Endosome Escape Strategies for Improving the Efficacy of Oligonucleotide Delivery Systems

Gene therapy requires safe and effective vectors to deliver genes to their target site of action. Non-viral gene delivery systems have attracted growing attention due to their low toxicity, low immunogenicity and ease of production compared to viral vectors. Most non-viral gene delivery systems enter cells via endocytic pathways, and their escape from endosomes is therefore crucial for successful transfection. Several reagents have been developed to promote endosomal escape, including peptides, polymers and lipids. Among these, endosome-disrupting peptides have been used in many studies, and have proven to be one of the most promising approaches to overcome endosomal entrapment and lysosomal degradation. This review provides an up-to-date summary of strategies for enhancing endosomal escape, with a focus on the modification of endosome-disrupting peptides to further increase the efficient delivery of oligonucleotides.

[Clinical and genetic features of dyskeratosis congenital with bone marrow failure in eight patients]

目的

加深对先天性角化不良（dyskeratosis congenital，DC）伴骨髓衰竭的认识。

方法

收集2010年9月30日至2015年9月30日8例伴骨髓衰竭DC患儿的临床资料，利用二代测序技术对DKC1、TERC、TERT、NOP10、NHP2、TINF2等16种端粒相关基因进行全外显子及剪接位点测序分析。

结果

8例DC患儿中男6例、女2例，中位发病月龄为42(15~60）个月。初诊血常规：中位WBC 3.99（1.26~5.44）×10⁹/L，中位中性粒细胞计数1.11(0.38~2.15）×10⁹/L，中位RBC 2.45(0.37~3.56）×10¹²/L，中位HGB 82.5(15~127) g/L，中位PLT 27（2~112）×10⁹/L。8例患儿中6例骨髓增生减低或重度减低。3例患儿检出DKC1基因突变：c.961C>A 1例，c.1058C>T 2例；4例患儿检出TINF2基因突变：c.849delC、c.844C>T、c.811C>T、c.862T>A合并c.871delA各1例；1例患儿检出TINF2基因突变（c.848C>A）合并TERT基因突变（c.1138C>T）。其中DKC c.961C>A、TINF2 c.849delC、TINF2 c.871delA突变为首次报道。7例患儿口服雄激素治疗，其中5例血常规指标改善。1例患儿死于重症感染，其余7例患儿维持治疗。

结论

DC伴骨髓衰竭以TINF2突变和DKC1突变为主。雄激素治疗对部分病例有效。

Pre-attentive dysfunction of musical processing in major depressive disorder: A mismatch negativity study

BACKGROUND

Deficits of pre-attentive information processing have been frequently found in patients with major depressive disorder, nevertheless the results are quite inconsistent due to clinical heterogeneity and methodological difference. Cognitive processing of music is a useful tool for investigating human cognition and its underlying brain mechanisms. Although general auditory processing and perception of musical sound are hampered in patients with MDD, whether the deficits in musical processing begin from pre-attentive stage is not well investigated yet. The present study aimed to investigate the MMN of musical sound in patients with MDD.

METHOD

MMN responses to different musical features were compared in 20 patients with MDD and 20 age-matched healthy controls. The multi-feature paradigm was used to examine automatic change detection of six different musical sound features (pitch, timbre, location, intensity, slide, rhythm) in a complex musical context. Severity of depression and co-morbid anxiety were evaluated using the Hamilton Rating Scale of Depression (HRSD-17) and the Hamilton Anxiety Rating Scale (HAMA).

RESULTS

MMNs were obtained with all deviants. The timbre-MMN was significantly larger in MDD patients than in healthy controls, while the other deviants (pitch, location, intensity, slide and rhythm) elicited similar MMN across groups. For MDD patients, the amplitudes and latencies of MMNs did not correlate with severity of depression or co-morbid anxiety.

LIMITATIONS

The sample size in this study is relatively small.

CONCLUSION

Patients with MDD do not perform at the same level as controls in automatic change detection of timbre. This dysfunction is considered to be a trait-dependent feature of MDD.

