Capacitive biosensors for label-free and ultrasensitive detection of biomarkers

Capacitive biosensors are label-free capacitors that can detect biomarkers with the outstanding advantages of simplicity, low cost, and ultrahigh sensitivity. A typical capacitive biosensor consists of a bioreceptor and a transducer, where the bioreceptor captures the biomarker to form a bioreceptor/biomarker conjugate and the transducer generates a detectable signal. In general, antibodies, aptamers, or proteins are exploited as the bioreceptor, while various electrodes including carbon electrodes (CEs), gold electrodes (AuEs), or interdigitated electrodes (IDEs) may serve as the transducer. Because the formation of bioreceptor/biomarker conjugates often leads to a change in capacitance, the capacitive signal is then employed for biomarker detection. This review summarizes recent advances in capacitive biosensors for the detection of biomarkers over the last five years. With a focus on the three common types of bioreceptors, i.e., antibodies, aptamers, and proteins, capacitive biosensors using CEs, AuEs, and IDEs as the transducers are discussed in detail. The immobilization of bioreceptors and signal amplification strategies are described to provide a robust overview of capacitive biosensors for biomarker detection. In addition, analytical methods and future prospects are given to support the application of capacitive biosensors.

The complete chloroplast genome of Vaccinium oxycoccos (Ericaceae)

Vaccinium species have great significance as fruit crops due to their economic and food values. Here we report the chloroplast genome of V. oxycoccos. The chloroplast genome of V. oxycoccos was 177,088 bp in length with a GC content of 36.74%. LSC, SSC, and IR regions were 104,139 bp, 3031 bp, and 34,959 bp in length, respectively. The chloroplast genome contained 105 different genes, including 73 protein-coding genes, 4 rRNA genes, and 28 tRNA genes. The phylogenetic analysis indicated that V. oxycoccos was closely related to V. microcarpum in the family Ericaceae. This chloroplast genome not only enriches the genome information of Vaccinium, but also will be useful in the evolution study of the family Ericaceae.

The impact of multi-level interventions on the second-wave SARS-CoV-2 transmission in China

Background

A re-emergence of COVID-19 occurred in the northeast of China in early 2021. Different levels of non-pharmaceutical interventions, from mass testing to city-level lockdown, were implemented to contain the transmission of SARS-CoV-2. Our study is aimed to evaluate the impact of multi-level control measures on the second-wave SARS-CoV-2 transmission in the most affected cities in China.

Methods

Five cities with over 100 reported COVID-19 cases within one month from Dec 2020 to Feb 2021 were included in our analysis. We fitted the exponential growth model to estimate basic reproduction number (R₀), and used a Bayesian approach to assess the dynamics of the time-varying reproduction number (R_t). We fitted linear regression lines on R_t estimates for comparing the decline rates of R_t across cities, and the slopes were tested by analysis of covariance. The effect of non-pharmaceutical interventions (NPIs) was quantified by relative R_t reduction and statistically compared by analysis of variance.

Results

A total of 2,609 COVID-19 cases were analyzed in this study. We estimated that R₀ all exceeded 1, with the highest value of 3.63 (1.36, 8.53) in Haerbin and the lowest value of 2.45 (1.44, 3.98) in Shijiazhuang. Downward trends of R_t were found in all cities, and the starting time of R_t < 1 was around the 12th day of the first local COVID-19 cases. Statistical tests on regression slopes of R_t and effect of NPIs both showed no significant difference across five cities (P = 0.126 and 0.157).

Conclusion

Timely implemented NPIs could control the transmission of SARS-CoV-2 with low-intensity measures for places where population immunity has not been established.

Evaluations of candidate markers of dihydroartemisinin-piperaquine resistance in Plasmodium falciparum isolates from the China-Myanmar, Thailand-Myanmar, and Thailand-Cambodia borders

Background

The fast-declining clinical efficacy of dihydroartemisinin-piperaquine (DHA-PPQ) in Cambodia is a warning of the underlying westward dissemination of piperaquine resistance in the Greater Mekong Subregion (GMS). Mutations in the Plasmodium falciparum Kelch 13-propeller (PfK13) and the P. falciparum chloroquine resistance transporter (PfCRT), as well as plasmepsin 2/3 gene amplification, have been discovered as molecular markers for predicting DHA-PPQ treatment failure. Determining whether these genetic variations of P. falciparum are linked to DHA-PPQ resistance is critical, especially along the China–Myanmar (CM) border, where PPQ has been utilized for decades.

Methods

A total of 173 P. falciparum samples of dried blood spots (DBS) were collected along the CM border between 2007 and 2010, the Thailand–Cambodia (TC) border between 2009 and 2013, and the Thailand–Myanmar (TM) border between 2012 and 2014. PCR and sequencing were used to identified PfCRT mutations, while qPCR was used to determine the copy number of plasmepsin 2/3. The prevalence of DHA-PPQ resistance in three locations was investigated using data paired with K13 mutations.

Results

Three fragments of the pfcrt gene were amplified for all 173 samples, and seven SNPs were identified (M74I, N75E/D, K76T, H97L, I218F, A220S, I356L). No new PfCRT mutations conferring resistance to PPQ (T93S, H97Y, F145I, M343L, and G353V) were discovered, except for one mutant I218F identified in the TM border (2.27%, 1/44). Additionally, mutant H97L was found in the TC, TM, and CM borders at 3.57% (1/28), 6.82% (3/44), and 1% (1/101), respectively. A substantial K13 C580Y variant prevalence was found in the TC and TM border, accounting for 64.29% (18/28) and 43.18% (19/44), respectively, while only 1% (1/101) was found in the CM border. The K13 F446I variant was only identified and found to reach a high level (28.71%, 29/101) in the CM border. Furthermore, 10.71% (3/28) of TC isolates and 2.27% (1/44) of TM isolates carried more than one copy of plasmepsin 2/3 and K13 C580Y variant, while no plasmepsin 2/3 amplification was identified in the CM isolates.

Conclusions

Compared with the P. falciparum samples collected from the TC and TM borders, fewer parasites carried plasmepsin 2/3 amplification and novel PfCRT variants, while more parasites carried predominant K13 mutations at position F446I, in the CM border. Clear evidence of DHA-PPQ resistance associated with candidate markers was not found in this border region suggesting a further evaluation of these markers and continuous surveillance is warranted.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-022-05239-1.

