Cobalt-Catalyzed Acceptorless Dehydrogenation of Primary Amines to Nitriles.

The direct double dehydrogenation from primary amines to nitriles without an oxidant or hydrogen acceptor is both intriguing and challenging. In this paper, we describe a non-noble metal catalyst capable of realizing such a transformation with high efficiency. A cobalt-centered N,N-bidentate complex was designed and employed as a metal-ligand cooperative dehydrogenation catalyst. Detailed kinetic studies, control experiments, and DFT calculations revealed the crucial hydride transfer, proton transfer, and hydrogen evolution processes. Finally, a tandem outer-sphere/inner-sphere mechanism was proposed for the dehydrogenation of amines to nitriles through an imine intermediate.

Apoptosis of Dendritic Cells and Autoimmune Disease.

Dendritic cells (DCs), the most efficient antigen-presenting cells (APCs), bridge the innate and adaptive immune systems. As such, the turn-over of DCs is critical during autoimmune responses, and the dysregulation of DC apoptosis could cause severe immune destruction in the host. For example, reduction of immunogenic DCs by increased apoptosis could lead to immune tolerance to pathogen infection that might allow exposure of nuclear autoantigens, whereas reduced apoptosis could result in long-term lymphocyte activation to break the immune tolerance for the development of autoimmune disease. Thus, keeping a balance between survival and apoptosis of DCs is crucial to maintain immune homeostasis. In this review, we summarize the recent development on the factors inducing DC apoptosis and their underlying mechanisms to provide insights into the immunopathogenesis of some autoimmune diseases, which could lead to effective therapeutic interventions in the clinics.

Effects of Liver-Regulating Herb Compounds on Varicocele-Associated Testicular Dysfunction Through Restoring Hormones and Spermatocytes Apoptosis.

PURPOSE: Varicocele is considered one of the causes of male infertility. Though varicocelectomy is supposed to improve semen parameters in adult infertile men, some patients with varicocele were still infertile after varicocelectomy. Previous studies showed Traditional Chinese Medicine, Liver-regulating herb compounds (LRHC) could improve the semen quality and increase fertility rates of infertile patients with varicocele. This study aimed to throw light on the mechanism of LRHC on varicocele-associated infertility. MATERIALS AND METHODS: Rats with varicocele-induced were treated with LRHC at dosage of 1mL/100g by intragastric administration for 90 days. The effects of LRHC on hormones and spermatocytes apoptosis were examined using ELISA assay, Western blotting, and flow cytometry. RESULTS: Rats induced with varicocele showed a higher level of follicle stimulating hormone (FSH) in serum, which was brought back to normal level by LRHC. After treatment with LRHC, both testicular tissue in vivo and Sertoli cell TM4 cells in vitro showed elevated expressions of FSHR. Cell viabilities of TM4 cells and spermatocyte GC-2 cells were improved by LRHC treatment under normoxia and hypoxia conditions. Moreover, LRHC protected GC-2 cells from apoptosis induced by hypoxia. The expression of Bax reduced, while that of Bcl-2 increased after treatment with LRHC. CONCLUSION: This study revealed that LRHC had protective effects on spermatogenic disturbance caused by varicocele through regulating hormones and reducing spermatogenic cell apoptosis under hpoxia conditions.

RESPIRATORY VARIABILITY OF VALVULAR PEAK SYSTOLIC VELOCITY AS A NEW INDICATOR OF FLUID RESPONSIVENESS IN PATIENTS WITH SEPTIC SHOCK.

