The Complications of Corticosteroid for Patients with Community-acquired Pneumonia: A Systematic Review and Meta-Analysis.

Background: Many randomized controlled trials (RCTs) have reported the complications of corticosteroids for patients with community-acquired pneumonia with inconsistent results. An explicit systematic review and meta-analysis were conducted in this study to evaluate the complications of corticosteroids for patients with community-acquired pneumonia. Methods: Using PubMed, Embase, the Global Index Medicus of the World Health Organization (WHO), the WHO clinical trial registry, and Clinicaltrials.gov, a thorough literature search of RCTs was carried out. Inclusion criteria included RCTs comparing the use of any kind of a specified corticosteroid with the placebo control group. The complications were analyzed, including gastrointestinal (GI) bleeding, healthcare-associated infection (HAI), acute kidney injury (AKI), hospital readmission, hyperglycemia, neuropsychiatric complications, and adverse cardiac events. Results: The result can be concluded that the risk of gastrointestinal (GI) bleeding, healthcare-associated infection (HAI), acute kidney injury (AKI), hospital readmission, neuropsychiatric complications, and adverse cardiac events between the intervention and control groups were not significantly different. However, corticosteroids can increase the risk of hyperglycemia as compared to the control group who did not receive corticosteroids (RR= 1.72, 95 % CI: 1.38-2.14, P < .01). In the subgroup analysis, the meta-analysis showed a significant difference in the risk of hyperglycemia between the prednisolone and control groups (RR= 1.81, 95 % CI: 1.29-2.54, P < .01). There is no heterogeneity between studies (I2= 0%). The subgroup difference was not significant (P = .11). Conclusions: Through our analysis, the use of corticosteroids can increase the risk of hyperglycemia for patients with community-acquired pneumonia. Further studies are required to be conducted to confirm the findings due to limited clinical trials.

Changes in expression levels of erythrocyte and immune-related genes are associated with high altitude polycythemia.

BACKGROUND: As a chronic mountain sickness(CMS) with the highest incidence and the greatest harm, the pathogenesis of high altitude polycythemia (HAPC) is still not fully understood. METHODS: 37 HAPC patients and 42 healthy subjects were selected from plateau, and peripheral venous blood samples were collected for transcriptome sequencing on Illumina NovaSeq platform. The sequenced data were analyzed by bioinformatics and phenotypic association analysis. RESULTS: The results showed significant differences in multiple clinical indicators including RBC and HGB et al. existed between HAPC and control. Based on the RNA-seq data, 550 genes with significant differential expression were identified in HAPC patients. GO and KEGG pathway enrichment analysis showed that the up-regulated genes were mainly enriched in processes such as erythrocyte differentiation and development and homeostasis of number of cells, while the down-regulated genes were mainly enriched in categories such as immunoglobulin production, classical pathway of complement activation and other biological processes. The coupling analysis of differential expression genes(DEGs) and pathological phenotypes revealed that 91 DEGs were in close correlation with in the phenotype of red blood cell volume distribution (width-CV and width-SD), and they were all up-regulated in HAPC and involved in the process of erythrocyte metabolism. Combined with the functional annotation of DEGs and literature survey, we found that the expression of several potential genes might be responsible for pathogenesis of HAPC. Besides, cell type deconvolution analysis result suggested that the changes in the number of some immune cell types was significantly lower in HAPC patients than control, implying the autoimmune level of HAPC patients was affected to a certain extent. CONCLUSION: This study provides an important data source for understanding the pathogenesis and screening pathogenic genes of HAPC. We found for the first time that there was a significant correlation between HAPC and the pathological phenotype of width-CV and width-SD, wherein the enriched genes were all up-regulated expressed and involved in the process of erythrocyte metabolism. Although the role of these genes needs to be further studied, the candidate genes can provide a starting point for functionally pinning down the underlying mechanism of HAPC.

HPLC-MS/MS analysis of zinc-thiazole residues in foods of plant origin by a modified derivatization-QueChERS method.

