A Novel Algorithm for Movement Artifact Removal in ECG Signals Acquired from Wearable Systems Applied to Horses

This study reports on a novel method to detect and reduce the contribution of movement artifact (MA) in electrocardiogram (ECG) recordings gathered from horses in free movement conditions. We propose a model that integrates cardiovascular and movement information to estimate the MA contribution. Specifically, ECG and physical activity are continuously acquired from seven horses through a wearable system. Such a system employs completely integrated textile electrodes to monitor ECG and is also equipped with a triaxial accelerometer for movement monitoring. In the literature, the most used technique to remove movement artifacts, when noise bandwidth overlaps the primary source bandwidth, is the adaptive filter. In this study we propose a new algorithm, hereinafter called Stationary Wavelet Movement Artifact Reduction (SWMAR), where the Stationary Wavelet Transform (SWT) decomposition algorithm is employed to identify and remove movement artifacts from ECG signals in horses. A comparative analysis with the Normalized Least Mean Square Adaptive Filter technique (NLMSAF) is performed as well. Results achieved on seven hours of recordings showed a reduction greater than 40% of MA percentage (between before- and after- the application of the proposed algorithm). Moreover, the comparative analysis with the NLMSAF, applied to the same ECG recordings, showed a greater reduction of MA percentage in favour of SWMAR with a statistical significant difference (p–value < 0.0.5).     

Glomerular podocytes in cultured rat kidney slices

Summary The ultrastructure of rat glomerular epithelial cells (podocytes) in kidney slices in vitro was examined using qualitative and quantitative electron microscopy. The kidney slices were cultured in Medium 199 with Hanks' salts in a 5% CO₂/95% O₂ environment for up to 14 days. Few changes in podocyte ultrastructure occurred in the first 12 h of culture, but by 24 h cell bodies were rounded, microvilli were present on all podocyte surfaces, and some foot processes had been replaced by flattened expanses of cytoplasm. These changes were more pronounced by 3 days, when some podocytes had developed pseudopodal extensions and appeared to be migrating from glomeruli onto the slice surface. Podocytes could still be identified after 8, 10 and 14 days of culture, although relatively few glomeruli remained at 14 days. Morphometric methods were used to analyse podocyte shape, volume and surface area during the first 4 days of culture. The most significant change involved loss of foot processes: the number of filtration slits per 100 m of basement membrane decreased from 211.8 ± 15.0 (mean ± SD) at the commencement of culture, to 55.3 ± 22.6 after 2 days (P < 0.001). These data provide baseline information for in vitro studies on the effects of nephrotoxins on podocytes.     

Modulation of the cell-mediated immune function by interferon α, β or γ can partially reverse the immunosuppression induced by human T-cell leukemia virus I in human cord blood cultures

Summary Infection with human T-cell leukemia virus type I (HTLV-I) is associated in vitro and in vivo with a remarkable depression of cell-mediated immune functions. In the present report it is shown that early events following virus-induced suppression of the cell-mediated immune response of freshly isolated cord blood mononuclear cells (CBL) infected with HTLV-I can be partially counteracted by treatment with interferons , or (IFN). All three types of IFN exerted a protective effect on CBL cultures exposed to the virus. This resulted in: (a) a reduced number of virus-positive cells until 4 weeks of culture; (b) delay in the clonal expansion of infected cells (IFN and ); (c) increased natural killer cell activity of CBL, 1 week post-infection (p.i.), mediated by IFN; (d) increase of allospecific recognition of infecting and priming HTLV-I donor MT-2 cells by CBL in a cytotoxic-T-lymphocyte-like response, mediated by IFN and particularly by IFN; (e) phenotype distribution of CBL subpopulations, tested 4 days p.i., more similar to that of non-infected CBL cultures.In contrast, the overall CBL proliferation, that is profoundly depressed during the first week p.i., was not restored by IFN treatments, suggesting that boosting of the cell-mediated killing induced by IFN might involve the maturation of undifferentiated precursor cells rather than stimulation of their proliferation. The improvement of the efficiency of the antiviral immune response induced by treatment with IFN is likely to contribute to the clearance of virus-positive cells during the early phase of infection. This would provide experimental evidence to support an immunopharmacological approach contributing to the conversion of HTLV-I carriers from positive to negative.     

