Inhibition of hyphal formation together with biochar addition promotes erythritol production by Yarrowia lipolytica.

This study aimed to investigate the effect of hyphal formation in Yarrowia lipolytica and biochar addition on erythritol production by submerged fermentation. Hyphal formation significantly inhibited erythritol production by Y. lipolytica. Transcriptome analysis suggested that the impaired erythritol synthesis of hyphal cells was associated with the differential expression of genes involved in amino acid metabolism, lipid metabolism, and cell wall stability. Deletion of RAS2 responsible for yeast-to-hypha transition and EYD1 included in erythritol degradation blocked hyphal formation and improved erythritol production. Biochar prepared from corncob, sugarcane bagasse (SB), corn straw, peanut shell, coconut shell, and walnut shell (WS) had a positive effect on erythritol production, of which WS pyrolyzed at 500°C (WSc) performed the best in flask fermentation. In a 3.7 L bioreactor, 220.20 ± 10 g/L erythritol with a productivity of 2.30 ± 0.10 g/L/h was obtained in the presence of 1.4% (w/v) WSc and 0.7% SBc (SB pyrolyzed at 500°C) within 96 h. These results suggest that inhibition of hyphal formation together with biochar addition is an efficient way to promote erythritol production.

Adaptive responses of erythritol-producing Yarrowia lipolytica to thermal stress after evolution.

Elucidation of the thermotolerance mechanism of erythritol-producing Yarrowia lipolytica is of great significance to breed robust industrial strains and reduce cost. This study aimed to breed thermotolerant Y. lipolytica and investigate the mechanism underlying the thermotolerant phenotype. Yarrowia lipolytica HT34, Yarrowia lipolytica HT36, and Yarrowia lipolytica HT385 that were capable of growing at 34 °C, 36 °C, and 38.5 °C, respectively, were obtained within 150 days (352 generations) by adaptive laboratory evolution (ALE) integrated with 60Co-γ radiation and ultraviolet ray radiation. Comparative genomics analysis showed that genes involved in signal transduction, transcription, and translation regulation were mutated during adaptive evolution. Further, we demonstrated that thermal stress increased the expression of genes related to DNA replication and repair, ceramide and steroid synthesis, and the degradation of branched amino acid (BCAA) and free fatty acid (FFA), while inhibiting the expression of genes involved in glycolysis and the citrate cycle. Erythritol production in thermotolerant strains was remarkably inhibited, which might result from the differential expression of genes involved in erythritol metabolism. Exogenous addition of BCAA and soybean oil promoted the growth of HT385, highlighting the importance of BCAA and FFA in thermal stress response. Additionally, overexpression of 11 out of the 18 upregulated genes individually enabled Yarrowia lipolytica CA20 to grow at 34 °C, of which genes A000121, A003183, and A005690 had a better effect. Collectively, this study provides novel insights into the adaptation mechanism of Y. lipolytica to thermal stress, which will be conducive to the construction of thermotolerant erythritol-producing strains. KEY POINTS: • ALE combined with mutagenesis is efficient for breeding thermotolerant Y. lipolytica • Genes encoding global regulators are mutated during thermal adaptive evolution • Ceramide and BCAA are critical molecules for cells to tolerate thermal stress.

Mechanism and evolutionary analysis of Yarrowia lipolytica CA20 capable of producing erythritol with a high yield based on comparative genomics.

