Role of Lanthanides and Bilayer Fe2As2 in the Electronic Properties of RbLn2Fe4As4O2 (Ln = Gd, Tb, and Dy) Superconductors

The superconducting transition temperatures (Tc) of RbGd2Fe4As4O2, RbTb2Fe4As4O2, and RbDy2Fe4As4O2 are 35 K, 34.7 K, and 34.3 K without doping, respectively. For the first time, we have studied the high-temperature nonmagnetic state and the low-temperature magnetic ground state of 12442 materials, RbTb2Fe4As4O2 and RbDy2Fe4As4O2, using first principles calculations and comparing them with RbGd2Fe4As4O2. We also performed a detailed study of the effects of lanthanides and bilayer Fe2As2. We predict that the ground state of RbLn2Fe4As4O2 (Ln = Gd, Tb, and Dy) is spin-density-wave-type, in-plane, striped antiferromagnets, and the magnetic moment around each Fe atom is about 2 μB. We also found that the structural differences caused by the simple ionic radius have little effect on the properties of these three materials. Different lanthanide elements themselves play a major role in the electronic properties of the materials. It can be confirmed that the effect of Gd on RbLn2Fe4As4O2 is indeed different from that of Tb and Dy, and the presence of Gd is more conducive to interlayer electron transfer. This means that Gd can transfer more electrons from the GdO layer to the FeAs layer compared to Tb and Dy. Therefore, RbGd2Fe4As4O2 has a stronger internal coupling strength of the bilayer Fe2As2 layer. This can explain why the Tc of RbGd2Fe4As4O2 is slightly higher than that of RbTb2Fe4As4O2 and RbDy2Fe4As4O2.

Role of Doping Effect and Chemical Pressure Effect Introduced by Alkali Metal Substitution on 1144 Iron-Based Superconductors

CaAFe4As4 with A = K, Rb, and Cs are close to the doped 122 system, and the parent material can reach a superconducting transition temperature of 31-36 K without doping. To study the role of alkali metals, we investigated the induced hole doping and chemical pressure effects as a result of the introduction of alkali metals using density-functional-based methods. These two effects can affect the superconducting transition temperature by changing the number of electrons and the structure of the FeAs conductive layer, respectively. Our study shows that the dxz and dyz orbitals, which are degenerate in CaFe2As2, become nondegenerate in CaAFe4As4 due to two nonequivalent arsenic atoms (As1 and As2). The unusual oblate ellipsoid hole pocket at Γ point in CaAFe4As4 results from a divalent cation Ca²+ replaced by a monovalent cation A⁺. It shows one of the main differences in fermiology compared to a particular form of CaFe2As2 with reduced 1144 symmetry, due to the enhancement of As2-Fe hybridization. The unusual band appears in CaFe2As2 (1144) and gradually disappears in the change of K to Cs. Further analysis shows that this band is contributed by As1 and has strong dispersion perpendicular to the FeAs layer, suggesting that it is related to the peculiar van Hove singularity below the Fermi level. In addition, various aspects of CaFe2As2 (1144) and CaAFe4As4 in the ground state are discussed in terms of the influence of hole doping and chemical pressure.

Prevalence and Risk Factors of Frailty in Stroke Patients: A Meta-Analysis and Systematic Review

OBJECTIVES

Summarize the existing evidence regarding the prevalence and risk factors of frailty in stroke patients.

DESIGN

A meta-analysis and systematic review.

PARTICIPANTS

Stroke patients in hospitals or communities.

METHODS

We undertook a systematic review and meta-analysis using articles available in 8 databases, including PubMed, The Cochrane Library, Web of Science, Embase, Chinese Biomedical Database (CBM), China National Knowledge Infrastructure Database (CNKI), Wanfang Database, and Weipu Database (VIP) from January 1990 to April 2022. Studies were quality rated using the Newcastle-Ottawa Scale and Agency for Healthcare Research and Quality tool.

RESULTS

A total of 24 studies involving 30,423 participants were identified. The prevalence of frailty and pre-frailty in stroke patients was 27% (95%CI: 0.23-0.31) and 47.9% (95%CI: 0.43-0.53). Female gender (OR = 1.76, 95%CI: 1.63-1.91), advanced age (MD = 6.73, 95%CI: 3.55-9.91), diabetes (OR = 1.34, 95%CI: 1.06-1.69), hyperlipidemia (OR = 1.46, 95%CI: 1.04-2.04), atrial fibrillation (OR = 1.36, 95%CI: 1.01-1.82), National Institutes of Stroke Scale (NIHSS) admission scores (MD = 2.27, 95%CI: 1.72-2.81) were risk factors of frailty in stroke patients.

CONCLUSIONS

Frailty was more prevalent in stroke patients. Female gender, advanced age, diabetes, hyperlipidemia, atrial fibrillation, and National Institutes of Stroke Scale (NIHSS) admission scores were identified as risk factors for frailty in stroke patients. In the future, medical staff should pay attention to the early screening of frailty in high-risk groups and provide information on its prevention.

[Effects of cinepazide maleate injection on blood pressure in patients with acute ischemic stroke and hypertension]

Objective: To investigate the blood pressure change in patients with acute ischemic stroke (AIS) and hypertension treated with cinepazide maleate injection. Methods: This was a subgroup analysis of post-marketing clinical confirmation study of cinepazide maleate injection for acute ischemic stroke: a randomized, double-blinded, multicenter, placebo-parallel controlled trial, which conducted in China from August 2016 to February 2019. Eligible patients fulfilled the inclusive criteria of acute anterior circulation ischemic stroke with National Institutes of Health Stroke Scale (NIHSS) scores of 7-25. The primary endpoints were mean blood pressure of AIS patients treated with cinepazide maleate or control, which were assessed during the treatment period (14 days), and the proportion of the patients with normal blood pressure was analyzed after the treatment period. Furthermore, a subgroup analysis was performed to investigate a possible effect of the history of hypertension on outcomes. Results: This analysis included 809 patients with hypertension. There was no significant difference in patients blood pressure and the proportion of patients with normal blood pressure (60.5% vs. 59.0%,P>0.05) between cinepazide maleate group and control group. Conclusion: Administration of cinepazide maleate injection does not affect the management of clinical blood pressure in patients with AIS.

