Construction and function of a recombinant adenovirus encoding a human aquaporin 1-green fluorescent protein fusion product

Transfer of the human aquaporin 1 (hAQP1) gene provides a novel way to potentially correct the severe salivary hypofunction associated with therapeutic radiation for head and neck cancer. To facilitate the study of individual cells transduced with this gene, we have designed a fusion product of the hAQP1 and jellyfish green fluorescent protein (GFP) cDNAs. An expression plasmid, pACCMVhAQP1GFP, and a recombinant adenovirus, AdhAQP1GFP, encoding this fusion product were constructed. Both the recombinant plasmid and virus directed the expression of the encoded, 55-kDa fusion protein (hAQP1GFP), which was detected in the plasma membranes of several epithelial cell lines (293, SMIE, and A5). hAQP1GFP was functionally active and facilitated fluid movement across a polarized salivary epithelial cell monolayer (approximately 5-fold noninfected controls) in response to an osmotic gradient. In response to a hypotonic challenge, individual epithelial cells expressing the fusion protein exhibited significantly more capacitance (used herein as an indicator of cell swelling) than control cells. Conversely, in response to a hypertonic challenge, individual infected cells shrunk more rapidly (approximately 2- to 3-fold) and to a greater extent than control cells. We conclude that AdhAQP1GFP is a useful experimental tool to identify and study individual cells expressing a water channel transgene.     

Automatic versus strategic effects of phonology and orthography on auditory lexical access in brain-damaged patients as a function of inter-stimulus interval

The influence of both phonological and orthographic information on auditory lexical access was examined in left- and right-hemisphere-damaged individuals using a lexical decision paradigm. Subjects were presented with prime-target pairs that were either phonologically related (tooth-youth), orthographically related (touch-couch), both phonologically and orthographically related (blood-flood), or unrelated (bill-tent), at two inter-stimulus intervals (ISI) – 100 ms and 750 ms – to tap more automatic versus more strategic processing. All groups demonstrated effects of orthography at both ISIs (facilitory at 100 ms ISI and inhibitory at 750 ms ISI), supporting the findings by Leonard and Baum (1997) that effects of orthography emerge independent of site of brain damage and suggesting that orthographic effects in auditory word recognition tend to be largely strategic. A facilitory effect of phonology was also found for all groups at both ISIs. The findings are discussed in relation to theories of lexical activation in brain-damaged individuals.     

Upper respiratory symptoms in elderly patients. Hypertension complicates treatment decisions

Approximately 6% of elderly patients present to primary care offices with hypertension and upper respiratory infection. Elderly people develop an acquired immunity to many rhinoviruses, making them less susceptible than younger people to the common cold. But because of the decreased vigor of their immune systems, they are less able to fight infection, particularly secondary bacterial infections. Upper respiratory infections require close monitoring in elderly patients to detect secondary infections and other complications. Most published research on respiratory symptom treatment is not limited to elderly subjects.     

Retroviral vector-mediated gene expression in hematopoietic cells

Gene transfer vectors based on simple retroviruses and more complex lentiviruses are currently the most reliable tools for stable establishment of transgenes in hematopoietic cells. While important hurdles in basic gene transfer technologies have been overcome in recent years, there is still some uncertainty in the choice of the cis-regulatory elements of the vector. These elements dictate the overall level, clonal variability, response to differentiation and persistence of transgene expression in vivo and thus have a significant influence on the outcome of therapeutic applications of somatic gene transfer. The rationale underlying the further improvement of such cis-elements is reviewed here.