N-Protecting group tuning of the enantioselectivity in Strecker reactions of trifluoromethyl ketimines to synthesize quaternary α-trifluoromethyl amino nitriles by ion pair catalysis

An enantioselective Strecker reaction to construct trifluoromethylated quaternary stereocenters with N-PMP and unexplored N-Boc trifluoromethyl ketimines catalyzed using an organophosphine dual-reagent catalyst has been developed. The enantioselectivities of the corresponding products with the same catalyst could be switched by using different N-protecting groups (N-PMP or N-Boc). The trifluoromethyl amino nitriles were obtained in high yield and high enantioselectivity in a short time and could be easily converted to a variety of useful trifluoromethyl-containing compounds.

Relationships of Lipids Profile with Health-Related Quality of Life in Chinese Centenarians

OBJECTIVES

With the acceleration of the process of aging population, to enjoy a higher health-related quality of life (HRQoL) is the goal of the elderly population and public health. Studies on relationship between HRQoL and lipid profile through a large sample of representative elderly population are scare.

OBJECTIVE

This study was conducted to firstly explore the relationships of lipid profile with HRQoL in Chinese centenarian population.

PARTICIPANTS

A complete sample of 1002 participants aged over 100 years from Hainan province were recruited in the current study.

MAIN MEASURE

Questionnaire investigation, physical examination and blood specimen collection were carried out by family survey. The EuroQol-5 Dimensions(EQ-5D, and EQ-VAS were used to assess HRQoL.

RESULTS

In multivariate linear regression analyses, a significant association was found between EQ-5D and lipid profile, including total cholesterol (TC), triglyceride (TG), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), and similar association was also existed between EQ-VAS and TC, LDL-C HDL-C, after adjustment. The score of EQ-5D and EQ-VAS in male centenarian was higher than that of the female centenarian.

CONCLUSION

Lipid profile was positively associated with the HRQoL in Chinese centenarians.

Association of Anemia with Activities of Daily Living in Chinese Female Centenarian

OBJECTIVES

Although anemia and activities of daily living (ADL) disability in female elderly are common conditions and are more likely to occur as people age, little is known about the association of anemia with ADL in female centenarians. The objective of this study was to examine the relationship between anemia and ADL disability in Chinese female centenarians.

DESIGN, SETTING AND PARTICIPANTS

We conducted a population-based cross-sectional study of a sample of 822 Chinese female centenarians from 2014 to 2016.

MEASUREMENTS

Blood analysis, home interview, and physical examination were performed following standard procedures. ADL disability was defined as a Barthel Index total score≤60.

RESULTS

The prevalence of anemia and ADL disability were 66.8% and 29.7% respectively in Chinese female centenarians. Multiple logistic regression analyses revealed that inflammation (OR = 2.280, 95% CI, 1.524-3.410), underweight (OR = 1.653, 95% CI, 1.186-2.303), anemia (OR = 1.775, 95% CI, 1.250-2.521), and living with family (OR = 0.518, 95% CI, 0.302-0.888) were significant factors related to ADL disability. Centenarians with severe anemia had an approximately fourfold greater likelihood of ADL disability than those without anemia (OR =3.747; 95% CI 1.525-9.206). An apparent dose-response relationship was found between anemia and ADL disability.

CONCLUSION

These findings may provide some insights into targeted intervention for maintaining ADL independence in female centenarians, especially encouraging the interventions of anemia to improve ADL.

Multi-scale characterizations of colon polyps via computed tomographic colonography

Texture features have played an essential role in the field of medical imaging for computer-aided diagnosis. The gray-level co-occurrence matrix (GLCM)-based texture descriptor has emerged to become one of the most successful feature sets for these applications. This study aims to increase the potential of these features by introducing multi-scale analysis into the construction of GLCM texture descriptor. In this study, we first introduce a new parameter - stride, to explore the definition of GLCM. Then we propose three multi-scaling GLCM models according to its three parameters, (1) learning model by multiple displacements, (2) learning model by multiple strides (LMS), and (3) learning model by multiple angles. These models increase the texture information by introducing more texture patterns and mitigate direction sparsity and dense sampling problems presented in the traditional Haralick model. To further analyze the three parameters, we test the three models by performing classification on a dataset of 63 large polyp masses obtained from computed tomography colonoscopy consisting of 32 adenocarcinomas and 31 benign adenomas. Finally, the proposed methods are compared to several typical GLCM-texture descriptors and one deep learning model. LMS obtains the highest performance and enhances the prediction power to 0.9450 with standard deviation 0.0285 by area under the curve of receiver operating characteristics score which is a significant improvement.

