Tyrosine hydroxylase plays crucial roles in larval cuticle formation and larval-pupal tanning in the rice stem borer, Chilo suppressalis

The striped stem borer, Chilo suppressalis (Walker), a notorious pest infesting rice, has evolved a high level of resistance to many commonly used insecticides. In this study, we investigate whether tyrosine hydroxylase (TH), which is required for larval development and cuticle tanning in many insects, could be a potential target for the control of C. suppressalis. We identified and characterized the full-length cDNA (CsTH) of C. suppressalis. The complete open reading frame of CsTH (MW690914) was 1683 bp in length, encoding a protein of 560 amino acids. Within the first to the sixth larval instars, CsTH was high in the first day just after molting, and lower in the ensuing days. From the wandering stage to the adult stage, levels of CSTH began to rise and reached a peak at the pupal stage. These patterns suggested a role for the gene in larval development and larval-pupal cuticle tanning. When we injected dsCsTH or 3-iodotyrosine (3-IT) as a TH inhibitor or fed a larva diet supplemented with 3-IT, there were significant impairments in larval development and larval-pupal cuticle tanning. Adult emergence was severely impaired, and most adults died. These results suggest that CsTH might play a critical role in larval development as well as larval-pupal tanning and immunity in C. suppressalis, and this gene could form a potential novel target for pest control.

Comparison of the efficacy of steroid-free versus classic steroid-containing regimens in primary membranous nephropathy

Objective: To compare the efficacy of a steroid-free regimen with steroid-based treatment in managing primary membranous nephropathy (PMN) and investigate the potential benefits of steroid-free regimens in PMN therapy. Methods: This was a single-centre prospective cohort study. A total of 81 patients were divided into two groups according to their medication regimen: a rituximab (RTX)/tacrolimus (TAC) group (low-dose RTX combined with low-dose TAC group, without steroids, n = 31) and a prednisone (P)/TAC group (P combined with TAC group, n = 61). The changes in 24-h urine protein quantification, levels of blood albumin, blood creatinine, total cholesterol, triglyceride and fasting blood glucose as well as anti-phospholipase A2 receptor antibody titres were observed in both groups before treatment and after 1, 3, 6 and 12 months of treatment. Clinical remission (complete and partial remission), serological remission and recurrence were assessed in both groups after treatment, and the occurrence of adverse reactions was observed. Results: 1) Before treatment, there was no significant difference in baseline values between the two groups (p > 0.05). 2) After 12 months of treatment, the 24-h proteinuria and total cholesterol levels in the RTX/TAC group were significantly lower than those in the P/TAC group (p < 0.05). 3) After 6 months of treatment, the clinical remission rate of the RTX/TAC group was significantly higher than that of the P/TAC group (p < 0.05). After 12 months of treatment, the clinical remission rate of the RTX/TAC group was significantly higher than that of the P/TAC group (p < 0.05). (4) After 3, 6 and 12 months of treatment, serological remission rates in the RTX/TAC group were significantly higher than those in the P/TAC group (p < 0.05). During treatment, the anti-PLA2R antibody titres in the RTX/TAC group remained lower than those in the P/TAC group (p < 0.05). Conclusion: The low-dose RTX combined with low-dose TAC steroid-free regimen induces serological remission in patients with PMN earlier than the classic regimen of P combined with TAC, and there was no significant difference in adverse effects between the two groups. Besides, the long-term clinical remission effect of low-dose RTX combined with low-dose TAC is better than that of P combined with TAC.

[Research advances on allergen component-resolved diagnosis in respiratory allergic diseases]

Allergen component-resolved diagnosis (CRD) is an emerging molecular diagnostic technology, which can further clarify the protein profile of allergen components in allergic patients, achieve accurate detection of allergens, and have great significance and value for the precise prevention and treatment of allergic diseases. In this article, the CRD technology and its research progress in respiratory allergic diseases are introduced, and the importance of CRD in the evaluation, prevention and treatment of respiratory allergic diseases are discussed.

Palmitic acid combined with γ-interferon inhibits gastric cancer progression by modulating tumor-associated macrophages' polarization via the TLR4 pathway

BACKGROUND

Tumor-associated macrophages (TAMs) constitute the main infiltrating immune cells in the solid tumor microenvironment. Amounting studies have analyzed the antitumor effect on immune response induced by Toll-like receptor (TLR) agonists, such as lipopolysaccharide (LPS), γ-interferon (γ-IFN), and palmitic Acid (PA). However, their combined treatment for gastric cancer (GC) has not been illuminated.

METHODS

We investigated the relevance of macrophage polarization and the effect of PA and γ-IFN in GC in vitro and in vivo. M1 and M2 macrophage-associated markers were measured by real-time quantitative PCR and flow cytometry, and the activation level of the TLR4 signaling pathways was evaluated by western blot analysis. The effect of PA and γ-IFN on the proliferation, migration, and invasion of GC cells (GCCs) was evaluated by Cell-Counting Kit-8, transwell assays, and wound-healing assays. In vivo animal models were used to verify the effect of PA and γ-IFN on tumor progression, and the M1 and M2 macrophage markers, CD8 + T lymphocytes, regulatory T cells (Treg) cells, and the myeloid-derived suppressor cells (MDSCs) in tumor tissues were analyzed by flow cytometry and immunohistochemical (IHC).

RESULTS

The results showed that this combination strategy enhanced M1-like macrophages and diminished M2-like macrophages through the TLR4 signaling pathway in vitro. In addition, the combination strategy impairs the proliferative and migratory activity of GCC in vitro and in vivo. While, the antitumor effect was abolished using the TAK-424 (a specific TLR-4 signaling pathway inhibitor) in vitro.

CONCLUSIONS

The combined treatment of PA and γ-IFN inhibited GC progression by modulating macrophages polarization via the TLR4 pathway.

