Cystathionine β-synthase expression correlates with tumor development and poor prognosis in patients with adenocarcinoma of the gastroesophageal junction

OBJECTIVES

To reveal the expression level of cystathionine β-synthase (CBS) in adenocarcinoma of esophagogastric junction (AEG) and discuss the relationship between CBS expression level and tumor microvascular density (MVD), clinical features and prognosis.

METHODS

Paraffin samples from 214 patients with AEG were selected to make pathological microchips. Immunohistochemistry was performed based on the microchips to detect the expression level of CBS and microvascular density (MVD) in cancer tissues and adjacent control tissues. Relationships between expression level of CBS and MVD, clinical characteristics and prognosis were analyzed.

RESULTS

In total, 214 AEG cases were classified into three groups: CBS negative staining (n=26), low staining (n=44), and high staining (n=144). Quantitative alterations in CBS and CD31 expression were explored using immunohistochemistry. The 5-year recurrence rate of enrolled patients was followed up and found that CBS expression was significantly increased in tumor tissue compared with adjacent non-tumor tissue (P<0.0001). There were significant differences in microvascular density between the groups with negative and high CBS staining (P<0.0001), and between the groups with low and high CBS staining (P<0.0001). Univariate analysis revealed significant differences in tumor stage (P<0.0001), T stage (P=0.008), N stage (P=0.028), differentiation degree (P=0.037), and 5-year survival (P=0.0034) among the three groups. Multivariate logic regression analysis showed that increased CBS scores were associated with an increased probability of 5-year recurrence (P=0.018). Finally, different CBS expression levels were associated with disease-free survival in AEG patients.

CONCLUSIONS

CBS expression level is closely related to microvascular density and tumor stage in AEG. High level of CBS not only accelerates tumor angiogenesis but also affects patient's survival and prognosis.

PDK4 Decrease Neuronal Apoptosis via Inhibiting ROS-ASK1/P38 Pathway in Early Brain Injury After Subarachnoid Hemorrhage

Aims: Metabolic disorders may play key roles in oxidative stress and neuronal apoptosis in response to early brain injury (EBI) after subarachnoid hemorrhage (SAH). Pyruvate dehydrogenase (PDH) is related to oxidative stress in EBI, and its activity obviously decreases after SAH. We discovered that only pyruvate dehydrogenase kinase 4 (PDK4) expression was obviously increased among the four PDK isozymes after SAH in preliminary experiments. Therefore, we attempted to investigate the effects and corresponding mechanisms of PDK4 on oxidative stress after SAH. Results: First, we confirmed that PDK4 overexpression promoted PDH phosphorylation, inhibited PDH activity, and changed cell metabolism after SAH. A small interfering RNA (siRNA) targeting PDK4, a lentiviral PDK4 overexpression vector, and dichloroacetic acid (DCA) were used to regulate the expression and activity of PDK4. The siRNA decreased PDH phosphorylation, promoted reactive oxygen species (ROS) production, activated the apoptosis signal-regulating kinase 1 (ASK1)/P38 pathway, and induced neuronal apoptosis. The lentivirus further attenuated PDH activity, oxidative stress, and neuronal apoptosis. DCA inhibited the activity of PDK4, but increased the expression of PDK4 due to a feedback mechanism. Inactivated PDK4 did not effectively suppress PDH activity, which increased ROS production, activated the ASK1/P38 pathway, and led to neuronal apoptosis. Innovation: This study provides new insights into the potential antioxidant and antiapoptotic effects of the PDK4-PDH axis on EBI after SAH. Conclusions: The early overexpression of PDK4 after SAH may attenuate neuronal apoptosis by reducing oxidative stress via the ROS/ASK1/P38 pathway. PDK4 may be a new potential therapeutic target to ameliorate EBI after SAH. Antioxid. Redox Signal. 36, 505-524.

LncRNA B4GALT1-AS1 promotes non-small cell lung cancer cell growth via increasing ZEB1 level by sponging miR-144-3p

Background

Long noncoding RNAs (lncRNAs) are emerging as key players in the development and progression of cancer. Several malignancies involve dysregulated long noncoding ribonucleic acids (lncRNAs) in non-small cell lung cancer cell growth and their aggressive phenotypes. LncRNA B4GALT1-AS1 is important in the advancement of various malignancies, although its contribution to non-small cell lung cancer (NSCLC) remains unexplored.

Methods

LncRNA B4GALT1-AS1 in NSCLC tissues was detected and further validated in a cohort of non-small cell lung cancer tissues. The effects of lncRNA B4GALT1-AS1 on proliferation were determined by in vitro experiments. The B4GALT1-AS1-miR-144-3p-ZEB1 axis was assessed by dual-luciferase reporter and RNA immunoprecipitation (RIP) assays. Furthermore, the mechanism of B4GALT1-AS1 was investigated using loss-of-function assays in vitro.

Results

We showed significant upregulation of B4GALT1-AS1 in cell lines and tissues of NSCLC. B4GALT1-AS1 knockdown impeded the in vitro proliferation-related characteristics of the NSCLC cells. The demonstration of the binding capacity of B4GALT1-AS1 and miR-144-3p was predicted by bioinformatics and luciferase reporter activity assay. The B4GALT1-AS1 and miR-144-3p interaction was shown by using rescue experiments. NSCLC has a positive association with its target, zinc finger e-box binding homeobox 1 (ZEB1).

Conclusions

In summary, the progression of NSCLC was facilitated by lncRNA B4GALT1-AS1 via interaction with miR-144-3p and positive regulation of ZEB1 expression.

[Comparison and application of postprandial and fasting blood lipid levels in 839 physical examinees in Beijing]

Objective: To investigate the feasibility of application of non-fasting dyslipidemia cutoff values in community population. Methods: Self-control study was used. 839 physical examinees (292 males and 547 females) were recruited in clinical laboratory of Guang'an men Hospital from January to October 2018. The median (interquartile range) of age was 60 (54, 66) years. Blood samples were collected before and at 4 h after a standard breakfast. Comparison of fasting and postprandial lipoprotein levels was performed using Paired-Samples T Test or Two-Related-Samples Wilcoxon. The changes of 4-hour postprandial blood lipid levels and the percentages of postprandial dyslipidemia according to different stratification of fasting dyslipidemia were performed using one-way ANOVA and χ² test, respectively. Results: Compared with fasting, 4-hour postprandial total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), non-high density lipoprotein cholesterol (non-HDL-C), apolipoprotein A1 (ApoA1) and apolipoprotein B (ApoB) decreased slightly, postprandial triglyceride (TG) increased by 0.72 mmol/L, and postprandial remnant-like lipoprotein cholesterol (RLP-C) increased by 0.27 mmol/L (t or Z values = 10.26,22.94,24.22,4.71,16.61,26.92,-23.58,-19.35, P<0.05, respectively). According to the non-fasting dyslipidemia cut-off values recommended by the European consensus, there were 10%, 16.6%, 10.1%, 12.3%, 30% and 34.9% of the population in the appropriate levels of fasting TC, LDL-C, HDL-C, non-HDL-C, TG and RLP-C distributed in elevated levels of postprandial, respectively. The changes of 4-hour postprandial TC, LDL-C, non-HDL-C and HDL-C increased with the elevation of fasting level (F=9.50,6.18,8.07,3.86,P<0.01), and the maximum changes of TC≤3.5%, LDL-C≤6.8%, non-HDL-C≤2.9%, HDL-C≤6.3%; the change of 4-hour postprandial TG increased slightly first and then decreased significantly (51.3% vs. 57.9% vs. 39.2%, F=19.05, P<0.01); the change of 4-hour postprandial RLP-C decreased (50.8% vs. 33.2%, F=10.40, P<0.01). The cut-off values of 4-hour postprandial dyslipidemia were TC ≥5.1 mmol/L, LDL-C ≥3.2 mmol/L, HDL-C ≤0.9 mmol/L, non-HDL-C ≥4.0 mmol/L and RLP-C ≥1.0 mmol/L. The cut-off values of borderline elevated and elevated TG levels were ≥2.2 mmol/L and ≥3.4 mmol/L, respectively. Conclusions: The cut-off values of postprandial dyslipidemia including TC, LDL-C, HDL-C, non-HDL-C and RLP-C were preliminarily established in community population, which could be applied to the routine lipid profile evaluation in the physical examination population. And it might be needed that postprandial TG was managed hierarchically according to different cut-off values.

Resolvin D1 Attenuates Innate Immune Reactions in Experimental Subarachnoid Hemorrhage Rat Model

Excessive inflammation is a major cause contributing to early brain injury (EBI) and is associated with negative or catastrophic outcomes of subarachnoid hemorrhage (SAH). Resolvin D1 (RvD1) exerts strong anti-inflammatory and pro-resolving effects on either acute or chronic inflammation of various origin. Henceforth, we hypothesized that RvD1 potentially attenuates excessive inflammation in EBI following SAH. Therefore, we generated a filament perforation SAH model and administered 3 different doses (0.3, 0.6, and 1.2 nmol) of RvD1 after experimental SAH. Neurological scores, brain edema, and blood-brain barrier integrity were evaluated; besides, neutrophil infiltration, neuronal deaths, and microglial pro-inflammatory polarization were observed using histopathology or immunofluorescence staining, western blots, and qPCR. After confirming the effectiveness of RvD1 in SAH, we administered the FPR2-specific antagonist Trp-Arg-Trp-Trp-Trp-Trp-NH2 (WRW4) 30 min before SAH establishment to observe whether this compound could abolish the anti-inflammatory effect of RvD1. Altogether, our results showed that RvD1 exerted a strong anti-inflammatory effect and markedly reduced neutrophil infiltration and microglial pro-inflammatory activation, leading to remarkable improvements in neurological function and brain tissue restoration. After addition of WRW4, the anti-inflammatory effects of RvD1 were abolished. These results indicated that RvD1 could exert a good anti-inflammatory effect and alleviate EBI, which suggested that RvD1 might be a novel therapeutic alternative for SAH-induced injury.