Combined mutagenesis is widely applied for the breeding of robust Yarrowia lipolytica used in the production of erythritol. However, the changes of genome after mutagenesis remains unclear. This study aimed to unravel the mechanism involved in the improved erythritol synthesis of CA20 and the evolutionary relationship between different Y. lipolytica by comparative genomics analysis. The results showed that the genome size of Y. lipolytica CA20 was 20,420,510 bp, with a GC content of 48.97%. There were 6330 CDS and 649 ncRNA (non-coding RNA) in CA20 genome. Average nucleotide identity (ANI) analysis showed that CA20 genome possessed high similarity (ANI > 99.50%) with other Y. lipolytica strains, while phylogenetic analysis displayed that CA20 was classified together with Y. lipolytica IBT 446 and Y. lipolytica H222. CA20 shared 5342 core orthologous genes with the 8 strains while harbored 65 specific genes that mainly participated in the substrate and protein transport processes. CA20 contained 166 genes coding for carbohydrate-active enzymes (CAZymes), which was more than that found in other strains (108－137). Notably, 4, 2, and 13 different enzymes belonging to glycoside hydrolases (GHs), glycosyltransferases (GTs), and carbohydrate esterases (CEs), respectively, were only found in CA20. The enzymes involved in the metabolic pathway of erythritol were highly conserved in Y. lipolytica, except for transaldolase (TAL1). In addition, the titer and productivity of erythritol by CA20 were 190.97 g/L and 1.33 g/L/h, respectively, which were significantly higher than that of WT5 wherein 128.61 g/L and 0.92 g/L/h were obtained (P< 0.001). Five frameshift mutation genes and 15 genes harboring nonsynonymous mutation were found in CA20 compared with that of WT5. Most of these genes were involved in the cell division, cell wall synthesis, protein synthesis, and protein homeostasis maintenance. These findings suggested that the genome of Y. lipolytica is conserved during evolution, and the variance of living environment is one important factor leading to genome divergence. The varied number of CAZymes existed in Y. lipolytica is one factor that contributes to the performance difference. The increased synthesis of erythritol by Y. lipolytica CA20 is correlated with the improvement of the stability of cell structure and internal environment. The results of this study provide a basis for the directional breeding of robust strains used in erythritol production.

Melatonin ameliorates lung cell inflammation and apoptosis caused by Klebsiella pneumoniae via AMP-activated protein kinase.

Klebsiella pneumoniae is a Gram-negative bacterium and the causative agent of several life-threatening nosocomial infections, including pneumonia. K. pneumoniae induces acute lung injury and inflammation in humans that require immediate hospitalization and treatment. Therefore, attenuation of K. pneumoniae-induced inflammation is necessary for the survival of patients. This study investigated the mechanisms by which melatonin abrogated K. pneumoniae-induced inflammation and apoptosis of lung cell lines, HLF-1 and BEAS-2B. Our results showed that in vitro infection of HLF-1 and BEAS-2B cells by K. pneumoniae significantly induced inflammation and apoptosis increased elevated levels of IL-6, CXCL1, CXCL2, and caspase-9 mRNA. However, these effects were abrogated by melatonin treatment. Infection with K. pneumoniae significantly increased the expression of AMP-induced protein kinase (AMPK). Furthermore, AMPK silencing significantly abrogated the suppression of inflammation and apoptosis in melatonin-infected K. pneumoniae lung cells. Melatonin could alleviate K. pneumoniae infection-induced inflammation in three-dimensional lung spheroids. In conclusion, our study demonstrated that melatonin abrogated K. pneumoniae-induced inflammation and apoptosis in lung cells through AMPK. Our study demonstrated the potential of melatonin for therapy against K. pneumoniae infections including pneumonia.

[Microvascular decompression for hemifacial spasm induced by vertebral artery dissecting aneurysm: one case report].

A 61-year-old female presented with 4 years history of left-sided hemifacial spasm. Head MRI and angiography indicated left vertebral artery dissecting aneurysm which compressed ipsilateral cranial nerves Ⅶ and Ⅷ. Microvascular decompression was performed. The dissecting aneurysm was pushed apart and the distal part of the parent artery was adhered to the dura on the petrosum. The compressed nerves were totally decompressed. The symptom of facial spasm was completely resolved immediately after surgery and did not recur during 6 months of follow up.

Population pharmacokinetics of intravenous moxifloxacin 400 mg once-daily dosage in infected patients.

