[Performance evaluation of two N95 filtering-facepiece respirators on decomposition products of sulfur hexafluoride]

OBJECTIVE

To assess the filtration efficiency of two N95 filtering-facepiece respirators (FFRs) for the decomposition products of sulfur hexafluoride (SF6).

METHODS

Two types of N95 FFRs (the particulate and the acid-proof respirators) were selected in this study. The decomposition products of SF6, including particles, hydrogen fluoride (HF) and sulfur dioxide (SO2) , were measured under experimental condition by using TSI PortaCount Plus, fluorine ion-selective electrodes and spectrophotometer separately. The filtration efficiency was then calculated and compared.

RESULTS

Both two models of N95 respirators had lowest filtration efficiency larger than 95% for particles under airflow ranged from 10 to 95 L/min. When exposed to different concentrations of HF (low: 0.00~1.99 mg/m(3), middle: 2.00~3.99 mg/m(3), high: >4 mg/m(3)) , the acid-proof N95 respirator was more effective than the particulate respirator (P<0.05) with a filtration efficiency of 98.83%, 99.08%, and 99.03% versus 48.44%, 45.71%, and 47.31%. For four SO2 concentration ranges (0.00~2.49 mg/m(3), 2.50~4.99 mg/m(3), 5.00~9.99 mg/m(3), and >10.00 mg/m(3)) , the acid-proof respirator showed a high filtration efficiency within exposure to 1.5 hours: 95.73%, 98.67%, 98.14%, and 97.78%, respectively, when exposure duration extended to 4 hours, the filtration efficiency of the acid-proof respirator decreased to 91.97%, 82.28%, 70.12%, and 58.56%, respectively.

CONCLUSION

Both the particulate and the acid-proof N95 FFRs met national standards on the particulate filtration efficiency. The acid-proof N95 respirator demonstrates to be more effective in filtering HF and SO2 than the particulate respirator. The filtration efficiency could decrease to an unsafe condition under longer exposure duration, timely replacement of respirator is recommended at the workplace.

Evaluation of the GenoType(®) MTBDRplus line probe assay on sputum-positive samples in routine settings in China

BACKGROUND

Rapid molecular methods have been recommended for early detection of drug-resistant tuberculosis (TB).

OBJECTIVE

To evaluate the performance of the GenoType(®) MTBDRplus assay in routine settings in China.

METHODS

Sputum-positive samples were collected consecutively from 1 April to 31 December 2010. MTBDRplus results were compared to those of conventional drug susceptibility testing (DST). The McNemar χ(2) test and κ coefficient were used to assess performance.

RESULTS

Of 427 smear-positive sputum samples collected, conventional DST and MTBDTplus confirmed drug resistance in 326. The sensitivities and specificities for MTBDRplus in detecting isoniazid (INH) and rifampicin (RMP) resistance were respectively 76.47%, 95.44%, 85.94% and 93.13%. The McNemar χ(2) test indicated no significant difference between the two methods (P = 0.106 for INH and P = 0.083 for RMP). The κ values for INH, RMP and multidrug resistance were respectively 0.75, 0.75 and 0.70.

CONCLUSIONS

Although the MTBDRplus assay was moderately concordant with conventional DST in detecting INH and RMP resistance, as a prospective rapid molecular method for MDR-TB detection, potential resistant mutations need to be incorporated to improve the accuracy of detection.

Brief Questionnaire Derived from PANSS Using a General Probability Model to Assess and Monitor the Clinical Features of Schizophrenia

AIM

Patients with schizophrenia require continuous treatment much longer than the duration of their hospitalization, which makes their family members essential in their medical care. However, the evaluation of the disease state could only be done by professionals. This prompted us to seek potent indicators of disease states that are understandable and easy to use for the patients' family.

METHOD

Specific items were firstly extracted from the total PANSS scale. Then 3 096 PANSS scores were analyzed using a nonlinear mixed-effects model (NONMEM). A questionnaire was subsequently developed for family members to assess and monitor the overall severity of schizophrenia. Finally this questionnaire was validated in 33 patients.

