Chromodomain Helicase Binding Protein 8 (Chd8) Is a Novel A-Kinase Anchoring Protein Expressed during Rat Cardiac Development

A-kinase anchoring proteins (AKAPs) bind the regulatory subunits of protein kinase A (PKA) and localize the holoenzyme to discrete signaling microdomains in multiple subcellular compartments. Despite emerging evidence for a nuclear pool of PKA that rapidly responds to activation of the PKA signaling cascade, only a few AKAPs have been identified that localize to the nucleus. Here we show a PKA-binding domain in the amino terminus of Chd8, and demonstrate subcellular colocalization of Chd8 with RII. RII overlay and immunoprecipitation assays demonstrate binding between Chd8-S and RIIα. Binding is abrogated upon dephosphorylation of RIIα. By immunofluorescence, we identified nuclear and perinuclear pools of Chd8 in HeLa cells and rat neonatal cardiomyocytes. We also show high levels of Chd8 mRNA in RNA extracted from post-natal rat hearts. These data add Chd8 to the short list of known nuclear AKAPs, and implicate a function for Chd8 in post-natal rat cardiac development.     

Glucose-Coated Gold Nanoparticles Transfer across Human Brain Endothelium and Enter Astrocytes In Vitro

The blood-brain barrier prevents the entry of many therapeutic agents into the brain. Various nanocarriers have been developed to help agents to cross this barrier, but they all have limitations, with regard to tissue-selectivity and their ability to cross the endothelium. This study investigated the potential for 4 nm coated gold nanoparticles to act as selective carriers across human brain endothelium and subsequently to enter astrocytes. The transfer rate of glucose-coated gold nanoparticles across primary human brain endothelium was at least three times faster than across non-brain endothelia. Movement of these nanoparticles occurred across the apical and basal plasma membranes via the cytosol with relatively little vesicular or paracellular migration; antibiotics that interfere with vesicular transport did not block migration. The transfer rate was also dependent on the surface coating of the nanoparticle and incubation temperature. Using a novel 3-dimensional co-culture system, which includes primary human astrocytes and a brain endothelial cell line hCMEC/D3, we demonstrated that the glucose-coated nanoparticles traverse the endothelium, move through the extracellular matrix and localize in astrocytes. The movement of the nanoparticles through the matrix was >10 µm/hour and they appeared in the nuclei of the astrocytes in considerable numbers. These nanoparticles have the correct properties for efficient and selective carriers of therapeutic agents across the blood-brain barrier.     

Differences in zinc status between patients with osteoarthritis and osteoporosis

Zinc has been suggested to play an important role in the development of osteoporosis, whereas the influence of zinc on osteoarthritis has attracted much less attention. The aim of the study was to investigate and compare the zinc status and bone turnover, density, and biomechanical properties of osteoarthritic and osteoporotic patients. The study comprised 40 women who underwent hip replacement due to osteoarthritis or osteoporosis. Serum and urine zinc content, and bone resorption markers and serum bone formation markers were determined. The unaffected hip and the exarticulated affected femoral head underwent DEXA scanning. Bone biopsies were obtained from the femoral heads and the biomechanical properties were determined. The biopsies were ashed and the bone zinc content was ascertained. Osteoarthritic patients had significantly higher serum zinc concentrations and lower urine zinc concentrations than osteoporotic patients, whereas the bone zinc content did not differ. The zinc status was not found to be a predictor for the bone strength. In conclusion, the finding that the zinc status of osteoporotic patients is significantly different from that of osteoartritic patients is new and supports the view that osteoporosis and osteoarthritis rarely occur in the same individual.     

Isolation of Pectolytic clostridia from Potatoes

S ummary : A method for selective counting and isolation of pectolytic clostridia in the presence of Erwinia carotovora is described; using this method pectolytic clostridia have been found in numbers of 8 × 10⁵–1 × 10⁸/g of rotting potato tissue in the presence of 1–4 × 10⁸ E. carotovora /g.     

Production of lactic acid from whey using hydrolysed whey protein as nitrogen source

Summary Hydrolysed whey (lactose 4% w/vol) was fermented in laboratory reactors for production of lactic acid. By using a non0sterile unsupplemented continuous process with a hydraulic retention time of 10 hours, lactic acid was produced in a concentration of approx. 2.5 w/vol % with less than 0.1% volatile fatty acids and less than 0.2% lactose/galactose present in the effluent.     

Carnitine palmitoyltransferase: activation and inactivation in liver mitochondria from fed, fasted, hypo- and hyperthyroid rats

The sensitivity of carnitine palmitoyltransferase to malonyl-CoA is lost when liver mitochondria are preincubated in a KCl-containing medium. This loss of sensitivity is slowed down in mitochondria from hypothyroid rats and accelerated in mitochondria from fasted and hyperthyroid rats. Glucagon seems to enhance the effect of fasting. The loss of sensitivity is significantly slowed down by 50-500 nM malonyl-CoA and accelerated by small amounts of palmitoyl-CoA in the preincubation medium.