Association of lower serum Brain-derived neurotrophic factor levels with larger infarct volumes in acute ischemic stroke.

OBJECTIVE: Brain-derived neurotrophic factor (BDNF) plays a potential role in stroke recovery, as it promotes plasticity. The aim of this study is to investigate the association between infarct volume using DWI and BDNF at admission in patients with acute ischemic stroke (AIS). METHODS: The study population comprised consecutive patients with an AIS diagnosis who had been referred to our hospital between January 2015 and June 2016. The severity of stroke was evaluated by the National Institutes of Health Stroke Scale (NIHSS) at admission. Infarct volumes indicated by DWI were measured with MIPAV software. The relationship between median DWI infarct volume and serum BDNF level quartiles was evaluated using a semiparametric approach with univariate and multivariate quartile regression analysis. RESULTS: In this study, 270 patients were included and met the study criteria. The median DWI infarct volumes for the serum BDNF level quartiles (lowest to highest) were 10.56, 5.13, 3.75 and 2.43ml. Nonparametric Spearman rank correlation revealed a statistically significant negative correlation between serum BDNF level and DWI infarct volume (r=-0.363; P<0.001). The median DWI infarct volume in the lowest BDNF quartile was significantly larger than those in the upper 3 quartiles (P<0.001). Further, median adjusted DWI infarct volumes (IQR) for each of the BDNF level quartiles were 7.77, 4.56, 3.75, and 2.43ml from lowest to highest quartiles. CONCLUSIONS: Larger stroke infarct volumes using DWI are associated with lower levels of BDNF at admission. Further investigations are suggested to elucidate the role of BDNF as part of a potential neuroprotective strategy.

Formal nomenclature and description of cryptic species of the Encyrtus sasakii complex (Hymenoptera: Encyrtidae).

With the recent development of molecular approaches to species delimitation, a growing number of cryptic species have been discovered in what had previously been thought to be single morpho-species. Molecular methods, such as DNA barcoding, have greatly enhanced our knowledge of taxonomy, but taxonomy remains incomplete and needs a formal species nomenclature and description to facilitate its use in other scientific fields. A previous study using DNA barcoding, geometric morphometrics and mating tests revealed at least two cryptic species in the Encyrtus sasakii complex. (Hymenoptera: Encyrtidae). To describe these two new species formally (Encyrtus eulecaniumiae sp. nov. and Encyrtus rhodococcusiae sp. nov.), a detailed morphometric study of Encyrtus spp. was performed in addition to the molecular analysis and evaluation of biological data. Morphometric analyses, a multivariate ratio analysis (MRA) and a geometric morphometric analysis (GMA) revealed a great number of differences between the species, but reliable characteristics were not observed for diagnosing the cryptic species. We thus diagnosed these three Encyrtus species on the basis of the characteristics that resulted from genetic markers (mitochondrial cytochrome c oxidase subunit I and nuclear 28S rRNA) and biological data. A formal nomenclature and description of cryptic species was provided on the basis of an integrated taxonomy.

Biomarkers of Renal Function in Type 2 Diabetic Patients with Cognitive Impairment.

Kidney disease is associated with cognitive impairment in studies of nondiabetic adults. We examined the cross-sectional relation between three measures of renal function and cognitive impairment (CI) in type 2 diabetic patients. A total of 357 patients with type 2 diabetes were prospectively enrolled. There were 108 patients with CI and 249 patients without CI (control). We calculated the urinary albumin/creatinine ratio (UACR) from morning spot urine and the estimated glomerular filtration rate (eGFR) in serum samples. Serum Cystatin C (Cys C) was measured with an automated particle-enhanced turbidimetric immunoassay. UACR and Cystatin C levels were significantly higher in patients with CI than those without CI (P<0.001), and the eGFR was lower in patients with CI than those without (P=0.003). A logistic regression analysis indicates that kidney impairment biomarkers levels were significantly associated with an increased risk of CI after adjustment for age and gender. The OR of each kidney biomarker (eGFR, UACR, Cystatin C) for CI status was 1.78 (0.89-3.27), 2.36 (1.29-4.42), and 2.77 (1.36-5.97), respectively. Among three kidney biomarkers (eGFR, UACR, Cystatin C), only elevated serum Cystatin C was associated with increased risk of CI in type 2 diabetic patients, with an OR of 1.42 (1.25-4.24) after additional adjustment for duration of diabetes, hypertension, hyperlipidemia, hemoglobin A1c (HbA1c), high-sensitivity C-reactive protein (Hs-CRP), intima-media thickness (IMT), ankle brachial index (ABI), and brachial-ankle pulse wave velocity (ba-PWV). Furthermore, combination of conventional risk factors and Cystatin C levels exhibited a fair diagnostic value for CI, with an area under the curve (AUC) of 0.91. Among three kidney impairment biomarkers (eGFR, UACR, Cystatin C), only elevated serum Cystatin C was associated with increased risk of CI in type 2 diabetic patients, independent of conventional risk factors. Furthermore, Cystatin C may be a better marker for CI than eGFR and UACR, and exhibited diagnostic value.