Multi-scale attention network (MSAN) for track circuits fault diagnosis

As one of the three major outdoor components of the railroad signal system, the track circuit plays an important role in ensuring the safety and efficiency of train operation. Therefore, when a fault occurs, the cause of the fault needs to be found quickly and accurately and dealt with in a timely manner to avoid affecting the efficiency of train operation and the occurrence of safety accidents. This article proposes a fault diagnosis method based on multi-scale attention network, which uses Gramian Angular Field (GAF) to transform one-dimensional time series into two-dimensional images, making full use of the advantages of convolutional networks in processing image data. A new feature fusion training structure is designed to effectively train the model, fully extract features at different scales, and fusing spatial feature information through spatial attention mechanisms. Finally, experiments are conducted using real track circuit fault datasets, and the accuracy of fault diagnosis reaches 99.36%, and our model demonstrates better performance compared to classical and state-of-the-art models. And the ablation experiments verified that each module in the designed model plays a key role.

AKR1C3 silencing inhibits autophagy-dependent glycolysis in thyroid cancer cells by inactivating ERK signaling

Thyroid cancer is a highly differentiated and poorly malignant tumor. Interfering with glycolysis has become an effective means of controlling cancer progression and autophagy is negatively correlated with glycolysis. Aldo-keto reductase family 1 member C3 (AKR1C3) has been demonstrated to be highly expressed in thyroid cancer tissue and the higher AKR1C3 expression predicted the worse prognosis. We aimed to explore whether AKR1C3 could affect thyroid cancer progression by regulating autophagy-dependent glycolysis. AKR1C3 expression in thyroid cancer cells was detected by western blot. Then, AKR1C3 was knocked down by transfection with short hairpin RNA specific to AKR1C3 in the absence or presence of 3-methyladenine (3-MA) or PMA treatment. Cell cycle and apoptosis was detected by flow cytometry. Immunofluorescence staining was used to analyze LC3B expression. Extracellular acidification, glucose uptake and lactic acid secretion were detected. To evaluate the tumorigenicity of AKR1C3 insufficiency on thyroid cancer in vivo, TPC-1 cells with AKR1C3 knockdown were injected subcutaneously into nude mice. Then, cyclinD1 and Ki67 expression in tumorous tissues was measured by immunohistochemical analysis. Apoptosis was assessed by terminal-deoxynucleoitidyl transferase mediated nick end labeling staining. Additionally, the expression of proteins related to cell cycle, apoptosis, glycolysis, autophagy, and extracellular signal-regulated kinase (ERK) signaling in cells and tumor tissues was assessed by western blot. Highly expressed AKR1C3 was observed in thyroid cancer cells. AKR1C3 knockdown induced cell cycle arrest and apoptosis of TPC-1 cells. Besides, autophagy was activated and glycolysis was inhibited following AKR1C3 silencing, and 3-MA treatment restored the impacts of AKR1C3 silencing on glycolysis. The further experiments revealed that AKR1C3 insufficiency inhibited ERK signaling and PMA application reversed AKR1C3 silencing-induced autophagy in TPC-1 cells. The in vivo results suggested that AKR1C3 knockdown inhibited the development of subcutaneous TPC-1 tumors in nude mice and inactivated the ERK signaling. Collectively, AKR1C3 silencing inhibited autophagy-dependent glycolysis in thyroid cancer by inactivating ERK signaling.

Genetic and pathogenicity analysis for the two FCV strains isolated from Eastern China

In this study, the diversity and regularity of two new feline calicivirus (FCV) isolates, QD-7 and QD-164, were investigated. The genomes of these new strains were compared with 39 strains from the NCBI database including isolates from China, United States, Germany, South Korea, the United Kingdom and Japan. The nucleotide sequence identities ranged from 75-88%, indicating a high degree of variability. These variations were not related to distributions of the virus by time of isolation and geographical location. Cats that were experimentally infected with the new isolate QD-164 showed typical clinical symptoms of sneezing, fever and conjunctivitis and all recovered within 30 days. In contrast, QD-7 infections were asymptomatic and the virus was cleared within 16 days. These results indicate that QD-7 and QD-164 were naturally attenuated strains. NNS mutations characteristic of highly virulent strains at positions 441-443 were absent in QD-7 while QD-164 possessed an N at position 442. This indicated that mutations in regions 441-443 may be linked to disease severity.

Sigma-1 receptor-regulated efferocytosis by infiltrating circulating macrophages/microglial cells protects against neuronal impairments and promotes functional recovery in cerebral ischemic stroke

Background: Efferocytosis of apoptotic neurons by macrophages is essential for the resolution of inflammation and for neuronal protection from secondary damage. It is known that alteration of the Sigma-1 receptor (Sig-1R) is involved in the pathological development of some neurological diseases, including ischemic stroke. The present study aimed to investigate whether and how Sig-1R regulates the phagocytic activity of macrophages/microglia and its significance in neuroprotection and neurological function in stroke. Methods: The roles of Sig-1R in the efferocytosis activity of microglia/macrophages using bone marrow-derived macrophages (BMDMs) or using Sig-1R knockout mice subjected to transient middle artery occlusion (tMCAO)-induced stroke were investigated. The molecular mechanism of Sig-1R in the regulation of efferocytosis was also explored. Adoptive transfer of Sig-1R intact macrophages to recipient Sig-1R knockout mice with tMCAO was developed to observe its effect on apoptotic neuron clearance and stroke outcomes. Results: Depletion of Sig-1R greatly impaired the phagocytic activity of macrophages/microglia, accordingly with worsened brain damage and neurological defects in Sig-1R knockout mice subjected to tMCAO. Adoptive transfer of Sig-1R intact bone marrow-derived macrophages (BMDMs) to Sig-1R knockout mice restored the clearance activity of dead/dying neurons, reduced infarct area and neuroinflammation, and improved long-term functional recovery after cerebral ischemia. Mechanistically, Sig-1R-mediated efferocytosis was dependent on Rac1 activation in macrophages, and a few key sites of Rac1 in its binding pocket responsible for the interaction with Sig-1R were identified. Conclusion: Our data provide the first evidence of the pivotal role of Sig-1R in macrophage/microglia-mediated efferocytosis and elucidate a novel mechanism for the neuroprotection of Sig-1R in ischemic stroke.

Heat wave induces oxidative damage in the Chinese pond turtle (Mauremys reevesii) from low latitudes

Introduction

Global warming has led to frequent heat waves, causing global organisms to face severe survival challenges. However, the way in which heat waves threaten the fitness and survival of animals remains largely unclear. Oxidative damage and immunity are widely considered the link between heat waves and threats to animals.

