Expression of deletion-containing dystrophins in mdx muscle: implications for gene therapy and dystrophin function

The expression of full-length dystrophin and various dystrophin deletion mutants was monitored in mdx mouse muscle after intramuscular injection of dystrophin-encoding plasmid DNAs. Recombinant dystrophin proteins, including those lacking either the amino terminus, carboxyl terminus, or most of the central rod domain, showed localization to the plasma membrane. This suggests that there are multiple attachment sites for dystrophin to the plasma membrane. Only those constructs containing the carboxyl terminus were able to stabilize dystrophin-associated proteins (DAP) at the membrane, consistent with other studies that suggest that this domain is critical to DAP binding. Colocalization with DAP was not necessary for membrane localization of the various dystrophin molecules. However, stabilization and co-localization of the DAP did seem to be a prerequisite for expression and/or stabilization of mutant dystrophins beyond 1 wk and these same criteria seemed important for mitigating the histopathological consequences of dystrophin deficiency.     

Pulmonary complications after bone marrow transplantation: high-resolution CT and pathologic findings

The explosion of new knowledge about the complex mechanisms mediating high blood pressure is providing new targets for drug therapy of hypertension and other cardiovascular disorders. This article reviews the current status of several new approaches in the management of hypertension, including vasopressin antagonists, natriuretic peptide clearance inhibitors, endothelin antagonists, renin inhibitors, angiotensin receptor antagonists, and selective T-type calcium ion channel antagonists.     

Stool patterns of infants diagnosed with necrotizing enterocolitis

A retrospective study of the stool patterns of 68 infants was conducted. The sample included 34 infants who developed necrotizing enterocolitis (NEC) and 34 infants who did not. The objective was to compare the stool patterns of the two groups. Data regarding number and characteristics of stools; time, types, and methods of feeding; feeding additives; and demographic information were extracted from inpatient medical records. Length of time between the passage of the first stool and initiation of the first feeding in the two groups was compared using the Wilcoxin Rank Sum Test. Findings were statistically significant (p = .008). Numbers of stools were compared using the Fisher Exact Test. Findings were significantly greater for the NEC group. Infants in the NEC group had 26 percent more stools and more than twice as many seedy stools as infants in the non-NEC group.     

The paired-pulse index: a measure of hippocampal dentate granule cell modulation

This study was undertaken to assess whether the paired-pulse index (PPI) is an effective measure of the modulation of dentate granule cell excitability during normal development. Paired-pulse stimulations of the perforant path were, therefore, used to construct a PPI for 15-, 30-, and 90-day old, freely moving male rats. Significant age-dependent differences in the PPI were obtained. Fifteen-day old rats showed significantly less inhibition at short interpulse intervals [interpulse interval (IPI): 20 to 30 msec), a lack of facilitation at intermediate IPIs (50 to 150 msec), and significantly less inhibition at longer IPIs (300 to 1,000 msec) than adults.     

Long-term synaptic plasticity in the honeybee

A monosynaptic response was recorded in vivo in the mushroom body of the bee brain, an important site for memory consolidation. Focal electrical stimulation of a major afferent input evoked an extracellular field potential that consisted of a presynaptic fiber volley and a postsynaptic response. We report a long-lasting potentiation of the synaptic response (2.6-fold increase; < or = 3.5 h). Potentiation of the response was induced by low-frequency stimulation (0.02-1.0 Hz), was input specific, and was maintained in the absence of stimulation. Paired-pulse facilitation of the response was converted to paired-pulse depression after potentiation, suggesting a presynaptic mechanism. This is the first demonstration of long-term synaptic plasticity in the insect brain.