Label-free monitoring of whole cell vitality

The Intelligent Mobile Lab (IMOLA) delivers metabolic and morphological parameters of living cells in a label-free and real time way. It represents a key technology for the development of new cell-based assays. Electrochemical microsensors are used to measure the extracellular acidification (pH), cellular respiration (pO2), changes in cell number and morphology (electric impedance) in a controlled environment. These parameters are closely linked to the intracellular signaling network of the living cells. They are thus likely to respond sensitively to changes in cellular vitality. A wide spectrum of cell types can be tested with the system, including adherent and suspended cells, continuous cell lines, primary cells or tissue samples. The platform is described in detail and applications in the field's oncology, toxicology and environmental monitoring are shown.

[Efficacy of epidural steroid injections for chronic lumbar pain syndromes without neurological deficits. A randomized, double blind study as part of a multimodal treatment concept]

BACKGROUND

Chronic lumbar pain syndromes without neurological deficits are generated by a multitude of causes. Functional, morphological and psychosocial factors are discussed. In many cases a diseased intervertebral disc is found on radiological examination but the clinical relevance of these findings is not clear. For this study it was postulated that a diseased disc results in a local inflammatory reaction therefore causing pain and impairing treatability of patients. An epidural injection of steroids can reduce inflammation and therefore improve treatability and ultimately treatment outcome.

METHODS

A double blind randomized prospective trial was carried out. Patients treated in hospital for a chronic lumbar pain syndrome without neurological deficits within a multimodal treatment program were screened for indications for an epidural steroid injection (e.g. diseased lumbar disc and intention to treat). Patients eligible for the study were randomized into two groups. The treatment group received an epidural injection of 80 mg triamcinolone and 8 ml bupivacaine 0.25 %. The control group received only an epidural injection of 8 ml bupivacaine 0.25 %.

RESULTS

In both groups pain intensity and treatability showed a statistically significant improvement after the epidural injection. The differences between the control and treatment groups were small and not clinically relevant. A small subgroup might profit from the steroid injection. In addition the treatability was dependent on psychometric values and the long-term outcome from a reduction of muscular skeletal dysfunctions.

DISCUSSION

After the epidural injection the decrease in pain and increase in treatability was statistically significant. The mechanism of the improvement is not clear and should be examined further. The epidural injection of a steroid in this subgroup of patients did not lead to a clinical improvement in the outcome.

Nutrient depletion and metabolic profiles in breast carcinoma cell lines measured with a label-free platform

The response of two well-characterized human breast cancer cell lines (MCF-7 and MDA-MB-231) to a series of nutrient deficiencies is investigated with a label-free cell assay platform. The motivation of the research is to analyze adaptive responses of tumor cell metabolism and to find limiting conditions for cell survival. The platform measures extracellular values of pH and dissolved oxygen saturation to provide data of extracellular acidification rates and oxygen uptake rates. Additional electric cell substrate impedance sensing and bright-field cell imaging supports the data interpretation by providing information about cell morphological parameters. A sequential administration of nutrient depletions does not cause metabolic reprogramming, since the ratios of oxygen uptake to acidification return to their basal values. While the extracellular acidification drops sharply upon reduction of glucose and glutamine, the oxygen uptake is not affected. In contrast to other published data, cell death is not observed when both glucose and glutamine are depleted and cell proliferation is not inhibited, at least in MCF-7 cultures. It is assumed that residual concentrations of nutrients from the serum component are able to maintain cell viability when delivered regularly by active flow like in the cell assay platform, and, in a similar way, under physiological conditions.

LINE-1 induces hTERT and ensures telomere maintenance in tumour cell lines

A hallmark of cancer cells is an activated telomere maintenance mechanism, which allows prolonged survival of the malignant cells. In more than 80% of tumours, telomeres are elongated by the enzyme telomerase, which adds de novo telomere repeats to the ends of chromosomes. Cancer cells are also characterized by expression of active LINE-1 elements (L1s, long interspersed nuclear elements-1). L1 elements are abundant retrotransposons in the eukaryotic genome that are primarily known for facilitating aberrant recombination. Using L1-knockdown (KD), we show for the first time that L1 is critical for telomere maintenance in telomerase-positive tumour cells. The reduced length of telomeres in the L1-KD-treated cells correlated with an increased rate of telomere dysfunction foci, a reduced expression of shelterin proteins and an increased rate of anaphase bridges. The decreased telomere length was associated with a decreased telomerase activity and decreased telomerase mRNA level; the latter was increased upon L1 overexpression. L1-KD also led to a decrease in mRNA and protein expression of cMyc and KLF-4, two main transcription factors of telomerase and altered mRNA levels of other stem-cell-associated proteins such as CD44 and hMyb, as well as a corresponding reduced growth of spheroids. The KD of KLF-4 or cMyc decreased the level of L1-ORF1 mRNA, suggesting a specific reciprocal regulation with L1. Thus, our findings contribute to the understanding of L1 as a pathogenicity factor in cancer cells. As L1 is only expressed in pathophysiological conditions, L1 now appears to be target in the rational treatment of telomerase-positive cancer.