Methods

To evaluate the oxidative damage caused by heat waves and to reveal the physiological resistance to heat waves by the antioxidant defense of animals from different latitudes, we exposed both high-latitude (Zhejiang) and low-latitude (Hainan) populations of Chinese pond turtle (Mauremys reevesii) to simulate heat waves and a moderate thermal environment for 1 week, respectively. Next, we compared the oxidative damage by malondialdehyde (MDA) and antioxidant capacity by superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and total antioxidant capacity (T-AOC) in the liver tissues and evaluated the innate immunity by serum complement protein levels (C3, C4) and lysozyme activity in plasma of turtles.

Results and discussion

We found that heat waves significantly increased the content of MDA and the activity of CAT, whereas it decreased the activity of SOD, T-AOC, and GSH/GSSG in turtles from low latitudes. Furthermore, heat waves increased CAT activity but decreased GSH/GSSG in turtles from high latitudes. Although the turtles from high latitudes had higher levels of innate immunity, the heat waves did not affect the innate immunity of C3, C4, or lysozyme in either population. These results indicate that the low-latitude population suffered higher oxidative damage with lower antioxidant capacities. Therefore, we predict that Chinese pond turtles from low latitudes may be more vulnerable to heat waves caused by climate warming. This study reveals the physiological and biochemical resistance to heat waves in Chinese pond turtles from different latitudes and highlights the importance of integrative determination of fitness-related responses in evaluating the vulnerability of ectotherms from different latitudes to climate warming.

An Analytical Algorithm for Tensor Tomography From Projections Acquired About Three Axes

Tensor fields are useful for modeling the structure of biological tissues. The challenge to measure tensor fields involves acquiring sufficient data of scalar measurements that are physically achievable and reconstructing tensors from as few projections as possible for efficient applications in medical imaging. In this paper, we present a filtered back-projection algorithm for the reconstruction of a symmetric second-rank tensor field from directional X-ray projections about three axes. The tensor field is decomposed into a solenoidal and irrotational component, each of three unknowns. Using the Fourier projection theorem, a filtered back-projection algorithm is derived to reconstruct the solenoidal and irrotational components from projections acquired around three axes. A simple illustrative phantom consisting of two spherical shells and a 3D digital cardiac diffusion image obtained from diffusion tensor MRI of an excised human heart are used to simulate directional X-ray projections. The simulations validate the mathematical derivations and demonstrate reasonable noise properties of the algorithm. The decomposition of the tensor field into solenoidal and irrotational components provides insight into the development of algorithms for reconstructing tensor fields with sufficient samples in terms of the type of directional projections and the necessary orbits for the acquisition of the projections of the tensor field.

[Investigation on prevalence of Schistosoma japonicum infections in wild mice in Shitai County, Anhui Province, 2018]

OBJECTIVE

To investigate the prevalence of Schistosoma japonicum infection in wild mice in Shitai County, Anhui Province, so as to provide insights into precise control of the source of S. japonicum infections.

METHODS

Wild mice were captured using the trapping method for three successive nights at snail-infested settings from Jitan Village of Jitan Township, and Shiquan Village and Xibai Village of Dingxiang Township, Shitai County, Anhui Province in June and October, 2018. All trapped wild mice were sacrificed and liver and mesenteric vein specimens were collected for detection of S. japonicum eggs using microscopy, while the fecal samples in mouse intestines were collected for identification of S. japonicum infections using Kato-Katz technique. In addition, the population density of trapped wild mice was estimated and the prevalence of S. japonicum infection was calculated in trapped wild mice.

RESULTS

A total of 376 wild mice were trapped from three villages in Shitai County. The population density of trapped wild mice was 9.1% (376/4 124), and the prevalence of S. japonicum infection was 24.2% (91/376) in trapped wild mice. The highest prevalence of S. japonicum infection was detected in Shiquan Village of Dingxiang Township (30.1%), and the lowest prevalence was seen in Xibai Village of Dingxiang Township; however, there was no significant difference in the prevalence of S. japonicum infection in trapped wild mice among three villages (χ²= 4.111, P > 0.05). In addition, there was no significant difference in the prevalence of S. japonicum infection in wild mice captured between on June (26.8%, 34/127) and October (22.9%, 57/249) (χ² = 0.690, P = 0.406). The trapped wild mice included 6 species, including Rattus norvegicus, Niviventer niviventer, R. losea, Apodemus agrarius, Mus musculus and N. coning, and the two highest prevalence of S. japonicum infection was detected in R. losea (34.9%, 22/63) and R. norvegicus (31.2%, 44/141).

CONCLUSIONS

The prevalence of S. japonicum infections is high in wild mice in Shitai County, and there is a natural focus of schistosomiasis transmission in Shitai County.

The Safety and Efficacy of Flow Diversion versus Conventional Endovascular Treatment for Intracranial Aneurysms: A Meta-analysis of Real-world Cohort Studies from the Past 10 Years

BACKGROUND

Although the flow diverter has advantages in the treatment of intracranial aneurysms, pooled studies that directly compare it with conventional endovascular treatments are rare.

PURPOSE

Our aim was to compare the safety and efficacy of flow-diverter and conventional endovascular treatments in intracranial aneurysms.

DATA SOURCES

We performed a comprehensive search of the literature using PubMed, EMBASE, and the Cochrane Database.

STUDY SELECTION

We included only studies that directly compared the angiographic and clinical outcomes of flow-diverter and conventional endovascular treatments.

DATA ANALYSIS

Random effects or fixed effects meta-analysis was used to pool the cumulative rate of short- and long-term angiographic and clinical outcomes.

DATA SYNTHESIS

Eighteen studies with 1001 patients with flow diverters and 1133 patients with conventional endovascular treatments were included; 1015 and 1201 aneurysm procedures were performed, respectively. The flow-diverter group had aneurysms of a larger size (standard mean difference, 0.22; 95% CI, 0.03-0.41; P = .026). There was a higher risk of complications in the flow-diverter group compared with the conventional endovascular group (OR, 1.4; 95% CI, 1.01-1.96; P = .045) during procedures. The follow-up angiographic results of flow-diverter treatment indicated a higher rate of complete occlusion (OR, 2.55; 95% CI, 1.70-3.83; P < .001) and lower rates of recurrence (OR, 0.24; 95% CI, 0.12-0.46; P < .001) and retreatment (OR, 0.31; 95% CI, 0.21-0.47; P < .001).

LIMITATIONS

Limitations include a retrospective, observational design in some studies, high heterogeneity, and selection bias.

CONCLUSIONS

Compared with the conventional endovascular treatments, the placement of a flow diverter may lead to more procedure-related complications, but there is no difference in safety, and it is more effective in the long term.

A back‐projection‐and‐filtering‐like (BPF‐like) reconstruction method with the deep learning filtration from listmode data in TOF‐PET

PURPOSE

The time-of-flight (TOF) information improves signal-to-noise ratio (SNR) for positron emission tomography (PET) imaging. Existing analytical algorithms for TOF PET usually follow a filtered back-projection process on reconstructing images from the sinogram data. This work aims to develop a back-projection-and-filtering-like (BPF-like) algorithm that reconstructs the TOF PET image directly from listmode data rapidly.