The presence of immunoreactive vertebrate bioactive peptide substances in hemocytes of the freshwater snailViviparus ater (gastropoda,prosobranchia)

1. Using an immunocytochemical procedure a wide range of immunoreactive vertebrate bioactive peptides (BAPs) has been found in hemocytes of Viviparus ater: bombesin, calcitonin, CCK-8, CCK-39, GH, glucagon, insulin, oxytocin, neurotensin, secretin, serotonin, somatostatin, substance P, vasopressin, and VIP. 2. No immunostaining was observed for antigastrin and antithyroglobulin antibodies. 3. The presence of BAP-like molecules in hemocytes suggests a correlation between hemocyte and APUD cells and is evidence of a relationship between the neuroendocrine and the immune systems.     

Heat-soaked PCR: an efficient method for DNA amplification with applications to forensic analysis.

Heat-soaked PCR (HS-PCR) is a method for enhancing amplification performed by heating the DNA sample at 94 degrees C in 90 microliters 1.1 x buffer for 30 min. A 10-microliters bolus of concentrated (10x) deoxynucleotides, Taq DNA polymerase and primers prepared without buffer is then added just prior to thermal cycling. We have investigated the application of this method in a variety of forensically important DNA samples and compared it with regular PCR (R-PCR). DNA samples extracted from bone, postmortem tissues, bloodstains and hair contained low concentrations of human DNA or were contaminated with either non- human DNA or hemoglobin degradation products. Optimal conditions for HS-PCR were determined for the 3' ApoB VNTR locus and applied to a centromeric repeat element and to a single-copy locus. HS-PCR consistently and reproducibly enhanced product yield and specificity over R-PCR at all three loci in the entire set of DNA samples. HS-PCR was also effective in overcoming the inhibitory effect of hemoglobin at concentrations that fully impeded R-PCR.     

Diurnal beta-endorphin changes in human cerebrospinal fluid

Plasma and cerebrospinal fluid (CSF) beta-endorphin levels were determined by a RIA method in seven hydrocephalic male patients. The samples were simultaneously collected every two hours from 8 AM to 12 midnight and every hour from 1 AM to 7 AM. In both plasma and CSF beta-endorphin levels showed significant time-related variations during the 24 hour period. These results suggest the existence of diurnal CSF beta-endorphin variations analogous to those observed in plasma.     

Studies on Analogues of Succinic Semialdehyde as Substrates for Succinate Semialdehyde Dehydrogenase from Rat Brain

The methyl ester of succinic semialdehyde (SSA) was examined as a substrate for succinate semialdehyde dehydrogenase (SSADH) from rat brain. It was found that the ester can be oxidized by the enzyme. Values of Km for SSA-Me were higher than for those for SSA, and for this substrate the enzyme showed a substrate-dependent inhibition. This finding suggests that the carboxylate group of SSA is not essential in the process of inhibition of SSADH by the substrate. Cyclopropyl analogues of SSA, cis- and trans-1-formyl-cyclopropan-2-carboxylic acids, were also individually tested as substrates of SSADH. Only the trans isomer was found to be oxidized to the corresponding dicarboxylic acid; it inhibited the enzyme in the same range of concentrations as SSA. The above data suggest that, as for gamma-aminobutyric acid, SSA is present in an unfolded, transoid conformation at the active site of SSADH.     

Human keratinocyte growth factor activity on proliferation and differentiation of human keratinocytes: differentiation response distinguishes KGF from EGF family.

Human keratinocyte growth factor (KGF) is an epithelial cell specific mitogen which is secreted by normal stromal fibroblasts. In the present studies, we demonstrate that KGF is as potent as EGF in stimulating proliferation of primary or secondary human keratinocytes in tissue culture. Exposure of KGF- or EGF-stimulated keratinocytes to 1.0 mM calcium, an inducer of differentiation, led to cessation of cell growth. However, immunologic analysis of early and late markers of terminal differentiation, K1 and filaggrin, respectively, revealed striking differences in keratinocytes propagated in the presence of these growth factors. With KGF, the differentiation response was associated with expression of both markers whereas their appearance was retarded or blocked by EGF. TGF alpha, which also interacts with the EGF receptor, gave a similar response to that observed with EGF. These findings functionally distinguish KGF from the EGF family and support the role of KGF in the normal proliferation and differentiation of human epithelial cells.