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To improve the independence of brain impairment patients in ADL, we sought to identify influential parameters from information commonly collected in hospitals, prioritize the factors, and specify the degree to which those factors are necessary. In total, 64 patients with hemiplegia, who had been admitted to the one of the authors, were examined using various evaluation tools. Afterwards, we checked the difference between the capable group and the incapable group with an independent t-test or chi-squared test to determine the significant factors, and we prioritized the significant factors with Spearman’s rho test. The degree of their necessity was determined with the ROC curve. Standing balancing ability and hip joint and knee extensor strength are necessary in most ADL except for eating. In order to independently perform most ADL except eating and one gait cycle, the strength of the knee extensor and hip flexor was required to exceed grade 3 on the MRC scale. However, one gait cycle was possible even if the strength of the hip joint and knee extensors rated lower than 3 on the MRC scale. Additionally, upper limb motor recovery was required up to the distal parts in the order of bathing, dressing, and grooming.

Airborne particulate matter has been designated as a class 1 carcinogen by the World Health Organization. Nitrate is a toxic substance that accounts for a large proportion of particulate matter, and nitrate toxicity has long been reported. In this study, we aimed to optimize the adsorption and removal of particulate matter containing nitrate for effective elimination by the lungs. To this end, particles were designed to optimize the inhalation and removal efficiencies. These particles were prepared as chitosan-based particles containing N-acetylcysteine by using emulsion diffusion methods. Chitosan adsorbs nitrate, while N-acetylcysteine dissolves mucus. This removal mechanism has been found to occur in various in vitro models that mimic respiratory environments and in vivo models. In particular, the removal of exogenous substances, such as particulate matter, by the motility of respiratory cilia through mucolytic effect was investigated. This new approach for the adsorption and elimination of toxic substances entering the lungs represents an alternative defense mechanism against exposure to nitrates from air pollution.

Natural arylnaphthalene lactones are representative lignans that are found in various dietary and medicinal plants. Their unique structural features and significant pharmacological activity have attracted considerable attention from both synthetic and medicinal chemists. Owing to their unique structural features such as relative rigid tetracyclic skeleton, structural diversity of more than five substituents, and no chiral center, arylnaphthalene lactones are recognized as a valuable scaffold for drug discovery, in addition to their significant pharmacological activities. This review covers the structures and isolation of all naturally occurring arylnaphthalene lactone congeners reported. Based on the aryl substituents, they were categorized as Type I and Type II and further classified according to the oxidation state of the ring and glycosylation level. Special attention has been paid to natural arylnaphthalene lactones owing to their broad spectrum of biological activities such as cytotoxic, antiplatelet, antiviral, anti-HIV, antifungal, neuroprotective, and anti-inflammatory properties. All the products were reorganized based on their biological activities, and selected data are presented.

Purpose Although tamoxifen remains the frontline treatment for ERα-positive breast cancers, resistance to this drug limits its clinical efficacy. Most tamoxifen-resistant patients retain ERα expression which may support growth and progression of breast cancers. Therefore, we investigated epigenetic regulation of ERα that may provide a rationale for targeting ERα in these patients. Methods Expression levels of the mixed-lineage leukemia (MLL) family of proteins in tamoxifen-resistant breast cancer cells and publicly available breast cancer patient data sets were analyzed. Histone methylation levels in ERα promoter regions were assessed using chromatin immunoprecipitation. Expression levels of ERα and its target gene were analyzed using western blotting and real-time qPCR. Cell-cycle was analyzed by flow cytometry. Results The expression of MLL3 and SET-domain-containing 1A (SET1A) were increased in tamoxifen-resistant breast cancers. An MLL3 chromatin immunoprecipitation-sequencing data analysis and chromatin immunoprecipitation experiments for MLL3 and SET1A suggested that these proteins bound to enhancer or intron regions of the ESR1 gene and regulated histone H3K4 methylation status. Depletion of MLL3 or SET1A downregulated the expression level of ERα and inhibited the growth of tamoxifen-resistant breast cancer cells. Additional treatment with fulvestrant resulted in a synergistic reduction of ERα levels and the growth of the cells. Conclusions The enhanced expression of MLL3 and SET1A in tamoxifen-resistant breast cancer cells supported the ERα-dependent growth of these cells by increasing ERα expression. Our results suggest that targeting these histone methyltransferases might provide an attractive strategy to overcome endocrine resistance.

