck. After computed tomography scanning at a local hospital, he was transferred to our hospital, where he underwent tracheotomy, neck exploration, extraction of the foreign object, debridement and repair of the thyroid cartilage using titanium miniplates. An endo laryngeal stent was inserted, which was removed 12 days later. The patient recovered well and his voice rapidly improved after surgery. CONCLUSION: Penetrating laryngeal trauma is uncommon. We successfully treated a patient with early laryngeal reconstruction and management by interdisciplinary cooperation.

[Isolation and Identification of the Plant Endophyte R-13 and Its Effect on Cadmium Accumulation in Solanum nigrum L.]

The combination of endophytes and hyperaccumulator plants can significantly improve the efficiency of heavy metal phytoremediation in contaminated soil. A plant endophyte named Herbaspirillum R-13 was isolated from rice roots in a cadmium (Cd) contaminated paddy field. This strain exhibited a strong tolerance to Cd2+ and could grow on a solid medium with a Cd2+ concentration of 300 mg·kg-1. The R-13 strain was able to produce siderophores and Indole acetic acid (IAA), through color reactions. In addition, Pikovskaya's and Ashby's solid medium tests showed that the R-13 strain had a lower capacity for dissolving phosphorus but a higher capacity for fixing nitrogen. In the pot experiment, high-throughput sequencing technology was used to track the colonization of the R-13 strain in Solanum nigrum L. roots. Three days after inoculation, the relative abundance of Herbaspirillum in the root of Solanum nigrum L. had increased by 201.88% compared to the blank control (CK) and after two inoculations, the relative abundance of Herbaspirillum in the root of Solanum nigrum L. had increased by 1182.44% compared to CK. The relative abundance of Herbaspirillum in the root of Solanum nigrum L. began to decrease significantly from 5 days after inoculation. Inoculation with 20 mL·pot-1 of R-13 fermentation broth resulted in no significant effects on the Cd content of roots, stems, leaves, or fruits of S. nigrum L. With 40 mL·pot-1 of fermentation broth, the Cd content of vegetative organs and fruits was significantly increased. When it reached 200 mL·pot-1, the Cd content of vegetative organs was the highest, with Cd concentrations in the roots, stems, leaves, and fruits increasing by 84.42%, 43.67%, 64.06%, and 20.29%, respectively. In conclusion, root inoculation with endophytic Herbaspirillum R-13 can significantly increase the relative content of Herbaspirillum in the root system and enhance Cd absorption of S. nigrum L. Therefore, this strain has excellent prospects for application in the phytoremediation of soil contaminated with Cd.

[Foliar Application of L-Cysteine: Effects on the Concentration of Cd and Mineral Elements in Rice].

To evaluate the feasibility of applying L-cysteine (L-Cys) as a foliar conditioner for Cd reduction in rice, a field experiment was conducted to investigate the concentration of Cd and mineral elements in rice after the foliar application of L-Cys. The variation in Cd distribution and morphology in key rice organs was examined to study the Cd reduction mechanisms of spraying L-Cys on rice. The results showed that foliar application of L-Cys at the rice-flowering stage significantly decreased Cd concentration in grains, in a concentration dependent manner, without inhibiting the accumulation of mineral elements Ca, Mg, K, Mn, and Zn. With a 10 mmol ·L-1 L-Cys application, Cd concentration in rice grains decreased by 59.2%, to below 0.2 mg ·kg-1, which is the maximum safety limit in China. Foliar application of L-Cys also inhibited Cd accumulation in rice vegetative organs, including rachises, first nodes, neck-panicles, flag leaves, second internodes, second nodes, second leaves, stalks, and roots (58.3%, 56.0%, 62.7%, 67.0%, 59.3%, 61.5%, 60.2%, 54.9%, and 50.3%, respectively). After transfer factor calculation, first nodes were found to be the key organ for Cd blocking in rice. The application of L-Cys increased Cd transfer from flag leaves and second internodes to first nodes (105.4% and 45.8%, respectively), but decreased Cd transfer from first nodes up to neck-panicles (27.5%). In rice first nodes, the concentrations of Cd in the inorganic, water soluble, and residue states were all lower following L-Cys application, and the proportion of residual Cd increased to 94.4%. Therefore, foliar application of L-Cys significantly inhibited Cd transport and accumulation in rice grains, by decreasing the Cd concentrations of various vegetative organs and improving Cd interception in the first nodes. This is a promising way to produce rice with lower Cd concentrations and normal mineral element concentrations in Cd-contaminated paddy fields.

