Replacement of acetonitrile by ethanol as solvent in reversed phase chromatography of biomolecules

Acetonitrile, which is a by-product of acrylonitrile synthesis, is the commonly used solvent in ion-pair reversed phase chromatography. In consequence of the decreasing demand for acrylonitrile due to the financial crisis, a worldwide shortage of acetonitrile is observed. Therefore, the aim of this study was to establish ion-pair reversed phase chromatographic assays using alternative eluents for acetonitrile and to decrease costs incurred hereby. We compared the performance of ion-pair reversed phase chromatography using acetonitrile with the alternative eluents methanol, ethanol and n-propanol, using monolithic reversed phase C5 as well as C18 chromatography columns. We used triethylammonium acetate (TEAA) and tetrabutylammonium sulfate (TBA) as representative cationic ion-pair reagents and trifluoroacetic acid (TFA) as representative anionic ion-pair reagent. For covering a large field of applications, we fractionated representative low, middle and high-molecular weight biomolecules, in particular dinucleoside polyphosphates, peptides, proteins and tryptic digested human serum albumin. Whereas the chromatographic characteristics of both methanol and n-propanol were partly insufficient, ethanol was characterised equally or partly even better in the matter of elution strength and separation quality compared to the eluent water-acetonitrile. In conclusion, ethanol is an appropriate alternative for acetonitrile in ion-pair reversed phase chromatography of biomolecules.

Hematopoietic stem cell transplantation from matched unrelated donors in chronic granulomatous disease

We report on 12 patients with chronic granulomatous disease transplanted with hematopoietic stem cells from matched unrelated (n = 9) or matched sibling donors (n = 3). The most common infectious complication was pulmonary aspergillosis, which nine patients had previously developed. Only 5 of 12 individuals had normal lung function prior to transplantation. At a mean follow-up of 53 months 9 of the 12 patients are alive including 7 of 9 following matched unrelated donor (MUD) transplantation. One patient died from ARDS, another from systemic BK virus infection, the third from complications of chronic graft-versus-host disease. Seven of nine surviving patients have normal lung function now. HSCT from a MUD is an option worth considering when no matched family donor is available. Restricted lung function prior to HSCT does not appear to be a limiting factor for such treatment.

Survival, neuron-like differentiation and functionality of mesenchymal stem cells in neurotoxic environment: the critical role of erythropoietin

Mesenchymal stem cells (MSCs) can ameliorate symptoms in several neurodegenerative diseases. However, the toxic environment of a degenerating central nervous system (CNS) characterized by hypoxia, glutamate (Glu) excess and amyloid beta (Abeta) pathology may hamper the survival and regenerative/replacing capacities of engrafted stem cells. Indeed, human MSC (hMSC) exposed to hypoxia were disabled in (i) the capacity of their muscarinic receptors (mAChRs) to respond to acetylcholine (ACh) with a transient increase in intracellular [Ca(2+)], (ii) their capacity to metabolize Glu, reflected by a strong decrease in glutamine synthetase activity, and (iii) their survival on exposure to Glu. Cocultivation of MSC with PC12 cells expressing the amyloid precursor protein gene (APPsw-PC12) increased the release of IL-6 from MSC. HMSC exposed to erythropoietin (EPO) showed a cholinergic neuron-like phenotype reflected by increased cellular levels of choline acetyltransferase, ACh and mAChR. All their functional deficits observed under hypoxia, Glu exposure and APPsw-PC12 cocultivation were reversed by the application of EPO, which increased the expression of Wnt3a. EPO also enhanced the metabolism of Abeta in MSC by increasing their neprilysin content. Our data show that cholinergic neuron-like differentiation of MSC, their functionality and resistance to a neurotoxic environment is regulated and can be improved by EPO, highlighting its potential for optimizing cellular therapies of the CNS.

