[Short-term efficacy and safety of cardiac contractility modulation in patients with heart failure]

Objective: To investigate the short-term efficacy and safety of cardiac contractility modulation (CCM) in patients with heart failure. Methods: This was a cross-sectional study of patients with heart failure who underwent CCM placement at the First Affiliated Hospital of Xinjiang Medical University from February to June 2022. With a follow-up of 3 months, CCM sensation, impedance, percent output, and work time were monitored, and patients were compared with pre-and 3-month postoperative left ventricular ejection fraction (LVEF) values, and 6-minute walk test distance and New York Heart Association (NYHA) cardiac function classification, and the occurrence of complications was recorded. Results: CCM was successfully implanted in all 9 patients. Seven(7/9) of them were male, aged (56±14) years, 3 patients had ischaemic cardiomyopathy and 6 patients had dilated cardiomyopathy. At 3-month postoperative follow-up, threshold was stable, sense was significantly lower at follow-up than before (right ventricle: (16.3±7.0) mV vs. (8.2±1.1) mV, P<0.05; local sense: (15.7±4.9) mV vs. (6.7±2.5) mV, P<0.05), and impedance was significantly lower at follow-up than before (right ventricle (846±179) Ω vs. (470±65) Ω, P<0.05, local sense: (832±246) Ω vs. (464±63) Ω, P<0.05). The CCM output percentage was (86.9±10.7) %, the output amplitude was (6.7±0.4) V, and the daily operating time was (8.6±1.0) h. LVEF was elevated compared to preoperative ((29.4±5.2) % vs. (38.3±4.3) %, P<0.05), the 6-minute walk test was significantly longer than before ((96.8±66.7)m vs. (289.3±121.7)m, P<0.05). No significant increase in the number of NYHA Class Ⅲ-Ⅳ patients was seen (7/9 vs. 2/9, P>0.05). The patient was not re-hospitalised for worsening heart failure symptoms, had no malignant arrhythmic events and experienced significant relief of symptoms such as chest tightness and shortness of breath. No postoperative complications related to pocket hematoma, pocket infection and rupture, electrode detachment, valve function impairment, pericardial effusion, or cardiac perforation were found. Conclusions: CCM has better short-term safety and efficacy in patients with heart failure.

[The efficacy and safety of laparoscopic radical gastrectomy after neoadjuvant chemotherapy combined with immunotherapy and targeted therapy]

Objectives: To explore the efficacy and safety of laparoscopic radical gastrectomy after neoadjuvant chemotherapy combined with immunotherapy and targeted therapy in patients with gastric cancer. Methods: A retrospective analysis of clinical and pathological data of 20 patients with locally advanced gastric cancer (clinical TNM stage T3-4aN+M0) admitted to the Cancer Hospital, Chinese Academy of Medical Sciences from July 2021 to July 2023. All patients received 3 cycles of SOX (Oxaliplatin+S-1) regimen combined with immunotherapy (Trastuzumab) and targeted therapy (Apatinib) as neoadjuvant treatment followed by laparoscopic radical gastrectomy for gastric cancer. Surgical outcomes, postoperative pathological response, and postoperative recovery were observed. Quantitative data, except for age and operation time, were expressed using Median (range). Results: Among the 20 patients, there were 18 males and 2 females, aged 41 to 73 years [(60.6±9.7) years]. All 20 patients underwent laparoscopic surgical treatment after neoadjuvant therapy, with one patient undergoing laparoscopic conversion to open total gastrectomy with partial transverse colon resection due to tumor invasion into the transverse mesocolon. Eight patients underwent totally laparoscopic radical gastrectomy, all with Billroth Ⅱ+Braun anastomosis at the distal stomach. Eleven patients underwent laparoscopic-assisted radical gastrectomy, among which total gastrectomy with Roux-en-Y anastomosis was performed in ten cases, and proximal gastrectomy with esophagogastrostomy overlap anastomosis was performed in one case. The mean operation time for the 20 patients was (165.0±34.1) minutes; intraoperative blood loss was 80 (20-100) ml; and the number of lymph nodes retrieved was 68 (21-89). Postoperative pathological TNM staging revealed stage T0N0M0 in six cases, stage Ⅰ in two cases, stage Ⅱ in three cases, and stage Ⅲ in nine cases. Six patients (30.0%) achieved pathological complete response, and nine patients (45.0%) achieved significant pathological response. The median postoperative time to flatus was 4 (1-5) days; oral intake resumed after 3 (2-5) days; and the median length of hospital stay was 13 (6-19) days. One patient developed colonic anastomotic leakage with intra-abdominal infection, and one patient developed duodenal stump leakage with intra-abdominal infection, both classified as Clavien-Dindo grade 3A complications, and improved after treatment and discharged. One patient developed gastric paresis, and two patients developed pleural effusion, classified as Clavien-Dindo grade 2 complications, and improved after treatment and discharged. There were no deaths within 30 days after discharge. Conclusions: Laparoscopic radical gastrectomy for gastric cancer after neoadjuvant treatment with the SOX regimen combined with immunotherapy and targeted therapy is safe and feasible, with satisfactory short-term efficacy. However, there is an increase in overall surgical risk and difficulty, and it is recommended to be performed in experienced gastric cancer centers.

Clinical outcomes of SMILE and WFG-LASIK used to treat myopia and astigmatism: A systematic review and meta-analysis

PURPOSE

To evaluate the safety, efficacy and postoperative visual quality of small incision lenticule extraction (SMILE) and Wavefront-Guided Laser in situ keratomileusis (WFG-LASIK) and to analyze their efficacy in correcting astigmatism.

METHODS

A systematic literature search was performed using Cochrane Collaboration methodology. Databases searched included PubMed, Embase, the Cochrane Library and Web of Science. RevMan software version 5.3.0 was used for meta-analysis.

RESULTS

A total of 976 eyes were included in 8 studies, of which 539 eyes underwent SMILE and 437 eyes underwent WFG-LASIK. There were no statistically significant differences in the proportion of eyes achieving uncorrected distance visual acuity of 20/20 or better (P=0.18), the proportion of eyes within±0.50 diopter of target refraction postoperatively (P=0.10), or the postoperative magnitude of cylinder (P=0.10). Regarding the Alpins vector analysis of astigmatism, there was no statistically significant difference in the surgical magnitude of error (P=0.09) between the two groups. WFG-LASIK has a lower surgical angle of error (P= 0.002) and higher surgical correction index of cylinder (P=0.03) than SMILE. In terms of aberrations, higher order aberrations (P=0.46), spherical aberrations (P=0.22) and trefoil (P=0.56) were not statistically different, while WFG-LASIK induced less coma than SMILE surgery (P=0.02).

CONCLUSION

Both SMILE and WFG-LASIK are safe and effective ways to correct myopia and astigmatism. Compared with SMILE, WFG-LASIK has a lower surgical angle of error, higher surgical correction index of cylinder and induces less coma.

Visual and auditory attention defects in children with intermittent exotropia

BACKGROUND

Previous studies have shown that children with intermittent exotropia (IXT) have a higher rate of psychiatric abnormalities as they grow up, such as attention deficit. This study explored visual and hearing attention among children with IXT, and evaluated its association with clinical characteristics and cognitive development.

METHODS

Forty-nine children with a diagnosis of IXT and 29 children with traditional development were recruited. The Integrated Visual and Auditory Continuous Performance Test (IVA-CPT) was used to measure the subjects' full-scale response control quotient (FSRCQ), full-scale attention quotient (FSAQ), auditory response control quotient (ARCQ), auditory attention quotient (AAQ), visual response control quotient (VRCQ), and visual attention quotient (VAQ). The Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV) was used to assess their cognitive function. The differences between the scores of children with IXT and normal controls were analyzed.

RESULTS

The results showed that the FSRCQ, FSAQ, ARCQ, AAQ, VRCQ, and VAQ of children with IXT were all lower than those of normal controls with the same age (P < 0.05). The level of attention was significantly correlated with the age of strabismus onset (P < 0.05), but not with the degree of strabismus, stereopsis, or fusion control score. In addition, audiovisual attention was correlated significantly with their cognitive development level. The random forest classifier prediction model showed that age of strabismus onset was an important predictor of attention.

