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).     

Tyrosine phosphorylated proteins in different tissues during chick embryo development

A high affinity polyclonal antibody specific for phosphotyrosyl residues has been used in immunoblotting experiments to survey developing embryonic chicken tissues for the presence and characteristics of tyrosine phosphorylated proteins. Proteins phosphorylated on tyrosine were found to be present in all the embryonic tissues examined, including heart, thigh, gizzard, intestine, lung, liver, kidney, brain, and lens, from 7 to 21 d of development in ovo, but were greatly reduced or absent in the same tissues taken from adult chickens. A limited number of major tyrosine phosphorylated proteins were seen in all the tissues examined and they ranged in molecular mass from 35 to 220 kD. Most of the tissues contained proteins phosphorylated on tyrosine with apparent molecular masses of 120, 70, 60, and 35 kD, suggesting that the substrates of tyrosine protein kinases in different tissues may be related proteins. One-dimensional peptide mapping of the 120- and 70-kD protein bands indicated a close structural relationship among the phosphotyrosine-containing proteins of 120 kD, and similarly among those of 70 kD, from the different tissues.     

Tricyclic Imipramine Modification of the Circadian Rhythms of Hypothalamic Serotonin, its Precursors and Acid Catabolite in Individually Housed Rats

Circadian rhythms of serotonin (5HT), its precursors tryptophan (TP) and 5-hydroxy-tryptophan (5HTP) and its acid catabolite 5-hydroxy-indoleacetic acid (5HIAA), were determined in the hypothalamus of control rats and rats which had been treated continuously with subcutaneous imipramine (10 mg/kg/day) for 2 weeks.

Rats were individually housed and entrained to LD12:12. Controls showed the 5HT and TP peaks in the light and dark periods respectively, as reported in the literature, but no inverted correlation (antiphase) between SHT and 5HIAA rhythms.

Imipramine significantly modified circadian rhythm characteristics: the 5HT acrophase was advanced, that of TP and 5HIAA was delayed. Imipramine also significantly increased hypothalamic SHT and TP concentrations.     

Reduced mechanical activity of perfused rat heart following morphine or enkephalin peptides administration

In the isolated and perfused rat heart, the addition of morphine, methionine-enkephalin or leucine-enkephalin to the coronary perfusate, significantly reduces the mechanical activity by negatively affecting both the heart rate and the developed tension. These effects are dose dependent and maximally evident with leucine-enkephalin. Furthermore all the opioids strongly reduce the activity of isoproterenol-stimulated hearts. The suggestion is made that opioid peptides directly influence the cardiac mechanical activity possibly by interacting with membrane-receptor systems.     

Heat shock induces protein tyrosine phosphorylation in cultured cells

We examined the effect of heat shock on protein tyrosine phosphorylation in cultured animal cells using antiphosphotyrosine antibodies in immunoblotting and immunofluorescence microscopy experiments. Heat shock significantly elevated the level of phosphotyrosine in proteins in most of the cultured cells examined, including fibroblasts, epithelial cells, nerve cells, and muscle cells, but not in Rous sarcoma virus-transformed fibroblasts. The increase in protein tyrosine phosphorylation induced by heat shock occurred in proteins with a wide range of molecular masses and was dependent on the temperature and duration of the heat shock.     

Screening for mutations in the neurofibromatosis type 2 (NF2) gene in sporadic meningiomas

Meningiomas are benign tumors of the central nervous system. They are usually sporadic but can also occur associated with the neurofibromatosis type 2 (NF2) syndrome. The gene responsible for NF2, recently isolated from chromosome 22, encodes a membrane-organizing protein that shows high sequence homology to a protein family thought to link the cytoskeleton with membrane proteins. Mutations of the NF2 gene have been described in sporadic meningiomas, exclusively in tumors that show loss of heterozygosity (LOH) of 22q. These preliminary results indicate that the NF2 gene is involved in the pathogenesis of at least a subset of meningiomas, where it does indeed behave as a tumor suppressor gene. In order to characterize better the role of the NF2 gene in the genesis of meningiomas we have examined the entire coding sequence of the gene in 125 meningiomas by single-strand conformational polymorphism analysis; furthermore, LOH analysis for markers of 22q has been carried out. Inactivating mutations were identified in 30% of our samples, all of which also showed LOH of 22q. The majority of mutations identified were frameshifts and nonsense mutations, which are predicted to produce a truncated or non-functional protein. We also found two missense and three in-frame deletions that may pinpoint specific regions of the protein critical to its function. Furthermore, the distribution of mutations throughout the gene, suggested that exons 2, 3, 5, 11 and 13 are more frequently involved. Our results reconfirm the importance of the NF2 gene in the pathogenesis of meningiomas and also suggest that there may be a nonrandom clustering of mutations throughout the gene.     

Membrane-bound LERK2 ligand can signal through three different Eph-related receptor tyrosine kinases.

The Eph-related family of receptor tyrosine kinases consists of at least 13 members, several of which display distinctive expression patterns in the developing and adult nervous system. Recently, a small family of ligands, structurally related to the B61 protein, was identified. Binding of these ligands to Eph-related receptors did not, however, elicit measurable biological signals in cultured cells. In order to study functional interactions between B61-related ligands and Eph-related receptors, we constructed chimeric receptors, containing an Eph-related ectodomain and the cytoplasmic domain of the TrkB neurotrophin receptor. Expression and activation of such chimeric receptors in NIH 3T3 cells induced transformation in focus formation assays. Membrane-bound LERK2 ligand is shown to signal through three different Eph-related receptors, namely Cek5, Cek10 and Elk. LERK2, however, fails to interact functionally with the Cek9 receptor. Quantitative analysis including binding assays indicates that Cek10 is the preferred LERK2 receptor. Preliminary mutagenesis of the LERK2 protein suggests a negative regulatory role for its cytoplasmic domain in LERK2 signaling.     

Reactivity of sulphydryl groups of cytosolic and mitochondrial bovine aspartate aminotransferases

Summary Reactivity of sulphydryl groups of cytosolic and mitochondrial aspartate aminotransferases from ox heart has been studied. A total of 5 and 7 cysteine residues per monomer are present in cAATo and mAATo, respectively. In native conditions only a single sulphydryl group can be titrated by Nbs₂ while the catalytic activity remains unchanged, however in the mitochondrial isozyme the reactivity depends on the functional state of the enzyme. Reactivity toward NEM reveals the existence of a syncatalytic sulphydryl group in the cytosolic isozyme. Titration of cAATo with pMB at pH 8 and pH 5 confirms the existence of two exposed sulphydryl groups with a different reactivity. The results compared with those reported on the corresponding isozymes from pig and chicken heart show that syncatalytic sulphydryl groups are of general occurrence in these enzymes.     

The Yale Affiliated Hospital Program in Internal Medicine

In July, 1975, the Departments of Internal Medicine at the Yale University School of Medicine and eight community hospitals in southern and western Connecticut formed the Yale Affiliated Hospital Program (YAHP) in Internal Medicine. The YAHP provides a planned and focused program of continuing education for medical staff and housestaff at the affiliated hospitals. Six formats for the over 1,000 rounds, lectures, and conferences given annually are used. The members of the YAHP also cooperate in housestaff and faculty recruiting, evaluation of quality of care and evaluation of the process of continuing medical education itself. This report summarizes the organization, goals and future plans of the YAHP.