Age-related increases in parathyroid hormone may be antecedent to both osteoporosis and dementia

<p>Abstract</p> <p>Background</p> <p>Numerous studies have reported that age-induced increased parathyroid hormone plasma levels are associated with cognitive decline and dementia. Little is known about the correlation that may exist between neurological processing speed, cognition and bone density in cases of hyperparathyroidism. Thus, we decided to determine if parathyroid hormone levels correlate to processing speed and/or bone density.</p> <p>Methods</p> <p>The recruited subjects that met the inclusion criteria (n = 92, age-matched, age 18-90 years, mean = 58.85, SD = 15.47) were evaluated for plasma parathyroid hormone levels and these levels were statistically correlated with event-related P300 potentials. Groups were compared for age, bone density and P300 latency. One-tailed tests were used to ascertain the statistical significance of the correlations. The study groups were categorized and analyzed for differences of parathyroid hormone levels: parathyroid hormone levels <30 (n = 30, mean = 22.7 ± 5.6 SD) and PTH levels >30 (n = 62, mean = 62.4 ± 28.3 SD, p ≤ 02).</p> <p>Results</p> <p>Patients with parathyroid hormone levels <30 showed statistically significantly less P300 latency (P300 = 332.7 ± 4.8 SE) relative to those with parathyroid hormone levels >30, which demonstrated greater P300 latency (P300 = 345.7 ± 3.6 SE, p = .02). Participants with parathyroid hormone values <30 (n = 26) were found to have statistically significantly higher bone density (M = -1.25 ± .31 SE) than those with parathyroid hormone values >30 (n = 48, M = -1.85 ± .19 SE, p = .04).</p> <p>Conclusion</p> <p>Our findings of a statistically lower bone density and prolonged P300 in patients with high parathyroid hormone levels may suggest that increased parathyroid hormone levels coupled with prolonged P300 latency may become putative biological markers of both dementia and osteoporosis and warrant intensive investigation.</p

Priming food intake with weight control cues: systematic review with a meta-analysis

Background A growing number of studies suggest that exposure to cues which are associated with weight control can prime or prompt controlled food intake in tempting food environments. However, findings are mixed and understanding which types of cues and for whom such cues may be most effective is needed to inform subsequent research and societal applications. A systematic review and meta-analysis were conducted to evaluate the effects of exposure to weight control cues compared with control cues on food intake. Methods PsycINFO, Medline, Embase and Web of Science were searched using key terms. Hedge’s g was used to calculate effect sizes based on mean food intake, standard deviations and sample sizes extracted from relevant publications and, a random effects model was used for the meta-analysis. Results Twenty-five articles consisting of 26 studies were eligible. Data from 25 studies (31 effect sizes) were available for the meta-analysis. Overall, weight control cues reduced food intake, albeit to a trivial effect (ES: -0.149, 95% CI: -0.271 to − 0.027). Subgroup analyses when studies which induced negative affect were removed showed that for individuals with strong weight control goals the effect was small-to-moderate (ES: -0.440, 95% CI: -0.718 to − 0.163), whereas for individuals with weak weight control goals this effect was trivial and non-significant (ES: 0.014, 95% CI: -0.249 to 0.278). Cue type and level of engagement did not significantly moderate the effect; however, specific cues (low-calorie foods and thin models) and attended engagement yielded significant effects. Caution is needed interpreting these findings as most studies were rated with high risk of bias and a number of studies could not be included in the subgroup analyses. Conclusions Based on the data available, weight control cues reduce food intake in individuals with strong weight control goals. Further research is needed to explore longer term effects of cue exposure and confirm underlying mechanisms. PROSPERO registry#CRD42016052396

Who is Who in Knowledge Economy in Africa?

