Analysis of the expression and significance of lymphocyte ratio in different stages and clinical types of COVID-19

This study aimed to analyze the expression of lymphocyte ratio (LY%) in different stages and clinical staging of COVID-19 and explore the relationship between peripheral blood lymphocyte (PBL) ratio and COVID-19 severity to provide reference for early intervention. For this purpose, a total of 125 patients with COVID-19 admitted to Hebei Provincial People's Hospital from February 1, 2020, to March 1, 2022, were reviewed and divided into moderate, severe, and critical groups by the severity to analyze and compare peripheral lymphocyte ratios of patients with different clinical typing. Results showed that lymphocyte count, lymphocyte percentage, CD3+ T-lymphocyte count, CD4+ T-lymphocyte count, and CD8+ T-lymphocyte count all decreased gradually with increasing severity (F = 27.84, P<0.05; F = 15.28, P<0.05; F = 46.12, P<0.05; F = 34.65, P<0.05); the absolute numbers of CD3+, CD4+ and CD8+ cells in peripheral blood were higher in the recovery phase than in the acute phase (P<0.05). In conclusion, COVID-19 may cause a decrease in the number of lymphocytes, and the decrease in the number of lymphocytes and T-lymphocyte subsets may predict the severity of the disease. The fewer lymphocytes there are, the more likely they are to progress to the severe type and the worse the prognosis.

Radiation Induced Lung Injury in Rats after Pre-Oxygenation Radiotherapy

PURPOSE/OBJECTIVE(S)

Deep inspiratory breath holding (DIBH) has been widely used during the radiotherapy of thoracic tumors. The main disadvantage of voluntary DIBH is the short duration of each breath hold. The hypocapnia induced by hyperoxia (oxygen concentration > 50%) pre-oxygenation (PreO2) combined with mechanical hyperventilation has been reported to prolong the duration of single breath hold, but its safety remains controversial, especially the sensitivity of lung tissue to radiation damage under hyperoxia exposure has not been elucidated. In this study, we aim to investigate the changes of radiation induced lung injury in rats after PreO2 radiation.

MATERIALS/METHODS

We evaluated the lung tissue of rats at different time points (48h, 2w, 4w, 8w, 12w) after thoracic radiation (15Gy single fraction to the right lung), and sequenced the transcriptome of lung tissue at 48 hours after irradiation. Rat cohorts (n = 7/group): 1. Control (Con); 2. Radiation group (RT); 3. Pre-oxygenation (oxygen concentration > 90%) for 8 hours before thoracic radiation (PreO2).

RESULTS

The inflammatory exudation emerged in the pulmonary interstitium at 48 hours, and reached the most serious alveolitis after four weeks of irradiation (the comparison of alveolitis scores in RT4w vs Con4w and PreO2(4w) vs Con4w, P<0.001) on hematoxylin-eosin staining. While the alveolitis scores in RT group and PreO2 group were not statistically different at each time point. Masson staining showed that the pulmonary fibrosis in the RT group and the PreO2 group reached an obvious pathological change at 12 weeks after irradiation, but the difference between the two groups was not significant. Transcriptome sequencing showed that the number of differential genes in PreO2 vs Con was 559 (302 up-regulated genes and 257 down-regulated genes). The GO enrichment analysis indicated that chromosome segregation was the most significant functional item with P value in the comparative analysis, and the KEGG enrichment analysis suggested that cell division was the most significant enrichment pathway of these differential genes. While there was a small quantity of differential genes in PreO2 vs RT group (3 up-regulated genes and 12 down-regulated genes). Pentose and glucuronate conversions were the most significant enrichment pathway of these differential genes.

CONCLUSION

This study demonstrated that PreO2 radiotherapy did not increase the severity of radiation induced lung injury in rats compared to conventional radiotherapy. Further study should be conducted to confirm these results and to investigate the regulatory mechanism of pneumonia caused by PreO2 radiotherapy.

Deep Learning-Based Multi-Modality Segmentation of Primary Gross Tumor Volume in CT and MRI for Nasopharyngeal Carcinoma

PURPOSE/OBJECTIVE(S)

The delineation of primary gross tumor volume (GTV) of nasopharyngeal carcinoma (NPC) is an essential step for radiotherapy planning. In clinical practice, radiation oncologists manually delineate the GTV in planning CT with the help of diagnostic MRI. This is because NPC tumors are closely adjacent to many important anatomic structures, and CT and MRI provide complementary strength to accurately determine the tumor extension boundary. Manual delineation is time-consuming with the potential registration errors between MRI and CT decreasing the delineation accuracy. In this study, we propose a fully automated GTV segmentation method based on CT and MRI by first aligning MRI to CT, and then, segmenting the GTV using a multi-modality deep learning model.

