Isolation and characterization of fifteen microsatellite loci for the giant clam Tridacna maxima

Conservation Genetics Resources - Fifteen polymorphic microsatellite markers were developed for Tridacna maxima in order to assess self-recruitment and larval dispersal within and among MPAs in New...     

Measuring wearing time of knee-ankle-foot orthoses in children with cerebral palsy: comparison of parent-report and objective measurement

Purpose state: Orthotic wearing time may be an important confounder in efficacy studies of treatment in children with spastic cerebral palsy (SCP). Most studies measure parent-reported wearing time (WT_parent) with questionnaires, but it is questionable whether this yields valid results. This study aims to compare WT_parent with objectively measured wearing time (WT_obj) in children with SCP receiving orthotic treatment.

Method: Eight children with SCP participated in this observational study. For one year, they received knee-ankle-foot orthosis (KAFO) treatment. WT_parent was measured using questionnaires. WT_obj was measured using temperature sensor-data-loggers that were attached to the KAFOs. The 2.5th and 97.5th percentiles and median of differences between methods (per participant) were used to calculate limits of agreement and systematic differences.

Results: There was no systematic difference between WT_parent and WT_obj (0.1?h per week), but high inter-individual variation of the difference was found, as reflected by large limits of agreement (lower limit/2.5th percentile: ?1.7?h/week; upper limit/97.5th percentile: 11.1?h/week).

Conclusions: Parent-reported wearing time (WTparent) of a KAFO differs largely from objectively measured wearing time (WT_obj) using temperature sensors. Therefore, parent-reported wearing time (WT_parent) of KAFOs should be interpreted with utmost care.

• Implications for Rehabilitation

• Low wearing time of orthoses may be a cause of inefficacy of orthotic treatment and incorrect reported wearing time may bias results of efficacy studies.

• Results of this study show that parent-reported wearing time is not in agreement with objectively measured wearing time.

• Parent-reported wearing time of KAFOs should be interpreted with utmost care.

• Objective methods are recommended for measuring orthotic wearing time.

     

Adult trkB Signaling in Parvalbumin Interneurons is Essential to Prefrontal Network Dynamics

Inhibitory interneurons expressing parvalbumin (PV) are central to cortical network dynamics, generation of γ oscillations, and cognition. Dysfunction of PV interneurons disrupts cortical information processing and cognitive behavior. Brain-derived neurotrophic factor (BDNF)/tyrosine receptor kinase B (trkB) signaling regulates the maturation of cortical PV interneurons but is also implicated in their adult multidimensional functions. Using a novel viral strategy for cell-type-specific and spatially restricted expression of a dominant-negative trkB (trkB.DN), we show that BDNF/trkB signaling is essential to the integrity and maintenance of prefrontal PV interneurons in adult male and female mice. Reduced BDNF/trkB signaling in PV interneurons in the medial prefrontal cortex (mPFC) resulted in deficient PV inhibition and increased baseline local field potential (LFP) activity in a broad frequency band. The altered network activity was particularly pronounced during increased activation of the prefrontal network and was associated with changed dynamics of local excitatory neurons, as well as decreased modulation of the LFP, abnormalities that appeared to generalize across stimuli and brain states. In addition, our findings link reduced BDNF/trkB signaling in prefrontal PV interneurons to increased aggression. Together our investigations demonstrate that BDNF/trkB signaling in PV interneurons in the adult mPFC is essential to local network dynamics and cognitive behavior. Our data provide direct support for the suggested association between decreased trkB signaling, deficient PV inhibition, and altered prefrontal circuitry.SIGNIFICANCE STATEMENT Brain-derived neurotrophic factor (BDNF)/tyrosine receptor kinase B (trkB) signaling promotes the maturation of inhibitory parvalbumin (PV) interneurons, neurons central to local cortical dynamics, γ rhythms, and cognition. Here, we used a novel viral approach for reduced BDNF/trkB signaling in PV interneurons in the medial prefrontal cortex (mPFC) to establish the role of BDNF/trkB signaling in adult prefrontal network activities. Reduced BDNF/trkB signaling caused pronounced morphologic alterations, reduced PV inhibition, and deficient prefrontal network dynamics. The altered network activity appeared to manifest across stimuli and brain states and was associated with aberrant local field potential (LFP) activities and increased aggression. The results demonstrate that adult BDNF/trkB signaling is essential to PV inhibition and prefrontal circuit function and directly links BDNF/trkB signaling to network integrity in the adult brain.     

