Maternal exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin suppresses male reproductive functions in their adulthood

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a ubiquitous environmental contaminant in the environment. The developmental period is more sensitive to TCDD and there is a possibility that maternal exposure to TCDD may affect in adulthood. Adult female Wistar rats were exposed to 0.5, 1.0, and 2.0 µg/kg TCDD during the critical stage of organogenesis, that is, on GD15. The results revealed a significant decrease in indices of reproductive organ weight in adult male rats exposed to prenatal TCDD, and dose-dependent reduction in epididymal sperm reserves, percent motile, and viable sperm with an increase in percent morphological abnormal sperm. Polymerase chain reaction analysis revealed downregulated expression levels of steroidogenic markers such as steroidogenic acute regulatory, cholesterol side-chain cleavage, and 3β- and 17β-hydroxysteroid dehydrogenase (HSDs) in experimental rats. Immunofluorescence sections portrayed reduced distribution of 3β- and 17β-HSD proteins in testes of experimental rats. Furthermore, spermatogenic markers (acid phosphatase, alkaline phosphatase, lactate dehydrogenase, and sorbitol dehydrogenase) were significantly altered in the testes. Serum levels of testosterone, follicle stimulating hormones, and luteinizing hormone were significantly decreased. Testicular levels of hydrogen peroxide and lipid peroxidation were significantly elevated with a decline in superoxide dismutase, catalase, glutathione peroxidase activities, and total thiol levels. Moreover, histological and morphometric examination of testicular cross-sections depicted degenerative changes. Male fertility assessment in adult rats revealed a significant decrease in mating index, fertility index, and mean number of pre- and postimplantations with an increase in pre- and postimplantation losses in rats cohabited with in utero TCDD-exposed adult males. In conclusion, the findings of this study provided clear evidence that maternal exposure to TCDD during the critical stage of development results in suppressed reproductive health in adulthood.

Tailoring spontaneous infrared emission of HgTe quantum dots with laser-printed plasmonic arrays

Chemically synthesized near-infrared to mid-infrared (IR) colloidal quantum dots (QDs) offer a promising platform for the realization of devices including emitters, detectors, security, and sensor systems. However, at longer wavelengths, the quantum yield of such QDs decreases as the radiative emission rate drops following Fermi's golden rule, while non-radiative recombination channels compete with light emission. Control over the radiative and non-radiative channels of the IR-emitting QDs is crucially important to improve the performance of IR-range devices. Here, we demonstrate strong enhancement of the spontaneous emission rate of near- to mid-IR HgTe QDs coupled to periodically arranged plasmonic nanoantennas, in the form of nanobumps, produced on the surface of glass-supported Au films via ablation-free direct femtosecond laser printing. The enhancement is achieved by simultaneous radiative coupling of the emission that spectrally matches the first-order lattice resonance of the arrays, as well as more efficient photoluminescence excitation provided by coupling of the pump radiation to the local surface plasmon resonances of the isolated nanoantennas. Moreover, coupling of the HgTe QDs to the lattice plasmons reduces the influence of non-radiative decay losses mediated by the formation of polarons formed between QD surface-trapped carriers and the IR absorption bands of dodecanethiol used as a ligand on the QDs, allowing us to improve the shape of the emission spectrum through a reduction in the spectral dip related to this ligand coupling. Considering the ease of the chemical synthesis and processing of the HgTe QDs combined with the scalability of the direct laser fabrication of nanoantennas with tailored plasmonic responses, our results provide an important step towards the design of IR-range devices for various applications.

Recent Advances in Radical Nitration Using tert-Butyl Nitrite

Nitro compounds serve as valuable intermediates for pharmaceuticals, agrochemicals, dyes, and polymers. In recent years, radical nitration using tert-butyl nitrite (t-BuONO) has attracted wide attention and desirable progress has been made. On the one hand, t-BuONO is a potential active nitro radical source and can react with various functional groups. On the other hand, as a green and novel nitration reagent, t-BuONO has relatively low price and can easily produce a radical under mild conditions, which undoubtedly provides a simple and efficient way for nitration reactions. To date, some important reviews are available that summarize the synthesis of nitro compounds. To the best of our knowledge, however, there is still no review that exclusively discusses the synthesis of nitro compounds using t-BuONO through a radical strategy. Therefore, this review aims to highlight the recent advances in radical nitration using t-BuONO as nitration reagent. The main progress in this area has been presented according to the type of reaction substrates. Special attention has been paid discussion of the reaction mechanisms and selected examples of substrates have been given. We hope this paper will be a useful reference and inspiration for those who are exploring the synthesis of nitro compounds using t-BuONO.