[Slim despite a genetic predisposition for obesity--influence of environmental factors as chance? A case report]

CASE HISTORY AND CLINICAL FINDINGS

A 4-year-old, slightly overweight (BMI 18 kg/m2, BMI SDS 1.29 approximately 90.1 (th) percentile) and otherwise healthy girl presented with accelerated linear growth (99.6 (th) percentile) and hyperphagia due to loss of satiety feeling. These findings are consistent with melanocortin-4 receptor ( MC4R) mutations. GENETIC ANALYSIS AND DIAGNOSIS: We found the partially inactivating mutation Arg (165)Trp by direct sequencing of the MC4R coding region. Interestingly, the patient's mother is also heterozygous for this mutation, but lean (BMI 19 kg/m2).

TREATMENT AND COURSE

Carriers of MC4R mutations develop hyperphagia due to lack of satiety feeling as a result of central dysregulation. The reduction of energy intake and the encouragement of physical activity can be successful to control the body weight.

CONCLUSION

Early diagnosis can promote lifestyle intervention to prevent the development of obesity even in the presence of a genetic predisposition.

[Anti-inflammatory action of a hyaluronic acid-chondroitin sulfate preparation in an in vitro bladder model]

PURPOSE

Interstitial cystitis and BPS (bladder pain syndrome) are chronic inflammatory diseases of the bladder. They are as yet imperfectly understood diseases, possibly originating from damage to the glycosaminoglycan layer of the bladder epithelium . Hyaluronic acid-containing preparations are currently utilised for palliation of the symptoms and protection of the bladder epithelium . The aim of the work described here was the evaluation of one of these preparations containing chondroitin sulfate together with hyaluronic acid.

MATERIAL AND METHODS

The preparation was evaluated for its anti-inflammatory potential as well as regarding the tolerance by the bladder epithelium. The urothelial cell line T24 was employed as an in vitro model of the human bladder because of its ability to react to adequate stimuli with the release of interleukin 6. To this end the cells were treated with hyaluronic acid and chondroitin sulfate. Subsequently, TNF-alpha was applied to induce inflammation. The severity of inflammation was measured on the basis of the IL-6 released by the cells in comparison to untreated control cultures.

RESULTS

A reduction of TNF-alpha-induced IL-6 release after treatment with hyaluronic acid and chondroitin sulfate was observed, indicating the anti-inflammatory action of the preparation. As shown by the large number of living cells after treatment the test preparation did not affect cell viability even in high concentrations. These data suggest a good tolerance of the product by the patients.

CONCLUSION

The administration of the preparation in patients suffering from interstitial cystitis or BPS appears promising. In additional, the presented work demonstrates the feasibility of the cell culture model for the screening of new therapeutic approaches.

Catabolic properties of microdissected human endosteal bone lining cells

Bone lining cells cover > 80% of endosteal surfaces of human cancellous bone. Current research assigns to them a dual role: (1) as a biological membrane regulating exchange of substrates between the bone fluid compartment and the extracellular fluid of bone marrow and (2) as a signaling link between the osteocytic network as mechanical receptor and the osteoclastic cell pool for local induction of bone resorption. Furthermore, a catabolic role has been considered. We therefore examined the presence of matrix-metalloproteinases (MMPs) and their physiological tissue inhibitors (TIMPs) as putative proteolytic elements. Firstly, human cancellous bone from 60 patients was examined by immunofluorescence with antibodies against MMPs and TIMPs. Secondly, we applied laser-assisted microdissection (LMD) to isolate bone lining cells from frozen sections of human trabecular bone. mRNA analysis was performed using a single-cell PCR protocol. Three laser microdissection systems were tested: the new generation of Leica LMD and P.A.L.M. laser pressure catapulting (LPC) were compared to P.A.L.M. laser microdissection and micromanipulation (LMM). In a few pooled cell profiles, mRNA of MMP13, MMP14, TIMP1, and CBFA-1 was clearly detected. By immunofluorescence MMP13 and -14 as well as TIMP1 and -2 were strongly present in lining cells, while MMP2, TIMP3, and TIMP4 showed weak or negative signals. Although the functional impact of these enzymatic components remains open, there is additional evidence for a catabolic function of lining cells. The new diode-laser microdissection with LMD and LPC proved to be especially suitable to gain new insights into the properties of bone lining cells.