CONCLUSION

Children with IXT have lower visual and auditory attention and control than their peers, and the age of onset of strabismus may be a major factor.

[Analysis of factors related to systemic embolism in patients≥75 years old with non-valvular atrial fibrillation]

Objective: To explore the related risk factors for systemic embolism (SE) in patients aged≥75 years with non-valvular atrial fibrillation (NVAF). Methods: A case-control study. NVAF patients aged≥75 years who were hospitalized at the First Affiliated Hospital of Xinjiang Medical University from October 2018 to October 2020 were divided into no SE (n=1 127) and SE (n=433) groups according to the occurrence of SE after NVAF. Multivariate logistic regression was used to analyze SE-related factors in patients with NVAF without anticoagulation treatment. Results: In the multivariate model, the following factors were associated with an increased risk of SE in patients with NVAF: history of AF≥5 years [odds ratio (OR)=2.75, 95% confidence interval (CI) 1.98-3.82, P<0.01], lipoprotein(a)>300 g/L (OR=2.07, 95%CI 1.50-2.84, P<0.01), apolipoprotein (Apo)B>1.2 g/L (OR=1.91, 95%CI 1.25-2.93, P=0.003), left ventricular ejection fraction (LVEF) of 30%-49% (OR=2.45, 95%CI 1.63-3.69, P<0.01), left atrial diameter>40 mm (OR=1.54, 95%CI 1.16-2.07, P=0.003), and CHA₂DS₂-VASc score≥3 (OR=15.14, 95%CI 2.05-112.13, P=0.01). ApoAI>1.6 g/L was negatively correlated with the occurrence of SE (OR=0.28, 95%CI 0.15-0.51, P<0.01). Conclusions: History of AF≥5 years, lipoprotein(a)>300 g/L, elevated ApoB, left atrial diameter>40 mm, LVEF of 30%-49%, and CHA₂DS₂-VASC score≥3 are independent risk factors for SE whereas ApoAI>1.6 g/L is a protective factor against SE in patients with NVAF.

[Effects of vaccines on the viral negative conversion of children with COVID-19]

Objective: To explore the effect of vaccination on viral negative conversion of children with COVID-19. Methods: A retrospective cohort study was conducted. A cohort of 189 children aged 3-14 years with COVID-19 admitted to Renji Hospital (South branch) of Shanghai Jiao Tong University School of Medicine from April 7^th to May 19^th 2022 was enrolled in the study. According to the vaccination status, the infected children were divided into an unvaccinated group and a vaccinated group. Age, gender, severity, clinical manifestations, and laboratory tests, etc. were compared between groups, by rank sum test or chi-square test. The effects of vaccination on viral negative conversion were analyzed by a Cox mixed-effects regression model. Additionally, a questionnaire survey was conducted among the parents of unvaccinated children to analyze the reasons for not being vaccinated. Results: A total of 189 children aged 3-14 years were enrolled, including 95 males (50.3%) and 94 females (49.7%), aged 5.7 (4.1,8.6) years. There were 117 cases (61.9%) in the unvaccinated group and 72 cases (38.1%) in the vaccinated group. The age of the vaccinated group was higher than that of the unvaccinated group (8.8 (6.8, 10.6) vs. 4.5 (3.6, 5.9) years, Z=9.45, P<0.001). No significant differences were found in clinical manifestations, disease severity, and laboratory results between groups (all P>0.05), except for the occurrence rate of cough symptoms, which was significantly higher in the vaccinated group than in the non-vaccinated group (68.1% (49/72) vs. 50.4% (59/117),χ²=5.67, P=0.017). The Kaplan-Meier survival curve and Cox mixed-effects regression model showed that the time to the viral negative conversion was significantly shorter in the vaccinated group compared with the unvaccinated group (8 (7, 10) vs. 11 (9, 12) d, Z=5.20, P<0.001; adjusted HR=2.19 (95%CI 1.62-2.97)). For questionnaire survey on the reasons for not receiving a vaccination, 115 questionnaires were distributed and 112 valid questionnaires (97.4%) were collected. The main reasons for not being vaccinated were that parents thought that their children were not in the range of appropriate age for vaccination (51 cases, 45.5%) and children were in special physical conditions (47 cases, 42.0%). Conclusion: Vaccination can effectively shorten the negative conversion time of children with COVID-19 and targeted programs should be developed to increase eligible children's vaccination rate for SARS-CoV-2 vaccination.

[Correlation between abnormal left atrial appendage function and thrombotic events in patients with non-valvular atrial fibrillation]

Objective: To investigate the association between abnormal left atrial appendage function and thrombotic events in patients with non-valvular atrial fibrillation, and the independent risk factors affecting left atrial appendage function. Methods: Patients with non-valvular atrial fibrillation, who visited the Atrial Fibrillation Center of the First Affiliated Hospital of Xinjiang Medical University from June 1, 2019 to June 1, 2021, were selected. According to left atrial appendage flow velocity (LAAFV), they were divided into normal left atrial appendage function group (297 patients with LAAFV ≥ 40 cm/s) and abnormal left atrial appendage function group (85 patients with LAAFV<40 cm/s). Baseline data and transesophageal echocardiography images were collected from all the patients. The occurrence of thrombotic events was recorded. Univariate and multivariate unconditional logistic regression analyses were conducted to investigate the correlation between abnormal left atrial appendage function and the occurrence of thrombotic events. Results: There were significant differences in gender, type of atrial fibrillation, CHA₂DS₂-VASc score, anticoagulant therapy, total cholesterol, low-density lipoprotein cholesterol, international normalized ratio (INR), left atrial diameter, proportion of patients with right atrial enlargement, left ventricular ejection fraction, inner diameter, sum of inner diameter, depth, and sum of depth of all angles of the left atrial appendage, and incidence of thrombotic events between the two groups (all P<0.05). After adjusting for confounders, multivariate unconditional logistic regression analyses showed that abnormal left atrial appendage function was closely associated with thrombotic events (β=1.168 P=0.002), and left atrial diameter (OR=1.084, 95%CI 1.019-1.153, P=0.011) and persistent atrial fibrillation (OR=2.323, 95%CI 1.226-4.403, P=0.010) were independent risk factors affecting left atrial appendage function. Conclusions: Abnormal left atrial appendage function is closely associated with thrombosis. The left atrial diameter and persistent atrial fibrillation were independent risk factors affecting left atrial appendage function.

UV response characteristics of mixed-phase MgZnO thin films with different structure distributions, high Iuv/Idark ratios, and fast speed MgZnO UV detectors with tunneling breakdown mechanisms

High-performance ultraviolet (UV) detectors with both high responses and fast speeds are hard to make on homogeneous crystal semiconductor materials. Here, the UV response characteristics of mixed-phase MgZnO thin films with different internal structure distributions are studied. The mixed-phase MgZnO-based detector with the given crystal composition has a high response at both deep UV light (96 A W-1 at 240 nm) and near UV light (80 A W-1 at 335 nm). Meanwhile, because of the quasi-tunneling breakdown mechanism within the device, the high-response UV detector also shows a fast response speed (tr = 0.11 μs) and recovery speed (td1 = 26 μs) at deep UV light, which is much faster than both low-response mixed-phase MgZnO-based UV detectors with other structure constitutions and reported high-response UV devices on homogenous crystal materials. The Idark of the device is just 4.27 pA under a 5 V bias voltage, so the signal-to-noise ratio of the device reached 23852 at 5.5 uW cm-2 235 nm UV light. The new quasi-tunneling breakdown mechanism is observed in some mixed-phase MgZnO thin films that contain both c-MgZnO and h-MgZnO parts, which introduce a high response, signal-to-noise ratio, and fast speed into mixed-phase MgZnO-based UV detectors at weak deep UV light.

