Contactless facial video recording with deep learning models for the detection of atrial fibrillation.

Atrial fibrillation (AF) is often asymptomatic and paroxysmal. Screening and monitoring are needed especially for people at high risk. This study sought to use camera-based remote photoplethysmography (rPPG) with a deep convolutional neural network (DCNN) learning model for AF detection. All participants were classified into groups of AF, normal sinus rhythm (NSR) and other abnormality based on 12-lead ECG. They then underwent facial video recording for 10 min with rPPG signals extracted and segmented into 30-s clips as inputs of the training of DCNN models. Using voting algorithm, the participant would be predicted as AF if > 50% of their rPPG segments were determined as AF rhythm by the model. Of the 453 participants (mean age, 69.3 ± 13.0 years, women, 46%), a total of 7320 segments (1969 AF, 1604 NSR & 3747others) were analyzed by DCNN models. The accuracy rate of rPPG with deep learning model for discriminating AF from NSR and other abnormalities was 90.0% and 97.1% in 30-s and 10-min recording, respectively. This contactless, camera-based rPPG technique with a deep-learning model achieved significantly high accuracy to discriminate AF from non-AF and may enable a feasible way for a large-scale screening or monitoring in the future.

DNA Demethylation by DNMT3A and DNMT3B in vitro and of Methylated Episomal DNA in Transiently Transfected Cells.

The DNA methylation program in vertebrates is an essential part of the epigenetic regulatory cascade of development, cell differentiation, and progression of diseases including cancer. While the DNA methyltransferases (DNMTs) are responsible for the in vivo conversion of cytosine (C) to methylated cytosine (5mC), demethylation of 5mC on cellular DNA could be accomplished by the combined action of the ten-eleven translocation (TET) enzymes and DNA repair. Surprisingly, the mammalian DNMTs also possess active DNA demethylation activity in vitro in a Ca2+- and redox conditions-dependent manner, although little is known about its molecular mechanisms and occurrence in a cellular context. In this study, we have used LC-MS/MS to track down the fate of the methyl group removed from 5mC on DNA by mouse DNMT3B in vitro and found that it becomes covalently linked to the DNA methylation catalytic cysteine of the enzyme. We also show that Ca2+ homeostasis-dependent but TET1/TET2/TET3/TDG-independent demethylation of methylated episomal DNA by mouse DNMT3A or DNMT3B can occur in transfected human HEK 293 and mouse embryonic stem (ES) cells. Based on these results, we present a tentative working model of Ca2+ and redox conditions-dependent active DNA demethylation by DNMTs. Our study substantiates the potential roles of the vertebrate DNMTs as double-edged swords in DNA methylation-demethylation during Ca2+-dependent physiological processes.

Epigenetic Enhancement of the Post-replicative DNA Mismatch Repair of Mammalian Genomes by a Hemi-mCpG-Np95-Dnmt1 Axis.

DNA methylation at C of CpG dyads (mCpG) in vertebrate genomes is essential for gene regulation, genome stability and development. We show in this study that proper functioning of post-replicative DNA mismatch repair (MMR) in mammalian cells relies on the presence of genomic mCpG, as well as on the maintenance DNA methyltransferase Dnmt1 independently of its catalytic activity. More importantly, high efficiency of mammalian MMR surveillance is achieved through a hemi-mCpG-Np95(Uhrf1)-Dnmt1 axis, in which the MMR surveillance complex(es) is recruited to post-replicative DNA by Dnmt1, requiring its interactions with MutSα, as well as with Np95 bound at the hemi-methylated CpG sites. Thus, efficiency of MMR surveillance over the mammalian genome in vivo is enhanced at the epigenetic level. This synergy endows vertebrate CpG methylation with a new biological significance and, consequently, an additional mechanism for the maintenance of vertebrate genome stability.

Development of Home-Based Frailty Detection Device Using Wireless Sensor Networks.

