Proteome signatures of joint toxicity to arsenic (As) and lead (Pb) in human brain organoids with optic vesicles

Arsenic (As) and lead (Pb) are toxins found in the natural surroundings, and the harmful health outcomes caused by the co-exposure of such toxins have become a considerable problem. However, the joint neurotoxicity of As and Pb to neurodevelopment and the underlying mechanisms remain unclear. Pluripotent stem cell-derived human brain organoids are emerging animal model alternatives for understanding neurological-related diseases. Therefore, we utilized brain organoids with optic vesicles (OVB-organoids) to systematically analyze the neurotoxicity of As and Pb. After 24 h of As and/or Pb exposure, hematoxylin-eosin staining revealed that As and Pb exposure could cause disorders in the structure of the ventricular zone and general cell disarrangement in OVB-organoids. Immunostaining displayed that OVB-organoids are more susceptible to As and Pb co-exposure than independent exposure in apoptosis, proliferation, and cell differentiation. Meanwhile, even though As and Pb could both hinder cell proliferation, contrary to Pb, As could induce an increasing proportion of mitotic (G2/M) cells. The proteome landscape of OVB-organoids illustrated that Pb synergized with As in G2/M arrest and the common role of As and Pb in carcinogenesis. Besides, proteomics analyses suggested the consequential role of autophagy and Wnt pathway in the neurotoxicity of As and Pb co-exposure. Overall, our findings provide penetrating insights into the cell cycle, carcinogenesis, autophagy, and Wnt pathway underlying the As and Pb binary exposure scenarios, which could enhance our understanding of the mixture neurotoxicity mechanisms.

Sex differences in musculoskeletal injury epidemiology and subsequent loss of tactical readiness during Marine Corps Officer Candidates School

INTRODUCTION

The US Marine Corps (USMC) Officer Candidates School (OCS) is a 10-week training course for Marine Officer Candidates (MOCs). OCS training is rigorous and demanding, which results in a high risk of musculoskeletal injuries (MSIs). The objective of this analysis was to describe MSIs among women and men during the USMC OCS at Quantico, Virginia, from September 2020 to November 2021.

METHODS

This prospective cohort study assessed MSIs that occurred among 736 MOCs (women: 17.8% of sample, men: 82.2%). Data for the study were derived from routinely collected injury data by athletic trainers and physical therapists embedded within the training units. Injury incidence, event at the time of injury occurrence, anatomic location, injury type and disposition following injury were described. Fisher's exact tests were used to compare proportions of injured women and men.

RESULTS

The cumulative injury incidence was higher among women (39.7%) compared with men (23.1%, p<0.001). When specific events associated with injuries were reported, most frequent events were the obstacle course (women: 20.9% of injuries, men: 12.9%) and the conditioning hike (women: 11.6%, men: 6.9%). Most injures affected the lower body (women: 67.4%, men: 70.8%). The most frequent body part injured was the lower leg (18.6%) in women and the knee (23.3%) in men. The most frequent injury type was strain (women: 39.5%, men: 24.3%), followed by sprain (women: 16.3%, men: 14.9%). A greater percentage of female (92.3%) compared with male MOCs (69.3%; p<0.001) were assigned light duty status following MSIs.

CONCLUSIONS

Mitigation of injuries during OCS events such as the obstacle course and the conditioning hike needs further investigation. The high risk of overuse lower leg injuries among women and the higher incidence of injuries among women compared with men underscore the need for further investigation of modifiable sex-specific injury risk factors.

[Clinical analysis of 60 children with anaplastic large cell lymphoma in a single center]