ABSTRACT: Objective: The aim of this study was to evaluate the reliability and feasibility of pulse Doppler measurements of peak velocity respiratory variability of mitral and tricuspid valve rings during systole as new dynamic indicators of fluid responsiveness in patients with septic shock. Methods: Transthoracic echocardiography (TTE) was performed to measure the respiratory variability of aortic velocity-time integral (∆VTI), respiratory variability of tricuspid annulus systolic peak velocity (∆RVS), respiratory variability of mitral annulus systolic peak velocity (∆LVS), and other related indicators. Fluid responsiveness was defined as a 10% increase in cardiac output after fluid expansion, assessed by TTE. Results: A total of 33 patients with septic shock were enrolled in this study. First, there was no significant difference in the population characteristics between the fluid responsiveness positive group (n = 17) and the fluid responsiveness negative group (n = 16) ( P > 0.05). Second, Pearson correlation test showed that ∆RVS, ∆LVS, and TAPSE with the relative increase in cardiac output after fluid expansion ( R = 0.55, P = 0.001; R = 0.40, P = 0.02; R = 0.36, P = 0.041). Third, multiple logistic regression analysis demonstrated that ∆RVS, ∆LVS, and TAPSE were significantly correlated with fluid responsiveness in patients with septic shock. Fourth, receiver operating characteristic (ROC) curve analysis revealed that ∆VTI, ∆LVS, ∆RVS, and TAPSE had good predictive ability for fluid responsiveness in patients with septic shock. The area under the curve (AUC) of ∆VTI, ∆LVS, ∆RVS, and TAPSE for predicting fluid responsiveness was 0.952, 0.802, 0.822, and 0.713, respectively. The sensitivity (Se) values were 1.00, 0.73, 0.81, and 0.83, whereas the specificity (Sp) values were 0.84, 0.91, 0.76, and 0.67, respectively. The optimal thresholds were 0.128, 0.129, 0.130, and 13.9 mm, respectively. Conclusion: Tissue Doppler ultrasound evaluation of respiratory variability of mitral and tricuspid annular peak systolic velocity could be a feasible and reliable method for the simple assessment of fluid responsiveness in patients with septic shock.

Mechanistic Insights into the Synergistic Effect of Palladium(0) and Copper(I) on the Selective Transformation of Isocyanate to Indole.

Density functional theory calculations have been utilized to investigate the synergistic effect of palladium(0) and copper(I) catalyzed selective formation of allylated indole from (2-alkynyl)-phenylisocyanate and allyl methyl carbonate. The main competing reaction yielding the N-allyl carbamate was also considered. Calculated results indicate that using the Pd(0)-complex alone, the generation of indole is kinetically much less favored than producing the N-allyl carbamate compound. However, the co-addition of Cu(I) catalyst can considerably decrease the barrier for the intramolecular cyclization step, leading to the formation of the indole product. Analysis of the cyclization process suggests that Cu(I) complex can act as a Lewis acid to activate the linear alkyne group via a π-coordination manner prior to the formation of a 5-membered ring transition state toward indole formation. Altogether, the mechanistic insights revealed in the present study aim at a better understanding of the mechanism and the factors governing the selectivity in synergistic Pd/Cu catalysis.

Effects of liver-regulating herb compounds on testicular morphological and ultrastructural changes in varicocele rats through SCF/C-KIT pathway.

Liver-regulating herb compound (LRHC) has good effects on improving sperm quality and male fertility of varicocele (VC) patients. But the mechanism of LRHC on VC is still not clear. This study explored the effects of LRHC on histomorphological and ultrastructural changes and expression of stem cell factor (SCF) and C-KIT of VC rat testis. Twenty-four male rats were divided into three groups with eight rats in each group as sham, varicocele and LRHC groups. Testis specimens were collected for light microscopy and transmission electron microscopy respectively. The expression of SCF/C-KIT was detected with Western blot. Results showed that seminiferous tubules in VC rats were damaged and cell numbers were decreased. Ultrastructural alterations were observed, such as increased thickness of lamina propria, vacuolation in Sertoli cells, spermatocytes and spermatids, and abnormal head and mitochondria in spermatozoa. While in LRHC-treated rats, the architectures of seminiferous tubules were as organised and compact as that of sham animals, and ultrastructure of Sertoli, Leydig and germ cells developed well. LRHC ameliorated histological appearance and ultrastructure by VC. In addition, the abnormal expression of SCF and C-KIT were observed in testicular tissues from rats with VC, which were brought back to normal level by LRHC.

Elevated Expression of NOTCH1 Associates with Lymph Node Metastasis of Gastric Cancer and Knock-Down of NOTCH1 Attenuates Tumor Cell Progression.