Zinc-thiazole is a new fungicide that was independently developed in China and has a high efficiency and low toxicity. A modified derivatization method was established to measure zinc-thiazole in foods of plant origin. Zinc-thiazole decomposed into 2-amino-5-mercapto-1,3,4-thiadiazole (AMT) under alkaline conditions, and the AMT was extracted with acidic acetonitrile (pH = 3). The AMT was quantitated by HPLC-MS/MS, and then the amount of zinc-thiazole residue was calculated. Good linearity (R2 > 0.9997) was obtained in 0.001-1 mg/L. The limit of quantification of zinc-thiazole was 0.02 mg/kg in peaches, grapes, brown rice and soybeans. A qualified accuracy (recoveries of 75%-90%) and precision (RSD of 1%-5%) were obtained at three fortified levels. This method was applied to peach samples collected from farmland, and the zinc-thiazole residues complied with the residue limits. In the future, this method could be used to analyze residues and in the risk assessment of metal-thiazole fungicides.

Population-Based Incidence of Guillain-Barré Syndrome During Mass Immunization With Viral Vaccines: A Pooled Analysis.

Misunderstanding temporal coincidence of adverse events during mass vaccination and invalid assessment of possible safety concerns have negative effects on immunization programs, leading to low immunization coverage. We conducted this systematic review and meta-analysis to identify the incidence rates of GBS that are temporally associated with viral vaccine administration but might not be attributable to the vaccines. By literature search in Embase and PubMed, we included 48 publications and 2,110,441,600 participants. The pooled incidence rate of GBS was 3.09 per million persons (95% confidence interval [CI]: 2.67 to 3.51) within six weeks of vaccination, equally 2.47 per 100,000 person-year (95%CI: 2.14 to 2.81). Subgroup analyses illustrated that the pooled rates were 2.77 per million persons (95%CI: 2.47 to 3.07) for individuals who received the influenza vaccine and 2.44 per million persons (95%CI: 0.97 to 3.91) for human papillomavirus (HPV) vaccines, respectively. Our findings evidence the GBS-associated safety of virus vaccines. We present a reference for the evaluation of post-vaccination GBS rates in mass immunization campaigns, including the SARS-CoV-2 vaccine.

Epitopes prediction for microcystin-LR by molecular docking.

Microcystin-LR (MC-LR) is one of the most worldwide harmful cyanobacterial toxins. A lots of antibodies against MC-LR have been generated and characterized. However, the knowledge about the epitopes of MC-LR was still limited. The objective of this study was to analyze the epitopes of MC-LR and demonstrate the binding mode of MC-LR with its antibody. The variable genes of a mouse hybridoma cell line (Mab5H1-3B3) raised against MC-LR have been cloned and assembled in a single chain variable fragment (scFv), and then soluble expressed in E.coli BL21. Based on the scFv, the IC50 and IC10 for MC-LR were determined to be 7.45 nM and 0.30 nM by competitive ELISA. And the scFv also showed 115% and 112% cross-reactivities to MC-RR and MC-YR, and 59% to MC-LA. By molecular docking, the binding mode between MC-LR and its scFv was demonstrated. A hydrogen bond interaction was observed between the carbonyl group of Adda5 residue of MC-LR and its scFv, and the guanidyl group of Arg4 residue and phenyl group of Adda5 residue of MC-LR were also involved in the interaction. These predicted epitopes were supported by antibody cross-reactivity data. By comparing the antibody informatics of MC-LR scFv with its predicted paratopes, VH-CDR1 was crucial for MC-LR binding, and its specificity could be tuned by engineering in Vκ-CDR1 and Vκ-CDR3. These information would be useful for the hapten design for microcystins or improving the properties of MC-LR scFv in vitro.

The chloroplast genome of Archontophoenix alexandrae (Arecaceae): an important landscape tree for the subtropics.