RESULTS

2 items (P1 and N4) were extracted from the 8 effective remission items according to the correlation coefficients between the total PANSS score and different combinations of items. P1N4 was defined as the sum of these 2 items. A model was then developed to describe the probability of PANSS≥60, with P1N4 as indicators. The results indicated that P1N4 could make a good predictor of the overall probability of PANSS≥60, which was independent of treatment. A brief questionnaire with 7 questions was developed based on the results. External validation results indicated the questionnaire's suitability for a good assessment.

CONCLUSION

Questionnaire developed based on P1 and N4 may facilitate the patients' family members to better understand the disease state and help to prevent relapse.

Hematogones: a sensitive prognostic factor for Chinese adult patients with acute myeloid leukemia

BACKGROUND

Hematogones (hgs) are normal B-lymphocyte precursors that increase in some hematologic diseases. Many studies indicate that hgs might be a favourable prognostic factor. We thus considered it important to determine whether hgs are also a prognostic factor for Chinese adult patients with acute myeloid leukemia (aml) and whether the hg-positive and hg-negative groups show any serologic or phenotypic differences.

METHODS

Chinese adult aml patients (n = 177) who were all initially hg-negative underwent standard chemotherapy and were thereafter divided into hg-positive and hg-negative groups according to hg levels in bone marrow during their first remission.

RESULTS

The follow-up study confirmed that survival duration (both leukemia-free and overall) was significantly greater in the hg-positive group than in the hg-negative group and was accompanied by a lower relapse rate. A retrospective study of patient characteristics at the time of first diagnosis revealed some differences between the hg-positive and the hg-negative groups, including elevations in white blood cells, lactate dehydrogenase, and β2-microglobulin in the hg-negative group. Retrospective phenotypic analysis revealed a significantly lower proportion of abnormal chromosome karyotype and CD34 expression in hg-positive patients. Finally, we evaluated whether additional intensive chemotherapy after standard chemotherapy could further increase hgs.

CONCLUSIONS

The present work verified the validity of hgs as a prognostic factor for Chinese adult patients with aml. Compared with hg-negative patients, hg-positive patients not only experienced longer survival and a lower relapse rate, but they also had some serologic and phenotypic characteristics that are all considered indicators of better outcome. Additional intensive chemotherapy could further increase the level of hgs, which might imply better clinical results.

[Clinical outcomes of early repair for open orbital fracture]

OBJECTIVE

To investigate the clinical outcomes following early repair for orbital fracture and soft tissue simultaneously for open orbital fractures.

METHODS

Retrospective clinical study. This study comprised of 19 patients(20 eyes) with open orbital fracture who underwent surgery within 48 hours in the Second Hospital of Dalian Medical University between August 2011 and August 2014. The wounds were evaluated at the same time and the surgical debridement was done. The surgical exposure was achieved through direct approach and auxiliary cosmetic incisions. Titanium mesh and plate was used for orbital reconstruction. Local flaps or island flaps were used for soft tissue repair. With the post-operative CT scan, the condition of the soft tissue which was herniated, the orbital rim and orbital wall were observed. The measurement of the exophthalmos of both eyes was performed using Hertel exophthalmometer. Compared with the intact eye, the globe displacement (upward or downward) of the reconstructed eye was measured. The follow up duration was 12-24 months. The eye movement, diplopia, restriction of mouth opening, depression of midface, the condition of soft tissue and scar as well as post-operative complications were recorded. Comparison of the reconstructed eye's globe displacement before and after operation were analyzed with wilcoxon signed ranks test. Comparison of the exophthalmos of the reconstructed eye relative to the intact eye were analyzed with t-paired test.

RESULTS

In all 19 cases (20 eyes), fractures were anatomically reconstructed, and no cases of infection, titanium mesh and plate migration and rejection occured during the follow-up. Seven cases had eyeball hypoglobus with median 3.0 mm (min 2.0 mm, max 4.0 mm) pre-operatively. The Reconstructed eye globe were corrected in 6 cases and 1 case had residual hypoglobus of 1.0 mm ,median 0.0 mm (min 0.0 mm, max 1.0 mm). The amount of the eye globe displacement between pre-and post-operation was statistically significant(z=-2.40, P<0.05). Enophthalmos was corrected in 16 cases (the mean of posterior globe displacement in reconstructed orbit relative to intact orbit was less than or equal to 2.0mm), but in 2 patients the residual enophthalmos was 3.0 mm. The difference of the exophthalmos of both eyes was not obvious (t=-0.46,P>0.05). Among 20 eyes, 16 patients had restrictive eye movement. After 12 months follow-up, 13 eyes with restrictive eye movement were corrected while the other 3 showed improvement. Eight patients of restriction of mouth opening or midface depression were corrected and no infection complications were noted. There was no flap necrosis in 13 patients of soft tissue defect.