Energy enhanced tissue texture in spectral computed tomography for lesion classification

Tissue texture reflects the spatial distribution of contrasts of image voxel gray levels, i.e., the tissue heterogeneity, and has been recognized as important biomarkers in various clinical tasks. Spectral computed tomography (CT) is believed to be able to enrich tissue texture by providing different voxel contrast images using different X-ray energies. Therefore, this paper aims to address two related issues for clinical usage of spectral CT, especially the photon counting CT (PCCT): (1) texture enhancement by spectral CT image reconstruction, and (2) spectral energy enriched tissue texture for improved lesion classification. For issue (1), we recently proposed a tissue-specific texture prior in addition to low rank prior for the individual energy-channel low-count image reconstruction problems in PCCT under the Bayesian theory. Reconstruction results showed the proposed method outperforms existing methods of total variation (TV), low-rank TV and tensor dictionary learning in terms of not only preserving texture features but also suppressing image noise. For issue (2), this paper will investigate three models to incorporate the enriched texture by PCCT in accordance with three types of inputs: one is the spectral images, another is the co-occurrence matrices (CMs) extracted from the spectral images, and the third one is the Haralick features (HF) extracted from the CMs. Studies were performed on simulated photon counting data by introducing attenuation-energy response curve to the traditional CT images from energy integration detectors. Classification results showed the spectral CT enriched texture model can improve the area under the receiver operating characteristic curve (AUC) score by 7.3%, 0.42% and 3.0% for the spectral images, CMs and HFs respectively on the five-energy spectral data over the original single energy data only. The CM- and HF-inputs can achieve the best AUC of 0.934 and 0.927. This texture themed study shows the insight that incorporating clinical important prior information, e.g., tissue texture in this paper, into the medical imaging, such as the upstream image reconstruction, the downstream diagnosis, and so on, can benefit the clinical tasks.

[The 471st case: duodenal ulcer, mucor infection, and elevated IgG(4)]

Mucor infection is rarely reported in non-immunocompromised population, especially in isolated gastrointestinal tracts. IgG(4)-related diseases (IgG(4)-RD) have been recognized in recent years, but secondary causes of IgG(4) elevation should be differentiated. We reported a young man with duodenal mass and ulcer and high serum IgG(4) level. Histological biopsy of the mass revealed positive mucor mycelium and infiltration of IgG(4) positive plasma cells. Serum IgG(4) decreased to normal range after surgical resection and systemic antifungal treatment. This case suggests that isolated mucor mycosis infection can develop in the digestive tract and mimics as IgG(4)-related disease.

DFMD: Fast and Effective DelPhiForce Steered Molecular Dynamics Approach to Model Ligand Approach Toward a Receptor: Application to Spermine Synthase Enzyme

Here we report a novel approach, the DelPhiForce Molecular Dynamics (DFMD) method, for steered molecular dynamics simulations to model receptor-ligand association involving charged species. The main purpose of developing DFMD is to simulate ligand's trajectory toward the receptor and thus to predict the "entrance" of the binding pocket and conformational changes associated with the binding. We demonstrate that the DFMD is superior compared with molecular dynamics simulations applying standard cut-offs, provides correct binding forces, allows for modeling the ligand approach at long distances and thus guides the ligand toward the correct binding spot, and it is very fast (frequently the binding is completed in <1 ns). The DFMD is applied to model the binding of two ligands to a receptor (spermine synthase) and it is demonstrated that it guides the ligands toward the corresponding pockets despite of the initial ligand's position with respect to the receptor. Predicted conformational changes and the order of ligand binding are experimentally verified.

