Prelimbic cortex-nucleus accumbens core projection positively regulates itch and itch-related aversion

Itch is one of the most common clinical symptoms in patients with diseases of the skin, liver, or kidney, and it strongly triggers aversive emotion and scratching behavior. Previous studies have confirmed the role of the prelimbic cortex (Prl) and the nucleus accumbens core (NAcC), which are reward and motivation regulatory centers, in the regulation of itch. However, it is currently unclear whether the Prl-NAcC projection, an important pathway connecting these two brain regions, is involved in the regulation of itch and its associated negative emotions. In this study, rat models of acute neck and cheek itch were established by subcutaneous injection of 5-HT, compound 48/80, or chloroquine. Immunofluorescence experiments determined that the number of c-Fos-immunopositive neurons in the Prl increased during acute itch. Chemogenetic inhibition of Prl glutamatergic neurons or Prl-NAcC glutamatergic projections can inhibit both histaminergic and nonhistaminergic itch-scratching behaviors and rectify the itch-related conditioned place aversion (CPA) behavior associated with nonhistaminergic itch. The Prl-NAcC projection may play an important role in the positive regulation of itch-scratching behavior by mediating the negative emotions related to itch.

The Anterior Insula and its Projection to the Prelimbic Cortex are Involved in the Regulation of 5-HT-Induced Itch

Itch is an unpleasant sensation that urges people and animals to scratch. Neuroimaging studies on itch have yielded extensive correlations with diverse cortical and subcortical regions, including the insular lobe. However, the role and functional specificity of the insular cortex (IC) and its subdivisions in itch mediation remains unclear. Here, we demonstrated by immunohistochemistry and fiber photometry tests, that neurons in both the anterior insular cortex (AIC) and the posterior insular cortex (PIC) are activated during acute itch processes. Pharmacogenetic experiments revealed that nonselective inhibition of global AIC neurons, or selective inhibition of the activity of glutaminergic neurons in the AIC, reduced the scratching behaviors induced by intradermal injection of 5-hydroxytryptamine (5-HT), but not those induced by compound 48/80. However, both nonselective inhibition of global PIC neurons and selective inhibition of glutaminergic neurons in the PIC failed to affect the itching-scratching behaviors induced by either 5-HT or compound 48/80. In addition, pharmacogenetic inhibition of AIC glutaminergic neurons effectively blocked itch-associated conditioned place aversion behavior, and inhibition of AIC glutaminergic neurons projecting to the prelimbic cortex significantly suppressed 5-HT-evoked scratching. These findings provide preliminary evidence that the AIC is involved, at least partially via aversive emotion mediation, in the regulation of 5-HT-, but not compound 48/80-induced itch.

A versatile control program for positioning and shooting targets in laser-plasma experiments

We introduce a LabVIEW-based control program that significantly improves the efficiency and flexibility in positioning and shooting solid targets in laser-plasma experiments. The hardware driven by this program incorporates a target positioning subsystem and an imaging subsystem, which enables us to install up to 400 targets for one experimental campaign and precisely adjust them in six freedom degrees. The overall architecture and the working modes of the control program are demonstrated in detail. In addition, we characterized the distributions of target positions of every target holder and simultaneously saved the target images, resulting in a large dataset that can be used to train machine learning models and develop image recognition algorithms. This versatile control system has become an indispensable platform when preparing and conducting laser-plasma experiments.

Dysgranular retrosplenial cortex modulates histaminergic and nonhistaminergic itch processing

Itch is an unpleasant sensation followed by an intense desire to scratch. Previous researches have advanced our understanding about the role of anterior cingulate cortex and prelimbic cortex in itch modulation, whereas little is known about the effects of retrosplenial cortex (RSC) during this process. Here we firstly confirmed that the neuronal activity of dysgranular RSC (RSCd) is significantly elevated during itch-scratching processing through c-Fos immunohistochemistry and fiber photometry recording. Then with designer receptors exclusively activated by designer drugs approaches, we found that pharmacogenetic inhibition of global RSCd neurons attenuated the number of scratching bouts as well as the cumulative duration of scratching bouts elicited by both 5-HT or compound 48/80 injection into rats' nape or cheek; selective inhibition of the pyramidal neurons in RSCd, or of the excitatory projections from caudal anterior cingulate cortex (cACC) to RSCd, demonstrated the similar effects of decreasing itch-related scratching induced by both 5-HT or compound 48/80. Pharmacogenetic intervention of the neuronal or circuitry activities did not affect rats' motor ability. This study presents direct evidence that pyramidal neurons in RSCd, and the excitatory projection from cACC to RSCd are critically involved in central regulation of both histaminergic and nonhistaminergic itch.

Machine learned clusters explain heterogeneity in outcomes from map-guided ablation of Atrial Fibrillation results from the large PROspective STanford AF Registry (ProSTAR)

Background

Several mapping systems are being introduced to guide atrial fibrillation (AF) ablation to patient-specific regions of interest. However, results have been extremely heterogeneous between studies, ranging from very poor to very promising. It is unknown if this reflects specific patient characteristics or procedural factors because most prior series were middle sized (N∼30–100 patients).

Purpose

To study 1 year and 3 year very long-term outcomes from map guided AF-driver ablation in a large patient registry with multiple operators, to identify clinical and procedural features influencing outcomes. In real-world AF patients with diverse comorbidities, we applied a consistent patient-tailored AF mapping and ablation strategy, monitored outcomes carefully and applied statistical and unsupervised machine learning approaches to identify features of success and failure.

Method

We studied 632 consecutive patients (65±10 y, 178 F) undergoing ablation for drug-refractory AF. 59.7% had persistent AF, and 29.9% had prior unsuccessful ablation (median 1 procedure). All patients underwent pulmonary vein isolation (PVI), followed by ablation of AF regions of interest mapped from 64 pole baskets (RhythmView, Abbott, IL), by 11 operators. Patients were followed using ambulatory ECG monitors quarterly for one year, and at the time of symptoms for 3 years.

Results

Fig. 1A shows overall freedom from AF at 1-year of 77.5% (95% CI: 74.2%, 80.9%) and at 3 years of 55.5% (95% CI: 51.2%, 60.1%). Freedom from AF/AT at 1-year was 70.1% (95% CI: 66.5%, 73.8%), and at 3 years was 48.6% (95% CI: 44.3%, 53.3%). Success was higher in patients with procedural termination, first ablation versus prior unsuccessful procedures, for paroxysmal AF than non-paroxysmal AF (1 year: AT/AF freedom 74.9% versus 66.7%, p=0.006), and smaller left atrium. Three clusters (Fig 1B) were identified comprising CHA2DS2VASc score, enlarged LA, prior failed case, presenting rhythm and termination during the procedure (Table 2). At 1 year, freedom from AT/AF was 77.8% (95% CI: 72.2%, 82.1%) for cluster 3 and 56.2% (95% CI: 48.3%, 65.4%) for cluster 1 (Fig. 1B).