Isolation and characterization of fifteen microsatellite loci for the giant clam Hippopus hippopus (family Tridacnidae)

Fifteen polymorphic microsatellite markers were developed for Hippopus hippopus in order to assess the effectiveness of population replenishment within marine protected areas in New Caledonia. Number of alleles varied from 2 to 11 per locus, observed and expected heterozygosities ranged from 0.300 to 0.866 and 0.495 to 0.858 respectively. Significant deviations from HWE were detected in two loci. Cross-amplifications were tested in four other species of Tridacnidae.     

Relationship Between A1C and Glucose Levels in the General Dutch Population: The New Hoorn Study

OBJECTIVE

To investigate the relationship among A1C, fasting plasma glucose (FPG), and 2-h postload plasma glucose in the Dutch general population and to evaluate the results of using A1C for screening and diagnosis of diabetes.

RESEARCH DESIGN AND METHODS

In 2006–2007, 2,753 participants of the New Hoorn Study, aged 40–65 years, who were randomly selected from the population of Hoorn, the Netherlands, underwent an oral glucose tolerance test (OGTT). Glucose status (normal glucose metabolism [NGM], intermediate hyperglycemia, newly diagnosed diabetes, and known diabetes) was defined by the 2006 World Health Organization criteria. Spearman correlations were used to investigate the agreement between markers of hyperglycemia, and a receiver operating characteristic (ROC) curve was calculated to evaluate the use of A1C to identify newly diagnosed diabetes.

RESULTS

In the total population, the correlations between fasting plasma glucose and A1C and between 2-h postload plasma glucose and A1C were 0.46 and 0.33, respectively. In patients with known diabetes, these correlations were 0.71 and 0.79. An A1C level of ≥5.8%, representing 12% of the population, had the highest combination of sensitivity (72%) and specificity (91%) for identifying newly diagnosed diabetes. This cutoff point would identify 72% of the patients with newly diagnosed diabetes and include 30% of the individuals with intermediate hyperglycemia.

CONCLUSIONS

In patients with known diabetes, correlations between glucose and A1C are strong; however, moderate correlations were found in the general population. In addition, based on the diagnostic properties of A1C defined by ROC curve analysis, the advantage of A1C compared with OGTT for the diagnosis of diabetes is limited.Fasting glucose levels and glucose levels 2 h after a glucose tolerance test (postload glucose levels) are used for diagnosis and management of diabetes (1). In addition, the A1C level is used to monitor glycemia in patients with diabetes because it has less day-to-day variability than glucose levels and is thought to reflect chronic glycemia (2).In 2007, a consensus statement reported on the worldwide standardization of the A1C measurement (3). One of the conclusions was that glycemic goals in clinical practice should be expressed in three types of units, one of which is the International Federation of Clinical Chemistry and Laboratory Medicine standardized method. Use of this method implies that the unit of measurement of A1C will change from a percentage to millimoles per mole. The introduction of this new unit of measurement may be confusing for patients and health care providers. Therefore, the A1C-Derived Average Glucose (ADAG) Study Group investigated whether A1C can be translated into average blood glucose levels in patients with diabetes (4). A major advantage of using the average glucose level for chronic glycemia is that it has the same unit of measurement (millimoles per liter) as that for acute glycemia. The ADAG Study Group concluded that the average glucose level was strongly correlated with A1C and that the translation of A1C into average glucose levels was therefore possible (4). Moreover, Saudek et al. (5) recommended 1) the use of an A1C level of ≥6.0% as a screening standard for the detection of individuals at high risk of developing diabetes, 2) an A1C level of ≥6.5% confirmed by a glucose test (fasting or oral glucose tolerance test [OGTT]) for the diagnosis of diabetes, and 3) A1C levels of ≥7.0% measured twice or confirmed by a glucose test for the diagnosis of diabetes. During the review process for the present article, a consensus statement from an International Expert Committee that recommended the use of A1C levels ≥6.5% for the diagnosis of diabetes instead of glucose measures was published. A1C levels between 6.0 and 6.5% are proposed to identify individuals at high risk of developing diabetes (6). It may, however, be questioned whether A1C is a good indicator of glucose in individuals with normal or moderately elevated glucose levels and whether it can therefore be used to identify those with intermediate hyperglycemia or undiagnosed diabetes. Therefore, our aim was to investigate the relationship between glucose and A1C in the general population and to evaluate the use of A1C for the screening and diagnosis of diabetes.