[Clinical characteristics and prognostic factors of breast cancer patients with tumor deposits in the ipsilateral axillary region]

Objective: To investigate the clinicopathologic features and prognostic factors of breast cancer patients with tumor deposits in the ipsilateral axillary region. Methods: We retrospectively analyzed the clinicopathologic data and follow-up results of 155 patients with breast cancer diagnosed for the first time and complicated with tumor deposits in the ipsilateral axillary region in the Department of Thyroid-Breast-Vascular Surgery of Xijing Hospital from January 2008 to September 2018. Kaplan-Meier method was used for survival analysis. Log rank test was used for the univariate analysis of prognostic factors, and Cox regression was used for multivariate analysis. Results: The median disease free survival (DFS), median distant metastasis free survival (DMFS), and median overall survival (OS) of the 155 patients were 52.0 months, 66.6 months, and 102.2 months, respectively. The 5-year and 10-year DFS rates were 45.7% and 23.1%, the 5-year and 10-year DMFS rates were 56.9% and 28.9%, and the 5-year and 10-year OS rates were 79.3% and 46.0%, respectively. Multivariate Cox regression analysis showed that family tumor history (HR=0.362, 95% CI: 0.140-0.937), clinical T stage (T3: HR=3.508, 95% CI: 1.380-8.918; T4: HR=2.220, 95% CI: 1.076-4.580), estrogen/progesterone receptor status (HR=0.476, 95% CI: 0.261-0.866), number of tumor deposits (HR=1.965, 95% CI:1.104-3.500) and neoadjuvant chemotherapy (HR=1.961, 95% CI: 1.032-3.725) were independent influencing factors for DFS. Molecular subtype [human epidermal growth factor receptor-2(HER-2) positive and hormone receptor negative: HR=7.862, 95% CI: 3.189-19.379], number of tumor deposits (HR=2.155, 95% CI: 1.103-4.212), neoadjuvant chemotherapy (HR=5.002, 95% CI: 2.300-10.880) and radiotherapy (HR=2.316, 95% CI: 1.005-5.341) were independent influencing factors of DMFS. Histological grade (HR=4.362, 95% CI: 1.932-9.849), estrogen/progesterone receptor expression (HR=0.399, 95% CI: 0.168-0.945), HER-2 expression (HR=2.535, 95% CI: 1.114-5.768) and neoadjuvant chemotherapy (HR=4.080, 95% CI: 1.679-9.913) were independent influencing factors of OS. Conclusions: The presence of tumor deposits weakens the influence of axillary lymph node status and distant metastases on the prognosis of breast cancer patients. Therefore, a clinicopathological staging system taking into account tumor deposits should be developed. Since the number of tumor deposits affects the risk of recurrence and metastasis of breast cancer patients, we recommend that the number of tumor deposits should be reported in detail in the pathological report after breast cancer surgery.

A deep-learning-based framework for identifying and localizing multiple abnormalities and assessing cardiomegaly in chest X-ray

Accurate identification and localization of multiple abnormalities are crucial steps in the interpretation of chest X-rays (CXRs); however, the lack of a large CXR dataset with bounding boxes severely constrains accurate localization research based on deep learning. We created a large CXR dataset named CXR-AL14, containing 165,988 CXRs and 253,844 bounding boxes. On the basis of this dataset, a deep-learning-based framework was developed to identify and localize 14 common abnormalities and calculate the cardiothoracic ratio (CTR) simultaneously. The mean average precision values obtained by the model for 14 abnormalities reached 0.572-0.631 with an intersection-over-union threshold of 0.5, and the intraclass correlation coefficient of the CTR algorithm exceeded 0.95 on the held-out, multicentre and prospective test datasets. This framework shows an excellent performance, good generalization ability and strong clinical applicability, which is superior to senior radiologists and suitable for routine clinical settings.

TREX2 enables efficient genome disruption mediated by paired CRISPR-Cas9 nickases that generate 3'-overhanging ends

Paired SpCas9 nickases (SpCas9n) are an effective strategy to reduce off-target effect in genome editing. However, this approach is not efficient with 3'-overhanging ends, limiting its applications. In order to expand the utility of paired SpCas9n in genome editing, we tested the effect of the TREX2 3'-5' exonuclease on repair of 3'-overhanging ends. We found ectopic overexpression of Trex2 stimulates the efficiency of paired SpCas9n in genome disruption with 3'-overhanging ends up to 400-fold with little stimulation of off-target editing. TREX2 overexpressed preferentially deletes entire 3' overhangs but has no significant effect on 5' overhangs. Trex2 overexpression also stimulates genome disruption by paired SpCas9n that potentially generate short 3'-overhanging ends at overlapping SpCas9n target sites, suggesting sequential nicking of overlapping target sites by SpCas9n. This approach is further simplified with improved efficiency and safety by fusion of TREX2 and particularly its DNA-binding-deficient mutant to SpCas9n. Junction analysis at overlapping targets revealed the different extent of end resection of 3' single-stranded DNA (ssDNA) by free TREX2 and TREX2 fused to SpCas9n. SpCas9n-TREX2 fusion is more convenient and safer than overexpression of free TREX2 to process 3'-overhanging ends for efficient genome disruption by paired SpCas9n, allowing practical use of this TREX2-based strategy in genome editing.

Construction and evaluation of intrauterine adhesion model in rats by different methods of mechanical injury

PURPOSE

The study aimed to establish a stable and effective animal model for the experimental study of intrauterine adhesion (IUA) by evaluating various mechanical injury methods.

METHODS

A total of 140 female rats were divided into four groups according to the extent and area of endometrial injury: group A (excision area: 2.0 × 0.5 cm²), group B (excision area: 2.0 × 0.25 cm²), group C (endometrial curettage) and group D (sham operation). On the 3rd, 7th, 15th and 30th day after the operation, the tissue samples of each group were collected, and the uterine cavity stenosis and histological changes were recorded by HE and Masson staining. Immunohistochemistry of CD31 was applied to visualize microvessel density (MVD). The pregnancy rate and the number of gestational sacs were used to evaluate the reproductive outcome.

RESULTS

The results showed that endometrium injured by small-area endometrial excision or simple curettage could be repaired. The ratio of fibrosis in groups A and B was higher than that in groups C and group D 30 days after modeling (P < 0.001). The number of endometrial glands and MVD in group A was significantly lower than those in groups B, C and D (P < 0.05). The pregnancy rate in group A was 20%, which was lower than that in groups B (33.3%), C (89%) and D (100%) (P < 0.05).

CONCLUSION

Full-thickness endometrial excision has a high rate of success in constructing stable and effective IUA models in rats.