1 Introduction

2 Radical Nitration of Alkenes

3 Radical Nitration of Aromatics

4 Radical Nitration of Alkynes

5 Radical Nitration of 1,n-Enynes

6 Radical Nitration of Alkanes

7 Summary and Perspective

A study of dynamic contrast-enhanced MR imaging features and influence factors of pelvic bone marrow in adult females

Perfusion of the pelvic bone marrow is reduced in the postmenopausal group and with age. Quantitative dynamic contrast-enhanced MRI could reflect the blood supply characteristics and hemodynamic changes of the pelvic bone marrow. These results contribute to the description of osteoporosis in the postmenopausal females and the elderly.

INTRODUCTION

To investigate the effect of menstrual status and age on the perfusion of pelvic bone marrow in adult females using quantitative dynamic contrast-enhanced MRI (DCE-MRI).

METHODS

In total, 96 adult females who underwent DCE-MRI between September 2017 and December 2017 were included. All the subjects' quantitative DCE-MRI parameters of pelvic bone marrow were measured and retrospectively analyzed, including K^trans (volume transfer constant), K_ep (efflux rate constant), and V_e (interstitial volume). According to their menstrual status, the subjects were divided into a premenopausal group (n = 39) and a postmenopausal group (n = 57), and the two groups were then divided into four subgroups according to age. The intraobserver reliability was assessed by the intraclass correlation coefficient (ICC). The parameters were compared between different menstrual status groups and age subgroups by Mann-Whitney test, and Spearman correlation analysis was used to evaluate the correlation between the age and the quantitative parameters.

RESULTS

The ICCs of the K^trans, K_ep, and V_e values were 0.989, 0.974, and 0.920, respectively. K^trans, K_ep, and V_e of the premenopausal group were significantly higher than those of the postmenopausal group (P < 0.05). The overall age was negatively correlated with K^trans, K_ep, and V_e (r = - 0.590, - 0.357, and - 0.381, respectively, P < 0.05). In the premenopausal group, K^trans and V_e were significantly higher in subgroup 1 (≤ 40 years) compared with subgroup 2 (> 40 years) (P < 0.05), and age showed a negative correlation with K^trans and V_e (r = - 0.344 and - 0.334, respectively, P < 0.05). In the postmenopausal group, K^trans and K_ep were significantly higher in subgroup 3 (≤ 60 years) compared with subgroup 4 (> 60 years) (P < 0.05), and age showed a negative correlation with K^trans and K_ep (r = - 0.460 and - 0.303, respectively, P < 0.05).

CONCLUSION

Menstrual status and age have significant effects on the perfusion of the pelvic bone marrow microenvironment in adult females and that the microenvironment of the pelvic bone marrow displays different changes at different age stages. Quantitative DCE-MRI has contributed to the interpretation of the pelvic bone marrow perfusion status.

Protective effect of tauroursodeoxycholic acid on the autophagy of nerve cells in rats with acute spinal cord injury

OBJECTIVE

To investigate the impact and protective effect of tauroursodeoxycholic acid (TUDCA) on the autophagy of nerve cells in rats with acute spinal cord injury.

MATERIALS AND METHODS

Seventy-two 6-8-week-old male Sprague-Dawley (SD) rats were selected and were randomly divided into a sham operation group, a saline control group and a TUDCA treatment group (high and low dose groups). The experimental animals were sacrificed at 24 hours, 5 days and 10 days after spinal cord injury. The Basso, Beattie, Bresnahan locomotor scale was used to assess the hind limb locomotor function after the rats were injured but before sudden death. Electron microscopy, hematoxylin and eosin (HE) staining, TUNEL assays and immunohistochemistry techniques were used to observe the autophagy of the cells. Western blotting was used to analyze the expression of the autophagy-related factor Beclin-1 and the apoptosis-related factor caspase-3, and reverse transcription polymerase chain reaction (RT-PCR) was used to analyze the mRNA expression levels of the above proteins.

RESULTS

The locomotor scores of the rats in the saline group were significantly reduced, their Beclin-1 expression levels in neurons were decreased, and caspase-3 expression was increased. The hind limb locomotor scores of rats in the TUDCA groups were decreased, with no difference between the high- and low-dose groups. Beclin-1 expression in their neurons was increased, and caspase-3 expression was decreased; there was a significant difference when compared with the control group, while there was no significant difference between the high- and low-dose groups.