Elevated hippocampal CD24 in astrocytes participates in neural regeneration possibly via activating SHP2/ERK pathway after experimental traumatic brain injury in mice

Massive neuron loss is the key reason for poor prognoses in patients with traumatic brain injury (TBI), and astrocytes function as nutrition-providing neurons. Therefore, researchers must determine the potential role of astrocytes in neural regeneration after TBI. Our previous studies established that upregulating CD24 in the hippocampus might improve cognitive functions after TBI. However, whether CD24 in hippocampal astrocytes is involved in neural regeneration after TBI remains unknown. Therefore, we detected the CD24 expression in the ipsilateral hippocampus via western blot and quantitative real-time PCR. We further investigated the CD24 expression patterns in hippocampal astrocytes via immunofluorescence staining. We then injected adeno-associated virus-Gfa2-siRNA-CD24 (AAV-CD24) into the astrocytes to downregulate CD24 and analyzed the related cellular signals. Golgi-Cox staining and the growth associated protein-43 (GAP43) level were used to observe neuronal morphology and neural regeneration around the astrocytes in the ipsilateral hippocampus, and the Morris water maze test was used to assess neural functional recovery. The CD24 protein and mRNA levels in the cornu ammonis and dentate gyrus regions of the ipsilateral hippocampus were elevated after TBI, and high CD24 expression was widespread in the hippocampal astrocytes after TBI. Specific inhibition of CD24 in the hippocampal astrocytes interfered with the activation of Src homology region 2 containing protein tyrosine phosphatase 2 (SHP2) and extracellular signal regulated kinase (ERK), shortened the neuronal dendritic spines, decreased the GAP43 level and impaired the cognitive functions of the TBI-model mice. These results revealed that elevated hippocampal CD24 in astrocytes participated in neural regeneration in mice after TBI, possibly by activating the SHP2/ERK pathway.

Fucoxanthin Mitigates Subarachnoid Hemorrhage-Induced Oxidative Damage via Sirtuin 1-Dependent Pathway

Oxidative stress is a key component of the pathological cascade in subarachnoid hemorrhage (SAH). Fucoxanthin (Fx) possesses a strong antioxidant property and has shown neuroprotective effects in acute brain injuries such as ischemic stroke and traumatic brain injury. Here, we investigated the beneficial effects of Fx against SAH-induced oxidative insults and the possible molecular mechanisms. Our data showed that Fx could significantly inhibit SAH-induced reactive oxygen species production and lipid peroxidation, and restore the impairment of endogenous antioxidant enzymes activities. In addition, Fx supplementation improved mitochondrial morphology, ameliorated neural apoptosis, and reduced brain edema after SAH. Moreover, Fx administration exerted an improvement in short-term and long-term neurobehavior functions after SAH. Mechanistically, Fx inhibited oxidative damage and brain injury after SAH by deacetylation of forkhead transcription factors of the O class and p53 via sirtuin 1 (Sirt1) activation. EX527, a selective Sirt1 inhibitor, significantly abated Fx-induced Sirt1 activation and abrogated the antioxidant and neuroprotective effects of Fx after SAH. In primary neurons, Fx similarly suppressed oxidative insults and improved cell viability. These effects were associated with Sirt1 activation and were reversed by EX527 treatment. Taken together, our study explored that Fx provided protection against SAH-induced oxidative insults by inducing Sirt1 signaling, indicating that Fx might serve as a potential therapeutic drug for SAH.

Functions of resolvin D1-ALX/FPR2 receptor interaction in the hemoglobin-induced microglial inflammatory response and neuronal injury

Background

Early brain injury (EBI) has been thought to be a key factor affecting the prognosis of subarachnoid hemorrhage (SAH). Many pathologies are involved in EBI, with inflammation and neuronal death being crucial to this process. Resolvin D1 (RvD1) has shown superior anti-inflammatory properties by interacting with lipoxin A4 receptor/formyl peptide receptor 2 (ALX/FPR2) in various diseases. However, it remains not well described about its role in the central nervous system (CNS). Thus, the goal of the present study was to elucidate the potential functions of the RvD1-ALX/FPR2 interaction in the brain after SAH.

Methods

We used an in vivo model of endovascular perforation and an in vitro model of hemoglobin (Hb) exposure as SAH models in the current study. RvD1 was used at a concentration of 25 nM in our experiments. Western blotting, quantitative polymerase chain reaction (qPCR), immunofluorescence, and other chemical-based assays were performed to assess the cellular localizations and time course fluctuations in ALX/FPR2 expression, evaluate the effects of RvD1 on Hb-induced primary microglial activation and neuronal damage, and confirm the role of ALX/FPR2 in the function of RvD1.

Results

ALX/FPR2 was expressed on both microglia and neurons, but not astrocytes. RvD1 exerted a good inhibitory effect in the microglial pro-inflammatory response induced by Hb, possibly by regulating the IRAK1/TRAF6/NF-κB or MAPK signaling pathways. RvD1 could also potentially attenuate Hb-induced neuronal oxidative damage and apoptosis. Finally, the mRNA expression of IRAK1/TRAF6 in microglia and GPx1/bcl-xL in neurons was reversed by the ALX/FPR2-specific antagonist Trp-Arg-Trp-Trp-Trp-Trp-NH2 (WRW4), indicating that ALX/FPR2 could mediate the neuroprotective effects of RvD1.

Conclusions

The results of the present study indicated that the RvD1-ALX/FPR2 interaction could potentially play dual roles in the CNS, as inhibiting Hb promoted microglial pro-inflammatory polarization and ameliorating Hb induced neuronal oxidant damage and death. These results shed light on a good therapeutic target (ALX/FPR2) and a potential effective drug (RvD1) for the treatment of SAH and other inflammation-associated brain diseases.

Aucubin alleviates oxidative stress and inflammation via Nrf2-mediated signaling activity in experimental traumatic brain injury

Background

Aucubin (Au), an iridoid glycoside from natural plants, has antioxidative and anti-inflammatory bioactivities; however, its effects on a traumatic brain injury (TBI) model remain unknown. We explored the potential role of Au in an H₂O₂-induced oxidant damage in primary cortical neurons and weight-drop induced-TBI in a mouse model.

Methods

In vitro experiments, the various concentrations of Au (50 μg/ml, 100 μg/ml, or 200 μg/ml) were added in culture medium at 0 h and 6 h after neurons stimulated by H₂O₂ (100 μM). After exposed for 12 h, neurons were collected for western blot (WB), immunofluorescence, and M29,79-dichlorodihydrofluorescein diacetate (DCFH-DA) staining. In vivo experiments, Au (20 mg/kg or 40 mg/kg) was administrated intraperitoneally at 30 min, 12 h, 24 h, and 48 h after modeling. Brain water content, neurological deficits, and cognitive functions were measured at specific time, respectively. Cortical tissue around focal trauma was collected for WB, TdT-mediated dUTP Nick-End Labeling (TUNEL) staining, Nissl staining, quantitative real time polymerase chain reaction (q-PCR), immunofluorescence/immunohistochemistry, and enzyme linked immunosorbent assay (ELISA) at 72 h after TBI. RNA interference experiments were performed to determine the effects of nuclear factor erythroid-2 related factor 2 (Nrf2) on TBI mice with Au (40 mg/kg) treatment. Mice were intracerebroventricularly administrated with lentivirus at 72 h before TBI establishment. The cortex was obtained at 72 h after TBI and used for WB and q-PCR.

Results

Au enhanced the translocation of Nrf2 into the nucleus, activated antioxidant enzymes, suppressed excessive generation of reactive oxygen species (ROS), and reduced cell apoptosis both in vitro and vivo experiments. In the mice model of TBI, Au markedly attenuated brain edema, histological damages, and improved neurological and cognitive deficits. Au significantly suppressed high mobility group box 1 (HMGB1)-mediated aseptic inflammation. Nrf2 knockdown in TBI mice blunted the antioxidant and anti-inflammatory neuroprotective effects of the Au.

Conclusions

Taken together, our data suggest that Au provides a neuroprotective effect in TBI mice model by inhibiting oxidative stress and inflammatory responses; the mechanisms involve triggering Nrf2-induced antioxidant system.

Extranodal natural killer/T cell lymphoma with involvement of the bilateral submandibular lymph node mimicking a rhinoscleroma: a diagnostic challenge

Extranodal natural killer/T-cell lymphoma, nasal type (ENKL) is a rare and aggressive tumor that can mimic inflammatory conditions and other tumors, and present a diagnostic challenge. We report a 57-year-old Chinese man previously misdiagnosed with rhinoscleroma. The patient had undergone multiple biopsies when the histopathological diagnosis of ENKL was made. Because the diagnosis may be obscured by extensive necrosis, multiple biopsies are necessary to make a certain diagnosis. According to the diagnosis process of this patient, the need to consider a neoplastic cause should be highlighted when faced with an aggressive nasal disease not responsive to maximal treatment.