Efficient photoelectrochemical CO2 conversion for selective acetic acid production

Amidst the development of photoelectrochemical (PEC) CO₂ conversion toward practical application, the production of high-value chemicals beyond C₁ compounds under mild conditions is greatly desired yet challenging. Here, through rational PEC device design by combining Au-loaded and N-doped TiO₂ plate nanoarray photoanode with Zn-doped Cu₂O dark cathode, efficient conversion of CO₂ to CH₃COOH has been achieved with an outstanding Faradaic efficiency up to 58.1% (91.5% carbon selectivity) at 0.5 V vs. Ag/AgCl. Temperature programmed desorption and in situ Raman spectra reveal that the Zn-dopant in Cu₂O plays multiple roles in selective catalytic CO₂ conversion, including local electronic structure manipulation and active site modification, which together promote the formation of intermediate *CH₂/*CH₃ for C-C coupling. Apart from that, it is also unveiled that the sufficient electron density provided by the Au-loaded and N-doped TiO₂ plate nanoarray photoanode plays an equally important role by initiating multi-electron CO₂ reduction. This work provides fresh insights into the PEC system design to reach the multi-electron reduction reaction and facilitate the C-C coupling reaction toward high-value multicarbon (C₂₊) chemical production via CO₂ conversion.

Altering Hydrogenation Pathways in Photocatalytic Nitrogen Fixation by Tuning Local Electronic Structure of Oxygen Vacancy with Dopant

To avoid the energy-consuming step of direct N≡N bond cleavage, photocatalytic N₂ fixation undergoing the associative pathways has been developed for mild-condition operation. However, it is a fundamental yet challenging task to gain comprehensive understanding on how the associative pathways (i.e., alternating vs. distal) are influenced and altered by the fine structure of catalysts, which eventually holds the key to significantly promote the practical implementation. Herein, we introduce Fe dopants into TiO₂ nanofibers to stabilize oxygen vacancies and simultaneously tune their local electronic structure. The combination of in situ characterizations with first-principles simulations reveals that the modulation of local electronic structure by Fe dopants turns the hydrogenation of N₂ from associative alternating pathway to associative distal pathway. This work provides fresh hints for rationally controlling the reaction pathways toward efficient photocatalytic nitrogen fixation.

AMnAs3S6 (A = Cs, Rb): Phase-Matchable Infrared Nonlinear Optical Functional Motif [As3S6]3- Obtained via Surfactant-Thermal Method

Exploration of a new nonlinear optical (NLO)-active functional motif is important in the rational design of promising infrared (IR) NLO materials. Compared with typical tetrahedral MQ₄ (M = IIB, III, IV metals; Q = S, Se) motifs, MQ₃ (M = As, Sb) pyramids favor high second-harmonic generation (SHG) efficiency while frequently hindering phase matching (PM) because of excessively large optical anisotropy. The surfactant-thermal method was first adopted to achieve PM in MQ₃-containing systems and synthesize mixed covalent-ionic IR NLO materials. Two new thioarsenates of AMnAs₃S₆ (A = Cs, Rb) exhibiting strong PM SHG efficiencies comparable to commercial AGS and laser-induced damage thresholds of one order higher than AGS were obtained. The [As₃S₆]^3- unit in their structures is an unprecedented NLO-active functional motif, which can be useful in designing new IR NLO compounds with large SHG efficiency. In addition, the surfactant-thermal method provides a new general strategy for synthesizing new IR NLO materials.

Tuning the size of photo-deposited metal nanoparticles via manipulating surface defect structures of TiO2 nanocrystals

Here we report a new method for controlling photo-deposited metal nanoparticle size by manipulating surface defect structures of TiO2 nanocrystals. Our results demonstrate that the isolated oxygen vacancy could serve as an electron trapper while the oxygen vacancy cluster could act as an electron-hole recombination site in the photo-deposition process.

Ionic strength effect on regulating the synthetic assembly of polyoxometalate clusters with slow magnetic relaxation behavior

Three novel polyoxometalate (POM) clusters of K10Na10[Dy3(H2O)6Ni(H2O)(W3O11)(B-α-SbW9O33)3]·(H2O)45 (1), (NH4)5K4Na8[Dy3(H2O)6SbV(H2O)(W3O11)(B-α-SbW9O33)3]·(H2O)50 (2), and (NH4)9Na[Ni2(H2O)6(WO2)2(B-β-SbW9O33)2]·(H2O)24 (3) were successfully obtained using the same precursor under different ionic strength conditions. Structural analysis showed that compounds 1-3 possess discrepant structural characteristics in 1 M KCl, 1 M NH4Cl, and saturated NH4Cl, respectively. Among them, 2 is the first reported lanthanide cluster including both Sb3+ and Sb5+ in POM derivatives. Furthermore, the analysis of ac magnetic data proved that 1 and 2 embodied dramatic field-induced slow magnetic relaxation, and the effective barrier of 2 was estimated as Ueff/KB = 21.10 K based on the Orbach process. It was found that the structure and magnetic properties of POM materials can be regulated using an effective and satisfactory ionic strength-controlled strategy.

Genome-Wide Analysis of Genetic Diversity in Plasmodium falciparum Isolates From China-Myanmar Border

Plasmodium falciparum isolates from China-Myanmar border (CMB) have experienced regional special selective pressures and adaptive evolution. However, the genomes of P. falciparum isolates from this region to date are poorly characterized. Herein, we performed whole-genome sequencing of 34 P. falciparum isolates from CMB and a series of genome-wide sequence analyses to reveal their genetic diversity, population structures, and comparisons with the isolates from other epidemic regions (Thai-Cambodia border, Thai-Myanmar border, and West Africa). Totally 59,720 high-quality single-nucleotide polymorphisms (SNPs) were identified in the P. falciparum isolates from CMB, with average nucleotide diversity (π = 4.59 × 10^-4) and LD decay (132 bp). The Tajima's D and Fu and Li's D values of the CMB isolates were -0.8 (p < 0.05) and -0.84 (p < 0.05), respectively, suggesting a demographic history of recent population expansion or purifying selection. Moreover, 78 genes of the parasite were identified that could be under positive selection, including those genes conferring drug resistance such as pfubp1. In addition, 33 SNPs were identified for tracing the source of the parasites with a high accuracy by analysis of the most differential SNPs among the four epidemic regions. Collectively, our data demonstrated high diversity of the CMB isolates' genomes forming a distinct population, and the identification of 33-SNP barcode provides a valuable surveillance of parasite migration among the regions.