[The mediating role of worker-occupation fit between occupational stress and anxiety symptoms in medical staff]

Objective: To analyze the mediating effect of work-occupation fit between occupational stress and anxiety symptoms in medical staff. Methods: Convenience sampling method was adopted to select participants of one general hospital and three specialized hospitals as respondents for a questionnaire survey in Henan Province from October 2020 to January 2021. A total of 2050 medical staff were investigated, and 1988 valid questionnaires were collected, and the effective rate of the questionnaire was 97.0% (1988/2050) . The "Depression-Anxiety-Stress Scale" and "Worker-Occupation Fit Inventory" were used to evaluate the occupational stress, anxiety symptoms and worker-occupation fit level of medical staff, and the mediation effect of work-occupation fit on the relationship between occupational stress and anxiety symptoms was analyzed using a mediating effect model. Results: The average age of the 1988 medical staff was (32.7±7.8) years old, the positive detection rates of occupational stress and anxiety symptoms were 42.5% (845/1988) and 56.7% (1127/1988) , respectively. Anxiety symptoms of medical staff were positively correlated with occupational stress, negatively correlated with worker-occupation fit (r=0.831, -0.364, P<0.001) , work-occupation fit was negatively correlated with occupational stress (r=-0.259, P<0.001) . The results of the mediation effect analysis showed that occupational stress had a direct effect on anxiety symptoms (β=0.677, BCa 95%CI: 0.648-0.707) , and worker-occupation fit (β=0.047, BCa 95%CI: 0.039-0.056) , characteristic fit (β=0.089, BCa 95%CI: 0.074-0.104) , need-supply fit (β=0.075, BCa 95%CI: 0.062-0.089) , and ability-demand fit (β=0.035, BCa 95%CI: 0.026-0.044) mediated the association between occupational stress and anxiety symptoms in medical staff, with the mediating effect as a percentage of 6.5%, 12.3%, 10.3%, and 4.8%, respectively. Conclusion: Worker-occupation fit has a mediating effect between occupational stress and anxiety symptoms in medical staff, but mainly direct effect.

[Literature analysis of hot topics on occupational noise-induced hearing loss]

Objective: To analyze the literature of related research reports on occupational hearing loss (ONIHL) , study the characteristics of the subject and determine the research hotspots. Methods: In December 2020, PubMed database was searched by bibliometrics for ONIHL published in PubMed database from January 1971 to December 2020. Bicomb 2.03 software was used to extract the subject. The publication year, publication country, source magazine and subject words were summarized and analyzed. Results: A total of 1 473 papers were included in this study, and the number of papers was 66 from 1971 to 1980, and 628 from 2011 to 2020, an increase of nearly 10 times. The top three countries were the United States, China and Germany, with 31.5% (464/1473) , 11.5% (171/1473) and 6.2% (91/1473) ; The cross-sectional study was the most applied type; The top five words for 2011-2020: Mental Illness, polymorphism, cardiovascular disease, high frequency hearing impairment and standards and regulations. Conclusion: Susceptibility Genes, Psychological Disorders, Cardiovascular Diseases and Risk Assessment are hot areas in ONIHL at present. Researchers should focus on major fields and grasp future trends as a whole.

[The influence of subjective comfort of working environment on occupational stress of railway station workers]

Objective: To explore the influential factors of job stress suffered by workers in railway stations, the level of job stress of were measured and subjective comfort of employees targeting to working environment were reported. Methods: In March 2019, a cluster sampling study was designed to collect the personal characteristics, job characteristics and subjective comfort degree of working environment of 432 employees in Chongqing railway stations. Meanwhile, job stress was assessed using the effort-reward imbalance scale. Chi-square test was used to compare the difference of occupational stress detection rate among different stratified factors such as occupational characteristics. Logistic regression was applied to analyze the influential factors of occupational stress. Results: The detection rate of job stress of workers in the railway stations was 31.02% (134/432) . The detection rate of job stress was higher among the divorced workers in railway stations, those earning less than 5, 000 yuan per month, those with 10-20 years' length of service, those who worked as a conductor and other workers including baggageman, station master on duty and assistant engineer (χ(2)=9.61, 14.76, 23.28, 11.06, P=0.008, 0.002, 0.000, 0.011) . The detection rate of job stress was higher among those whose working environment subjective feelings were uncomfortable, the differences were statistically significant (P<0.001) . The results showed that the occupational stress of the staff in the railway stations was influenced by their subjective feeling of air quality, noise and Space Layout (P<0.05) . The risk factors of occupational stress were air quality, noise and uncomfortable space layout (OR=0.571, 0.068, 0.441, P=0.051, 0.054, 0.007) . Conductor, other (Bellboy, Duty Station Master, assistant engineer) were the risk factors of occupational stress (OR=1.884, 2.703, P=0.065, 0.019) . The employees of station A and station B were the risk factors of occupational stress (OR=4.681, 1.811, P=0.002, 0.067) . Conclusion: The higher detection rate of job stress of workers in the railway stations is correlated with the subjective comfort degree of the working environment of the workers.

[Clinical phenotype and gene mutation analysis of 12 patients with hereditary protein C deficiency in different families]

Objective: To investigate the molecular pathogenesis and clinical features of unrelated 12 patients with inherited coagulation protein C (PC) deficiency in Chinese population. Methods: The PC activity (PC:A) and PC antigen (PC:Ag) were detected by chromogenic substrate and enzyme linked immunosorbent assay, respectively. The nine exons and flanking sequences of the protein C (PROC) gene were amplified by polymerase chain reaction with direct sequencing, and the suspected mutations were validated by reverse sequencing (clone sequencing for deletion mutations) . Results: The PC:A of the 12 probands decreased significantly, ranging from 18% to 55%, and the PC:Ag of the 10 probands decreased significantly. Eleven mutations were found, out of which four mutations [c.383G>A (p.Gly128Asp) , c.997G>A (p.Ala291Thr) , c.1318C>T (p.Arg398Cys) , and c.532G>C (p.Leu278Pro) ] were discovered for the first time. Six mutations were in the serine protease domain, four mutations were located in epidermal growth factor (EGF) -like domains, and one mutation was located in activation peptide. There were two deletion mutations (p.Met364Trp fsX15 and p.Lys192del) , and the rest were missense mutations. Mutations p.Phe181Val and p.Arg189Trp were identified in three unrelated families. All mutations may be inherited, and consanguineous marriages were reported in two families. Among the probands, nine cases had venous thrombosis, two cases had poor pregnancy manifestations, and one case had purpura. Conclusion: Patients with PC deficiency caused by PROC gene defects are prone to venous thrombosis, especially when there are other thrombotic factors present at the same time.

Application of Chlorophyte ChlB Gene and Cyanophyte NIES Gene in the Detection of Drowning-Related Plankton

Abstract

Objective To construct a polymerase chain reaction-capillary electrophoresis （PCR-CE） detection method using ChlB gene and NIES gene, investigate the method's specificity and sensitivity, and to evaluate its application value in drowning diagnosis. Methods The specific primers ChlB and NIES were designed for the conserved sequence of chlorophyte ChlB gene and cyanophyte NIES gene in GenBank to construct PCR-CE detection method; 50 species of standard DNA samples were amplified; the sensitivity was determined by gradient concentration detection of positive standard samples; 25 actual cadaver lung tissue samples （drowned： 20, natural death： 5） were detected, and the simultaneous detection results of microwave digestion-vacuum filtration-automated scanning electron microscopy （MD-VF-Auto SEM） were simultaneously compared. Results The minimum DNA detection concentration of primers ChlB and NIES was 0.161 ng and 0.109 ng, respectively, which could specifically amplify chlorophyte （Chlorella pyrenoidosa） and cyanophyte ［Microcystis aeruginosa （producing and not producing toxin）］ widespread in water. The product fragments were 156 bp and 182 bp, respectively. The results of non-drowning tissues were negative. Conclusion This method has high sensitivity and specificity. It can be applied to the detection of plankton related to drowning and combined with MD-VF-Auto SEM method, can increase the detection range of plankton related to drowning and improve the evidence power of drowning diagnosis.