[Mechanism of S-allyl-L-cysteine Alleviating Cadmium Stress in Seedling Roots and Buds of Rice Seedlings].

Cd has toxic effects on rice seed germination and plant growth, which may eventually lead to decreased yield and excessive Cd content in rice grains. The potential mechanism of S-allyl-L-cysteine (SAC), a natural sulfur compound derived from garlic extract, in alleviating Cd2+ stress in young roots and buds of rice seedlings was studied by a seed germination experiment. "Zhong zao 35", one of the main rice varieties in Southern China, was selected as the test material. Firstly, the alleviating effect of SAC on Cd2+ stress in rice seedling roots and buds was studied. Following this, the physiological mechanism of Cd2+ stress alleviation by SAC was examined based on the expression of the Cd transporter coding gene using real-time fluorescent quantitative PCR. The results showed that when the Cd2+ stress concentration reached 50 µmol·L-1, the young roots and buds of rice seedlings were significantly inhibited, and when the SAC concentration reached 200 µmol·L-1, Cd2+ stress was significantly alleviated. Compared to a Cd2+ stress treatment group, the total root length, surface area, and volume of young roots was increased by 173.5%, 65.52%, and 37.04%, respectively; CAT and SOD activity in young roots and buds was increased by 212.42% and 110.76%, and 31.41% and 47.31%, respectively; MDA and GSH content was decreased by 43.09% and 34.12%, and 33.97% and 35.74%, respectively; and Cd content was decreased by 35.91% and 28.86%, respectively. The results of quantitative real-time PCR showed that the relative expression levels of OsNramp5 and OsHMA2 were significantly reduced by 33.38% and 34.99% compared with the Cd2+ stress group, respectively. However, the relative expression level of OsHMA3 was significantly increased by 33.96%. From the above experimental results, the main mechanism by which SAC reduces Cd2+ stress in the young roots and buds of rice is via the regulation of Cd transporter-encoding genes, reducing Cd2+ transport to young roots and buds, and increasing transport to vacuoles.

[Effects of Foliar Spraying of 2,3-dimercaptosuccinic Acid on Cadmium Uptake, Transport, and Antioxidant System in Rice Seedlings].

Rice contaminated by Cd has aroused widespread public concern. It is of great importance to find effective ways to reduce Cd translocation from roots to shoots and alleviate Cd stress in rice to ensuring food quality and safety. In this study, 2,3-dimercaptosuccinic acid (DMSA) was sprayed onto the leaves of rice seedlings to evaluate the feasibility of DMSA reducing Cd translocation to rice shoots and alleviating Cd stress. Therefore, seedlings of Zhongzao 35, one of the main rice cultivars in southern China, were used to study the effects of different concentrations of DMSA on the uptake and transport of Cd in rice seedlings by hydroponics. The effects of DMSA on MDA and GSH content, and activities of antioxidant enzymes such as CAT and SOD in rice seedlings, were also investigated. The results showed that after four iterations of foliar application of DMSA at concentrations of 0.2, 0.4, and 1.0 mmol·L-1, the Cd concentration in the rice seedling shoots decreased significantly with increasing DMSA spraying concentration. Compared with the control, the Cd concentration in shoots decreased by 22.1%, 39.7%, and 43.5%, respectively, but had no significant effect on the root Cd concentration. There was no significant effect on the concentrations of K, Ca, Mg, Fe, Zn, or Mn in the shoot or root. The content of MDA and GSH in the shoots of rice seedlings decreased significantly after four spraying times of DMSA and the activity of CAT and SOD increased significantly, which shows that spraying DMSA alleviated the stress effect of Cd on rice seedlings. Foliar application of DMSA can significantly reduce the accumulation of Cd in rice shoots but has no significant effect on the content of six common mineral elements, and can effectively relieve the oxidative damage caused by Cd stress. DMSA has the potential to develop a foliar modulator for reducing rice grain Cd content.