CONCLUSIONS

TUDCA significantly activates the neuronal autophagic expression in rats with acute spinal cord injury to inhibit the apoptosis of nerve cells; therefore, it has a protective effect on neurons.

Long noncoding RNA Lnc01614 promotes the occurrence and development of gastric cancer by activating EMT pathway

OBJECTIVE

To investigate the expression characteristics of long noncoding ribonucleic acid (lncRNA) lnc01614 in gastric cancer, so as to further investigate its roles in the occurrence and development of gastric cancer and its potential regulatory mechanism.

PATIENTS AND METHODS

Quantitative Real-time polymerase chain reaction (qRT-PCR) was used to detect the expression levels of lnc01614 in 79 pairs of gastric cancer tissues and normal adjacent tissues. The correlations of lnc01614 expression with pathological parameters of gastric cancer and prognoses of patients were also analyzed. QRT-PCR was employed to further verify the expression of lnc01614 in gastric cancer cells. Lnc01614 knockdown expression models were established using small interfering RNA (siRNA) in gastric cancer cell strains (SGC-7901 and AGS). The effect of lnc01614 on the biological function of gastric cancer cells was analyzed by Cell Counting Kit-8 (CCK-8) and transwell invasion and migration assay. Lastly, Western blotting was performed to explore its potential mechanism.

RESULTS

The results of qRT-PCR showed that the expression of lnc01614 in gastric cancer tissues was significantly higher than that in normal tissues. Compared with patients with low expression of lnc01614, patients with high expression of lnc01614 had higher tumor staging, greater lymph node metastasis and distant metastasis rates, and lower overall survival rate. In comparison with the negative control si-NC group, cell proliferation, invasion and migration abilities in lnc01614 knockdown expression group (si-lnc01614) were significantly decreased. Western blotting results indicated that si-lnc01614 group exhibited increased E-cadherin expression, and significantly reduced vimentin and snail expression.

CONCLUSIONS

Lnc01614 was upregulated in gastric cancer and significantly correlated with gastric cancer staging, lymph node metastasis, distant metastasis and poor prognosis. Lnc01614 may promote the proliferation, invasion and migration capabilities of gastric cancer through the regulation of epithelial-mesenchymal transition (EMT) pathway.

Secondary radiation measurements for particle therapy applications: Charged secondaries produced by 16O ion beams in a PMMA target at large angles

Particle therapy is a therapy technique that exploits protons or light ions to irradiate tumor targets with high accuracy. Protons and ¹²C ions are already used for irradiation in clinical routine, while new ions like ⁴He and ¹⁶O are currently being considered. Despite the indisputable physical and biological advantages of such ion beams, the planning of charged particle therapy treatments is challenged by range uncertainties, i.e. the uncertainty on the position of the maximal dose release (Bragg Peak - BP), during the treatment. To ensure correct 'in-treatment' dose deposition, range monitoring techniques, currently missing in light ion treatment techniques, are eagerly needed. The results presented in this manuscript indicate that charged secondary particles, mainly protons, produced by an ¹⁶O beam during target irradiation can be considered as candidates for ¹⁶O beam range monitoring. Hereafter, we report on the first yield measurements of protons, deuterons and tritons produced in the interaction of an ¹⁶O beam impinging on a PMMA target, as a function of detected energy and particle production position. Charged particles were detected at 90° and 60° with respect to incoming beam direction, and homogeneous and heterogeneous PMMA targets were used to probe the sensitivity of the technique to target inhomogeneities. The reported secondary particle yields provide essential information needed to assess the accuracy and resolution achievable in clinical conditions by range monitoring techniques based on secondary charged radiation.

Review and performance of the Dose Profiler, a particle therapy treatments online monitor

Particle therapy (PT) can exploit heavy ions (such as He, C or O) to enhance the treatment efficacy, profiting from the increased Relative Biological Effectiveness and Oxygen Enhancement Ratio of these projectiles with respect to proton beams. To maximise the gain in tumor control probability a precise online monitoring of the dose release is needed, avoiding unnecessary large safety margins surroundings the tumor volume accounting for possible patient mispositioning or morphological changes with respect to the initial CT scan. The Dose Profiler (DP) detector, presented in this manuscript, is a scintillating fibres tracker of charged secondary particles (mainly protons) that will be operating during the treatment, allowing for an online range monitoring. Such monitoring technique is particularly promising in the context of heavy ions PT, in which the precision achievable by other techniques based on secondary photons detection is limited by the environmental background during the beam delivery. Developed and built at the SBAI department of "La Sapienza", within the INSIDE collaboration and as part of a Centro Fermi flagship project, the DP is a tracker detector specifically designed and planned for clinical applications inside a PT treatment room. The DP operation in clinical like conditions has been tested with the proton and carbon ions beams of Trento proton-therapy center and of the CNAO facility. In this contribution the detector performances are presented, in the context of the carbon ions monitoring clinical trial that is about to start at the CNAO centre.