Proximal binding of dCas9 at a DNA double strand break stimulates homology-directed repair as a local inhibitor of classical non-homologous end joining

In CRISPR/Cas9 genome editing, the tight and persistent target binding of Cas9 provides an opportunity for efficient genetic and epigenetic modification on genome. In particular, technologies based on catalytically dead Cas9 (dCas9) have been developed to enable genomic regulation and live imaging in a site-specific manner. While post-cleavage target residence of CRISPR/Cas9 could alter the pathway choice in repair of Cas9-induced DNA double strand breaks (DSBs), it is possible that dCas9 residing adjacent to a break may also determine the repair pathway for this DSB, providing an opportunity to control genome editing. Here, we found that loading dCas9 onto a DSB-adjacent site stimulated homology-directed repair (HDR) of this DSB by locally blocking recruitment of classical non-homologous end-joining (c-NHEJ) factors and suppressing c-NHEJ in mammalian cells. We further repurposed dCas9 proximal binding to increase HDR-mediated CRISPR genome editing by up to 4-fold while avoiding exacerbation of off-target effects. This dCas9-based local inhibitor provided a novel strategy of c-NHEJ inhibition in CRISPR genome editing in place of small molecule c-NHEJ inhibitors, which are often used to increase HDR-mediated genome editing but undesirably exacerbate off-target effects.

[Experimental study of improved sclerotherapy injection in rat model of vertebral arteriocervical spondylopathy]

OBJECTIVE

To improve the rat model of cervical spondylosis of vertebral artery type (CSA) induced by injecting sclerosing agent. To evaluate the efficacy of injecting sclerosing agent to induce CSA.

METHODS

Forty Health SPF SD rats(20 males and 20 females), were randomly divided into two groups:the model group (20) and the blank group (20). All the animals were followed up for 4 weeks for the observation of general situation, transcranial Doppler(TCD) detection of blood flow velocity, pulsatility index and resistive index of the vertebral artery, measurement of mental distress by open-field test.

RESULTS

One to two days after establish the animal model, rats in the model group appeared apathetic with decreased autonomic activities, trembling, squinting, increased eye excrement, etc., and no rats died during the experiment. The mean blood flow velocity of the model group was lower than that of the blank group (P<0.05), and the pulsatilit index and resistive index of the model group were higher than that of the blank group (P<0.05). The mental distress of the model group was significantly higher than that of the blank group.

CONCLUSION

The modified injection of sclerosing agent is a practical method to establish the rat model of CSA, with high success rate, high stability, low mortality and simple operation.

Target residence of Cas9-sgRNA influences DNA double-strand break repair pathway choices in CRISPR/Cas9 genome editing

Background

Due to post-cleavage residence of the Cas9-sgRNA complex at its target, Cas9-induced DNA double-strand breaks (DSBs) have to be exposed to engage DSB repair pathways. Target interaction of Cas9-sgRNA determines its target binding affinity and modulates its post-cleavage target residence duration and exposure of Cas9-induced DSBs. This exposure, via different mechanisms, may initiate variable DNA damage responses, influencing DSB repair pathway choices and contributing to mutational heterogeneity in genome editing. However, this regulation of DSB repair pathway choices is poorly understood.

Results

In repair of Cas9-induced DSBs, repair pathway choices vary widely at different target sites and classical nonhomologous end joining (c-NHEJ) is not even engaged at some sites. In mouse embryonic stem cells, weakening the target interaction of Cas9-sgRNA promotes bias towards c-NHEJ and increases target dissociation and reduces target residence of Cas9-sgRNAs in vitro. As an important strategy for enhancing homology-directed repair, inactivation of c-NHEJ aggravates off-target activities of Cas9-sgRNA due to its weak interaction with off-target sites. By dislodging Cas9-sgRNA from its cleaved targets, DNA replication alters DSB end configurations and suppresses c-NHEJ in favor of other repair pathways, whereas transcription has little effect on c-NHEJ engagement. Dissociation of Cas9-sgRNA from its cleaved target by DNA replication may generate three-ended DSBs, resulting in palindromic fusion of sister chromatids, a potential source for CRISPR/Cas9-induced on-target chromosomal rearrangements.

Conclusions

Target residence of Cas9-sgRNA modulates DSB repair pathway choices likely through varying dissociation of Cas9-sgRNA from cleaved DNA, thus widening on-target and off-target mutational spectra in CRISPR/Cas9 genome editing.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13059-022-02736-5.

Genomic and phenotypic biology of a novel Dickeya zeae WH1 isolated from rice in China: Insights into pathogenicity and virulence factors

Soft rot caused by Dickeya zeae is an important bacterial disease affecting rice and other plants worldwide. In this study, Nanopore and Illumina sequencing platforms were used to sequence the high-quality complete genome of a novel D. zeae strain WH1 (size: 4.68 Mb; depth: 322.37x for Nanopore, 243.51x for Illumina; GC content: 53.59%), which was isolated from healthy rice root surface together with Paenibacillus polymyxa, a potential biocontrol bacterium against D. zeae strain WH1. However, the pure WH1 culture presented severe pathogenicity. Multilocus sequence analysis (MLSA) indicated that strains WH1, EC1, and EC2 isolated from rice were grouped into a clade differentiated from other D. zeae strains. The average nucleotide identity (ANI) and DNA-DNA hybridization (DDH) analyses demonstrated that WH1 was phylogenetically closest to EC2. Furthermore, the pathogenicity determinants and virulence factors of WH1 were mainly analyzed through genomic comparison with complete genomes of other D. zeae strains with high virulence (EC1, EC2, MS1, and MS2). The results revealed that plant cell wall-degrading extracellular enzymes (PCWDEs), flagellar and chemotaxis, and quorum sensing were highly conserved in all analyzed genomes, which were confirmed through phenotypic assays. Besides, WH1 harbored type I, II, III, and VI secretion systems (T1SS, T2SS, T3SS, and T6SS), but lost T4SS and T5SS. Like strains MS1 and MS2 isolated from bananas, WH1 harbored genes encoding both capsule polysaccharide (CPS) and exopolysaccharide (EPS) biosynthesis. The results of pathogenicity assays demonstrated that WH1 produced severe soft rot symptoms on potato tubers, carrots, radishes, and Chinese cabbage. Meanwhile, WH1 also produced phytotoxin(s) to inhibit rice seed germination with an 87% inhibitory rate in laboratory conditions. More importantly, we confirmed that phytotoxin(s) produced by WH1 are different from zeamines produced by EC1. Comparative genomics analyses and phenotypic and pathogenicity assays suggested that WH1 likely evolved through a pathway different from the other D. zeae strains from rice, producing a new type of rice foot rot pathogen. These findings highlight the emergence of a new type of D. zeae strain with high virulence, causing soft rot in rice and other plants.