Searching for new molecules in areas like drug discovery often starts from the core structures of known molecules. Such a method has called for a strategy of designing derivative compounds retaining a particular scaffold as a substructure. On this account, our present work proposes a graph generative model that targets its use in scaffold-based molecular design. Our model accepts a molecular scaffold as input and extends it by sequentially adding atoms and bonds. The generated molecules are then guaranteed to contain the scaffold with certainty, and their properties can be controlled by conditioning the generation process on desired properties. The learned rule of extending molecules can well generalize to arbitrary kinds of scaffolds, including those unseen during learning. In the conditional generation of molecules, our model can simultaneously control multiple chemical properties despite the search space constrained by fixing the substructure. As a demonstration, we applied our model to designing inhibitors of the epidermal growth factor receptor and show that our model can employ a simple semi-supervised extension to broaden its applicability to situations where only a small amount of data is available., We propose a scaffold-based graph generative model for designing novel drug candidates that include the desired scaffold as a substructure.

Team members commonly collaborate on visual documents remotely and asynchronously. Particularly, students are frequently restricted to this setting as they often do not share work schedules or physical workspaces. As communication in this setting has delays and limits the main modality to text, members exert more effort to reference document objects and understand others’ intentions. We propose Winder, a Figma plugin that addresses these challenges through linked tapes—multimodal comments of clicks and voice. Bidirectional links between the clicked-on objects and voice recordings facilitate understanding tapes: selecting objects retrieves relevant recordings, and playing recordings highlights related objects. By periodically prompting users to produce tapes, Winder preemptively obtains information to satisfy potential communication needs. Through a five-day study with eight teams of three, we evaluated the system’s impact on teams asynchronously designing graphical user interfaces. Our findings revealed that producing linked tapes could be as lightweight as face-to-face (F2F) interactions while transmitting intentions more precisely than text. Furthermore, with preempted tapes, teammates coordinated tasks and invited members to build on each others’ work.

Signal distortion, called ringing, in a controller area network with flexible data rate (CAN-FD) causes asymmetry in propagation delay throughout a network, which is dependent on its physical bus design and becomes a critical issue in limiting the data rate. Thus, in this paper, the bus structure of a CAN-FD is investigated and a transfer function of ringing is modeled by considering the physical bus configuration and features of a controller area network transceiver. The effects of the main parameters of the physical bus, such as the stub line length and number of stub lines connected to a joint connector, are then quantitatively analyzed using the presented model. When a practical bus structure is considered, additional signal distortion owing to a neighboring connector in a physical bus is modeled and analyzed. These analytical results are confirmed experimentally. Their comparison shows that the presented model-based analysis can closely approximate the size and time response of ringing and the extent of bit time distortion. The presented model-based analysis facilitates reliable communication performance by estimating the ringing and resulting asymmetry of the propagation delay for a given physical bus design and, if necessary, adjusting the design.

Tamoxifen is commonly used to treat patients with ESR/ER-positive breast cancer, but its therapeutic benefit is limited by the development of resistance. Recently, alterations in macroautophagy/autophagy function were demonstrated to be a potential mechanism for tamoxifen resistance. Although MTA1 (metastasis-associated 1) has been implicated in breast tumorigenesis and metastasis, its role in endocrine resistance has not been studied. Here, we report that the level of MTA1 expression was upregulated in the tamoxifen resistant breast cancer cell lines MCF7/TAMR and T47D/TR, and knockdown of MTA1 sensitized the cells to 4-hydroxytamoxifen (4OHT). Moreover, knockdown of MTA1 significantly decreased the enhanced autophagy flux in the tamoxifen resistant cell lines. To confirm the role of MTA1 in the development of tamoxifen resistance, we established a cell line, MCF7/MTA1, which stably expressed MTA1. Compared with parental MCF7, MCF7/MTA1 cells were more resistant to 4OHT-induced growth inhibition in vitro and in vivo, and showed increased autophagy flux and higher numbers of autophagosomes. Knockdown of ATG7 or cotreatment with hydroxychloroquine, an autophagy inhibitor, restored sensitivity to 4OHT in both the MCF7/MTA1 and tamoxifen resistant cells. In addition, AMP-activated protein kinase (AMPK) was activated, probably because of an increased AMP:ATP ratio and decreased expression of mitochondrial electron transport complex components. Finally, publicly available breast cancer patient datasets indicate that MTA1 levels correlate with poor prognosis and development of recurrence in patients with breast cancer treated with tamoxifen. Overall, our findings demonstrated that MTA1 induces AMPK activation and subsequent autophagy that could contribute to tamoxifen resistance in breast cancer.