OBJECTIVE: The purpose of this study was to explore the population pharmacokinetic features of moxifloxacin in infected patients. METHOD: A total of 37 Chinese adult infected patients were treated with intravenous moxifloxacin (400 mg/day). In total, 67 plasma samples of moxifloxacin were collected immediately after intravenous dripping and before administration on the 3rd, 4th or 5th day. A nonlinear mixed effect model was used to model the population pharmacokinetic (PK) behavior of moxifloxacin. The final population pharmacokinetic models were validated using the bootstrap method. Some covariates, including demographic characteristics and hematological and biological indicators, were analyzed. RESULTS: A structural model was developed based on a one-compartment model with intravenous infusion and first-order elimination. The typical population values of moxifloxacin for the pharmacokinetic parameters of apparent clearance (CL) and apparent distribution volume (V) were 12.9 L/h and 115 L, respectively. The inter-individual variabilities of CL and V were 36% and 28%, respectively. The covariates of WT influenced the CL and V values determined by the final model. CONCLUSION: The present study developed population pharmacokinetic models for moxifloxacin in infected Chinese patients. The results detailed here could provide a reference for individualized moxifloxacin therapy in the clinical setting.

Population pharmacokinetics of intravenous levofloxacin 500 mg/day dosage in infected patients.

The purpose of this study was to explore the population pharmacokinetic features of levofloxacin in Chinese infected patients. A total of 27 Chinese adult infected patients were treated with intravenous levofloxacin (500 mg/day). In total, 49 plasma samples of levofloxacin were collected immediately after intravenous dripping and before administration on the 3rd, 4th or 5th day. A nonlinear mixed effect model was used to model the population pharmacokinetic (PK) behavior of levofloxacin. The final population pharmacokinetic models were validated using the bootstrap method. Some covariates, including demographic characteristics and hematological and biological indicators, were analyzed. A structural model was developed based on a one-compartment model with intravenous infusion and first-order elimination. The typical population values for pharmacokinetic parameters of apparent clearance (CL) and apparent distribution volume (V) were 5.84 L/h and 43.3L, respectively. The inter-individual variabilities of CL and V were 7.75% and 6.4%, respectively, while the intra-individual variability of observed concentrations was 0.06 microg/mL. The covariates of age and AST influenced the CL and V values determined by the final model. The present study developed population pharmacokinetic models for levofloxacin in infected Chinese patients. The results detailed here could provide a reference for individualized levofloxacin therapy in the clinical setting.

Melatonin-induced upregulation of telomerase activity interferes with macrophage mitochondrial metabolism and suppresses NLRP3 inflammasome activation in the treatment of Pneumonia.

Objective: This study aims to investigate the effects of melatonin-induced upregulation of telomerase activity on mitochondrial metabolism and NLRP3 inflammasome activation in macrophages, with the ultimate goal of elucidating potential therapeutic implications for pneumonia treatment. Materials and methods: Macrophages were treated with melatonin to assess its impact on telomerase activity. Mitochondrial function was evaluated through the measurement of reactive oxygen species (ROS) levels and cellular energy production. NLRP3 inflammasome activation was assessed by examining the production of inflammatory cytokines, such as interleukin-1ß (IL-1ß). The expression levels of key proteins involved in mitochondrial metabolism and NLRP3 inflammasome signaling were also analyzed. Results: Our findings demonstrated that melatonin treatment significantly upregulated telomerase activity in macrophages. This was associated with a reduction in ROS levels and enhanced cellular energy production, indicating improved mitochondrial function. Moreover, melatonin treatment suppressed NLRP3 inflammasome activation, resulting in reduced secretion of IL-1ß. The expression levels of proteins involved in mitochondrial metabolism and NLRP3 inflammasome signaling were modulated by melatonin. Conclusion: These results suggest that melatonin-induced upregulation of telomerase activity can interfere with mitochondrial metabolism and inhibit NLRP3 inflammasome activation in macrophages. This indicates a potential therapeutic role for melatonin in the treatment of pneumonia. Understanding the molecular mechanisms underlying these effects may lead to the development of novel therapeutic strategies targeting mitochondria and NLRP3 inflammasome activation for the management of pneumonia. Further investigations are warranted to fully uncover the therapeutic potential of melatonin and its implications for pneumonia treatment.

miR-520f-3p blocks MNNG-induced gastric precancerous lesions via the KLF7/NFκB pathway.