[Stratified research on related risk factors of CINⅡ+ in CINⅠ patients diagnosed by endocervical curettage under colposcopy]

Objective: To estimate risks of cervical intraepithelial neoplasia (CIN) Ⅱ or worse (CINⅡ⁺) on loop electrosurgical excisional procedure (LEEP) specimens with the diagnosis of endocervical curettage (ECC) CINⅠ compared with biopsy CINⅠ, and also to investigate the hierarchical management scheme of ECC CINⅠ based on the relevant factors of CINⅡ⁺ risk. Methods: (1) A retrospective computer-based research for subjects enrolled in the Obstetrics and Gynecology Hospital, Fudan University from Jan. 2013 to Jun. 2021 was performed. The case group comprised women with an ECC CINⅠ (ECC results of CINⅠ with colposcopy-directed biopsy results ≤CINⅠ), and the control group comprised women with a biopsy CINⅠ (colposcopy-directed biopsy results of CINⅠ with negative ECC findings) were divided after LEEP surgery and diagnosis in the next three months. The clinical data of all patients before LEEP were analyzed, and the pathological diagnosis between two groups after LEEP was compared. (2) Variables, including age, cytology, high-risk human papillomavirus (HR-HPV), ECC results, cervical transformation zone (TZ) and colposcopy impression, were included to describe the characteristics and compare the incidence of LEEP CINⅡ⁺. (3) Univariate analysis and Multivariate logistic regression method were used to analyze the related factors that affect the LEEP CINⅡ⁺ in CINⅠ patients. Further, the specific risks caused by related factors and conduct a stratified study in LEEP CINⅡ⁺ were analyzed. Results: (1) Overall, 2 581 women with ECC CINⅠ or biopsy CINⅠ diagnosis who underwent LEEP participated in the study with the mean age (43.6±9.5) years old. Chi square test found that the age and cytology of patients in ECC CINⅠ group were statistically different from those of biopsy CINⅠ group (all P<0.05). There was no significant difference in HR-HPV detection, TZ type and colposcopy impression between the two groups (all P>0.05). ECC CINⅠ comprised 957 women, with LEEP histopathology results revealing 288 (30.1%, 288/957) CINⅡ⁺, which was significantly higher than that of biopsy CINⅠ which was comprised 1 624 women, with LEEP histopathology results showing 333 (20.5%, 333/1 624) CINⅡ⁺ (χ²=30.31, P<0.001). (2) Compared by LEEP CINⅡ⁺ with LEEP ≤CINⅠ group, there were no significant difference in the age, HR-HPV, colposcopy impression (all P>0.05); but there were significantly differences in cytology, ECC CINⅠ, type Ⅲ TZ (all P<0.001). Multivariate logistic regression analysis showed that atypical squamous epithelial cells (ASC-H; OR=2.77, 95%CI: 2.04-3.77), high-grade squamous intraepithelial lesions and worse (HSIL⁺; OR=2.93, 95%CI: 2.24-3.81), ECC CINⅠ (OR=1.89, 95%CI: 1.56-2.29) and type Ⅲ of TZ (OR=1.76, 95%CI: 1.45-2.11) were independent risk factors for LEEP CINⅡ⁺ (all P<0.05). (3) When cytology was ≤low-grade squamous intraepithelial lesion (LSIL) and ≥ASC-H, the detection rate of CINⅡ⁺ in ECC CINⅠ was significantly higher than that of biopsy CINⅠ (all P<0.001). In ECC CINⅠ, the rate of CINⅡ⁺ with cytology ≤LSIL was significantly lower than that in cytology ≥ASC-H (56.0% vs 25.9%; χ²=49.38, P<0.001). In type Ⅰ/Ⅱ of TZ, the detection rate of CINⅡ⁺ between ECC CINⅠand biopsy CINⅠ had no significantly different; while in type Ⅲ of TZ, there was significantly different (72.7% vs 46.2%; χ²=4.02, P=0.045). In ECC CINⅠ, type Ⅲof TZ was significantly higher in the rate of CINⅡ⁺ than that of type Ⅰ/Ⅱ of TZ (72.7% vs 21.7%; χ²=16.38, P<0.001). When cytology ≥ASC-H, type Ⅲ of TZ and colposcopy impression of HSIL were combined, the rate of CINⅡ⁺ in ECC CINⅠ was 6/6 while 1/3 in biopsy CINⅠ. Conclusions: Cytology ≥ASC-H, ECC CINⅠ and type Ⅲ TZ are the risk factors of LEEP CINⅡ⁺. However, cytology ≥ASC-H is more valuable in predicting LEEP CINⅡ⁺ than ECC CINⅠ. For patients with ECC CINⅠ to perform LEEP, it is recommended that cytology ≥ASC-H is taken as the first level stratification, and type Ⅲ TZ is taken as the second level stratification. The colposcopy impression of patients is recommended for a reference parameter.

Fluorescence in situ hybridization-based confirmation of acute graft-vs-host disease diagnosis following liver transplantation: A case report

BACKGROUND

Although acute graft-vs-host disease (aGvHD) is a rare complication of liver transplantation, it is poorly understood and has an extremely high mortality rate. No standardized diagnostic criteria or treatment regimens currently exist.

CASE SUMMARY

The present study investigated the etiology, diagnosis, and treatment of aGvHD following liver transplantation. Presentation, diagnosis, disease course, histology, and treatment of an aGvHD case are reported, and associated literature is reviewed. A 64-year-old female required LTx due to primary biliary cirrhosis. The donor was a 12-year-old male. Three weeks following liver transplantation, the recipient developed pyrexia, diarrhea, rashes, and antibiotic-unresponsive pancytopenia. Clinical symptoms together with laboratory investigations suggested a diagnosis of aGvHD, which was confirmed via peripheral blood fluorescent in situ hybridization. Donor XY chromosome fluorescent in situ hybridization indicating early chimerism achieved 93% sensitivity in the detection of GvHD. Existing immunosuppressants were discontinued, and high-dose intravenous methylprednisolone was initiated along with antibiotics. While diarrhea resolved, the patient’s general condition continued to deteriorate until demise due to multi-system organ failure at 37 d post-liver transplantation. This case illustrates the life-threatening nature of aGvHD.

CONCLUSION

Herein, we have summarized a post-LTx aGvHD case and reviewed associated literature in order to increase awareness and provide potentially risk-mitigating recommendations.

CaFtsH06, A Novel Filamentous Thermosensitive Protease Gene, Is Involved in Heat, Salt, and Drought Stress Tolerance of Pepper (Capsicum annuum L.)