Two Splice Isoforms of Leptinotarsa Ecdysis Triggering Hormone Receptor Have Distinct Roles in Larva-Pupa Transition

Insect ecdysis triggering hormone (ETH) receptors (ETHRs) are rhodopsin-like G protein-coupled receptors. Upon binding its ligand ETH, ETHR initiates a precisely programed ecdysis behavior series and physiological events. In Drosophila melanogaster, the ethr gene produces two functionally distinct splicing isoforms, ethra and ethrb. ETH/ETHRA activates eclosion hormone (EH), kinin, crustacean cardioactive peptide (CCAP), and bursicon (burs and pburs) neurons, among others, in a rigid order, to elicit the behavioral sequences and physiological actions for ecdysis at all developmental stages, whereas ETH/ETHRB is required at both pupal and adult ecdysis. However, the role of ETHRB in regulation of molting has not been clarified in any non-drosophila insects. In the present paper, we found that 20-hydroxyecdysone (20E) signaling triggers the expression of both ethra and ethrb in a Coleopteran insect pest, the Colorado potato beetle Leptinotarsa decemlineata. RNA interference (RNAi) was performed using double-stranded RNAs (dsRNAs) targeting the common (dsethr) or isoform-specific (dsethra, dsethrb) regions of ethr. RNAi of dsethr, dsethra, or dsethrb by the final-instar larvae arrested larva development. The arrest was not rescued by feeding 20E. All the ethra depleted larvae stopped development at prepupae stage; the body cavity was expanded by a large amount of liquid. Comparably, more than 80% of the ethrb RNAi larvae developmentally halted at the prepupae stage. The remaining Ldethrb hypomorphs became pupae, with blackened wings and highly-expressed burs, pburs and four melanin biosynthesis genes. Therefore, ETHRA and ETHRB play isoform-specific roles in regulation of ecdysis during larva-pupa transition in L. decemlineata.

[Effect of complement C5a on the expression of MCP-1 and NGAL in immune kidney injury of trichloroethylene sensitized mice]

Objective: To explore the possible role of C5a in the pathogenesis of renal injury in TCE- sensitized mice, to analyze the impact of expression of neutrophil gelatinase-associated lipocalin (NGAL) and monocyte chemotactic protein-1 (MCP-1) in the presence or absence of C5a receptor antagonist (C5aRA) pretreatment. Methods: A total of 50 female specific pathogens free(SPF) BALB/c mice were randomly divided into blank control group (n=5) , solvent control group (n=5) , TCE group (n=20) , and TCE+C5aRA group (n= 20) . After one week for adaptive feeding, a mouse model of TCE-induced skin sensitization was established by treating with 50% TCE and 30% TCE in turn. The mice in solvent control group accept same reagents without TCE and the mice in blank control group underwent nothing. In TCE +C5aRA group, except for the TCE solution treatment, mice were intraperitoneally injected with 0.5 mg/kg C5aRA solution at the time of challenge. And the skin erythema and edema reaction were scored 24 h after the last challenge. The mice were divided into sensitization positive group and sensitization negative group according to the scoring result. The mice were aseptically sacrificed 72 h after the last challenge to obtain the kidneys. The structural damage of kidney was observed after histopathological staining. The levels of NGAL and MCP-1 mRNA and proteins were detected by quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemistry (IHC) , respectively. Results: The sensitization rate of mice in TCE group and TCE+C5aRA group was 45.0% (9/20) and 40.0% (8/20) , respectively. No skin lesions was found in the mice of blank control group and solvent control group. The results of histopathological staining showed that the TCE sensitization positive mice showed renal tubular dilatation, vacuolar degeneration of renal tubular epithelial cells, and infiltration of interstitial cells. The pathological damage of the kidney in TCE sensitization positive group was mild, and no inflammatory cell infiltration was seen. The data of qRT-PCR showed that the expression levels of NGAL and MCP-1 mRNA in the TCE sensitization positive group were significantly increased than in solvent control group and TCE sensitization negative group (P<0.05) , while the levels of NGAL and MCP-1 mRNA in TCE+C5aRA sensitization positive group were decreased than TCE sensitization positive group (P <0.05) . The results of IHC showed that the expression levels of NGAL and MCP-1 in TCE protein sensitization positive group were significantly higher than those in solvent control group and TCE sensitization negative group (P<0.05) . After C5aRA pretreatment, the expression levels of NGAL and MCP-1 protein were decreased than the mice in TCE sensitization positive group (P<0.05) . Conclusion: The regulation of C5a on the expression of MCP-1 and NGAL may participate in TCE- induced mice kidney damage, and pharmacological inhibition of C5a seems to be an effective way to protect the kidney injury in TCE-sensitized mice.

Epigenetic therapies in acute myeloid leukemia: the role of hypomethylating agents, histone deacetylase inhibitors and the combination of hypomethylating agents with histone deacetylase inhibitors

Epigenetic regulation includes changes of DNA methylation and modifications of histone proteins and is essential for normal physiologic functions, especially for controlling gene expression. Epigenetic dysregulation plays a key role in disease pathogenesis and progression of some malignancies, including acute myeloid leukemia (AML). Epigenetic therapies, including hypomethylating agents (HMAs) and histone deacetylase (HDAC) inhibitors, were developed to reprogram the epigenetic abnormalities in AML. However, the molecular mechanisms and therapeutic effects of the two agents alone or their combination remain unknown. An overview of these epigenetic therapies is given here. A literature search was conducted through PubMed database, looking for important biological or clinical studies related to the epigenetic regimens in the treatment of AML until October 15th, 2019. Various types of articles, including original research and reviews, were assessed, identified, and eventually summarized as a collection of data pertaining the mechanisms and clinical effects of HMAs and HDAC inhibitors in AML patients. We provided here an overview of the current understanding of the mechanisms and clinical therapeutic effects involved in the treatment with HMAs and HDAC inhibitors alone, the combination of epigenetic therapies with intensive chemotherapy, and the combination of both types of epigenetic therapies. Relevant clinical trials were also discussed. Generally speaking, the large number of studies and their varied outcomes demonstrate that effects of epigenetic therapies are heterogeneous, and that HMAs combination regimens probably contribute to significant response rates. However, more research is needed to explore therapeutic effects of HDAC inhibitors and various combinations of HMAs and HDAC inhibitors.