Assessing the TP53 marker type in patients treated with or without neoadjuvant chemotherapy for resectable colorectal liver metastases: a p53 Research Group study

The type of a biomarker - whether it is prognostic or predictive - is frequently not known, although such information is crucial for assessing the clinical value of a marker. In order to evaluate the type of marker TP53 is, we identified a cohort of 76 patients with colorectal liver metastases (CLM), homogeneously staged as resectable, who had been treated either with or without fluorouracil-based neoadjuvant chemotherapy. The TP53 genotype was assessed retrospectively from paraffin-embedded, diagnostic tumour biopsies using a standardised, p53 gene-specific sequencing protocol (mark53(®) kit). The overall median survival was 44.2 months, and the overall TP53 mutation frequency was 55%. A significant interaction was observed between chemotherapy and TP53 status (P = 0.045). To illustrate this effect, the 51 patients with and the 25 patients without neoadjuvant chemotherapy were described separately. In patients with neoadjuvant chemotherapy, mutated TP53 was significantly associated with poor survival (P = 0.0025), resulting in five-year survival rates of 22%, compared to 60% in patients with normal TP53. The hazard ratio was 3.12 (95% confidence intervals (CI): 1.46-6.95) to the disadvantage of TP53-mutated patients and 5.49 (P = 0.0001; 95% CI: 2.28-13.24) after adjustment for known prognostic factors. In patients treated with surgery alone, a mutated TP53 did not have a negative effect on survival (P = 0.54). A mutated TP53 status independently predicted survival disadvantage in CLM patients in the presence, but not in the absence, of neoadjuvant chemotherapy. Our data suggest that TP53 might be a pure predictive marker.

Association of TNFRSF10D DNA-methylation with the survival of melanoma patients

In this retrospective pilot study, the DNA-methylation status of genes that have been demonstrated to be involved in melanoma carcinogenesis was analyzed in order to identify novel biomarkers for the risk assessment of melanoma patients. We analyzed DNA extracted from punch-biopsies from 68 formalin-fixed paraffin-embedded (FFPE) melanoma specimens. Using MethyLight PCR, we examined 20 genes in specimens from a training set comprising 36 melanoma patients. Selected candidate genes were validated in a test set using FFPE tissue samples from 32 melanoma patients. First, we identified the TNFRSF10D DNA-methylation status (TNFRSF10D methylated vs. unmethylated) as a prognostic marker for overall (p = 0.001) and for relapse-free survival (p = 0.008) in the training set. This finding was confirmed in the independent test set (n = 32; overall survival p = 0.041; relapse-free survival p = 0.012). In a multivariate Cox-regression analysis including all patients, the TNFRSF10D DNA-methylation status remained as the most significant prognostic parameter for overall and relapse-free survival (relative-risk (RR) of death, 4.6 (95% CI: 2.0–11.0; p < 0.001), RR of relapse, 7.2 (95% CI: 2.8–18.3; p < 0.001)). In this study, we demonstrate that TNFRSF10D DNA-methylation analysis of a small tissue-punch from archival FFPE melanoma tissue is a promising approach to provide prognostic information in patients with melanoma.

Novel mutations causing biotinidase deficiency in individuals identified by newborn screening in Michigan including an unique intronic mutation that alters mRNA expression of the biotinidase gene

Biotinidase deficiency (BD) is an autosomal recessive disorder resulting in the inability to recycle the vitamin biotin. Individuals with biotinidase deficiency can develop neurological and cutaneous symptoms if they are not treated with biotin. To date, more than 165 mutations in the biotinidase gene (BTD) have been reported. Essentially all the mutations result in enzymatic activities with less than 10% of mean normal serum enzyme activity (profound biotinidase deficiency) with the exception of the c.1330G>C (p.D444H) mutation, which results in an enzyme having 50% of mean normal serum activity and causes partial biotinidase deficiency (10-30% of mean normal serum biotinidase activity) if there is a mutation for profound biotinidase deficiency on the second allele. We now reported eight novel mutations in ten children identified by newborn screening in Michigan from 1988 to the end of 2012. Interestingly, one intronic mutation, c.310-15delT, results in an approximately two-fold down-regulation of BTD mRNA expression by Quantitative real-time reverse-transcription PCR (qRT-PCR). This is the first report of an intronic mutation in the BTD gene with demonstration of its effect on enzymatic activity by altering mRNA expression. This study identified three other mutations likely to cause partial biotinidase deficiency. These results emphasize the importance of full gene sequencing of BTD on patients with biotinidase deficiency to better understand the genotype and phenotype correlation in the future.

