Previous experimental studies have documented the neuroprotection of damaged or diseased cells after applying, from outside the brain, near-infrared light (NIr) to the brain by using external ...light-emitting diodes (LEDs) or laser devices. In the present study, the authors describe an effective and reliable surgical method of applying to the brain, from inside the brain, NIr to the brain. They developed a novel internal surgical device that delivers the NIr to brain regions very close to target damaged or diseased cells. They suggest that this device will be useful in applying NIr within the large human brain, particularly if the target cells have a very deep location.
An optical fiber linked to an LED or laser device was surgically implanted into the lateral ventricle of BALB/c mice or Sprague-Dawley rats. The authors explored the feasibility of the internal device, measured the NIr signal through living tissue, looked for evidence of toxicity at doses higher than those required for neuroprotection, and confirmed the neuroprotective effect of NIr on dopaminergic cells in the substantia nigra pars compacta (SNc) in an acute 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) model of Parkinson disease in mice.
The device was stable in freely moving animals, and the NIr filled the cranial cavity. Measurements showed that the NIr intensity declined as distance from the source increased across the brain (65% per mm) but was detectable up to 10 mm away. At neuroprotective (0.16 mW) and much higher (67 mW) intensities, the NIr caused no observable behavioral deficits, nor was there evidence of tissue necrosis at the fiber tip, where radiation was most intense. Finally, the intracranially delivered NIr protected SNc cells against MPTP insult; there were consistently more dopaminergic cells in MPTP-treated mice irradiated with NIr than in those that were not irradiated.
In summary, the authors showed that NIr can be applied intracranially, does not have toxic side effects, and is neuroprotective.
AIM To evaluate the rate of adverse events(AEs) during consecutive gastric and duodenal polypectomies in several Spanish centers. METHODS Polypectomies of protruded gastric or duodenal polyps ≥ 5 mm ...using hot snare were prospectively included. Prophylactic measures of hemorrhage were allowed in predefined cases. AEs were defined and graded according to the lexicon recommended by the American Society for Gastrointestinal Endoscopy. Patients were followed for 48 h, one week and 1 mo after theprocedure. RESULTS308 patients were included and a single polypectomy was performed in 205. Only 36(11.7%) were on prior anticoagulant therapy. Mean polyp size was 15 ± 8.9 mm(5-60) and in 294 cases(95.4%) were located in the stomach. Hemorrhage prophylaxis was performed in 219(71.1%) patients. Nine patients presented AEs(2.9%), and 6 of them were bleeding(n = 6, 1.9%)(in 5 out of 6 AE, different types of endoscopic treatment were performed). Other 24 hemorrhagic episodes could be managed without any change in the outcome of the endoscopy and, consequently, were considered incidents. We did not find any independent risk factor of bleeding.CONCLUSION Gastroduodenal polypectomy using prophylactic measures has a rate of AEs small enough to consider this procedure a safe and effective method for polyp resection independently of the polyp size and location.
A simple way for photochemical patterning of biological molecules onto the inner wall of fused-silica capillary is described. The method is based on a modification of the inner capillary surface with ...photoactive benzophenone (BP) derivative. The UV irradiation at 365 nm of the capillary filled with a sample solution results in cross-linking of the solutes to the BP moiety via a stable covalent bond. As a proof of concept, oligonucleotides and proteins were arrayed inside the capillary using an inverted microscope as an irradiation device. We demonstrated that the capillary arrays produced in this way are functional and could be used in different bioassays including DNA hybridization, protein interaction studies, and immunoassays. Having a sensitivity comparable to the fluorophore-based assays in a planar format, the capillary array possesses several advantages including submicroliter sample volume and a short assay time. The capillary format should therefore be considered as a possible alternative to a planar format in a number of low-density array applications such as mutation detection and diagnostic immunoassays.
Flap monitoring in reconstructive surgery is particularly important because flap failure is a dramatic event for the patient and for the medical team. Noninvasive deep tissue oxygenation monitoring ...is a challenge. The aim of this experimental study was to assess the performance of time-resolved near-infrared spectroscopy compared with continuous-wave near-infrared spectroscopy and with invasive oxygen partial pressure measurement in pigs.
Thirty fasciocutaneous flaps based on the superficial epigastric inferior pedicle were harvested and buried under the transcutaneous dorsal muscle (approximately 1 cm thick). An optical probe was placed on the skin above each buried flap. For each pig, two buried flaps were performed, one submitted to arterial occlusion and one to venous occlusion. Oxyhemoglobin and deoxyhemoglobin concentrations were observed for over 40 minutes before clamping, almost 20 minutes during clamping and during a period of release of approximately 20 minutes. Variations in time-resolved near-infrared spectroscopy were compared to the oxygen partial pressure and continuous-wave near-infrared spectroscopy variations.
All vascular events were detected by the time-resolved near-infrared spectroscopy. During arterial clamping, oxyhemoglobin decreased rapidly, whereas deoxyhemoglobin increased moderately. The divergence of oxyhemoglobin and deoxyhemoglobin curves indicated arterial occlusion. During venous clamping, deoxyhemoglobin increased, whereas oxyhemoglobin increased briefly then remained stable or decreased moderately. The initial increases in the oxyhemoglobin and deoxyhemoglobin curves indicated venous occlusion. Oxygen partial pressure failed to detect vascular events in three cases. Continuous-wave near-infrared spectroscopy could not clearly identify vascular occlusions.