Archontophoenix alexandrae, known as king palm, is an important landscape tree for the subtropics and potential sources of dietary fiber. In this study, the complete chloroplast genome of A. alexandrae was determined through Illumina sequencing method. The chloroplast genome was 159,196 bp in length and contained a small single-copy region (17,763 bp), a large single-copy region (87,055 bp) and a pair of IR regions (27,189 bp). 135 genes were determined in the A. alexandrae chloroplast genome, including 86 CDS, 39 tRNA genes, and 8 rRNA genes. Archontophoenix alexandrae showed the closest relationship with Veitchia arecina in the phylogenetic analysis.

Characterization of the complete chloroplast genome of Plumeria rubra cv. Acutifolia (Apocynaceae).

Plumeria rubra cv. Acutifolia is a widely planted landscape tree in the subtropics. In this study, the complete chloroplast genome of P. rubra cv. Acutifolia was determined through Illumina sequencing method. The complete chloroplast genome has a length of 153,912 bp, containing a small single-copy region (18,036 bp), a large single-copy region (84,852 bp), and a pair of IR regions (25,512 bp). The chloroplast genome possesses 130 genes, including 85 CDS, 37 tRNA genes and 8 rRNA genes. P. rubra cv. Acutifolia exhibited the closest relationship with P. cubensis in phylogenetic analysis.

Efficacy of transconjunctival approach for the treatment of orbital fractures: A protocol for systematic review and meta-analysis.

BACKGROUND: This study aims to assess the efficacy of transconjunctival approach (TCA) for the treatment of orbital fractures (OF) comprehensively and systematically. METHODS: In this study, we plan to search electronic databases of Cochrane Library, MEDLINE, EMBASE, Web of Science, Allied and Complementary Medicine Database, Chinese Biomedical Literature Database, China National Knowledge Infrastructure and for relevant randomized controlled trials. All these databases will be searched from inception to the March 1, 2020 without limitations of language and publication status. Two independent authors will carry out study selection, data collection, and study quality assessment. Any disagreements will be resolved by discussion with another author if necessary. The study quality will be assessed using Cochrane risk of bias tool. Statistical analysis will be conducted using RevMan 5.3 software. RESULTS: This study will be the first 1 to exert direct evidence to evaluate the efficacy of TCA for the treatment of OF. CONCLUSIONS: The findings of this study will provide an exhaustive view of TCA for the treatment of OF. STUDY REGISTRATION NUMBER: INPLASY202040154.

Construction and characterization of a class-specific single-chain variable fragment against pyrethroid metabolites.

Pyrethroids are insecticides that are widely used in rural and urban areas worldwide. After entering the environment, pyrethroids are rapidly metabolized or degraded by various biological or abiotic methods. In this study, a single-chain variable fragment (scFv) which could simultaneously detect three pyrethroid metabolites was constructed based on a hybridoma raised against 3-phenoxybenzoic acid (3-PBA). By molecular docking, it showed that there were hydrogen bonds, hydrophobic interactions, CH-π interaction, and cation-π interaction between 3-PBA and its scFv. All the contact residues contributing to hydrogen bonds are located in VH-CDR2 or its neighboring region, and two of them were mutants of the closest germline sequence. Based on competitive ELISA, the half maximal inhibitory concentration (IC50) of the scFv for 3-PBA, 3-phenoxybenzaldehyde (PBAld), and 3-phenoxybenzyl alcohol (PBAlc) were calculated to be 0.55, 0.59, and 0.63 µgmL-1, respectively. The scFv also showed 23.91%, 13.41%, 1.15%, 1.00%, and 0.56% cross-reactivity with phenothrin, deltamethrin, fenvalerate, beta-cypermethrin, and fenpropathrin. The broad specificity of the scFv may be due to its hapten design. The scFv could be employed in class-specific immunoassays for pyrethroid metabolites with phenoxybenzyl (PB) group. It is also potentially used for characterizing degradation of pyrethroids or detecting PBAlc (PBAld) alone, and the detection results should be confirmed by other selective methods. KEY POINTS: • A scFv which can simultaneously detect 3-PBA, PBAlc, and PBAld was constructed. • Antibody informatics and binding mode of the scFv were obtained. • The reason for its broad specificity was discussed. • It could be used to monitor single or multi-pyrethroid metabolites with PB group.

