Evaluation of the In Vivo Activity of Different Concentrations of Clerodendrum Umbellatum Poir Against Schistosoma Mansoni Infection in Mice

Clerodendrum umbellatum Poir (Verbenaceae) is traditionally used in Cameroon for the treatment of many diseases including intestinal helminthiasis. This study was undertaken to assess the in vivo antischistosomal activity of its leaves aqueous extract on a Schistosoma mansoni mice model and to determine the most effective dose of this extract. Mice showing a patent infection of S. mansoni were daily treated with C. umbellatum leaves aqueous extract at the doses of 40, 80 or 160 mg/kg body weight for 14 days. Seven days after administration of the extract, schistosomicidal activity was evaluated on the liver and spleen weights, faecal eggs releasing, liver egg count and worm burden. Treatment using C. umbellatum leaves aqueous extract resulted in an important reduction in faecal egg output by 75.49 % and 85.14 % for 80 mg/kg and 160 mg/kg of the extract respectively. These reduction rates did not differ significantly from the 100 % obtained in the group of infected mice treated with 100 mg/kg of praziquantel. C. umbellatum leaves aqueous extract was lethal to S. mansoni worm. A 100 % reduction rate was recorded in the group of infected mice treated with 160 mg/kg of the extract, as well as in praziquantel-treated mice. An amelioration of the hepatosplenomegaly was noticed in both the extract-treated mice and the praziquantel-treated mice. From these results, we can conclude that C. umbellatum leaves aqueous extract demonstrated schistosomicidal properties in S. mansoni model at doses of at least 80 mg/kg body weight.     

Novel mutations in CRB1 and ABCA4 genes cause Leber congenital amaurosis and Stargardt disease in a Swedish family

This study aimed to identify genetic mechanisms underlying severe retinal degeneration in one large family from northern Sweden, members of which presented with early-onset autosomal recessive retinitis pigmentosa and juvenile macular dystrophy. The clinical records of affected family members were analysed retrospectively and ophthalmological and electrophysiological examinations were performed in selected cases. Mutation screening was initially performed with microarrays, interrogating known mutations in the genes associated with recessive retinitis pigmentosa, Leber congenital amaurosis and Stargardt disease. Searching for homozygous regions with putative causative disease genes was done by high-density SNP-array genotyping, followed by segregation analysis of the family members. Two distinct phenotypes of retinal dystrophy, Leber congenital amaurosis and Stargardt disease were present in the family. In the family, four patients with Leber congenital amaurosis were homozygous for a novel c.2557C>T (p.Q853X) mutation in the CRB1 gene, while of two cases with Stargardt disease, one was homozygous for c.5461-10T>C in the ABCA4 gene and another was carrier of the same mutation and a novel ABCA4 mutation c.4773+3A>G. Sequence analysis of the entire ABCA4 gene in patients with Stargardt disease revealed complex alleles with additional sequence variants, which were evaluated by bioinformatics tools. In conclusion, presence of different genetic mechanisms resulting in variable phenotype within the family is not rare and can challenge molecular geneticists, ophthalmologists and genetic counsellors.     

bcl-2 transgene expression promotes survival and reduces proliferation of CD3-CD4-CD8- T cell progenitors

Proliferative expansion and apoptotic cell death play prominent roles in T cell development. The molecular control of cell cycle progression and apoptosis appear to be inter-connected since the Bcl-2 protein can inhibit apoptosis and slow cell cycle progression in cortical thymocytes and mature T cells, particularly during the transition from the quiescent state into the cell cycle. Here the impact of bcl-2 transgene expression on CD3-CD4-CD8- T cell progenitors was assessed. Bcl-2 enhanced the survival of these progenitors at all of the four major differentiation stages, CD25- CD44+ (pro-T1), CD25 + CD44+ (pro- T2), CD25 + CD44- (pro-T3) and CD25-CD44- (pro-T4). However, it reduced cell cycling and slowed turnover only in the pro-T4 subset. From an analysis of bcl-2 transgenic mice expressing a TCR transgene or bearing a mutation in the scid or rag-1 gene we conclude that Bcl-2 inhibits proliferation only of T cell progenitors that are activated via the pre- TCR, not those stimulated via c-Kit and the IL-7 receptor.      

