Neuronal nitric oxide synthase inhibition reduces brain damage by promoting collateral recruitment in a cerebral hypoxia-ischemia mice model

OBJECTIVE

The collateral circulation development is considered as a compensatory inherent mechanism to restore damaged blood perfusion after ischemia. We aimed to detect the collateral flow and the mean blood-flow velocities (mBFVs) level in the basilar trunk during or after cerebral hypoxia-ischemia in the mice brain and explore the effect of neuronal nitric oxide synthase (nNOS) inhibition on the collateral flow.

MATERIALS AND METHODS

C57BL/6J mice and the nNOS knockout (KO) mice were randomly divided into a sham-operated group (control) and the hypoxia-ischemia (HI) groups that were treated with the phosphate buffered solution (PBS) control or 7-nitroindazole (7-NI). Cortexes were harvested after the HI treatment for analysis of nNOS expression using Western blot and reverse transcription-polymerase chain reaction (RT-PCR). Ultrasound imaging experiments were performed to detect the collateral flow and the mBFVs level in the basilar trunk.

RESULTS

After cerebral HI, the cortical nNOS mRNA and protein levels increased markedly compared with the sham-operated control mice. Besides, 7-NI treatment had no effect on the blood flow in the sham-operated control mice. What's more, either the 7-NI pretreatment or the nNOS gene knockdown before the HI procedure could attenuate the brain injury by the increased collateral flow and the decreased mBFVs level in the basilar trunk.

CONCLUSIONS

nNOS inhibition protected hypoxic-ischemic-induced mice brain damage by the increased collateral flow and the decreased mBFVs level in the basilar trunk. Therefore, the 7-NI administration may have potential utility for the treatment of HI injury in human beings.

RPYFMM: Parallel Adaptive Fast Multipole Method for Rotne-Prager-Yamakawa Tensor in Biomolecular Hydrodynamics Simulations

RPYFMM is a software package for the efficient evaluation of the potential field governed by the Rotne-Prager-Yamakawa (RPY) tensor interactions in biomolecular hydrodynamics simulations. In our algorithm, the RPY tensor is decomposed as a linear combination of four Laplace interactions, each of which is evaluated using the adaptive fast multipole method (FMM) [1] where the exponential expansions are applied to diagonalize the multipole-to-local translation operators. RPYFMM offers a unified execution on both shared and distributed memory computers by leveraging the DASHMM library [2, 3]. Preliminary numerical results show that the interactions for a molecular system of 15 million particles (beads) can be computed within one second on a Cray XC30 cluster using 12, 288 cores, while achieving approximately 54% strong-scaling efficiency.

All-polymer fiber-optic pH sensor

A novel all-polymer fiber-optic pH sensor using a UV-cured pH-sensitive hydrogel, poly(ethylene glycol) diacrylate (PEGDA), coated on a polymer fiber Bragg grating was developed. The PEGDA increased in volume according to the pH value of the surrounding fluid, which subsequently induced a lateral stress in the polymer fiber Bragg grating. The proposed pH sensor exhibits a pH sensitivity of up to -0.41 nm/pH and a fast response time of 30 s.

Prospective plasma efavirenz concentration assessment in Chinese HIV-infected adults enrolled in a large multicentre study

OBJECTIVES

Few studies have explored the optimal dosing for efavirenz in individuals from China. We investigated plasma efavirenz concentrations and their association with efficacy and tolerance of efavirenz 600 mg daily in Chinese HIV-infected adults.

METHODS

An analysis was performed using plasma samples from 455 patients enrolled in a prospective multicentre trial in China. A total of 1198 plasma samples collected at weeks 4, 24 and 48 following antiretroviral therapy initiation were analysed. The mid-dose interval efavirenz concentrations (C12 ) were determined using high-performance liquid chromatography.

RESULTS

The median efavirenz concentration (interquartile range) steadily increased over time from 3.02 (2.28-4.23) to 3.71 (2.91-4.91) mg/L from week 4 to 48 (P < 0.001). The proportion of patients with C12 > 4.0 mg/L also rose from 28.0% to 34.2% and 43.8%, measured at 4, 24 and 48 weeks, respectively (P < 0.001). Five patients had efavirenz concentrations < 1.0 mg/L at week 4, 24 or 48. In the multivariable regression analysis, lower body weight and non-Han ethnicities were associated with higher efavirenz concentrations over time. At each time-point, patients with a body weight < 60 kg had significantly higher efavirenz C12 compared with those with body weight ≥ 60 kg (P < 0.05).