Josephson-current-induced conformational switching of a molecular quantum dot

We discuss the behavior of a two-level system coupled to a quantum dot contacted by superconducting source and drain electrodes, representing a simple model for the conformational degree of freedom of a molecular dot or a break junction. The Josephson current is shown to induce conformational changes, including a complete reversal. For small bias voltage, periodic conformational motions induced by Landau-Zener transitions between Andreev states are predicted.

[Postoperative manifestation of acute compartment syndrome by previously unknown heterozygote sickle cell anemia. A clinical case report]

Patients suffering from sickle cell disease show an increased ischemic intolerance due to continuous pro-inflammatory activation and dysfunction of the endothelium by recurrent vaso-occlusive episodes. The presented case shows the manifestation of a postoperative compartment syndrome of the lower leg following the intraoperative use of blood arrest in a patient with previously unknown sickle cell disease. Preexisting vulnerability for tissue hypoxia in patients at risk should be a major concern for intraoperative use of blood arrest during surgery of the extremities.

Mass spectrometry for monitoring protease reactions

More than 560 genes are annotated as proteases in the human genome. About half of the genes are not or are only marginally characterized. Over the past decade, mass spectrometry has become the basis for proteomics, especially for protein identification, performed in a high-throughput manner. This development was also very fruitful for exploring the complex systems associated with protease functions, as briefly reviewed here. Mass spectrometry is an ideal tool for monitoring protease reactions, as will be highlighted in this review.

[Percutaneous lumbar interbody fusion using autogenous osteoblasts in vivo]

AIM

In the present study we have investigated the potential of autogenous osteoblasts for osteoinduction in a spinal arthrodesis model.

METHOD

After posterolateral instrumentation of 3 segments of a sheep spine the intervertebral space was filled with cancellous bone, osteoblasts or left empty after nucleotomy and elimination of cartilage.

RESULTS

Radiological and histological analyses proved a significant osseous reaction in segments treated with cancellous bone or osteoblasts in contrast to the control segment. This outcome provides evidence of spondylodeses by spinal instrumentation in combination with osteoblasts in a sheep model.

CONCLUSION

The results suggest a possible application of autologous osteoblasts as an osteoinductor after percutaneous nucleotomy in spinal fusion. The possible application in a human model should be examined.

In vitro differentiation of skin sensitizers by cell signaling pathways

Animal testing causes ethical problems and in view of EU regulations (e.g. EU-Guideline (76/768/EEC, February 2003)) or REACH the development of reliable in vitro assays has become even more important. Up to now, we use the modified local lymph node assay (IMDS) for toxicological hazard identification of sensitizing and irritant properties of chemicals in accordance with OECD Guideline 429. In this study, we investigated whether analyses of cell signaling pathways can provide a methodology for the detection of sensitizing compounds in vitro. Murine and human skin explants as well as reconstituted skin models (epidermal model EST-1000 and full-thickness model AST-2000) were exposed to sensitizing (oxazolone and DNFB) or irritant compounds (SDS and TritonX-100). Phosphorylation of MAP-kinases (p38, ERK1/2 and JNK1/2), STAT1 and PLCgamma were determined by cytometric bead array (CBA). In skin explants, all three MAP-kinases were exclusively activated after exposure to sensitizing compounds. For the reconstituted skin models phosphorylations of p38 and JNK1/2 were obtained after stimulation with allergens, whereas treatments with irritant compounds led to ERK1/2 activation. Activation of PLCgamma and STAT1 were never detected. In conclusion, MAP-kinase activation provides a promising in vitro tool for the discrimination between sensitizers and irritants.