Conclusion

In our large registry of N=632 patients undergoing AF-map guided ablations, machine learned clusters identified cohorts with success of 56.2 to 77.8% at 1 year. Future studies should identify if lower success represents technical challenges, such as difficulties in mapping very large atria, or more difficult to treat mechanisms. These results may inform patient inclusion and ablation strategy in upcoming AF treatment trials.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): National budget only - NIH, R01 HL149134, R01HL83359

[Study on the dynamic changes of peripheral platelet-to-lymphocyte ratio in the prognosis of neoadjuvant chemotherapy patients with gastric cancer]

Objective: To investigate the significance of platelet lymphocyte ratio (PLR) before and after neoadjuvant chemotherapy in advanced gastric cancer (AGC). Methods: The medical records of 247 AGC patients who underwent surgery between May 2015 and October 2016 were retrospectively reviewed. The relationship between PLR value and its changes before and after neoadjuvant therapy and clinicopathological features and prognosis was further analyzed. Results: △PLR was defined according to the different states of PLR before and after neoadjuvant therapy. If negative value was defined as"Reduced Group"(138) and positive value or 0 was defined as "Unreduced group"(109). There were statistical differences between the two groups of△PLR in tumor size, nerve invasion, presence or absence of vascular tumor thrombus, ypT staging, ypN staging, ypTNM staging, and pathological response (all P<0.05), but there was no statistical difference between age, gender, and postoperative adjuvant chemotherapy (all P>0.05). Survival analysis showed that the 5-year disease-free survival rates between the two groups were 39.0% and 54.0%, respectively (P=0.025); the 5-year overall survival rates between the two groups were 41.8% and 58.1%, respectively (P=0.035); the difference were statistically significant. Multivariate analysis showed that ypT3-4 stage, ypN3b stage and △PLR were independent risk factors for 5-year disease-free survival rate (HR=2.731/2.676, 95%CI: 1.026-7.268/1.014-6.985; HR=4.717, 95%CI: 1.922-11.579; HR=2.854, 95%CI: 1.117-4.124; all P<0.05) and 5-year overall survival rate (HR=3.226/2.655, 95%CI: 1.280-9.227/0.945-7.548; HR=4.550, 95%CI: 1.842-11.239; HR=2.897, 95%CI: 1.049-5.251; all P<0. 05). Conclusion: △PLR can better predict the prognosis of AGC patients receiving neoadjuvant chemotherapy.

[Effect of thrombolytic therapy and influencing factors of Budd-Chiari syndrome with inferior vena cava thrombosis]

Objective: To examine the effect of thrombolytic therapy of Budd-Chiari syndrome (B-CS) with inferior vena cava (IVC) thrombosis, and the prognosis factors of it. Methods: The clinical data of 67 patients of B-CS with IVC thrombosis treated in the Department of Hepatopancreatobiliary Surgery, the First Affiliated Hospital of Zhengzhou University from January 2013 to August 2020 were analyzed retrospectively. There were 30 males and 37 females. The age was (47.7±11.1) years(range: 18 to 72 years). All patients received catheter directed thrombolysis, and the thrombolysis process, complications and outcomes were analyzed. All patients received IVC balloon angioplasty after thrombolytic therapy. The t test, χ² test, Mann-Whitney U test were used for univariate analysis of the prognosis factors of thrombolysis effects, while unconditional Logistic regression model were used for multivariate analysis. Results: In the 67 patients, 47 cases succerssed in thrombolytic therapy. The successful rates of thrombolysis at 1-, 2-, 3- and 4-week were 9.0%, 29.9%, 64.2% and 70.1%, respectively. The rates of thrombolytic catheter-related infection at 1-, 2-, 3- and 4-week were 1.5%, 4.5%, 14.9% and 31.3%, respectively. No serious complications such as symptomatic and acute pulmonary embolism occurred during perioperative period of IVC balloon angioplasty. Univariate analysis showed that differences in thrombus length ((36.7±18.1) mm vs. (52.0±16.4) mm, t=-3.234, P=0.002), Child-Pugh classification (class A/B/C: 37/8/2 vs. 10/8/2, Z=-2.310, P=0.021) and pre-opening IVC proportion (68.1% (32/47) vs. 35.0% (7/20), χ²=6.313, P=0.012) were statistically significant. The thrombus length (OR=0.948, 95%CI: 0.913 to 0.984, P=0.005), pre-opening IVC (OR=5.451, 95%CI: 1.469 to 20.228, P=0.011) were independent prognosis factors of thrombolytic effect. Conclusions: Thrombolytic therapy for B-CS with IVC thrombosis were satisfactory, and the thrombolysis duration should be confined within 3 weeks. IVC balloon angioplasty is safe and effective for patients failing in thrombolysis, and pre-opening IVC is an important method to improve the thrombolytic effect.

[The role of Artificial intelligent-based FFRCT in assessing the hemodynamic relevance of deep myocardial bridge of the left anterior descending coronary artery]

Objective: To investigate the role of artificial intelligence-based coronary CT blood flow reserve score (FFR_CT) in assessing hemodynamic relevance in patients with deep myocardial bridge (MB) of the left anterior descending coronary artery. Methods: A total of 113 patients diagnosed with deep MB of the left anterior descending coronary artery by coronary CT angiography (CCTA) at the Department of Radiology of Tongji Hospital Affiliated to Tongji University from January 2017 to December 2019 were retrospectively analyzed. The location, length, depth, and degree of systolic compression of the MB were measured. The artificial intelligence-based coronary FFR_CT software was employed to calculate the FFR_CT value of the deep MB of the left anterior descending coronary artery. With the boundary of 0.80, all patients were divided into FFR_CT normal group (FFR_CT>0.80) and FFR_CT abnormal group (FFR_CT≤0.80), and the relationship between FFR_CT abnormality and the location, length, depth, and degree of systolic stenosis of the deep MB of the left anterior descending branch was analyzed. The effectiveness of the receiver operating characteristic (ROC) curve in predicting FFR_CT abnormalities was measured by using ROC curve to analyze the length, depth, and degree of systolic stenosis of MB. Results: There were no significant differences in age, gender and high-risk factors between FFR_CT normal group (n=79) and FFR_CT abnormal group (n=34) (P>0.05). In terms of clinical symptoms, unstable angina, asymptomatic myocardial ischemia, stable angina in the FFR_CT normal group were 15.2%, 41.8%, 32.9%,respectively, while 32.4%, 23.5%, 35.3% in the FFR_CT abnormal group,respectively. Except for unstable angina (χ²=4.32,P=0.038), there were no significant differences in asymptomatic myocardial ischemia and stable angina between the two groups (χ²=3.42, 0.06, P>0.05). The length of deep MB was about (36±5) mm in the FFR_CT normal group and (44±5) mm in the FFR_CT abnormal group, respectively. The difference between the two groups was statistically significant (t=-7.703, P<0.001). The ROC curve showed that the optimal critical value of the length of the deep MB was 39.7 mm, the area under the curve was 0.88 (95%CI:0.81-0.95, P<0.001), and the accuracy rate of diagnosing FFR_CT ≤0.80 was 82.3%. Conclusion: FFR_CT value is of great value in the evaluation of hemodynamics in patients with deep myocardial bridge of left anterior descending coronary artery, and the length of deep myocardial bridge is an important factor affecting FFR_CT value.

[Present and future: artificial intelligence in medical imaging]

Artificial intelligence (AI) is a hot point in clinical medicine research. In recent years, AI has played an important role in recognizing the lesion, improving the diagnostic accuracy and assessing the diagnostic efficacy. To accelerate the pace of AI industry, it should be a first thing to improve relevant industrial policies and regulations and to build a transformation platform for industry-university-research. All these will contribute to the standardization in further development of medical imaging AI industry.

[Retrospective analysis of mechanical thrombectomy for distal branch occlusion of middle cerebral artery]

Objective: To explore the necessity, feasibility, technical points, operative complications and prognosis of mechanical thrombectomy for distal branch occlusion of middle cerebral artery. Methods: Mechanical thrombectomy was performed on 42patients (28 males,14 females; age ranged from 43 to 88 years, mean 65.48years)with distal branch occlusion of middle cerebral artery (M2, M3), between May 2017 to July 2019. Theclinical feature was retrospectively analyzed. The NIHSS score before operation, 24 hours after operation and 1 week after operation, the recanalization of occluded vessels during operation, the complications and the recovery after 3 months (3 months mRS score) were analyzed. Results: Of the 42 patients, 38 patients were successfully recanalized, and the recanalization rate was 90.48%. Postoperative hemorrhage in 6 cases and vasospasm in 17 cases. At 90 days after operation, the mRS score was 0 in 13 cases, 1 in 11 cases, 2 in 6 cases, and 0 cases died. Conclusions: Mechanical thrombotomy is safe and feasible for patients with distal branch occlusion of middle cerebral artery (M2, M3). However, the risks and benefits of patients should be fully considered.