[Ovarian Sertoli-Leydig cell tumors: DICER1 hotspot mutations and associated clinicopathological features]

Objective: To investigate DICER1 hotspot mutations in ovarian Sertoli-Leydig cell tumor (SLCT) and its associated clinicopathological features. Methods: Forty-three SLCTs and 40 other sex cord-stromal tumors (SCSTs) diagnosed between 2010 and 2017 at Fudan University Shanghai Cancer Center were examined for somatic DICER1 hotspot mutations by Sanger sequencing. The associations between mutation status and clinicopathological features, including patient age, tumor differentiation and recurrence, were analyzed. Results: Somatic DICER1 mutations were found in 51% (22/43) of SLCTs, while none in the other 40 SCSTs. The most common mutation of DICER1 was p.D1709N in exon 24 (41%, 9/22) and the second most common mutation of DICER1 was p.E1813K in exon 25 (14%, 3/22). A novel frameshift mutation (c.5464delG, p.M1837fs*16) was identified in one SLCT with microcystic pattern. Mutations were more likely to occur in patients under forty years of age (P=0.046), whereas no significant associations were found between DICER1 mutations and clinical symptoms, morphology or tumor recurrence. Conclusions: Somatic DCIER1 hotspot mutations are specifically found in SLCT and may serve as an ancillary marker in differential diagnosis of SLCT from other SCST. The mutations occur more often in young patients (<40 years old). Additional studies are warranted to examine the associations between DICER1 mutations and clinicopathological features and prognosis of SLCT.

[Analysis of the KCNQ1 gene mutation in 2 families with congenital long QT syndrome type 1 in Xinjiang Uygur Autonomous Region]

Objective: Present study analyzed the association betwen the postassium voltage-gated channel KQT-like subfamily member 1 gene (KCNQ1) mutation and the clinical and the electrocardiographic features in 2 pedigrees with congenital long QT syndrome type 1 (LQT1) in Xinjiang Uygur Autonomous Region. Methods: Three family members were diagnosed as LQT1 patients in 2 Uygur congenital LQT1 families, these 3 LQT1 patients served as long QT group, 24 Uygur healthy volunteers served as control group. Electrocardiogram (ECG) and the gene detection were applied to compare the ECG and molecular genetic features between the long QT group and control group, and to explore the relationship between the KCNQ1 gene mutation and the clinical and the electrocardiographic features in these 2 families with congenital long QT syndrome type 1. Results: The LQT1 was diagnosed in 3 cases of the 2 pedigrees. The common features of ECG were QTc>480 ms, prolonged ST segment, and delayed T wave. The gene test evidenced a polymorphism of KCNQ1 gene exon 13:47G➝A(R16R). The mutation of 133G➝A9(G45S) of exon 16 resulted in the change of the original glycine (G) to serine (s). The ECG of the control group were normal, and there were no KCNQ1 gene mutations in control group. Conclusion: The exon sequencing results of KCNQ1 gene in 2 Xinjiang Uygur congenital long LQT1 families showed that exon16 missense changes (133G to A (G45S)) can lead to amino acid mutation, this mutation may be a pathogenic mutation. Subsequent validation of the expanded sample will provide a reference for revealing the relationship between the KCNQ1 gene and the pathogenesis of LQT1.

[The relationship between LDL-C and ischemic stroke in 2 470 patients with nonvalvular atrial fibrillation in Xinjiang region]

Objective: To evaluate the association between LDL-C and ischemic stroke in patients with nonvalvular atrial fibrillation (AF). Method: A total of 2 470 patients with nonvalvular AF were included in the present study. The clinical data and laboratory examination results of the patients in the hospital were collected. The subjects were either divided into the ischemic stroke history (n=560), and non- ischemic stroke history groups (n=1 910), or divided into the low-middle risk (n=566) and high risk groups (n=1 904) based on CHA(2)DS(2) - VASc score. Results: There were significant differences in the proportion of Han, the ratio of gender, age, hemoglobin, hematocrit, ALT, serum uric acid, HDL-C and LDL-C between the patients with ischemic stroke history and without (all P<0.05). Similarly, there were significant differences in the proportion of Han, the ratio of gender, age, white blood cell count, hemoglobin, hematocrit, platelet count, ALT, albumin, TG and LDL-C between subjects in the low-middle risk group and those in the high risk group (all P<0.05). A logistical regression analysis showed that LDL-C was an independent risk factor for both the ischemic stroke history (OR 2.089, 95% CI 1.860-2.347, P<0.05), and future ischemic stroke risk (OR 1.270, 95% CI 1.079-1.494, P<0.05) in patients with nonvalvular AF. Conclusion: LDL-C is associated with ischemic stroke in patients with nonvalvular AF, and it is also an independent risk factor for future ischemic stroke in these patients.

[Impact of 2013 American Society of Clinical Oncology/College of American Pathologist guidelines on borderline immunostaining results for HER2: a retrospective study on HER2 FISH results in 1 780 cases of invasive breast cancers]

OBJECTIVE

To analyze the impact of the revised 2013 American Society of Clinical Oncology/College of American Pathologist(ASCO/CAP)HER2 testing guidelines on the status of HER2 and its clinical significance in invasive breast cancers by fluorescent in situ hybridization(FISH).

METHODS

One thousand seven hundred and eighty invasive breast cancer cases with equivocal 2+ immunostaining detected by FISH were retrospectively selected from 2010 to 2014, and the HER2/CEP17 dual-probe results were evaluated according to both the 2007 and 2013 ASCO/CAP guidelines for comparative analysis.

RESULTS

Among the 1 780 IHC HER2 (2+ ) invasive breast cancers, the number of HER2 positive, equivocal and negative case were 310(17.41%), 66(3.71%)and 1 404(78.88%) respectively, basing on the 2007 guidelines; whereas basing on the 2013 ASCO/CAP HER2 guidelines, the number of HER2 positive, equivocal and negative case was 360 (20.22%), 182 (10.23%)and 1 238 (69.55%) respectively. Compared with the 2007 guidelines, the proportion of positive and equivocal cases were higher in the 2013 guidelines (17.41% versus 20.22%, 3.71% versus 10.23% respectively), while the proportion of negative cases was lower(78.88% versus 69.55%).

CONCLUSIONS

Using the 2013 ASCO/CAP guidelines could lead to an increase in positive and equivocal cases, and a decrease in negative cases. The increase can probably be attributable to the inclusion of HER2 copy number besides HER2/CEP17 ratio as positive criteria, and it improves the accuracy and may be of important value for screening more population who benefit from HER2 targeting treatment; however the benefits for HER2 positive with low HER2 copy number and the clinical significance of the equivocal cases need to be further investigated.

Classification and phylogenetic analysis of Chinese hawthorn assessed by plant and pollen morphology

The Chinese hawthorn (Crataegus pinnatifida Bge. var. major N.E.Br.) is uniquely originated in northern China. The ecological and horticultural importance of Chinese hawthorn is considerable and some varieties are valued for their fruit or medicine extracts. Its taxonomy and phylogeny remain poorly understood. Apart from general plant morphological traits, pollen is an important trait for the classification of plants and their evolutionary origin. However, few studies have investigated the pollen of Chinese hawthorn. Here, an analysis of plant and pollen morphological characteristics was conducted in 57 cultivars from the Shenyang region. Thirty plant morphological characters and nine pollen grain characters were investigated. The plant morphological analysis revealed that the coefficient of variation for 13 traits was >20%, which indicates a high degree of variability. We also found that the pollen grains varied greatly in size, shape (from prolate to perprolate), and exine pattern (striate-perforate predominantly). The number of apertures was typically three. Based on these findings, we suggest that pollen morphology associated with plant morphological traits can be used for classification and phylogenetic analysis of Chinese hawthorn cultivars. In sum, our results provide new insights and constitute a scientific basis for future studies on the classification and evolution of Chinese hawthorn.

[A study on the evaluation of anticoagulation status comparing of CHADS2 versus CHA2DS2-VASc scores in patients with non valvular atrial fibrillation in Xinjiang area]

OBJECTIVE

To evaluate the current status of anticoagulation therapy in patients with atrial fibrillation(AF)in Xinjiang, and compare the two scoring systems(CHADS2 and CHA2DS2-VASc scores) in determining the risk of strokes in AF patients in Xinjiang.

METHODS

Subjects with AF were collected by searching the electronic and paper medical records from 35 hospitals in Xinjiang area during October 2013 to October 2014, and followed up for the incident strokes after 10 to 12 months.