Texture analysis of multi-phase MRI images to detect expression of Ki67 in hepatocellular carcinoma

AIM

To determine whether texture analysis of preoperative magnetic resonance imaging (MRI) images could be used to detect Ki67 expression, a widely used cell proliferation marker in hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

In total, 83 patients were included, 25 with low Ki67 (Ki67 ≤10%) HCC expression and 58 with high Ki67 (Ki67 ≥10%) HCC expression as demonstrated by retrospective surgical evaluation. All patients were examined using a 3 T MRI unit with one standard protocol. The region of interest was drawn manually by one radiologist. Texture analysis included histogram, co-occurrence matrix, run-length matrix, gradient, auto-regressive model, and wavelet transform features as calculated by MaZda (version 4.6; quantitative texture analysis software). The features reduced by the Fisher, probability of classification error, and average correlation coefficient (POE+ACC), mutual information were used to select the features that predicted Ki67 proliferation status with highest accuracy and then using the B11 program for data analysis and classification.

RESULTS

The misclassification rate of the principal component analysis (PCA) in the hepatobiliary phase (HBP), T2-weighted imaging (T2WI), arterial phase (AP), and portal vein phase (PVP) was 36/83 (43.37%), 35/82 (42.68%), 40/83 (48.19%), and 34/83 (40.96%), respectively. The misclassification of the linear discriminant analysis in HBP, T2WI, AP, and PVP phase was 13/83 (15.66%), 21/82 (25.61%), 9/83 (10.84%), and 8/83 (9.64%), respectively. The misclassification of the nonlinear discriminant analysis in HBP, T2WI, AP, and PVP phase was 7/83 (8.43%), 6/82 (7.32%), 5/83 (6.02%), and 7/83 (8.43%), respectively.

CONCLUSIONS

Texture analysis of HBP, AP, and PVP were helpful for predicting Ki67 expression and may provide a less-invasive method to investigate critical histopathology markers for HCC.

Effects of aging, baseline renal function and stage of HIV infection on post-treatment changes in renal function among HIV-infected patients: a retrospective cohort study

OBJECTIVES

The use of combination antiretroviral therapy (cART) increases clinical uncertainty about changes in renal function. Specifically, little is known regarding the interaction of the effects of aging, baseline renal impairment, and stages of HIV infection on post-treatment changes in renal function.

METHODS

This analysis included 5533 HIV-infected patients on cART in 2004-2016. Progression to chronic kidney disease (CKD) was defined as either two consecutive estimated glomerular filtration rate (eGFR) measurements < 60 mL/min/1.73 m² for baseline eGFR ≥ 60 mL/min/1.73 m² (mild renal impairment or normal renal function) or a 25% decline for baseline eGFR < 60 mL/min/1.73 m² (moderate renal impairment).

RESULTS

During follow-up (median 4.8 years), 130 (2.3%) of the patients progressed to CKD. A total of 20.1% of patients with baseline normal renal function progressed to mild renal impairment, while 74.0% of patients with baseline mild or moderate renal impairment improved to normal renal function. In multivariable analysis, a significant positive baseline-eGFR-by-World Health Organization (WHO)-stage interaction effect on progression to CKD in all patients was identified, indicating a cross-over effect from a reduced risk to an increased risk. A significant negative baseline-age-by-WHO-stage interaction effect on progression to mild renal impairment in patients with baseline normal renal function was identified, with adjusted hazard ratios progressively lower at older ages. In addition, there were significant associations with older age, lower baseline eGFR, Dai ethnic minority, and anaemia for both outcomes, hyperglycaemia for CKD only, and higher CD4 count, tenofovir and ritonavir-boosted lopinavir use for mild renal impairment only.

CONCLUSIONS

Our data suggest a complex pattern of renal function dynamics in patients on cART, which requires precise management with systematic monitoring of the interaction of the effects of sociodemographic, nephrological and HIV-specific clinical characteristics.

Small hepatocellular carcinoma: using MRI to predict histological grade and Ki-67 expression

AIMS

To investigate the predictive indicators of small aggressive hepatocellular carcinomas by examining the association between preoperative magnetic resonance imaging (MRI) parameters and Ki-67 expression and histological grade.

MATERIALS AND METHODS

Sixty patients with small hepatocellular carcinomas (tumour diameter: ≤3 cm, tumour numbers: ≤2) who underwent curative resection or biopsy after contrast-enhanced and diffusion-weighted MRI were evaluated retrospectively. Signal intensity (SI) of the whole lesion and erector spinae muscle was measured quantitatively. Tumour-to-muscle SI ratio was calculated. The association between these MRI parameters and histological grade and Ki-67 level was then investigated.

RESULTS

There was a significant correlation between tumour-to-muscle SI ratio and histological grade in tissues captured during the non-enhanced T1-weighted (p=0.001), arterial phase (p=0.001), and portal venous phase (p=0.036) of dynamic contrast-enhanced MRI and apparent diffusion coefficient (p=0.027). Arterial inhomogeneous enhancement was also correlated with high-Ki-67 expression (p=0.032).

CONCLUSIONS

Preoperative MRI may serve as a non-invasive tool for prediction of small, aggressive hepatocellular carcinomas, which may otherwise be treated conservatively.

Hitherto-Unexplored Photodynamic Therapy of Ag2 S and Enhanced Regulation Based on Polydopamine In Vitro and Vivo

Given their superior penetration depths, photosensitizers with longer absorption wavelengths present broader application prospects in photodynamic therapy (PDT). Herein, Ag₂ S quantum dots were discovered, for the first time, to be capable of killing tumor cells through the photodynamic route by near-infrared light irradiation, which means relatively less excitation of the probe compared with traditional photosensitizers absorbing short wavelengths. On modification with polydopamine (PDA), PDA-Ag₂ S was obtained, which showed outstanding capacity for inducing reactive oxygen species (increased by 1.69 times). With the addition of PDA, Ag₂ S had more opportunities to react with surrounding O₂ , which was demonstrated by typical triplet electron spin resonance (ESR) analysis. Furthermore, the PDT effects of Ag₂ S and PDA-Ag₂ S achieved at longer wavelengths were almost identical to the effects produced at 660 nm, which was proved by studies in vitro. PDA-Ag₂ S showed distinctly better therapeutic effects than Ag₂ S in experiments in vivo, which further validated the enhanced regulatory effect of PDA. Altogether, a new photosensitizer with longer absorption wavelength was developed by using the hitherto-unexplored photodynamic function of Ag₂ S quantum dots, which extended and enhanced the regulatory effect originating from PDA.