Harsh environmental factors have continuous negative effects on plant growth and development, leading to metabolic disruption and reduced plant productivity and quality. However, filamentation temperature-sensitive H protease (FtsH) plays a prominent role in helping plants to cope with these negative impacts. In the current study, we examined the transcriptional regulation of the CaFtsH06 gene in the R9 thermo-tolerant pepper (Capsicum annuum L.) line. The results of qRT-PCR revealed that CaFtsH06 expression was rapidly induced by abiotic stress treatments, including heat, salt, and drought. The CaFtsH06 protein was localized to the mitochondria and cell membrane. Additionally, silencing CaFtsH06 increased the accumulation of malonaldehyde content, conductivity, hydrogen peroxide (H₂O₂) content, and the activity levels of superoxide dismutase and superoxide (·O₂⁻), while total chlorophyll content decreased under these abiotic stresses. Furthermore, CaFtsH06 ectopic expression enhanced tolerance to heat, salt, and drought stresses, thus decreasing malondialdehyde, proline, H₂O₂, and ·O₂⁻ contents while superoxide dismutase activity and total chlorophyll content were increased in transgenic Arabidopsis. Similarly, the expression levels of other defense-related genes were much higher in the transgenic ectopic expression lines than WT plants. These results suggest that CaFtsH06 confers abiotic stress tolerance in peppers by interfering with the physiological indices through reducing the accumulation of reactive oxygen species, inducing the activities of stress-related enzymes and regulating the transcription of defense-related genes, among other mechanisms. The results of this study suggest that CaFtsH06 plays a very crucial role in the defense mechanisms of pepper plants to unfavorable environmental conditions and its regulatory network with other CaFtsH genes should be examined across variable environments.

Inhibition of cell proliferation and radioresistance by miR-383-5p through targeting RNA binding protein motif (RBM3) in nasopharyngeal carcinoma

Background

RNA binding protein motif (RBM3) is associated with radioresistance in nasopharyngeal carcinoma (NPC), and miR-383-5p was predicted to target the 3'-untranslated region (3'UTR) of RBM3 messenger RNA (mRNA). Our study aimed to investigate the role and the mechanisms of miR-383-5p targeting RBM3 in NPC cell proliferation and radioresistance (RR).

Methods

The expression of miR-383-5p was detected by Real-time quantitative PCR (qRT-PCR) between RS (Radiosensitivity) and RR (Radioresistance) NPC patient- tissue specimens and cell lines. Cell Counting Kit-8 (CCK-8) and Clonogenic survival assay were applied to analyze the effect of miR-383-5p on NPC cell proliferation and radioresistance. Possible downstream target of miR-383-5p in NPC cells, RBM3was evaluated by luciferase assay and qRT-PCR. miR-383-5p inhibited NPC cell proliferation and radioresistance through RBM3 by rescue experiments. The effect of miR-383-5p on radiation-induced apoptosis was explored through Flow cytometric analysis and Western blotting. Western blotting was analyzed the molecular of RBM3-mediated Jun N-terminal kinase (JNK) and extracellular signal-related kinase (ERK) signaling pathways

Results

The expression of miR-383-5p was decreased in radioresistant NPC tissues and cells. miR-383-5p inhibited cell proliferation and radioresistance in CNE1/IR cells. We also observed that therapeutic administration of a miR-383-5p agomir dramatically sensitized NPC xenografts to radiation in a mouse model. Conversely, in the same xenograft model, administration of a miR-383-5p antagomir dramatically increased NPC resistance to radiation. miR-383-5p targeted the 3'UTR of RBM3. miR-383-5p inhibited NPC cell proliferation and radioresistance through RBM3. Finally, we found that miR-383-5p increased radiation-induced apoptosis, activated JNK signaling, and inhibited ERK signaling.

Conclusions

Our study revealed that miR-383-5p targeted the 3'UTR of RBM3 and contributed to the efficacy of NPC radiation therapy by altering the RBM3-mediated JNK and ERK signaling pathways.

CaHsfA1d Improves Plant Thermotolerance via Regulating the Expression of Stress- and Antioxidant-Related Genes

Heat shock transcription factor (Hsf) plays an important role in regulating plant thermotolerance. The function and regulatory mechanism of CaHsfA1d in heat stress tolerance of pepper have not been reported yet. In this study, phylogenetic tree and sequence analyses confirmed that CaHsfA1d is a class A Hsf. CaHsfA1d harbored transcriptional function and predicted the aromatic, hydrophobic, and acidic (AHA) motif mediated function of CaHsfA1d as a transcription activator. Subcellular localization assay showed that CaHsfA1d protein is localized in the nucleus. The CaHsfA1d was transcriptionally up-regulated at high temperatures and its expression in the thermotolerant pepper line R9 was more sensitive than that in thermosensitive pepper line B6. The function of CaHsfA1d under heat stress was characterized in CaHsfA1d-silenced pepper plants and CaHsfA1d-overexpression Arabidopsis plants. Silencing of the CaHsfA1d reduced the thermotolerance of the pepper, while CaHsfA1d-overexpression Arabidopsis plants exhibited an increased insensitivity to high temperatures. Moreover, the CaHsfA1d maintained the H2O2 dynamic balance under heat stress and increased the expression of Hsfs, Hsps (heat shock protein), and antioxidant gene AtGSTU5 (glutathione S-transferase class tau 5) in transgenic lines. Our findings clearly indicate that CaHsfA1d improved the plant thermotolerance via regulating the expression of stress- and antioxidant-related genes.

Palladium-Catalyzed Regioselective Coupling Cyclohexenone into Indoles: Atom-Economic Synthesis of β-Indolyl Cyclohexenones and Derivatization Applications

Herein, we report a palladium-catalyzed dehydrogenative cross-coupling of indoles with cyclic enones to give β-indolyl cyclic enones under mild and neutral reaction conditions. The key to the success is to explore a mild condition, which ensures the indole C-H activation and subsequent syn β-hydride elimination through rapid enolization isomerization of Pd(II)-enolate while suppressing other undesired side reactions. Synthetic utility has also been demonstrated in the flexible transformation of the coupling products to meta-phenols and benzo[a]carbazoles.

P5396CRISPR/Cas9 mediated miR-29b editing restores muscle atrophy and exercise capacity in mice

Background

Muscle atrophy is the loss of skeletal muscle mass and strength in response to diversity catabolic stimuli, such as heart failure. At present, no effective treatment except exercise is validated on reducing multiple muscle atrophy clinically. We have recently reported that microRNA-29b (miR-29b) promotes multiple types of muscle atrophy.

Purpose

The goal of this study was to assess whether genome editing using a clustered regularly interspaced short palindromic repeat/Cas9 (CRISPR/Cas9) system can efficiently introduce loss-of-function mutations into the endogenous miR-29b in vivo and as a potential therapy by treating muscle atrophy.

Methods

We used lentivirus to express CRISPR-associated 9 and a CRISPR guide RNA targeting miR-29b. Mutagenesis rate of miR-29b and off-target mutagenesis were detected by T7 Endonuclease I (T7EI) Assay. The expression level of miR-29b were measured in vitro and vivo after administration of the virus by using qRT-PCR. After intramuscular administration of the virus, the angiotensin II (AngII), immobilization and denervation-induced muscle atrophy were performed. Then muscle function was assessed in exercise capacity, the appearance and weight of muscle, the size of the muscle fibers, molecular and cellular detection.