RESULTS

Totally, 5 953 AF patients were enrolled in the study with the age of (67.9±12.0) years old, and men to women ratio of 1.44. Most patients were in age groups of 60-69 (23.92%) and 70-79 years (37.81%). Among patients with a CHADS2 score of 1 or less, the CHA2DS2-VASc scores of these subjects ranged from 0 to 3. After 10 to 12 months of follow-up, 22 patients developed new strokes. Only 30.79% patients ( n=1 460) received the anticoagulation treatment among those (n=4 742) who need to be treated with anticoagulation drugs. In patients receiving anticoagulant therapy, 1 162 patients were treated with warfarin, and 298 patients with new oral anticoagulant drugs.Totally 1 110 patients treated with warfarin were monitored with international normalized ratio (INR). The median INR was 1.14 with only 97 cases meeting the recommended INR ranging of 2.0-3.0 in the guidelines. The compliance rate was 8.74%.

CONCLUSIONS

The current status of anticoagulation for AF in Xinjiang area is characterized by "low anticoagulation rate" and "low compliance rate". The CHA2DS2-VASc score is more suitable for predicting the risk of strokes in patients with non valvular atrial fibrillation in Xinjiang area.

Structural Signature of Plasticity Unveiled by Nano-Scale Viscoelastic Contact in a Metallic Glass

Room-temperature plasticity in metallic glasses (MGs) is commonly associated with local structural heterogeneity; however, direct observation of the subtle structural change caused by plasticity is vitally important but the data are extremely scarce. Based on dynamic atomic force microscopy (DAFM), here we show that plasticity-induced structural evolution in a Zr-Ni MG can be revealed via nano-scale viscoelastic contacts between an AFM tip and plastically deformed MG surface layers. Our experimental results clearly show a spatial amplification of the nano-scale structural heterogeneity caused by the distributed plastic flow, which can be linked to the limited growth, reorientation and agglomeration of some nano-scale energy-absorbing regions, which are reminiscent of the behavior of the defect-like regions with non-affine deformation as conceived in many theories and models. Furthermore, we are able to experimentally extract the thermodynamic properties of these nano-scale regions, which possess an energy barrier of 0.3–0.5 eV, about half of that for a typical shear transformation event that usually occurs at the onset of plasticity. The outcome of our current work sheds quantitative insights into the correlation between plasticity and structural heterogeneity in MGs.

Shear-banding Induced Indentation Size Effect in Metallic Glasses

Shear-banding is commonly regarded as the “plasticity carrier” of metallic glasses (MGs), which usually causes severe strain localization and catastrophic failure if unhindered. However, through the use of the high-throughput dynamic nanoindentation technique, here we reveal that nano-scale shear-banding in different MGs evolves from a “distributed” fashion to a “localized” mode when the resultant plastic flow extends over a critical length scale. Consequently, a pronounced indentation size effect arises from the distributed shear-banding but vanishes when shear-banding becomes localized. Based on the critical length scales obtained for a variety of MGs, we unveil an intrinsic interplay between elasticity and fragility that governs the nanoscale plasticity transition in MGs. Our current findings provide a quantitative insight into the indentation size effect and transition mechanisms of nano-scale plasticity in MGs.

Origin of Shear Stability and Compressive Ductility Enhancement of Metallic Glasses by Metal Coating

Metallic glasses (MGs) are notorious for the poor macroscopic ductility and to overcome the weakness various intrinsic and extrinsic strategies have been proposed in past decades. Among them, the metal coating is regarded as a flexible and facile approach, yet the physical origin is poorly understood due to the complex nature of shear banding process. Here, we studied the origin of ductile enhancement in the Cu-coating both experimentally and theoretically. By examining serrated shear events and their stability of MGs, we revealed that the thin coating layer plays a key role in stopping the final catastrophic failure of MGs by slowing down shear band dynamics and thus retarding its attainment to a critical instable state. The mechanical analysis on interplay between the coating layer and shear banding process showed the enhanced shear stability mainly comes from the lateral tension of coating layer induced by the surface shear step and the bonding between the coating layer and MGs rather than the layer thickness is found to play a key role in contributing to the shear stability.

Genetic variability and diversity of the main resources of lily assessed via phenotypic characters, pollen morphology, and ISSR markers

Lily (Lilium spp), which belongs to Lilium, is one kind of monocotyledon. As a perennial ornamental plant with extremely high esthetic, edible, and medicinal value, lily has gained much favor due to its mostly showy flowers of various colors and elegant shape. In this research, we studied experimental materials in a sample of 49 individuals including 40 cultivars, nine species of wild lily, and their variants. The collection of 40 cultivars covered all six hybrids in the genus, i.e., Asiatic hybrids, Oriental hybrids, Longiflorum hybrids, LA hybrids, LO hybrids, and OT hybrids. Genetic diversity and inter-relationships were assessed through analysis of phenotypic characteristics, pollen morphology, and ISSR molecular markers. Quantitative characters were selected to analyze phenotypic variation, with results indicating greater variability in petiole length as compared to other characters. Pollen morphological observations suggested that the largest variation coefficient between all hybrids and wild species was the lumina. ISSR makers demonstrated that both cultivars and wild species possess a high level of genetic diversity. Specifically, the genetic diversity of wild lily was higher than cultivars.

Clinical significance of hmgb1 expression in human gastric cancer

High mobility group box 1 (HMGB1) has been proved to be implicated in a variety of cell physiological and pathological behaviors including immune response, inflammation and cancer. Accumulating evidence suggests that HMGB1 plays a critical role in the development and progression of multiple malignancies. However, the clinical significance and prognosis of HMGB1 expression in some cancers remain controversial. The present study aimed to investigate whether overexpression of HMGB1 is an independent prognostic factor in patients with gastric cancer. The correlation of HMGB1 expression with clinicopathologic characteristics and prognosis was assessed by immunohistochemical assay through tissue microarray procedure in 50 primary gastric cancer cases. Our results indicated that the positive expression of HMGB1 was significantly increased in the nucleus of gastric cancer tissues compared with the adjacent non-cancerous tissues (ANCT) (64.0&#x0025; vs 44.0&#x0025;, P=0.025), but was not linked to the clinicopathologic features, including the TNM stage (P=0.533) and metastatic lymph node (P=0.771), in patients with gastric cancer. Kapalan-Meier and log-rank analysis demonstrated that overexpression of HMGB1 did not exert significant impact on the overall survival of patients with gastric cancer (P=0.805). Furthermore, Cox regression analysis showed that high HMGB1 protein expression did not represent an independent risk factor for patients with gastric cancer (P=0.677). Taken together, our findings suggest that high expression of HMGB1 is not correlated with the clinicopathologic characteristics of gastric cancer, and cannot serve as an independent prognostic biomarker for patients with gastric cancer.

Dominant factor determining the conduction-type of nitrogen-doped ZnO film

Nitrogen-doped zinc oxide (ZnO) film has been grown by molecular beam epitaxy. The as-grown sample showed p-type conduction with a hole concentration of 3.1 x 10(17) cm(-3). After an annealing process in O2 at 600 degrees C for 30 min, p-type conduction was still remained, and the hole concentration of the film decreased to 6.8 x 10(16) cm(-3). Secondary ion mass spectroscopy revealed that the concentration of both nitrogen and hydrogen decreased after the annealing process. It is demonstrated that the intrinsic compensation source has been decreased after the annealing process. Because the variation trend of the hole concentration in the ZnO:N film is opposite to that of hydrogen and intrinsic defects, but in good accordance with nitrogen, the extrinsically substituted nitrogen (N(o)) should be the dominant factor that determines the conduction-type of the ZnO:N film.