Characteristics of miliary tuberculosis in pregnant women after in vitro fertilisation and embryo transfer

OBJECTIVE

To analyse the clinical characteristics of miliary tuberculosis (TB) in pregnant women after in vitro fertilisation and embryo transfer (IVF-ET).

METHODS

Six pregnant women with miliary TB after IVF-ET between October 2010 and July 2015 were retrospectively analysed.

RESULTS

The patients were aged between 29 and 39 years. Fever, cough and dyspnoea were the main symptoms, and started during the first and second trimesters of pregnancy. Erythrocyte sedimentation rate and C-reactive protein were increased. White blood cell count was normal or slightly increased. Tuberculin purified protein derivative and acid-fast smear of sputum tests were negative. T-SPOT^®.TB was performed in two cases and the results were positive. Chest computed tomography showed typical miliary nodules. One patient had tuberculous meningitis. Although all patients were cured, the foetuses died.

CONCLUSIONS

The principal symptoms of miliary TB in pregnant women after IVF-ET were fever and dyspnoea. Physicians should consider the occurrence of miliary TB, particularly in the case of fever of long duration, respiratory symptoms and no response to antibiotic treatment.

BaMnSnS4 and BaCdGeS4: infrared nonlinear optical sulfides containing highly distorted motifs with centers of moderate electronegativity

IR NLO sulfides BaMnSnS₄ and BaCdGeS₄ exhibit significant SHG efficiencies (1.2 and 0.3AgGaS₂) with phase-matching behavior and high laser-induced damage thresholds (10 and 13AgGaS₂).

[Efficacy of endoscopic approach to reconstruct the medial orbital fracture with perpendicular plate of ethmoid]

Objective:To study the efficacy of endoscopic sinus approach in the repair of medial orbital fracture with perpendicular plate of ethmoid.Method:Retrospective chart was reviewed in 10 cases receiving endoscopic approach to reconstruct the medial orbital fracture with perpendicular plate of ethmoid.We observed the improvement of the symptom such as diplopia, eye movement,and enophthalmos of the preoperative and postoperative.Result:After postoperative follow-up of 4 months to 23 months, all the patients had no graft loss or displacement, infection and other complications, and except for 1 patient with mild diplopia, other patients recovered completely, including eye movement disorder, diplopia,and enophthalmos.Conclusion:Endoscopic approach is a safe and effective treatment in the repair of medial orbital fracture with perpendicular plate of ethmoid.

Efficacy and safety of pramipexole extended-release in Parkinson's disease: a review based on meta-analysis of randomized controlled trials

BACKGROUND AND PURPOSE

We performed a meta-analysis of randomized controlled trials to evaluate the efficacy and safety of pramipexole extended-release (pramipexole ER) versus pramipexole immediate-release (pramipexole IR) or placebo in Parkinson's disease.

METHODS

We performed a systematic online search for clinical trials for pramipexole ER treatment up to 1 August 2016. We assessed differences in Unified Parkinson's Disease Rating Scale (UPDRS) scores, percentage of 'on' time or 'off' time, withdrawals, adverse events (AEs) and life quality between pramipexole ER and pramipexole IR or placebo. Data analyses were performed by the Cochrane Collaboration's Review Manager 5.3 software.

RESULTS

Six randomized controlled trials were included. Compared with placebo, pramipexole ER achieved a significant improvement in the UPDRS Part II + III score [weighted mean difference, -4.81; 95% confidence interval (CI), -6.40 to -3.23], whereas no significant difference was found in the UPDRS Part III + III score between pramipexole ER and pramipexole IR groups (weighted mean difference, -0.26; 95% CI, -1.15 to 0.64). No differences were found in total AEs (relative risk, 0.97; 95% CI, 0.92 to 1.03), drug-related AEs (relative risk, 0.97; 95% CI, 0.92 to 1.03) or the commonly reported AEs between pramipexole ER and pramipexole IR.

CONCLUSIONS

Pramipexole ER is as safe and effective as pramipexole IR in the treatment of Parkinson's disease.

More improvement than progression of liver fibrosis following antiretroviral therapy in a longitudinal cohort of HIV-infected patients with or without HBV and HCV co-infections

We examined the effect of combination antiretroviral therapy (cART) on liver fibrosis among HIV-infected patients with or without hepatitis B (HBV) or C virus (HCV) co-infection. This was a retrospective cohort study of HIV-infected patients receiving cART during 2004-2016. Liver fibrosis was assessed using Fibrosis-4 (FIB-4) score with three classifications: Class 1, <1.45; Class 2, 1.45-3.25; Class 3, >3.25. Of 3900 participants, 68.6% were HIV mono-infected, 5.3% were HIV/HBV co-infected, 23.8% were HIV/HCV co-infected and 2.3% were HIV/HBV/HCV co-infected. Participants received follow-up treatment (median was 3.3 years). Improvement to a lower class was observed in Class 2 (52.6%) and Class 3 (74.2%), respectively. Progression to a higher class was observed in 12.8% and 5.0% in Class 1 and Class 2, respectively, and with a median time of 5.7 months. For improvement to lower classes, older age, male, Dai ethnicity, injection drug use, HCV co-infection and tenofovir for treatment were negative predictors, but in Class 3 of FIB-4 and time-updated increases in CD4 count from baseline were positive predictors. For progression to higher classes, older age, male, Jingpo ethnicity and HCV co-infection were positive predictors, while baseline CD4 count and in Class 2 of FIB-4 were negative predictors. Improvement to lower class linked with decreased mortality risk among patients in Class 3. Early cART initiation for HIV-infected patients with and without hepatitis co-infections may mitigate or slow down some of liver fibrosis, but special attention should be given to those who are older, male, co-infected with HCV.