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

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

Low-Temperature Selective Catalytic Reduction of NO with NH₃ over Mn₂O₃-Doped Fe₂O₃ Hexagonal Microsheets

Mn2O3-doped Fe2O3 hexagonal microsheets were prepared for the low-temperature selective catalytic reduction (SCR) of NO with NH3. These hexagonal microsheets were characterized by SEM, TEM, XRD, BET, XPS, NH3-TPD, H2-TPR, and in situ DRIFT and were shown to exhibit a considerable uniform hexagonal microsheet structure and excellent low temperature SCR efficiency. When doped with different Mn molar ratios, Mn2O3 was detected in the Fe2O3 hexagonal microsheets based on the XRD results without the presence of other MnOX species. In addition, the hexagonal microsheets with a Mn/Fe molar ratio of 0.2 showed the best SCR removal performance among the materials, where a 98% NO conversion ratio at 200 °C at a space velocity of 30,000 h(-1) was obtained. Meanwhile, excellent tolerances to H2O and SO2, as well as high thermal stability, were obtained in Mn2O3-doped Fe2O3 hexagonal microsheets. Moreover, on the basis of the XPS and in situ DRIFT results, it can be suggested that coupled Mn2O3 nanocrystals played a key role at low temperatures and produced a possible redox reaction mechanism in the SCR process.

Long-term association between dairy consumption and risk of childhood obesity: a systematic review and meta-analysis of prospective cohort studies

BACKGROUND/OBJECTIVES

Data from small-scale, short-term, clinical trials suggest a beneficial effect of dairy consumption on the risk of childhood obesity; however, the long-term association is unclear. Therefore, we aim to examine the longitudinal association between dairy consumption and the risk of overweight/obesity in children and adolescents by conducting a systematic review and meta-analysis of prospective cohort studies.

SUBJECTS/METHODS

Eligible studies were identified by searching PubMed and EMBASE through March 2015. Additional studies were retrieved via Google Scholar or a hand review of the reference lists from relevant articles. Pooled associations of interest were estimated by using a random-effects model. The heterogeneity for each pooled analysis was evaluated by I(2) statistic as well as by Cochran's Q test. Publication bias was assessed by using both Egger's and Begg's tests.

RESULTS

Ten studies comprising 46,011 children and adolescents with an average 3-year follow-up were included. As compared with those who were in the lowest group of dairy consumption, children in the highest intake group were 38% less likely to have childhood overweight/obesity (pooled odds ratio (OR)=0.62; 95% confidence interval (CI): 0.49, 0.80). With each 1 serving/day increment in dairy consumption, the percentage of body fat was reduced by 0.65% (β=0.65; 95% CI: -1.35, 0.06; P=0.07), and the risk of overweight/obesity was 13% lower (OR=0.87; 95% CI: 0.74, 0.98).

CONCLUSIONS

Accumulated evidence from prospective cohort studies suggests that dairy consumption is inversely and longitudinally associated with the risk of childhood overweight/obesity. Further studies are warranted to examine the types of dairy products in relation to the risk of childhood overweight/obesity.

Risk of Incident Colorectal Cancer and Death After Colonoscopy: A Population-based Study in Utah

BACKGROUND & AIMS

Colonoscopy is widely recommended for colorectal (CRC) screening in the United States, but evidence of effectiveness is limited. We examined whether exposure to colonoscopy decreases the odds of incident CRC and death from CRC in Utah.

METHODS

We performed a case-control study of Utah residents, 54 to 90 years old, who received a CRC diagnosis from 2000 through 2010 (cases). Age- and sex-matched controls with no history of CRC (controls) were selected for each case. We determined receipt of colonoscopy 6 months to 10 years before the reference date for each case and control through administrative claims data. Colonoscopy exposure was compared by using conditional logistic regression.