Sodium salicylate enhances neural excitation via reducing GABAergic transmission in the dentate gyrus area of rat hippocampus in vivo

Sodium salicylate, one of the non-steroidal anti-inflammatory drugs, is widely prescribed in the clinic, but a high dose of usage can cause hyperactivity in the central nervous system, including the hippocampus. At present, the neural mechanism underlying the induced hyperactivity is not fully understood, in particular, in the hippocampus under an in vivo condition. In this study, we found that systemic administration of sodium salicylate increased the field excitatory postsynaptic potential slope and the population spike amplitude in a dose-dependent manner in the hippocampal dentate gyrus area of rats with in vivo field potential extracellular recordings, which indicates that sodium salicylate enhances basal synaptic transmission and neural excitation. In the presence of picrotoxin, a GABA-A receptor antagonist, sodium salicylate failed to increase the initial slope of the field excitatory postsynaptic potential and the amplitude of the population spike in vivo. To further explore how sodium salicylate enhances the neural excitation, we made whole-cell patch-clamp recordings from hippocampal slices. We found that perfusion of the slice with sodium salicylate decreased electrically evoked GABA receptor-mediated currents, increased paired-pulse ratio, and lowered frequency and amplitude of miniature inhibitory postsynaptic currents. Together, these results demonstrate that sodium salicylate enhances the neural excitation through suppressing GABAergic synaptic transmission in presynaptic and postsynaptic mechanisms in the hippocampal dentate gyrus area. Our findings may help understand the side effects caused by sodium salicylate in the central nervous system.

Resveratrol noncompetitively inhibits glycine receptor-mediated currents in neurons of rat central auditory neurons

Resveratrol, a naturally occurring stilbene found in red wine, is known to modulate the activity of several types of ion channels and membrane receptors, including Ca²⁺, K⁺, and Na⁺ ion channels. However, little is known about the effects of resveratrol on some important receptors, such as glycine receptors and GABA_A receptors, in the central nervous system (CNS). In the present study, the effects of resveratrol on glycine receptor or GABA_A receptor-mediated currents in cultured rat inferior colliculus (IC) and auditory cortex (AC) neurons were studied using whole-cell voltage-clamp recordings. Resveratrol itself did not evoke any currents in IC neurons but it reversibly decreased the amplitude of glycine-induced current (I_Gly) in a concentration-dependent manner. Resveratrol did not change the reversal potential of I_Gly but it shifted the concentration-response relationship to the right without changing the Hill coefficient and with decreasing the maximum response of I_Gly. Interestingly, resveratrol inhibited the amplitude of I_Gly but not that of GABA-induced current (I_GABA) in AC neurons. More importantly, resveratrol inhibited GlyR-mediated but not GABA_AR-mediated inhibitory postsynaptic currents in IC neurons using brain slice recordings. Together, these results demonstrate that resveratrol noncompetitively inhibits I_Gly in auditory neurons by decreasing the affinity of glycine to its receptor. These findings suggest that the native glycine receptors but not GABA_A receptors in central neurons are targets of resveratrol during clinical administrations.

Cross-talk pattern between GABAA- and glycine-receptors in CNS neurons is shaped by their relative expression levels

GABA_A receptors (GABA_ARs) and glycine receptors (GlyRs) are two principal inhibitory chloride ion channels in the central nervous system. The two receptors do not function independently but cross-talk to each other, i.e., the activation of one receptor would inhibit the other. This cross-talk is present in different patterns across various regions in the central nervous system; however, the factor that determines these patterns is not understood. Here, we show that the pattern of cross-talk between the two receptors is shaped by their relative expression level in a neuron: a higher expression level correlates with louder talk. In line with a tendency of decrease in expression level of GlyRs and increase in expression level of GABA_ARs from the spinal cord, the brainstem to the neocortex, GlyRs talked much louder (i.e. produced greater inhibition) than GABA_ARs (one-way pattern) in spinal cord neurons, about equally loud as GABA_ARs (symmetric pattern) in inferior colliculus neurons and less loud (i.e. less inhibition) than GABA_ARs (asymmetric pattern) in auditory cortex neurons. Overexpression of GlyRs in inferior colliculus neurons produced an asymmetric pattern that should otherwise have been observed in spinal cord neurons. These expression level-dependent patterns of cross-talk between the two receptors may suggest how the central nervous system uses an alternative mechanism to maintain a delicate level of inhibition through adjusting the proportion of the two receptors in a neuron along its pathway.

Periodontal disease and emotional disorders: A meta-analysis

OBJECTIVE

The objective of this study was to evaluate the relationship of periodontal disease with depression and anxiety via a systematic review and meta-analysis.

METHOD

We systematically searched the EMBASE, PubMed, Web of Science, PsycINFO, and SinoMed databases (until August 4, 2019) with language restricted to English and Chinese. Case-control, cross-sectional, and cohort studies that calculated the risk ratio (RR), odds ratio (OR)/prevalence OR (POR), and hazard ratio (HR) of depression/anxiety with periodontal disease or the OR/POR/RR/HR of periodontal disease caused by depression/anxiety were included. Observational studies that reported the depression/anxiety scale score of patients with periodontal disease and healthy periodontal subjects aged ≥14 years were also included. We used the standard format to extract the following information from each included study: author/s, survey year, study design, age of participants, periodontal disease definition, depression/anxiety measurement, and summary of results. The Newcastle-Ottawa scale was used to ascertain the quality of the included citations.

RESULTS

After screening, 40 studies were included. A meta-analysis of the case-control studies showed that periodontal disease was positively associated with depression (OR = 1.70, 95% confidence interval [CI]  = 1.01-2.83). A meta-analysis of 12 studies showed that periodontal disease was significantly correlated with anxiety (OR = 1.36, 95% CI = 1.11-1.66). A meta-analysis of 18 studies showed that subjects with periodontal disease had higher depression scale score (standardized mean difference [SMD] = 1.05, 95% CI = 0.68-1.41) and anxiety scale score (SMD = 0.70, 95% CI = 0.44-0.96).

