A new transparent Bio-MEMS for uni-axial single cell stretching

A novel, completely transparent bio-MEMS (bio-Micro Electro Mechanical System) device has been devised and manufactured using finite element analysis (FEA) and micro-fabrication techniques. The device has been designed to be used for testing the mechanical properties of single living cells, it is versatile and suitable for coupling with other analysis techniques. Furthermore, being completely transparent, it can be used with either transmission or reflection microscopes. The transparent bio-MEMS is based on a silicon dioxide?Csilicon nitride structure and, since the main goal is to test living cells, it is meant to work in a liquid environment and allow for cell stretching. Sensors for cell deformation and for platform displacement are also present and the required sensitivity for single cell analyses is granted. The device will moreover allow the recording of the stress?Cstrain curve for single living cells.     

ILB®, a Low Molecular Weight Dextran Sulphate,Restores Glutamate Homeostasis,Amino Acid Metabolism and Neurocognitive Functions in a Rat Model of Severe Traumatic Brain Injury

In a previous study, we found that administration of ILB^®, a new low molecular weight dextran sulphate, significantly improved mitochondrial functions and energy metabolism, as well as decreased oxidative/nitrosative stress, of brain tissue of rats exposed to severe traumatic brain injury (sTBI), induced by the closed-head weight-drop model of diffused TBI. Using aliquots of deproteinized brain tissue of the same animals of this former study, we here determined the concentrations of 24 amino acids of control rats, untreated sTBI rats (sacrificed at 2 and 7 days post-injury) and sTBI rats receiving a subcutaneous ILB^® administration (at the dose levels of 1, 5 and 15 mg/kg b.w.) 30 min post-impact (sacrificed at 2 and 7 days post-injury). Additionally, in a different set of experiments, new groups of control rats, untreated sTBI rats and ILB^®-treated rats (administered 30 min after sTBI at the dose levels of 1 or 5 mg/kg b.w.) were studied for their neurocognitive functions (anxiety, locomotor capacities, short- and long-term memory) at 7 days after the induction of sTBI. Compared to untreated sTBI animals, ILB^® significantly decreased whole brain glutamate (normalizing the glutamate/glutamine ratio), glycine, serine and γ-aminobutyric acid. Furthermore, ILB^® administration restored arginine metabolism (preventing nitrosative stress), levels of amino acids involved in methylation reactions (methionine, L-cystathionine, S-adenosylhomocysteine), and N-acetylaspartate homeostasis. The macroscopic evidences of the beneficial effects on brain metabolism induced by ILB^® were the relevant improvement in neurocognitive functions of the group of animals treated with ILB^® 5 mg/kg b.w., compared to the marked cognitive decline measured in untreated sTBI animals. These results demonstrate that ILB^® administration 30 min after sTBI prevents glutamate excitotoxicity and normalizes levels of amino acids involved in crucial brain metabolic functions. The ameliorations of amino acid metabolism, mitochondrial functions and energy metabolism in ILB^®-treated rats exposed to sTBI produced significant improvement in neurocognitive functions, reinforcing the concept that ILB^® is a new effective therapeutic tool for the treatment of sTBI, worth being tested in the clinical setting.     

The Role of Cytoskeleton Revealed by Quartz Crystal Microbalance and Digital Holographic Microscopy

The connection between cytoskeleton alterations and diseases is well known and has stimulated research on cell mechanics, aiming to develop reliable biomarkers. In this study, we present results on rheological, adhesion, and morphological properties of primary rat cardiac fibroblasts, the cytoskeleton of which was altered by treatment with cytochalasin D (Cyt-D) and nocodazole (Noc), respectively. We used two complementary techniques: quartz crystal microbalance (QCM) and digital holographic microscopy (DHM). Qualitative data on cell viscoelasticity and adhesion changes at the cell–substrate near-interface layer were obtained with QCM, while DHM allowed the measurement of morphological changes due to the cytoskeletal alterations. A rapid effect of Cyt-D was observed, leading to a reduction in cell viscosity, loss of adhesion, and cell rounding, often followed by detachment from the surface. Noc treatment, instead, induced slower but continuous variations in the rheological behavior for four hours of treatment. The higher vibrational energy dissipation reflected the cell’s ability to maintain a stable attachment to the substrate, while a cytoskeletal rearrangement occurs. In fact, along with the complete disaggregation of microtubules at prolonged drug exposure, a compensatory effect of actin polymerization emerged, with increased stress fiber formation.     