Application of Quantitative Analysis of Diatoms in Lung Tissue for the Diagnosis of Drowning of Experimental Animals

Abstract

Objective To discuss the application value of diatom examination in lung tissue for the forensic diagnosis of drowning. Methods The experimental animals were divided randomly into drowning, postmortem submergence and dying on land group. Diatoms in lung tissue and drowning fluid were analyzed quantitatively by microwave digestion-vacuum filtration-automated scanning electron microscopy diatom examination method. The ratios of content of diatoms in lung tissue and drowning fluid （C_L/C_D ratio） were recorded. Results The C_L/C_D ratios of experimental rabbits in the drowning group （5.82±3.50） were much higher than that of postmortem submergence group （0.47±0.35）; the C_L/C_D ratios of different parts of the lung lobes of experimental pigs in the drowning group were higher than that of postmortem submergence group （P<0.05）; in seawater, brackish water, river fresh water and lake fresh water, the C_L/C_D ratios of experimental pigs in the drowning group were higher than that of postmortem submergence group （P<0.05）. In animal experiments, all the cases with C_L/C_D ratio >1.6 were from drowning group. Conclusion C_L/C_D ratio is an indicator with good application prospects in the diagnosis of drowning.

Silencing Taiman impairs larval development in Leptinotarsa decemlineata

An exploration of novel control strategies for Leptinotarsa decemlineata is becoming more pressing given rapid evolution of insecticide resistance and rise of production loss of potato. Dietary delivery of bacterially expressed double-stranded RNA (dsRNA) is a promising alternative for management. An important first step is to uncover possible RNA-interference (RNAi)-target genes effective against both young and old larvae. Taiman (Tai) is a basic-helix-loop-helix/Per-Arnt-Sim transcription factor that is involved in the mediation of both juvenile hormone (JH) and 20-hydroxyecdysone (20E) signaling. In the present paper, we found that continuous ingestion of dsTai for three days by third (penultimate)-instar larvae caused approximately 20% larval mortality and 80% pupation failure. The larval lethality resulted from failed cuticle and tracheae shedding, which subsequently reduced foliage consumption and nutrient absorption, and depleted lipid stores. In contrast, pupation failure derived from disturbed JH and 20E signals, and disordered nutrient homeostasis including, among others, inhibition of trehalose metabolism and reduction of chitin content. Knockdown of LdTai caused similar larval lethality and pupation impairment in second and fourth (final) larval instars. Therefore, LdTai is among the most attractive candidate genes for RNAi to control L. decemlineata larvae.

Importance of Taiman in Larval-Pupal Transition in Leptinotarsa decemlineata

Insect Taiman (Tai) binds to methoprene-tolerant to form a heterodimeric complex, mediating juvenile hormone (JH) signaling to regulate larval development and to prevent premature metamorphosis. Tai also acts as a steroid receptor coactivator of 20-hydroxyecdysone (20E) receptor heterodimer, ecdysone receptor (EcR) and Ultraspiracle (USP), to control the differentiation of early germline cells and the migration of specific follicle cells and border cells in ovaries in several insect species. In holometabolous insects, however, whether Tai functions as the coactivator of EcR/USP to transduce 20E message during larval-pupal transition is unknown. In the present paper, we found that the LdTai mRNA levels were positively correlated with circulating JH and 20E titers in Leptinotarsa decemlineata; and ingestion of either JH or 20E stimulated the transcription of LdTai. Moreover, RNA interference (RNAi)-aided knockdown of LdTai at the fourth (final) instar stage repressed both JH and 20E signals, inhibited larval growth and shortened larval developing period. The knockdown caused 100% larval lethality due to failure of larval-pupal ecdysis. Under the apolysed larval cuticle, the LdTai RNAi prepupae possessed pupal thorax. In contrast, the process of tracheal ecdysis was uncompleted. Neither JH nor 20E rescued the aforementioned defectives in LdTai RNAi larvae. It appears that Tai mediates both JH and 20E signaling. Our results uncover a link between JH and 20E pathways during metamorphosis in L. decemlineata.

A new O-cinnamoyl threonine derivative from gene adpA overexpression strain Streptomyces sp. HS-NF-1222A

A new O-cinnamoyl threonine derivative, O-(2-(3-methyloxiranyl) cinnamoyl) threonine (1), was isolated from the gene adpA overexpression strain Streptomyces sp. HS-NF-1222A. The structure of 1 was determined based on HRESIMS and extensive NMR analysis.

RNA interference against the putative insulin receptor substrate gene chico affects metamorphosis in Leptinotarsa decemlineata

It is noted that insect insulin/insulin-like growth factor/target of rapamycin signaling is critical for the regulation of metamorphosis in holometabolous insects. However, the molecular mechanism remains undetermined. Our previous findings reveal that RNA interference (RNAi)-mediated knockdown of an insulin gene (LdILP2) in Leptinotarsa decemlineata disturbs both 20-hydroxyecdysone (20E) and juvenile hormone (JH) signaling, and impairs pupation. In the present paper, we further observed that the expression of the insulin receptor substrate gene chico (Ldchico) and the phosphoinositide-3-kinase gene pi3k (Ldpi3k92E) was repressed in LdILP2 depleted larvae. Moreover, RNAi of Ldchico or Ldpi3k92E decreased food consumption, affected absorption and metabolism of amino acids and sugars, and reduced expression of several 20E (LdEcR, LdHR3 and LdE75) and JH (LdJHAMT, LdKr-h1 and LdHairy) signaling genes. As a result, larval development was postponed and larval growth was inhibited. Intriguingly, knockdown of Ldchico, rather than Ldpi3k92E, impaired larval-pupal and pupal-adult ecdysis, and specifically repressed transcription of another 20E signaling gene LdUSP. Ingestion of 20E rescued the expression of LdEcR, LdHR3 and LdE75, whereas 20E feeding restored neither the decreased LdUSP mRNA level, nor the reduced pupation and adult emergence rates in Ldchico RNAi larvae. Therefore, Chico is critical for the regulation of larval-pupal-adult transition by a PI3K-independent pathway, perhaps through activation of USP in L. decemlineata.