[Effects of dynamic contrast enhancement on diffusion weighted imaging score of 3 in prostate imaging reporting and data system version 2 of peripheral zone]

Objective: To investigate the effects and value of dynamic contrast-enhanced (DCE) on diffusion-weighted imaging (DWI) score 3 in the prostate imaging data and reporting system version 2(PI-RADS V2)of peripheral zone. Methods: A retrospective study of consecutive 204 cases of prostate disease in peripheral zone was conducted from January 2015 to January 2018, including 169 cases of prostate cancer and 35 cases of non-prostate cancer. All cases were examined multi-parametric MR imaging on a 3-T MR scanner and confirmed by pathology. Images were analyzed according to PI-RADS V2.Inter-reader agreement of scores was evaluated by kappa coefficient. The constituent ratio of clinically significant prostate cancer (csPCa) in PI-RADS V2 overall scores 3, 3+1 and 4 were calculated and analyzed by non-parametric Chi-square test to determine whether the difference in composition ratio was significant. The positive rate of DCE in diffusion weighted imaging (DWI) score 3 and 4 were calculated. Results: There were 68.6%(140/204) cases in 204 patients with peripheral prostate disease who scored PI-RADS V2 overall score of 3,3+1 and 4. Kappa value was higher for the PI-RADS V2 overallscore of 4 than 3 or 3+1 in the PZ (k values of 0.802 vs 0.737 or 0.591, respectively; all P<0.01). The constituent ratio of csPCa in PI-RADS V2 overallscore of 3, 3+1 and 4 were 16.7%(3/18),43.2%(19/44),78.2%(61/78), the difference of which was significant (χ(2)=29.839, P<0.05).There was also a significant difference between the constituent ratio of csPCa in the score of 3+1 and 4 (χ(2)=15.286, P<0.01).The positive rate of DCE in cases of PI-RADS V2 overall score 3,3+1 and 4 was 76.4%(107/140).The positive rate of DCE incases of DWI score 3 and 4 were 71.0%(44/62), 80.8%(63/78),respectively. Conclusion: DCE has a certain value in PI-RADS V2 due to its high positive rate in the detection of prostate cancer in peripheral zone.DCE is helpful to DWI score 3 to improve the detection rate of csPCa.The PI-RADS V2 overall score 3+1 and 4 in the peripheral zone maybe need to be distinguished due to the different detection of csPCa.

Negative magnetization, complex magnetic ordering and applications of Cr-doped Co2TiO4

Polycrystalline Co2Ti1-xCrxO4 (0 ≤ x ≤ 0.2) inverse spinel ceramics have been synthesized via a sol-gel technique. The dc magnetization measurement in the field-cooled mode shows that negative magnetization could be observed until x reaches 0.2. The exchange constants are calculated using the ferrimagnetic Curie-Weiss fitting and the mean-field theory. This reveals that the strength of the inter sublattice magnetic interaction presents a non-monotonic trend with the increase in Cr content and reaches the minimum at x = 0.1, giving rise to the highest compensation temperature in the x = 0.1 sample. The applicability of the x = 0.1 sample is investigated in light of two prominent magnetic effects: (i) the stable magnetic switching effect indicates the potential applications in magnetic switching and data storage and (ii) the coexistence of normal and inverse magnetocaloric effects suggests a potential application in a constant temperature bath at 54 K.

[Changing trends of topical anti-glaucoma medications in the Eye Hospital of Wenzhou Medical University during the past ten years]

Objective: To investigate the changing trends of topical anti-glaucoma medications in the outpatient of the Eye Hospital of Wenzhou Medical University over the decade 2005-2014. Methods: Retrospective case series study. The medications data of glaucoma outpatients in the Eye Hospital of Wenzhou Medical University were collected for the period of January 1(st) 2005 to December 31(st) 2014. SPSS 20.0 statistical software was used, mainly for statistical description of the data. The main outcome measures were the proportions of the prescriptions of different medications, and the proportions of the monotherapy and combination therapies. Results: During the 10 years, the number of glaucoma outpatients increased year by year, from 994 in 2005 to 3 266 in 2014, the gender ration was close to 1∶1, and the age were (57±18) years. The proportion of β-blockers decreased from 56.7% (750/1 323) in 2005 to 33.1% (2 120/6 407) in 2014. The proportion of cholinergic agents decreased from 17.2% (227/1 323) in 2005 to 10.3% (663/6 407) in 2014. While the proportion of prostaglandins increased from 13.3% (176/1 323) in 2005 to 36.8% (1 916/5 209) in 2011, which was close to the 37.9% (1 972/5 209) of β-blockers in 2011. In 2012, the prostaglandins proportion increased to 41.9% (2 435/5 810) exceeding the 37.2% (2 161/5 810) of β-blockers, and became the most prescribed medication. The proportion of prostaglandins continued to increase to 46.9% (3 008/6 407) in 2014. The proportion of α(2)-agonists increased from 17.0% (225/1 323) in 2005 to 22.8% (1 460/6 407) in 2014. The proportion of carbonic anhydrase inhibitors increased from 9.6% (127/1 323) in 2005 to 24.1% (1 546/6 407) in 2014.The proportion of monotherapy decreased from 78.0% (1 032/1 323) in 2005 to 58.6% (3 757/6 407) in 2014. The proportion of two drugs combination increased from 20.0% (264/1 323) in 2005 to 26.7% (1 709/6 407) in 2014. The proportion of three drugs combination increased from 2.0% (26/1 323) in 2005 to 12.3% (788/6 407) in 2014. The proportion of four drugs combination increased from 0.1% (1/1 323) in 2005 to 2.3% (150/6 407) in 2014. Conclusions: The changes of the proportions of topical anti-glaucoma medications were remarkable from 2005 to 2014 in the outpatient of the Eye Hospital of Wenzhou Medical University. The β-blockers and cholinergic agents were declining, while the prostaglandins, α(2)-agonists and carbonic anhydrase inhibitors were increasing, and the prostaglandins became the most prescribed medication since 2012. The proportion of combination therapy was increasing. (Chin J Ophthalmol, 2018, 54: 520-525).

Comparing phase and electrographic flow mapping for persistent atrial fibrillation

BACKGROUND

An increasing number of methods are being used to map atrial fibrillation (AF), yet the sensitivity of identifying potential localized AF sources of these novel methods are unclear. Here, we report a comparison of two approaches to map AF based upon (1) electrographic flow mapping and (2) phase mapping in a multicenter registry of patients in whom ablation terminated persistent AF.

METHODS

Fifty-three consecutive patients with persistent AF in whom ablation terminated AF in an international multicenter registry were enrolled. Electrographic flow mapping (EGF) and phase mapping were applied to the multipolar simultaneous electrograms recorded from a 64-pole basket catheter in the chamber (left vs right atrium) where AF termination occurred. We analyzed if the mapping methods were able to detect localized sources at the AF termination site. We also analyzed global results of mapping AF for each method, patterns of activation of localized sources.

RESULTS

Patients were 64.3 ± 9.4 years old and 69.8% were male. EGF and phase mapping identified localized sources at AF termination sites in 81% and 83% of the patients, respectively. Methods were complementary and in only n = 2 (3.7%) neither method identified a source. Globally, EGF identified more localized sources than phase mapping (5.3 ± 2.8 vs 1.8 ± 0.5, P < 0.001), with a higher prevalence of focal (compared to rotational) activation pattern (49% vs 2%, P < 0.01).

CONCLUSIONS

EGF is a novel vectorial-based AF mapping method, which can detect sites of AF termination, agreeing with, and complementary to, an alternative AF mapping method using phase analysis.