Studying the regulatory mechanism of gastric disease progression to gastric cancer (GC) is essential. miR-520f expression is down-regulated in GC and inhibits the proliferation of gastric cancer cells, suggesting that it is associated with the development of GC, but whether it plays a role in the gastric precancerous lesion (GPL) is unclear. This study aimed to investigate the effect of miR-520f-3p in the N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced GPL model and to elucidate the role of its downstream target gene Kruppel-like factor 7 (KLF7) in it. The experimental results showed that miR-520f-3p expression was down-regulated in the MNNG-induced GES-1 cell model, and overexpression of miR-520f-3p reversed the effects of MNNG on cell migration, invasion and epithelial-mesenchymal transition (EMT) -related protein expression. Meanwhile, overexpression of KLF7 attenuated the effect of miR-520f-3p on GPL. In a mouse GPL model, it was observed that MNNG elicited inflammation and EMT processes in mouse gastric tissues through the KLF7/ Nuclear Factor Kappa B (NFκB) pathway, and silencing KLF7 alleviated MNNG-induced gastric epithelial cell injury and gastric atrophy symptoms. These results provide a new perspective for understanding the development of GPL, and the development of new therapies targeting miR-520f-3p and KLF7 may provide new ideas for the prevention and treatment of gastric cancer.

Combination of Network Pharmacology and In Vitro Experiments on LPSinduced A549 Cells to Explore the Molecular Mechanisms of Huanglian Jiedu Decoction Treating Pneumonia.

OBJECTIVE: Huanglian Jiedu Decoction (HLJDD) was shown to exert a therapeutic effect on pneumonia for a long time in China. However, its pharmacological mechanism remains to be elucidated. METHODS: The active compounds and target proteins of HLJDD were screened from TCMSP, and the pneumonia targets were obtained from GeneCards. GO, and KEGG enrichment was applied in this study. Cytoscape established networks with R-Bioconductor. The affinity between components and targets was detected by molecular docking. Finally, active ingredients and targets were selected to be verified in an inflammatory model established in LPS-induced A549 cells. CCK8 proliferation assay and western blot were performed to test the relative indicators. RESULTS: 102 bioactive components and 205 targets from 4 herbs in HLJDD were collected. 68 potential therapeutic targets and 55 corresponding compounds were screened to establish the networks. 4 active compounds (quercetin, wogonin, kaempferol and baicalein) and 5 hub genes (IL6, AKT1, CXCL8, CCL2 and IL1B) were then selected to make molecular docking. The results indicated that quercetin and wogonin had a better affinity with CXCL8, CCL2 or IL1B. In vitro experiments revealed that quercetin and wogonin could decrease the proliferation inhibiting and apoptosis of A549 cells injured by LPS. CXCL8, CCL2 or IL1B were downregulated after quercetin or wogonin treatment, compared with LPS-induced A549 cells (P < 0.01). CONCLUSION: The current study suggested that the mechanism of HLJDD treating pneumonia might inhibit apoptosis by targeting inflammatory factors, mainly quercetin and wogonin.

Cancer-suppressing miR-520-3p gene inhibits proliferation, migration, and invasion of gastric cancer cells through targeted regulation of KLF7.