This study develops a home-based frailty detection device that uses embedded systems and wireless sensing technology. This system helps monitor the impact of aging among the elderly through wireless automatic detection. The detection system consists of four devices. The first device, called eScale, simulates the traditional falling ruler test to measure reaction time. Another device, called eChair, measures the pressure exerted by a test subject through a pressure sensor. It is used to test three symptoms of frailty, namely slowness of movement, physical weakness, and body weight. The third device, called ePad, consists of a soft membrane switch placed on the ground to detect footsteps and is used to test balance. The fourth device, called eReach, measures displacement through ultrasound sensors. It is used to carry out the functional reach test. The sampling rate of each device is the main factor that determines system performance. When the test distance was set to 5 m for Home-Gateway, a 1-Hz sampling rate showed the best performance (98 %). Up to eight devices can be connected simultaneously to the gateway. The proposed system was compared with conventional approaches through testing with test subjects (n = 8). The results of the five tests were as follows: standing forward bend (r = 0.929), balance (r = 0.996), slowness of movement (r = 0.976), and physical weakness (r = 0.991), with p < 0.01. In the reaction time test, r = 0.871, with p < 0.1. All results suggest high correlations. Tests of aging symptoms were performed on 309 people aged over 65 years. Among males, degradation of over 20 % was found in the areas of physical weakness, slowness of movement, and functional reach. Among females, a degradation of 75 % was found in the balance test.

Active DNA demethylation of the vertebrate genomes by DNA methyltransferases: deaminase, dehydroxymethylase or demethylase?

Vertebrate DNA methyltransferases (DNMTs) have been thought to primarily function to covalently add a methyl group to the 5-position of cytosine. However, recent discovery of the DNA demethylation and dehydroxymethylation activities of DNMTs in vitro suggest new routes to complete the dynamic cycle of DNA methylation-demethylation of the vertebrate genomes. The in vitro reaction conditions suggest that vertebrate DNMTs can switch from DNA methylases to DNA dehydroxymethylases under oxidative stress and to DNA demethylases in the presence of calcium ion under nonreducing conditions. These environmental parameters provide clues regarding the choices in vivo of DNMT activities utilized in different physiological systems. In particular, the nature of these parameters suggest that the DNA demethylation and dehydroxymethylation activities of the vertebrate DNMTs play essential roles in multiple biological processes including early embryo development, regulation of neuronal plasticity, tumorigenesis and hormone-regulated transcription.

Matrix metalloproteinase-9 in the ventricular cerebrospinal fluid correlated with the prognosis of traumatic brain injury.

AIM: Matrix metalloproteinase 9 (MMP-9) has been shown to be a potential biomarker for outcome prediction after neuron damage. This study investigated whether MMP-9 could be used for outcome prediction after traumatic brain injury (TBI). MATERIAL AND METHODS: For the TBI group, cerebrospinal fluid (CSF) was collected at different days after surgery from 6 head injury patients who had received surgical intervention with external ventricular drainage insertion. CSF collected from non-TBI patients (N=85) diagnosed with isolated hydrocephalus by a ventricular puncture during a ventriculo-peritoneal shunt surgery was used as control. RESULTS: The mean concentration of MMP-9 in the CSF of 85 non-TBI patients was determined to be 1.172 ± 0.859 ng/mL. We found that the CSF MMP-9 concentration from TBI patients was elevated immediately after head injury with a median of 1.926 ng/mL (range, 0.673 to 24.990). Despite an early increase in the concentration of MMP-9, levels decreased within 72 hrs and nearly reached the normal range. Nevertheless, the concentration of MMP-9 was negatively correlated with the Glasgow Coma Scale (γ = - 0.337, p = 0.013). CONCLUSION: MMP-9 concentration in the CSF of TBI patients correlated with neurological outcome and may represent an early indicator for the prognosis of this condition.

DNA 5-methylcytosine demethylation activities of the mammalian DNA methyltransferases.