MATERIALS/METHODS

We collected 104 nasopharyngeal carcinoma patients with both planning CT and diagnostic MRI scans (T1 & T2 phases). An experienced radiation oncologists manually delineated the GTV, which was further examined by another senior radiation oncologist. Then, a coarse to fine cross-modality registration from MRI to CT was conducted as follows: (1) A rigid transformation was performed on MRI to roughly align MRI to CT with similar anatomic position. (2) Then, the region of interest (RoI) on both CT and rigid-transformed MRI were cropped. (3) A leading cross-modality deformable registration algorithm, named DEEDS, was applied on the cropped MRI and CT RoIs to find an accurate local alignment. Next, using CT and registered MRI as the combined input, a multi-modality deep segmentation network based on nnUNet was trained to generate the GTV prediction. 20% patients were randomly selected as the unseen testing set to quantitatively evaluate the performance.

RESULTS

The quantitative NPC GTV segmentation performance is summarized in Table 1. The deep segmentation model using CT alone achieved reasonable high performance with 76.6% Dice score and 1.34mm average surface distance (ASD). When both CT and registered MRI were used, the segmentation model further improved the performance by 0.9% Dice score increase and 11% relative ASD error reduction, demonstrating the complementary strength of CT and MRI in determining NPC GTV. Notably, the achieved 77.5% Dice score and 1.19mm ASD by the multimodality model is among the top performing results reported in recent automatic NPC GTV segmentation using either CT or MRI modality.

CONCLUSION

We developed a fully automated multi-modal deep-learning model for NPC GTV segmentation. The developed model can segment the NPC GTV in high accuracy. With further optimization and validation, this automated model has potential to standardize the NPC GTV segmentation and significantly decrease the workload of radiation oncologists in clinical practice.

Invasive fungal infection is associated with antibiotic exposure in preterm infants: a multi-centre prospective case-control study

BACKGROUND

Previous antibiotic exposure is an important risk factor for invasive fungal infection (IFI). Antibiotic overexposure is common in lower-income countries; however, multi-centre studies concerning IFI in relation to antibiotic exposure are scarce.

AIM

This prospective, multi-centre matched case-control study explored the correlation of IFI and antibiotic exposure in very preterm infants or very-low-birthweight infants admitted to 23 tertiary hospitals in China between 2018 and 2021.

METHODS

Using a 1:2 matched design for gestational age, birth weight and early-onset sepsis (yes/no), the risk factors between infants diagnosed with IFI and infection-free controls were compared. The antibiotic use rate (AUR) was calculated using calendar days of antibiotic therapy in the 4 weeks preceding IFI onset divided by onset day of IFI.

FINDINGS

In total, 6368 infants were included in the study, of which 90 (1.4%) were diagnosed with IFI. Median AUR, length of antibiotic therapy (LOT) and days of antibiotic therapy (DOT) within the 4 weeks preceding IFI onset were 0.90, 18 days and 30 days, respectively. Multi-variate analysis showed that a 10% increase in AUR, each additional day of DOT and LOT, and each additional day of third-generation cephalosporins and carbapenems were notably associated with IFI.

CONCLUSION

Prolonged antibiotic therapy is common before the onset of IFI, and is an important risk factor, especially the use of third-generation cephalosporins and carbapenems. Antibiotic stewardship should be urgently developed and promoted for preterm infants in order to reduce IFI in lower-income countries such as China.

[Cytotoxic effect of photodynamic liposome gel combined with trastuzumab on drugresistant breast cancer cells in vitro]

OBJECTIVE

To evaluate the cytotoxic effect of photodynamic therapy (PDT) combined with targeted therapy using cross-linked liposomes and gels (Ce6-PC-Tmab@A-Gel) loaded with photosensitizer Chlorin (Ce6) and the tumor-targeting drug Trastuzumab (Tmab) in drug-resistant HER2+ breast cancer cells.

OBJECTIVE

Ce6-PC-Tmab liposomes were prepared using the thin-film hydration method. The general properties, encapsulation efficiency and near-infrared responsivity of the nanoparticles were evaluated. Ce6-PC-Tmab@A-Gel with a shear response was prepared by freeze drying and stirring crosslinking, and its microstructure was observed with scanning electron microscopy (SEM) and the shear response evaluated using a rheometer. The inhibitory effect of Ce6-PC-Tmab@A-Gel in drug-resistant HER2⁺ breast cancer SK-BR-3 cells was assessed with cytotoxicity assay (MTT assay) combined with near-infrared light.

