Loss-of-function screen in rhabdomyosarcoma identifies CRKL-YES as a critical signal for tumor growth.

To identify novel signaling pathways necessary for rhabdomyosarcoma (RMS) survival, we performed a loss-of-function screen using an inducible small hairpin RNA (shRNA) library in an alveolar and an embryonal RMS cell line. This screen identified CRKL expression as necessary for growth of alveolar RMS and embryonal RMS both in vitro and in vivo. We also found that CRKL was uniformly highly expressed in both RMS cell lines and tumor tissue. As CRKL is a member of the CRK adapter protein family that contains an SH2 and two SH3 domains and is involved in signal transduction from multiple tyrosine kinase receptors, we evaluated CRKL interaction with multiple tyrosine kinase receptor signaling pathways in RMS cells. While we saw no interaction of CRKL with IGFIR, MET or PI3KAKT/mTOR pathways, we determined that CRKL signaling was associated with SRC family kinase (SFK) signaling, specifically with YES kinase. Inhibition of SFK signaling with dasatinib or another SFK inhibitor, sarcatinib, suppressed RMS cell growth in vitro and in vivo. These data identify CRKL as a novel critical component of RMS growth. This study also demonstrates the use of functional screening to identify a potentially novel therapeutic target and treatment approach for these highly aggressive pediatric cancers.

Phenotype in parkinsonian and nonparkinsonian LRRK2 G2019S mutation carriers.

OBJECTIVES: Using a family study design, we describe the motor and nonmotor phenotype in probands with LRRK2 G2019S mutations and family members and compare these individuals to patients with idiopathic Parkinson disease (iPD) and unrelated controls. METHODS: Probands with G2019S mutations and their first-degree relatives, subjects with iPD, and unrelated control subjects were identified from 4 movement disorders centers. All underwent neurologic examinations and tests of olfaction, color vision, anxiety, and depression inventories. RESULTS: Tremor was more often a presenting feature among 25 individuals with LRRK2-associated PD than among 84 individuals with iPD. Subjects with LRRK2-PD had better olfactory identification compared with subjects with iPD, higher Beck Depression Inventory scores, and higher error scores on Farnsworth-Munsell 100-Hue test of color discrimination. Postural or action tremor was more common among 29 nonmanifesting mutation carriers compared with 53 noncarriers within the families. Nonparkinsonian family members had higher Unified Parkinson's Disease Rating Scale motor scores, more constipation, and worse color discrimination than controls, regardless of mutation status. CONCLUSIONS: Although tremor is a more common presenting feature of LRRK2-PD than iPD and some nonmotor features differed in degree, the phenotype is largely overlapping. Postural or action tremor may represent an early sign. Longitudinal evaluation of a large sample of nonmanifesting carriers will be required to describe any premotor phenotype that may allow early diagnosis.

Factors influencing resource allocation decisions and equity in the health system of Ghana.

OBJECTIVE: Allocation of financial resources in the health sector is often seen as a formula-driven activity. However, the decision to allocate a certain amount of resources to a particular health jurisdiction or facility may be based on a broader range of factors, sometimes not reflected in the existing resource allocation formula. This study explores the 'other' factors that influence the equity of resource allocation in the health system of Ghana. The extent to which these factors are, or can be, accounted for in the resource allocation process is analysed. STUDY DESIGN: An exploratory design focusing on different levels of the health system and diverse stakeholders. METHODS: Data were gathered through semi-structured qualitative interviews with health authorities at national, regional and district levels, and with donor representatives and local government officials in 2003 and 2004. RESULTS: The availability of human resources for health, local capacity to utilize funds, donor involvement in the health sector, and commitment to promote equity have considerable influence on resource allocation decisions and affect the equity of funding allocations. However, these factors are not accounted for adequately in the resource allocation process. CONCLUSION: This study highlights the need for a more transparent resource allocation system in Ghana based on needs, and takes into account key issues such as capacity constraints, the inequitable human resource distribution and donor-earmarked funding.

Movement disorders in patients taking anticonvulsants.

BACKGROUND: A wide variety of movement disorders may occur as a consequence of the administration of antiepileptic drugs (AEDs). Although it has been suggested that the risk of parkinsonism is 10-fold higher in those taking valproate as compared with other AEDs, there have been no large, systematic trials assessing this. AIM: To establish more precisely the prevalence of and risk factors for developing parkinsonism associated with valproate use,and to assess the occurrence of movement disorders with the newer AEDs. METHODS: Patients with epilepsy were recruited from the Toronto Western Hospital Epilepsy Clinic (University of Toronto, Toronto, Ontario, Canada). Each patient was examined by a movement disorder specialist who was blinded to the treatment status of the patient. RESULTS: 201 patients were included. Postural tremor was the most common movement disorder (45%), followed by parkinsonism (4.5%). The odds of having parkinsonism were 5 times higher with valproate than with other AEDs. No single factor predicted the presence of parkinsonism; however, many (5/9) of the patients concurrently used other drugs or had comorbidities that could have caused or exacerbated parkinsonism. None of the newer AEDs were clearly associated with the presence of movement disorders; however, the numbers were too small to make a formal analysis. CONCLUSION: Although the risk of parkinsonism with valproate is higher than with other AEDs, it is lower than originally reported. The cases available were not enough to accurately comment on the prevalence of movement disorders with the newer AEDs.

Asystole following treadmill exercise in a man without organic heart disease.

A 52-year-old man without evidence of organic heart disease by clinical and extensive noninvasive examination experienced an 11-s episode of asystole ten minutes after completing a maximal treadmill test. Four years previously, symptomatic sinus bradycardia and hypotension had also followed cessation of treadmill exercise. This case illustrates that vagally mediated complications of treadmill exercise occurring in persons without apparent heart disease may be potentially life-threatening and can be elicited on repeated testing.