Identification of MEN1 gene mutations in sporadic carcinoid tumors of the lung

Lung carcinoids occur sporadically and rarely in association with multiple endocrine neoplasia type 1 (MEN1). There are no well defined genetic abnormalities known to occur in these tumors. We studied 11 sporadic lung carcinoids for loss of heterozygosity (LOH) at the locus of the MEN1 gene on chromosome 11q13, and for mutations of the MEN1 gene using dideoxy fingerprinting. Additionally, a lung carcinoid from a MEN1 patient was studied. In four of 11 (36%) sporadic tumors, both copies of the MEN1 gene were inactivated. All four tumors showed the presence of a MEN1 gene mutation and loss of the other allele. Observed mutations included a 1 bp insertion, a 1 bp deletion, a 13 bp deletion and a single nucleotide substitution affecting a donor splice site. Each mutation predicts truncation or potentially complete loss of menin. The remaining seven tumors showed neither the presence of a MEN1 gene mutation nor 11q13 LOH. The tumor from the MEN1 patient showed LOH at chromosome 11q13 and a complex germline MEN1 gene mutation. The data implicate the MEN1 gene in the pathogenesis of sporadic lung carcinoids, representing the first defined genetic alteration in these tumors.      

High throughput parallel analysis of hundreds of patient samples for more than 100 mutations in multiple disease genes

As more mutations are identified in genes of known sequence, there is a crucial need in the areas of medical genetics and genome analysis for rapid, accurate and cost-effective methods of mutation detection. We have developed a multiplex allele-specific diagnostic assay (MASDA) for analysis of large numbers of samples (> 500) simultaneously for a large number of known mutations (> 100) in a single assay. MASDA utilizes oligonucleotide hybridization to interrogate DNA sequences. Multiplex DNA samples are immobilized on a solid support and a single hybridization is performed with a pool of allele-specific oligonucleotide (ASO) probes. Any probes complementary to specific mutations present in a given sample are in effect affinity purified from the pool by the target DNA. Sequence-specific band patterns (fingerprints), generated by chemical or enzymatic sequencing of the bound ASO(s), easily identify the specific mutation(s). Using this design, in a single diagnostic assay, we tested samples for 66 cystic fibrosis (CF) mutations, 14 beta-thalassemia mutations, two sickle cell anemia (SCA) mutations, three Tay-Sachs mutations, eight Gaucher mutations, four mutations in Canavan disease, four mutations in Fanconi anemia, and five mutations in BRCA1. Each mutation was correctly identified. Finally, in a blinded study of 106 of these mutations in > 500 patients, all mutations were properly identified. There were no false positives or false negatives. The MASDA assay is capable of detecting point mutations as well as small insertion or deletion mutations. This technology is amenable to automation and is suitable for immediate utilization for high-throughput genetic diagnostics in clinical and research laboratories.      

反复种植失败的相关对策新进展

辅助生殖技术的迅速发展使众多不孕症患者借助体外受精-胚胎移植(IVF-ET)及其衍生技术获得了后代。然而很大一部分妇女经历多次优质胚胎移植亦不能获得妊娠,反复种植失败(RIF)已经成为阻碍妊娠率进一步提高的瓶颈问题,且日益受到生殖医学界的广泛关注。就目前的条件而言,对RIF患者给予药物或者机械操作以提高子宫内膜容受性,行宫腹腔镜检查排除宫腔及盆腔病变以改善胚胎种植环境,通过辅助孵化、选择性囊胚移植、植入前胚胎遗传学筛查、共培养等技术提高胚胎着床能力都有可能改善和提高其种植率及妊娠率。RIF成为了我们亟待解决的问题,现综述近年有关反复种植失败的相关对策新进展。     

Impact of Acute Cardiac Complications After Subarachnoid Hemorrhage on Long-Term Mortality and Cardiovascular Events

Background

Cardiac complications frequently occur after subarachnoid hemorrhage (SAH) and are associated with an increased risk of neurological complications and poor outcomes. The aim of this study was to evaluate the impact of acute cardiac complications after SAH on long-term mortality and cardiovascular events.

Methods

All patients admitted to our Neuro intensive care unit with verified SAH from January 2010 to April 2015, and electrocardiogram, echocardiogram, and troponin T or NTproBNP data obtained within 72 h of admission were included in the study. Mortality data were obtained from the Swedish population register. Data regarding cause of death and hospitalization for cardiovascular events were obtained from the Swedish Board of Health and Welfare.