METHODS

We extended the 2D conventional non-TOF PET projection model to a TOF case, where projection data are represented as line integrals weighted by the one-dimensional TOF kernel along the projection direction. After deriving the central slice theorem and the TOF back-projection of listmode data, we designed a deep learning network with a modified U-net architecture to perform the spatial filtration (reconstruction filter). The proposed BP-Net method was validated via Monte Carlo simulations of TOF PET listmode data with three different time resolutions for two types of activity phantoms. The network was only trained on the simulated full-dose XCAT dataset and then evaluated on XCAT and Jaszczak data with different time resolutions and dose levels.

RESULTS

Reconstructed images show that when compared with the conventional BPF algorithm and the MLEM algorithm proposed for TOF PET, the proposed BP-Net method obtains better image quality in terms of peak signal-to-noise ratio, relative mean square error, and structure similarity index; besides, the reconstruction speed of the BP-Net is 1.75 times faster than BPF and 29.05 times faster than MLEM using 15 iterations. The results also indicate that the performance of the BP-Net degrades with worse time resolutions and lower tracer doses, but degrades less than BPF or MLEM reconstructions.

CONCLUSION

In this work, we developed an analytical-like reconstruction in the form of BPF with the reconstruction filtering operation performed via a deep network. The method runs even faster than the conventional BPF algorithm and provides accurate reconstructions from listmode data in TOF-PET, free of rebinning data to a sinogram.

[Prospective comparison of greenlight laser anatomic vaporization-incision technique and photoselective vaporization of the prostate in the treatment of benign prostatic hyperplasia]

Objective: To prospectively compare the efficacy and safety of the greenlight laser anatomical vaporization-incision technique (AVIT) and photoselective vaporization of the prostate(PVP)in the treatment of benign prostatic hyperplasia (BPH). Methods: From November 2019 to September 2020, a randomized controlled study was conducted on 136 BPH patients undergoing greenlight laser surgery in the Department of Urology, the Second Affiliated Hospital of Soochow University. The patient's age ranged from 53 to 85 years and the prostatic volume ranged from 30 to 104 ml. They were divided into two groups by random number table method,including 68 cases of AVIT(observation group)and 68 cases of PVP(control group). The clinical data of the two groups before, during and after operation were collected and analyzed. Results: Operations were successfully completed in the two groups. At 6 months after operation, 63 cases in the observation group and 66 cases in the control group completed the follow-up. There was no significant difference in the prevalence of hypertension, diabetes, coronary heart disease, atrial fibrillation and renal insufficiency between the two groups before operation (all P>0.05). The differences of preoperative age [(66.8±6.5) vs (67.3±5.4) years], international prostate symptom score (IPSS) [(24.2±4.7) vs (23.5±4.5) ], quality of life score (QOL) [4.7(4.1, 4.9) vs 4.6(4.2, 5.0)], peak urinary flow rate (Qmax) [(6.9±2.8) vs (6. 8±2.6) ml/s], post-void residual volume (PVR) [(137(52.8, 190.9) vs 119(70.6, 172.1) ml], prostate volume (PV) [70.5(60.6, 80.9) vs 68.2(61.2, 80.5) ml], serum prostate specific antigen (PSA) [4.4(3.5, 5.1) vs 4.4(3.4, 5.0) ng/ml] were not statistically significant between the two groups (all P>0.05). There was no significant difference in the amount of intraoperative blood loss, catheterization time and the postoperative hospitalization time between the two groups (all P>0.05). Compared with the control group, the operation time and lasing time of the observation group were longer[69.0(64.6, 75.0) vs 55.8(49.1, 63.4) min,(36.3±9.9) vs (31.3±9.3) min], and the intraoperaive laser energy consumption and laser energy density were higher[(297±20) vs (240±20) kJ,(4.50±1.35) vs (3.73±1.17) kJ/ml]. The differences were all statistically significant (all P<0.05). At the follow-up of 1, 3 and 6 months after operation, IPSS and QOL in the observation group were lower than those in the control group, and the differences were all statistically significant (all P<0.05). Qmax in the observation group was higher and PVR was lower than those in the control group, with statistically significant differences (P<0.05). Six months after operation, PV and PSA in the observation group decreased more significantly than those in the control group (56% vs 47%, 70% vs 60%, both P<0.05). No urethral stricture and urinary incontinence occurred in two groups after operation. The incidence rate of urinary tract irritation in the observation group was 6.3%(4/63),lower than the 18.2%(12/66)in the control group (P<0.05). There was no significant difference in the incidence rates of urinary retention, bladder neck contracture and secondary bleeding between the two groups (all P>0.05). Conclusions: Greenlight laser anatomical vaporization-incision technique is safe and effective in the treatment of BPH. Compared with PVP, AVIT has more prostate tissue removed and better curative effect, which is worthy of clinical promotion.

Genome-wide association study reveals a quantitative trait locus and two candidate genes on Sus scrofa chromosome 5 affecting intramuscular fat content in Suhuai pigs

Intramuscular fat content (IFC) is an essential quantitative trait of meat, affecting multiple meat quality indicators. A certain amount of IFC could not only improve the sensory score of pork but also increase the flavour, tenderness, juiciness and shelf-life. To dissect the genetic determinants of IFC, two methods, including genome-wide efficient mixed-model analysis (GEMMA) and linkage disequilibrium adjusted kinships (LDAKs), were used to carry out genome-wide association studies for IFC in Suhuai pig population. A total of 14 and 18 significant single nucleotide polymorphisms (SNPs) were identified by GEMMA and LDAK, respectively. The results of these two methods were highly consistent and all 14 significant SNPs in GEMMA were detected by LDAK. Seven of the 18 SNPs reached the genome-wide significance level (P < 9.85E-07) while 11 cases reached the suggestive significance level (P < 1.77E-05). These significant SNPs were mainly distributed on Sus scrofa chromosome (SSC) 5, 3, and 7. Moreover, one locus resides in a 2.27 Mb (71.37-73.64 Mb) region on SSC5 harbouring 13 significant SNPs associated with IFC, and the lead SNP (rs81302978) also locates in this region. Linkage disequilibrium (LD) analysis showed that there were four pairs of complete LD (r² = 1) among these 13 SNPs, and the remaining 9 SNPs with incomplete LD (r² ≠ 1) were selected for subsequent analyses of IFC. Association analyses showed that 7 out of 9 SNPs were significantly associated with IFC (P < 0.05) in 330 Suhuai pigs, and the other 2 SNPs tended to reach a significant association level with IFC (P < 0.1). The phenotypic variance explained (PVE) range of these 9 SNPs was 0.92-3.55%. Meanwhile, the lead SNP was also significantly associated (rs81302978) with IFC (P < 0.05) in 378 commercial hybrid pigs (Pietrain × Duroc) × (Landrace × Yorkshire) (PDLY), and the PVE was 1.38%. Besides, two lipid metabolism-relevant candidate genes, the leucine rich repeat kinase 2 (LRRK2) and PDZ domain containing ring finger 4 (PDZRN4) were identified in the 2.27 Mb region on SSC5. In conclusion, our results may provide a set of markers useful for genetic improvement of IFC in pigs and will advance the genome selection process of IFC on pig breeding programmes.

