A pilot study to investigate the induction and manipulation of learned helplessness in healthy adults.

Eliminating the controllability of a noxious stimulus may induce a learned helplessness (LH) that resembles aspects of depression and post-traumatic stress disorder (PTSD). This study examined whether repetitive transcranial magnetic stimulation (rTMS) of the left dorsolateral prefrontal cortex (DLPFC) promotes resilience in an aversive stimulus model of LH. All 55 participants were told that an undisclosed sequence of button presses would terminate an aversive stimulus on their forearm.

Classification of distal radius fractures: an analysis of interobserver reliability and intraobserver reproducibility.

The Frykman, Melone, Mayo, and AO classification systems for distal radius fractures were evaluated for interobserver reliability and intraobserver reproducibility in a clinical setting using initial plain radiographs. Two attending orthopedic hand surgeons and two attending radiologists classified 55 sets of distal radius fractures. kappa-statistics were used to establish a relative level of agreement between observers for the two readings and between separate readings by the same observer.

Superoxide production by porcine retinal pigment epithelium in vitro.

Cultured porcine retinal pigment epithelial cells release superoxide, measured as superoxide dismutase (SOD)-suppressible reduction of cytochrome C, and SOD-suppressible luminol-dependent chemiluminescence. Latex beads stimulated a significant release of superoxide that reached 82 nmol/mg protein in the first 15 min and declined thereafter. Formation of an insoluble blue formazan following reduction of nitroblue tetrazolium histochemically demonstrated that superoxide was released over the region of the cell vicinal to the bead.

X-linked congenital stationary night blindness. Review and report of a family with hyperopia.

X-linked congenital stationary night blindness is almost always associated with myopia. We have reviewed all previously reported pedigrees and have found only two with patients without myopia. A recently proposed classification of night blindness includes a complete type associated with myopia and an incomplete type in which both hyperopia and myopia were found.

In-situ breakage of an implantable venous access system.

A totally implantable system for venous access (Port-A-Cath, Pharmacia, Nu-tech) has now entered clinical use. This system consists of a silastic catheter secured to a stainless steel reservoir with a locking ring. The system has been shown to have several advantages when compared with earlier venous access systems.