CONCLUSIONS

Efavirenz concentrations increased steadily over 48 weeks, and a substantial proportion of participants had efavirenz C12 above the upper limit of the proposed therapeutic window, especially those with low body weight (< 60 kg). Based upon these findings, a dosage reduction of efavirenz to 400 mg daily may warrant consideration in this population, especially for those with lower body weight.

The optimal anatomic site for a single slice to estimate the total volume of visceral adipose tissue by using the quantitative computed tomography (QCT) in Chinese population

BACKGROUND/OBJECTIVES

To investigate the relationship between the cross-sectional visceral adipose tissue (VAT) areas at different anatomic sites and the total VAT volume in a healthy Chinese population using quantitative computed tomography (QCT), and to identify the optimal anatomic site for a single slice to estimate the total VAT volume.

SUBJECTS/METHODS

A total of 389 healthy Chinese subjects aged 19-63 years underwent lumbar spine QCT scans. The cross-sectional area of total adipose tissue and VAT were measured using the tissue composition module of the software (QCT Pro, Mindways) at each intervertebral disc level from T₁₂/L₁ to L₅/S₁, as well as at the umbilical level. The total VAT volume was defined as the fat areas multiplied by the height of vertebral body for all six slices. Statistical analysis was performed to determine the correlation between single-slice VAT areas and the total VAT volume. Moreover, the optimal anatomic site for a single slice to estimate the total VAT volume was identified by multiple regression analysis.

RESULTS

The cross-sectional area of VAT and subcutaneous adipose tissue (SAT) measured at each anatomic site was all highly correlated with the total VAT volume and the total SAT volume (r = 0.89-0.98). Additionally, the VAT area measured at the L₂/L₃ level showed the strongest correlation with the total VAT volume (r = 0.98, P < 0.001). Covariates including age, gender, BMI, waist, and hypertension make a slight effect on the prediction of the total VAT volume.

CONCLUSION

It is feasible to perform measurements of VAT area on a single slice at L₂/L₃ level for estimating the total VAT volume.

Period Increase and Amplitude Distribution of Kink Oscillation of Coronal Loop

Coronal loops exist ubiquitously in the solar atmosphere. These loops puzzle astronomers over half a century. Solar magneto-seismology (SMS) provides a unique way to constrain the physical parameters of coronal loops. Here, we study the evolution of oscillations of a coronal loop observed by the Atmospheric Imaging Assembly (AIA). We measure geometric and physical parameters of the loop oscillations. In particular, we find that the mean period of the oscillations increased from 1048 to 1264 s during three oscillatory cycles. We employ the differential emission measure method and apply the tools of SMS. The evolution of densities inside and outside the loop is analyzed. We found that an increase of density inside the loop and decrease of the magnetic field strength along the loop are the main reasons for the increase in the period during the oscillations. Besides, we also found that the amplitude profile of the loop is different from a profile would it be a homogeneous loop. It is proposed that the distribution of magnetic strength along the loop rather than density stratification is responsible for this deviation. The variation in period and distribution of amplitude provide, in terms of SMS, a new and unprecedented insight into coronal loop diagnostics.

[Clinical significance of targeting drug-based molecular biomarkers expression in ovarian clear cell carcinoma]