Involvement of methoprene-tolerant (Met) in the determination of the final body size in Leptinotarsa decemlineata (Say) larvae

In the tobacco hornworm Manduca sexta, juvenile hormone (JH) is critical for the control of species-specific size. However, whether the basic helix-loop-helix/Per-Arnt-Sim domain receptor methoprene-tolerant (Met) is involved remains unconfirmed. In the present paper, we found that RNA interference (RNAi)-aided knockdown of Met gene (LdMet) lowered the larval and pupal fresh weights and shortened the larval development period in the Colorado potato beetle Leptinotarsa decemlineata. Dietary introduction of JH into the LdMet RNAi larvae rescued neither the decreased weights nor the reduced development phase, even though JH ingestion by control larvae extended developmental time and caused large pupae. Moreover, the transcript levels of five genes involved in prothoracicotropic hormone and cap 'n' collar isoform C/Kelch-like ECH associated protein 1 pathways were upregulated in the LdMet silenced larvae. Ecdysteroidogenesis was thereby activated; 20-hydroxyecdysone (20E) titer was increased; and 20E signaling pathway was elicited in the LdMet RNAi larvae. Therefore, JH, acting through its receptor Met, inhibits PTTH production and release before the attainment of critical weight. Once the critical weight is reached, JH production and release are averted; and the hemolymph JH is removed. The elimination of JH allows the brain to release PTTH. PTTH subsequently stimulates ecdysteroid biosynthesis and release to start larval-pupal transition in L. decemlineata.

Leptinotarsa hormone receptor 4 (HR4) tunes ecdysteroidogenesis and mediates 20-hydroxyecdysone signaling during larval-pupal metamorphosis

Hormone receptor 4 (HR4) is involved in the regulation of 20-hydroxyecdysone (20E) biosynthesis and the mediation of 20E signaling during larval-pupal transition in a holometabolan Drosophila melanogaster, whereas it acts as a repressor in 20E-responsive transcriptional cascade in a hemimetabolan, Blattella germanica. Here we characterized two HR4 splicing variants, LdHR4X1 and LdHR4X2, in a coleopteran Leptinotarsa decemlineata. LdHR4X1 was highly expressed in the prothoracic gland and epidermis while LdHR4X2 was abundantly transcribed in the nervous system. In vivo results showed that both prothoracicotropic hormone and 20E pathways transcriptionally regulated LdHR4, in an isoform-dependent pattern. RNA interference of LdHR4 at the final (fourth) larval instar, in contrast to the second- and third-instar periods, enhanced the expression of two ecdysteroidogenesis genes, increased 20E titer, upregulated transcription of five 20E-response genes, and reduced the mRNA level of Fushi tarazu-factor 1 (FTZ-F1). As a result, the fourth-instar LdHR4 RNAi larvae exhibited accelerated development and reduced body weight. Moreover, knockdown of LdHR4 at the fourth instar resulted in larval lethality and impaired pupation. Feeding of pyriproxyfen (a mimic of juvenile hormone) or silencing of a juvenile hormone degrading enzyme gene restored the normal course of ecdysteroidogenesis, duration of larval development, and body weight in fourth-instar LdHR4 RNAi larvae. The treatment partially suppressed the larval mortality but not the failure to pupate. The dual role of HR4 during larval-pupal metamorphosis appears to be evolutionarily conserved among holometabolans.

[Research Progress on Determination of Drowning Site]

The bodies found in water are one of the most common types in forensic practice. The discovery site of the body is often not the drowning site. However, the determination of drowning site is vital for the identification of victim. Inorganic particles and planktons, such as granular impurities, diatoms and bacteria, are valuable markers for the diagnosis of drowning. By comparing the granular impurities and planktons in tissues and suspicious drowning mediums, the drowning site can be concluded based on their similarity of types and distribution, which has practical applied value. In this paper, the research progress on determination of drowning site is summarized to provide reference for the peers.

Novaluron ingestion causes larval lethality and inhibits chitin content in Leptinotarsa decemlineata fourth-instar larvae

To accomplish consistent, long-term, integrated management (IPM) of the Colorado potato beetle, Leptinotarsa decemlineata (Say), research assessing the potential of novel, IPM-compatible insecticides is essential. Novaluron is a potent benzoylurea insecticide. In the present paper, we found that novaluron ingestion by the fourth-instar larvae inhibited foliage consumption, reduced larval fresh weight, and delayed development period, in a dose dependent manner. Most of the resulting larvae fail to pupate, and died at prepupae stage, with larvicidal activity comparable with those of cyhalothrin and spinosad but lower than those of fipronil and abamectin. Moreover, many surviving pupae that fed novaluron failed to emerge as adults, in a dose dependent pattern. Furthermore, feeding of novaluron significantly decreased chitin contents in body carcass (without midgut) and integument specimen, whereas the chitin concentration in the midgut peritrophic matrix was not affected. Furthermore, uridine diphosphate-N-acetylglucosamine-pyrophosphorylase gene (LdUAP1) and chitin synthase Aa (LdChSAa), which were mainly responsible for chitin biosynthesis in ectodermally-derived tissues, were surpressed and activated respectively after novaluron ingestion. Therefore, novaluron is an effective benzoylurea insecticide to L. decemlineata fourth-instar larvae. It inhibited chitin biosynthesis in ectodermally-derived tissues, disrupted ecdysis, impaired pupation and adult emergence, and led to death in juvenile life stages.

Leptinotarsa cap 'n' collar isoform C/Kelch-like ECH associated protein 1 signaling is critical for the regulation of ecdysteroidogenesis in the larvae

Drosophila cap 'n' collar isoform C (CncC) and Kelch-like ECH associated protein 1 (Keap1) regulate metamorphosis by transcriptional control of a subset of genes involved in ecdysteroidogenesis, 20-hydroxyecdysone (20E) signaling, and juvenile hormone (JH) degradation. In the present paper, we found that prothoracicotropic hormone signal was required for the activation of LdCncC and LdKeap1 in Leptinotarsa decemlineata. Moreover, RNA interference of LdCncC or LdKeap1 in the fourth-instar larvae delayed development. As a result, the treated larvae obtained heavier larval and pupal fresh weights and had larger body sizes than the controls. Furthermore, knockdown of LdCncC or LdKeap1 significantly reduced the mRNA levels of four ecdysone biosynthetic genes (Ldspo, Ldphm, Lddib and Ldsad), lowered 20E titer and decreased the transcript levels of five 20E response genes (LdEcR, LdUSP, LdE75, LdHR3 and LdFTZ-F1). However, the expression of two JH epoxide hydrolase genes and JH contents were not affected in the LdCncC and LdKeap1 RNAi larvae. Dietary supplementation with 20E shortened the developmental period to normal length, rescued the larval and pupal body mass rises, and recovered or even overcompensated the expression levels of the five 20E response genes in either LdCncC or LdKeap1 RNAi hypomorphs. Therefore, LdCncC/LdKeap1 signaling regulates several ecdysteroidogenesis genes, and consequently 20E pulse, to modulate the onset of metamorphosis in L. decemlineata.