CONCLUSION

Surgical treatment of open orbital fractures with simultaneous repair of orbital fracture and soft tissue within 48 hours after trauma could correct enophthalmos, hypoglobus and eye movement function effectively and improve periorbital aesthetics. (Chin J Ophthalmol, 2016, 52: 273-277).

[Cortical auditory evoked potentials in congenital hearing impaired children with cochlear implants]

OBJECTIVE

By investigating the auditory cortical evoked potential in congenital hearing impaired children with cochlear implants, the association between central auditory development and the age of implantation was studied.

METHODS

P1-N1-P2 were recorded in 110 profound hearing impaired children, aged from 12 to 80 months old and being implanted with cochlear implants before the age of 5 years. Their implant using time ranged from just at the switch-on to 48 months. The stimuli were /m/, /t/, /g/, presented at 65 dB SPL in sound field. The presence rate of each wave was obtained and the relationship between P1 latency and implant age, the time of speech processor switch-on were analyzed.

RESULTS

The presence rate of P1, N1 and P2 was 66.4%, 15.5% and 12.7%, respectively. The presence of P1 was significantly higher than that of N1(χ(2)=228.542, P=0.00)and P2(χ(2)=257.438, P=0.00). There was no significant difference of P1 presence rate elicited by /m/, /t/ and /g/(64.1%, 66.9% and 68.3%, χ(2)=0.589, P=0.75). There existed no significant difference either among P1 latency(P=0.22)or amplitude(P=0.09) elicited by /m/, /t/ and /g/. There was significant difference between the implant age before and after 42-month-old regarding the proportion that entered the age-appropriate normal P1 latency range(P=0.02). No significant difference was found among groups of implant using time of 1, 2, 3 and 4 years in aspect of the proportion that entered the age-appropriate normal P1 latency range(P=1.00).

CONCLUSIONS

Compared with implanted after the age of 42-month-old children with prelingual hearing impairment younger than 5 years old, the ones implanted before 42-month-old have more chance for normal development for central auditory system. Once implanted before 42-month-old, the cortical auditory system restored its normal development as early as 1 year after implantation.

Improved Proliferation and Differentiation of Bone Marrow Mesenchymal Stem Cells Into Vascular Endothelial Cells With Sphingosine 1-Phosphate

The practical use of bone marrow mesenchymal stem cells (MSCs), considered to be the best candidate in the field of regenerative medicine, is limited by the low efficiency of MSC differentiation. Sphingosine 1-phosphate (S1P) could promote proliferation, survival, and differentiation of many types of cells, but its effects on MSCs remain elusive. In this study, S1P was added during primary MSCs (PR-MSCs) culture and the effects of S1P on proliferation, survival, and differentiation of PR-MSCs were evaluated. The results showed that S1P could improve PR-MSCs proliferation activity in a concentration-dependent manner, and the apoptosis of PR-MSCs cultured in hypoxia was significantly reduced in the S1P-treated group compared to the control group. After being cultured with vascular endothelial growth factor for 7 days, the specific genes of endothelial cells were highly expressed in S1P-treated PR-MSCs compared to control group, which coincided with the augumented production of hepatocyte growth factor, stromal cell-derived factor-1, and insulin-like growth factor-1. In summary, our results suggest that S1P can promote proliferation, survival, and differentiation into vascular endothelial cells of PR-MSCs. These results will promote the clinical application of PR-MSCs and deepen our understanding of the function mechanism of S1P.

Could intensive anti-hypertensive therapy produce the "J-curve effect" in patients with coronary artery disease and hypertension after revascularization?

OBJECTIVE

Intervention and prospective long-term follow-up was performed to observe the presence of the "J-curve effect" in patients with Coronary Artery Disease (CAD) who underwent intensive anti-hypertensive therapy after (PCI or CABG).