MiR-146a Ameliorates Hemoglobin-Induced Microglial Inflammatory Response via TLR4/IRAK1/TRAF6 Associated Pathways

Microglial activation and sustained inflammation in the brain can lead to neuronal damage. Hence, limiting microglial activation and brain inflammation is a good therapeutic strategy for inflammatory-associated central nervous disease. MiR-146a is a promising therapeutic microRNA, since it can negatively regulate the inflammatory response. We thus investigated the expression changes of miR-146a after experimental induction of a subarachnoid hemorrhage (SAH) in vivo and in vitro, and we assessed the anti-inflammatory effects of miR-146a in microglial cells in vitro. Primary microglial cells were preincubated with miR-146a before hemoglobin (Hb) treatment. The results indicated that miR-146a decreased gene expression of Hb-induced pro-inflammatory cytokines (TNF-α and IL-1β) and phenotype-related genes (iNOS and CD86) through IRAK1/TRAF6/NF-κB or MAPK signaling pathways, suggesting its pro-resolution activity in microglia. However, contrary to the LPS-induced microglia or macrophage activation model, we did not observe an elevation in miR-146a after activation. Overall, our findings demonstrated that miR-146a was involved in the regulation of brain inflammation and could be considered a novel therapeutic agent for treating brain inflammation.

Meta-analysis: Supplementary artificial light and goose reproduction

Photoperiod affects poultry reproduction, and in birds, photoperiod regulation is a complex physiological process. In modern poultry production, lighting management has become an important and effective management approach for increasing egg production. Geese are domesticated fowl and in many goose production enterprises animals are allowed to roam in outside pens during the day and are housed indoors at night, so the animals can be exposed to artificial lighting during the night periods. Supplementary artificial lighting resulted in improved reproduction in some studies, but reports have been inconsistent. To evaluate the results from previous studies of supplementary lighting on goose egg production, a meta-analysis was conducted to determine optimal supplementary artificial lighting regimens for geese egg production. Results indicated supplementary artificial light increases mean egg production, the length of the period of egg production before there is cessation of egg production capacity, and fertility. In summary, there were evaluations of data from five studies focused on White Roman geese in the meta-analysis conducted in the present study, however, examination of more breeds is necessary to make more definitive assessments of the findings from this meta-analysis.

DHEA Attenuates Microglial Activation via Induction of JMJD3 in Experimental Subarachnoid Haemorrhage

Background

Microglia are resident immune cells in the central nervous system and central to the innate immune system. Excessive activation of microglia after subarachnoid haemorrhage (SAH) contributes greatly to early brain injury, which is responsible for poor outcomes. Dehydroepiandrosterone (DHEA), a steroid hormone enriched in the brain, has recently been found to regulate microglial activation. The purpose of this study was to address the role of DHEA in SAH.

Methods

We used in vivo models of endovascular perforation and in vitro models of haemoglobin exposure to illustrate the effects of DHEA on microglia in SAH.

Results

In experimental SAH mice, exogenous DHEA administration increased DHEA levels in the brain and modulated microglial activation. Ameliorated neuronal damage and improved neurological outcomes were also observed in the SAH mice pretreated with DHEA, suggesting neuronal protective effects of DHEA. In cultured microglia, DHEA elevated the mRNA and protein levels of Jumonji d3 (JMJD3, histone 3 demethylase) after haemoglobin exposure, downregulated the H3K27me3 level, and inhibited the transcription of proinflammatory genes. The devastating proinflammatory microglia-mediated effects on primary neurons were also attenuated by DHEA; however, specific inhibition of JMJD3 abolished the protective effects of DHEA. We next verified that DHEA-induced JMJD3 expression, at least in part, through the tropomyosin-related kinase A (TrkA)/Akt signalling pathway.

Conclusions

DHEA has a neuroprotective effect after SAH. Moreover, DHEA increases microglial JMJD3 expression to regulate proinflammatory/anti-inflammatory microglial activation after haemoglobin exposure, thereby suppressing inflammation.

Effects of dietary Enteromorpha powder supplementation on productive performance, egg quality, and antioxidant performance during the late laying period in Zi geese

This study investigated the effects of dietary Enteromorpha powder supplementation on the productive performance, egg quality, and antioxidant performance of Zi geese during the late laying period. Three hundred twelve Zi geese (1 yr old) were randomly allocated into 2 cohorts to form a control group and an experimental group (with each cohort including 6 replicates and 21 female geese and 5 male geese in each replicate). The control group was fed a basal diet, and the experimental group was fed a diet containing 3% Enteromorpha powder. The data showed that Enteromorpha powder supplementation significantly improved egg production, laying rate, average daily egg weight (P < 0.01), and egg yolk color (P < 0.05). Supplementation decreased the ADFI and feed conversion rate (P < 0.01). Compared with the control group, glutathione peroxidase (GSH-Px) activity was significantly higher in serum and ovary tissue (P < 0.05), but GSH-Px activity was lower in liver tissue (P < 0.01). Malondialdehyde was reduced in liver and ovary tissue (P < 0.05) in the Enteromorpha powder supplementation group. Meanwhile, the expression of the CAT gene was significantly upregulated in the liver (P < 0.01) in the Enteromorpha group. These results indicate that dietary Enteromorpha powder supplementation improved productive performance and reduced the level of lipid peroxidation in Zi geese during the late laying period.

Curcumin Mitigates Neuro-Inflammation by Modulating Microglia Polarization Through Inhibiting TLR4 Axis Signaling Pathway Following Experimental Subarachnoid Hemorrhage

Subarachnoid hemorrhage (SAH) elicits destruction of neuronal cells and neurological function, which is exacerbated by neuro-inflammation in EBI, and toll-like receptor 4 (TLR4) plays an important role in inflammatory cascade via modulation microglia polarization. Curcumin (Cur), as a natural phytochemical compound, has the potential characteristics on anti-inflammatory and microglia phenotype transformation. In this study, we verified the hypothesis curcumin promotes M2 polarization to inhibiting neuro-inflammation, which through suppressing TLR4 signaling pathway after SAH. In tlr4^–/– mice and wild type (WT) subjected to prechiasmatic cistern blood injection, Western blotting, brain water content, neurological score, enzyme-linked immunosorbent assay (ELISA) and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining were performed to investigate the role of TLR4 on neuro-inflammation response and microglia polarization. Curcumin with three different concentrations (50 mg/kg, 100 mg/kg and 200 mg/kg) were injected intraperitoneally (i.p.) at 15 min after SAH. The levels of TLR4, myeloid differentiation factor 88 (MyD88), nuclear factor- κB (NF-κB), Iba-1, CD86, CD206 and pro/anti-inflammation cytokines were measured by Western blotting and immunofluorescence staining at 24 h after SAH. SAH induction increased the protein levels of TLR4, pro-inflammation cytokines and proportion of M1 phenotype. Curcumin with 100 mg/kg treatment dramatically inhibited the release of pro-inflammatory mediators, and elevated the protein levels of anti-inflammatory cytokines and promoted microglia switch to M2. Meanwhile, curcumin treatment also decreased the expressions of TLR4, Myd88 and NF-κB at 24 h post SAH. TLR4 deficiency ameliorated brain water content, neurological deficit and reduced pro-inflammation cytokines after SAH. Moreover, curcumin treatment in tlr4^–/– mice further induced M2 polarization, while had no statistic difference on brain water content and neurological score at 24 h post SAH. Our results indicated that curcumin treatment alleviated neuro-inflammation response through promoting microglia phenotype shift toward M2, and which might inhibiting TLR4/MyD88/NF-κB signaling pathway after SAH.

Inhibition of Elevated Hippocampal CD24 Reduces Neurogenesis in Mice With Traumatic Brain Injury

In the adult rodents' brain, CD24 expression is restricted to immature neurons located in the neurogenesis areas. Our previous studies have confirmed that CD24 expression could be markedly elevated in the cerebral cortex after traumatic brain injury (TBI) both in humans and in mice. Although there is a close relationship between CD24 and neurogenesis, it remains unknown about the specific role of CD24 in neurogenesis areas after TBI. Here, the expression of CD24 was detected in the ipsilateral hippocampus by the Western blotting and real-time quantitative polymerase chain reaction. RNA interference was applied to investigate the effects of CD24 on post-traumatic neurogenesis. Brain sections were labeled with CD24 and doublecortin (DCX) via immunofluorescence. The Morris water maze test was used to assess cognitive functions. The results indicated that both mRNA and protein levels of CD24 were markedly elevated in the hippocampus after TBI. Meanwhile, TBI could cause a decrease of DCX-positive cells in the dentate gyrus of the hippocampus. Downregulation of CD24 significantly inhibited the phosphorylation of Src homology region 2-containing protein tyrosine phosphatase 2 in the ipsilateral hippocampus. Meanwhile, inhibition of CD24 could reduce the number of DCX-positive cells in the dentate gyrus area and impair cognitive functions of the TBI mice. These data suggested that hippocampal expression of CD24 might positively regulate neurogenesis and improve cognitive functions after TBI.