Objective: To summarize the clinical features, treatment outcome and prognostic factors of childhood anaplastic large cell lymphoma (ALCL). Methods: Clinical data of 60 newly diagnosed and biopsy-proven ALCL pediatric patients (≤18 years of age) at Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine from January 2010 to December 2018 were collected. All patients were treated with the Chinese Children Cancer Group-B cell-non-Hodgkin Lymphoma 2010 (CCCG-BNHL-2010) regimen. Overall survival (OS), event free survival (EFS) and progression free survival (PFS) rates were calculated by the Kaplan-Meier method. Univariate analysis was performed with Log-Rank test to find factors of poor prognosis. Results: Among 60 ALCL patients included in the current study, 39 were males and 21 females, the age of onset was 7.9 (1.2-16.7) years. Among all cases, 43 (72%) had B syndrome (any of the following: fever, drenching, weight loss). Forty-nine (82%) cases had lactate dehydrogenase (LDH) levels<2 times upper limit of normal (ULN) and 11 (18%) cases had LDH levels 2-<4 times ULN. The distribution of stages was stage Ⅰ,Ⅱ,Ⅲ, and Ⅳ in 2% (1/60), 5% (3/60), 92% (55/60), and 2% (1/60) of patients, respectively. Of 58 cases who had results of anaplastic lymphoma kinase (ALK) immunohistochemical staining, 53 (91%, 53/58) cases were positive. Visceral involvement was observed in 12 patients (20%). The 4-year OS and EFS rates were (88±4)% and (76±6)% for the entire group, respectively. Univariate analysis for gender, B symptoms, LDH level, ALK expression, clinical stage and visceral involvement showed that only LDH level correlated with an inferior OS rate (χ²=6.571, P=0.010) while not correlated with EFS rate. No independent risk factor for disease progression or recurrence was found by Logistic regression. Up to the last follow-up, 44 cases were continuously at complete remission state, and their follow-up time was 50 (13-119) months. Of 13 (23%) cases experienced disease progression or relapse, 3 cases abandoned treatment, 2 cases progressed to death, 8 cases received second line or salvage treatment (6 survived at last follow-up). For post progression or relapse cases, the 2-year OS and PFS rates were (60±16)% and (16±14)%, respectively. The treatment related death occurred in 3 cases (5%) and all of them were due to severe infection during the chemotherapy. Conclusions: The efficacy of CCCG-BNHL-2010 regimen in the treatment of children with ALCL was good. However, the safety needs to be improved as the treatment-related mortality in the present study was slightly higher. Efficient second line or salvage treatment can achieve cure in pediatric patients post progression or recurrence. LDH ≥2 times ULN was associated with worse prognosis.

Luminescence Processes in Si1-xGex/Si Heterostructures Grown by Chemical Vapor Deposition

Well-resolved band-edge exciton photoluminescence (PL) has been observed in strained Si1-xGex. heterostructures grown on Si(100) by rapid thermal chemical vapor deposition. The luminescence is due to shallow-impurity bound excitons at low temperatures (under 20K) and at higher temperatures is due to free excitons or electron-hole plasmas, depending on the pump power. The luminescence can also be electrically pumped, with both the electroluminescence and PL persisting above room temperature in samples with a sufficient bandgap offset. Loss of carrier confinement and subsequent non-radiative recombination outside the Si1-xGex. is found to be the reason for reduced PL and EL at high temperature.

Different pathways are involved in arsenic-trioxide-induced cell proliferation and growth inhibition in human keratinocytes

BACKGROUND

Arsenic is a carcinogen that is associated with an increased risk of human skin cancer. On the other hand, arsenic trioxide (As(2)O(3)) has potential anticancer activity against a wide range of carcinomas. The mechanisms involved in these two opposing processes remain unclear.

METHODS

We used normal human keratinocytes (NHK), the human keratinocyte HaCaT cell line and human epidermal carcinoma cells (A431 cell line) to investigate potential pathways involved in the effects on cell proliferation and growth inhibition by different concentrations of As(2)O(3).

RESULTS

At low concentrations (0.5-32 nM), As(2)O(3) enhanced keratinocyte proliferation and regulated the expression of about 172 genes. Among them, cell cycling pathway genes (including CDK4 and E2F1) were significantly upregulated. At high concentrations (0.5-10 microM), As(2)O(3) inhibited cell growth in NHK and HaCaT cells, but not in A431 cells. As(2)O(3) significantly induced NHK and HaCaT apoptosis through the activation of caspase-3, as well as cell cycle arrest at the G2-M phase.

CONCLUSION

Our data suggest that different pathways are involved in As(2)O(3)-mediated proliferation and growth inhibition. In addition, skin carcinoma cells were resistant to As(2)O(3)-induced cell growth inhibition and apoptosis when compared to NHK and HaCaT cells. Therefore, As(2)O(3) may not be appropriate for treatment of skin carcinomas.

Macharistol, a new cytotoxic cinnamylphenol from the stems of Machaerium aristulatum

A new cinnamylphenol, macharistol (1), along with a known pterocarpan, (+)-medicarpin (2), were isolated as cytotoxic constituents from the stems of Machaerium aristulatum. In addition, a known pterocarpan, (+)-maackiain (3), and a known isoflavone, formononetin (4), were identified as inactive constituents. Compound 1 was evaluated in the in vivo hollow fiber assay with KB, Col-2, and hTERT-RPE1 cells and found to be inactive at the highest dose (25 mg/kg body weight) tested.

