Validating a firefly luciferase-based high-throughput screening assay for antimalarial drug discovery

The emergence and spread of multidrug-resistant Plasmodium falciparum and recent detection of potential artemisinin-resistant strains in Southeast Asia highlight the importance of developing novel antimalarial therapies. Using a previously generated stable transgenic P. falciparum line with high-level firefly luciferase expression, we report the adaptation, miniaturization, optimization, and validation of a high-throughput screening assay in 384-well plates. Assay conditions, including the percentage of parasitemia and hematocrit, were optimized. Parameters of assay robustness, including Z'-value, coefficient variation (CV), and signal-to-background (S/B) ratio, were determined. The LOPAC(1280) small-compound library was used to validate this assay. Our results demonstrated that this assay is robust and reliable, with an average Z'-value of >0.7 and CV of <10%. Moreover, this assay showed a very low background, with the S/B ratio up to 71. Further, identified hits were selected and confirmed using a SYBR Green I-based confirmatory assay. It is evident that this assay is suitable for large-scale screening of chemical libraries for antimalarial drug discovery.     

Muscle strengthening in children and adolescents with spastic cerebral palsy: considerations for future resistance training protocols

Resistance training of the lower limbs is now commonly used in clinical practice in children and adolescents with spastic cerebral palsy (CP). However, the effectiveness of this type of training is still disputed. The most recently published systematic review with meta-analysis included interventions such as electrical stimulation and resistance training and found insufficient evidence to support or refute the efficacy of these exercises in children with CP. Thus, the aim of this article is to evaluate the extent to which training protocols from the most recent randomized controlled trials are in keeping with the evidence for effective resistance training in children who are developing typically, as reflected in the training guidelines of the National Strength and Conditioning Association. RECOMMENDATIONS: for resistance training protocols, based on this evidence and appropriate to children with CP, are provided to help guide both future research and clinical practice for resistance training in children with CP.     

Effect of pain and pain expectation on primary motor cortex excitability

Objective

The study aimed to test whether pain and pain expectation affect corticospinal excitability.

Methods

Transcranial magnetic stimulation was used to measure corticospinal excitability among 15 subjects in five experimental conditions in which thermic stimulations were applied to the hand: (1) neutral stimulus; (2) actual heat; (3) actual pain; (4) expected heat; and (5) expected pain. Motor-evoked potentials were recorded in two intrinsic hand muscles.

Results

A significant difference was found between experimental conditions for both muscles (p < 0.005). Contrast analysis showed that actual pain led to a significant corticospinal inhibition compared with both neutral and actual heat conditions, whereas no effect was observed during pain expectation.

Conclusions

Our results suggest that acute pain (low-to-moderate intensity (∼3/10)) does elicit motor inhibition but that its expectation does not.

Significance

The fact that low and short-lasting pain can induce motor inhibition suggests that even moderate pain might interfere with optimal motor function in patients with both pain and motor deficits.     

Novel therapeutic options in anaplastic large cell lymphoma: molecular targets and immunological tools

Anaplastic large cell lymphoma (ALCL) is a CD30-positive, aggressive T-cell lymphoma, and about half of the patients with this disease harbor the t(2;5)(p21;q35) translocation. This chromosomal aberration leads to fusion of the NPM gene with the ALK tyrosine kinase, leading to its constitutive activation. To date, treatment options include polychemotherapy (e.g., cyclophosphamide, doxorubicin, vincristine, and prednisone), which is sometimes combined with radiation in the case of bulky disease, leading to remission rates of ～80%. However, the remaining patients do not respond to therapy, and some patients experience chemo-resistant relapses, making the identification of new and better treatments imperative. The recent discovery of deregulated ALK in common cancers such as non-small cell lung cancer and neuroblastoma has reinvigorated industry interest in the development of ALK inhibitors. Moreover, it has been shown that the ALK protein is an ideal antigen for vaccination strategies due to its low expression in normal tissue. The characterization of microRNAs that are deregulated in ALCL will yield new insights into the biology of ALCL and open new avenues for therapeutic approaches in the future. Also, CD30 antibodies that have been tested in ALCL for quite a while will probably find a place in forthcoming treatment strategies.     

Risk factors and complications following percutaneous endoscopic gastrostomy: a case series of 1041 patients

BACKGROUND:

Most studies exclude patients with severe coagulation disorders or those taking anticoagulants when evaluating the outcomes of percutaneous endoscopic gastrostomy (PEG).

OBJECTIVE:

To investigate complications and risk factors of PEG in a large clinical series including patients undergoing antiplatelet and anticoagulant therapy.

METHODS:

During a six-year period, 1057 patients referred for PEG placement were prospectively audited for clinical outcome. Exclusion criteria and follow-up care were defined. Complications were defined as minor or severe. Uni- and multivariate analyses were used to evaluate 14 risk factors. No standardized antibiotic prophylaxis was given.

RESULTS:

A total of 1041 patients (66% male, 34% female) with the following conditions underwent PEG: neurogenic dysphagia (n=450), cancer (n=385) and others (n=206). No anticoagulants were administered to 351 patients, thrombosis prophylaxis was given to 348 while full therapeutic anticoagulation was received by 313. No increased bleeding risk was associated with patients who had above-normal international normalized ratio values (OR 0.79 [95% CI 0.08 to 7.64]; P=1.00). The total infection rate was 20.5% in patients with malignant disease, and 5.5% in those with nonmalignant disease. Severe complications occurred in 19 patients (bleeding 0.5%, peritonitis 1.3%). Cirrhosis (OR 2.91 [95% CI 1.31 to 6.54]; P=0.008), cancer (OR 2.34 [95% CI 1.33 to 4.12]; P=0.003) and radiation therapy (OR 2.34 [95% CI 1.35 to 4.05]; P=0.002) were significant predictors of post-PEG infection. The 30-day mortality rate was 5.8%. There were no procedure-related deaths.

CONCLUSIONS:

Cancer, cirrhosis and radiation therapy were predictors of infection. Post-PEG bleeding and other complications were rare events. Collectively, the data suggested that patients taking concurrent anticoagulants had no elevated risk of post-PEG bleeding.