BACKGROUND Gastric cancer is the third leading cause of cancer-related death, while its molecular mechanism has not been fully clarified. This study aims to explore the role of Notch signaling in the pathogenesis of gastric cancer. MATERIAL AND METHODS A total of 64 patients with gastric cancer were enrolled. The expressions of NOTCH1 in tumor tissues and adjacent non-tumor tissues were detected by immunohistochemistry staining. The correlation between NOTCH1 expression and clinicopathological features of patients was analyzed. NOTCH1 was knocked down in gastric cancer cells. The effects of NOTCH1 blockade on cell proliferation, migration and cell cycle distribution were analyzed. The expressions of ERK1/2 and phospho-ERK1/2 (p-ERK1/2) were detected using western blotting. RESULTS Gastric cancer tissues expressed higher level of NOTCH1 than adjacent non-tumor tissues (P<0.05). The high level of NOTCH1 was found to be correlated with gender (male) and lymph node metastasis. However, the expression level of NOTCH1 did not affect the overall survival of patients with gastric cancer. NOTCH1 knock-down repressed the migration and proliferation of gastric cancer cells. Moreover, the cell cycle was arrested at G0/G1 phase by NOTCH1 blockade. The expressions of ERK1/2 and p-ERK1/2 decreased with NOTCH1 knock-down. Further inhibition of ERK1/2 signaling by a MEK1/2 inhibitor U0126 reduced the proliferation of AGS cells, which aggravated the inhibition effect of NOTCH1 knock-down on cell proliferation. CONCLUSIONS NOTCH1 may play an oncogenic role in gastric cancer. Inhibition of NOTCH1 can efficiently attenuate gastric cancer cell progression, probably in part through cross-talking with ERK1/2 signaling pathway.

Application effect of pneumatic tourniquet with individualized pressure setting in orthopaedic surgery of extremities: A meta-analysis.

AIMS: To evaluate the application effect of individualized pressure setting strategy of pneumatic tourniquet in orthopaedic surgery. BACKGROUND: Some individualized setting pressures of pneumatic tourniquet are lower than the standard pressure recommended in the textbook (Nursing of Operating Room, People's Military Publishing House, 2008). DESIGN: Meta-analysis. DATA SOURCES: CL, WOS, PubMed, CNKI, CBM, VIP and Wan-fang DATA. REVIEW METHODS: We searched studies on the application effect of individualized pressure of pneumatic tourniquet from the establishment date of the databases to September 2017. Study quality was assessed using the quality evaluation method recommended in the Cochrane Handbook 5.1.0 (Higgins, 2011). The primary outcome was inflation pressure. RESULTS: We identified nine studies including 1,200 patients. The individualized pressure setting strategy can provide a lower inflation pressure (four studies), improve haemostatic effect (six studies) and reduce the incidence of related complications (eight studies). CONCLUSIONS: An individualized inflation pressure is recommended when using the tourniquet in orthopaedic surgery. And the setting pressure might be a minimum and efficiency one, by accessing the the systolic blood pressure and limb circumferences of the patient. IMPACT: This study addressed that the individualized pressure setting strategy of pneumatic tourniquet can provide a lower inflation pressure and a higher application value in orthopaedic limb surgery. However, greater attention should be focused on how to unify the individualized pressure setting strategy. Meanwhile, the instructions for use from manufacturers need to be updated. Therefore, it is recommended to conduct a large-sample multi-centre high-quality randomized controlled trial in strict accordance with the CONSORT standard.

Increased Level of c-kit in Semen of Infertile Patients with Varicocele.

PURPOSE: Varicocele is the most common risk factor for male infertility, however, not all males with varicocele experience infertility. In fact, most patients with varicocele have normal spermatogenesis. The molecular mechanism of varicocele-associated infertility is yet to be completely understood. The aim of this study is to assess the association of a number of fertility regulatory factors on varicocele associated infertility and to throw light on the mechanism of varicocele-associated infertility. MATERIALS AND METHODS: Semen from 30 infertile patients with varicocele and 30 fertile men with varicocele were collected. The concentrations of the following factors in seminal plasma were determined by ELISA: follicle stimulating hormone (FSH), luteinizing hormone (LH), testosterone (T), androgen binding protein (ABP), transferrin (Trf), inhibin B (INHB) and stem cell factor (SCF). The expression level of c-kit in seminal precipitate of patients with varicocele was detected by real-time PCR. RESULTS: The concentrations of sexual hormones, FSH, LH and T, had no differences between infertile patients with varicocele and fertile men with varicocele (P > 0.05). Factors secreted by Sertoli cells, ABP, Trf, INHB andSCF, showed no significant differences between the two groups (P > 0.05). Interestingly, the expression of c-kit was significant higher in infertile patients with varicocele than that in fertile men with varicocele (P < 0.01). CONCLUSION: Neither the sexual hormones nor the Sertoli cells was responsible for the infertility induced by varicocele.The aberrant expression of c-kit in infertile patients with varicocele may provide new insight into the mechanism of varicocele-associated infertility.