Time-resolved optical reflectivity of the electron-doped Nd(2-x)Ce(x)CuO(4+δ) cuprate superconductor: evidence for an interplay between competing orders

We use pump-probe spectroscopy to measure the photoinduced reflectivity ΔR of the electron-doped cuprate superconductor Nd(2-x)Ce(x)CuO(4+δ) at a value of x near optimal doping, as a function of time, temperature, and laser fluence. We observe the onset of a negative ΔR signal at T(*)≈75 K, above the superconducting transition temperature, T(c), of 23 K. The relatively slow decay of ΔR, compared to the analogous signal in hole doped compounds, allows us to resolve time-temperature scaling consistent with critical fluctuations. A positive ΔR signal onsets at T(c) that we associate with superconducting order. We find that the two signals are strongly coupled below T(c), in a manner that suggests a repulsive interaction between superconductivity and another fluctuating order.

Pt magnetic polarization on Y3Fe5O12 and magnetotransport characteristics

Thin Pt films on an yttrium iron garnet (YIG = Y(3)Fe(5)O(12)) show ferromagneticlike transport properties, which may impact the functionality of Pt in spin current detection, but do not provide direct quantitative information on the Pt magnetization. We report magnetic x-ray magnetic circular dichroism measurements of YIG/Pt(1.5 nm) showing an average Pt moment of 0.054 μ(B) at 300 K and 0.076 μ(B) at 20 K. This observation indicates strong proximity effects and induced magnetic ordering in Pt on magnetic insulators and their contribution to the spin-related measurements should not be neglected. The transport characteristics also suggest considerable modifications in the Pt electronic structure due to magnetic ordering.

Optical properties of ZnMgO nanowalls grown by plasma-assisted molecular beam epitaxy

ZnMgO nanowalls were prepared by plasma-assisted molecular beam epitaxy without a catalyst on c-Al2O3 substrate. The obtained nanowalls have preferred orientation along c axis. The nanowalls are about 10 to 20 nm in thickness and about 50 nm in height. Only Zn, Mg, O and Al signals are detected in the nanowalls from the energy dispersive spectroscopy (EDS). The Mg content is about 3% in ZnMgO nanowalls. The room temperature photoluminescence (PL) spectra shows the emission peak of the ZnMgO nanowalls at 3.346 eV. The origin of the ultraviolet emission is discussed with the help of temperature-dependent PL spectra. The ultraviolet emission band is free exiton recombination observed in the low temperature PL spectra (at 81 K). We also observe the free-to-acceptor (FA) emission of the ZnMgO nanowalls. The acceptor binding energy obtained from photoluminescence studies is about 123 meV. The results show that Mg doping leads to an increase of the acceptor binding energy. The possible growth mechanism of the ZnMgO nanowall networks was discussed.

A first-principle analysis on the phase stabilities, chemical bonds and band gaps of wurtzite structure A(x)Zn(1-x)O alloys (A = Ca, Cd, Mg)

The phase stabilities and structural and electronic properties of three zinc-based oxide alloy systems (Ca(x)Zn(1-x)O, Cd(x)Zn(1-x)O and Mg(x)Zn(1-x)O) are studied by first-principle methods. We examine all alloy configurations in three 16-atom supercells (1 × 1 × 2 B1 phase structure, 2 × 2 × 1 and 2 × 1 × 2 B4 phase structures) and utilize symmetry of the bulk materials to reduce the amount of calculation. Taking into account the contribution of the alloy statistics, we have drawn the regions of phase stability for Ca(x)Zn(1-x)O (0.25<x<0.375), Mg(x)Zn(1-x)O (0.375<x<0.5) and Cd(x)Zn(1-x)O (0.75<x<0.875). We have also analyzed lattice constants (a and c), structural parameter u and the bond lengths in the wurtzite phases. We found that the averaged lattice constants of Mg(x)Zn(1-x)O and Ca(x)Zn(1-x)O do not follow the Vegard rule and this is related to the degree of instability of the wurtzite MgO and CaO. Wurtzite CaO is not stable and turns into hexagonal CaO upon geometry optimization. The calculated band gaps are found to be consistent with the experimental values for alloys Cd(x)Zn(1-x)O and Mg(x)Zn(1-x)O. The bowing parameters for alloys Mg(x)Zn(1-x)O and Cd(x)Zn(1-x)O are estimated to be 0.87 and 1.30 eV, respectively.

Photoluminescence of ZnO nanocrystals embedded in BaF2 matrices by magnetron sputtering

This paper describes ZnO nanocrystals embedded in BaF2 matrices by the magnetron sputtering method in an attempt to use fluoride as a shell layer to embed ZnO nanocrystals core. BaF2 is a wide-band gap material, and can confine carriers in the ZnO films. As a result, the exciton emission intensity should be enhanced. The sample was annealed at 773 K, and X-ray diffraction (XRD) results showed that ZnO nanocrystals with wurtzite structure were embedded in BaF2 matrices. Raman-scattering spectra also confirmed the formation of ZnO nanoparticles. Abnormal longitudinal-optical (LO) phonon-dominant multiphonon Raman scattering was observed in the sample. Room-temperature photoluminescence (PL) spectra showed an ultraviolet emission peak at 374 nm. The origin of the ultraviolet emission is discussed here with the help of temperature-dependent PL spectra. The ultraviolet emission band was a mixture of free exciton and bound exciton recombination observed in the low temperature PL spectra (at 77 K). Abnormal temperature dependence of ultraviolet near-band-edge emission-integrated intensity of the sample was observed. The band tail state was observed in the absorption spectra, illustrating that the impurity-related defects were caused by the shell of the BaF2 grain layer. For comparison, ZnO films on BaF2 substrates were also fabricated by the magnetron sputtering method, and the same measurement methods were used.

Expression and quantification of LYVE-1 in human colorectal cancer

The recent discovery of a new hyaluronan (HA) receptor, LYVE-1 (lymphatic vessel endothelial HA receptor), has been received with great interest regarding its specific expression in the lymphatic system. The process of lymphangiogenesis or the formation of new lymphatics in tumours is important because it serves as a major route for cancer metastasis. Therefore, methods to quantify lymphangiogenesis by measuring LYVE-1 have been studied extensively in searching for its possible role in cancer diagnosis, prognosis and even targeted treatment of lymphatic tumour metastasis. Here we report a quantitation study on lymphangiogenesis by either quantitative PCR or immunohistochemistry approaches in detecting LYVE-1 expression in human colorectal tumour. Real-time quantitative polymerase chain reaction (RTQ-PCR) was carried out to quantify LYVE-1 levels in colorectal cancer samples. Also, the same specimen was observed for LYVE-1 expression by immunohistochemical stain. By RTQ-PCR amplification, LYVE-1 was highly expressed in colorectal specimens and LYVE-1 signal from non-cancer tissue of normal control was much weaker by conventional RTPCR. Immunohistochemical stain showed that LYVE-1 was significantly expressed in cancer tissues (especially in the margin region of cancer), whereas in non-cancer specimens fewer positive stains were revealed. The results suggested that the LYVE-1 molecule was expressed significantly in colorectal specimens, which may imply a new marker for a malignant situation.

Preparation of ZnO colloids by aggregation of the nanocrystal subunits

Colloidal ZnO particles with narrow size distribution were prepared via a sol-gel process by base-catalyzed hydrolysis of zinc acetate. The morphology of ordered arrays of the particles was recorded by SEM. SEM also reveals that these uniform particles were composed of tiny ZnO subunits (singlets) sized of several nanometers. The size of the singlets, which is confirmed by X-ray diffraction and UV-vis absorption spectra, increases as the aging time is prolonged. The size-selective formation of colloids by aggregation of nanosized subunits is proposed to consist of two-stage growth by nucleation of nanosized crystalline primary particles and their subsequent aggregation into polycrystalline secondary colloids. The aggregates are all spherical because the internal rearrangement processes are fast enough. The ZnO colloids, i.e., the aggregates, tend to self-assemble into well-ordered hexagonal close-packed structures. Room-temperature photoluminescence was characterized for green and aged ZnO.