Methylation at the 5-position of DNA cytosine on the vertebrate genomes is accomplished by the combined catalytic actions of three DNA methyltransferases (DNMTs), the de novo enzymes DNMT3A and DNMT3B and the maintenance enzyme DNMT1. Although several metabolic routes have been suggested for demethylation of the vertebrate DNA, whether active DNA demethylase(s) exist has remained elusive. Surprisingly, we have found that the mammalian DNMTs, and likely the vertebrates DNMTs in general, can also act as Ca(2+) ion- and redox state-dependent active DNA demethylases. This finding suggests new directions for reinvestigation of the structures and functions of these DNMTs, in particular their roles in Ca(2+) ion-dependent biological processes, including the genome-wide/local DNA demethylation during early embryogenesis, cell differentiation, neuronal activity-regulated gene expression, and carcinogenesis.

Wireless sensor networks for indoor air quality monitoring.

The purpose of this study is to build an indoor air quality monitoring system based on wireless sensor networks (WSNs) technology. The main functions of the system include (1) remote parameter adjustment and firmware update mechanism for the sensors to enhance the flexibility and convenience of the system, (2) sensor nodes are designed by referring to the IEEE 1451.4 standard. This way, sensor nodes can automatically adjust and be plug and play, and (3) calibration method to strength the measurement value's sensitivity and accuracy. The experimental results show that transmission speed improves 30% than Trickle, transmission volume reduced to 42% of the original volume, updating task in 5*5 network topology can be executed 1.79 times and power consumption reduced to 30%. When baseline drifts, we can use the firmware update mechanism to adjust the reference value. The way can reduce error percentage from 15% to 7%.

eFurniture for home-based frailty detection using artificial neural networks and wireless sensors.

The purpose of this study is to integrate wireless sensor technologies and artificial neural networks to develop a system to manage personal frailty information automatically. The system consists of five parts: (1) an eScale to measure the subject's reaction time; (2) an eChair to detect slowness in movement, weakness and weight loss; (3) an ePad to measure the subject's balancing ability; (4) an eReach to measure body extension; and (5) a Home-based Information Gateway, which collects all the data and predicts the subject's frailty. Using a furniture-based measuring device to provide home-based measurement means that health checks are not confined to health institutions. We designed two experiments to obtain optimum frailty prediction model and test overall system performance: (1) We developed a three-step process to adjust different parameters to obtain an optimized neural identification network whose parameters include initialization, L.R. dec and L.R. inc. The post-process identification rate increased from 77.85% to 83.22%. (2) We used 149 cases to evaluate the sensitivity and specificity of our frailty prediction algorithm. The sensitivity and specificity of this system are 79.71% and 86.25% respectively. These results show that our system is a high specificity prediction tool that can be used to assess frailty.

The mammalian de novo DNA methyltransferases DNMT3A and DNMT3B are also DNA 5-hydroxymethylcytosine dehydroxymethylases.

For cytosine (C) demethylation of vertebrate DNA, it is known that the TET proteins could convert 5-methyl C (5-mC) to 5-hydroxymethyl C (5-hmC). However, DNA dehydroxymethylase(s), or enzymes able to directly convert 5-hmC to C, have been elusive. We present in vitro evidence that the mammalian de novo DNA methyltransferases DNMT3A and DNMT3B, but not the maintenance enzyme DNMT1, are also redox-dependent DNA dehydroxymethylases. Significantly, intactness of the C methylation catalytic sites of these de novo enzymes is also required for their 5-hmC dehydroxymethylation activity. That DNMT3A and DNMT3B function bidirectionally both as DNA methyltransferases and as dehydroxymethylases raises intriguing and new questions regarding the structural and functional aspects of these enzymes and their regulatory roles in the dynamic modifications of the vertebrate genomes during development, carcinogenesis, and gene regulation.