CONCLUSION

Periodontal disease is associated with emotional disorders. However, the high degree of heterogeneity among studies should be considered. More high-quality prospective studies are required to confirm the relationship.

Green Enzyme-Linked Immunosorbent Assay Based on the Single-Stranded Binding Protein-Assisted Aptamer for the Detection of Mycotoxin

In this work, a green enzyme-linked immunosorbent assay (ELISA) based on the single-stranded binding protein (SSB)-assisted aptamer was designed for biosensing applications. Combined with the biotin-streptavidin (SA) system and the high catalytic activity of horseradish peroxidase (HRP), this SSB-assisted aptamer sensor was applied for the detection of aflatoxin B1, ochratoxin A, and zearalenone. In this novel ELISA, mycotoxin-protein conjugations were replaced by SSB to avoid the hazard of mycotoxin, whereas antibodies were replaced by aptamer to avoid the complex and tedious preparation of antibodies. In the absence of target mycotoxins, SSB can bind the aptamer-biotin specifically. Detection was performed using the strong combination of biotin and SA after adding SA-HRP and substrate/chromogen solution, thereby resulting in a strong yellow color signal. In the presence of target mycotoxins, the aptamer-biotin cannot bind to the SSB, thereby leading to a weak yellow color signal. Under optimal conditions, the designed method was successfully applied for the determination of real sample and exhibited high specificity and low limits of detection in corn (112 ng L^-1 for aflatoxin B1, 319 ng L^-1 for ochratoxin A, and 377 ng L^-1 for zearalenone). The green ELISA may also be extended to the detection of other biohazardous targets by changing the aptamer.

Normal-state properties of the quasi-one-dimensional superconductor Ta4Pd3Te16

We examined the physical properties of the quasi-one-dimensional superconductor Ta₄Pd₃Te₁₆ in the normal state by detailed measurements of susceptibility, in-plane anisotropic resistivity, magnetoresistance, Hall resistivity, and Seebeck coefficient. The large Wilson ratio, as inferred from normal-state susceptibility, indicates strong electron-electron interaction. The Hall and Seebeck coefficients show not only significant temperature-dependent behavior, indicating the multiband effect, but also an obvious anomaly around T ₁  =  40 K. Analyses of both the Hall resistivity and thermopower using a two-band model indicate that the electrons dominate the electrical transport at low temperatures. Our results imply that it is the quantum fluctuations of the charge order taking place in the temperature range 30-50 K that may result in the abnormal normal-state properties of Ta₄Pd₃Te₁₆.

[Prediction of syncope with nonlinear dynamic analysis during head-up tilt in vasovagal syncope patients]

OBJECTIVE

To quantify the relationship between cerebral blood flow velocity and peripheral blood pressure during hypotension period, aiming to predict the brain hypotension before symptomatic occurrence.

METHODS

Twenty vasovagal syncope (VVS) patients who had a previous clinical history were selected in groups and 20 pair-matched control subjects underwent 70° tilt-up test. The subjects remained supine for 30 minutes before recordings when Doppler probes, electrodes and Finapres device were prepared. After continuous baseline recordings for 10 min, the subjects underwent head up tilt (HUT) test (70°), and were standing upright for 30 minutes or until syncope was imminent. For ethical reasons, the subjects were turned back to supine position immediately after SBP dropped to ≥20 mmHg, when their consciousness persisted. The point of syncope was synchronized for all the subjects by the point SBP reached the minima. Their beat-to-beat blood pressures (BP) were recorded continuously and bilateral middle cerebral artery (MCA) flow velocities were obtained with two 2 MHz Doppler probes from a transcranial Doppler ultrasonography (TCD) system. A nonlinear dynamic method--multimodal pressure flow (MMPF) analysis was introduced to access cerebral autoregulation during different time intervals. We introduced a new indicator--syncope index (SI), which was extracted from blood flow velocity (BFV) signal to evaluate the variation of cerebral vascular tension, and could reflect the deepness of dicrotic notch in BFV signal.

RESULTS

Compared with the syncope index of the baseline value at the beginning of the tilt test, SI in VVS group showed significantly lower when the VVS occurred (0.16±0.10 vs.0.27±0.10,P<0.01),while there was no significant difference in syncope index between the control group at the end of the tilt test and the baseline value at the beginning of the tilt test. For those VVS patients, pulse index and resistance index had no significant change. Syncope index decreased significantly 3 minutes before the point of syncope (0.23±0.07 vs.0.29±0.07,P<0.01).

CONCLUSION

Dynamic regulation is exhausted when vasovagal syncope occurred. Tension decrease of small vessels could have some relationship with loss of the cerebral autoregulation capability. The proposed syncope index could be a useful parameter in predicting syncope of VVS patients since it decreased significantly up to 3 minutes earlier from the point of syncope.

[Correlation between DCE-MRI quantitative perfusion histogram parameters, apparent diffusion coefficient and Ki-67 in different pathological types of lung cancer]

Objective: To explore the efficacy of dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) histogram molecular imaging index, apparent diffusion coefficient (ADC) in different types of lung cancer and explore their correlation with Ki-67. Methods: A total of 33 cases of lung cancer patients confirmed by pathology in Shaoxing People's Hospital from March 2017 to March 2018 were collected, 28 males and 5 females aged 50-85 years old, including 15 cases of squamous cell carcinoma, 12 cases of adenocarcinoma, and 6 cases of small cell carcinoma. All patients performed DCE-MRI and DWI imaging within one week before surgery or puncture. ADC values, DCE-MRI quantitative perfusion parameters by histogram metrics analysis (mean value, skewness, kurtosis, uniformity, entropy, energy, quantile) of K(trans), K(ep), V(e), and V(p) were then collected. Ki-67 expression in lung cancer tissue was detected by immunohistochemical method. One-way analysis of variance and least significant difference were used to compare the differences among the parameters of the three groups which were normal distribution and equal variances, while Kruskal-Walls test and Mann-Whitney U test were used to compare the parameters that did not conform to normal distribution or variance. Pearson correlation analysis was used to compare the correlations between quantitative perfusion histogram parameters, ADC values and immunohistochemical scores of Ki-67. Results: The Ki-67 count in small cell lung cancer(458±82, P=0.011) and squamous cell carcinoma(355±277, P=0.034)were significantly higher than that in adenocarcinoma (168±164). The correlation analysis showed that there was a significant negative correlation between ADC values and Ki-67 (P=0.018, r=-0.416). And V(e) (Q5, Q10) was negatively related to Ki-67 (P=0.017, r=-0.420; P=0.040, r=-0.366). In squamous cell carcinoma patients, V(e) (homogeneity) was significantly negatively correlated with the expression of Ki-67 (P=0.033, r=-0.570). K(trans)(homogeneity) and V(e) (homogeneity, Q5, Q10, Q25) were significantly positively correlated with ADC values (P value from 0.001 to 0.035, r value from 0.545 to 0.765). Conclusion: DCE-MRI quantitative perfusion histogram parameters, ADC value can evaluate the lung cancer cell proliferation activity in different pathological types.