Gastric cancer (GC) is among the most common malignant tumors. Numerous studies have reported that microRNAs (miRNAs) play significant roles in carcinogenesis and treatment. An miRNA, miR-520-3p, has been identified as a cancer-suppressing gene in several cancers. However, the role and underlying mechanism of miR-520-3p regulation of GC remain unknown. In this study, the expression levels of miR-520-3p in cancer tissues of patients with GC - and in adjacent normal tissues, gastric cancer cell lines, and human normal gastric epithelial cells - were detected by qRT-PCR. RNA interference was performed in GC cell lines. After the corresponding treatment, the cells were characterized in vitro or in vivo to evaluate their molecular function. CCK-8, cell colony formation, and a Transwell assay were used to detect cell proliferation rate, viability, and invasion ability. A dual-luciferase reporter gene experiment was used to explore the potential molecular mechanisms of miR-520-3p. The results showed that the expression of miR-520-3p was significantly downregulated in GC tissues and cells, and upregulation of miR-520-3p could inhibit the proliferation, vitality, and invasion of GC cells both in vivo and in vitro. The expression of Kruppel-like factor 7 (KLF7) was greatly upregulated in GC tissues. MiR-520-3p can adsorb KLF7 in GC cells, and KLF7 can reverse the inhibitory effect of miR-520-3p overexpression on the proliferation of GC cells. This study revealed that miR-520-3p plays a significant role in inhibiting the proliferation, invasion, and migration of GC cells by targeting KLF7. These data demonstrate that miR-520-3p may serve as a novel prognostic biomarker and a potential therapeutic target for GC.

ALS3 Expression as an Indicator for Candida albicans Biofilm Formation and Drug Resistance.

Resistance caused by the formation of the Candida albicans (C. albicans) biofilm is one of the main reasons for antifungal therapy failure. Thus, it is important to find indicators that predict C. albicans biofilm formation to provide evidence for the early prevention and treatment of the C. albicans biofilms. In this study, C. albicans samples were selected from C. albicans septicemia that were sensitive to common antifungal agents. It was found that the agglutinin-like sequence 3 (ALS3) gene was differentially expressed in free, antifungal, drug-sensitive C. albicans. The average ALS3 gene expression was higher in the C. albicans strains with biofilm formation than that in the C. albicans strains without biofilm formation. Then, it was further confirmed that the rate of biofilm formation was higher in the high ALS3 gene expression group than that in the low ALS3 gene expression group. It was found that C. albicans with biofilm formation was more resistant to fluconazole, voriconazole, and itraconazole. However, it maintained its sensitivity to caspofungin and micafungin in vitro and in mice. Further experiments regarding the prevention of C. albicans biofilm formation were performed in mice, in which only caspofungin and micafungin prevented C. albicans biofilm formation. These results suggest that the expression level of ALS3 in C. albicans may be used as an indicator to determine whether C. albicans will form biofilms. The results also show that the biofilm formation of C. albicans remained sensitive to caspofungin and micafungin, which may help to guide the selection of clinical antifungal agents for prevention and therapy.

Effectiveness of Educational Intervention on Influenza Vaccine Uptake: A Meta-Analysis of Randomized Controlled Trials.

BACKGROUND: This study aimed to explore effective education method to improve influenza vaccine uptake rate. METHODS: Meta-analysis of Randomized Clinical Trials was conducted in this study including subgroup analysis and publication bias test. Electronic databases comprised PubMed, EBSCO, Elsevier, Springer, Wiley, and Cochrane were searched for studies published up to Oct 8, 2019. RESULTS: Influenza vaccination was significantly different in massages or letters intervention group (OR=1.30, 95%CI: 1.05-1.61). No heterogeneity and publication bias existed in this meta-analysis (I2 =43.60%, P=0.131, Pbegg =0.754, Pegger =0.051). CONCLUSION: Education by messages and letters was effective according to this study. Education messages could be more efficacy combined with easer vaccine access.

Klebsiella pneumoniae presents antimicrobial drug resistance for ß-lactam through the ESBL/PBP signaling pathway.