[Combination of environmental friendly reagent and ultrasonic assisted rapid processing for protein and molecular detection in tumor biopsy specimens]

Objective: To investigate the impact of ultrasonic assisted rapid processing technique combined with the environment friendly reagent (which can be utilized in fixing,dehydrating and clearing) on processing tumor biopsy specimens and the subsequent target detection. Methods: Postoperative tissue samples of 56 cases of breast cancer, colorectal cancer, lung cancer, stomach cancer, liver mass, bladder mass, uterus mass were obtained at the National Cancer Center, Cancer Hospital, Chinese Academy of Medical Sciences from February to April, 2017. Three specimens ranging in size from 1 to 3 mm were collected from each sample, and were separated into control group (traditional tissue-processing method); experiment group 1 (3.7% neutral buffered formaldehyde fixation, composite environment friendly reagent and ultrasonic assisted rapid processing) and experimental group 2 (composite environment friendly reagent direct fixation, higher temperature and longer time for tissue processing). Two pathologists blinded to the experimental groups scored totally the nuclear, cytoplasmic, and membrane staining of 43 cases of immunohistochemistry (IHC), four HER2 fluorescence in situ hybridization (FISH), 20 extracted DNA quality and four EGFR gene mutation detection in lung adenocarcinoma; the results were compared with the control group. Results: There was no difference in the IHC staining, HER2 FISH, the DNA quality, and EGFR genetic results between experimental group 1 and control group. For experiment group 2, comparing results of IHC staining, HER2 FISH and the quality of DNA, there was no obvious difference from control group and experiment group 1, but might show an increase in the background of IHC staining. The difference between the treatment temperature and time in the experimental group 2 did not affect the results of the gene mutation detection. Conclusions: Environment freindly reagent and ultrasonic assisted rapid processing equipment could be used for rapid processing and diagnosis for tumor biopsies. Using complex environment-friendly reagents supplement fixation, higher treatment temperature and longer treatment time do not significantly affect the IHC, FISH and molecular detection accuracy.

[Functional lateralization of major Chinese language cortex for presurgical evaluation in neurosurgery]

Objective: To investigate the functional lateralization of major Chinese language cortex in patients with cerebral arteriovenous malformation (AVM) in dominant hemispheric via functional magnetic resonance imaging (fMRI). Methods: Nine right-handed normal volunteers and fourteen patients with cerebral AVM in dominant hemisphere diagnosed in Beijing Tiantan Hospital between December 2017 and June 2018 were included. Three language tasks (semantic judgment, word reading, and listening comprehension) were applied to activate language areas. Lateralization index (LI) was used to show the dominant hemisphere. Results: In the control group, right-sided lateralization of BOLD signal activations was observed in 0/27 (0%) of the language tasks. While in the AVM patients, right-sided lateralization of BOLD signal activations was observed in 8/42 (19%) language tasks. The difference was statistically significant (χ(2)=5.73, P=0.019). Conclusions: The dominant hemisphere of different language tasks may be different in patients with cerebral lesions. Compared with normal controls, patients with cerebral AVM in dominant hemispheric are more likely to have right-sided lateralization of language cortex.

[In vitro early detection of amyloid plaques in Alzheimer's disease by Pittsburgh compound B-modified magnetic nanoparticles]

Objective: To construct magnetic nanoparticles targeting β-amyloid (Aβ) plaques, the pathological biomarker of Alzheimer's disease (AD) and to study their binding capability in vitro. Methods: Superparamagnetic nanoparticles Mn(0.6)Zn(0.4)Fe(2)O(4) (MZF) were coated with amphiphilic star-block copolymeric micelles and modified with Aβ-specific probe Pittsburgh compound B (PiB) to construct a novel magnetic nanoparticle MZF-PiB, which specifically targeted amyloid plaques. Transmission electron microscope was used to study the morphological features of MZF-PiB. Superparamagnetism of MZF-PiB was assessed by its r(2) relaxation rate by using 3.0 T MRI scanner. Cytotoxic test was applied to determine biosafety of MZF-PiB nanoparticles in differentiated human neuroblastoma cells (SH-SY5Y) and Madin-Darby canine kidney (MDCK). In vitro binding tests were conducted via immunohistochemistry on 6-month old AD mice brain sections. Differences of cell viability between groups were compared with one-way analysis of variance. Results: MZF-PiB nanoparticles were successfully constructed. Transmission electron microscope images showed that the nanoparticles were about 100 nm in size. The r(2) relaxation rate was 163.11 mMS(-1). No differences were found in cell viability of SH-SY5Y and MDCK incubated with MZF-PiB suspension for 24 h or 48 h when compared with those of untreated cells (F=2.336, 2.539, 0.293, 1.493, all P>0.05). In vitro binding tests indicated that the MZF-PiB were specifically bound to amyloid plaques. The smallest size of detected plaques was 27 μm. Conclusion: PiB-modified nanoparticles targeting Aβ are biologically safe and highly superparamagnetic, possessing the capability to detect amyloid plaques early in vitro and the potential for early diagnosis of AD.

Tunable quantum dot arrays as efficient sensitizers for enhanced near-infrared electroluminescence of erbium ions

Under electrical pumping conditions, high-efficiency Si-based near-infrared light generation and amplification on a chip have long been pursued for future optical interconnection technology. However, the overall performance of Si-based near-infrared electroluminescence (EL) devices, including the overall efficiency, turn-on voltage and stability under operational conditions, can rarely meet the requirements of monolithic optoelectronic integration. In this work, we designed a confined crystallization growth strategy for fabricating metal oxide quantum dot (QD) arrays embedded in Si-based films as sensitizers of Er³⁺ ions. Through the precise control of particle size and number density of QD sensitizers, the near-infrared photoluminescence (PL) emission of Er³⁺ ions can be enhanced by more than three orders of magnitude. More significantly, such hierarchical control over the regular arrangement of QD arrays not only considerably enhances the resonance energy transfer efficiency, but also offers an effective conduction path for carrier transport. Therefore, the corresponding near-infrared EL device exhibits a decreased turn-on voltage of 4.5 V, a high external quantum efficiency of 0.7%, and a long operational lifetime of more than 1000 hours, making this device superior to most Si-based on-chip near-infrared EL devices. This well-controlled metal oxide QD array represents an ideal sensitizer to effectively promote the EL emission of rare earth ions and reduce the turn-on voltage. Meanwhile, the analysis of the carrier transport mechanism paves the way for future research into resonance energy transfer under electrical pumping conditions.

[Effects of different computed high b-values on diffusion weighted imaging scores in Prostate Imaging Reporting and Data System version 2 of prostate cancer in peripheral zone]

Objective: To determine the effects of different computed high b-value on diffusion weighted imaging (DWI) scores in Prostate Imaging Reporting and Data System version 2 (PI-RADS v2) of prostate cancer in peripheral zone. Methods: A retrospective study of 104 cases of prostate cancer in peripheral zone was conducted, all of the patients were histopathologically confirmed by transrectal ultrasound guided saturation biopsy or radical prostatectomy in Tongji Hospital of Tongji University from January 2012 to December 2015.All MRI imaging examinations were performed by using a 3.0T Siemens Verio MRI scanner.The imaging protocol consisted of high-resolution axial and sagittal T(2) weighted imaging (T(2)WI), axial acquired diffusion weighted imaging (aDWI) with b=0, 50, 1 000 s/mm(2) and dynamic contrast-enhanced (DCE) scans.Computed diffusion weighted imaging (cDWI) images with b=1 000, 1 400, 2 000 s/mm(2) were processed by Matlab.These three groups of cDWI images were analyzed according to the PI-RADS v2 criteria, and signal intensity of ratio (SIR) of lesions were analyzed by independent t test and one-way ANOVA in each group. Results: The numbers of cases with a DWI score of 2 and 5 were similar among three groups.Nine cases (33.3%) in all 27 cases with a DWI score of 3 on b=1 000 s/mm(2) upgraded to score 4 when b-value rose to 1 400 and 2 000 s/mm(2).The ratios of SIR of lesions in cases upgraded from DWI score 3 to 4 to those unchanged cases on b=1 400 and 2 000 s/mm(2) were 1.86±0.21 to 1.61±0.27 and 2.18±0.26 to 1.75±0.30, respectively (t=2.486, t=3.671, both P<0.05). In these 9 cases who upgraded to DWI score 4, SIRs of the lesion were significantly different between groups when b=1 000, 1 400 and 2 000 s/mm(2) (F=10.907, 33.768, 8.043, all P<0.05), and their SIRs increased with the rising of b-value. Conclusions: The computed high b-value (b≥1 400 s/mm(2)) mainly affects cases with a DWI score of 3, but DWI scores would not change neither in b=1 400 s/mm(2) nor in 2 000 s/mm(2) cases. For DWI score in PI-RADS v2 of prostate cancer in peripheral zone, b=1 400 s/mm(2) is probably of more scoring value than b=1 000 or 2 000 s/mm(2).