Results

Here, we report that CRISPR/Cas9 mediated genome editing through intramuscular administration efficiently targeting the biogenesis processing sites in pre-miR-29b. No off-target mutagenesis was detected in 10 selected sites. This CRISPR-based treatment resulted in decreased miR-29b levels specifically. In vivo, this CRISPR-based treatment could ameliorate the muscle atrophy induced by angiotensin II (AngII), immobilization and denervation via activation of PI3K-AKT-mTOR signaling pathway and protect against AngII-induced apoptosis in mice. Moreover, the exercise capacity is also significantly enhanced.

Conclusion

Our work establishes CRISPR/Cas9 based gene targeting on miRNA as a potential durable therapy for treatment of muscle atrophy and expands the strategies available interrogating miRNA function in vivo.

Acknowledgement/Funding

The grants from National Natural Science Foundation of China (81722008, 91639101 and 81570362 to JJ Xiao)

RNA binding motif protein 3 (RBM3) drives radioresistance in nasopharyngeal carcinoma by reducing apoptosis via the PI3K/AKT/Bcl-2 signaling pathway

Radioresistance is an important obstacle to nasopharyngeal carcinoma (NPC) therapy. In this study, we explored the role of RNA-binding motif protein 3 (RBM3) in the radioresistance of NPC and its underlying mechanism. We measured the expression of RBM3 in 20 clinical NPC tissues and in NPC cell lines. We found that RBM3 was upregulated in radioresistant NPC tissues and cells. Radioresistant NPC cells (CNE1/IR) and parental NPC cells (CNE1) were subjected to RBM3-shRNA knockdown and RBM3 overexpression, respectively. RBM3 depletion in CNE1/IR cells sensitized cells to radiotherapy, increased DNA damage, and accelerated the rate of apoptosis. In contrast, RBM3 overexpression in CNE1 cells significantly enhanced radioresistance and reduced the rate of apoptosis. Additionally, radioresistance conferred by RBM3 was attributed to the activation of the AKT/Bcl-2 signaling pathway and reduction of caspase 3. Inhibition of AKT signaling attenuated RBM3-mediated radioresistance. Furthermore, RBM3 directly interacted with PI3K subunit p85 in NPC cell lines. Altogether, our data demonstrate that RBM3 enhances radioresistance by inhibiting the apoptotic response to radiotherapy through the PI3K/AKT/Bcl-2 signaling pathway. RBM3 may serve as a novel factor for predicting radioresistance and as a molecular target in the treatment of NPC.

Harnessing accurate non-homologous end joining for efficient precise deletion in CRISPR/Cas9-mediated genome editing

Background

Many applications of CRISPR/Cas9-mediated genome editing require Cas9-induced non-homologous end joining (NHEJ), which was thought to be error prone. However, with directly ligatable ends, Cas9-induced DNA double strand breaks may be repaired preferentially by accurate NHEJ.

Results

In the repair of two adjacent double strand breaks induced by paired Cas9-gRNAs at 71 genome sites, accurate NHEJ accounts for about 50% of NHEJ events. This paired Cas9-gRNA approach underestimates the level of accurate NHEJ due to frequent + 1 templated insertions, which can be avoided by the predefined Watson/Crick orientation of protospacer adjacent motifs (PAMs). The paired Cas9-gRNA strategy also provides a flexible, reporter-less approach for analyzing both accurate and mutagenic NHEJ in cells and in vivo, and it has been validated in cells deficient for XRCC4 and in mouse liver. Due to high frequencies of precise deletions of defined “3n”-, “3n + 1”-, or “3n + 2”-bp length, accurate NHEJ is used to improve the efficiency and homogeneity of gene knockouts and targeted in-frame deletions. Compared to “3n + 1”-bp, “3n + 2”-bp can overcome + 1 templated insertions to increase the frequency of out-of-frame mutations. By applying paired Cas9-gRNAs to edit MDC1 and key 53BP1 domains, we are able to generate predicted, precise deletions for functional analysis. Lastly, a Plk3 inhibitor promotes NHEJ with bias towards accurate NHEJ, providing a chemical approach to improve genome editing requiring precise deletions.

Conclusions

NHEJ is inherently accurate in repair of Cas9-induced DNA double strand breaks and can be harnessed to improve CRISPR/Cas9 genome editing requiring precise deletion of a defined length.

Electronic supplementary material

The online version of this article (10.1186/s13059-018-1518-x) contains supplementary material, which is available to authorized users.

Spirometra erinaceieuropaei severely infect frogs and snakes from food markets in Guangdong, China: implications a highly risk for zoonotic sparganosis

Sparganosis is a parasitic disease caused by plerocercoid larvae of the genus Spirometra. In China, the main source of sparganosis is from Guangdong, 16.1% of the country's human sparganosis cases occur in this province. Frequent international trade of amphibians and reptiles in Guangdong may introduce new species of Spirometra into the local market. In this study, a large-scale, high-intensity sampling survey was conducted to find out the causative species and epidemic situation of Sparganosis in Guangdong. The prevalence of sparganum infection in five species of frogs (Boulengerana guentheri, Fejervarya multistriata, Hoplobatrachus chinensis, Pelophylax nigromaculatus and Quasipaa spinosa) and nine species of snakes (Elaphe carinata, Lycodon rufozonatum, Hypsiscopus plumbea, Ptyas dhumnades, P. korros, P. mucosa, Naja atra, Sinonatrix annularis and Xenochrophis piscator) was investigated in Guangdong, Southern China from May 2014 to August 2015. The results showed that 9.8% (50/511) of the frogs and 40.8% (141/ 346) of snakes were found to be infected by plerocercoids (spargana). To identify the species of the collected spargana, a partial sequence of the mitochondrial cytochrome c oxidase subunit1 gene (cox1) was amplified and sequenced. Phylogenetic analysis identified all the spargana specimens as Spirometra erinaceieuropaei. Our study indicated that S. erinaceieuropaei, a highly pathogenic parasite, is the only causative agent of sparganosis in Guangdong, China. This study suggests that the large numbers of frogs and snakes in food markets in Guangdong may impact public health in China by transmitting S. erinaceieuropaei sparganum. Additional steps should be considered by the governments and public health agencies to prevent the risk of food-associated Spirometra infections in humans in China.

Broadband full-color multichannel hologram with geometric metasurface

Due to the abilities of manipulating the wavefront of light with well-controlled amplitude, and phase and polarization, optical metasurfaces are very suitable for optical holography, enabling applications with multiple functionalities and high data capacity. Here, we demonstrate encoding two- and three-dimensional full-color holographic images by an ultrathin metasurface hologram whose unit cells are subwavelength nanoslits with spatially varying orientations. We further show that it is possible to achieve full-color holographic multiplexing with such kind of geometric metasurfaces, realized by a synthetic spectrum holographic algorithm. Our results provide an efficient way to design multi-color optical display elements that are ready for fabrication.