Overuse and misuse of antibiotics leads to antibiotic resistance which has become a significant public health concern. Klebsiella pneumoniae is the most common pathogenic bacteria underlying nosocomial infections due to the expression of virulence factors and occurrence of antibiotic resistance. Evidence indicates that ß-lactamase is involved in the antibiotic resistance of Klebsiella pneumoniae to ß-lactam antibiotics. The aim of the present study was to investigate the association between the molecular biological mechanisms of antibiotic resistance of Klebsiella pneumoniae and extended-spectrum ß-lactamase (ESBL). In order to assess temporal trends in prevalence and antimicrobial susceptibility, Klebsiella pneumoniae bacteria were isolated and the ESBL expression level was analyzed. Susceptibility tests were performed using automated systems. The ß-lactam-resistance in Klebsiella pneumoniae was assessed by the ß-lactam agar screen plate and respective MIC values were evaluated using E-test strips. The confirmatory disk diffusion methods were applied for phenotypic identification of the ESBL production of Klebsiella pneumoniae. The results showed that Klebsiella pneumoniae bacteria exhibited higher ESBL production after treatment with ß-lactam compared to the control. The ESBL gene expression was upregulated in Klebsiella pneumoniae after treatment with ß-lactam. Results identified that penicillin-binding proteins (PBPs) were associated with the growth and resistance to ß-lactams. Zinc finger nuclease markedly inhibited the antibiotic resistance of Klebsiella pneumoniae to ß-lactam. PBP knockdown abolished the inhibitory effects of zinc finger nuclease on the growth of Klebsiella pneumonia e induced by ß-lactam antibiotic treatment. In conclusion, these results suggest that the resistance of Klebsiella pneumoniae bacteria to antimicrobial drugs is through the ESBL signaling pathway, which indicates that ESBL may be a potential target for abolishing resistance to ß-lactam.

Epstein-Barr virus circRNAome as host miRNA sponge regulates virus infection, cell cycle, and oncogenesis.

Epstein-Barr virus (EBV) is an oncogenic virus that infects more than 90% of the world's population. The proteins and miRNAs encoded by EBV are involved in multiple human malignancies. Recently R-resistance RNA-seq demonstrated that EBV-encoded circular RNAs. The current research aims to explore their functions in EBV-associated malignancies. Total 56 miRNAs were sponged by circRNAome. 24 and 9 in EBV host B and epithelial cells out of 56 miRNAs were detectable by miRNA-seq. 18 and 5 miRNAs were down-regulated in both types of host cells, respectively, after EBV infection. The network between five miRNAs and their targets included 1414 genes, 1419 nodes, and 2423 edges. These targets were enriched in multiple categories, and most of them were up-regulated in EBV-infected cells. These data represented the first report that EBV circRNAs could sponge the miRNAs to promote the up-regulated expression of their targets, involving in malignancies associated with EBV.

Elevation of neuron-specific enolase and S-100beta protein level in experimental acute spinal cord injury.

We evaluated the protein levels of neuron-specific enolase (NSE) and S-100beta in serum and cerebrospinal fluid (CSF) in an animal model of acute spinal cord injury and ascertained their relevance. Spinal cord injury was induced at the T8 level in rats. Enzyme-linked immunosorbent assay was used to measure the protein levels of NSE and S-100beta in both serum and CSF at different time points (30 min, 2 h, 6 h, 12 h and 24 h after induction of spinal cord injury). There existed a significant correlation between neurological deficits and the severity of spinal cord injury (p<0.05). Compared with the control group, the protein levels of NSE and S-100beta in serum and CSF significantly increased from 2 h after injury (p<0.05) and reached a maximum at 6 h. Within a certain time window, the protein levels of NSE and S-100beta in serum and CSF were closely related to the severity of injury level (p<0.05). The protein levels of NSE and S-100beta in serum and CSF significantly increased after experimental spinal cord injury in a time-dependent manner and thus may be considered specific biomarkers for acute spinal cord injury.

Determination of lymph node micrometastases in patients with supraglottic carcinoma.

