An Objective Pronator Drift Test Application (iPronator) Using Handheld Device

Background

The pronator drift test is widely used to detect mild arm weakness. We developed an application that runs on a handheld device to objectify the pronator drift test and investigated its feasibility in stroke patients.

Methods

The iPronator application, which uses the built-in accelerometer in handheld devices, was developed. We enrolled acute ischemic stroke patients (n = 10) with mild arm weakness and healthy controls (n = 10) to validate the iPronator. In addition to conventional neurological examinations, the degree of average, maximum, and oscillation in drift and pronation were measured and compared using the iPronator. Follow-up tests using the iPronator were also conducted in the patient group one week later.

Results

There was a strong correlation between the average degree of pronation and drift measured by the iPronator (r = 0.741, p<0.001). The degrees of average and maximum in pronation were greater in the patient group than in the control group [in average, 28.9°, interquartile range (IQR) 18.7–40.3 vs. 3.8° (IQR 0.3–7.5), p<0.001], in maximum, 33.0° (IQR 24.0–52.1) vs. 6.2° (IQR 1.4–9.4), p<0.001]. The degree of oscillation in pronation was not different between the groups (p = 0.166). In drift, the degrees of average, maximum, and oscillation were greater in the patient group. In stroke patients, a follow-up study at one week revealed improvements in the degrees of pronation and drift compared with baseline parameters.

Conclusions

The iPronator can reliably detect mild arm weakness of stroke patients and was also useful in detecting functional recovery for one week in patients with acute stroke.     

Predictors of decrease in ankle-brachial index among patients with diabetes mellitus

Diabet. Med. 29, e304-e307 (2012) ABSTRACT: Aim Screening for peripheral arterial disease, a complication among patients with diabetes, is performed by periodic assessment of ankle-brachial index. We aimed to study the degree of ankle-brachial index change over time and factors associated with significant change. Method We assessed difference between two ankle-brachial index measurements over time in a consecutive series of 82 patients with Type?2 diabetes. All patients had ankle-brachial index >?0.9 but ≤?1.3 for the first measurement, and significant ankle-brachial index decrease was defined as a decrease of >?0.1 in the follow-up measurement compared with the baseline. Results The mean follow-up duration was 27.6 (median 30.0) months. Significant ankle-brachial index decrease was seen in 20.7% of patients, including 5% with follow-up ankle-brachial index of ≤?0.9, consistent with the diagnosis of peripheral arterial disease. After adjusting for age and gender, higher baseline HbA(1c) and serum creatinine levels, increase in follow-up serum LDL cholesterol levels compared with baseline and history of retinopathy were predictors of significant ankle-brachial index decrease. Conclusions Our study suggests that, within two?years, one in five patients with diabetes and a normal ankle-brachial index may have significant progression of peripheral arterial disease. Annual ankle-brachial index assessment and better control of hyperlipidaemia may thus be required for at-risk patients with poor glycaemic control, renal impairment and retinopathy.     

LoFreq: a sequence-quality aware,ultra-sensitive variant caller for uncovering cell-population heterogeneity from high-throughput sequencing datasets

The study of cell-population heterogeneity in a range of biological systems, from viruses to bacterial isolates to tumor samples, has been transformed by recent advances in sequencing throughput. While the high-coverage afforded can be used, in principle, to identify very rare variants in a population, existing ad hoc approaches frequently fail to distinguish true variants from sequencing errors. We report a method (LoFreq) that models sequencing run-specific error rates to accurately call variants occurring in <0.05% of a population. Using simulated and real datasets (viral, bacterial and human), we show that LoFreq has near-perfect specificity, with significantly improved sensitivity compared with existing methods and can efficiently analyze deep Illumina sequencing datasets without resorting to approximations or heuristics. We also present experimental validation for LoFreq on two different platforms (Fluidigm and Sequenom) and its application to call rare somatic variants from exome sequencing datasets for gastric cancer. Source code and executables for LoFreq are freely available at http://sourceforge.net/projects/lofreq/.     