A microfluidic chip based ratiometric aptasensor for antibiotic detection in foods using stir bar assisted sorptive extraction and rolling circle amplification

A ratiometric and sensitive microfluidic chip based aptasensor was developed for antibiotic detection with kanamycin (Kana) as a model analyte. A novel stir bar assisted sorptive extraction and rolling circle amplification strategy was designed to largely amplify the signal and overcome complex matrix interference in food samples. The detection mechanism was as follows: firstly, many duplex DNA probes (a single-stranded DNA as a primer hybrid with an aptamer sequence) were modified on a stir bar. In the presence of Kana, the probes on the bar could specifically capture Kana and release the primer to trigger RCA in the presence of a circular DNA template (CDT). As the reaction proceeds, the amount of CDT decreased and the number of RCA products increased. It is worth mentioning that they can be efficiently separated and detected using a microfluidic chip. The signal ratio of RCA products and CDT (IR/IC) can be employed to qualify Kana in a wide linear range from 0.8 pg mL-1 to 10 ng mL-1 with a low detection limit of 0.3 pg mL-1. This method exhibited excellent sensitivity and selectivity and can obviously reduce the matrix interference through a ratiometric strategy combined with stir bar extraction. The aptasensor was successfully tested in milk and fish samples, confirming that it can be applied for on-site quantitation of antibiotic residues in foods.

Mutation of the rice TCM12 gene encoding 2,3-bisphosphoglycerate-independent phosphoglycerate mutase affects chlorophyll synthesis, photosynthesis and chloroplast development at seedling stage at low temperatures

Glycolysis is a central metabolic pathway that provides energy and products of primary metabolites. 2,3-Biphosphoglycerate-independent phosphoglycerate mutase (iPGAM) is a key enzyme that catalyses the reversible interconversion of 3-phosphoglycerate (3-PGA) to 2-phosphoglycerate (2-PGA) in glycolysis. Low temperature is a common abiotic stress in rice production. However, the mechanism for rice iPGAM genes is not fully understood at low temperature. In this study, the rice mutant tcm12, with chlorosis, malformed chloroplasts and impaired photosynthesis, was grown at a low temperature (<20 °C) to the three-leaf stage, while the normal phenotype at 32 °C was used. Chlorophyll fluorescence analysis and transmission electron microscopy were used to examine features of the tcm12 mutant. The inheritance behaviour and function of TCM12 were then analysed thorough map-based cloning, transgenic complementation and subcellular localisation. The thermo-sensitive chlorosis phenotype was caused by a single nucleotide mutation (T→C) on the fifth exon of TCM12 (LOC_Os12g35040) encoding iPGAM, localised to both nucleus and membranes. In addition, TCM12 was constitutively expressed, and its disruption resulted in down-regulation of some genes associated with chlorophyll biosynthesis and photosynthesis at low temperatures (20 °C). This is the first report of the involvement of rice iPGAM gene in chlorophyll synthesis, photosynthesis and chloroplast development, providing new insights into the mechanisms underlying early growth of rice at low temperatures.

[SIVA1 Regulates the Stability of Single-Stranded DNA-Binding Protein 3 Isoforms]

The assembly of LIM-homeodomain (LIM-HD) transcriptional complex plays important roles in early neuronal development. The stability of LIM-HD is controlled by single-strand binding protein 3 (SSBP3) via a cascade mechanism protecting it from proteasomal degradation. The expression level of SSBP3 has to be precisely regulated. Although a decrease of SSBP3 level is associated with several diseases, the mechanism of SSBP3 downregulation and whether SSBP3 itself is subject to proteasomal degradation remain largely unknown. Two strongly conserved transcripts of the SSBP3 gene, SSBP3a and SSBP3c, were cloned from a human brain cDNA library. By RT-PCR, we show that Ssbp3c is continuously expressed in both embryonic and adult mouse brain, whereas Ssbp3a is restricted to embryonic brain tissue. By co-IP and GST pulldown assays, we identified SIVA1 as a novel SSBP3-binding factor. In a ubiquitination assay, we show that SIVA1 enhances the ubiquitination of SSBP3 and regulates its abundance. Our findings reveal the proteasomal degradation of SSBP3 for the first time and provide a rationale for an SIVAl-SSBP3-dependent mechanism for the disassembly of LIM-HD multiprotein complexes.