Physiological roles of trehalose in Leptinotarsa larvae revealed by RNA interference of trehalose-6-phosphate synthase and trehalase genes

Trehalose is proposed to serve multiple physiological roles in insects. However, its importance remains largely unconfirmed. In the present paper, we knocked down either a trehalose biosynthesis gene (trehalose-6-phosphate synthase, LdTPS) or each of three degradation genes (soluble trehalases LdTRE1a, LdTRE1b or membrane-bound LdTRE2) in Leptinotarsa decemlineata by RNA interference (RNAi). Knockdown of LdTPS decreased trehalose content and caused larval and pupal lethality. The LdTPS RNAi survivors consumed a greater amount of foliage, obtained a heavier body mass, accumulated more glycogen, lipid and proline, and had a smaller amount of chitin compared with the controls. Ingestion of trehalose but not glucose rescued the food consumption increase and larval mass rise, increased survivorship, and recovered glycogen, lipid and chitin to the normal levels. In contrast, silencing of LdTRE1a increased trehalose content and resulted in larval and pupal lethality. The surviving LdTRE1a RNAi hypomorphs fed a smaller quantity of food, had a lighter body weight, depleted lipid and several glucogenic amino acids, and contained a smaller amount of chitin. Neither trehalose nor glucose ingestion rescued these LdTRE1a RNAi defects. Silencing of LdTRE1b caused little effects. Knockdown of LdTRE2 caused larval death, increased trehalose contents in several tissues and diminished glycogen in the brain-corpora cardiaca-corpora allata complex (BCC). Feeding glucose but not trehalose partially rescued the high mortality rate and recovered glycogen content in the BCC. It seems that trehalose is involved in feeding regulation, sugar absorption, brain energy supply and chitin biosynthesis in L. decemlineata larvae.

Emergence of a Novel Bluetongue Virus Serotype, China 2014

One hundred and twenty-six blood samples were collected from healthy sheep and goats in Xinjiang, China, during July 2014. Seventy-three samples (57.93%) were bluetongue virus (BTV) serology-positive, and 39 samples (30.95%) were BTV NS1 gene-positive. BTV strain XJ1407 was isolated from the blood of BTV NS1 gene-positive animals and sequenced. Analysis of its genome sequence suggests that XJ1407 is a novel BTV serotype.

Association between interleukin-10 gene polymorphisms and susceptibility to diabetic nephropathy in a Chinese population

In this study, we investigated the association between the interleukin (IL)-10 -592C/A, -819C/T, and -1082G/A genetic variations and susceptibility to diabetic nephropathy in a Chinese population. The IL-10 -592C/A, -819C/T, and -1082G/A polymorphisms were genotyped in diabetic nephropathy patient and control samples by polymerase chain reaction-restriction fragment length polymorphism. The results were then statistically analyzed using SPSS 17.0. The results of the χ(2) test revealed a significant difference in the frequencies of the GG, GA, and AA genotypes of IL-10 -1082G/A between patients with diabetic nephropathy and control subjects (χ(2) = 10.03, P = 0.007). Unconditional logistic regression analysis revealed that the AA genotype of IL-10 -1082G/A significantly increased the susceptibility to diabetic nephropathy [adjusted odds ratio (OR) = 2.52, 95% confidence interval (CI) = 1.31-4.82] compared to the wild-type genotype. Moreover, the A allele of this polymorphism was associated with an increased risk of diabetic nephropathy compared to the G allele (adjusted OR = 1.51, 95%CI = 1.15-1.99). However, the IL-10 -819T/C and -592A/C genetic polymorphisms did not increase the risk of diabetic nephropathy. In conclusion, the IL-10 -1082G/A polymorphism was found to be correlated with the development of diabetic nephropathy.

Perceptions of public attitudes towards persons with mental illness in Beijing, China: results from a representative survey

OBJECTIVES

Many studies have examined the general public's attitudes towards people with mental illness, but such studies are scarce in China. This study examined the perceptions of the Beijing population regarding their society's prevalent attitudes towards people with mental illness.

METHODS

A total of 5000 individuals aged 18 or above living in Beijing were selected using a multistage, stratified, cluster and random sampling method. This was followed by a face-to-face interview which used a standardized questionnaire asking about societal attitudes towards individuals with mental illness.

RESULTS

4602 out of 5000 eligible individuals met the inclusion criteria and participated in the interview. 4596 questionnaires were deemed valid and included in the analyses. A large proportion of respondents believed that most individuals within their society held negative attitudes and had a strong desire to distance themselves from people with mental illness. Respondents aged 60 or older, who lived farther to downtown Beijing, or with higher education tended to believe that most individuals have relatively positive and tolerant attitudes towards people with mental illness.

CONCLUSIONS

Many people in Beijing perceive that most members of their society have negative beliefs towards people with mental illness. Further efforts are needed to determine if these perceptions are accurate and to reduce the stigma that is reinforced by these perceptions.

Comparison on hypoglycemic and antioxidant activities of the fresh and dried Portulaca oleracea L. in insulin-resistant HepG2 cells and streptozotocin-induced C57BL/6J diabetic mice

ETHNOPHARMACOLOGICAL RELEVANCE

Fresh Portulaca oleracea L. (family: Portulacaceae; POL) has been used as a folk medicine for the treatment of diabetes mellitus for a long time. More bioactive components with higher activity could be retained in fresh medicinal herbs compared to the dried ones. The present study was conducted to compare different antidiabetic activity between fresh and dried POL, including hypoglycemic and antioxidant activities both in vivo and in vitro. Furthermore, in order to explore which components were responsible for the antidiabetic activity, the difference on chemical components between fresh and dried POL was analyzed and compared.

MATERIALS AND METHODS

Insulin-resistant HepG2 cells induced by insulin were used to evaluate the promoting effect of the fresh and dried POL on glucose utilization in vitro. Streptozotocin (STZ)-induced C57BL/6J diabetic mice were used to compare the differences on hypoglycemic and antioxidant activities of fresh and dried POL, including the fasting blood glucose, glucose tolerance, serum insulin level, malondialdehyde (MDA) level and superoxide dismutase (SOD) activity in vivo. UPLC/Q-TOF-MS method was performed to analyze the difference of antidiabetic components between fresh and dried POL.

RESULTS

Compared with the dried POL extract, the fresh POL extract significantly increased the consumption of extracellular glucose in insulin-resistant HepG2 cells (P<0.05). In STZ-induced C57BL/6J diabetic mice, both fresh and dried extracts decreased markedly the fasting blood glucose (FBG) levels, and improved significantly oral glucose tolerance test (OGTT), as well as enhanced significantly insulin secretion and antioxidative activities (P<0.05; P<0.01). Furthermore, the fresh extract showed stronger antidiabetic activity (P<0.05). The UPLC/Q-TOF-MS analysis results also revealed that the relative contents of polyphenols and alkaloids in the fresh herbs were more abundant than those in the dried POL.