Abstract P5-11-11: A phase I safety study of topical calcitriol (BPM31543) for the prevention of chemotherapy-induced alopecia (CIA)

Background: Chemotherapy induced alopecia (CIA) may lead to significant psychosocial and quality of life issues. Currently there are no FDA approved oral or topical agents available to prevent CIA. In murine studies, topical calcitriol reduced CIA, due to arrest of cell cycle in healthy hair follicles, and reduction in the sensitivity of follicular epithelium to chemotherapy.

Methods: A prospective dose escalation study is being performed in up to 31 women with breast cancer, gynecologic cancer and sarcomas. Each patient is applying 1mL of BPM31543 to her scalp bid, ≥ 5 days prior to initiation of taxane-based chemotherapy for at least 3 months or until the completion of chemotherapy. The study cohorts are: 5/10/20/40/60/80μg/mL. The first 5 cohorts are completely enrolled and the final cohort is currently being enrolled. Each patient undergoes pk analysis, adverse event (AE) monitoring, patient self-assessment diaries (1-10 scale), and blinded photographic assessments. Efficacy and pK data are still being collected and analyzed for the patients on study, but will be available by December.

Results: Twenty-four subjects have been enrolled so far (evaluable at this time, n = 13). Pk data (n = 16; 5-40μg/mL) showed inter-individual variability, but no significant dose-dependent increase in systemic absorption (range, &lt; 20-110 pg/mL). Treatment-related AEs (probably/possibly) were mild/moderate in nature and included scalp pain (n = 1; 5 μg/mL), elevated vitamin D levels in 1 patient (20μg/mL) and passage of renal calculus in another (n = 1; 40μg/mL). All subjects reported changes in overall hair fullness, thickness, and volume of hair during chemotherapy. At the 5/10 μg/mL dose level, ≥ 75% hair loss was reported in 85% of patients. At the ≥ 20 μg/mL dose level, ≥ 75% hair loss was seen only in 43% of patients. Hair loss/ thinning caused all subjects to change their hair style (onset, week 2; peak, weeks 5-6).

Conclusions: Data have shown that the twice daily application of BPM31543 in patients receiving taxane-based chemotherapy was safe and well-tolerated. Efficacy data from the preliminary analysis was promising and led to the amendment of the study to evaluate two additional higher dose cohorts: 60 and 80 μg/ml.

Citation Format: Goldfarb SB, Konner J, Stevens J, Brouwer S, Narain NR, Ye R, Ravipaty S, Sarangarajan R, Akmaev VR, Jimenez JJ, Belum VR, 'Kitts S, Ciccolini K, Berman B, Lacouture ME. A phase I safety study of topical calcitriol (BPM31543) for the prevention of chemotherapy-induced alopecia (CIA) [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-11-11.

Stage-Specific Relationship between Frailty and Cognitive Impairment in a Specialist Memory Clinic Setting

BACKGROUND

It is unclear if the complex relationship between physical frailty and cognition varies across the severity of cognitive impairment.

OBJECTIVES

We therefore aimed to explore if there are stage-specific differences in the relationship between frailty and cognitive impairment.

DESIGN

Cross-sectional study.

SETTING

A specialist Memory Clinic setting.

PARTICIPANTS

Mild cognitive impairment (MCI) and mild-moderate Alzheimer's disease (AD) community-dwelling subjects.

MEASUREMENTS

We obtained data on demographics, multimorbidity, cognition-related measures, nutrition, neuroimaging measures, muscle mass, Vitamin D level, apolipoprotein - e (APOE) status and physical performance measures. Frailty measures of gait speed, hand grip strength, question on exhausation and weight loss, classified subjects according to the Buchmann criteria into non-frail and frail categories.

RESULTS

Forty-five MCI, 64 mild AD and 13 moderate AD subjects (total n=122) were studied. The prevalence of frailty for MCI, mild AD and moderate AD was 35.6%, 21.9% and 46.2% respectively, indicating a u-shaped trend. Significant differences were noted in fatigue, grip strength and gait speed frailty sub-items. Significant correlation of frailty with cognition were noted in mild-moderate AD (Spearman's coefficient 0.26, p<0.05) but not in MCI (0.01, p=0.6). No other differences in multimorbidity, Vitamin D, APOE, nutritional measures, white matter lesions were observed. Sarcopenia interestingly had an inverse stage-specific relationship unlike frailty.

CONCLUSIONS

Our results suggest a U-shaped relationship between frailty and cognition, characterized by initial dissociation with cognitive impairment and subsequent convergence at later stages. Future studies incorporating immune markers and endocrine pathways with longitudinal follow-up could potentially elucidate intermediary mechanisms in the frailty cascade.

Distinctive origin of artemisinin-resistant Plasmodium falciparum on the China-Myanmar border

The artemisinin (ART), discovered in China, has been widely used against malaria in China over the last 30 years. Understanding the emergence and origin of ART resistance in China is therefore of great interest. We analyzed 111 culture-adapted isolates of P. falciparum from China-Myanmar (CM) border for their susceptibility to dihydroartemisinin using the ring stage survival assay (RSA_0−3h) and genotyped their K13 genes. Of the isolates, 59 had a wild type of the K13 marker and a median ring survival rate of 0.26% (P₉₅ = 1.005%). Among the remaining isolates harboring single mutations in the K13 marker, 26 survived at >P₉₅(median survival rate = 2.95%). Further, we genotyped the K13 gene of 693 isolates collected from different regions in China and China-Myanmar/Thai-Cambodia/Thai-Myanmar (CM/TC/TM) borders, 308 (44.4%) had K13 mutations and marked differences in the patterns of K13 mutations were observed between the CM and the TC/TM borders. A network diagram showed that majority of the K13 mutant alleles from the CM border clustered together including those harboring the high resistant-associated R539T mutations. The resistant parasites carrying distinct halplotypes suggested the multiple indigenous origins of the resistant alleles, which highlight the importance of surveillance of resistance in all malaria endemic areas where ART has been introduced.