OBJECTIVE

The particle size of Ce6-PC-Tmab was 239.7±9.7 nm and the potential was -2.03±0.09 mV. The entrapment efficiency of Tmab by Ce6-PC-Tmab liposomes was (40.22± 0.73)%. The prepared Ce6-PC-Tmab@A-Gel had a good shear response with excellent drug release characteristics under nearinfrared light, and increased intensity and duration of near-infrared light exposure enhanced Tmab release from the gel. Ce6-PC-Tmab@A-Gel was stable at room temperature and in a simulated tumor microenvironment (pH 6.25). Cytotoxicity assay (MTT) showed that Ce6-PC-Tmab@A-Gel combined with near-infrared light resulted in a survival rate of (31.37±1.73)% in SKBR-3 cells, much lower than that in the control group and other treatment groups (P < 0.01); the combined treatment also had a high efficiency of ROS production, and ROS release reached (22.36 ± 0.11)% after 2 min of near-infrared light exposure.

OBJECTIVE

The prepared Ce6-PC-Tmab@A-Gel has good near-infrared light response release characteristics to ensure effective targeted therapy with Tmab. The injectable gel system potentially allows long-term local drug release in the tumor to improve the treatment efficacy against drug-resistant breast cancer.

3,4-Methylenedioxymethamphetamine causes retinal damage in C57BL/6J mice

3,4-Methylenedioxymethamphetamine (MDMA) is a powerfully addictive psychostimulant with pronounced effects on the central nervous system, but the precise mechanism of MDMA-induced toxicity remains unclear, specifically on the retina. This study was performed to investigate the effects of MDMA treatment on the retina and explore the underlying mechanism. C57BL/6J mice were randomly divided into control and MDMA groups. Mice were treated with MDMA at progressively increasing doses (1-6 mg/kg) intraperitoneally 4 times per day. Electroretinography was used to test the retinal function. Pathological changes of the retina were examined by toluidine blue staining and terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick end labeling assay. Enzyme-linked immunosorbent assays were used to measure the levels of cytokines in the retina. Real-time polymerase chain reaction and Western blot were used to measure gene and protein expression in the retina, respectively. Our study showed that MDMA treatment impaired retinal function and decreased retinal thickness. MDMA treatment also increased transforming growth factor β as well as inflammatory factors in the retina. Moreover, MDMA treatment increased protein expression of matrix metalloproteinases (MMPs) and decreased tight junction protein expression in the retina. Our study indicated that treatment of MDMA caused retinal damage in C57BL/6J mice, associated with an increase of MMPs and a decrease of tight junction proteins.

THU0226 MESENCHYMAL STEM CELL TRANSPLANTATION AMELIORATES EXPERIMENTAL SJÖGREN’S SYNDROME BY DOWNREGUALTING MDSCS VIA COX2/PGE2 PATHWAY

Background:

Although mesenchymal stem cells (MSCs) transplantation have been demonstrated to be an effective therapeutic approach to treat experimental Sjögren’s syndrome (ESS)1, the specific underlying mechanisms remain to be elucidated. Myeloid-derived suppressor cells (MDSCs) were significantly increased with decreased suppressive capacity during disease development in ESS2-3. However, the therapeutic effects and mechanisms by which MSCs regulating MDSCs in SS still remain unknown.

Objectives:

Here we aim to explore whether regulation of MDSCs was responsible for the beneficial effects of MSC transplantation on SS.

Methods:

The MSCs were infused intonon-obese diabetic (NOD) mice via the tail vein. The histological features of submandibular glands, lung, saliva flow rate were evaluated. The number and immune-suppressive activity of MDSCs, the subsets of MDSCs, polymorphonuclear MDSCs (PMN-MDSCs) and monocytic-MDSCs (M-MDSCs) in NOD mice were determined. The bone marrow cells under MDSCs differentiation conditions were co-cultured with or without MSCs. The COX2 inhibitor NS-398, anti-TGF-β1, or anti-IFN-β antibodies were added to coculture medium of MSCs and MDSCs induced from bone marrow cells respectively.

Results:

We found that MDSCs in bone marrow and peripheral blood increased in ESS mice. MSC transplantation ameliorated SS-like syndrome and down-regulated the percentages of MDSCs, PMN-MDSCs and M-MDSCs and promoted their suppressive ability in ESS mice significantly (Figure 1). In vitro, MSCs could down-regulate the differentiation and up-regulate the suppressive ability of MDSCs. Mechanistically, MSCs inhibited the differentiation of MDSCs and PMN-MDSCs via secreting prostaglandin E2, and inhibited the differentiation of M-MDSCs by secreting interferon-β (Figure 2).

Figure 1.

