LYMPHATIC SYSTEM MALFORMATIONS IN NOONAN SYNDROME: TWO CASE REPORTS AND IMAGING ANALYSIS

Lymphedema is a well-known complication of Noonan syndrome (NS) but the lymphatic malformations in NS are poorly understood. We report clinical, genetic, and imaging information about a boy and girl with NS and late-onset lower extremity lymphedema. A de novo mission mutation of RIT1 (NM_006912.5) c.246T>A, p.Phe82Leu was identified in the girl, who also showed systemic lymphatic hyperplasia and dysfunction. Magnetic resonance lymphangio-graphy (MRL) of the boy clearly demonstrated segmental dilated and hyperplastic lymphatics with impaired transport function in an affected limb and pelvic region. Indocyanine green lymphography (ICGL) showed delayed and partial enhancement of the lymph vessels in the affected limb but no lymph reflux was detected. No causative mutation was identified in the second case. Lymphoscintigraphy (LSG) failed to show lymph vessels in either of the children. Our study showed that MRL is a reliable and accurate test that can be used to demonstrate morpho-logical and functional defects of the lymphatic system. Moreover, ICGL is sufficiently sensitive to determine the functional condition of peripheral lymph vessels. The combined use of imaging modalities can give an accurate diagnosis of complex lymphatic system anomalies in NS and other syndromic diseases.

The organic arsenic derivative GMZ27 induces PML-RARα-independent apoptosis in myeloid leukemia cells

Arsenic trioxide (ATO) is an inorganic arsenic derivative that is very effective against acute promyelocytic leukemia. However, organic arsenic derivatives (OAD) have a more favorable toxicity profile than ATO. We herein characterized dipropil-S-glycerol arsenic (GMZ27), a novel OAD. GMZ27 had potent antiproliferative activity against human acute myeloid leukemia (AML) cell lines that was higher than that of ATO. In contrast to ATO, GMZ27 only marginally induced maturation of leukemia cells and had no effect on the cell cycle. The anti-leukemia activity of GMZ27 against AML cells was independent of the presence of the PML-RARα fusion protein. GMZ27 dissipates mitochondrial transmembrane potential, and induces cleavage of caspase 9 and activation of caspase 3 without altering the expression levels of (BCL-2), BAX and BCL-xl. GMZ27 induces the formation of intracellular superoxide, a reactive oxygen species (ROS) which plays a major role in the antileukemia activity of this OAD. In addition to ROS generation, GMZ27 concomitantly reduces intracellular glutathione which markedly weakens the cellular antioxidant capacity, thus enhancing the detrimental intracellular effects of ROS production. These results indicate that GMZ27 induces apoptosis in AML cells in a PML-RARα-independent fashion, through the induction of ROS production. This activity provides the rationale for the testing of GMZ27 in patients with AML.

[Experimental study on different concentration alcohol humidifying oxygen supply improving hypoxia caused by pulmonary edema]

In order to research the best alcoholic concentration in the humidifying bottle when pneumonedema oxygen inhalation, 32 rabbits, divided into 4 groups, are replicated into pneumonedema models using method of rapid transfusion, and given oxygen inhalation with 20%, 50%, 70%, and 90% alcohol as humidifying agent (shortly called alcoholic oxygen). The results are as follows: using 20% alcohol as humidifying agent, the increasing amplitude of blood PaO2 is 147.30% (P < 0.001), the injury to the pulmonary bronchial mucosa and the wall of pulmonary alveoli is slight; using 50% alcohol, the increasing amplitude of blood PaO2 is 39.46% (P < 0.001), the injury to the parts mentioned above exacerbates and bronchiole cavity mucosa has moderate bleeding; using 70% alcohol, the increasing amplitude of blood PaO2 is 21.97% (P < 0.05), pneumorrhagia occurs; using 90% alcohol, the increasing amplitude of blood PaO2 is 94.46% (P < 0.01), a great number of blood cells aggregate inside the pulmonary alveoli and the bronchiole. This study proves that choosing 20% alcohol as humidifying agent has the best result, and as well, the explanation of the mechanism of alcohol suppressing foam, meaning being able to decrease only the surface tension of the foam inside the pulmonary alveoli, is incomprehensive, and the nature of the material itself forming foam has decisive function.