Classification of inertial sensor-based gait patterns of orthopaedic conditions using machine learning: A pilot study.

Elderly patients often have more than one disease that affects walking behavior. An objective tool to identify which disease is the main cause of functional limitations may aid clinical decision making. Therefore, we investigated whether gait patterns could be used to identify degenerative diseases using machine learning. Data were extracted from a clinical database that included sagittal joint angles and spatiotemporal parameters measured using seven inertial sensors, and anthropometric data of patients with unilateral knee or hip osteoarthritis, lumbar or cervical spinal stenosis, and healthy controls. Various classification models were explored using the MATLAB Classification Learner app, and the optimizable Support Vector Machine was chosen as the best performing model. The accuracy of discrimination between healthy and pathologic gait was 82.3%, indicating that it is possible to distinguish pathological from healthy gait. The accuracy of discrimination between the different degenerative diseases was 51.4%, indicating the similarities in gait patterns between diseases need to be further explored. Overall, the differences between pathologic and healthy gait are distinct enough to classify using a classical machine learning model; however, routinely recorded gait characteristics and anthropometric data are not sufficient for successful discrimination of the degenerative diseases.

Nicotine leads to improvements in behavioral impairment and an increase in the nicotine acetylcholine receptor in transgenic mice.

Nicotine is the principal psychoactive ingredient in cigarette smoke, and has been associated with health problems in humans. However, the pure form of nicotine may prove to be a valuable pharmaceutical agent for the treatment of AD. However, the beneficial effects of nicotine remain a matter of much controversy. In order to clarify this issue, 12-month-old transgenic mice, expressing neuron-specific enolase (NSE)-controlled APPsw, were treated with low, middle, and high doses of nicotine for 6 months. Herein, we have concluded that the nicotine-treated groups evidenced improvements in behavior and increases in the nicotine acetylcholine receptor, nAchRalpha7. These findings provide experimental evidence that nicotine effects an improvement in impaired memory, and that this improvement is associated with an increase in nAchRalpha7. Thus, nicotine may prove a good preventative or therapeutic modality for AD patients.

Impacts of environmental conditions on the sorption of volatile organic compounds onto tire powder.

A series of batch tests were performed and the impacts of environmental conditions and phase change on the sorption of volatile organic compounds (VOCs) were investigated. Benzene, trichloroethylene, tetrachloroethylene, and ethylbenzene were selected as target VOCs. Sorption of VOCs onto tire powder was well demonstrated by a linear-partitioning model. Water-tire partition coefficients of VOCs (not tested in this study) could be estimated using a logarithmic relationship between observed water-tire partition coefficients and octanol-water partition coefficients of the VOCs tested. The target VOCs did not seem to compete with other VOCs significantly when sorbed onto the tire powder for the range of concentrations tested. The influence of environmental conditions, such as pH and ionic strength also did not seem to be significant. Water-tire partition coefficients of benzene, trichloroethylene, tetrachloroethylene, and ethylbenzene decreased as the sorbent dosage increased. However, they showed stable values when the sorbent dosage was greater than 10 g/L. Air-tire partition coefficient could be extrapolated from Henry's law constants and water-tire partition coefficient of VOCs.

Analysis of differentially expressed genes in early- and late-stage APPsw-transgenic and normal mice using cDNA microarray.

The complexity of Alzheimer's disease (AD) has made it difficult to examine its underlying mechanism. A gene microarray offers a solution to the complexity through a parallel analysis of most of the genes expressed in the brains from AD-transgenic mice. In our previous study, a total of 52 differentially expressed genes were identified in 18-month-old APPsw-transgenic mice compared to age-matched normal mice. We extended our work to better understand the relevant gene profiles from both early- and late-stage transgenic and normal mice. To accomplish this, cDNA microarray was used with the large-scale screening of the brain mRNA from transgenic and normal mice of 1 and 18 months of age. We identified a total of 48 genes, 6 up-regulated and 42 down-regulated, differentially expressed with a significant degree of induction and reduction in the brains from moderate 18-month-old transgenic mice compared to 1-month-old transgenic mice. In parallel, a total of 40 differentially expressed genes, 6 up-regulated and 34 down-regulated, were also found in the brains from moderate 18-month-old normal mice compared to 1-month-old normal mice. Thus, differentially expressed genes upon APPsw overexpression and the aging process are useful targets through which investigators can choose genes of particular interest. In the future, it will be necessary to study the function of differentially expressed genes, which are targets for developing drugs, using pharmacoproteomics.