CONCLUSION

Our results indicated that both fresh and dried POL possessed antidiabetic activities, besides stronger activity was observed in the fresh herb. These findings provided evidence for the application and development of fresh POL in the treatment of diabetes mellitus.

Effects of Replacement of Fish Meal by Soy Protein Isolate on the Growth, Digestive Enzyme Activity and Serum Biochemical Parameters for Juvenile Amur Sturgeon (Acipenser schrenckii)

An 8-wk experiment was conducted to evaluate the effect of replacing fish meal (FM) with soy protein isolate (SPI) on the growth, digestive enzyme activity and serum biochemical parameters of juvenile Amur sturgeon (Acipenser schrenckii). SPI was used to replace 0, 25, 50, 62.5, 75, 87.5, 100% of dietary FM and 100% replacement supplemented crystalline amino acid. Healthy sturgeon with an average initial weight of 26.38±0.24 g were randomly assigned to 24 aquaria (8 treatments with triplicates each) at an initial stocking density of 11 fish per aquarium and cultured for 8 wks. The results showed that 75.00% or more substitution resulted in a poor weight gain rate, feed conversion ratio and survival rate compared to that of fish fed the control diet (p<0.05), whereas no significant differences were observed between diets of 25.00% to 62.50% substitution. Protease, lipase and amylase activity in foregut, mid-gut and hindgut were significantly (p<0.05) decreased by diets where SPI replacement levels were 62.50% or more. Levels of serum total protein (TP) and globulin decreased significantly from 21.03, 10.34 to 14.05, 5.63 g/L with the increasing dietary SPI (p<0.05), but alkaline phosphatase activity significantly increased (p<0.05). In addition, supplemental crystalline amino acid in the FM absence diet did not improve growth performance, intestine digestive enzyme activities and serum biochemical parameters. In conclusion, the results from this study showed adverse effects of inclusion of SPI in diets on growth performance, feed utilization and serum biochemical parameters in juvenile Amur sturgeon. Based on WGR and replacement ratio presented in this report, a 57.64% replacement level was recommended.

Analysis of kidney biopsy data from a single center in the midland rural area of china, 1996-2010

Objective

To survey the clinical epidemiology and correlations between pathology and clinical features of major groups of kidney diseases in a rural area of China.

Methods

From January 1996 to December 2010, histologic diagnosis of renal disease was made on samples collected from 919 patients from a single center in the midland rural area of China. Demographic data were obtained from all patients, and clinical profiles were analyzed in 917 patients.

Results

The mean age of the whole group was 33.13 (14.13) years (range 16–72 years). Men accounted for 55.28% (n = 508) and women made up 45.72% (n = 408). Patients aged 16 to 50 years comprised 83.75% of the sample (n = 770). Lupus nephritis was the predominant diagnosis in women; renal diseases were predominant in men. In patients with nephrotic syndrome, mesangial proliferative glomerulonephritis was the most frequent pathologic pattern (39.46%), followed by IgA nephropathy (18.39%), whereas in patients with nephritic syndrome, IgA nephropathy (39.64%) was the most frequent pathologic pattern, followed by mesangial proliferative glomerulonephritis (32.38%). The most common pathologic pattern in patients with secondary glomerulonephritis was Henoch-Schoˇnlein purpura nephritis, followed by lupus nephritis.

Conclusions

Mesangial proliferative glomerulonephritis was the most common renal pathologic pattern. Male adolescents were predominant in this group of patients. The most common clinical syndrome was nephrotic syndrome.

Fluoroscopically guided nose tube drainage of mediastinal abscesses in post-operative gastro-oesophageal anastomotic leakage

OBJECTIVE

The aim of this study was to retrospectively evaluate the technical success rates and clinical effectiveness of fluoroscopically guided nose tube drainage of mediastinal abscesses and a nasojejunum feeding tube in post-operative gastro-oesophageal anastomotic leakage (GEAL).

METHODS

From January 2006 to June 2011, 18 cases of post-operative GEAL with mediastinal abscesses after oesophagectomy with intrathoracic oesophagogastric anastomotic procedures for oesophageal and cardiac carcinoma were treated by insertion of a nose drainage tube and nasojejunum feeding tube under fluoroscopic guidance. We evaluated the feasibility of two-tube insertion to facilitate leakage site closure and complete resolution of the abscess, and the patients' nutritional benefit was also evaluated by checking the serum albumin level between pre- and post-enteral feeding via the feeding tube.

RESULTS

The two tubes were placed successfully under fluoroscopic guidance in 18 patients (100%). The procedure time for two-tube insertion ranged from 20 to 40 min (mean 30 min). 17 patients (94%) achieved leakage site closure after two-tube insertion and had a good tolerance of two tubes in the nasal cavity. The serum albumin level was significant, increased from pre-enteral feeding (2.49 ± 0.42 g dl(-1)) to the post-enteral feeding (3.58 ± 0.47 g dl(-1)) via the feeding tube (p<0.001). The duration of follow-up ranged from 1 to 49 months (mean 19 months).

CONCLUSION

The insertion of nose tube drainage and a nasojejunum feeding tube under fluoroscopic guidance is safe, and it provides effective relief from mediastinal abscesses in GEAL after oesophagectomy. Moreover, our findings indicate that two-tube insertion may be used as a selective procedure to treat mediastinal abscesses in post-operative GEAL. Advances in knowledge Directive drainage of mediastinal abscesses in post-operative GEAL may be an effective treatment.

[Airway stenting with inhalation anesthesia in malignant airway stenosis or fistula under radiological guidance]

OBJECTIVE

To assess the efficacy and safety of airway stenting with inhalation anesthesia under radiological guidance in the palliation of malignant tracheobronchial stenosis.

METHODS

Between June 2001 and August 2010, 74 consecutive patients with malignant tracheobronchial stenosis were treated by the insertion of an ultraflex self-expandable metal stent with inhalation anesthesia under fluoroscopic guidance.

RESULTS

All patients achieved obvious symptomatic relief. The outcomes were as follows: dyspnea (n = 2), long-term angina (n = 1), strong irritation cough (n = 2), hard phlegm (n = 3), clotting expectoration (n = 3), blood-tinged expectoration (n = 64), airway stent displacement (n = 1) and tracheoesophageal fistulas (n = 1).

CONCLUSION

Performed with inhalation anesthesia under radiological guidance, tracheobronchial recanalization with a self-expandable metal stent is a safe and effective palliative treatment for malignant stenosis.