Sub-lethal effects of six neonicotinoids on avoidance behavior and reproduction of earthworms (Eisenia fetida).

Avoidance behavior of earthworms (Eisenia fetida) against six neonicotinoids (NEOs) (acetamiprid, dinotefuram, clothianidin, thiacloprid, nitenpyram, imidacloprid) was studied following the protocol of ISO. The results showed obvious avoidance behavior of E. fetida against the tested insecticides, and the medium effective concentration for avoidance behavior (EC50) of the six pesticides was 0.14, 0.55, 0.91, 7.87, 1.32 and 0.77 mg/kg, respectively. Compared to the acute toxicity, avoidance behavior was more sensitive as an indicator of soil contamination with NEOs. Chronic toxicity of above six NEOs to E. fetida was also evaluated; cocoon production, hatchability, cocoon weight and adult weight were all affected in the test. Cocoon production and hatchability were more sensitive than cocoon weight and adult weight. The reproduction of earthworms were significantly reduced with a 56 d half-maximal effective hatchability concentration (EC50) of 0.37, 0.74, 1.30, 3.57, 1.20 and 0.70 mg/kg (acetamiprid, dinotefuram, clothianidin, thiacloprid, nitenpyram, imidacloprid), respectively. Most of the tested NEOs were highly toxic to E. fetida. Avoidance behavior and reproduction damage of E. fetida was observed at very low concentrations. The existing levels of pollution with NEOs in soil frequently exceed the lowest observed adverse effect concentrations, which are likely to have negative biological and ecological impacts on earthworms.

Dissipation and distribution of chlorpyrifos in selected vegetables through foliage and root uptake.

Dissipation, distribution and uptake pathways of chlorpyrifos were investigated in pakchoi (Brassica chinensis L.) and lettuce (Lactuca sativa) with foliage treatments under a greenhouse trial and root treatments under a hydroponic experiment. The dissipation trends were similar for chlorpyrifos in pakchoi and lettuce with different treatments. More than 94% of chlorpyrifos was degraded in the samples for both of the vegetables 21 days after the foliage treatments. For the root treatment, the dissipation rate of chlorpyrifos in pakchoi and lettuce at the low concentration was greater than 93%, however, for the high concentrations, the dissipation rates were all under 90%. Both shoots and roots of the vegetables were able to absorb chlorpyrifos from the environment and distribute it inside the plants. Root concentration factor (RCF) values at different concentrations with the hydroponic experiment ranged from 5 to 39 for pakchoi, and from 14 to 35 for lettuce. The translocation factor (TF) representing the capability of the vegetables to translocate contaminants was significantly different for pakchoi and lettuce with foliage and root treatments. The values of TF with foliage treatments ranged from 0.003 to 0.22 for pakchoi, and from 0.032 to 1.63 for lettuce. The values of TF with root treatments ranged from 0.01 to 0.17 for pakchoi, and from 0.003 to 0.23 for lettuce. Significant difference of TF was found between pakchoi and lettuce with foliage treatments, and at high concentrations (10 and 50 mg L(-1)) with root treatments as well. However, there was no significant difference of TF between pakchoi and lettuce at 1 mg L(-1) with root treatment.

Changes of field incurred chlorpyrifos and its toxic metabolite residues in rice during food processing from-RAC-to-consumption.