CONCLUSIONS: The frequency of loss of heterozygosity (LOH) at D9S 171 microsatellite locus on 9p21 may serve as an available method to evaluate occult micrometastases in laryngeal squamous cell carcinoma. High frequency of LOH was associated with a decreased probability of survival time. OBJECTIVE: To explore an available and sensitive method to detect cervical lymph node micrometastases in patients with laryngeal squamous cell carcinoma, the frequency of LOH at D9S171 microsatellite locus on 9p21 was studied. PATIENTS AND METHODS: Twenty samples from supraglottic cancer and 182 lymph nodes from neck dissections were examined by LOH comparing immunohistochemical (IHC) staining using cytokeratin 19 (CK19), and hematoxylin and eosin (H&E) staining. The frequency of lymph node metastasis and the clinical relevance were analysed. RESULTS: The frequency of LOH was 37.4% of lymph nodes and all of the primary tumors. Occult micrometastases were present in 9 of 20 cases; 23.6% of lymph nodes were positive for CK19 by IHC; 16.5% of lymph nodes were positive by H&E. There was a highly significant difference among the three methods. The highest rate of positive lymph nodes was at level II of the neck. There was a highly significant difference between overall survival time and lymph node metastasis with LOH and CK19 analysis.

Establishment of a mechanical injury model of rat hippocampal neurons in vitro.

OBJECTIVE: To establish a simple, reproducible, and practical mechanical injury model of hippocampal neurons of Sprague-Dawley rats in vitro. METHODS: Hippocampal neurons isolated from 1-2-day old rats were cultured in vitro. Mild, moderate and severe mechanical injuries were delivered to the neurons by syringe needle tearing, respectively. The control neurons were treated identically with the exception of trauma. Cell damage was assessed by measuring the Propidium Iodide (PI) uptaking at different time points (0.5, 1, 6, 12 and 24 hours) after injury. The concentration of neuron specific enolase was also measured at some time points. RESULTS: Pathological examination showed that degeneration, degradation and necrosis occurred in the injured cultured neurons. Compared with the control group, the ratio of PI-positive cells in the injured groups increased significantly after 30 minutes of injury (P<0.05). More severe the damage was, more PI-positive neurons were detected. Compared with the control group, the concentration of neuron specific enolase in the injured culture increased significantly after 1 hour of injury (P<0.05). CONCLUSIONS: The established model of hippocampal neuron injury in vitro can be repeated easily and can simulate the damage mechanism of traumatic brain injury, which can be used in the future research of traumatic brain injury.

Is decompressive craniectomy for malignant middle cerebral artery infarction of any worth?

OBJECTIVE: Malignant middle cerebral artery (MCA) infarction is characterized by mortality rate of up to 80%. The aim of this study was to determine the value of decompressive craniectomy in patients presenting malignant MCA infarction compared with those receiving medical treatment alone. METHODS: Patients with malignant MCA infarction treated in our hospital between January 1996 and March 2004 were included in this retrospective analysis. The National Institute of Health Stroke Scale (NIHSS) was used to assess neurological status on admission and at one week after surgery. All patients were followed up for assessment of functional outcome by the Barthel index (BI) and modified Rankin Scale (RS) at 3 months after infarction. RESULTS: Ten out of 24 patients underwent decompressive craniectomy. The mean interval between stroke onset and surgery was 62.10 h. The mortality was 10.0% compared with 64.2% in patients who received medical treatment alone (P<0.001). The mean NIHSS score before surgery was 26.0 and 15.4 after surgery (P<0.001). At follow up, patients who underwent surgery had significantly better outcome with mean BI of 53.3, RS of 3.3 as compared to only 16.0 and 4.60 in medically treated patients. Speech function also improved in patients with dominant hemispherical infarction. CONCLUSION: Decompressive craniectomy in patients with malignant MCA infarction improves both survival rates and functional outcomes compared with medical treatment alone. A randomized controlled trial is required to substantiate those findings.