[Investigation and analysis of protein and energy intake in adult patients with severe burns]

Objective: To investigate and analyze the actual intake of protein and energy in adult patients with severe burns during post burn days (PBDs) 3 to 14. Methods: Records of 52 adult patients with severe burns [37 males and 15 females, (37±9) years old], admitted to the Department of Plastic Surgery and Burns of Tianjin First Central Hospital from January 1st 2011 to December 31st 2017 and meeting the study inclusion criteria, were retrospectively analyzed. Nutrition intake from routes of oral diet, enteral nutrition preparations, and parenteral nutrition preparations of patients during PBDs 3 to 14 were obtained from critical care records. During PBDs 3 to 7 and PBDs 8 to 14, the personal daily total energy intake and the ratio of it to energy target of patients were calculated and compared; the personal daily intake of carbohydrate, fat, and protein and calorigenic percentages of carbohydrate, fat, and protein accounted for total energy intake, and the ratios of non-protein calories to total nitrogen of patients were calculated and compared; the personal daily energy and protein intake of patients from routes of oral diet, enteral nutrition preparations, and parenteral nutrition preparations were analyzed; the percentages of energy intake from routes of oral diet, enteral nutrition preparations, and parenteral nutrition preparations accounted for total energy intake, and the percentages of protein intake from routes of oral diet, enteral nutrition preparations, and parenteral nutrition preparations accounted for total protein intake of patients were calculated. Vomiting and diarrhea of patients during PBDs 3 to 7 and PBDs 8 to 14 were recorded. Levels of serum albumin, prealbumin, blood glucose, and triglycerides, 24-hour excretion of urinary nitrogen, nitrogen balance values of patients on PBDs 7 and 14 were recorded or calculated. Data were processed with paired t test and chi-square test. Results: (1) The personal daily total energy intake of patients during PBDs 3 to 7 and PBDs 8 to 14 were (8 696±573) and (11 980±1 259) kJ respectively, and ratios of them to energy target [(13 290±1 561) kJ] were 65.4% and 90.1% respectively. The personal daily total energy intake of patients during PBDs 3 to 7 was obviously lower than that during PBDs 8 to 14 (t=18.172, P<0.01). (2) The personal daily intake of carbohydrate, fat, and protein of patients during PBDs 8 to 14 were obviously higher than those during PBDs 3 to 7 (t=15.628, 22.231, 10.403, P<0.01). The personal daily calorigenic percentages of carbohydrate, fat, and protein accounted for total energy intake of patients were 56.8%, 25.1%, and 18.3% respectively during PBDs 3 to 7 and 54.2%, 27.0%, and 18.7% respectively during PBDs 8 to 14. The calorigenic constituent ratio of personal daily intake of carbohydrate, fat, and protein accounted for total energy intake of patients during PBDs 3 to 7 was close to that during PBDs 8 to 14 (χ(2)=0.185, P>0.05). The ratios of non-protein calories to total nitrogen (kJ∶g) of patients during PBDs 3 to 7 and PBDs 8 to 14 were 469∶ 1 and 456∶ 1 respectively. (3) The personal daily energy intake of patients from routes of oral diet and parenteral nutrition preparations during PBDs 8 to 14 [(4 394±978), (5 723±898) kJ] were obviously higher than those during PBDs 3 to 7 [(2 137±453), (4 855±825) kJ, t=26.516, 6.583, P<0.01], while the personal daily energy intake of patients from routes of enteral nutrition preparations during PBDs 8 to 14 was close to that during PBDs 3 to 7 (t=1.922, P>0.05). The constituent ratio of personal daily energy during PBDs 3 to 7 was close to that during PBDs 8 to 14 (χ(2)=4.100, P>0.05). The personal daily protein intake of patients from route of oral diet during PBDs 8 to 14 was (58±22) g, obviously higher than (25±6) g during PBDs 3 to 7 (t=14.514, P<0.01). The personal daily protein intake of patients from routes of enteral nutrition preparations and parenteral nutrition preparations during PBDs 8 to 14 was close to those during PBDs 3 to 7 (t=1.924, 1.110, P>0.05). The constituent ratio of personal daily protein intake from routes of oral diet, enteral nutrition preparations, and parenteral nutrition preparations accounted for total protein intake during PBDs 8 to 14 was close to that during PBDs 3 to 7 (χ(2)=5.634, P>0.05). (4) There were 3 patients with vomiting and 4 patients with diarrhea during PBDs 3 to 7, and 1 patient experienced both of them during PBDs 8 to 14. The levels of serum albumin, prealbumin, blood glucose, and triglycerides, 24-hour excretion of urinary nitrogen, and nitrogen balance values of patients on PBDs 7 and 14 were (29±4) and (30±4) g/L, (132±42) and (171±48) mg/L, (7.4±2.8) and (6.7±2.8) mmol/L, (1.5±0.7) and (1.4±0.7) mmol/L, (30.5±4.3) and (34.5±2.2) g, -(25.1±2.6) and -(23.7±3.9) g, respectively. Conclusions: The personal daily total energy intake of patients during PBDs 3 to 7 was lower than that during PBDs 8 to 14. The calorigenic constituent ratio of personal daily intake of carbohydrate, fat, and protein accounted for total energy of patients during PBDs 3 to 7 was close to that during PBDs 8 to 14. Energy and protein intake were mostly derived from parenteral nutrition preparations during PBDs 3 to 7, while those during PBDs 8 to 14 were mainly derived from parenteral nutrition preparations and oral diet.

Peroxiredoxin 2 activates microglia by interacting with Toll-like receptor 4 after subarachnoid hemorrhage

BACKGROUND

Peroxiredoxin (Prx) protein family have been reported as important damage-associated molecular patterns (DAMPs) in ischemic stroke. Since peroxiredoxin 2 (Prx2) is the third most abundant protein in erythrocytes and the second most protein in the cerebrospinal fluid in traumatic brain injury and subarachnoid hemorrhage (SAH) patients, we assessed the role of extracellular Prx2 in the context of SAH.

METHODS

We introduced a co-culture system of primary neurons and microglia. Prx2 was added to culture medium with oxyhemoglobin (OxyHb) to mimic SAH in vitro. Neuronal cell viability was assessed by lactate dehydrogenase (LDH) assay, and neuronal apoptosis was determined by TUNEL staining. Inflammatory factors in culture medium were measured by ELISA, and their mRNA levels in microglia were determined by qPCR. Toll-like receptor 4 knockout (TLR4-KO) mice were used to provide TLR4-KO microglia; ST-2825 was used to inhibit MyD88, and pyrrolidine dithiocarbamate (PDTC) was used to inhibit NF-κB. Related cellular signals were analyzed by Western blot. Furthermore, we detected the level of Prx2 in aneurysmal SAH patients' cerebrospinal fluids (CSF) and compared its relationship with Hunt-Hess grades.

RESULTS

Prx2 interacted with TLR4 on microglia after SAH and then activated microglia through TLR4/MyD88/NF-κB signaling pathway. Pro-inflammatory factors were expressed and released, eventually caused neuronal apoptosis. The levels of Prx2 in SAH patients positively correlated with Hunt-Hess grades.

CONCLUSIONS

Extracellular Prx2 in CSF after SAH is a DAMP which resulted in microglial activation via TLR4/MyD88/NF-κB pathway and then neuronal apoptosis. Prx2 in patients' CSF may be a potential indicator of brain injury and prognosis.

Association between the pre-miR-196a2 rs11614913 polymorphism and gastric cancer susceptibility in a Chinese population

We did a case-control study to provide a more comprehensive evaluation of the association of the pre-miR-196a2 rs11614913 polymorphism with gastric cancer. Between January 2013 and December 2014, 182 patients newly diagnosed with primary gastric cancer and 182 control subjects were recruited at Zhengzhou People's Hospital. For SNP genotyping, we used the Assay Designer 3.1 to design the primers of polymerase chain reaction. Using the chi-square test, we found that patients with gastric cancer were more likely to be alcohol drinkers (χ(2) = 4.4, P = 0.04), to have a family history of cancer in the first relatives (χ(2) = 5.29, P = 0.02), and to be infected with Helicobacter pylori (χ(2) = 23.39, P < 0.001). A significant difference in the genotype distributions of rs11614913 was observed in our study (χ(2) = 6.66, P = 0.04). By logistic regression analysis, we found that the CC genotype of rs11614913 was associated with an increased risk of gastric cancer in a codominant model (OR = 2.68, 95%CI = 1.17-6.44). By stratification analysis, we found that the CC genotype was associated with a strongly increased risk of gastric cancer in drinkers when compared with the TT+TC genotype (OR = 5.63, 95%CI = 1.54-30.76). In conclusion, the results of our study suggest an association between the rs11614913 gene polymorphism and an elevated risk of gastric cancer, especially in drinkers.

Association between ERCC5 gene polymorphisms and gastric cancer risk in a Chinese population

We conducted a hospital-based case-control study to investigate the association between 3 common SNPs in the ERCC5 gene (rs1047768, rs751402, and rs17655) and the risk of developing gastric cancer. Between January 2013 and December 2014, samples were collected from 216 gastric cancer patients and 216 control subjects. ERCC5 rs1047768, rs751402, and rs17655 polymorphisms were genotyped by polymerase chain reaction combined with restriction fragment length polymorphism analysis. By conditional logistic regression analysis, the GG genotype of rs17655 was found to be associated with an elevated risk of gastric cancer in a codominant model, and the adjusted OR (95%CI) was 1.96 (1.10-3.50). Moreover, in a dominant model, the CG + GG genotype of rs17655 was correlated with an increased risk of gastric cancer compared to the CC genotype (OR = 1.48; 95%CI = 1.00-2.22). rs1047768 and rs751402 were not significantly correlated with an increased or decreased gastric cancer risk.

Identification of a novel HLA-B*40 allele, HLA-B*40:324, by sequence-based typing, in a Chinese individual

The new allele, HLA-B*40:324 differs from B*40:63 by two nucleotide changes in exon 3.