This study assesses the knowledge economy (KE) performance of lagging African countries vis-à-vis their frontier counterparts with regard to the four dimensions of the World Bank’s knowledge economy index (KEI). The empirical exercise is for the period 1996-2010. It consists of first establishing leading nations before suggesting policy initiatives that can be implemented by sampled countries depending on identified gaps that are provided with the sigma convergence estimation approach. The following are established frontier knowledge economy countries. (i) For the most part, North African countries are dominant in education. Tunisia is overwhelmingly dominant in 11 of the 15 years, followed by Libya which is a frontier country in two years while Cape Verde and Egypt lead in a single year each. (ii) With the exception of Morocco that is leading in the year 2009, Seychelles is overwhelmingly dominant in ICT. (iii) South Africa also indomitably leads in terms of innovation. (iv) While Botswana and Mauritius share dominance in institutional regime, economic incentives in terms of private domestic credit are most apparent in Angola (8 years), the Democratic Republic of Congo (3 years) and Tanzania, Sierra Leone and Malawi (each leading in one year)

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals &lt;1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Modularity of Endpoint Force Patterns Evoked Using Intraspinal Microstimulation in Treadmill Trained and/or Neurotrophin-Treated Chronic Spinal Cats

Chronic spinal cats with neurotrophin-secreting fibroblasts (NTF) transplants recover locomotor function. To ascertain possible mechanisms, intraspinal microstimulation was used to examine the lumbar spinal cord motor output of four groups of chronic spinal cats: untrained cats with unmodified-fibroblasts graft (Op-control) or NTF graft and locomotor-trained cats with unmodified-fibroblasts graft (Trained) or NTF graft (Combination). Forces generated via intraspinal microstimulation at different hindlimb positions were recorded and interpolated, generating representations of force patterns at the paw. Electromyographs (EMGs) of hindlimb muscles, medial gastrocnemius, tibialis anterior, vastus lateralis, and biceps femoris posterior, were also collected to examine relationships between activated muscles and force pattern types. The same four force pattern types obtained in spinal-intact cats were found in chronic spinal cats. Proportions of force patterns in spinal cats differed significantly from those in intact cats, but no significant differences in proportions were observed among individual spinal groups (Op-control, NTF, Trained, and Combination). However, the proportions of force patterns differed significantly between trained (Trained and Combination) and untrained groups (Op-control and NTF). Thus the frequency of expression of some response types was modified by injury and to a lesser extent by training. Force pattern laminar distribution differed in spinal cats compared with intact, with more responses obtained dorsally (0–1,000 μm) and fewer ventrally (3,200–5,200 μm). EMG analysis demonstrated that muscle activity highly predicted some force pattern types and was independent of hindlimb position. We conclude that spinal motor output modularity is preserved after injury

Intramuscular AAV delivery of NT-3 alters synaptic transmission to motoneurons in adult rats

We examined whether elevating levels of neurotrophin-3 (NT-3) in the spinal cord and dorsal root ganglion (DRG) would alter connections made by muscle spindle afferent fibers on motoneurons. Adeno-associated virus (AAV) serotypes AAV1, AAV2 and AAV5, selected for their tropism profile, were engineered with the NT-3 gene and administered to the medial gastrocnemius muscle in adult rats. ELISA studies in muscle, DRG and spinal cord revealed that NT-3 concentration in all tissues peaked about 3 months after a single viral injection; after 6 months NT-3 concentration returned to normal values. Intracellular recording in triceps surae motoneurons revealed complex electrophysiological changes. Moderate elevation in cord NT-3 resulted in diminished segmental excitatory postsynaptic potential (EPSP) amplitude, perhaps as a result of the observed decrease in motoneuron input resistance. With further elevation in NT-3 expression, the decline in EPSP amplitude was reversed indicating that NT-3 at higher concentration could increase EPSP amplitude. No correlation was observed between EPSP amplitude and NT-3 concentration in the DRG. Treatment with control viruses could elevate NT-3 levels minimally resulting in measurable electrophysiological effects, perhaps as a result of inflammation associated with injection. EPSPs elicited by stimulation of the ventrolateral funiculus underwent a consistent decline in amplitude independent of NT-3 level. These novel correlations between modified NT-3 expression and single-cell electrophysiological parameters indicate that intramuscular administration of AAV(NT-3) can exert long lasting effects on synaptic transmission to motoneurons. This approach to neurotrophin delivery could be useful in modifying spinal function after injury