Neuronal nitric oxide synthase-derived nitric oxide inhibits neurogenesis in the adult dentate gyrus by down-regulating cyclic AMP response element binding protein phosphorylation

Neuronal nitric oxide synthase, the major nitric oxide synthase isoform in the mammalian brain, is implicated in some developmental processes, including neuronal survival, precursor proliferation and differentiation. However, reports about the role of neuronal nitric oxide synthase in neurogenesis in the adult dentate gyrus are conflicting. Here we show that 5-bromodeoxyuridine-labeled dividing progenitor cells in the dentate gyrus were significantly increased in mice receiving 7-nitroindazole, a selective neuronal nitric oxide synthase inhibitor, and in null mutant mice lacking neuronal nitric oxide synthase gene (nNOS-/-) 6 h and 4 weeks after 5-bromodeoxyuridine incorporation. The increase in 5-bromodeoxyuridine positive cells in 7-nitroindazole-treated mice was accompanied by activation of cyclic AMP response element binding protein phosphorylation in the dentate gyrus. Pretreatment with N-methyl-D-aspartate receptor antagonist MK-801 fully abolished the effects of 7-nitroindazole on neurogenesis and cyclic AMP response element binding protein phosphorylation. Furthermore, neuronal nitric oxide synthase inhibition significantly enhanced the survival of newborn cells and the number of 5-bromodeoxyuridine positive/NeuN positive cells in the dentate gyrus. These results indicate that neuronal nitric oxide synthase-derived nitric oxide suppresses neurogenesis in the adult dentate gyrus, in which N-methyl-D-aspartate receptor functions and cyclic AMP response element binding protein phosphorylation may be involved.

Optical properties of ZnO and ZnO:In nanorods assembled by sol-gel method

Self-assembled zinc oxide (ZnO) and indium-doping zinc oxide (ZnO:In) nanorod thin films were synthesized on quartz substrates without catalyst in aqueous solution by sol-gel method. The samples were characterized by x-ray diffraction (XRD), scanning electron microscope (SEM), Raman-scattering spectroscopy, room-temperature photoluminescence (PL) spectra, and temperature-dependent PL spectra measurements. XRD and Raman spectra illustrated that there were no single In2O3 phase in ZnO lattice after indium doping. The PL spectra of ZnO showed a strong UV emission band located at 394 nm and a very weak visible emission associated with deep-level defects. Indium incorporation induced the shift of optical band gap, quenching of the near-band-edge photoluminescence and enhanced LO mode multiphonon resonant Raman scattering in ZnO crystals at different temperatures. Abnormal temperature dependence of UV emission integrated intensity of ZnO and ZnO:In samples is observed. The local state emission peak of ZnO:In samples at 3.37 eV is observed in low-temperature PL spectra. The near-band-edge emission peak at room temperature was a mixture of excitons and impurity-related transitions for both of two samples.

The optical properties of ZnO hexagonal prisms grown from poly (vinylpyrrolidone)-assisted electrochemical assembly onto Si (111) substrate

ZnO hexagonal prisms have been grown from poly (vinylpyrrolidone)-assisted electrochemical assembly onto p-type Si (111) substrate. These ZnO prisms arrays are highly (0002) orientated. The (0001) end facets and {1010} side facets of the hexagonal prisms are well defined. The photoluminescence (PL) spectrum of these ZnO prisms shows an intense ultraviolet near band-gap emission with a full width at half maximum of 86 meV at room temperature. The low-temperature PL spectrum is split into well-resolved free and bound exciton emission lines. The temperature dependence of the exciton emission intensities shows a nonmonotonic decaying behavior, which can be explained by the existence of interfacial states.

Effects of thermal annealing on the structural and optical properties of MgxZn1−xO nanocrystals

Mg(x)Zn(1-x)O ternary alloy nanocrystals with hexagonal wurtzite structures were fabricated by using the sol-gel method. X-ray diffraction patterns, UV-vis absorption spectra, and photoluminescence spectra were used to characterize the structural and optical properties of the nanocrystals. For as-prepared nanocrystals, the band gap increases with increasing Mg content. Weak excitonic emission with strong deep-level emission related to oxygen vacancy and interface defects is observed in the photoluminescence spectra at room temperature. Thermal annealing in oxygen was used to decrease the number of defects and to improve the quality of the nanocrystals. In terms of XRD results, the grain sizes of nanocrystals increase with increasing annealing temperature and the lattice constants of alloy are smaller than those of pure ZnO. The band gap becomes narrower with increasing annealing temperature. For Mg(x)Zn(1-x)O nanocrystals (x=0.03-0.15) annealed at temperatures ranging from 500 to 1000 degrees C, intense near-band-edge (NBE) emissions and weak deep-level (DL) emissions are observed. Consequently, the quality of Mg(x)Zn(1-x)O nanocrystals can be improved by thermal annealing.

The effect of surface properties on visible luminescence of nanosized colloidal ZnO membranes

Luminescence properties of nanosized zinc oxide (ZnO) colloids depend greatly on their surface properties, which are in turn largely determined by the method of preparation. ZnO nanoparticles in the size range from 3 to 9 nm were prepared by addition of tetramethylammonium hydroxide ((CH3)4NOH) to an ethanolic zinc acetate solution. X-ray diffraction (XRD) indicates nanocrystalline ZnO membranes with polycrystalline hexagonal wurtzite structure. The ZnO membranes have a strong visible-emission intensity and the intensity depends upon hydrolysis time. The infrared spectra imply a variety of forms of zinc acetate complexes present on the surface of ZnO particles. The effect of the ZnO membrane surface properties on photoluminescence is discussed.

Spectrum of severe infections in an Asian renal transplant population

Infections in renal transplant recipients (RTX) account for 26% of hospitalization days annually and 40% of overall mortalities. A retrospective study of infections requiring hospitalization occurring among 725 Asian RTX in 2002 was performed.

RESULTS

Serious infections requiring at least one hospitalization occurred in 9.2% of RTX (n = 67). Multiple pathogens affected 28.4% of patients, resulting in 118 infectious episodes during 93 hospitalizations. Mean age of affected patients was 48 years and female to male ratio was 2:1. Forty-one (61.2%) had impaired renal function (serum creatinine >141 mumol/L). Mean duration of hospitalization per patient was 17 days and the in-patient mortality rate was 17.9% eighty-one (87%) hospitalizations were for late infections (>6 months posttransplant). Cyclosporine (CsA) with prednisolone with or without azathioprine was the immunosuppressant in 62.7% (n = 42) of RTX but proportionally, infections were more frequent among RTX on other more potent immunosuppressants (n = 21; 7.4% CsA-based vs. 19.3%, potent, P < .05). Bacterial, viral, fungal, and Pneumocystis carinii infections comprised 64.4%, 20.3%, 5.9%, and 4.2% respectively. Urinary tract infection, pneumonia, and bacterial septicemia (35.52%, 31.6%, and 11.8%, respectively) were the major presentations. E. coli, cytomegalovirus (CMV), and Candida were the most common pathogens. Notably, 13 out of 18 (72.2%) viral CMV infections were co- infections, occurring together with bacterial infections.

CONCLUSIONS

Late infections with the use of potent immunosuppressives and concurrent CMV reactivation are a major cause of morbidity. Longer antibacterial prophylaxis and closer monitoring for CMV infections may help reduce morbidity.

Deletion of mitochondrial ATPase inhibitor in the yeast Saccharomyces cerevisiae decreased cellular and mitochondrial ATP levels under non-nutritional conditions and induced a respiration-deficient cell-type

T(1), a mutant yeast lacking three regulatory proteins of F(1)F(o)ATPase, namely ATPase inhibitor, 9K protein and 15K protein, grew on non-fermentable carbon source at the same rate as normal cells but was less viable when incubated in water. During the incubation, the cellular ATP content decreased rapidly in the T(1) cells but not in normal cells, and respiration-deficient cells appeared among the T(1) cells. The same mutation was also induced in D26 cells lacking only the ATPase inhibitor. Overexpression of the ATPase inhibitor in YC63 cells, which were derived from the D26 strain harboring an expression vector containing the gene of the ATPase inhibitor, prevented the decrease of cellular ATP level and the mutation. Isolated T(1) mitochondria exhibited ATP hydrolysis for maintenance of membrane potential when antimycin A was added to the mitochondrial suspension, while normal and YC63 mitochondria continued to show low hydrolytic activity and low membrane potential. Thus, it is likely that deletion of the ATPase inhibitor induces ATPase activity of F(1)F(o)ATPase to create a dispensable membrane potential under the non-nutritional conditions and that this depletes mitochondrial and cellular ATP. The depletion of mitochondrial ATP in turn leads to occurrence of aberrant DNA in mitochondria.

