A 12-Vertex Metallacarborane of Silver(I).

The discovery of ferrocene in 1951 was a significant landmark in the field of organometallic chemistry, and since then, numerous sandwich- or half-sandwich metallic complexes have been reported. However, silver stands as an intriguing exception in this regard, and knowledge of its bonding situation has remained undisclosed. Herein, unprecedented 12-vertex metallacarboranes of Ag(I) (2a and 2b) were synthesized through the reaction of sodium hexamethyldisilazide (NaHMDS) with the mixture of nido-C2B9 carborane anion-supported N-heterocyclic carbene precursors (1a and 1b) and [Ag(PPh3)Cl]4. The X-ray structural analysis of the resulting metallacarboranes revealed a unique "slipped" half-sandwich structure, which is a rarity among cyclopentadienyl analogues. DFT calculations provided insights into the asymmetric π-interactions between the pentagonal C2B3 face and the silver ion.

The protective effect of apolipoprotein H in paediatric sepsis.

BACKGROUND: Sepsis is a severe condition characterized by acute organ dysfunction resulting from an imbalanced host immune response to infections. Apolipoprotein H (APOH) is a critical plasma protein that plays a crucial role in regulating various biological processes. However, the precise role of APOH in the immunopathology of paediatric sepsis remains unclear. METHODS: In this study, we evaluated the concentration of APOH in paediatric patients with sepsis and healthy individuals. In an experimental sepsis model of caecal ligation and puncture (CLP), the impact of APOH on survival, organ injury, and inflammation was measured. Furthermore, the anti-inflammatory effects of APOH were investigated across diverse immune cell types, encompassing peripheral blood mononuclear cells (PBMCs), peritoneal macrophages (PMs), bone marrow-derived macrophages (BMDMs), and RAW 264.7 macrophages. RESULTS: In the pilot cohort, the relative abundance of APOH was found to be decreased in patients with sepsis (2.94 ± 0.61) compared to healthy controls (1.13 ± 0.84) (p < 0.001), non-survivors had lower levels of APOH (0.50 ± 0.37) compared to survivors (1.45 ± 0.83) (p < 0.05). In the validation cohort, the serum concentration of APOH was significantly decreased in patients with sepsis (202.0 ± 22.5 ng/ml) compared to healthy controls (409.5 ± 182.9 ng/ml) (p < 0.0001). The application of recombinant APOH protein as a therapeutic intervention significantly lowered the mortality rate, mitigated organ injury, and suppressed inflammation in mice with severe sepsis. In contrast, neutralizing APOH with an anti-APOH monoclonal antibody increased the mortality rate, exacerbated organ injury, and intensified inflammation in mice with non-severe sepsis. Intriguingly, APOH exhibited minimal effects on the bacterial burden, neutrophil, and macrophage counts in the sepsis mouse model, along with negligible effects on bacterial phagocytosis and killing during Pseudomonas aeruginosa infection in PMs, RAW 264.7 cells, and PBMCs. Mechanistic investigations in PMs and RAW 264.7 cells revealed that APOH inhibited M1 polarization in macrophages by suppressing toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) signalling pathway. CONCLUSION: This proof-of-concept study demonstrated that APOH has a protective role in the host defense response to sepsis, highlighting the potential therapeutic value of APOH in sepsis treatment.

Biofortification of different maize cultivars with zinc, iron and selenium by foliar fertilizer applications.

Fertilizer-based biofortification is a strategy for combating worldwide malnutrition of zinc (Zn), iron (Fe) and selenium (Se). Field experiments were conducted to investigate the effects of foliar treatments on concentrations of Zn, Fe, Se, N and bioavailability of Zn and Fe in grains of three maize cultivars grown at three locations. We compared the efficacy of ZnO nanoparticles (ZnO-NPs), Zn complexed chitosan nanoparticles (Zn-CNPs), conventional ZnSO4 and a cocktail solution (containing Zn, Fe and Se). All treatments were foliar-applied at rate of 452 mg Zn L-1, plus urea. Applying ten-fold less Zn (at rate of 45.2 mg Zn L-1) plus urea in the form of ZnO-NPs, Zn-CNPs, or ZnSO4 resulted in no increase, or a negligible increase, in grain Zn concentration compared with deionized water. By contrast, among the different Zn sources plus urea applied by foliar sprays, conventional ZnSO4 was the most efficient in improving grain Zn concentration. Furthermore, foliar application of a cocktail solution effectively improved grain concentrations of Zn, Fe, Se and N simultaneously, without a grain yield trade-off. For example, the average grain concentrations were simultaneously increased from 13.8 to 22.1 mg kg-1 for Zn, from 17.2 to 22.1 mg kg-1for Fe, from 21.4 to 413.5 ug kg-1 for Se and from 13.8 to 14.7 g kg-1 for N by foliar application of a cocktail solution. Because grain yield was significantly negatively correlated with grain nutrient concentrations, the magnitude of increase in grain concentrations of Zn and Fe was most pronounced in the maize cultivar with the lowest grain yield (Zhengdan958 grown in Linyi). Foliar application of a cocktail solution also significantly decreased the phytic acid (PA) concentration, ratios of PA/Fe and PA/Zn in grains, indicating an increased bioavailability of Fe and Zn for human health. In conclusion, we found that a foliar application of a cocktail solution including Zn, Fe, Se and N was most effective for biofortification, but that the grains with the lowest yield contained the greatest concentration of these elements. This finding highlights the need to breed maize varieties that are capable of achieving both high grain yield and high grain nutritional quality to address food security and human health challenges.