MSCs ameliorated SS symptoms and decreased MDSCs in NOD mice.

Figure 2.

MSCs inhibited the differentiation of PMN-MDSCs and M-MDSCs by COX2/PGE2 and IFN-β respectively.

Conclusion:

Our findings suggested that MSCs alleviated SS-like symptoms by suppressing the aberrant accumulation and improving the suppressive function of MDSCs in ESS mice via COX2/PGE2 pathway.

References:

[1]Shi B, Qi J, Yao G, et al. Mesenchymal stem cell transplantation ameliorates Sjögren’s syndrome via suppressing IL-12 production by dendritic cells. Stem Cell Res Ther, 2018; 9(1):308.

[2]Qi J, Li D, Shi G, et al. Myeloid-derived suppressor cells exacerbates Sjögren’s syndrome by inhibiting Th2 immune responses. Mol Immunol, 2018; 101:251-258.

[3]Tian J, Rui K, Hong Y, et al. Increased GITRL impairs the function of myeloid-derived suppressor cells and exacerbates primary Sjögren’s syndrome. J Immunol, 2019; 202(6):1693-1703.

Disclosure of Interests:

None declared

DR10601, a novel recombinant long-acting dual glucagon-like peptide-1 and glucagon receptor agonist for the treatment of obesity and type 2 diabetes mellitus

PURPOSE

Both glucagon-like peptide-1 (GLP-1) and glucagon (GCG) belong to the incretin family. This study aimed to investigate the pharmacokinetics and pharmacodynamics of DR10601, a fully recombinant hybrid peptide with dual GLP-1/GCG receptor agonistic activity.

METHODS

The agonistic ability of DR10601 was indirectly assessed by inducing cAMP accumulation in Chinese hamster ovary cells transfected with GLP-1R or GCGR in vitro. Following s.c. administration, the plasma pharmacokinetics of DR10601 were analysed in male Sprague-Dawley rats. The antiobesity effects and improved glycaemic control of DR10601 in vivo were evaluated by administering DR10601 to high-fat DIO mice and ICR mice as a single dose or repeated s.c. doses once every 4 days for 24 days.

RESULTS

DR10601 exhibits dual agonistic activity on GLP-1 and glucagon receptors. The plasma half-life of DR10601 in Sprague-Dawley rats following s.c. administration was 51.9 ± 12.2 h. In an IPGTT, a single s.c. dose of DR10601 (30 nmol/kg) produced similar glycaemic control effects and a longer duration of action compared to dulaglutide (10 nmol/kg). Compared with that achieved with liraglutide (40 nmol/kg) s.c. administered daily, DR10601 administered s.c. once every 4 days at 90 nmol/kg exerted a nearly equivalent effect on food intake and significantly reduced the body weights of high-fat DIO mice at 24 days.

CONCLUSIONS

Repeated administration of DR1060 provides potent and sustained glycemic control and body weight loss effect in high-fat DIO mice. DR10601 is a promising long-acting agent deserving further investigation for the treatment of type 2 diabetes and obesity.

[An RNA Scoring Function for Tertiary Structure Prediction Based on Multi-layer Neural Networks]

A good scoring function is necessary for ab inito prediction of RNA tertiary structures. In this study, we explored the power of a machine learning based approach as a scoring function. Compared with the traditional scoring functions, the present approach is more flexible in incorporating different kinds of features; it is also free of the difficult problem of choosing the reference state. Two multi-layer neural networks were constructed and trained. They took RNA a structural candidate as input and then output its likeness score that evaluates the likeness of the candidate to the native structure. The first network was working at the coarse-grained level of RNA structures, while the second at the all-atom level. We also built an RNA database and split it into the training, validation, and testing sets, containing 322, 70, and 70 RNAs, respectively. Each RNA was accompanied with 300 decoys generated by high-temperature molecular dynamics simulations. The networks were trained on the training set and then optimized with an early-stop strategy, based on the loss of the validation set. We then tested the performance of the networks on the testing set. The results were found to be consistently better than a recent knowledge-based all-atom potential.

Heart structural remodeling in a mouse model of Duchenne cardiomyopathy revealed using optical polarization tractography [Invited]

We investigated the heart structural remodeling in the mdx4cv mouse model of Duchenne cardiomyopathy using optical polarization tractography. Whole heart tractography was obtained in freshly dissected hearts from six mdx4cv mice. Six hearts from C57BL/6J mice were also imaged as the normal control. The mdx4cv hearts were significantly larger than the control hearts and had significantly higher between-subject variations in myofiber organization. While both strains showed classic cross-helical fiber organization in the left ventricle, the rate of the myocardial fiber orientation change across the heart wall was significantly altered in the right ventricle of the mdx4cv heart.