The objectives of this study were to determine the effects of food processing on field incurred residues levels of chlorpyrifos and its metabolite 3,5,6-Trichloro-2-pyridinol (TCP) in rice. The chlorpyrifos and TCP were found to be 1.27 and 0.093 mg kg-1 in straw and 0.41 and 0.073 mg kg-1 in grain, respectively. It is observed that the sunlight for 2 hours does not decrease the chlorpyrifos and TCP residues in grain significantly. Their residues in rice were reduced by up to 50% by hulling. The cooking reduced the chlorpyrifos and TCP in rice to undetectable level (below 0.01 mg kg-1). Processing factors (PFs) of chlorpyrifos and TCP residues in rice during food processing were similar. Various factors have impacts on the fates of chlorpyrifos and TCP residues and the important steps to reduce their residues in rice were hulling and cooking. The results can contribute to assure the consumer of a safe wholesome food supply.

Residues and dissipation kinetics of triazole fungicides difenoconazole and propiconazole in wheat and soil in Chinese fields.

An analytical method for simultaneously determining the residues of difenoconazole and propiconazole in wheat straw, wheat grain and soil was developed. Mean recoveries and relative standard deviations in all samples ranged 86.2-101.3% and 3.1-12.1% for propiconazole and difenoconazole. The half-lives of difenoconazole and propiconazole were 3.6-5.5days and 5.1-6.9days in wheat straws, and 4.9-5.8days and 6.1-8.4days in soil, respectively. The residues in wheat grain were found to be <0.01mg/kg, based on the application rate (135g a.i./ha) and the pre-harvest interval (PHI=28days) recommended by the manufacturer. The results suggest that the use of difenoconazole and propiconazole on wheat is considered to be safe under the Good Agricultural Practices (GAP) in the Chinese fields, and the main factors for pesticide residue in crops are application times, rates and pre-harvest intervals.

Effects of epigallocatechin-3-gallate on behavioral impairments induced by psychological stress in rats.

This study was conducted to explore the effects of epigallocatechin-3-gallate (EGCG) on cognitive performances in psychological stress rats. An animal model of psychological stress was developed by restraint stress for three weeks. Male Wistar rats were randomly assigned to four groups as follows: normal control group, stress control group and two stress groups with green tea polyphenols (GTPs) and EGCG modulation, respectively. The changes of behavioral performances of rats were examined by the open-field test and step-through test. Results showed that behavioral performances of stress control group were changed abnormally, and they were improved in GTPs and EGCG modulation groups. In addition, plasma levels of cortisol, dopamine, norepinephrine, 5-hydroxytryptamine, interleukin-6 and interleukin-2 were detected. Stress control group had increased contents of cortisol, interleukin-6 and interleukin-2, and meanwhile had declined levels of 5-hydroxytryptamine and catecholamines. These changes in GTPs and EGCG modulation groups were similar to that of the normal control group. The expressions of metallothioneins in the hippocampus were detected by reverse transcription polymerase chain reaction. In contrast with the normal control group, their expressions in all the three stress groups were enhanced clearly. The results suggested that GTPs and EGCG modulation could improve the cognitive impairments induced by psychological stress. The related mechanisms may be involved with the changes of catecholamines, 5-hydroxytryptamine, cytokines and expressions of metallothioneins.

Acute toxicity to zebrafish of two organophosphates and four pyrethroids and their binary mixtures.

BACKGROUND: Environmental pollutants, including metals, pesticides and other organics, pose serious risks to many aquatic organisms. The acute toxicities to zebrafish (Brachydanio rerio Hamilton & Buchanan) were determined for two organophosphorus insecticides, four pyrethroid insecticides and 50:50 binary mixtures. RESULTS: At 24, 48, 72 and 96 h after treatment, LC(50) of permethrin, tetramethrin, bifenthrin, etofenprox, dichlorvos and phoxim to zebrafish were 0.0052-0.0025, 0.0782-0.0460, 0.0065-0.0032, 0.0969-0.0791, 51.3-13.0 and 1.28-0.469 mg L(-1) respectively. LC(50) of permethrin + dichlorvos, permethrin + phoxim, tetramethrin + dichlorvos, tetramethrin + phoxim, bifenthrin + dichlorvos, bifenthrin + phoxim, etofenprox + dichlorvos and etofenprox + phoxim were 0.0082-0.0046, 0.0078-0.0042, 0.264-0.124, 0.141-0.121, 0.0251-0.0154, 0.0154-0.0087, 0.396-0.217 and 0.213-0.0391 mg L(-1). CONCLUSION: Toxicity levels of all pyrethroid insecticides to the zebrafish were high or very high. The organophosphate dichlorvos showed low toxicity, but phoxim showed high or intermediate toxicities to zebrafish, and the toxicities of binary mixtures of permethrin and dichlorvos or phoxim, bifenthrin and dichlorvos or phoxim and etofenprox and phoxim (48, 72 and 96 h exposure) were very high. The toxicities of binary mixtures of tetramethrin and dichlorvos or phoxim, etofenprox and dichlorvos and etofenprox and phoxim (24 h exposure) were high.