[Differentiation of induced pluripotent stem cells into neural stem cells induced by brain-derived neurotrophic factor via Wnt/β-catenin and extracellular signal-regulated kinase/mitogen-activated protein kinases signal pathway]

Objective: To investigate the mechanism of brain-derived neurotrophic factor (BDNF) promoting induced pluripotent stem cells (iPSCs) to differentiate into neural stem cells (NSCs) via Wnt/β-catenin and extracellular signal-regulated kinase/mitogen-activated protein kinases (ERK/MAPK) signal pathways. Methods: iPSCs were cultured and identified. The iPSCs were induced to differentiate into NSCs by BDNF and retinoic acid (RA). Nestin was detected by immunofluorescence and flow cytometry after iPSCs differentiated. The technique of small interfering RNA (siRNA) was used to silence the gene expression of β-catenin and ERK, and iPSCs were divided into control group, BDNF group (adding 10 μg/L BDNF), siRNA-ERK/BDNF group (transfected with siRNA-ERK and adding 10 μg/L BDNF) and siRNA-β-catenin/BDNF group (transfected with siRNA-β-catenin and adding 10 μg/L BDNF). Real-time polymerase chain reaction (RT-PCR) and Western blotting were used to detect the mRNA and protein expression of key elements of Wnt/β-catenin and ERK/MAPK signaling pathways, included β-catenin, ERK1/2, c-fos, c-jun, and c-myc. The least significant difference test was used when data were compared between groups. Results: The immunofluorescence showed that iPSCs expressed octamer-binding transcription factor-4 (Oct4), SRY-related HMG box protein-2 (Sox2) and Nanog genes. The flow cytometry showed that Nestin-positive cells were 78.7% for BDNF and 43.5% for RA, and it was only 7.8% for routine medium. Compared with those in the control group, the mRNA expression of β-catenin, ERK1/2, c-fos, c-jun, and c-myc in the BDNF group were upregulated significantly (t=2.80, 2.318, 2.255, 1.799, 1.582, 1.663, all P<0.05), and the same results were acquired with the protein expression (t=2.805, 2.318, 2.255, 1.799, 1.582, 1.663, all P<0.050). Compared with those in BDNF group, the mRNA and protein expression of ERK1/2 in siRNA-ERK/BDNF group down-regulated obviously (t=1.917, 2.042, 1.673, 1.540, all P<0.05), and the mRNA and protein expression of c-fos and c-jun were down-regulated (t=1.022, 0.907, 0.848, 0.801, all P<0.05). However, the mRNA and protein expression of β-catenin and c-myc were not suppressed by siRNA-ERK (t=0.216, 0.185, 0.097, 0.112, all P>0.05). In siRNA-β-catenin/BDNF group, the mRNA and protein expression of β-catenin and c-myc was obviously down-regulated when compared with those in BDNF group (t=3.104, 2.774, 2.235, 1.911, all P<0.05), and expression of ERK1/2, c-fos and c-jun were down-regulated too (t=0.776-1.192, all P<0.05). Conclusion: BDNF promotes the differentiation of iPSCs by activating Wnt/β-catenin and ERK/MAPK signal pathway, there should be cross-talk between the two signal pathways, and c-fos and c-jun may be common nuclear transcription factors.

Effects of monomethoxypolyethylene glycol-chitosan nanoparticle-mediated dual silencing of livin and survivin genes in prostate cancer PC-3M cells

Monomethoxypolyethylene glycol-chitosan (mPEG-CS) nanoparticles were used as interfering RNA carriers to transfect human prostate cancer PC-3M cells to evaluate the effects of livin and survivin gene silencing on the proliferation and apoptosis. mPEG-CS nanoparticles with sizes of approximately 60 nm were first synthesized by ionic crosslinking. Through electrostatic adsorption, mPEG-CS-livin short hairpin RNA (shRNA), mPEG-CS-survivin shRNA, and mPEG-CS-(livin shRNA + survivin shRNA) nanoparticles were then prepared to transfect PC-3M cells. The mRNA and protein expression levels of livin and survivin were measured by reverse transcription-PCR and western blotting, respectively. The inhibitory effects of down-regulated livin and survivin gene expression on the cell proliferation were evaluated by MTT assay. Cell apoptosis was assessed visually using Hoechst staining. Livin and survivin expression levels in all shRNA interference groups were effectively down-regulated at both the mRNA and protein levels. Dual silencing of livin and survivin genes markedly inhibited cell proliferation and facilitated apoptosis, with better outcomes than those of individual shRNA treatments. mPEG-CS nanoparticle-mediated dual shRNA interference of livin and survivin genes significantly reduced the expression levels in PC-3M cells, inhibited proliferation, and promoted apoptosis. As these effects were superior to single interference, this method may have synergistic effects.

Chemical composition of yak colostrum and transient milk

The objective of this study was to assess the changes in the chemical composition of yak colostrum and transient milk. Samples were collected from 12 yaks on days 1, 2, 3, 4, 5, 6 and 7 post-partum (PP). The gross composition, nitrogen fraction distribution, amino acid (AA) profile and fatty acid (FA) profile were analysed. All the components decreased rapidly during the first 3 days except lactose which increased. The ratio of whey protein to casein protein decreased from 46:54 to 17:83 during the first 7 days PP. The content of all the AAs decreased, while the percentages of eight essential AAs in protein of samples increased during the study period. Monounsaturated FAs and polyunsaturated FAs decreased in the first 7 days PP, whereas saturated FAs increased. In conclusion, the changes in chemical composition were remarkable during the first 3 days. The slight variations, happened during the transient period, are not negligible, which also should be taken into account in the development of yak colostrum supplements.

Effective process to achieve enhanced electrochromic performances based on poly(4,4',4″-tris[4-(2-bithienyl)pheny]amine)/ZnO nanorod composites

Poly(4,4',4″-tris[4-(2-bithienyl)pheny]amine) (PTBTPA) was electrochemically synthesized on a ZnO-coated ITO electrode to form a PTBTPA/ZnO nanocomposite electrode. The composite film exhibited a noticeable electrochromism, with reversible color changes from orange in the reduced state (0 V), olive green in the middle state (0.9 V) to dark gray in the oxidized state (1.2 V). Furthermore, the composite film showed a fast switching time of 0.92 s and a high optical contrast of 65% at 1100 nm, and retained 97% of its original electroactivity after 500 cycles, while PTBTPA film had switching time of 1.63 s and an optical contrast of 52% at 1100 nm, and retained 75% of its original electroactivity. The results demonstrated that the electrochromic performances were significantly enhanced through incorporating PTBTPA with ZnO nanorods. ZnO nanorods were introduced to modify the structure of the electrode: on one hand, to offer a directional attraction for the counterions, and on the other hand, to enhance the adhesion between the polymer and the ITO electrode. Accordingly, a conducting polymer/inorganic nanocomposite system could improve the polymer's electrochromic performance, especially in terms of the switching speed and long-term stability of the electrochromic materials.