Changes in presenilin 2-binding Wnt proteins, behavior, amyloid-beta 42, gamma-secretase activity, and testosterone sensitivity in transgenic mice coexpressing tetracycline-controlled transactivator and human mutant presenilin 2.

Nonregulatable promoters have been mainly used to produce transgenic mice that express the human genes for Alzheimer's disease (AD). The aim of this study was to produce doubly transgenic mice expressing the regulatable tet promoter-controlled transactivator (tTA) and human mutant presenilin 2 (N141I, hPS2m) genes in order to examine the AD-related phenotypes at the basal and inducible levels. To achieve this, the first lineage of the transgenic line, expressing Tet/tTA and the second lineage of transgenic mice, expressing Tet/hPS2m, were created, and the doubly transgenic mice were produced by crossing the Tet/tTA-transgenic mice with the Tet/hPS2m-transgenic mice. The doubly transgenic mice and nontransgenic littermates were then treated with or without doxycycline. The results showed that removing doxycycline from the transgenic mice resulted in the induction of the transgene, a Wnt signaling defect, behavioral impairment, elevated amyloid-beta-42 and gamma-secretase activity compared with in the group given doxycyline. Moreover, the expression levels of the hPS2m transgene decreased gradually in the transgenic males, with clear changes becoming apparent between 2 and 4 wk of age. Castrating these males resulted in an increased expression level of the hPS2m gene. This was restored to the normal levels by treatment with testosterone. Therefore, tetregulated transgenic mice can be used to examine the effect of the basal or inducible expression levels of hPS2m on the pathology of AD at the "on/off" states at any stage of development.

Vascular NADH oxidase is involved in impaired endothelium-dependent vasodilation in OLETF rats, a model of type 2 diabetes.

Superoxide anion can modulate vascular smooth muscle tone and is potentially involved in diabetic vascular complications. The present study was undertaken to characterize both vascular production and the enzymatic source of superoxide anion in type 2 diabetic rats. In the thoracic aorta of OLETF rats, endothelium-dependent relaxation was markedly attenuated compared with that of control (LETO) rats in association with a significant increase in superoxide production (2,421.39 +/- 407.01 nmol x min(-1) x mg(-1)). The increased production of superoxide anion was significantly attenuated by diphenyleneiodonium (DPI; 10 micromol/l), an inhibitor of NAD(P)H oxidase. The production of superoxide anion in response to NADH as a substrate was markedly increased in the vascular homogenates, but NADPH, arachidonic acid, xanthine, and succinate produced only small increases in chemiluminescence. In line with these results, studies using various enzyme inhibitors, such as DPI, allopurinol, rotenone, N(G)-monomethyl-L-arginine, and indomethacin, suggest that the predominant source of superoxide anion in vascular particulate fraction is NADH-dependent membrane-bound oxidase. Furthermore, the expression of p22phox, a major component of vascular NAD(P)H oxidase, was markedly increased in the aorta from OLETF rats compared with that of LETO rats. These findings suggest that upregulated expression of p22phox mRNA and enhanced NADH oxidase activity contribute to the impaired endothelium-dependent vasodilation in OLETF rats.

Alterations in behavior, amyloid beta-42, caspase-3, and Cox-2 in mutant PS2 transgenic mouse model of Alzheimer's disease.