PATIENTS AND METHODS

Four hundred and thirty-six successive CAD patients were included in this study, 67 patients with CAD only (Group A) and the 369 patients with both CAD and hypertension who were randomly assigned to Group B (no control of blood pressure (BP), n=72), Group C (n=83, target BP 130-140/80-90 mmHg), Group D (n=78, target BP 120-130/75-80 mmHg), Group E (n=74, target BP 110-120/70-75 mmHg) and Group F (n=62, target BP <110/70 mmHg). All patients had undergone revascularization and anti-hypertensive therapy. The composite endpoint was the end of the follow-up, i.e. major adverse cardiac events (MACE) (cardiac death, nonfatal myocardial infarction and target vessel revascularization) and stroke.

RESULTS

1) Results showed that smoking, total cholesterol (Tc), low density lipoprotein-C (LDL-C), high-sensitivity C-reactive protein (hs-CRP), β-blockers, ACEI or ARB (except for Group A and Group B), diuretics and follow-up duration among the 6 groups were not significantly different, However significantly lower than those results on admission (p<0.05). The difference between systolic blood pressure (SBP) and diastolic blood pressure (DBP) was significant, p<0.05, both BP achieved target values. 2) The "J-curve effect" was present in the actual occurrence of composite endpoint and MACE for SBP and DBP, with a reasonable BP-lowering range of 120-130/75-80 mmHg, while the "J-curve effect" was absent in the occurrence of stroke.

CONCLUSIONS

For the patients who had CAD and hypertension, intensive anti-hypertensive therapy could produce the "J-curve effect" after revascularization with the optimal blood pressure (BP) range being 120-130/75-80 mmHg.

Physics of Phase Space Matching for Staging Plasma and Traditional Accelerator Components Using Longitudinally Tailored Plasma Profiles

Phase space matching between two plasma-based accelerator (PBA) stages and between a PBA and a traditional accelerator component is a critical issue for emittance preservation. The drastic differences of the transverse focusing strengths as the beam propagates between stages and components may lead to a catastrophic emittance growth even when there is a small energy spread. We propose using the linear focusing forces from nonlinear wakes in longitudinally tailored plasma density profiles to control phase space matching between sections with negligible emittance growth. Several profiles are considered and theoretical analysis and particle-in-cell simulations show how these structures may work in four different scenarios. Good agreement between theory and simulation is obtained, and it is found that the adiabatic approximation misses important physics even for long profiles.

Advancement of highly charged ion beam production by superconducting ECR ion source SECRAL (invited)

At Institute of Modern Physics (IMP), Chinese Academy of Sciences (CAS), the superconducting Electron Cyclotron Resonance (ECR) ion source SECRAL (Superconducting ECR ion source with Advanced design in Lanzhou) has been put into operation for about 10 years now. It has been the main working horse to deliver intense highly charged heavy ion beams for the accelerators. Since its first plasma at 18 GHz, R&D work towards more intense highly charged ion beam production as well as the beam quality investigation has never been stopped. When SECRAL was upgraded to its typical operation frequency 24 GHz, it had already showed its promising capacity of very intense highly charged ion beam production. And it has also provided the strong experimental support for the so called scaling laws of microwave frequency effect. However, compared to the microwave power heating efficiency at 18 GHz, 24 GHz microwave heating does not show the ω(2) scale at the same power level, which indicates that microwave power coupling at gyrotron frequency needs better understanding. In this paper, after a review of the operation status of SECRAL with regard to the beam availability and stability, the recent study of the extracted ion beam transverse coupling issues will be discussed, and the test results of the both TE01 and HE11 modes will be presented. A general comparison of the performance working with the two injection modes will be given, and a preliminary analysis will be introduced. The latest results of the production of very intense highly charged ion beams, such as 1.42 emA Ar(12+), 0.92 emA Xe(27+), and so on, will be presented.

High intensity high charge state ion beam production with an evaporative cooling magnet ECRIS

LECR4 (Lanzhou ECR ion source No. 4) is a room temperature electron cyclotron resonance ion source, designed to produce high current, high charge state ion beams for the SSC-LINAC injector (a new injector for sector separated cyclotron) at the Institute of Modern Physics. LECR4 also serves as a PoP machine for the application of evaporative cooling technology in accelerator field. To achieve those goals, LECR4 ECR ion source has been optimized for the operation at 18 GHz. During 2014, LECR4 ion source was commissioned at 18 GHz microwave of 1.6 kW. To further study the influence of injection stage to the production of medium and high charge state ion beams, in March 2015, the injection stage with pumping system was installed, and some optimum results were produced, such as 560 eμA of O(7+), 620 eμA of Ar(11+), 430 eμA of Ar(12+), 430 eμA of Xe(20+), and so on. The comparison will be discussed in the paper.