Noise measurements in resonant tunnelling structures as a functionof current and temperature

The authors present the results of noise measurements performed on custom designed resonant tunnelling structures. The shot-noise suppression has been measured as a function of bias current and temperature in the 14-223 K range, and results have been compared with those predicted by existing theories     

A revertible, autonomous, self-assembled DNA-origami nanoactuator

A DNA-origami actuator capable of autonomous internal motion in accord to an external chemical signal was designed, built, operated and imaged. The functional DNA nanostructure consists of a disk connected to an external ring in two, diametrically opposite points. A single stranded DNA, named probe, was connected to two edges of the disk perpendicularly to the axis of constrain. In the presence of a hybridizing target molecule, the probe coiled into a double helix that stretched the inner disk forcing the edges to move toward each other. The addition of a third single stranded molecule that displaced the target from the probe restored the initial state of the origami. Operation, dimension and shape were carefully characterized by combining microscopy and fluorescence techniques.     

Secondary acute myeloid leukemia following treatment with VP16-containing regimens for non-Hodgkin's lymphoma

We report on two patients who developed a secondary acute myeloid leukemia (sAL) after treatment for non-Hodgkin's lymphoma (NHL) with regimens containing low to intermediate doses of VP16. Clinical and hematologic features in these two patients were consistent with epipodophyllotoxin-associated sAL. In one case, a rearrangement of chromosome band 11q23 was detected.     

A new transparent Bio-MEMS for uni-axial single cell stretching

A novel, completely transparent bio-MEMS (bio-Micro Electro Mechanical System) device has been devised and manufactured using finite element analysis (FEA) and micro-fabrication techniques. The device has been designed to be used for testing the mechanical properties of single living cells, it is versatile and suitable for coupling with other analysis techniques. Furthermore, being completely transparent, it can be used with either transmission or reflection microscopes. The transparent bio-MEMS is based on a silicon dioxide–silicon nitride structure and, since the main goal is to test living cells, it is meant to work in a liquid environment and allow for cell stretching. Sensors for cell deformation and for platform displacement are also present and the required sensitivity for single cell analyses is granted. The device will moreover allow the recording of the stress–strain curve for single living cells.

     

Metabolic Signature of Energy Metabolism Alterations and Excess Nitric Oxide Production in Culture Media Correlate with Low Human Embryo Quality and Unsuccessful Pregnancy

Notwithstanding the great improvement of ART, the overall rate of successful pregnancies from implanted human embryos is definitely low. The current routine embryo quality assessment is performed only through morphological criteria, which has poor predictive capacity since only a minor percentage of those in the highest class give rise to successful pregnancy. Previous studies highlighted the potentiality of the analysis of metabolites in human embryo culture media, useful for the selection of embryos for implantation. In the present study, we analyzed in blind 66 human embryo culture media at 5 days after in vitro fertilization with the aim of quantifying compounds released by cell metabolism that were not present as normal constituents of the human embryo growth media, including purines, pyrimidines, nitrite, and nitrate. Only some purines were detectable (hypoxanthine and uric acid) in the majority of samples, while nitrite and nitrate were always detectable. When matching biochemical results with morphological evaluation, it was found that low grade embryos (n = 12) had significantly higher levels of all the compounds of interest. Moreover, when matching biochemical results according to successful (n = 17) or unsuccessful (n = 25) pregnancy, it was found that human embryos from the latter group released higher concentrations of hypoxanthine, uric acid, nitrite, and nitrate in the culture media. Additionally, those embryos that developed into successful pregnancies were all associated with the birth of healthy newborns. These results, although carried out on a relatively low number of samples, indicate that the analysis of the aforementioned compounds in the culture media of human embryos is a potentially useful tool for the selection of embryos for implantation, possibly leading to an increase in the overall rate of ART.     