Optical image encryption with multistage and multichannel fractional Fourier-domain filtering

We present a novel image-encryption algorithm that employs multichannel and multistage fractional Fourier-domain filtering architecture. We perform the encryption and decryption by randomly filtering the spatial frequency of the image and then recombining the information from the algorithm in a multistage fractional Fourier domain with pure random-intensity-encoded masks and their complements in a multichannel scheme. The algorithm can be implemented iteratively in an electro-optical setup. Numerical simulations have verified the validity of the algorithm.

Overexpression of Smad2 reveals its concerted action with Smad4 in regulating TGF-beta-mediated epidermal homeostasis

Members of the transforming growth factor-beta (TGF-beta) superfamily are critical regulators for epithelial growth and can alter the differentiation of keratinocytes. Transduction of TGF-beta signaling depends on the phosphorylation and activation of Smad proteins by heteromeric complexes of ligand-specific type I and II receptors. To understand the function of TGF-beta and activin-specific Smad, we generated transgenic mice that overexpress Smad2 in epidermis under the control of keratin 14 promoter. Overexpression of Smad2 increases endogenous Smad4 and TGF-beta 1 expression while heterozygous loss of Smad2 reduces their expression levels, suggesting a concerted action of Smad2 and -4 in regulating TGF-beta signaling during skin development. These transgenic mice have delayed hair growth, underdeveloped ears, and shorter tails. In their skin, there is severe thickening of the epidermis with disorganized epidermal architecture, indistinguishable basement membrane, and dermal fibrosis. These abnormal phenotypes are due to increased proliferation of the basal epidermal cells and abnormalities in the program of keratinocyte differentiation. The ectodermally derived enamel structure is also abnormal. Collectively, our study presents the first in vivo evidence that, by providing an auto-feedback in TGF-beta signaling, Smad2 plays a pivotal role in regulating TGF-beta-mediated epidermal homeostasis.

Pervilleine A, a novel tropane alkaloid that reverses the multidrug-resistance phenotype

P-Glycoprotein-mediated drug efflux can yield a multidrug-resistance (MDR) phenotype that is associated with a poor response to cancer chemotherapy. Pervilleine A, a novel tropane alkaloid obtained from a chloroform extract of Erythroxylum pervillei as the result of bioactivity-guided fractionation, was found to restore the vinblastine sensitivity of cultured multidrug-resistant KB-V1 and CEM/VLB(100) cells, with IC(50) values of 0.36 and 0.02 microM, respectively. Similarly, the chemosensitivity of KB-8-5 cells to colchicine was restored with an IC(50) value of 0.61 microM. The mechanism of this response was evaluated with a number of model systems. First, incubation of multidrug-resistant KB-V1 and CEM/VLB(100) cells with up to 45 microM pervilleine A for 72 h did not significantly affect either the transcription of MDR1, as revealed by reverse transcriptional-PCR-based analysis of MDR1 mRNA, or levels of P-glycoprotein, as shown by Western blots. ATP-dependent binding of [(3)H]vinblastine observed with isolated multidrug-resistant KB-V1 cell membrane vesicles was inhibited by pervilleine A in a dose-dependent manner, and kinetic analysis indicted competitive inhibition with respect to vinblastine binding with a K(i) of 7.3 microM. Consistent with this effect, intracellular accumulation of [(3)H]vinblastine was increased from 0.18 pmol [(3)H]vinblastine/50 x 10(4) cells to approximately 5 pmol [(3)H]vinblastine/50 x 10(4) cells in the presence of 40 microM pervilleine A. To explore the potential relevance of these responses, KB-V1 or KB-8-5 cells were placed in hollow fibers and implanted into NCr nu/nu mice. Cell growth was not significantly inhibited when vinblastine or pervilleine A were administered as single agents, but when used in combination, inhibition of up to 75% was observed. Equimolar doses of verapamil were less effective. These data suggest that pervilleine A is an effective inhibitor of P-glycoprotein and should be further evaluated for clinical utility.

Characterization of mesogen-jacketed liquid crystalline polymers by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

For synthetic polymers, a proper sample preparation method is essential for successful characterization by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. In this work, six synthetic mesogen-jacketed liquid crystalline polymers (MJLCPs) with different main-chain, spacer and mesogenic units were investigated by MALDI-TOF mass spectrometry. Several factors that affect the analysis of these polymers were examined. These factors include matrices used, cationization salts used, the concentration of polymers, and the ratio of sample to matrix. After testing different conditions, we found a suitable sample preparation method for these six polymers. The number average molecular weight (M(n)), weight average molecular weight (M(w)) and polydispersity (PD) were calculated using data obtained in the linear mode. The end groups of the polymers were proposed using data obtained in reflectron mode. Copyright 2000 John Wiley & Sons, Ltd.