Protective effects of green tea polyphenols on cognitive impairments induced by psychological stress in rats.

This study was conducted to explore the modulation of GTPs on cognitive performances in psychological stress rats. Wistar rats were randomly assigned to five groups as follows: control group, stress group, and three stress groups with low, medium and high-doses of GTPs modulation respectively. The changes of cognitive performances were examined by open-field test, water maze and step-through test. Results demonstrated that serum levels of cortisol were all increased obviously in four stress groups. The cognitive performances of stress group were changed evidently. And these changes were improved in stress medium and high-doses of GTPs modulation groups. In addition, plasma levels of IL-6 and IL-2 were increased in four stress groups, serum norepinephrine and dopamine were decreased dramatically in stress group and stress low-dose GTPs modulation group. The serum norepinephrine and dopamine levels in stress medium and high-doses of GTPs modulation groups were increased in contrast to that of stress group. Furthermore, the changes of anti-oxidative capacity in brain tissue were also measured. Except superoxide dismutase, the changes of malondialdehyde, reactive oxidative species and total anti-oxidative capacity of stress group were significantly different from that of control group. These changes in stress medium and high-doses of GTPs modulation groups were improved. Our results suggested that psychological stress impaired body's cognitive performances, and moderate GTPs modulation could improve these abnormal changes. To our knowledge, this is the first report showing the improving effects of GTPs on cognitive dysfunctions induced by psychological stress.

[Effects of psychological stress on performances in open-field test of rats and tyrosine's modulation].

AIM: To explore the effects of different doses of tyrosine modulation on behavioral performances in open field test of psychological stress rats. METHODS: The animal model of psychological stress was developed by restraint stress for 21 days. Wistar rats were randomly assigned to five groups (n = 10) as follows: control group (CT), stress control group (SCT), low, medium and high-doses of tyrosine modulation stress groups (SLT, SMT and SIT). The changes of behavioral performances were examined by open-field test. Serum levels of cortisol, norepinephrine and dopamine were also detected. RESULTS: The levels of serum cortisol were all increased obviously in the four stress groups, and their bodyweight gainings were diminished. The behavioral performances of SCT rats in open-field test were changed significantly in contrast to that of CT rats. However, The behavioral performances of SMT and SHT rats were not different from that of CT rats. In addition, the serum levels of norepinephrine and dopamine were downregulated obviously in SCT and SLT groups, and no differences were observed in other groups. CONCLUSION: Psychological stress can impair body behavioral performances, and moderate tyrosine modulation may improve these abnormal changes. The related mechanisms may be involved with the changes of norepinephrine and dopamine.

Acute toxicity of organophosphorus and pyrethroid insecticides to Bombyx mori.

