Non-cultured cell transplantation in an ovine model of non-ischemic heart failure.

OBJECTIVE: Cell therapy may be a promising alternative or adjunct to current treatment modalities for ischemic heart failure. But little is known on the impact of myogenic cell transplantation in large animal models of non-ischemic cardiomyopathy. The aim of the present study was to explore whether an ovine model of toxin-induced heart disease could benefit from non-cultured skeletal muscle cell transplantation. METHODS: Sequential intracoronary injections of doxorubicin (0.75 mg/kg) were carried out every 2 weeks until echocardiographic detection of myocardial dysfunction. Sheep were then randomly assigned to either non-cultured cell transplantation (n=8) or placebo injection (n=5). For the cell therapy group, a skeletal muscle biopsy (about 10 g) was explanted from each animal approximately 3h before grafting. After thoracotomy, 20 epicardial injections were carried out. The animals were assessed one last time before sacrifice, 2 months after the thoracotomy. Cells were tracked with cmDiI (red fluorescence) and characterized with immunohistochemistry with monoclonal antibodies to a fast skeletal isoform of myosin heavy chain. RESULTS: Two months after intramyocardial grafting, tissue Doppler imaging and conventional echocardiographic assessment of the groups showed a marked improvement in the non-cultured cell therapy group. Ejection fraction (EF) (p<0.05) as well as systolic endocardial velocities (p<0.01) improved versus the placebo group. CmDiI and skeletal myosin heavy chain expression was detected in all animals at 2 months after implantation confirming engraftment of skeletal muscle cells. CONCLUSIONS: In conclusion, our data indicate that non-cultured muscle cell transplantation is feasible and may translate into a functional benefit in an ovine model of dilated heart failure.     

Hypertension following renal transplantation in children

The files of 334 consecutive cadaver kidney (CK) and of 27 living related (LR) transplantations (T) in children and adolescents performed from 1973 to 1984 have been reviewed. Following cadaver transplantation, 52 patients (15%) never had hypertension (HT), 41 patients (12%) had only initial HT up to 6 months after transplantation and 18 other patients (5%) exhibited transient HT episodes while on high-dose steroid therapy. Finally, 209 patients (62%) had HT for periods longer than 6 months and 16 patients (5%) until death or graft failure within the first 3 months. Chronic graft rejection was the major cause of HT, but other factors either isolated or in association were also present. Renal artery stenosis (RAS) was diagnosed in 43 cases (13%) 2–17 months post-transplantation; 10 of these were operated upon (5 successfully) and 9 underwent transluminal angioplasty with a single success. Nine cases of RAS resolved spontaneously. HT was attributed to the host kidney in 10 cases (3%) and to recurrence of primary renal disease in 9 (3%). HT observed after CKT was sometimes severe and difficult to control. Acute complications from HT were recorded in 35 cases, with 6 deaths and 2 severe neurological sequelae. Among 25 LRT, 11 cases (40%) had no HT 13 (48%) had HT for longer than 6 months. In this group, no case of RAS was observed and only one complication (without sequelae) was noted. In conclusion, HT is a frequent and sometimes severe complication post-transplantation in children and adolescents.     

Alternative methods to analyse the impact of HIV mutations on virological response to antiviral therapy

Background  

Principal component analysis (PCA) and partial least square (PLS) regression may be useful to summarize the HIV genotypic information. Without pre-selection each mutation presented in at least one patient is considered with a different weight. We compared these two strategies with the construction of a usual genotypic score.     

Neutralizing antibodies in gene-defective hosts

In a host with a normal immune system and a complete gene defect, the nondefective gene product will be immunogenic. Consequently, neutralizing antibodies against the respective protein can arise either 'spontaneously' or after immunization, as shown in patients and in animal models, such as knockout mice. Accordingly, patients with X-linked or homozygous autosomal gene defects are at risk of developing neutralizing antibodies, in particular after protein substitution or gene therapy. This Review compares and exemplifies the various genetic and immunological contexts that lead to 'neutralizing and generated by gene defect' or 'nagged' antibodies, and outlines implications and solutions for therapeutic strategies.     