The Chinese National Twin Registry: a 'gold mine' for scientific research

The Chinese National Twin Registry (CNTR) currently includes data from 61 566 twin pair from 11 provinces or cities in China. Of these, 31 705, 15 060 and 13 531 pairs are monozygotic, same-sex dizygotic and opposite-sex dizygotic pairs, respectively, determined by opposite sex or intrapair similarity. Since its establishment in 2001, the CNTR has provided an important resource for analysing genetic and environmental influences on chronic diseases especially cardiovascular diseases. Recently, the CNTR has focused on collecting biologic specimens from disease-concordant or disease-discordant twin pairs or from twin pairs reared apart. More than 8000 pairs of these twins have been registered, and blood samples have been collected from more than 1500 pairs. In this review, we summarize the main findings from univariate and multivariate genetic effects analyses, gene-environment interaction studies, omics studies exploring DNA methylation and metabolomic markers associated with phenotypes. There remains further scope for CNTR research and data mining. The plan for future development of the CNTR is described. The CNTR welcomes worldwide collaboration.

An investigation of CNN models for differentiating malignant from benign lesions using small pathologically proven datasets

Cancer has been one of the most threatening diseases to human health. There have been many efforts devoted to the advancement of radiology and transformative tools (e.g. non-invasive computed tomographic or CT imaging) to detect cancer in early stages. One of the major goals is to identify malignant from benign lesions. In recent years, machine deep learning (DL), e.g. convolutional neural network (CNN), has shown encouraging classification performance on medical images. However, DL algorithms always need large datasets with ground truth. Yet in the medical imaging field, especially for cancer imaging, it is difficult to collect such large volume of images with pathological information. Therefore, strategies are needed to learn effectively from small datasets via CNN models. To forward that goal, this paper explores two CNN models by focusing extensively on expansion of training samples from two small pathologically proven datasets (colorectal polyp dataset and lung nodule dataset) and then differentiating malignant from benign lesions. Experimental outcomes indicate that even in very small datasets of less than 70 subjects, malignance can be successfully differentiated from benign via the proposed CNN models, the average AUCs (area under the receiver operating curve) of differentiating colorectal polyps and pulmonary nodules are 0.86 and 0.71, respectively. Our experiments further demonstrate that for these two small datasets, instead of only studying the original raw CT images, feeding additional image features, such as the local binary pattern of the lesions, into the CNN models can significantly improve classification performance. In addition, we find that our explored voxel level CNN model has better performance when facing the small and unbalanced datasets.

Amphiphilic surface chemistry of fullerenols is necessary for inhibiting the amyloid aggregation of alpha-synuclein NACore

Featuring small sizes, caged structures, low cytotoxicity and the capability to cross biological barriers, fullerene hydroxy derivatives named fullerenols have been explored as nanomedicinal candidates for amyloid inhibition. Understanding the surface chemistry effect of hydroxylation extents and the corresponding amyloid inhibition mechanisms is necessary for enabling applications of fullerenols and also future designs of nanomedicines in mitigating amyloid aggregation. Here, we investigated effects of C60(OH)n with n = 0-40 on the aggregation of NACore (the amyloidogenic core region of the non-amyloid-β component in α-synuclein), the amyloidogenic core of α-synuclein, by computational simulations, transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, thioflavin-T (ThT) fluorescence kinetics and viability assays. Computationally, NACore assembled into cross-β aggregates via intermediates including β-barrels, which are postulated as toxic oligomers of amyloid aggregation. Hydrophobic C60 preferred to self-assemble, and NACore bound to the surface of C60 nano-clusters formed β-sheet rich aggregates - i.e., having little inhibition effect. Amphiphilic C60(OH)n with n = 4-20 displayed significant inhibition effects on NACore aggregation, where hydrogen bonding between hydroxyls and peptide backbones interrupted the formation of β-sheets between peptides adsorbed onto the surfaces of fullerenols or fullerenol nano-assemblies due to hydrophobic interactions. Thus, both cross-β aggregates and β-barrel intermediates were significantly suppressed. With hydroxyls increased to 40, fullerenols became highly hydrophilic with reduced peptide binding and thus an inhibition effect on amyloid aggregation. ThT, FTIR and TEM characterization of C60(OH)n with n = 0, 24, & 40 confirmed the computational predictions. Our results and others underscore the importance of amphiphilic surface chemistry and the capability of polar groups in forming hydrogen bonds with peptide backbones to render amyloid inhibition, offering a new insight for de-novo design of anti-amyloid inhibitors.

The maximum diameter of cervical lymph node was not a prognostic factor for local-regional advanced nasopharyngeal carcinoma treated with intensity modified radiotherapy

Background

Cervical lymph node metastasis was an important prognostic factor. However, the prognosis of the maximum diameter of cervical lymph nodes before treatment has always been controversial. The aim of this study was to analyze the relationship between treatment outcomes and the maximum diameter of lymph nodes (Dmax) in loco-regional advanced nasopharyngeal carcinoma (NPC) after intensity modified radiotherapy.

