Response to Therapeutic Plasma Exchange as a Rescue Treatment in Clinically Isolated Syndromes and Acute Worsening of Multiple Sclerosis: A Retrospective Analysis of 90 Patients

Objectives

Experience with therapeutic plasma exchange (TPE) for acute relapses in clinically isolated syndrome (CIS) or multiple sclerosis (MS) patients has been derived from small and inhomogeneous patient populations so far. In the present study, we retrospectively evaluated features associated with TPE response in a larger cohort of CIS and MS patients with acute worsening of disease.

Participants

Ninety CIS and MS patients with acute relapses or acute worsening of symptoms were firstly treated with TPE. The population consisted of 62 women and 28 men with a median age of 38 years (range 18–69 years).

Outcome Measures

Primary endpoint was the clinical response to TPE, focused on the functional improvement of the target neurologic deficit. Secondary endpoint was an improvement in expanded disability status scale (EDSS) scoring.

Results

A clinical response to TPE was observed in 65 out of 90 patients (72.2%), with marked improvement in 18 (20.0%) and moderate improvement in 47 out of 90 patients (52.2%). The median EDSS was reduced from 3.75 before to 3.0 after TPE (p = 0.001). Response to TPE was significantly more frequent in patients with relapsing courses of disease (CIS, RR-MS, p = 0.001), no disease modifying drugs (p = 0.017), gadolinium-positive (Gd⁺) MRI lesions (p = 0.001) and EDSS ≤ 5.0 before TPE (p = 0.014). In the multiple logistic regression analysis only the detection of Gd⁺ MRI lesions was significantly altered (p = 0.004).

Conclusion

Clinical response to TPE was achieved in the majority of our patients. We identified clinical and diagnostic features in CIS and MS relapses that might be helpful to identify patients responding to TPE. Gd⁺ MRI lesions before treatment were the best predictor of the response to TPE in our cohort.     

Development and perspectives of scientific services offered by genomic biological resource centres.

A number of fundamental technical developments like the evolvement of oligonucleotide microarrays, new sequencing technologies and gene synthesis have considerably changed the character of genomic biological resource centres in recent years. While genomic biological resource centres traditionally served mainly as providers of sparsely characterized cDNA clones and clone sets, there is nowadays a clear tendency towards well-characterized, high-quality clones. In addition, major new service units like microarray services have developed, which are completely independent of clone collections, reflecting the co-evolution of data generation and technology development. The new technologies require an increasingly higher degree of specialization, data integration and quality standards. Altogether, these developments result in spin-offs of highly specialized biotech companies, some of which will take a prominent position in translational medicine.     

Statistical distribution of amino acid sequences: a proof of Darwinian evolution

MOTIVATION: The article presents results of the listing of the quantity of amino acids, dipeptides and tripeptides for all proteins available in the UNIPROT-TREMBL database and the listing for selected species and enzymes. UNIPROT-TREMBL contains protein sequences associated with computationally generated annotations and large-scale functional characterization. Due to the distinct metabolic pathways of amino acid syntheses and their physicochemical properties, the quantities of subpeptides in proteins vary. We have proved that the distribution of amino acids, dipeptides and tripeptides is statistical which confirms that the evolutionary biodiversity development model is subject to the theory of independent events. It seems interesting that certain short peptide combinations occur relatively rarely or even not at all. First, it confirms the Darwinian theory of evolution and second, it opens up opportunities for designing pharmaceuticals among rarely represented short peptide combinations. Furthermore, an innovative approach to the mass analysis of bioinformatic data is presented. CONTACT: eitner@amu.edu.pl SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.     

In vitro reconstitution of fibrillar collagen type I assemblies at reactive polymer surfaces

The reconstitution of fibrillar collagen and its assemblies with heparin and hyaluronic acid was studied in vitro. Fibril formation kinetics were analyzed by turbidity and depletion measurements in solutions containing varied concentrations of collagen and glycosaminoglycans. Fibril-forming collagen solutions were further applied for the coating of planar substrates which had been modified with alternating maleic anhydride copolymer films before. The immobilized collagen assemblies were characterized with respect to the deposited amount of protein using ellipsometry and acidic hydrolysis/HPLC-based amino acid analysis, respectively. AFM, SEM, and cLSM were utilized to gain information on structural features and patterns formed by surface-attached fibrils depending on the initial solution concentrations of collagen. The results revealed that the addition of heparin and hyaluronic acid affected both the fibril dimensions and the meshwork characteristics of the surface-bound fibrils.     