Cloning and expression pattern analysis of BkGRAS2 from Betula kirghisorum

GRAS proteins are plant-specific transcription factors that are involved in the regulation of root and shoot growth. Here, we cloned BkGRAS2 from Betula kirghisorum (abbreviated to Bk) and analyzed the physicochemical properties and expression pattern of the encoded protein. BkGRAS2 had an open reading frame of 1614 bp encoding 537 amino acid residues. The deduced BkGRAS2 protein was hydrophilic, and it contained highly conserved VHIID and SAW motifs. BkGRAS1 and BkGRAS2 showed considerable sequence similarities. An expression analysis indicated that BkGRAS2 was expressed in root, stem, and leaf, with the highest level in the leaf. Expression of BkGRAS2 was increased following stress treatment with 0.6% NaHCO3. Transient expression analysis of GFP-BkGRAS2 in onion epidermal cells revealed that the BkGRAS2 protein was localized in the cytoplasm, but could also be detected in the nucleus. Our study provides the basis for future research on the role of the GRAS gene family in B. kirghisorum.

Protective immunity of rAd5/NR2B vaccine against concomitant aversiveness of spontaneous neuropathic pain following spinal nerve ligation injury

OBJECTIVE

Peripheral nerve injury elicits an aversive state of spontaneous neuropathic pain, and up to now, the modulation of this concomitant aversive state remains a major therapeutic challenge. NMDA receptor subunits NR2B in the rACC are critically involved in the processing of this aversive state and then a strategy targeted at the NR2B subunit might be promising for modulation of the aversive state. Thus, in the present study, using negative reinforcement animal model to reveal spontaneous pain, we investigated the effect of oral immunization with recombinant adenovirus serotype 5-mediated NR2B gene transfer (rAd5/NR2B) on the modulation of the tonic pain.

MATERIAL AND METHODS

Following oral administration of the rAd5/NR2B vaccine, NR2B-specific antibodies were induced in serum. And the humoral response was involved in the decreased expression of NR2B protein in the rACC.

RESULTS

The present study demonstrated that CPP achieved by spinal administration of clonidine in spinal nerve ligation (SNL) rats revealed the presence of aversive state of spontaneous neuropathic pain. Notably, the humoral autoimmune response blocked the CPP by spinal clonidine, suggesting the relief of the concomitant aversive of spontaneous neuropathic pain in the SNL rats.

CONCLUSION

These data proved the feasibility of oral immunization with rAd5/NR2B for modulation of concomitant aversive of spontaneous neuropathic pain due to peripheral nerve injury.

Effect of hydrogen sulfide on inflammatory cytokines in acute myocardial ischemia injury in rats

Hydrogen sulfide (H₂S) is believed to be involved in numerous physiological and pathophysiological processes, and now it is recognized as the third endogenous signaling gasotransmitter, following nitric oxide and carbon monoxide; however, the effects of H₂S on inflammatory factors in acute myocardial ischemia injury in rats have not been clarified. In the present study, sodium hydrosulfide (NaHS) was used as the H₂S donor. Thirty-six male Sprague Dawley rats were randomly divided into five groups: Sham, ischemia, ischemia + low-dose (0.78 mg/kg) NaHS, ischemia + medium-dose (1.56 mg/kg) NaHS, ischemia + high-dose (3.12 mg/kg) NaHS and ischemia + propargylglycine (PPG) (30 mg/kg). The rats in each group were sacrificed 6 h after the surgery for sample collection. Compared with the ischemia group, the cardiac damage in the rats in the ischemia + NaHS groups was significantly reduced, particularly in the high-dose group; in the ischemia + PPG group, the myocardial injury was aggravated compared with that in the ischemia group. Compared with the ischemia group, the levels of interleukin (IL)-1β, IL-6 and tumor necrosis factor-α (TNF-α) in the serum of rats in the ischemia + medium- and high-dose NaHS groups were significantly reduced, and the expression of intercellular adhesion molecule-1 (ICAM-1) mRNA and nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) protein in the myocardial tissues of rats was significantly reduced. In the ischemia + PPG group, the TNF-α, IL-1β and IL-6 levels in the serum were significantly increased, the expression of ICAM-1 mRNA was increased, although without a significant difference, and the expression of NF-κB was increased. The findings of the present study provide novel evidence for the dual effects of H₂S on acute myocardial ischemia injury via the modulation of inflammatory factors.

Propofol pretreatment attenuates lipopolysaccharide-induced acute lung injury in rats by activating the phosphoinositide-3-kinase/Akt pathway

The aim of this study was to investigate the effect of propofol pretreatment on lipopolysaccharide (LPS)-induced acute lung injury (ALI) and the role of the phosphoinositide-3-kinase/protein kinase B (PI3K/Akt) pathway in this procedure. Survival was determined 48 h after LPS injection. At 1 h after LPS challenge, the lung wet- to dry-weight ratio was examined, and concentrations of protein, tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) in bronchoalveolar lavage fluid (BALF) were determined using the bicinchoninic acid method or ELISA. Lung injury was assayed via lung histological examination. PI3K and p-Akt expression levels in the lung tissue were determined by Western blotting. Propofol pretreatment prolonged survival, decreased the concentrations of protein, TNF-α, and IL-6 in BALF, attenuated ALI, and increased PI3K and p-Akt expression in the lung tissue of LPS-challenged rats, whereas treatment with wortmannin, a PI3K/Akt pathway specific inhibitor, blunted this effect. Our study indicates that propofol pretreatment attenuated LPS-induced ALI, partly by activation of the PI3K/Akt pathway.

Expression analysis of miRNA and target mRNAs in esophageal cancer

We aimed to investigate miRNAs and related mRNAs through a network-based approach in order to learn the crucial role that they play in the biological processes of esophageal cancer. Esophageal squamous-cell carcinoma (ESCC) and adenocarcinoma (EAC)-related miRNA and gene expression data were downloaded from the Gene Expression Omnibus database, and differentially expressed miRNAs and genes were selected. Target genes of differentially expressed miRNAs were predicted and their regulatory networks were constructed. Differentially expressed miRNA analysis selected four miRNAs associated with EAC and ESCC, among which hsa-miR-21 and hsa-miR-202 were shared by both diseases. hsa-miR-202 was reported for the first time to be associated with esophageal cancer in the present study. Differentially expressed miRNA target genes were mainly involved in cancer-related and signal-transduction pathways. Functional categories of these target genes were related to transcriptional regulation. The results may indicate potential target miRNAs and genes for future investigations of esophageal cancer.

In vitro proliferation and differentiation of hepatic oval cells and their potential capacity for intrahepatic transplantation

Hepatic oval cells (HOCs) are recognized as facultative liver progenitor cells that play a role in liver regeneration after acute liver injury. Here, we investigated the in vitro proliferation and differentiation characteristics of HOCs in order to explore their potential capacity for intrahepatic transplantation. Clusters or scattered HOCs were detected in the portal area and interlobular bile duct in the liver of rats subjected to the modified 2-acetylaminofluorene and partial hepatectomy method. Isolated HOCs were positive for c-kit and CD90 staining (99.8% and 88.8%, respectively), and negative for CD34 staining (3.6%) as shown by immunostaining and flow cytometric analysis. In addition, HOCs could be differentiated into hepatocytes and bile duct epithelial cells after leukemia inhibitory factor deprivation. A two-cuff technique was used for orthotopic liver transplantation, and HOCs were subsequently transplanted into recipients. Biochemical indicators of liver function were assessed 4 weeks after transplantation. HOC transplantation significantly prolonged the median survival time and improved the liver function of rats receiving HOCs compared to controls (P=0.003, Student t-test). Administration of HOCs to rats also receiving liver transplantation significantly reduced acute allograft rejection compared to control liver transplant rats 3 weeks following transplantation (rejection activity index score: control=6.3±0.9; HOC=3.5±1.5; P=0.005). These results indicate that HOCs may be useful in therapeutic liver regeneration after orthotopic liver transplantation.

Analysis of uncertainty in equilibrium reconstruction in the EAST superconducting tokamak

The analysis of uncertainties of magnetic measurements in equilibrium reconstruction is carried out on the EAST (Experimental Advanced Superconducting Tokamak) tokamak. It is shown that uncertainties of magnetic diagnostics are about 0.2% and 10 mWb for flux loops and 0.6% and 20 G for magnetic probes. Analyzing the sensitivity of the magnetic data uncertainty in the plasma shape reconstruction is presented, based on EFIT fixed boundary and fitting mode and applying overall uncertainty as fitting weight in EFIT. It is found that reconstruction uncertainties are ranged in 0.5-1.4 cm for 6 control segments, less than 0.8 cm for X-points, and 1.0-1.6 cm for strike points with 95% confidence, in the last experimental campaign on the EAST tokamak.

Huperzine A for Alzheimer's disease

BACKGROUND

Alzheimer's disease (AD) has become a major public health problem around the world due to its increasing prevalence, long duration, caregiver burden, and high financial cost of care. The degeneration of acetylcholine-containing neurons in the basal forebrain has been implicated in the symptoms of AD. Cholinesterase inhibitors may block the degradation of acetylcholine, thus increasing the efficacy of the remaining cholinergic neurons. Huperzine A is a linearly competitive, reversible inhibitor of acetyl cholinesterase that is said to have both central and peripheral activity with the ability to protect cells against hydrogen peroxide, beta-amyloid protein (or peptide), glutamate, ischemia and staurosporine-induced cytotoxicity and apoptosis. These properties might qualify Huperzine A as a promising agent for treating dementia (including AD).

OBJECTIVES

To assess the efficacy and safety of Huperzine A for the treatment of patients with AD.