Glial fibrillary acidic protein (GFAP) is a homopolymeric type III intermediate filament (IF) that plays essential roles in cell migration, mitosis, development, and signaling in astrocytes and a specific type of glial cells. Its overexpression and genetic mutations lead to abnormal IF networks and accumulation of Rosenthal fibers, which results in the fatal neurodegenerative disorder Alexander disease. Herein, we present the first crystal structure of human GFAP spanning the central coiled-coil 1B domain at 2.5 A resolution. The domain forms a tetramer comprising two equivalent parallel coiled-coil dimers that pack together in an antiparallel manner. Its assembly is stabilized by extensive networks of intermolecular hydrogen bonds, salt bridges, and hydrophobic interactions. Furthermore, mapping of the GFAP mutations associated with Alexander disease reveals that most involve residues buried in the core of the interface, and are likely to disrupt the intermolecular interactions and/or introduce steric clashes, thereby decreasing GFAP solubility and promoting aggregation. Based on our structural analysis and previous biochemical studies, we propose that GFAP assembles in the A11 mode in which coiled-coil 1B dimers lie in close axial proximity in an antiparallel fashion to provide a stable tetrameric platform for the organization of the GFAP filament.

Estrogen receptor (ER)-positive breast cancers depend on ER signaling for growth and progression. Although tamoxifen remains the frontline treatment for such cancers, resistance to this drug limits its clinical efficacy. Nevertheless, the majority of tamoxifen-resistant patients retain ERα expression, providing a rationale for targeting ERα in these patients. Here, we found that the expression of mixed lineage leukemia (MLL) family proteins are increased in tamoxifen-resistant breast cancer cells and patients. Specifically, mixed lineage leukemia 3 (MLL3) and SET domain containing 1A (SET1A) depletion downregulated the expression of ERα protein and mRNA levels in a ER-positive breast cancer cell. Chromatin Immunoprecipitation analysis revealed that the knock-down of MLL3 and SET1A reduce the histone H3K4 methylation status in ESR1 promoter regions. We also observed the positive correlation between ERα level and MLL3/SET1A level in breast cancer clinical data sets. Importantly, MLL3 and SET1A depletion downregulated the ERα and its downstream growth-related protein levels, as well as the growth of both ER-positive and tamoxifen-resistant breast cancer cells. Likewise, MLL3 and SET1A knockdown decreased the proportion of cells entering the cell cycle. Additional fulvestrant treatment resulted in synergistic reduction of ERα levels and growth of the tamoxifen-resistant breast cancer cells. Thus, enhanced expression of MLL3 and SET1A in tamoxifen-resistant breast cancer cells supported ERα-dependent growth of breast cancer cells, suggesting that MLL3 SET1A might provide an attractive target for overcoming endocrine resistance. Citation Format: Seungsu Kim, Min-Ho Lee, Mi-Ock Lee. Enhanced expression of histone methyltransferases increase ERα expression in tamoxifen-resistant breast cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4320.

Current enzymatic methods for the analysis of glycated proteins use flavoenzymes that catalyze the oxidative deglycation of fructosyl peptides, designated as fructosyl peptidyl oxidases (FPOXs). However, as FPOXs are oxidases, the signals derived from electron mediator-type electrochemical monitoring based on them are affected by dissolved O(2). Improvement of dye-mediated dehydrogenase activity of FPOXs and its application to enzyme electrode construction were therefore undertaken. Saturation mutagenesis study on Asn56 of FPOX from Phaeosphaeria nodorum, produced mutants with marked decreases in the catalytic ability to employ O(2) as the electron acceptor, while showing higher dye-mediated dehydrogenase activity employing artificial electron acceptors than the parental enzyme. Thus constructed virtually fructosyl peptide dehydrogenase, Asn56Ala, was then applied to produce an enzyme electrode for the measurement of fructosyl-(α) N-valyl-histidine (f-(α)Val-His), the protease-digested product of HbA1c. The enzyme electrode could measure f-(α)Val-His in the physiological target range in air.