Mapping 3D fiber orientation in tissue using dual-angle optical polarization tractography

Optical polarization tractography (OPT) has recently been applied to map fiber organization in the heart, skeletal muscle, and arterial vessel wall with high resolution. The fiber orientation measured in OPT represents the 2D projected fiber angle in a plane that is perpendicular to the incident light. We report here a dual-angle extension of the OPT technology to measure the actual 3D fiber orientation in tissue. This method was first verified by imaging the murine extensor digitorum muscle placed at various known orientations in space. The accuracy of the method was further studied by analyzing the 3D fiber orientation of the mouse tibialis anterior muscle. Finally we showed that dual-angle OPT successfully revealed the unique 3D "arcade" fiber structure in the bovine articular cartilage.

Time to positivity of blood culture and its prognostic value in bloodstream infection

The purpose of this study was to investigate the relationship between the time to positivity (TTP) of blood cultures and outcome in patients with bloodstream infections (BSIs). Between January 1st, 2011 and December 31st, 2013, the blood cultures of inpatients with BSI or catheter-related BSI were collected at Peking University Third Hospital. The TTP of different isolates was analyzed, and the relationship between the TTP of isolates and outcome of patients with Enterobacter BSI was retrospectively analyzed. We analyzed the TTP of 886 isolates. Escherichia coli has the shortest (11.97 ± 10.06 h) and Candida has the longest first TTP (61.62 ± 42.77 h). 68.01 % of isolates reached positivity within 24 h and 88.33 % within 48 h. Over 90 % of E. coli isolates reached positivity within 24 h. Over 50 % of Candida isolates reached positivity within 48 h. The TTP differed significantly between cultures that were single or double positive for coagulase-negative staphylococci isolates, Enterobacteriaceae, and Pseudomonas aeruginosa, and between aerobic and anaerobic cultures of E. coli (p < 0.05). However, the TTP did not differ significantly between coagulase-negative staphylococci (double positivity) and Staphylococcus aureus. The best TTP threshold for prediction of mortality from Enterobacter species BSI was 16.3 h [area under the curve (AUC) 0.730, 95 % confidence interval (CI) 0.557, 0.864, sensitivity 100 %, specificity 44.4 %]. The TTP of clinical isolates may represent a valuable marker of the clinical significance of BSIs. Laboratories and clinics should consider using the TTP to predict the prognosis of patients with BSI by bacteria, including Enterobacter and other species.

Insulinotropic action of bombesin-like peptides mediated by gastrin-releasing peptide receptors in steers

The present study characterizes the receptor that mediates the insulinotropic action of bombesin-like peptides (BLP) in ruminants. Eight Holstein steers were randomly and intravenously injected with synthetic bovine gastrin-releasing peptide (GRP; 0.9 nmol/kg BW), neuromedin B (NMB; 0.9 nmol/kg BW), or neuromedin C (NMC; 0.9 nmol/kg BW), each alone or combined with the antagonist of GRP receptors N-acetyl-GRP-OCHCH (N-GRP-EE; 22.5 nmol/kg BW) or the antagonist of GH secretagogue receptor type 1a (GHS-R1a) [D-Lys]-GHRP-6 (21.5 nmol/kg BW). Blood samples were collected at -10, 0 (just before injection), 5, 10, 15, 20, 30, 45, 60, 75, and 90 min relative to injection time. Levels of injected peptides, insulin, and glucose in plasma were analyzed. Results showed that the peak of insulin levels was seen at 5 min after injection of NMC or GRP. Plasma glucose was observed in 2 phases; a significant rise followed a remarkable fall after NMC or GRP administration compared with injection of the vehicle ( < 0.05). On a same molar basis, effects of GRP on insulin and glucose were more potent than those of NMC ( < 0.05). The NMC-induced changes of insulin and glucose were completely blocked by N-GRP-EE, but [D-Lys]-GHRP-6 did not block any of these changes. Administration of NMB or N-GRP-EE alone did not change the circulating levels of insulin or glucose during any of the sampling time points ( > 0.05). These results indicated that the insulinotropic action of BLP is mediated by GRP receptors but not through a ghrelin/GHS-R1a pathway and that BLP may be involved in the regulation of glucose homeostasis in ruminants.

Routine screening for pain combined with a pain treatment protocol in head and neck cancer: a randomised controlled trial

BACKGROUND

We compared the effectiveness and cost of a pain screening and treatment program, with usual care in head and neck cancer patients with significant pain.

METHODS

Patients were screened for the presence of pain and then randomly assigned to either an intervention group, consisting of a pain treatment protocol and an education program, or to usual care. Primary outcome was change in the Pain Severity Index (PSI) over three months.