Alzheimer's disease (AD) occurs when neurons in the memory and cognition regions of the brain are accompanied by an accumulation of the long amyloid beta-proteins of the 39 to 43 amino acids derived from the amyloid precursor protein (APP) by cleavage with beta- and gamma-secretase. An increased production of Abeta-42 by mutation of PS2 genes promotes caspase expression and is associated with the Cox-2 found in the brain of AD patients. To address this question in vivo, we expressed the human mutant PS2 (hPS2m) (N141I) as well as wild PS2 (hPS2w) as a control in transgenic (Tg) mice under control of the neuron-specific enolase (NSE) promoter. Water maze tests were used to demonstrate the behavioral defect; dot blot, Western blot, and immunohistochemical analyses were performed on the brain with the hPS2, Abeta-42, caspase-3, and Cox-2 antibody. We concluded that 1) Tg mice showed a behavioral dysfunction in the water maze test, 2) levels of hPS2, Abeta-42, caspase-3, and Cox-2 expression were modulated in the brains of both Tg mice, 3) dense staining with antibody to hPS2, Abeta-42, caspase-3, and Cox-2 was visible in the brains of Tg mice compared with age-matched control mice, and 4) distinguishable AD phenotypes between hPS2w- and hPS2m-Tg mice did not appear. These results suggest that an elevation of Abeta-42 by overexpression of hPS2 and mutation of hPS2m might induce the behavioral deficit and caspase-3 and Cox-2 induction, which could be useful in the therapeutic testing of compounds to have considerable clinical effects.

cDNA microarray-based analysis of differentially expressed genes in transgenic brains expressing NSE-controlled APPsw.

cDNA microarray technique has been widely used for the detection and elucidation of differentially expressed genes on a large scale and at a speed never before possible. The aim of this study was to gain insight into the potentially overexpressed effects of APPsw on the modulation of genes for Alzheimer's disease (AD), which is central to understanding the complexity of AD. APPsw transgenic mice, which we previously produced, provide an important resource for identifying differentially expressed genes since this transgenic line was shown to have cognitive deficits along with Abeta-42 deposits at 12 months of age. To identify differentially expressed genes, cDNA microarray technique was conducted to get a large-scale screening of brain mRNA from 18 month-old NSE/APPsw transgenic and non-transgenic mice. A total of 52 differentially expressed genes, 10 up-regulated and 42 down-regulated, were found in the brains of moderately transgenic mice compared to non-transgenic littermates. Thus, the results suggest the need for future studies on gene functions, pathology, toxicogenomics, and pharmacogenomics.

Enhanced vascular production of superoxide in OLETF rat after the onset of hyperglycemia.

This study was aimed to characterize the vascular production of superoxide in Otsuka Long-Evans Tokushima Fatty (OLETF) rat, a model of type 2 diabetes. The nitroblue tetrazolium staining in the aorta from old (30 weeks) OLETF rat was more prominent than that of age-matched control (LETO) rat, which was significantly inhibited by diphenyleneiodonium (10 micromol/l), but not by inhibitors for other oxidases such as xanthine oxidase, mitochondrial oxidase, nitric oxide synthase, and cyclooxygenase. In the aorta from old OLETF rat with hyperglycemia, the enhanced NADH oxidase activity in association with upregulated expression of p22phox and gp91phox was observed, but not in both LETO and young (10 weeks) OLETF rats without hyperglycemia. Furthermore, there was a positive correlation (P<0.01) between elevation of blood glucose level and increase in vascular NADH oxidase activity. Based on these results, it was suggested that the enhanced NADH oxidase activity in the aorta from OLETF rat occurred after the onset of hyperglycemia, thereby resulting in the increased vascular production of superoxide.

Carboxyl-terminus of the amyloid protein precursor and ERbeta are required for estrogenic effect in activating mitogen-activated protein kinase.