Severe combined immunodeficiency signalized by eosinophilia and lymphopenia in rotavirus infected infants

BACKGROUND

Severe combined immunodeficiency (SCID) is a heterogeneous disease consisting of several different subtypes. Most subtypes present during infancy and without treatment, infections usually lead to early death. Diagnosis of SCID can be difficult as new subtypes are expected to be discovered soon. Late diagnosis is associated with a poorer outcome. Infections like rotavirus enteritis cannot be cleared in children with SCID due to impaired immunity. The aim of our study was to identify clues in children with rotavirus enteritis that aid to diagnose SCID early.

PATIENTS AND METHODS

Total white blood counts in a cohort of SCID patients with persistent rotavirus infection at diagnosis (n=18) were compared to total white blood counts in matched control patients without SCID but with rotavirus infection.

RESULTS

Relative and absolute lymphopenia and eosinophilia were more common in SCID patients (p<0.005).

CONCLUSION

In infants with rotavirus infection, a full blood count should be performed: Eosinophilia and/or lymphopenia raise a high suspicion of SCID.

Glomerular hypertrophy precedes albuminuria and segmental loss of podoplanin in podocytes in Munich-Wistar-Frömter rats

Focal segmental glomerulosclerosis (FSGS) is a common cause of end-stage renal disease. Albuminuria is a risk factor for FSGS and is influenced by environmental, genetic, and sex-specific factors. Podocytes play a central role in the development of albuminuria, but the precise relationship between early glomerular and podocyte-associated damage and albuminuria is unclear. Furthermore, experimental findings demonstrate a sex difference in development of albuminuria and FSGS. We investigated the early glomerular changes in male Munich-Wistar-Frömter (MWF) rats, which spontaneously develop albuminuria, and male albuminuria-resistant spontaneously hypertensive rats (SHR). In addition, since female MWF rats are protected from overt proteinuria and progressive renal disease, we compared the phenotypic changes in podocytes during early development of albuminuria in male and female MWF rats. In male MWF rats, glomerular hypertrophy preceded the onset of albuminuria and was greater than in male SHR. Albuminuria developed starting at 6 wk of age and coincided with focal and segmental loss of podoplanin, increased expression of desmin, entrapment of albumin in affected podocytes, and focal and segmental foot process effacement at the ultrastructural level. Other podocyte-associated molecules, such as nephrin and zonula occludens 1, were unaffected. Early glomerular hypertrophy and podocyte damage did not differ between male and female MWF rats. Our data show for the first time that albuminuria in male and female MWF rats is preceded by glomerular hypertrophy and accompanied by focal and segmental loss of podoplanin when FSGS was not yet present.

[An improved model of a catheterised human bladder for screening bactericidal agents]

PURPOSE

Catheter encrustation and associated blockage by a crystalline Proteus mirabilis biofilm constitute a continuous problem in long-term catheterised patients. The objective of the present work was to verify a new, physiological bladder model possessing the ability to show that triclosan-blocking solutions exert bactericidal and bacteriostatic activities.

MATERIAL AND METHODS

Catheterised sterile infusion bags served as human bladder models. Artificial urine inoculated with Proteus mirabilis was administered by a further aperture. Samples for measurement of pH value and microbial count were collected at intervals of 24 h. Upon completion of testing catheter encrustation was assessed and visualised by scanning electron microscopy.

RESULTS

In contrast to the application of placebo solution, in models filled with triclosan-blocking solution the catheters drained freely for the experimental period. Similar results were obtained for pH values and microbial count. The pH of the artificial urine did not exceed a critical value of pH 7 and the numbers of organisms correspond approximately to the initially inoculated number of organisms.

CONCLUSION

In the model developed here, triclosan inhibits the growth of Proteus mirabilis over the test period by diffusing into the artificial urine through the catheter balloon. Thus, triclosan acts against the pH increase as well as the formation of a crystalline biofilm. Taken together, the adaptability of this new, physiological model of the human bladder could be shown.