Inhibitory effect of a natural phenolic compound, 3-p-trans-coumaroyl-2-hydroxyquinic acid against the attachment phase of biofilm formation of Staphylococcus aureus through targeting sortase A

3-p-trans-Coumaroyl-2-hydroxyquinic acid (CHQA), a natural phenolic compound, prevented Staphylococcus aureus biofilm formation due to the inhibition of the initial attachment stage of biofilm development by targeting sortase A.

Temporary conductive hearing loss in early life impairs spatial memory of rats in adulthood

INTRODUCTION

It is known that an interruption of acoustic input in early life will result in abnormal development of the auditory system. Here, we further show that this negative impact actually spans beyond the auditory system to the hippocampus, a system critical for spatial memory.

METHODS

We induced a temporary conductive hearing loss (TCHL) in P14 rats by perforating the eardrum and allowing it to heal. The Morris water maze and Y-maze tests were deployed to evaluate spatial memory of the rats. Electrophysiological recordings and anatomical analysis were made to evaluate functional and structural changes in the hippocampus following TCHL.

RESULTS

The rats with the TCHL had nearly normal hearing at P42, but had a decreased performance with the Morris water maze and Y-maze tests compared with the control group. A functional deficit in the hippocampus of the rats with the TCHL was found as revealed by the depressed long-term potentiation and the reduced NMDA receptor-mediated postsynaptic current. A structural deficit in the hippocampus of those animals was also found as revealed the abnormal expression of the NMDA receptors, the decreased number of dendritic spines, the reduced postsynaptic density and the reduced level of neurogenesis.

CONCLUSIONS

Our study demonstrates that even temporary auditory sensory deprivation in early life of rats results in abnormal development of the hippocampus and consequently impairs spatial memory in adulthood.

Antibacterial Effect of 2R,3R-dihydromyricetin on the Cellular Functions of Staphylococcus aureus

The C-3-OH, C-4 carbonyl oxygen and hydrogenation of C2=C3 bond on the C-ring of 2R,3R-dihydromyricetin (DMY) proved to be not necessary for the antibacterial activity against Staphylococcus aureus. DMY significantly decreased the intracellular ATP of S. aureus cells but had few effects on pH_in, proline oxidation, succinate dehydrogenase activity or malate dehydrogenase activity.

Gene expression and enzyme activity of lipoprotein lipase correlate with intramuscular fat content in Guangxi san-huang and Arbor Acres chickens

Lipoprotein lipase (LPL) is a key enzyme in lipid metabolism. This study investigated LPL gene expression, LPL enzyme activity, and the correlation of each with intramuscular fat (IMF) in Chinese Guangxi san-huang (GXSH) and Arbor Acres (AA) chickens. The results showed that age and breed had significant effects on LPL expression and enzyme activity. Correlation analyses showed significant positive correlations between LPL expression levels and IMF contents in the breast and thigh tissues of both GXSH (r = 0.712, P = 0.001; r = 0.792, P < 0.001, respectively) and AA (r = 0.644, P < 0.001; r = 0.545, P < 0.001, respectively) chickens. The results also indicated a significant positive correlation between LPL enzyme activity and IMF contents in the breast and thigh tissues of both GXSH (r = 0.615, P = 0.001; r = 0.685, P < 0.001, respectively) and AA (r = 0.600, P = 0.001; r = 0.528, P = 0.003, respectively) chickens. The results indicated that the LPL gene was significantly correlated with IMF in these two breeds. The results presented here could contribute to knowledge of LPL mRNA developmental expression patterns and enzyme activity, and it could facilitate further research on the molecular mechanisms underlying IMF deposition in chickens.

The curative effect comparison of two kinds of therapeutic regimens on decreasing the relative intensity of microembolic signal in CLAIR trial

BACKGROUND

Microembolic signals (MESs) are direct markers of unstable large artery atherosclerotic plaques. In a previous study, we found that the number of MESs is associated with stroke recurrence and that clopidogrel plus aspirin more effectively reduce the number of MESs than does aspirin alone. Stroke recurrence is associated with not only the number of MESs but also the size of the MES, which can theoretically be estimated by monitoring the MES intensity via transcranial doppler (TCD). Thus, we compared the effects of clopidogrel and aspirin with aspirin alone on MES intensity using TCD.

METHODS

We recruited 100 patients who experienced acute ischemic stroke or transient ischemic attack (TIA) within 7days of symptom onset. All patients also had large artery stenosis in the cerebral or carotid arteries and the presence of MES as revealed by TCD. The patients were randomized to receive either aspirin or clopidogrel and aspirin for 7days. MES monitoring was performed on days 2 and 7.

RESULTS

Intent-to-treat (ITT) analysis (46 patients in the dual therapy group, 52 patients in the monotherapy group) and per-protocol (PP) analysis (25 patients in the dual therapy group, 31 patients in the monotherapy group) were performed on 98 patients. The primary finding was that the MES intensity was dramatically reduced in the dual therapy group. ITT analysis of the dual therapy group revealed that the MES intensity was 8.04 (0-16) dB before treatment, 0.00 (0-17) dB on day 2, and 0.00 (0-12) dB on day 7 (P=0.000). In the monotherapy group, the MES intensity was 9.00 (0-20) dB before treatment, 8.25 (0-17) dB on day 2, and 7.0 (0-18) dB on day 7 (P=0.577). PP analysis revealed similar results. No severe hemorrhagic complications were detected. The two patients in this study who experienced stroke recurrence were in the monotherapy group.