RESULTS

We identified 5128 cases and 20,512 controls; 741 cases (14%) and 5715 controls (28%) received a colonoscopy. Exposure to colonoscopy reduced the odds for a diagnosis of CRC; the odds ratios (ORs) were 0.41 for any CRC (95% confidence interval [CI], 0.38-0.44), 0.58 for proximal colon cancer (95% CI, 0.51-0.65), and 0.29 for distal colon or rectal cancer (95% CI, 0.25-0.33). This finding was consistent among sexes, age groups, and cancer stages. Similarly, in a subgroup analysis, colonoscopy was associated with decreased odds of death from CRC (OR, 0.33; 95% CI, 0.28-0.39) in both the proximal colon (OR, 0.43; 95% CI, 0.34-0.55) and distal colon or rectum (OR, 0.23; 95% CI, 0.18-0.30).

CONCLUSIONS

In the population of Utah, colonoscopy is associated with a large reduction in risk of new-onset CRC and death from CRC. This reduction in risk for CRC was greatest for the distal colon and rectum, with a more modest reduction for proximal colon cancer.

Spontaneous renal hemorrhage caused by invasive mole: a case report

CASE

The authors report a case with spontaneous renal hemorrhage caused by invasive mole. The diagnosis was gestational trophoblastic disease (GTD), with metastasis to brain, kidneys, and lungs at Stage IV. The patient was given etoposide-methotrexate-actinomycin D plus cyclophosphamide-vincristine (EMACO) treatment regimen for 11 times including three times with consolidation chemotherapies. Laparoscopically-assisted vaginal hysterectomy (LAVH) + laparoscopic-assisted left renal excision + evacuation of the left perirenal hematoma were performed during the eighth chemotherapy.

CONCLUSION

Post-operational pathological examination revealed trophoblasts within the lesions present in uterine fundus and the residue images of a few trophoblasts present in the left renal mass.

Structure–performance relationships of MnO2 nanocatalyst for the low-temperature SCR removal of NOX under ammonia

To investigate the corresponding relationship between catalytic efficiency and structure, MnO₂ nanomaterials (nanospheres, nanosheets, nanorods) have been prepared successfully, and were thoroughly characterized by SEM and TEM.

Nucleic acid aptamers in cancer research, diagnosis and therapy

Aptamers are single-stranded DNA or RNA oligomers, identified from a random sequence pool, with the ability to form unique and versatile tertiary structures that bind to cognate molecules with superior specificity. Their small size, excellent chemical stability and low immunogenicity enable them to rival antibodies in cancer imaging and therapy applications. Their facile chemical synthesis, versatility in structural design and engineering, and the ability for site-specific modifications with functional moieties make aptamers excellent recognition motifs for cancer biomarker discovery and detection. Moreover, aptamers can be selected or engineered to regulate cancer protein functions, as well as to guide anti-cancer drug design or screening. This review summarizes their applications in cancer, including cancer biomarker discovery and detection, cancer imaging, cancer therapy, and anti-cancer drug discovery. Although relevant applications are relatively new, the significant progress achieved has demonstrated that aptamers can be promising players in cancer research.

Inhibitory effect of liposomal quercetin on acute hepatitis and hepatic fibrosis induced by concanavalin A

Immune response plays an important role in the development of hepatic fibrosis. In the present study, we investigated the effects of quercetin on hepatitis and hepatic fibrosis induced by immunological mechanism. In the acute hepatitis model, quercetin (2.5 mg/kg) was injected iv into mice 30 min after concanavalin A (Con A) challenge. Mice were sacrificed 4 or 24 h after Con A injection, and aminotransferase tests and histopathological sections were performed. Treatment with quercetin significantly decreased the levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Consistent with this observation, treatment with quercetin markedly attenuated the pathologic changes in the liver. A hepatic fibrosis model was also generated in mice by Con A challenge once a week for 6 consecutive weeks. Mice in the experimental group were treated with daily iv injections of quercetin (0.5 mg/kg). Histopathological analyses revealed that treatment with quercetin markedly decreased collagen deposition, pseudolobuli development, and hepatic stellate cells activation. We also examined the effects of quercetin on the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and transforming growth factor beta (TGF-β) pathways by immunohistochemistry and real-time reverse transcriptase-polymerase chain reaction (RT-PCR). NF-κB and TGF-β production was decreased after treatment with quercetin, indicating that the antifibrotic effect of quercetin is associated with its ability to modulate NF-κB and TGF-β production. These results suggest that quercetin may be an effective therapeutic strategy in the treatment of patients with liver damage and fibrosis.