Objective: To assess the expression level of targeting drug-based molecular biomarkers in ovarian clear cell carcinoma (OCCC) tissues and its clinical significance. Methods: A total of 63 OCCC patients included 40 primary OCCC and 23 recurrent OCCC for secondary cytoreductive surgery (SCS), who had received primary surgeries at Fudan University Shanghai Cancer Center between January, 2008 and December, 2015 were enrolled, and immunohistochemistry SP method was used to test human epidermal growth factor receptor (EGFR), human epidermal growth factor receptor-2 (HER2), aurora kinase A (AURKA), breast cancer susceptibility gene 1 (BRCA1), BRCA2 and programmed death-ligand 1 (PD-L1)protein expression in paraffin-embedded tissues. Results: The positive rates of EGFR, HER2, AURKA,BRCA1, BRCA2 and PD-L1 in primary and recurrent tumor tissues were respectively 20% (8/40) vs 30% (7/23) , 22% (9/40) vs 35% (8/23) , 38% (15/40) vs 35% (8/23) , 42% (17/40) vs 39% (9/23) , 20% (8/40) vs 22% (5/23) , 25% (10/40) vs 17% (4/23) , and there were no significant differences between primary and recurrent OCCC (all P>0.05). χ(2)-test or Fisher exact analysis revealed that HER2 expression in recurrent tumor tissues had a relationship with chemoresistance (P<0.05), while the expression of other biomarkers showed no significant relationship with chemoresistance (all P>0.05). Further, Kaplan-Meier survival analysis showed that patients with HER2 and AURKA-positive expression had a significantly shorter progression-free survival time in primary OCCC (4 months vs 10 months, log-rank test, P<0.05 for HER2; and 4 months vs 10 months, P<0.05 for AURKA); and a shorter overall survival time after SCS in recurrent OCCC (10 months vs 44 months, P<0.05 for HER2; and 13 months vs 43 months, P<0.05 for AURKA). However, multivariate Cox proportional hazards regression analysis indicated that none of these 6 biomarkers was independent risk factor of progression-free survival time of primary OCCC or overall survival time after SCS for recurrent OCCC (P>0.05). Conclusion: HER2 and AURKA could serve as prognostic factors in ovarian clear cell carcinoma.

Effects of coexisting BDE-47 on the migration and biodegradation of BDE-99 in river-based aquifer media recharged with reclaimed water

Two prominent polybrominated diphenyl ether (PBDE) congeners have been included in the persistent organic pollutant list, 2,2',4,4',5-tetrabromodiphenyl ether (BDE-99) and 2,2,4,4'-tetrabromodiphenyl ether (BDE-47), which have been detected in treated municipal wastewater, river water, and sediments in China. A lab-scale column experiment was established to investigate the effects of the competitive sorption of BDE-47 on BDE-99 biodegradation and migration in two types of river-based aquifer soils during groundwater recharge with reclaimed water. Two types of recharge columns were used, filled with either silty clay (SC) or black carbon-amended silty clay (BCA). The decay rate constants of BDE-99 in the BCA and SC systems were 0.186 and 0.13 m^-1 in the single-solute system and 0.128 and 0.071 m^-1 in the binary-solute system, respectively, showing that the decay of BDE-99 was inhibited by the coexistence of BDE-47. This was particularly evident in the SC system because the higher hydrophobicity of BDE-99 determined the higher affinity and competition for sorption sites onto black carbon. The biodegradation of BDE-99 was suppressed by the coexistence of BDE-47, especially in the SC system. Lesser-brominated congeners (BDE-47 and BDE-28) and higher-brominated congeners (BDE-100, BDE-153, BDE-154, and BDE-183) were generated in the four recharge systems, albeit at different ratios. Bacterial biodiversity was influenced by the presence of BDE-47 in the SC system, while it had no significant effect on the BCA system, because the high sorption capacity of black carbon on the hydrophobic PBDEs effectively reduced their toxicity. The ranking order of the most abundant classes changed markedly due to the coexistence of BDE-47 in both the SC and BCA systems. The ranking order of the most abundant genera changed from Azospira, Methylotenera, Desulfovibrio, Methylibium, and Bradyrhizobium to Halomonas, Hyphomicrobium, Pseudomonas, Methylophaga, and Shewanella, which could be involved in PBDE degradation.

A circular white-light flare with impulsive and gradual white-light kernels

White-light flares are the flares with emissions visible in the optical continuum. They are thought to be rare and pose the most stringent requirements in energy transport and heating in the lower atmosphere. Here we present a nearly circular white-light flare on 10 March 2015 that was well observed by the Optical and Near-infrared Solar Eruption Tracer and Solar Dynamics Observatory. In this flare, there appear simultaneously both impulsive and gradual white-light kernels. The generally accepted thick-target model would be responsible for the impulsive kernels but not sufficient to interpret the gradual kernels. Some other mechanisms including soft X-ray backwarming or downward-propagating Alfvén waves, acting jointly with electron beam bombardment, provide a possible interpretation. However, the origin of this kind of white-light kernel is still an open question that induces more observations and researches in the future to decipher it.