CONCLUSIONS

Clopidogrel and aspirin more effectively decrease the MES intensity than aspirin alone in patients with large artery stenotic minor stroke or TIA.

Complete mitochondrial genome of the Cyclemys dentata and phylogenetic analysis of the major family Geoemydidae

In the present study, the complete mitochondrial (mt) genome of Cyclemys dentata was determined using PCR reactions. The structural organization and gene order of C. dentata were equivalent to those of most other vertebrates. The mt genome was 16,489 bp in length, has rich A+T content, consisting of 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes, and a control region (D-loop). All protein-coding genes started with ATG, many genes have complete stop codons, except ND2, COX3, ND3, and cyt-b genes had incomplete stop codons of T. The light-strand replication origin (OL) of C. dentata might fold into a stable stem-loop secondary structure, and its loop had 2 nt less than that of the Cyclemys atripons OL sequence. The D-Loop of C. dentata contained a central domain (CD), 2 extended termination associated sequences (ETAS1, ETAS2) and 3 conserved sequence blocks (CSB1, CSB2, CSB3). The average length of 20 turtles' mt genomes was 16,692.5 bp, including 34.1% A, 27.0% T, 26.0% C and 12.9% G. The C. dentata mitochondrial genome could provide useful data for further studies on phylogenetics and conservation genetics of this species. The phylogenetic relationships of the family Geoemydidae were analyzed by maximum-likelihood (ML) and neighbor-joining (NJ) based on concatenated sequences of 13 protein-coding genes from 20 turtle species. The ML and NJ trees had homologous topologies. The results support the existing classification of the genera of Geoemydidae, that C. dentata was a sister species of C. atripons, Pyxidea nested in Cuora, and Chinemys was synonymous with Mauremys.

Anti-hyperglycemic effect of chebulagic acid from the fruits of Terminalia chebula Retz

In the present study, we firstly compared rat intestinal α-glucosidase inhibitory activity by different ethanol-aqueous extractions from the dried fruits of Terminalia chebula Retz. The enzymatic assay showed that the 80% ethanol extract was more potent against maltase activity than both 50% and 100% ethanol extracts. By HPLC analysis, it was determined that the 80% ethanol extract had a higher content of chebulagic acid than each of 50% or 100% ethanol extract. Next, we investigated how efficiently chebulagic acid could inhibit sugar digestion by determining the glucose level on the apical side of the Caco-2 cell monolayer. The result showed that the maltose-hydrolysis activity was down-regulated by chebulagic acid, which proved to be a reversible inhibitor of maltase in Caco-2 cells. On the other hand, chebulagic acid showed a weak inhibition of sucrose-hydrolysis activity. Meanwhile, chebulagic acid did not have an obvious influence on intestinal glucose uptake and was not effective on glucose transporters. Further animal studies revealed that the oral administration of chebulagic acid (100 mg/kg body weight) significantly reduced postprandial blood glucose levels by 11.1% in maltose-loaded Sprague-Dawley (SD) rats compared with the control group, whereas the oral administration of chebulagic acid did not show a suppressive effect on postprandial hyperglycemia in sucrose- or glucose-loaded SD-rats. The results presented here suggest that chebulagic acid from T. chebula can be used to control blood glucose and manage type 2 diabetes, although clinical trials are needed.

Chemical composition and antimicrobial activity of the essential oil of kumquat (Fortunella crassifolia Swingle) peel

The aim of this study was to determine the main constituents of the essential oil isolated from Fortunella crassifolia Swingle peel by hydro-distillation, and to test the efficacy of the essential oil on antimicrobial activity. Twenty-five components, representing 92.36% of the total oil, were identified by GC-MS analysis. The essential oil showed potent antimicrobial activity against both Gram-negative (E. coli and S. typhimurium) and Gram-positive (S. aureus, B. cereus, B. subtilis, L. bulgaricus, and B. laterosporus) bacteria, together with a remarkable antifungal activity against C. albicans. In a food model of beef extract, the essential oil was observed to possess an effective capacity to control the total counts of viable bacteria. Furthermore, the essential oil showed strongly detrimental effects on the growth and morphological structure of the tested bacteria. It was suggested that the essential oil from Fortunella crassifolia Swingle peel might be used as a natural food preservative against bacteria or fungus in the food industry.

High doses of salicylate and aspirin are inhibitory on acid-sensing ion channels and protective against acidosis-induced neuronal injury in the rat cortical neuron

Aspirin and its main metabolite salicylate are widely used to relieve pain, treat inflammatory diseases, and prevent ischemic stroke. Multiple pathways are responsible for the therapeutic actions exerted by these drugs. One of the pathways is targeting neuronal receptors/ion channels in the central nervous system. Correspondingly, increasing evidence has implicated acid-sensing ion channels (ASICs) in the processes of the diseases that are medicated by aspirin and salicylate. We therefore employed whole-cell patch-clamp recordings to examine the effects of salicylate as well as aspirin on ASICs in cultured cortical neurons of the rat. We recorded rapid and reversible inhibition of ASIC current by millimolar concentrations of aspirin and salicylate and found that salicylate reduced acidosis-induced membrane depolarization. These data suggest that ASICs in the cortex are molecular targets of high doses of aspirin and salicylate. In addition, the results from lactate dehydrogenase release measurement showed that high doses of aspirin and salicylate protected the cortical neuron from acidosis-induced neuronal injury. These findings may contribute to a better understanding of the therapeutic mechanisms of aspirin and salicylate actions in the brain and provide new evidence on aspirin and salicylate used as neuroprotective agents in the treatment of ischemic stroke.