Fructosyl valyl-histidine, which is released from protease digestion of the major diabetes indicator HbA1c, is recognized as a target molecule for HbA1c sensors. The flavoenzyme fructosyl amino acid oxidase (FAOD) is an enzyme catalyzing the oxidative deglycation of fructosyl amino acids, with those also possessing high activity towards fructosyl dipeptides being referred to as fructosyl peptidyl oxidases (FPOXs). The high oxygen reactivity of FAODs and FPOXs limits their potential utility in amperometric enzyme sensors employing artificial electron mediators. We successfully modified the proton relay system of Pichia N1-1 FAOD, significantly decreasing its catalytic ability to employ oxygen as the electron acceptor, while having little effect on the dye-mediated dehydrogenase activity employing artificial electron acceptors instead of oxygen. We expect that similar engineering of a recently discovered FPOX will produce an enzyme that is ideally suited for HbA1c sensing.

Site-directed mutagenesis was carried out at the putative active site of fructosyl amine oxidase (FAOD) to improve its substrate specificity based on information from the structural model. Substitution of the His51 residue with other amino acids predicted to interact with the substrate resulted in mutant FAODs with improved specificity for fructosyl-αN-valine (f-αVal), a model compound of hemoglobin A1c (HbA1c). Kinetic analysis of these mutant FAODs indicated that these His51 variants had decreased V max K m − 1 values for fructosyl-ɛN-lysine (f-ɛLys) compared to the wild-type enzyme, while the V max K m − 1 values for f-αVal remained unaffected or were increased. Among the 19 variants at His51, His51Lys/Arg was combined with previously reported mutants, such as Asn354His [Miura S, Ferri S, Tsugawa W, Kim S, Sode K. Development of fructosyl amine oxidase specific to fructosyl valine by site-directed mutagenesis. Protein Eng Des Sel 2008;21:233–9]; the His51/Asn354 double mutant showed a greater improvement in the specificity for f-αVal over f-ɛLys and higher activity toward f-αVal than the single mutants and the wild-type. In order to develop a biosensor for the measurement of HbA1c, an FAOD enzyme specific to f-αVal is required to avoid influence of f-ɛLys derived from other glycated proteins. Our results support the proposed 3D model, and the resulting f-αVal-specific mutants are expected to be applied to the enzymatic measurement of HbA1c.

Androgen receptor (AR) is expressed in more than 80% of ER-positive breast cancer and its expression is correlated with better prognosis in ER-positive breast cancer. However, little is known about the regulation of AR expression in breast cancer. We have previously reported that metastasis-associated protein 1 (MTA1), a cancer-promoting gene that is overexpressed in breast cancer, increases the expression of ERα in breast cancer. Here, we investigated the role of MTA1 on AR expression in three different ER-positive breast cancer cell lines. First, small interfering RNA-mediated knockdown of MTA1 increased protein and mRNA expression of AR in MCF7, T47D, and ZR75-1. Overexpression of MTA1 down-regulated expression of AR in these cell lines. Activity of the reporter-encoding AR promoter (-2408 bp ~ +1126 bp) was decreased in the presence of MTA1 in a dose-dependent manner. Analysis of the chromatin immunoprecipitation sequencing data (http://encodeproject.org/ENCODE) revealed that MTA1 may bind to 1 kilo base downstream of AR transcription start site. Together, our results demonstrated that MTA1 negatively regulates expression of AR in breast cancer cells. These results suggest that the negative regulation of AR may be associated with the cancer promoting effects of MTA1, which may provide a therapeutic opportunity against ER-positive breast cancer. Citation Format: SeungSu Kim. Metastasis-associated protein 1 negatively regulates expression of androgen receptor in ER-positive breast cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3607. doi:10.1158/1538-7445.AM2017-3607

Uplink scheduling for relay stations in mobile multi-hop relay network has not been widely addressed in the literature under common belief that downlink traffic overwhelms uplink traffic. Recently, data traffic from user created content (UCC) is rapidly growing with a potential to create a huge amount of uplink (UL) traffic. Overlapped resource allocation in uplink transmission allows MSs attached to different RSs can reuse the same frequency band to increase the network throughput. However, the uplink traffic from MSs located on the boundary between two neighboring RSs may cause interference to each other RS. The interference degrades the uplink throughput or even leads to service outage for MSs located on the boundary, resulting in poor fairness in QoS among subscribers. We propose an uplink transmission scheme with reduced interference. We reduce the interference by grouping MSs in such a way the uplink transmission from the MSs in a group do not interfere each other at the receiving RSs. Simulation results show that the proposed scheme removes service outage by 61.5% and increases average throughput by 13.3% compared with a simple overlapped resource allocation scheme(similar to the overlapped resource allocation scheme for downlink transmission). In terms of fairness, the proposed scheme excels by 38.7% the simple overlapped scheme.