SEARCH STRATEGY

The Specialized Register of the Cochrane Dementia and Cognitive Improvement Group was searched on 1 February 2006 using the search term: huperzin*. The CDCIG Specialized register contains records from all major health care databases (MEDLINE, EMBASE, PsycINFO, CINAHL, SIGLE, ISTP, INSIDE, LILACS) as well as from many trials databases and grey literature sources. In addition, the CBM and AMED databases and relevant websites were searched and some journals were hand-searched. Specialists in the field were approached for unpublished material and any publications found were searched for additional references.

SELECTION CRITERIA

All relevant randomized controlled trials (RCTs) studying the efficacy and safety of Huperzine A for AD.

DATA COLLECTION AND ANALYSIS

Data were extracted independently by two reviewers using a self-developed data extraction form and entered into RevMan 4.2.10 software. Meta-analyses were performed when more than one trial provided data on a comparable outcome on sufficiently similar patients. Random effects analyses were performed whenever heterogeneity between results appeared to be present. Standardized differences in mean outcome measures were used due to the use of different scales and periods of treatment.

MAIN RESULTS

Six trials including a total of 454 patients met our inclusion criteria. The methodological quality of most included trials was not high. It was shown that compared to placebo, Huperzine A had beneficial effects on the improvement of general cognitive function measured by MMSE (WMD 2.81; 95% CI 1.87 to 3.76; P < 0.00001) and ADAS-Cog at six weeks (WMD 1.91; 95% CI 1.27 to 2.55) and at 12 weeks (WMD 2.51; 95% CI 1.74 to 3.28), global clinical assessment measured by CDR (WMD -0.80; 95% CI -0.95 to -0.65) and CIBIC-plus (OR 4.32, 95% CI 2.37 to 7.90), behavioral disturbance measured by ADAS-non-Cog at six weeks (WMD -1.33, 95%CI -2.12 to -0.54) and at 12 weeks (WMD -1.52, 95% CI-2.39 to -0.65), and functional performance measured by ADL (WMD = -7.17; 95% CI -9.13 to -5.22; P < 0.00001). However, Huperzine A was not superior to placebo in the improvement of general cognitive function measured by Hasegawa Dementia Scale (HDS) (WMD: 2.78; 95% CI -0.17 to 5.73, P = 0.06) and specific cognitive function measured by Weshler Memory Scale (WMS) (WMD = 6.64; 95% CI -3.22 to 16.50; P = 0.19). No data were available on quality of life and caregiver burden. The adverse events of Huperzine A were mild and there were no significant differences of adverse events between Huperzine A groups and control groups.

AUTHORS' CONCLUSIONS

From the available evidence, Huperzine A seems to have some beneficial effects on improvement of general cognitive function, global clinical status, behavioral disturbance and functional performance, with no obvious serious adverse events for patients with AD. However, only one study was of adequate quality and size. There is therefore inadequate evidence to make any recommendation about its use. Rigorous design, randomized, multi-centre, large-sample trials of Huperzine A for AD are needed to further assess the effects.

Chinese medicinal herbs for influenza

BACKGROUND

Influenza is an acute respiratory communicable disease which, during epidemics, can cause high morbidity and mortality. Traditional Chinese medicinal herbs, often administered following a particular theory, may be a potential medicine of choice.

OBJECTIVES

To assess the effect of Chinese medicinal herbs in preventing and treating influenza, and to estimate the frequency of adverse effects.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 1, 2007), which includes the Cochrane Acute Respiratory Infections Review Group specialised register; MEDLINE (January 1966 to January 2007); EMBASE (January 1988 to January 2007); CBM (Chinese Biomedical Database) (January 1980 to January 2007); and the Chinese Cochrane Center's Controlled Trials Register (up to January 2007). We also searched Current Controlled Trials (www.controlled-trials.com) and the National Research Register (http://www.update-software.com/National/) for ongoing trials and reference lists of articles. For more information we telephoned and wrote to researchers in the field, as well as trial authors of studies evaluated in the review

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing traditional Chinese medicinal herbs with placebo, no treatment, or chemical drugs normally used in preventing and treating uncomplicated influenza patients.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed trial quality.

MAIN RESULTS

Two studies involving 1012 participants were reviewed. The methodological quality of both studies was 'poor'. Included RCTs separately compared two medicinal herbs with two different antiviral drugs, precluding any pooling of results. 'Ganmao' capsules were found to be more effective than amantadine in decreasing influenza symptoms and speeding recovery in one study, (in which adverse reactions were mentioned in the amantadine group although no data were reported). There were no significant differences between 'E Shu You' and ribavirin in treating influenza, nor in the occurrence of adverse reaction.

AUTHORS' CONCLUSIONS

The present evidence is too weak to support or reject the use of Chinese medicinal herbs for preventing and treating influenza. More RCTs with good methodological quality, larger numbers of participants and clear reporting are needed in the future. We recommend that all the clinical trials registered in the Chinese Clinical Trial Register and Chinese journals join in the Joint Statement of Establishing Chinese Clinical Trial Registration and Publishing System.

Contractility of retinal pericytes grown on silicone elastomer substrates is through a protein kinase A-mediated intracellular pathway in response to vasoactive peptides

The normal function of retinal capillaries to distribute blood within the retina depends on appropriate contractility of retinal pericytes, which is thought to be modulated by agents that alter intracellular cyclic adenosine-3'-monophosphate (cAMP) levels. We examined the hypothesis that the vasoactive peptides Vasoactive Intestinal Peptide (VIP) and Pituitary Adenylate Cyclase Activating Peptide (PACAP) reduce pericyte contractility via a protein kinase A (PKA)-mediated intracellular pathway that utilises cAMP. We utilised a single-call assay of contractility that is based on visualising the contractile force exerted by the pericytes on a silicone elastomer substrate and quantified, as a contractility index, from the number and length of wrinkles induced in the silicone elastomer by the pericytes. Pericytes were cultured from the retinas of freshly killed abattoir cattle, and identified in culture using immunohistochemical techniques. The pericytes contracted in response to norepinephrine (EC(50)=8 microM) and relaxed in response to both VIP (EC(50)=48 nM) and PACAP (EC(50)=3 nM). The relaxation induced by PACAP was inhibited by Rp-cAMPS (EC(50)=26 microM), which is an agent that inhibits cAMP binding at PKA. We confirmed the activation of PKA by PACAP in experiments where H89 also inhibited the PACAP-induced relaxation. U71322, which inhibits phospholipase C-linked events, was also able to inhibit the PACAP-induced pericyte relaxation. Our results support the hypothesis that PACAP leads to the relaxation of pericytes via a PKA-mediated intracellular pathway and a phospholipase C-mediated pathway, which probably relies on hyperpolarisation because of activation of Ca(2+)-dependent potassium channels. This single-cell assay has proved useful as the basis for the development of a diagnostic procedure for diabetic retinopathy, which is an eye disease caused by abnormal regulation of blood flow in the retinal capillaries.

Bicyclol for chronic hepatitis C

BACKGROUND

Bicyclol is a novel synthetic 'anti-hepatitis' drug, used in China for chronic hepatitis C. Until now, systematic reviews on bicyclol therapy have not been performed.

OBJECTIVES

To study the benefits and harms of bicyclol for patients with chronic hepatitis C.

SEARCH STRATEGY

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register (July 2005), the Cochrane Central Register of Controlled Trials in The Cochrane Library (Issue 2, 2005), MEDLINE (1994 to July 2005), EMBASE (1994 to July 2005), Science Citation Index Expanded (1994 to July 2005), The Chinese Biomedical Database (1994 to August 2005), Chinese Journals Full-article Database (1994 to August 2005), VIP Chinese Science and Technique Journals Database (1994 to August 2005), and China National Infrastructure (CNKI) (1994 to August 2005). We also contacted manufacturers and researchers in the field.

SELECTION CRITERIA

Randomised clinical trials on bicyclol versus no intervention, placebo, or other interventions in patients with chronic hepatitis C were included, irrespective of blinding, publication status, or language.

DATA COLLECTION AND ANALYSIS

The primary outcome measures were total and liver-related mortality and liver-related morbidity (eg, cirrhosis and carcinoma). Secondary outcome measures were viral response and liver histology.

MAIN RESULTS

The search identified one randomised clinical trial comparing bicyclol with placebo for 39 patients with chronic hepatitis C. The follow-up was three months. In the trial, there was no evidence that bicyclol was superior to placebo for clearance of HCV RNA (RR 3.80, 95% CI 0.47 to 31.0) and anti-HCV antibodies, but bicyclol was associated with statistically significant decrease in alanine aminotransferase activity at 12-th week after treatment (WMD -69 IU/L, 95% CI -115 to -24).

AUTHORS' CONCLUSIONS

Only one randomised clinical trial has examined bicyclol for patients with chronic hepatitis C. This small, short-term trial found no evidence to support or refute its use. Large, randomised, double-blind clinical trials with long-term follow-up are needed to examine the possible benefits and harms associated with bicyclol. Bicyclol can only be recommended for use in randomised trials.

Chinese medicinal herbs for the common cold

BACKGROUND

Chinese herbal medicines are frequently used to treat the common cold in China. Until now, their efficacy has not been systematically reviewed.

OBJECTIVES

To assess the effectiveness and safety of Chinese herbal medicines for the common cold.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 3, 2006) which contains the Acute Respiratory Infections Group's specialised register; MEDLINE (1966 to July 2006); EMBASE (1980 to March 2006); AMED (1985 to July 2006); and the Chinese Biomedical Database (CBM) (1975 to July 2005).

SELECTION CRITERIA

Randomised controlled trials (RCTs) studying the efficacy of Chinese herbal medicine(s) for the treatment of the common cold were included, irrespective of publication status or language.