Effect of daily short-duration weight-bearing on disuse-induced deterioration of musculoskeletal system

OBJECTIVES

To investigate deterioration of musculoskeletal system due to prolonged disuse and the potential of daily short-duration weight-bearing as countermeasures.

METHODS

Twenty-four adult male Sprague-Dawley rats were divided into Control Group (CG, no intervention), Tail-suspension Group (TG, tail-suspension without treatment), and Weight-Bearing Group (WBG, tail-suspension with 20 min/day, 5 days/week body weight loading). After four weeks of treatment, femur and tibia, soleus and extensor digitorum longus were evaluated for bone and muscle quality respectively. Tensile properties of bone-tendon insertion (BTI) were evaluated using patella-patellar tendon complex.

RESULTS

Disuse induced deterioration on bone, muscle, and BTI after four weeks. Compared with CG, TG and WBG showed significant decrease in bone mineral density (BMD) of trabecular bone in distal femur (4.3-15.2%), muscle mass (31.3-52.3%), muscle cross-sectional area (29.1-35%), and failure strength of BTI (23.9-29.4%). Tensile test showed that the failure mode was avulsion of bone at the BTI. No significant difference was detected between TG and WBG for all assessments on bone, muscle, and BTI.

CONCLUSIONS

Disuse caused deterioration of bone, muscle, and BTI while daily short-duration of weight-bearing did not prevent this deterioration. Mechanical stimulation with higher intensity and longer duration may be necessary to prevent musculoskeletal deterioration resulted from prolonged disuse.

Expression of Mitochondria-Associated Genes (PPARGC1A, NRF-1, BCL-2 and BAX) in Follicular Development and Atresia of Goat Ovaries

Most follicles undergo atresia during the developmental process. Follicular atresia is predominantly regulated by apoptosis of granulosa cells, but the mechanism underlying apoptosis via the mitochondria-dependent apoptotic pathway is unclear. We aimed to investigate whether the mitochondria-associated genes peroxisome proliferator-activated receptor-gamma, coactivator1-alpha (PPARGC1A), nuclear respiratory factor-1 (NRF-1), B-cell CLL/lymphoma 2 (BCL-2) and BCL2-associated X protein (BAX) played a role in follicular atresia through this pathway. The four mitochondria-associated proteins (PGC-1α, which are encoded by the PPARGC1A gene, NRF-1, BCL-2 and BAX) mainly expressed in granulosa cells. The mRNA and protein levels of PPARGC1A/PGC-1α and NRF-1 in granulosa cells increased with the follicular development. These results showed that these genes may play a role in the regulation of the follicular development. In addition, compared with healthy follicles, the granulosa cell in atretic follicles had a reduced expression of NRF-1, increased BAX expression and increased ratio of BAX to BCL-2 expression. These results suggested that changes of the mitochondria-associated gene expression patterns in granulosa cells may lead to follicular atresia during goat follicle development.

Graphitized porous carbon prepared from pyrolysis of Sterculia scaphigera and its application in lithium ion batteries

Sterculia scaphigera exhibits exceptional capability to inhale a large amount of water, which is accompanied by great volume expansion.