The measurement of glycated hemoglobin A1c (HbA1c) has important implications for diagnosis of diabetes and assessment of treatment effectiveness. We proposed specific sequence motifs to identify enzymes that oxidize glycated compounds from genome database searches. The gene encoding a putative fructosyl amino acid oxidase was found in the Phaeosphaeria nodorum SN15 genome and successfully expressed in Escherichia coli. The recombinant protein (XP_001798711) was confirmed to be a novel fructosyl peptide oxidase (FPOX) with high specificity for α-glycated compounds, such as HbA1c model compounds fructosyl-αN-valine (f-αVal) and fructosyl-αN-valyl-histidine (f-αVal-His). Unlike previously reported FPOXs, the P. nodorum FPOX has a Km value for f-αVal-His (0.185 mM) that is considerably lower than that for f-αVal (0.458 mM). Based on amino acid sequence alignment, three dimensional structural modeling, and site-directed mutagenesis, Gly60 was found to be a determining residue for the activity towards f-αVal-His. A flexible surface loop region was also found to likely play an important role in accepting f-αVal-His. Biotechnol. Bioeng. 2010; 106: 358–366. © 2010 Wiley Periodicals, Inc.

The flavoenzyme fructosyl amino acid oxidase (FAOD) catalyzes the oxidative deglycation of fructosyl amino acids, model compounds of glycated proteins. The high oxygen reactivity of FAODs limits their potential utility in amperometric enzyme sensors employing artificial electron mediators. To alter their electron acceptor availability, site-directed mutagenesis was carried out on conserved residues predicted to be involved in the proton relay system (PRS) of two eukaryotic FAODs, the FAOD from the marine yeast Pichia sp. N1-1 and amadoriase II from the fungus Aspergillus fumigatus. The substitution of a single conserved Asn residue in the putative PRS, Asn47Ala of N1-1 FAOD and Asn52Ala of amadoriase II, resulted in significant loss in the catalytic ability to employ O(2) as the electron acceptor, while having little effect on the dye-mediated dehydrogenase activity employing artificial electron acceptors instead of O(2).

This work presents a methodology to generate dynamically stable whole-body motions for a humanoid robot, which are converted from human motion capture data. The methodology consists of the kinematic and dynamical mappings for human-likeness and stability, respectively. The kinematic mapping includes the scaling of human foot and Zero Moment Point (ZMP) trajectories considering the geometric differences between a humanoid robot and a human. It also provides the conversion of human upper body motions using the method in [1]. The dynamic mapping modifies the humanoid pelvis motion to ensure the movement stability of humanoid whole-body motions, which are converted from the kinematic mapping. In addition, we propose a simplified human model to obtain a human ZMP trajectory, which is used as a reference ZMP trajectory for the humanoid robot to imitate during the kinematic mapping. A human whole-body dancing motion is converted by the methodology and performed by a humanoid robot with online balancing controllers.

The purpose of this study is to develop a methodology that enables a humanoid robot to imitate a whole body motion of a human. In the communication and interaction with a human being with motions and gestures, a humanoid robot needs not only to look like a human but to behave as a human does to make sure the meanings of motions and gestures. To act like a human, the humanoid robot has to imitate the kinematical and dynamical movement of human. For this, a methodology for a humanoid robot to imitate human whole body motions, is presented. Human motions are acquired from a motion capture system. The proposed methodology first converts the captured motions into the motions for a humanoid robot considering kinematical differences between human and robot. In addition, the methodology proposes a simplified human model to analyze a human ZMP trajectory using an optimization scheme. The methodology computes a stable ZMP trajectory for the humanoid robot based the ZMP trajectory of this simplified human model. From the computed ZMP trajectory, the whole body motion for the humanoid robot is generated through this off-line process. A human whole body motion, a dancing motion, is converted to examine the developed methodology.