Tomography of dark-field scatter including single-exposure Moiré fringe analysis with X-ray biprism interferometry-A simulation study

PURPOSE

In this work, we present tomographic simulations of a new hardware concept for X-ray phase-contrast interferometry wherein the phase gratings are replaced with an array of Fresnel biprisms, and Moiré fringe analysis is used instead of "phase stepping" popular with grating-based setups.

METHODS

Projections of a phantom consisting of four layers of parallel carbon microfibers is simulated using wave optics representation of X-ray electromagnetic waves. Simulated projections of a phantom with preferential scatter perpendicular to the direction of the fibers are performed to analyze the extraction of small-angle scatter from dark-field projections for the following: (1) biprism interferometry using Moiré fringe analysis; (2) grating interferometry using phase stepping with eight grating steps; and (3) grating interferometry using Moiré fringe analysis. Dark-field projections are modeled as projections of voxel intensities represented by a fixed finite vector basis set of scattering directions. An iterative MLEM algorithm is used to reconstruct, from simulated projection data, the coefficients of a fixed set of seven basis vectors at each voxel representing the small-angle scatter distribution.

RESULTS

Results of reconstructed vector coefficients are shown comparing the three simulated imaging configurations. The single-exposure Moiré fringe analysis shows not only an increase in noise because of one-eighth the number of projection samples but also is obtained with less dose and faster acquisition times. Furthermore, replacing grating interferometry with biprism interferometry provides better contrast-to-noise.

CONCLUSION

The simulations demonstrate the feasibility of the reconstruction of dark-field data acquired with a biprism interferometry system. With the potential of higher fringe visibility, biprism interferometry with Moiré fringe analysis might provide equal or better image quality to that of phase stepping methods with less imaging time and lower dose.

O-174 Individualized versus standard FSH dosing in predicted poor responders: an RCT

Study question

Is there a difference in fertility outcomes between individualized or standard FSH dosing in women scheduled for IVF with an expected poor response?

Summary answer

In predicted poor responders (AFC&lt;10) undergoing IVF/ICSI, individualized FSH dosing does not improve ongoing pregnancy rates as compared to a standard FSH dose.

What is known already

Poor responders usually lead to many detrimental effects on IVF outcomes due to low oocyte number and quality which in turn result in low pregnancy outcomes and an increased chance of cycle cancellation. Clinicians often individualize the FSH dose using ovarian reserve tests (ORT), including antral follicle count (AFC), basal FSH (bFSH), and anti-Mullerian hormone (AMH). However, it is unclear whether individualized FSH dosing improves clinical outcomes.

Study design, size, duration

Between March 2019 and April 2020, we performed a single-center, parallel, open-label RCT in women with an AFC&lt;10. A total of 661 women were randomized either to start FSH dosing at 300IU/225IU or 150IU. The primary outcome was live birth attributable to the first ART cycle within 18 months of randomization. In this abstract, we report ongoing pregnancy rates. Live birth date will be available at the meeting.

Participants/materials, setting, methods

Women referred for their first IVF/ICSI cycle, &lt;43 years of age, AFC&lt;10 were approached. A total of 328 women were allocated to the individualized group and 333 women were allocated to the standard group. In the individualized group, women with AFC 1-6 were assigned to 300IU/day (n = 122), while women with AFC 7-9 were assigned to 225IU/day (n = 206). In the standard group, women were assigned 150IU/day. Outcomes were evaluated from an intention-to-treat perspective.

Main results and the role of chance

For ongoing pregnancy rate attributable to the first ART cycle for individualized versus standard dosing was comparable [52.44% vs 46.25%, relative risk (RR): 1.29 (95%CI, 0.94-1.74), P = 0.11]. Biochemical pregnancy rate [62.50% vs 62.16%, RR: 1.01 (95%CI, 0.74-1.39), P = 0.929], clinical pregnancy rate [59.45% vs 58.86%, RR: 1.02 (95%CI, 0.75-1.40), P = 0.877] and multiple pregnancy rate [5.18% vs 5.12%, RR: 1.01 (95%CI, 0.51-2.02), P = 0.971] also did not differ between individualized and standard dosing. There are 24 women who are ongoing pregnancy but do not reach live birth in the completed embryo transfer cycle. The individualized group reported less poor response (31.1% vs 48.7%: P &lt; 0.001), more obtained oocytes (6.80 ± 3.85 vs 5.28 ± 3.22; P &lt; 0.001), less embryos (3.76 ± 2.70 vs 3.16 ± 2.42; P = 0.004), and less good quality embryos (2.61 ± 2.29 vs 2.21 ± 2.05; P = 0.018). When outcomes were compared over the first embryo transfer, ongoing pregnancy rates were 39.0% (128/328) versus 37.2% (124/333), respectively [RR:1.08 (95%CI, 0.79-1.48), P = 0.636], without differences in the other outcomes. There are 7 women who are ongoing pregnancy but do not reach live birth in the first embryo transfer cycle.

Limitations, reasons for caution

Due to the open-label character, potential selective canceling and small dose adjustments of standard dosing were allowed. This abstract reports on ongoing pregnancy. At the meeting, we will present live birth rates.

Wider implications of the findings

In women with predicted poor response, an increased dose does not increase ongoing pregnancy rates. A standard dose of 150IU/day is recommended in these women.

Trial registration number

ChiCTR1900021944

Evaluation of a variable-aperture full-ring SPECT system using large-area pixelated CZT modules: A simulation study for brain SPECT applications

PURPOSE

Single photon emission computed tomography (SPECT) scanners using cadmium zinc telluride (CZT) offer compact, lightweight, and improved imaging capability over conventional NaI(Tl)-based SPECT scanners. The main purpose in this study is to propose a full-ring SPECT system design with eight large-area CZT detectors that can be used for a broad spectrum of SPECT radiopharmaceuticals and demonstrate the performance of our system in comparison to the reference conventional NaI(Tl)-based two-head Anger cameras.

METHODS

A newly designed full-ring SPECT system is composed of eight large-area CZT cameras (128 mm × 179.2 mm effective area) that can be independently swiveled around their own axes of rotation independently and can have radial motion for varying aperture sizes that can be adapted to different sizes of imaging volume. Extended projection data were generated by conjoining projections of two adjacent detectors to overcome the limited field-of-view (FOV) by each CZT camera. Using Monte Carlo simulations, we evaluated this new system design with digital phantoms including a Derenzo hot rod phantom and a Zubal brain phantom. Comparison of performance metrics such as spatial resolution, sensitivity, contrast-to-noise ratio (CNR), and contrast-recovery ratio was made between our design and conventional SPECT scanners having different pixel sizes and radii of rotation (one clinically well-known type and two arbitrary types matched to our proposed CZT-SPECT geometries).

