Randomized clinical trial of tacrolimus- vs cyclosporine-based immunosuppression in pediatric heart transplantation: preliminary results at 15-month follow-up.

BACKGROUND: While Tacrolimus (Tac) and Cyclosporine (Cya) immunosuppression are used after cardiac transplantation (tx), few studies have evaluated their use in pediatric patients. METHODS: We randomized 26 heart transplant recipients (pts) in a prospective, open-label trial to Tac (n = 14) or Cya (n = 12) to compare their efficacy and side-effects. Mean age at tx was 4.2 years for Tac and 5.8 years for Cya. Mean follow-up was 26 months (range: 11-39 months) for Tac and 24 months for Cya (range: 33-13 months). RESULTS: Our data suggest that both regimens are efficacious in the pediatric population. Conversion from Cya to Tac was useful for dealing with persistent rejection, although this sample did not suggest lower incidence of acute cellular rejection in the Tac group. CONCLUSIONS: Further studies are required to establish pharmacokinetic parameters to enhance therapeutic monitoring of these patients to minimize side effects and enhance outcomes.     

Polyesters prepared by polycondensation in the presence of carbodiimides, 2. On the reaction of methyl α-(S)-malate with N,N′-dicyclohexylcarbodiimide under mild conditions

The reaction of methyl α-(S)-malate with N,N′-dicyclohexylcarbodiimide in the presence of amines under mild conditions was studied. It was established that in solvents with weak donor properties, N-acyl derivatives are preferentially formed instead of ester condensation products. An optically active polymer fraction was separated by precipitation in diethyl ether (yield up to 30%) with M?_n,GPC 1 000 to 4 000 and of low polydispersity M?_w/M?_n = 1,1–1,4. The method permits the preparation of optically active biodegradable condensation products with controlled molecular structure.     

Adjuvant-dependent modulation of Th1 and Th2 responses to immunization with beta-amyloid

The role of adjuvant on the T(h)1 and T(h)2 immune responses to Abeta-immunotherapy (Abeta(42 )peptide) was examined in wild-type mice. Fine epitope analysis with overlapping oligomers of the Abeta(42) sequence identified the 1-15 region as a dominant B cell epitope. The 6-20 peptide was recognized only weakly by antisera from mice administrated with Abeta(42) peptide formulated in complete Freund's adjuvant (CFA), alum or TiterMax Gold (TMG). However, mice immunized with Abeta(42) mixed with QS21 induced a significant antibody response to the 6-20 peptide. The only T cell epitope found was within the 6-28 sequence of Abeta(42). QS21 and CFA induced the strongest humoral response to Abeta, alum was intermediate, and TMG the weakest adjuvant. Analysis of antibody isotypes specific for Abeta indicates that alum induces primarily T(h)2-type immune response, whereas TMG, CFA and QS21 shift the immune responses toward a T(h)1 phenotype. Stimulation of splenocytes from Abeta-immunized mice with Abeta(40) peptide induced strikingly different cytokine expression profiles. QS21 and CFA induced significant IFN-gamma, IL-4 and tumor necrosis factor-alpha expression, whereas alum induced primarily IL-4 production. As T(h)1-type immune responses have been implicated in many autoimmune disorders, whereas T(h)2-type responses have been shown to inhibit autoimmune disease, the choice of adjuvant may be critical for the design of a safe and effective immunotherapy for Alzheimer's disease.     

Adult pancreas generates multipotent stem cells and pancreatic and nonpancreatic progeny

Strategies designed to produce functional cells from stem cells or from mature cells hold great promise for treatment of different cell-degenerative diseases. Type 1 and type 2 diabetes are examples of such diseases. Although different in origin, both involve inadequate cell mass of insulin-producing beta cells, the most abundant cell type of pancreatic islets of Langerhans. Practical realization of such strategies is highly dependent on the elucidation of physiological mechanisms responsible for generation of new beta cells in the pancreas, which at this time are poorly defined. The in vitro differentiation systems allowing generation of new beta cells provide a valuable experimental tool for studying these mechanisms. Few such systems are currently available. In this work, we present an in vitro differentiation system, derived from adult mouse pancreas, capable of generating insulin-producing beta-like cells, which self-organize into islet-like cell clusters (ILCCs) during the course of the culture. Surprisingly, we found that along with the ILCCs, multiple cell types with phenotypic characteristics of embryonic central nervous system and neural crest are also generated. Moreover, several embryonic stem cell-specific genes are induced during the course of these cultures. These results suggest that the adult pancreas may contain cells competent to give rise to new endocrine and neural cells.     

The use of Lepidium sativum in a plant bioassay system for the detection of microcystin-LR.

Toxin-producing cyanobacteria pose a worldwide health threat to humans and animals due to their increasing presence in both drinking and recreational waters. Detection of microcystins in water generally relies on specialised equipment and a delay of several days for transport and analysis. Little work has, however, been done on establishing a simple, cost-effective and sensitive plant bioassay for the detection of microcystin-LR (MCLR) in water at the WHO Tolerable Daily Intake guideline level of 1 microg/l. We investigated the effect of a MCLR extract at 1 and 10 microg/l on the growth of Lepidium sativum over 6 days. Exposure to 10 microg/l MCLR resulted in a significant decrease in root and leaf lengths and fresh weights of seedlings when compared to the controls. These results were consistent with seedlings exposed to pure MCLR at 10 microg/l. Seedlings exposed to 1 microg/l MCLR showed a significant decrease in root development from day 2 to day 6. Glutathione S-transferase and glutathione peroxidase activities were also significantly raised in plants from days 5 and 4, respectively, at both toxin levels investigated.     

Differential organization of the local immune response in patients with active cavitary tuberculosis or with nonprogressive tuberculoma

BACKGROUND: In 90% of all cases, Mycobacterium tuberculosis infection results in latency rather than active disease, with the pathogen being contained within granulomatous lesions at the site of primary infection. Failure of this containment leads to reactivation of postprimary tuberculosis (TB). The regional immune processes that sustain the delicate balance with persistent M. tuberculosis, however, remain unclear. METHODS: We compared activation statuses, biological functions, and interactions of host immune cells in human nonprogressive tuberculoma and active cavitary tuberculous lung tissue. RESULTS: Dissection of early granuloma formations revealed differential cellular distribution and activation statuses of distinct cell types in different regions relative to the central caseotic caverna or the tuberculoma in tuberculous lung tissue. In patients with tuberculoma with latent infection, distant parts of lung tissue exhibited strong vascularization and profound proliferative activity, indicating that continuous immune defense is required for mycobacterial containment, which is absent in cavitary tuberculous lung lesions. CONCLUSIONS: We conclude that differential regulation of the local immune response is crucial for the containment of M. tuberculosis and that a continuous antigen-specific cross talk between the host immune system and M. tuberculosis is ensured during latency. This activation requires sufficient supply of nutrients and well-coordinated structural organization, both of which are lost during reactivation of TB.     

Can FDG-PET/MR help to overcome limitations of sequential MRI and PET-FDG for differential diagnosis between recurrence/progression and radionecrosis of high-grade gliomas?

The aim of our study was assessing the potential of FDG-PET-MRI to overcome limitations of separately performed MRI and PET-FDG and improving the performance of high-grade gliomas evaluation. Combined PET-MRI analysis allowed differentiating between recurrence/progression and radionecrosis with improved diagnostic accuracy (95% vs 63% for PET and 82% for MRI). FDG being a reliable, cost-saving tracer in this indication, combined FDG PET-MRI analysis could play a significant role in the follow-up of high-grade brain tumors.