Biochemical mechanisms of cyclosporine neurotoxicity

Proper management of chemotoxicity in transplant patients requires detailed knowledge of the biochemical mechanisms underlying immunosuppressant toxicity. Neurotoxicity is one of the most significant clinical side effects of the immunosuppressive undecapeptide cyclosporine, occurring at some degree in up to 60% of transplant patients. The clinical symptoms of cyclosporine-mediated neurotoxicity consist of decreased responsiveness, hallucinations, delusions, seizures, cortical blindness, and stroke-like episodes that mimic those clinical symptoms of mitochondrial encephalopathy. Clinical computed tomography (CT) and magnetic resonance imaging (MRI) studies have revealed a correlation between clinical symptoms of cyclosporine-mediated neurotoxicity and morphological changes in the brain, such as hypodensity of white matter, cerebral edema, metabolic encephalopathy, and hypoxic damages. Paradoxically, in animal models cyclosporine protects the brain from ischemia-reperfusion (I/R) injury. Interestingly, cyclosporine appears to mediate both neurotoxicity (under normoxic conditions) and I/R protection across the same range of drug concentration. Both toxicity and protection might arise from the intersection of cyclosporine with mitochondrial energy metabolism. This review addresses basic biochemical mechanisms of: 1) cyclosporine toxicity in normoxic brain, and 2) its protective effects in the same organ during I/R. The marked and unparallel potential of magnetic resonance spectroscopy (MRS) as a novel quantitative approach to evaluate metabolic drug toxicity is described.     

High Fat Feeding Induces Hepatic Fatty Acid Elongation in Mice

Background

High-fat diets promote hepatic lipid accumulation. Paradoxically, these diets also induce lipogenic gene expression in rodent liver. Whether high expression of these genes actually results in an increased flux through the de novo lipogenic pathway in vivo has not been demonstrated.

Methodology/Principal Findings

To interrogate this apparent paradox, we have quantified de novo lipogenesis in C57Bl/6J mice fed either chow, a high-fat or a n-3 polyunsaturated fatty acid (PUFA)-enriched high-fat diet. A novel approach based on mass isotopomer distribution analysis (MIDA) following 1-¹³C acetate infusion was applied to simultaneously determine de novo lipogenesis, fatty acid elongation as well as cholesterol synthesis. Furthermore, we measured very low density lipoprotein-triglyceride (VLDL-TG) production rates. High-fat feeding promoted hepatic lipid accumulation and induced the expression of lipogenic and cholesterogenic genes compared to chow-fed mice: induction of gene expression was found to translate into increased oleate synthesis. Interestingly, this higher lipogenic flux (+74 µg/g/h for oleic acid) in mice fed the high-fat diet was mainly due to an increased hepatic elongation of unlabeled palmitate (+66 µg/g/h) rather than to elongation of de novo synthesized palmitate. In addition, fractional cholesterol synthesis was increased, i.e. 5.8±0.4% vs. 8.1±0.6% for control and high fat-fed animals, respectively. Hepatic VLDL-TG production was not affected by high-fat feeding. Partial replacement of saturated fat by fish oil completely reversed the lipogenic effects of high-fat feeding: hepatic lipogenic and cholesterogenic gene expression levels as well as fatty acid and cholesterol synthesis rates were normalized.

Conclusions/Significance

High-fat feeding induces hepatic fatty acid synthesis in mice, by chain elongation and subsequent desaturation rather than de novo synthesis, while VLDL-TG output remains unaffected. Suppression of lipogenic fluxes by fish oil prevents from high fat diet-induced hepatic steatosis in mice.     

Functional expression, purification, and characterization of the recombinant Baeyer-Villiger monooxygenase MekA from Pseudomonas veronii MEK700

For the investigation of the NADPH-dependent Baeyer-Villiger monooxygenase MekA from Pseudomonas veronii MEK700, the encoding gene mekA with a C-terminal strep-tag was cloned and expressed under the control of a l-rhamnose inducible promoter from Escherichia coli. The mekA gene was found by analyzing the methylethylketone (MEK) degradation pathway by Onaca et al. J Bacteriol 189:3759–3767, 2007. Sequence analysis of the corresponding protein, which catalyzes the Baeyer-Villiger oxidation of MEK to ethyl acetate, showed two binding sites (Rossman-fold motifs) for cofactors NAD(P)H and FAD. Although expression of mekA resulted in large amounts of inclusion bodies compared to soluble protein, high amounts of purified and active MekA were obtained by affinity chromatography. The substrate spectrum of MekA was investigated with purified enzyme and whole cells using a variety of aliphatic, aromatic, and cyclic ketones including four chiral substrates. The specific activity of MekA with MEK as substrate was determined to be 1.1 U/mg protein. K _M values were determined for MEK and the cofactors NADPH and NADH to be 6, 11, and 29 μM, respectively.     

Inhibition of GSK3 promotes replication and survival of pancreatic beta cells

Recent developments indicate that the regeneration of beta cell function and mass in patients with diabetes is possible. A regenerative approach may represent an alternative treatment option relative to current diabetes therapies that fail to provide optimal glycemic control. Here we report that the inactivation of GSK3 by small molecule inhibitors or RNA interference stimulates replication of INS-1E rat insulinoma cells. Specific and potent GSK3 inhibitors also alleviate the toxic effects of high concentrations of glucose and the saturated fatty acid palmitate on INS-1E cells. Furthermore, treatment of isolated rat islets with structurally diverse small molecule GSK3 inhibitors increases the rate beta cell replication by 2-3-fold relative to controls. We propose that GSK3 is a regulator of beta cell replication and survival. Moreover, our results suggest that specific inhibitors of GSK3 may have practical applications in beta cell regenerative therapies.