Gene targeting reveals a role for the glutamate receptors mGluR5 and GluR2 in learning and memory

This work suggests that class I mGluRs are involved in long-term potentiation (LTP) at CA1 synapses within the hippocampus. Our data support a pathway linking class I-mGluRs with PKC and src to enhance the open probability of the NMDAR channel. This leads to LTP of the NMDAR, but not the AMPAR. We are currently analyzing double mGluR1 X mGluR5 knockouts with Collingridge for a loss of the LTP induction switch [Nature 368 (1994) 740.]. This induction of LTP of the NMDAR is necessary for "spatial" learning and memory to occur, since mice lacking the mGluR5 are deficient in the Morris water maze and context-dependent fear conditioning. We postulate that AMPARs may provide negative feedback inhibition to the NMDAR. Hence, in null mutants lacking the AMPAR subtype, GluR2, LTP in the CA1 region of hippocampal slices was markedly enhanced (twofold) and non-saturating, whereas neuronal excitability and paired-pulse facilitation were normal. The ninefold increase in Ca(2+) permeability, in response to kainate application, suggests one possible mechanism for enhanced LTP. Enhanced LTP could result from enhanced AMPAR channel conductance or increased recruiting of previously silent synapses. Since the GluR2 null mutants showed reduced exploration and impaired motor coordination, we could make no conclusion about its role in learning and memory. Future work will be directed to inducible deletion of GluR2 only in CA1 after development is complete. These results support the correlation between LTP and learning and memory.

Transthyretin, thyroxine, and retinol-binding protein in human cerebrospinal fluid: effect of lead exposure

Transthyretin (TTR), synthesized by the choroid plexus, is proposed to have a role in transport of thyroid hormones in the brain. Our previous studies in animals suggest that sequestration of lead (Pb) in the choroid plexus may lead to a marked decrease in TTR levels in the cerebrospinal fluid (CSF). The objectives of this study were to establish in humans whether TTR and thyroxine (T(4)) are correlated in the CSF, and whether CSF levels of Pb are associated with those of TTR, T(4), and/or retinol-binding protein (RBP). Eighty-two paired CSF and blood/serum samples were collected from patients undergoing clinical diagnosis of CSF chemistry. Results showed that the mean value of CSF concentrations for TTR was 3.33 +/- 1.60 microg/mg of CSF proteins (mean +/- SD, n = 82), for total T(4) (TT(4)) was 1.56 +/- 1.68 ng/mg (n = 82), for RBP was 0.34 +/- 0.19 microg/mg (n = 82), and for Pb was 0.53 +/- 0.69 microg/dl (n = 61 for those above the detection limit). Linear regression analyses revealed that CSF TTR levels were positively associated with those of CSF TT(4) (r = 0.33, p < 0.005). CSF TTR concentrations, however, were inversely associated with CSF Pb concentrations (r = -0.29, p < 0.05). There was an inverse, albeit weak, correlation between CSF TT(4) and CSF Pb concentrations (r = -0.22, p = 0.09). The concentrations of TTR, TT(4), and Pb in the CSF did not vary as the function of their levels in blood or serum, but RBP concentrations in the CSF did correlate to those of serum (r = 0.39, p < 0.0005). Unlike TTR, CSF RBP concentrations were not influenced by PB: These human data are consistent with our earlier observations in animals, which suggest that TTR is required for thyroxine transport in the CSF and that Pb exposure is likely associated with diminished TTR levels in the CSF.

Transthyretin, thyroxine, and retinol-binding protein in human cerebrospinal fluid: effect of lead exposure

Transthyretin (TTR), synthesized by the choroid plexus, is proposed to have a role in transport of thyroid hormones in the brain. Our previous studies in animals suggest that sequestration of lead (Pb) in the choroid plexus may lead to a marked decrease in TTR levels in the cerebrospinal fluid (CSF). The objectives of this study were to establish in humans whether TTR and thyroxine (T(4)) are correlated in the CSF, and whether CSF levels of Pb are associated with those of TTR, T(4), and/or retinol-binding protein (RBP). Eighty-two paired CSF and blood/serum samples were collected from patients undergoing clinical diagnosis of CSF chemistry. Results showed that the mean value of CSF concentrations for TTR was 3.33 +/- 1.60 microg/mg of CSF proteins (mean +/- SD, n = 82), for total T(4) (TT(4)) was 1.56 +/- 1.68 ng/mg (n = 82), for RBP was 0.34 +/- 0.19 microg/mg (n = 82), and for Pb was 0.53 +/- 0.69 microg/dl (n = 61 for those above the detection limit). Linear regression analyses revealed that CSF TTR levels were positively associated with those of CSF TT(4) (r = 0.33, p < 0.005). CSF TTR concentrations, however, were inversely associated with CSF Pb concentrations (r = -0.29, p < 0.05). There was an inverse, albeit weak, correlation between CSF TT(4) and CSF Pb concentrations (r = -0.22, p = 0.09). The concentrations of TTR, TT(4), and Pb in the CSF did not vary as the function of their levels in blood or serum, but RBP concentrations in the CSF did correlate to those of serum (r = 0.39, p < 0.0005). Unlike TTR, CSF RBP concentrations were not influenced by PB: These human data are consistent with our earlier observations in animals, which suggest that TTR is required for thyroxine transport in the CSF and that Pb exposure is likely associated with diminished TTR levels in the CSF.

CAKbeta/Pyk2 kinase is a signaling link for induction of long-term potentiation in CA1 hippocampus

Long-term potentiation (LTP) is an activity-dependent enhancement of synaptic efficacy, considered a model of learning and memory. The biochemical cascade producing LTP requires activation of Src, which upregulates the function of NMDA receptors (NMDARs), but how Src becomes activated is unknown. Here, we show that the focal adhesion kinase CAKbeta/Pyk2 upregulated NMDAR function by activating Src in CA1 hippocampal neurons. Induction of LTP was prevented by blocking CAKbeta/Pyk2, and administering CAKbeta/Pyk2 intracellularly mimicked and occluded LTP. Tyrosine phosphorylation of CAKbeta/Pyk2 and its association with Src was increased by stimulation that produced LTP. Finally, CAKbeta/Pyk2-stimulated enhancement of synaptic AMPA responses was prevented by blocking NMDARS, chelating intracellular Ca(2+), or blocking Src. Thus, activating CAKbeta/Pyk2 is required for inducing LTP and may depend upon downstream activation of Src to upregulate NMDA receptors.

Weight-correction formula for maternal serum screening for Down syndrome in Taiwan

BACKGROUND AND PURPOSE

This study examined the relationship between maternal weight and serum marker concentrations (alpha-fetoprotein [AFP] and human chorionic gonadotropin [hCG]) to develop a weight-correction formula for second-trimester Down syndrome screening in Taiwan.

METHODS

We conducted a prospective observational study based on data from 18, 016 pregnant Taiwanese women who participated in a second-trimester Down syndrome screening program at Taiwan Adventist Hospital. The relationship between maternal weight and the multiple of median (MoM) concentrations of serum markers was analyzed using two methods; one involved all the observational data (all point method), while the other involved only the median concentrations at various gestational ages (median regression method). In each method, several statistical approaches were used, including simple-linear, reciprocal, quadratic, and log-transformation linear regression.

RESULTS

The correlation between maternal body weight and serum marker concentrations using the all point regression method was very poor, while the median regression method achieved a good fit. The reciprocal regression analysis had the best fit between AFP MoM concentration and maternal weight, while the best fit between hCG MoM concentration and maternal weight was achieved with quadratic regression analysis.

CONCLUSION

The present study has developed a race-specific weight-correction formula for Taiwanese women. This formula is expected to be helpful in second-trimester Down syndrome screening programs in Taiwan.