Cytokine release assays: current practices and future directions

As a result of the CD28 superagonist biotherapeutic monoclonal antibody (TGN 1412) "cytokine storm" incident, cytokine release assays (CRA) have become hazard identification and prospective risk assessment tools for screening novel biotherapeutics directed against targets having a potential risk for eliciting adverse pro-inflammatory clinical infusion reactions. Different laboratories may have different strategies, assay formats, and approaches to the reporting, interpretation, and use of data for either decision making or risk assessment. Additionally, many independent contract research organizations (CROs), academic and government laboratories are involved in some aspect of CRA work. As a result, while some pharmaceutical companies are providing CRA data as part of the regulatory submissions when necessary, technical and regulatory practices are still evolving to provide data predictive of cytokine release in humans and that are relevant to safety. This manuscript provides an overview of different approaches employed by the pharmaceutical industry and CROs, for the use and application of CRA based upon a survey and post survey follow up conducted by ILSI-Health and Environmental Sciences Institute (HESI) Immunotoxicology Committee CRA Working Group. Also discussed is ongoing research in the academic sector, the regulatory environment, current limitations of the assays, and future directions and recommendations for cytokine release assays.

Biotinidase knockout mice show cellular energy deficit and altered carbon metabolism gene expression similar to that of nutritional biotin deprivation: clues for the pathogenesis in the human inherited disorder

Biotin is the prosthetic group of carboxylases that have important roles in the metabolism of glucose, fatty acids and amino acids. Biotinidase has a key role in the reutilization of the biotin, catalyzing the hydrolysis of biocytin (ε-N-biotinyl-l-lysine) and biocytin-containing peptides derived from carboxylase turnover, thus contributing substantially to the bioavailability of this vitamin. Deficient activity of biotinidase causes late-onset multiple carboxylase in humans, whose pathogenic mechanisms are poorly understood. Here we show that a knock-out biotinidase-deficient mouse from a C57BL/6 background that was fed a low biotin diet develops severe ATP deficit with activation of the energy sensor adenosine monophosphate (AMP)-activated protein kinase (AMPK), inhibition of the signaling protein mTOR, driver of protein synthesis and growth, and affecting the expression of central-carbon metabolism genes. In addition, sensitivity to insulin is augmented. These changes are similar to those observed in nutritionally biotin-starved rats. These findings further our understanding of the pathogenesis of human biotinidase deficiency.

Automated platform for sensor-based monitoring and controlled assays of living cells and tissues

Cellular assays have become a fundamental technique in scientific research, pharmaceutical drug screening or toxicity testing. Therefore, the requirements of technical developments for automated assays raised in the same rate. A novel measuring platform was developed, which combines automated assay processing with label-free high-content measuring and real-time monitoring of multiple metabolic and morphologic parameters of living cells or tissues. Core of the system is a test plate with 24 cell culture wells, each equipped with opto-chemical sensor-spots for the determination of cellular oxygen consumption and extracellular acidification, next to electrode-structures for electrical impedance sensing. An automated microscope provides the optical sensor read-out and allows continuous cell imaging. Media and drugs are supplied by a pipetting robot system. Therefore, assay can run over several days without personnel interaction. To demonstrate the performance of the platform in physiologic assays, we continuously recorded the kinetics of metabolic and morphologic parameters of MCF-7 breast cancer cells under the influence of the cytotoxin chloroacetaldehyde. The data point out the time resolved effect kinetics over the complete treatment period. Thereby, the measuring platform overcomes problems of endpoint tests, which cannot monitor the kinetics of different parameters of the same cell population over longer time periods.

KRAS status and outcome of liver resection after neoadjuvant chemotherapy including bevacizumab

Background

The prognostic value of KRAS mutation in patients with colorectal cancer liver metastases (CLM) receiving neoadjuvant chemotherapy including bevacizumab before liver resection is unclear.

Methods

The KRAS and BRAF status of resected CLM was assessed in prospectively studied patients. Mutations were correlated with recurrence-free and overall survival. Only patients with remaining vital tumour cells in the resected specimen and those without disease progression were analysed; those with progressive disease did not undergo resection.

