Pulmonary hypertension without heart failure causes cardiorenal syndrome in a porcine model

Cardiorenal syndromes type 1 and 2 are complex disorders in which cardiac dysfunction leads to kidney dysfunction. However, the mechanisms remain incompletely explained, during pulmonary hypertension in particular. The objective of this study is to develop an original preclinical model of cardiorenal syndrome secondary to a pulmonary hypertension in piglets. Twelve 2-month-old Large White piglets were randomized in two groups: (1) induction of pulmonary hypertension by ligation of the left pulmonary artery and iterative embolizations of the right lower pulmonary artery, or (2) Sham interventions. We evaluated the cardiac function using right heart catheterization, echocardiography and measurement of biochemistry markers). Kidney was characterized using laboratory blood and urine tests, histological evaluation, immunostainings for renal damage and repair, and a longitudinal weekly assessment of the glomerular filtration rate using creatinine-based estimation and intravenous injection of an exogenous tracer on one piglet. At the end of the protocol (6 weeks), the mean pulmonary artery pressure (32 ± 10 vs. 13 ± 2 mmHg; p = 0.001), pulmonary vascular resistance (9.3 ± 4.7 vs. 2.5 ± 0.4 WU; p = 0.004) and central venous pressure were significantly higher in the pulmonary hypertension group while the cardiac index was not different. Piglets with pulmonary hypertension had higher troponin I. We found significant tubular damage and an increase in albuminuria in the pulmonary hypertension group and negative correlation between pulmonary hypertension and renal function. We report here the first porcine model of cardiorenal syndrome secondary to pulmonary hypertension.

Fluorescence excitation analysis by two-photon confocal laser scanning microscopy: a new method to identify fluorescent nanoparticles on histological tissue sections

In the present study, we make use of the ability of two-photon confocal laser scanning microscopes (CLSMs) equipped with tunable lasers to produce spectral excitation image sequences. Furthermore, unmixing, which is usually performed on emission image sequences, is performed on these excitation image sequences. We use factor analysis of medical image sequences (FAMIS), which produces factor images, to unmix spectral image sequences of stained structures in tissue sections to provide images of characterized stained cellular structures. This new approach is applied to histological tissue sections of mouse aorta containing labeled iron nanoparticles stained with Texas Red and counterstained with SYTO13, to obtain visual information about the accumulation of these nanoparticles in the arterial wall. The possible presence of Texas Red is determined using a two-photon CLSM associated with FAMIS via the excitation spectra. Texas Red and SYTO13 are thus differentiated, and corresponding factor images specify their possible presence and cellular localization. In conclusion, the designed protocol shows that sequences of images obtained by excitation in a two-photon CLSM enables characterization of Texas Red-stained nanoparticles and other markers. This methodology offers an alternative and complementary solution to the conventional use of emission spectra unmixing to localize fluorescent nanoparticles in tissue samples.

Barotrauma-induced tension pneumoperitoneum

We report the case of a massive tension-pneumoperitoneum developing immediately after starting mechanical ventilation (barotrauma). Careful analysis of CT-data provided meaningful informations in assessing the non surgical pulmonary source of pneumo peritoneum.

Hyperammonemia after high-dose chemotherapy and stem cell transplantation

We report a patient with multiple myeloma who suffered from hyperammonemia after a second stem cell autograft. This syndrome is not well known but is associated with a high mortality rate. Considering the possibility of this diagnosis in patients developing confusion and neurological degradation with respiratory alkalosis after intensive chemotherapy, could allow earlier treatment and perhaps improved survival. Possible mechanisms and potential therapies are discussed. With rapid recognition and treatment of the syndrome, the patient fully recovered. One and a half years later, she is still alive and well, on interferon for persisting myeloma.

Redox states and associated interchain processes of thienylenevinylene oligomers

The electronic structure of successive redox states of two series of thienylenevinylene oligomers (nTVs, n=4, 5, 6, 8, and 12) that carry hexyl substituents at the alpha- or beta-positions in order to increase the solubility was investigated in detail by means of UV/ Vis/near-IR and ESR spectroscopy in solution. The nTV redox states have been fully characterized up to the dication for the shorter oligomers (n < or = 6) and up to the tetracation for the longer oligomers (n > or = 8). While the monocation radicals of the nTVs exhibit two dipole-allowed electronic transitions in the Vis/near-IR region, all the higher oxidized states invariably show a single strong absorption in the near-IR region. The electronic transitions of the various oxidized states and those of their vibronic replicas shift to lower energies with increasing conjugation length. The ESR spectra, recorded as a function of the degree of oxidation, provide evidence for the presence of electron spin in the odd-charged and the absence of spin in even-charged cations. Variable-temperature UV/Vis/near-IR and ESR spectroscopy establish that the tendency of the nTV monocation radicals to form spin-less alpha dimers in solution strongly depends on the number of solubilizing hexyl groups. While the oligomers that carry two hexyl chains at the a-positions of the terminal thiophenes (alpha-nTVs) readily form pi dimers at low temperature, the oligomers that carry hexyl groups on the beta- and beta'-positions of every thiophene ring (beta-nTVs) do not form pi dimers. Low-temperature UV/ Vis/near-IR and ESR experiments on solutions in which neutral and singly oxidized nTVs are simultaneously present, reveal the occurrence of interchain interactions between these two species, accompanied by a pronounced change in the existing disproportionation equilibrium.