Endogenous Zn(2+) is required for the induction of long-term potentiation at rat hippocampal mossy fiber-CA3 synapses

The functional role of the abundant Zn(2+) found in some hippocampal synapses has been an enigma. We show here, using N-[6-methoxy-8-quinolyl]-P-toluenesulfonamide (TSQ) staining, that chelatable-Zn(2+) can be removed from hippocampal synaptic boutons using dietary depletion or with Zn(2+) chelators. A chronic dietary deficiency of bouton Zn(2+) resulted in the impairment of long-term potentiation (LTP) at mossy fiber-CA3 synapses. The averaged normalized fEPSP slope 30 min after tetanus was 209 +/- 28% of baseline value in control (mean +/- SEM, n = 10), and 118 +/- 12% in Zn(2+)-deficient rats (mean +/- SEM, n = 12, P < 0.01). In the deficient rats with Zn(2+) supplements, mossy fiber LTP returned to normal levels. The acute depletion of bouton Zn(2+) in the hippocampal slice with membrane-permeable Zn(2+) chelators, dithizone, or diethyldithiocarbamic acid (DEDTC) blocked the induction of mossy fiber LTP. The mean amplitudes of EPSCs after tetanus were 194 +/- 22% of baseline value in control (n = 5), compared to 108 +/- 14% in dithizone (n = 6) and 101 +/- 12% in DEDTC (n = 5). The averaged value of LTP, at the associational commisural fiber-CA3 synapses, was 193 +/- 20% in the control (n = 6), compared to 182 +/- 21% (n = 6, P > 0.1) in the presence of dithizone. The blockade of mossy fiber LTP by dithizone was reversible after washout. In addition, normal LTP could be induced by tetanus if exogenous Zn(2+) was applied immediately following dithizone. Our results indicate that the endogenous Zn(2+) is specifically required for LTP induction at the mossy fiber input into CA3 neurons.

Binding of an intrinsic ATPase inhibitor to the F(1)FoATPase in phosphorylating conditions of yeast mitochondria

Yeast mitochondrial ATP synthase has three regulatory proteins; ATPase inhibitor, 9K protein, and 15K protein. A mutant yeast lacking these three regulatory factors was constructed by gene disruption. Rates of ATP synthesis of both wild-type and the mutant yeast mitochondria decreased with decrease of respiration, while their membrane potential was maintained at 170-160 mV under various respiration rates. When mitochondrial respiration was blocked by antimycin A, the membrane potential of both types of mitochondria was maintained at about 160 mV by ATP hydrolysis. ATP hydrolyzing activity of F(1)FoATPase solubilized from normal mitochondria decreased in proportion to the rate of ATP synthesis, while the activity of the mutant F(1)FoATPase was constant regardless of changes in the rate of phosphorylation. These observations strongly suggest that F(1)FoATPase in the phosphorylating mitochondria is a mixture of two types of enzyme, phosphorylating and non-phosphorylating enzymes, whose ratio is determined by the rate of respiration and that the ATPase inhibitor binds preferentially to the non-phosphorylating enzyme.

Calcineurin-mediated LTD of GABAergic inhibition underlies the increased excitability of CA1 neurons associated with LTP

Coincident pre- and postsynaptic activity generates long-term potentiation (LTP), a possible cellular model of learning and memory. LTP has two components: (1) an increase in the excitatory postsynaptic potential (EPSP), and (2) an increase in the ability of the EPSP to generate a spike (E-S coupling of LTP). We have used pharmacological and genetic approaches to address the molecular nature of E-S coupling in CA1 pyramidal neurons. Blockade of the Ca2+-sensitive phosphatase, calcineurin, prevents induction of E-S coupling without interfering with LTP of the EPSP. Calcineurin produces its effect on E-S coupling by inducing a long-lasting depression (LTD) of the GABA(A)-mediated inhibitory postsynaptic potentials (IPSPs). This LTD of the IPSP was prevented by blockade of NMDA receptors. Thus, the tetanus that elicits NMDA-dependent LTP mediates a coordinately regulated double function. It produces LTP of the EPSP and, concomitantly, LTD of the IPSP that leads to enhancement of E-S coupling.

Src potentiation of NMDA receptors in hippocampal and spinal neurons is not mediated by reducing zinc inhibition

The protein-tyrosine kinase Src is known to potentiate the function of NMDA receptors, which is necessary for the induction of long-term potentiation in the hippocampus. With recombinant receptors composed of NR1-1a/NR2A or NR1-1a/2B subunits, Src reduces voltage-independent inhibition by the divalent cation Zn2+. Thereby the function of recombinant NMDA receptors is potentiated by Src only when the Zn2+ level is sufficient to cause tonic inhibition. Here we investigated whether the Src-induced potentiation of NMDA receptor function in neurons is caused by reducing voltage-independent Zn2+ inhibition. Whereas chelating extracellular Zn2+ blocked the Src-induced potentiation of NR1-1a/2A receptors, we found that Zn2+ chelation did not affect the potentiation of NMDA receptor (NMDAR) currents by Src applied into hippocampal CA1 or CA3 neurons. Moreover, Src did not alter the Zn2+ concentration-inhibition relationship for NMDAR currents in CA1 or CA3 neurons. Also, chelating extracellular Zn2+ did not prevent the upregulation of NMDA single-channel activity by endogenous Src in membrane patches from spinal dorsal horn neurons. Taking these results together we conclude that Src-induced potentiation of NMDAR currents is not mediated by reducing Zn2+ inhibition in hippocampal and dorsal horn neurons.

Evaluation of the quality of surgical gloves among four different manufactures

A randomized trial was conducted to evaluate the quality of four different brands of surgical gloves in terms of the perforation rate, ventilation, fitness, allergic reaction, elasticity, thickness, powder, and satisfaction. Gloves of four different manufactures which were used by various medical centres were distributed to participants according to a computer-generated randomization table. A structured questionnaire was self-administered by volunteers immediately after the surgical procedure to gather the information from participants, including the demographic data, allergy history, length of use, and variables of quality measures. Two brands, A and D, were significantly inferior to the best manufacture among the four, B, in terms of the ventilation, elasticity, and thickness, odds ratios ranging from 6 to 24, p < 0.05. For the amount of corn starch powder and satisfaction, all three other brands were inferior to brand B, odds ratios ranging from 6 to 44, p < 0.05. Gloves worn longer than 2 hours had a slightly higher perforation rate post procedures (11.5% vs. 2.1%, p = 0.048). The rate of latex allergic reaction was not significantly different between surgeons (8.3%) and the others (6.7%). No difference of the allergic reaction rate was found between subjects with allergy history (7.7%) and those without the history (7.5%). The quality of surgical gloves differs from brand to brand. The government and institutions should take the responsibility of monitoring the quality of surgical gloves in order to provide a safer and more comfortable environment for the surgical personnel and patients.

Mutagenicity of various organic fractions of diesel exhaust particles

Treated with various organic fractions of Diesel Exhaust Particles (DEP), the Ames test withSalmonella typhimurium strains TA98 and TA100, and the mice micronucleus test were employed to study the mutagenic activity in the bacterial reverse mutation system, with and without a mammalian S(9) activation component, and the clastogenic activity in mice polychromatic erythrocyte (PCE) stem cells. Extracted ultrasonically with dichloromethane then using the acid and base separated reaction and column chromatography, DEP were divided into five organic fractions. They are the organic acid fraction (Fl), the organic base fraction (F2), the aliphatic hydrocarbon fraction (F3), the aromatic hydrocarbon fraction (F4) and the polar fraction (F5). Results showed that an increase in the counted numbers of histidine revertants on theSalmonella TA100 and TA98 was observed with or without (S(9) mix), but these activities were more pronounced in the TA98 strains especially in the absence of the S(9) mix. These results suggest that the organic fractions of DEP contain mainly compounds with direct frame-shift mutaganicity. Positive results were also obtained from mice micronucleus assay. The frequency of mice bone marrow micronucleated polychromatic erythrocytes (PCE) was increased using this assay and it showed a definite dose-response relationship. The results suggest that various organic fractions could affect spindle fiber function or formation in mammalian cells. Compared with the results of different organic fraction, the effects of the F2, F4 and F5 were found to be stronger than those of other fractions. Based on the findings obtaind in the Ames and micronucleus tests, DEPs have genotoxic effects in both of the test systems.