1H-MRS can monitor metabolites changes of lateral intraventricular BDNF infusion into a mouse model of Alzheimer's disease in vivo

Proton magnetic resonance spectroscopy (1H-MRS) can provide noninvasive detection of brain metabolite changes in vivo in Alzheimer's disease (AD). AD is a prevalent neurodegenerative disorder characterized by deposition of β-amyloid peptides (Aβ) in multiple brain regions. Brain-derived neurotrophic factor (BDNF) is a neurotrophic factor whose level has been shown to be decreased in AD. BDNF supplementation can offer improvement in AD. However, the means of evaluation are still relatively limited. In the present study, 1H-MRS was applied to evaluate the therapeutic effects of bilateral intraventricular BDNF infusion into APP+PS1 (amyloid precursor protein+presenilin 1) transgenic mice. For comparison to the 1H-MRS changes in the prefrontal cortex, Morris water maze (MWM) test, Fluoro-Jade B staining and immunofluorescence for Aβ, glial fibrillary acidic protein and tropomyosin-related kinase B (TrkB) were also performed. Our results showed that N-acetylaspartate (NAA) levels increased and myo-inositol levels decreased in Tg-BDNF mice compared with Tg-PBS mice. But NAA level in Tg-BDNF mice was still lower than that in wild-type mice at 6weeks after infusion. These changes correlated with increased immunoreactivity of TrkB, reduced compact Aβ peptide and FJB+ neurons in Tg-BDNF mice compared to Tg-PBS mice. However, Tg-BDNF mice did not present obvious changes in behavior in the MWM. Taken together, we suggest that 1H-MRS may be a sensitive means of evaluating metabolic changes in response to therapeutic strategies in AD. Moreover, BDNF, may be a viable means of offering trophic support during disease.

[Study of microelements in plant's ash and environmental soil by microwave digestion ICP-AES]

A model MDS-2002A microwave digestion sample preparation system with auto control pressure in obturation was developed for the determination of microelements in clearing-up plant's ash and environment soil sample by ICP-AES. The authors discussed sample preparation result influenced by mixed acid system, scale of mixed acid dispensation, proportion between solid and liquid and time of microwave clearing. Excellent project was A2B1C2, work procedure 2 in microwave process. When the dispensation scale was 6 : 2 : 1 : 1 and mixed acid system was HNO3-HCl-HF-HClO4, the result was the best in 10 min of microwave clearing at highest power. The reagent was dried at constant temperature electric heating board, with its salinity being dissolved by aqua fortis. The method was validated through the soil (GBW07401) and plant (GBW07603) for national standard matter. The relative error of its result is between 0.00% and 7.14%, and the relative standard deviation is between 0.87% and 5.25%. The method is quick, handy, saving reagent and completely digesting in dealing with plant's ash and soil sample, and the accuracy and precision of results are satisfying.

Predictors of ventricular tachycardia recurrence in 100 patients receiving tiered therapy defibrillators

BACKGROUND AND HYPOTHESIS

Programmed electrical stimulation (PES) is a time-honored diagnostic tool in patients with ventricular tachyarrhythmias. The response to PES can be used to assess efficacy of pharmacologic or electrical therapy, as well as to obtain prognostic information. Reproducible induction of ventricular tachycardia with invasive electrophysiologic testing, or stimulation through defibrillator lead systems, can help optimize antiarrhythmic drug therapy and device programming during clinical follow-up.

METHODS

We present our experience with 100 patients who had inducible sustained monomorphic ventricular tachycardia (SMVT) during invasive PES at baseline, and received a third-generation implantable cardioverter-defibrillator (ICD) alone, or in combination with antiarrhythmic drug therapy. Noninvasive programmed stimulation (NIPS) was performed prior to hospital discharge in 61 patients.

RESULTS

The inducibility of SMVT was concordant between the invasive study and NIPS in a subgroup of 40 (82%) patients who had invasive PES on the same drug regimen. During a mean follow-up of 16 months, there were 12 nonarrhythmic deaths and recurrence of spontaneous SMVT in 36 (40%) of the surviving patients. Using a Cox proportional hazards model, the following variables were associated with early arrhythmia recurrence: persistent inducibility of SMVT during the NIPS session (relative risk 11, range 2.6-47); induction of SMVT with a cycle length > 280 ms during invasive baseline PES (2.5, 1.2-5) and presence of prior inferior myocardial infarction (2.1, 1-4.2). Timing to initial recurrence of spontaneous tachycardia was unaffected by other clinical variables or concomitant antiarrhythmic drug use.

CONCLUSION

Programmed electrical stimulation techniques offer insight into the patterns of spontaneous ventricular tachycardia recurrence and have significant practical utility in the management of patients receiving third-generation ICDs.

Characterization of reflection intermittency in a composite granular chain

The physical factors controlling the power-law behavior of impact energy in a composite granular chain remain elusive. Based on event-driven simulations and the on-off intermittency of wave reflections, we obtain the probability distribution functions of the waiting time tau and the energy leakage DeltaE . They exhibit lognormal distributions, which together with the relationship between DeltaE and tau allow one to explain directly the power-law behavior of the confined energy. This work may be extended to higher dimensions and help us understand the complex dynamics in granular materials.

The Mammalian synaptonemal complex: a scaffold and beyond

During the first meiotic cell division (meiosis I), homologous chromosomes pair, synapse, recombine, and segregate, using highly coordinated and tightly regulated mechanisms. The synaptonemal complex (SC), a proteinaceous tripartite structure, plays an important role both as a scaffold for the close juxtaposition of homologous chromosomes and in regulating the overall process of homologous recombination. Specifically, it mediates chromosome synapsis during the lengthy prophase of meiosis I. The SC consists of two parallel lateral elements, one central element, and numerous transverse filaments. Recent genetic studies in mice have provided novel insights into the mechanisms by which the SC regulates meiosis and into the etiology of diseases such as aneuploidy. Even though the tripartite ultrastructure and meiotic functions of the SC are similar in different species, the SC components are not well-conserved at the protein sequence level. This review will focus on the identification, characterization, and functions of the synaptonemal complex proteins in mammals.

Crossover in the power-law behavior of confined energy in a composite granular chain

We present a numerical study of the impact energy decay in a composite granular chain containing two heavy and one light sections. We observe a marked crossover in the power-law behavior of the impact-energy decay. The average reflection frequency first increases with a decreasing acceleration, and arrives at its maximum at "crossing" time then decays almost exponentially. The analysis demonstrates that this phenomenon is related to the structural transition from compression to dilation state in both heavy-particle sections. The further calculations suggest the dependence relation of the power-law exponent (gammacb) in compression state on the mass ratio (m2/m1) and the Hertz law exponent (n) of the composite granular chain gammacb approximately (m2/m1)1/(n+1).

CT-guided percutaneous neurolytic celiac plexus block technique

Up to now, the studies in the world have demonstrated that CT-guided percutaneous neurolytic celiac plexus block (PNCPB) is an invaluable therapeutic modality in the treatment of refractory abdominal pain caused by cancer. Its efficacy of pain relief varied in reported studies. The main technical considerations which would affect the analgesic effects on abdominal pain included the patients' cooperation, needle entry approaches, combined use of blocking approaches, localization of the target area, dosage of the blocker, and so on. A success of PNCPB depends greatly on close cooperation with patients. The patient should be educated about the purpose and steps of the procedure, and trained of breathing in and breathing hold. The needle entry can be divided into the posterior approach and the anterior approach. The former one is the most commonly used in clinical practice, but the latter one is rarely used except in the cases that the posterior approach becomes technically difficult. Bilateral multiple blocking of celiac plexus and splanchnic nerves is often required to achieve optimal analgesia. The needle entry site, insertion course, and depth should be preselected and simulated on CT monitor prior to the procedure in order to ensure an accurate and safe celiac plexus block. The magnitude of analgesic effect is closely related to the degree of degeneration and necrosis of the celiac plexus. Maximally filling with blocker in the retropancreatic space is an indication of sufficient blocking. We also provided an overview of indications and contraindications, preoperative preparations, complications and its treatment of PNCPB.