Results

A total of 60 patients were enrolled. Fifteen (25 per cent) had a KRAS mutation, but none of the 60 patients had a BRAF mutation. The radiological response to neoadjuvant chemotherapy including bevacizumab, assessed according to the Response Evaluation Criteria In Solid Tumours, was partial in 52 patients (87 per cent) and the remaining eight had stable disease. The partial response rate was similar in patients with a KRAS mutation and those with the wild-type gene (12 of 15 versus 40 of 45 patients; P = 0·400). KRAS mutation had a negative prognostic effect on recurrence-free survival (hazard ratio (HR) 2·48, 95 per cent confidence interval 1·26 to 4·89; P = 0·009) and overall survival (HR 3·51, 1·30 to 9·45; P = 0·013).

Conclusion

This study provided further evidence for the prognostic importance of KRAS status in terms of recurrence-free and overall survival. Neoadjuvant chemotherapy including bevacizumab elicited a response, irrespective of KRAS status, in this selected group of patients with CLM.

Revision ACL reconstruction outcomes: MOON cohort

Many clinicians believe that the results of revision anterior cruciate ligament (ACL) reconstruction compare unfavorably with primary ACL reconstruction. However, few prospective studies have evaluated revision ACL reconstruction using validated patient-based metrics. This study was performed to evaluate and compare the results of revision ACL reconstruction and primary ACL reconstruction. The Multicenter Orthopaedic Outcomes Network consortium is an NIH-funded, hypothesis-driven, multicenter prospective cohort study of patients undergoing ACL reconstruction. All patients preoperatively complete a series of validated patient-oriented questionnaires. At scheduled 2-year follow-up all patients are given the same series of questionnaires to complete. The study evaluated the results of 2-year follow-up of revision ACL reconstruction performed in 2001. Parameters evaluated included Marx activity level, Knee Injury and Osteoarthritis Outcome Score (KOOS), and International Knee Documentation Committee (IKDC) scores. For this study 446 subjects met inclusion criteria; 2-year follow-up was obtained on 393 (88%). The study group consisted of 55% males with median age of 22 years. There were 33 revision ACL reconstruction cases, for which follow-up was available for 29 (88%). Median baseline Marx (interquartile range) was 12 (8 to 16) and 12 (6 to 16) for the primary ACL reconstruction and revision ACL reconstruction groups, respectively (p= 0.81). At 2 years, median Marx was 9 (4 to 13) and 5 (0 to 10) for the primary ACL reconstruction and revision ACL reconstruction groups, respectively (p= 0.03). Median 2-year IKDC was 75.9 (revision) versus 83.9 (primary) (p=0.003). Median KOOS subscale Knee Related Quality of Life (KRQOL) at 2 years was 62.5 (revision) versus 75 (primary) (p < 0.001), subscale Sports and Recreation was 75 (revision) and 85 (primary) (p = 0.005), subscale Pain was 83.3 (revision) and 91.7 (primary) (p= 0.002). Marx activity score declined at 2-year follow-up in revision ACL reconstruction compared with primary ACL reconstruction. IKDC and KRQOL were significantly decreased in revision ACL reconstruction compared with primary ACL reconstruction at 2-year followup. Revision ACL reconstruction resulted in a significantly worse outcome as measured by these patient-based measures at 2 years.

Popliteal cystic adventitial disease: a case report and literature review

Cystic adventitial disease (CAD) is rare. The popliteal artery is the most commonly affected artery. Patients with CAD are usually young and present with ischaemic lower limb symptoms. We report a case of a 39-year-old male patient with popliteal CAD. The affected segment was resected and repaired with an interposition vein graft. In conclusion, we highlight the importance of correct diagnosis and outline the different management strategies.

Concept for a gas-cell-driven drug delivery system for therapeutic applications

This paper presents a concept for an implantable micro-pump based on hydrogen- generating gas cells. The gas-generating cell is separated from the drug reservoir by an expandable latex membrane. The system offers linear drug delivery with flowrates ranging from 8 nl/s to 2 μl/s and a total delivery volume of up to 160 ml. Drugs can be dispensed over a wide backpressure range. The device is scalable based on the size of the gas-producing cell and requires no external energy source. Possible fields of application include in vivo local drug delivery for chemotherapy, diabetes, and pain management.

1-year left ventricular assist device (LVAD) experience as bridge to heart transplantation in an infant with Bland-White-Garland syndrome

Left ventricular assist device (LVAD) implantation has become an established therapy in adults as well as in children as a bridge to heart transplantation or to aid myocardial recovery. We describe the first case worldwide of an infant suffering from Bland-White-Garland syndrome successfully treated with a left ventricular assist device (Berlin Heart(R); Excor(R) Pediatric) as a bridge to heart transplantation for a period of more than one year.