A meta-analysis to evaluate the effectiveness of real-time PCR for diagnosing novel coronavirus infections

Novel coronavirus (nCoV) belongs to the Coronaviridae family, which includes the virus that causes SARS, or severe acute respiratory syndrome. However, infection source, transmission route, and host of nCoV have not yet been thoroughly characterized. In some cases, nCoV presented a limited person-to-person transmission. Therefore, early diagnosis of nCoV may be of importance for reducing the spread of disease in public. Methods for nCoV diagnosis involve smear dyeing inspection, culture identification, and real-time PCR detection, all of which are proved highly effective. Here, we performed a meta-analysis to evaluate the effectiveness of real-time PCR for diagnosing nCoV infection. Fifteen articles conformed to the inclusion and exclusion criteria for further meta-analysis on the basis of a wide range of publications searched from databases involving PubMed, EMBASE, Web of Science, Medline, ISI. We analyzed the stability and publication bias as well as examined the heterogeneity inspection of real-time PCR detection in contrast to smear staining and culture identification. The fixed-effect model was adopted in our meta-analysis. Our result demonstrated that the combination of real-time PCR and smear diagnostics yielded an odds ratio (OR) = 1.91, 95% confidence interval (CI) = 1.51-2.41, Z = 5.43, P < 0.05, while the combination of real-time PCR and culture identification yielded OR = 2.44, 95%CI = 1.77-3.37, Z = 5.41, P < 0.05. Therefore, we propose real-time PCR as an efficient method that offers an auxiliary support for future nCoV diagnosis.

Timing of antiretroviral therapy initiation after diagnosis of recent human immunodeficiency virus infection and CD4(+) T-cell recovery

We retrospectively examined the timing of antiretroviral therapy (ART) initiation and CD4(+) T-cell recovery over 36 months among recent human immunodeficiency virus (HIV) infections using BED (HIV-1 subtypes B, E and D) immunoglobulin G capture enzyme immunoassay (BED-CEIA). Regardless of baseline CD4(+) counts, individuals (n = 393) who initiated ART >2 months after diagnosis had significantly decreased probability and rate of achieving CD4(+) counts ≥900 cells/μL or ≥600 cells/μL than those individuals (n = 135) who started ART earlier (≤2 months). But the mean CD4(+) counts in two groups converged after 30 months of treatment. Early ART initiation leads to accelerated CD4(+) recovery, but does not offer a long-term advantage in CD4(+) counts.

Impact of renin-angiotensin system-targeting antihypertensive drugs on treatment of Alzheimer's disease: a meta-analysis

OBJECTIVE

The impacts of renin-angiotensin system (RAS)-targeting antihypertensive drugs on Alzheimer's disease (AD) remain controversial. We performed this meta-analysis to evaluate the precise value of RAS-targeting antihypertensive drugs in terms of attenuating incidence of AD and slowing down cognitive decline in patients with AD.

METHODS

A systematic literature search was conducted using PubMed, Embase, ScienceDirect and CBM (China Biology Medicine Disc) before September 2014. Studies analysing incidence of AD and cognitive changes in AD patients with RAS-targeting antihypertensive drugs were identified. The principal outcome measures were hazard ratios (HRs) for incidence of AD and standardised mean difference (SMD) for cognitive changes in AD patients. Pooled data were calculated using fixed or random effects models according to the heterogeneity.

RESULTS

In total, 12 studies involving 896,410 participants met our inclusion criteria. RAS-targeting antihypertensive drugs were significantly associated with a reduced incidence rate of AD (HR 0.81, 95% CI 0.72-0.92, p = 0.001). In subgroup analysis, both angiotensin renin blockers and angiotensin converting enzyme inhibitors were shown to effectively decrease the incidence rate of AD. In the analysis of cognitive changes, a slower rate of cognitive decline was observed in AD patients with RAS-targeting antihypertensive drug (SMD 0.30, 95% CI 0.09-0.50, p = 0.004), when randomised trials and observational trials were combined. However, analysis of randomised trials alone did not show the same result (SMD 0.20, 95% CI -0.10 to 0.50, p = 0.182).

CONCLUSIONS

Renin-angiotensin system-targeting antihypertensive drugs may be a potential treatment for reducing the incidence and progression of AD. Further studies on RAS-targeting antihypertensive drugs, especially large randomised clinical trials, should be conducted in the future.

Highly efficient one-step PCR-based mutagenesis technique for large plasmids using high-fidelity DNA polymerase

Gene mutation plays an important role in molecular biological studies. A highly efficient one-step polymerase chain reaction-based mutagenesis technique for site-directed mutagenesis was developed in this study. One complementary pair of primers was designed that contained the desired mutations in the middle of the primers. The amplification products of mutation were amplified using a high-fidelity DNA polymerase and the original plasmid templates were digested by DpnI. This method was successfully used to introduce mutations in two different-sized plasmids (12 and 6 kb) with high efficiency. The results indicate that this technique can be widely used to introduce any plasmid mutations quickly and efficiently.

Transcription of the var genes from a freshly-obtained field isolate of Plasmodium falciparum shows more variable switching patterns than long laboratory-adapted isolates

Background

Antigenic variation in Plasmodium falciparum involves switching among multicopy var gene family and is responsible for immune evasion and the maintenance of chronic infections. Current understanding of var gene expression and switching patterns comes from experiments conducted on long laboratory-adapted strains, with little known about their wild counterparts.

Methods

Genome sequencing was used to obtain 50 var genes from a parasite isolated from the China-Myanmar border. Four clones with different dominant var genes were cultured in vitro in replicates for 50 generations. Transcription of the individual var gene was detected by real-time PCR and then the switching process was analysed.

Results

The expression of multicopy var genes is mutually exclusive in clones of a wild P. falciparum isolate. The activation of distinct primary dominant var genes leads to different and favoured switching patterns in the four clones. The on/off rates of individual var genes are variable and the choice of subsequent dominant var genes are random, which results in the different switching patterns among replicates of each clonal wild P. falciparum isolate with near identical initial transcription profiles.

Conclusions

This study suggests that the switching patterns of var genes are abundant, which consist of both conserved and random parts.

Electronic supplementary material

The online version of this article (doi:10.1186/s12936-015-0565-y) contains supplementary material, which is available to authorized users.

iTRAQ-based proteomic profiling of the marine medaka (Oryzias melastigma) gonad exposed to BDE-47

A recent study demonstrated that 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) may have an adverse effect on the reproduction in marine medaka (Oryzias melastigma), but the molecular mechanisms remain largely unknown. In this study, we investigated the protein expression profiles of male and female gonads of O. melastigma exposed to dietary BDE-47 at two dosages (0.65 and 1.30 μg/g/day, respectively) for 21 days. Extracted proteins were labeled with iTRAQ and analyzed on a MALDI TOF/TOF analyzer, as results, 133 and 144 unique proteins were identified in testis and ovary, respective, and they exerted dose- and sex-dependent expression patterns. In testis, among the 42 differentially expressed proteins; down-regulation of histone variants and parvalbumins implicated BDE-47 may disrupt the spermatogenesis and induce sterility in fishes. In ovary, 38 proteins were differentially expressed; the elevation of vitellogenins and apolipoprotein A-I expression indicated BDE-47 acts as an estrogen-mimicking compound and led to reproductive impairment in O. melastigma.