Estrogen influences the processing of the amyloid beta precursor protein (APP) in the pathogenesis of Alzheimer's disease, and this effect is mediated by estrogen receptors (ERs) in activating mitogen-activated protein kinase (MAPK)-signaling pathway. To test whether the estrogenic effect on both carboxyl-terminal amino acid fragment (C-terminal) of APP (APP-C105)- and ERbeta-mediated MAPK activation in in vitro, two hybrid genes containing each human ERbeta and APP-C105 gene fused to the neuron-specific enolase (NSE) promoter were constructed and were transfected to the neuronal SK-N-MC cells. Western blot shows that the activation of JNK-signaling pathway, but not p38 and ERK, is dependent on ERbeta through estrogen treatment and APP-C105 is also mediated through estrogen in activating MAPK-signaling pathway. The results suggest that ERbeta and APP-C105 derived from APP are necessary for estrogenic effect in activating MAPK-signaling pathway.

Differential expression of proteins of caspases and Bcl-2 families in the brain of mice.

Apoptosis is an important process in the variety of different biological system including cell death and embryonic development. Inappropriate apoptosis is implicated in many human diseases such as Alzheimer's disease. Central component of the machinery of apoptosis program in neurons of patients with Alzheimer's disease includes proteins of caspases and Bcl-2 families. We examined whether endogenous protein levels of caspases and Bcl-2 families are expressed in a differential manner during the embryonic and postnatal development of BDF1 strain. Here, all four proteins with caspases-3, -9, Bcl-2 and Bax were highly expressed between embryonic day 19 and 1 week age of early postnatal development, but thereafter the expression dramatically declined. These patterns are needed to compare the proteins in the brains of APPsw-transgenic mice that are expected to be expressed highly in the brain of adult mice. Thus, the results are useful to understand fundamentally the mechanisms of the apoptotic changes during the embryonic and postnatal development of Alzheimer's model mice.

Silibinin induces apoptosis via calpain-dependent AIF nuclear translocation in U87MG human glioma cell death.

BACKGROUND: Silibinin, a natural polyphenolic flavonoid, has been reported to induce cell death in various cancer cell types. However, the molecular mechanism is not clearly defined. Our previous study showed that silibinin induces glioma cell death and its effect was effectively prevented by calpain inhibitor. The present study was therefore undertaken to examine the role of calpain in the silibinin-induced glioma cell death. METHODS: U87MG cells were grown on well tissue culture plates and cell viability was measured by MTT assay. ROS generation and △ψm were estimated using the fluorescence dyes. PKC activation and Bax expression were measured by Western blot analysis. AIF nuclear translocation was determined by Western blot and immunocytochemistry. RESULTS: Silibinin induced activation of calpain, which was blocked by EGTA and the calpain inhibitor Z-Leu-Leu-CHO. Silibinin caused ROS generation and its effect was inhibited by calpain inhibitor, the general PKC inhibitor GF 109203X, the specific PKCδ inhibitor rottlerin, and catalase. Silibinin-induce cell death was blocked by calpain inhibitor and PKC inhibitors. Silibinin-induced PKCδ activation and disruption of △ψm were prevented by the calpain inhibitor. Silibinin induced AIF nuclear translocation and its effect was prevented by calpain inhibitor. Transfection of vector expressing microRNA of AIF prevented the silibinin-induced cell death. CONCLUSIONS: Silibinin induces apoptotic cell death through a calpain-dependent mechanism involving PKC, ROS, and AIF nuclear translocation in U87MG human glioma cells.

PEN-2 overexpression induces gamma-secretase protein and its activity with amyloid beta-42 production.

PEN-2 is a component of the gamma-secretase complex, which is involved in the cleavage of the beta-amyloid precursor protein. The aim of this study was to determine the mechanism by which PEN-2 overexpression regulates gamma-secretase expression and the production of Abeta-42. In order to determine this, a hybrid gene harboring human PEN-2 was constructed, and used in the transfection of SK-N-MC human neuroepitheliomal cells. This cell line was also co-transfected with a combination of human mutant presenilin 2 (hPS2m) and APPsw. Our results indicated that (i) human PEN-2 overexpression induced an increase in gamma-secretase activity and its proteins, including PS1-CTF, APH-1, and nicastrin, thus production of Abeta-42, (ii) co-transfection of human PEN-2 with both hPS2m and APPsw exerted no more profound effects on the induction of gamma-secretase proteins and its activity than did transfection with hPEN-2 alone. Thus, PEN-2 overexpression may facilitate assembly into the more active gamma-secretase complex, and may also induce an increase in activity, thus affecting Abeta-42 production.