Methods

From Jan. 2012 to Dec. 2017, 163 patients with locally advanced NPC treated with intensity modified radiotherapy were retrospectively analyzed. The T-stage distribution was 6.7% in T1, 23.3% in T2, 38.7% in T3, and 31.3% in T4. The N-classifications were 6.1% in N0, 23.3% in N1, 47.9% in N2, and 22.7% in N3. TNM stages were III 51.5% and IVa 48.5%. All patients received intensity modified radiotherapy to the nasopharynx and neck. The dose was 66–70.4 Gy, 2–2.2 Gy per fraction over 6–7 weeks to the primary tumor and lymph nodes and 54–60 Gy to clinical target volumes (CTVs). One hundred fifty patients were received induction chemotherapy and/or concurrent chemotherapy. The maximum diameter of the lymph node is measured on the axial or coronal MRI image.

Results

The median follow-up time was 31 months (range, 6.1–79.3 months). Six cases developed neck recurrence and 9 cases developed nasopharynx recurrence. The lymph nodes diameter was 0–12 cm, median 2.9 cm. Three-year overall survival (OS) rate was 77.8%. Three-year local failure-free rate (L-FFR), distant failure-free rate (D-FFR) and disease-free survival (DFS) rate were 88.1%, 77.6% and 63.9% respectively. Multivariate analysis showed Dmax was not a prognostic factor for OS, L-FFR, D-FFR, DFS. Both uni- and multivariate analyses demonstrated that N-classification and age is the significant prognostic factor for predicting OS while the maximum diameter of lymph nodes, T-classification, N-classification and AJCC-classification are the significant prognostic factor for predicting OS in univariate analyses in local-regional advanced NPC.

Conclusions

The maximum diameter of the lymph nodes was not a prognostic factor for local-regional advanced NPC treated with intensity modulated radiotherapy.

Patterns of local failure in patients with high-grade glioma after postoperative radiotherapy with or without chemotherapy

Background

To retrospectively analyze the failure patterns of postoperative adjuvant chemoradiotherapy for high-grade glioma (HGG) under the new WHO classification, particularly focusing on relationship of recurrence pattern and molecular subtypes.

Methods

This retrospective study was conducted in Ruijin Hospital of Shanghai Jiaotong University from April 2014 to April 2018. A total of 56 patients diagnosed as WHO III–IV were included. Patients, who underwent pathological typing according to the 2016 WHO Classification of Tumors of the Central Nervous (CNCS), including tumor grade and IDH status. We collected the basic data. The initial relapsed T1 enhancement MRI imaging was transferred and fused to the original treatment planning CT. The tumors were classified as in-field, marginal, or out-field if greater than 80%, 20–80%, or less than 20% of the recurrent volume fell within the 95% isodose line, respectively.

Results

The median overall survive was 22.0 months (95% CI: 16.7–27.2). The 1-, 2-, and 3-year survival rates were 85.8%, 43.9%, and 28.8%, respectively. Thirty-three (58.9%) patients progressed with a median progression survival of 15.9 (95% CI: 12.9–19.0) months. Of 33 patients experienced recurrence, 22 (66.7%) had in-field recurrence within a 9.3-month median period (range, 3–32.7 months), and 3 patients (9.1%) were respectively marginal recurrence occurred at 5.9, 6.4, and 15 months, and 6 patients (18.2%) developed out-field progression at a median of 16.1 (4.5–27.1) months, and 2 patients developed both in- and out-field recurrence (6.1%) at 3.2, 4.7 months, respectively. There were16 cases of WHO III, 40 cases of WHO IV, 13 cases of IDH mutation (IDHmt), 30 cases of wildtype (wt) and 13 cases of NOS. The incidence of recurrence of IDHmt (4 cases, 30%) was significantly lower than that of IDHwt (19 cases, 63.3%) and IDH NOS (10 cases, 76.9%) (P=0.001). Local recurrence (in the field and margin) of radiotherapy was 16 cases (84.2%) of IDHwt and 2 cases (50%) of IDHmt type (P=0.05).