The POZ/BTB protein NAC1 interacts with two different histone deacetylases in neuronal-like cultures

NAC1 is a cocaine-regulated POZ/BTB (Pox virus and Zinc finger/Bric-a-brac Tramtrack Broad complex) protein. NAC1 is increased by cocaine selectively in the nucleus accumbens, a CNS region important for drug addiction. NAC1's role in the cell, however, is not known. Each of the two NAC1 isoforms, sNAC1 (short NAC1) and lNAC1 (long NAC1), may serve as corepressors for other POZ/BTB proteins. This study investigated whether sNAC1 and lNAC1 demonstrated protein-protein interactions with other corepressors. Histone deacetylase (HDAC) inhibition reversed sNAC1 and lNAC1 repression of Gal4 luciferase, but only in neuronal-like cultures. Because these inhibitors do not distinguish among histone deacetylases, two histone deacetylases were selected for further study. HDAC 3 and 4 both demonstrated protein-protein interactions with sNAC1 and lNAC1. This was shown using coimmunoprecipitations, glutathione-S-transferase (GST) pulldowns and mammalian two-hybrids. Importantly, either the POZ domain or NAC1 without the POZ domain can bind these two HDACs. Other corepressors, specifically NCoR (nuclear receptor corepressor), SMRT (silencing mediator for retinoid and thyroid hormone receptor) and mSin3a, do not exhibit protein-protein interactions with sNAC1 and lNAC1. None showed protein-protein interactions in GST pulldowns or mammalian two-hybrids. Taken together, the results of these experiments indicate sNAC1 and lNAC1 recruit histone deacetylases for transcriptional repression, further enhancing POZ/BTB protein mediated repression.

The relationship between cocaine-induced increases in NAC1 and behavioral sensitization

Repeated exposure to cocaine can cause long-term behavioral changes in mammals, including an augmented locomotor response known as behavioral sensitization. A major goal of research is the identification of molecules associated with these behaviors. NAC1, a member of the POZ/BTB transcription factor family, exhibited increased mRNA levels in the nucleus accumbens of the rat weeks after cocaine use. NAC1 exists as two isoforms, each demonstrating the ability to inhibit transcription, but to different extents. The present experiments examined the time course for both NAC1 isoforms after five consecutive days of systemic cocaine administration in male rats. Tissues were collected from several central nervous system regions and underwent Western blot analysis. There was significantly greater expression of the long isoform, lNAC1 (cocaine 1.341+/-0.641; saline 1+/-0.321; P=.044), and the short isoform, sNAC1 (cocaine 3.038+/-2.816; saline 1+/-0.720; P=.001), in the nucleus accumbens of cocaine-treated rats. The olfactory tubercle also showed a significant increase, but only in sNAC1 expression and at only one time period. No other significant differences were observed for either isoform of NAC1 in any other brain region. The expression of lNAC1 exhibited an inverse relationship with behavioral sensitization in rats 1-3 months following repeated cocaine injections predicting approximately 40% of the variance in the behavior variables (R(2)=.387; and P=.031 for distance and P=.025 for ambulatory count). These results indicate that NAC1 expression is increased for a period of several months after chronic cocaine exposure. Furthermore, these data suggest that NAC1 may function as an endogenous inhibitor of behavioral sensitization. NAC1 represents a target for future studies examining cocaine-induced behavioral changes.

Differences in expression, actions and cocaine regulation of two isoforms for the brain transcriptional regulator NAC1

BTB/POZ proteins can influence the cell cycle and contribute to oncogenesis. Many family members are present in the mammalian CNS. Previous work demonstrated elevated NAC1 mRNA levels in the rat nucleus accumbens in response to cocaine. NAC1 acts like other BTB/POZ proteins that regulate transcription but is unusual because of the absence of identifiable DNA binding domains. cDNAs were isolated encoding two NAC1 isoforms differing by only 27 amino acids (the longer isoform contains 514 amino acids). The mRNAs for both isoforms were simultaneously expressed throughout the rat brain and peripheral tissues. Semi-quantitative reverse transcription-polymerase chain reaction analysis revealed that the mRNA of the longer isoform was more abundant than the mRNA of the shorter isoform. Western blot analysis demonstrated a similar unequal distribution between the isoforms in the CNS. The longer isoform was the more abundant of the two NAC1 proteins and the ratio between them differed throughout the rat brain. The shorter isoform was not detected in most of the examined peripheral tissues, suggesting differences from the CNS in post-transcriptional processing. Both isoforms repressed transcription in H293T cells using a Gal4-luciferase reporter system. However, the shorter isoform did not repress transcription as effectively as the longer isoform. Transfection of different ratios for both isoforms, in order to replicate the relative amounts observed throughout the CNS, supported an interaction between the isoforms. The net effect on transcriptional repression was determined by the ratio of the two NAC1 isoforms. Each isoform exhibited the subnuclear localization that is characteristic of many BTB/POZ proteins. A rapid and transient increase in the level of the shorter isoform occurred in the nucleus accumbens 2 h following a single i.p. cocaine injection. We conclude that the two isoforms of NAC1 may differentially affect neuronal functions, including the regulation of cocaine-induced locomotion.

Self-organized nanoscale pattern formation on vicinal Si(111) surfaces via a two-stage faceting transition

We demonstrate a self-organized pattern formation on vicinal Si(111) surfaces that are miscut toward the [2;11] direction. All the patterns, consisting of a periodic array of alternating (7 x 7) reconstructed terraces and step-bunched facets, have the same periodicity and facet structure, independent of the miscut angle, while the width of the facets increases linearly with miscut angle. We attribute such unique pattern formation to a surface faceting transition that involves two transition stages: the first stage forms a stress-domain structure defining the universal periodicity; the second stage forms the low-energy facets controlling the facet width.

Risk factors associated with infantile spasms: a hospital-based case-control study in Taiwan

We investigated the risk factors associated with infantile spasms (IS) by a hospital-based case-control study in Taiwan. Twenty-five patients with IS were recruited from one medical center (National Taiwan University Hospital) between 1990 and 1997. Based on a close-structured questionnaire, standardized interviews were carried out to obtain information on risk factors associated with IS. Two comparison groups are used, including a total of 106 subjects in the Disease Control group, and 139 subjects in the Normal Control group. Unconditional logistic regression is used to calculate odds ratios (OR) and 95% confidence interval (CI). Univariate analysis revealed gestational age, congenital cerebral anomalies, tuberous sclerosis (TS), asphyxia, febrile seizure, and developmental delay (before onset of spasm) were at increased risk of IS. After adjustment of multiple risk factors through unconditional logistic regression, significant risk factors for IS include congenital cerebral anomalies, TS, asphyxia, postterm, and developmental delay were highly associated with IS. The risk factors of IS may closely relate to underlying neurological abnormalities. Our results are consistent with the previous findings.