RESULTS

We screened 1074 patients of whom 156 were randomized to either intervention or usual care. Mean PSI was reduced over three months in both groups, with no significant difference between the two groups. The Pain Management Index (PMI) at three months, was significantly improved in the intervention group compared with usual care (P<0.001), as was Patient Satisfaction (mean difference in scores was statistically significant: -0.30 [-0.60 to -0.15]). All subjects reported clinically significant levels of anxiety and depression throughout the study. Treatment costs were significantly higher for intervention (mean=£400) compared with usual care (£200), with a low likelihood of being cost-effective.

CONCLUSIONS

There was no difference in the Pain Severity Index between the two groups. However there were significant improvements in the intervention group in patient satisfaction and PMI. The pain screening process itself was effective. Sufficient benefit was demonstrated as a result of the intervention to allow continued development of pain treatment pathways, rather than allowing pain treatment to be left to nonformalised ad hoc arrangements.

Riluzole promotes motor and respiratory recovery associated with enhanced neuronal survival and function following high cervical spinal hemisection

Cervical spinal cord injury (SCI) can result in devastating functional deficits that involve the respiratory and hand function. The mammalian spinal cord has limited ability to regenerate and restore meaningful functional recovery following SCI. Riluzole, 2-amino-6-trifluoromethoxybenzothiazole, an anti-glutamatergic drug has been shown to reduce excitotoxicity and confer neuroprotection at the site of injury following experimental SCI. Based on promising preclinical studies, riluzole is currently under Phase III clinical trial for the treatment of SCI (ClinicalTrials.gov: NCT01597518). Riluzole's anti-glutamatergic role has the potential to regulate neuronal function and provide neuroprotection and influence glutamatergic connections distal to the initial injury leading to enhanced functional recovery following SCI. In order to investigate this novel role of riluzole we used a high cervical hemisection model of SCI, which interrupts all descending input to motoneurons innervating the ipsilateral forelimb and diaphragm muscles. Following C2 spinal cord hemisection, animals were placed into one of two groups: one group received riluzole (8 mg/kg) 1 h after injury and every 12 h thereafter for 7 days at 6 mg/kg, while the second group of injured rats received vehicle solution for the same duration of time. A third group of sham injured rats underwent a C2 laminectomy without hemisection and served as uninjured control rats. Interestingly, this study reports a significant loss of motoneurons within the cervical spinal cord caudal to C2 hemisection injury. Disruption of descending input led to a decrease in glutamatergic synapses and motoneurons caudal to the injury while riluzole treatment significantly limited this decline. Functionally, Hoffmann reflex recordings revealed an increase in the excitability of the remaining ipsilateral cervical motoneurons and significant improvements in skilled and unskilled forelimb function and respiratory motor function in the riluzole-treated animals. In conclusion, using a C2 hemisection injury model, this study provides novel evidence of motoneuron loss caudal to the injury and supports riluzole's capacity to promote neuronal preservation and function of neural network caudal to the SCI resulting in early and sustained functional improvements.

Association between pupillary light reflex and sensory behaviors in children with autism spectrum disorders

Atypical pupillary light reflexes (PLR) has been observed in children with autism spectrum disorders (ASD), which suggests potential autonomic nervous system (ANS) dysfunction in ASD. ANS is also involved in modulating sensory processing and sensory dysfunction has been widely reported in children with ASD. However, the potential association between physiological measurements of PLR and behavioral observations (e.g. sensory behaviors) has not been examined extensively in literature. In this study, we investigated the potential correlation between PLR and frequently observed sensory behaviors in children with ASD. We found a significant association between PLR constriction amplitude and a set of sensory behaviors in the ASD group but not in typically developing children. Children with ASD who showed more atypical sensory behaviors also had smaller PLR constriction amplitudes. A smaller PLR constriction amplitude suggests lower parasympathetic modulation. This observation implies that some atypical sensory behaviors in children with ASD could be associated with decreased parasympathetic modulation.

Optical polarization tractography revealed significant fiber disarray in skeletal muscles of a mouse model for Duchenne muscular dystrophy

Optical polarization tractography (OPT) was recently developed to visualize tissue fiber architecture with cellular-level resolution and accuracy. In this study, we explored the feasibility of using OPT to study muscle disease in the mdx4cv mouse model of Duchenne muscular dystrophy. The freshly dissected tibialis anterior muscles of mdx4cv and normal mice were imaged. A "fiber disarray index" (FDI) was developed to quantify the myofiber disorganization. In necrotic muscle regions of the mdx4cv mice, the FDI was significantly elevated and can be used to segment the 3D necrotic regions for assessing the overall muscle damage. These results demonstrated the OPT's capability for imaging microscopic fiber alternations in muscle research.