The characteristic of evaporative cooling magnet for ECRIS

Compared with traditional de-ionized pressurized-water cooled magnet of ECRIS, evaporative cooling magnet has some special characteristics, such as high cooling efficiency, simple maintenance, and operation. The analysis is carried out according to the design and operation of LECR4 (Lanzhou Electron Cyclotron Resonance ion source No. 4, since July 2013), whose magnet is cooled by evaporative cooling technology. The insulation coolant replaces the de-ionized pressurized-water to absorb the heat of coils, and the physical and chemical properties of coolant remain stable for a long time with no need for purification or filtration. The coils of magnet are immersed in the liquid coolant. For the higher cooling efficiency of coolant, the current density of coils can be greatly improved. The heat transfer process executes under atmospheric pressure, and the temperature of coils is lower than 70 °C when the current density of coils is 12 A/mm(2). On the other hand, the heat transfer temperature of coolant is about 50 °C, and the heat can be transferred to fresh air which can save cost of water cooling system. Two years of LECR4 stable operation show that evaporative cooling technology can be used on magnet of ECRIS, and the application advantages are very obvious.

24 GHz microwave mode converter optimized for superconducting ECR ion source SECRAL

Over-sized round waveguide with a diameter about Ø33.0 mm excited in the TE01 mode has been widely adopted for microwave transmission and coupling to the ECR (Electron Cyclotron Resonance) plasma with the superconducting ECR ion sources operating at 24 or 28 GHz, such as SECRAL and VENUS. In order to study the impact of different microwave modes on ECRH (Electron Cyclotron Resonance Heating) efficiency and especially the production of highly charged ions, a set of compact and efficient TE01-HE11 mode conversion and coupling system applicable to 24 GHz SECRAL whose overall length is 330 mm has been designed, fabricated and tested. Good agreements between off-line tests and calculation results have been achieved, which indicates the TE01-HE11 converter meets the application design. The detailed results of the optimized coupling system will be presented in the paper.

Treatment of tibia avulsion fracture of posterior cruciate ligament with high-strength suture fixation under arthroscopy

Aim

To evaluate the outcome of arthroscopy treatment using high-strength line in the treatment of tibial avulsion fracture of posterior cruciate ligament.

Methods

Both the avulsed bone block and the tibia bone bed were refreshed. The procedure was completed with the assistance of PCL director drill guide. The reduction and fixation using high-strength line were used to fix the avulsed bone by from posterior middle portal. Rehabilitation began early postoperatively.

Results

From January 2010 to June 2012, a total of 18 arthroscopically treated cases of PCL tibial avulsion fracture were retrospectively evaluated. Reduction of the avulsion fragment was obtained in all cases. 16 cases were followed up for 7–30 months (average 13.6), and 2 cases were out of follow-up. In the 16 followed patients, flexion and extension were back to normal within 6 weeks, and return to normal walk in 12 weeks. The bone healing was good without any vascular or nerve complications. All the patients regained the preinjury activity level. The mean score (and standard deviation) increased from 38.9 ± 4.9 points to 95.2 ± 3.8 points with the system of Lysholm, from 57.1 ± 10.3 points to 94.3 ± 4.4 points with the system of IKDC. Post-test displacement of KT3000 declined from 3.6 ± 0.39 to 1.1 ± 0.27 mm.

Conclusion

Arthroscopic vertical fixation by high-strength line is a simple, safe, reliable, and micro-invasive treatment to PCL tibial avulsion fracture. It is a kind of real all arthroscopic technique, and good for early postoperative rehabilitation. The total stability of the knee could be gained, and the second operation to remove the internal fixation is avoided.