DATA COLLECTION AND ANALYSIS

Four review authors telephoned original trial authors of the RCTs identified by our searches to verify the randomisation procedure. Two review authors extracted and analysed data from the trials which met the inclusion criteria.

MAIN RESULTS

Fourteen studies involving 2440 patients were included. The methods of all studies were rated of poor quality (category C). Included studies used "effective drugs" as controls; however, the efficacy of these control drugs was not reported. Different Chinese herbal preparations were tested in nearly all trials; in only one was a Chinese herbal preparation tested twice. In six studies, five herbal preparations were found to be more effective at enhancing recovery than the control; and in the other eight studies, five herbal preparations were shown to be equal to the control. There was a strong probability of different biases in all of the included studies.

AUTHORS' CONCLUSIONS

Chinese herbal medicines may shorten the symptomatic phase in patients with the common cold. However, the lack of high quality clinical trials means we are unable to recommend any kind of Chinese herbal preparation for the common cold.

Complementary DNA microarray analysis of chemokines and their receptors in allergic rhinitis

OBJECTIVE

To analyze the roles of chemokines and their receptors in the pathogenesis of allergic rhinitis by observing the complementary DNA (cDNA) expression of the chemokines and their receptors in the nasal mucosa of patients with and without allergic rhinitis, using gene chips.

METHODS

The total RNAs were isolated from the nasal mucosa of 20 allergic rhinitis patients and purified to messenger RNAs, and then reversely transcribed to cDNAs and incorporated with samples of fluorescence-labeled with Cy5-dUPT (rhinitis patient samples) or Cy3-dUTP (control samples of nonallergic nasal mucosa). Thirty-nine cDNAs of chemokines and their receptors were latticed into expression profile chips, which were hybridized with probes and then scanned with the computer to study gene expression according to the different fluorescence intensities.

RESULTS

The cDNAs of the following chemokines were upregulated: CCL1, CCL2, CCL5, CCL7, CCL8, CCL11, CCL13, CCL14, CCL17, CCL18, CCL19, CCL24, and CX3CL1 in most of the allergic rhinitis sample chips. CCR2, CCR3, CCR4, CCR5, CCR8 and CX3CR1 were the highly expressed receptor genes. Low expression of CXCL4 was found in these tissues.

CONCLUSION

The T helper cell (T(H)) immune system is not well regulated in allergic rhinitis. Most of the upregulated genes we identified are of chemokines and their receptors that play important roles in T(H)2 response, and some are involved in the induction of allergic reaction, accumulation of inflammatory cells, and degranulation of sensitized cells. These findings can point to new strategies for allergic rhinitis immunotherapy.

Rifampicin plus pyrazinamide versus isoniazid for treating latent tuberculosis infection: a meta-analysis

SETTING

Six trials from Haiti, Mexico, the U.S.A., Brazil, Spain, Zambia and Hong Kong.

OBJECTIVE

To evaluate the efficacy and safety of rifampicin plus pyrazinamide (RZ) vs. isoniazid (INH) for the prevention of tuberculosis (TB) among persons with or without human immunodeficiency virus (HIV) infection.

DESIGN

Meta-analysis of randomised controlled trials (RCTs) and quasi-RCTs that compared RZ for 2-3 months with INH for 6-12 months. Endpoints were development of active TB, severe adverse effects and death. Treatment effects were summarised as risk difference (RD) with 95% confidence intervals (CI).

RESULTS

Three trials conducted in HIV-infected patients and three trials conducted in non-HIV-infected persons were identified. The rates of TB in the RZ group were similar to those in the INH group, whether the subjects were HIV-infected or not (HIV-infected patients: pooled RD = 0%, 95% CI -1-2, P = 0.89; non-HIV-infected persons: pooled RD = 0%, 95% CI -2-1, P = 0.55). There was no difference in mortality between the two treatment groups (HIV-infected patients: pooled RD = -1%, 95% CI -4-2, P = 0.53; non-HIV-infected persons: pooled RD = 0%, 95% CI -1-1, P = 1.00). However, both subgroup analyses showed that a higher incidence of all severe adverse events was associated with 2RZ than INH among non-HIV-infected persons (RD = 29%, 95% CI 13-46, P = 0.0005 vs. RD = 7%, 95% CI 4-10, P < 0.0001).

CONCLUSION

RZ is equivalent to INH in terms of efficacy and mortality in the treatment of latent tuberculosis infection. However, this regimen increases the risk of severe adverse effects compared with INH in non-HIV-infected persons.

Short-term dynamic change of gill copper in common carp, Cyprinus carpio, evaluated by a sequential extraction

Dynamic changes in Cu speciation and its binding to fish gills were investigated by exposing common carp (Cyprinus carpio) to a 1 mg/1 Cu solution for 7 hours. Cu speciation in the bulk solution and fish gill microenvironment was calculated using general chemical equilibrium modeling. A sequential extraction procedure using distilled water, magnesium dichloride (1.0 mol/1), and acetic acid (10%) was used to characterize the Cu associated with the fish gills. Cu residual in the gill tissue was measured after the sequential extraction. Changes in total Cu concentration, pH, and dissolved organic carbon (Doc) in the bulk solution were recorded during the experimental period and calculated for the fish gill microenvironment. Cu-hydroxide species and Cu2 were dominant Cu species in both bulk solution and the fish gill microenvironment, whereas increased Cu-mucus was found in the fish gill microenvironment. DOC in the exposure medium, assumed to arise from mucus release, also increased and complexed Cu in solution. Forty-three percent of the Cu associated with the gills was readily water extractable, with an additional 22% exchangeable with Mg2+ or protons. Only 35% of the Cu accumulated within the gill tissues. The binding of Cu to the fish gills reached apparent equilibrium after 3 hours of exposure. Furthermore, the amount of water-extractable Cu within the gills showed significant correlation to the concentration of Cu predicted to be complexed with calculated free mucus in the gill microenvironment.

Chinese medicinal herbs for measles

BACKGROUND

Measles is an infectious disease caused by Morbillivirus. Chinese physicians believe that medicinal herbs are effective in alleviating symptoms and preventing complications. Chinese herbal medicines are dispensed according to the particular symptoms.

OBJECTIVES

To assess the effectiveness and possible adverse events of Chinese medicinal herbs in treating measles.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Clinical Trials (CENTRAL) (The Cochrane Library Issue 4, 2005); MEDLINE (1966 to June 2005); EMBASE (1980 to June 2005); the Chinese Biomedical Database (1976 to June 2005); VIP Information (1989 to June 2005); China National Knowledge Infrastructure (CNKI) (1994 to June 2005); and the metaRegister of Controlled Trials was searched for ongoing trials.

SELECTION CRITERIA

Randomised controlled trials (RCTs) in which patients with measles without complications were treated with Chinese medicinal herbs were included.

DATA COLLECTION AND ANALYSIS

The primary outcome measure was death from any cause. The secondary outcome measure was improvement of overall symptoms. The tertiary outcome measure was fever clearance time.

MAIN RESULTS

We identified 28 trials which claimed to use random allocation. Nineteen study authors were contacted by telephone and we discovered that the allocation methods they had used were not actually randomised. Three studies were excluded because the patients experienced complications. We were unable to contact the remaining six authors. These require further assessment and have been allocated to the 'Studies awaiting assessment' section.

AUTHORS' CONCLUSIONS

Two authors independently assessed trial quality and extracted data. We interviewed by telephone the study authors for missing information regarding random allocation of the study process. Some trials allocated the participants according to the sequence they were admitted to the trials, that is to say, by using a pseudo-random allocation method. None of the trials concealed the allocation or blinding method. We hope future randomised controlled trials (RCTs) in this field will be conducted.

Chinese medicinal herbs for influenza

BACKGROUND

Influenza is an acute respiratory communicable disease which can cause high morbidity and mortality in an epidemic. Traditional Chinese medicinal herbs following a particular theory may be a potential medicine of choice.

OBJECTIVES

The objective of this review was to assess the therapeutic effect and adverse reaction of Traditional Chinese medicinal herbs in treating uncomplicated influenza.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 3, 2004); MEDLINE (January 1966 to October 2004); EMBASE (January 1988 to October 2004); CBM (Chinese Biomedical Database) (January 1980 to December 2003); and the Chinese Cochrane Center's Controlled Trials Register (up to December 2003). We also searched Current Controlled Trials (www.controlled-trials.com) and the National Research Register (http://www.update-software.com/National/) for ongoing trials and reference lists of articles. We wrote to researchers in the field, or authors of studies evaluated in the review for more information.

SELECTION CRITERIA

Randomised and quasi-randomised trials comparing traditional Chinese medicinal herbs with placebo, or various other Chinese medicinal herbs, or with other current regimes normally used in care or comparing drugs with herbal preparations to simple drugs in treating defined uncomplicated influenza patients.

DATA COLLECTION AND ANALYSIS

At least two reviewers extracted data and assessed trial quality.

MAIN RESULTS

Eleven studies with the number of participants ranged from 52 to 479. In total 2,088 participants were included in the review. As the interventions of the included studies were different from each other and most of the studies were of low quality, we did not perform a summary meta-analysis. Some of the studies showed positive results favouring Traditional Chinese medicinal herb treatment compared to antiviral or antipyretic-analgesic drugs or the combination of them. Only three studies mentioned adverse reactions but no detailed data were acquired in the included studies. Eleven studies with the number of participants ranged from 52 to 479, 2,088 in total were included. As the interventions of the included studies were different from each other and most of the studies were of low quality, we failed to perform a summary meta-analysis. Some of the studies showed positive results favouring Traditional Chinese medicinal herb treatment compared to antiviral or antipyretic-analgesic drugs or the combination of them. Only three studies mentioned adverse reactions but no detailed data was acquired in the included studies.