Quantitative trait loci mapping and gene network analysis implicate protocadherin-15 as a determinant of brain serotonin transporter expression

Presynaptic serotonin (5-hydroxytryptamine, 5-HT) transporters (SERT) regulate 5-HT signaling via antidepressant-sensitive clearance of released neurotransmitter. Polymorphisms in the human SERT gene (SLC6A4) have been linked to risk for multiple neuropsychiatric disorders, including depression, obsessive-compulsive disorder and autism. Using BXD recombinant inbred mice, a genetic reference population that can support the discovery of novel determinants of complex traits, merging collective trait assessments with bioinformatics approaches, we examine phenotypic and molecular networks associated with SERT gene and protein expression. Correlational analyses revealed a network of genes that significantly associated with SERT mRNA levels. We quantified SERT protein expression levels and identified region- and gender-specific quantitative trait loci (QTLs), one of which associated with male midbrain SERT protein expression, centered on the protocadherin-15 gene (Pcdh15), overlapped with a QTL for midbrain 5-HT levels. Pcdh15 was also the only QTL-associated gene whose midbrain mRNA expression significantly associated with both SERT protein and 5-HT traits, suggesting an unrecognized role of the cell adhesion protein in the development or function of 5-HT neurons. To test this hypothesis, we assessed SERT protein and 5-HT traits in the Pcdh15 functional null line (Pcdh15(av-) (3J) ), studies that revealed a strong, negative influence of Pcdh15 on these phenotypes. Together, our findings illustrate the power of multidimensional profiling of recombinant inbred lines in the analysis of molecular networks that support synaptic signaling, and that, as in the case of Pcdh15, can reveal novel relationships that may underlie risk for mental illness.

Caesarean delivery, caesarean delivery on maternal request and childhood overweight: a Chinese birth cohort study of 181 380 children

What is already known about this subject Both rates of caesarean section and childhood overweight have been steadily increasing over the past decade in many parts of the world. Caesarean delivery on maternal request contributes remarkably to the rising trend of caesarean births. A few small-scale studies suggest that caesarean section may be associated with later overweight and obesity, whereas little is known about the impact of caesarean delivery on maternal request. What this study adds Caesarean section is associated with an increased risk of childhood overweight. Children born by caesarean delivery on maternal request are also more likely to be overweight. The strength of the caesarean-overweight association is modest.

OBJECTIVES

To assess the impact of caesarean delivery including non-medically indicated maternal request caesarean delivery on childhood overweight.

METHODS

We conducted a prospective investigation of a Chinese birth cohort involving 181 380 children, who were born during 1993-1996 to mothers registered in a perinatal care surveillance system and whose weight and height were measured in 2000. Information on delivery mode and covariates was obtained from the surveillance system. Overweight was defined according to the International Obesity Task Force body mass index (BMI) cutoffs. Multivariable logistic regression was used to estimate adjusted odds ratios. Stratified analyses were done to test whether the association between caesarean section and overweight persisted across subgroups.

RESULTS

The adjusted odds ratio of overweight for children born by caesarean compared with vaginal delivery was 1.13 [95% confidence interval {CI}: 1.08, 1.18]. The association persisted in subgroups stratified by gender, maternal education, maternal BMI, weight gain during pregnancy and child birthweight (all P values for interaction test ≥0.30). The adjusted odds ratio of overweight for children born by non-medically indicated caesarean delivery compared with vaginal delivery was 1.18 (95% CI: 1.00, 1.41).

CONCLUSION

Caesarean delivery including non-medically indicated maternal request caesarean delivery compared with vaginal delivery modestly increases childhood overweight risk.

Evaluation of heritable determinants of blood and brain serotonin homeostasis using recombinant inbred mice

The biogenic amine serotonin (5-HT, 5-hydroxytryptamine) exerts powerful, modulatory control over multiple physiological functions in the brain and periphery, ranging from mood and appetite to vasoconstriction and gastrointestinal motility. In order to gain insight into shared and distinct molecular and phenotypic networks linked to variations in 5-HT homeostasis, we capitalized on the stable genetic variation present in recombinant inbred mouse strains. This family of strains, all derived from crosses between C57BL/6J and DBA/2J (BXD) parents, represents a unique, community resource with approximately 40 years of assembled phenotype data that can be exploited to explore and test causal relationships in silico. We determined levels of 5-HT and 5-hydroxyindoleacetic acid from whole blood, midbrain and thalamus/hypothalamus (diencephalon) of 38 BXD lines and both sexes. All 5-HT measures proved highly heritable in each region, although both gender and region significantly impacted between-strain correlations. Our studies identified both expected and novel biochemical, anatomical and behavioral phenotypes linked to 5-HT traits, as well as distinct quantitative trait loci. Analyses of these loci nominate a group of genes likely to contribute to gender- and region-specific capacities for 5-HT signaling. Analysis of midbrain mRNA variations across strains revealed overlapping gene expression networks linked to 5-HT synthesis and metabolism. Altogether, our studies provide a rich profile of genomic, molecular and phenotypic networks that can be queried for novel relationships contributing risk for disorders linked to perturbed 5-HT signaling.

Apparent diffusion coefficient values of necrotic and solid portion of lymph nodes: differential diagnostic value in cervical lymphadenopathy

AIM

To evaluate whether the analysis of the apparent diffusion coefficient (ADC) values of the necrotic and solid portions of lymph nodes aids differentiation between the causes of cervical lymphadenopathy.

MATERIALS AND METHODS

Thirty-six patients with cervical lymph node metastasis from head and neck squamous cell carcinomas (SCC), 19 patients with lymphoma, and 23 patients with tuberculous lymphadenitis underwent conventional magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI). The ADC values of necrotic and solid portions of lymph nodes were measured and compared. Receiver operating characteristic (ROC) analysis was employed to investigate whether ADC values could help to discriminate between the causes of cervical lymphadenopathy, and to obtain the optimal ADC threshold values.