Intestinal alpha-glucosidase inhibitory activity and toxicological evaluation of Nymphaea stellata flowers extract

AIM OF THE STUDY

Nymphaea stellata willd. flowers (NSF) are used as a traditional medicine in India and Nepal to treat diabetic disease. Different works have demonstrated that NSF extract showed antihyperglycemic effect on alloxan-induced diabetic rats. In the present work we evaluated in vitro intestinal alpha-glucosidase inhibition as the possible mode of action of NSF extract on suppressing postprandial hyperglycemia for curing diabetic mellitus. In addition, NSF extract was studied to assess its possible acute oral toxicity and genotoxicity.

MATERIALS AND METHODS

Rat intestinal crude enzyme preparation and Caco-2 monolayer were used to evaluate alpha-glucosidase inhibitory activity of NSF extract. The main alpha-glucosidase inhibitors were detected by HPLC. For acute toxicity test, NSF extract was administered at doses of 2000, 5000 and 10,000 mg/kg body to three groups of 10 ICR mice each, and then clinical symptoms including mortality, clinical sign and gross findings were observed once a day for 14 days. In Ames test, histidine-dependent auxotrophic mutants of Salmonella typhimurium (strains TA97, TA98, TA100, TA102 and TA1535) were used and incubated in the presence and absence of S9 metabolic activation using NSF extract with concentrations of 150-5000 microg/plate. The chromosome aberration test was conducted with Chinese hamster lung (CHL) cells treated with NSF extract at doses of 150-5000 microg/ml in the presence and absence of S9 metabolic activation. In the in vivo mouse micronucleus assay, 9-week-old male and female ICR mice (n=90, 25-30 g) were administered daily by oral gavage at doses of 2.5, 5.0 and 10.0 g/kg body for 1 or 2 days. Bone marrow smears were prepared from each treatment group 24h after last administration and then polychromatic erythrocytes (PCEs) and normochromatic erythrocytes (NCEs) were identified.

RESULTS

NSF extract showed potent rat intestinal alpha-glucosidase inhibitory activity for maltose hydrolysis with ED(50) value of 0.1 mg/ml. In Caco-2 monolayer, alpha-glucosidase activity for the maltose hydrolysis was down-regulated by NSF extract at a concentration of 0.05 mg/well level, showing 74% inhibition compared to the saline treated control. NSF was rich in phenol contents and the main alpha-glucosidase inhibitor, 1,2,3,4,6-penta-O-galloyl-beta-D-glucose, was identified together with two phenolic compounds of gallic acid and corilagin. In acute toxicity test, NSF extract did not produce any toxic signs or deaths and the LD(50) value of this extract could be greater than 10,000 mg/kg body weight. These results of genotoxicity assessment showed that NSF extract did not cause genotoxic effects in Ames test, in the in vitro chromosomal aberration assay and in the in vivo micronucleus assay.

CONCLUSION

The current study shows that the extract from Nymphaea stellata flowers exhibits significant intestinal alpha-glucosidase inhibitory activity, without showing any acute toxicity or genotoxicity, which may be useful in suppressing postprandial hyperglycemia in diabetics. The results presented here suggest that the use of NSF in folk medicine as a natural antidiabetic treatment could be safe as well as beneficial.

Analysis of magnetic elements in otoliths of the macula lagena in homing pigeons with inductively coupled plasma mass spectrometry

OBJECTIVE

The macula lagena in birds is located at the apical end of the cochlea and contains many tiny otoliths. The macula lagena is innervated and has neural projections to the brainstem, but its physiological function is still unclear. It remains disputable that it is because otoliths in the lagena are rich in elements Fe and Zn that birds can obtain geomagnetic information for homing. To clarify this issue, we carried out a study to determine whether or not otoliths in the lagena of homing pigeons are richer in magnetic elements than those in the saccule and the utricle.

METHODS

The contents of ferromagnetic elements (Fe, Co, Ni) and other metal elements in lagenal otoliths of adult homing pigeons were precisely analyzed with inductively coupled plasma mass spectrometry (ICP-MS) of high sensitivity, and then they were compared with those in saccular and utricular otoliths (all the contents were normalized to Ca).

RESULTS

In adult homing pigeons, the contents of ferromagnetic elements (Fe, Co, Ni) in lagenal otoliths were less than 0.7% (normalized to Ca element) and were the same order in magnitude as those in saccular and utricular otoliths. The content of Fe in lagenal otoliths was not significantly different from that in utricular otoliths and was even lower than that in saccular otoliths. The content of Co in lagenal otoliths was lower than that in saccular otoliths and higher than that in utricular otoliths. The content of Ni in lagenal otoliths was not significantly different from that in saccular otoliths and was higher than that in utricular otoliths. The contents of other metal elements Na, Mg, K, Al, Mn and Pb in lagenal otoliths were not significantly different from those in utricular and saccular otoliths. The contents of metal elements Zn, Ba and Cu in lagenal otoliths were lower than those in saccular otoliths.

CONCLUSION

The contents of magnetic elements in lagenal otoliths of homing pigeons are not much higher than those in utricular and saccular otoliths, which does not support the hypothesis that birds depend on high contents of Fe and Zn in lagenal otoliths for sensation of geomagnetic information. Similarities in morphology, element ingredient and element content between lagenal otoliths and utricular otoliths suggest that the two types of otolithic organs may play similar roles in sensing gravitational and acceleration signals.

A door-to-door survey of intracranial atherosclerosis in Liangbei County, China

We studied 590 asymptomatic villagers aged > or =40 years in Liangbei County in central rural China and found 41 subjects (prevalence 6.9%) with intracranial atherosclerosis. In a multivariate analysis, the significant risk factors for intracranial stenosis were hypertension (OR 2.53; 95% CI 1.12 to 5.72), glycosuria (OR 3; 1.19 to 7.97), heart disease (OR 4; 1.39 to 11.6), and family history of stroke (OR 5.2; 1.38 to 20). Intracranial atherosclerosis is not uncommon among asymptomatic Chinese subjects.