[Comparative analysis of the ankle joints in juvenile male soccer players with imaging]

OBJECTIVE

To investigate the characteristics of children male soccer players' ankle imaging features.

METHODS

From October 2015 to February 2016, a total of 32 male children players of two soccer clubs in Guangzhou were enrolled in this study.The ages of all cases were from 10 to 14 years, average age was (11.3±0.9) years.A total of 15 male children in region ordinary primary and secondary school students were set as control group, ages were from 10 to 14 years, average age was (12.1±1.2) years. All objects' ankle were examined by X-ray for positive and lateral positions; routine CT scanning and then on the workstation restructuring for axial, coronal and sagittal slices; and examined by MR. MR scan was with special surface coil for ankle joint for horizontal axis T2WI; coronal T1WI; coronary proton density weighted imaging (PWI); sagittal T2WI with fat suppression; sagittal PWI with isotropic and fat suppression sequence of fast field echo. The ankle bone morphological structures were observed on X-ray; the ankle bone mineral density, cortical bone thickness and sesamoid bone quantity was being observed and measured on CT; and the tenosynovitis, Achilles tendinitis, synovitis, and cancellous bone edema signal were observed on MR.

RESULTS

For study group, a total of 32 cases and 64 ankles joints were completed by X-ray, CT and MR examination.A total of 15 cases and 30 ankles joints were completed by X-ray in control group, 26 ankle joints were completed by CT scan and 22 ankle joints were completed by MR examination.X-ray examination showed there was no statistically significant difference between the two groups in ankle bone structure.CT showed that navicular bone CT value was (296±82) HU in research group and navicular bone CT value was (266±107) HU in control group, the difference was statistically significant (P=0.03). MR showed the incidence of diseases in research group that the tendon sheath peripheral inflammation was 92.2% (59/64), Achilles tendon lesions was 18.8%(12/64), edema of cancellous bone was 73.4% (47/64) , lateral malleous ligaments injuried was 43.8%(28/64), synovitis or effusion in posterior ankle was 87.5% (56/64). The incidence of diseases in control group was that tendon sheath peripheral inflammation was 31.8%(7/22), Achilles tendon lesions was 0/22, edema of cancellous bone was 0/22, lateral malleous ligaments injuried was 0/22, synovitis or effusion in posterior ankle was 54.5% (12/22). There was statistically significant difference between these two groups (all P<0.05).

CONCLUSION

Compared with the control group, children's male soccer players ankle bone structure, bone cortex thickness and bone mineral density there were no obvious difference. In the tenosynovitis, Achilles tendinitis, synovitis, bone marrow edema, lateral malleous ligaments injuried were significantly higher than the control group.

Association of miR-196a2, miR-27a, and miR-499 polymorphisms with isolated congenital heart disease in a Chinese population

We hypothesized that single nucleotide polymorphisms (SNPs) in certain microRNAs contribute to congenital heart disease (CHD) phenotypes. Five hundred and seventy-three subjects were enrolled in this study. DNA extracted from peripheral blood cells was used for SNP genotyping of miR-196a2 (rs11614913), miR-27a (rs11671784, rs895819), and miR-499 (rs3746444). Allele and genotype association analyses were performed to evaluate the correlation between certain microRNA SNPs and three phenotypes of isolated CHD: atrial septal defect (ASD), ventricular septal defect (VSD), and patent ductus arteriosus (PDA). All the participants carried a homozygous CC variant of miR-27a (rs11671784). The homozygous CC variant of miR-196a2 (rs11614913, T>C) was negatively associated with ASD compared with the wild-type TT variant (OR = 0.379, 95%CI = 0.209-0.686, P = 0.001). The miR-196a2 C allele was negatively associated with ASD compared with the T allele (OR = 0.646, 95%CI = 0.491-0.849, P = 0.002). The statistically significant results were further confirmed by dominant and recessive model assays. SNPs of miR-27a (rs895819, T>C) and miR-499 (rs3746444, A>G) showed diverse association with ASD, VSD, or PDA, but the differences were not statistically significant. The rs11614913 (T>C) SNP of miR-196a2 is associated with ASD, and the homozygous CC variant and the C allele are protective factors associated with ASD. The homozygous CC variant and the C allele of the rs11614913 (T>C) SNP of miR-196a2 are associated with a significantly reduced risk of ASD.

SNP in Differentially Methylated Region Upstream of H19 Gene in Guangdong Han Population

OBJECTIVES

To investigate the single nucleotide polymorphism （SNP） and haplotypes in differentially methylated region （DMR） upstream of H19 gene in Guangdong Han population.

METHODS

The PIA typing and restriction enzyme McrBC and HpaⅡ were used to digest the genomic DNA and obtain the individual uniparental DNA template strand. The data of uniparental SNP alleles, genotypes and haplotypes in DMR upstream of H19 gene were obtained by sequencing.

RESULTS

A total of 13 SNPs （rs10840167, rs2525883, rs12417375, rs4930101, rs2525882, rs2735970, rs2735971, rs11042170, rs2735972, rs10732516, rs2071094, rs2107425, and rs4930098） and one mutation locus （g7351c） were found. All loci followed the Hardy-Weinberg equilibrium （P>0.05） by statistical analysis. Except for rs12417375 （DP=0.279） locus, the DP of remaining 12 SNPs were 0.446-0.614, and the g7351c mutation locus （DP=0.013） was the particular loci of the Southern Chinese Han population. Eight haplotypes （designated as haplotype 1-8） were detected, in which 3 haplotypes had not yet been reported and the DP, PIC, PE and H were 0.891, 0.714, 0.524 and 0.758, respectively.

CONCLUSIONS

Obtained by PIA typing, the SNP in DMR upstream of H19 gene and its haplotypes genetic marker system have a high determination power and show a good practical value in forensic identification.

Establishment and Clinical Application of an Electronic Database for Breast Cancer in China

PURPOSE

To establish a database for breast cancer patients to save and manage clinical data and to preliminarily investigate its clinical application.

MATERIALS AND METHODS

Information on breast cancer patients hospitalized in our department from 2008.01 to 2013.01 were input into our breast cancer management system. SPSS 16.0 software was used as a convenient reference to evaluate the accuracy of the newly built database.

RESULTS

A database of 2403 breast cancer patients was successfully established. Information in the database clearly displayed capabilities of storage, addition, retrieval, statistical analysis and other functions. As the continuously updated database showed, the distribution of age, sex, nationality, allergy history, pausimenia and marriage of patients was identical to that achieved by SPSS analysis, indicating reliable and accurate data analysis.

CONCLUSIONS

The described database is easy and convenient to operate and manage, and should prove suitable for application in clinical research and treatment.

