Evaluation of the anticonvulsant and muscle relaxant effects of the methanol root bark extracts of Annona senegalensis

ObjectiveTo investigate the potentials of the root bark of Annona (A.) senegalensis in the control of seizure and related hypnotic and motor incoordination effects in mice using experimental models.MethodsThe methanol extract (ME) of the root bark of A. senegalensis was studied in mice using pentylenetetrazole (PTZ) induced convulsions, phenobarbitone induced sleeping time and motor coordination test on rota-rod performance. Acute toxicity and lethality (LD₅₀) test as well as phytochemical analysis were also carried out.ResultsThe extract (200, 400, 800 mg/kg) exhibited a non-dose dependent significant (P <0.05) delay in the onset of both tonic and clonic phases of seizure induced by PTZ (60 mg/kg, s.c.) as well as offered a 100% protection (200 mg/kg) in mice from PTZ induced seizures. The extract significantly (P <0.05) decreased the latency and increased the duration of phenobarbitone induced sleeping time. At 200 mg/kg, the extract exhibited a significant (P <0.05) motor incoordination. The acute toxicity test revealed an oral LD₅₀ of 1 296 mg/kg, while the phytochemical studies showed the presence of alkaloids, resins, glycosides, carbohydrate, reducing sugar, flavonoids, terpenoids, saponins and tannins.ConclusionThe extract of A. senegalensis possessed anticonvulsant activity with pronounced hypnotic and muscle relaxant effects.     

Elevated telomere-telomere recombination in WRN-deficient, telomere dysfunctional cells promotes escape from senescence and engagement of the ALT pathway

Werner Syndrome (WS) is characterized by premature aging, genomic instability, and cancer. The combined impact of WRN helicase deficiency and limiting telomere reserves is central to disease pathogenesis. Here, we report that cells doubly deficient for telomerase and WRN helicase show chromosomal aberrations and elevated recombination rates between telomeres of sister chromatids. Somatic reconstitution of WRN function, but not a WRN helicase-deficient mutant, abolished telomere sister chromatid exchange (T-SCE), indicating that WRN normally represses T-SCEs. Elevated T-SCE was associated with greater immortalization potential and resultant tumors maintained telomeres via the alternative lengthening of telomere (ALT) pathway. We propose that the increased incidence of chromosomal instability and cancer in WS relates in part to aberrant recombinations between sister chromatids at telomeres, which facilitates the activation of ALT and engenders cancer-relevant chromosomal aberrations and tumor formation.     

Larvicidal activity of pectolinaringenin from Clerodendrum phlomidis L. against Culex quinquefasciatus Say and Aedes aegypti L. (Diptera: Culicidae)

Larvicidal activity of 12 fractions and a compound of chloroform extract of Clerodendrum phlomidis L. (Lamiaceae) was assayed for their toxicity against the early fourth-instar larvae of the filarial vector Culex quinquefasciatus Say and dengue vector Aedes aegypti L. The fractions were tested at 100-, 50-, 25- and 12.5-ppm concentrations. The compound pectolinaringenin was tested at 5-, 2.5-, 1.0- and 0.5-ppm concentrations. Among the different fractions, fraction 5 recorded the lowest LC(50) and LC(90) values of 5.02, 61.63?ppm and 32.86, 73.62?ppm against C. quinquefasciatus and A. aegypti, respectively. The compound pectolinaringenin showed the lowest LC(50) and LC(90) values of 0.62, 2.87?ppm and 0.79, 5.31?ppm against C. quinquefasciatus and A. aegypti, respectively. This is the first report on the mosquito larvicidal activity of the isolated compound pectolinaringenin from C. phlomidis. The results of this study show that the chloroform extract of C. phlomidis can be used as a potent source and pectolinaringenin as a new natural mosquito larvicidal agent.     

X-Ray Image Review of the Bone Remodeling Around an Osseointegrated Trans-femoral Implant and a Finite Element Simulation Case Study

The insertion of an implant into a bone leads to stress/strain redistribution, hence bone remodeling occurs adjacent to the implant. The study of the bone remodeling around the osseointegration implants can predict the long-term clinical success of the implant. The clinical medial–lateral X-rays of 11 patients were reviewed. To eliminate geometrical distortion of different X-rays, they were converted into a digital format and geometrical correction was carried out. Furthermore, the finite element (FE) method was used to investigate how the bone remodeling was affected by the stress/strain distribution in the femur. The review of clinical X-rays showed cortical bone growth around the proximal end of the implant and absorbtion at the distal end of the femur. The FE simulation revealed the stress/strain distribution in the femur of a selected patient. This provided a biomechanical interpretation of the bone remodeling. The existing bone remodeling theories such as minimal strain and strain rate theories were unable to offer satisfactory explanation for the cortical bone growth at the implant side of the proximal femur, where the stress/strain level was much lower than the one in the intact side of the femur. The study established the correlation between stress/strain distribution obtained from FE simulations and the bone remodeling of the clinical review. The cortical bone growth was initiated by the stress/strain gradient in the bone. Through the review of clinical X-rays and FE simulations, the study confirmed that the bone remodeling in a femur with an implant was influenced by the stress/strain redistribution. The strain level and stress gradient hypothesis is presented to offer an explanation for the implanted cortical bone remodeling observed in this study.     