Reduced Glutamate Release in Adult BTBR Mouse Model of Autism Spectrum Disorder.

Autism spectrum disorder (ASD) is a developmental disorder characterized by impairments in social and communication abilities, as well as by restricted and repetitive behaviors. The BTBR T + Itpr3 tf (BTBR) mice have emerged as a well characterized and widely used mouse model of a range of ASD-like phenotype, showing deficiencies in social behaviors and unusual ultrasonic vocalizations as well as increased repetitive self-grooming. However, the inherited neurobiological changes that lead to ASD-like behaviors in these mice are incompletely known and still under active investigation. The aim of this study was to further evaluate the structure and neurotransmitter release of the glutamatergic synapse in BTBR mice. C57BL/6J (B6) mice were used as a control strain because of their high level of sociability. The important results showed that the evoked glutamate release in the cerebral cortex of BTBR mice was significantly lower than in B6 mice. And the level of vesicle docking-related protein Syntaxin-1A was reduced in BTBR mice. However, no significant changes were observed in the number of glutamatergic synapse, level of synaptic proteins, density of dendritic spine and postsynaptic density between BTBR mice and B6 mice. Overall, our results suggest that abnormal vesicular glutamate activity may underlie the ASD relevant pathology in the BTBR mice.

Inhibition of IL-6 trans-signaling in the brain increases sociability in the BTBR mouse model of autism.

Autism is a severe neurodevelopmental disorder with a large population prevalence, characterized by abnormal reciprocal social interactions, communication deficits, and repetitive behaviors with restricted interests. The BTBR T(+)Itpr3(tf) (BTBR) mice have emerged as strong candidates to serve as models of a range of autism-relevant behaviors. Increasing evidences suggest that interleukin (IL)-6, one of the most important neuroimmune factors, was involved in the pathophysiology of autism. It is of great importance to further investigate whether therapeutic interventions in autism can be achieved through the manipulation of IL-6. Our previous studies showed that IL-6 elevation in the brain could mediate autistic-like behaviors, possibly through the imbalances of neural circuitry and impairments of synaptic plasticity. In this study, we evaluate whether inhibiting IL-6 signaling in the brain is sufficient to modulate the autism-like behaviors on the BTBR mice. The results showed that chronic infusion of an analog of the endogenous IL-6 trans-signaling blocker sgp130Fc protein increased the sociability in BTBR mice. Furthermore, no change was observed in the number of excitatory synapse, level of synaptic proteins, density of dentitic spine and postsynaptic density in BTBR cortices after inhibiting IL-6 trans-signaling. However, inhibition of IL-6 trans-signaling increased the evoked glutamate release in synaptoneurosomes from the cerebral cortex of BTBR mice. Our findings suggest that inhibition of excessive production of IL-6 may have selective therapeutic efficacy in treating abnormal social behaviors in autism.

Abnormal glutamate release in aged BTBR mouse model of autism.

Autism is a neurodevelopmental disorder characterized by abnormal reciprocal social interactions, communication deficits, and repetitive behaviors with restricted interests. Most of the available research on autism is focused on children and young adults and little is known about the pathological alternation of autism in older adults. In order to investigate the neurobiological alternation of autism in old age stage, we compared the morphology and synaptic function of excitatory synapses between the BTBR mice with low level sociability and B6 mice with high level sociability. The results revealed that the number of excitatory synapse colocalized with pre- and post-synaptic marker was not different between aged BTBR and B6 mice. The aged BTBR mice had a normal structure of dendritic spine and the expression of Shank3 protein in the brain as well as that in B6 mice. The baseline and KCl-evoked glutamate release from the cortical synaptoneurosome in aged BTBR mice was lower than that in aged B6 mice. Overall, the data indicate that there is a link between disturbances of the glutamate transmission and autism. These findings provide new evidences for the hypothesis of excitation/inhibition imbalance in autism. Further work is required to determine the cause of this putative abnormality.