AUTHORS' CONCLUSIONS

The small number of included studies and participants, as well as the low quality of most studies, made the evidence far from conclusive for clinical decision making, although traditional Chinese medicinal herbs as a whole seem to be comparatively or more effective compared to different chemical drugs. A certain herbal preparation could not be recommended for there was not enough evidence. More high quality randomised controlled trials (RCTs) with similar interventions are required to strengthen the evidence for the efficacy and safety of certain herbal preparation.

Iodised salt for preventing iodine deficiency disorders

BACKGROUND

Iodine deficiency is the main cause for potentially preventable mental retardation in childhood, as well as causing goitre and hypothyroidism in people of all ages. It is still prevalent in large parts of the world.

OBJECTIVES

To assess the effects of iodised salt in comparison with other forms of iodine supplementation or placebo in the prevention of iodine deficiency disorders.

SEARCH STRATEGY

We searched the Cochrane Library, Medline, the Register of Chinese trials developed by the Chinese Cochrane Centre, and the Chinese Med Database. We performed handsearching of a number of journals (Chinese Journal of Control of Endemic Diseases, Chinese Journal of Epidemiology, Chinese Journal of Preventive Medicine, and Studies of Trace Elements and Health up to February 2001), and searched reference lists, databases of ongoing trials and the Internet. Date of latest search: November 2001.

SELECTION CRITERIA

We included prospective controlled studies of iodised salt versus other forms of iodine supplementation or placebo in people living in areas of iodine deficiency. Studies reported mainly goitre rates and urinary iodine excretion as outcome measures.

DATA COLLECTION AND ANALYSIS

The initial data selection and quality assessment of trials was done independently by two reviewers. Subsequently, after the scope of the review was slightly widened from including only randomised controlled trials to including non-randomised prospective comparative studies, a third reviewer repeated the trials selection and quality assessment. As the studies identified were not sufficiently similar and not of sufficient quality, we did not do a meta-analysis but summarised the data in a narrative format.

MAIN RESULTS

We found six prospective controlled trials relating to our question. Four of these were described as randomised controlled trials, one was a prospective controlled trial that did not specify allocation to comparison groups, and one was a repeated cross-sectional study comparing different interventions. Comparison interventions included non-iodised salt, iodised water, iodised oil, and salt iodisation with potassium iodide versus potassium iodate. Numbers of participants in the trials ranged from 35 to 334; over 20,000 people were included in the cross-sectional study. Three studies were in children only, two investigated both groups of children and adults and one investigated pregnant women. There was a tendency towards goitre reduction with iodised salt, although this was not significant in all studies. There was also an improved iodine status in most studies (except in small children in one of the studies), although urinary iodine excretion did not always reach the levels recommended by the WHO. None of the studies observed any adverse effects of iodised salt.

REVIEWER'S CONCLUSIONS

The results suggest that iodised salt is an effective means of improving iodine status. No conclusions can be made about improvements in other, more patient-oriented outcomes, such as physical and mental development in children and mortality. None of the studies specifically investigated development of iodine-induced hyperthyroidism, which can be easily overlooked if just assessed on the basis of symptoms. High quality controlled studies investigating relevant long term outcome measures are needed to address questions of dosage and best means of iodine supplementation in different population groups and settings.

Low mutational burden of individual acquired mitochondrial DNA mutations in brain

Neurons may be particularly susceptible to oxidative damage, which has been proposed to induce somatic mutations, particularly in mitochondrial DNA (mtDNA). Therefore, acquired mtDNA mutations might preferentially accumulate in the brain and could play a role in aging and neurodegenerative disorders. Recently, a somatic T to G mtDNA mutation at noncoding nucleotide position 414 was reported in fibroblasts specifically from elderly subjects, with mutational burdens of up to 50%. We screened for this mutation in brain-derived mtDNA from 8 Alzheimer's disease patients, 27 Parkinson's disease patients, 4 multiple system atrophy patients, and 44 controls using up to three RFLP analyses. A total of 73 of these subjects were over the age of 65. The 414 mutation was absent in all cases. Next, individual mtDNA fragments from 6 elderly subjects were cloned, and a total of 70 clones were sequenced. The 414 mutation was absent in all clones, though occasional sequence variations were identified at other sites in single clones. The 414 mutation also was absent in blood (n = 6) and fibroblasts (n = 11) from elderly subjects. Our data suggest that it is rare for any one particular acquired mtDNA mutation to reach levels in the brain that are functionally significant. This does not exclude the possibility that the cumulative burden of multiple, individually rare, acquired mutations impairs mitochondrial function.

[Study on improving the dissolution rate of tanshinone in vitro by solvent deposition method]

OBJECTIVE

To improve the dissolution rate of a poorly watersoluble drug, tanshinone.

METHOD

Using pregeletinged starch as carrier, to prepare solvent deposition systems of tanshinone solvent method. The dissolution rate of tanshinone, solvent deposition systems and physical mixture were detected, and the physico-chemical properties of these study forms were investigated with scanning electron microscopy and infrared spectroscopy.

RESULT

The dissolution rate of tanshinone from the solvent deposition systems in vitro was significantly higher than that from physical mixtures and tanshinone powered alone. Tanshinone deposited on the surface of the carrier in crystal form, and the size was obviously reduced. A lot of acerose crystals of tanshinone on the surface of the carrier occurred. No chemical reaction acted between tanshinone and carrier.

CONCLUSION

The dissolution rate of tanshinone in vitro can be improved with solvent deposition method.

Evidence for cooperativity between nicotinic acetylcholine receptors in patch clamp records

It is often assumed that ion channels in cell membrane patches gate independently. However, in the present study nicotinic receptor patch clamp data obtained in cell-attached mode from embryonic chick myotubes suggest that the distribution of steady-state probabilities for conductance multiples arising from concurrent channel openings may not be binomial. In patches where up to four active channels were observed, the probabilities of two or more concurrent openings were greater than expected, suggesting positive cooperativity. For the case of two active channels, we extended the analysis by assuming that 1) individual receptors (not necessarily identical) could be modeled by a five-state (three closed and two open) continuous-time Markov process with equal agonist binding affinity at two recognition sites, and 2) cooperativity between channels could occur through instantaneous changes in specific transition rates in one channel following a change in conductance state of the neighboring channel. This allowed calculation of open and closed sojourn time density functions for either channel conditional on the neighboring channel being open or closed. Simulation studies of two channel systems, with channels being either independent or cooperative, nonidentical or identical, supported the discriminatory power of the optimization algorithm. The experimental results suggested that individual acetylcholine receptors were kinetically identical and that the open state of one channel increased the probability of opening of its neighbor.

Production of hydroxyl free radical by brain tissues in hyperglycemic rats subjected to transient forebrain ischemia

Preischemic hyperglycemia is known to aggravate brain damage resulting from transient ischemia. In the present study, we explored whether this aggravation is preceded by an enhanced formation of reactive oxygen species (ROS) during the early reperfusion period. To that end, normo- and hyperglycemic rats were subjected to 15 min of forebrain ischemia and allowed recovery periods of 5, 15, and 60 min. Sodium salicylate was injected intraperitoneally in a dose of 100 mg/kg, and tissues were sampled during recirculation to allow analyses of salicylic acid (SA) and its hydroxylation products, 2,3- and 2,5-dihydroxybenzoate (DHBA). Tissue sampled from thalamus and caudoputamen in normoglycemic animals failed to show an increase in 2,3- or 2,5-DHBA after 5 and 15 min of recirculation. However, such an increase was observed in the neocortex after 60 min of recirculation, with a suggested increase in the hippocampus as well. Hyperglycemia had three effects. First, it increased 2,5-DHBA in the thalamus and caudoputamen to values exceeding normoglycemic ones after 15 min of recirculation. Second, it increased basal values of 2,5- and total DHBA in the neocortex. Third, it increased the 60-min values for 2,5- and total DHBA in the hippocampus. These results hint that, at least in part, hyperglycemia may aggravate damage by enhancing basal- and ischemia-triggered production of ROS.

Apatite-organic polymer composites prepared by a biomimetic process: improvement in adhesion of the apatite layer to the substrate by ultraviolet irradiation

A dense and uniform layer of highly bioactive apatite can be formed in arbitrary thickness on any kind and shape of organic polymer substrates by the following biomimetic process. The substrate is first placed in contact with granular particles of CaO, SiO2-based glass soaked in a simulated body fluid with ion concentrations nearly equal to those of human blood plasma for forming apatite nuclei, and then soaked in another fluid highly supersaturated with respect to the apatite for making the apatite nuclei grow. In the present study, the polymer substrates were pretreated with ultraviolet (UV) light, and then subjected to the biomimetic process described above. By UV irradiation, the induction period for the apatite nucleation of poly(ethylene terephthalate) (PET), poly-ether sulphone (PESF), polyethylene (PE), poly(methyl methacrylate) (PMMA) and polyamide 6 (N6) substrates were reduced form 24 h to 10 h. The adhesive strengths of the apatite layer to the substrates increased from 2.5-3.2 MPa to 4.5-6.0 MPa for PET, PESF and PMMA, and from about 1.0 MPa to 4.0-6.5 MPa for PE and N6 substrates. These results have been explained by assuming that silicate ions, which induce apatite nucleation, are easily adsorbed on the substrates due to the formation of polar groups, with an improved hydrophilic nature, on the polymer surfaces by UV irradiation.