Morphofunctional ontogeny of the urinary system of the European sea bass Dicentrarchus labrax

European sea bass (Dicentrarchus labrax) are euryhaline fish that tolerate wide salinity fluctuations owing to several morphofunctional adaptations. Among the osmoregulatory sites (tegument, branchial chambers, digestive tract, urinary system), little is known about the kidney and the urinary bladder. The present study describes the ontogeny of the urinary system (kidney and urinary bladder) and focuses on the progressive expression of the Na⁺/K⁺-ATPase in the cells of these ion-transporting epithelia. A structural approach has shown that two pronephric urinary tubules are already present at hatching while the urinary bladder starts to differentiate. The glomus, an ultrafiltration site, occurs at day 5 (D5). The opisthonephros differentiates at D19/25 from the pronephric collecting tubules, then it rapidly grows longer and becomes folded. Na⁺/K⁺-ATPase immunolocalization and transmission electron microscopy show that ionocyte-like cells line the urinary tubules and the dorsal wall of the urinary bladder from D2/D5 on. Tubule ionocytes present a basolateral-localized fluorescence. Ionocytes of the collecting ducts and of the dorsal wall of the bladder present a fluorescence distributed in the whole cytoplasm. Fluorescence becomes stronger in later stages, suggesting a progressively increasing functionality of the urinary system in active ion transports. This observation is closely correlated with the ontogeny of osmoregulatory abilities. In juvenile and preadult fish kept in seawater, osmolality measurements demonstrate that urine is isotonic to blood. At low salinity, urine is hypotonic to blood in both stages. The capacity to produce hypotonic urine increases during ontogeny, a fact that suggests an increasing involvement of the urinary system in osmoregulation. The occurrence and the progressive functionality of the urinary system during the ontogeny, along with those of other osmoregulatory sites, are major adaptations allowing the sea bass to live in habitats of variable salinity such as lagoons and estuaries.     

Clinical and molecular overlap in overgrowth syndromes

Here, we report the clinical and molecular analysis of 75 patients with overgrowth and mental retardation, including 45 previously reported cases [Rio et al., 2003; Baujat et al., 2004]. Two groups are distinguished: group I corresponding to patients with recognizable overgrowth syndromes (Sotos syndrome (SS), Weaver syndrome (WS), Beckwith-Wiedemann syndrome, Simpson-Golabi-Behmel syndrome (SGBS), and del(22)(qter) syndrome) (60 cases) and group II corresponding to unclassified cases (15 patients). We investigated NSD1 and GPC3 deletions or mutations, 11p15 abnormalities, and 22qter deletions. Surprisingly, in Group I, two SS patients had 11p15 abnormalities and two patients with Beckwith-Wiedemann syndrome had NSD1 aberrations. In group II, two cases of del(22)(qter) were identified but neither NSD1, 11p15, nor GPC3 abnormalities were detected. These results emphasize the clinical and molecular overlap in overgrowth conditions.     

Spermine increases the active and passive transport across the alveolar epithelium in situ: effect of thiol reagents

An intact alveolar epithelial barrier is thought to be important for alveolar liquid absorption. However, polycations increase alveolar permeability without affecting alveolar liquid absorption (Saumon et al., Am J Physiol 1995: 269:L185-L194). We have reconsidered this issue using polyamines. The polyamine spermine (10(-3) mol/l) produced a large (up to 20-fold), sustained increase in the permeability of the alveolar barrier to mannitol (PAMan) and in alveolar liquid absorption (Jw, twofold) in isolated rat lungs. These increases were inhibited by 5 x 10(-3) mol/l putrescine and 2 x 10(-3) mol/l spermidine. Because spermine is known to affect the phosphoinositide/Ca2+ signalling pathway, we evaluated the effects of thiol reagents known to interfere with this pathway in different ways. Thimerosal, a thiol reagent which sensitizes the inositol 1,4,5-trisphosphate (IP3) receptor, inhibited the spermine-induced increase in PA(Man) and, to a lesser extent, that of Jw. Mersalyl, a thiol reagent which blocks IP3-gated Ca2+ channels, enhanced spermine's effect, whereas N-ethylmaleimide, a non-specific thiol reagent, had no effect. These observations show that large increases in permeability may coexist with increases in Jw. They also suggest that the phosphoinositide/Ca2+ second messenger pathway is involved in modulating the tightness of the alveolar barrier and alveolar liquid absorption.