Correction: Associations Between Affective States and Sexual and Health Status Among Men Who Have Sex With Men in China: Exploratory Study Using Social Media Data.

[This corrects the article DOI: 10.2196/13201.].

Associations Between Affective States and Sexual and Health Status Among Men Who Have Sex With Men in China: Exploratory Study Using Social Media Data.

BACKGROUND: Affective states, including sentiment and emotion, are critical determinants of health. However, few studies among men who have sex with men (MSM) have examined sentiment and emotion specifically using real-time social media technologies. Moreover, the explorations on their associations with sexual and health status among MSM are limited. OBJECTIVE: This study aimed to understand and examine the associations of affective states with sexual behaviors and health status among MSM using public data from the Blued (Blued International Inc) app. METHODS: A total of 843,745 public postings of 377,610 MSM users located in Guangdong were saved from the Blued app by automatic screen capture. Positive affect, negative affect, sexual behaviors, and health status were measured using the Simplified Chinese Linguistic Inquiry and Word Count. Emotions, including joy, sadness, anger, fear, and disgust, were measured using the Weibo Basic Mood Lexicon. A positive sentiment score and a positive emotion score were also calculated. Univariate and multivariate linear regression models on the basis of a permutation test were used to assess the associations of affective states with sexual behaviors and health status. RESULTS: A total of 5871 active MSM users and their 477,374 postings were finally selected. Both positive affect and positive emotions (eg, joy) peaked between 7 AM and 9 AM. Negative affect and negative emotions (eg, sadness and disgust) peaked between 2 AM and 4 AM. During that time, 25.1% (97/387) of negative postings were related to health and 13.4% (52/387) of negative postings were related to seeking social support. A multivariate analysis showed that the MSM who were more likely to post sexual behaviors were more likely to express positive affect (beta=0.3107; P<.001) and positive emotions (joy: beta=0.027; P<.001), as well as negative emotions (sadness: beta=0.0443; P<.001 and disgust: beta=0.0256; P<.001). They also had a higher positive sentiment score (beta=0.2947; P<.001) and a higher positive emotion score (beta=0.1612; P<.001). The MSM who were more likely to post their health status were more likely to express negative affect (beta=0.8088; P<.001) and negative emotions, including sadness (beta=0.0705; P<.001), anger (beta=0.0058; P<.001), fear (beta=0.0052; P<.001), and disgust (beta=0.3065; P<.001), and less likely to express positive affect (beta=-0.0224; P=.02). In addition, they had a lower positive sentiment score (beta=-0.8306; P<.001) and a lower positive emotion score (beta=-0.3743; P<.001). CONCLUSIONS: The MSM social media community mainly expressed their positive affect in the early morning and negative affect after midnight. Positive affective states were associated with being sexually active, whereas negative affective states were associated with health problems, mostly about mental health. Our finding suggests the potential to deliver different health-related intervention strategies (eg, psychological counseling and safe sex promotion) on a social media app according to the affective states of MSM in real time.

Rice vegetative organs alleviate cadmium toxicity by altering the chemical forms of cadmium and increasing the ratio of calcium to manganese.