RESULTS

The proposed scanner could result in up to about three times faster in acquisition time over conventional scan time at same acquisition time per step. The spatial resolution improvement, or deterioration, of our proposed scanner compared to the clinical-type scanner was dependent upon the location of the point source. However, there were overall performance improvements over the three different setups of the conventional scanner particularly in volume sensitivity (approximately up to 1.7 times). Overall, we successfully reconstructed the phantom image for both ^99m Tc-based perfusion and ¹²³ I-based dopamine transporter (DaT) brain studies simulated for our new design. In particular, the striatal/background contrast-recovery ratio in 3-to-1 reference ratio was over 0.8 for the ¹²³ I-based DaT study.

CONCLUSIONS

We proposed a variable-aperture full-ring SPECT system using combined pixelated CZT and energy-optimized parallel-hole collimator modules and evaluated the performance of this scanner using relevant digital phantoms and MC simulations. Our studies demonstrated the potential of our new full-ring CZT-SPECT design, showing reduced acquisition time and improved sensitivity with acceptable CNR and spatial resolution.

MicroRNA-296 functions as a tumor suppressor in breast cancer by targeting FGFR1 and regulating the Wnt/β-catenin signaling pathway

OBJECTIVE

Breast cancer (BC) is a common malignancy all over the world. However, the detailed mechanism underlying BC progression remains incompletely understood. MicroRNAs (miRNAs) have been observed to play crucial roles in tumorigenesis. The present study aimed to determine the expression and function of miR-296 in BC.

PATIENTS AND METHODS

MiR-296 expressions in BC tissue samples and cell lines were examined by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). After that, we performed functional assays, including MTT (3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assays and transwell assays, to show the functions of miR-296 in BC cell proliferation, invasion and migration. Immunological histological chemistry (IHC) assays were carried out to detect the expression levels of fibroblast growth factor receptor 1 (FGFR1) in BC tissue samples. Western blot was used to explore potential mechanisms of miR-296 in regulating BC progression. A Luciferase reporter assay was carried out to confirm the target gene of miR-296.

RESULTS

Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) results demonstrated a significant decrease of miR-296 expressions in BC when compared to the corresponding normal controls. In addition, the decreased miR-296 was correlated with the malignant phenotypes and poorer prognosis of BC patients. The functional assays indicated that miR-296 restoration could repress the proliferation, invasion and migration abilities of BC cells. Moreover, the results of the current study revealed that miR-296 exerted the repressive functions in BC cells via regulating FGFR1, the Wnt/β-catenin signaling pathway and EMT. Additionally, miR-296 up-regulation could inhibit in vivo BC cell growth.

CONCLUSIONS

All these findings indicated that miR-296 exerted anti-BC functions, providing novel therapeutic strategies in BC treatment.

Design study of fully wearable high-performance brain PETs for neuroimaging in free movement

A practical wearable brain PET scanner capable of dynamic neuroimaging during free bodily movement will enable potential breakthrough basic neuroscience studies and help develop imaging-based neurological diagnoses and treatments. Weight, brain coverage, and sensitivity are three fundamental technical obstacles in the development of Fully Wearable High-Performance (FWHP) brain PET scanners. The purpose of this study is to investigate the feasibility of building a FWHP brain PET using a limited volume of lutetium-yttrium oxyorthosilicate (LYSO) scintillator crystals. Six scanners, consisted of the same volume (2.66 kg) of LYSO scintillators with combinations of 2 different crystal pitches (3 mm and 1.5 mm) and 3 different crystal lengths (20 mm, 10 mm, and 5 mm), were simulated. The performances of the six scanners were assessed and compared with Siemen's HRRT brain PET and mCT whole-body PET, in terms of aperture, axial field of views (AFOV), sensitivity, spatial resolution, count rates, and image noise property. The time-of-flight (TOF) information was included in the image reconstruction to improve the effective sensitivity. The effects of the TOF was assessed by scanning a Jaszczak phantom and reconstructing images with the maximum likelihood expectation maximization (MLEM) algorithm with different timing settings (non-TOF, 500 ps, 200 ps, 100 ps and 50 ps Coincidence Time Resolution, CTR). The signal-noise ratio (SNR) of the images were assessed and compared with those of the HRRT scanner and mCT scanner. The results show that it is possible to construct a FWHP brain PET with better spatial resolution than the dedicated HRRT brain PET, comparable effective sensitivity (with 50 ∼ 100 ps CTR), and whole-brain coverage (23.7 cm inner diameter and 13.4 cm axial field of view) using 2.66 kg of LYSO.

Reintervention or mortality within 90 days of bariatric surgery: population-based cohort study

Background

Bariatric surgery carries a risk of severe postoperative complications, sometimes leading to reinterventions or even death. The incidence and risk factors for reintervention and death within 90 days after bariatric surgery are unclear, and were examined in this study.

Methods

This population-based cohort study included all patients who underwent bariatric surgery in one of the five Nordic countries between 1980 and 2012. Data on surgical and endoscopic procedures, diagnoses and mortality were retrieved from national high-quality and complete registries. Multivariable Cox regression analysis was used to calculate hazard ratios (HRs), adjusted for country, age, sex, co-morbidity, type of surgery and approach, year and hospital volume of bariatric surgery.

Results

Of 49 977 patients, 1111 (2·2 per cent) had a reintervention and 95 (0·2 per cent) died within 90 days of bariatric surgery. Risk factors for the composite outcome reintervention/mortality were older age (HR 1·65, 95 per cent c.i. 1·36 to 2·01, for age at least 50 years versus less than 30 years) and co-morbidity (HR 2·66, 1·53 to 4·62, for Charlson co-morbidity index score 2 or more versus 0). The risk of reintervention/mortality was decreased for vertical banded gastroplasty compared with gastric bypass (HR 0·37, 0·28 to 0·48) and more recent surgery (HR 0·51, 0·39 to 0·67, for procedures undertaken in 2010 or later versus before 2000). Sex, surgical approach (laparoscopic versus open) and hospital volume did not influence risk of reintervention/mortality, but laparoscopic surgery was associated with a lower risk of 90-day mortality (HR 0·29, 0·16 to 0·53).

Conclusion

Reintervention and death were uncommon events within 90 days of bariatric surgery even in this unselected nationwide cohort from five countries. Older patients with co-morbidities have an increased relative risk of these outcomes.