Early epileptic encephalopathy with suppression burst electroencephalographic pattern--an analysis of eight Taiwanese patients

Early epileptic encephalopathy with suppression burst (SB) comprises two distinct epileptic syndromes, early infantile epileptic encephalopathy (EIEE) and early myoclonic encephalopathy (EME). We reviewed etiologies, neurological outcome and clinico-electroencephalographic features of EIEE and EME. Chart records of early epileptic encephalopathy with SB from January 1997 to December 2000 were reviewed. These cases fulfilled the diagnostic criteria of EIEE and EME. Totally eight patients (four females, four males) were enrolled. They consisted of three cases of EIEE and five cases of EME. The follow-up periods ranged from 6 to 30 months. For EIEE, two cases had migrational disorders, and one was cryptogenic; for EME, three cases had non-ketotic hyperglycinemia (NKH), one was pyridoxine dependency and one was cryptogenic. The main initial seizure patterns were tonic spasms in EIEE, and were erratic myoclonus in EME. The age of seizure onset ranged from 26 h to 5 days after birth for EIEE, and 2 h to 7 days of life for EME. The SB pattern in the electroencephalography (EEG) was noted mainly during sleep state in EME, but in both awake and sleep states in EIEE. Asymmetric SB pattern and background activities in EEG were found in migrational disorders. The EEG in all cases of EIEE changed to hypsarrhythmia at 4-6 months of age. In EME, only the EEG in cases of NKH evolved to hypsarrhythmia. Response to anti-convulsants was generally poor. All had severe psychomotor retardation. Although EIEE and EME share several common features, differences in terms of seizure seminology and evolution, EEG patterns and etiologies still exist.

Control of microtubule dynamics by Stu2p is essential for spindle orientation and metaphase chromosome alignment in yeast

Stu2p is a member of a conserved family of microtubule-binding proteins and an essential protein in yeast. Here, we report the first in vivo analysis of microtubule dynamics in cells lacking a member of this protein family. For these studies, we have used a conditional Stu2p depletion strain expressing alpha-tubulin fused to green fluorescent protein. Depletion of Stu2p leads to fewer and less dynamic cytoplasmic microtubules in both G1 and preanaphase cells. The reduction in cytoplasmic microtubule dynamics is due primarily to decreases in both the catastrophe and rescue frequencies and an increase in the fraction of time microtubules spend pausing. These changes have significant consequences for the cell because they impede the ability of cytoplasmic microtubules to orient the spindle. In addition, recovery of fluorescence after photobleaching indicates that kinetochore microtubules are no longer dynamic in the absence of Stu2p. This deficiency is correlated with a failure to properly align chromosomes at metaphase. Overall, we provide evidence that Stu2p promotes the dynamics of microtubule plus-ends in vivo and that these dynamics are critical for microtubule interactions with kinetochores and cortical sites in the cytoplasm.

Auditory brainstem evoked potentials in healthy full-term and pre-term infants

BACKGROUND

Auditory brainstem evoked potentials (ABEP) are used to evaluate the integrity of auditory pathways. Since there are difficulties in the performance and still no reference ranges for pre-term infants in Taiwan, the purpose of this study was to evaluate the characteristics of ABEP in full-term and pre-term infants.

METHODS

Forty full-term and 52 pre-term infants were enrolled between January and December 1997. ABEP study was performed at 3-7 days after birth, 3, 6 and 12 months of age in the full-term group while the pre-term infants were assessed at 34-36 weeks of gestational age, at term age, and at 3, 6, 12 months of corrected age. Acoustic stimulation of mixed frequency rarefaction clicks was presented to each ear through earphones. The clicks were presented at an intensity of 70-90 dB (hearing level) and a gradual decrement of intensity to 20-40 dB to determine the threshold. Electrical activity was picked up by surface electrodes. Latency of peaks I, III, V, inter-peak latency I-III, III-V, I-V and the threshold were assessed.

RESULTS

In the full-term group, the peak and inter-peak latencies decreased with age. In the pre-term group, the responses of 70 dB stimulus intensity were 53.8%, 58%, 82.8%, 88.9%, 100% in the sequence and the threshold of response decreased with age.

CONCLUSION

There are maturational changes after birth in both full-term and pre-term infants. We conclude that ABEP study is a sensitive, non-invasive tool for the evaluation of auditory pathway in infants.

Two closely related human nuclear export factors utilize entirely distinct export pathways

Nuclear mRNA export mediated by the human protein TAP requires a carboxy-terminal domain that directly interacts with components of the nuclear pore complex. Here we demonstrate that NXF3, a human RNA binding protein related to TAP, lacks this domain yet retains the ability to export tethered RNA transcripts and to shuttle between the nucleus and the cytoplasm. NXF3 contains a novel Crm1-dependent nuclear export signal that compensates in cis for the loss of the nuclear pore targeting domain. NXF3-dependent RNA export is therefore blocked by Crm1-specific inhibitors that do not affect TAP function. Thus, while the related TAP and NXF3 proteins are both capable of mediating nuclear RNA export, they do so via unrelated export pathways.

[Effect of bushen huoxue decoction on in vitro fertilization and early embryonic development in mice]

OBJECTIVE

To explore the effect of Bushen Huoxue decoction (BSHX) on female reproduction and elucidate its therapeutic mechanism to infertility.

METHODS

The BSHX medicated serum of rabbit, as a supplement, was co-cultured with the sperm and ovum of non-copulated mice, and the 2-cell embryos of copulated female mice separately, to observe the changes of in vitro fertilization rate (IVF) and early embryogenesis rate.

RESULTS

By co-cultured with BSHX medicated serum, IVF rate was increased obviously (P < 0.01), and the follow-up early embryogenesis rate at various period was promoted, particularly that of the 4-cell and 8-cell embryos (P < 0.05). No influence on developmental rate of in vitro 4-cell embryos obtained from the in vivo 2-cell embryos. But the development of the 8-cell embryos, morula, blastula and hatching were promoted significantly.

CONCLUSION

BSHX could raise the fertilization rate and promote the early embryonic development.

Cardiac conduction abnormalities in a mouse model of Lyme borreliosis

BACKGROUND

Borrelia Burgdorferi (BB) induces cardiac conduction abnormalities in infected humans. Mice models of Lyme disease have been developed, however their electrophysiologic (EP) properties of conduction are unknown.

METHODS

Seventy-six C3H/J mice (BB infected and age- and gender-matched controls) underwent blinded in vivo EP studies. In a first phase of the study, 40 male C3H/J mice were divided into 2 groups: Group (A) mice were infected at age 3 (weeks) and studied at 5, and Group (B) mice were infected at 9 and studied at 11. In a second phase, 36 female mice were divided into 2 groups: Group (C) mice were infected at 3 weeks and studied at 5, and Group (D) mice were infected at 3 and studied at 11.

RESULTS

Infected mice of group (A) and (C) had wider QRS complexes (21.0+/-1.6 versus 17.3+/-1.3ms, p< or =0.0001 and 20.3+/-2.1 versus 18.5+/-1.7, p = 0.05, respectively) compared to the healthy controls (HC). Infected mice of group (B) and group (D) were similar to the HC. In all groups, the presence of conduction abnormalities correlated very closely with the amount of inflammation on pathology.

CONCLUSION

This study describes the first EP mouse model of Lyme carditis. C3H/J mice exhibit conduction abnormalities that are reversible 8 weeks after inoculation, closely paralleling the resolution of inflammation on pathology. This model can be a valuable tool in the developing and testing of new modalities for the prevention and treatment of Lyme carditis.

An abundance of X-linked genes expressed in spermatogonia

Spermatogonia are the self-renewing, mitotic germ cells of the testis from which sperm arise by means of the differentiation pathway known as spermatogenesis. By contrast with hematopoietic and other mammalian stem-cell populations, which have been subjects of intense molecular genetic investigation, spermatogonia have remained largely unexplored at the molecular level. Here we describe a systematic search for genes expressed in mouse spermatogonia, but not in somatic tissues. We identified 25 genes (19 of which are novel) that are expressed in only male germ cells. Of the 25 genes, 3 are Y-linked and 10 are X-linked. If these genes had been distributed randomly in the genome, one would have expected zero to two of the genes to be X-linked. Our findings indicate that the X chromosome has a predominant role in pre-meiotic stages of mammalian spermatogenesis. We hypothesize that the X chromosome acquired this prominent role in male germ-cell development as it evolved from an ordinary, unspecialized autosome.