[Clinical analysis of CT guided unilateral PVP for the treatment of osteoporotic vertebral compression fracture in senile patients].

OBJECTIVE: To evaluate the therapeutic effect and security of CT guided unilateral percutaneous vertebroplasty (PVP) for the treatment of osteoporotic vertebral compression fracture (OVCF) in senile patients. METHODS: From April 2009 to June 2010, 26 patients undergoing CT guided unilateral percutaneous vertebroplasty were analyzed retrospectively. There were 9 males and 17 females,ranging in age from 60 to 85 years with an average of (67.50+/-6.76) years, ranging in course of disease from 2 to 30 days with an average of (8.92+/-4.36) d. The affected segments involved 35 vertebras. The major clinical manifestations of OVCF were lumbar-back pain (especially when turning over or stooping down) and unable to bear. The needle was punctured into vertebral of lesions through unilateral puncture under the CT guidance; and then 3-5 ml bone cement was injected into vertebral. Antibiotic was used 3 days to prevent postoperative infections. Postoperative complications were observed after operation, such as local leakage of bone cement, penetrating spinal cord and/or segmental spinal nerve injuries and pulmonary embolism. X-ray was used to measure the height of anterior, middle and exterior of vertebral before and after treatment. A visual analog scale (VAS) scoring was applied to evaluate pain score preoperative, 48 hours postoperative and the terminal follow-up. RESULTS: Twenty-six patients achieved success in punctuation without serious complications. Local leakage of bone cement occurred in 6 cases, but without clinical symptoms or signs. One patient suffered from acute intraoperative reactions to bone cement and relieved by 5 mg dexamethasone and oxygen. All patients were followed up for 6 to 12 months [averaged (8.4+/-1.6) months]. The postoperative vertebrae height was higher than preoperative,but there was no statistical difference between postoperative and preoperative (P>0.05). Preoperative VAS scores was 7.63+/-0.92, postoperative score was 3.00+/-1.09, the final follow-up score was 2.38+/-1.17; there was significant difference between preoperative and postoperative at 48 hours (P<0.05), but there was no statistical difference between final follow-up and postoperative at 48 hours (P>0.05). CONCLUSION: Unilateral PVP under CT guided can increase the vertebral strength and stabilize vertebral body,and the procedure is a safe and effective method for OVCF in elderly patients.

Inhibitory effects of Group I metabotropic glutamate receptors antagonists on the expression of NMDA receptor NR1 subunit in morphine tolerant rats.

N-methyl-D-aspartate receptor (NMDAR) and Group I metabotropic glutamate receptors (mGluRs) are involved in the process of morphine tolerance. Previous studies have shown that Group I mGluRs can modulate NMDAR functions in the central nervous system. The aim of the present study was to examine the influence of Group I mGluRs antagonists on the expression of NMDA receptor NR1 subunit (NR1) in the rat spinal cord. Morphine tolerance was induced in rats by repeated administration of 10 microg morphine (intrathecal, i.t.) twice a day for 7 consecutive days. Tail flick test was used to assess the effect of Group I mGluRs antagonist, AIDA ((RS)-1-Aminoindan-1,5 dicarboxylic acid) or mGluR5 antagonist, MPEP (2-methyl-6-(phenylethynyl)pyridine) on morphine antinociceptive tolerance. The expression of NR1 was measured by immunofluorescence and Western blot. Behavioral tests revealed that both AIDA and MPEP attenuated the development of morphine tolerance. The expression of NR1 was upregulated in the dorsal horn of spinal cord after chronic morphine treatment. AIDA or MPEP co-administered with morphine attenuated morphine induced upregulation of NR1. These findings suggest that the development of morphine tolerance partly prevented by Group I mGluRs antagonists may due to its inhibitory effect on the expression of NR1 subunit.

[Expression of metabotropic glutamate receptor 5 in spinal cord of morphine tolerant rats].

OBJECTIVE: To investigate the expression of metabotropic glutamate receptor 5 (mGluRS) in spinal cord of morphine tolerant rats and understand the influence of mGluR5 antagonist MPEP upon the expression of mGluRS. METHODS: Male Sprague-Dawley rats were randomly divided into four groups with 8 rats each:control group (NS), morphine group, morphine plus MPEP group and MPEP group. A morphine tolerance model of rat was established by repeated administration of 10 microg morphine intrathecally twice daily for 7 days. The effects of morphine co-administrated with MPEP upon the thermal pain threshold were examined by tail flick test. Tail flick latency (TFL) was measured at 30 min pre- and postdosing. MPE% (percentage of maximal possible effect) was calculated by the equation: MPE (%) = [(test response time-basal response time)/(cut-off time-basal response time)] x 100%. The rats were sacrificed and L4-5 spinal cord tissue was removed. The expression of mGluR5 in every group was examined by immunofluorescence and Western blot. RESULTS: MPE% of morphine group decreased gradually after chronic administration of morphine intrathecally. There was no significant difference between morphine group and control group at Day 7 (P > 0.05). Morphine plus MPEP group had significant analgesic effect as compared with morphine group at Day 7 (P < 0.05). The expression of mGluR5 was up-regulated in the dorsal horn of spinal cord in morphine tolerant rats. The protein level of mGluRS in morphine plus MPEP group was lower than that in morphine group (P < 0.05), but higher than control group (P < 0.05). CONCLUSION: The mGluR5 antagonist MPEP can prevent the development of morphine tolerance. The expression of mGluR5 protein increases in the spinal cord of morphine tolerant rats. MPEP plays its role in morphine tolerance by partly inhibiting the expression of mGluRS.