Differential effect of 7,12-dimethylbenz[a]anthracene on human and mouse CYP1B1 from livers of castrated transgenic mice.

Humanized transgenic mice coexpressing tetracycline-controlled transactivator (tTA) and human cytochrome P450 1B1 (CYP1B1) (hCYP1B1) have been created by this group. The aims of this study was to determine if 7,12-dimethylbenz[a]anthracene (DMBA) functions as testosterone or doxycycline in its ability to induce or reduce expression of hCYP1B1 or endogenous mouse CYP1B1 (mCYP1B1). This was tested in the livers by treating castrated transgenic males and hCYP1B1/luciferase-transfected cells with DMBA. Herein, DMBA-treated group exhibited (i) gradual reduction of hCYP1B1 expression at the transcript, protein, and activity levels but gradually induced its transcript level during DMBA release; (ii) gradual reduction of hCYP1B1 at the transcript and protein levels, as in the case of doxycycline or testosterone; (iii) gradual induction of mCYP1B1 expression at the transcript and protein levels but gradually reduced its transcript level during DMBA release. In parallel, DMBA-treated transfected cells exhibited gradual increase in luciferase activity in a time-and dose-dependent manner. Thus, castrated transgenic males or in vitro system could be useful as models for the detection of polycyclic aromatic hydrocarbons (PAHs) or environmental toxicants by measuring either hCYP1B1 or mCYP1B1 expressions.

Oligonucleotide-based analysis of differentially expressed genes in hippocampus of transgenic mice expressing NSE-controlled APPsw.

The complexity of Alzheimer's disease (AD) has made it difficult to examine its underlying mechanisms. A gene microarray offers a solution to the complexity through parallel analysis of most of the genes expressed in the hippocampal tissues from AD-transgenic and age-matched control littermates. This study examined the potential effect of APPsw over-expression on the modulation of genes for AD. To accomplish this, an oligonucleotide array was used with the large-scale screening of the hippocampus mRNA from 12-month-old APPsw-transgenic and control mice. There was a total of 116 differentially expressed genes, 59 up-regulated and 57 down-regulated, in the hippocampal region of the transgenic mice compared with the control mice. Initially, two of each of the down-regulated (Xlr3b and Mup3) and up-regulated genes (Serpina9 and Ccr6) were chosen for further investigation if the magnitude of change in these genes on the oligonucleotide array would correspond to those in the RT-PCR analysis from APPsw-transgenic mice. We also found that the changes in the differentially expressed genes are reliable. Thus, these genes might associate with AD neuropathology in neurodegenerative process of AD, although relevance of long lists altered genes should be evaluated in a future study.

Aging-related correlation of insulin-degrading enzyme with gamma-secretase-generated products involving insulin and glucose levels in transgenic mice.

Insulin-degrading enzyme (IDE) is a 110-kDa thiol zinc-methalloendopeptidase that can cleave small Abeta peptides and the APP intracellular domain (AICD). The aim of this study was to examine aging-related correlation of IDE with gamma-secretase-generated products involving insulin and glucose levels in transgenic brains expressing neuron-specific enolase (NSE)-controlled human mutant presenilin-2 (hPS2m). Herein, we concluded that the levels of IDE expression in transgenic brains were decreased relative to those of control mice at 15 months of age. In parallel, inhibition in the IDE expression at this age underlies to the levels-up of Abeta-42, AICD, gamma-secretase, and glucose with a level-down of insulin. Thus, IDE expression is critical target for the therapeutic trials.

NSE-controlled carboxyl-terminus of APP gene over-expressing in transgenic mice induces altered expressions in behavior, Abeta-42, and GSK3beta binding proteins.