The -308G/A of Tumor Necrosis Factor (TNF)-α and 825C/T of Guanidine Nucleotide Binding Protein 3 (GNB3) are associated with the onset of acute myocardial infarction and obesity in Taiwan.

Acute myocardial infarction is a highly prevalent cardiovascular disease in Taiwan. Among several etiological risk factors, obesity and inflammation are strongly associated with the frequency of hypertension, cardiovascular disease, diabetes, and myocardial infarction. To discriminate obesity- and inflammation-related genes and the onset of acute myocardial infarction (AMI), a case-control study was conducted to investigate the association of the -308G/A polymorphisms of tumor necrosis factor (TNF)-α and the C825T polymorphism of guanidine nucleotide binding protein 3 (GNB3) with the onset of AMI among Taiwanese cohorts. A total of 103 AMI patients and 163 matched normal control samples were enrolled in the present study. The genomic DNA was extracted and subjected into polymerase chain reaction-based restriction fragment length polymorphism (PCR-RFLP) analysis. An association between the A homozygosity of the TNF-α-308G/A polymorphism and the onset of AMI was observed among the male subjects (p = 0.026; Spearman index = 0.200, p = 0.008). An association between the T homozygosity of GNB3 C825T polymorphism and obesity was also observed (Fisher's exact, p = 0.009). The TT genotype has a protective effect against acquiring AMI among the obese female population in Taiwan (Fisher's exact, p = 0.032). In conclusion, TNF-α-308G/A and the GNB3 C825T polymorphisms are associated with obesity and AMI in the Taiwanese population.

Purification and characterization of a new Rhizopuspepsin from Rhizopus oryzae NBRC 4749.

A secretory aspartic protease (also termed as rhizopuspepsin) was purified from Rhizopus oryzae NBRC 4749 by ion exchange chromatography with a yield of 45%. The enzyme was a nonglycoprotein with a molecular mass of 37 kDa as determined by SDS-PAGE analysis. N-terminal sequence and LC-MS/MS analyses revealed that this rhizopuspepsin corresponded to the hypothetical protein RO3G_12822.1 in the R. oryzae genome database. Comparison of genomic and cDNA genes demonstrated that the rhizopuspepsin contained two introns, whereas only one intron was reported in other rhizopuspepsin genes. Phylogenetic analysis also indicated that this rhizopuspepsin was distinct from other rhizopuspepsins. The temperature and pH optima for the purified rhizopuspepsin were 50 degrees C and pH 3.0, respectively, and a half-life of about 3.5 h was observed at 40 degrees C. The enzyme preferentially cleaved the peptides with hydrophobic and basic amino acids in the P1 site but had no activity for the Glu, Pro, Trp, and aliphatic amino acids containing the beta-branch side chain.

Patterns of internal gene duplication in the course of metazoan evolution.

Internal duplication can enhance the function of a gene or provide raw material for the emergence of a new function in a gene. Therefore, it is interesting to see whether the frequency of internal duplication has increased during metazoan evolution. The growing number of sequenced eukaryotic genomes provides an excellent opportunity to study the change in the pattern of internal duplication in the course of metazoan evolution. We studied repeated segments in proteins in the proteomes of 11 eukaryotes. We found that the frequency of internal duplication in Caenorhabditis elegans and Drosophila melanogaster (two protostomes) is higher than that in fungi but lower than that in chordates. Moreover, the frequencies of internal duplication for the chordates studied are largely similar. We classified orthologous proteins of chordates into three antiquity groups and found that more recently derived proteins in the metazoan lineage have higher repetitiveness than older ones. Our analysis suggests that lineage-specific internal duplication in protein evolution increases with organismal complexity before the emergence of chordates but not so afterward. Proteins with repeated regions might have been preferred before the protostome-chordate split. This finding supports the suggestion that exon-shuffling occurred more frequently after the first multicellular organism appeared and might have contributed to the metazoan radiation.