Docking models of fructosyl amine oxidase (FAOD) from the marine yeast Pichia N1-1 (N1-1 FAOD) with the substrates fructosyl valine (f-Val) and fructosyl-(epsilon)N-lysine (f-(epsilon)Lys) were produced using three-dimensional protein model as reported previously (Miura et al., 2006, Biotechnol. Lett., 28, 1895-1900). The residues involved in recognition of substrates were proposed, particularly Asn354, which interacts closely with f-(epsilon)Lys, but not with f-Val. Substitution of Asn354 to histidine and lysine simultaneously resulted in an increase in activity of f-val and a decrease in activity of f-(epsilon)Lys and thus, increasing the specificity for f-Val from 13- to 19-fold. In addition to creating two mutant FAODs with great potential for the measurement of glycated hemoglobin, we have provided the first structural model of substrate binding with eukaryotic FAOD, which is expected to contribute to further investigation of FAOD.

A method to regenerate a new human-like arm motion by modifying and scaling a human arm motion is presented. The humanoid robot may not obtain all the necessary human-like motions from motion capture data. When the robot communicates with a person, the robot has to keep attention to the person by aligning the direction of the motion. The robot needs to modify human arm motions and regenerate new human-like arm motions without loosing the original meanings. The developed method modifies and scales the wrist trajectory of a human arm motion and reproduces the human-like arm. The motion of drawing multiple circles with a various radius and direction is examined.

This paper proposes CORBA-based visual servoing system of humanoid robot. To effectively control the humanoid robot which is connected to network, it needs to define necessary services for visual servoing as distribution object, and realize them in the middleware. For realizing it following services should be addressed. Naming service for searching a necessary service with unique name assigned to each object, image service for supplying image obtained from stereo camera. In the experiment, we show the result of balloon tracking and bursting that the robot tracks balloons as target objects in the real time, and if a balloon stop for a certain time, then the robot bursts the balloon.

During the communication and interaction with a human using motions or gestures, a humanoid robot needs to not only look like a human but also behavior like a human to avoid confusions in the communication and interaction. Among human-like behaviors, arm motions of the humanoid robot are essential for the communication with people through motions. In this work, a mathematical representation for characterizing human arm motions is first proposed. The human arm motions are characterized by the elbow elevation angle that is determined using the position and orientation of human hands. That representation is mathematically obtained using an approximation tool, Response Surface Method (RSM). Then a method to generate human-like arm motions in real time using the proposed representation is presented. The proposed method was evaluated to generate human-like arm motions when the humanoid robot was asked to move its arms from a point to another point including the rotation of hand. An example motion was performed using the KIST humanoid robot, MAHRU.

A three-dimensional structural model of fructosyl amine oxidase from the marine yeast Pichia N1-1 was generated using the crystal structure of monomeric sarcosine oxidase from Bacillus sp. B-0618 as template. The putative active site region was investigated by site-directed mutagenesis, identifying several amino acid residues likely playing important roles in the enzyme reaction. Asn354 was identified as a residue that plays an important role in substrate recognition and that can be substituted in order to change substrate specificity while maintaining high catalytic activity. While the Asn354Ala substitution had no effect on the V (max) K (m) (-1) value for fructosyl valine, the V (max) K (m) (-1) value for fructosyl-(epsilon) N-lysine was decreased 3-fold, thus resulting in a 3-fold improvement in specificity for fructosyl valine over fructosyl-(epsilon) N-lysine.

This paper develops a model-free method to estimate the dynamics of free-flying objects. We take a realistic perspective to the problem and investigate tracking accurately and very rapidly the trajectory and orientation of an object so as to catch it in flight. We consider the dynamics of complex objects where the grasping point is not located at the center of mass. To achieve this, a density estimate of the translational and rotational velocity is built based on the trajectories of various examples. We contrast the performance of six non-linear regression methods (Support Vector Regression (SVR) with Radial Basis Function (RBF) kernel, SVR with polynomial kernel, Gaussian Mixture Regression (GMR), Echo State Network (ESN), Genetic Programming (GP) and Locally Weighted Projection Regression (LWPR)) in terms of precision of recall, computational cost and sensitivity to choice of hyper-parameters. We validate the approach for real-time motion tracking of 5 daily life objects with complex dynamics (a ball, a fully-filled bottle, a half-filled bottle, a hammer and a pingpong racket). To enable real-time tracking, the estimated model of the object's dynamics is coupled with an Extended Kalman Filter for robustness against noisy sensing. (C) 2012 Elsevier B.V. All rights reserved.