A preclinical PET detector constructed with a monolithic scintillator ring

This paper presents a unique preclinical positron emission tomography (PET) detector constructed with a monolithic scintillator ring (MSR) and two rings of silicon photomultipliers (SiPM). The inner diameter, outer diameter and length of the MSR were 48.5 mm, 58.5 mm, and 25.1 mm, respectively. The two SiPM rings, constructed with 46 SiPMs, were air-coupled to the two ends of the MSR detector. The center of gravity (COG) and artificial neural network (ANN) methods were adapted to decode the positions of the gamma interactions in the circumferential (θ) and axial (Z) directions, respectively. Collimating systems, consisting of a tungsten collimator and a high-precision displacement and rotating platform, were constructed to assess the decoding accuracies of the MSR detector in both θ and Z directions. The average intrinsic full-width half maximums (FWHMs) and mean absolute errors (MAEs) of the decoding accuracies were 0.94 mm and 0.33 mm in the circumferential direction, 2.45 mm and 1.08 mm in the axial direction. An energy resolution of 10.7% was measured at 511 keV. The scintillating photons generated by a pair of coincidence gamma photons overlap with each other, and cause circumferential parallax errors in the lines of response (LOR). The experimental results show that the average FWHM errors in the θ direction increased slightly from 0.94 mm to 1.14 mm when Δθ of the two single events was larger than 70°. The imaging performance of the MSR detector was also initially assessed with a Derenzo phantom filled with 18F-FDG. The rods with a diameter larger than 1.2 mm can be resolved. The energy resolutions were 12.3% at 511 keV (single events), and 11.4% at 1022 keV (coincidence events). We concluded that it is feasible to construct the high-performance preclinical PET scanners using one or multiple MSR detectors.

White matter integrity disruption in the pre-dementia stages of Alzheimer's disease: from subjective memory impairment to amnestic mild cognitive impairment

BACKGROUND AND PURPOSE

Subjective memory impairment (SMI) and amnestic mild cognitive impairment (aMCI) are thought to represent the pre-dementia stages of Alzheimer's disease (AD). SMI is considered a more advanced pre-clinical status prior to aMCI. Understanding the neuromechanism of SMI will have great benefits for monitoring the disease progression of AD. The study aims to explore whether SMI shows alterations of white matter (WM) integrity similar to the patterns of aMCI.

METHODS

The atlas-based analyses were performed to investigate the diffusion changes in the major WM tracts amongst 22 individuals with normal cognition (NC), 22 SMI patients and 25 aMCI patients. The correlations between the altered diffusion metrics and cognitive performance in the SMI and aMCI groups were assessed.

RESULTS

The diffusion tensor metrics of SMI were intermediate between the NC and aMCI groups. The aMCI group presented disrupted integrity in multiple WM tracts, including the left anterior thalamic radiation, right corticospinal tract and left cingulum of the hippocampus (CgH), compared to the NC group. The left CgH showed diffusion alterations in the SMI group. In the aMCI group, the mean diffusivity of the left CgH was negatively correlated with episodic memory, whilst the radial diffusivity of the right corticospinal tract was negatively correlated with executive function. No significant relationship was found in the SMI group.

CONCLUSION

The study suggested that SMI patients might present detectable WM integrity changes in the left CgH before exhibiting objective cognitive dysfunction, which may provide novel insights into the pathological mechanisms of AD.

Enhancing the Image Quality via Transferred Deep Residual Learning of Coarse PET Sinograms

Increasing the image quality of positron emission tomography (PET) is an essential topic in the PET community. For instance, thin-pixelated crystals have been used to provide high spatial resolution images but at the cost of sensitivity and manufacture expense. In this paper, we proposed an approach to enhance the PET image resolution and noise property for PET scanners with large pixelated crystals. To address the problem of coarse blurred sinograms with large parallax errors associated with large crystals, we developed a data-driven, single-image super-resolution (SISR) method for sinograms, based on the novel deep residual convolutional neural network (CNN). Unlike the CNN-based SISR on natural images, periodically padded sinogram data and dedicated network architecture were used to make it more efficient for PET imaging. Moreover, we included the transfer learning scheme in the approach to process cases with poor labeling and small training data set. The approach was validated via analytically simulated data (with and without noise), Monte Carlo simulated data, and pre-clinical data. Using the proposed method, we could achieve comparable image resolution and better noise property with large crystals of bin sizes of thin crystals with a bin size from to . Our approach uses external PET data as the prior knowledge for training and does not require additional information during inference. Meanwhile, the method can be added into the normal PET imaging framework seamlessly, thus potentially finds its application in designing low-cost high-performance PET systems.

Edge toroidal charge exchange spectra analysis in the EAST

An edge toroidal charge exchange recombination spectroscopy (eCXRS) diagnostic has been deployed successfully on the Experimental Advanced Superconducting Tokamak (EAST) recently, providing edge plasma ion temperature and toroidal rotation. Edge CXRS on EAST typically monitors the carbon vi (529.059 nm, n = 8 → 7) spectral line. Spectral lines emitted from other different impurities that appeared in the wavelength ranges of 528 nm-530 nm illustrate the need to revise the edge change exchange spectra analysis in this region. Since the eCXRS sightlines end on the ion cyclotron range of frequencies (ICRF) stainless steel antenna, the passive Fe lines coming from the antenna could be recorded by eCXRS diagnostic when ICRF is used. A revised edge toroidal charge exchange spectra analysis including Fe spectral lines is presented. The accuracy of eCXRS measurement has been improved by the revised spectra analysis.

Simultaneous measurement of C VI, Ne X, and Li III charge exchange lines on EAST

The core toroidal charge exchange recombination spectroscopy system on experimental advanced superconducting tokamak (EAST) has been enhanced recently to extend the spectral range. The C VI charge exchange line at 529.059 nm, Ne X line at 524.897 nm, and Li III line at 516.67 nm are observed successfully. The measurements were performed by injecting neon gas and dropping lithium powder simultaneously during the 2016 EAST experimental campaign. One channel connected to a neon lamp is used to perform the real-time wavelength calibration on a shot-to-shot basis. The preliminary results indicate that ion temperature profiles from the carbon and neon impurities are in excellent agreement and provide a consistency check of the measurement from different impurities. Toroidal velocity correction associated with the energy-dependent cross section has been performed. Toroidal rotation of neon impurity is obviously faster than C VI across the whole profile. A cumulative and saturated effect of core lithium ions was observed.

Developing a 'multiPatchPET' system in GATE for a PET system design with irregular geometries

This work modified the commonly used Monte Carlo tool package GATE by developing a new 'multiPatchPET' system so that GATE users can easily simulate PET systems with irregular geometries. The motivation was to design a brain PET scanner with high sensitivity. It is known that compact PET scanners with a large solid coverage angle can achieve high sensitivity with fewer scintillation detectors, and thus have the potential to provide better image quality in brain PET imaging than conventional ring PET scanners. However, considering a straightforward example with the largest possible solid angle, a spherical PET scanner is hard to manufacture. A more practical alternative would be a sphere-like polyhedral PET scanner with flat detector patches. Moreover, when monolithic scintillators are chosen to construct these flat detector modules, detection efficiency is further improved. Thus, we plan to design a sphere-like polyhedral PET scanner made up of monolithic scintillators. Unfortunately, in our design study, we found that simulating such a scanner with the latest GATE version (8.0) was not trivial, since no predefined systems could be used. In this work we introduced a 'multiPatchPET' system to GATE, which we and other GATE users will be able to use to develop PET scanners with any irregular geometry and any shape of patch. To validate our modification, a single block detector and an mCT scanner were simulated via both the original 'ecat' system and the new 'multiPatchPET' system. The results show no difference in terms of the detecting efficiency and reconstruction image. Then we used the 'multiPatchPET' system to simulate an 86 surface polyhedral brain PET scanner. Compared with two cylindrical brain scanners, the polyhedral brain scanner shows a higher sensitivity and has fewer noisy images. Thus, it was proved that our modification, which is accessible to the nuclear imaging research community, equipped GATE with a powerful and user-friendly tool to simulate complex scanners with irregular patches easily.