Research Challenges of Heat Transfer to Supercritical Fluids

Supercritical fluids (SCFs) become more and more important in various engineering applications. In nuclear power systems, SCFs are considered as coolant of the reactor core such as the supercritical water-cooled reactor (SCWR), superconducting magnets and blankets in the fusion reactors, or as fluid in the energy conversion systems of the next generation nuclear reactors. Accurate determination of heat transfer and the temperature of the structural material (e.g., fuel rod cladding) is of crucial importance for the system design. Thus, extensive studies on heat transfer to SCFs have been carried out in the past five decades and are still ongoing worldwide. However, no breakthrough is recognized or expected in the near future. In this paper, the status, main challenges, and future R&D needs are briefly reviewed. Three aspects are taken into consideration, i.e., experimental studies, numerical analysis, and model development for the prediction of heat transfer coefficient (HTC). Several key challenges and also the important subjects of the future R&D needs are identified. They are (a) data base for turbulence quantities, (b) multisolution of wall temperature, (c) extensive Reynolds-averaged Navier–Stokes (ERANS) method, and (d) new prediction method for HTC.

Break-through bleeding in relation to pharmacokinetics of Factor VIII in paediatric patients with severe haemophilia A

INTRODUCTION

As the pharmacokinetics (PK) of factor VIII (FVIII) is individualized in children with haemophilia A (HA), PK parameters may be indicators of patients' bleeding phenotype and instruction for their personalized replacement program.

AIM

The aim of this study was to investigate the possible relationship between PK/FVIII level and bleeding frequency in Chinese paediatric patients with severe (HA).

METHODS

A total of 24 patients were enrolled in Beijing Children's Hospital from February to October 2015, all of whom were given 50 IU/kg of FVIII concentrates after a 72-hours washout period. Samples' activities (FVIII:C) were tested at 5 time points, using WinNonlin software for PK testing, and then the individual half-life(t_1/2 ) and the time (h) of FVIII concentrations <1 IU/dL within a week during prophylaxis were calculated. Baseline and the annual bleeding rate (ABR), annual joint bleeding rate (AJBR) were recorded and analyzed.

RESULTS

The mean t_1/2 of FVIII was 10.20 ± 2.72 hours and the mean time of FVIII <1 IU/dL in 1 week was 44.7 hours (-38.56 to 102.33 hours). A significant relationship between t_1/2 of FVIII and ABR₀ /AJBR₀ (baseline bleeding) was found (R²  = 0.75 and 0.62, P < .001). Besides, baseline and the annual bleeding rate during prophylactic treatment of haemophilia had a positive correlation with the time (hours) of FVIII <1 IU/dL in 1 week (R²  = 0.67 and 0.52, P < .001).

CONCLUSION

t_1/2 was an important indicator to prevent bleeding in severe HA; the frequency of bleeding will be reduced with the increased of t_1/2 of FVIII. The data also demonstrates that increasing the time with a FVIII<1 IU/dL is associated with an increased rate of bleeding during prophylaxis.

Age-related changes of bone mineral density in mandible by quantitative computed tomography