Polysaccharide-induced apoptosis in H22 cells through G2/M arrest and BCL2/BAX caspase-activated Fas pathway

The aim of the present work was to investigate the effect and the mechanism of growth inhibition on mouse H22 hepatocarcinoma cell of ascitic tumor induced by cartilage polysaccharides (PS). Our results showed that PS prolonged the survival time of the mice and increased the life span. In addition, PS induced the apoptosis of the H22 cells with the typical apoptotic morphological and biochemical changes confirmed by HE staining and TUNEL assay. The subsequent analysis of cell cycle distribution and relevant proteins revealed that decrease of cells in G0/G1phase and a G2/M arrest might due to the down-regulation of Cyclin D1 and AFP and up-regulation of P21 proteins. Moreover, BCL2/BAX caspase-activated Fas pathway was activated in PS-induced H22 apoptosis.

Multi-gigaelectronvolt acceleration of positrons in a self-loaded plasma wakefield

Electrical breakdown sets a limit on the kinetic energy that particles in a conventional radio-frequency accelerator can reach. New accelerator concepts must be developed to achieve higher energies and to make future particle colliders more compact and affordable. The plasma wakefield accelerator (PWFA) embodies one such concept, in which the electric field of a plasma wake excited by a bunch of charged particles (such as electrons) is used to accelerate a trailing bunch of particles. To apply plasma acceleration to electron-positron colliders, it is imperative that both the electrons and their antimatter counterpart, the positrons, are efficiently accelerated at high fields using plasmas. Although substantial progress has recently been reported on high-field, high-efficiency acceleration of electrons in a PWFA powered by an electron bunch, such an electron-driven wake is unsuitable for the acceleration and focusing of a positron bunch. Here we demonstrate a new regime of PWFAs where particles in the front of a single positron bunch transfer their energy to a substantial number of those in the rear of the same bunch by exciting a wakefield in the plasma. In the process, the accelerating field is altered--'self-loaded'--so that about a billion positrons gain five gigaelectronvolts of energy with a narrow energy spread over a distance of just 1.3 metres. They extract about 30 per cent of the wake's energy and form a spectrally distinct bunch with a root-mean-square energy spread as low as 1.8 per cent. This ability to transfer energy efficiently from the front to the rear within a single positron bunch makes the PWFA scheme very attractive as an energy booster to an electron-positron collider.

Acquisition of second-line drug resistance and extensive drug resistance during recent transmission of Mycobacterium tuberculosis in rural China

Multidrug-resistant tuberculosis (MDR-TB) is prevalent in countries with a high TB burden, like China. As little is known about the emergence and spread of second-line drug (SLD) -resistant TB, we investigate the emergence and transmission of SLD-resistant Mycobacterium tuberculosis in rural China. In a multi-centre population-based study, we described the bacterial population structure and the transmission characteristics of SLD-resistant TB using Spoligotyping in combination with genotyping based on 24-locus MIRU-VNTR (mycobacterial interspersed repetitive unit-variable-number tandem repeat) plus four highly variable loci for the Beijing family, in four rural Chinese regions with diverse geographic and socio-demographic characteristics. Transmission networks among genotypically clustered patients were constructed using social network analysis. Of 1332 M. tuberculosis patient isolates recovered, the Beijing family represented 74.8% of all isolates and an association with MDR and simultaneous resistance between first-line drugs and SLDs. The genotyping analysis revealed that 189 isolates shared MIRU-VNTR patterns in 78 clusters with clustering rate and recent transmission rate of 14.2% and 8.3%, respectively. Fifty-three SLD-resistant isolates were observed in 31 clusters, 30 of which contained the strains with different drug susceptibility profiles and genetic mutations. In conjunction with molecular data, socio-network analysis indicated a key role of Central Township in the transmission across a highly interconnected network where SLD resistance accumulation occurred during transmission. SLD-resistant M. tuberculosis has been spreading in rural China with Beijing family being the dominant strains. Primary transmission of SLD-resistant strains in the population highlights the importance of routine drug susceptibility testing and effective anti-tuberculosis regimens for drug-resistant TB.

High-powered microwave ablation of larger hepatocellular carcinoma: evaluation of recurrence rate and factors related to recurrence

AIM

To evaluate the safety and efficacy of high-powered (80-100 W) percutaneous microwave ablation (MWA) at a frequency of 2450±10 MHz for treating larger hepatocellular carcinoma (HCC) and to predict the risk factors of local recurrence after high-powered MWA.