Indiscernible benefit of high-resolution HLA typing in improving long-term clinical outcome of unrelated umbilical cord blood transplant

The success of allogeneic hematopoietic stem cell transplantation depends in part on the accuracy of human leukocyte antigen (HLA) matching between the donor-recipient pair. The higher the number of matching HLA alleles, the smaller the chance that the transplant recipient will develop complications. Umbilical cord blood (UCB) transplantation was noted to result in a remarkably low frequency and severity of graft-versus-host disease (GvHD) and graft rejection compared to that in unrelated bone marrow transplant recipients. At present most banks match UCB donors for respective recipients by HLA-A, -B low-resolution typing and -DRB1 high-resolution typing. We retrospectively conducted high-resolution sequence-based HLA typing on DNA samples available from 65 Chinese UCB-recipient pairs typed previously by using low-resolution sequence-specific oligonucleotide probes and sequence-specific primers, and evaluated the clinical outcome. High-resolution typing revealed imperceptible HLA alleles that were hardly identified in low-resolution typing. Univariate analyses demonstrated no significant correlation between the extents of high-resolution HLA disparity with engraftment, graft failure, acute GvHD, transplant-related mortality and long-term 6-year overall survival. Data from the study suggest that high-resolution typing for HLA-A, -B and -DRB1 contributed no substantial improvement to UCB transplant outcome. Low-resolution typing appears to be amenable to matching UCB-recipient pairs without compromising the quality of transplant.

Banking and transplantation of umbilical cord blood in Guangzhou, China

BACKGROUND

Umbilical cord blood (UCB) is an alternative source of hematopoietic stem cells (HSC) for transplantation of patients with hematologic malignancies or hereditary diseases.

METHODS

We developed a provincial UCB bank in Guangzhou, China, using good manufacturing practices and standard operating procedures to address donor eligibility, collection, characterization, processing, storage and release from quarantine. The banking activities were analyzed.

RESULTS

From June 1998 to May 2005, 8623 UCB units of Han ethnic origin were collected; 4147 (48.1%) were stored, while 4476 (51.9%) were discarded as a result of pre-determined exclusion criteria. A median volume of 95.5 mL (range 60-227.7) and 1.2 x 10(9) (0.8-9.3) nucleated cells were collected. The cell viability was 97.8% (90-100%). The CD34+ cell count of 3691 (89.0%) UCB units was 5.2 x 10(6) (0.3-131.6) and clonogenic assays of 4036 (97.3%) UCB units demonstrated 9.8 x 10(5) (0.04-135.8) CFU-GM, 0.3 x 10(5) (0.0-18.6) CFU-GEMM and 8.8 x 10(5) (0.0-74.2) BFU-E. A total of 0.4% (15/3863) UCB derived from babies known to have health problems at age 6 months was discarded. Up to May 2005, 151 units were issued for transplantation to 127 patients [90 (70.9%) children and 37 (29.1%) adults]. The infused nucleated cells in unrelated single-unit recipients were 3.4 x 10(7)/kg (1.7-14.9) for adults (n=19) and 5.7 x 10(7)/kg (2.0-20.5) for children (n=71), respectively. The numbers of days for the engraftment of neutrophils among 65 children and 22 adults were 17 (7-41) and 20 (10-42), respectively.

DISCUSSION

Data of this study show that stringent procedures and comprehensive policies are requisite for pursuing the banking and release of quality UCB for successful transplantation.

Morphometry of otoliths in chicken macula lagena

The macula lagena located at the apical end of the cochlea in birds is characterized by the presence of numerous otoliths with unclear sensory functions. These otoliths are reported to be similar to those in the vestibular system but their detailed features in morphology are unknown. In the present study, we examined the number, size and shape of otoliths from the macula lagena in Chinese domestic chickens (Gallus Ling Nan) with a scanning electron microscope for morphometry. For chickens aged 10-15 post-hatch days, the otoliths in each macula lagena were counted to be 16,055 +/- 4038 (mean +/- S.D., n = 4). The average length and width were 12.98 +/- 3.70 microm and 5.10 +/- 1.48 microm (n = 526 otoliths), respectively. The ratio of length to width for the otolith was 2.58 +/- 0.39 (n = 526 otoliths) and remained relatively constant despite their variations in physical size. Almost all the otoliths were in regular shape and appeared like isolated cylinders with smooth facets at each end, but a few of them (0.025% of 64,221 otoliths screened) were found to be in odd shapes, such as T-shape and cross-shape. The results suggest that otoliths in the macula lagena and those in the vestibular system of bird's inner ear have similar physical properties and may play a similar role in sensing gravitational and acceleration signals.

Hemoglobin H hydrops fetalis syndrome resulting from the association of the - -SEA deletion and the alphaQuong Szealpha mutation in a Chinese woman

A case with Hb H hydrops fetalis syndrome resulting from the association of the - -(SEA) deletion and the alpha(Quong Sze)alpha mutation is reported. This is the first description of Hb H hydrops associated with the Hb Quong Sze mutation.

Superdipole liquid scenario for the dielectric primary relaxation in supercooled polar liquids

We propose a dynamic structure of coupled dynamic molecular strings for supercooled small polar molecule liquids and accordingly we obtain the Hamiltonian of the rotational degrees of freedom of the system. From the Hamiltonian, the strongly correlated supercooled polar liquid state is renormalized to a normal superdipole liquid state. This scenario describes the following main features of the primary or alpha-relaxation dynamics in supercooled polar liquids: (1) the average relaxation time evolves from a high temperature Arrhenius to a low temperature non-Arrhenius or super-Arrhenius behavior; (2) the relaxation function crosses over from the high temperature exponential to low temperature nonexponential form; and (3) the temperature dependence of the relaxation strength shows non-Curie features. According to the present model, the crossover phenomena of the first two characteristics arise from the transition between the superdipole gas and the superdipole liquid. The model predictions are quantitatively compared with the experimental results of glycerol, a typical glass former.