Altering Cd chemical form is one of the mechanisms to alleviate Cd toxicity in rice plant. Field experiments were carried out in this study to investigate the potential of rice vegetative organs in altering Cd into insoluble chemical forms in the natural environment. Experimental results showed that more than 80% of Cd in rice roots existed in the insoluble forms. Uppermost nodes altered Cd into insoluble form preferentially and generally had higher content of insoluble Cd than other organs. Rachises displayed a slow increasing trend in soluble Cd when total Cd in roots was less than 1.8 mg kg-1. However, when Cd content in roots exceeded 2.8 mg kg-1, the ratio of insoluble to soluble Cd remained stable at 85:15 in rachises and roots, and at 75:25 in uppermost nodes and flag leaves. Cd concentration in grains was greatly lower than that in vegetative organs, and closely correlated with the content of soluble Cd in rachises (r = 0.991**) as well as in uppermost nodes. Soluble Cd in the uppermost nodes displayed a much lower mobility than that in other organs. Accumulation of soluble Cd was always companied by decrease of Ca and increase of Mn in roots, uppermost nodes and rachises. A small increase of soluble Cd from 0.05 to 0.1 mg kg-1 caused a sharp decline of Ca:Mn ratio in roots and rachises. Roots and nodes had much higher Ca:Mn ratio than rachises when soluble Cd was less than 0.5 mg kg-1 in them. These results indicate that vegetative organs have a great potential to alter more than 75% Cd into insoluble forms and increasing Ca:Mn ratio may be another way to alleviate Cd toxicity by establishing new ionic homeostasis in rice plants.

Obesity May Not Induce Dynamic Stability Disadvantage during Overground Walking among Young Adults.

Obesity has been related to postural instability during static standing. It remains unknown how obesity influences stability during dynamic movements like gait. The primary aim of this study was to investigate the effects of obesity on dynamic gait stability control in young adults during gait. Forty-four young adults (21 normal-weight and 23 obese) participated in this study. Participants walked five times at their self-selected gait speeds on a linear walkway. Their full-body kinematics were gathered by a motion capture system. Compared with normal-weight group, individuals with obesity walked more slowly with a shorter but wider step. People with obesity also spent an elongated double stance phase than those with normal weight. A reduced gait speed decreases the body center of mass's velocity relative to the base of support, leading to a reduction in dynamic stability. On the other hand, a shortened step in accompanying with a less backward-leaning trunk has the potential to bring the center of mass closer to the base of support, resulting in an increase in dynamic stability. As the result of these adaptive changes to the gait pattern, dynamic gait stability among people with obesity did not significantly differ from the one among people with normal weight. Obesity seems to not be inducing dynamic stability disadvantage in young adults during level overground walking. These findings could provide insight into the mechanisms of stability control among people affected by obesity during dynamic locomotion.

[Predicting the cadmium bioavailability in the soil of sugarcane field based on the diffusive gradients in thin films with binding phase of sodium polyacrylate].

The diffusive gradients in thin films (DGT) technique with solid-state binding phases has been widely used for in situ collection and measurement of available heavy metals in waters, soils or sediments, whereas DGT with liquid binding phase is primarily used in the in situ analysis of heavy metals in waters. In this paper, rhizosphere soils of sugarcane were collected in Guangxi and the concentrations of cadmium (Cd) were determined by DGT with a solid-state binding phase of chelex100 (chelex100-DGT) and modified DGT with a liquid binding phase of sodium polyacrylate (CDM-PAAS-DGT). The result showed that the Cd contents in soils measured by DGT with both binding phases and Cd in the roots, leaves and unpolished stems of sugarcane had significant positive correlation. The extraction ability of the CDM-PAAAS-DGT was much higher than that of the chelex100-DGT. In addition, multivariate analyses were used to assess the impact of pH, cation exchange capacity (CEC), soil organic matter (OM) and texture. Two principal components were extracted and the linear regression models were established. The Cd bioavailability in soils could be accurately predicted by the CDM-PAAAS-DGT technique, which expanded its applicable area.

The continuous accumulation of Na+ in detached leaf sections is associated with over-expression of NTHK1 and salt tolerance in poplar plants.