Nanostructured polystyrene well plates allow unbiased high-throughput characterization of circulating tumor cells

Rapid, reliable and unbiased circulating tumor cell (CTC) isolation and molecular characterization methods are urgently required for implementation in routine clinical diagnostic and prognostic procedures. We report on the development of a novel unbiased CTC detection approach that combines high-throughput automated microscopy with a simple yet efficient approach for achieving a high level of tumor cell binding in standard tissue culture polystyrene (PS) well plates. A single 5 min high-power oxygen plasma treatment was used to create homogeneous nanoscale roughness on standard PS tissue culture plates and, in turn, drastically enhance the binding of a range of tumor cells. After physical adsorption of an adlayer of poly-l-lysine, binding yields above 97% were obtained at 2 h for all tumor cell lines used in the study. Morphological analysis of the cells confirmed strong adherence to the nanorough PS substrates. Clinically relevant concentrations of a highly metastatic breast cancer cell line, used as model for CTCs, could be reliably detected among blood cells on the nanorough polystyrene plates using an automated microscopy system. The approach was then successfully used to detect CTCs in the blood of a stage IIIc colorectal cancer patient. By combining the high binding abilities of nanorough PS well plates with the high-throughput nature of high-content analysis systems, this methodology has great potential toward enabling unbiased routine clinical analysis of CTCs. It could be applied, once clinically validated, in any clinical center equipped with an automated microscopy facility at a fraction of the cost of current CTC isolation technologies.

Micro+nanotexturing of substrates to enhance ligand-assisted cancer cell isolation

This paper presents a simple approach to create a two-tiered surface for superior cancer cell isolation. The idea is inspired by the interactions of cells with a nanotextured basement membrane. The texture mimicked the extracellular matrix and basement membrane for superior target cell adhesion. Prepared micro+nanotextured surfaces showed enhanced cell capture. Preparation of the two-tiered surface was done using micro- and nanotexturing and was easily reproducible. It has been shown before that the larger surface area of a nanotextured surface assists the cell's attachment through surface-anchored ligands. Taking it a step further, ligand functionalized two-level micro+nanotextured surfaces improved the sensitivity of the cancer cell isolation over simple flat nanotexturing. The isolation efficiency increased by 208% compared to the surface with a single-level nanotexture. The two-tiered surface was compatible with previously reported nanotextured devices used for cancer cell isolation. Micro-texture on the glass surface was created using simple sand gritting, followed by reactive ion etching (RIE) of the entire surface. The approach could create large surface areas within a short time while maintaining superior cell isolation efficiency.

Effects of nanopillar array diameter and spacing on cancer cell capture and cell behaviors

While substrates with nanopillars (NPs) have emerged as promising platforms for isolation of circulating tumor cells (CTCs), the influence of diameter and spacing of NPs on CTC capture is still unclear. In this paper, CTC-capture yield and cell behaviors have been investigated by using antibody functionalized NPs of various diameters (120-1100 nm) and spacings (35-800 nm). The results show a linear relationship between the cell capture yield and effective contact area of NP substrates where a NP array of small diameter and reasonable spacing is preferred; however, spacing that is too small or too large adversely impairs the capture efficiency and specificity, respectively. In addition, the formation of pseudopodia between captured cells and the substrate is found to be dependent not only on cell adhesion status but also on elution strength and shear direction. These findings provide essential guidance in designing NP substrates for more efficient capture of CTCs and manipulation of cytomorphology in future.

Damage-free single-mode transmission of deep-UV light in hollow-core PCF

Transmission of UV light with high beam quality and pointing stability is desirable for many experiments in atomic, molecular and optical physics. In particular, laser cooling and coherent manipulation of trapped ions with transitions in the UV require stable, single-mode light delivery. Transmitting even ~2 mW CW light at 280 nm through silica solid-core fibers has previously been found to cause transmission degradation after just a few hours due to optical damage. We show that photonic crystal fiber of the kagomé type can be used for effectively single-mode transmission with acceptable loss and bending sensitivity. No transmission degradation was observed even after >100 hours of operation with 15 mW CW input power. In addition it is shown that implementation of the fiber in a trapped ion experiment increases the coherence time of the internal state transfer due to an increase in beam pointing stability.