Multiple fano resonances in spatially compact and spectrally efficient spoof surface plasmon resonators with composite textures

Spoof surface plasmons derive their properties from structure resonance rather than from electronic resonance, enabling an extremely high degree of freedom for tuning and modulating different resonances. Here, a composite resonator based on multiscale textured metal surface of different grooves is presented, and spoof localized surface plasmons (LSPs) are shown to emerge and interact coherently. Each band of the spoof LSPs resembles those generated by the homogenously textured surface with the corresponding groove. By adjusting the geometry and filling medium of each substructure in the composite system, we find that the multipole resonant modes sustained by one substructure can couple with those in the other, giving rise to multi-band Fano resonances. Such multiple-Fano resonance structures are spatially more compact while spectrally more comprehensive than usual spoof structures. They can be used for unique resonant devices such as microwave antennas and metasurfaces.

Plasmonic TM-like cavity modes and the hybridization in multilayer metal-dielectric nanoantenna

Plasmonic hybridized transverse magnetic like (TM-like) cavity modes in multi-layered metal-dielectric circular nanoantenna are systematically studied. The main purpose is to explore the symmetry features of the vertical modal profile and its impact on the in-plane interference of gap plasmonic waves that are responsible to the resonant mode. It is found that only vertically in-phase modes are excitable when illuminated by a plane wave under normal incidence and more could be selectively excited using a dipole source, within the wavelength range from 430 nm-1250 nm. More specifically, the excitation of localized cavity modes is shown to be highly sensitive to the dipole position which determines symmetry matching and the degree of field overlap between the dipole source and the cavity mode pattern. Furthermore, we show that the resonance frequencies can be approximately predicted by the dispersion relations of plasmonic wave in the corresponding two-dimensional multilayered structure. Our results would be helpful for the design of photonic nanoantennas with alternative metal and dielectric medium.

Exome sequencing identifies novel compound heterozygous IFNA4 and IFNA10 mutations as a cause of impaired function in Crohn's disease patients

Previous studies have highlighted the role of genetic predispositions in disease, and several genes had been identified as important in Crohn’s disease (CD). However, many of these genes are likely rare and not associated with susceptibility in Chinese CD patients. We found 294 shared identical variants in the CD patients of which 26 were validated by Sanger sequencing. Two heterozygous IFN variants (IFNA10 c.60 T > A; IFNA4 c.60 A > T) were identified as significantly associated with CD susceptibility. The single-nucleotide changes alter a cysteine situated before the signal peptide cleavage site to a stop code (TGA) in IFNA10 result in the serum levels of IFNA10 were significantly decreased in the CD patients compared to the controls. Furthermore, the IFNA10 and IFNA4 mutants resulted in an impairment of the suppression of HCV RNA replication in HuH7 cells, and the administration of the recombinant IFN subtypes restored DSS-induced colonic inflammation through the upregulation of CD4⁺ Treg cells. We identified heterozygous IFNA10 and IFNA4 variants as a cause of impaired function and CD susceptibility genes in Chinese patients from multiple center based study. These findings might provide clues in the understanding of the genetic heterogeneity of CD and lead to better screening and improved treatment.

Antiboding and bonding lasing modes with low gain threshold in nonlocal metallic nanoshell

Based on a full-wave nonlocal Mie theory, we establish the spaser generation condition for compact plasmonic nanolasers in the long-wavelength limit for dielectric-metal core-shell nanoparticles. We found that there exist two lasing states arising from the hybridized antibonding and bonding modes for this coated nanolaser. By varying the surrounding medium and the gain materials, we can achieve low gain threshold for each mode with flexible radii ratios on the purpose of realistic easy fabrication. Numerical results show that nonlocal effects have different influences on the required gain threshold and gain refractive index of these two lasing modes, which may be of great importance in the design of such kind of ultrasmall nanoparticle lasers.

Effect of Jianpi Bushen prescription on the expression of SHP-1 and apoptosis-related genes in chemically damaged model mice

We investigated the effect of Jianpi Bushen prescription (JBP) on the expression of the SHP-1 and apoptosis-related genes in chemically damaged model mice and a compound e-jiao slurry (EJS) group (positive control). Kunming mice received an abdominal injection of 100 mg/kg cyclophosphamide once a day for 3 consecutive days to induce chemical damage. The mice underwent lavage at a suspension of 0.1 g/kg low-dose JBP (100%), high-dose JBP (200%), and 0.2 mL/10 g EJS twice a day for 9 days. mRNA and protein expression of SHP-1 in bone marrow mononuclear cells was detected using real-time polymerase chain reaction and Western blot; mRNA expression of B-cell lymphoma 2 (Bcl-2) and Bcl-2-associated X (Bax) protein was detected by in situ hybridization. Expression of SHP-1 and Bax mRNA was significantly upregulated in the model group compared to the control group (P < 0.05). Expression in the low-dose JBP, high-dose JBP, and EJS groups was significantly downregulated compared with the model group (P < 0.05). The low-dose JBP group exhibited much lower SHP-1 and Bax mRNA expression levels. Compared with controls, Bcl-2 mRNA expression was significantly reduced in the model group (P < 0.05). Expression in the low-dose JBP, high-dose JBP, and EJS groups significantly increased compared with the model group (P < 0.05). The low-dose JBP group showed much higher Bcl-2 mRNA expression. Therefore, JBP regulates the expression of the SHP- 1, Bax, and Bcl-2 genes in chemically damaged mice.

Effect of the Jianpi Bushen Prescription on the expression of SHP-1, Wnt3a, and AP-1 proteins in chemically damaged mice

This study investigated the effect of the Jianpi Bushen Prescription (JBP) on the expression of 3 major proteins in chemically damaged model mice. The 3 proteins were the Wnt3a, the SHP-1, and the transcription factors (NF-E2, c-jun, and c-fos) of the AP-1 protein family. Kunming mice were randomly divided into chemically damaged group (N=48), which received an abdominal injection of (100 mg/kg) cyclophosphamide once a day for 3 consecutive days, and control group (N=12), which received the same amount of saline. Then, the chemically damaged mice were randomly divided into chemically damaged model group (N=12), which received 0.2 mL/10 g of saline twice a day for 9 days, positive control group (N=12), which received 0.2 mL/10 g of the e-jiao slurry (EJS) compound twice a day for 9 days, low dose JBP group (N=12), which received 0.1 g/kg suspension JBP (100% concentration) twice a day for 9 days and high dose JBP group (N=12), which received 0.1 g/kg suspension JBP (200% concentration) twice a day for 9 days. The bilateral femur and tibia bone marrow were collected from the mice in all groups. The protein expression of the specified proteins and transcription factors in the bone marrow mononuclear cells were detected by Western blot analysis. The results showed that the protein expression of Wnt3a was significantly downregulated in the chemically damaged model group compared to the control group (P<0.05). The low dose JBP, high dose JBP, and e-jiao slurry treatments significantly upregulated the protein expression of Wnt3a compared to the chemically damaged model group (P<0.05), with the low dose JBP producing the best results. Compared to the control group, the protein expressions of SHP-1, c-fos, c-jun, and NF-E2 were significantly higher in the chemically damaged model group (all P<0.05). The protein expressions of SHP-1, c-fos, c-jun, and NF-E2 were significantly lower in the chemically damaged model+the low dose JBP, chemically damaged model+high dose JBP, or chemically damaged model+EJS group compared to chemically damaged model (all P<0.05), with the low dose JBP producing the best results. These results indicate that JBP regulates the expressions of SHP-1, Wnt3a, and AP-1 proteins in chemically damaged mice.

