Casein kinase 1 is tightly associated with paired-helical filaments isolated from Alzheimer's disease brain

The protein kinase activity tightly associated with paired helical filaments (PHFs) purified from the brain tissue of individuals with Alzheimer's disease has been characterized in vitro. The activity is shown to phosphorylate casein, an exogenous substrate, with a maximal velocity of approximately 2 nmol/min/mg, suggesting it comprises a significant component of the total protein in the PHF preparation. On the basis of substrate selectivity, isoquinoline sulfonamide inhibitor selectivity, in-gel renaturation assays, and western analysis, the activity consists of closely related members of the alpha branch of the casein kinase 1 family of protein kinases. Because of its tight association with PHFs and its phosphate-directed substrate selectivity, casein kinase 1 is positioned to participate in the pathological hyperphosphorylation of tau protein that is observed in neurodegenerative diseases such as Alzheimer's disease.     

Orthopaedic aspects of prune belly syndrome

Prune belly syndrome is a relatively uncommon disorder that is characterized by intrauterine urinary obstruction associated with cryptorchisdism, oligohydramnios, and orthopaedic deformations. The oligohydramnios is believed to produce limited intrauterine space, which in turn leads to fetal compression and the resultant deformities. The deformities observed in our patients were developmental dislocation of the hip (DDH), clubfeet, metatarsus adductus, vertical talus, and congenital muscular torticollis. These deformations should be treated aggressively because children with prune belly syndrome may be expected to have a relatively normal life if their renal function is good. The one exception is that as infants these children are very susceptible to pulmonary infections because of their inability to cough. Therefore, treatment of the hip and other deformations should be delayed until the children are old enough to be able to clear pulmonary secretions easily.     

Propagation by sporulation in the guinea pig symbiont Metabacterium polyspora

The Gram-positive bacterium Metabacterium polyspora is an uncultivated symbiont of the guinea pig gastrointestinal tract. Here we present evidence that in M. polyspora vegetative cell division has taken on a minor, and apparently dispensable, role in propagation. Instead, this unusual bacterium has evolved the capacity to produce progeny in the form of multiple endospores. Endospore formation is coordinated with transit of the bacterium through the gastrointestinal tract of the guinea pig. For the majority of cells, sporulation is initiated in the ileum, whereas later stages of development take place in the cecum. We show that multiple endospores are generated both by asymmetric division at both poles of the cell and by symmetric division of the endospores at an early stage of their development. Our findings suggest that M. polyspora represents an intermediate step in the evolution of a novel mode of cellular propagation that originates with endospore-forming Bacillus and Clostridium spp., which reproduce by binary fission, and extends to Epulopiscium spp., which create multiple viviparous offspring by a process of internal reproduction.