Characterization of a bifunctional aminoacylase/carboxypeptidase from radioresistant bacterium Deinococcus radiodurans R1.

The gene encoding a Deinococcus radiodurans R1 bifunctional aminoacylase/carboxypeptidase (DR_ACY/CP) was amplified by polymerase chain reaction and cloned into pQE-30 to generate pQE-DRAC. The cloned gene consists of an open reading frame of 1197 bp encoding a protein with a molecular mass of 42,729 Da. The predicted amino acid sequence shows high homology with those of Geobacillus kaustophilus aminoacylase, Geobacillus stearothermophilus aminoacylase, Pyrococcus horikoshii carboxypeptidase/aminoacylase and Thermoanaerobacter tengcongensis aminoacylase/carboxypeptidase. The expressed enzyme was purified from the crude extract of IPTG-induced Escherichia coli M15 (pQE-DRAC) to homogeneity by nickel-chelate chromatography. The molecular mass of the purified enzyme was determined to be 43kDa by SDS-PAGE. Maximal aminoacylase activity with N-acetyl-methionine as the substrate occurred at pH 8.0 and 40 degrees C in the sodium phosphate buffer. The aminoacylase activity was strongly inhibited by metal-chelating agents, and was largely restored by divalent cations, such as Co(2+), Mn(2+) and Ni(2+). The purified enzyme had broad specificity toward N-acetylated L-amino acids as well as N-CBZ-peptides. Carboxypeptidase activity of DR_ACY/CP to N-CBZ-Gly-Ala exhibited K(m) and k(cat) values of 4.3mM and 28s(-1), respectively. The enzyme also had activity toward the cell wall-related substrates, D-Ala-Gly, D-Ala-Gly-Gly and L-Orn-L-Ala.

Design and implementation of a mobile-care system over wireless sensor network for home healthcare applications.

According to home healthcare requirement of chronic patients, this paper proposes a mobile-care system integrated with a variety of vital-sign monitoring, where all the front-end vital-sign measuring devices are portable and have the ability of short-range wireless communication. In order to make the system more suitable for home applications, the technology of wireless sensor network is introduced to transmit the captured vital signs to the residential gateway by means of multi-hop relay. Then the residential gateway uploads data to the care server via Internet to carry out patient's condition monitoring and the management of pathological data. Furthermore, the system is added in the alarm mechanism, which the portable care device is able to immediately perceive the critical condition of the patient and to send a warning message to medical and nursing personnels in order to achieve the goal of prompt rescue.

Purification, characterization, and genetic analysis of a leucine aminopeptidase from Aspergillus sojae.

Extracellular leucine aminopeptidase (LAP) from Aspergillus sojae was purified to protein homogeneity by sequential fast protein liquid chromatography steps. LAP had an apparent molecular mass of 37 kDa, of which approximately 3% was contributed by N-glycosylated carbohydrate. The purified enzyme was most active at pH 9 and 70 degrees C for 30 min. The enzyme preferentially hydrolyzed leucine p-nitroanilide followed by Phe, Lys, and Arg derivatives. The LAP activity was strongly inhibited by metal-chelating agents, and was largely restored by divalent cations like Zn(2+) and Co(2+). The lap gene and its corresponding cDNA fragment of the A. sojae were cloned using degenerated primers derived from internal amino acid sequences of the purified enzyme. lap is interrupted by three introns and is transcribed in a 1.3-kb mRNA that encodes a 377-amino-acid protein with a calculated molecular mass of 41.061 kDa. The mature LAP is preceded by a leader peptide of 77 amino acids, predicted to include an 18-amino-acid signal peptide and an extra sequence of 59 amino acids. Two putative N-glycosylation sites are identified in Asn-87 and Asn-288. Southern blot analysis suggested that lap is a single-copy gene in the A. sojae genome. The deduced amino acid sequence of A. sojae LAP shares only 11-33.1% identity with those of LAPs from 18 organisms.