Atomic force and confocal microscopy for the study of cortical cells cultured on silicon wafers

The primary cortical cells were selected as a model to study the adherence and neural network development on chemically roughened silicon substrates without any coatings using confocal laser scanning microscopy (CLSM) and atomic force microscopy (AFM). The silicon substrates have a nano-range roughness (RMS) achieved by chemical etching using hydrofluoric (HF) acid. After 7 days of culturing, the neurons were observed to connect together and form dense neural networks. Furthermore, AFM results revealed that some porous structures at a few micrometer range existed between the neuron cells and the silicon substrates. It is suggested that the porous structures are made of extracellular matrix (ECM) components and play an important role in the neuronal adhesion and neurite outgrowth on the inert silicon wafers.

Hyaluronic acid hydrogel immobilized with RGD peptides for brain tissue engineering

In this paper, hyaluronic acid hydrogels with open porous structure have been developed for scaffold of brain tissue engineering. A short peptide sequence of arginine-glycine-aspartic acid (RGD) was immobilized on the backbone of the hydrogels. Both unmodified hydrogels and those modified with RGD were implanted into the defects of cortex in rats and evaluated for their ability to improve tissue reconstruction. After 6 and 12 weeks, sections of brains were processed for DAB and Glees staining. They were also labeled with GFAP and ED1 antibodies, and observed under the SEM for ultrastructral examination. After implanting into the lesion of cortex, the porous hydrogels functioned as a scaffold to support cells infiltration and angiogenesis, simultaneously inhibiting the formation of glial scar. In addition, HA hydrogels modified with RGD were able to promote neurites extension. Our experiments showed that the hyaluronic acid-RGD hydrogel provided a structural, three-dimensional continuity across the defect and favoured reorganization of local wound-repair cells, angiogenesis and axonal growth into the hydrogel scaffold, while there was little evidence of axons regeneration in unmodified hydrogel.

Regulation of charged groups and laminin patterns for selective neuronal adhesion

Primary neuronal cultures on substrates patterned with extracellular matrix proteins such as laminin have yielded much information regarding the physiological characteristics of neuronal cells in vitro. Surface charge also influences neuronal adherence, and a positive charge can have stimulatory effects. The attraction between laminin patterns and polycation films are of interest in the study of neuronal adhesion. We cultured primary hippocampal neurons on poly(ethylenimine) (PEI) films with laminin grids and evaluated their viability and morphology by means of fluorescent microscopy after 5-7 days. The results showed that the neurons did not form networks on the laminin grids. It is inferred that the PEI films were more favourable for neuronal adhesion than the laminin grid.

Hyaluronic acid-poly-D-lysine-based three-dimensional hydrogel for traumatic brain injury

Brain tissue engineering in the postinjury brain represents a promising option for cellular replacement and rescue, providing a cell scaffold for either transplanted or resident cells. In this article, a hyaluronic acid (HA)-poly-D-lysine (PDL) copolymer hydrogel with an open porous structure and viscoelastic properties similar to neural tissue has been developed for brain tissue engineering. The chemicophysical properties of the hydrogel with HA:PDL ratios of 10:1, 5:1, and 4:1 were investigated by scanning electron microscopy (SEM) and X-ray photoelectron spectrometry. Neural cells cultured in the hydrogel were studied by phase-contrast microscope and SEM. The incorporation of PDL peptides into the HA-PDL hydrogel allowed for the modulation of neuronal cell adhesion and neural network formation. Macrophages and multinucleated foreign body giant cells found at the site of implantation of the hydrogel in the rat brain within the first weeks postimplantation decreased in numbers after 6 weeks, consistent with the host response to inert implants in numerous tissues. Of importance was the infiltration of the hydrogel by glial fibrillary acidic protein-positive cells-reactive astrocytes-by immunohistochemistry and the contiguity between the hydrogel and the surrounding tissue demonstrated by SEM. These findings indicated the compatibility of this hydrogel with brain tissue. Collectively, the results demonstrate the promise of an HA-PDL hydrogel as a scaffold material for the repair of defects in the brain.

AFM study of hippocampal cells cultured on silicon wafers with nano-scale surface topograph

The rat hippocampal cells were selected as model to study the interaction between the neural cells and silicon substrates using atomic force microscopy (AFM). The hippocampal cells show tight adherence on silicon wafers with nano-scale surface topograph. The lateral friction force investigated by AFM shows significant increase on the boundary around the cellular body. It is considered to relate to the cytoskeleton and cellular secretions. After ultrasonic wash in ethanol and acetone step by step, the surface of silicon wafers was observed by AFM sequentially. We have found that the culture leftovers form tight porous networks and a monolayer on the silicon wafers. It is concluded that the leftovers overspreading on the silicon substrates are the base of cell adherence on such smooth inert surfaces.

Hyaluronic acid hydrogel as Nogo-66 receptor antibody delivery system for the repairing of injured rat brain: in vitro

Nogo-66 and NgR are important receptors inhibiting neuronal regeneration and therefore are targets for treating CNS injury. Antagonists of this receptor including blocking antibodies are potential therapeutic agents for CNS axonal injuries such as spinal cord and brain trauma. A new antibody (IgG) releasing system has been developed by covalently attaching IgG to the biodegradable hyaluronic acid (HA) hydrogel via the hydrolytically unstable hydrazone linkage, aiming to deliver the antibody of CNS regeneration inhibitors to the injured brain. In this paper we describe the synthesis, physico-chemical characteristics and test results of biological activity of antibody released from hyluronic acid hydrogel. To form the conjugates the antibody is attached to the polymer backbone using a condensation reaction between aldehyde group of the antibody and hydrazide group of the HA hydrogel. Furthermore, pH sensitive linkage-hydrozone has been formed between hydrogel and antibody. The amount of conjugated antibodies can reach 135 microg antibody/mg hydrogel in the dry state. At low pH, the antibodies released quite fast. However, the antibodies released much slower in neutral and alkaline environment. The bioactivity of antibody released from hydrogel was retained as demonstrated by indirect immunofluorescence technique.

Electron holography study on the microstructure of magnetic tunnelling junctions

Electron holography was applied to study the microstructure evolution of magnetic tunnelling junctions (MTJs) CoFe/AlO(x)/Co annealed at different temperatures. A mean inner potential barrier was observed in the as-deposited MTJ sample, while it was changed to a potential well after a 200 degrees C or a 400 degrees C annealing. It is suggested that the oxygen atoms were redistributed during the annealing, which left metallic atoms acting as acceptors to confine the electrons, leading to the decrease of the potential of the AlO(x) barrier layer. The results suggest that the electron holography may be a useful tool for the study of the microstructure of amorphous materials.