Barley plasma membrane intrinsic proteins (PIP aquaporins) as water and CO2 transporters

We identified barley aquaporins and demonstrated that one, HvPIP2;1, transports water and CO2. Regarding water homeostasis in plants, regulations of aquaporin expression were observed in many plants under several environmental stresses. Under salt stress, a number of plasma membrane-type aquaporins were down-regulated, which can prevent continuous dehydration resulting in cell death. The leaves of transgenic rice plants that expressed the largest amount of HvPIP2;1 showed a 40% increase in internal CO2 conductance compared with leaves of wild-type rice plants. The rate of CO2 assimilation also increased in the transgenic plants. The goal of our plant aquaporin research is to determine the key aquaporin species responsible for water and CO2 transport, and to improve plant water relations, stress tolerance, CO2 uptake or assimilation, and plant productivity via molecular breeding of aquaporins.</p

Complex cardiac anatomy and catheter access: the role of imaging in patients referred for catheter ablation

A 66-year-old man with Kartagener's syndrome, situs inversus totalis, and recurrent supraventricular tachycardia and a 49-year-old man with atrial fibrillation and drug-refractory rapid ventricular rate response were referred for catheter ablation. In the first case, the mirrored anatomy of the right atrium was reconstructed using three-dimensional electroanatomical mapping, which guided successful ablation of a typical atrioventricular nodal reentrant tachycardia. In the second case, computerized tomography showed the presence of left atrial isomerism with interruption of the inferior vena cava and azygous continuation into the superior vena cava, guiding advancement of the ablation catheter for access into the positionally right atrial ablation site. These cases illustrate the role of imaging in patients with unusual anatomy of the cardiac chambers and major blood vessels guiding optimal catheter access for catheter ablation