Correlation between MMP-2 gene polymorphism and cataract susceptibility

OBJECTIVE

To investigate the correlation between matrix metalloproteinase-2 (MMP-2) gene polymorphism and cataract.

PATIENTS AND METHODS

104 cataract patients and 100 healthy subjects were enrolled and assigned to the observation group and control group, respectively. General clinical data of the enrolled subjects were collected. The inflammatory factors were detected, and the rs243865 polymorphism of MMP-2 gene was detected using the TaqMan-MGB probe.

RESULTS

The levels of interleukin-6 (IL-6), IL-1β, C-reactive protein (CRP), and tumor necrosis factor-1α (TNF-1α) in the observation group were higher than those in the control group (p<0.05). There were significant differences in the genotype and allele distribution frequency between the two groups (p<0.05). In the genetic model analysis, the additive model was remarkably different between the two groups (p<0.05). However, the recessive model and dominant model were not different between the two groups (p>0.05).

CONCLUSIONS

Cataract is correlated with inflammatory factors, and the rs243865 polymorphism of MMP-2 gene has a correlation with the incidence of cataract.

Urban blue: A global analysis of the factors shaping people's perceptions of the marine environment and ecological engineering in harbours

Marine harbours are the focus of a diverse range of activities and subject to multiple anthropogenically induced pressures. Support for environmental management options aimed at improving degraded harbours depends on understanding the factors which influence people's perceptions of harbour environments. We used an online survey, across 12 harbours, to assess sources of variation people's perceptions of harbour health and ecological engineering. We tested the hypotheses: 1) people living near impacted harbours would consider their environment to be more unhealthy and degraded, be more concerned about the environment and supportive of and willing to pay for ecological engineering relative to those living by less impacted harbours, and 2) people with greater connectedness to the harbour would be more concerned about and have greater perceived knowledge of the environment, and be more supportive of, knowledgeable about and willing to pay for ecological engineering, than those with less connectedness. Across twelve locations, the levels of degradation and modification by artificial structures were lower and the concern and knowledge about the environment and ecological engineering were greater in the six Australasian and American than the six European and Asian harbours surveyed. We found that people's perception of harbours as healthy or degraded, but not their concern for the environment, reflected the degree to which harbours were impacted. There was a positive relationship between the percentage of shoreline modified and the extent of support for and people's willingness to pay indirect costs for ecological engineering. At the individual level, measures of connectedness to the harbour environment were good predictors of concern for and perceived knowledge about the environment but not support for and perceived knowledge about ecological engineering. To make informed decisions, it is important that people are empowered with sufficient knowledge of the environmental issues facing their harbour and ecological engineering options.

Galanin receptor 1 plays an antinociceptive effect via inhibiting PKA activation in the nucleus accumbens of rats with neuropathic pain

Galanin and galanin receptors (GalRs) have been reported to be involved in the transmission and modulation of nociceptive information in the central nervous system (CNS). However, the underlying mechanism of the antinociception of GalRs in neuropathic pain remains unclear. This study investigated the antinociception induced by galanin receptor 1 (GalR1) via protein kinase A (PKA) signaling pathway in the nucleus accumbens (NAc) of rats with neuropathic pain. A mononeuropathy model was replicated by ligation of the left sciatic nerve, following which the expression of phospho-PKA (p-PKA) in the NAc were markedly up-regulated at 14(th) and 28(th) day after ligation of sciatic nerve, and p-PKA expression was down-regulated by intra-NAc injection of GalR1 agonist M617, but the GalR1 antagonist M35 did not have an effect. We also found that M35 in the NAc blocked the M617-induced increase in the hind paw withdrawal latencies (HWLs) of rats with mononeuropathy, but M35 alone had no effect on HWLs, and PKA inhibitor H-89 attenuated the M617-induced an increase in the HWLs. These results suggested that GalR1 induced an antinociception via inhibiting PKA activation, implying that GalR agonists may be potential and potent therapeutic options to treat chronic neuropathic pain.