Results

A total of 455 patients were included in the study analysis. There were 102 deaths during the study period. Cardiac troponin release (HR 1.08, CI 1.02–1.15 per 100 ng/l, p?=?0.019), NTproBNP (HR 1.05, CI 1.01–1.09 per 1000 ng/l, p?=?0.018), and ST-T abnormalities (HR 1.53, CI 1.02–2.29, p?=?0.040) were independently associated with an increased risk of death. However, these associations were significant only during the first 3 months after the hemorrhage. Cardiac events were observed in 25 patients, and cerebrovascular events were observed in 62 patients during the study period. ST-T abnormalities were independently associated with an increased risk of cardiac events (HR 5.52, CI 2.07–14.7, p?<?0.001), and stress cardiomyopathy was independently associated with an increased risk of cerebrovascular events (HR 3.65, CI 1.55–8.58, p?=?0.003).

Conclusion

Cardiac complications after SAH are associated with an increased risk of short-term death. Patients with electrocardiogram abnormalities and stress cardiomyopathy need appropriate follow-up for the identification of cardiac disease or risk factors for cardiovascular disease.

     

Inactivation of purified human alpha 2-antiplasmin and purified human C1 inhibitor by synthetic fibrinolytic agents

3-Hydroxypropyl flufenamide (Flu-HPA) is one of a series of flufenamic acid derivatives that enhances blood clot lysis in vitro. Studies of possible mechanisms of action of Flu-HPA were undertaken. The profibrinolytic activity of Flu-HPA in clot lysis assays was found to be dependent on plasminogen. The influence of Flu-HPA on the ability of purified alpha 2-antiplasmin to inhibit purified plasmin was studied. Plasmin activity was determined using 125I-fibrin plates or the spectrophotometric tripeptide substrate, Val-Leu-Lys-paranitroanilide. At Flu-HPA concentrations greater than 1 mM, the inhibitory activity of alpha 2-antiplasmin was abolished in a time-dependent and concentration- dependent manner. The influence of Flu-HPA on the ability of purified Cl inhibitor to inhibit purified plasma kallikrein and beta-Factor XIIa was also studied. Cl inhibitor activity was abolished by Flu-HPA at concentrations greater than 2 mM. Notably, Flu-HPA up to 60 mM did not affect the amidolytic activities of plasmin, kallikrein, or beta-Factor XIIa. Flu-HPA did not release enzyme activity from preformed complexes of either alpha 2-antiplasmin and plasmin of Cl inhibitor and kallikrein. A water-soluble derivative of flufenamic acid, N-flufenamyl- glutamic acid, also inactivated alpha 2-antiplasm and Cl inhibitor. This inactivation was shown to be reversible. These results indicate that synthetic fibrinolytic compounds such as flufenamic acid derivatives may promote fibrinolysis by directly inactivating alpha 2- antiplasmin and Cl inhibitor.     

Mini-plasminogen: a mechanism for leukocyte modulation of plasminogen activation by urokinase

Urokinase activation of blood fibrinolysis involves polymorphonuclear leukocytes. To determine if a leukocyte proteinase can modulate plasminogen activation, plasminogen was digested with leukocyte elastase. A major product was a small, approximately 34,000 dalton fragment (mini-plasminogen), without lysine-binding function, but with fibrin-binding activity. After urokinase activation, the resulting mini- plasmin had amidolytic activity for a tripeptide plasmin substrate and fibrinolytic activity. By 125I-fibrin assay, activities of mini-plasmin and plasmin (12 nmole/liter) were 38 and 20 ng fibrin lysed/min, respectively. Lysis times of fibrin clots containing urokinase, and mini-plasminogen or plasminogen (800 nmole/liter), were 282 and 290 sec, respectively. Mini-plasmin and plasmin were inhibited similarly by epsilon-aminocaproic acid and normal plasma, but differed in responses to gel filtration fractions of plasma containing alpha 2-antiplasmin and alpha 2-macroglobulin, the primary and secondary plasmin inhibitors. With purified inhibitors, mini-plasmin required higher concentrations of, or longer preincubation with, alpha 2-antiplasmin, and lower concentrations of, or shorter preincubation with, alpha 2- macroglobulin, to produce inhibition equivalent to that observed with plasmin. Leukocyte elastase digests plasminogen to generate a mini- plasminogen which, when activated by urokinase, has a novel pattern of response to the major plasmin inhibitors in plasma.