Quantitative Computed Tomography (QCT) was used to investigate age-related changes in trabecular bones of the mandible. The volumetric Bone Mineral Density (vBMD) of mandibles was found to be increasing with aging in the 20-29, 30-39, 40-49 age groups, while resulted decreasing in the 50~ years age group in a Chinese population. The aim of this study was to validate QCT as a reliable method to measure the vBMD of the mandible and to assess vBMD of the mandible in a Chinese population. A total of seven hundred and eighteen volunteers (299 males, 419 females), ranging from 20 to 63 years of age, previously enrolled in another study, were included for vBMD measurements by QCT. A total of 50 subjects were enrolled for the validation of QCT measurement. Basic information (age, height and weight), and vBMD of the mandible (middle, body and angle) were recorded. Comparisons among age and sex groups were analyzed using the Mann-Whitney test. Linear correlation analysis between vBMD and age was performed. The mandibular vBMD was twice measured with QCT by one operator and resulted highly repeatable (ICC 0. 97, P 0. 05). The vBMD in the middle of the mandible was the highest, followed by that in the body and at the angle of mandible. In each age group, the mean vBMD increased with aging except for the 50~ years age group (P less than 0.05) in which it decreased. The mean mandibular vBMD was higher in females than males in each age group (P less than 0.05). Correlation between vBMD and age was statistically significant (r=0.15, P less than 0.01). QCT shows high precision for the measurement of BMD in the mandible. The present study provides normative data of the mandible in an age- and sex-stratified manner, which can be helpful in clinical practice.

Inhibition of Nkcc1 promotes axonal growth and motor recovery in ischemic rats

Bumetanide is a selective inhibitor of the Na⁺-K⁺-Cl^--co-transporter 1(NKCC1). We studied whether bumetanide could affect axonal growth and behavioral outcome in stroke rats. Adult male Wistar rats were randomly assigned to four groups: sham-operated rats treated with vehicle or bumetanide, and ischemic rats treated with vehicle or bumetanide. Endothelin-1 was used to induce focal cerebral ischemia. Bumetanide administration (i.c.v.) started on postoperative day 7 and continued for 3 weeks. Biotinylated dextran amine (BDA) was injected into the right imotor cortex on postoperative day 14 to trace corticospinal tract (CST) fibers sprouting into the denervated cervical spinal cord. Nogo-A, NKCC1, KCC2 and BDNF in the perilesional cortex and BDA, PSD-95 and vGlut1 in the denervated spinal cord were measured by immunohistochemistry and/or Western blot. Behavioral outcome of rats was assessed by the beam walking and cylinder tests. The total length of CST fibers sprouting into the denervated cervical spinal cord significantly increased after stroke and bumetanide further increased this sprouting. Bumetanide treatment also decreased the expressions of NKCC1 and Nogo-A, increased the expressions of KCC2 and BDNF in the perilesional cortex and enhanced the synaptic plasticity in the denervated cervical spinal cord after cerebral ischemia. The behavioral performance of ischemic rats was significantly improved by bumetanide. In conclusion, bumetanide promoted post-stroke axonal sprouting together accompanied by an improved behavioral outcome possibly through restoring and maintaining neuronal chloride homeostasis and creating a recovery-promoting microenvironment by overcoming the axonal growth inhibition encountered after cerebral ischemia in rats.

[Dynamic change in Th17/regulatory T cell ratio in peripheral blood of patients with acute hepatitis B and its significance]

Objective: To investigate the dynamic changes in the frequencies of Th17 (CD3⁺CD8-IL-17⁺) and regulatory T cells (Treg, CD4⁺CD25⁺CD127^low) and Th17/Treg ratio in the peripheral blood in patients with acute hepatitis B (AHB), as well as their association with the outcome of AHB. Methods: A total of 10 AHB patients were enrolled as observation group, and according to the outcome of AHB, these patients were further divided into acute stage group, early recovery group, and full recovery group. Another 10 healthy subjects who underwent physical examination were enrolled as control group. Flow cytometry was used to measure the frequencies of Th17 and Treg in peripheral blood, and the Th17/Treg ratio was calculated. An automatic biochemical analyzer was used to measure liver function parameters, and RT-PCR was used to measure HBV DNA. An one-way analysis of variance was used for comparison between groups, and the t-test was used for comparison between any two groups. Results: Compared with the control group, the acute stage group showed significant increases in the frequencies of Th17 and Treg (18.22%±4.13%/6.46%±2.46% vs 0.68%±0.29%/1.62%±0.18%,P< 0.01) and the Th17/Treg ratio (3.37±1.73 vs 0.42±0.20,P< 0.01). Compared with the acute stage group, the early recovery group showed a significant reduction in the frequency of Th17 (3.14%±1.90%,P< 0.01), a significant increase in the frequency of Treg (11.73%±1.76%,P< 0.01), and a significant reduction in the Th17/Treg ratio (0.27±0.19,P< 0.01). Compared with the early recovery group, the full recovery group showed a slight increase in the frequency of Th17 (3.31±0.95,P= 0.888), a significant reduction in the frequency of Treg (6.83%±1.85%,P< 0.01), but which was significantly higher than that in the control group (P< 0.01), and a slight increase in the Th17/Treg ratio (0.52±0.21,P< 0.05), which showed no significant difference between this group and the control group (P= 0.286). In the acute stage of AHB, HBsAg and HBeAg levels were positively correlated with Th17/Treg ratio (r= 0.639,P< 0.05;r= 0.633,P< 0.05). Conclusion: The dynamic changes in the frequencies of Th17 and Treg and the Th17/Treg ratio may be associated with the outcome of AHB.