The amyloid protein precursor (APP) is cleaved in its intramembranous domain by gamma-secrease to generate amyloid beta and a free carboxyl-terminal intracellular fragment. The carboxyl-terminal of 105 amino acids of APP (APP-C105) plays a crucial role in the neuropathology of Alzheimer's disease (AD), but it is incompletely understand how APP-C105 overexpression interacts and regulates the brain function and Abeta-42 levels, and whether or not it is associated with the expressions of GSK3beta-binding proteins. To test this, transgenic mice expressing NSE-controlled APP-C105 were produced and tested for their above phenotypes. A behavioral deficit was observed in the 9 months old transgenic mice, and western blot indicated that there was a predominant expression of APP-C105 in transgenic brains compared with those of non-transgenic brains. In parallel, APP-C105 overexpression resulted in the modulation of the Abeta-42 level, gamma-secretase activity, GSK3beta-binding proteins including PS1, tau, and beta-catenin in the brains of the transgenic mice relative to the non-transgenic mice. Thus, altered expressions of these neuropathological phenotypes in APP-C105 transgenic mice could be useful targets in developing new therapeutic treatments.

Early changes in behavior deficits, amyloid beta-42 deposits and MAPK activation in doubly transgenic mice co-expressing NSE-controlled human mutant PS2 and APPsw.

1. Doubly transgenic mice were some differences in the period proceeding of the development of Abeta-42 deposits and behavioral deficits. It was not characterized human mutant PS2 (hPS2) with APPsw in the brains of double transgenic mice. The aim of this study was to examine whether doubly transgenic mice co-expressing NSE-controlled APPsw and hPS2m develop AD-like phenotypes much earlier than singly APPsw or hPS2m alone. 2. We produced doubly transgenic mice from a cross between our previously created NSE-controlled hPS2m and an APPsw transgenic line. This doubly transgenic line was quantitatively produced by cross with age-matched control mice, and the produced mice were separated into 5, 6, 7 and 8-month old age groups. At the age of 8 months, the four groups of mice were tested for behavioral function, levels of Abeta-42 deposition, and potential signaling events. 3. It was shown that all the AD-like phenotypes, including behavior deficits, Abeta-42 levels, MAPK activation and ER expressions in doubly transgenic mice develop much earlier in the early time of AD development than their singly transgenic and non-transgenic littermates. 4. The results suggest that elevated Abeta-42 levels, and MAPK activation in doubly transgenic mice are model for early diagnosis and treatment of AD with therapeutic drug.

An in vivo bioassay for detecting antiandrogens using humanized transgenic mice coexpressing the tetracycline-controlled transactivator and human CYP1B1 gene.

The typical strategy used in analysis of antiandrogens involves the morphological changes of a marker in castrated rats Hershberger assay for the prostate, seminal vesicle, levator ani plus bulbocavernosus muscles (LABC), Cowper's gland, and glans penis. However, there are disadvantages to this approach, such as the time required, and the results may not correspond to those in actual human exposure. To evaluate its ability for detecting antiandrogens, in vivo the dose effect of di-(2-ethylhexyl) phthalate (DEHP) and time effect of five antiandrogens, DEHP, di-n-butyl phthalate (DBP), diethyl phthalate (DEP), linuron (3-(4-dichlorophenyl)-methoxy-1-methylurea), and 2,4'-DDE (1,1-dichloro-2-(p-chlorophenyl)-2-(o-chlorophenyl)ethylene), were investigated using humanized transgenic mice coexpressing tetracycline-controlled transactivator (tTA) and the human cytochrome P450 (CYP) enzyme CYP1B1 (hCYP1B1). Adult transgenic males were treated with each of the five antiandrogens, and their tTA-driven hCYP1B1 expressions analyzed by real-time polymerase chain reaction (PCR) and/or Western blot and for O-debenzylation activity. Herein, the treatments of adult males with the five antiandrogens were shown to affect the increased levels of tTA-driven hCYP1B1 expression in both dose-dependent and repeated experiments. Thus, this novel in vivo bioassay, using humanized transgenic mice, is useful for measuring antiandrogens, and is a means to a more relevant bioassay relating to actual human exposure.