Simulation study of a high-performance brain PET system with dodecahedral geometry

PURPOSE

In brain imaging, the spherical PET system achieves the highest sensitivity when the solid angle is concerned. However, it is not practical. In this work, we designed an alternative sphere-like scanner, the dodecahedral scanner, which has a high sensitivity in imaging and a high feasibility to manufacture. We simulated this system and compared the performance with a few other dedicated brain PET systems.

METHODS

Monte Carlo simulations were conducted to generate data of the dedicated brain PET system with the dodecahedral geometry (11 regular pentagon detectors). The data were then reconstructed using the in-house developed software with the fully three-dimensional maximum-likelihood expectation maximization (3D-MLEM) algorithm.

RESULTS

Results show that the proposed system has a high-sensitivity distribution for the whole field of view (FOV). With a depth-of-interaction (DOI) resolution around 6.67 mm, the proposed system achieves the spatial resolution of 1.98 mm. Our simulation study also shows that the proposed system improves the image contrast and reduces noise compared with a few other dedicated brain PET systems. Finally, simulations with the Hoffman phantom show the potential application of the proposed system in clinical applications.

CONCLUSIONS

In conclusion, the proposed dodecahedral PET system is potential for widespread applications in high-sensitivity, high-resolution PET imaging, to lower the injected dose.

Gallbladder perforation in a patient with alcoholic liver cirrhosis and asymptomatic gallstones: A case report

RATIONALE

Gallbladder perforation is a relatively uncommon complication of alcoholic liver cirrhosis and may happen with or without gallstones.

PATIENT CONCERNS

Here we report a 52-year-old male patient who was diagnosed as gallbladder perforation with chronic liver cirrhosis and asymptomatic gallstones. The patient was admitted with acute and severe abdominal pain during weight-bearing physical labor. He had a history of alcoholic liver cirrhosis but no chronic abdominal pain or gallstones. The patient presented with localized peritoneal irritation, and abdominal puncture showed non-clotting blood. A preliminary clinical diagnosis was made as hepatocellular carcinoma rupture based on imaging findings. However, this diagnosis changed to gangrenous cholecystitis with gallbladder perforation by the laparotomy examination.

DIAGNOSES

He was diagnosed with gangrenous cholecystitis with gallbladder perforation.

INTERVENTIONS AND OUTCOMES

The patient performed well postoperatively.

LESSONS

This case suggests that gallbladder perforation should be considered as a potential cause of acute abdominal pain even without evidence of gallstones. Early examination with a laparotomy examination can help achieve a timely diagnosis.

Acute kidney injury following the first stage of the ALPPS procedure: A case report

Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) is a novel approach for performing liver resection, and the number of clinical applications of this technique has rapidly increased within recent years. ALPPS is important in patients who have insufficient residual liver volume and cannot undergo radical hepatic resection. The most common postoperative complications of ALPPS include biliary fistula and infection. To date, postoperative acute kidney injury following ALPPS has not been reported. The current study reports the case of a 63-year-old patient with hepatitis B-induced cirrhosis who underwent the first stage of ALPPS without completion of the second step. The patient developed postoperative acute kidney injury following ALPPS. The present case study suggests that the use of ALPPS in patients at risk of chronic renal damage should be approached with caution in order to avoid postoperative acute kidney injury. Furthermore, improvements in surgical techniques and skills of the surgeons performing the procedure are required to reduce the surgery duration and improve patient outcomes.

A low-temperature scanning tunneling microscope capable of microscopy and spectroscopy in a Bitter magnet at up to 34 T

We present the design and performance of a cryogenic scanning tunneling microscope (STM) which operates inside a water-cooled Bitter magnet, which can attain a magnetic field of up to 38 T. Due to the high vibration environment generated by the magnet cooling water, a uniquely designed STM and a vibration damping system are required. The STM scan head is designed to be as compact and rigid as possible, to minimize the effect of vibrational noise as well as fit the size constraints of the Bitter magnet. The STM uses a differential screw mechanism for coarse tip-sample approach, and operates in helium exchange gas at cryogenic temperatures. The reliability and performance of the STM are demonstrated through topographic imaging and scanning tunneling spectroscopy on highly oriented pyrolytic graphite at T = 4.2 K and in magnetic fields up to 34 T.

Copolymerisation of ethylene with polar monomers by using palladium catalysts bearing an N-heterocyclic carbene–phosphine oxide bidentate ligand

We report the synthesis and characterisation of palladium complexes bearing an N-heterocyclic carbene–phosphine oxide bidentate ligand and their use as catalysts for ethylene polymerisation and ethylene/polar monomer copolymerisation.

[Application of DNA-image cytometry in the diagnosis of lung cancer]

OBJECTIVE

To explore the value of DNA-image cytometry (DNA-ICM) in diagnosis of lung cancer.

METHODS

532 cases of bronchoalveolar lavage fluid (BALF) and (or) bronchial brushing cytology (216 cases from lung cancer patients and 209 cases from benign lung disease patients) were detected by DNA-ICM and liquid-based cytology (LBC), respectively. The sensitivity and specificity of the two methods were compared.

RESULTS

The sensitivity and specificity of DNA-ICM were 69.2% and 100.0%, and which of LBC were 46.7% and 97.9%, respectively. The sensitivity of DNA-ICM was significantly higher than that of LBC method in the diagnosis of lung cancer (P<0.05). The sensitivity and specificity of DNA-ICM of BALF were 71.9% and 100.0%, while those of LBC were 48.2% and 98.5%. The sensitivity and specificity of DNA-ICM of bronchial brushing cytology were 62.8% and 100.0%, while those of LBC were 43.0% and 95.3%. The sensitivity of DNA-ICM of BALF and bronchial brushing cytology were higher than that of LBC method (P<0.05). There were 107 patients who underwent BALF and bronchial brushing cytology simultaneously, the sensitivity of DNA-ICM of BALF was higher than that of bronchial brushing cytology (P<0.05). Among different histologic types of the lung cancers, the sensitivity of squamous carcinoma was higher that of adenocarcinoma.