Nature of the spin dynamics and 1/3 magnetization plateau in azurite

We present a specific heat and inelastic neutron scattering study in magnetic fields up into the 1/3 magnetization plateau phase of the diamond chain compound azurite Cu3(CO3)2(OH)2. We establish that the magnetization plateau is a dimer-monomer state, i.e., consisting of a chain of S=1/2 monomers, which are separated by S=0 dimers on the diamond chain backbone. The effective spin couplings Jmono/kB=10.1(2) K and Jdimer/kB=1.8(1) K are derived from the monomer and dimer dispersions. They are associated to microscopic couplings J1/kB=1(2) K, J2/kB=55(5) K and a ferromagnetic J3/kB=-20(5) K, possibly as result of dz2} orbitals in the Cu-O bonds providing superexchange (SE) pathways with JSE=6.5 K.

Effects of two energy scales in weakly dimerized antiferromagnetic quantum spin chains

By means of thermal expansion and specific heat measurements on the high-pressure phase of (VO)(2)P(2)O(7), the effects of two energy scales of the weakly dimerized antiferromagnetic S=1/2 Heisenberg chain are explored. The low-energy scale, given by the spin gap Delta, is found to manifest itself in a pronounced thermal expansion anomaly. A quantitative analysis, employing the density-matrix renormalization-group approach for transfer matrices calculations, shows that this feature originates from changes in the magnetic entropy with respect to Delta, partial differentialS(m)/partial differentialDelta. This term, inaccessible by specific heat, is visible only in the weak-dimerization limit, where it reflects peculiarities of the excitation spectrum and its sensitivity to variations in Delta.

Anomalous lattice response at the Mott transition in a quasi-2D organic conductor

Discontinuous changes of the lattice parameters at the Mott metal-insulator transition are detected by high-resolution dilatometry on deuterated crystals of the layered organic conductor kappa-(BEDT-TTF)(2)Cu[N(CN)(2)]Br. The uniaxial expansivities uncover a striking and unexpected anisotropy, notably a zero effect along the in-plane c axis along which the electronic interactions are relatively strong. A huge thermal expansion anomaly is observed near the end point of the first-order transition line enabling us to explore the critical behavior with very high sensitivity. The analysis yields critical fluctuations with an exponent alpha approximately 0.8+/-0.15 at odds with the novel criticality recently proposed for these materials [Kagawa et al., Nature (London) 436, 534 (2005)]. Our data suggest an intricate role of the lattice degrees of freedom in the Mott transition for the present materials.

Cross-sectional study discloses a positive family history for Parkinson’s disease and male gender as epidemiological risk factors for substantia nigra hyperechogenicity

Hyperechogenicity of the substantia nigra (SN) has been proposed to be a typical finding in Parkinson's disease (PD) and a marker of vulnerability to nigrostriatal dysfunction in healthy subjects. This large cross-sectional study including 1120 subjects older than 50 years without any signs of PD was performed to evaluate the association of SN hyperechogenicity and other proposed epidemiological risk factors for PD. Among all variables assessed only family history of PD and male gender proved to be significantly associated with SN hyperechogenicity, indicating a genetic predisposition for the ultrasound marker.

New concepts for chip-supported multi-well-plates: realization of a 24-well-plate with integrated impedance-sensors for functional cellular screening applications and automated microscope aided cell-based assays

Based on the experience with multiparametric bioelectronic sensor chips for the monitoring of living cells, we have combined the established multi-well-format with the advantages of microelectronic sensors. The result is a 24-well-plate where the bottom of the wells is replaced by glass-based chips with integrated IDES (interdigital electrode structure). By using IDES it is possible to detect adhesion and morphological changes of adherent growing cell cultures. Up to now these measurements were inaccessible in conjunction with multi-well-plates, especially in high throughput applications. If microscopic monitoring of the cell culture is required, the IDES can be fabricated using transparent conductor materials like ITO (indium tin oxide). Both the transparent material for the sensors and the sensor-carrier make the multi-well-plate also applicable for all kinds of fluorescence and luminescence biological tests. In addition to the impedance-sensors optical read-out sensor layers for pH and pO2 can be integrated. For this reason there are many possible fields of application in biological and biomedical areas such as drug screening, chemosensitive testing and environmental toxicology as well as in biosensing for biological and chemical warfare. Especially the possibility of using this multi-well-plate together with automated imaging-systems has the great advantage of combining optical and sensory monitoring accessible to high-throughput-applications.