Chemical and mechanical strains tuned dielectric properties in Zr-doped CaCu3Ti4O12 highly epitaxial thin films

The dielectric properties of CaCu₃Ti₄O₁₂ highly epitaxial thin films were successfully tuned by the in-plane strain.

Histology validation of mapping depth-resolved cardiac fiber orientation in fresh mouse heart using optical polarization tractography

Myofiber organization in cardiac muscle plays an important role in achieving normal mechanical and electrical heart functions. An imaging tool that can reveal microstructural details of myofiber organization is valuable for both basic research and clinical applications. A high-resolution optical polarization tractography (OPT) was recently developed based on Jones matrix optical coherence tomography (JMOCT). In this study, we validated the accuracy of using OPT for measuring depth-resolved fiber orientation in fresh heart samples by comparing directly with histology images. Systematic image processing algorithms were developed to register OPT with histology images. The pixel-wise differences between the two tractographic results were analyzed in details. The results indicate that OPT can accurately image depth-resolved fiber orientation in fresh heart tissues and reveal microstructural details at the histological level.

The effect of Astragalus polysaccharide on the Epstein-Barr virus lytic cycle

Effects of a polysacharide from Chinese herbal plant Astragalus membranaceus (APS) on the expression of Epstein-Barr virus (EBV) immediate early proteins Zta, Rta and EA-D in Raji cells were examined. EBV switch from latent to lytic cycle in Raji cells was induced by 12-O-tetradecanoylphorbol-13-acetate (TPA) and sorbol butyrate (SB) and the effects of APS were examined by immunofluorescence, western blotting and flow cytometry. APS in a non-cytotoxic concentration of 30 μg/ml significantly suppressed the expression of Zta, Rta and EA-D during the EBV lytic cycle. Our observations indicate that APS is potentially useful as an anti-EBV drug.

Knockdown of neuropilin-1 suppresses invasion, angiogenesis, and increases the chemosensitivity to doxorubicin in osteosarcoma cells - an in vitro study

OBJECTIVES

Neuropilin-1 (NRP-1) is a novel co-receptor for vascular endothelial growth factor (VEGF). NRP-1 expression in osteosarcoma tissues was significantly higher, and high NRP-1 expression was more frequently occurred in osteosarcoma tissues with advanced clinical stage, positive distant metastasis and poor response to chemotherapy. We tested a hypothesis that the NRP-1 gene plays a role in the invasiveness, angiogenesis and chemoresistance of human OS.

MATERIALS AND METHODS

To determine the role of NRP-1 in OS, NRP-1 was stably transfected into the human OS cell line MG-63 to increase the NPR-1 level, and NRP-1 siRNA was stably transfected into the human OS cell line SaOS-2 to knockdown of NRP-1. The effect of NRP-1 on invasion and angiogenesis was assessed by Matrigel invasion assay and in vitro angiogenesis assay. Chemosensitivity to doxorubicin was assessed by MTT assay in the MG-63 and SaOS-2 cells following NRP-1 overexpression or siRNA-induced downregulation of NRP-1.

RESULTS

The NRP-1 transfected MG-63 cells showed a markedly higher level of invasion in Matrigel invasion assay. The capillary-like structure formation of endothelial cells was also increased by coculture with the NRP-1 transfected MG-63 cells. On the contrary, the NRP-1 siRNA transfected SaOS-2 cells showed a markedly lower level of invasion in Matrigel invasion assay. The capillary-like structure formation of endothelial cells was also repressed by coculture with the NRP-1 siRNA transfected SaOS-2 cells. NRP-1 overexpression in MG-63 cells increased survival of cells after exposure to doxorubicin. In contrast, downregulation of NRP-1 expression in SaOS-2 cells markedly increased chemosensitivity after exposure to doxorubicin.

CONCLUSIONS

We suggest that NRP-1 could be used as a biomarker for OS progression and a novel therapeutic or chemopreventive target for human OS treatment.