Acute toxicities of two organophosphorus insecticides (dichlorvos and phoxim), four pyrethroid insecticides (permethrin, tetramethrin, bifenthrin, and ethofenprox), and their combined uses to the third instar of the silkworm, Bombyx mori (L.), were determined by feeding the insect with the insecticide-treated mulberry, Morus albus (L.), leaves. Twenty-four and 48 h after treatment, toxicity levels of all insecticides to the silkworm were in the very high or high range, and the LC50 values of permethrin, tetramethrin, bifenthrin, ethofenprox, dichlorvos, and phoxim were 1.60 and 0.75, 3.86 and 2.83, 0.09 and 0.06, 2.87 and 0.80, 6.63 and 4.11, and 1.05 and 0.45 mg liter(-1), respectively. The toxicity levels of 50:50 binary mixtures of organophosphorus and pyrethroid insecticides to the silkworm were in the high or middle range. Twenty-four and 48 h after treatment, the LC50 values of 50:50 binary mixtures permethrin + phoxim, permethrin + dichlorvos, tetramethrin + phoxim, tetramethrin + dichlorvos, bifenthrin + phoxim, bifenthrin + dichlorvos, ethofenprox + phoxim, and ethofenprox + dichlorvos to the silkworm were 1.49 and 0.85, 1.24 and 0.79, 2.20 and 1.08, 14.62 and 13.16, 0.33 and 0.13, 0.12 and 0.10, 2.81 and 1.37, and 4.82 and 3.00 mg liter(-1), respectively. Based on the combinations coefficient values, the toxicities of binary mixtures of organophosphorus and pyrethroid insecticides had additive effect except for the binary mixture of etramethrin + dichlorvos, which showed antagonism effect.

[The impairment of homocysteine on neurons and the related mechanisms].

AIM: To observe the impairment of homocysteine (Hcy) on neurons in vitro and the related mechanisms. METHODS: We examined the consequences of treatment of cultured rat cortical and hippocampal neurons with Hcy and detected the neurons' apoptosis, calcium influx, DNA damage and oxidative injury. RESULTS: Primary cortical and hippocampal neurons were treated with Hcy (250 micromol/L) for 4 h resulted in apoptosis time-dependently. S-adenosyl methionine (SAM) could significantly, but MK-801, an NMDA receptor inhibitor, couldn't repress the Hcy induced neuron apoptosis. Hcy could induce neuron calcium overload through activating the NMDA receptors. The DNA of neurons was damaged by Hcy because the methylation reactions were inhibited. Hcy treatment also induced MDA level significantly increased, but did not affect the neurons' T-AOC. CONCLUSION: These findings indicate that Hcy compromises neuronal homeostasis by multiple, divergent routes, including DNA damage, neuron exitotoxicity, and oxidative injury. Hcy mediated neuron apoptosis was mainly due to DNA damage.

[Effects of zinc on the expression of metallothionein isoforms in hippocampus of stressed rats].

OBJECTIVE: This study was conducted to evaluate the effects of different doses of zinc on the expression of metallothionein isoforms in hippocampus of stressed rats. METHODS: The animal model of psychological stress was developed by restraint stress for four weeks. Wistar rats were randomly assigned to eight groups as follows: control group, zinc deficiency group, pair-feed group, zinc complementarity group and their corresponding stressed groups. RESULTS: In zinc deficiency group, plasm zinc content was decreased, while in zinc complementarity group it's slightly increased. On the one hand, the expressions of metallothionein in brain and MT-1 mRNA, MT-3 mRNA in hippocampus were downregulated in zinc deficiency group, however, their expressions were evidently enhanced in stressed zinc deficiency group. On the other hand, inductions of metallothionein and it' s mRNAs in zinc complementarity group were increased, furthermore, stressed zinc complementarity group has more significantly yield of metallothionein and it' s mRNAs. In addition, the levels of plasma cortisol, IL-6, IL-1 and NO were increased clearly in zinc deficiency group and stressed zinc deficiency group. CONCLUSION: Our results suggested that zinc deficiency may decrease while zinc complementarity increase the expressions of metallothionein in brain and MT-1 mRNA, MT-3 mRNA in hippocampus, moreover, stress can increased their expressions dramatically. The impairment of stress on body may be involved with the nutrition status of zinc, and zinc deficiency can lower the body's resistibility to stress.