Detached leaf sections (2×2cm2) from transgenic poplar line 18-1 and its wild type (WT) (Populus× euramericana 'Neva') were used to test their salt tolerance and gene expression under controlled environment conditions. The sections from line 18-1 displayed better tolerance to NaCl stress, indicated by high chlorophyll retention and K+ content but low relative electrolyte leakage (REL). Transient overexpression of NTHK1 (Nicotiana tabacum histidine kinase 1) and V-H+-PPase was found in the detached young leaves from line 18-1 after they had been stressed for a few minutes. The activities of vacuolar-type H+-ATPase and H+-PPase in line 18-1 were boosted initially and then decreased to normal level as in unstressed leaves. After sections were stressed for 10 days, the maximal Na+ concentration in line 18-1 was much higher than that in the WT. The higher capacity for Na+ accumulation in line 18-1 may be due to stable Na+ sequestration into the vacuoles. Osmotic stress imposed little effect on REL and chlorophyll content of the sections. The capacity of detached leaf sections in NaCl solution to tolerate stress and to accumulate Na+ may be useful for identifying genotypes with good salt tolerance in poplar and other plants.

[Detecting caries susceptible population in children with gtfB oligonucleotide probe].

OBJECTIVE: To establish a quick, exact and inexpensive method to detect caries susceptibility in children. METHODS: 125 caries free children, aged 3-4 years, were randomly sampled. A combination of polymerase chain reaction (PCR) and gtfB oligonucleotide probe hybridization method was used to detect Streptococcus mutans in saliva. The participants were followed up for a year and the clinical examination results were compared with the laboratory results. The perspective study was used to evaluate the detecting approach. RESULTS: When the combination of PCR and hybridization method was used to detect caries susceptibility of the sample, the predictive sensitivity, predictive specificity and predictive reliability were all increased to 69.2%, 46.8% and 54.3%, respectively as compared to only PCR, which were 56.4%, 44.2% and 48.3%, respectively. The samples with both the positive and negative results of hybridization detection had caries clinically, but the dmft index and prevalence were higher in the positive (dmft was 2.15 +/- 0.86, and the prevalence was 23.28%) than in the negative(dmft was 1.58 +/- 0.51, and the prevalence was 10.34%) which was statistically significant (P < 0.05). CONCLUSION: The probe was found to be quite potential in detecting caries susceptibility, but the predictive specificity and predictive reliability values were not significant.

Alteration of gene expression during nasopharyngeal carcinogenesis revealed by oligonucleotide microarray after microdissection of tumor tissue and normal epithelia from nasopharynx.

BACKGROUND: Microarray and microdissection techniques were being used for many applications to study the carcinogenesis of some human tumors. But seldom studies had hitherto combined these two techniques to study carcinogenesis mechanism of nasopharyngeal carcinoma (NPC). To identify a set of genes involved in the carcinogenesis and development of NPC, we used the microdissected homogeneous NPC tissue cells and the pure normal epithelium pillar cells to construct the whole human genome expression profiles. METHODS: We preserved the tissue samples from nasopharynx of 18 patients (including 13 samples of NPC and 5 samples of normal or inflammatory mucous tissue samples from nasopharynx) in RNAlater Stabilization Reagent. The tissue samples were microdissected to harvest the homogeneous tissue cells, then total RNA was isolated from them. The sufficient antisense RNA (aRNA) was amplified from these total RNA. HG-U133.Plus.2.0 GeneChip was used to construct the human whole genome expression profiling of each sample. Differential patterns of expression of genes correlated with the carcinogenesis, classification and progression of NPC were identified with comparing the expression profiling data respectively in leave one out cross-validation analysis. Correlation between aRNA expression measured by the microarrays and semi-quantitative reverse transcription polymerase chain reaction (sqRT-PCR) were also ascertained, and found that hybridization results were validated in all of the 18 patients. RESULTS: Differential patterns of expression of 127 genes correlated with the carcinogenesis (A P value less than 0.001 with the 2-fold differentiated expression between case group and control group) of the NPC were filtered. The top most up-regulated and down-regulated 8 genes by the way of permutation test were also selected and listed in the paper. Expression of genes E2F6 and TSPAN-1 was identified using aRNA by sqRT-PCR and showed that there was significant difference between the average value of case groups and that of control group respectively (t = 2.170, df = 16, P = 0.045 and t = -2.946, df = 16, P = 0.009). CONCLUSIONS: We had identified some genes which could be the molecular marker during the carcinogenesis and the development of the NPC. The genes which selected from the different subgroups seemed to be implicated for the diagnosis,classification, and progression of NPC, and provided important insights into their underlying biology.