MATERIALS AND METHODS

The study was approved by the Institutional Review Board, and informed consent was waived because of the retrospective study design. Forty-five patients with a total of 60 lesions received high-power (80-100 W) MWA at a frequency of 2450±10 MHz through a percutaneous approach that was guided by ultrasound. Of the 60 lesions with a maximum tumour measuring 3-8 cm, 46 lesions were 3-5 cm and 14 were 5-8 cm. The complete ablation rates, local recurrence rates, complications, and short-term survival were analysed. Ten possible risk factors for local recurrence were analysed.

RESULTS

The complete ablation rates were 82.61% for the first ablation and 100% for the second ablation for 3-5 cm lesions. The complete ablation rates were 64.29% (82.61% versus 64.29%, p=0.037) for the first ablation and 85.71% (100% versus 85.71%, p=0.055) for the second ablation for 5-8 cm lesions. Local recurrence was observed in 11 out of the 45 (24.44%) successfully treated patients. The 1-year and 2-year survival rates were 95.56% (43/45) and 86.67% (39/45), respectively. No procedure-related mortality was observed and no major bleeding, liver rupture, or liver abscesses occurred. Univariate analysis showed that a positive correlation existed between the number of lesions (p=0.022), proximity to the risk area (p=0.001), pre-ablation alpha-fetoprotein (AFP) levels (p=0.025), hepatitis B virus (HBV)-DNA replication (p=0.027) and local recurrence. Multivariate analysis identified HBV-DNA (p=0.031) and proximity to the risk area (p=0.039) as the independent prognosis factors causing postoperative HCC local recurrence.

CONCLUSION

High-powered MWA of larger hepatocellular carcinomas appears to be a safe and effective treatment. HBV-DNA and proximity to the risk area appear to be independent predictors of local tumour recurrence.

The Elimination Rate after Clozapine Overdose in Chinese Schizophrenia Patients: A Population Pharmacokinetics Model Study

INTRODUCTION

The prescribing of clozapine in China is common because of its outstanding efficacy and low price. There have been many cases of clozapine overdose in China. However, studies about the pharmacokinetics after overdose in the Chinese have rarely been reported. Population pharmacokinetics (PopPK) can analyze sparse data, and it is appropriate to compute clozapine pharmacokinetics after overdose.

METHODS

There were 47 clozapine overdose cases. We constructed a single-compartment first-order elimination PopPK model. We also considered some covariates that can influence the pharmacokinetics parameters.

RESULTS

21 cases were included in the analysis. When the reported toxic dosage was 3,740 mg, the elimination rate constant of the population was 0.0258(h(-1)). The elimination half-life was 26.9 h. The coefficient of random variation was 17%.

DISCUSSION

PopPK can solve the problem of sparse data after overdose. The area under the concentration-time curve after clozapine overdose exhibited the "two peaks phenomenon." The reported toxic dosage could impact clozapine elimination after overdose. Delayed absorption of clozapine is the best explanation for this finding.

MacroH2A1 downregulation enhances the stem-like properties of bladder cancer cells by transactivation of Lin28B

The histone variant, macroH2A1, has an important role in embryonic stem cell differentiation and tumor progression in various types of tumors. However, the regulatory roles of macroH2A1 on bladder cancer progression have not been fully elucidated. Here, we show that macroH2A1 knockdown promotes stem-like properties of bladder cancer cells. The knockdown of macroH2A1 in bladder cancer cells increased tumorigenicity, radioresistance, degeneration of reactive oxygen species, increased sphere formation capability and an increase in the proportion of side populations. We found that macroH2A1 is required for the suppression of Lin28B identified as a novel downstream target of macroH2A1 in bladder cancer. Loss of macroH2A1 expression significantly correlated with the elevated levels of Lin28B expression and subsequently inhibited the mature let-7 microRNA expression. Furthermore, the stable overexpression of Lin28B enhances the several phenotypes, including tumorigenicity and sphere-forming ability, which are induced by macroH2A1 depletion. Importantly, Lin28B expression was regulated by macroH2A1-mediated reciprocal binding of p300 and EZH2/SUV39H1. Our results suggest that Lin28B/let-7 pathway is tightly regulated by macroH2A1 and its cofactors, and have a pivotal role in the bladder tumor progression and the regulation of stem-like characteristics of bladder cancer cells.