The importance of amino acid interactions in the crystallization of hydroxyapatite

Non-collagenous proteins (NCPs) inhibit hydroxyapatite (HA; Ca(5)(PO(4))(3)OH) formation in living organisms by binding to nascent nuclei of HA and preventing their further growth. Polar and charged amino acids (AAs) are highly expressed in NCPs, and the negatively charged ones, such as glutamic acid (Glu) and phosphoserine (P-Ser) seem to be mainly responsible for the inhibitory effect of NCPs. Despite the recognized importance of these AAs on the behaviour of NCPs, their specific effect on HA crystallization is still unclear, and controversial results have been reported concerning the efficacy of HA inhibition of positively versus negatively charged AAs. We focused on a positively charged (arginine, Arg) and a negatively charged (Glu) AA, and their combination in the same solution. We studied their inhibitory effect on HA nucleation and growth at physiological temperature and pH and we determined the mechanism by which they can affect HA crystallization. Our results showed a strong inhibitory effect of Arg on HA nucleation; however, Glu was more effective in inhibiting HA crystal growth during the growth stage. The combination of Glu and Arg was less effective in controlling HA nucleation, but it inhibited HA crystal growth. We attributed these differences to the stability of complexes formed between AAs and calcium and phosphate ions at the nucleation stage, and in bonding strength of AAs to HA crystal faces during the growth stage. The AAs also influenced the morphology of synthesized HA. Presence of either Arg or Glu resulted in the formation of spherulites consisting of preferentially oriented nanoplatelets orientation. This was attributed to kinetic factors favoring growth front nucleation (GFN) mechanism.

Simultaneously measured pupillary light reflex and heart rate variability in healthy children

We investigated the potential inter-relationship between two measures of autonomic nervous system: pupillary light reflex (PLR) and heart rate variability (HRV), in healthy children of 8-16 years old. PLR was measured at both dark- and light-adapted conditions with various stimulation intensities. Simultaneously measured HRV was obtained in five different PLR testing phases: before PLR test, light-adapted PLR test, dark adaptation, dark-adapted PLR test and after PLR test. The frequency domain HRV parameters measured during the PLR test were significantly different from those measured during rest. Both the regression analysis and factor analysis indicated that PLR and HRV parameters were not correlated, which suggests that they may provide complementary assessment of different aspects of the overall autonomic nervous system.

Telomerase inhibition strategies by siRNAs against either hTR or hTERT in oral squamous cell carcinoma

Human telomerase RNA (hTR) and human telomerase reverse transcriptase (hTERT) are considered effective molecular targets for current anticancer therapy. In this study, we investigated the therapeutic effects of targeting hTR and hTERT individually or in combination by recombinant adenovirus-delivered small interfering RNA (siRNA) in oral squamous cell carcinoma (OSCC) Tca8113. Further, we screened the optimal strategy for RNA interference. Our results show that these different recombinant adenoviruses specifically reduced the levels of hTR mRNA, hTERT mRNA, hTERT protein and telomerase activity in Tca8113 cells. Moreover, they successfully inhibited xenograft tumor growth in nude mice. The potency of their antitumor activities was ranked as follows: anti-hTR >anti-hTR+anti-hTERT >anti-hTERT. Therefore, we demonstrated that the siRNA-expressing recombinant adenoviruses were an effective anticancer tool for treatment of OSCC. Furthermore, the anticancer effect of solely targeting hTR was more direct and efficient, compared with the effect of targeting hTR and hTERT in combination, or hTERT exclusively. The mechanism of this anticancer effect in OSCC was not only related to the inhibition of cell proliferation and the induction of cell apoptosis, but might also involve the inhibition of tumor angiogenesis.

Transplantation of umbilical cord mesenchymal stem cells alleviates lupus nephritis in MRL/lpr mice

Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease, which, despite the advances in immunosuppressive medical therapies, remains potentially fatal in some patients, especially in treatment-refractory patients. This study found that transplantation of umbilical cord mesenchymal stem cells (UC-MSCs) has the same therapeutic effect as transplantation of bone marrow mesenchymal stem cells (BM-MSCs), which has been reported to be efficient in treating SLE-related symptoms in MRL/lpr mice. Multi-treatment (at the 18th, 19th, and 20th weeks of age) of 1 × 10(6) UC-MSCs was able to decrease the levels of 24-h proteinuria, serum creatinine, and anti-double-stranded DNA (dsDNA) antibody, and the extent of renal injury such as crescent formation in MRL/lpr mice. A lower, but still significant, reduction in these parameters was also observed in mice receiving a single dose of UC-MSCs (at the 18th week). UC-MSCs treatment also inhibited expression of monocyte chemotactic protein-1 (MCP-1) and high-mobility group box 1 (HMGB-1) expression in a similar fashion. UC-MSCs labeled with carboxyfluorescein diacetate succinimidyl ester (CFSE) were found in the lungs and kidneys 1 week post infusion. In addition, after 11 weeks post UC-MSCs infusion, human cells were found in kidney of UC-MSCs-treated mice. These findings indicated that UC-MSCs transplantation might be a potentially promising approach in the treatment of lupus nephritis, possibly by inhibiting MCP-1 and HMGB-1 production.