[Expression of desmoglein 3 in nasopharyngeal carcinoma: research of 22 cases].

OBJECTIVE: To investigate the expression of desmoglein 3 (DSG3), a candidate target gene in the antisense RNA (aRNA) from the purified nasopharyngeal tissues in nasopharyngeal carcinoma (NPC). METHODS: Specimens of nasopharyngeal tissues were harvested from 22 NPC patients, aged 44 +/- 11 (NPC group), and 12 normal persons or patients with nasopharyngeal infectious diseases, aged 46 +/- 14. Microdissection technique was used to get homogenous tissue cells from which total RNA was isolated (control group). aRNA was amplified from the total RNA by "in vitro transcription" (IVT). The expression of DSG3 gene was identified using these aRNA by semi-quantitative reverse transcriptase polymerase chain reaction (sqRT-PCR). RESULTS: The average expression level of DSG3 in the NPC group was 3.536 +/- 2.689, significantly higher than that of the control group (0.95 +/- 0.23, df = 32, t = 3.307, P = 0.002). The expression level of DSG3 in the whole expression profiling of the NPC group was 1.06 +/- 1.60, significantly higher than that of the control group (0.48 +/- 0.23, df = 16, t = 2.145, P = 0.048). CONCLUSION: The whole genome expression profiling detected by sqRT-PCR can be used to shift the marker genes from biopsy tissue samples. DSG3 may be a tumor candidate gene in NPC.

[Cloning, antisense construction and tomato transformation of Lecop1like gene].

Here reported a 1060 bp cDNA cloning of LeCOP1LIKE gene by EST probing and RT-PCR method. In order to characterize function of this gene, a LeCOP1LIKE antisense expression vector was transformed into Micro-Tom via Agrobacterium-mediated transformation method and 10 independent transgenic lines were obtained. RT-PCR analysis showed that the expression of LeCOP1LIKE gene was evidently repressed in 4 lines of them. The transgenic plants were much shorter than their wild type control, their chlorophyll content was increased but the seed development was obviously suppressed. All these results suggested that the cloned LeCOP1LIKE gene was a negative regulator of photomorphogenesis in tomato.

[Advances in the RNA-directed DNA methylation in plants].

The RNA-directed DNA Methylation (RdDM) is one type of epigenetic modification which was firstly discovered in plant. RdDM can directly cause DNA modifications of the genome through RNA-DNA interactions. In plant, both of RdDM and mRNA degradation induced by siRNA can silence sequence specific genes through RNA. They play very significant roles in chromosome rearrangement, defence of virus invasion, regulation of gene expression and many processes of plant development. However, the mechanisms of RdDM are still unclear. In this paper the basic characteristics of RdDM were briefly summarized and advances in studies on mechanisms of RdDM were reviewed. These include the kinds of DNA methyltransferases and their functional mechanisms in RdDM, the relationships between DNA methylation and chromatin modification, and important proteins involved in the RdDM process. In plants, RdDM may occur at both the transcriptional and post-transcriptionnal levels, both of which induce gene silencing. Methylation of the target gene promoter correlates with transcriptional gene silencing (TGS) whereas methylation of the coding sequence is associated with post-transcriptional gene silencing (PTGS). RdDM and RNAi all depend on the similar siRNA and enzymes, such as DCL3, RdR2, SDE4 and AGO4. There are at least three kinds of DNA methyltransferases, DRM1/2, MET1 and CMT3, in pants. They can interact with and modifies all cytidines within the DNA regions homologous to RNA sequence. Furthermore, methylation of lysine 9 in Histone H3 can affect the methylation of cytidines.