[Retroperitoneal laparoscopic with renal pedicle rotation for partial nephrectomy of ventro-renal tumor]

OBJECTIVE

Retro-laparoscopic partial nephrectomy is a challenge for ventro-renal tumors, especially hilar tumors. The tumors are partial or entirely out of operative field and there is blind space for operation. To solve this problem, a set of techniques including renal pedicle rotation is developed.

METHODS

A set of techniques including renal pedicle rotation, double-layer suture, early artery unclamping for retro-laparoscopic nephrectomy for ventro-renal tumors, especially hilar tumors were developed. Hilar tumors were located anteriorly to the angle of the renal and renal arteries and in contact with the anterior surface of the renal artery. The evaluation of the outcomes included the operation time, warm ischemia time, estimated haemorrhage, surgical margin, renal function after operation, and complications. This study reviewed the data of 28 patients with ventro-renal tumor, including 15 patients with complex hilar tumors.

RESULTS

The average tumor size was (3.8±0.5) cm. The average R.E.N.A.L score was 8 (ranging from 7 to 9). The average warm ischemia time was (23.8±4.7) min, and suture time was (26.2±6.5) min, and operation time was (124.1±12.1) min. The median hospital stay was 4 days and the average estimated haemorrhage was (139.1±54.0) mL. All the surgeries were operated under laparoscope and no surgery switched to open surgery. Seven patients developed Clavien Dindo I-II complications after operation. Three patients (10.7%) developed collective system damage and received repair of collective system in time and three patients (10.7%) developed slightly gross hematuria (Clavien-Dindo I). Two patients developed wound infection (Clavien-Dind II). Three patients (10.7%) got renal vein clamped because of capillary hemorrhage from basilar part of tumors. There were 14 patients received early unclamping of renal artery, and no obvious renal vessel damage was found. There were statistically significant differences between the serum creatinine levels (P<0.05) and the estimated glomerular filtration rates (P=0.02) before and after surgery. All the patients' serum creatinine levels were in normal range and no patient needed regular dialysis. There was no positive surgical margin and the median follow-up was 7 months without local recurrence or distant metastasis.

CONCLUSION

It is safe and effective to apply renal pedicle rotation technique in retro-laparoscopic partial nephrectomy for ventro-renal tumors. The short-term follow-up results are optimistic, but long follow-up is required.

Micropatterned macroporous structures in microfluidic devices for viral separation from whole blood

Separation and enrichment of bio-nanoparticles from cell suspensions and blood are critical steps in many chemical and biomedical practices. We demonstrate here the design and fabrication of a microfluidic immunochromatographic device incorporating regular and multiscale monolithic structures to capture viruses from blood. The device contains micropatterned arrays of macroporous materials to perform size-exclusion and affinity chromatography in a simple flow-through process. The microscale gaps in the array allow the passage of cells while the macroporous matrices promote viral capture. Computational analyses reveal that fluid permeation into the porous matrices is controllable by the micropattern shape, separation distance and dimensions. Experimental analyses using blood samples containing human immunodeficiency viruses (HIV) as a model system further prove significantly improved viral capture efficiency using devices incorporating multiscale structures than those containing solid micropatterns. Such microfluidic devices with regular and multiscale structures have a potential for the separation and concentration of a wide range of bio-nanoparticles as well as macromolecules from complex mixtures containing both nano- and micro-sized species.