Treatment with recombinant human erythropoietin (rHuEpo) in a patient with paroxysmal nocturnal haemoglobinuria: evaluation of membrane proteins CD55 and CD59 with cytofluorometric assay

We describe a 28-year-old man with paroxysmal nocturnal haemoglobinuria (PNH) and a high transfusion requirement. Prior to and during therapy with recombinant human erythropoietin (rHuEpo), we evaluated the levels of 'decay-accelerating-factor', CD55, and 'membrane-inhibitor-of-reactive-lysis', CD59, as markers of the disease, whilst CD58, a marker present on leucocytes, was utilized to monitor normal haemopoietic activity. The patient became transfusion independent 1 month after beginning rHuEpo and remains well. The analysis of CD55, CD59 and CD58 suggests that the efficacy of rHuEpo was due to a selective rHuEpo action on normal erythroid clones.     

The risk of acute leukemia in patients treated for Hodgkin's disease is significantly higher aft [see bined modality programs than after chemotherapy alone and is correlated with the extent of radiotherapy and type and duration of chemotherapy: a case-control study

BACKGROUND AND OBJECTIVE: Patients treated for Hodgkin's disease have an increased risk of developing subsequent acute leukemia. This co-operative study was conducted to assess the relative risk associated with several candidate factors including age, splenectomy, combined modality therapy and cumulative drug dose including alkylating agents and nitrosurea derivatives. DESIGN AND METHODS: This study evaluated the risk of acute leukemia according to pretreatment variables and therapy modalities among 1659 patients treated for Hodgkin's disease and followed for a median time of 10 years. Both case-control and actuarial risk studies were performed. Median age was 34 years (range: 12-83); 53% of patients were splenectomized. As to the overall therapy, 348 patients (21%) were given radiotherapy (RT) alone, 375 (23%) chemotherapy (CT) alone (including MOPP, MOPP + ABVD or MOPP + ABVD + lomustine); 936 (56%) received both CT and RT, either as primary or salvage treatment. RESULTS: The overall 15-year actuarial risk of leukemia was 4.2%; the hazard function curve showed two peaks of risk at the 3th and the 8th year from the initiation of therapy and no leukemia beyond the 12th year of follow-up. Risk of leukemia was 0.3% after RT alone, 2.8% after CT alone (2.2% after MOPP; 4.4% after MOPP + ABVD + lomustine), and 5.4% in patients given combined modality therapy (10.2% for RT + MOPP; 15.6% for RT + MOPP + lomustine). No leukemia occurred after ABVD alone and the risk was low (0.6%) when neither mechlorethamine nor lomustine were utilized. Patients who had received extended radiotherapy including abdomen and pelvis in addition to MOPP showed a significantly higher risk of leukemia compared to those given limited RT + MOPP (P = 0.01). Case-control analysis indicated advanced stage, type and duration (> 8 months) of CT and extension of RT as significant risk factors for leukemia. Compared to RT alone, the odds ratio was 5.9 after MOPP + extended RT, and 8 when a lomustine-containing regimen was used, as well. Neither age nor splenectomy were independent risk factors for leukemia; splenectomy was influential only when patients had been given MOPP chemotherapy, as well. INTERPRETATIONS AND CONCLUSIONS: Both case-control and actuarial analyses indicated that: a) combined modality therapy with MOPP and extensive RT (including abdomen and pelvis), and the use of lomustine added to the leukemogenic risk of MOPP alone; b) programs without mechlorethamine, procarbazine and lomustine were almost devoid of leukemogenic risk.