Conclusions

In this study, we highlighted the importance of genomic research on identifying local failure patterns and providing recommendations of target delineation for HGG treatment. IDHwt HGG had a higher probability of in-field recurrence after radiotherapy, and RTOG target delineation guide was appropriate, while EORTC guidelines were recommended to IDHmt HGG. Further investigations in prospective randomized clinical trials were warranted to confirm our results.

Suicide inactivation of the uracil DNA glycosylase UdgX by covalent complex formation

A uracil DNA glycosylase (UDG) from Mycobacterium smegmatis (MsmUdgX) shares sequence similarity with family 4 UDGs and forms exceedingly stable complexes with single-stranded uracil-containing DNAs (ssDNA-Us) that are resistant to denaturants. However, MsmUdgX has been reported to be inactive in excising uracil from ssDNA-Us and the underlying structural basis is unclear. Here, we report high-resolution crystal structures of MsmUdgX in the free, uracil- and DNA-bound forms, respectively. The structural information, supported by mutational and biochemical analyses, indicates that the conserved residue His109 located on a characteristic loop forms an irreversible covalent linkage with the deoxyribose at the apyrimidinic site of ssDNA-U, thus rendering the enzyme unable to regenerate. By proposing the catalytic pathway and molecular mechanism for MsmUdgX, our studies provide an insight into family 4 UDGs and UDGs in general.

Genotyping of Circulating Tumor DNA Reveals the Clinically Actionable Mutation Landscape of Advanced Colorectal Cancer

Circulating tumor DNA (ctDNA) enables genomic profiling of colorectal cancer. We investigated therapeutic targets by performing ctDNA panel-captured sequencing of 152 blood samples from advanced stage patients, from which somatic mutations and potentially actionable targets were evaluated. An additional 11 matched tissue samples were retrospectively obtained to verify target validity. The mutation frequencies of 1,127 collective genetic variants identified in our study strongly correlated with those of multiple public databases (Pearson R ² = 0.92, P < 0.0001). The clonal fraction of driver genes was 90.3%, which was significantly higher than that of potential passenger genes (58.12%). Totally, 90 drug-sensitive genes from 56 patients (36.84%) were identified, including recurring targets PIK3CA, FBXW7, EGFR, BRAF, and NRAS Various resistance mechanisms of anti-EGFR antibodies were revealed via ctDNA profiling, with 29 patients individually exhibiting multiple mechanisms, suggesting considerable resistance heterogeneity in our study population. Of the matched tissue/blood pairs, 88.14% of tissue-derived mutations were detected in ctDNA, and 88.9% of actionable targets were validated. The mutational landscape of ctDNA was highly consistent with tissue databases, and ctDNA profiling showed favorable concordance with tumor tissues in our matched analysis. Thus, comprehensive ctDNA genotyping is a promising noninvasive alternative to biopsy-derived analysis for determining targeted therapy in advanced colorectal cancer.

[Effect of data missing on population based viral load survey in HIV infected men who have sex with men sampled in 16 large cities, China]

Objective: To analyze the effect of missing data in population based viral load (PVL) survey in HIV infected men who have sex with men (MSM) sampled in 16 cities in China. Methods: The database of 3 virus load sampling survey conducted consecutively in HIV infected MSM population in 16 large cities (Beijing, Shanghai, Nanjing, Hangzhou, Wuhan, Chongqing, Kunming, Xi'an, Guangzhou, Shenzhen, Nanning, Urumuqi, Harbin, Changchun, Chengdu and Tianjin) during 2013-2015 was used. SPSS 17.0 software was used to describe distribution of the missing data and analyze associated factors. Results: A total of 12 150 HIV infected MSM were randomly selected for the surveys, in whom, 9 141 (75.2%) received virus load tests, while 3 009 (24.8%) received no virus load tests, whose virus load data missed. The virus load data missing rates in MSM with or without access to antiretroviral therapy (ART) were 11.5% (765/6 675) and 39.4% (2 060/5 223) respectively, and the virus load data missing rates were 21.9% (1 866/8 523) and 28.4% (959/3 374), respectively, in local residents and non-local residents (migrants). Conclusions: The analysis indicated that the data missing occurred in the virus load survey in HIV infected MSM population. ART status and census registering status were the main influencing factors. Data missing could influence the accurate evaluation of community viral load (CVL) and population viral load(PVL) levels in HIV infected MSM in China.