CONCLUSIONS

DNA-ICM has great application value in the diagnosis of lung cancer. DNA-ICM in combination with LBC can increase the detection rate of lung cancer. DNA-ICM of BALF is worthy of application in clinical practice.

A genomics-led approach to deciphering the mechanism of thiotetronate antibiotic biosynthesis

Thiolactomycin (TLM) is a thiotetronate antibiotic that selectively targets bacterial fatty acid biosynthesis through inhibition of the β-ketoacyl-acyl carrier protein synthases (KASI/II) that catalyse chain elongation on the type II (dissociated) fatty acid synthase. It has proved effective in in vivo infection models of Mycobacterium tuberculosis and continues to attract interest as a template for drug discovery. We have used a comparative genomics approach to uncover the (hitherto elusive) biosynthetic pathway to TLM and related thiotetronates. Analysis of the whole-genome sequence of Streptomyces olivaceus Tü 3010 producing the more ramified thiotetronate Tü 3010 provided initial evidence that such thiotetronates are assembled by a novel iterative polyketide synthase-nonribosomal peptide synthetase, and revealed the identity of other pathway enzymes, encoded by adjacent genes. Subsequent genome sequencing of three other thiotetronate-producing actinomycetes, including the Lentzea sp. ATCC 31319 that produces TLM, confirmed that near-identical clusters were also present in these genomes. In-frame gene deletion within the cluster for Tü 3010 from Streptomyces thiolactonus NRRL 15439, or within the TLM cluster, led to loss of production of the respective thiotetronate, confirming their identity. Each cluster houses at least one gene encoding a KASI/II enzyme, suggesting plausible mechanisms for self-resistance. A separate genetic locus encodes a cysteine desulfurase and a (thiouridylase-like) sulfur transferase to supply the sulfur atom for thiotetronate ring formation. Transfer of the main Tü 3010 gene cluster (stu gene cluster) into Streptomyces avermitilis led to heterologous production of this thiotetronate, showing that an equivalent sulfur donor can be supplied by this host strain. Mutational analysis of the Tü 3010 and TLM clusters has revealed the unexpected role of a cytochrome P450 enzyme in thiotetronate ring formation. These insights have allowed us to propose a mechanism for sulfur insertion, and have opened the way to engineering of the biosynthesis of TLM and other thiotetronates to produce novel analogues.

High hydrostatic pressure upon the vasa vasorum of the greater saphenous and splenic vein walls: a comparative study

AIMS

Hypoxia and high hydrostatic pressure can induce an increase in the thickness of the tunica media and intima; secondary vasa vasorum (VV) increase to fit the remodeling of the vessel wall. We aimed to investigate the impact of high hydrostatic pressure on VV in the varicose greater saphenous veins (VGSVs) and diseased splenic veins (DSVs).

METHODS

We collected 34 VGSVs and DSVs. Thirty-four normal greater saphenous veins (GSVs) and splenic veins (SVs) were also collected (control group). Samples were cut into slices, and observed under both light and electron microscopy. The mean density and cross-sectional areas of the VV in the adventitia were measured.

RESULTS

In both VGSVs and DSVs, VV density increased, in the adventitia and exterior tunica media, offering an intensive linear distribution. However, sporadic distribution of the interior tunica media and intima were seen on light microscopy. The integrated structure of the cell nucleus of endothelial cells in VV, normal morphology and distribution of chromatin, partially hyperchromatic mitochondria matrix, fuzzy or fractured mitochondria cristae, and medullary cristae changes were observed by electron microscopy. Mean density and cross-sectional areas of VV in the adventitia of GSVs and SVs were significantly different.

CONCLUSION

Under high hydrostatic pressure conditions, the number of VV were increased in the wall of VGSVs and DSVs. There was heterogeneity between both types of veins. The splenic vein has a higher number of VV, but the greater saphenous vein has a higher average cross-sectional area. The same ultrastructural changes are seen in the endothelial cells of the VV in both vessels.

HMGB1 may act via RAGE to promote angiogenesis in the later phase after intracerebral hemorrhage

Following intracerebral hemorrhage (ICH), high-mobility group box 1 protein (HMGB1) may promote vascular remodeling. Whether HMGB1 supports angiogenesis after ICH is unclear, as are the receptors and downstream signaling pathway(s) involved. We used the rat model of collagenase-induced ICH to determine whether HMGB1 acts via the receptor for advanced glycation end-products (RAGE) to upregulate vascular endothelial growth factor (VEGF), a potent mitogen of endothelial cells and key regulator of normal and abnormal angiogenesis in the late phase of injury. At 3d after ICH induction, rats were treated with saline, ethyl pyruvate (EP) or N-benzyl-4-chloro-N-cyclohexylbenzamide (FPS-ZM1). ICH induced the movement of HMGB1 from the nucleus into the cytoplasm. Levels of HMGB1 and RAGE in the ipsilateral striatum increased within a few days of induction and continued to rise for 7-14d afterward. By 14d after induction, levels of VEGF and vessel density were higher than in the Sham group. Administering EP 3 days after ICH induction prevented much of the stroke-induced increases in vessel density and in expression of HMGB1, RAGE, and VEGF. Administering FPS-ZM1 after ICH blocked much of the stroke-induced increases in vessel density and VEGF expression. Our results suggest that after ICH, HMGB1 may upregulate VEGF in the ipsilateral striatum predominantly via RAGE. Hence, targeting the HMGB1/RAGE signaling pathway may help reduce inappropriate angiogenesis after ICH.

Effects of cyclopamine on the biological characteristics of human breast cancer MCF-7 cell line and its mechanism

PURPOSE

To observe the effects of cyclopamine on the biological characteristics of human breast cancer MCF-7 cell line and explore its mechanism.

MATERIALS AND METHODS

After human breast cancer MCF-7 cells were treated with different-concentration cyclopamine for different periods, MTT assay was used to detect the inhibitory effect of cyclopamine on MCF-7 cell proliferation, flow cytometry was used to determine the distribution of MCF-7 cell cycle and the effect of cyclopamine on MCF-7 apoptosis, and Western blot was used to measure the protein levels of cyclins D1 and p21 in MCF-7 cells.

RESULTS

In certain range, MCF-7 cell proliferation was inhibited by cyclopamine in a dose- and time-dependent manner, and the optimal inhibiting concentration was ten µmol/L and the optimal action time at 48 hours. With the time prolongation of cyclopamine action, the cells in G0/G1 phase were significantly increased, but the cells in S phase were significantly decreased (compared with blank control group, allp < 0.05). With the time prolongation of cyclopamine action, apoptosis rate of MCF-7 cells was also significantly increased (compared with blank control group, allp < 0.05). The level of cyclin D1 of MCF-7 cells was decreased, but cyclin p21 was increased (compared with blank control group, all p < 0.05).

CONCLUSION

Cyclopamine inhibits MCF-7 cell proliferation via arresting MCF-7 cell transformation from G1 phase to S phase. This may be associated with the expressions of Hedgehog (Hh) signaling pathway-related cyclins.