Taurine activates strychnine-sensitive glycine receptors in neurons of the rat inferior colliculus

Taurine (Tau) is one of the most abundant free amino acids in the mammalian central nervous system. Whether the neurotransmission of the central auditory system is regulated or modulated by Tau is not clear. In the present study, we investigated the electrophysiological and pharmacological properties of Tau-activated currents in acutely dissociated neurons of the rat inferior colliculus (IC) using whole cell patch clamp recordings. At a holding potential of -60 mV and under a condition of chloride equilibrium potential near 0 mV, Tau activated an inward current and its half-maximal activation concentration was equal to 0.37 mM. The measured reversal potential of Tau-activated currents was close to theoretical chloride equilibrium potential. The currents evoked by Tau at both low (1 mM) and high (10 mM) concentrations were almost completely inhibited by strychnine, a glycine receptor antagonist. The Tau-activated current, however, was not affected by bicuculline, a GABA(A) receptor antagonist. Tau at increased concentrations progressively reduced the current response to subsequent glycine application. At saturated concentrations, Tau-activated current and glycine-activated current were mutually cross-desensitized by each other. These findings indicate that Tau activates glycine receptors in neurons of the rat IC and thus may have a functional role in regulating or modulating the neurotransmission of the central auditory system in mammals.

Modeling dynamically heterogeneous coupled relaxations

A model describing dynamically heterogeneous relaxation in complex coupled systems is presented. The model predicts the splitting of a high-temperature single Debye relaxation to a low-temperature bimodal relaxation. The bimodal process shows a crossover from a Debye-type relaxation to an approximately stretched-exponential relaxation. Some general features of relaxation in complex systems emerge from the predictions of the model, and a comparison of the model with experiments is reported.

Reynolds stress under a change of frame of reference

In this paper, we study the characteristics of the Reynolds stress under a change of frame, as defined by the Euclidean group of transformation. We show that being subject to the dynamical processes induced from the mean Navier-Stokes equations, the invariance group of the fluctuating velocity and the Reynolds stress is no longer the Euclidean group of transformation, which is merely a kinematical aspect, but reduces to the extended Galilean group of transformation. As a consequence, in contrast to developing the constitutive equations for the Cauchy stress in continuum mechanics, wherein the principle of material frame-indifference is a guiding principle, the frame-dependent kinematical quantities, e.g., the mean spin tensor, may be allowed to play an effective role as the constitutive variable in turbulence modeling.

Cerebrovascular disease among Chinese populations--recent epidemiological and neuroimaging studies

Stroke mortality in individuals of Chinese descent has declined during the past decades, although the absolute number of patients with first-ever stroke is escalating. This review summarises recent epidemiological and imaging studies conducted among Chinese populations. Data indicating differences between Chinese and Caucasian ethnic groups in the pathophysiological mechanisms of stroke are highlighted, and the potential implications of these findings for prevention and management of stroke are discussed.

Intracranial stenosis in Chinese patients with acute stroke

We studied 100 consecutive acute stroke patients in a Chinese population with transcranial Doppler and CT. Twenty patients had intracerebral hemorrhage and 14 patients did not have adequate temporal windows for transcranial Doppler examination. Among the remaining 66 patients, 22 patients (33%) had intracranial occlusive diseases and 3 (6%) had extracranial carotid stenosis. Our data showed that intracranial occlusive disease is the most commonly found vascular lesion in our acute stroke patients.

Vascular lesions in Chinese patients with transient ischemic attacks

We studied 96 Chinese patients with TIAs using transcranial Doppler and duplex ultrasonography. We found intracranial stenosis or occlusion in 51% of cases and extracranial disease in 19% of cases. The most common intracranial lesion was stenosis of the terminal internal carotid artery or proximal middle cerebral artery, whereas the most common extracranial lesion was stenosis of the carotid bifurcation.

Variability of magnetic resonance angiography and computed tomography angiography in grading middle cerebral artery stenosis

BACKGROUND AND PURPOSE

Magnetic resonance angiography and computed tomography angiography are new, noninvasive methods to provide images of the cerebral vasculature. The reliability of magnetic resonance angiography and computed tomography angiography when used to grade middle cerebral artery stenosis remains to be established. We sought to study the interobserver and intraobserver variabilities of magnetic resonance angiography and computed tomography angiography in grading middle cerebral artery stenosis.

METHODS

A total of 50 middle cerebral arteries in 25 patients were studied with magnetic resonance angiography and computed tomography angiography. All patients had a history of ischemic stroke. The films were read independently by two observers on separate occasions. Films were shown again to the same observer 4 weeks after the first reading. The degree of middle cerebral artery stenosis was categorized into four grades: normal/mild, moderate, severe, and occluded. The interobserver and intraobserver variabilities were calculated by the kappa statistic method.

RESULTS

Interobserver variability for grading middle cerebral artery stenosis was good (kappa = 0.78) for magnetic resonance angiography and moderate (kappa = 0.51) for computed tomography angiography. There was perfect agreement between two observers in 86% of the vessels shown in magnetic resonance angiography and in 76% of the vessels shown in computed tomography angiography. Intraobserver variability for both imaging methods was good, with the kappa value in the range of 0.70 to 0.76.

CONCLUSIONS

Our results suggest that according to our protocol, magnetic resonance angiography is more reliable than computed tomography angiography in grading middle cerebral artery stenosis.

Spiral computed tomography angiography in the assessment of middle cerebral artery occlusive disease

There has been no report on the use of spiral computed tomography angiography (CTA) in the investigation of intracranial cerebral artery stenosis. A prospective pilot study was conducted to investigate the feasibility of CTA in the diagnosis of intracranial occlusive disease and its correlation with transcranial Doppler. With transcranial Doppler, 10 patients with acute ischaemic stroke with middle cerebral artery stenosis or occlusion were identified. There were seven middle cerebral artery stenoses and five middle cerebral artery occlusions. The CTA confirmed all diagnoses by transcranial Doppler except in one patient with middle cerebral artery occlusion in whom the embolus had probably propagated. The results showed that CTA is feasible and potentially useful in the diagnosis of middle cerebral artery occlusive disease. Further studies are required to assess its validity, sensitivity, and specificity in the diagnosis of middle cerebral artery occlusive disease.

On the dynamics of a toxicant-individual system

The dynamics of a toxicant-individual model where the individual is represented by von Bertalanffy dynamics and the uptake model component is one developed by Barber, Suarez & Lassiter is discussed. A sufficient condition for the death of an individual subjected to chemical stress is found. Another possible behavior of the system is an oscillatory mode of individual size and internal chemical concentration determined by a limit cycle. These fluctuations are a consequence of formulations of growth, maintenance, and the dose-response functions in the model system.