Exploring genotype‐phenotype relationships in the CDKL5 deficiency disorder using an international dataset

Characterized by early‐onset seizures, global developmental delay and severe motor deficits, CDKL5 deficiency disorder is caused by pathogenic variants in the cyclin‐dependent kinase‐like 5 gene. Previous efforts to investigate genotype‐phenotype relationships have been limited due to small numbers of recurrent mutations and small cohort sizes. Using data from the International CDKL5 Disorder Database we examined genotype‐phenotype relationships for 13 recurrent CDKL5 variants and the previously analyzed historic variant groupings. We have applied the CDKL5 Developmental Score (CDS) and an adapted version of the CDKL5 Clinical Severity Assessment (CCSA), to grade the severity of phenotype and developmental outcomes for 285 individuals with CDKL5 variants. Comparisons of adapted CCSA and CDS between recurrent variants and variant groups were performed using multiple linear regression adjusting for age and sex. Individuals with the missense variant, p.Arg178Trp, had the highest mean adapted CCSA and lowest mean developmental scores. Other variants producing severe phenotypes included p.Arg559* and p.Arg178Gln. Variants producing milder phenotypes included p.Arg134*, p.Arg550*, and p.Glu55Argfs*20. There are observed differences in phenotype severity and developmental outcomes for individuals with different CDKL5 variants. However, the historic variant groupings did not seem to reflect differences in phenotype severity or developmental outcomes as clearly as analyzed by individual variants.     

Immunogenic and tolerogenic signatures in human immunodeficiency virus (HIV)-infected controllers compared with progressors and a conversion strategy of virus control

Epidemiological studies have identified a small cohort of controllers of human immunodeficiency virus (HIV)-1 infection, who without treatment have no detectable virus, and others who progress at a variable rate. The objective of this study was to distinguish immune signatures in HIV controllers and progressors, by evaluating tolerogenic and immunogenic factors in untreated HIV-1 infected individuals. The recruited population was divided into putative elite controllers (PEC), long-term non-progressors (LTNP), normal progressors (NP) and fast progressors (FP). The proportion of regulatory T cells [T(regs) , CD4+ CD25+ forkhead box P3 (FoxP3+)], programmed death (PD)-1 and cytotoxic T lymphocyte antigen (CTLA)-inhibitory molecules and CD40L, CD69 and Ki67 activation markers were evaluated in peripheral blood mononuclear cells (PBMC) by flow cytometry. Significant differences were found between HIV controllers and HIV progressors, with up-regulation of T(regs) , PD-1 and CTLA-4 and decrease of CD40L expression in progressors compared with controllers. Expression of CD40L and concentrations of interleukin (IL)-6, CCL-3, and CCL-4 were significantly higher in PEC and LTNP than in NP and FP. In an attempt to convert immune signatures of progressors to those of controllers, seven agents were used to stimulate PBMC from the four cohorts. Treatment with CD40L and IL-4 or PD-1 antibodies in vitro were most effective in converting the immune signatures of progressors to those observed in controllers by down-regulating T(regs) and up-regulating CD40L expression in CD4+ T cells. The conversion concept merits translation to in vivo immune control of HIV infection.     

Soluble flagellin, FliC, induces an Ag-specific Th2 response, yet promotes T-bet-regulated Th1 clearance of Salmonella typhimurium infection

Clearance of disseminated Salmonella infection requires bacterial-specific Th1 cells and IFN-γ production, and Th1-promoting vaccines are likely to help control these infections. Consequently, vaccine design has focused on developing Th1-polarizing adjuvants or Ag that naturally induce Th1 responses. In this study, we show that, in mice, immunization with soluble, recombinant FliC protein flagellin (sFliC) induces Th2 responses as evidenced by Ag-specific GATA-3, IL-4 mRNA, and protein induction in CD62L(lo) CD4(+) T cells without associated IFN-γ production. Despite these Th2 features, sFliC immunization can enhance the development of protective Th1 immunity during subsequent Salmonella infection in an Ab-independent, T-cell-dependent manner. Salmonella infection in sFliC-immunized mice resulted in augmented Th1 responses, with greater bacterial clearance and increased numbers of IFN-γ-producing CD4(+) T cells, despite the early induction of Th2 features to sFliC. The augmented Th1 immunity after sFliC immunization was regulated by T-bet although T-bet is dispensable for primary responses to sFliC. These findings show that there can be flexibility in T-cell responses to some subunit vaccines. These vaccines may induce Th2-type immunity during primary immunization yet promote Th1-dependent responses during later infection. This suggests that designing Th1-inducing subunit vaccines may not always be necessary since this can occur naturally during subsequent infection.     

Role of microRNAs in sepsis

Introduction

MicroRNAs have been found to be of high significance in the regulation of various genes and processes in the body. Sepsis is a serious clinical problem which arises due to the excessive host inflammatory response to infection. The non-specific clinical features and delayed diagnosis of sepsis has been a matter of concern for long time.

Findings

MicroRNAs could enable better diagnosis of sepsis and help in the identification of the various stages of sepsis. Improved diagnosis may enable quicker and more effective treatment measures. The initial acute and transient phase of sepsis involves excessive secretion of pro-inflammatory cytokines which causes severe damage. MicroRNAs negatively regulate the toll-like receptor signaling pathway and regulate the production of inflammatory cytokines during sepsis. Likewise, microRNAs have shown to regulate the vascular barrier and endothelial function in sepsis. They are also involved in the regulation of the apoptosis, immunosuppression, and organ dysfunction in later stages of sepsis. Their importance at various levels of the pathophysiology of sepsis has been discussed along with the challenges and future perspectives.

Conclusion

MicroRNAs could be key players in the diagnosis and staging of sepsis. Their regulation at various stages of sepsis suggests that they may have an important role in altering the outcome associated with sepsis.