Effect of the Jianpi Bushen Prescription on expressions of the Wnt3a and Cyclin D1 genes in radiation-damaged mice

The effects of the traditional Chinese drug Jianpi Bushen Prescription (JBP) were investigated on expressions of Wnt3a and Cyclin D1 genes in radiation-damaged mice. The radiation damage model was induced in Kumming mice by single total body irradiation treatment for 9 days. Mice were divided into the radiation group, low-dose (100%) JBP group, high-dose (200%) JBP group, or batyl alcohol group (positive control), which were administered twice a day for 9 days. mRNA and protein expressions of Wnt3a were detected in bone marrow mononuclear cells by real-time polymerase chain reaction and Western blot, whereas Cyclin D1 mRNA was detected by in situ hybridization. Wnt3a expressions were significantly downregulated in the radiation damage model group compared with all other groups (P < 0.05). The positive cell rate of Cyclin D1 mRNA expression and the number of granulocyte macrophage colonies were significantly decreased in the radiation damage model group relative to all other groups (P < 0.05). Furthermore, mRNA and protein expressions of Wnt3a, the positive cell rate of Cyclin D1 mRNA expression in bone marrow cells, and the number of granulocyte macrophage colonies were all significantly higher in the low-dose JBP group than in the high-dose JBP group (P < 0.05). In summary, JBP plays a protective role on radiation-induced bone marrow through the activation of the Wnt3a signaling pathway, and promotes the transcription and expression of Cyclin D1.

Using next-generation sequencing as a genetic diagnostic tool in rare autosomal recessive neurologic Mendelian disorders

Next-generation sequencing was used to investigate 9 rare Chinese pedigrees with rare autosomal recessive neurologic Mendelian disorders. Five probands with ataxia-telangectasia and 1 proband with chorea-acanthocytosis were analyzed by targeted gene sequencing. Whole-exome sequencing was used to investigate 3 affected individuals with Joubert syndrome, nemaline myopathy, or spastic ataxia Charlevoix-Saguenay type. A list of known and novel candidate variants was identified for each causative gene. All variants were genetically verified by Sanger sequencing or quantitative polymerase chain reaction with the strategy of disease segregation in related pedigrees and healthy controls. The advantages of using next-generation sequencing to diagnose rare autosomal recessive neurologic Mendelian disorders characterized by genetic and phenotypic heterogeneity are demonstrated. A genetic diagnostic strategy combining the use of targeted gene sequencing and whole-exome sequencing with the aid of next-generation sequencing platforms has shown great promise for improving the diagnosis of neurologic Mendelian disorders.

Reversal of optical binding force by Fano resonance in plasmonic nanorod heterodimer

We present calculations of the optical force on heterodimer of two gold nanorods aligned head-to-tail, under plane wave illumination that is polarized along the dimer axis. It is found that near the dipole-quadrupole Fano resonance, the optical binding force between the nanorods reverses, indicating an attractive to repulsive transition. This is in contrast to homodimer which in similar configuration shows no negative binding force. Moreover, the force spectrum features asymmetric line shape and shifts accordingly when the Fano resonance is tuned by varying the nanorods length or their gap. We show that the force reversal is associated with the strong phase variation between the hybridized dipole and quadrupole modes near the Fano dip. The numerical results may be demonstrated by a near-field optical tweezer and shall be useful for studying "optical matters" in plasmonics.

Bipolar optical forces on dielectric and metallic nanoparticles by evanescent wave

We numerically show that both repulsive and attractive (bipolar) optical forces can be exerted on a dielectric or metallic cylindrical nanoparticle by a totally internal refracted wave. This requires that the particles possesses either a whispering gallery (WG) resonance or a localized surface plasmon (LSP) resonance. We further explore the force spectrum that is governed by competition between the separation-dependent resonant Q factor and the coupling strength of the nanoparticle to the evanescent wave. In spite of a much smaller Q of the LSP as compare to the WG resonances, the metallic particle gains much stronger trapping force.

Unique histological features of the left atrial posterior wall

The left atrial posterior wall (LAPW) plays a critical role in atrial fibrillation, but the underlying mechanism remains unclear. In the present study, we sought to characterize the histological features of the LAPW. Different atrial regions were dissected from hearts of normal Sprague-Dawley rats and humans. Haematoxylin/eosin and van Gieson staining were used to analyse atrial cardiomyocyte arrangement and collagen distribution, respectively. Intercellular junctions were evaluated by transmission electron microscopy. In contrast with other atrial regions, the LAPW exhibited more disorganized cardiomyocytes, larger intercellular spaces and variable myocardial fibre arrangement. The proportion of collagen was significantly higher in the LAPW than in other atrial regions. Interestingly, desmosomes were sparse along with intercellular gaps in the LAPW. In summary, distinct disarrangement of cardiomyocytes and an abundance of collagen exist in the LAPW. The sparsity of desmosomes in the LAPW may be related to the heterogeneous distribution and separation of atrial myocytes.

Correlating gene expression with chemical scaffolds of cytotoxic agents: ellipticines as substrates and inhibitors of MDR1

To facilitate a systematic study of chemoresistance across diverse classes of anticancer drug candidates, we performed correlation analyses between cytotoxic drug potency and gene expression in 60 tumor cell lines (NCI-60; NCI-National Cancer Institute). Ellipticine analogs displayed a range of correlation coefficients (r) with MDR1 (ABCB1, encoding multidrug resistance (MDR) protein MDR1 or P-glycoprotein). To determine MDR1 interactions of five ellipticines with diverse MDR1-r values, we employed MDR1-transport and cytotoxicity assays, using MDR1 inhibitors and siRNA-mediated MDR1 downregulation, in MDR1-overexpressing cells. Ellipticines with negative correlations-indicative of MDR1-mediated resistance-were shown to be MDR1 substrates, whereas those with neutral or positive correlations served as MDR1 inhibitors, which escape MDR1-mediated chemoresistance. Correlation with additional genes in the NCI-60 confirmed topoisomerases as ellipticine targets, but suggested distinct mechanisms of action and chemoresistance among them, providing a guide for selecting optimal drug candidates.