Thus, the authors demonstrated the relevance of time-resolved near-infrared spectroscopy to buried flap monitoring. Time-resolved near-infrared spectroscopy could differentiate between arterial occlusion and venous occlusion.
Mouse vas deferens protein (MVDP) is an aldose reductase-like protein that is highly expressed in the vas deferens and adrenal glands and whose physiological functions were unknown. We hereby ...describe the enzymatic characteristics of MVDP and its role in murine adrenocortical Y1 cells. The murine aldose reductase (AR) and MVDP cDNAs were expressed in bacteria to obtain recombinant proteins and to compare their enzymatic activities. Recombinant MVDP was functional and displayed kinetic properties distinct from those of murine AR toward various substrates, a preference for NADH, and insensitivity to AR inhibitors. For MVDP, isocaproaldehyde, a product of side-chain cleavage of cholesterol generated during steroidogenesis, is the best natural substrate identified so far. In Y1 cells, we found that NADH-linked isocaproaldehyde reductase (ICR) activity was much higher than NADPH-linked ICR activity and was not abolished by AR inhibitors. We demonstrate that in Y1 cells, forskolin-induced MVDP expression enhanced NADH-linked ICR activity by 5–6-fold, whereas no variation in ICR-linked NADPH activity was observed in the same experiment. In cells stably transfected with MVDP antisense cDNA, NADH-linked ICR activity was abolished even in the presence of forskolin, and the isocaproaldehyde toxicity was increased compared with that of intact Y1 cells, as measured by isocaproaldehyde LD50. In Y1 cells transfected with MVDP antisense cDNA, forskolin-induced toxicity was abolished by aminoglutethimide. These results indicate that in adrenocortical cells, MVDP is responsible for detoxifying isocaproaldehyde generated by steroidogenesis.
Proven strategies for integrating mobile technologies into your business to gain a competitive advantage The rate at which companies are deploying wireless and mobile technology is astounding. But as ...the dot-com crash demonstrated, implementing solutions without clearly defined business requirements can lead to skyrocketing budgets and possible failure. As a business leader, it is critical that you understand the reasons for investing in this technology. Why should you develop a mobile technology strategy? What are the business requirements that drive potential mobility solutions? How will those solutions impact your internal and external constituencies? What are the strategic, qualitative, and quantitative value propositions that mobile technology can offer you? This innovative book provides you with the insight to answer these key questions and successfully integrate mobile technologies into your business. Inside you'll explore several wireless implementations and uncover business integration lessons learned from a host of Microsoft and Cap Gemini Ernst and Young customers in the United States and Europe. As an experienced team of practitioners, the authors guide you through the maze of mobile and wireless technologies, offering hands-on advice on how to develop a strategy that meets the needs of your business. Along with helping you prepare to launch your initiatives, they: Deliver specific guidelines for integrating mobile technologies into your business in order to produce specific revenue streams Arm you with a strong background on the terminology, drivers, devices, and networks that you must know Introduce you to a Value Web strategy analysis tool that will improve planning Include extensive real-world case studies and business organization models that demonstrate effective implementations.
We report a method for deriving the absolute value of absorption coefficients at depth in bilayered media. The method was simplified from that of time-resolved diffuse optical tomography (TR-DOT) ...into one dimension to validate and set up the main parameters with the help of simulations, and to test it in an easy preclinical model. The method was applied to buried flaps as used in reconstructive surgery, and absolute chromophore concentrations in the flap and in the upper (skin and fat) layer were derived. The encouraging results obtained lay a foundation for developing more complex multidimensional models.
The MVDP (mouse vas deferens protein) gene encodes an aldose reductase-like protein (AKR1B7) highly expressed in vas deferens epithelium and zona fasciculata of the adrenal cortex. Recombinant MVDP ...showed kinetic properties distinct from those of aldose reductase, including its spectrum of substrates, cofactor preference and sensitivity to inhibitors. We demonstrate that in adrenocortical cells, MVDP, rather than aldose reductase, is the principal reductase for isocaproaldehyde (a product of side-chain cleavage of cholesterol) and 4-hydroxynonenal (a lipid peroxidation product). In steroidogenic tissues MVDP expression is regulated by pituitary trophic hormones, namely ACTH in adrenals, FSH in ovaries, and LH in testicular Leydig cells.
To approach wide-field optical properties quantification in real heterogeneous biological tissue, we developed a Dual-Step setup that couples a punctual diffuse reflectance spectroscopy (DRS) ...technique with multispectral imaging (MSI). The setup achieves wide-field optical properties assessment through an initial estimation of scattering with DRS, which is used to estimate absorption with MSI. The absolute quantification of optical properties is based on the ACA-Pro algorithm that has been adapted both for DRS and for MSI. This paper validates the Dual-Step system not only on homogeneous Intralipid phantoms but also on a heterogeneous gelatine phantom with different scattering and absorbing properties.
We have developed an adaptive calibration algorithm and protocol (ACA-Pro) that corrects from the instrumental response of various spatially resolved diffuse reflectance spectroscopy (DRSsr) systems ...to enable the quantification of absorption and scattering properties based on a Monte Carlo-based look-up-table approach. The protocol involves the use of a calibration reference base built with measurements of a range of different diffusive intralipid phantoms. Moreover, an advanced strategy was established to take into account the experimental variations with an additional measurement of a common solid material, allowing the use of a single calibration reference base for all experiments. The ACA-Pro is validated in contact and noncontact probe-based DRSsr systems. Furthermore, the first results of a setup replacing the probe with a CCD detector are shown to confirm the robustness of the approach.
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