RESULTS

The mean ADC values of the solid portions of metastatic nodes, lymphomatous nodes, and tuberculous nodes were (0.93±0.16)×10(-3)mm(2)/s, (0.64±0.13)×10(-3)mm(2)/s and (1.01±0.11)×10(-3)mm(2)/s, respectively (p<0.01). The mean ADC values of necrosis of metastatic and tuberculous nodes were (2.02±0.36)×10(-3)mm(2)/s and (1.25±0.15)×10(-3)mm(2)/s (p<0.01). By using the ADC value of the solid portion, the optimal ADC threshold values for distinguishing between metastasis and lymphoma, between metastasis and tuberculosis, and between lymphoma and tuberculosis were 0.77×10(-3), 0.98×10(-3) and 0.81×10(-3)mm(2)/s, respectively, and the sensitivities and specificities were 83 and 89%, 70 and 68%, 93 and 100%, respectively. By using ADC values of necrosis, the optimal ADC threshold value for distinguishing between metastasis and tuberculosis was 1.59×10(-3)mm(2)/s, and the sensitivity and specificity were 88 and 100%, respectively.

CONCLUSION

The ADC values both of the necrotic and solid portions of the lymph nodes are useful in differentiation between the causes of cervical lymphadenopathy. The ADC value of necrosis is especially helpful in discriminating metastasis from tuberculosis.

Ginsenoside Rd attenuates mitochondrial dysfunction and sequential apoptosis after transient focal ischemia

We previously found that ginsenoside Rd (Rd), one of the major active ingredients in Panax ginseng, protects neuronal cells from hydrogen peroxide and oxygen-glucose deprivation, an in vitro model of cerebral ischemia. In this study, we examined the protective effects of Rd in an animal model of focal cerebral ischemia. Rats administered with Rd or vehicle were subjected to transient middle cerebral artery occlusion (MCAO). Rd (50 mg/kg) significantly reduced the infarct volume by 52.8%. This reduction of injury volume was associated with an improvement in neurological function and was sustained for at least 2 weeks after the induction of ischemia. To evaluate the underlying mechanisms of Rd against stroke, brain tissues were assayed for mitochondrial enzyme activities, mitochondrial membrane potential (MMP), production of reactive oxygen species (ROS), energy metabolites, and apoptosis. Rd markedly protected mitochondria as indicated by preserved respiratory chain complex activities and aconitase activity, lowered mitochondrial hydrogen peroxide production, and hyperpolarized MMP. Microdialysis results illustrated that Rd significantly decreased the accumulation of lactate, the end product of anaerobic glycolysis, and increased pyruvate, the end product of aerobic glycolysis, hence inducing a lower lactate/pyruvate ratio. Additionally, in vitro studies further exhibited that Rd protected isolated mitochondria from calcium-induced damage by attenuating mitochondrial swelling, preserving MMP and decreasing ROS production. Moreover, Rd treatment reduced mitochondrial release of cytochrome c (CytoC) and apoptosis-inducing factor (AIF), thereby minimizing mitochondria-mediated apoptosis following ischemia. In conclusion, these findings demonstrated that Rd exerts neuroprotective effects in transient focal ischemia, which may involve an integrated process of the mitochondrial protection, energy restoration and inhibition of apoptosis.

Caesarean delivery on maternal request and childhood psychopathology: a retrospective cohort study in China

OBJECTIVE

To prospectively examine the association between mode of delivery and childhood psychopathology.

DESIGN

Retrospective cohort study.

SETTING

Eighteen counties and three cities in China.

POPULATION

A total of 4190 preschool children whose mothers were registered in a perinatal surveillance programme were assessed with the Child Behaviour Checklist (CBCL), an instrument to assess child emotional (internalising) and behavioural (externalising) problems.

METHODS

Differences in CBCL problem scores were analysed both quantitatively and categorically among children born by caesarean delivery on maternal request (CDMR), assisted vaginal delivery (AVD), and spontaneous vaginal delivery (SVD).

MAIN OUTCOME MEASURES

The CBCL total, externalising, and internalising scores.

RESULTS

There were significant differences in the mean scores of total (20.9, 23.0, and 25.0), externalising (7.6, 8.4, and 9.1), and internalising (4.7, 5.2, and 5.6) problems among children born by CDMR, SVD, and AVD, after adjusting for potential confounding factors (P = 0.007, 0.014, and 0.031). Children born by AVD were more likely than those born by SVD to have total (OR 1.43; 95% CI 1.10-1.86), externalising (OR 1.46; 95% CI 1.11-1.92), and internalising (OR 1.41; 95% CI 1.08-1.84) scores in the highest quartile, whereas children born by CDMR were less likely to have externalising scores in the highest quartile (OR 0.64; 95% CI 0.42-0.97). Furthermore, there were significant increasing linear trends on all problem scores, and in the odds of being in the highest quartile, from children born by CDMR to those born by SVD and AVD.

CONCLUSION

The likelihood of childhood psychopathological problems may be the lowest in children born by CDMR, followed by those born by SVD, whereas the highest probability was observed in those born by AVD.

Essential role of the unfolded protein response regulator GRP78/BiP in protection from neuronal apoptosis

Neurodegenerative diseases are often associated with dysfunction in protein quality control. The endoplasmic reticulum (ER), a key site for protein synthesis, senses stressful conditions by activating the unfolded protein response (UPR). Here we report the creation of a novel mouse model where GRP78/BiP, a major ER chaperone and master regulator of UPR, is specifically eliminated in the Purkinje cells (PCs). GRP78 depleted PCs activate UPR including induction of GRP94, PDI, CHOP and GADD34, feedback suppression of eIF2α phosphorylation and apoptotic cell death. In contrast to current models of protein misfolding where abnormal accumulation of ubiquitinated protein is prominent, cytosolic ubiquitin staining is dramatically reduced in GRP78 null PCs. Ultrastructural evaluation reveals that the ER shows prominent dilatation with focal accumulation of electron-dense material within the ER. The mice show retarded growth and severe motor coordination defect by week 5 and cerebellar atrophy by week 13. Our studies uncover a novel link between GRP78 depletion and reduction in cytosolic ubiquitination and establish a novel mouse model of accelerated cerebellar degeneration with basic and clinical applications.