Carbon monoxide activates NF-kappaB via ROS generation and Akt pathways to protect against cell death of hepatocytes

Heme oxygenase overexpression or exogenous carbon monoxide (CO) protects against hepatocyte apoptosis and fulminant hepatitis. The prevention of hepatocyte apoptosis by CO has been shown to require activation of NF-kappaB. The purpose of these investigations was to determine the mechanism of CO-induced hepatocyte NF-kappaB activation and protection against apoptosis. Primary rat or mouse hepatocytes and Hep3B cells were utilized. CO exposure was performed at 250 parts per million. Main outcome measures included cell viability, reactive oxygen species (ROS) generation, and changes in the levels of the intracellular antioxidants glutathione and ascorbate. Western blotting was performed for phospho-Akt, total Akt, and IkappaBalpha. NF-kappaB activation was determined by electrophoretic mobility shift assay and luciferase reporter assays. We found that CO treatment of hepatocytes prevents spontaneous apoptosis and leads to an increase in ROS production in association with Akt phosphorylation and IkappaB degradation. CO did not increase ROS production in respiration-deficient (rho0) Hep3B cells. Both Akt phosphorylation and IkappaB degradation can be inhibited by the addition of antioxidants. Furthermore, CO-induced NF-kappaB activation is reversed by phosphatidylinositol 3-kinase (PI3-K) inhibitor (LY294002) or antioxidants. Additionally, prevention of spontaneous hepatocyte apoptosis by CO is reversed by PI3-K inhibition and antioxidants. In conclusion, these data implicate a survival pathway of CO-induced ROS, Akt phosphorylation, and NF-kappaB activation in cultured hepatocytes. This pathway may prove to be important in maintenance of hepatic function in both physiological and pathophysiological conditions.     

DEMETER DNA glycosylase establishes MEDEA polycomb gene self-imprinting by allele-specific demethylation

MEDEA (MEA) is an Arabidopsis Polycomb group gene that is imprinted in the endosperm. The maternal allele is expressed and the paternal allele is silent. MEA is controlled by DEMETER (DME), a DNA glycosylase required to activate MEA expression, and METHYLTRANSFERASE I (MET1), which maintains CG methylation at the MEA locus. Here we show that DME is responsible for endosperm maternal-allele-specific hypomethylation at the MEA gene. DME can excise 5-methylcytosine in vitro and when expressed in E. coli. Abasic sites opposite 5-methylcytosine inhibit DME activity and might prevent DME from generating double-stranded DNA breaks. Unexpectedly, paternal-allele silencing is not controlled by DNA methylation. Rather, Polycomb group proteins that are expressed from the maternal genome, including MEA, control paternal MEA silencing. Thus, DME establishes MEA imprinting by removing 5-methylcytosine to activate the maternal allele. MEA imprinting is subsequently maintained in the endosperm by maternal MEA silencing the paternal allele.     

Cloning and Production of a Novel Bacteriocin, Lactococcin K, from Lactococcus lactis Subsp. lactis MY23

A gene encoding the antimicrobial peptide, lactococcin K, was isolated from Lactococcus lactis subsp. lactis MY23 then cloned and expressed in Escherichia coli. Because the expressed lactococcin K was formed as an inclusion body in recombinant E. coli, a fusion protein containing lactococcin K and maltose-binding protein (MBP) was produced in a soluble form. For high-level production of lactococcin K, we performed a pH-stat fed-batch culture to produce 43,000 AU lactococcin K ml⁻¹ in 12 h. Revisions requested 3 November 2005; Revisions received 7 December 2005     

Cellular programming of plant gene imprinting

Gene imprinting, the differential expression of maternal and paternal alleles, independently evolved in mammals and in flowering plants. A unique feature of flowering plants is a double-fertilization event in which the sperm fertilize not only the egg, which forms the embryo, but also the central cell, which develops into the endosperm (an embryo-supporting tissue). The distinctive mechanisms of gene imprinting in the endosperm, which involve DNA demethylation and histone methylation, begin in the central cell and sperm prior to fertilization. Flowering plants might have coevolved double fertilization and imprinting to prevent parthenogenetic development of the endosperm.